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1

Fault Current Limiters  

Broader source: Energy.gov (indexed) [DOE]

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

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

3

Summary of Superconducting Fault Current Limiter Technology  

Science Journals Connector (OSTI)

In recent years, superconducting fault current limiter (SFCL) has become one of the forefront topics of current-limiting technology in the world. In this...

Linmang Wang; Pengzan Jiang; Dada Wang

2012-01-01T23:59:59.000Z

4

Development of Superconducting AC Fault Current Limiter  

Science Journals Connector (OSTI)

The authors have developed a new superconducting fault current limiter whose impedance during normal operation is very small. During fault conditions, the limiter behaves as a superconducting reactor. The limiter

Daisuke Ito; Eriko Yoneda; Tsutomu Fujioka…

1990-01-01T23:59:59.000Z

5

Test on Superconducting AC Fault Current Limiter  

Science Journals Connector (OSTI)

The authors have developed a new superconducting fault current limiter whose impedance during normal operation is very small. During fault conditions, the limiter behaves as a superconducting reactor. The limiter

Daisuke Ito; Eriko S. Yoneda…

1990-01-01T23:59:59.000Z

6

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,

7

An Assessment of Fault Current Limiter Testing Requirements ...  

Broader source: Energy.gov (indexed) [DOE]

An Assessment of Fault Current Limiter Testing Requirements An Assessment of Fault Current Limiter Testing Requirements The U.S. Department of Energy's (DOE) Office of Electricity...

8

Novel 3-Phase Inductive Fault Current Limiter  

Science Journals Connector (OSTI)

The paper describes the inductive three-phase fault current limiter. In this work I examine the novel arrangements of the perfect closed superconducting loop made of HTS wire. I applied one iron core with 3 limbs and special loops for uniform temperature of the superconducting wire. In this work I present the results of my experiments with this device. I present the static and dynamic measured results of this solution. It has got several advantages e. g. fast switching and less fault power for high-power electric machines. The advantage of the equipment is that in the case of single-phase short circuit the current will decrease in all the three phases. This can be an appropriate solution for high power machines. For example, in the case of high-power electric motor if there is a single-phase breaking or a single phase short circuit, we can decrease the current in the three phases.

Janos Kosa

2012-01-01T23:59:59.000Z

9

A Magnetic Shielding Type Superconducting Fault-Current Limiter  

Science Journals Connector (OSTI)

In a Magnetic Shielding type Fault-Current Limiter (MSFCL), the characteristics of the magnetic ... ) is an important factor in limiting the current flow. In this study, to improve the efficiency of the fault current

N. Miyauchi; H. Nakane; S. Haseyama; S. Yoshizawa

1999-01-01T23:59:59.000Z

10

Optimal power flow considering fault current level constraints and fault current limiters  

Science Journals Connector (OSTI)

Abstract The aim of this paper is to present a novel method to dispatch the active generation power properly in the power system while incorporating fault current levels as constraints for the optimization problem. Due to the limited capacity of protective devices such as circuit breakers, allocating active power without considering fault current levels can probably lead to fault currents exceeding the rating of these devices. Hence restricting the fault current levels to an allowable amount while minimizing a specified objective function seems to be necessary. In a number of cases even the appropriate allocation of active power is not able to reduce the fault current levels to the permitted amount therefore using fault current limiters (FCL) is unavoidable. In this paper also a planning scheme is presented for the location and sizing of fault current limiters and the effect of fault current limiters on the objective functions is investigated.

Amirhossein Khazali; Mohsen Kalantar

2014-01-01T23:59:59.000Z

11

Fault current limiters and power switches  

SciTech Connect (OSTI)

Five papers give an overview of the Los Alamos National Lab`s collaboration with private industry and universities in developing High-Temperature Superconductor (HTS) Devices. Highlighted is the lab`s general approach and technical progress towards: design and fabrication of HTS current leads; high gradient magnetic separation for treatment of drinking and waste water; development of coils based on superconductor tape windings; testing of a HTS fault current limiter; and AC loss measuments of multifilament layered HTS conductors. Listed for each of these projects are commercial and university research/development partners along with the proposed projects for FY 1995.

Boenig, H. [Los Alamos National Lab., NM (United States)

1994-07-29T23:59:59.000Z

12

A transformer type fault current limiter with spark gap  

Science Journals Connector (OSTI)

A novel fault current limiter (FCL) is proposed in this paper. ... of the capacitor. During the short-circuit faults, the FCL resonantly produces a high impedance in the fault circuit after the breakdown of the s...

Zhang Xiaoqing; Ming Li

2010-06-01T23:59:59.000Z

13

Modeling and Simulation of Resistive Superconducting Fault-Current Limiters  

Science Journals Connector (OSTI)

Superconducting fault-current limiters (SFCL) offer ideal performance in electrical ... simulation model for a novel resistive type superconducting fault-current limiter is proposed. This model includes the elect...

S. Nemdili; S. Belkhiat

2012-10-01T23:59:59.000Z

14

Superconducting Fault Current Limiter for Transmission Voltage  

Science Journals Connector (OSTI)

Within a collaboration of American Superconductor, Siemens, Nexans and Southern California Edison one electrical phase of a resistive superconducting fault current limiter for the 115 kV transmission voltage level has been designed and manufactured. The active part of the limiter consists of 63 bifilar coils made of 12 mm wide steel-stabilized YBCO conductor and is housed in a cryostat operated at 5 bar and 74 K. The first phase was completely assembled and successfully subjected to power switching tests and high voltage tests. The basic design of the system and the test results are reported. The work was funded in part by US-DOE under Contract Number DE-FC26-07NT43243.

Hans-Peter Kraemer; Wolfgang Schmidt; Hong Cai; Bruce Gamble; David Madura; Tim MacDonald; Joe McNamara; Walther Romanosky; Greg Snitchler; Nicolas Lallouet; Frank Schmidt; Syed Ahmed

2012-01-01T23:59:59.000Z

15

Dynamic Inductance in Saturated Cores Fault Current Limiters  

Science Journals Connector (OSTI)

The saturated cores Fault Current Limiter (FCL) is one of the leading ... for providing a commercial robust solution to the fault current problem. Basically, the saturated cores FCL ... its saturated cores state ...

Y. Nikulshin; Y. Wolfus; A. Friedman…

2014-09-01T23:59:59.000Z

16

Coil and HTS Development for Fault Current Limiters  

Science Journals Connector (OSTI)

Fault current limiters are being developed to limit peak currents in transmission and distribution systems. The authors ... and a coil configuration specifically for high transient currents and the resulting high...

B. Gamble; G. Snitchler; M. Manlief…

1997-01-01T23:59:59.000Z

17

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

18

Fault current limiter and alternating current circuit breaker  

SciTech Connect (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

19

High Temperature Superconducting Fault Current Limiter for Utility Applications  

Science Journals Connector (OSTI)

One of the most near term High Temperature Superconductor (HTS) applications is the Fault Current Limiter (FCL). It is a device that...

E. M. W. Leung; G. W. Albert; M. Dew…

1997-01-01T23:59:59.000Z

20

Fault current limiter with shield and adjacent cores  

DOE Patents [OSTI]

In a fault current limiter (FCL) of a saturated core type having at least one coil wound around a high permeability material, a method of suppressing the time derivative of the fault current at the zero current point includes the following step: utilizing an electromagnetic screen or shield around the AC coil to suppress the time derivative current levels during zero current conditions.

Darmann, Francis Anthony; Moriconi, Franco; Hodge, Eoin Patrick

2013-10-22T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

Fault current limiter based on triggered vacuum switch  

Science Journals Connector (OSTI)

A new type of fault current limiter (FCL) based on triggered vacuum switch ... is mainly composed of a capacitor, a current-limiting reactor connected with a capacitor in ... behaves as a conventional series comp...

Jing Shi; Ji-yan Zou; Jun-jia He…

2000-12-01T23:59:59.000Z

22

Melt-processed YBCO for a Fault Current Limiter  

Science Journals Connector (OSTI)

Bulk High-Tc...-Superconductors (HTSC) offer applications in the field of fault current limiters in power networks: Current limitation can be accomplished by means of ... with a primary winding carrying the power...

H. Kanbach; E. Bochenek; M. Trautmann; R. Fischer…

1994-01-01T23:59:59.000Z

23

Superconducting fault current limiter for power utility application  

SciTech Connect (OSTI)

Recent accomplishments in the development of superconducting fault current limiters for power systems are outlined. These accomplishments include the comprehensive requirement for fault current limiters developed by SCE; down-selection; bridge concepts; shunt concepts; and high resistivity matrix substrates for HTS conductors. The proposed Phase II SPI-FCL Program is outlined. It is concluded that the SPI fault current limiter program will benefit both the power utility industry as well as the high temperature superconductivity community and progress of Phase I is right on target.

