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1

Fault Current Limiters  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Fault Fault Current Limiters Superconducting & Solid-state Power Equipment Office of Electricity Delivery and Energy Reliability www.oe.energy.gov Office of Electricity Delivery and Energy Reliability, OE-1 U.S. Department of Energy - 1000 Independence Avenue, SW - Washington, DC 20585 Plugging America Into the Future of Power What are FCLs? A fault is an unintentional short circuit, or partial short-circuit, in an electric circuit. A variety of factors such as lightning, downed power lines, or crossed power lines cause faults. During a fault, excessive current-called fault current- flows through the electrical system often resulting in a failure of one section of that system by causing a

2

Passive fault current limiting device  

DOE Patents (OSTI)

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment. 6 figs.

Evans, D.J.; Cha, Y.S.

1999-04-06T23:59:59.000Z

3

Definition: Fault Current Limiter | Open Energy Information  

Open Energy Info (EERE)

Limiter Limiter Jump to: navigation, search Dictionary.png Fault Current Limiter A fault current limiter prevents current in an electrical circuit from exceeding a predetermined level by increasing the electrical impedance of that circuit before the current through the circuit exceeds that level. Fault current limiters are designed so as to minimize the impedance of the circuit under normal conditions to reduce losses, but increase the impedance of the circuit under fault conditions to limit fault current.[1] View on Wikipedia Wikipedia Definition A Fault Current Limiter (FCL) is a device which limits the prospective fault current when a fault occurs (e.g. in a power transmission network). The term includes superconducting devices and non-superconducting devices, however some of the more simple non-superconducting devices (such

4

Definition: Fault Current Limiting | Open Energy Information  

Open Energy Info (EERE)

Limiting Limiting Jump to: navigation, search Dictionary.png Fault Current Limiting Fault current limiting can be achieved through sensors, communications, information processing, and actuators that allow the utility to use a higher degree of network coordination to reconfigure the system to prevent fault currents from exceeding damaging levels. Fault current limiting can also be achieved through the implementation of special stand alone devices known as Fault Current Limiters (FCLs) which act to automatically limit high through currents that occur during faults.[1] Related Terms fault, fault current limiter References ↑ SmartGrid.gov 'Description of Functions' Temp LikeLike UnlikeLike You like this.Sign Up to see what your friends like. late:ISGANAttributionsmart grid,smart grid,smart grid,smart grid,

5

High temperature superconducting fault current limiter  

DOE Patents (OSTI)

A fault current limiter for an electrical circuit is disclosed. The fault current limiter includes a high temperature superconductor in the electrical circuit. The high temperature superconductor is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter. 15 figs.

Hull, J.R.

1997-02-04T23:59:59.000Z

6

Fault Current Limiters (FCL) Fact Sheet | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

& Publications An Assessment of Fault Current Limiter Testing Requirements Superconductivity Program Overview Superconductivity for Electric Systems: 2008 Annual Peer Review...

7

Self field triggered superconducting fault current limiter  

DOE Patents (OSTI)

A superconducting fault current limiter array with a plurality of superconductor elements arranged in a meanding array having an even number of supconductors parallel to each other and arranged in a plane that is parallel to an odd number of the plurality of superconductors, where the odd number of supconductors are parallel to each other and arranged in a plane that is parallel to the even number of the plurality of superconductors, when viewed from a top view. The even number of superconductors are coupled at the upper end to the upper end of the odd number of superconductors. A plurality of lower shunt coils each coupled to the lower end of each of the even number of superconductors and a plurality of upper shunt coils each coupled to the upper end of each of the odd number of superconductors so as to generate a generally orthoganal uniform magnetic field during quenching using only the magenetic field generated by the superconductors.

Tekletsadik, Kasegn D. (Rexford, NY)

2008-02-19T23:59:59.000Z

8

Fault current limiter and alternating current circuit breaker  

DOE Patents (OSTI)

A solid-state circuit breaker and current limiter are disclosed for a load served by an alternating current source having a source impedance, the solid-state circuit breaker and current limiter comprising a thyristor bridge interposed between the alternating current source and the load, the thyristor bridge having four thyristor legs and four nodes, with a first node connected to the alternating current source, and a second node connected to the load. A coil is connected from a third node to a fourth node, the coil having an impedance of a value calculated to limit the current flowing therethrough to a predetermined value. Control means are connected to the thyristor legs for limiting the alternating current flow to the load under fault conditions to a predetermined level, and for gating the thyristor bridge under fault conditions to quickly reduce alternating current flowing therethrough to zero and thereafter to maintain the thyristor bridge in an electrically open condition preventing the alternating current from flowing therethrough for a predetermined period of time. 9 figs.

Boenig, H.J.

1998-03-10T23:59:59.000Z

9

Fault current limiter and alternating current circuit breaker  

Science Conference Proceedings (OSTI)

A solid-state circuit breaker and current limiter for a load served by an alternating current source having a source impedance, the solid-state circuit breaker and current limiter comprising a thyristor bridge interposed between the alternating current source and the load, the thyristor bridge having four thyristor legs and four nodes, with a first node connected to the alternating current source, and a second node connected to the load. A coil is connected from a third node to a fourth node, the coil having an impedance of a value calculated to limit the current flowing therethrough to a predetermined value. Control means are connected to the thyristor legs for limiting the alternating current flow to the load under fault conditions to a predetermined level, and for gating the thyristor bridge under fault conditions to quickly reduce alternating current flowing therethrough to zero and thereafter to maintain the thyristor bridge in an electrically open condition preventing the alternating current from flowing therethrough for a predetermined period of time.

Boenig, Heinrich J. (Los Alamos, NM)

1998-01-01T23:59:59.000Z

10

An Assessment of Fault Current Limiter Testing Requirements ...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Energy Reliability (OE) is conducting research and development (R&D) on next-generation electricity delivery equipment including fault current limiters (FCLs). Prototype FCL...

11

Testing of 3-meter Prototype Fault Current Limiting Cables  

Science Conference Proceedings (OSTI)

Two 3-m long, single-phase cables have been fabricated by Ultera from second generation (2G) superconductor supplied by American Superconductor. The first cable was made with two layers of 2G tape conductor and had a critical current of 5,750 A while the second cable had four layers and a critical current of 8,500 A. AC loss was measured for both cables at ac currents of up to 4 kArms. Ultera performed initial fault current studies of both cables in Denmark with limited currents in the range from 9.1 to 44 kA. Results from these tests will provide a basis for a 25-m long, three-phase, prototype cable to be tested at ORNL early next year and a 300-m long, fault current limiting, superconducting cable to be installed in a ConEd substation in New York City.

Gouge, Michael J [ORNL; Duckworth, Robert C [ORNL; Demko, Jonathan A [ORNL; Rey, Christopher M [ORNL; Thompson, James R [ORNL; Lindsay, David T [ORNL; Tolbert, Jerry Carlton [ORNL; Willen, Dag [Ultera; Lentge, Heidi [Ultera; Thidemann, Carsten [Ultera; Carter, Bill [AMSC

2009-01-01T23:59:59.000Z

12

Wind Power Plant Enhancement with a Fault-Current Limiter: Preprint  

DOE Green Energy (OSTI)

This paper investigates the capability of a saturable core fault-current limiter to limit the short circuit current of different types of wind turbine generators.

Muljadi, E.; Gevorgian, V.; DeLaRosa, F.

2011-03-01T23:59:59.000Z

13

Solid-state fault current limiter for voltage sag mitigation and its parameters design  

Science Conference Proceedings (OSTI)

Due to the difficulty in electric distribution network reinforcement and the interconnection of more distributed generations, fault current level has become a serious problem in system operations. The utilization of solid-state fault current limiters ... Keywords: power quality, simulation, solid-state fault current limiter, voltage sag

B. Boribun; T. Kulworawanichpong

2010-07-01T23:59:59.000Z

14

Superconducting matrix fault current limiter with current-driven trigger mechanism  

DOE Patents (OSTI)

A modular and scalable Matrix-type Fault Current Limiter (MFCL) that functions as a "variable impedance" device in an electric power network, using components made of superconducting and non-superconducting electrically conductive materials. An inductor is connected in series with the trigger superconductor in the trigger matrix and physically surrounds the superconductor. The current surge during a fault will generate a trigger magnetic field in the series inductor to cause fast and uniform quenching of the trigger superconductor to significantly reduce burnout risk due to superconductor material non-uniformity.

Yuan, Xing (Albany, NY)

2008-04-15T23:59:59.000Z

15

Enhancement of power system transient stability using superconducting fault current limiters  

E-Print Network (OSTI)

Abstract|Transient stability investigations consist in studying the rotor oscillations of generators (electro-mechanic oscillations, 0.1-2 Hz) followed by a fault of large amplitude, e.g. short circuit. The goal is to indicate if the generators are capable to stay synchronous after a fault has occurred. The fault duration is one of the most important factors to be given an answer. In fact, the shorter the fault, the more the maintaining of synchronisation can be guaranteed. Now in case of a fault, a fault current limiter has an extremely fast current transition in comparison with electro-mechanic time constants. This implies a quasi-instantaneous elimination of the fault through a limitation of the current and consequently a better ability to maintain the synchronisation of the system. We recall, in a classic system the elimination of a fault, by opening a circuit breaker, is carried out in two or three cycles in the best case. We have here studied a simple, radial electric network con guration with a machine and an in nite network. The study covers simulations of di erent faults that can occur in a network and the consequences of the recovery time of the fault current limiter. I.

Marten Sjostrom; Rachid Cherkaoui

1999-01-01T23:59:59.000Z

16

High Temperature Superconducting Matrix Fault Current Limiter: Proof-of-Concept Test Results  

Science Conference Proceedings (OSTI)

This report describes the design and proof-of-concept test results of a pre-prototype superconducting fault current limiter (FCL). The device employs SuperPower's Matrix Fault Current Limiter (MFCL) technology and BSCCO-2212 bulk material manufactured by Nexans SuperConductors' melt cast processing (MCP) technique. The MFCL technology is targeted to address fault current over-duty problems at the transmission voltage level of 138kV and higher. In addition to EPRI sponsorship, this $12M development progra...

2004-09-27T23:59:59.000Z

17

Program on Technology Innovation: Application of a High Temperature Superconducting Fault Current Limiter at AEP's Sporn Substation  

Science Conference Proceedings (OSTI)

This report describes the application of a Superconducting Fault Current Limiter (SFCL) to address fault current over-duty problems in American Electric Power's 138kV Sporn Substation. EPRI is current developing SFCL technology targeted to address fault current over-duty problems at the transmission voltage level of 138kV and higher. The technology under development is termed the Matrix Fault Current Limiter (MFCL) due to the modular nature arrangements of its High Temperature Superconducting (HTS) eleme...

2007-10-30T23:59:59.000Z

18

Design, Test and Demonstration of Saturable Reactor High-Temperature Superconductor Fault Current Limiters  

Science Conference Proceedings (OSTI)

Zenergy Power has successfully designed, built, tested, and installed in the US electrical grid a saturable reactor Fault Current Limiter. Beginning in 2007, first as SC Power Systems and from 2008 as Zenergy Power, Inc., ZP used DOE matching grant and ARRA funds to help refine the design of the saturated reactor fault current limiter. ZP ultimately perfected the design of the saturated reactor FCL to the point that ZP could reliably design a suitable FCL for most utility applications. Beginning with a very basic FCL design using 1G HTS for a coil housed in a LN2 cryostat for the DC bias magnet, the technology progressed to a commercial system that was offered for sale internationally. Substantial progress was made in two areas. First, the cryogenics cooling system progressed from a sub-cooled liquid nitrogen container housing the HTS coils to cryostats utilizing dry conduction cooling and reaching temperatures down to less than 20 degrees K. Large, round cryostats with â??warm boreâ?ť diameters of 1.7 meters enabled the design of large tanks to hold the AC components. Second, the design of the AC part of the FCL was refined from a six legged â??spiderâ?ť design to a more compact and lighter design with better fault current limiting capability. Further refinement of the flux path and core shape led to an efficient saturated reactor design requiring less Ampere-turns to saturate the core. In conclusion, the development of the saturable reactor FCL led to a more efficient design not requiring HTS magnets and their associated peripheral equipment, which yielded a more economical product in line with the electric utility industry expectations. The original goal for the DOE funding of the ZP project â??Design, Test and Demonstration of Saturable Reactor High-Temperature Superconductor Fault Current Limitersâ?ť was to stimulate the HTS wire industry with, first 1G, then 2G, HTS wire applications. Over the approximately 5 years of ZPâ??s product development program, the amount of HTS wire employed per FCL and its cost as a percentage of the total FCL product content had not dropped substantially from an unsustainable level of more than 50% of the total cost of the FCL, nor had the availability increased (today the availability of 2G wire for commercial applications outside of specific partnerships with the leading 2G wire manufacturers is extremely limited). ZP had projected a very significant commercial potential for FCLs with higher performance and lower costs compared to the initial models built with 1G wire, which would come about from the widespread availability of low-cost, high-performance 2G HTS wire. The potential for 2G wires at greatly reduced performance-based prices compared to 1G HTS conductor held out the potential for the commercial production of FCLs at price and performance levels attractive to the utility industry. However, the price of HTS wire did not drop as expected and today the available quantities of 2G wire are limited, and the price is higher than the currently available supplies of 1G wire. The commercial option for ZP to provide a reliable and reasonably priced FCL to the utility industry is to employ conventional resistive conductor DC electromagnets to bias the FCL. Since the premise of the original funding was to stimulate the HTS wire industry and ZP concluded that copper-based magnets were more economical for the foreseeable future, DOE and ZP decided to mutually terminate the project.

Frank Darmann; Robert Lombaerde; Franco Moriconi; Albert Nelson

2011-10-31T23:59:59.000Z

19

Design, Fabrication and Testing of a Superconducting Fault Current Limiter (SFCL)  

SciTech Connect

The purpose of this project was to conduct R&D on specified components and provide technical design support to a SuperPower team developing a high temperature superconducting Fault Current Limiter (SFCL). ORNL teamed with SuperPower, Inc. on a Superconductivity Partnerships with Industry (SPI) proposal for the SFCL that was submitted to DOE and approved in FY 2003. A contract between DOE and SuperPower, Inc. was signed on July 14, 2003 to design, fabricate and test the SFCL. This device employs high temperature superconducting (HTS) elements and SuperPower's proprietary technology. The program goal was to demonstrate a device that will address a broad range of the utility applications and meet utility industry requirements. This DOE-sponsored Superconductivity Partnership with Industry project would positively impact electric power transmission reliability and security by introducing a new element in the grid that can significantly mitigate fault currents and provide lower cost solutions for grid protection. The project will conduct R&D on specified components and provide technical design support to a SuperPower-led team developing a SFCL as detailed in tasks 1-5 below. Note the SuperPower scope over the broad SPI project is much larger than that shown below which indicates only the SuperPower tasks that are complementary to the ORNL tasks. SuperPower is the Project Manager for the SFCL program, and is responsible for completion of the project on schedule and budget. The scope of work for ORNL is to provide R&D support for the SFCL in the following four broad areas: (1) Assist with high voltage subsystem R&D, design, fabrication and testing including characterization of the general dielectric performance of LN2 and component materials; (2) Consult on cryogenic subsystem R&D, design, fabrication and testing; (3) Participate in project conceptual and detailed design reviews; and (4) Guide commercialization by participation on the Technical Advisory Board (TAB). SuperPower's in-kind work for the SFCL will be provided in the following areas: (1) Work with ORNL to develop suitable test platforms for the evaluation of subsystems and components; (2) Provide cryogenic and high voltage subsystem designs for evaluation; (3) Lead the development of the test plans associated with the subsystem and components and participate in test programs at ORNL; and (4) Based on the test results, finalize the subsystem and component designs and incorporate into the respective SFCL prototypes.

Gouge, M..; Schwenterly, S.W.; Hazelton, D. (SuperPower, Inc.)

2011-06-15T23:59:59.000Z

20

EPRI Fault Current Management Guidebook, Fifth Edition  

Science Conference Proceedings (OSTI)

This document is an update of EPRI report 1020029, Fault Current Management Guidebook, Fourth Edition, on fault current effects and management in transmission and distribution systems. This guide is intended to be a snapshot of available references, information, and literature on the effects of high fault current on a number of power system components and various available and emerging fault-current-limiting technologies.

2011-12-19T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Solid-State Fault Current Limiter Development: Design of a 15.5-kV Field-Ready Unit  

Science Conference Proceedings (OSTI)

The solid-state current limiter (SSCL) is power-electronics-based equipment designed to work with the present utility system. The SSCL monitors the line current and dynamically inserts additional impedance into the line if a fault is detected. The SSCL is based on a modular design and can be configured for 5-kV through 69-kV systems at nominal current ratings of 1000A–4000A.In this report, a complete design is presented for 15.5-kV, 1200A and 4000A, single-phase and three-phase ...

2013-02-14T23:59:59.000Z

22

Solid-State Fault Current Limiter Development : Design and Testing Update of a 15kV SSCL Power Stack  

Science Conference Proceedings (OSTI)

ABSTRACT The Solid-State Fault Current Limiter (SSCL) is a promising technology that can be applied to utility power delivery systems to address the problem of increasing fault currents associated with load growth. As demand continues to grow, more power is added to utility system either by increasing generator capacity or by adding distributed generators, resulting in higher available fault currents, often beyond the capabilities of the present infrastructure. The SSCL is power-electronics based equipment designed to work with the present utility system to address this problem. The SSCL monitors the line current and dynamically inserts additional impedance into the line in the event of a fault being detected. The SSCL is based on a modular design and can be configured for 5kV through 69kV systems at nominal current ratings of 1000A to 4000A. Results and Findings This report provides the final test results on the development of 15kV class SSCL single phase power stack. The scope of work included the design of the modular standard building block sub-assemblies, the design and manufacture of the power stack and the testing of the power stack for the key functional tests of continuous current capability and fault current limiting action. Challenges and Objectives Solid-State Current Limiter technology impacts a wide spectrum of utility engineering and operating personnel. It addresses the problems associated with load growth both at Transmission and Distribution class networks. The design concept is pioneering in terms of developing the most efficient and compact power electronics equipment for utility use. The initial test results of the standard building blocks are promising. The independent laboratory tests of the power stack are promising. However the complete 3 phase system needs rigorous testing for performance and reliability. Applications, Values, and Use The SSCL is an intelligent power-electronics device which is modular in design and can provide current limiting or current interrupting capabilities. It can be applied to variety of applications from distribution class to transmission class power delivery grids and networks. It can also be applied to single major commercial and industrial loads and distributed generator supplies. The active switching of devices can be further utilized for protection of substation transformers. The stress on the system can be reduced substantially improving the life of the power system. It minimizes the voltage sag by speedy elimination of heavy fault currents and promises to be an important element of the utility power system. DOE Perspective This development effort is now focused on a 15kV system. This project will help mitigate the challenges of increasing available fault current. DOE has made a major contribution in providing a cost effective SSCL designed to integrate seamlessly into the Transmission and Distribution networks of today and the future. Approach SSCL development program for a 69kV SSCL was initiated which included the use of the Super GTO advanced semiconductor device which won the 2007 R&D100 Award. In the beginning, steps were identified to accomplish the economically viable design of a 69kV class Solid State Current Limiter that is extremely reliable, cost effective, and compact enough to be applied in urban transmission. The prime thrust in design and development was to encompass the 1000A and the 3000A ratings and provide a modular design to cover the wide range of applications. The focus of the project was then shifted to a 15kV class SSCL. The specifications for the 15kV power stack are reviewed. The design changes integrated into the 15kV power stack are discussed. In this Technical Update the complete project is summarized followed by a detailed test report. The power stack independent high voltage laboratory test requirements and results are presented. Keywords Solid State Current Limiter, SSCL, Fault Current Limiter, Fault Current Controller, Power electronics controller, Intelligent power-electronics Device, IED

Dr. Ram Adapa; Mr. Dante Piccone

2012-04-30T23:59:59.000Z

23

Analytical and Experimental Studies on the Hybrid Fault Current Limiter Employing Asymmetric Non-Inductive Coil and Fast Switch  

E-Print Network (OSTI)

This paper deals with design and operating test of a novel hybrid FCL. The FCL system consists of a coil, a fast switch and a resistor for bypassing the fault current. The switch is driven by novel non-inductive coil ...

Yang, Seong Eun

24

Fault Current Management Guidebook - Updated  

Science Conference Proceedings (OSTI)

Under the new paradigm of power market operation, electric utilities are forcing more power through the existing transmission lines; and these increased loads will increase the fault current level throughout the power system. Also, new generation sources including distributed generation added at the transmission and distribution network will increase power flows and, consequently, fault current levels. Under increased power flow conditions on the existing assets, managing fault currents is crucial in ord...

2007-12-20T23:59:59.000Z

25

EPRI Fault Current Management Guidebook, Sixth Edition (Maroon Book)  

Science Conference Proceedings (OSTI)

This document is an update of the document Fault Current Management Guidebook, Fifth Edition on fault current effects and management in transmission and distribution systems. This guide is intended to be a snapshot of available references, information, and literature on the effects of high fault current on a number of power system components and various available and emerging fault-current-limiting technologies.Results and FindingsDue to increased ...

2012-12-31T23:59:59.000Z

26

Fault Current Management Guidebook--Updated  

Science Conference Proceedings (OSTI)

Due to increased load demands and reduced incentives to build new transmission, energy companies are increasing power flows on existing transmission assets, which will increase fault current levels throughout the power system. Also, new generation sources to be added at the transmission and distribution network will increase power flows and, consequently, fault current levels. Under increased power flow conditions on existing assets, managing fault currents is crucial for avoiding damage to equipment as ...

2006-11-28T23:59:59.000Z

27

System for detecting and limiting electrical ground faults within electrical devices  

DOE Patents (OSTI)

An electrical ground fault detection and limitation system for employment with a nuclear reactor utilizing a liquid metal coolant. Elongate electromagnetic pumps submerged within the liquid metal coolant and electrical support equipment experiencing an insulation breakdown occasion the development of electrical ground fault current. Without some form of detection and control, these currents may build to damaging power levels to expose the pump drive components to liquid metal coolant such as sodium with resultant undesirable secondary effects. Such electrical ground fault currents are detected and controlled through the employment of an isolated power input to the pumps and with the use of a ground fault control conductor providing a direct return path from the affected components to the power source. By incorporating a resistance arrangement with the ground fault control conductor, the amount of fault current permitted to flow may be regulated to the extent that the reactor may remain in operation until maintenance may be performed, notwithstanding the existence of the fault. Monitors such as synchronous demodulators may be employed to identify and evaluate fault currents for each phase of a polyphase power, and control input to the submerged pump and associated support equipment.

Gaubatz, Donald C. (Cupertino, CA)

1990-01-01T23:59:59.000Z

28

Fault Current Limiters | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Security News Archive Control Systems Security Publications Library Energy Storage Power Electronics Advanced Modeling Grid Research Transmission Reliability Renewable...

29

Impact of Wind Power Integration on Fault Current Management  

Science Conference Proceedings (OSTI)

This report presents a study on the impact of wind power integration on the grid fault current level due to various types of faults that might take place inside or outside of wind farms. Wind power is one of the renewable energy sources that has shown tremendous growth in recent years. The increasing integration of wind energy generation and other distributed renewable energy generation could change grid behavior under fault situations and influence system stability. Specifically, integration of addition...

2010-01-14T23:59:59.000Z

30

Microgrid Fault Protection Based on Symmetrical and Differential Current Components  

E-Print Network (OSTI)

Microgrid Fault Protection Based on Symmetrical and Differential Current Components Prepared.........................................................................................8 2. AEP CERTS MICROGRID .........................................................................9 ........................................................................67 #12;3 Index of Figures Figure 1: Schematic representation of the AEP CERTS microgrid

31

Development of a 15-kV Class Solid-State Current Limiter  

Science Conference Proceedings (OSTI)

The solid-state current limiter (SSCL) is a promising technology that can be applied to utility power delivery systems to address the growing problems associated with increasing fault current levels in the electric system. The present utility power delivery infrastructure is on the verge of reaching its maximum capacity and yet demand continues to grow, leading to increases in generation and transmission that result in higher fault currents. The power-electronics-based SSCL is designed to work with the p...

2009-12-23T23:59:59.000Z

32

The bridge-type fault current controller--a new facts controller  

Science Conference Proceedings (OSTI)

The operation of a novel current controller, which can also function as a fault current limiter and as a solid-state ac circuit breaker, is presented. The controller, which consists of a thyristor bridge, an inductor, and an optional bias power supply, is installed in series with the voltage source and the load, For load current values smaller than a preset value, the inductor of the current controller presents no impedance to the ac current flow. For values higher than the preset current value, the inductor is switched automatically into the ac circuit and limits the amount of current flow. Theoretical results in the form of circuit simulations and experimental results with a single-phase unit, operating on a 13.7 kV three-phase system with peak short-circuit currents of 3140 Arms, are presented.

Boenig, Heinrich J.; Mielke, C. H. (Charles H.); Burley, B. L. (Burt L.); Chen, Hong; Waynert, J. A. (Joseph A.); Willis, J. O. (Jeffrey O.)

2002-01-01T23:59:59.000Z

33

New fault locating system for air-insulated substations using optical current detector  

Science Conference Proceedings (OSTI)

This paper deals with a newly developed fault locating system. This fault locating system helps to shorten the time required for restoration of service after the occurrence of a busbar fault in an air-insulated distribution substation. Recent optical and electronic technologies allow highly accurate and compact fault locating system, which consists of optical current detectors using Faraday effect and a fault locating processor employing digital data processing technique. The fault location is made by discriminating the direction of zero-sequence currents. Through various tests and field operations it has been confirmed that the system has sufficient performance for practical application.

Yoshida, Y.; Kawazoe, S. (Kansai Electric Power Co., Inc., Osaka (Japan)); Ibuki, K.; Yamada, K.; Ochi, N. (Mitsubishi Electric Corp., Amagasaki, Hyogo (Japan). Itami Works)

1992-10-01T23:59:59.000Z

34

Restoration and testing of an HTS fault current controller  

Science Conference Proceedings (OSTI)

A three-phase, 1200 A, 12.5 kV fault current controller using three HTS 4 mH coils, was built by industry and tested in 1999 at the Center Substation of Southern California Edison in Norwalk, CA. During the testing, it appeared that each of the three single-phase units had experienced a voltage breakdown, one externally and two internally. Los Alamos National Laboratory (LANL) was asked by DOE to restore the operation of the fault current controller provided the HTS coils had not been damaged during the initial substation tests. When the internally-failed coil vacuum vessels were opened it became evident that in these two vessels, a flashover had occurred at the high voltage bus section leading to the terminals of the superconducting coil. An investigation into the failure mechanism resulted in six possible causes for the flashover. Based on these causes, the high voltage bus was completely redesigned. Single-phase tests were successfully performed on the modified unit at a 13.7 kV LANL substation. This paper presents the postulated voltage flashover failure mechanisms, the new high voltage bus design which mitigates the failure mechanisms, the sequence of tests used to validate the new design, and finally, the results of variable load and short-circuit tests with the single-phase unit operating on the LANL 13.7 kV substation.

Waynert, J. A. (Joseph A.); Boenig, H. (Heinrich E.); Mielke, C. H. (Charles H.); Willis, J. O. (Jeffrey O.); Burley, B. L. (Burt L.)

2002-01-01T23:59:59.000Z

35

Theory of space charge limited currents  

SciTech Connect

Space-charge-limited currents are important in energy devices such as solar cells and light-emitting diodes, but the available theory from the 1950's finds it necessary to postulate an exponential density of defect energy levels to match data. Here we revisit the theory and show that this postulate is not warranted. Instead, we demonstrate that dopants and the concomitant Frenkel effect, which have been neglected, control the shape of measured current-voltage characteristics. We also account for the observed peak in the noise power. Finally, the new theory can anchor efforts to develop experimental techniques to measure deep-trap levels.

Zhang, Xiaoguang [ORNL; Pantelides, Sokrates T. [Vanderbilt University

2012-01-01T23:59:59.000Z

36

New Limits on Fault-Tolerant Quantum Computation  

E-Print Network (OSTI)

We show that quantum circuits cannot be made fault-tolerant against a depolarizing noise level of approximately 45%, thereby improving on a previous bound of 50% (due to Razborov). Our precise quantum circuit model enables perfect gates from the Clifford group (CNOT, Hadamard, S, X, Y, Z) and arbitrary additional one-qubit gates that are subject to that much depolarizing noise. We prove that this set of gates cannot be universal for arbitrary (even classical) computation, from which the upper bound on the noise threshold for fault-tolerant quantum computation follows.

Harry Buhrman; Richard Cleve; Monique Laurent; Noah Linden; Alexander Schrijver; Falk Unger

2006-04-19T23:59:59.000Z

37

Current Practice and a Direction Forward in Checkpoint/Restart Implementations for Fault Tolerance  

Science Conference Proceedings (OSTI)

Checkpoint/restart is a general idea for which particular implementations enable various functionalities in computer systems, including process migration, gang scheduling, hibernation, and fault tolerance. For fault tolerance, in current practice, implementations ... Keywords: Fault tolerance, checkpoint/restart, autonomic computing, Linux

Jose Carlos Sancho; Fabrizio Petrini; Kei Davis; Roberto Gioiosa; Song Jiang

2005-04-01T23:59:59.000Z

38

System and method for motor fault detection using stator current noise cancellation  

Science Conference Proceedings (OSTI)

A system and method for detecting incipient mechanical motor faults by way of current noise cancellation is disclosed. The system includes a controller configured to detect indicia of incipient mechanical motor faults. The controller further includes a processor programmed to receive a baseline set of current data from an operating motor and define a noise component in the baseline set of current data. The processor is also programmed to acquire at least on additional set of real-time operating current data from the motor during operation, redefine the noise component present in each additional set of real-time operating current data, and remove the noise component from the operating current data in real-time to isolate any fault components present in the operating current data. The processor is then programmed to generate a fault index for the operating current data based on any isolated fault components.

Zhou, Wei (Los Angeles, CA); Lu, Bin (Kenosha, WI); Nowak, Michael P. (Menomonee Falls, WI); Dimino, Steven A. (Wauwatosa, WI)

2010-12-07T23:59:59.000Z

39

System and method for bearing fault detection using stator current noise cancellation  

Science Conference Proceedings (OSTI)

A system and method for detecting incipient mechanical motor faults by way of current noise cancellation is disclosed. The system includes a controller configured to detect indicia of incipient mechanical motor faults. The controller further includes a processor programmed to receive a baseline set of current data from an operating motor and define a noise component in the baseline set of current data. The processor is also programmed to repeatedly receive real-time operating current data from the operating motor and remove the noise component from the operating current data in real-time to isolate any fault components present in the operating current data. The processor is then programmed to generate a fault index for the operating current data based on any isolated fault components.

Zhou, Wei (Los Angeles, CA); Lu, Bin (Kenosha, WI); Habetler, Thomas G. (Snellville, GA); Harley, Ronald G. (Lawrenceville, GA); Theisen, Peter J. (West Bend, WI)

2010-08-17T23:59:59.000Z

40

Fault Current Contribution from Single-Phase PV Inverters  

DOE Green Energy (OSTI)

A significant increase in photovoltaic (PV) system installations is expected to come on line in the near future and as the penetration level of PV increases, the effect of PV may no longer be considered minimal. One of the most important attributions of additional PV is what effect this may have on protection systems. Protection engineers design protection systems to safely eliminate faults from the electric power system. One of the new technologies recently introduced into the electric power system are distributed energy resources (DER). Currently, inverter-based DER contributes very little to the power balance on all but a few utility distribution systems. As DER become prevalent in the distribution system, equipment rating capability and coordination of protection systems merit a closer investigation. A collaborative research effort between the National Renewable Energy Laboratory (NREL) and Southern California Edison (SCE) involved laboratory short-circuit testing single-phase (240 VAC) residential type (between 1.5 and 7kW) inverters. This paper will reveal test results obtained from these short-circuit tests.

Keller, J.; Kroposki, B.; Bravo, R.; Robles, S.

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Computation of the split factor of earth fault currents by considering the proximity effects  

Science Conference Proceedings (OSTI)

To determine a safe substation grounding grid in power systems, it is important to compute the split factor for earth fault current including the proximity influences among the grid and the earthing systems of the incoming/outgoing transmission lines' ... Keywords: earth fault currents, grounding grid design, proximity effects, split factor, touch and step voltages

N. Ramezani; S. M. Shahrtash

2010-06-01T23:59:59.000Z

42

Critical Current Metrology for Nb3Sn  

Science Conference Proceedings (OSTI)

... research magnets, fault-current limiters, magnetic energy storage, motors, generators, transformers, transmission lines, synchronous condensers ...

2010-09-01T23:59:59.000Z

43

Limitations for detecting small-scale faults using the coherency analysis of seismic data  

E-Print Network (OSTI)

Coherency analyzes the trace to trace amplitude similarities recorded by seismic waves. Coherency algorithms have been used to identify the structural or stratigraphic features of an area but the limitations for detecting small-scale features are not known. These limitations become extremely important when interpreting coherency within poorly acquired or processed data sets. In order to obtain a better understanding of the coherency limitations, various synthetic seismic data sets were created. The sensitivity of the coherency algorithms to variations in wave frequency, signal-to-noise ratio and fault throw was investigated. Correlation between the coherency values of a faulted reflector and the known offset shows that coherency has the ability to detect the presence of various scale features that may be previously thought to be below seismic resolution or difficult to discriminate with conventional interpretation methods. Coherency values had a smaller standard deviation and were less sensitive to noise when processed with a temporal window length less than one period. A fault could be detected by coherency when the signal-to-noise ratio was >3. A fault could also be detected as long as the throw-to-wavelength ratio was >5% or two-way traveltime-toperiod >10%. Therefore, this study suggests that coherency has the ability to detect a fault as long as the frequency of the data imaging that fault has a period no greater than one order of magnitude to the traveltime through the fault and that the signal can easily be distinguished from noise. Results from application of the coherency analysis were applied to the characterization of a very deep fault and fracture system imaged by a field seismic data set. A series of reverse and strike-slip faults were detected and mapped. Magnitudes of the throws for these faults were not known, but subtle amplitude anomalies in seismic sections confirmed the coherency analysis. The results of this study suggest that coherency has demonstrated an ability to detect features that would normally beoverlooked using traditional interpretation methods and has many future implications for poorly imaged seismic areas, such as sub-salt.

Barnett, David Benjamin

2003-05-01T23:59:59.000Z

44

Solid-state circuit breaker with current-limiting characteristic using a superconducting coil  

DOE Patents (OSTI)

A thyristor bridge interposes an ac source and a load. A series connected DC source and superconducting coil within the bridge biases the thyristors thereof so as to permit bidirectional ac current flow therethrough under normal operating conditions. Upon a fault condition a control circuit triggers the thyristors so as to reduce ac current flow therethrough to zero in less than two eyeles and to open the bridge thereafter. Upon a temporary overload condition the control circuit triggers the thyristors so as to limit ac current flow therethrough to an acceptable level.

Boenig, H.J.

1982-08-16T23:59:59.000Z

45

Solid-state circuit breaker with current limiting characteristic using a superconducting coil  

DOE Patents (OSTI)

A thyristor bridge interposes an ac source and a load. A series connected DC source and superconducting coil within the bridge biases the thyristors thereof so as to permit bidirectional ac current flow therethrough under normal operating conditions. Upon a fault condition a control circuit triggers the thyristors so as to reduce ac current flow therethrough to zero in less than two cycles and to open the bridge thereafter. Upon a temporary overload condition the control circuit triggers the thyristors so as to limit ac current flow therethrough to an acceptable level.

Boenig, Heinrich J. (Los Alamos, NM)

1984-01-01T23:59:59.000Z

46

Symmetrical and Unsymmetrical Fault Currents of a Wind Power Plant: Preprint  

DOE Green Energy (OSTI)

This paper investigates the short-circuit behavior of a wind power plant for different types of wind turbines. Both symmetrical faults and unsymmetrical faults are investigated. The size of wind power plants (WPPs) keeps getting bigger and bigger. The number of wind plants in the U.S. has increased very rapidly in the past 10 years. It is projected that in the U.S., the total wind power generation will reach 330 GW by 2030. As the importance of WPPs increases, planning engi-neers must perform impact studies used to evaluate short-circuit current (SCC) contribution of the plant into the transmission network under different fault conditions. This information is needed to size the circuit breakers, to establish the proper sys-tem protection, and to choose the transient suppressor in the circuits within the WPP. This task can be challenging to protec-tion engineers due to the topology differences between different types of wind turbine generators (WTGs) and the conventional generating units. This paper investigates the short-circuit behavior of a WPP for different types of wind turbines. Both symmetrical faults and unsymmetrical faults are investigated. Three different soft-ware packages are utilized to develop this paper. Time domain simulations and steady-state calculations are used to perform the analysis.

Gevorgian, V.; Singh, M.; Muljadi, E.

2011-12-01T23:59:59.000Z

47

Practical method for evaluating ground fault current distribution in station supplied by an unhomogeneous line  

SciTech Connect

The paper presents an analytical procedure which enables a quick and, at the design stage, correct evaluation of the ground fault current distribution, for a fault in a substation supplied by a line composed of two or more uniform and different sections. The advantages of the method are based on the simplicity and accuracy of the formulae for solving uniform lumped parameter ladder circuits of any size and under any terminal conditions. The formulae are obtained by applying the general equations of the line represented by discrete parameters on a specific electrical circuit formed by a transmission line ground wire during ground faults. The paper also derives simple and exact expressions for solving ladder circuits formed by the discretization of underground conductors which are in continuous contact with earth (e.g., the sheaths of a cable, an interconnecting copper buried in the soil, a pipeline, etc.). The correct prediction of the expected ground fault current parts in soil and neutral conductors is of great importance in designing safe and economical substation grounding installations.

Popovic, L.M. [JP Elektroprivreda Srbije, Belgrade (Yugoslavia)] [JP Elektroprivreda Srbije, Belgrade (Yugoslavia)

1997-04-01T23:59:59.000Z

48

Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude  

DOE Patents (OSTI)

A beam current limiter is disclosed for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity. 6 figs.

Bogaty, J.M.; Clifft, B.E.; Bollinger, L.M.

1995-08-08T23:59:59.000Z

49

Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude  

DOE Patents (OSTI)

A beam current limiter for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity.

Bogaty, John M. (Lombard, IL); Clifft, Benny E. (Park Forest, IL); Bollinger, Lowell M. (Downers Grove, IL)

1995-01-01T23:59:59.000Z

50

A 4000-A HVDC (high-voltage direct-current) circuit breaker with fast fault-clearing capability: Final report  

Science Conference Proceedings (OSTI)

This project is a follow-up of the first development of a 500 kV HVDC airblast circuit breaker (EPRI project 1507-3). The objective was to increase the current interrupting capability from 2200 A to 4000 A and shorten its fault clearing time. A high current 500 kV HVDC circuit breaker has been built using the passive commutation circuit. The breaker is modular in construction and can be designed for a wide variety of system conditions. More than 400 current interruptions were carried out successfully. Tests have shown that this circuit breaker is capable of interrupting more than 4000 A dc. Practical breakers with current interrupting capability of even 5500 A dc could be built. The circuit breaker operation and the fault-clearing process can be materially speeded up if the trip signal is given as soon as the fault is detected and without waiting for the current levels to come down in response to converter control action. The new dc breakers are shown to be capable of withstanding these transient arc currents of 8000 A without affecting its ability to interrupt the direct current that follows the transient. This transient current withstand capability is greater than is likely to occur during dc faults. The fault clearing time of this HVDC circuit breaker is comparable to the fault clearing time of conventional ac breakers for ac faults. The developed HVDC circuit breaker is now commercially available and can be supplied for use in HVDC systems. Its use in such systems is expected to provide flexibility in system design and contribute to system stability. 38 refs., 52 figs., 9 tabs.

Not Available

1988-04-01T23:59:59.000Z

51

Current parallel I/O limitations to scalable data analysis.  

Science Conference Proceedings (OSTI)

This report describes the limitations to parallel scalability which we have encountered when applying our otherwise optimally scalable parallel statistical analysis tool kit to large data sets distributed across the parallel file system of the current premier DOE computational facility. This report describes our study to evaluate the effect of parallel I/O on the overall scalability of a parallel data analysis pipeline using our scalable parallel statistics tool kit [PTBM11]. In this goal, we tested it using the Jaguar-pf DOE/ORNL peta-scale platform on a large combustion simulation data under a variety of process counts and domain decompositions scenarios. In this report we have recalled the foundations of the parallel statistical analysis tool kit which we have designed and implemented, with the specific double intent of reproducing typical data analysis workflows, and achieving optimal design for scalable parallel implementations. We have briefly reviewed those earlier results and publications which allow us to conclude that we have achieved both goals. However, in this report we have further established that, when used in conjuction with a state-of-the-art parallel I/O system, as can be found on the premier DOE peta-scale platform, the scaling properties of the overall analysis pipeline comprising parallel data access routines degrade rapidly. This finding is problematic and must be addressed if peta-scale data analysis is to be made scalable, or even possible. In order to attempt to address these parallel I/O limitations, we will investigate the use the Adaptable IO System (ADIOS) [LZL+10] to improve I/O performance, while maintaining flexibility for a variety of IO options, such MPI IO, POSIX IO. This system is developed at ORNL and other collaborating institutions, and is being tested extensively on Jaguar-pf. Simulation code being developed on these systems will also use ADIOS to output the data thereby making it easier for other systems, such as ours, to process that data.