Leung, E. [Martin Marietta Corp., Oak Ridge, TN (United States)

1994-07-29T23:59:59.000Z

24

A dc superconducting fault current limiter using die-pressed  

Science Journals Connector (OSTI)

A model of a superconducting fault current limiter on a polycrystalline high-temperature superconductor basis is checked in the dc short circuit regime. Protection of load takes place under the conditions described in this paper. The use of ceramic materials with superconducting-normal metal-superconducting Josephson junction network having an S-type current-voltage characteristic (CVC) is shown to be effective for fault current limiter devices.

A G Mamalis; M I Petrov; D A Balaev; K A; D M Gohfeld; S V Militsyn; S G; V I Kirko; I N Vottea

2001-01-01T23:59:59.000Z

25

Experimental study on characteristics of superconducting fault current limiters connected  

Science Journals Connector (OSTI)

Superconducting fault current limiters (SCFCLs) can reduce fault current; thus SCFCLs allow the capacity of circuit breakers to be reduced and lend flexibility to power system network designs. Furthermore, SCFCLs are expected to improve power system stability, as has been confirmed by some experiments. Therefore, various kinds of SCFCLs were proposed and have been studied. For introducing SCFCLs in power systems, there should be some specifications, such as the impedance, the trigger current level, and the recovery time. Fault analyses pointed out that accuracy of the trigger current level is required. A transformer type SCFCL with an adjustable trigger current level was proposed, designed, made, and tested. Then, limiting tests on three-phase SCFCLs by use of an artificial transmission line with a small generator were carried out. The test results indicated that at phase-to-phase faults, the SCFCLs for the fault phases do not always turn into the limiting mode. From two points of view, it is important to study characteristics of the series connection for SCFCLs: one is as mentioned above, and the other is that a series connection of some SCFCLs of small impedance may be installed in place of an SCFCL of larger impedance. This paper describes the results of limiting tests on two SCFCLs connected in series. The tests were carried out under some different conditions of fault currents, fault phases, and trigger current levels of SCFCLs. Some discussion on characteristics of series connection of SCFCLs appears also.

Hiroyuki Hatta; Tanzo Nitta; Tomomi Oide; Masakuni Chiba; Yasuyuki Shirai; Akihiro Mochida

2004-01-01T23:59:59.000Z

26

8 - Superconducting fault current limiters and power cables  

Science Journals Connector (OSTI)

Abstract: This chapter addresses the technology of superconducting power cables and superconducting fault current limiters. The first part of the chapter is a general summary of the electric power grid. This sets the stage for a discussion of the historical development of superconducting AC and DC cables, which begins with low temperature superconductor-based systems. It then describes the present state of superconducting cable technology and gives a summary of some of the major programs around the world. Whereas power cables may be thought of as a replacement for conventional power system components, fault current limiters and fault current controllers have no conventional equivalent in the power grid. Several conceptually different fault current limiter designs are described. Their state of development and installation on the power grid are described.

W. Hassenzahl

2012-01-01T23:59:59.000Z

27

Fault Current Limit (FCL) Technology (Magnetic Valve Controlled Reactor-Type Fault Current Limiter Principle and Simulation)  

Science Journals Connector (OSTI)

Summarized the FCL practical research which faces to the key technical problems, briefly introduces the study of magnetic valve controllable reactor type fault current limiter principle, and the simulation result...

Chunzhe Shi

2012-01-01T23:59:59.000Z

28

Limiting characteristics of the superconducting fault current limiter applied to the neutral line of conventional transformer  

Science Journals Connector (OSTI)

Abstract The increased electricity demands influenced by the recent industrial development make the electric power distribution system more comprehensive, and the risks are high to cause failures to steady state electric line due to the extended range of fault at the time of fault occurrence. Also, the high performance and the high precision electric appliances that sensitive to switching surge and fault current expose vulnerability of reduced life span and increased fault occurrence ratio. Therefore, this thesis analyzed the fault limiting characteristics by the fault types by applying the superconducting fault current limiter to the neutral line of the transformer in order to reduce the fault currents that flow such high performance appliances. A current transformer (CT) that detects the fault current in the simulated power distribution system, a switching control system that is self-developed and a transformer are used in constructing a circuit. When a fault occurs, the initial fault current is restricted by the superconducting fault current limiter and simultaneously detours the fault current by operating the SCR contact of the switching control system through the detection by CT. This thesis analyzed the limiting characteristics of the superconducting fault current limiter that are applied to the neutral line of the transformer by the fault types.

I.G. Im; H.S. Choi; B.I. Jung

2013-01-01T23:59:59.000Z

29

Design and current-limiting simulation of magnetic-shield type superconducting fault current limiter with high-Tc superconductors  

SciTech Connect (OSTI)

The continuous development of electric power utilities has led to the increase in the problems concerning fault currents. The use of fault current limiters, which suppress fault currents below a prescribed level, has been examined in many places. The authors have studied a superconducting fault current limiter that is based on the magnetic shielding effect of superconductors. In this paper, the authors derive a requirement for leading to a flux-jumping inside a ceramic superconductor at liquid nitrogen temperature. Next, two kinds of magnetic-shield type superconducting fault current limiters are designed, and their current-limiting simulations are tried using a computer.

Kajikawa, K.; Kaiho, K.; Tamada, N. [Electrotechnical Lab., Tsukuba, Ibaraki (Japan)] [Electrotechnical Lab., Tsukuba, Ibaraki (Japan); Onishi, T. [Hokkaido Univ., Sapporo (Japan)] [Hokkaido Univ., Sapporo (Japan)

1996-07-01T23:59:59.000Z

30

Bias current influence on the characteristic of the magnetic-controlled switcher type fault current limiter  

Science Journals Connector (OSTI)

A novel magnetic-controlled switcher type fault current limiter (FCL) for high voltage electric network is presented. The current limiting principle of the FCL and the bias current influence on the characteristic...

Yan-xia Pan ???; Jian-guo Jiang ???

2009-06-01T23:59:59.000Z

31

Dynamic core length in saturated core fault current limiters  

Science Journals Connector (OSTI)

A saturated core fault current limiter (SCFCL) is a non-linear core-reactor where the core is saturated by an external superconducting DC bias source to achieve a low core permeability at nominal AC currents. Fault current levels in the AC coils de-saturate the core and transform it to a higher permeability state, hence limiting the fault current. In this work we describe the transition between saturated and de-saturated states in three SCFCL configurations. The 'effective core length', Leff, of the SCFCL, defined as the length of the de-saturated AC core limb, is introduced for exploring this transition as a function of the current, I, in the AC coil. Practically, Leff allows one to see the SCFCL as an inductor with a variable core length, allowing calculations of the impedance of the SCFCL over the whole range of operating currents. The Leff(I) curve is further used to calculate the dynamics of the demagnetization factor in a SCFCL. We show that the strong change in the magnetic induction of a SCFCL at high current is the result of both increasing the effective core length and decreasing the demagnetization factor. The method and results presented here serve as an important tool for comparing between various SCFCL concepts not only by comparing their impedance values at the extreme fault and nominal current conditions but also by providing an insight into the full de-saturation process.

Y Nikulshin; Y Wolfus; A Friedman; Y Yeshurun

2013-01-01T23:59:59.000Z

32

Testing of 3-meter Prototype Fault Current Limiting Cables  

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

2009-01-01T23:59:59.000Z

33

Superconducting fault-current limiter and inductor design  

SciTech Connect (OSTI)

A superconducting fault current limiter (SFCL) that uses a biased superconducting inductor in a diode or thyristor bridge circuit was analyzed for transmission systems in 69, 138, and 230 rms kV utility transmission systems. The limiter was evaluated for costs with all components - superconducting coil, diode and/or SCR power electronics, high voltage insulation, high voltage bushings and vapor cooled leads, dewar, and refrigerator - included. A design was undertaken for the superconducting cable and coils for both diode and SCR 69 kV limiter circuits.

Rogers, J.D.; Boenig, H.J.; Chowdhuri, P.; Schermer, R.I.; Wollan, J.J.; Weldon, D.M.

1982-01-01T23:59:59.000Z

34

New Concept of a Superconducting Fault Current Limiter and Its Evaluation of Quenching Feature  

Science Journals Connector (OSTI)

The present paper reviews the concept of a new superconducting fault current limiter with NbTi AC superconducting wire for the suppression of short-circuit currents. This fault current limiter takes full advantag...

Kiyoshi Okaniwa; Tsukushi Hara; Takahiko Yamamoto…

1991-01-01T23:59:59.000Z

35

Alternating Current Loss of Strip Arrays as a Model for Resistive Fault Current Limiters  

Science Journals Connector (OSTI)

Hysteretic alternating current (ac) loss P...in arrays of superconducting strip lines are calculated on the bases of the critical state model. For a simplified model of a film-type fault current limiter, we consi...

Yasunori Mawatari; Hirofumi Yamasaki

2000-01-01T23:59:59.000Z

36

9 - Superconducting fault current limiters and power cables  

Science Journals Connector (OSTI)

Abstract: This chapter addresses the technology of superconducting power cables and superconducting fault current limiters (FCL). The first part of the chapter is a general summary of the electric power grid. This sets the stage for a discussion of the historical development of superconducting AC and DC cables, which begins with low temperature superconductor (LTS)-based systems. It then describes the present status of superconducting cable technology and summarizes some of the major programs around the world. Whereas power cables may be thought of as a replacement for conventional power system components, \\{FCLs\\} and fault current controllers (FCC) have no conventional equivalent in the power grid. Several conceptually different FCL designs are described. The status of their development and installation on the power grid are described.

W. Hassenzahl

2013-01-01T23:59:59.000Z

37

A Study on a High-Tc Superconducting Fault Current Limiter  

Science Journals Connector (OSTI)

The application of a high-Tc superconductor with a high critical current density (Jc) to a fault current limiter has been investigated. When the superconductor changes ... , it has a resistance which can limit fault

Tatsuya Hayashi; Teijiro Mori; Yuuichi Wada…

1992-01-01T23:59:59.000Z

38

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

SciTech Connect (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

39

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

Science Journals Connector (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

40

Superconducting fault current limiter with fast vacuum commutation modulus  

Science Journals Connector (OSTI)

A new approach to a problem of creation of a resistive version of superconducting fault current limiters (FCL) on the basis of HTS materials has been considered. According to this approach, a scheme of FCL is added by a commutation modulus which contains a fast vacuum interrupter. This interrupter allows one to switch off the transport current as soon as 5 ms after transition of the HTS element to the normal state. The proposed scheme allows one to restrict more than an order in value a necessary operation time of FCL in a regime of a current limitation. As a result, a time of recovering the superconducting state can be significantly reduced that allows FCL to operate in automatic iterative regime. The considering device can operate not only in high voltage ac transmission lines but also in dc electrical networks. A numerical simulation of transit processes in a proposed scheme of FCL has been performed for different regimes and its features are analyzed with respect to other schemes of FCL. An experimental study of test mock-up commutation elements of FCL has been performed. This study demonstrates an efficiency of the proposed scheme. A test of a FCL model with the limiting current up to 15 kA has been realized.

D Alferov; D Yevsin; L Fisher; V Ivanov; V Sidorov

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

Quenching Characteristics of a 400V-100A Class Superconducting Fault Current Limiter  

Science Journals Connector (OSTI)

The suppression of large fault currents in large electric power systems constitutes an ... previously proposed a conceptually new type of superconducting fault current limiter and its application to model distrib...

Takeshi Okuma; Tsukushi Hara; Takahiko Yamamoto…

1992-01-01T23:59:59.000Z

42

Power System Feedback from High-Tc Superconductor Shielded Core Fault Current Limiter  

Science Journals Connector (OSTI)

The shielded core fault current limiter is attractive with high critical temperature superconductors. ... acts during normal operation as an ideally shorted current transformer; the secondary superconducting loop...

J. Gerhold

1998-01-01T23:59:59.000Z

43

Modelling and Simulation of Inductive Fault Current Limiters  

Science Journals Connector (OSTI)

Inductive superconducting fault current limiters have already demonstrated their technical viability in electrical networks. Its architecture and robustness make them potentially adequate for distribution networks, and this type of devices is considered as an enabling technology for the advent of embedded generation with renewable energy sources. In order to promote the growth and maturity of these superconducting technologies, fast design tools must be developed, allowing simulating devices with different materials in grids with diverse characteristics. This work presents advances in the development of such tool, which, at present stage, is an effective alternative to software simulations by finite elements methods, reducing dramatically computation time. The algorithms are now compared with experimental results from a laboratory scale prototype, showing the need to refine them.

João Murta Pina; Pedro Pereira; Anabela Pronto; Pedro Arsénio; Tiago Silva

2012-01-01T23:59:59.000Z

44

Resistive fault current limiter using HTS single-layer coils  

Science Journals Connector (OSTI)

This paper presents the work that is being done as a part of the project to develop a resistive current limiter using HTS Bi-2223/Ag tapes with the same construction scheme previously reported using LTS NbTi/CuNi wire with normal operating current of 170 A in liquid helium bath. The Bi–2223/Ag tape was helically wounded on several cylindrical G-10 tubes forming concentric coils connected in series, parallel or anti-parallel configurations in order to reduce the equivalent inductance of the complete winding. The design targets are the impedance of the electromagnetic system rising to 1.5 ? during a fault occurrence in absence of inductance both in the normal state and in the superconducting state, rated voltage and current of 15 kV and 400 A, respectively, with maximum flux density of 0.1 T. The test results in low voltage (AC/DC) as well as magnetic field measurements at 77 K and 4.2 K are presented and the limiting performance of the system are also discussed.

Carlos A. Baldan; Carlos Y. Shigue; Daltro G. Pinatti; Ernesto Ruppert-Filho; Rafael C. Freitas; Roberto P. Homrich

2004-01-01T23:59:59.000Z

45

Fault current limiting and voltage sag mitigation by means of a resonant type FCL  

Science Journals Connector (OSTI)

In this paper a resonant type of fault current limiter and its application are presented. During normal operation of circuit, the thyristors is off and the resonant branches are short circuit. Therefore there is not any voltage drop on FCL. In this way, ... Keywords: bypass resistance, fault analysis, power quality, resonant type fault current limiter

M. S. Mohebbi Nazar; M. Abapour

2006-08-01T23:59:59.000Z

46

Study of Superconducting Fault Current Limiter Using Saturated Magnetic Core  

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This paper presents a saturated magnetic core superconducting current limiter (SCSFCL) operation simulation results using finite element technique. The superconducting current limiter uses BSCCO tape to produce m...

F. Fajoni; E. Ruppert; C. A. Baldan…

2014-11-01T23:59:59.000Z

47

Recovery time of superconducting non-inductive reactor type fault current limiter  

SciTech Connect (OSTI)

A superconducting fault current limiting device for electric power systems has been investigated to find out its feasibility. Non-inductive reactor type fault current limiter has been constructed using metal superconductor. Two bifilar wound solenoids were connected in antiparallel or antiseries. On each connection, the fault current limiting test was performed by short-circuiting a resistive load suddenly. The recovery (normal-to-superconductive state transition) time after the current limiting mode has been studied using small scale model of fault current limiter for the low voltage distribution line. The results reveal that the current limiter could be operated under repetitive fault current accident which was removed within a few cycle of the limiting mode. The recovery time is a function of the dissipated energy under current limiting mode. Test results are presented.

Hoshino, T.; Muta, I.; Tsukiji, H. [Saga Univ., Honjo, Saga (Japan)] [Saga Univ., Honjo, Saga (Japan); Ohkubo, K.; Etoh, M. [Kyushu Electric Power Co., Kono-Higashi, Saga (Japan)] [Kyushu Electric Power Co., Kono-Higashi, Saga (Japan)

1996-07-01T23:59:59.000Z

48

Proposal of DC shield reactor type superconducting fault current limiter  

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Saturated DC reactor type superconducting fault current limiter (SFCL) had been proposed two years ago. It was classified to rectifier type SFCL. The changing inductance value with the operating mode has superior characteristics to reduce voltage sag during step increase of the load current. But it has the disadvantage of its weight. In this paper, rectifier type SFCL with shielded reactor has been proposed. The reactor which has superconducting ring or tube inside its winding is substituted to the DC link of the rectifier. The configuration looks like an air core transformer with secondary short winding. When the current through the bulk shield-ring reaches to a certain level, the flux penetrates to the shield body and finite impedance appears in the primary winding. In other words, when the surface flux density exceeds its critical flux density, the flux penetrates into the bulk superconductor, and increases equivalent inductance. The equivalent transient resistance of the shield was represented as a function of exponential of the time. Using this equivalent transient resistance, the transient impedance was expressed. The transient wave analysis using EMTDC (electro-magnetic transients in DC systems) has been described. Simulated waveforms are shown considering the source inductance, the leakage inductance, the coupling coefficient and the forward voltage drop of the semiconductor. And voltage sag was also investigated with 50% step load increase. Preliminary design was also performed. The coil size and number of turns are designed to obtain adequate inductance for the current limitation, and the central magnetic field of the coils are calculated. There is optimal aspect ratio to minimize the magnetic field with restriction in outer diameter of the coil.

Itsuya Muta; Tsutomu Hoshino; Khosru Mohammad Salim; Akio Kawasaki; Taketsune Nakamura; Masato Yamada

2004-01-01T23:59:59.000Z

49

Quench Properties and Fault Current Limiters of YBCO Thin-Film Superconductors  

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We measured the current dependence of quench propagation velocities in strip-shaped YBCO thin films and the current-limiting properties of fault current limiters consisting of a YBCO thin film and ... -300 cm/sec...

Hiroshi Kubota; Yuki Kudo; Mutsuki Yamazaki…

1998-01-01T23:59:59.000Z

50

400V Class Resistive Fault Current Limiter using YBCO Thin Films  

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A resistive fault current limiter with 410 Vrms x 56 Arms was realized by connecting six current limiting elements in series. An element was...3...single crystal and a metal film on AIN. The YBCO thin film was co...