Mascarenhas, Ajith Arthur; Pebay, Philippe Pierre

2011-07-01T23:59:59.000Z

52

A new converter fault discrimination method for a 12-pulse high-voltage direct current system based on wavelet transform and Hidden Markov Models  

Science Conference Proceedings (OSTI)

The progressive development in high-voltage direct current (HVDC) transmission enhances the need to implement an efficient protection scheme to distinguish the minimum faulty part of the system and to relieve the stressed equipment. This paper proposes ... Keywords: Discrete Hidden Markov Models, converter faults, fault discrimination, high-voltage direct current, wavelet transform

Mohamad Tahan; Hassan Monsef; Shahrokh Farhangi

2012-06-01T23:59:59.000Z

53

Wind Turbines Condition Monitoring and Fault Diagnosis Using Generator Current Amplitude  

E-Print Network (OSTI)

detection in a Doubly-Fed Induction Generator (DFIG) based wind turbine for stationary and nonstationary cases. Index Terms--Wind turbine, DFIG, fault detection, diagnosis, amplitude modulation, Hilbert and maintaining older system, becomes more costly and challenging with obsolescence of key components. DFIG

Paris-Sud XI, Université de

54

Fault Tolerance in Petascale/ Exascale Systems: Current Knowledge, Challenges and Research Opportunities  

Science Conference Proceedings (OSTI)

The emergence of petascale systems and the promise of future exascale systems have reinvigorated the community interest in how to manage failures in such systems and ensure that large applications, lasting several hours or tens of hours, are completed ... Keywords: challenges, fault tolerance, knowledge, opportunities, petascale/exascale

Franck Cappello

2009-08-01T23:59:59.000Z

55

Fault-Current Limiter (FCL) Application in a Wind Power Plant (Poster)  

DOE Green Energy (OSTI)

This poster describes how the power system switchgear and power system protection for WPPs should be carefully designed to be compatible with the operation of conventional synchronous generators connected to the same grid.

Muljadi, E.; Gevorgian, V.

2011-05-01T23:59:59.000Z

56

Wind Power Plant Short Circuit Current Contribution for Different Fault and Wind Turbine Topologies: Preprint  

SciTech Connect

This paper presents simulation results for SC current contribution for different types of WTGs obtained through transient and steady-state computer simulation software.

Gevorgian, V.; Muljadi, E.

2010-10-01T23:59:59.000Z

57

Estimating Heat and Mass Transfer Processes in Green Roof Systems: Current Modeling Capabilities and Limitations (Presentation)  

Science Conference Proceedings (OSTI)

This presentation discusses estimating heat and mass transfer processes in green roof systems: current modeling capabilities and limitations. Green roofs are 'specialized roofing systems that support vegetation growth on rooftops.'

Tabares Velasco, P. C.

2011-04-01T23:59:59.000Z

58

Arc fault detection system  

DOE Patents (OSTI)

An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.

Jha, Kamal N. (Bethel Park, PA)

1999-01-01T23:59:59.000Z

59

Arc fault detection system  

DOE Patents (OSTI)

An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard. 1 fig.

Jha, K.N.

1999-05-18T23:59:59.000Z

60

Method and apparatus for generating motor current spectra to enhance motor system fault detection  

DOE Patents (OSTI)

A method and circuitry for sampling periodic amplitude modulations in a nonstationary periodic carrier wave to determine frequencies in the amplitude modulations. The method and circuit are described in terms of an improved motor current signature analysis. The method insures that the sampled data set contains an exact whole number of carrier wave cycles by defining the rate at which samples of motor current data are collected. The circuitry insures that a sampled data set containing stationary carrier waves is recreated from the analog motor current signal containing nonstationary carrier waves by conditioning the actual sampling rate to adjust with the frequency variations in the carrier wave. After the sampled data is transformed to the frequency domain via the Discrete Fourier Transform, the frequency distribution in the discrete spectra of those components due to the carrier wave and its harmonics will be minimized so that signals of interest are more easily analyzed.

Linehan, Daniel J. (Knoxville, TN); Bunch, Stanley L. (Oak Ridge, TN); Lyster, Carl T. (Knoxville, TN)

1995-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Method and apparatus for generating motor current spectra to enhance motor system fault detection  

DOE Patents (OSTI)

A method and circuitry are disclosed for sampling periodic amplitude modulations in a nonstationary periodic carrier wave to determine frequencies in the amplitude modulations. The method and circuit are described in terms of an improved motor current signature analysis. The method insures that the sampled data set contains an exact whole number of carrier wave cycles by defining the rate at which samples of motor current data are collected. The circuitry insures that a sampled data set containing stationary carrier waves is recreated from the analog motor current signal containing nonstationary carrier waves by conditioning the actual sampling rate to adjust with the frequency variations in the carrier wave. After the sampled data is transformed to the frequency domain via the Discrete Fourier Transform, the frequency distribution in the discrete spectra of those components due to the carrier wave and its harmonics will be minimized so that signals of interest are more easily analyzed. 29 figs.

Linehan, D.J.; Bunch, S.L.; Lyster, C.T.

1995-10-24T23:59:59.000Z

62

Reevaluation of IEEE and IEC Substation Design, Operations, and Maintenance Standards Considering Increased Fault Currents  

Science Conference Proceedings (OSTI)

The ever-increasing demand for utility substations to pass higher and higher levels of throughput power has the consequence of driving up levels of short circuit (SC) currents from 63 kA to as high as 100 kA. Knowing whether substation bus structures and electrical equipment are capable of safely passing these higher levels of currents is a pressing need of substation personnel responsible for design, operation, and maintenance of station assets. This report presents results of a preliminary study ...

2012-12-04T23:59:59.000Z

63

Hospital remedies architect's lighting overdesign for $22k: installs current limiters  

SciTech Connect

St. Luke's Hospital in Racine, Wisconsin is spending $22,000 to install current limiters in the fluorescent lamps of a new wing after finding that the architectural firm overdesigned the lighting fixtures so much that the hospital's lighting expenses were 50% higher than necessary. The hospital expects an 8-month payback on the current limiters. The hospital's corridor lighting reached 45-55 footcandles (fc), when only three fc are required for emergency lighting and 15 for corridor lighting. Representatives of the architectural firm argued that the design did not exceed state wattage requirements.

Ponczak, G.

1984-10-29T23:59:59.000Z

64

Limiter  

DOE Patents (OSTI)

A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

1984-10-19T23:59:59.000Z

65

Limiter  

SciTech Connect

A limiter with a specially contoured front face accommodates the various power scrape-off distances .lambda..sub.p, which depend on the parallel velocity, V.sub..parallel., of the impacting particles. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution.

Cohen, Samuel A. (Hopewell, NJ); Hosea, Joel C. (Princeton, NJ); Timberlake, John R. (Allentown, NJ)

1986-01-01T23:59:59.000Z

66

Transient fault modeling and fault injection simulation  

E-Print Network (OSTI)

An accurate transient fault model is presented in this thesis. A 7-term exponential current upset model is derived from the results of a device-level, 3-dimensional, single-event-upset simulation. A curve-fitting algorithm is used to extract the numerical model from the empirical data. The model is implemented in a HSPICE simulation environment as a current-injection source for fault simulation. The current transient model is used to conduct electrical-level fault injection simulations on a static RAM cell and subcircuits from two commercial microprocessors. The results from the 7-term exponential model are compared with the results from the widely accepted double-exponential transient model. The experimental data indicate that, for a given charge level, the 7-term exponential fault model results in a higher chance of having a latch error. More importantly, different latch-error patterns are captured from the target circuits under the new fault model.

Yuan, Xuejun

1996-01-01T23:59:59.000Z

67

An arc fault detection system  

DOE Patents (OSTI)

An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn, opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.

Jha, Kamal N.

1997-12-01T23:59:59.000Z

68

Iron distribution and phytoplankton iron limitation in the southern California Current System  

E-Print Network (OSTI)

zero. As a biomass-limiting nutrient, the supply of nitratesupply of upwelled macronutrient nitrate - phytoplankton biomass andphytoplankton biomass is generally limited by the supply of

King, Andrew Luke

2008-01-01T23:59:59.000Z

69

Fault Locating, Prediction and Protection (FLPPS)  

Science Conference Proceedings (OSTI)

One of the main objectives of this DOE-sponsored project was to reduce customer outage time. Fault location, prediction, and protection are the most important aspects of fault management for the reduction of outage time. In the past most of the research and development on power system faults in these areas has focused on transmission systems, and it is not until recently with deregulation and competition that research on power system faults has begun to focus on the unique aspects of distribution systems. This project was planned with three Phases, approximately one year per phase. The first phase of the project involved an assessment of the state-of-the-art in fault location, prediction, and detection as well as the design, lab testing, and field installation of the advanced protection system on the SCE Circuit of the Future located north of San Bernardino, CA. The new feeder automation scheme, with vacuum fault interrupters, will limit the number of customers affected by the fault. Depending on the fault location, the substation breaker might not even trip. Through the use of fast communications (fiber) the fault locations can be determined and the proper fault interrupting switches opened automatically. With knowledge of circuit loadings at the time of the fault, ties to other circuits can be closed automatically to restore all customers except the faulted section. This new automation scheme limits outage time and increases reliability for customers. The second phase of the project involved the selection, modeling, testing and installation of a fault current limiter on the Circuit of the Future. While this project did not pay for the installation and testing of the fault current limiter, it did perform the evaluation of the fault current limiter and its impacts on the protection system of the Circuit of the Future. After investigation of several fault current limiters, the Zenergy superconducting, saturable core fault current limiter was selected for installation. Because of some testing problems with the Zenergy fault current limiter, installation was delayed until early 2009 with it being put into operation on March 6, 2009. A malfunction of the FCL controller caused the DC power supply to the superconducting magnet to be turned off. This inserted the FCL impedance into the circuit while it was in normal operation causing a voltage resonance condition. While these voltages never reached a point where damage would occur on customer equipment, steps were taken to insure this would not happen again. The FCL was reenergized with load on December 18, 2009. A fault was experienced on the circuit with the FCL in operation on January 14, 2010. The FCL operated properly and reduced the fault current by about 8%, what was expected from tests and modeling. As of the end of the project, the FCL was still in operation on the circuit. The third phase of the project involved the exploration of several advanced protection ideas that might be at a state where they could be applied to the Circuit of the Future and elsewhere in the SCE electrical system. Based on the work done as part of the literature review and survey, as well as a number of internal meetings with engineering staff at SCE, a number of ideas were compiled. These ideas were then evaluated for applicability and ability to be applied on the Circuit of the Future in the time remaining for the project. Some of these basic ideas were implemented on the circuit including measurement of power quality before and after the FCL. It was also decided that we would take what was learned as part of the Circuit of the Future work and extend it to the next generation circuit protection for SCE. Also at this time, SCE put in a proposal to the DOE for the Irvine Smart Grid Demonstration using ARRA funding. SCE was successful in obtaining funding for this proposal, so it was felt that exploration of new protection schemes for this Irvine Smart Grid Demonstration would be a good use of the project resources. With this in mind, a protection system that uses fault interrupting switches, hi

Yinger, Robert, J.; Venkata, S., S.; Centeno, Virgilio

2010-09-30T23:59:59.000Z

70

Instantaneous Active and Nonactive Power Control of Distributed Energy Resources with Current Limiter  

SciTech Connect

Abstract -- Distributed energy resources (DER) with a power electronics inverter interface can provide both active power and nonactive power simultaneously and independently. A decoupled control algorithm of active power and nonactive power is developed based on the instantaneous active power and nonactive power theory. A current limiter is combined to the control algorithm, and it ensures that the inverter is not overloaded. During the normal system operation, the active power has higher priority over the nonactive power so that the energy from a DER can be fully transferred to the grid. Within the inverter s capability, nonactive power is provided to the grid as required. With this control algorithm, the inverter s capabilities are taken full advantage at all times, both in terms of functionality as well as making use of its full KVA rating. Through the algorithm, the inverter s active power and nonactive power are controlled directly, simultaneously, and independently. Several experimental results fully demonstrate the validity and effectiveness of this new control algorithm. As evidenced by the fast dynamic response that results, a DER system with the control algorithm can provide full services to the grid in both steady state and during transient events.

Xu, Yan [ORNL; Li, Huijuan [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Kueck, John D [ORNL

2010-01-01T23:59:59.000Z

71

Definition: Enhanced Fault Protection | Open Energy Information  

Open Energy Info (EERE)

Enhanced Fault Protection Enhanced Fault Protection Enhanced fault protection requires higher precision and greater discrimination of fault location and type with coordinated measurement among multiple devices. For distribution applications, these systems will detect and isolate faults without full-power re-closing, reducing the frequency of through-fault currents. Using high resolution sensors and fault signatures, these systems can better detect high impedance faults. For transmission applications, these systems will employ high speed communications between multiple elements (e.g., stations) to protect entire regions, rather than just single elements. They will also use the latest digital techniques to advance beyond conventional impedance relaying of transmission lines.[1] Related Terms

72

Factors Affecting Limiting Current in Solid Oxide Fuel Cells or Debunking the Myth of Anode Diffusion Polarization  

DOE Green Energy (OSTI)

Limiting current densities for solid oxide fuel cells were measured using both button cells and a flow-through cell. The cell anodes were supplied mixtures of humidified hydrogen and various inert gasses. It was demonstrated that the true limiting current in flow-through cells is reached when either: the hydrogen is nearly or completely depleted at the anode-electrolyte interface near the outlet; or when the concentration of steam at that interface becomes high enough to interfere with adsorption or transport of the remaining hydrogen near the triple-phase boundaries. Choice of inert gas had no effect on limiting currents in the flow-through tests, indicating that diffusion within the porous anode had no significant effect on cell performance at high currents. In the button cells, the apparent limiting currents were significantly changed by the choice of inert gas, indicating that they were determined by diffusion through the bulk gas within the support tube. It was concluded that the apparent limiting currents measured in button cells are influenced more by parameters of the experimental setup, such as the proximity of the fuel tube outlet, than by the physical properties of the anode.

Chick, Lawrence A.; Meinhardt, Kerry D.; Simner, Steven P.; Kirby, Brent W.; Powell, Michael R.; Canfield, Nathan L.

2011-04-25T23:59:59.000Z

73

Power Line Fault Current Coupling to Nearby Natural Gas Pipelines, Volume 3: Analysis of Pipeline Coating Impedance  

Science Conference Proceedings (OSTI)

As regulatory agencies encourage construction of transmission lines and gas pipelines along shared utility corridors, the likelihood of voltage and current coupling increases. Development of equations that determine the electrical characteristics of pipeline coatings will help utility engineers to accurately predict induced voltages and currents.

1988-08-01T23:59:59.000Z

74

Fault finder  

DOE Patents (OSTI)

A fault finder for locating faults along a high voltage electrical transmission line. Real time monitoring of background noise and improved filtering of input signals is used to identify the occurrence of a fault. A fault is detected at both a master and remote unit spaced along the line. A master clock synchronizes operation of a similar clock at the remote unit. Both units include modulator and demodulator circuits for transmission of clock signals and data. All data is received at the master unit for processing to determine an accurate fault distance calculation.

Bunch, Richard H. (1614 NW. 106th St., Vancouver, WA 98665)

1986-01-01T23:59:59.000Z

75

CIFTS: Coordinated Infrastructure for Fault-Tolerant Systems...  

NLE Websites -- All DOE Office Websites (Extended Search)

CIFTS: Coordinated Infrastructure for Fault-Tolerant Systems CIFTS: Coordinated Infrastructure for Fault-Tolerant Systems Current systems software components for large-scale...

76

Defect prediction from static code features: current results, limitations, new approaches  

Science Conference Proceedings (OSTI)

Building quality software is expensive and software quality assurance (QA) budgets are limited. Data miners can learn defect predictors from static code features which can be used to control QA resources; e.g. to focus on the parts of the code predicted ... Keywords: Defect prediction, Static code features, WHICH

Tim Menzies; Zach Milton; Burak Turhan; Bojan Cukic; Yue Jiang; Ay?e Bener

2010-12-01T23:59:59.000Z

77

Environmental limits on the non-resonant cosmic-ray current-driven instability  

E-Print Network (OSTI)

We investigate the so-called non-resonant cosmic-ray streaming instability, first discussed by Bell (2004). The extent to which thermal damping and ion-neutral collisions reduce the growth of this instability is calculated. Limits on the growth of the non-resonant mode in SN1006 and RX J1713.7-3946 are presented.

B. Reville; J. G. Kirk; P. Duffy; S. O'Sullivan

2008-02-22T23:59:59.000Z

78

A Technique to Reduce Peak Current and Average Power Dissipation in Scan Designs by Limited Capture  

Science Conference Proceedings (OSTI)

In this paper, a technique that can efficiently reduce peak and average switching activity during test application is proposed. The proposed method does not require any specific clock tree construction, special scan cells, or scan chain reordering. Test ... Keywords: ATPG, peak current reduction, average power dissipation, scan designs, clock tree construction, special scan cells, scan chain reordering

Seongmoon Wang; Wenlong Wei

2007-01-01T23:59:59.000Z

79

Post Irradiation Examination for Advanced Materials at Burnups Exceeding the Current Limit  

SciTech Connect

Permitting fuel to be irradiated to higher burnups limits can reduce the amount of spent nuclear fuel (SNF) requiring storage and/or disposal and enable plants to operate with longer more economical cycle lengths and/or at higher power levels. Therefore, Framatome ANP (FANP) and the B&W Owner's Group (BWOG) have introduced a new fuel rod design with an advanced M5 cladding material and have irradiated several test fuel rods through four cycles. The U.S. Department of Energy (DOE) joined FANP and the BWOG in supporting this project during its final phase of collecting and evaluating high burnup data through post irradiation examination (PIE).

John H. Strumpell

2004-12-31T23:59:59.000Z

80

A fault-tolerant strategy for virtualized HPC clusters  

Science Conference Proceedings (OSTI)

Virtualization is a common strategy for improving the utilization of existing computing resources, particularly within data centers. However, its use for high performance computing (HPC) applications is currently limited despite its potential for both ... Keywords: Benchmark, Checkpointing, Fault-tolerance, MPI, Virtualization

John Paul Walters; Vipin Chaudhary

2009-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Shootthrough fault protection system for bipolar transistors in a voltage source transistor inverter  

SciTech Connect

Faulted bipolar transistors in a voltage source transistor inverter are protected against shootthrough fault current, from the filter capacitor of the d-c voltage source which drives the inverter over the d-c bus, by interposing a small choke in series with the filter capacitor to limit the rate of rise of that fault current while at the same time causing the d-c bus voltage to instantly drop to essentially zero volts at the beginning of a shootthrough fault. In this way, the load lines of the faulted transistors are effectively shaped so that they do not enter the second breakdown area, thereby preventing second breakdown destruction of the transistors.

Wirth, W.F.

1982-01-12T23:59:59.000Z

82

Distribution Fault Location Support Tools, Algorithms, and Implementation Approaches  

Science Conference Proceedings (OSTI)

Distribution grid modernization applications such as fault location and automatic sectionalizing require an accurate assessment of fault current. More-accurate prediction of fault locations will shorten the fault investigation (patrol) time, which in turn can reduce the total restoration time and duration of the outage experienced by the customer. This EPRI technical update report presents information on fault location applications, enumerates different methods used to detect the location of faults, ...

2013-08-14T23:59:59.000Z

83

Distribution Fault Location and Waveform Characterization  

Science Conference Proceedings (OSTI)

Automated fault location algorithms for distribution systems require monitoring equipment to record voltage and current waveforms during an event. In addition, most of these algorithms require circuit-impedance parameters to evaluate the fault location. Locating incipient faults and fault waveform characterization is the main aim of this project. This project builds on work done in 2008 towards sub-cycle blip identification using an algorithm based on arc voltage.

2009-12-11T23:59:59.000Z

84

Benchmarking of Fault-Location Technologies  

Science Conference Proceedings (OSTI)

This report resumes the studies on fault-location technologies that were conducted in 2009. These studies were undertaken in a joint project done with the collaboration of Hydro-Qubec, Long Island Power Authority, and the Electric Power Research Institute (EPRI). Two fault-location technologies were tested, the Reactance to Fault (RTF) implemented in the PQView application and the Voltage Drop Fault Location (VDFL) implemented in the MILE application. The RTF is based on substation voltage and current me...

2011-03-31T23:59:59.000Z

85

Understanding Fault Characteristics of Inverter-Based Distributed Energy Resources  

SciTech Connect

This report discusses issues and provides solutions for dealing with fault current contributions from inverter-based distributed energy resources.

Keller, J.; Kroposki, B.

2010-01-01T23:59:59.000Z

86

Current:  

Office of Legacy Management (LM)

OWNE3 (55) OWNE3 (55) -------- past: _--_-------------------- Current: Owner contacted I-J yes ,Fqna; ------------_------------- if yes, date contacted TYPE OF OPEF(ATION ---__-------_____ c] Research & Development -4 Facility Type ci Production scale testing 0 Pilbt Scale 0 Bench Scale Process 0 Theoretical Studies 0 Sample & Analysis C Productian E Disposal/Storage TYPE OF CONTRACi _------_-------_ tlanuf acturi ng University Research Organizaticn q Prime --. _' cl Other information (i.e., cost price, + fixed fee, unit time % material, qtr) ------- ~----~---~~------__--------- YuncOntractor Purchase Order Contract/Purkhase Order # cc-km ----_----~~-----___--------- --------------------------------- OWNEKSHIP: AEC/ME3 AEC/MED GOVT GOUT CONTRACTOR CCNTRACTOR

87

Current:  

Office of Legacy Management (LM)

Qwner contacted n yes Qwner contacted n yes Current: ---------------------L---- if yes, date contacted Research & Development cl Facility Type 0 . Productioff 0 Di 3pcsal /Storage TYPE OF CONTRACT ---------------- q Prime q Subcontractor 0 Purchase Order 0 Other information (i.e. q cast + fixed fee, unit piice, time & material, etr) ------- ------_-----_--------------- 0 Production scale testing 0 Pilot Scale 0 Bench Scale Process a Theoretical Studies Sample & Analysis rcc t O' L~1 q Manufacturing 0 University 0 Research Organization 0 Government Sponsored Facility 0 Other ~--~~---_--__-____--- ' Contract/Purchase Order # __-u~-rc,~~--___~~I_IzI__zpI------------ CONTRACTING PE3IOD: lW/ ------------------ _----__--~-~~--~~_-----~~~~~~~~~~~~~~ ClWNERSHIP:

88

Dynamic Fault Detection Chassis  

Science Conference Proceedings (OSTI)

Abstract The high frequency switching megawatt-class High Voltage Converter Modulator (HVCM) developed by Los Alamos National Laboratory for the Oak Ridge National Laboratory's Spallation Neutron Source (SNS) is now in operation. One of the major problems with the modulator systems is shoot-thru conditions that can occur in a IGBTs H-bridge topology resulting in large fault currents and device failure in a few microseconds. The Dynamic Fault Detection Chassis (DFDC) is a fault monitoring system; it monitors transformer flux saturation using a window comparator and dV/dt events on the cathode voltage caused by any abnormality such as capacitor breakdown, transformer primary turns shorts, or dielectric breakdown between the transformer primary and secondary. If faults are detected, the DFDC will inhibit the IGBT gate drives and shut the system down, significantly reducing the possibility of a shoot-thru condition or other equipment damaging events. In this paper, we will present system integration considerations, performance characteristics of the DFDC, and discuss its ability to significantly reduce costly down time for the entire facility.

Mize, Jeffery J [ORNL

2007-01-01T23:59:59.000Z

89

Approach to Recover Hydrocarbons from Currently Off-Limit Areas of the Antrim Formation, MI Using Low-Impact Technologies  

SciTech Connect

The goal of this project was to develop and execute a novel drilling and completion program in the Antrim Shale near the western shoreline of Northern Michigan. The target was the gas in the Lower Antrim Formation (Upper Devonian). Another goal was to see if drilling permits could be obtained from the Michigan DNR that would allow exploitation of reserves currently off-limits to exploration. This project met both of these goals: the DNR (Michigan Department of Natural Resources) issued permits that allow drilling the shallow subsurface for exploration and production. This project obtained drilling permits for the original demonstration well AG-A-MING 4-12 HD (API: 21-009-58153-0000) and AG-A-MING 4-12 HD1 (API: 21-009-58153-0100) as well as for similar Antrim wells in Benzie County, MI, the Colfax 3-28 HD and nearby Colfax 2-28 HD which were substituted for the AG-A-MING well. This project also developed successful techniques and strategies for producing the shallow gas. In addition to the project demonstration well over 20 wells have been drilled to date into the shallow Antrim as a result of this project's findings. Further, fracture stimulation has proven to be a vital step in improving the deliverability of wells to deem them commercial. Our initial plan was very simple; the 'J-well' design. We proposed to drill a vertical or slant well 30.48 meters (100 feet) below the glacial drift, set required casing, then angle back up to tap the resource lying between the base to the drift and the conventional vertical well. The 'J'-well design was tested at Mancelona Township in Antrim County in February of 2007 with the St. Mancelona 2-12 HD 3.

James Wood; William Quinlan

2008-09-30T23:59:59.000Z

90

Rough neural fault classification for hvdc power systems  

Science Conference Proceedings (OSTI)

This Ph.D. thesis proposes an approach to classify faults that commonly occur in a High Voltage Direct Current (HVDC) power system. These faults are distributed throughout the entire HVDC system. The most recently published techniques for power system ...

Liting Han

2008-01-01T23:59:59.000Z

91

Petri net modeling of fault analysis for probabilistic risk assessment.  

E-Print Network (OSTI)

??Fault trees and event trees have been widely accepted as the modeling strategy to perform Probabilistic Risk Assessment (PRA). However, there are several limitations associated… (more)

Lee, Andrew

2013-01-01T23:59:59.000Z

92

Lens of Eye Dose Limit Changes: Current Status of the Potential Regulatory Changes and Possible Effects on Radiation Protection Programs at Nuclear Power Plants  

Science Conference Proceedings (OSTI)

Recent research suggests that the threshold for cataract formation as a result of exposure to radiation could be lower than previously considered. The International Commission on Radiological Protection (ICRP) is now recommending a dose limit for the lens of the eye of an average of 20 mSv (2 rem) per year, equivalent to their current recommendation for Total Effective Dose Equivalent (TEDE). The Nuclear Regulatory Commission (NRC) is considering reducing the lens of the eye dose limit to 50 mSv/yr ...

2013-10-29T23:59:59.000Z

93

Coordinated Fault Tolerance for High-Performance Computing  

SciTech Connect

Our work to meet our goal of end-to-end fault tolerance has focused on two areas: (1) improving fault tolerance in various software currently available and widely used throughout the HEC domain and (2) using fault information exchange and coordination to achieve holistic, systemwide fault tolerance and understanding how to design and implement interfaces for integrating fault tolerance features for multiple layers of the software stack—from the application, math libraries, and programming language runtime to other common system software such as jobs schedulers, resource managers, and monitoring tools.

Dongarra, Jack; Bosilca, George; et al.

2013-04-08T23:59:59.000Z

94

Definition: Enhanced Fault Detection Technology | Open Energy Information  

Open Energy Info (EERE)

Technology Technology Jump to: navigation, search Dictionary.png Enhanced Fault Detection Technology Enhanced fault detection technology enables higher precision and greater discrimination of fault location and type with coordinated measurement among multiple devices. For distribution applications, this technology can detect and isolate faults without full-power re-closing, reducing the frequency of through-fault currents. Using high resolution sensors and fault signatures, this technology can better detect high impedance faults. For transmission applications, this technology will employ high speed communications between multiple elements (e.g., stations) to protect entire regions, rather than just single elements. It can also use the latest digital techniques to advance beyond conventional impedance relaying of

95

Nail-it-down: nailing and fixing configuration faults in cloud environments  

Science Conference Proceedings (OSTI)

Faults due to configuration of resources account for majority of errors in distributed software systems. Yet, the problem of identifying faulty configuration remains at large. Current approaches for fault identification are focused on event correlation ...

Kalapriya Kannan; Anuradha Bhamidipaty

2013-05-01T23:59:59.000Z

96

Space-charge-limited currents in an Se{sub 95}As{sub 5} chalcogenide glass-like semiconductor system containing EuF{sub 3} impurities  

Science Conference Proceedings (OSTI)

It is established that charge carrier (hole) transport in the Al-Se{sub 95}As{sub 5} Left-Pointing-Angle-Bracket EuF{sub 3} Right-Pointing-Angle-Bracket -Te structure is effected by unipolar injection currents limited by space charges with the involvement of two capture trap groups. Shallow traps corresponding to charged intrinsic defects C{sub 1}{sup -} are related to broken selenium bonds. Deep traps corresponding to charged intrinsic defects P{sub 2}{sup -} are formed by arsenic atoms with broken coordination. It is shown that the EuF{sub 3} impurity strongly affects the concentration of the capture traps, especially those localized near the Fermi level.

Isayev, A. I.; Mekhtiyeva, S. I.; Qaribova, S. N., E-mail: sqaribova@rambler.ru [Azerbaijan National Academy of Sciences, Abdullaev Institute of Physics (Azerbaijan)

2011-12-15T23:59:59.000Z

97

Low-cost motor drive embedded fault diagnosis systems  

E-Print Network (OSTI)

Electric motors are used widely in industrial manufacturing plants. Bearing faults, insulation faults, and rotor faults are the major causes of electric motor failures. Based on the line current analysis, this dissertation mainly deals with the low cost incipient fault detection of inverter-fed driven motors. Basically, low order inverter harmonics contributions to fault diagnosis, a motor drive embedded condition monitoring method, analysis of motor fault signatures in noisy line current, and a few specific applications of proposed methods are studied in detail. First, the effects of inverter harmonics on motor current fault signatures are analyzed in detail. The introduced fault signatures due to harmonics provide additional information about the motor faults and enhance the reliability of fault decisions. It is theoretically and experimentally shown that the extended fault signatures caused by the inverter harmonics are similar and comparable to those generated by the fundamental harmonic on the line current. In the next chapter, the reference frame theory is proposed as a powerful toolbox to find the exact magnitude and phase quantities of specific fault signatures in real time. The faulty motors are experimentally tested both offline, using data acquisition system, and online, employing the TMS320F2812 DSP to prove the effectiveness of the proposed tool. In addition to reference frame theory, another digital signal processor (DSP)-based phasesensitive motor fault signature detection is presented in the following chapter. This method has a powerful line current noise suppression capability while detecting the fault signatures. It is experimentally shown that the proposed method can determine the normalized magnitude and phase information of the fault signatures even in the presence of significant noise. Finally, a signal processing based fault diagnosis scheme for on-board diagnosis of rotor asymmetry at start-up and idle mode is presented. It is quite challenging to obtain these regular test conditions for long enough time during daily vehicle operations. In addition, automobile vibrations cause a non-uniform air-gap motor operation which directly affects the inductances of electric motor and results quite noisy current spectrum. The proposed method overcomes the challenges like aforementioned ones simply by testing the rotor asymmetry at zero speed.

Akin, Bilal

2007-08-01T23:59:59.000Z

98

Solar system fault detection  

SciTech Connect

A fault detecting apparatus and method are provided for use with an active solar system. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solar system. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solar system and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solar system are increased.

Farrington, Robert B. (Wheatridge, CO); Pruett, Jr., James C. (Lakewood, CO)

1986-01-01T23:59:59.000Z

99

Solar system fault detection  

DOE Patents (OSTI)

A fault detecting apparatus and method are provided for use with an active solar system. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solar system. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solar system and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solar system are increased.

Farrington, R.B.; Pruett, J.C. Jr.

1984-05-14T23:59:59.000Z

100

Neural net application to transmission line fault detection and classification  

E-Print Network (OSTI)

Today, in electric power systems, a large amount of data is made readily available at the occurrence of a fault due to the use of advanced communication systems, digital relays and fault recorders. Such systems are intended to obtain data from contacts of the relays and circuit breakers under operation. In addition, corresponding voltages and currents are recorded during prefault, fault and postfault periods. Restoration of power Systems after a fault occurred requires quick judgment. Hence, fault analysis, as the first step of restoration is very important. However, since faults in power systems are various and relaying systems may be complex, fault analysis is difficult to automate. Common practice in power utility companies, today, is to perform fault analysis by expert operators using their knowledge about the power systems and experience with past faults. Because of the time required to deal with complex fault situations, detailed fault analysis can not be performed by human operators in a short time. Therefore, on-line automated fault analysis system is strongly desired. Traditional approaches to the problem of analysis is to construct a heuristic, rule-based system which embodies a portion of the compiled experience of a human expert. These systems perform fault analysis by mapping fault indications to fault hypotheses. 'These hypotheses are used as inputs for next level of rules. After completion of inferencing process, conclusions are given. The knowledge acquisition process is exhaustive and time consuming. Also, data processing is usually too slow to be effectively applied in a real-time environment. Neural computing is one of the rapidly expanding areas of current research. Neural nets have some obvious advantages over expert systems. They are computationally more effective because of their parallel processing capabilities. Also, there is no need for detailed knowledge acquisition part, because neural nets learn by example. This thesis presents results of a study on using the new neural net system that can perform both on-line and off-line fault detection and classification. Fault analysis is conceptualized as a pattern classification problem which involves the association of input patterns representing the power system state to one or more fault conditions.

Rikalo, Igor

1994-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Optimal fault location  

E-Print Network (OSTI)

Basic goal of power system is to continuously provide electrical energy to the users. Like with any other system, failures in power system can occur. In those situations it is critical that correct remedial actions are applied as soon as possible after the accurate fault condition and location are detected. This thesis has been focusing on automated fault location procedure. Different fault location algorithms, classified according to the spatial placement of physical measurements on single ended, multiple ended and sparse system-wide, are investigated. As outcome of this review, methods are listed as function of different parameters that influence their accuracy. This comparison is than used for generating procedure for optimal fault location algorithm selection. According to available data, and position of the fault with respect to the data, proposed procedure decides between different algorithms and selects an optimal one. A new approach is developed by utilizing different data structures such as binary tree and serialization in order to efficiently implement algorithm decision engine. After accuracy of algorithms is strongly influenced by available input data, different data sources are recommended in proposed architecture such as the digital fault recorders, circuit breaker monitoring, SCADA, power system model and etc. Algorithm for determining faulted section is proposed based on the data from circuit breaker monitoring devices. This algorithm works in real time by recognizing to which sequence of events newly obtained recording belongs. Software prototype of the proposed automated fault location analysis is developed using Java programming language. Fault location analysis is automatically triggered by appearance of new event files in a specific folder. The tests were carried out using the real life transmission system as an example.

Knezev, Maja

2007-12-01T23:59:59.000Z

102

Fault Intersection | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Fault Intersection Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Fault Intersection Dictionary.png Fault Intersection: Fault intersections are junctions between normal faults and either transversely oriented strike-slip or oblique-slip faults. Subsurface fluid flow in these areas is enhanced by multiple minor faults that connect the major intersecting structures, forming highly fractured zones or dilational quadrants with increased permeability. Other definitions:Wikipedia Reegle Controlling Structures List of controlling structures typically associated with geothermal

103

A fuzzy neural network based fault detection scheme for synchronous generator with internal fault  

Science Conference Proceedings (OSTI)

A fuzzy neural network (FNN) based inter-turn short circuit fault detection scheme for generator is proposed. The second harmonic magnitude of field current and the negative sequence components of voltages and currents are used as inputs for the FNN ...

Hongwei Fang; Changliang Xia

2009-08-01T23:59:59.000Z

104

Optimized Fault Location Final Project Report  

E-Print Network (OSTI)

excessive currents and voltages last long enough to cause equipment damage. CBs have the purpose to connect describes connectivity of the various components in the power system. In order to process retrieved fault, the system topology must be known. Beside the connectivity it is necessary to obtain information about

105

Discretized streams: fault-tolerant streaming computation at scale  

Science Conference Proceedings (OSTI)

Many "big data" applications must act on data in real time. Running these applications at ever-larger scales requires parallel platforms that automatically handle faults and stragglers. Unfortunately, current distributed stream processing models provide ...

Matei Zaharia, Tathagata Das, Haoyuan Li, Timothy Hunter, Scott Shenker, Ion Stoica

2013-11-01T23:59:59.000Z

106

Parallel fault backtracing for calculation of fault coverage  

Science Conference Proceedings (OSTI)

A new improved method for calculation of fault coverage with parallel fault backtracing in combinational circuits is proposed. The method is based on structurally synthesized BDDs (SSBDD) which represent gate-level circuits at higher, macro level where ...

Raimund Ubar; Sergei Devadze; Jaan Raik; Artur Jutman

2008-01-01T23:59:59.000Z

107

Multi Agent System based fault location and isolation in a smart microgrid system  

Science Conference Proceedings (OSTI)

In this paper, a Multi Agent System (MAS) based on sequence current magnitudes and current direction is proposed for fault location and isolation in a smart microgrid system. Each of the fault types has a different impact on the sequence current components, ...

Seetaram Alwala; Ali Feliachi; M. A. Choudhry

2012-01-01T23:59:59.000Z

108

rMPI : increasing fault resiliency in a message-passing environment.  

SciTech Connect

As High-End Computing machines continue to grow in size, issues such as fault tolerance and reliability limit application scalability. Current techniques to ensure progress across faults, like checkpoint-restart, are unsuitable at these scale due to excessive overheads predicted to more than double an applications time to solution. Redundant computation, long used in distributed and mission critical systems, has been suggested as an alternative to checkpoint-restart on its own. In this paper we describe the rMPI library which enables portable and transparent redundant computation for MPI applications. We detail the design of the library as well as two replica consistency protocols, outline the overheads of this library at scale on a number of real-world applications, and finally outline the significant increase in an applications time to solution at extreme scale as well as show the scenarios in which redundant computation makes sense.

Stearley, Jon R.; Laros, James H., III; Ferreira, Kurt Brian; Pedretti, Kevin Thomas Tauke; Oldfield, Ron A.; Riesen, Rolf (IBM Research, Ireland); Brightwell, Ronald Brian

2011-04-01T23:59:59.000Z

109

DIFFERENTIAL FAULT SENSING CIRCUIT  

DOE Patents (OSTI)

A differential fault sensing circuit is designed for detecting arcing in high-voltage vacuum tubes arranged in parallel. A circuit is provided which senses differences in voltages appearing between corresponding elements likely to fault. Sensitivity of the circuit is adjusted to some level above which arcing will cause detectable differences in voltage. For particular corresponding elements, a group of pulse transformers are connected in parallel with diodes connected across the secondaries thereof so that only voltage excursions are transmitted to a thyratron which is biased to the sensitivity level mentioned.

Roberts, J.H.

1961-09-01T23:59:59.000Z

110

Computer hardware fault administration  

DOE Patents (OSTI)

Computer hardware fault administration carried out in a parallel computer, where the parallel computer includes a plurality of compute nodes. The compute nodes are coupled for data communications by at least two independent data communications networks, where each data communications network includes data communications links connected to the compute nodes. Typical embodiments carry out hardware fault administration by identifying a location of a defective link in the first data communications network of the parallel computer and routing communications data around the defective link through the second data communications network of the parallel computer.

Archer, Charles J. (Rochester, MN); Megerian, Mark G. (Rochester, MN); Ratterman, Joseph D. (Rochester, MN); Smith, Brian E. (Rochester, MN)

2010-09-14T23:59:59.000Z

111

Automatic Fault Characterization via Abnormality-Enhanced Classification  

Science Conference Proceedings (OSTI)

Enterprise and high-performance computing systems are growing extremely large and complex, employing hundreds to hundreds of thousands of processors and software/hardware stacks built by many people across many organizations. As the growing scale of these machines increases the frequency of faults, system complexity makes these faults difficult to detect and to diagnose. Current system management techniques, which focus primarily on efficient data access and query mechanisms, require system administrators to examine the behavior of various system services manually. Growing system complexity is making this manual process unmanageable: administrators require more effective management tools that can detect faults and help to identify their root causes. System administrators need timely notification when a fault is manifested that includes the type of fault, the time period in which it occurred and the processor on which it originated. Statistical modeling approaches can accurately characterize system behavior. However, the complex effects of system faults make these tools difficult to apply effectively. This paper investigates the application of classification and clustering algorithms to fault detection and characterization. We show experimentally that naively applying these methods achieves poor accuracy. Further, we design novel techniques that combine classification algorithms with information on the abnormality of application behavior to improve detection and characterization accuracy. Our experiments demonstrate that these techniques can detect and characterize faults with 65% accuracy, compared to just 5% accuracy for naive approaches.

Bronevetsky, G; Laguna, I; de Supinski, B R

2010-12-20T23:59:59.000Z

112

Soft Computing Application in Fault Detection of Induction Motor  

Science Conference Proceedings (OSTI)

The paper investigates the effectiveness of different patter classifier like Feed Forward Back Propagation (FFBPN), Radial Basis Function (RBF) and Support Vector Machine (SVM) for detection of bearing faults in Induction Motor. The steady state motor current with Park's Transformation has been used for discrimination of inner race and outer race bearing defects. The RBF neural network shows very encouraging results for multi-class classification problems and is hoped to set up a base for incipient fault detection of induction motor. SVM is also found to be a very good fault classifier which is highly competitive with RBF.