Yuki Kudo; Hiroshi Kubota; Mutsuki Yamazaki…

2000-01-01T23:59:59.000Z

51

Prototype Fault Current Limiter Using Transformer and a Modular Device of YBCO Coated Conductor  

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A superconducting fault current limiter (SCFL) consisted of a transformer with ... secondary winding short-circuited by a modular superconducting limiter device with 16 elements connected in series ... a 0.125 ? ...

C. A. Baldan; J. S. Lamas; A. A. Bernardes…

2013-04-01T23:59:59.000Z

52

Basic Test of A 3-Phase Superconducting Fault Current Limiting Reactor  

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A novel 3-phase superconducting fault current limiting reactor (SCFCLR) for power system ... some experiments, the fundamental behavior of the limiter is confirmed. In the experiment, two ... exhibits very small ...

H. Kado; T. Ishigohka

1990-01-01T23:59:59.000Z

53

Electrothermal Modeling of Coated Conductor for a Resistive Superconducting Fault-Current Limiter  

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Coated conductors are very promising for the design of a novel and efficient superconducting fault-current limiter (SFCL). The thermal and electrical behaviors ... of SFCL in the presence of over-critical currents

S. Nemdili; S. Belkhiat

2013-08-01T23:59:59.000Z

54

1.2 MVA High-Tc Superconducting Fault Current Limiter  

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A 3-phase high Tc superconducting fault current limiter with a rated power of 1.2 ... a special partial melt process. The nominal current and voltage of the device are 70 ... 3-phase short circuit tests with a pr...

W. Paul; M. Chen; M. Lakner; J. Rhyner; L. Widenhorn…

1998-01-01T23:59:59.000Z

55

Principle and characteristics of a fault current limiter with series compensation  

SciTech Connect (OSTI)

A fault current limiter with series compensation, which is composed of a compensation capacitor and a limiting reactor in series, is proposed. A solid-state switch connected in parallel with the capacitor controls either the ordinal series compensation or fault current limitations. A feasibility study of the current limiter by simulation analysis is presented and the effectiveness of the current limiter is evaluated from the viewpoints of transient stability improvement and device capacity. The current limiter is a useful protection device for large, high power transmission systems.

Sugimoto, S. [Chubu Electric Power Co., Inc., Nagoya (Japan). Electric Power Research and Development Center] [Chubu Electric Power Co., Inc., Nagoya (Japan). Electric Power Research and Development Center; Kida, J.; Arita, H.; Fukui, C. [Hitachi Ltd., Ibaraki (Japan)] [Hitachi Ltd., Ibaraki (Japan); Yamagiwa, T. [Hitachi Ltd., Kokubu (Japan). Kokubu Works] [Hitachi Ltd., Kokubu (Japan). Kokubu Works

1996-04-01T23:59:59.000Z

56

Operating principle of a high Tc superconducting saturable magnetic core fault current limiter  

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An electrical fault current limiter (FCL) designed with a high Tc superconducting (HTS) dc bias winding is described. The winding is prepared by using a Ag-clad (Bi,Pb)2Sr2Ca2Cu3O10+x HTS wire. The limiting behaviour of this FCL is investigated and considered with respect to operation in a 6 kV power system. The results show that the FCL limits fault currents effectively, and is a possible solution for reducing power system fault currents.

J.X. Jin; S.X. Dou; C. Grantham; D. Sutanto; H.K. Liu

1997-01-01T23:59:59.000Z

57

Study On Magnetic Shielding Type Superconducting Fault Current Limiter Using Bi-Sr-Ca-Cu-O Cylinder  

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The power application of a superconductor to restrain a fault current has been researched. A superconducting fault current limiter using a Bi-Sr-Ca-Cu-O cylinder has been developed. This limiter consists of the p...

Michiharu Ichikawa; Hiroyuki Kado; Kunikazu Izumi

1994-01-01T23:59:59.000Z

58

A Conceptual Design of Superconducting Fault Current Limiter with Bi2223 in 6.6 kV Distribution System  

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We have proposed a new type fault current limiter, which consists of a flux-lock reactor...c...superconducting (HTS) element and ac magnetic field coil (Flux-Lock Type Fault Current Limiter: FLT-FCL). This paper ...

Yu-Hong Guo; Toshiyuki Uchii; Yasunobu Yokomizu…

1998-01-01T23:59:59.000Z

59

Numerical Analysis of Overvoltage and Accumulated Energy at Quenching in Superconducting Fault Current Limiters  

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The present paper is devoted to a discussion of the overvoltage and accumulated energy which constitute problems when superconducting fault current limiters are introduced into electric power systems. These ... b...

S. Honjo; T. Hara; T. Yamamoto

1994-01-01T23:59:59.000Z

60

Quench current degradation in superconducting coil for 6.6 kV/2 fault current limiter  

SciTech Connect (OSTI)

A 6.6 kV/2 kA class fault current limiter that consists of non-inductive superconducting windings was developed and tested. The limiter can deliver continuous power at 2 kArms and limit fault current of more than 20 kA to 4 kA in 6 kV. The limiter recovers to the superconducting state within a few seconds and can perform a fault current limiting operation in 60 seconds after the last limiting operation. After high-voltage operation, however, the quench current of the limiter dropped significantly. This quench current degradation is related to the coil bobbin strain due to helium pressure raised by large ohmic heating in quenching. The degradation is a fatal problem for a fault current limiter if the quench current falls below the operating current because the limiter cannot revert to the normal operation. High Young`s modulus bobbin is effective to remove the coil degradation. They have obtained a fault current limiter without any degradation after repeated limiting operations.

Tasaki, K.; Yazawa, T.; Yoneda, E.S.; Nomura, S.; Maeda, H. [Toshiba Corp., Kawasaki (Japan). Research and Development Center] [Toshiba Corp., Kawasaki (Japan). Research and Development Center; Ohkuma, T.; Nakade, M.; Hara, T. [Tokyo Electric Power Co., Yokohama (Japan). Power Engineering R and D Center] [Tokyo Electric Power Co., Yokohama (Japan). Power Engineering R and D Center

1996-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

Development, Updating and Long-Term Operations of a 10.5 kV HTS Fault Current Limiter  

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There are many irreplaceable advantages of high temperature superconducting (HTS) fault current limiter, applying in electric utilities. It is expected to be able to solve excessive fault current problems and to ...

J. Zhang; S. Dai; Y. Teng; D. Zhang; N. Song…

2014-10-01T23:59:59.000Z

62

A hybrid superconducting fault current limiter for enhancing transient stability in Korean power systems  

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Abstract Additional power generation sites have been limited in Korea, despite the fact load demands are gradually increasing. In order to meet these increasing demands, Korea’s power system company has begun constructing new generators at existing sites. Thus, multi-unit plants can create problems in terms of transient stability when a large disturbance occurs. This paper proposes a hybrid superconducting fault current limiter (SFCL) application to enhance the transient stability of multi-unit power plants. \\{SFCLs\\} reduce fault currents, and limitation currents decrease the imbalance of the mechanical and electrical torque of the generators, resulting in an improvement in transient stability.

Sangsoo Seo; Seog-Joo Kim; Young-Hwan Moon; Byongjun Lee

2013-01-01T23:59:59.000Z

63

Development of A 1 kA Class Alternating Current Lead System for a Fault Current Limiter  

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A thermal design of a 1 kA/6.6 kV class superconducting fault current limiter was discussed, and specifications for a current lead system were obtained. According to these specifications, a 1 kA rms current lead ...

M. Takahashi; T. Kuriyama; H. Nakagome; K. Yamamoto…

1996-01-01T23:59:59.000Z

64

Experimental and Numerical Study of Co-ordination of Resistive-Type Superconductor Fault Current Limiter and Relay Protection  

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Superconducting fault current limiter (SFCL) has become one of the most ideal current limiting devices to solve the problem of increasing short-circuit current in high-voltage power grid. This paper...

Y. Chen; S. Li; J. Sheng; Z. Jin; Z. Hong…

2013-11-01T23:59:59.000Z

65

A study on DC hybrid three-phase fault current limiting interrupter for a power distribution system  

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For the purpose of protecting electric power system, many researches and developments of fault current limiters are being performed. The authors studied a dc hybrid three-phase fault current limiting interrupter (FCLI) composed of a superconducting reactor and an S/N transition element, connected in series each other. The dc hybrid type fault current limiting interrupter can limit a fault current by means of the inductance of high temperature superconducting (HTS) coil together with the normal transition of HTS bulk material (HTSB). In the case of an accident, the normal transition of the bulk material can be accelerated by the magnetic field of the HTS coil. In this paper, the dc hybrid type fault current limiting interrupter for 5.5 km long 6.6 kV–600 A power distribution system is analyzed, and performances of fault current limitation and interruption are confirmed. Moreover, a reclosing operation is discussed for this power distribution system.

Hongtian Shao; Tomoyuki Satoh; Mitsugi Yamaguchi; Satoshi Fukui; Jun Ogawa; Takao Satoh; Hiroyuki Ishikawa

2005-01-01T23:59:59.000Z

66

Influence of fault type on the optimal location of superconducting fault current limiter in electrical power grid  

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Abstract This paper presents a novel approach to determine the optimal location of a resistive superconducting fault current limiter (SFCL) to improve the transient stability of an electric power grid (EPG). The presented method use the angular separation of the rotors of synchronous machines present in the power system to select the optimal location of SFCL. The selection of this optimal location is coordinated with the corresponding optimal resistive value to improve transient stability in case of short-circuit fault. To obtain a global study on the optimal placement of SFCL in case of fault, various types of short-circuits are considered (single phase grounded fault, two phases grounded fault, etc.). To evaluate the effectiveness of the proposed method, the IEEE benchmarked four-machine two-area test system is used to carry out several case studies. It is shown that the optimal location of SFCL as well as its optimal resistance value are not the same for each fault studied. A global analysis of EPG stability is presented in the paper to select only one location of the SFCL in the EPG. Results show that the optimal location of SFCL combined with its optimal resistive value reduces the angular separation of the rotors that improves effectively the stability of the EPG for any type of short-circuit.

G. Didier; J. Lévêque

2014-01-01T23:59:59.000Z

67

Implementation of superconducting fault current limiter for flexible operation in the power substation  

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Abstract The concentration of large-scale power loads located in the metropolitan areas have resulted in high fault current levels during a fault thereby requiring the substation to operate in the double busbar configuration mode. However, the double busbar configuration mode results in deterioration of power system reliability and unbalanced power flow in the adjacent transmission lines which may result in issues such as overloading of lines. This paper proposes the implementation of the superconducting fault current limiter (SFCL) to be installed between the two substation busbars for a more efficient and flexible operation of the substation enabling both single and double busbar configurations depending on the system conditions for guaranteeing power system reliability as well as fault current limitations. Case studies are being performed for the effectiveness of the SFCL installation and results are compared for the cases where the substation is operating in single and double busbar mode and with and without the installation of the SFCL for fault current mitigation.

Chong Suk Song; Hansang Lee; Yoon-sung Cho; Jaewan Suh; Gilsoo Jang

2014-01-01T23:59:59.000Z

68

Controllable resistive type fault current limiter (CR-FCL) with frequency and pulse duty-cycle  

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Abstract In this paper a controllable resistive type fault current limiter (CR-FCL) is introduced. The CR-FCL inserts a pre-specified value of resistance based on a pre-defined function, by using a simple switching method, in series with the fault current path. When a fault occurs, a self turn off switch starts switching with a pre-specified frequency and duty cycle. By this switching pattern, the controlled value of resistance enters to the fault current path. So, the CR-FCL limits the fault current to the desired values. In addition, from transient stability point of view, by inserting the optimal resistance value, the CR-FCL is capable to enhance power system transient stability in a good manner. In fact, generation of the controllable resistance that depends on the duty cycle of the self turn off switch is the main idea of the CR-FCL. The variable duty cycle results the variable resistance and the fixed duty cycle results the fixed resistance. Analytical analyses of the proposed FCL are presented in details. Simulation results by power system computer-aided design/electromagnetic transients, including dc (PSCAD/EMTDC) software and corresponding experimental results are studied to validate the effectiveness of the CR-FCL. Considering error analyses, there is the good agreement between the simulation results and the experimental results.

Seyed Behzad Naderi; Mehdi Jafari; Mehrdad Tarafdar Hagh

2014-01-01T23:59:59.000Z

69

A superconducting fault current limiter integrated in the cold heat exchanger of a  

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In this work we probe a compact superconducting fault current limiter (SFCL) integrated in the cold heat exchanger of a thermoacoustic refrigerator. A design for an SFCL device with a power of about 2.2 kW is presented and described in detail. A thermoacoustic refrigerator is also proposed which, under fault conditions, must be able to remove around 50 W at 80 K. A simulation routine is run to test the performance of the SFCL, based on YBCO films, in terms of both the limiting capacity and the energy to be dissipated and removed inside the heat exchanger.

M R Osorio; A Bétrancourt; M X François; J A Veira; F Vidal

2008-01-01T23:59:59.000Z

70

The high voltage problem in the saturated core HTS fault current limiter  

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A small model of a one-phase saturated core HTS fault current limiter was developed. It consists of an iron core, an AC coil and a DC HTS coil. The HTS coil comprised six 126 turns double-pancakes (ID 70 mm), wound after heat treatment from Bi-2223 multifilamentary tape in Ag matrix. A fault simulation circuit was set up to characterize the dynamic properties of the model limiter. The voltages and currents of the AC coil and the DC HTS coil were measured through a computer-based data acquisition system. The tests have shown that the limiter has a fast response and the first current peak can be easily limited, but a high voltage will be induced on the DC HTS coil side during the fault state. This high voltage can badly affect the DC current equipment on the DC HTS coil side. The origin and value of the high voltage can be explained using a transformer model. For a limiter with n1 turns AC coil and n2 turns DC coil, the largest induced voltage will be roughly close to (n2/n1)U, where U is the rated voltage of the limiter. To commercialize this kind of limiter, the high voltage problem must be solved. Some different designs were introduced to lower the induced voltage.

Y.F. He; J.H. Li; X.H. Zong; J. Sun; Y.N. Wang; C.L. Wu; J.X. Wang

2003-01-01T23:59:59.000Z

71

Fault current limiter using a series impedance combined with bus sectionalizing circuit breaker  

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The necessity and procedure for application of series fault current limiter (FCL) composed to bus sectionalizing in power network of IRAN have been discussed. In this regard, all of the high voltage substations in the power network of IRAN were evaluated in point of view of the fault current amplitude. The short circuit analysis of the power network was done based on the actual and future network specifications which have been designed and published by Iran Generation Transmission & Distribution Company in 2005. The overall results of this analysis and the detail data of using FCL together bus sectionalizing for two of the most important high voltage substations of Iran are presented. This method allows decreasing of 27% in fault current amplitude. The economical observation shows this method can be profitable if high voltage substation contains more than four feeders.

Hamid Javadi

2011-01-01T23:59:59.000Z

72

Modeling of Shield-Type Superconducting Fault-Current-Limiter Operation Considering Flux Pinning Effect on Flux and Supercurrent Density in High-Temperature Superconductor Cylinders  

Science Journals Connector (OSTI)

Superconducting fault current limiter, SFCL, forms an important category of fault-current-limiting devices which limit the short-circuit current levels in electrical networks. Therefore, modeling ... its main ope...

Arsalan Hekmati

2014-03-01T23:59:59.000Z

73

Magnetic saturable reactor type HTS fault current limiter for electrical application  

Science Journals Connector (OSTI)

An electrical fault current limiter (FCL) developed based on the principle of a magnetic saturable reactor requires a high current ampere-turn coil as its dc bias, and this coil is necessary to use a high temperature superconducting (HTS) winding. This HTS FCL has been studied, and identified with several advantages compared to other HTS FCLs, and therefore is further considered for its practical industry application.

J.X. Jin; S.X. Dou; C. Cook; C. Grantham; M. Apperley; T. Beales

2000-01-01T23:59:59.000Z

74

Design and Development of the First Polish Superconducting Fault Current Limiter For MV Distribution Systems  

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Superconducting fault current limiters (SFCL) are designed to protect the electrical grid from faults. The rapid increase of impedance of the SFCL reduces the short current in the circuit. In this paper, we present the design and development of coreless inductive SFCL for MV distribution systems. It is a very attractive design which reduces the weight of the device thanks to the coreless construction and the size of primary winding, reduced thanks to cryogenic cooling. The primary 2G HTS and secondary 2G HTS windings are magnetically coupled to one another. Copper primary winding connected parallely to the HTS primary winding is magnetically coupled to HTS windings and ensure that in cases of lack of cooling or superconductor failure, the protected circuit will not be disrupted. Tests performed at high power test facility shows the limiting performance of the coreless inductive SFCL.

Janusz Kozak; Michal Majka; Tadeusz Janowski; Slawomir Kozak

2012-01-01T23:59:59.000Z

75

Development of a 220 kV/300 MVA superconductive fault current limiter  

Science Journals Connector (OSTI)

After we developed a saturated iron core type 35 kV/90 MVA superconductive fault current limiter and installed the device in a transmission network at Puji substation of China Southern Power Grid for live-grid operation in 2007, we continued our efforts in advancing this technology. A 220 kV/300 MVA device has been designed, manufactured and factory tested. This device differs from the 35 kV device in its form of electrical insulation even though the two devices have the same working principle and similar core structure. Improvements in the dc magnetization circuit and the cryogenic system were also achieved. This 220 kV/300 MVA superconductive fault current limiter has been installed and has passed all field tests at Shigezhuang substation in Tianjin, China. Trial operation is underway. This paper introduces the major design parameters, key functional specifications and some testing results of the device.