Konar, P.; Puhan, P. S.; Chattopadhyay, P. Dr. [Electrical Engineering Department, BESUS, Shibpur (India)

2010-10-26T23:59:59.000Z

113

Transmission Line Fault Inspection and Root Cause Analysis Approach  

Science Conference Proceedings (OSTI)

Transmission lines are designed to transfer electric power from source locations, sometimes over great distances through different terrains and exposed to several influences. These challenges include faulty equipment, misoperation, human errors, and aging of components, as well as meteorological and ecological factors such as storms, lightning, and the effects of plants and animals. A number of techniques are currently used to isolate the faulting line and provide the fault position. Sustained or ...

2013-12-20T23:59:59.000Z

114

The application of satellite time references to HVDC fault location  

Science Conference Proceedings (OSTI)

An HVdc fault location scheme is described which relies on very precise detection of the time of arrival of fault created surges at both ends of the line. Such detection is achieved by a very accurate data acquisition and processing system combined with the time reference signals provided by a global positioning system receiver. Extensive digital simulation is carried out to determine the voltage and current waveforms, to identify the main sources of error and suggest possible compensation techniques.

Dewe, M.B.; Sankar, S.; Arrillaga, J. (Univ. of Canterbury, Christchurch (New Zealand))

1993-07-01T23:59:59.000Z

115

Transmission Line Fault Inspection and Root Cause Analysis Approach  

Science Conference Proceedings (OSTI)

Transmission lines are designed to transfer electric power from source locations sometimes over great distances through different terrains and exposed to several influences. These challenges include faulty equipment, misoperation, human errors, and aging of components, and meteorological and ecological factors such as storms, lightning, and the effects of plants and animals. A number of techniques are currently used to isolate the faulting line and provide the fault position. Sustained or permanent ...

2012-12-20T23:59:59.000Z

116

Tolerance Limits  

Science Conference Proceedings (OSTI)

... LIMITS Y ** *** 2-SIDED NORMAL TOLERANCE LIMITS: XBAR +- K*S REFERENCE--CRC HANDBOOK, PAGES 32-35 ...

2010-12-06T23:59:59.000Z

117

Fault Mapping | Open Energy Information  

Open Energy Info (EERE)

form form View source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit with form History Facebook icon Twitter icon » Fault Mapping Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Fault Mapping Details Activities (2) Areas (2) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Field Techniques Exploration Sub Group: Data Collection and Mapping Parent Exploration Technique: Data Collection and Mapping Information Provided by Technique Lithology: Stratigraphic/Structural: Locates active faults in the area of interest Hydrological: Can reveal whether faults are circulating hydrothermal fluids Thermal: Dictionary.png

118

Sideband Algorithm for Automatic Wind Turbine Gearbox Fault Detection and Diagnosis: Preprint  

DOE Green Energy (OSTI)

Improving the availability of wind turbines (WT) is critical to minimize the cost of wind energy, especially for offshore installations. As gearbox downtime has a significant impact on WT availabilities, the development of reliable and cost-effective gearbox condition monitoring systems (CMS) is of great concern to the wind industry. Timely detection and diagnosis of developing gear defects within a gearbox is an essential part of minimizing unplanned downtime of wind turbines. Monitoring signals from WT gearboxes are highly non-stationary as turbine load and speed vary continuously with time. Time-consuming and costly manual handling of large amounts of monitoring data represent one of the main limitations of most current CMSs, so automated algorithms are required. This paper presents a fault detection algorithm for incorporation into a commercial CMS for automatic gear fault detection and diagnosis. The algorithm allowed the assessment of gear fault severity by tracking progressive tooth gear damage during variable speed and load operating conditions of the test rig. Results show that the proposed technique proves efficient and reliable for detecting gear damage. Once implemented into WT CMSs, this algorithm can automate data interpretation reducing the quantity of information that WT operators must handle.

Zappala, D.; Tavner, P.; Crabtree, C.; Sheng, S.

2013-01-01T23:59:59.000Z

119

Computer programs for fault studies using symmetrical components in undergraduate and postgraduate teaching  

Science Conference Proceedings (OSTI)

The paper first reviews development of a digital fault studies program for use in undergraduate and postgraduate teaching, highlighting aspects of program design. System data details: arrays containing details of system data: fault data; positive-negative-, and zero-sequence network data; voltage arrays which store node voltages before and after the fault; corresponding current arrays; in addition to the file editor; routines for printing system data on screen or on paper; modifying system data; together with line data; and diagnostics are discussed for various shunt and series faults. Improves routines which employ complex impedances to represent generators, transformers and transmission lines on the more common PC's are explained. Phase voltages and currents for both shunt and series faults which illustrate the effect of the more common approximations such as neglecting system resistance or approximating complex impedance to constant angle impedance in shunt and series faults are made.

Hammons, T.J.; Flett, A. (Glasgow Univ. (United Kingdom)); Kacejko, P. (Technical Univ. of Lublin, Lublin 20-618 (Poland))

1992-01-01T23:59:59.000Z

120

Multiple signal fault detection using fuzzy logic  

Science Conference Proceedings (OSTI)

In this paper, we describe a multiple Signal Fault Detection system that employs fuzzy logic at two levels of detection: signal segment fault and signal fault. The system involves signal segmentation, feature extraction and fuzzy logic based segment ...

Yi Lu Murphey; Jacob Crossman; ZhiHang Chen

2003-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Major Normal Fault | Open Energy Information  

Open Energy Info (EERE)

Major Normal Fault Major Normal Fault Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Major Normal Fault Dictionary.png Major Normal Fault: Normal faults are structures in which the hanging wall is down dropped along the fault plane relative to the foot wall. They are the predominant type of structure in extensional tectonic environments, but are commonly encountered in a number of geologic settings. Other definitions:Wikipedia Reegle Controlling Structures List of controlling structures typically associated with geothermal systems: Major Normal Fault Termination of a Major Normal Fault Stepover or Relay Ramp in Normal Fault Zones Apex or Salient of Normal Fault Fault Intersection Accommodation Zone Displacement Transfer Zone Pull-Apart in Strike-Slip Fault Zone

122

Definition: Fault Mapping | Open Energy Information  

Open Energy Info (EERE)

Mapping Jump to: navigation, search Dictionary.png Fault Mapping Faults are structural features of crustal rocks that are caused by tectonic forces. These features can create...

123

Discrimination among mechanical fault types in induction motors using electrical measurements  

E-Print Network (OSTI)

Rotating machine failures are a major cause of downtime in a wide variety of industrial processes and are a burden on maintenance personnel and facilities. Some of these failures occur suddenly and are seemingly unpredictable. However, the overwhelming majority develop slowly over time and produce characteristic warning signs. A system capable of detecting and diagnosing these incipient faults before they become critical would significantly reduce downtime and serve to facilitate maintenance and repair of these machines. The ability to accurately distinguish between different types of incipient faults would be a critical aspect of such a system. In this research, a model-based method for diagnosing motor faults is examined and tested using two squirrel-cage AC induction motors with staged fault conditions. The proposed method involves the multi-resolution signal analysis of the current residuals. These residuals are generated by comparing the measured motor current with the current predicted by a recurrent neural network. The frequency content of the distortion of the residuals is used to identify the type of fault present. Although "steady-state" conditions are examined exclusively in this research, the nonstationarities of the current signals are sufficient to warrant the use of multi-resolution analysis. The fault diagnosis system is tested using data taken from an 800 hp motor and a 3 hp motor. The method is successful in identifying residual distortion in the frequency range expected for broken-bar faults. Because the magnitude of the distortion grows with increasing fault severity, the method is also useful for evaluating fault severity for broken-bar faults. However, the current distortions caused by rotor eccentricities and damaged bearings are too small to be identified in a statistically significant manner using this approach. Nevertheless, this research demonstrates the feasibility of a general method by which the characteristic frequencies produced by a particular type of fault can be identified in the output of a system.

McFatter, Justin Robert

2002-01-01T23:59:59.000Z

124

Designing fault-tolerant manipulators: How many degrees of freedom?  

SciTech Connect

One of the most important parameters to consider when designing a manipulator is the number of degrees of freedom (DOFs). This article focuses on the question: How many DOFs are necessary and sufficient for fault tolerance, and how should these DOFs be distributed along the length of the manipulator? A manipulator is fault tolerant if it can complete its task even when one of its joints fails and is immobilized. The number of DOFs needed for fault tolerance strongly depends on the knowledge available about the task. In this article, two approaches are explored. First, for the design of a general purpose fault-tolerant manipulator, it is assumed that neither the exact task trajectory nor the redundancy resolution algorithm are known a priori and the manipulator has no joint limits. In this case, two redundant DOFs are necessary and sufficient to sustain one joint failure, as is demonstrated in two design templates for spatial fault-tolerant manipulators. In this second approach, both the Cartesian task path and the redundancy resolution algorithm are assumed to be known. The design of such a task-specific fault-tolerant manipulator requires only one degree of redundancy. 22 refs., 11 figs., 2 tabs.

Paredis, C.J.J.; Khosla, P.K. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

1996-12-01T23:59:59.000Z

125

Observer-based fault detection for nuclear reactors  

E-Print Network (OSTI)

This is a study of fault detection for nuclear reactor systems. Basic concepts are derived from fundamental theories on system observers. Different types of fault- actuator fault, sensor fault, and system dynamics fault ...

Li, Qing, 1972-

2001-01-01T23:59:59.000Z

126

DFIG Driven Wind Turbine Grid Fault-Tolerance Using High-Order Sliding Mode Control  

E-Print Network (OSTI)

DFIG Driven Wind Turbine Grid Fault-Tolerance Using High-Order Sliding Mode Control Mohamed (DFIG), control, second-order sliding mode, grid fault-tolerance. Nomenclature WT = Wind Turbine; DFIG increased currents, which may lead to converter failure. Achieving ride-through requirement for DFIG

Brest, Université de

127

New approach to the fault location problem using synchronized sampling  

E-Print Network (OSTI)

This thesis presents a new approach to solving the problem of fault location on a transmission line using synchronized data from both ends of the line. The synchronized phase voltage and current samples taken during the fault transient are used to calculate the location of the fault. Time domain models of lines are used as a basis for derivation of two different algorithms. One algorithm is developed using the RL line model and the other one is developed using the traveling wave based line model. The main idea of the fault location concept is based on the general characteristics of any transmission line. At any location along the unfaulted line, the instantaneous values of voltage and current signals are related to the instantaneous values of the corresponding values of voltage and current signals at both ends of the line, line parameters, and distance between that particular location and each of the line ends. This enables the derivation of the generic fault location equation of the following form: [ ] where Lv is the linear operator, VA, t'A, VB, z'B are vectors of voltage and current samples at line ends, d is the length of the line, and x is the unknown distance to the fault point. For a particular transmission line, the generic equation has a unique form that determines the way it is solved. In any case, the Minimum Square Error Estimation Method is used since an overspecified system of linear equations needs to be solved. The performance evaluation of both algorithms was done using the Electromagnetic Transient Program (EMTP) generated data [1]. Obtained results indicate the high accuracy of the approach and its robustness regarding various fault conditions. The following are the conclusions based on the results presented in this thesis: The error of the approach is rather small and almost invariant to the various fault conditions and, hence, the technique provides a robust solution to the fault location problem. The new approach has high accuracy while the computational burden is still kept relatively low. The synchronized sampling technique required for this approach is emerging as a reliable and cost effective practice.

Mrkic, Jasna

1994-01-01T23:59:59.000Z

128

Memory Fault Modeling Trends: A Case Study  

Science Conference Proceedings (OSTI)

In recent years, embedded memories are the fastest growing segment of system on chip. They therefore have a major impact on the overall Defect per Million (DPM). Further, the shrinking technologies and processes introduce new defects that cause previously ... Keywords: data backgrounds, dynamic faults, fault coverage, fault models, memory tests, static faults

Said Hamdioui; Rob Wadsworth; John Delos Reyes; Ad J. Van De Goor

2004-06-01T23:59:59.000Z

129

Fault Tree Analysis - A Bibliography  

Science Conference Proceedings (OSTI)

Fault tree analysis is a top-down approach to the identification of process hazards. It is touted as one of the best methods for systematically identifying and graphically displaying the many ways something can go wrong. This bibliography references ...

Program NASA Scientific and Technical Information

2000-07-01T23:59:59.000Z

130

SWIFT: Software Implemented Fault Tolerance  

Science Conference Proceedings (OSTI)

To improve performance and reduce power, processor designers employ advances that shrink feature sizes, lower voltage levels, reduce noise margins, and increase clock rates. However, these advances make processors more susceptible to transient faults ...

George A. Reis; Jonathan Chang; Neil Vachharajani; Ram Rangan; David I. August

2005-03-01T23:59:59.000Z

131

Page not found | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

results. Download An Assessment of Fault Current Limiter Testing Requirements http:energy.govoedownloadsassessment-fault-current-limiter-testing-requirements Download...

132

Fault tolerance using lower fidelity data in adaptive mesh applications  

Science Conference Proceedings (OSTI)

Many high performance scientific simulation codes use checkpointing for multiple reasons. In addition to having the flexibility to complete the simulation in multiple job submissions, it has also provided an adequate recovery mechanism up to the current ... Keywords: AMR, fault tolerance, flash

Anshu Dubey; Prateeti Mohapatra; Klaus Weide

2013-06-01T23:59:59.000Z

133

Differential energy based microgrid protection against fault conditions  

Science Conference Proceedings (OSTI)

A differential energy based fault protection in microgrid is presented in this paper. Initially the currents at the respective buses are retrieved and processed through a novel time-frequency transform known as S-transform to generate time-frequency ...

S. R. Samantaray; Geza Joos; I. Kamwa

2012-01-01T23:59:59.000Z

134

SVM Theory and Its Application in Fault Diagnosis of HVDC System  

Science Conference Proceedings (OSTI)

Support Vector Machine (SVM), which based on Statistical Learning Theory, is a universal machine learning method. The fault diagnosis of nonlinear and high-controllable High Voltage Direct Current (HVDC) system based on SVM method is proposed, which ...

Xi-Mei Liu; Wan-Yun Wei; Fei Yu

2007-08-01T23:59:59.000Z

135

Design and test rules for CMOS circuits to facilitate IDDQ testing of bridging faults  

Science Conference Proceedings (OSTI)

All possible bridging faults (BFs) between any two circuit nodes are considered, where a circuit node may be the drain, source, or gate terminal of a transistor. Several examples are given to show that under certain circumstances current supply monitoring ...

K. -J. Lee; M. A. Breuer

2006-11-01T23:59:59.000Z

136

Automatic fault extraction and simulation of layout realistic faults for integrated analogue circuits  

Science Conference Proceedings (OSTI)

A comprehensive tool has been implemented for the comparison of different test preparation techniques and target faults. It comprises of the realistic fault characterisation program LIFT that can extract sets of various faults from a given analogue or ... Keywords: AnaFAUL, LIFT, VCO, analogue integrated circuits, automatic analogue fault simulation program, catastrophic faults, circuit analysis computing, circuit layout, fault diagnosis, integrated analogue circuits, integrated circuit layout, integrated circuit testing, mixed analogue-digital integrated circuits, mixed-signal circuit, parametric faults, realistic fault characterisation program, simulation, test preparation, voltage-controlled oscillators

C. Sebeke; J. P. Teixeira; M. J. Ohletz

1995-03-01T23:59:59.000Z

137

Fault detection of fault ride through for doubly-fed induction generator based wind energy systems.  

E-Print Network (OSTI)

??Fault detection and mitigation is of high importance for existing DFIG based wind energy conversion systems. Keeping the doubly-fed induction generator (DFIG) online during faults… (more)

Ramroop, Shoba AD

2008-01-01T23:59:59.000Z

138

Detection of Rooftop Cooling Unit Faults Based on Electrical Measurements  

Science Conference Proceedings (OSTI)

Non-intrusive load monitoring (NILM) is accomplished by sampling voltage and current at high rates and reducing the resulting start transients or harmonic contents to concise ''signatures''. Changes in these signatures can be used to detect, and in many cases directly diagnose, equipment and component faults associated with roof-top cooling units. Use of the NILM for fault detection and diagnosis (FDD) is important because (1) it complements other FDD schemes that are based on thermo-fluid sensors and analyses and (2) it is minimally intrusive (one measuring point in the relatively protected confines of the control panel) and therefore inherently reliable. This paper describes changes in the power signatures of fans and compressors that were found, experimentally and theoretically, to be useful for fault detection.

Armstrong, Peter R.; Laughman, C R.; Leeb, S B.; Norford, L K.

2006-01-31T23:59:59.000Z

139

Transmission Line Protection Support Tools: Fault Location Algorithms and the Potential of Using Intelligent Electronic Device Data for Protection Applications  

Science Conference Proceedings (OSTI)

Overhead transmission lines experience short-circuit faults due to lightning, stormy weather conditions, animal or tree contact, and insulation failure in power system equipment. To ensure continuity of electric service, utilities try to quickly determine the location of the fault, perform maintenance or repair, and return the line to service. Due to advances in modern technology, locating faults in a networked transmission system is now possible with substantial accuracy. Voltage and current ...

2013-12-23T23:59:59.000Z

140

Transmission Line Protection Support Tools: Fault Location Algorithms and Potential of using IED Data for Protection Applications  

Science Conference Proceedings (OSTI)

Transmission lines experience faults due to lightning, stormy weather conditions, animal or tree contact and insulation failure in various power system equipment. To ensure continuity of power, utility personnel try to quickly determine the location of fault, perform necessary repair and return the line to service. Due to advances in modern technology, locating faults in a networked transmission system is now possible. Voltage and current waveforms recorded by intelligent electronic devices (IED) ...

2012-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Award ER25750: Coordinated Infrastructure for Fault Tolerance Systems Indiana University Final Report  

SciTech Connect

The main purpose of the Coordinated Infrastructure for Fault Tolerance in Systems initiative has been to conduct research with a goal of providing end-to-end fault tolerance on a systemwide basis for applications and other system software. While fault tolerance has been an integral part of most high-performance computing (HPC) system software developed over the past decade, it has been treated mostly as a collection of isolated stovepipes. Visibility and response to faults has typically been limited to the particular hardware and software subsystems in which they are initially observed. Little fault information is shared across subsystems, allowing little flexibility or control on a system-wide basis, making it practically impossible to provide cohesive end-to-end fault tolerance in support of scientific applications. As an example, consider faults such as communication link failures that can be seen by a network library but are not directly visible to the job scheduler, or consider faults related to node failures that can be detected by system monitoring software but are not inherently visible to the resource manager. If information about such faults could be shared by the network libraries or monitoring software, then other system software, such as a resource manager or job scheduler, could ensure that failed nodes or failed network links were excluded from further job allocations and that further diagnosis could be performed. As a founding member and one of the lead developers of the Open MPI project, our efforts over the course of this project have been focused on making Open MPI more robust to failures by supporting various fault tolerance techniques, and using fault information exchange and coordination between MPI and the HPC system software stack?from the application, numeric libraries, and programming language runtime to other common system components such as jobs schedulers, resource managers, and monitoring tools.

Lumsdaine, Andrew

2013-03-08T23:59:59.000Z

142

Quaternary faulting of Deschutes County, Oregon.  

E-Print Network (OSTI)

??Sixty-one normal faults were identified in a 53-kilometer long by 21-kilometer wide northwest-trending zone in central and northern Deschutes County, Oregon. The faults are within… (more)

Wellik, John M.

2008-01-01T23:59:59.000Z

143

Consequences of Fault Currents Contributed by Distributed Generation  

E-Print Network (OSTI)

into account the phase-locked loop (PLL) dynamics. An example, in which two SOFC plants provide power of a simple microgrid.1 The generators, in this case solid oxide fuel cells (SOFCs), are grid connected. When the circuit breaker opens, however, buses 1 to 4 form an autonomous microgrid, with the two SOFC sources

144

Consequences of Fault Currents Contributed by Distributed Generation  

E-Print Network (OSTI)

-- The paper presents a model for a solid oxide fuel cell (SOFC) stack operating at relatively low pressures. The model in- corporates the electrochemical reaction dynamics and the major voltage losses in SOFCs, but is not concerned with the thermal dynamics. A DC-DC boost converter interfaces the SOFC stack to a DC bus, where

145

Fault diagnosis and fault tolerant control using set-membership approaches: Application to real case studies  

Science Conference Proceedings (OSTI)

This paper reviews the use of set-membership methods in fault diagnosis (FD) and fault tolerant control (FTC). Setmembership methods use a deterministic unknown-but-bounded description of noise and parametric uncertainty (interval ... Keywords: Fault Detection, Fault-Tolerant Control, Interval Models, Robustness, Set-Membership

Vicenç Puig

2010-12-01T23:59:59.000Z

146

Application of Control Charts for Detecting Faults in Variable ...  

Science Conference Proceedings (OSTI)

... where Tzone = zone temperature, CSP = cooling setpoint ... Fault Implementation and Impact To test ... fault imple- mentations and impacts are provided ...

147

Autonomic fault mitigation in embedded systems  

Science Conference Proceedings (OSTI)

Autonomy, particularly from a maintenance and fault-management perspective, is an increasingly desirable feature in embedded (and non-embedded) computer systems. The driving factors are several-including increasing pervasiveness of computer systems, ... Keywords: Autonomic computing, Embedded systems, Fault mitigation, Fault tolerance, Hierarchical concurrent finite-state machines, Model-based design

Sandeep Neema; Ted Bapty; Shweta Shetty; Steven Nordstrom

2004-10-01T23:59:59.000Z

148

Fault detection and diagnosis of technical systems  

Science Conference Proceedings (OSTI)

Sensors, actuators and/or physical components in technical systems are often affected by unpermitted or un-expected deviations from normal operation behaviour. The fault diagnosis task consists of determination of the fault type with as many details ... Keywords: fault detection and diagnosis, residuals, symptoms, technical systems

Ioana Fagarasan; S. ST. Iliescu

2008-06-01T23:59:59.000Z

149

CRT RSA algorithm protected against fault attacks  

Science Conference Proceedings (OSTI)

Embedded devices performing RSA signatures are subject to Fault Attacks, particularly when the Chinese Remainder Theorem is used. In most cases, the modular exponentiation and the Garner recombination algorithms are targeted. To thwart Fault Attacks, ... Keywords: RSA, chinese remainder theorem, fault attacks, modular exponentiation, simple power analysis, smart card

Arnaud Boscher; Robert Naciri; Emmanuel Prouff

2007-05-01T23:59:59.000Z

150

Designing Fault-Tolerant Mobile Systems  

Science Conference Proceedings (OSTI)

The purpose of this paper is to investigate how several innovative techniques, not all initially intended for fault-tolerance, can be applied in providing fault tolerance of complex mobile agent systems. Due to their roaming nature, mobile agents usually ... Keywords: exception handling, fault tolerance, mobile agents, software engineering, system structuring

Giovanna Di Marzo Serugendo; Alexander B. Romanovsky

2002-11-01T23:59:59.000Z

151

Coordinated Fault-Tolerance for High-Performance Computing Final Project Report  

Science Conference Proceedings (OSTI)

With the Coordinated Infrastructure for Fault Tolerance Systems (CIFTS, as the original project came to be called) project, our aim has been to understand and tackle the following broad research questions, the answers to which will help the HEC community analyze and shape the direction of research in the field of fault tolerance and resiliency on future high-end leadership systems. #15; Will availability of global fault information, obtained by fault information exchange between the different HEC software on a system, allow individual system software to better detect, diagnose, and adaptively respond to faults? If fault-awareness is raised throughout the system through fault information exchange, is it possible to get all system software working together to provide a more comprehensive end-to-end fault management on the system? #15; What are the missing fault-tolerance features that widely used HEC system software lacks today that would inhibit such software from taking advantage of systemwide global fault information? #15; What are the practical limitations of a systemwide approach for end-to-end fault management based on fault awareness and coordination? #15; What mechanisms, tools, and technologies are needed to bring about fault awareness and coordination of responses on a leadership-class system? #15; What standards, outreach, and community interaction are needed for adoption of the concept of fault awareness and coordination for fault management on future systems? Keeping our overall objectives in mind, the CIFTS team has taken a parallel fourfold approach. #15; Our central goal was to design and implement a light-weight, scalable infrastructure with a simple, standardized interface to allow communication of fault-related information through the system and facilitate coordinated responses. This work led to the development of the Fault Tolerance Backplane (FTB) publish-subscribe API specification, together with a reference implementation and several experimental implementations on top of existing publish-subscribe tools. #15; We enhanced the intrinsic fault tolerance capabilities representative implementations of a variety of key HPC software subsystems and integrated them with the FTB. Targeting software subsystems included: MPI communication libraries, checkpoint/restart libraries, resource managers and job schedulers, and system monitoring tools. #15; Leveraging the aforementioned infrastructure, as well as developing and utilizing additional tools, we have examined issues associated with expanded, end-to-end fault response from both system and application viewpoints. From the standpoint of system operations, we have investigated log and root cause analysis, anomaly detection and fault prediction, and generalized notification mechanisms. Our applications work has included libraries for fault-tolerance linear algebra, application frameworks for coupled multiphysics applications, and external frameworks to support the monitoring and response for general applications. #15; Our final goal was to engage the high-end computing community to increase awareness of tools and issues around coordinated end-to-end fault management.

Panda, Dhabaleswar Kumar [The Ohio State University; Beckman, Pete

2011-07-01T23:59:59.000Z

152

Integration of InSAR and GIS in the Study of Surface Faults Caused by Subsidence-Creep-Fault Processes in Celaya, Guanajuato, Mexico  

Science Conference Proceedings (OSTI)

In Celaya city, Subsidence-Creep-Fault Processes (SCFP) began to become visible at the beginning of the 1980s with the sprouting of the crackings that gave rise to the surface faults 'Oriente' and 'Poniente'. At the present time, the city is being affected by five surface faults that display a preferential NNW-SSE direction, parallel to the regional faulting system 'Taxco-San Miguel de Allende'. In order to study the SCFP in the city, the first step was to obtain a map of surface faults, by integrating in a GIS field survey and an urban city plan. The following step was to create a map of the current phreatic level decline in city with the information of deep wells and using the 'kriging' method in order to obtain a continuous surface. Finally the interferograms maps resulted of an InSAR analysis of 9 SAR images covering the time interval between July 12 of 2003 and May 27 of 2006 were integrated to a GIS. All the maps generated, show how the surface faults divide the city from North to South, in two zones that behave in a different way. The difference of the phreatic level decline between these two zones is 60 m; and the InSAR study revealed that the Western zone practically remains stable, while sinkings between the surface faults 'Oriente' and 'Universidad Pedagogica' are present, as well as in portions NE and SE of the city, all of these sinkings between 7 and 10 cm/year.

Avila-Olivera, Jorge A. [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, C.U., 04510 Mexico D.F. (Mexico); Instituto de Investigaciones Metalurgicas, Universidad Michoacana de San Nicolas de Hidalgo, C.U., 58030 Morelia, Michoacan (Mexico); Farina, Paolo [Dipartimento di Scienze della Terra, Universita degli Studi di Firenze, Via G. La Pira 4, 50121 Firenze (Italy); Garduno-Monroy, Victor H. [Instituto de Investigaciones Metalurgicas, Universidad Michoacana de San Nicolas de Hidalgo, C.U., 58030 Morelia, Michoacan (Mexico)

2008-05-07T23:59:59.000Z

153

Ground grid design changes due to potential rise limits outside substations  

SciTech Connect

To ensure safe grounding for personnel and to provide for correct operation of relays, several design factors are critical to assessing the adequacy of a station ground grid design. These difficult to alter parameters are soil resistivity, clearing times for single line to ground station faults, size and location of the substation, and the magnitude of the single line to ground fault current. These are the critical parameters for the grounding system, leaving the designer with the grid area, grid geometry, wire size, surface material, number of ground rods, and burial depth as the tools for reducing step and touch potentials to adequate levels. Grounding practices for substations are based on maintaining step and touch potentials below the limits described in IEEE-80. Guide for AC Substation Grounding. Recently, requirements to limit step and touch potentials outside the substation perimeter were proposed by particular government agencies in Commonwealth Edison's service territory. This limit imposes design changes that would increase construction costs and prevent locating substation at existing sites. This paper compares the design changes needed to meet lower limits with a standard installation designed according to the IEEE-80 guide.

Lodwig, S.G. (Commonwealth Edison Co., Chicago, IL (United States))

1992-01-01T23:59:59.000Z

154

www.elsevier.com/locate/arcontrol Bibliographical review on reconfigurable fault-tolerant control systems  

E-Print Network (OSTI)

In this paper, a bibliographical review on reconfigurable (active) fault-tolerant control systems (FTCS) is presented. The existing approaches to fault detection and diagnosis (FDD) and fault-tolerant control (FTC) in a general framework of active fault-tolerant control systems (AFTCS) are considered and classified according to different criteria such as design methodologies and applications. A comparison of different approaches is briefly carried out. Focuses in the field on the current research are also addressed with emphasis on the practical application of the techniques. In total, 376 references in the open literature, dating back to 1971, are compiled to provide an overall picture of historical, current, and future developments in this area.

Youmin Zhang A; Jin Jiang B

2007-01-01T23:59:59.000Z

155

Fault-zone seals in siliciclastic strata of the Columbus Basin, offshore Trinidad  

Science Conference Proceedings (OSTI)

This study combines observations from outcrop and drill core with an analysis of the hydrocarbon distribution in two mature oil and gas fields to document the factors controlling the existence of fault seals in the Tertiary sandstone-shale sequence of the Columbus Basin. Juxtaposition of reservoir sandstones against shale intervals across normal faults cannot explain the oil and gas distribution in this area, indicating that fault zones serve as the lateral seals for these hydrocarbon accumulations. The fault-zone seals for the largest hydrocarbon columns (50-200 m) consist of shale smears formed by ductile deformation of shale beds during fault slip. Fault segments that do not meet the criteria for development of a shale smear appear to be transmissible or can seal only small columns (shale smears are discontinuous, such as where a sandstone body is partially juxtaposed against itself, column heights are cross-fault spill-point limited and can be analyzed using fault-plane sections combined with mapping of shale-smear continuity. These traps are likely to preferentially spill high-density hydrocarbons once trap capacity is reached. In contrast, traps bounded by spatially continuous shale smears probably leak through the pore network of the fault-zone material at the top of the trap, thus favoring preferential movement of low-density hydrocarbons in a two-phase system. Hydrocarbon migration through stratigraphic sections containing fault-sealed traps of these two types may result in geochemical fractionation and phase segregation, both of which are observed in the Columbus Basin fields.

Gibson, R.G. [Amoco Production Research, Tulsa, OK (United States)

1994-09-01T23:59:59.000Z

156

Fault-ignorant Quantum Search  

E-Print Network (OSTI)

We investigate the problem of quantum searching on a noisy quantum computer. Taking a 'fault-ignorant' approach, we analyze quantum algorithms that solve the task for various different noise strengths, which are possibly unknown beforehand. We prove lower bounds on the runtime of such algorithms and thereby find that the quadratic speedup is necessarily lost (in our noise models). However, for low but constant noise levels the algorithms we provide (based on Grover's algorithm) still outperform the best noiseless classical search algorithm.

Peter Vrana; David Reeb; Daniel Reitzner; Michael M. Wolf

2013-07-02T23:59:59.000Z

157

CONTROL AND FAULT DETECTOR CIRCUIT  

DOE Patents (OSTI)

A power control and fault detectcr circuit for a radiofrequency system is described. The operation of the circuit controls the power output of a radio- frequency power supply to automatically start the flow of energizing power to the radio-frequency power supply and to gradually increase the power to a predetermined level which is below the point where destruction occurs upon the happening of a fault. If the radio-frequency power supply output fails to increase during such period, the control does not further increase the power. On the other hand, if the output of the radio-frequency power supply properly increases, then the control continues to increase the power to a maximum value. After the maximumn value of radio-frequency output has been achieved. the control is responsive to a ''fault,'' such as a short circuit in the radio-frequency system being driven, so that the flow of power is interrupted for an interval before the cycle is repeated.

Winningstad, C.N.

1958-04-01T23:59:59.000Z

158

Internal structure of the Kern Canyon Fault, California: a deeply exhumed strike-slip fault  

E-Print Network (OSTI)

Deformation and mineral alteration adjacent to a 2 km long segment of the Kern Canyon fault near Lake Isabella, California are studied to characterize the internal structure of the fault zone and to understand the development of fault structure and constitution and the mechanical and chemical processes responsible for them. The 140 km long Kern Canyon fault (KCF) is a fault of 15 km right-lateral separation exhumed from seismogenic depth that cuts batholithic and metamorphic rocks of the southern Sierra Nevada. The fault consists of at least three distinct phases: an early phase of lower-greenschist-grade ductile shear with an S-C' phyllonite, a subsequent, dominant phase of brittle faulting characterized by a through-going zone of cataclastic rock, and a late stage of minor faulting along discontinuous, thin, hematitic gouge zones. The S-C' fabric and subsidiary fault-slip data indicate that both the phyllonitic and cataclastic zones are approximately vertical and strike-slip; slip lineations within the hematitic gouge suggest oblique-slip. The phyllonite zone trends N20-40E and accommodated ~175 m of separation. The cataclastic zone cuts the phyllonite, trends N21E, and consists of foliated and non-foliated cataclasites; it accommodates the majority of displacement along the fault. Abundant veins and fluid-assisted alteration in the rock surrounding the fault zone attest to the presence of fluids of evolving chemistry during both ductile and brittle faulting. Mass balance calculations indicate quartz loss during phyllonite faulting and imply that the fault system was open and experienced a negative change in volume during phyllonite faulting. Mesoscale and microscale fracture intensities decrease with log distance from the foliated cataclasites and approach a relatively low level at approximately 500 m. The internal structure of the Kern Canyon fault is similar to other large displacement faults in that it consists of a broad zone of fractured and altered rock and a narrow zone of intense cataclasis.

Neal, Leslie Ann

2002-01-01T23:59:59.000Z

159

Steps toward fault-tolerant quantum chemistry.  

SciTech Connect

Developing quantum chemistry programs on the coming generation of exascale computers will be a difficult task. The programs will need to be fault-tolerant and minimize the use of global operations. This work explores the use a task-based model that uses a data-centric approach to allocate work to different processes as it applies to quantum chemistry. After introducing the key problems that appear when trying to parallelize a complicated quantum chemistry method such as coupled-cluster theory, we discuss the implications of that model as it pertains to the computational kernel of a coupled-cluster program - matrix multiplication. Also, we discuss the extensions that would required to build a full coupled-cluster program using the task-based model. Current programming models for high-performance computing are fault-intolerant and use global operations. Those properties are unsustainable as computers scale to millions of CPUs; instead one must recognize that these systems will be hierarchical in structure, prone to constant faults, and global operations will be infeasible. The FAST-OS HARE project is introducing a scale-free computing model to address these issues. This model is hierarchical and fault-tolerant by design, allows for the clean overlap of computation and communication, reducing the network load, does not require checkpointing, and avoids the complexity of many HPC runtimes. Development of an algorithm within this model requires a change in focus from imperative programming to a data-centric approach. Quantum chemistry (QC) algorithms, in particular electronic structure methods, are an ideal test bed for this computing model. These methods describe the distribution of electrons in a molecule, which determine the properties of the molecule. The computational cost of these methods is high, scaling quartically or higher in the size of the molecule, which is why QC applications are major users of HPC resources. The complexity of these algorithms means that MPI alone is insufficient to achieve parallel scaling; QC developers have been forced to use alternative approaches to achieve scalability and would be receptive to radical shifts in the programming paradigm. Initial work in adapting the simplest QC method, Hartree-Fock, to this the new programming model indicates that the approach is beneficial for QC applications. However, the advantages to being able to scale to exascale computers are greatest for the computationally most expensive algorithms; within QC these are the high-accuracy coupled-cluster (CC) methods. Parallel coupledcluster programs are available, however they are based on the conventional MPI paradigm. Much of the effort is spent handling the complicated data dependencies between the various processors, especially as the size of the problem becomes large. The current paradigm will not survive the move to exascale computers. Here we discuss the initial steps toward designing and implementing a CC method within this model. First, we introduce the general concepts behind a CC method, focusing on the aspects that make these methods difficult to parallelize with conventional techniques. Then we outline what is the computational core of the CC method - a matrix multiply - within the task-based approach that the FAST-OS project is designed to take advantage of. Finally we outline the general setup to implement the simplest CC method in this model, linearized CC doubles (LinCC).

Taube, Andrew Garvin

2010-05-01T23:59:59.000Z

160

Hardware Fault Insertion Techniques and Tools  

E-Print Network (OSTI)

The concept of dependability validation becomes more and more important regarding big public telecom systems. This is why fault insertion has been widely accepted as a means of testing the fault handling mechanisms of the systems. This master thesis classifies and compares fault insertion techniques used within the industry. It also looks into internal fault insertion techniques used by the people at Ericsson Telecom working with the AXD301 ATM switch. Hardware Fault Insertion Techniques and Tools 2 Acknowledgements The following people at Ericsson has contributed to this thesis in one way or another: Roger Nordmark Mattias Rimbark Bengt Kvist Anders strm Kenny Ohlsson Johan Jeppson Johan Eklv Also a thank you to my supervisor at KTH: Axel Jantsch A special thanks also to my good friend and colleague: Robert Thorhuus Hardware Fault Insertion Techniques and Tools 3 Abbreviations ASIC - Application Specific Integrated Circuit ATM - Asynchronous Transfer Mode BSDL - Boundary Scan De...

Emil Savqvist; Roger Nordmark; Mattias Rimbark; Bengt Kvist; Anders Ĺström; Kenny Ohlsson; Johan Eklöv; Axel Jantsch; Robert Thorhuus; Hw Hard Ware

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Investigation of Ground-Fault Protection Devices for Photovoltaic Power Systems Applications  

Science Conference Proceedings (OSTI)

Photovoltaic (PV) power systems, like other electrical systems, may be subject to unexpected ground faults. Installed PV systems always have invisible elements other than those indicated by their electrical schematics. Stray inductance, capacitance and resistance are distributed throughout the system. Leakage currents associated with the PV modules, the interconnected array, wires, surge protection devices and conduit add up and can become large enough to look like a ground-fault. PV systems are frequently connected to other sources of power or energy storage such as batteries, standby generators, and the utility grid. This complex arrangement of distributed power and energy sources, distributed impedance and proximity to other sources of power requires sensing of ground faults and proper reaction by the ground-fault protection devices. The different dc grounding requirements (country to country) often add more confusion to the situation. This paper discusses the ground-fault issues associated with both the dc and ac side of PV systems and presents test results and operational impacts of backfeeding commercially available ac ground-fault protection devices under various modes of operation. Further, the measured effects of backfeeding the tripped ground-fault devices for periods of time comparable to anti-islanding allowances for utility interconnection of PV inverters in the United States are reported.

BOWER,WARD I.; WILES,JOHN

2000-10-03T23:59:59.000Z

162

Apex or Salient of Normal Fault | Open Energy Information  

Open Energy Info (EERE)

Apex or Salient of Normal Fault Apex or Salient of Normal Fault Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Apex or Salient of Normal Fault Dictionary.png Apex or Salient of Normal Fault: Normal faults may intersect in the subsurface to form a fault apex or salient. Apices or salients of normal faults account for 3% of structural controls in the Great Basin. Other definitions:Wikipedia Reegle Controlling Structures List of controlling structures typically associated with geothermal systems: Major Normal Fault Termination of a Major Normal Fault Stepover or Relay Ramp in Normal Fault Zones Apex or Salient of Normal Fault Fault Intersection Accommodation Zone Displacement Transfer Zone Pull-Apart in Strike-Slip Fault Zone Intrusion Margins and Associated Fractures Stratigraphic Boundaries

163

Fault Tree Based Diagnostics Using Fuzzy Logic  

Science Conference Proceedings (OSTI)

Fuzzy set theory is investigated as a tool for the diagnostics of systems described by means of a fault tree. The objective is to diagnose component failures from the observation of fuzzy symptoms using the information contained in a fault tree. A two-step ... Keywords: causal reasoning, component failures, failure analysis, failure modes, fault tree based diagnostics, fuzzy logic, fuzzy symptoms, minimal cut-sets, triggered gates, two-step procedure

P. Gmytrasiewicz; J. A. Hassberger; J. C. Lee

1990-11-01T23:59:59.000Z

164

Fault diagnosis in reversible circuits under missing-gate fault model  

Science Conference Proceedings (OSTI)

This article presents a novel technique for fault detection as well as fault location in a reversible combinational circuit under the missing gate fault model. It is shown that in an (nxn) reversible circuit implemented with k-CNOT gates, addition of ...

Hafizur Rahaman; Dipak K. Kole; Debesh K. Das; Bhargab B. Bhattacharya

2011-07-01T23:59:59.000Z

165

Process fault tolerance: semantics, design and applications for high performance computing  

E-Print Network (OSTI)

With increasing numbers of processors on current machines, the probability for node or link failures is also increasing. Therefore, application-level fault tolerance is becoming more of an important issue for both end-users and the institutions running the machines. In this paper we present the semantics of a fault-tolerant version of the message passing interface (MPI), the de-facto standard for communication in scientific applications, which gives applications the possibility to recover from a node or link error and continue execution in a well-defined way. We present the architecture of fault-tolerant MPI, an implementation of MPI using the semantics presented above as well as benchmark results with various applications. An example of a fault-tolerant parallel equation solver, performance results as well as the time for recovering from a process failure are furthermore detailed.