Y Xin; W Z Gong; H Hong; Y Q Gao; X Y Niu; J Y Zhang; Y W Sun; A L Ren; H Z Wang; L F Zhang; Q Li; Z Q Wei; L Z Wang; J B Cui; G J Niu; Z Q Xiong

2012-01-01T23:59:59.000Z

76

Saturated iron-core superconductive fault current limiter developed at Innopower  

Science Journals Connector (OSTI)

Since 2002 we have been carrying out programs in developing Saturated Iron-core Superconducting Fault Current Limiters (SISFCLs). Innovative technologies were adopted in designing the iron-core and the magnetization circuit making our SISFCL more efficient useful and reliable. With our technology a 35 kV SISFCL with dry-type electrical insulation and a 220 kV SISFCL with oil electrical insulation were manufactured and installed for live-grid operation in 2008 and in 2012 respectively. Operation data and test results show that the performances of the devices meet design expectations and utility's needs. Our SISFCL is applicable for both transmission and distribution networks and can satisfy a wide range of fault current limiting impedance requirements.

2014-01-01T23:59:59.000Z

77

Extending the range of applicability of HTS cylinders in inductive superconducting fault current limiters  

Science Journals Connector (OSTI)

In the numerical routine used to estimate the temperature of the weak zones (channels) an error was introduced. Once the error is eliminated, the improvement in the thermal refrigeration of the inductive fault current limiters with artificial weak zones still remains but its importance is reduced; a channelled cylinder can refrigerate faster than a non-channelled one, as heat is removed also by conduction to the cold parts, but under a current fault the temperature of the weak zones is very much above those displayed in figure 3(b) and figure 4 (140 K is our best result, Tc being 105 K). As a consequence, the channelled cylinder needs about 9 s to get the critical temperature for the nominal current, whereas the non-channelled cylinder requires more than 15 s (both refrigerated by liquid nitrogen). Although appreciable, this improvement is still far from the usually required recovery time, which is about 1 s. This design could be more appropriate for a fault current limiter working in a slightly lower power grid or in a gaseous atmosphere, where the channelled sample is definitely much better than the non-channelled cylinder. To be competitive when operating in liquid nitrogen some additional mechanism should be implemented to avoid the excessive heating of the weak zones.

M R Osorio; J A Lorenzo; J A Veira; F Vidal

2008-01-01T23:59:59.000Z

78

Assessment on the influence of resistive superconducting fault current limiter in VSC-HVDC system  

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Abstract Due to fewer risk of commutation failures, harmonic occurrences and reactive power consumptions, Voltage Source Converter (VSC) based HVDC system is known as the optimum solution of HVDC power system for the future power grid. However, the absence of suitable fault protection devices for HVDC system hinders the efficient VSC-HVDC power grid design. In order to enhance the reliability of the VSC-HVDC power grid against the fault current problems, the application of resistive Superconducting Fault Current Limiters (SFCLs) could be considered. Also, \\{SFCLs\\} could be applied to the VSC-HVDC system with integrated AC Power Systems in order to enhance the transient response and the robustness of the system. In this paper, in order to evaluate the role of \\{SFCLs\\} in VSC-HVDC systems and to determine the suitable position of \\{SFCLs\\} in VSC-HVDC power systems integrated with AC power System, a simulation model based on Korea Jeju-Haenam HVDC power system was designed in Matlab Simulink/SimPowerSystems. This designed model was composed of VSC-HVDC system connected with an AC microgrid. Utilizing the designed VSC-HVDC systems, the feasible locations of resistive \\{SFCLs\\} were evaluated when DC line-to-line, DC line-to-ground and three phase AC faults were occurred. Consequently, it was found that the simulation model was effective to evaluate the positive effects of resistive \\{SFCLs\\} for the effective suppression of fault currents in VSC-HVDC systems as well as in integrated AC Systems. Finally, the optimum locations of \\{SFCLs\\} in VSC-HVDC transmission systems were suggested based on the simulation results.

Jong-Geon Lee; Umer Amir Khan; Jae-Sang Hwang; Jae-Kyu Seong; Woo-Ju Shin; Byung-Bae Park; Bang-Wook Lee

2014-01-01T23:59:59.000Z

79

Application of Hi-Tc superconducting current fault limiters to utility distribution networks  

SciTech Connect (OSTI)

A new classification of superconducting current fault limiter (SCFL) is described which is a non-quenching, variable-inductance-mode VIM current limiter with characteristics matched to utility distribution line parameters. A major application of this device is for replacement of fixed-inductance air-core reactors used in impedance and short-circuit levels from sub-transmission to distribution. The secondary application of the SCFL is for protection of distribution substation transformers in the 5--40 MVA range, as a replacement for current limiting fuses and air-blast circuit breakers. The SCFL devices have the unique characteristic of producing minimal or no transient recovery voltage (TRV) as is typical of conventional interruption technologies.

Kuznetsov, S.B.; Webb, T.J. [Power Superconducting Devices Inc., Pittsburgh, PA (United States)

1996-10-01T23:59:59.000Z

80

14 kV single-phase superconducting fault current limiter based on YBCO films  

Science Journals Connector (OSTI)

We present the fabrication and short circuit test results of a 14 kV single-phase resistive superconducting fault current limiter (SFCL) based on \\{YBa2Cu3O7\\} (YBCO) films. Individual components were processed using the 4? YBCO films and have the rated voltage and current of 600 V and 35 A at 77 K, respectively. Twenty four components, eight components in series and three lines in parallel, make a module having the rated voltage and current of 4.8 kV and 105 A, respectively. Three modules were assembled in series to produce the SFCL working at 77 K, a 14 kV single-phase machine for the 22.9 kV Y–Y grid. short circuit tests were successfully conducted in an accredited test facility with the maximum fault currents up to 14.1 kAP. All components quenched together upon faults and shared the rated voltage evenly without any supplementary device between the modules. This proves that the SFCL based on YBCO films may not only work reliably at 22.9 kV, but also provide technical feasibility for higher voltage application including the transmission grids.

J. Sim; K.B. Park; H.R. Kim; J.S. Kang; B.W. Lee; H.M. Kim; I.S. Oh; O.B. Hyun

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

CRYOGENIC SYSTEM FOR A 35 KV/90 MVA SATURATED IRON?CORE SUPERCONDUCTING FAULT CURRENT LIMITER  

Science Journals Connector (OSTI)

A cryogenic system was built as an open system for a 35 kV/90 MVA saturated iron?core superconducting fault current limiter. It consists of an annular cylindrical liquid nitrogen dewar cryogenic pipes sensors valves and a control unit. A HTS dc bias coil was immersed with liquid nitrogen in the dewar. The control circuit constantly monitors the liquid nitrogen level and controls the supply of liquid nitrogen in accordance with the liquid nitrogen level change. Nitrogen vapor was directly released into the environment. Heat loss under different working conditions such as no magnetization current 150 A magnetization current and on?grid condition was measured to evaluate the performance of the system. As compared with no magnetization current of the dc bias coil evaporation of liquid nitrogen increases about 20% under the on?grid condition.

H. Hong; W. Z. Gong; B. Tian; J. Y. Zhang; X. M. Hu; J. Z. Wang; X. Y. Niu; Y. Wang; L. F. Zhang; Y. W. Sun; T. Q. Wu; Y. Xin

2010-01-01T23:59:59.000Z

82

A YBCO-coated conductor for a fault current limiter: architecture influences and optical  

Science Journals Connector (OSTI)

YBaCuO-coated conductors (CC) are particularly interesting for the electric grid, especially for superconducting (SC) fault current limiters (FCL). This innovative device should play an important part in the future electric energy landscape. New network diagrams are indeed imagined with DC buses. The SC FCL would solve the delicate problem of DC fault currents. We have studied several YBaCuO-coated conductors with different architectures. A test bench for optical measurements has been developed to study the bubble development during limitation or over-current operation. The observations give useful information about the quench initiation and its propagation. The images were recorded every 0.2 ms (or less). Preliminary experiments have been carried out using a copper strip. Several operating temperatures have been investigated and important differences have been observed in some cases. The different YBaCuO CC studied show very different behaviours. Bubbles appear under the shape of strips across the tape or show a homogeneous behaviour. These behaviours are correlated by electrical measurements.

N T Nguyen; P Tixador

2010-01-01T23:59:59.000Z

83

Design and Test Results of a 1 MVA Resistive Type Fault Current Limiter  

Science Journals Connector (OSTI)

The 1 MVA resistive type single phase AC fault current limiter (FCL) was build and successfully tested by capacitors battery discharge. FCL rated voltage is 3.5 kV, current 250 Arms. The 240 m of HTS tape (type SF12100 by SupePower) was used for FCL production. The FCL consists of 8 bifilar coils each wound onto glass-fiber 70 mm diameter tube and connected in series. The HTS tapes were additionally stabilized with Cu laminated highly resistive foil. During the tests of separate FCL coils at 380 V an excellent limiting performance was observed. Tested FCL coil was switched off after 75 ms, the maximum temperature at the HTS tape was less then 230 K, the recovery time was about 5 s.

V.E. Keilin; V.V. Lobyntsev; M.S. Novikov; S.J. Novikov; V.I. Shcherbakov

2012-01-01T23:59:59.000Z

84

Finite-element modelling of YBCO fault current limiter with temperature dependent  

Science Journals Connector (OSTI)

In this paper, we present a numerical model which takes into account both the thermal and the electromagnetic aspects of the over-critical current regime for high-temperature superconducting (HTS) materials. The electromagnetic and thermal equations have been implemented in finite-element method (FEM) software in order to obtain a novel model for investigating the behaviour of the materials when the current exceeds Ic and the superconductor material goes to the normal state. The thermal dependence of the electrical parameters, such as the critical current density Jc, has been introduced. This model has been used to analyse the behaviour of strip lines of a YBCO/Au fault current limiter (FCL) on a sapphire substrate. Simulations with currents exceeding Ic have been performed, showing that the current limitation phase can be correctly reproduced. Such a model can be used to study the influence of the geometry on the performance of the FCL. It can replace experiments with currents exceeding Ic which may damage or destroy HTS samples and devices.

J Duron; F Grilli; L Antognazza; M Decroux; B Dutoit; Ø Fischer

2007-01-01T23:59:59.000Z

85

Development of 6.6kV/1.5kA-Class Superconducting Fault Current Limiter  

Science Journals Connector (OSTI)

The authors have developed and tested a 6.6kV/l.5kA-class superconducting fault current limiter, wound with an AC superconducting wire having ... up to 6.6kV were applied to the limiter. The limiter was able to s...

Kenji Tasaki; Kazuyuki Turunaga; Daisuke Ito…

1992-01-01T23:59:59.000Z

86

A Study of a High-Tc Superconducting Fault Current Limiter (No. 2): Development of an Element for 100-V Class Power Systems  

Science Journals Connector (OSTI)

The application of a high critical temperature (Tc) superconductor with a high critical current density (Jc) to a fault current limiter (FCL) was investigated to obtain a FCL which exhibits superior current limit...

Tatsuya Hayashi; Teijiro Mori; Yuuichi Wada…

1993-01-01T23:59:59.000Z

87

Proposed flux-based optimization method for determination of minimum superconductor material in shield-type superconducting fault current limiters  

Science Journals Connector (OSTI)

Distributed power generation and an ever growing load demand have caused the current level of fault to exceed the nominal rating of power system devices, and fault current limiters are needed even more. The Superconducting Fault Current Limiter, SFCL, forms an efficient category of current limiters. The superconductor part in \\{SFCLs\\} is the most costly part of the device, and minimizing its volume, while maintaining the required characteristics of the device, would be very beneficial. In this work, using a Simulated Annealing optimization algorithm, a method has been proposed to determine minimum required bulk superconductor material in inductive shield-type SFCL structures. The flux linkage balance, generated by the superconductor bulk and copper winding (being the base of the optimization process), has been formulated versus dimensions. The optimum dimensions of the bulk superconductor in a model SFCL, having a limitation current of 3 A , are determined using the proposed algorithm. A prototype has been fabricated using determined dimensions, and is tested in an experimental circuit by applying different types of faults. These experimental results demonstrated satisfactory limiting characteristics of the fabricated SFCL. The optimum volume of the bulk superconductor material needed for fabrication of larger scale \\{SFCLs\\} has been calculated and compared with the volume of superconductors employed in worldwide SFCL projects.

A. Hekmati; M. Vakilian; M. Fardmanesh

2012-01-01T23:59:59.000Z

88

Experimental testing and modelling of a resistive type superconducting fault current limiter using MgB2 wire  

Science Journals Connector (OSTI)

A prototype resistive superconducting fault current limiter (SFCL) was developed using single-strand round magnesium diboride (MgB2) wire. The MgB2 wire was wound with an interleaved arrangement to minimize coil inductance and provide adequate inter-turn voltage withstand capability. The temperature profile from 30 to 40 K and frequency profile from 10 to 100 Hz at 25 K were tested and reported. The quench properties of the prototype coil were tested using a high current test circuit. The fault current was limited by the prototype coil within the first quarter-cycle. The prototype coil demonstrated reliable and repeatable current limiting properties and was able to withstand a potential peak current of 372 A for one second without any degradation of performance. A three-strand SFCL coil was investigated and demonstrated scaled-up current capacity. An analytical model to predict the behaviour of the prototype single-strand SFCL coil was developed using an adiabatic boundary condition on the outer surface of the wire. The predicted fault current using the analytical model showed very good correlation with the experimental test results. The analytical model and a finite element thermal model were used to predict the temperature rise of the wire during a fault.

A C Smith; A Oliver; X Pei; M Husband; M Rindfleisch

2012-01-01T23:59:59.000Z

89

Thermal–electrical analogy for simulations of superconducting fault current limiters  

Science Journals Connector (OSTI)

Abstract In spite of the recent advances achieved with superconducting fault current limiters (SCFCL’s), modeling and simulation of such devices are still important issues. There are different approaches for modeling SCFCL’s, whereas computational simulations provide a better understanding of the behavior of SCFCL devices. In addition, results of hard experimental access may be achieved by means of computational simulation. The aim of this paper is to present a simple computational model to predict both the electrical and thermal behaviors of SCFCL devices. The main contribution of the present work is the use of a thermal–electrical analogy to solve the heat transfer equations inside SCFCL sub-components, which enables one to handle with relative easy the strong and nonlinear coupling between thermal and electrical phenomena. The limitation and quenching behavior of a resistive SCFCL assembly was investigated for overcurrents up to 67 kArms (Vo = 1 kVrms). Simulation results were compared to overcurrent experimental tests. A good agreement between simulations and tests has been found in the present work. Moreover, the results of the developed model were also compared with finite element results reported in the literature.

W.T.B. de Sousa; A. Polasek; R. Dias; C.F.T. Matt; R. de Andrade Jr.

2014-01-01T23:59:59.000Z

90

Observation of Transient Behavior of Magnetic Flux in Inductive-type Fault Current Limiter with YBCO Thin Film Disc  

Science Journals Connector (OSTI)

Recently, the installation of fault current limiters (FCLs) in power systems is expected for controlling large short circuit currents. In this study, we focus on inductive-type \\{FCLs\\} having a YBCO superconducting thin film disc that is fabricated by metal-organic deposition. AC currents were injected into the FCL so that the periodic transient behavior of the apparent magnetic flux density around the FCL could be measured by using a pick-up coil. The magnetic flux density exhibited hysteresis when AC current was injected into the FCL. The transition between the conducting states in the YBCO layer was explained by the hysteresis relationship between the magnetic flux density and current.

Kosuke Higuchi; Yin Guan; Yasunobu Yokomizu; Toshiro Matsumura

2012-01-01T23:59:59.000Z

91

Analysis of the influence of the normal zone propagation velocity on the design of resistive fault current limiters  

Science Journals Connector (OSTI)

Commercial high-temperature superconducting coated conductors (HTS-CCs) have low thermal diffusivity and nonuniform critical current density. These two factors lead commercial HTS-CCs to a partial quench when they are subjected to a transport current around their average critical current (). The consequence is the appearance of localized resistive zones, and a high risk of thermal runaway can arise when HTS-CCs are used for resistive fault current limiter (RFCL) purposes. The enhancement of the normal zone propagation velocity (NZPV) of HTS-CCs is a desirable solution for achieving sufficient thermal stability while keeping the cost of RFCLs under an acceptable threshold. Even though in recent years, several valid methods to increase the NZPV have been proposed, their impact on the design of RFCLs is not clear. For this reason, we developed a one-dimensional numerical model that enables us to simulate HTS-CCs with enhanced NZPV and to study the limitation performance of a HTS-CC-based RFCL in real operating conditions. Our preliminary re sults demonstrate that the NZPV enhancement can effectively limit the needed amount of HTS-CCs with important economic benefits for the design of RFCLs.

Daniele Colangelo; Bertrand Dutoit

2014-01-01T23:59:59.000Z

92

HTS dc bias coil for 35 kV/90 MVA saturated iron-core fault current limiter  

Science Journals Connector (OSTI)

A superconductive coil with 141,000 ampere-turns designed magnetizing power, made of 17,600 meters of BSCCO 2223 HTS tapes, was fabricated and tested. This coil was built for a 35 kV/90 MVA saturated iron-core fault current limiter. Computer simulations on the performance of the coil were carried out using ANSYS. The critical current of the superconducting coil and the dc resistance of the coil, including the non-superconducting joints, were investigated. Spatial distribution of the magnetic field was measured and compared with the simulation results. In this paper, we will report the configuration and the key parameters of the coil as well as the experimental and simulation results.