Jack J; Graham E. Fagg; Graham E. Fagg; Edgar Gabriel; Edgar Gabriel; Zizhong Chen; Zizhong Chen; Thara Angskun; Thara Angskun; George Bosilca; George Bosilca; Jelena Pjesivac-grbovic; Jelena Pjesivac-grbovic; Jack J. Dongarra

2004-01-01T23:59:59.000Z

166

Thoughts Regarding the Dimensions of Faults at Rainier and Aqueduct Mesas, Nye County, Nevada, Based on Surface and Underground Mapping  

Science Conference Proceedings (OSTI)

The geologic setting and history, along with observations through 50 years of detailed geologic field work, show that large-displacement (i.e., greater than 30 meters of displacement) syn- to post-volcanic faults are rare in the Rainier Mesa area. Faults observed in tunnels and drill holes are mostly tight, with small displacements (most less than 1.5 meters) and small associated damage zones. Faults are much more abundant in the zeolitized tuffs than in the overlying vitric tuffs, and there is little evidence that faults extend downward from the tuff section through the argillic paleocolluvium into pre-Tertiary rocks. The differences in geomechanical characteristics of the various tuff lithologies at Rainier Mesa suggest that most faults on Rainer Mesa are limited to the zeolitic units sandwiched between the overlying vitric bedded tuffs and the underlying pre-Tertiary units (lower carbonate aquifer–3, lower clastic confining unit–1, and Mesozoic granite confining unit).

Drellack, S.L.; Prothro, L.B.; Townsend, M.J.; Townsend, D.R.

2011-02-01T23:59:59.000Z

167

ARMor: fully verified software fault isolation  

Science Conference Proceedings (OSTI)

We have designed and implemented ARMor, a system that uses software fault isolation (SFI) to sandbox application code running on small embedded processors. Sandboxing can be used to protect components such as the RTOS and critical control loops from ... Keywords: arm executables, automated theorem proving, program logic, software fault isolation

Lu Zhao; Guodong Li; Bjorn De Sutter; John Regehr

2011-10-01T23:59:59.000Z

168

A switch level fault simulation environment  

Science Conference Proceedings (OSTI)

This paper presents a fault simulation environment which accepts pure switch level or mixed switch/RT level descriptions of the design under test. Switch level fault injection strategies for the stuck-at, transition and logic bridge models are presented. ...

V. Krishnaswamy; J. Casas; T. Tetzlaff

2000-06-01T23:59:59.000Z

169

Representing parameterised fault trees using Bayesian networks  

Science Conference Proceedings (OSTI)

Fault trees are used to model how failures lead to hazards and so to estimate the frequencies of the identified hazards of a system. Large systems, such as a rail network, do not give rise to endless different hazards. Rather, similar hazards arise repeatedly ... Keywords: Bayesian network, fault tree, risk analysis

William Marsh; George Bearfield

2007-09-01T23:59:59.000Z

170

Gas Turbine Fault Diagnosis using Random Forests  

Science Conference Proceedings (OSTI)

In the present paper, Random Forests are used in a critical and at the same time non trivial problem concerning the diagnosis of Gas Turbine blading faults, portraying promising results. Random forests-based fault diagnosis is treated as a Pattern Recognition ...

Manolis Maragoudakis; Euripides Loukis; Panayotis-Prodromos Pantelides

2008-06-01T23:59:59.000Z

171

BASE: Using abstraction to improve fault tolerance  

Science Conference Proceedings (OSTI)

Software errors are a major cause of outages and they are increasingly exploited in malicious attacks. Byzantine fault tolerance allows replicated systems to mask some software errors but it is expensive to deploy. This paper describes a replication ... Keywords: Byzantine fault tolerance, N-version programming, asynchronous systems, proactive recovery, state machine replication

Miguel Castro; Rodrigo Rodrigues; Barbara Liskov

2003-08-01T23:59:59.000Z

172

Numeric simulation of faults in electrical networks  

Science Conference Proceedings (OSTI)

In the paper is presented a virtual simulator for three-phased medium voltage electric circuits. The simulator allows analyzing transient regimes caused by the faults produced in electric distribution networks (simple grounding, double grounding, broken ... Keywords: faults in electric network, numerical simulation, three phased circuits, transient regimes

Toader Dumitru; Haragus Stefan; Blaj Constantin

2009-03-01T23:59:59.000Z

173

INDUCTION MOTOR FAULT DIAGNOSTIC AND MONITORING METHODS  

E-Print Network (OSTI)

INDUCTION MOTOR FAULT DIAGNOSTIC AND MONITORING METHODS by Aderiano M. da Silva, B.S. A Thesis;i Abstract Induction motors are used worldwide as the "workhorse" in industrial applications material. However, induction motor faults can be detected in an initial stage in order to prevent

Povinelli, Richard J.

174

Detect and classify faults using neural nets  

SciTech Connect

The analysis of transmission line faults is essential to the proper performance of the power system. It is required if protective relays are to take the appropriate action and in monitoring the performance of relays, circuit breakers, and other protective and control elements. The detection and classification of transmission line faults is a fundamental component of such fault analysis. Another application of fault analysis is in software packages for automated analysis of digital fault recorder (DFR) files. Recently, such a package, called DFR Assistant, was developed for substation applications. This program can be installed locally in a substation, in which case it is connected directly to the DFR via a high speed parallel link, or it can be installed at a central station, in which case it can be configured to automatically analyze events coming from all DFRs.

Kezunovic, M.; Rikalo, I.

1996-10-01T23:59:59.000Z

175

A methodology for experimentally verifying simulation models for distribution transformer internal faults  

E-Print Network (OSTI)

Internal winding faults comprise 70-80% of modem transformer breakdown. In this era of deregulation, this phenomenon is likely to increase since loading transformers to their optimum capacity is becoming normal practice. These internal faults result from degradation of the transformer winding insulation, which tends to cause a breakdown in the dielectric strength. This breakdown either causes adjacent windings to short or a winding to be shorted to a grounded part of the transformer. Such faults can be very catastrophic and hence expensive. Utilities therefore welcome inexpensive methods employed to detect such faults in the incipient stage. The long-term objective of this research is the development of an inexpensive technique for the detection of transformer incipient winding faults. As part of this research, the thesis presents: 1. Internal winding models of single-phase, distribution transformers. These models are adapted from an earlier work of modeling internal winding faults of three-phase power transformers. They are compatible with the Alternative Transients Program and enable the transformer winding terminal parameters to be monitored. They allow the simulation of faults between any turn and the earth or between any two turns of the transformer windings. 2. Simulation of various internal winding faults of a single-phase distribution transformer using the models. 3. A general methodology to experimentally verify simulation models for distribution transformer internal winding faults including details of the design and layout of a field experimental setup containing a 25kVA, 7200V/240V/120V single-phase, custom-built transformer and a 25kW resistor load bank. 4. A comparison of the simulation and corresponding field experiment results. Although the simulation models neglected factors such as saturation and consequently transformer nonlinearities, the simulation and field results were very similar. As a contribution, the experimental setup presented in this work could generally be used for simulation model verification by following the proposed methodology with appropriate modifications. The validated models can be utilized to generate fault data for all kinds of scenarios including those that would be impossible to stage experimentally due to high levels of fault currents. These data can be used as a basis for a single-phase transformer incipient fault detection system.

Palmer-Buckle, Peter

1999-01-01T23:59:59.000Z

176

Modeling and Measurement Constraints in Fault Diagnostics for HVAC Systems  

E-Print Network (OSTI)

in Fault Diagnostics for HVAC Systems Massieh Najafi 1 ,tools for determining HVAC diagnostics, methods todetect faults in HVAC systems are still generally

Najafi, Massieh

2010-01-01T23:59:59.000Z

177

Modeling and simulation of HVAC faults in EnergyPlus  

NLE Websites -- All DOE Office Websites (Extended Search)

simulation of HVAC faults in EnergyPlus Title Modeling and simulation of HVAC faults in EnergyPlus Publication Type Conference Paper Refereed Designation Refereed Year of...

178

Modeling and Measurement Constraints in Fault Diagnostics for...  

NLE Websites -- All DOE Office Websites (Extended Search)

Modeling and Measurement Constraints in Fault Diagnostics for HVAC Systems Title Modeling and Measurement Constraints in Fault Diagnostics for HVAC Systems Publication Type Journal...

179

fault diagnosis of a high voltage transmission line using waveform ...  

E-Print Network (OSTI)

Oct 4, 2013 ... FAULT DIAGNOSIS OF A HIGH VOLTAGE TRANSMISSION LINE USING ... Fault types such as single line to ground, line to line, double line to ...

180

CIFTS: A Coordinated Infrastructure for Fault-Tolerant Systems...  

NLE Websites -- All DOE Office Websites (Extended Search)

CIFTS: A Coordinated Infrastructure for Fault-Tolerant Systems Title CIFTS: A Coordinated Infrastructure for Fault-Tolerant Systems Publication Type Conference Paper Year of...

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Automated Fault Location In Smart Distribution Systems  

E-Print Network (OSTI)

Fault location in distribution systems is a critical component of outage management and service restoration, which directly impacts feeder reliability and quality of the electricity supply. Improving fault location methods supports the Department of Energy (DOE) “Grid 2030” initiatives for grid modernization by improving reliability indices of the network. Improving customer average interruption duration index (CAIDI) and system average interruption duration index (SAIDI) are direct advantages of utilizing a suitable fault location method. As distribution systems are gradually evolving into smart distribution systems, application of more accurate fault location methods based on gathered data from various Intelligent Electronic Devices (IEDs) installed along the feeders is quite feasible. How this may be done and what is the needed methodology to come to such solution is raised and then systematically answered. To reach this goal, the following tasks are carried out: 1) Existing fault location methods in distribution systems are surveyed and their strength and caveats are studied. 2) Characteristics of IEDs in distribution systems are studied and their impacts on fault location method selection and implementation are detailed. 3) A systematic approach for selecting optimal fault location method is proposed and implemented to pinpoint the most promising algorithms for a given set of application requirements. 4) An enhanced fault location method based on voltage sag data gathered from IEDs along the feeder is developed. The method solves the problem of multiple fault location estimations and produces more robust results. 5) An optimal IED placement approach for the enhanced fault location method is developed and practical considerations for its implementation are detailed.

Lotfifard, Saeed

2011-08-01T23:59:59.000Z

182

Fault-tolerance for exascale systems.  

Science Conference Proceedings (OSTI)

Periodic, coordinated, checkpointing to disk is the most prevalent fault tolerance method used in modern large-scale, capability class, high-performance computing (HPC) systems. Previous work has shown that as the system grows in size, the inherent synchronization of coordinated checkpoint/restart (CR) limits application scalability; at large node counts the application spends most of its time checkpointing instead of executing useful work. Furthermore, a single component failure forces an application restart from the last correct checkpoint. Suggested alternatives to coordinated CR include uncoordinated CR with message logging, redundant computation, and RAID-inspired, in-memory distributed checkpointing schemes. Each of these alternatives have differing overheads that are dependent on both the scale and communication characteristics of the application. In this work, using the Structural Simulation Toolkit (SST) simulator, we compare the performance characteristics of each of these resilience methods for a number of HPC application patterns on a number of proposed exascale machines. The result of this work provides valuable guidance on the most efficient resilience methods for exascale systems.

Riesen, Rolf E.; Varela, Maria Ruiz (University of Delaware); Ferreira, Kurt Brian

2010-08-01T23:59:59.000Z

183

Fault diagnosis using substation computer  

SciTech Connect

A number of substation integrated control and protection systems (ICPS) are being developed around the world, where the protective relaying, control, and monitoring functions of a substation are implemented using microprocessors. In this design, conventional relays and control devices are replaced by clusters of microprocessors, interconnected by multiplexed digital communication channels using fibre optic, twisted wire pairs or coaxial cables. The ICPS incorporates enhanced functions of value to the utility and leads to further advancement of the automation of transmission substations. This paper presents an automated method of fault diagnosis which can be incorporated in the station computer of an integrated control and protection system. The effectiveness of this method is demonstrated using a transmission-level substation as an example.

Jeyasurya, B. (Indian Inst. of Tech., Bombay (India)); Venkata, S.S. (Washington Univ., Seattle, WA (USA). Dept. of Electrical Engineering); Vadari, S.V. (ESCA Corp., Bellevue, WA (USA)); Postforoosh, J. (T and D. Protection Group, Puget Sound Power and Light, Bellevue, WA (US))

1990-04-01T23:59:59.000Z

184

Apparatus for and method of testing an electrical ground fault circuit interrupt device  

DOE Patents (OSTI)

An apparatus for testing a ground fault circuit interrupt device includes a processor, an input device connected to the processor for receiving input from an operator, a storage media connected to the processor for storing test data, an output device connected to the processor for outputting information corresponding to the test data to the operator, and a calibrated variable load circuit connected between the processor and the ground fault circuit interrupt device. The ground fault circuit interrupt device is configured to trip a corresponding circuit breaker. The processor is configured to receive signals from the calibrated variable load circuit and to process the signals to determine a trip threshold current and/or a trip time. A method of testing the ground fault circuit interrupt device includes a first step of providing an identification for the ground fault circuit interrupt device. Test data is then recorded in accordance with the identification. By comparing test data from an initial test with test data from a subsequent test, a trend of performance for the ground fault circuit interrupt device is determined.

Andrews, Lowell B. (2181-13th Ave. SW., Largo, FL 34640)

1998-01-01T23:59:59.000Z

185

Apparatus for and method of testing an electrical ground fault circuit interrupt device  

DOE Patents (OSTI)

An apparatus for testing a ground fault circuit interrupt device includes a processor, an input device connected to the processor for receiving input from an operator, a storage media connected to the processor for storing test data, an output device connected to the processor for outputting information corresponding to the test data to the operator, and a calibrated variable load circuit connected between the processor and the ground fault circuit interrupt device. The ground fault circuit interrupt device is configured to trip a corresponding circuit breaker. The processor is configured to receive signals from the calibrated variable load circuit and to process the signals to determine a trip threshold current and/or a trip time. A method of testing the ground fault circuit interrupt device includes a first step of providing an identification for the ground fault circuit interrupt device. Test data is then recorded in accordance with the identification. By comparing test data from an initial test with test data from a subsequent test, a trend of performance for the ground fault circuit interrupt device is determined. 17 figs.

Andrews, L.B.

1998-08-18T23:59:59.000Z

186

Energy and entropy-based feature extraction for locating fault on transmission lines by using neural network and wavelet packet decomposition  

Science Conference Proceedings (OSTI)

The aim of this paper is to estimate the fault location on transmission lines quickly and accurately. The faulty current and voltage signals obtained from a simulation are decomposed by wavelet packet transform (WPT). The extracted features are applied ... Keywords: Energy, Entropy, Fault location, Neural network, Wavelet packet

Sami Ekici; Selcuk Yildirim; Mustafa Poyraz

2008-05-01T23:59:59.000Z

187

Cooperative application/OS DRAM fault recovery.  

Science Conference Proceedings (OSTI)

Exascale systems will present considerable fault-tolerance challenges to applications and system software. These systems are expected to suffer several hard and soft errors per day. Unfortunately, many fault-tolerance methods in use, such as rollback recovery, are unsuitable for many expected errors, for example DRAM failures. As a result, applications will need to address these resilience challenges to more effectively utilize future systems. In this paper, we describe work on a cross-layer application/OS framework to handle uncorrected memory errors. We illustrate the use of this framework through its integration with a new fault-tolerant iterative solver within the Trilinos library, and present initial convergence results.

Ferreira, Kurt Brian; Bridges, Patrick G. (University of New Mexico, Albuquerque, NM); Heroux, Michael Allen; Hoemmen, Mark; Brightwell, Ronald Brian

2012-05-01T23:59:59.000Z

188

Mechanical Models of Fault-Related Folding  

SciTech Connect

The subject of the proposed research is fault-related folding and ground deformation. The results are relevant to oil-producing structures throughout the world, to understanding of damage that has been observed along and near earthquake ruptures, and to earthquake-producing structures in California and other tectonically-active areas. The objectives of the proposed research were to provide both a unified, mechanical infrastructure for studies of fault-related foldings and to present the results in computer programs that have graphical users interfaces (GUIs) so that structural geologists and geophysicists can model a wide variety of fault-related folds (FaRFs).

Johnson, A. M.

2003-01-09T23:59:59.000Z

189

Intelligent ICA-SVM fault detector for non-Gaussian multivariate process monitoring  

Science Conference Proceedings (OSTI)

Recently, the independent component analysis (ICA) has been widely used for multivariate non-Gaussian process monitoring. For principal component analysis (PCA) based monitoring method, the control limit can be determined by a specific distribution (F ... Keywords: Autocorrelated, Fault detector, ICA, PCA, SVM

Chun-Chin Hsu; Mu-Chen Chen; Long-Sheng Chen

2010-04-01T23:59:59.000Z

190

CAT: a computer code for the automated construction of fault trees. [In FORTRAN  

SciTech Connect

A computer code, CAT (Computer Automated Tree, is presented which applies decision table methods to model the behavior of components for systematic construction of fault trees. The decision tables for some commonly encountered mechanical and electrical components are developed; two nuclear subsystems, a Containment Spray Recirculation System and a Consequence Limiting Control System, are analyzed to demonstrate the applications of CAT code.

Apostolakis, G.E.; Salem, S.L.; Wu, J.S.

1978-03-01T23:59:59.000Z

191

Neural Fault Diagnosis and Fuzzy Fault Control for a Complex Dynamic System  

E-Print Network (OSTI)

Fault diagnosis has become an issue of primary importance in modern process automation as it provides the prerequisites for the task of fault detection. The ability to detect the faults is essential to improve reliability and security of a complex control system. Parameter estimation methods, state observation schemes, statistical likelihood ratio tests, rule-based expert system reasoning, pattern recognition techniques, and artificial neural network approaches are the most common methodologies developed actively during recent years. In this paper, we describe a completed feasibility study demonstrating the merit of employing pattern recognition and an artificial neural network for fault diagnosis through back propagation learning algorithm and making the use of fuzzy approximate reasoning for fault control via parameter changes in a dynamic system. As a test case, a complex magnetic levitation vehicle (MLV) system is studied. Analytical fault symptoms are obtained by system dynamics m...

Ching-yu Tyan; Paul P. Wang; Dennis R. Bahler

1995-01-01T23:59:59.000Z

192

Quantification of Priority-OR gates in temporal fault trees  

Science Conference Proceedings (OSTI)

Fault Tree Analysis has been used in reliability engineering for many decades and has seen various modifications to enable it to analyse fault trees with dynamic and temporal gates so it can incorporate sequential failure in its analysis. Pandora is ... Keywords: Markov chains, Monte Carlo, Pandora, dynamic fault trees, fault trees, safety

Ernest Edifor; Martin Walker; Neil Gordon

2012-09-01T23:59:59.000Z

193

Development of Hydrologic Characterization Technology of Fault Zones  

E-Print Network (OSTI)

pathways in the Monterey Formation, California: Americanalong faults in the Monterey Formation, coastal California.

Karasaki, Kenzi

2009-01-01T23:59:59.000Z

194

Online fault detection and tolerance for photovoltaic energy harvesting systems  

Science Conference Proceedings (OSTI)

Photovoltaic energy harvesting systems (PV systems) are subject to PV cell faults, which decrease the efficiency of PV systems and even shorten the PV system lifespan. Manual PV cell fault detection and elimination are expensive and nearly impossible ... Keywords: fault detection, fault tolerance, photovoltaic panel reconfiguration, photovoltaic system

Xue Lin; Yanzhi Wang; Di Zhu; Naehyuck Chang; Massoud Pedram

2012-11-01T23:59:59.000Z

195

A transmission line fault locator based on Elman recurrent networks  

Science Conference Proceedings (OSTI)

In this paper, a transmission line fault location model which is based on an Elman recurrent network (ERN) has been presented for balanced and unbalanced short circuit faults. All fault situations with different inception times are implemented on a 380-kV ... Keywords: Elman networks, Fault location, Transmission lines, Wavelet transform

Sami Ekici; Selcuk Yildirim; Mustafa Poyraz

2009-01-01T23:59:59.000Z

196

Original articles: Optimal current waveforms for torque control of permanent magnet synchronous machines with any number of phases in open circuit  

Science Conference Proceedings (OSTI)

Polyphase permanent magnet synchronous motors are well suited for electromechanical actuation systems demanding a high level of reliability. They are indeed able to run on a reduced number of phases and therefore to make the actuation system fault tolerant. ... Keywords: Fault tolerance, Open phase fault, Optimal currents, Polyphase motor

F. Baudart, E. Matagne, B. Dehez, F. Labrique

2013-04-01T23:59:59.000Z

197

Fault intersections and hybrid transform faults in the southern Salton Trough geothermal area, Baja California, Mexico  

DOE Green Energy (OSTI)

Analysis of 55 wells drilled at the Cerro Prieto Geothermal Field and a suite of geological and geophysical studies throughout the southern Salton Trough from the Mexican-United States border to the Gulf of California clarify two concepts important to geothermal development: (1) increased natural convective fluid flow and better permeability should occur at intersecting faults both regionally and within a producing field, and (2) the Cerro Prieto and Imperial faults are best conceived of as hybrid types having features of both San Andreas style wrench faults and oceanic tranform faults.

Vonder Haar, S.; Puente Cruz, I.

1979-07-01T23:59:59.000Z

198

Fault Detection, Location, Isolation and Reconnection in ...  

A University of Colorado research team led by Jae-Do Park has developed a fault detection, location and isolation scheme for a low-voltage DC-bus microgrid system, ...

199

Fault tolerance for holonomic quantum computation  

E-Print Network (OSTI)

We review an approach to fault-tolerant holonomic quantum computation on stabilizer codes. We explain its workings as based on adiabatic dragging of the subsystem containing the logical information around suitable loops along which the information remains protected.

Ognyan Oreshkov; Todd A. Brun; Daniel A. Lidar

2013-12-01T23:59:59.000Z

200

Keywords: Photovoltaic System, fault-tolerance, recon-figurable PV panel  

E-Print Network (OSTI)

1 Keywords: Photovoltaic System, fault-tolerance, recon- figurable PV panel Photovoltaic (PV plants, and satellites. The output power of a PV cell (also called solar cell) is dependent on the solar irradiance level and temperature. Figure 1 shows PV cell output current-voltage and power

Pedram, Massoud

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

The Response of Long-Span Bridges to Low Frequency, Near-Fault Earthquake Ground Motions  

SciTech Connect

Historical seismic hazard characterizations did not include earthquake ground motion waveforms at frequencies below approximately 0.2 Hz (5 seconds period). This resulted from limitations in early strong motion instrumentation and signal processing techniques, a lack of measurements in the near-field of major earthquakes and therefore no observational awareness, and a delayed understanding in the engineering community of the potential significance of these types of motions. In recent years, there is a growing recognition of the relevance of near-fault, low frequency motions, particularly for long-period structures such as large bridges. This paper describes a computationally based study of the effects of low frequency (long-period) near-fault motions on long-span bridge response. The importance of inclusion of these types of motions for long span cable supported bridges is demonstrated using actual measured broad-band, near-fault motions from large earthquakes.

McCallen, David; Astaneh-Asl, A.; Larsen, S.C.; Hutchings, Larry

2009-02-27T23:59:59.000Z

202

Distributed Fault-Tolerant Avionic Systems - A Real-Time Perspective  

E-Print Network (OSTI)

This paper examines the problem of introducing advanced forms of fault-tolerance via reconfiguration into safety-critical avionic systems. This is required to enable increased availability after fault occurrence in distributed integrated avionic systems(compared to static federated systems). The approach taken is to identify a migration path from current architectures to those that incorporate re-configuration to a lesser or greater degree. Other challenges identified include change of the development process; incremental and flexible timing and safety analyses; configurable kernels applicable for safety-critical systems.

Burke, Michael

2010-01-01T23:59:59.000Z

203

Measuring and Modeling Fault Density for Plume-Fault Encounter Probability Estimation  

Science Conference Proceedings (OSTI)

Emission of carbon dioxide from fossil-fueled power generation stations contributes to global climate change. Storage of this carbon dioxide within the pores of geologic strata (geologic carbon storage) is one approach to mitigating the climate change that would otherwise occur. The large storage volume needed for this mitigation requires injection into brine-filled pore space in reservoir strata overlain by cap rocks. One of the main concerns of storage in such rocks is leakage via faults. In the early stages of site selection, site-specific fault coverages are often not available. This necessitates a method for using available fault data to develop an estimate of the likelihood of injected carbon dioxide encountering and migrating up a fault, primarily due to buoyancy. Fault population statistics provide one of the main inputs to calculate the encounter probability. Previous fault population statistics work is shown to be applicable to areal fault density statistics. This result is applied to a case study in the southern portion of the San Joaquin Basin with the result that the probability of a carbon dioxide plume from a previously planned injection had a 3% chance of encountering a fully seal offsetting fault.

Jordan, P.D.; Oldenburg, C.M.; Nicot, J.-P.

2011-05-15T23:59:59.000Z

204

A fault location approach for fuzzy fault section estimation on radial distribution feeders  

E-Print Network (OSTI)

Locating the faulted section of a distribution system is a difficult task because of lack of accurate system models and the presence of uncertainty in the data used for estimating the fault section. Many of the methods used to account for the uncertainty use fuzzy logic techniques to estimate bounds of possibility of the input data and calculated quantities, or probabilistic modeling of the input data to estimate the likelihood of the location of the fault on a particular section of the feeder. Heuristic knowledge of control center dispatchers has also been used for uncertainty management. This thesis presents the design and implementation of a phase selector algorithm and a fault distance algorithm for use in an automated modular scheme for fault section estimation on radial distribution systems. These two algorithms will be executed in combination with two other fault location algorithms. The scheme is executed using the data record of an abnormal event in a three-stage scheme. The phase selector algorithm was used to obtain event-phase possibility values representing the possibility of involvement of each of the phases and the neutral in an event. A section-event possibility value that indicated the possibility that a section of the feeder was involved in the fault was evaluated using the event-phase possibility values and line section phase topology information. The fault distance algorithm was used to eliminate sections of the feeder that were not likely to be possible faulted section candidates by assuming a bolted fault and estimating its location. Each line section was assigned a fault possibility value of zero or one according to its location relative to the location of the fault. The phase selector algorithm was tested using real data measured at feeder substations and the fault distance algorithm was tested using data obtained by staging faults on a model of an overhead feeder using EMTP/ATP simulation. The results obtained from the tests were promising. A simple illustration of the combination of the results of the two algorithms is given. The result of this combination shows the potential of the simultaneous use of the two algorithms.

Andoh, Kwame Sarpong

2000-01-01T23:59:59.000Z

205

Stress and fault rock controls on fault zone hydrology, Coso geothermal  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Stress and fault rock controls on fault zone hydrology, Coso geothermal field, CA Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Stress and fault rock controls on fault zone hydrology, Coso geothermal field, CA Details Activities (1) Areas (1) Regions (0) Abstract: In crystalline rock of the Coso Geothermal Field, CA, fractures are the primary source of permeability. At reservoir depths, borehole image, temperature, and mud logs indicate fluid flow is concentrated in extensively fractured damage zones of large faults well-oriented for slip.

206

Fast Fault Recovery in Switched Networks for Carrying IP Telephony Traffic.  

E-Print Network (OSTI)

?? One of the most parts of VOIP management is fault management and, in having a good fault management, finding good mechanisms to detect faults… (more)

Eisazadeh, Ali Akbar

2010-01-01T23:59:59.000Z

207

Process Limits on Euclid  

NLE Websites -- All DOE Office Websites (Extended Search)

Process Limits Process Limits Limit Hard Soft core file size (blocks) 0 unlimited data seg size (kbytes) unlimited unlimited scheduling priority 0 0 file size (blocks) unlimited...

208

A Sentinel Approach to Fault Handling in Multi-Agent Systems  

E-Print Network (OSTI)

Fault handling in Multi-Agent Systems (MAS) is not much addressed in current research. Normally, it is considered difficult to address in detail and often well covered by traditional methods, relying on the underlying communication and operating system. In this paper it is shown that this is not necessarily true, at least not with the assumptions on applications we have made. These assumptions are a massive distribution of computing components, a heterogeneous underlying infrastructure (in terms of hardware, software and communication methods), an emerging configuration, possibly different parties in control of sub-systems, and real-time demands in parts of the system. The key problem is that while a MAS is modular and therefore should be a good platform for building fault tolerant systems, it is also non-deterministic, making it difficult to guarantee a specific behaviour, especially in fault situations. Our proposal is to introduce sentinels to guard certain functionality and to pro...

Staffan Hgg Department; Staffan Hägg

1996-01-01T23:59:59.000Z

209

VCSEL fault location apparatus and method  

DOE Patents (OSTI)

An apparatus for locating a fault within an optical fiber is disclosed. The apparatus, which can be formed as a part of a fiber-optic transmitter or as a stand-alone instrument, utilizes a vertical-cavity surface-emitting laser (VCSEL) to generate a test pulse of light which is coupled into an optical fiber under test. The VCSEL is subsequently reconfigured by changing a bias voltage thereto and is used as a resonant-cavity photodetector (RCPD) to detect a portion of the test light pulse which is reflected or scattered from any fault within the optical fiber. A time interval .DELTA.t between an instant in time when the test light pulse is generated and the time the reflected or scattered portion is detected can then be used to determine the location of the fault within the optical fiber.

Keeler, Gordon A. (Albuquerque, NM); Serkland, Darwin K. (Albuquerque, NM)

2007-05-15T23:59:59.000Z

210

Geometry of Cenozoic extensional faulting: Dixie Valley, Nevada | Open  

Open Energy Info (EERE)

Geometry of Cenozoic extensional faulting: Dixie Valley, Nevada Geometry of Cenozoic extensional faulting: Dixie Valley, Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Geometry of Cenozoic extensional faulting: Dixie Valley, Nevada Abstract Precise definition of geometric relationships between individual basins and ranges may help to reveal the mechanical processes of Basin and Range Cenozoic extensional faulting at depth. Previous studies have attempted to identify simple horsts and grabens, tilted crustal blocks with planar faulting, or tilted crustal blocks with listric faulting in the shallow crust. Normal faults defining these crustal blocks may root (1) individually in the ductile lower crust, (2) in regional or local low-angle detachment faults, or (3) in igneous intrusions or decoupling surfaces

211

Synthesis and evaluation of fault-tolerant quantum computer architectures  

E-Print Network (OSTI)

Fault-tolerance is the cornerstone of practical, large-scale quantum computing, pushed into its prominent position with heroic theoretical efforts. The fault-tolerance threshold, which is the component failure probability ...

Cross, Andrew W. (Andrew William), 1979-

2005-01-01T23:59:59.000Z

212

Scalable Distributed Consensus to Support MPI Fault Tolerance  

Science Conference Proceedings (OSTI)

As system sizes increase, the amount of time in which an application can run without experiencing a failure decreases. Exascale applications will need to address fault tolerance. In order to support algorithm-based fault tolerance, communication libraries ...

Darius Buntinas

2012-05-01T23:59:59.000Z

213

High-level test synthesis for delay fault testability  

Science Conference Proceedings (OSTI)

A high-level test synthesis (HLTS) method targeted for delay fault testability is presented. The proposed method, when combined with hierarchical test pattern generation for embedded modules, guarantees 100% delay test coverage for detectable faults ...

Sying-Jyan Wang; Tung-Hua Yeh

2007-04-01T23:59:59.000Z

214

MODELING AND SIMULATION OF HVAC FAULTS IN ENERGYPLUS  

E-Print Network (OSTI)

sensor faults, Energy and Buildings. 42(4). April 2010.faults in buildings. Energy and Buildings. 42(1). Januaryon the DOE-2 model, Energy and Buildings. 21(2). 1994, Pages

Basarkar, Mangesh

2013-01-01T23:59:59.000Z

215

Stability of Distributed Algorithms in the Face of Incessant Faults  

Science Conference Proceedings (OSTI)

For large distributed systems built from inexpensive components, one expects to see incessant failures. This paper proposes two models for such faults and analyzes two well-known self-stabilizing algorithms under these fault models. For a small number ...

Robert E. Lee Deville; Sayan Mitra

2009-11-01T23:59:59.000Z

216

Design and Evaluation of Hybrid Fault-Detection Systems  

Science Conference Proceedings (OSTI)

As chip densities and clock rates increase, processors are becoming more susceptible to transient faults that can affect program correctness. Up to now, system designers have primarily considered hardware-only and software-only fault-detection mechanisms ...

George A. Reis; Jonathan Chang; Neil Vachharajani; Ram Rangan; David I. August; Shubhendu S. Mukherjee

2005-06-01T23:59:59.000Z

217

Two-person control administration: preventing administration faults through duplication  

Science Conference Proceedings (OSTI)

Modern computing systems are complex and difficult to administer, making them more prone to system administration faults. Faults can occur simply due to mistakes in the process of administering a complex system. These mistakes can make the system insecure ...

Shaya Potter; Steven M. Bellovin; Jason Nieh

2009-11-01T23:59:59.000Z

218

Underground Cable Fault Location Reference and Application Guide  

Science Conference Proceedings (OSTI)

This report summarizes underground cable fault location methods and details the application of the methods for transmission and distribution cable systems. It summarizes both terminal location and tracer location methods that can be applied to transmission and distribution cable systems. The report is an update to a summary of fault location methods. It provides practical technical material in the art and science of locating cable faults, including a description of common fault location instruments and p...

2011-12-23T23:59:59.000Z

219

Fault Diagnosis of Transformer Based on Probabilistic Neural Network  

Science Conference Proceedings (OSTI)

In order to improve the correct rate of transformer fault diagnosis based on three-ratio method of traditional dissolved gas analysis (DGA), a novel intelligent transformer fault diagnosis method based on both DGA and probabilistic neural network (PNN) ... Keywords: transformer fault diagnosis, probabilistic neural network (PNN), improved three-ratio method

Li Song; Li Xiu-ying; Wang Wen-xu

2011-03-01T23:59:59.000Z

220

New Burnside Anticline: part of Fluorspar area fault complex  

SciTech Connect

Field mapping in the Abbott Formation and examination of topographic lineaments in the Creal Springs, Stonefort, Eddyville, and Harrisburg Quadrangles (southeastern Illinois) reveal the New Burnside anticline and its northeastern extension, the Stonefort anticline to be a single, extensively faulted structure. Interpretation of this evidence also leads to the conclusion that this is a fault-block structure rather than an anticline. Trending notheast-southwest, the structure seems to be the northwesternmost extent of the Fluorspar Area fault complex. The authors found evidence for two episodes of faulting. The first involved northeast-trending, high-angle faults similar to those in the known Fluorspar complex to the southeast. Faults on the northeast (Stonefort antilcine) step down toward the center of the structure, forming a graben. Vertical movement also occurred to the southwest (New Burnside anticline), but the structure in this vicinity is a horst with some blocks tilted. As with other faults in the Fluorspar complex, horizontal slickensides are present locally. The second episode of movement occurred along northwest-southeast-trending strike-slip faults that offset the northeast-trending high-angle faults. This second phase of faulting may correspond with previously reported reactivation of northwest-trending faults elsewhere in the Fluorspar Area fault complex.

Jacobson, R.J.; Trask, C.B.

1983-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Rigorous Development of Dependable Systems Using Fault Tolerance Views  

Science Conference Proceedings (OSTI)

This paper introduces the Mode and Fault Tolerance Views approach to stepwise rigorous development of critical systems. It supports systematic, structured and recursive modelling of system fault tolerance, including error detection, error recovery and ... Keywords: formal methods, Event-B, fault tolerance, modal systems, case study, AOCS

Ilya Lopatkin; Alexei Iliasov; Alexander Romanovsky

2011-11-01T23:59:59.000Z

222

Yet Another Fault Injection Technique : by Forward Body Biasing Injection  

E-Print Network (OSTI)

expensive fault injection tech- niques, like clock or voltage glitches, are well taken into accountYet Another Fault Injection Technique : by Forward Body Biasing Injection K. TOBICH1,2, P. MAURINE1 Injection, Electromag- netic Attacks, RSA, Chinese Remainder Theorem 1 Introduction Fault injection

223

Statistical estimation of multiple faults in aircraft gas turbine engines  

E-Print Network (OSTI)

415 Statistical estimation of multiple faults in aircraft gas turbine engines S Sarkar, C Rao of multiple faults in aircraft gas-turbine engines, based on a statistical pattern recognition tool called commercial aircraft engine. Keywords: aircraft propulsion, gas turbine engines, multiple fault estimation

Ray, Asok

224

Applications of fault detection methods to industrial processes  

Science Conference Proceedings (OSTI)

Components of industrial processes are often affected by un-permitted or un-expected deviations from normal operation behaviour. The fault detection task consists of determination of the fault present in a system and the time of detection. In addition ... Keywords: fault detection and diagnosis, industrial processes, residuals, symptoms

Ioana Fagarasan; S. S. T. Iliescu

2008-06-01T23:59:59.000Z

225

Collective operations in application-level fault-tolerant MPI  

Science Conference Proceedings (OSTI)

Fault-tolerance is becoming a critical issue on high-performance platforms. Checkpointing techniques make programs fault-tolerant by saving their state periodically and restoring this state after failure. System-level checkpointing saves the state ... Keywords: MPI, application-level checkpointing, collective communication, fault-tolerance, non-FIFO communication, scientific computing

Greg Bronevetsky; Daniel Marques; Keshav Pingali; Paul Stodghill

2003-06-01T23:59:59.000Z

226

Outlier Detection Rules for Fault Detection in Solar Photovoltaic Arrays  

E-Print Network (OSTI)

fault detection. Furthermore, the proposed models become more reliable as the number of PV measurements analysis specifically for PV installation. Several fault detection models and monitoring systems have been studied for PV systems [8]­[14]. PV monitoring and fault detection models based on energy yield and power

Lehman, Brad

227

A lightweight fault tolerance framework for Web services  

Science Conference Proceedings (OSTI)

In this paper, we present the design and implementation of a lightweight fault tolerance framework for Web services. With our framework, a Web service can be rendered fault tolerant by replicating it across several nodes. A consensus-based algorithm ... Keywords: Fault tolerance, Web services, distributed consensus, reliable messaging, replication

Wenbing Zhao; Honglei Zhang; Hua Chai

2009-08-01T23:59:59.000Z

228

Fault reconnaissance agent for sensor networks  

Science Conference Proceedings (OSTI)

One of the key prerequisite for a scalable, effective and efficient sensor network is the utilization of low-cost, low-overhead and high-resilient fault-inference techniques. To this end, we propose an intelligent agent system with a problem solving ... Keywords: Management, expectation maximization algorithm, intelligent agents, wireless sensor networks

Elhadi M. Shakshuki; Xinyu Xing; Tarek R. Sheltami

2010-08-01T23:59:59.000Z

229

Current Titles  

Science Conference Proceedings (OSTI)

This booklet is published for those interested in current research being conducted at the National Center for Electron Microscopy. The NCEM is a DOE-designated national user facility and is available at no charge to qualified researchers. Access is controlled by an external steering committee. Interested researchers may contact Jane Cavlina, Administrator, at 510/486-6036.

Various

2006-06-01T23:59:59.000Z

230

Active Fault Segments As Potential Earthquake Sources- Inferences From  

Open Energy Info (EERE)

Active Fault Segments As Potential Earthquake Sources- Inferences From Active Fault Segments As Potential Earthquake Sources- Inferences From Integrated Geophysical Mapping Of The Magadi Fault System, Southern Kenya Rift Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Active Fault Segments As Potential Earthquake Sources- Inferences From Integrated Geophysical Mapping Of The Magadi Fault System, Southern Kenya Rift Details Activities (0) Areas (0) Regions (0) Abstract: Southern Kenya Rift has been known as a region of high geodynamic activity expressed by recent volcanism, geothermal activity and high rate of seismicity. The active faults that host these activities have not been investigated to determine their subsurface geometry, faulting intensity and constituents (fluids, sediments) for proper characterization of tectonic

231

New method for abbreviating the fault tree graphical representation  

SciTech Connect

Fault tree analysis is being widely used for reliability and safety analysis of systems encountered in the nuclear industry and elsewhere. A disadvantage of the fault tree method is the voluminous fault tree graphical representation that conventionally results from analysis of a complex system. Previous methods for shortening the fault tree graphical representation include (1) transfers within the fault tree, and (2) the use of the SAMPLE (K out of N logic) gate, the MATRIX gate, and the SUMMATION gate. The purpose of this presentation is to introduce TABULATION gates as a method to abbreviate the fault tree graphical representation. These new gates reduce the cost of analysis and generally increase the system behavior visibility that is inherent in the fault tree technique. (auth)

Stewart, M.E.; Fussell, J.B.; Crump, R.J.

1974-12-01T23:59:59.000Z

232

Upper crustal faulting in an obliquely extending orogen, structural control  

Open Energy Info (EERE)

faulting in an obliquely extending orogen, structural control faulting in an obliquely extending orogen, structural control on permeability and production in the Coso Geothermal Field, eastern California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Upper crustal faulting in an obliquely extending orogen, structural control on permeability and production in the Coso Geothermal Field, eastern California Details Activities (1) Areas (1) Regions (0) Abstract: New multifold seismic reflection data from the Coso geothermal field in the central Coso Range, eastern California, image brittle faults and other structures in a zone of localized crustal extension between two major strike-slip faults. The Coso Wash fault, a Quaternary-active normal fault that is a locus of surface geothermal activity, is well-imaged as a

233

Methodology for designing the fuzzy resolver for a radial distribution system fault locator  

E-Print Network (OSTI)

The Power System Automation Lab at Texas A&M University developed a fault location scheme that can be used for radial distribution systems. When a fault occurs, the scheme executes three stages. In the first stage, all data measurements and system information is gathered and processed into suitable formats. In the second stage, three fault location methods are used to assign possibility values to each line section of a feeder. In the last stage, a fuzzy resolver is used to aggregate the outputs of the three fault location methods and assign a final possibility value to each line section of a feeder. By aggregating the outputs of the three fault location methods, the fuzzy resolver aims to obtain a smaller subset of line sections as potential faulted sections than the individual fault location methods. Fuzzy aggregation operators are used to implement fuzzy resolvers. This dissertation reports on a methodology that was developed utilizing fuzzy aggregation operators in the fuzzy resolver. Three fuzzy aggregation operators, the min, OWA, and uninorm, and two objective functions were used to design the fuzzy resolver. The methodologies to design fuzzy resolvers with respect to a single objective function and with respect to two objective functions were presented. A detailed illustration of the design process was presented. Performance studies of designed fuzzy resolvers were also performed. In order to design and validate the fuzzy resolver methodology, data were needed. Due to the lack of real field data, simulating a distribution feeder was a feasible alternative to generate data. The IEEE 34 node test feeder was modeled. Time current characteristics (TCC) based protective devices were added to this feeder. Faults were simulated on this feeder to generate data. Based on the performance studies of designed fuzzy resolvers, the fuzzy resolver designed using the uninorm operator without weights is the first choice. For this fuzzy resolver, no optimal weights are needed. In addition, fuzzy resolvers using the min operator and OWA operator can be used to design fuzzy resolvers. For these two operators, the methodology for designing fuzzy resolvers with respect to two objective functions was the appropriate choice.

Li, Jun

2005-12-01T23:59:59.000Z

234

Recovery Act: Online Nonintrusive Condition Monitoring and Fault Detection for Wind Turbines  

DOE Green Energy (OSTI)

The penetration of wind power has increased greatly over the last decade in the United States and across the world. The U.S. wind power industry installed 1,118 MW of new capacity in the first quarter of 2011 alone and entered the second quarter with another 5,600 MW under construction. By 2030, wind energy is expected to provide 20% of the U.S. electricity needs. As the number of wind turbines continues to grow, the need for effective condition monitoring and fault detection (CMFD) systems becomes increasingly important [3]. Online CMFD is an effective means of not only improving the reliability, capacity factor, and lifetime, but it also reduces the downtime, energy loss, and operation and maintenance (O&M) of wind turbines. The goal of this project is to develop novel online nonintrusive CMFD technologies for wind turbines. The proposed technologies use only the current measurements that have been used by the control and protection system of a wind turbine generator (WTG); no additional sensors or data acquisition devices are needed. Current signals are reliable and easily accessible from the ground without intruding on the wind turbine generators (WTGs) that are situated on high towers and installed in remote areas. Therefore, current-based CMFD techniques have great economic benefits and the potential to be adopted by the wind energy industry. Specifically, the following objectives and results have been achieved in this project: (1) Analyzed the effects of faults in a WTG on the generator currents of the WTG operating at variable rotating speed conditions from the perspective of amplitude and frequency modulations of the current measurements; (2) Developed effective amplitude and frequency demodulation methods for appropriate signal conditioning of the current measurements to improve the accuracy and reliability of wind turbine CMFD; (3) Developed a 1P-invariant power spectrum density (PSD) method for effective signature extraction of wind turbine faults with characteristic frequencies in the current or current demodulated signals, where 1P stands for the shaft rotating frequency of a WTG; (4) Developed a wavelet filter for effective signature extraction of wind turbine faults without characteristic frequencies in the current or current demodulated signals; (5) Developed an effective adaptive noise cancellation method as an alternative to the wavelet filter method for signature extraction of wind turbine faults without characteristic frequencies in the current or current demodulated signals; (6) Developed a statistical analysis-based impulse detection method for effective fault signature extraction and evaluation of WTGs based on the 1P-invariant PSD of the current or current demodulated signals; (7) Validated the proposed current-based wind turbine CMFD technologies through extensive computer simulations and experiments for small direct-drive WTGs without gearboxes; and (8) Showed, through extensive experiments for small direct-drive WTGs, that the performance of the proposed current-based wind turbine CMFD technologies is comparable to traditional vibration-based methods. The proposed technologies have been successfully applied for detection of major failures in blades, shafts, bearings, and generators of small direct-drive WTGs. The proposed technologies can be easily integrated into existing wind turbine control, protection, and monitoring systems and can be implemented remotely from the wind turbines being monitored. The proposed technologies provide an alternative to vibration-sensor-based CMFD. This will reduce the cost and hardware complexity of wind turbine CMFD systems. The proposed technologies can also be combined with vibration-sensor-based methods to improve the accuracy and reliability of wind turbine CMFD systems. When there are problems with sensors, the proposed technologies will ensure proper CMFD for the wind turbines, including their sensing systems. In conclusion, the proposed technologies offer an effective means to achieve condition-based smart maintenance for wind turbines and have a gre

Wei Qiao

2012-05-29T23:59:59.000Z

235

Final Technical Report Recovery Act: Online Nonintrusive Condition Monitoring and Fault Detection for Wind Turbines  

SciTech Connect

The penetration of wind power has increased greatly over the last decade in the United States and across the world. The U.S. wind power industry installed 1,118 MW of new capacity in the first quarter of 2011 alone and entered the second quarter with another 5,600 MW under construction. By 2030, wind energy is expected to provide 20% of the U.S. electricity needs. As the number of wind turbines continues to grow, the need for effective condition monitoring and fault detection (CMFD) systems becomes increasingly important [3]. Online CMFD is an effective means of not only improving the reliability, capacity factor, and lifetime, but it also reduces the downtime, energy loss, and operation and maintenance (O&M) of wind turbines. The goal of this project is to develop novel online nonintrusive CMFD technologies for wind turbines. The proposed technologies use only the current measurements that have been used by the control and protection system of a wind turbine generator (WTG); no additional sensors or data acquisition devices are needed. Current signals are reliable and easily accessible from the ground without intruding on the wind turbine generators (WTGs) that are situated on high towers and installed in remote areas. Therefore, current-based CMFD techniques have great economic benefits and the potential to be adopted by the wind energy industry. Specifically, the following objectives and results have been achieved in this project: (1) Analyzed the effects of faults in a WTG on the generator currents of the WTG operating at variable rotating speed conditions from the perspective of amplitude and frequency modulations of the current measurements; (2) Developed effective amplitude and frequency demodulation methods for appropriate signal conditioning of the current measurements to improve the accuracy and reliability of wind turbine CMFD; (3) Developed a 1P-invariant power spectrum density (PSD) method for effective signature extraction of wind turbine faults with characteristic frequencies in the current or current demodulated signals, where 1P stands for the shaft rotating frequency of a WTG; (4) Developed a wavelet filter for effective signature extraction of wind turbine faults without characteristic frequencies in the current or current demodulated signals; (5) Developed an effective adaptive noise cancellation method as an alternative to the wavelet filter method for signature extraction of wind turbine faults without characteristic frequencies in the current or current demodulated signals; (6) Developed a statistical analysis-based impulse detection method for effective fault signature extraction and evaluation of WTGs based on the 1P-invariant PSD of the current or current demodulated signals; (7) Validated the proposed current-based wind turbine CMFD technologies through extensive computer simulations and experiments for small direct-drive WTGs without gearboxes; and (8) Showed, through extensive experiments for small direct-drive WTGs, that the performance of the proposed current-based wind turbine CMFD technologies is comparable to traditional vibration-based methods. The proposed technologies have been successfully applied for detection of major failures in blades, shafts, bearings, and generators of small direct-drive WTGs. The proposed technologies can be easily integrated into existing wind turbine control, protection, and monitoring systems and can be implemented remotely from the wind turbines being monitored. The proposed technologies provide an alternative to vibration-sensor-based CMFD. This will reduce the cost and hardware complexity of wind turbine CMFD systems. The proposed technologies can also be combined with vibration-sensor-based methods to improve the accuracy and reliability of wind turbine CMFD systems. When there are problems with sensors, the proposed technologies will ensure proper CMFD for the wind turbines, including their sensing systems. In conclusion, the proposed technologies offer an effective means to achieve condition-based smart maintenance for wind turbines and have a gre

Wei Qiao

2012-05-29T23:59:59.000Z

236

Current Status  

NLE Websites -- All DOE Office Websites (Extended Search)

Current Status Current Status > Content on this page requires a newer version of Adobe Flash Player. Get Adobe Flash player July 31, 1942 The Army Corp of Engineers leases 1,025 acres of the Cook County Forest Preserve to build a research facility. November 1942 Under the direction of Enrico Fermi, a group of scientists at the University of Chicago begin building Chicago Pile-1 (CP-1). Security and secracy were essential. December 2, 1942 Enrico Fermi's team creates the world's first self-sustaining nuclear chain reaction using the CP-1 reactor under Stagg Field at the University of Chicago. CP-1 1943 The experiments under Stagg Field shut down, and the scientists move to a 19 acre section of the leased forest preserve, known as Site A. CP-1 is reconstructed and modified at Site A and renamed Chicago Pile 2 (CP-2).

237

Methods for Fault Detection, Diagnostics and Prognostics for Building Systems - A Review Part I  

Science Conference Proceedings (OSTI)

This paper provides an overview of fault detection, diagnostics, and prognostics (FDD&P) starting with descriptions of the fundamental processes and some important definitions. This is followed by a review of FDD&P research in the HVAC&R field, and the paper concludes with discussions of the current state of applications in buildings and likely contributions to operating and maintaining buildings in the future.

Katipamula, Srinivas; Brambley, Michael R.

2005-01-31T23:59:59.000Z

238

Methods for Fault Detection, Diagnostics and Prognostics for Building Systems - A Review Part II  

Science Conference Proceedings (OSTI)

This paper provides the second part of an overview of fault detection, diagnostics, and prognostics (FDD&P) starting with descriptions of the fundamental processes and some important definitions. This is followed by a review of FDD&P research in the HVAC&R field, and the paper concludes with discussions of the current state of applications in buildings and likely contributions to operating and maintaining buildings in the future.

Katipamula, Srinivas; Brambley, Michael R.

2005-04-01T23:59:59.000Z

239

Undulator Hall Air Temperature Fault Scenarios  

SciTech Connect

Recent experience indicates that the LCLS undulator segments must not, at any time following tuning, be allowed to change temperature by more than about {+-}2.5 C or the magnetic center will irreversibly shift outside of acceptable tolerances. This vulnerability raises a concern that under fault conditions the ambient temperature in the Undulator Hall might go outside of the safe range and potentially could require removal and retuning of all the segments. In this note we estimate changes that can be expected in the Undulator Hall air temperature for three fault scenarios: (1) System-wide power failure; (2) Heating Ventilation and Air Conditioning (HVAC) system shutdown; and (3) HVAC system temperature regulation fault. We find that for either a system-wide power failure or an HVAC system shutdown (with the technical equipment left on), the short-term temperature changes of the air would be modest due to the ability of the walls and floor to act as a heat ballast. No action would be needed to protect the undulator system in the event of a system-wide power failure. Some action to adjust the heat balance, in the case of the HVAC power failure with the equipment left on, might be desirable but is not required. On the other hand, a temperature regulation failure of the HVAC system can quickly cause large excursions in air temperature and prompt action would be required to avoid damage to the undulator system.

Sevilla, J.

2010-11-17T23:59:59.000Z

240

Research on Fault Diagnosis on High Voltage SF6 Circuit Breaker Based on the Db Wavelet and Fuzzy Theory  

Science Conference Proceedings (OSTI)

This dissertation aims at providing a quick and accurate fault diagnosis method for on high voltage SF6circuit breaker. This method indirectly monitors the functioning of the breaker by observing the electric current in the coil of its switch. The electrical ... Keywords: SF6 circuit breaker, monitor, wavelet transform, fuzzy theory

Li Yang; Zhuo Yang; Yang Lei; Kejie Dai; Weiming Guan

2012-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Calculating the probability of injected carbon dioxide plumes encountering faults  

Science Conference Proceedings (OSTI)

One of the main concerns of storage in saline aquifers is leakage via faults. In the early stages of site selection, site-specific fault coverages are often not available for these aquifers. This necessitates a method using available fault data to estimate the probability of injected carbon dioxide encountering and migrating up a fault. The probability of encounter can be calculated from areal fault density statistics from available data, and carbon dioxide plume dimensions from numerical simulation. Given a number of assumptions, the dimension of the plume perpendicular to a fault times the areal density of faults with offsets greater than some threshold of interest provides probability of the plume encountering such a fault. Application of this result to a previously planned large-scale pilot injection in the southern portion of the San Joaquin Basin yielded a 3% and 7% chance of the plume encountering a fully and half seal offsetting fault, respectively. Subsequently available data indicated a half seal-offsetting fault at a distance from the injection well that implied a 20% probability of encounter for a plume sufficiently large to reach it.

Jordan, P.D.

2011-04-01T23:59:59.000Z

242

Application of Support Vector Machine (SVM) and Proximal Support Vector Machine (PSVM) for fault classification of monoblock centrifugal pump  

Science Conference Proceedings (OSTI)

Monoblock centrifugal pumps are widely used in a variety of applications. Defects and malfunctions (faults) of these pumps result in significant economic loss. Therefore, the pumps must be under constant monitoring. When a possible fault is detected, ... Keywords: CAV, PSVM, bearing faults, cavitation, decision trees, fault classification, fault diagnosis, impeller faults, monoblock centrifugal pumps, proximal SVM, seal faults, support vector machines, vibration signals

N. R. Sakthivel; V. Sugumaran; Binoy B. Nair

2010-12-01T23:59:59.000Z

243

Energy Currents  

NLE Websites -- All DOE Office Websites (Extended Search)

7 7 Energy Currents Survey Result Our thanks to all of you who responded to our reader survey. We were pleased that many of you find this a useful publication. Your opinions will help us improve it further. The CBS News' readers include a variety of professions. 17% of respondents were consultants, 15% were engineers, 11% were teachers, 11% were scientists, 10% were program managers. The remainder included contractors, designers, marketing professionals policy analysts, journalists and others. Ranked according to highest response first, the majority of readers work in education, various levels of government, utilities, non-profit organizations, and a variety of private concerns. A surprisingly large number, 52% of the respondents, are Internet users and 23% have browsed the World Wide Web. 8% have browsed the Center's Web site

244

Energy Currents  

NLE Websites -- All DOE Office Websites (Extended Search)

1 1 Energy Currents LBL Scientist Joins Clinton Administration Art Rosenfeld Art Rosenfeld, former head of LBL's Center for Building Science, has been named a senior advisor in the U.S. Department of Energy, serving under Assistant Secretary for Energy Efficiency and Renewable Energy Christine Ervin. His appointment began July 1. In Washington, Rosenfeld will sit on President Clinton's National Science and Technology Council. He will also serve as national spokesperson for the Administration's "Cool Communities" program and will help steer through the political process a proposed new "government-sponsored enterprise"- called EFFIE MAE for Energy Efficiency Mortgage and Loan Agency-that would guarantee loans for retrofitting energy-inefficient public buildings.

245

Type E: Extensional Tectonic, Fault-Controlled Resource | Open Energy  

Open Energy Info (EERE)

Type E: Extensional Tectonic, Fault-Controlled Resource Type E: Extensional Tectonic, Fault-Controlled Resource Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Print PDF Type E: Extensional Tectonic, Fault-Controlled Resource Dictionary.png Type E: Extensional Tectonic, Fault-Controlled Resource: No definition has been provided for this term. Add a Definition Brophy Occurrence Models This classification scheme was developed by Brophy, as reported in Updating the Classification of Geothermal Resources.[1] Type A: Magma-heated, Dry Steam Resource Type B: Andesitic Volcanic Resource Type C: Caldera Resource Type D: Sedimentary-hosted, Volcanic-related Resource Type E: Extensional Tectonic, Fault-Controlled Resource Type F: Oceanic-ridge, Basaltic Resource Extensional-tectonic, fault-controlled resources typically result from a

246

Fault Mapping At Raft River Geothermal Area (1993) | Open Energy  

Open Energy Info (EERE)

Fault Mapping At Raft River Geothermal Area (1993) Fault Mapping At Raft River Geothermal Area (1993) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Fault Mapping At Raft River Geothermal Area (1993) Exploration Activity Details Location Raft River Geothermal Area Exploration Technique Fault Mapping Activity Date 1993 Usefulness useful DOE-funding Unknown Exploration Basis Geologic mapping, strain and kinematic analysis Notes The mountains expose a detachment fault that separates a hanging wall of Paleozoic rocks from Proterozoic and Archean rocks of the footwall. Beneath the detachment lies a 100 to 300m-thick top-to-the-east extensional shear zone. Geologic mapping, strain and kinematic analysis, and 40Ar/39Ar thermochronology suggest that the shear zone and detachment fault had an

247

Scalable distributed consensus to support MPI fault tolerance.  

Science Conference Proceedings (OSTI)

As system sizes increase, the amount of time in which an application can run without experiencing a failure decreases. Exascale applications will need to address fault tolerance. In order to support algorithm-based fault tolerance, communication libraries will need to provide fault-tolerance features to the application. One important fault-tolerance operation is distributed consensus. This is used, for example, to collectively decide on a set of failed processes. This paper describes a scalable, distributed consensus algorithm that is used to support new MPI fault-tolerance features proposed by the MPI 3 Forum's fault-tolerance working group. The algorithm was implemented and evaluated on a 4,096-core Blue Gene/P. The implementation was able to perform a full-scale distributed consensus in 305 {mu}s and scaled logarithmically.

Buntinas, D. (Mathematics and Computer Science)

2011-01-01T23:59:59.000Z

248

Similarity Matching Techniques for Fault Diagnosis in Automotive Infotainment Electronics  

E-Print Network (OSTI)

Fault diagnosis has become a very important area of research during the last decade due to the advancement of mechanical and electrical systems in industries. The automobile is a crucial field where fault diagnosis is given a special attention. Due to the increasing complexity and newly added features in vehicles, a comprehensive study has to be performed in order to achieve an appropriate diagnosis model. A diagnosis system is capable of identifying the faults of a system by investigating the observable effects (or symptoms). The system categorizes the fault into a diagnosis class and identifies a probable cause based on the supplied fault symptoms. Fault categorization and identification are done using similarity matching techniques. The development of diagnosis classes is done by making use of previous experience, knowledge or information within an application area. The necessary information used may come from several sources of knowledge, such as from system analysis. In this paper similarity matching tec...

Kabir, Mashud

2009-01-01T23:59:59.000Z

249

Active Faulting in the Coso Geothermal Field, Eastern California | Open  

Open Energy Info (EERE)

Faulting in the Coso Geothermal Field, Eastern California Faulting in the Coso Geothermal Field, Eastern California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Active Faulting in the Coso Geothermal Field, Eastern California Details Activities (1) Areas (1) Regions (0) Abstract: New mapping documents a series of late Quaternary NNE-striking normal faults in the central Coso Range that dip northwest, toward and into the main production area of the Coso geothermal field. The faults exhibit geomorphic features characteristic of Holocene activity, and locally are associated with fumaroles and hydothermal alteration. The active faults sole into or terminate against the brittle-ductile transition zone (BDT) at a depth of about 4 to 5 km. The BDT is arched upward over a volume of crust

250

Ionization tube simmer current circuit  

DOE Patents (OSTI)

A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

Steinkraus, Jr., Robert F. (Livermore, CA)

1994-01-01T23:59:59.000Z

251

Ionization tube simmer current circuit  

DOE Patents (OSTI)

A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

Steinkraus, R.F. Jr.

1994-12-13T23:59:59.000Z

252

Enhancing and Testing Fast Fault Screening (FFS) Methodology  

Science Conference Proceedings (OSTI)

The aim of this multi-year study is to develop a methodology for fast prediction of the most severe three-phase fault locations for transient stability studies and rank them in order of severity. The methodology is called Fast Fault Screening (FFS).  The key advantage of the FFS is the ability to quickly scan through thousands of potential fault locations from transient stability perspective and identify the most severe locations. In the previous efforts, FFS was developed for angular ...

2012-12-31T23:59:59.000Z

253

Timer-based composition of fault-containing self-stabilizing protocols  

Science Conference Proceedings (OSTI)

One of the desired properties of distributed systems is self-adaptability against faults. Self-stabilizing protocols provide autonomous recovery from any finite number of transient faults. However, in practice, catastrophic faults rarely occur, while ... Keywords: Distributed system, Fault tolerance, Fault-containment, Hierarchical composition, Self-adaptability, Self-stabilization, Synchronizer, Timer

Yukiko Yamauchi; Sayaka Kamei; Fukuhito Ooshita; Yoshiaki Katayama; Hirotsugu Kakugawa; Toshimitsu Masuzawa

2010-05-01T23:59:59.000Z

254

Historic Surface Faulting and Paleoseismicity in the Area of...  

Open Energy Info (EERE)

Historic Surface Faulting and Paleoseismicity in the Area of the 1954 Rainbow Mountain-Stillwater Earthquake Sequence, Central Nevada Jump to: navigation, search OpenEI Reference...

255

Upper crustal faulting in an obliquely extending orogen, structural...  

Open Energy Info (EERE)

faulting in an obliquely extending orogen, structural control on permeability and production in the Coso Geothermal Field, eastern California Jump to: navigation, search...

256

Dynamic analysis and fault diagnosis of a water hydraulic motor.  

E-Print Network (OSTI)

??This research is concerned with condition monitoring and fault diagnosis of the piston of the water hydraulic motor by vibration signal analysis. Vibration signatures are… (more)

Chen, Hanxin.

2008-01-01T23:59:59.000Z

257

MICRO-SEISMICITY, FAULT STRUCTURE AND HYDRAULIC COMPARTMENTALIZATION...  

Open Energy Info (EERE)

MICRO-SEISMICITY, FAULT STRUCTURE AND HYDRAULIC COMPARTMENTALIZATION WITHIN THE COSO GETHERMAL FIELD, CALIFORNIA Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home...

258

Thermal Waters Along The Konocti Bay Fault Zone, Lake County...  

Open Energy Info (EERE)

Thermal Waters Along The Konocti Bay Fault Zone, Lake County, California- A Re-Evaluation Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Thermal...

259

Fault Detection and Diagnosis in Building HVAC Systems  

E-Print Network (OSTI)

diagnostic method for vapor compression air conditioners”,evaluation of faults in vapor compression cycle equipment”,Diagnostic Methods to Vapor Compression Cooling Equipment“,

Najafi, Massieh

2010-01-01T23:59:59.000Z

260

Intersecting Fault Trends and Crustal-Scale Fluid Pathways Below...  

Open Energy Info (EERE)

Intersecting Fault Trends and Crustal-Scale Fluid Pathways Below the Dixie Valley Geothermal Area, Nevada, Inferred from 3d Magnetotelluric Surveying Jump to: navigation, search...

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

CiFTS : Coordinated Infrastructure for Fault Tolerant Systems  

NLE Websites -- All DOE Office Websites (Extended Search)

Demos Team News Contact Us Coordinated and Improved Fault Tolerance for High Performance Computing Systems In the next few years SciDAC applications will utilize exascale...

262

Cryptic Faulting and Multi-Scale Geothermal Fluid Connections...  

Open Energy Info (EERE)

Cryptic Faulting and Multi-Scale Geothermal Fluid Connections in the Dixie Valley-Central Nevada Seismic Belt Area- Implications from Mt Resistivity Surveying Jump to: navigation,...

263

Recency Of Faulting And Neotechtonic Framework In The Dixie Valley...  

Open Energy Info (EERE)

Recency Of Faulting And Neotechtonic Framework In The Dixie Valley Geothermal Field And Other Geothermal Fields Of The Basin And Range Jump to: navigation, search GEOTHERMAL...

264

Recurrent faulting and petroleum accumulation, Cat Creek Anticline, central Montana  

SciTech Connect

The Cat Creek anticline, scene of central Montana's first significant oil discovery, is underlain by a south-dipping high-angle fault (Cat Creek fault) that has undergone several episodes of movement with opposite sense of displacement. Borehole data suggest that the Cat Creek fault originated as a normal fault during Proterozoic rifting concurrent with deposition of the Belt Supergroup. Reverse faulting took place in Late Cambrian time, and again near the end of the Devonian Period. The Devonian episode, coeval with the Antler orogeny, raised the southern block several hundred feet. The southern block remained high through Meramecian time, then began to subside. Post-Atokan, pre-Middle Jurassic normal faulting lowered the southern block as much as 1,500 ft. During the Laramide orogeny (latest Cretaceous-Eocene) the Cat Creek fault underwent as much as 4,000 ft of reverse displacement and a comparable amount of left-lateral displacement. The Cat Creek anticline is a fault-propagation fold; en echelon domes and listric normal faults developed along its crest in response to wrenching. Oil was generated mainly in organic-rich shales of the Heath Formation (upper Chesterian Series) and migrated upward along tectonic fractures into Pennsylvanian, Jurassic, and Cretaceous reservoir rocks in structural traps in en echelon domes. Production has been achieved only from those domes where structural closure was retained from Jurassic through Holocene time.

Nelson, W.J. (Illinois State Geological Survey, Champaign (United States))

1991-06-01T23:59:59.000Z

265

Recent earthquake sequences at Coso: Evidence for conjugate faulting...  

Open Energy Info (EERE)

Recent earthquake sequences at Coso: Evidence for conjugate faulting and stress loading near a geothermal field Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal...

266

Fault Prediction and Fault-Tolerant of Lithium-ion Batteries Temperature Failure for Electric Vehicle  

Science Conference Proceedings (OSTI)

Design and implementation of dual-redundancy was developed to predict Lithium-ion battery failure for electric vehicle. Data fusion unit, prediction unit and determination unit were designed. Outputs from original and redundant sensors were integrated ... Keywords: Lithium-ion battery, dual-redundancy, data fusion, prediction, Fault-tolerant

Hu Chunhua; He Ren; Wang Runcai; Yu Jianbo

2012-07-01T23:59:59.000Z

267

Prototyping a fault-tolerant multiprocessor SoC with run-time fault recovery  

Science Conference Proceedings (OSTI)

Modern integrated circuits (ICs) are becoming increasingly complex. The complexity makes it difficult to design, manufacture and integrate these high performance ICs. The advent of multiprocessor Systems-on-chips (SoCs) makes it even more challenging ... Keywords: fault-tolerance, multiprocessor system, network-on-chip, retargetable simulation, run-time verification, system-on-chip

Xinping Zhu; Wei Qin

2006-07-01T23:59:59.000Z

268

Detector limitations, STAR  

Science Conference Proceedings (OSTI)

Every detector has limitations in terms of solid angle, particular technologies chosen, cracks due to mechanical structure, etc. If all of the presently planned parts of STAR [Solenoidal Tracker At RHIC] were in place, these factors would not seriously limit our ability to exploit the spin physics possible in RHIC. What is of greater concern at the moment is the construction schedule for components such as the Electromagnetic Calorimeters, and the limited funding for various levels of triggers.

Underwood, D. G.

1998-07-13T23:59:59.000Z

269

Structural geology of Shawneetown fault zone, Southeastern Illinois  

SciTech Connect

Vertical movements of crustal blocks along the narrow east-west-trending Shawneetown fault zone in southeastern Illinois occurred between Early Permian and Late Cretaceous. The main blocks moved vertically and retured to roughly their orignal positions so that strata now show little relative offset across the fault zone. However, individual faults with displacements up to 3,500 ft (1,070 m) bound narrow slices of steeply tilted or overturned strata resulting in a juxtaposition of Kinderhookian (Lower Mississippian) and Upper Devonian strata with Lower Pennsylvanina strata. The bedrock is intensely fractured, commonly brecciated, and cemented with either silica or calcite. Slickensides and mullion display various orientations within the zone and on individual outcrops. The dominant movement, however, appears to be vertical with no evidence for significant strike-slip movements. Pleistocene deposits do not exhibit offsets across the fault zone, indicating that no tectonic activity has occurred since the beginning of that epoch. The trend of the fault zone changes abruptly from east-west in southern Gallatin and easternmost Saline Counties to south-southwest in southern Saline and northeastern Pope Counties, where it joins the Fluorspar area fault complex. Here the zone widens and develops a braided pattern as the amount of displacement along individual faults decreases. The Shawneetown fault zone and Flourspar area fault complex in part are younger than the Cottage Grove fault system to the northwest and the Wabash Valley fault system to the north. The hope of finding structural traps near the junctions of the fuel systems has spurred recent oil exploration in the area.

Lumm, D.K.; Nelson, W.J.

1983-09-01T23:59:59.000Z

270

Automating Power System Fault Diagnosis through Multi-Agent System Technology  

Science Conference Proceedings (OSTI)

Fault diagnosis within electrical power systems is a time consuming and complex task. SCADA systems, digital fault recorders, travelling wave fault locators and other monitoring devices are drawn upon to inform the engineers of incidents, problems and ...

S. D. J. McArthur; E. M. Davidson; J. A. Hossack; J. R. McDonald

2004-01-01T23:59:59.000Z

271

Feng shui of supercomputer memory: positional effects in DRAM and SRAM faults  

Science Conference Proceedings (OSTI)

Several recent publications confirm that faults are common in high-performance computing systems. Therefore, further attention to the faults experienced by such computing systems is warranted. In this paper, we present a study of DRAM and SRAM faults ...

Vilas Sridharan, Jon Stearley, Nathan DeBardeleben, Sean Blanchard, Sudhanva Gurumurthi

2013-11-01T23:59:59.000Z

272

Limited discrepancy search revisited  

Science Conference Proceedings (OSTI)

Harvey and Ginsberg's limited discrepancy search (LDS) is based on the assumption that costly heuristic mistakes are made early in the search process. Consequently, LDS repeatedly probes the state space, going against the heuristic (i.e., taking discrepancies) ... Keywords: Heuristic mistakes, limited discrepancy search, performance improvement

Patrick Prosser; Chris Unsworth

2011-05-01T23:59:59.000Z

273

Limited Warranty Research In Motion Limited (“RIM”), the ...  

Science Conference Proceedings (OSTI)

... Handheld Limited Warranty (Jordan) 072406 (English) (UK Version 082504) 1 Page 2. Handheld Limited Warranty (Jordan ...

2012-11-15T23:59:59.000Z

274

First step towards automatic correction of firewall policy faults  

Science Conference Proceedings (OSTI)

Firewalls are critical components of network security and have been widely deployed for protecting private networks. A firewall determines whether to accept or discard a packet that passes through it based on its policy. However, most real-life firewalls ... Keywords: Automatic fault fixing, firewall faults, firewall policy

Fei Chen; Alex X. Liu; Jeehyun Hwang; Tao Xie

2012-07-01T23:59:59.000Z

275

Fault Diagnosis of Transformer Based on Random Forest  

Science Conference Proceedings (OSTI)

Fault diagnosis of transformer in power system is studied in this paper. Considering the excellent performances of Random Forest (RF) in pattern recognition, we apply RF to construct a diagnosis model to predict the situation of transformer. The experiments ... Keywords: Rondom Forest, fault diagnosis of transformer, classification model

Xi Chen; Hongmei Cui; Linkai Luo

2011-03-01T23:59:59.000Z

276

ANFIS based sensor fault detection for continuous stirred tank reactor  

Science Conference Proceedings (OSTI)

In this paper, an Adaptive Neuro-Fuzzy Inference System (ANFIS) based Sensor fault detection and isolation for Continuous Stirred Tank Reactor (CSTR) is proposed. CSTR is a highly nonlinear process exhibiting stable and unstable steady state at different ... Keywords: ANFIS observer, Continuous stirred tank reactor, Dedicated observer, Fault detection

U. Sabura Banu; G. Uma

2011-03-01T23:59:59.000Z

277

Increasing fault-tolerance in cellular automata-based systems  

Science Conference Proceedings (OSTI)

In the light of emergence of cellular computing, new cellular computing systems based on yet-unknown methods of fabrication need to address the problem of fault tolerance in a way which is not tightly connected to used technology. This may not be possible ... Keywords: Byl's loop, Game of Life, TMR, cellular automata, cellular computing, fault tolerance, rule 30, static module redundance

Lud?k Žaloudek; Lukáš Sekanina

2011-06-01T23:59:59.000Z

278

Symbolic identification for fault detection in aircraft gas turbine engines  

E-Print Network (OSTI)

Symbolic identification for fault detection in aircraft gas turbine engines S Chakraborty, S Sarkar and computationally inexpensive technique of component-level fault detection in aircraft gas-turbine engines identification, gas turbine engines, language-theoretic analysis 1 INTRODUCTION The propulsion system of modern

Ray, Asok

279

CUDA accelerated fault tree analysis with C-XSC  

Science Conference Proceedings (OSTI)

Fault tree analysis is a widespread mathematical method for determining the failure probability of observed real-life systems. In addition to failure probability defined by wear, the system model has to take into account intrinsic and extrinsic system ... Keywords: C-XSC, CUDA, DSI, fault tree analysis

Gabor Rebner; Michael Beer

2012-09-01T23:59:59.000Z

280

GPS satellite oscillator faults mimicking ionospheric phase scintillation  

Science Conference Proceedings (OSTI)

It is possible for unreported Global Positioning System satellite faults to cause phase variations mimicking the effect of ionospheric scintillation. A case study of an event on 17 May, 2011 is presented. For approximately 695 s, the L1 signal from the ... Keywords: Anomaly, Fault, Navstar 43, PRN 13, Scintillation, Sigma-phi

Christopher J. Benton; Cathryn N. Mitchell

2012-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Towards Robustness in Neural Network Based Fault Diagnosis  

Science Conference Proceedings (OSTI)

Challenging design problems arise regularly in modern fault diagnosis systems. Unfortunately, classical analytical techniques often cannot provide acceptable solutions to such difficult tasks. This explains why soft computing techniques such as neural ... Keywords: Dynamic Neural Network, Fault Diagnosis, Gmdh Neural Network, Robustness

Krzysztof Patan; Marcin Witczak; JóZef Korbicz

2008-12-01T23:59:59.000Z

282

Fault detection in multivariate signals with applications to gas turbines  

Science Conference Proceedings (OSTI)

This paper proposes a fault detection method for multivariate signals. The method assesses whether or not the multivariate autocovariance functions of two independently sampled system signals coincide. If the first signal is known to be sampled from ... Keywords: autocovariances, fault detection, spectral analysis, stationary time series

Hany Bassily; Robert Lund; John Wagner

2009-03-01T23:59:59.000Z

283

COMPLETE FAULT ANALYSIS FOR LONG TRANSMISSION LINE USING  

E-Print Network (OSTI)

Plants and Power Systems Control, Kananaskis, Canada, 2006 #12;Area Measurement System (WAMS) and Phasor variables. Methods based on traveling waves and recently based on fault- generated high-frequency transients of the fault location. This method will be more attractive when the concept of Wide IFAC Symposium on Power

284

Online Fault Detection and Tolerance for Photovoltaic Energy Harvesting Systems  

E-Print Network (OSTI)

Online Fault Detection and Tolerance for Photovoltaic Energy Harvesting Systems Xue Lin 1 , Yanzhi, yanzhiwa, dizhu, pedram}@usc.edu, 2 naehyuck@elpl.snu.ac.kr ABSTRACT Photovoltaic energy harvesting systems (PV systems) are subject to PV cell faults, which decrease the efficiency of PV systems and even

Pedram, Massoud

285

Soft computing approach to fault diagnosis of centrifugal pump  

Science Conference Proceedings (OSTI)

Fault detection and isolation in rotating machinery is very important from an industrial viewpoint as it can help in maintenance activities and significantly reduce the down-time of the machine, resulting in major cost savings. Traditional methods have ... Keywords: Centrifugal pump, Decision tree algorithm, Fault diagnosis, Gene expression programming, Proximal support vector machine, Statistical features, Support vector machine

N. R. Sakthivel; Binoy.B.Nair; V. Sugumaran

2012-05-01T23:59:59.000Z

286

Effects of unbalanced faults on transient stability of cogeneration system  

Science Conference Proceedings (OSTI)

This paper evaluates the effects of unbalanced faults on the transient stability of a real cogeneration plant. First, a brief is given for the structure of the cogeneration system. Use of the electromagnetic transient program (EMTP) constructs the cogeneration ... Keywords: CCT curve, EMTP, cogeneration plant, transient stability, unbalanced faults

Wei-Neng Chang; Chia-Han Hsu

2011-10-01T23:59:59.000Z

287

Research on Fault Location of Power Cable with Wavelet Analysis  

Science Conference Proceedings (OSTI)

This article researChes for 10kV transmission cable form the ground substation to the underground central substation in the coal mine. The transient traveLing wave signal of the cable fault is disposed by the wavelet transformation based on the cable ... Keywords: Wavelet analysis, Fault Location, TraveLing wave

Ji-meng Zhang; Shuo Liang

2011-08-01T23:59:59.000Z

288

Dating of major normal fault systems using thermochronology- An example  

Open Energy Info (EERE)

Dating of major normal fault systems using thermochronology- An example Dating of major normal fault systems using thermochronology- An example from the Raft River detachment, Basin and Range, western United States Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Dating of major normal fault systems using thermochronology- An example from the Raft River detachment, Basin and Range, western United States Details Activities (1) Areas (1) Regions (0) Abstract: Application of thermochronological techniques to major normal fault systems can resolve the timing of initiation and duration of extension, rates of motion on detachment faults, timing of ductile mylonite formation and passage of rocks through the crystal-plastic to brittle transition, and multiple events of extensional unroofing. Here we determine

289

Recent earthquake sequences at Coso: Evidence for conjugate faulting and  

Open Energy Info (EERE)

earthquake sequences at Coso: Evidence for conjugate faulting and earthquake sequences at Coso: Evidence for conjugate faulting and stress loading near a geothermal field Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Recent earthquake sequences at Coso: Evidence for conjugate faulting and stress loading near a geothermal field Details Activities (1) Areas (1) Regions (0) Abstract: Two recent earthquake sequences near the Coso geothermal field show clear evidence of faulting along conjugate planes. We present results from analyzing an earthquake sequence occurring in 1998 and compare it with a similar sequence that occurred in 1996. The two sequences followed mainshocks that occurred on 27 November 1996 and 6 March 1998. Both mainshocks ruptured approximately colocated regions of the same fault

290

Definition: Apex or Salient of Normal Fault | Open Energy Information  

Open Energy Info (EERE)

Definition Definition Edit with form History Facebook icon Twitter icon » Definition: Apex or Salient of Normal Fault Jump to: navigation, search Dictionary.png Apex or Salient of Normal Fault Normal faults may intersect in the subsurface to form a fault apex or salient. Apices or salients of normal faults account for 3% of structural controls in the Great Basin.[2] View on Wikipedia Wikipedia Definition References ↑ James E. Faulds,Nicholas H. Hinz,Mark F. Coolbaugh,Patricia H. Cashman,Christopher Kratt,Gregory Dering,Joel Edwards,Brett Mayhew,Holly McLachlan. 2011. Assessment of Favorable Structural Settings of Geothermal Systems in the Great Basin, Western USA. In: Transactions. GRC Anual Meeting; 2011/10/23; San Diego, CA. Davis, CA: Geothermal Resources Council; p. 777-783

291

Probability Estimation of CO2 Leakage Through Faults at Geologic Carbon Sequestration Sites  

E-Print Network (OSTI)

for Geologic Carbon Sequestration Based on EffectiveFaults at Geologic Carbon Sequestration Sites Yingqi Zhang*,faults at geologic carbon sequestration (GCS) sites is a

Zhang, Yingqi

2009-01-01T23:59:59.000Z

292

Fault Analysis at a Wind Power Plant for One Year of Observation: Preprint  

DOE Green Energy (OSTI)

This paper analyzes the fault characteristics observed at a wind power plant, and the behavior of the wind power plant under fault events.

Muljadi, E.; Mills, Z.; Foster, R.; Conto, J.; Ellis, A.

2008-07-01T23:59:59.000Z

293

CONTROL LIMITER DEVICE  

DOE Patents (OSTI)

A control-limiting device for monltoring a control system is described. The system comprises a conditionsensing device, a condition-varying device exerting a control over the condition, and a control means to actuate the condition-varying device. A control-limiting device integrates the total movement or other change of the condition-varying device over any interval of time during a continuum of overlapping periods of time, and if the tothl movement or change of the condition-varying device exceeds a preset value, the control- limiting device will switch the control of the operated apparatus from automatic to manual control.

DeShong, J.A.

1960-03-01T23:59:59.000Z

294

Feb. 11, 2008 Advanced Fault Tolerance Solutions for High Performance Computing 1/47 Advanced Fault Tolerance Solutions  

E-Print Network (OSTI)

Feb. 11, 2008 Advanced Fault Tolerance Solutions for High Performance Computing 1/47 RAS RAS Advanced Fault Tolerance Solutions for High Performance Computing Christian Engelmann Oak Ridge National Solutions for High Performance Computing 2/47 · Nation's largest energy laboratory · Nation's largest

Engelmann, Christian

295

Fault tolerant hypercube computer system architecture  

SciTech Connect

This patent describes a fault-tolerant multi-processor computer system of the hypercube type. It comprises: a plurality of first computing nodes; a first network of message conducting path means for interconnecting the first computing nodes as a hypercube. The first network providing a path for message transfer between the first computing nodes; a first watch dog node; and, a second network of message conducting path means for directly connecting each of the first computing nodes to the first watch dog node independent from the first network. The second network providing an independent path for test message and reconfiguration affecting transfers between respective ones of the first computing nodes and the first watch dog node.

Madan, H.S.; Chow, E.

1989-09-19T23:59:59.000Z

296

Wavelet analysis for gas turbine fault diagnostics  

SciTech Connect

The application of wavelet analysis to diagnosing faults in gas turbines is examined in the present paper. Applying the wavelet transform to time signals obtained from sensors placed on an engine gives information in correspondence to their Fourier transform. Diagnostic techniques based on Fourier analysis of signals can therefore be transposed to the wavelet analysis. In the paper the basic properties of wavelets, in relation to the nature of turbomachinery signals, are discussed. The possibilities for extracting diagnostic information by means of wavelets are examined, by studying the applicability to existing data from vibration, unsteady pressure, and acoustic measurements. Advantages offered, with respect to existing methods based on harmonic analysis, are discussed as well as particular requirements related to practical application.

Aretakis, N.; Mathioudakis, K. [National Technical Univ. of Athens (Greece). Lab. of Thermal Turbomachines

1997-10-01T23:59:59.000Z

297

Development of Characterization Technology for Fault Zone Hydrology  

SciTech Connect

Several deep trenches were cut, and a number of geophysical surveys were conducted across the Wildcat Fault in the hills east of Berkeley, California. The Wildcat Fault is believed to be a strike-slip fault and a member of the Hayward Fault System, with over 10 km of displacement. So far, three boreholes of ~;; 150m deep have been core-drilled and borehole geophysical logs were conducted. The rocks are extensively sheared and fractured; gouges were observed at several depths and a thick cataclasitic zone was also observed. While confirming some earlier, published conclusions from shallow observations about Wildcat, some unexpected findings were encountered. Preliminary analysis indicates that Wildcat near the field site consists of multiple faults. The hydraulic test data suggest the dual properties of the hydrologic structure of the fault zone. A fourth borehole is planned to penetrate the main fault believed to lie in-between the holes. The main philosophy behind our approach for the hydrologic characterization of such a complex fractured system is to let the system take its own average and monitor a long term behavior instead of collecting a multitude of data at small length and time scales, or at a discrete fracture scale and to ?up-scale,? which is extremely tenuous.

Karasaki, Kenzi; Onishi, Tiemi; Gasperikova, Erika; Goto, Junichi; Tsuchi, Hiroyuki; Miwa, Tadashi; Ueta, Keiichi; Kiho, Kenzo; MIyakawa, Kimio

2010-08-06T23:59:59.000Z

298

Operational Ocean Search and Rescue Using AVHRR: Cloud Limitations  

Science Conference Proceedings (OSTI)

Sea surface currents can be derived from sequential Advanced Very High Resolution Radiometer (AVHRR) images. However, the operational feasibility of deriving ocean surface currents from AVHRR is severely limited by the inability of AVHRR to ...

J. E. Dick O’Donnell

1999-03-01T23:59:59.000Z

299

Security Clearances; Limitations  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

SEC. 1072. SECURITY CLEARANCES; LIMITATIONS. SEC. 1072. SECURITY CLEARANCES; LIMITATIONS. (a) In General.-Title III of the Intelligence Reform and Terrorism Prevention Act of 2004 (50 U.S.C. 435b) is amended by adding at the end the following new section: "SEC. 3002. SECURITY CLEARANCES; LIMITATIONS. "(a) Definitions.-In this section: "(1) Controlled substance.-The term `controlled substance' has the meaning given that term in section 102 of the Controlled Substances Act (21 U.S.C. 802). "(2) Covered person.-The term `covered person' means- "(A) an officer or employee of a Federal agency; "(B) a member of the Army, Navy, Air Force, or Marine Corps who is on active duty or is in an active status; and "(C) an officer or employee of a contractor of a Federal agency.

300

MICRO-SEISMICITY, FAULT STRUCTURE AND HYDRAULIC COMPARTMENTALIZATION WITHIN  

Open Energy Info (EERE)

MICRO-SEISMICITY, FAULT STRUCTURE AND HYDRAULIC COMPARTMENTALIZATION WITHIN MICRO-SEISMICITY, FAULT STRUCTURE AND HYDRAULIC COMPARTMENTALIZATION WITHIN THE COSO GETHERMAL FIELD, CALIFORNIA Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: MICRO-SEISMICITY, FAULT STRUCTURE AND HYDRAULIC COMPARTMENTALIZATION WITHIN THE COSO GETHERMAL FIELD, CALIFORNIA Details Activities (1) Areas (1) Regions (0) Abstract: High precision earthquake locations and subsurface velocity structure provide potential insights into fracture system geometry, fluid conduits and fluid compartmentalization critical to geothermal reservoir management. We analyze 16 years of seismicity to improve hypocentral locations and simultaneously invert for the seismic velocity structure within the Coso Geothermal Field (CGF). The CGF has been continuously

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

A core-based assessment of the spatial relationship of small faults associated with a basement-controlled, large normal fault in the Hickory Sandstone  

E-Print Network (OSTI)

This research characterized a system of small faults (displacement < 0.3 m) in seven closely-spaced continuous 2.4 inch (6.1 cm) diameter cores. Cores were obtained from central Texas, on the western edge of the Llano Uplift. Cores penetrate a dip-slip dominant, normal fault (Nobles Fault) with 18.3 m (60 ft) of stratigraphic throw. The spatial, geometric and kinematic attributes of small faults within the Nobles Fault system were characterized to explore potential cause-and-effect relationships. To quantify spatial distributions, a "density" measure based on individual small fault magnitude was utilized. Approximately half of the small faults in the core possessed no discernible offset markers; thus displacement amount for these faults could not be measured directly. Using a nonparametric method in which an alternating conditional expectation determined optimal transformations for the data, a statistically significant empirical correlation was established for faults with measurable gouge thickness, displacement, protolith mean grain size and sorting. Gouge thickness of small faults was found to be dependant upon the displacement amount of the small fault and the textural characteristics of the host protolith. The role of protolith lithology, proximity to crystalline basement, and structural position relative to the Nobles Fault system were examined to explain observed ubiquitous spatial distribution of small faults. Small faults were found to occur in clusters and the number of faults per foot only weakly correlates to the cumulative displacement of the corresponding faults. The amount of mudstone present is the dominant factor controlling small fault formation. Intervals with only minor quantities of mudstone have the largest number of faults per foot as well as largest associated cumulative displacement per foot. Frequency of occurrence of small faults near the basement is greater when compared to similar lithologies higher in the core. Intensity of small faults do not universally increase with proximity to large faults. To observe an increase in small faults, it is necessary to use a mean global cumulative displacement approach. Zones of greater than average cumulative displacement of small faults in close proximity to large faults were observed in zones that are compatible with faultfault interaction.

Graff, Mitchell C

2006-08-01T23:59:59.000Z

302

Pressure limits of an axisymmetric torus  

SciTech Connect

In order to clarify the pressure limit of a toroidal plasma equilibrium in a three-dimensional geometry, an azimuthally symmetric toroidal plasma was considered. In a tokamak-like plasma, the net toroidal current is necessary for a finite ..beta.. plasma equilibrium. If external conductors are used to provide the rotational transform, iota, the plasma pressure is limited to ..beta.. = (iota/2..pi..)/sup 2//2A, where A is the aspect ratio.

Yoshikawa, S.

1986-03-01T23:59:59.000Z

303

Estimation of steady-state unbalanced system conditions combining conventional power flow and fault analysis software  

Science Conference Proceedings (OSTI)

In real three-phase power systems the voltages and currents are not fully symmetrical. A method has been developed to estimate the effects of slight unbalanced network conditions for steady-state operation. A conventional power flow is followed by a linear incremental calculation using a three-phase model of the network. The unbalanced condition is handled like a multiple unbalanced fault. The process is illustrated for the case of a transformer bank with non-identical single phase units. The results show the effects of different transformer reactances and different voltage ratios, respectively.

Reichelt, D.; Ecknauer, E. [Nordostschweizerische Kraftwerke AG, Baden (Switzerland); Glavitsch, H. [Swiss Federal Inst. of Tech., Zurich (Switzerland)

1996-02-01T23:59:59.000Z

304

Fault Detection and Isolation of a Cryogenic Rocket Engine Combustion Chamber Using a Parity Space Approach  

Science Conference Proceedings (OSTI)

his paper presents a parity space (PS) approach for fault detection and isolation (FDI) of a cryogenic rocket engine combustion chamber. Nominal and non-nominal simulation data for three engine set points have been provided. The PS approach uses three ... Keywords: Fault Detection, Fault Isolation, Fault Diagnosis, Parity Space, Rocket Engine

Paul van Gelder; André Bos

2009-07-01T23:59:59.000Z

305

A Systematic Stochastic Petri Net Based Methodology for Transformer Fault Diagnosis and Repair Actions  

Science Conference Proceedings (OSTI)

Transformer fault diagnosis and repair is a complex task that includes many possible types of faults and demands special trained personnel. Moreover, the minimization of the time needed for transformer fault diagnosis and repair is an important task ... Keywords: power system reliability, stochastic petri nets, transformer fault diagnosis

P. S. Georgilakis; J. A. Katsigiannis; K. P. Valavanis; A. T. Souflaris

2006-02-01T23:59:59.000Z

306

Analysis of the growth of strike-slip faults using effective medium theory  

SciTech Connect

Increases in the dimensions of strike-slip faults including fault length, thickness of fault rock and the surrounding damage zone collectively provide quantitative definition of fault growth and are commonly measured in terms of the maximum fault slip. The field observations indicate that a common mechanism for fault growth in the brittle upper crust is fault lengthening by linkage and coalescence of neighboring fault segments or strands, and fault rock-zone widening into highly fractured inner damage zone via cataclastic deformation. The most important underlying mechanical reason in both cases is prior weakening of the rocks surrounding a fault's core and between neighboring fault segments by faulting-related fractures. In this paper, using field observations together with effective medium models, we analyze the reduction in the effective elastic properties of rock in terms of density of the fault-related brittle fractures and fracture intersection angles controlled primarily by the splay angles. Fracture densities or equivalent fracture spacing values corresponding to the vanishing Young's, shear, and quasi-pure shear moduli were obtained by extrapolation from the calculated range of these parameters. The fracture densities or the equivalent spacing values obtained using this method compare well with the field data measured along scan lines across the faults in the study area. These findings should be helpful for a better understanding of the fracture density/spacing distribution around faults and the transition from discrete fracturing to cataclastic deformation associated with fault growth and the related instabilities.

Aydin, A.; Berryman, J.G.

2009-10-15T23:59:59.000Z

307

Fault-based test suite prioritization for specification-based testing  

Science Conference Proceedings (OSTI)

Context: Existing test suite prioritization techniques usually rely on code coverage information or historical execution data that serve as indicators for estimating the fault-detecting ability of test cases. Such indicators are primarily empirical in ... Keywords: Fault class hierarchy, Fault-based prioritization, Fault-based testing, Software testing, Specification-based testing, Test suite prioritization

Yuen Tak Yu; Man Fai Lau

2012-02-01T23:59:59.000Z

308

A Power Transmission Line Fault Distance Estimation VLSI Chip: Design and Defect Tolerance  

Science Conference Proceedings (OSTI)

This paper presents a system-on-a-chip for fault detection and fault-distance-estimation for power transmission lines in the smart grid. Toward this goal we have designed and fabricated three chips: PGS4, PGS5 and PGS6, each successively more advanced ... Keywords: Smart grid, fault distance, arcing fault, system on a chip, defect tolerance, Radojevic algorithm.

E. MacLean; V. K. Jain

2011-10-01T23:59:59.000Z

309

Power Line Fault Current Coupling to Nearby Natural Gas Pipelines, Volumes 1-3  

Science Conference Proceedings (OSTI)

The Electromagnetic and Conductive Coupling Analysis of Powerlines and Pipelines (ECCAPP) computer program provides an easy-to-use method for analyzing the effects of transmission lines on gas pipelines. The program models conductive and inductive interference, enabling electrical and gas engineers to identify these effects and design mitigation systems when necessary.

1987-11-24T23:59:59.000Z

310

Recency Of Faulting And Neotechtonic Framework In The Dixie Valley  

Open Energy Info (EERE)

Of Faulting And Neotechtonic Framework In The Dixie Valley Of Faulting And Neotechtonic Framework In The Dixie Valley Geothermal Field And Other Geothermal Fields Of The Basin And Range Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Recency Of Faulting And Neotechtonic Framework In The Dixie Valley Geothermal Field And Other Geothermal Fields Of The Basin And Range Details Activities (6) Areas (3) Regions (0) Abstract: We studied the role that earthquake faults play in redistributing stresses within in the earths crust near geothermal fields. The geographic foci of our study were the sites of geothermal plants in Dixie Valley, Beowawe, and Bradys Hot Springs, Nevada. Our initial results show that the past history of earthquakes has redistributed stresses at these 3 sites in a manner to open and maintain fluid pathways critical for geothermal

311

Understanding Fault Characteristics And Sediment Depth For Geothermal  

Open Energy Info (EERE)

Understanding Fault Characteristics And Sediment Depth For Geothermal Understanding Fault Characteristics And Sediment Depth For Geothermal Exploration Using 3D Gravity Inversion In Walker Valley, Nevada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Understanding Fault Characteristics And Sediment Depth For Geothermal Exploration Using 3D Gravity Inversion In Walker Valley, Nevada Details Activities (2) Areas (1) Regions (0) Abstract: The Southern Walker Lake Basin, situated in the Walker Lake structural domain, consists of primarily E-W directed extension along N-NNW striking normal faults. Water well drilling on the eastern slopes of the Wassuk Range, west of the city of Hawthorne, Nevada showed elevated temperatures. Two recent drill holes reaching downhole depths of more than 4000 ft give some insight to the geologic picture, but more information

312

Fault Detection and Isolation in Low-Voltage DC Distribution ...  

A University of Colorado research team led by Jae-Do Park has developed a fault detection and isolation scheme for a low-voltage DC-bus microgrid system, ...

313

Recency of Faulting and Neotectonic Framework in the Dixie Valley  

Open Energy Info (EERE)

of Faulting and Neotectonic Framework in the Dixie Valley of Faulting and Neotectonic Framework in the Dixie Valley Geothermal Field and Other Geothermal Fields of the Basin and Range Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Recency of Faulting and Neotectonic Framework in the Dixie Valley Geothermal Field and Other Geothermal Fields of the Basin and Range Abstract We studied the role that earthquake faults play in redistributing stresses within in the earths crust near geothermal fields. The geographic foci of our study were the sites of geothermal plants in Dixie Valley, Beowawe, and Bradys Hot Springs, Nevada. Our initial results show that the past history of earthquakes has redistributed stresses at these 3 sites in a manner to open and maintain fluid pathways critical for geothermal development. The

314

Aksaray And Ecemis Faults - Diapiric Salt Relationships- Relevance To The  

Open Energy Info (EERE)

Aksaray And Ecemis Faults - Diapiric Salt Relationships- Relevance To The Aksaray And Ecemis Faults - Diapiric Salt Relationships- Relevance To The Hydrocarbon Exploration In The Tuz Golu (Salt Lake) Basin, Central Anatolia, Turkey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Aksaray And Ecemis Faults - Diapiric Salt Relationships- Relevance To The Hydrocarbon Exploration In The Tuz Golu (Salt Lake) Basin, Central Anatolia, Turkey Details Activities (0) Areas (0) Regions (0) Abstract: Due to activitiy of the Aksaray and Ecemis Faults, volcanic intrusion and westward movement of the Anatolian plate, diapiric salt structures were occurred in the Tuz Golu (Salt Lake) basin in central Anatolia, Turkey. With the collisions of the Arabian and Anatolian plates during the late Cretaceous and Miocene times, prominent ophiolitic

315

Fusing strategies for the dual-voltage fault  

E-Print Network (OSTI)

This thesis focuses on the 42V - 14V fault in a dual voltage system and discusses the possibility of effective fusing. A simple model for the system had been created from technical documentation. Based on the model and the ...

Shrivastava, Rupam, 1981-

2005-01-01T23:59:59.000Z

316

Local discriminant bases in machine fault diagnosis using vibration signals  

Science Conference Proceedings (OSTI)

Wavelets and local discriminant bases (LDB) selection algorithm is applied to vibration signals in a single-cylinder spark ignition engine for feature extraction and fault classification. LDB selects a complete orthogonal basis from a wavelet packet ...

R. Tafreshi; F. Sassani; H. Ahmadi; G. Dumont

2005-04-01T23:59:59.000Z

317

Adaptive Control and Fault Detection of HVAC Equipment in Commercial...  

NLE Websites -- All DOE Office Websites (Extended Search)

Adaptive Control and Fault Detection of HVAC Equipment in Commercial Buildings Speaker(s): John Seem Date: February 27, 2002 - 12:00pm Location: Bldg. 90 Seminar HostPoint of...

318

Non-intrusive fault detection in reciprocating compressors  

E-Print Network (OSTI)

This thesis presents a set of techniques for non-intrusive sensing and fault detection in reciprocating compressors driven by induction motors. The procedures developed here are "non-intrusive" because they rely only on ...

Schantz, Christopher James

2011-01-01T23:59:59.000Z

319

High-Resolution Aeromagnetic Survey to Image Shallow Faults,...  

Open Energy Info (EERE)

Number 02-384 DOI Not Provided Check for DOI availability: http:crossref.org Online Internet link for High-Resolution Aeromagnetic Survey to Image Shallow Faults, Dixie Valley...

320

Understanding Fault Characteristics And Sediment Depth For Geothermal...  

Open Energy Info (EERE)

of primarily E-W directed extension along N-NNW striking normal faults. Water well drilling on the eastern slopes of the Wassuk Range, west of the city of Hawthorne, Nevada...

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Characteristics of Wind Turbines Under Normal and Fault Conditions: Preprint  

SciTech Connect

This paper investigates the characteristics of a variable-speed wind turbine connected to a stiff or weak grid under normal and fault conditions and the role of reactive power compensation.

Muljadi, E.; Butterfield, C. P.; Parsons, B.; Ellis, A.

2007-02-01T23:59:59.000Z

322

CAPRI: A Common Architecture for Distributed Probabilistic Internet Fault Diagnosis  

E-Print Network (OSTI)

This thesis presents a new approach to root cause localization and fault diagnosis in the Internet based on a Common Architecture for Probabilistic Reasoning in the Internet (CAPRI) in which distributed, heterogeneous ...

Lee, George J.

2007-06-04T23:59:59.000Z

323

Dating of major normal fault systems using thermochronology-...  

Open Energy Info (EERE)

River detachment fault and shear zone by study of spatial gradients in 40Ar39 A and fission track cooling ages of footwall rocks and cooling histories and by comparison of...

324

Development of Hydrologic Characterization Technology of Fault Zones  

E-Print Network (OSTI)

one example being Dixie Valley, Nevada, an active normalrock at various sites: Dixie Valley, Nevada; Wasatch, Utah;20 m in parts of the Dixie Valley and Wasatch fault zones.

Karasaki, Kenzi

2009-01-01T23:59:59.000Z

325

A Fault Detection and Diagnosis Method for HVAC Systems  

NLE Websites -- All DOE Office Websites (Extended Search)

A Fault Detection and Diagnosis Method for HVAC Systems A Fault Detection and Diagnosis Method for HVAC Systems Speaker(s): Peng Xu Date: December 2, 2002 - 12:00pm Location: Bldg. 90 There is a growing consensus that most buildings do not perform as well as intended and that faults in HVAC systems are widespread in commercial buildings. An automated fault detection and diagnosis tool for HVAC systems is being developed, based on an integrated, life-cycle, approach to commissioning and performance monitoring. The tool uses component-level HVAC equipment models implemented in the SPARK equation-based simulation environment. The models are configured using design information and component manufacturers' data and then fine-tuned to match the actual performance of the equipment by using data measured during functional tests

326

Fault Mapping At Coso Geothermal Area (1980) | Open Energy Information  

Open Energy Info (EERE)

Fault Mapping At Coso Geothermal Area (1980) Fault Mapping At Coso Geothermal Area (1980) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Fault Mapping At Coso Geothermal Area (1980) Exploration Activity Details Location Coso Geothermal Area Exploration Technique Fault Mapping Activity Date 1980 Usefulness useful DOE-funding Unknown Exploration Basis To determine the Late Cenozoic volcanism, geochronology, and structure of the Coso Range Notes This system apparently is heated by a reservoir of silicic magma at greater than or equal to 8-km depth, itself produced and sustained through partial melting of crustal rocks by thermal energy contained in mantle-derived basaltic magma that intrudes the crust in repsonse to lithospheric extension. References Duffield, W.A.; Bacon, C.R.; Dalrymple, G.B. (10 May 1980) Late

327

Dynamic transient fault detection and recovery for embedded processor datapaths  

Science Conference Proceedings (OSTI)

As microprocessors continue to evolve and grow in functionality, the use of smaller nanometer technology scaling coupled with high clock frequencies and exponentially increasing transistor counts dramatically increases the susceptibility of transient ... Keywords: datapath, embedded, fault tolerance, reliability, soft errors

Garo Bournoutian; Alex Orailoglu

2012-10-01T23:59:59.000Z

328

Short Circuit Current Contribution for Different Wind Turbine Generator Types  

DOE Green Energy (OSTI)

An important aspect of wind power plant (WPP) impact studies is to evaluate the short circuit (SC) current contribution of the plant into the transmission network under different fault conditions. This task can be challenging to protection engineers due to the topology differences between different types of wind turbine generators (WTGs) and the conventional generating units. This paper represents simulation results for short circuit current contribution for different types of WTGs obtained through transient analysis using generic WTG models. The obtained waveforms are analyzed to explain the behavior, such as peak values and rate of decay, of the WTG. The effect of fault types and location, and the effect of the control algorithms of power converters on SC current contribution are investigated. It is shown that the response of the WPP to faults will vary based on the type of the installed WTGs. While in Type 1 and Type 2 WTGs, short circuit current will be determined by the physical characteristics of the induction generator, the contribu-tion of Type 3 and Type 4 WTG will be mostly characterized by the power converters control algorithms which are usually considered proprietary information by the wind turbine manufacturers.

Muljadi, E.; Samaan, Nader A.; Gevorgian, Vahan; Li, Jun; Pasupulati, Subbaiah

2010-09-28T23:59:59.000Z

329

Algorithmic Based Fault Tolerance Applied to High Performance Computing  

E-Print Network (OSTI)

We present a new approach to fault tolerance for High Performance Computing system. Our approach is based on a careful adaptation of the Algorithmic Based Fault Tolerance technique (Huang and Abraham, 1984) to the need of parallel distributed computation. We obtain a strongly scalable mechanism for fault tolerance. We can also detect and correct errors (bit-flip) on the fly of a computation. To assess the viability of our approach, we have developed a fault tolerant matrix-matrix multiplication subroutine and we propose some models to predict its running time. Our parallel fault-tolerant matrix-matrix multiplication scores 1.4 TFLOPS on 484 processors (cluster jacquard.nersc.gov) and returns a correct result while one process failure has happened. This represents 65% of the machine peak efficiency and less than 12% overhead with respect to the fastest failure-free implementation. We predict (and have observed) that, as we increase the processor count, the overhead of the fault tolerance drops significantly.

Bosilca, George; Dongarra, Jack; Langou, Julien

2008-01-01T23:59:59.000Z

330

Direct-Current Resistivity Survey | Open Energy Information  

Open Energy Info (EERE)

Direct-Current Resistivity Survey Direct-Current Resistivity Survey Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Direct-Current Resistivity Survey Details Activities (65) Areas (34) Regions (4) NEPA(0) Exploration Technique Information Exploration Group: Geophysical Techniques Exploration Sub Group: Electrical Techniques Parent Exploration Technique: Electrical Techniques Information Provided by Technique Lithology: Rock type, mineral and clay content may be inferred. Stratigraphic/Structural: Determination of fracture zones, faults, depth to groundwater aquifers. Hydrological: Resistivity influenced by porosity, permeability, fluid saturation, fluid type and phase state of the pore water. Thermal: Resistivity influenced by temperature.[1] Cost Information

331

Palaeoseismology of the North Anatolian Fault near the Marmara Sea: implications for fault segmentation and seismic hazard  

E-Print Network (OSTI)

Diego, CA 92182, USA 2 Institute of Geological and Nuclear Sciences, PO Box 30-368, Lower Hutt, New fault to the city of Istanbul, one of the largest cities in the Middle East. Across the 1912 rupture

Klinger, Yann

332

Evaluation of faulting characteristics and ground acceleration associated with recent movement along the Meers Fault, Southwestern Oklahoma  

E-Print Network (OSTI)

Recent studies have shown that a 27 km section of the Meers Fault was reactivated during Holocene time. Although these studies have proven the occurrence of recent fault activity, many basic characteristics of the faulting remain unresolved, For instance, the issue of whether recent deformation was dominantly vertical or laterally oriented is still a source of disagreement among many researchers. The number of events associated with recent movement is another area of uncertainty, with I to 4 events being cited as responsible for the Meers Fault scarp. Earthquakes of magnitude 7 to 8 occurring in conjunction with recent reactivation of the fault have been calculated. However, evidence found within the Wichita Mountains just south of the fault exhibits strong evidence against large recent earthquake events. Investigation of stream channel pathways where they cross the fault revealed that many streams previously identified as left-laterally offset are instead left-laterally deflected by folding on the upthrown block. These streams are in every case deflected much farther than any true lateral displacement recognized on the fault. Inclusion of the streams in past studies has apparently contributed to over-estimation of the recent component of left-lateral displacement. Exposure development into the Meers Fault scarp revealed deformed units and colluvial wedges that indicate 4 recent movements produced a total of 1.46 m of brittle deformation and another 1.04 m of monoclinal warping. A previously unidentified conglomerate uncovered in the exposure exhibits evidence for a lateral component of displacement during possible Late Pleistocene deformation. subsequent events identified in the exposure. Reconnaissance of the Wichita Mountains granitic terrain just south of the Meers Fault resulted in the identification of 27 precariously balanced rocks (tors). These geomorphic features lie within 18 km of the fault and have apparently been sitting in their present positions on the order of thousands of years. Quantitative analysis of the tors indicates that most could not have withstood the ground accelerations generated by magnitude 7 or above earthquakes estimated to have occurred with recent deformation.

Burrell, Richard Dennis

1997-01-01T23:59:59.000Z

333

Original article: An efficient, simplified multiple-coupled circuit model of the induction motor aimed to simulate different types of stator faults  

Science Conference Proceedings (OSTI)

This paper proposes an original simplified model aimed to simulate, an easy way, inter turns short circuit fault, phase to phase fault and phase to ground fault. In this model, the stator is considered as six magnetically coupled windings and the rotor ... Keywords: Fault diagnosis, Inter turns short circuit fault, Phase to ground fault, Phase to phase fault, Symmetrical components

M. Bouzid, G. Champenois

2013-04-01T23:59:59.000Z

334

Photon and graviton mass limits  

Science Conference Proceedings (OSTI)

We review past and current studies of possible long-distance, low-frequency deviations from Maxwell electrodynamics and Einstein gravity. Both have passed through three phases: (1) Testing the inverse-square laws of Newton and Coulomb, (2) Seeking a nonzero value for the rest mass of photon or graviton, and (3) Considering more degrees of freedom, allowing mass while preserving gauge or general-coordinate invariance. For electrodynamics there continues to be no sign of any deviation. Since our previous review the lower limit on the photon Compton wavelength (associated with weakening of electromagnetic fields in vacuum over large distance scale) has improved by four orders of magnitude, to about one astronomical unit. Rapid current progress in astronomical observations makes it likely that there will be further advances. These ultimately could yield a bound exceeding galactic dimensions, as has long been contemplated. Meanwhile, for gravity there have been strong arguments about even the concept of a graviton rest mass. At the same time there are striking observations, commonly labeled 'dark matter' and 'dark energy' that some argue imply modified gravity. This makes the questions for gravity much more interesting. For dark matter, which involves increased attraction at large distances, any explanation by modified gravity would be qualitatively different from graviton mass. Because dark energy is associated with reduced attraction at large distances, it might be explained by a graviton-mass-like effect.

Nieto, Michael [Los Alamos National Laboratory; Goldhaber Scharff, Alfred [SUNY

2008-01-01T23:59:59.000Z

335

Measured Breakdown Voltage and Leakage Current of Line Worker Boots  

Science Conference Proceedings (OSTI)

Worker safety is every electric power company's number one priority. Denergized line maintenance is an important task to ensure reliable operation of a transmission line. The grounding installed during this operation must be designed to shunt any unforeseen fault current and prevent electric shock and any associated consequences. The research described in this report describes electrical characteristics of work shoes, which comprise an important part of a model for minimizing hazardous outcomes.

2009-11-02T23:59:59.000Z

336

Development of a computer-aided fault tree synthesis methodology for quantitative risk analysis in the chemical process industry  

E-Print Network (OSTI)

There has been growing public concern regarding the threat to people and environment from industrial activities, thus more rigorous regulations. The investigation of almost all the major accidents shows that we could have avoided those tragedies with effective risk analysis and safety management programs. High-quality risk analysis is absolutely necessary for sustainable development. As a powerful and systematic tool, fault tree analysis (FTA) has been adapted to the particular need of chemical process quantitative risk analysis (CPQRA) and found great applications. However, the application of FTA in the chemical process industry (CPI) is limited. One major barrier is the manual synthesis of fault trees. It requires a thorough understanding of the process and is vulnerable to individual subjectivity. The quality of FTA can be highly subjective and variable. The availability of a computer-based FTA methodology will greatly benefit the CPI. The primary objective of this research is to develop a computer-aided fault tree synthesis methodology for CPQRA. The central idea is to capture the cause-and-effect logic around each item of equipment directly into mini fault trees. Special fault tree models have been developed to manage special features. Fault trees created by this method are expected to be concise. A prototype computer program is provided to illustrate the methodology. Ideally, FTA can be standardized through a computer package that reads information contained in process block diagrams and provides automatic aids to assist engineers in generating and analyzing fault trees. Another important issue with regard to QRA is the large uncertainty associated with available failure rate data. In the CPI, the ranges of failure rates observed could be quite wide. Traditional reliability studies using point values of failure rates may result in misleading conclusions. This dissertation discusses the uncertainty with failure rate data and proposes a procedure to deal with data uncertainty in determining safety integrity level (SIL) for a safety instrumented system (SIS). Efforts must be carried out to obtain more accurate values of those data that might actually impact the estimation of SIL. This procedure guides process hazard analysts toward a more accurate SIL estimation and avoids misleading results due to data uncertainty.

Wang, Yanjun

2004-12-01T23:59:59.000Z

337

(Limiting the greenhouse effect)  

SciTech Connect

Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

Rayner, S.

1991-01-07T23:59:59.000Z

338

(Limiting the greenhouse effect)  

SciTech Connect

Traveler attended the Dahlem Research Conference organized by the Freien Universitat, Berlin. The subject of the conference was Limiting the Greenhouse Effect: Options for Controlling Atmospheric CO{sub 2} Accumulation. Like all Dahlem workshops, this was a meeting of scientific experts, although the disciplines represented were broader than usual, ranging across anthropology, economics, international relations, forestry, engineering, and atmospheric chemistry. Participation by scientists from developing countries was limited. The conference was divided into four multidisciplinary working groups. Traveler acted as moderator for Group 3 which examined the question What knowledge is required to tackle the principal social and institutional barriers to reducing CO{sub 2} emissions'' The working rapporteur was Jesse Ausubel of Rockefeller University. Other working groups examined the economic costs, benefits, and technical feasibility of options to reduce emissions per unit of energy service; the options for reducing energy use per unit of GNP; and the significant of linkage between strategies to reduce CO{sub 2} emissions and other goals. Draft reports of the working groups are appended. Overall, the conference identified a number of important research needs in all four areas. It may prove particularly important in bringing the social and institutional research needs relevant to climate change closer to the forefront of the scientific and policy communities than hitherto.

Rayner, S.

1991-01-07T23:59:59.000Z

339

Similarity-based fuzzy limits  

Science Conference Proceedings (OSTI)

In this paper the concept of similarity-based fuzzy limits in metric spaces is introduced and it is shown that it is an application of limit maps of topologies on [0,1]-valued sets, introduced by Hohle and Sostak, furthermore it is observed that the ... Keywords: Fuzzy limit, Limit map, Similarity-based fuzzy limit, [0,1]-Valued topology

Gültekin Soylu

2008-12-01T23:59:59.000Z

340

Fault Oblivious eXascale Whitepaper  

Science Conference Proceedings (OSTI)

In this paper we present a software system which supports dynamic, irregular, adaptive applications. Data objects are created and structured in a hierarchical manner, with replication as needed to provide a high degree of redundancy. The data objects can contain data, code, tasks (work descriptors with references to data, code, and other tasks) and higher level structures such as work queues. The higher level structures benefit from the properties of the data objects: redundant storage to support resiliency in the face of hardware failure; hierarchical structure to optimize use of the HPC system; and a presence of object names, available in the per-user file system name space, which allows any application, not just specially written HPC applications, to make use of the data even while it is on the HPC system. Our use of hierarchy will make the runtime scalable to very large systems. Our use of redundancy will allow programs to be written in a fault-oblivious manner, eliminating the need for system-level checkpointing. Putting data object names into the file system name space allows for interactive use of the system by users. With this approach, we will be able to finally leave the batch era behind, a half-century after the invention of time sharing. We will be able to stop bounding program through- put by the checkpoint interval. Application data will be accessible at any time, not hidden behind opaque 128-bit pointers or MPI ranks, but given a name that is visible everywhere. Programmers can stop laying out data, and thinking about where the data is, and the code is, and the nodes are, and stick with the problem of what the application is supposed to be doing. This work, if it succeeds, will enable scientific computing to scale to the next generation of machines.

Minnich, Ronald G.; Janssen, Curtis L.; Krishnamoorthy, Sriram; Marquez, Andres; Gokhale, Maya; Sadayappan, Ponnuswamy; Van Hensbergen, Eric; McKie, Jim; Appavoo, Jonathan

2011-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
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341

Creating dynamic equivalent PV circuit models with impedance spectroscopy for arc-fault modeling.  

Science Conference Proceedings (OSTI)

Article 690.11 in the 2011 National Electrical Code{reg_sign} (NEC{reg_sign}) requires new photovoltaic (PV) systems on or penetrating a building to include a listed arc fault protection device. Currently there is little experimental or empirical research into the behavior of the arcing frequencies through PV components despite the potential for modules and other PV components to filter or attenuate arcing signatures that could render the arc detector ineffective. To model AC arcing signal propagation along PV strings, the well-studied DC diode models were found to inadequately capture the behavior of high frequency arcing signals. Instead dynamic equivalent circuit models of PV modules were required to describe the impedance for alternating currents in modules. The nonlinearities present in PV cells resulting from irradiance, temperature, frequency, and bias voltage variations make modeling these systems challenging. Linearized dynamic equivalent circuits were created for multiple PV module manufacturers and module technologies. The equivalent resistances and capacitances for the modules were determined using impedance spectroscopy with no bias voltage and no irradiance. The equivalent circuit model was employed to evaluate modules having irradiance conditions that could not be measured directly with the instrumentation. Although there was a wide range of circuit component values, the complex impedance model does not predict filtering of arc fault frequencies in PV strings for any irradiance level. Experimental results with no irradiance agree with the model and show nearly no attenuation for 1 Hz to 100 kHz input frequencies.

Johnson, Jay Dean; Kuszmaul, Scott S.; Strauch, Jason E.; Schoenwald, David Alan

2011-06-01T23:59:59.000Z

342

Variability management of safety and reliability models: an intermediate model towards systematic reuse of component fault trees  

Science Conference Proceedings (OSTI)

Reuse of fault trees helps in reducing costs and effort when conducting Fault Tree Analyses (FTAs) for a set of similar systems. Some approaches have been proposed for the systematic reuse of fault trees along with the development of a product line of ... Keywords: component fault trees, fault tree analysis, product line engineering, safety and reliability, variability management

Carolina Gómez; Peter Liggesmeyer; Ariane Sutor

2010-09-01T23:59:59.000Z

343

Risking fault seal in the Gulf Coast: A joint industry study  

SciTech Connect

Analysis of more than 200 faults in a joint-industry study of the Gulf Coast provides a database of actual fault seal behavior in producing fields. This empirical database demonstrates that fault seal behavior is predictable rather than random and that faults are more important than is commonly thought in controlling hydrocarbon accumulations. Quantitative fault seal analysis demonstrates that seal behavior is empirically related to the amount of sand and shale incorporated in the fault zone. Faults with sand-rich gouge leak. Faults with shale-rich gouge seal. An empirically defined threshold allows prediction of fault seal behavior with a high degree of confidence. Fewer than 10% of the faults in the Gulf Coast are exceptions to the rule. Exceptions are a result of other factors including low permeability and high displacement pressure sands, and thin-bedded sand/shale sequences. Examples from these Gulf Coast fields demonstrate the fundamental importance of faults in controlling hydrocarbon accumulations. Faults and fault seal behavior control the presence or absence of hydrocarbons, percent fill, hydrocarbon column heights, entrapment of oil versus gas, and high-side and low-side trap risk. Faults control the lateral distribution of hydrocarbon within fault compartments as well as the vertical distribution of hydrocarbon among stacked sands. Faults control fluid flow during both field development and hydrocarbon migration. Bypassed residual accumulations and unnecessary production wells result from neglecting routine fault seal analysis during field development. Dry holes and mistaken reserves assessments result from neglecting routine fault seal analysis during exploration.

Skerlec, G.M. (PetroQuest International Inc., Franklin, PA (United States))

1996-01-01T23:59:59.000Z

344

Accident Fault Trees for Defense Waste Processing Facility  

Science Conference Proceedings (OSTI)

The purpose of this report is to document fault tree analyses which have been completed for the Defense Waste Processing Facility (DWPF) safety analysis. Logic models for equipment failures and human error combinations that could lead to flammable gas explosions in various process tanks, or failure of critical support systems were developed for internal initiating events and for earthquakes. These fault trees provide frequency estimates for support systems failures and accidents that could lead to radioactive and hazardous chemical releases both on-site and off-site. Top event frequency results from these fault trees will be used in further APET analyses to calculate accident risk associated with DWPF facility operations. This report lists and explains important underlying assumptions, provides references for failure data sources, and briefly describes the fault tree method used. Specific commitments from DWPF to provide new procedural/administrative controls or system design changes are listed in the ''Facility Commitments'' section. The purpose of the ''Assumptions'' section is to clarify the basis for fault tree modeling, and is not necessarily a list of items required to be protected by Technical Safety Requirements (TSRs).

Sarrack, A.G.

1999-06-22T23:59:59.000Z

345

Identifying Efficiency Degrading Faults in Split Air Conditioning Systems  

E-Print Network (OSTI)

Studies estimate that as much as 50% of packaged air conditioning systems operate in faulty conditions that degrade system efficiency. Common faults include: under- and over-charged systems (too much or too little refrigerant), faulty expansions valves (stuck valves, valve hunting, poorly tuned valve controllers), and fouled evaporators and condensers. Furthermore, air conditioning systems can often be adjusted to improve efficiency while continuing to meet cooling loads (adjusting system pressures, decreasing superheat setpoints). This study presents the design of a low cost device that can non-invasively measure system operating conditions, diagnose faults, estimate potential energy savings, and provide recommendations on how the system should be adjusted or repaired. Using eight external temperature measurements, the device potentially can detect and diagnose up to ten faults commonly found in HVAC systems. Steady state temperatures are compared to threshold values obtained from literature and HVAC manufacturers to detect and determine the severity of faults and subsequent reductions in coefficient of performance. Preliminary tests reveal the potential for the device to detect and diagnose common efficiency-degrading faults in HVAC systems.

Terrill, T. J.; Brown, M. L.; Cheyne, R. W. Jr.; Cousins, A. J.; Daniels, B. P.; Erb, K. L.; Garcia, P. A.; Leutermann, M. J.; Nel, A. J.; Robert, C. L.; Widger, S. B.; Williams, A. G.; Rasmussen, B. P.

2013-01-01T23:59:59.000Z

346

Low cost fault detection system for railcars and tracks  

E-Print Network (OSTI)

A "low cost fault detection system" that identifies wheel flats and defective tracks is explored here. This is achieved with the conjunction of sensors, microcontrollers and Radio Frequency (RF) transceivers. The objective of the proposed research is to identify faults plaguing railcars and to be able to clearly distinguish the faults of a railcar from the inherent faults in the track. The focus of the research though, is mainly to identify wheel flats and defective tracks. The thesis has been written with the premise that the results from the simulation software GENSYS are close to the real time data that would have been obtained from an actual railcar. Based on the results of GENSYS, a suitable algorithm is written that helps segregate a fault in a railcar from a defect in a track. The above code is implemented using hardware including microcontrollers, accelerometers, RF transceivers and a real time monitor. An enclosure houses the system completely, so that it is ready for application in a real environment. This also involves selection of suitable hardware so that there is a uniform source of power supply that reduces the cost and assists in building a robust system.

Vengalathur, Sriram T.

2003-08-01T23:59:59.000Z

347

Methods, systems and apparatus for synchronous current regulation of a five-phase machine  

DOE Patents (OSTI)

Methods, systems and apparatus are provided for controlling operation of and regulating current provided to a five-phase machine when one or more phases has experienced a fault or has failed. In one implementation, the disclosed embodiments can be used to synchronously regulate current in a vector controlled motor drive system that includes a five-phase AC machine, a five-phase inverter module coupled to the five-phase AC machine, and a synchronous current regulator.

Gallegos-Lopez, Gabriel; Perisic, Milun

2012-10-09T23:59:59.000Z

348

Tests show ability of vacuum circuit breaker to interrupt fast transient recovery voltage rates of rise of transformer secondary faults  

Science Conference Proceedings (OSTI)

A vacuum circuit breaker demonstrated its ability to interrupt short circuits with faster than normal rates of rise of transient recovery voltage (TRV) at levels greater than those produced by most transformer secondary faults. Two recent exploratory test programs evaluated the interrupting ability of a 15kV vacuum circuit breaker containing interrupters of the rotating arc type with contacts made from a chromium-copper powder metal mixture. The interrupting conditions covered a wide range of currents from 10% to 130% of the 28kA rated short circuit current of the tested circuit breaker and a wide range of TRV rates of rise, including the relatively slow rate of rise, normally used in testing and found in most indoor circuit breaker applications, two faster rates of rise equaling and exceeding those found in a known power plant transformer secondary protection application, and the fastest rates of rise possible in the laboratory which exceed the requirements of most transformer secondary faults. These tests showed that the interrupting performance of the tested vacuum circuit breaker was unaffected by the TRV rate of rise to the fastest rates available in the test lab. Such a vacuum circuit breaker can therefore be used without TRV modifying capacitors to slow down the rate of rise provided by the power system. This ability is particularly important if analysis shows that the expected TRV from a transformer secondary fault has a fast rate of rise beyond the recognized ability of an older circuit breaker to acceptably interrupt.

Smith, R.K. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States)

1995-01-01T23:59:59.000Z

349

Propagation of Tracer Signals in Boundary Currents  

Science Conference Proceedings (OSTI)

The propagation of a range of tracer signals in a simple model of the deep western boundary current is examined. Analytical expressions are derived in certain limits for the transit-time distributions and the propagation times (tracer ages) of ...

Darryn W. Waugh; Timothy M. Hall

2005-09-01T23:59:59.000Z

350

Protection from ground faults in the stator winding of generators at power plants in the Siberian networks  

SciTech Connect

The experience of many years of experience in developing and utilization of ground fault protection in the stator winding of generators in the Siberian networks is generalized. The main method of protection is to apply a direct current or an alternating current with a frequency of 25 Hz to the primary circuits of the stator. A direct current is applied to turbo generators operating in a unit with a transformer without a resistive coupling to the external grid or to other generators. Applying a 25 Hz control current is appropriate for power generation systems with compensation of a capacitive short circuit current to ground. This method forms the basis for protection of generators operating on busbars, hydroelectric generators with a neutral grounded through an arc-suppression reactor, including in consolidated units with generators operating in parallel on a single low-voltage transformer winding.

Vainshtein, R. A., E-mail: vra@tpu.ru [Tomsk Polytechnical University (Russian Federation); Lapin, V. I. [ODU Sibiri (Integrated Dispatcher Control for Siberia), branch of JSC 'SO EES' (Russian Federation); Naumov, A. M.; Doronin, A. V. [JSC NPP 'EKRA' (Russian Federation); Yudin, S. M. [Tomsk Polytechnical University (Russian Federation)

2010-05-15T23:59:59.000Z

351

Maximum Error Modeling for Fault-Tolerant Computation using Maximum a posteriori (MAP) Hypothesis  

E-Print Network (OSTI)

The application of current generation computing machines in safety-centric applications like implantable biomedical chips and automobile safety has immensely increased the need for reviewing the worst-case error behavior of computing devices for fault-tolerant computation. In this work, we propose an exact probabilistic error model that can compute the maximum error over all possible input space in a circuit specific manner and can handle various types of structural dependencies in the circuit. We also provide the worst-case input vector, which has the highest probability to generate an erroneous output, for any given logic circuit. We also present a study of circuit-specific error bounds for fault-tolerant computation in heterogeneous circuits using the maximum error computed for each circuit. We model the error estimation problem as a maximum a posteriori (MAP) estimate, over the joint error probability function of the entire circuit, calculated efficiently through an intelligent search of the entire input space using probabilistic traversal of a binary join tree using Shenoy-Shafer algorithm. We demonstrate this model using MCNC and ISCAS benchmark circuits and validate it using an equivalent HSpice model. Both results yield the same worst-case input vectors and the highest % difference of our error model over HSpice is just 1.23%. We observe that the maximum error probabilities are significantly larger than the average error probabilities, and provides a much tighter error bounds for fault-tolerant computation. We also find that the error estimates depend on the specific circuit structure and the maximum error probabilities are sensitive to the individual gate failure probabilities.

Karthikeyan Lingasubramanian; Syed M. Alam; Sanjukta Bhanja

2009-06-17T23:59:59.000Z

352

Adiabatic Quantum Programming: Minor Embedding With Hard Faults  

SciTech Connect

Adiabatic quantum programming defines the time-dependent mapping of a quantum algorithm into the hardware or logical fabric. An essential programming step is the embedding of problem-specific information into the logical fabric to define the quantum computational transformation. We present algorithms for embedding arbitrary instances of the adiabatic quantum optimization algorithm into a square lattice of specialized unit cells. Our methods are shown to be extensible in fabric growth, linear in time, and quadratic in logical footprint. In addition, we provide methods for accommodating hard faults in the logical fabric without invoking approximations to the original problem. These hard fault-tolerant embedding algorithms are expected to prove useful for benchmarking the adiabatic quantum optimization algorithm on existing quantum logical hardware. We illustrate this versatility through numerical studies of embeddabilty versus hard fault rates in square lattices of complete bipartite unit cells.

Klymko, Christine F [ORNL] [ORNL; Sullivan, Blair D [ORNL] [ORNL; Humble, Travis S [ORNL] [ORNL

2013-01-01T23:59:59.000Z

353

Optimizing automated gas turbine fault detection using statistical pattern recognition  

SciTech Connect

A method enabling the automated diagnosis of Gas Turbine Compressor blade faults, based on the principles of statistical pattern recognition is initially presented. The decision making is based on the derivation of spectral patterns from dynamic measurements data and then the calculation of discriminants with respect to reference spectral patterns of the faults while it takes into account their statistical properties. A method of optimizing the selection of discriminants using dynamic measurements data is also presented. A few scalar discriminants are derived, in such a way that the maximum available discrimination potential is exploited. In this way the success rate of automated decision making is further improved, while the need for intuitive discriminant selection is eliminated. The effectiveness of the proposed methods is demonstrated by application to data coming from an Industrial Gas Turbine while extension to other aspects of Fault Diagnosis is discussed. 9 refs.

Loukis, E.; Mathioudakis, K.; Papailiou, K. (Athens National Technical Univ. (Greece))

1992-01-01T23:59:59.000Z

354

Optimizing automated gas turbine fault detection using statistical pattern recognition  

SciTech Connect

A method enabling the automated diagnosis of gas turbine compressor blade faults, based on the principles of statistical pattern recognition, is initially presented. The decision making is based on the derivation of spectral patterns from dynamic measurement data and then the calculation of discriminants with respect to reference spectral patterns of the faults while it takes into account their statistical properties. A method of optimizing the selection of discriminants using dynamic measurement data is also presented. A few scalar discriminants are derived, in such a way that the maximum available discrimination potential is exploited. In this way the success rate of automated decision making is further improved, while the need for intuitive discriminant selection is eliminated. The effectiveness of the proposed methods is demonstrated by application to data coming from an industrial gas turbine while extension to other aspects of fault diagnosis is discussed.

Loukis, E.; Mathioudakis, K.; Papailiou, K. (National Technical Univ. of Athens (Greece). Lab. of Thermal Turbomachines)

1994-01-01T23:59:59.000Z

355

Fault detection of multivariable system using its directional properties  

E-Print Network (OSTI)

A novel algorithm for making the combination of outputs in the output zero direction of the plant always equal to zero was formulated. Using this algorithm and the result of MacFarlane and Karcanias, a fault detection scheme was proposed which utilizes the directional property of the multivariable linear system. The fault detection scheme is applicable to linear multivariable systems. Results were obtained for both continuous and discrete linear multivariable systems. A quadruple tank system was used to illustrate the results. The results were further verified by the steady state analysis of the plant.

Pandey, Amit Nath

2004-12-01T23:59:59.000Z

356

Combined expert system/neural networks method for process fault diagnosis  

DOE Patents (OSTI)

A two-level hierarchical approach for process fault diagnosis of an operating system employs a function-oriented approach at a first level and a component characteristic-oriented approach at a second level, where the decision-making procedure is structured in order of decreasing intelligence with increasing precision. At the first level, the diagnostic method is general and has knowledge of the overall process including a wide variety of plant transients and the functional behavior of the process components. An expert system classifies malfunctions by function to narrow the diagnostic focus to a particular set of possible faulty components that could be responsible for the detected functional misbehavior of the operating system. At the second level, the diagnostic method limits its scope to component malfunctions, using more detailed knowledge of component characteristics. Trained artificial neural networks are used to further narrow the diagnosis and to uniquely identify the faulty component by classifying the abnormal condition data as a failure of one of the hypothesized components through component characteristics. Once an anomaly is detected, the hierarchical structure is used to successively narrow the diagnostic focus from a function misbehavior, i.e., a function oriented approach, until the fault can be determined, i.e., a component characteristic-oriented approach. 9 figs.

Reifman, J.; Wei, T.Y.C.

1995-08-15T23:59:59.000Z

357

Combined expert system/neural networks method for process fault diagnosis  

DOE Patents (OSTI)

A two-level hierarchical approach for process fault diagnosis is an operating system employs a function-oriented approach at a first level and a component characteristic-oriented approach at a second level, where the decision-making procedure is structured in order of decreasing intelligence with increasing precision. At the first level, the diagnostic method is general and has knowledge of the overall process including a wide variety of plant transients and the functional behavior of the process components. An expert system classifies malfunctions by function to narrow the diagnostic focus to a particular set of possible faulty components that could be responsible for the detected functional misbehavior of the operating system. At the second level, the diagnostic method limits its scope to component malfunctions, using more detailed knowledge of component characteristics. Trained artificial neural networks are used to further narrow the diagnosis and to uniquely identify the faulty component by classifying the abnormal condition data as a failure of one of the hypothesized components through component characteristics. Once an anomaly is detected, the hierarchical structure is used to successively narrow the diagnostic focus from a function misbehavior, i.e., a function oriented approach, until the fault can be determined, i.e., a component characteristic-oriented approach.

Reifman, Jaques (Westchester, IL); Wei, Thomas Y. C. (Downers Grove, IL)

1995-01-01T23:59:59.000Z

358

High voltage design structure for high temperature superconducting device  

DOE Patents (OSTI)

In accordance with the present invention, modular corona shields are employed in a HTS device to reduce the electric field surrounding the HTS device. In a exemplary embodiment a fault current limiter module in the insulation region of a cryogenic cooling system has at least one fault current limiter set which employs a first corona shield disposed along the top portion of the fault current limiter set and is electrically coupled to the fault current limiter set. A second corona shield is disposed along the bottom portion of the fault current limiter set and is electrically coupled to the fault current limiter set. An insulation barrier is disposed within the insulation region along at least one side of the fault current limiter set. The first corona shield and the second corona shield act together to reduce the electric field surrounding the fault limiter set when voltage is applied to the fault limiter set.

Tekletsadik, Kasegn D. (Rexford, NY)

2008-05-20T23:59:59.000Z

359

Current measuring system  

SciTech Connect

A current measuring system comprising a current measuring device having a first electrode at ground potential, and a second electrode; a current source having an offset potential of at least three hundred volts, the current source having an output electrode; and a capacitor having a first electrode electrically connected to the output electrode of the current source and having a second electrode electrically connected to the second electrode of the current measuring device.

Dahl, David A. (Idaho Falls, ID); Appelhans, Anthony D. (Idaho Falls, ID); Olson, John E. (Idaho Falls, ID)

1997-01-01T23:59:59.000Z

360

Current measurement apparatus  

DOE Patents (OSTI)

Apparatus and methods are provided for a system for measurement of a current in a conductor such that the conductor current may be momentarily directed to a current measurement element in order to maintain proper current without significantly increasing an amount of power dissipation attributable to the current measurement element or adding resistance to assist in current measurement. The apparatus and methods described herein are useful in superconducting circuits where it is necessary to monitor current carried by the superconducting elements while minimizing the effects of power dissipation attributable to the current measurement element.

Umans, Stephen D. (Belmont, MA)

2008-11-11T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Argonne Transportation Current News  

NLE Websites -- All DOE Office Websites (Extended Search)

one-stop shop for news, photographs and other interesting reference information on transportation research. Current News Read current news and research highlights. Archives: 2011...

362

Current to Current Corporation | Open Energy Information  

Open Energy Info (EERE)

to Current Corporation to Current Corporation Jump to: navigation, search Name Current to Current Corporation Place Burlington, Massachusetts Zip 1803 Sector Ocean Product Developing a technology which generates power from ocean currents : Submersible Power Generators (SPG). Coordinates 44.446275°, -108.431704° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.446275,"lon":-108.431704,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

363

The dynamics of oceanic transform faults : constraints from geophysical, geochemical, and geodynamical modeling  

E-Print Network (OSTI)

Segmentation and crustal accretion at oceanic transform fault systems are investigated through a combination of geophysical data analysis and geodynamical and geochemical modeling. Chapter 1 examines the effect of fault ...

Gregg, Patricia Michelle Marie

2008-01-01T23:59:59.000Z

364

Sherlock—a system for diagnosing power distribution ring network faults  

Science Conference Proceedings (OSTI)

This paper reports the development of a software system, SHERLOCK, for fault diagnosis in power distribution ring networks. The system consists of a fault diagnosis subsystem implemented using Prolog and a user interface subsystem developed in the SmallTalk ...

Kit Po Wong; Chi Ping Tsang; Wan Yee Chan

1988-06-01T23:59:59.000Z

365

Model Acceptability Measure for the Identification of Failures in Qualitative Fault Monitoring Systems  

E-Print Network (OSTI)

This paper deals with two of the main tasks of Fault Monitoring Systems (FMS): fault detection and fault identification. During fault detection, the FMS should recognize that the plant behavior is abnormal, and therefore, that the plant is not working properly. During fault identification, the FMS should conclude which type of failure has occurred. The first goal of this work is to consolidate a new fault detection technique, called enveloping, that was developed in the context of the Fuzzy Inductive Reasoning Fault Monitoring System (FIRFMS). The second and primary goal of this paper is to introduce the model acceptability measure as a tool to enhance and make more robust the fault identification process in the context of FIRFMS. The enveloping technique and the model acceptability measure are applied to an electric circuit model previously used for such purpose in the literature. It is shown that the new methods outperform the ones previously advocated in FIRFMS for that purpose 1 ...

Antoni Escobet Angela; Angela Nebot; Francois E. Cellier

1999-01-01T23:59:59.000Z

366

FERRARI: A Flexible Software-Based Fault and Error Injection System  

Science Conference Proceedings (OSTI)

AbstractżA major step toward the development offault-tolerant computer systems is the validation of the dependability properties of these systems. Fault/error injection has been recognized as a powerful approach to validate the fault tolerance mechanisms ...

Ghani A. Kanawati; Nasser A. Kanawati; Jacob A. Abraham

1995-02-01T23:59:59.000Z

367

Slip on ridge transform faults : insights from earthquakes and laboratory experiments  

E-Print Network (OSTI)

The relatively simple tectonic environment of mid-ocean ridge transform fault (RTF) seismicity provides a unique opportunity for investigation of earthquake and faulting processes. We develop a scaling model that is complete ...

Boettcher, Margaret S

2005-01-01T23:59:59.000Z

368

Interseismic strain accumulation and the earthquake potential on the southern San Andreas fault system  

E-Print Network (OSTI)

lat- ter would imply subsidence to the east of the fault.indicate uplift, rather subsidence, to the east of the faultlikely involves ground subsidence to the west of the fault.

Fialko, Y

2006-01-01T23:59:59.000Z

369

Wetland Loss Is Not The Fault of Any One Company | America's ...  

U.S. Energy Information Administration (EIA)

Wetland Loss Is Not The Fault of Any One Company. By: Berwick Duvall II, Houma Courrier | 9.28.2007 September 28, 2007 Wetlands loss is not the fault ...

370

A COTS Wrapping Toolkit for Fault Tolerant Applications under Windows NT  

Science Conference Proceedings (OSTI)

This paper presents a software toolkit that allows enhancing the fault tolerant characteristics of a user application running under a Windows NT platform through sets of interchangeable and customizable Fault Tolerant Interposition Agents (FTI Agents). ...

Alfredo Benso; Silvia Chiusano; Paolo Prinetto

2000-07-01T23:59:59.000Z

371

Observations on Faults and Associated Permeability Structures in Hydrogeologic Units at the Nevada Test Site  

SciTech Connect

Observational data on Nevada Test Site (NTS) faults were gathered from a variety of sources, including surface and tunnel exposures, core samples, geophysical logs, and down-hole cameras. These data show that NTS fault characteristics and fault zone permeability structures are similar to those of faults studied in other regions. Faults at the NTS form complex and heterogeneous fault zones with flow properties that vary in both space and time. Flow property variability within fault zones can be broken down into four major components that allow for the development of a simplified, first approximation model of NTS fault zones. This conceptual model can be used as a general guide during development and evaluation of groundwater flow and contaminate transport models at the NTS.

Prothro, Lance B.; Drellack, Sigmund L.; Haugstad, Dawn N.; Huckins-Gang, Heather E.; Townsend, Margaret J.

2009-03-30T23:59:59.000Z

372

A general method for calculating co-seismic gravity changes in complex fault systems  

Science Conference Proceedings (OSTI)

A general method for calculating the total, dilatational, and free-air gravity for fault systems with arbitrary geometry, slip motion, and number of fault segments is presented. The technique uses a Green's function approach for a fault buried within ... Keywords: 91.10.-v, 91.10.Kg, 91.10.Op, 91.30.Px, Alaska, California, Fault network, Time-variable gravity

T. J. Hayes; K. F. Tiampo; J. B. Rundle; J. Fernández

2008-11-01T23:59:59.000Z

373

A model for the evaluation of fault tolerance in the FERMI system  

Science Conference Proceedings (OSTI)

Experiments of high energy physics planned at the Large Hadron Collider (LHC) at CERN (CH) require digital data acquisition systems with high throughput. Such systems need also be fault tolerant to the permanent and transient faults induced by radiation, ... Keywords: FERMI microsystem, Large Hadron Collider, VLSI, VLSI devices, data acquisition, digital data acquisition system, fault tolerance, fault tolerant computing, high energy physics, high energy physics instrumentation computing, model, nuclear electronics, radiation effects

A. Antola; L. Breveglieri

1995-11-01T23:59:59.000Z

374

Fault analysis of a semisubmersible's ballast control system  

SciTech Connect

This paper presents a practical ballast system for a twinhull design semisubmersible as an answer to the problems which could result from faults both interior and exterior to the system. The design presented is then examined through a fault analysis technique common to other industries and applicable to the life-sustaining ballast system. This examination confirms the design philosophy that a single fault or reasonable multiple faults should not lead to destabilization of the vessel.

Hock, C.J.; Balaban, E.G.

1984-05-01T23:59:59.000Z

375

Computer Aided Fault Tree Analysis System (CAFTA), Version 6.0 Demo  

Science Conference Proceedings (OSTI)

CAFTA is a computer software program used for developing reliability models of large complex systems, using fault tree and event tree methodology.DescriptionCAFTA is designed to meet the many needs of reliability analysts while performing fault tree/event tree analysis on a system or group of systems.  It includes:Fault Tree Editor for building, updating and printing fault tree modelsEvent Tree Editor for building, ...

2013-02-18T23:59:59.000Z

376

Distribution Fault Anticipator: Year 2000 Interim Report  

Science Conference Proceedings (OSTI)

Utilities must balance service reliability with the maintenance costs that are necessary in order to provide this reliability. While this always has been true, current competitive trends emphasize it more and more. Traditional preventive maintenance programs require utilities to maintain facilities and equipment on a periodic basis. There is an inherent and obvious tradeoff between the length of the maintenance interval and service reliability. The utility provides the highest level of service by setting...

2000-12-13T23:59:59.000Z

377

State emissions limitations for boilers: particulate matter  

SciTech Connect

This document summarizes regulations applicable to boilers as reflected in current state and local air regulations. Not all of these regulations are officially part of Federally-approved State Implementation Plans (SIPs). Several regulations have only recently been adopted by the State and are now undergoing EPA review for incorporation into the SIP. Each summary also contains local regulations more stringent than the State rules. Most local regulations in this handbook are included in the State Implementation Plan. Site-specific emission limits (variances from State limits or limits more stringent than State limits) are not included in these summaries. Appendix A contains maps showing the location of Air Quality Control Regions or other districts by which several States regulate emissions. Appendix B contains a summary of National Ambient Air Quality Standards, which States are required to meet as a minimum. Appendix C contains a description and summary of Federal New Source Performance Standards. Appendix D contains formulas for conversion of emmissions limits expressed in one set of units to the most common units - No. PM/MMBtu. Appendix E contains Figure 2 of ASME APS-1, used for determining particulate emissions limits in some States.

Not Available

1980-01-01T23:59:59.000Z

378

Investigation of Auxiliary Power Substation 95A4 fault and fire, Portsmouth Gaseous Diffusion Plant, March 24, 1982  

SciTech Connect

On March 24, 1982, an electrical fault and resultant fire in the 480 volt Auxiliary Power Substation 95A4 at the Portsmouth Gaseous Diffusion Plant destroyed that substation. There were no personal injuries, the overall loss was limited to the Substation, and the cost of replacing the Substation with repaired and new components has been estimated at $184,000. At the time of the incident, Goodyear was involved in a project to replace the obsolete 480 volt circuit breaker of the Auxiliary Power System. This project involved the disassembly, refurishing, and reassembly of 480 volt circuit breaker carriages by Goodyear personnel. The fault occurred in a circuit breaker upgraded under this project. The investigation of this accident is reported. The evidence suggests the fault resulted from the improper assembly of an upgraded 480 volt circuit breaker. Compounding the problem and leading to the extensive damage was the failure of the transformer secondary breaker to trip open as designed and interrupt the flow of power to the substation. It is surmised that inadequate testing during preventive maintenance contributed to this condition. Additional factors which may have contributed to the accident included: no requirements for assuring the competence of the electricians who installed the circuit breakers, no specific assembly instructions to the electricians, inadequate procedure instructions, and an inadequate procedure governing operational or load testing of the breaker. (LCL)

1982-06-01T23:59:59.000Z

379

Fault diagnosis of regenerative water heater based-on multi-class support vector machines  

Science Conference Proceedings (OSTI)

The main idea of multi-class support vector machines (SVMs) is described. a multi-class model for regenerative water heater fault diagnosis is presented combining the fuzzy logic and SVMs. The typical faults set of regenerative water heater is built ... Keywords: fault diagnosis, fuzzy rules, regenerative water heater, steam turbine, support vector machines

Lei Wang; Rui-Qing Zhang

2009-08-01T23:59:59.000Z

380

Ant Colony Clustering Procedure Used in Vibration Fault Diagnosis of Beam Pumping Unit  

Science Conference Proceedings (OSTI)

The study of vibration fault diagnosis of beam pumping unit is an important task to reasonable production, scientific management and improvement of the oil recovery. The vibration fault diagnosis is a good method with direct result. In view of measurement ... Keywords: ant colony algorithm, clustering procedure, beam pumping unit, fault, diagnosis

Wuguang Li; Shenglai Yang; Ranran Xu; Xiaoxu Sun; Xing Zhang

2011-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Modeling and experimental validation of internal faults in salient pole synchronous machines including space harmonics  

Science Conference Proceedings (OSTI)

Considering the space harmonics caused by the faulted windings, a simulation model of internal faults in salient pole synchronous machines is proposed in this paper. The model is based on the winding function approach, which makes no assumption for sinusoidal ... Keywords: Internal faults, Space harmonics, Synchronous machines, Winding function

X. Tu; L. -A. Dessaint; M. El Kahel; A. Barry

2006-06-01T23:59:59.000Z

382

A CONTROLLER FOR HVAC SYSTEMS WITH FAULT DETECTION CAPABILITIES BASED ON SIMULATION MODELS  

E-Print Network (OSTI)

1 A CONTROLLER FOR HVAC SYSTEMS WITH FAULT DETECTION CAPABILITIES BASED ON SIMULATION MODELS T. I describes a control scheme with fault detection capabilities suitable for application to HVAC systems as a reference of correct operation. Faults that occur in the HVAC system under control cause the PI

383

Automatic fault diagnosis of internal combustion engine based on spectrogram and artificial neural network  

Science Conference Proceedings (OSTI)

This paper presents a signal analysis technique for internal combustion (IC) engine fault diagnosis based on the spectrogram and artificial neural network (ANN). Condition monitoring and fault diagnosis of IC engine through acoustic signal analysis is ... Keywords: acoustic analysis, fault diagnosis, internal combustion engine

Sandeep Kumar Yadav; Prem Kumar Kalra

2010-04-01T23:59:59.000Z

384

A systematic review of design diversity-based solutions for fault-tolerant SOAs  

Science Conference Proceedings (OSTI)

Context: Over recent years, software developers have been evaluating the benefits of both Service-Oriented Architecture and software fault tolerance techniques based on design diversity by creating fault-tolerant composite services that leverage ... Keywords: SLR, SOA, composite services, fault tolerance

Amanda S. Nascimento; Cecília M. F. Rubira; Rachel Burrows; Fernando Castor

2013-04-01T23:59:59.000Z

385

A SVDD approach of fuzzy classification for analog circuit fault diagnosis with FWT as preprocessor  

Science Conference Proceedings (OSTI)

In this paper, a new approach of fault diagnosis in analog circuits, which employs the Fractional Wavelet Transform (FWT) to extract fault features and adopts a fuzzy multi-classifier based on the Support Vector Data Description (SVDD) to diagnose circuit ... Keywords: Analog circuit, Fault diagnosis, Feature extraction, Fractional wavelet transform, KFCM, SVDD

Hui Luo; Youren Wang, Jiang Cui

2011-08-01T23:59:59.000Z

386

Assessment of power-frequency based algorithms for fault location in power grids  

Science Conference Proceedings (OSTI)

The increased accuracy of the faults' location is a very actual request of the power grids' operation and management, reason to develop new and as precise as possible techniques for the estimation of the short-circuits' location. The actual fault locating ... Keywords: ATP simulation, fault location, power grids, power-frequency based algorithms

Marcel Istrate

2010-10-01T23:59:59.000Z

387

High impedance fault location in transmission line using nonlinear frequency analysis  

Science Conference Proceedings (OSTI)

The detection and location of high impedance faults on power system has been one of the most difficult problems in power transmission and distribution systems. According to a very highly nonlinear behavior of high impedance faults, a methodology is presented ... Keywords: high impedance fault, nonlinear frequency analysis, power line carrier, transmission line

Min-You Chen; Jin-Qian Zhai; Zi-Qiang Lang; Ju-Cheng Liao; Zhao-Yong Fan

2010-09-01T23:59:59.000Z

388

Dynamic behaviour of a DFIG wind turbine subjected to power system faults  

E-Print Network (OSTI)

Dynamic behaviour of a DFIG wind turbine subjected to power system faults Gabriele Michalke+, Anca of the dynamic interaction between variable speed DFIG wind turbines and the power system subjected to disturbances, such as short circuit faults. Focus of the paper is the fault ride-through capability of DFIG

389

A general noise-reduction framework for fault localization of Java programs  

Science Conference Proceedings (OSTI)

Context: Existing fault-localization techniques combine various program features and similarity coefficients with the aim of precisely assessing the similarities among the dynamic spectra of these program features to predict the locations of faults. ... Keywords: Fault localization, Key block chain, Noise reduction, Program debugging

Jian Xu; Zhenyu Zhang; W. K. Chan; T. H. Tse; Shanping Li

2013-05-01T23:59:59.000Z

390

A Survey of NASA and Military Standards on Fault Tolerance and Reliability Applied to Robotics  

E-Print Network (OSTI)

. There are Hand­ books (Reliability of Electronic Equipment [7], MIL­HDBK­217F, Fault Tree Handbook [25], NUREG Com­ mission as NUREG­0492, the Fault Tree Hand­ book [25]. 2.2 Parts Specifications In addition and Mission Quality, Washington, DC, April 1991. [25] NUREG­0492. Fault Tree Handbook. Technical report

Rice University - Center for Cooperative Autonomous Robots for Hazardous Environments

391

Power Transformer Fault Diagnosis Based on Integrated of Rough Set Theory and Evidence Theory  

Science Conference Proceedings (OSTI)

When using chromatography data analysis in diagnosis of power transformer fault, fault information cannot be make full use, which can't effectively discover knowledge hidden in data. In this paper a method integreted of rough set theory and evidence ... Keywords: Rough Set, Evidence Theory, Power Transformer, Fault Diagnosis

Zhou Ai-Hua, Yao Yi, Song Hong, Zeng Xiao-Hui

2013-01-01T23:59:59.000Z

392

Fault Diagnosis of Regenerative Water Heater Based-On Multi-class Support Vector Machines  

Science Conference Proceedings (OSTI)

The main idea of multi-class support vector machines (SVMs) is described. a multi-class model for regenerative water heater fault diagnosis is presented combining the fuzzy logic and SVMs. The typical faults set of regenerative water heater is built ... Keywords: steam turbine, regenerative water heater, fuzzy rules, support vector machines, fault diagnosis

Lei Wang; Rui-qing Zhang

2009-08-01T23:59:59.000Z

393

Fault conditions classification of automotive generator using an adaptive neuro-fuzzy inference system  

Science Conference Proceedings (OSTI)

In this paper, an adaptive neuro-fuzzy inference system (ANFIS) was proposed for condition monitoring and fault diagnosis of an automotive generator. Conventional fault indication of an automotive generator generally uses an indicator to inform the driver ... Keywords: Adaptive neuro-fuzzy inference system, Automotive generator, Discrete wavelet transform, Fault diagnosis system

Jian-Da Wu; Jun-Ming Kuo

2010-12-01T23:59:59.000Z

394

Review article: Achieving maximum reliability in fault tolerant network design for variable networks  

Science Conference Proceedings (OSTI)

The objective of this paper is to present a novel method to achieve maximum reliability for fault tolerant optimal network design when network has variable size. Reliability calculation is most important and critical component when fault tolerant optimal ... Keywords: Fault tolerant optimal design, Fixed and varying link reliability, Maximizing reliability, Neural networks, Variable network size

B. Kaushik, N. Kaur, A. K. Kohli

2013-07-01T23:59:59.000Z

395

A systematic fuzzy rule based approach for fault classification in transmission lines  

Science Conference Proceedings (OSTI)

The paper presents a new approach for fault classification in transmission line using a systematic fuzzy rule based approach. Fault classification is one of the important requirements in distance relaying for identifying the accurate phases involved ... Keywords: DT-fuzzy rule base, Decision Tree, Distance relaying, Fault classification, Heuristic fuzzy system, S-transform, Wavelet transform

S. R. Samantaray

2013-02-01T23:59:59.000Z

396

Yemanja—A Layered Fault Localization System for Multi-Domain Computing Utilities  

Science Conference Proceedings (OSTI)

Yemanja is a model-based event correlation engine for multi-layer fault diagnosis. It targets complex propagating fault scenarios, and can smoothly correlate low-level network events with high-level application performance alerts related to quality-of-service ... Keywords: Problem determination, event correlation, fault and performance management, service level agreements

K. Appleby; G. Goldszmidt; M. Steinder

2002-06-01T23:59:59.000Z

397

Bearing fault prognosis based on health state probability estimation  

Science Conference Proceedings (OSTI)

In condition-based maintenance (CBM), effective diagnostic and prognostic tools are essential for maintenance engineers to identify imminent fault and predict the remaining useful life before the components finally fail. This enables remedial actions ... Keywords: Degradation stage, High pressure LNG pump, Prognosis, Remaining useful life (RUL), Support Vector Machine (SVM)

Hack-Eun Kim; Andy C. C. Tan; Joseph Mathew; Byeong-Keun Choi

2012-04-01T23:59:59.000Z

398

Conditional edge-fault-tolerant Hamiltonicity of dual-cubes  

Science Conference Proceedings (OSTI)

The dual-cube is an interconnection network for linking a large number of nodes with a low node degree. It uses low-dimensional hypercubes as building blocks and keeps the main desired properties of the hypercube. A dual-cube DC(n) has n+1 links per ... Keywords: Conditional fault-tolerant, Dual-cubes, Hamiltonian cycle, Hypercube, Interconnection network

Jheng-Cheng Chen; Chang-Hsiung Tsai

2011-02-01T23:59:59.000Z

399

Modeling of switching operations using fault matrix method  

Science Conference Proceedings (OSTI)

Switching operations in energy supply networks are either modeled by adding or removing artificial nodes which results in state dependent grid topology or by setting the switch impedance to high or low value. This procedure is not very accurate and can ... Keywords: admittance matrix, fault matrix method, power system, switching operation, transmission lines

Martin Wolter; Bernd R. Oswald

2007-05-01T23:59:59.000Z

400

Hybrid simulation of large electrical networks with assymmetrical fault modelling  

Science Conference Proceedings (OSTI)

Owing to the increasing attention placed on dynamic security assessment in the light of recent blackouts, hybrid simulation, involving the interfacing of electromagnetic transients (EMT) simulators and transient stability (TS) simulators for the more ... Keywords: asymmetrical fault modelling, electromagnetic transients, hybrid simulation, interaction protocol, transient stability

H. T. Su; K. W. Chan; L. A. Snider

2008-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Sensor Fault Detection in Power Plants Andrew Kusiak1  

E-Print Network (OSTI)

and Soroush 2003 . Any false reading could lead to di- sastrous outcomes. In a coal-fired power plant, faultySensor Fault Detection in Power Plants Andrew Kusiak1 and Zhe Song2 Abstract: This paper presents approach handles data from temporal processes by periodic updates of the knowledge base. An industrial

Kusiak, Andrew

402

IEEE TRANSACTION ON COMPUTERS 1 Adaptive Fault Management of Parallel  

E-Print Network (OSTI)

of high performance computing (HPC) continues to grow, application fault resilience becomes crucial- tions, High performance computing, Large-scale systems. I. INTRODUCTION IN the field of high performance Performance Computing Zhiling Lan, Member, IEEE, and Yawei Li, Student Member, IEEE Abstract--As the scale

Lan, Zhiling

403

Dominant Feature Identification for Industrial Fault Detection and Isolation Applications  

Science Conference Proceedings (OSTI)

Fault Detection and Isolation (FDI) is crucial to reduce production costs and down-time in industrial machines. In this paper, we show how to find a reduced feature subset which is optimal in both estimation and clustering least square errors using a ... Keywords: Least Square Error (LSE), Neural Network (NN), Principal Component Analysis (PCA), Principal Feature Analysis (PFA), Singular Value Decomposition (SVD)

Jun-Hong Zhou; Chee Khiang Pang; Frank L. Lewis; Zhao-Wei Zhong

2011-08-01T23:59:59.000Z

404

Using Write Protected Data Structures To Improve Software Fault Tolerance  

E-Print Network (OSTI)

Using Write Protected Data Structures To Improve Software Fault Tolerance in Highly Available critical DBMS data structures against software errors. Guarding (write-protecting) DBMS data improves protection to new data structures very easy. To implement the expose segment update model in Sprite, we

California at Irvine, University of

405

RIS-M-2326 FAULT TREE AND CAUSE CONSEQUENCE ANALYSIS  

E-Print Network (OSTI)

and control, nuclear reactor safety systems and aircraft landing systems. For systems of failure in operations. For example a nuclear reactor shutdown system should fail at a rate which Abstract. A theory underlying application of automatic fault tree analysis to computer programs

406

Distributed Fault Diagnosis Using Bayesian Reasoning in MAGNETO  

Science Conference Proceedings (OSTI)

Many of the emerging telecom services make use of Outer Edge Networks, in particular Home Area Networks. The configuration and maintenance of such services may not be under full control of the telecom operator which still needs to guarantee the service ... Keywords: Bayesian inference, distributed fault diagnosis, outer edge, agents, self-learning

Pablo Arozarena; Raquel Toribio; Alvaro Carrera

2011-10-01T23:59:59.000Z

407

Embedded holonic fault diagnosis of complex transportation systems  

Science Conference Proceedings (OSTI)

The use of electronic equipment and embedded computing technologies in modern complex transportation systems continues to grow in a highly competitive market, in which product maintainability and availability is vital. These technological advances also ... Keywords: Cooperative fault diagnosis, Corrective maintenance, Embedded diagnosis, Holonic architecture, Model-based diagnosis, Railway transportation system

Antoine Le Mortellec; Joffrey Clarhaut; Yves Sallez; Thierry Berger; Damien Trentesaux

2013-01-01T23:59:59.000Z

408

Critique of Fault-Tolerant Quantum Information Processing  

E-Print Network (OSTI)

This is a chapter in a book \\emph{Quantum Error Correction} edited by D. A. Lidar and T. A. Brun, and published by Cambridge University Press (2013)\\\\ (http://www.cambridge.org/us/academic/subjects/physics/quantum-physics-quantum-information-and-quantum-computation/quantum-error-correction)\\\\ presenting the author's view on feasibility of fault-tolerant quantum information processing.

Robert Alicki

2013-10-31T23:59:59.000Z

409

COMMENTARY:Limits to adaptation  

SciTech Connect

An actor-centered, risk-based approach to defining limits to social adaptation provides a useful analytic framing for identifying and anticipating these limits and informing debates over society s responses to climate change.

Preston, Benjamin L [ORNL

2013-01-01T23:59:59.000Z

410

Bound States for Magic State Distillation in Fault-Tolerant Quantum Computation  

E-Print Network (OSTI)

Magic state distillation is an important primitive in fault-tolerant quantum computation. The magic states are pure non-stabilizer states which can be distilled from certain mixed non-stabilizer states via Clifford group operations alone. Because of the Gottesman-Knill theorem, mixtures of Pauli eigenstates are not expected to be magic state distillable, but it has been an open question whether all mixed states outside this set may be distilled. In this Letter we show that, when resources are finitely limited, non-distillable states exist outside the stabilizer octahedron. In analogy with the bound entangled states, which arise in entanglement theory, we call such states bound states for magic state distillation.

Earl T. Campbell; Dan E. Browne

2009-08-06T23:59:59.000Z

411

Limitations on Carry Lookahead Networks  

Science Conference Proceedings (OSTI)

The fan-in and fan-out limitations imposed by specific gate circuits force corresponding limits-upon the sizes of carry lookahead circuits fabricated from those gates. The relationships between those limits are derived, providing simple formulae that ... Keywords: high-speed arithmetic, Binary addition, carry lookahead

T. Rhyne

1984-04-01T23:59:59.000Z

412

Fault trees for decision making in systems analysis  

SciTech Connect

The application of fault tree analysis (FTA) to system safety and reliability is presented within the framework of system safety analysis. The concepts and techniques involved in manual and automated fault tree construction are described and their differences noted. The theory of mathematical reliability pertinent to FTA is presented with emphasis on engineering applications. An outline of the quantitative reliability techniques of the Reactor Safety Study is given. Concepts of probabilistic importance are presented within the fault tree framework and applied to the areas of system design, diagnosis and simulation. The computer code IMPORTANCE ranks basic events and cut sets according to a sensitivity analysis. A useful feature of the IMPORTANCE code is that it can accept relative failure data as input. The output of the IMPORTANCE code can assist an analyst in finding weaknesses in system design and operation, suggest the most optimal course of system upgrade, and determine the optimal location of sensors within a system. A general simulation model of system failure in terms of fault tree logic is described. The model is intended for efficient diagnosis of the causes of system failure in the event of a system breakdown. It can also be used to assist an operator in making decisions under a time constraint regarding the future course of operations. The model is well suited for computer implementation. New results incorporated in the simulation model include an algorithm to generate repair checklists on the basis of fault tree logic and a one-step-ahead optimization procedure that minimizes the expected time to diagnose system failure. (80 figures, 20 tables) (auth)

Lambert, H.E.

1975-10-01T23:59:59.000Z

413

Microstructures and Rheology of a Limestone-Shale Thrust Fault  

E-Print Network (OSTI)

The Copper Creek thrust fault in the southern Appalachians places Cambrian over Ordovician sedimentary strata. The fault accommodated displacement of 15-20 km at 100-180 °C. Along the hanging wall-footwall contact, microstructures within a ~2 cm thick calcite and shale shear zone suggest that calcite, not shale, controlled the rheology of the shear zone rocks. While shale deformed brittley, plasticity-induced fracturing in calcite resulted in ultrafine-grained (shale into the shear zone, shows the evolution of rheology within the shear zone. Sedimentary laminations 1 cm below the shear zone are cut by minor faults, stylolites, and fault-parallel and perpendicular calcite veins. At vein intersections, calcite grain size is reduced (to ~0.3 ?m), and microstructures include inter-and-intragranular fractures, four-grain junctions, and interpenetrating boundaries. Porosity rises to 6 percent from shale clasts (5-350 ?m) lie within an ultrafine-grained calcite (shale matrix. Ultrafinegrained calcite (shale. Calcite vein microstructures suggest veins continued to form during deformation. Fractures at twin-twin and twin-grain boundary intersections suggest grain size reduction by plasticity-induced fracturing, resulting in <1 ?m grains. Interpenetrating boundaries, four-grain junctions, and no LPO indicate the ultrafine-grained calcite deformed by viscous grain boundary sliding. The evolution of the ultrafine-grain shear zone rocks by a combination of plastic and brittle processes and the deformation of the interconnected network of ultrafine-grained calcite by viscous GBS enabled a large displacement along a narrow fault zone.

Wells, Rachel Kristen

2010-12-01T23:59:59.000Z

414

Absolute dating of brittle fault movements: Late Permian and late Jurassic extensional fault breccias in western Norway  

E-Print Network (OSTI)

events has ad- vanced significantly since the quintes- sential fault-rock classification schemes metamorphosed, allochthonous units with broadly Ordovician, white-mica cooling ages. On AtlĂąy, the NSD was cut) and from the palaeomagnetic study of Torsvik et al. (1992) (`Site' prefixes). Paper 128 Disc #12

Andersen, Torgeir Bjørge

415

Design to Achieve Fault Tolerance and Resilience  

SciTech Connect

The purpose of this report is to provide initial scoping for follow on work designed to improve nuclear plant operation. The focus of this report is twofold. Selected trips over the last five years are examined to determine if there are potential opportunities to automate tasks that are currently performed manually. The second area is to evaluate the potential for avoiding reactor trips by reducing power in a controlled manner upon the loss of turbine generator load. Some candidate opportunities to reduce the frequency on reactor trips identified in this report are redundant feedwater controls, automated response to a feedwater or condensate pump trip reducing power vice a reactor trip, and elimination of air operators for the feedwater control valves or providing redundant air supplies.

Ted Quinn; Richard Bockhorst; Craig Peterson; Gregg Swindlehurst

2012-09-01T23:59:59.000Z

416

Analysis of Fault Permeability Using Mapping and Flow Modeling, Hickory Sandstone Aquifer, Central Texas  

Science Conference Proceedings (OSTI)

Reservoir compartments, typical targets for infill well locations, are commonly created by faults that may reduce permeability. A narrow fault may consist of a complex assemblage of deformation elements that result in spatially variable and anisotropic permeabilities. We report on the permeability structure of a km-scale fault sampled through drilling a faulted siliciclastic aquifer in central Texas. Probe and whole-core permeabilities, serial CAT scans, and textural and structural data from the selected core samples are used to understand permeability structure of fault zones and develop predictive models of fault zone permeability. Using numerical flow simulation, it is possible to predict permeability anisotropy associated with faults and evaluate the effect of individual deformation elements in the overall permeability tensor. We found relationships between the permeability of the host rock and those of the highly deformed (HD) fault-elements according to the fault throw. The lateral continuity and predictable permeability of the HD fault elements enhance capability for estimating the effects of subseismic faulting on fluid flow in low-shale reservoirs.

Nieto Camargo, Jorge E., E-mail: jorge.nietocamargo@aramco.com; Jensen, Jerry L., E-mail: jjensen@ucalgary.ca [University of Calgary, Department of Chemical and Petroleum Engineering (Canada)

2012-09-15T23:59:59.000Z

417

Active Fault Controls At High-Temperature Geothermal Sites- Prospecting For  

Open Energy Info (EERE)

Page Page Edit History Facebook icon Twitter icon » Active Fault Controls At High-Temperature Geothermal Sites- Prospecting For New Faults Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Active Fault Controls At High-Temperature Geothermal Sites- Prospecting For New Faults Details Activities (1) Areas (1) Regions (0) Abstract: Our previous studies found spatial associations between seismically active faults and high-temperature geothermal resources in the western Basin and Range, suggesting that recency of fault movement may be a useful criterion for resource exploration. We have developed a simple conceptual model in which recently active (Holocene) faults are preferred conduits for migration of thermal water from deep crustal depths, and we

418

Locating an active fault zone in Coso geothermal field by analyzing seismic  

Open Energy Info (EERE)

Locating an active fault zone in Coso geothermal field by analyzing seismic Locating an active fault zone in Coso geothermal field by analyzing seismic guided waves from microearthquake data Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Locating an active fault zone in Coso geothermal field by analyzing seismic guided waves from microearthquake data Details Activities (1) Areas (1) Regions (0) Abstract: Active fault systems usually provide high-permeability channels for hydrothermal outflow in geothermal fields. Locating such fault systems is of a vital importance to plan geothermal production and injection drilling, since an active fault zone often acts as a fracture-extensive low-velocity wave guide to seismic waves. We have located an active fault zone in the Coso geothermal field, California, by identifying and analyzing

419

Adiabatic Eastern Boundary Currents  

Science Conference Proceedings (OSTI)

The dynamics of the eastern boundary current of a high-resolution, idealized model of oceanic circulation are analyzed and interpreted in terms of residual mean theory. In this framework, it is clear that the eastern boundary current is adiabatic ...

Paola Cessi; Christopher L. Wolfe

2013-06-01T23:59:59.000Z

420

Principles of Stray Current  

Science Conference Proceedings (OSTI)

...current ( Ref 5 , 11 ) High voltage ac (HVAC) power lines ( Ref 12 , Ref 13 , Ref 14 ) Any current source that may use the earth as a path, either intentionally

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Intrusive gravity currents  

E-Print Network (OSTI)

The front speed of intrusive gravity currents. J. FluidP.F. Linden. Intrusive gravity currents. J. Fluid Mechanics,of mesoscale variability of gravity waves. Part II: Frontal,

Hang, Alice Thanh

2009-01-01T23:59:59.000Z

422

Current research - CECM  

E-Print Network (OSTI)

Current research interests. Computational paleogenomics and comparative genomics. See the website of our group: Computational Methods for Paleogenomics ...

423

Analysis of Test Generation Complexity for Stuck-At and Path Delay Faults Based on ?k-Notation  

Science Conference Proceedings (OSTI)

In this paper, we discuss the relationship between the test generation complexity for path delay faults (PDFs) and that for stuck-at faults (SAFs) in combinational and sequential circuits using the recently introduced ?k-notation. On ... Keywords: easily testable, path delay faults, stuck-at faults, test generation complexity

Chia Yee Ooi; Thomas Clouqueur; Hideo Fujiwara

2007-08-01T23:59:59.000Z

424

Sensor fault detection using the Mahalanobis distance  

Science Conference Proceedings (OSTI)

A method is described by which a localized sensor abnormality can be detected using the Mahalanobis distance. The Mahalanobis distance is approximately the weighted distance from the hyperplane formed by the principal components to the particular observation. Qualitatively, the principal components correspond to the physical laws that govern the behavior of the systems and constraints placed on the system. If there are more sensors than principal components, there are redundant measurements. This redundancy can be used to detect abnormalities that are due either to sensor failure or a localized change in the system being measured. The method compares the distribution of the Mahalanobis distance during normal operation with the distribution during the current operation. A likelihood ratio test is then used to determine if a sensor has gone bad or if operations in the reactor are different from normal. The sensor whose value is not normal is identified by comparing Mahalanobis distances computed with one sensor masked. When the abnormal sensor is masked, the Mahalanobis distance for this subset of sensors will be within prespecified bounds. The method is demonstrated on 20 subassembly output thermocouples in the core of Experimental Breeder Reactor II.

White, A.M.; Gross, K.C. (Argonne National Lab., IL (United States)); Kubic, W.L (Los Alamos National Lab., NM (United States))

1993-01-01T23:59:59.000Z

425

CIRCUITS FOR CURRENT MEASUREMENTS  

DOE Patents (OSTI)

Circuits are presented for measurement of a logarithmic scale of current flowing in a high impedance. In one form of the invention the disclosed circuit is in combination with an ionization chamber to measure lonization current. The particular circuit arrangement lncludes a vacuum tube having at least one grid, an ionization chamber connected in series with a high voltage source and the grid of the vacuum tube, and a d-c amplifier feedback circuit. As the ionization chamber current passes between the grid and cathode of the tube, the feedback circuit acts to stabilize the anode current, and the feedback voltage is a measure of the logaritbm of the ionization current.

Cox, R.J.

1958-11-01T23:59:59.000Z

426

Globalization and the Sustainability of Large Current Account Imbalances: Size Matters  

E-Print Network (OSTI)

2008 Globalization and the Sustainability of Large Currentpaper evaluates the sustainability of large current accountby the limited sustainability of the larger current account

Aizenman, Joshua; Sun, Yi

2008-01-01T23:59:59.000Z

427

Globalization and the Sustainability of Large Current Account Imbalances: Size Matters*  

E-Print Network (OSTI)

2009 Globalization and the Sustainability of Large Currentpaper evaluates the sustainability of large current accountby the limited sustainability of the larger current account

Aizenman, Joshua; Sun, Yi

2009-01-01T23:59:59.000Z

428

Gravity and fault structures, Long Valley caldera, California  

DOE Green Energy (OSTI)

The main and catastrophic phase of eruption in Long Valley occurred 0.73 m.y. ago with the eruption of over 600 km/sup 3/ of rhyolitic magma. Subsequent collapse of the roof rocks produced a caldera which is now elliptical in shape, 32 km east-west by 17 km north-south. The caldera, like other large Quarternary silicic ash-flow volcanoes that have been studied by various workers, has a nearly coincident Bouguer gravity low. Earlier interpretations of the gravity anomaly have attributed the entire anomaly to lower density rocks filling the collapsed structure. However, on the basis of many additional gravity stations and supporting subsurface data from several new holes, a much more complex and accurate picture has emerged of caldera structure. From a three-dimensional inversion of the residual Bouguer gravity data we can resolve discontinuities that seem to correlate with extensions of pre-caldera faults into the caldera and faults associated with the ring fracture. Some of these faults are believed related to the present-day hydrothermal upflow zone and the zone of youngest volcanic activity within the caldera.

Carle, S.F.; Goldstein, N.E.

1987-07-01T23:59:59.000Z

429

Detachment Faulting and Geothermal Resources - An Innovative Integrated  

Open Energy Info (EERE)

Detachment Faulting and Geothermal Resources - An Innovative Integrated Detachment Faulting and Geothermal Resources - An Innovative Integrated Geological and Geophysical Investigation in Fish Lake Valley, Nevada Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Detachment Faulting and Geothermal Resources - An Innovative Integrated Geological and Geophysical Investigation in Fish Lake Valley, Nevada Project Type / Topic 1 Recovery Act: Geothermal Technologies Program Project Type / Topic 2 Validation of Innovative Exploration Technologies Project Description This program is designed to provide valuable new subsurface information about one of the Nation's arguably most promising high-temperature geothermal targets. Until now, the Emigrant Geothermal Prospect has been tested by only shallow and relatively shallow thermal-gradient boreholes and a small number of exploration wells, all of which have lacked any detailed 2-D or 3-D structural context. The applicants propose to conduct an innovative integration of detailed 2- D and 3-D structural reconstructions (structural mapping and reflection/refraction source seismology integrated with available data).

430

Age and magnitude of dip-slip faulting deduced from differential cooling histories: An example from the Hope fault, northwest Montana  

Science Conference Proceedings (OSTI)

Determination of the age of fault motion poses a challenge in tectonics, yet rarely produces satisfactory results. The authors describe a new method in which the age and magnitude of dip-slip faulting are estimated from contrasting cooling histories of footwall and hanging wall rocks adjacent to the Hope fault, northwest Montana. The Hope fault has been interpreted in the past as a mostly right-slip fault. New kinematic data, {sup 40}Ar/{sup 39}Ar thermochronometry, and geobarometry indicate that cooling of footwall rocks at {approximately}40 Ma resulted from dip-slip movement. This movement caused vertical separation of about 3 to 5 km between footwall and hanging wall rocks, suggesting that a minimum dip-slip component of 4 km developed during the Late Eocene. These results indicate that the Hope fault experienced substantial normal slip in the Late Eocene, making it coeval with other normal and detachment-style faults in the northern U.S. Cordillera. The western Lewis and Clark line, which in part may share a common tectonic history with the Hope fault, should be re-evaluated for its role in transferring Tertiary extension between the Priest River and Bitterroot core complexes. 45 refs., 10 figs., 1 tab.

Fillipone, J.A.; Yin, An; Harrison, T.M. [Univ. of California, Los Angeles, CA (United States)] [and others

1995-03-01T23:59:59.000Z

431

Limit Cycle and Conserved Dynamics  

E-Print Network (OSTI)

We demonstrate that a potential coexists with limit cycle. Here the potential determines the final distribution of population. Our demonstration consists of three steps: We first show the existence of limit from a typical physical sciences setting: the potential is a type of Mexican hat type, with the strength of a magnetic field scale with the strength the potential gradient near the limit cycle, and the friction goes to zero faster than the potential near the limit cycle. Hence the dynamics at the limit cycle is conserved. The diffusion matrix is nevertheless finite at the limit cycle. Secondly, we construct the potential in the dynamics with limit cycle in a typical dynamical systems setting. Thirdly, we argue that such a construction can be carried out in a more general situation based on a method discovered by one of us. This method of dealing with stochastic differential equation is in general different from both Ito and Stratonovich calculus. Our result may be useful in many related applications, such as in the discussion of metastability of limit cycle and in the construction of Hopfield potential in the neural network computation.

X. -M. Zhu; L. Yin; P. Ao

2004-12-21T23:59:59.000Z

432

FUEL CASK IMPACT LIMITER VULNERABILITIES  

Science Conference Proceedings (OSTI)

Cylindrical fuel casks often have impact limiters surrounding just the ends of the cask shaft in a typical 'dumbbell' arrangement. The primary purpose of these impact limiters is to absorb energy to reduce loads on the cask structure during impacts associated with a severe accident. Impact limiters are also credited in many packages with protecting closure seals and maintaining lower peak temperatures during fire events. For this credit to be taken in safety analyses, the impact limiter attachment system must be shown to retain the impact limiter following Normal Conditions of Transport (NCT) and Hypothetical Accident Conditions (HAC) impacts. Large casks are often certified by analysis only because of the costs associated with testing. Therefore, some cask impact limiter attachment systems have not been tested in real impacts. A recent structural analysis of the T-3 Spent Fuel Containment Cask found problems with the design of the impact limiter attachment system. Assumptions in the original Safety Analysis for Packaging (SARP) concerning the loading in the attachment bolts were found to be inaccurate in certain drop orientations. This paper documents the lessons learned and their applicability to impact limiter attachment system designs.

Leduc, D; Jeffery England, J; Roy Rothermel, R

2009-02-09T23:59:59.000Z

433

Offline count-limited certificates  

Science Conference Proceedings (OSTI)

In this paper, we present the idea of offline count-limited certificates (or clics for short), and show how these can be implemented using minimal trusted hardware functionality already widely available today. Offline count-limited ... Keywords: authentication, offline payments, smartcards, trusted platform module (TPM)

Luis F. G. Sarmenta; Marten van Dijk; Jonathan Rhodes; Srinivas Devadas

2008-03-01T23:59:59.000Z

434

Study of a Fault Analysis System for a Heat Supply Network Based on GIS  

E-Print Network (OSTI)

Conventional methods cannot satisfy the request of the layout and operation management in a heating system. The geographical information system (GIS) in a heat supply network can realize information conformity and information share roundly, which makes management of information improve to a new level in district heating. When fault of the heat supply network occurs, the traditional methods make fault reaction time long and the efficiency low, and enlarge the fault harm. The system of fault analysis in a heat supply network based on GIS mainly simulates and calculates according to various fault conditions. By selection of valve shut-off schemes in fault conditions and simulation of various fault conditions, the fault treatment scheme can be optimized. The results of simulation can be shown in the GIS graphics with the aid of advanced image display function of GIS. The application of this system brings great significance to heating system on the management enhancing, fault number-reducing, quick decision-making and influence area diminishing in case of fault.

Zou, P.; Liu, M.; Tang, H.; Wang, X.; Li, N.; Wang, W.

2006-01-01T23:59:59.000Z

435

Effects of burial history, rock ductility and recovery magnitude on inversion of normal faulted strata  

E-Print Network (OSTI)

Inversion of normal faults at different burial depths is studied using physical models constructed with rock and deformed at confining pressure. Models consist of a 1 cm thick limestone layer above a fault dipping 70° in a rigid medium, and are subjected to a two-stage deformation path of layer-parallel extension followed by coaxial contraction. To investigate the effects of burial depth and relative ductility on kinematics of inversion, five model suites were run in which confining pressure and recovery magnitudes were varied. In all models, a normal fault forms in the limestone during extension. Subsequent inversion is accommodated in the limestone by reverse slip on the normal fault, creation and movement along new reverse faults, and distributed fracturing and folding. The relative contribution of these mechanisms depends on the relative ductility of the rock and magnitude of inversion. Reverse slip on the normal fault and distributed fracturing occur during early stages of inversion and new reverse faults form at intermediate stages. During late stage inversion, strata with low mean ductility shorten primarily by reverse slip on the pre-existing normal fault, whereas strata with high mean ductility shorten by continued slip on reverse faults. Evidence for inversion is provided by superposed fracture fabrics in the footwall at early stages (100% recovery). This change in fracture fabric during inversion could lead to an overpressured footwall in natural inversion structures. Reverse reactivation of the normal faults may occur during coaxial contraction even though such faults are unfavorably oriented assuming typical rock friction behavior and a homogeneous stress state. Localized reverse slip on normal faults is favored when strata display low ductility and less favored when strata work-harden during extension, however, the models show that the final inversion geometry is dependent on the ductility during both phases of deformation. Even a fault that is work-hardened during extension can reactivate if the ductility during contraction is low enough.

Kuhle, Nathan John

2001-01-01T23:59:59.000Z

436

Composite Biaxially Textured Substrates Using Ultrasonic ...  

Sensors used in quantum computing and medical imaging; Fault current limiters; HTS dynamic synchronous condensers; Electronic filters used in cell ...

437

Electric current locator  

DOE Patents (OSTI)

The disclosure herein provides an apparatus for location of a quantity of current vectors in an electrical device, where the current vector has a known direction and a known relative magnitude to an input current supplied to the electrical device. Mathematical constants used in Biot-Savart superposition equations are determined for the electrical device, the orientation of the apparatus, and relative magnitude of the current vector and the input current, and the apparatus utilizes magnetic field sensors oriented to a sensing plane to provide current vector location based on the solution of the Biot-Savart superposition equations. Description of required orientations between the apparatus and the electrical device are disclosed and various methods of determining the mathematical constants are presented.

King, Paul E. (Corvallis, OR); Woodside, Charles Rigel (Corvallis, OR)

2012-02-07T23:59:59.000Z

438

Direct-Current Resistivity Survey At Dixie Valley Geothermal Field Area  

Open Energy Info (EERE)

Direct-Current Resistivity Survey At Dixie Valley Direct-Current Resistivity Survey At Dixie Valley Geothermal Field Area (Laney, 2005) Exploration Activity Details Location Dixie Valley Geothermal Field Area Exploration Technique Direct-Current Resistivity Survey Activity Date Usefulness useful DOE-funding Unknown Notes Structural Controls, Alteration, Permeability and Thermal Regime of Dixie Valley from New-Generation Mt/Galvanic Array Profiling, Phillip Wannamaker. A new-generation MT/DC array resistivity measurement system was applied at the Dixie Valley thermal area. Basic goals of the survey are 1), resolve a fundamental structural ambiguity at the Dixie Valley thermal area (single rangefront fault versus shallower, stepped pediment; 2), delineate fault zones which have experienced fluid flux as indicated by low resistivity;

439

Current Openings : Bio Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

GO About Research Resources Education Industry Redefining the Frontiers of Bioenergy Research About BESC Current Openings Our Partners People Who's Who Job Listings Postdoctoral...

440

RF current sensor  

DOE Patents (OSTI)

An RF sensor having a novel current sensing probe and a voltage sensing probe to measure voltage and current. The current sensor is disposed in a transmission line to link all of the flux generated by the flowing current in order to obtain an accurate measurement. The voltage sensor is a flat plate which operates as a capacitive plate to sense voltage on a center conductor of the transmission line, in which the measured voltage is obtained across a resistance leg of a R-C differentiator circuit formed by the characteristic impedance of a connecting transmission line and a capacitance of the plate, which is positioned proximal to the center conductor.

Moore, James A. (Powell, TN); Sparks, Dennis O. (Maryville, TN)

1998-11-10T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiting" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Eddy Current Instruments  

Science Conference Proceedings (OSTI)

Table 2   Types and capabilities of commercially available eddy current instruments...measurement of four variables, analog

442

Energy flux limitation by tame turbulence  

SciTech Connect

A quasi-linear theory of energy flux limitation by ion acoustic turbulence is presented. This distribution function is modelled by a Maxwellian plus an additional piece which carries a heat flux Q. By taking the fourth moment of the Vlasov equation one finds the anomalous thermal conductivity K approximately 3 v/sub e/ delta/sub De/ (e phi/T/sub e/)$sup -2$. Other moments treated self-consistently include anomalous ion heating, electron cooling, current generation and enhanced inverse bremsstrahlung due to the nonthermal ion fluctuations. (auth)

Manheimer, W.M.

1975-11-01T23:59:59.000Z

443

BGE_Comments_CurrentComms.pdf  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Reading (based Reading (based on hourly reads) Cellular network 5000 30 minutes 19.2K >90% <15 sec >95% 4 1 2 Direct Load Control 22 250K 8 hours 1K 100% <120 sec >99% 2 1 2 Real time pricing At the customer premises At charging stations 53 1755 8 hours 9600 bps >90% 5 sec <5 per mo. >95% 5 2 1 CBC-5000 2330 CBC-7000 1621 LVC N/A 638 4 hours N/A N/A N/A N/A N/A N/A N/A See comment See comment N/A N/A Customer Calls N/A N/A N/A N/A N/A N/A N/A N/A Applications Distributed Generation Management in-Home Display of Customer Usage Automated Feeder Switching Transformer Monitoring Voltage and Current Monitoring 8 hours 1K >60% Capacitor Bank Control Fault Current Indicator 10 sec >99% 4 1 2 Quantified Estimates Ranking of Relative Importance of Each Estimated Number of End Point Devices to

444

High-Resolution Aeromagnetic Survey to Image Shallow Faults, Dixie Valley  

Open Energy Info (EERE)

Resolution Aeromagnetic Survey to Image Shallow Faults, Dixie Valley Resolution Aeromagnetic Survey to Image Shallow Faults, Dixie Valley Geothermal Field, Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: High-Resolution Aeromagnetic Survey to Image Shallow Faults, Dixie Valley Geothermal Field, Nevada Abstract N/A Author V. J. S. Grauch Published U.S. Geological Survey, 2002 Report Number 02-384 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for High-Resolution Aeromagnetic Survey to Image Shallow Faults, Dixie Valley Geothermal Field, Nevada Citation V. J. S. Grauch. 2002. High-Resolution Aeromagnetic Survey to Image Shallow Faults, Dixie Valley Geothermal Field, Nevada. (!) : U.S. Geological Survey. Report No.: 02-384. Retrieved from "http://en.openei.org/w/index.php?title=High-Resolution_Aeromagnetic_Survey_to_Image_Shallow_Faults,_Dixie_Valley_Geothermal_Field,_Nevada&oldid=682601"

445

Modeling fault-zone guided waves of microearthquakes in a geothermal  

Open Energy Info (EERE)

fault-zone guided waves of microearthquakes in a geothermal fault-zone guided waves of microearthquakes in a geothermal reservoir Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Modeling fault-zone guided waves of microearthquakes in a geothermal reservoir Details Activities (1) Areas (1) Regions (0) Abstract: Fault-zone guided waves have been identified in microearthquake seismograms recorded at the Coso Geothermal Field, California. The observed guided waves have particle motions and propagation group velocities similar to Rayleigh wave modes. A numerical method has been employed to simulate the guided-wave propagation through the fault zone. By comparing observed and synthetic waveforms the fault-zone width and its P- and S-wave velocity structure have been estimated. It is suggested here that the identification

446

Effect of HVDC line faults on transient torsional torques of turbine-generator shafts  

SciTech Connect

This paper investigates the effects of HVdc line faults, line de-energization, and line re-energization on the transient torsional stresses of steam turbine-generator (T-G) units. The studies are conducted on a bipole HVdc system which connects a T-G set to a large ac system. The shaft transient stresses of the T-G set as a result of HVac line fault, fault clearing, and automatic reclosure are also determined when the HVdc transmission system is replaced by an equivalent double-line HVac system. The EMTDC program is used for the simulation studies. The studies conclude that transient shaft stresses as a result of HVdc line fault and its subsequent switching events are (1) significantly less severe than those of HVac faults and subsequent switchings, and (2) not sensitive to the fault location and disturbance duration.

Shi, W. (Xi'an Jiaotong Univ. (China). Dept. of Electrical Engineering); Iravani, M.R. (Univ. of Toronto, Ontario (Canada). Dept. of Electrical Engineering)

1994-08-01T23:59:59.000Z

447

A High-Resolution Aeromagnetic Survey to Identify Buried Faults at Dixie Valley, Nevada  

Science Conference Proceedings (OSTI)

Preliminary results from a high-resolution aeromagnetic survey (200m line spacing) acquired in Dixie Valley early in 2002 provide confirmation of intra-basin faulting based on subtle surface indications. In addition the data allow identification of the locations and trends of many faults that have not been recognized at the surface, and provide a picture of intrabasin faulting patterns not possible using other techniques. The data reveal a suite of northeasterly-trending curving and branching faults that surround a relatively coherent block in the area of Humboldt Salt Marsh, the deepest part of the basin. The producing reservoir occurs at the north end of this coherent block, where rampart faults from the northwest side of the valley merge with anthithetic faults from the central and southeast parts of the valley.

Smith, Richard Paul; Grauch, V. J. S.; Blackwell, David D.

2002-09-01T23:59:59.000Z

448

Voltage controlled current source  

DOE Patents (OSTI)

A seven decade, voltage controlled current source is described for use in testing intermediate range nuclear instruments that covers the entire test current range of from 10 picoamperes to 100 microamperes. High accuracy is obtained throughout the entire seven decades of output current with circuitry that includes a coordinated switching scheme responsive to the input signal from a hybrid computer to control the input voltage to an antilog amplifier, and to selectively connect a resistance to the antilog amplifier output to provide a continuous output current source as a function of a preset range of input voltage. An operator controlled switch provides current adjustment for operation in either a real-time simulation test mode or a time response test mode.

Casne, Gregory M. (Pittsburgh, PA)

1992-01-01T23:59:59.000Z

449

A Hierarchical Rule-Based Fault Detection and Diagnostic Method for HVAC Systems  

E-Print Network (OSTI)

A rule-based, system-level fault detection and diagnostic (FDD) method for HVAC systems was developed. It functions as an interface between multiple, equipment-specific FDD tools and a human operator. The method resolves and prioritizes conflicting fault reports from equipment-specific FDD tools, performs FDD at the system level, and presents an integrated view of an HVAC system’s fault status to an operator. A simulation study to test and evaluate the method was conducted.

Jeffrey Schein; Steven T. Bushby

2005-01-01T23:59:59.000Z

450

Single event upset tests of a RISC-based fault-tolerant computer  

Science Conference Proceedings (OSTI)

The project successfully demonstrated that dual lock-step comparison of commercial RISC processors is a viable fault-tolerant approach to handling SEU in space environment. The fault tolerant approach on orbit error rate was 38 times less than the single processor error rate. The random nature of the upsets and appearance in critical code section show it is essential to incorporate both hardware and software in the design and operation of fault-tolerant computers.

Kimbrough, J.R.; Butner, D.N.; Colella, N.J.; Kaschmitter, J.L.; Shaeffer, D.L.; McKnett, C.L.; Coakley, P.G.; Casteneda, C.

1996-03-23T23:59:59.000Z

451

Paleoseismology of latest Pleistocene and Holocene fault activity in central Oregon  

SciTech Connect

Latest Pleistocene and Holocene fault activity in Oregon concentrates along four zones that splay northward from seismically active faults along the Central Nevada and Eastern California seismic zones. The Central Oregon fault zone is one of these zones, which splays northward from dextral faults of the Walker Lane, stretching across the flanks of several ranges in south-central Oregon along a N20[degree]W trend, and ultimately merges with the Cascade volcanic arc near Newberry volcano. Aerial-photo interpretations and field investigations reveal fault scarps with, on average about 4 m, but in places as much as [approximately]10 m of vertical expression across latest Pleistocene pluvial lake deposits and geomorphic surfaces. Trenches across three different faults in the Central Oregon zone reveal evidence for multiple episodes of faulting in the form of fault-related colluvial deposits and deformed horizons which have been cut by younger fault movements. Trench exposures reveal faults with relatively steep dips and anastomosing traces, which are interpreted locally as evidence for a small oblique-slip component. Vertical offsets measured in the trenches are [approximately]2 m or more for each event. Radiocarbon analyses and preliminary tephra correlations indicate that the exposed deposits are [approximately]30,000 yr in age and younger, and record the decline of latest Pleistocene pluvial lakes. Commonly, reworked or deformed lacustrine deposits and interlayered and faulted colluvial deposits mark the second and third events back, which probably occurred in the Latest Pleistocene, at a time during low to moderate lake levels. If offsets of the past 18,000 yr are representative of the long-term average, then faults along this zone have slip rates of from 0.2 mm/yr to 0.6 mm/yr and recurrence intervals that range from [approximately]4,000 yr to 11,000 yr.

Pezzopane, S.K.; Weldon, R.J. II (Univ. of Oregon, Eugene, OR (United States). Dept. of Geological Sciences)

1993-04-01T23:59:59.000Z

452

Groundwater penetrating radar and high resolution seismic for locating shallow faults in unconsolidated sediments  

Science Conference Proceedings (OSTI)

Faults in shallow, unconsolidated sediments, particularly in coastal plain settings, are very difficult to discern during subsurface exploration yet have critical impact to groundwater flow, contaminant transport and geotechnical evaluations. This paper presents a case study using cross-over geophysical technologies in an area where shallow faulting is probable and known contamination exists. A comparison is made between Wenner and dipole-dipole resistivity data, ground penetrating radar, and high resolution seismic data. Data from these methods were verified with a cone penetrometer investigation for subsurface lithology and compared to existing monitoring well data. Interpretations from these techniques are compared with actual and theoretical shallow faulting found in the literature. The results of this study suggests that (1) the CPT study, combined with the monitoring well data may suggest that discontinuities in correlatable zones may indicate that faulting is present (2) the addition of the Wenner and dipole-dipole data may further suggest that offset zones exist in the shallow subsurface but not allow specific fault planes or fault stranding to be mapped (3) the high resolution seismic data will image faults to within a few feet of the surface but does not have the resolution to identify the faulting on the scale of our models, however it will suggest locations for upward continuation of faulted zones (4) offset 100 MHz and 200 MHz CMP GPR will image zones and features that may be fault planes and strands similar to our models (5) 300 MHz GPR will image higher resolution features that may suggest the presence of deeper faults and strands, and (6) the combination of all of the tools in this study, particularly the GPR and seismic may allow for the mapping of small scale, shallow faulting in unconsolidated sediments.

Wyatt, D.E. [Westinghouse Savannah River Co., Aiken, SC (United States)]|[South Carolina Univ., Columbia, SC (United States). Earth Sciences and Resources Inst.; Waddell, M.G. [South Carolina Univ., Columbia, SC (United States). Earth Sciences and Resources Inst.; Sexton, B.G. [Microseeps Ltd., Pittsburgh, PA (United States)

1993-12-31T23:59:59.000Z

453

Data Acquisition-Manipulation At San Jacinto Fault Geothermal Area (1982) |  

Open Energy Info (EERE)

Fault Geothermal Area (1982) Fault Geothermal Area (1982) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Data Acquisition-Manipulation At San Jacinto Fault Geothermal Area (1982) Exploration Activity Details Location San Jacinto Fault Geothermal Area Exploration Technique Data Acquisition-Manipulation Activity Date 1982 Usefulness useful DOE-funding Unknown Exploration Basis Develop parameters to identify geothermal region Notes Statistical methods are outlined to separate spatially, temporally, and magnitude-dependent portions of both the random and non-random components of the seismicity. The methodology employed compares the seismicity distributions with a generalized Poisson distribution. Temporally related events are identified by the distribution of the interoccurrence times.

454

Dynamic Modeling, Sensor Placement Design, and Fault Diagnosis of Nuclear Desalination Systems.  

E-Print Network (OSTI)

??Fault diagnosis of sensors, devices, and equipment is an important topic in the nuclear industry for effective and continuous operation of nuclear power plants. All… (more)

Li, Fan

2011-01-01T23:59:59.000Z

455

Non-invasive Trigger-free Fault Injection Method Based on ...  

Science Conference Proceedings (OSTI)

... [2] H. Bar-El, H. Choukri, D. Naccache, M. Tunstall, and C. Whe- lan, “The sorcerer's apprentice guide to fault attack,” IACR ePrint archive, vol. ...

2011-09-21T23:59:59.000Z

456

Timing of late Quaternary faulting in the 1954 Dixie Valley earthquake area, central Nevada  

Science Conference Proceedings (OSTI)

The 1954 Dixie Valley earthquake (M 6.9) in central Nevada produced about 3 m of total vertical displacement distributed across two principal fault zones along the east flank of the Stillwater Range. Most of the 1954 displacement was along the range-front fault with minor amounts on the piedmont fault zone, in contrast to an earlier Holocene displacement that was restricted to the piedmont fault. Detailed chronostratigraphic, exploratory drilling, and trenching studies indicate that faulting events have migrated back and forth between the range-front and piedmont fault zones in the late Quaternary. Prior to the 1954 earthquake, the range-front fault last ruptured in the late Pleistocene, during a large-magnitude event here called the IXL event. The northern half of the piedmont fault zone last ruptured between 1.5 and 6.8 ka during a large-magnitude event here called the Bend event. On the basis of 6 m total slip since the deposition of shoreline gravels at {approximately} 12 ka, the estimated Holocene vertical-slip rate is 0.5 mm/yr for the Dixie Valley rupture zone. Overlapping and migratory patterns of late Quaternary faulting indicate that the Dixie Valley zone does not fit a simple segmentation model.

Bell, J.W. (Univ. of Nevada, Reno (USA)); Katzer, T. (Las Vegas Valley Water District, NV (USA))

1990-07-01T23:59:59.000Z

457

Core analysis of Chattanooga shale structures west of Pine Mountain fault, Whitley County, Kentucky  

SciTech Connect

A 100-ft oriented core from the Chandler 1 well in Whitley County, Kentucky, sampled the entire Chattanooga Shale section 10 mi west of the Pine Mountain fault. Cored slickenlined structures include 76 bedding-plane faults, four strike-slip faults, and 44 thrust faults. One interpreted kink band was encountered. Slickenline trends, fault geometry, interpreted paleo-stress fields, and chronology of structural evolution do not reflect the N30/sup 0/W transposition direction of the Pine Mountain sheet (seated in Chattanooga Shale) or N60/sup 0/E strike of the Pine Mountain fault. For example, 62% of 81 bedding-fault slickenline orientations trend N20/sup 0/-90/sup 0/W with N60/sup 0/-70/sup 0/W dominant. A secondary direction (32% of bedding slickenlines) strikes N40/sup 0/-80/sup 0/E with N60/sup 0/-70/sup 0/E dominant. Only 9% of bedding-fault slickenlines trend N25/sup 0/-35/sup 0/W. In addition, northwest-trending slickenlines formed first on four of five bedding faults containing both major trends. Thrust faults group into five mean attitudes. Four orientations (N31/sup 0/W, 38/sup 0/NE); N40/sup 0/W, 36/sup 0/SW; N15/sup 0/E, 45/sup 0/SE); and N46/sup 0/1E, 42/sup 0/NW) may define two conjugate shear sets that imply horizontal maximum compressive stress directions of N58/sup 0/W and N54/sup 0/E, respectively. The fifth trend (N88/sup 0/W, 48/sup 0/NE) may relate genetically to strike-slip faults oriented N20/sup 0/W and N60/sup 0/E that indicate horizontal maximum compressive stresses oriented N2/sup 0/-18/sup 0/E. Overprinted thrust-fault slickenlines and faults offsetting faults suggest that maximum compressive stresses first acted northwest-southeast, then northeast-southwest and, finally in a north-northeast-south-southwest direction. Furthermore, bedding faults preceded thrust faults. Differences between Pine Mountain sheet structures and those in the core may reflect local Chattanooga thickness variations or the absence of Chattanooga decollement structures.

Kulander, B.R.; Dean, S.L.; Kirr, J.; Feiler, J.

1987-09-01T23:59:59.000Z

458

A study of the robustness of magic state distillation against Clifford gate faults.  

E-Print Network (OSTI)

??Quantum error correction and fault-tolerance are at the heart of any scalable quantum computation architecture. Developing a set of tools that satisfy the requirements of… (more)

Jochym-O'Connor, Tomas Raphael

2012-01-01T23:59:59.000Z

459

Methodology for fault detection and diagnostics in an ocean turbine using vibration analysis and modeling.  

E-Print Network (OSTI)

??This thesis describes a methodology for mechanical fault detection and diagnostics in an ocean turbine using vibration analysis and modeling. This methodology relies on the… (more)

Mjit, Mustapha.

2009-01-01T23:59:59.000Z

460

Constructions of fault tolerant linear compressors and linear decompressors  

E-Print Network (OSTI)

Abstract — The constructions of optical buffers is one of the most critically sought after optical technologies in all-optical packet-switched networks, and constructing optical buffers directly via optical Switches and fiber Delay Lines (SDL) has received a lot of attention recently in the literature. A practical and challenging issue of the constructions of optical buffers that has not been addressed before is on the fault tolerant capability of such constructions. In this paper, we focus on the constructions of fault tolerant linear compressors and linear decompressors. The basic network element for our constructions is scaled optical memory cell, which is constructed by a 2 × 2 optical crossbar switch and a fiber delay line. We give a multistage construction of a self-routing linear compressor by a concatenation of scaled optical memory cells. We also show that if the delays, say d1, d2,..., dM, of the fibers in the scaled optical memory cells satisfy a certain condition (specifically, the condition in (A2) given in Section I), then our multistage construction can be operated as a self-routing linear compressor with maximum delay ? M?F even after up to F of the M scaled optical memory cells fail to function properly, where 0 ? F ? M ? 1. Furthermore, we prove that our multistage construction with the fiber delays d1, d2,..., dM given by the generalized Fibonacci series of order F is the best among all constructions of a linear compressor that can tolerate up to F faulty scaled optical memory cells by using M scaled optical memory cells. Similarly results are also obtained for the constructions of fault tolerant linear decompressors. I.

Cheng-shang Chang; Tsz-hsuan Chao; Jay Cheng; Duan-shin Lee

2007-01-01T23:59:59.000Z

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461

The South Atlantic Current  

Science Conference Proceedings (OSTI)

In this paper we use the historical hydrographic data base for the South Atlantic Ocean to investigate (i) the hydrographic boundary between the subtropical gyre and the Antarctic Circumpolar Current (ACC), the Sub-tropical Front (STF), and (ii) ...

Lothar Stramma; Ray G. Peterson

1990-06-01T23:59:59.000Z

462

Geothermal Energy: Current abstracts  

DOE Green Energy (OSTI)

This bulletin announces the current worldwide information available on the technologies required for economic recovery of geothermal energy and its use as direct heat or for electric power production. (ACR)

Ringe, A.C. (ed.)

1988-02-01T23:59:59.000Z

463

Beam current sensor  

DOE Patents (OSTI)

A current sensor for measuring the dc component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivities in the nano-ampere range.

Kuchnir, M.; Mills, F.E.

1984-09-28T23:59:59.000Z

464

Beam current sensor  

DOE Patents (OSTI)

A current sensor for measuring the DC component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivites in the nano-ampere range.

Kuchnir, Moyses (Elmhurst, IL); Mills, Frederick E. (Elburn, IL)

1987-01-01T23:59:59.000Z

465

Bioethanol Limited | Open Energy Information  

Open Energy Info (EERE)

Bioethanol Limited Bioethanol Limited Jump to: navigation, search Name Bioethanol Limited Place London, United Kingdom Zip SE1 7TJ Sector Renewable Energy Product Aims to develop a global renewable transport fuel business supplying primarily bioethanol but also biodiesel. Coordinates 51.506325°, -0.127144° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":51.506325,"lon":-0.127144,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

466

Ablamp Limited | Open Energy Information  

Open Energy Info (EERE)

Ablamp Limited Ablamp Limited Jump to: navigation, search Name Ablamp Limited Place Nanhai, Guangdong Province, China Sector Solar Product Manufacturer of energy-saving Compact Fluorescent Light Bulbs, solar-powered lights, LED bulbs, auto lamps and other speciality lamps. Coordinates 23.049681°, 113.173737° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":23.049681,"lon":113.173737,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}