W.Z. Gong; J.Y. Zhang; Z.J. Cao; H. Hong; B. Tian; Y. Wang; J.Z. Wang; X.Y. Niu; J. Qiu; S.H. Wang; Y. Xin

2008-01-01T23:59:59.000Z

93

Application of a combined superconducting fault current limiter and STATCOM to enhancement of power system transient stability  

Science Journals Connector (OSTI)

Abstract Stable and reliable operation of the power system network is dependent on the dynamic equilibrium between energy production and power demand under large disturbance such as short circuit or important line tripping. This paper investigates the use of combined model based superconducting fault current limiter (SFCL) and shunt FACTS Controller (STATCOM) for assessing the transient stability of a power system considering the automatic voltage regulator. The combined model located at a specified branch based on voltage stability index using continuation power flow. The main role of the proposed combined model is to achieve simultaneously a flexible control of reactive power using STATCOM Controller and to reduce fault current using superconducting technology based SFCL. The proposed combined model has been successfully adapted within the transient stability program and applied to enhance the transient power system stability of the WSCC9-Bus system. Critical clearing time (CCT) has been used as an index to evaluate and validate the contribution of the proposed coordinated Controller. Simulation results confirm the effectiveness and perspective of this combined Controller to enhance the dynamic power system performances.

Belkacem Mahdad; K. Srairi

2013-01-01T23:59:59.000Z

94

Hybrid model of quench propagation in coated conductors for fault current limiters  

Science Journals Connector (OSTI)

We developed a hybrid model of the quench propagation in coated conductors in the current limitation condition. This model combines the finite element method, to study the thermal behaviour of the coated conductors, and analytical calculation of the heat dissipation. We demonstrate that the evaluation of the heat dissipation can be conducted on a larger mesh than the FEM thermal problem. The results obtained with this model are in very good agreement with experiments, without the need of using free parameters for adjustment. Parametric studies are then conducted to evaluate the influence of both the substrate thickness and the layer interface thermal properties on the transition propagation behaviour. 3D simulations of a thin superconducting line placed on a wider substrate are also presented. Significant transverse heat propagation is observed in spite of the low thermal conductivity of the substrate, though this has little to no influence on the transition propagation along the line. These results are discussed in the context of FCL design.

Arnaud Badel; Louis Antognazza; Mathieu Therasse; Markus Abplanalp; C Schacherer; Michel Decroux

2012-01-01T23:59:59.000Z

95

Cost reduction of distribution network protection in presence of distributed generation using optimized fault current limiter allocation  

Science Journals Connector (OSTI)

Using Solid State Fault Current Limiters (SSFCLs) has been proposed as a potential cost-efficient candidate to minimize the effect of exposing Distributed Generation (DG) to the distribution system. Genetic Algorithm (GA) is employed to find the optimum number, location and size of \\{FCLs\\} to be used in the network. The numerical and simulation results show the efficiency of proposed GA-based FCL allocation and sizing method in terms of minimizing the cost of distribution protection system. The prices of \\{FCLs\\} are estimated using real market prices and simulations are performed in four cases assuming prices more than the estimated one, less than estimated price and equal to the real estimated cost for FCL. Numerical results show that FCL price highly affects the optimum choices for \\{FCLs\\} and the price imposed by using FCLs.

Sayyed Ali Akbar Shahriari; Ali Yazdian Varjani; Mahmood Reza Haghifam

2012-01-01T23:59:59.000Z

96

Preparing A (Bi,Pb)2Sr2Ca2Cu3O10+X Ag Clad HTS Wire for a Fault Current Limiter Prototype  

Science Journals Connector (OSTI)

A pair of rated 3.5 kVA magnetic cores are connected as a magnetic saturable reactor, and tested as a fault current limiting device, in which a high current ampere-turns dc coil is required to saturate the mag...

J. X. Jin; S. X. Dou; C. Grantham; R. Bhasale…

1996-01-01T23:59:59.000Z

97

Development of a 6.6kV/1.5kA-Class Superconductive Fault Current Limiter  

Science Journals Connector (OSTI)

The authors developed an AC current limiter, possessing extremely fine filaments and a high-resistance matrix, and noninductively wound with a single secondary strand. This device successfully limited a 54.5 k...

T. Hara; T. Okuma; M. Nakade; T. Yamamoto; D. Ito…

1993-01-01T23:59:59.000Z

98

LANSCE beam current limiter  

SciTech Connect (OSTI)

The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described.

Gallegos, F.R.

1996-06-01T23:59:59.000Z

99

Consequences of Fault Currents Contributed by Distributed Generation  

E-Print Network [OSTI]

Consequences of Fault Currents Contributed by Distributed Generation Intermediate Project Report Currents Contributed by Distributed Generation Intermediate Report for the Project "New Implications in systems with distributed generation. The main concept described is that fault current throughout power

100

Solid-state current limiter for power distribution system  

SciTech Connect (OSTI)

To prevent voltage decrease of distribution systems, the principle and fundamental characteristics of a solid-state current limiter using GTO thyristors were investigated. Basic components of the apparatus were a fast solid-state switch and a current limiting impedance of low resistance in parallel with the switch. Experimental results of the test current limiter showed the fault current was limited successfully, regardless of DC component size. The time from detection of fault current was limited successfully, regardless of DC component size. The time from detection of fault occurrence to interruption of the fault current by the solid-state switch was 40 [mu]s. This time was very short in comparison with that before the fault current reached a large value. Thermal rise of the solid-state switch for conduction was solved by a self-cooling apparatus using a non-combustible cooling liquid. The results indicated that the solid-state current limiter was a valuable protecting device for high fault current distribution systems.

Ueda, T.; Morita, M. (Chubu Electric Power Co. Inc., Nagoya (Japan)); Arita, H.; Kida, J.; Kurosawa, Y.; Yamagiwa, T. (Hitachi Ltd., Ibaraki (Japan). Hitachi Research Lab.)

1993-10-01T23:59:59.000Z

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

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

102

Fault-tolerant control for current sensors of doubly fed induction generators based on an improved fault detection method  

Science Journals Connector (OSTI)

Abstract Fault-tolerant control of current sensors is studied in this paper to improve the reliability of a doubly fed induction generator (DFIG). A fault-tolerant control system of current sensors is presented for the DFIG, which consists of a new current observer and an improved current sensor fault detection algorithm. The current observer is constructed by using only voltage signals as inputs. The fault detection algorithm is based on the current observer, in which an adaptive threshold and different fault duration times are considered. The performance of the proposed observer, improved fault detection algorithm, and fault-tolerant control system are investigated by simulation. The results indicate that the outputs of the observer and the sensor are highly coherent. The fault detection algorithm can efficiently detect both soft and hard faults in current sensors, and the fault-tolerant control system can effectively tolerate both types of faults.

H. Li; C. Yang; Y.G. Hu; B. Zhao; M. Zhao; Z. Chen

2014-01-01T23:59:59.000Z

103

500 V/200 A fault current limiter modules made of large-area MOD-YBa2Cu3O7 thin films with high-resistivity Au–Ag alloy shunt layers  

Science Journals Connector (OSTI)

We developed 500 Vrms/ 200 Arms superconducting thin-film fault current limiter (FCL) modules that can withstand high electric fields (E>30 Vrms cm?1) by using large-area YBa2Cu3O7 (YBCO) thin films with high-resistivity Au–Ag alloy shunt layers. Au–Ag alloy films about 60 nm thick were sputter-deposited on YBCO/CeO2/sapphire films (2.7 cm ? 20 cm) prepared using a fluorine-free MOD method. Each 20 cm long Au–Ag/YBCO film was then divided into three segments (each ~5.7 cm long) by four Ag electrodes deposited on the Au–Ag layer, resulting in an effective length of 17 cm. The 500 V/200 A FCL modules were then fabricated by first connecting two of the segmented films in parallel using Ag-sheathed Bi-2223 superconducting tapes and then connecting in parallel an external resistor and a capacitor for each segment to protect the Au–Ag/YBCO film from hot spots. Switching tests using a short-circuit generator revealed that all the modules carried a superconducting ac current of ?237 Arms and that modules prepared with YBCO films having a relatively homogeneous critical current Ic distribution successfully withstood ?515 Vrms for five cycles without any damage. These results demonstrate that (a) the FCL modules fabricated here successfully achieved the rated current of 200 Arms and rated voltage of 500 Vrms and (b) total area of the YBCO films on sapphire substrates required for the 500 V/200 A (100 kV A) module was less than one-third that for conventional thin-film FCL modules that use gold shunt layers, leading to the significantly reduced cost of thin-film FCLs. Film damage due to hot spots depended on the difference in Ic between the two parallel-connected films and on the inhomogeneity of the Ic distribution in the film, and is most probably due to nonlinear current flows at the moment of quenching that cause local overheating.

H Yamasaki; K Arai; K Kaiho; Y Nakagawa; M Sohma; W Kondo; I Yamaguchi; H Matsui; T Kumagai; N Natori; N Higuchi

2009-01-01T23:59:59.000Z

104

Consequences of Fault Currents Contributed by Distributed Generation  

E-Print Network [OSTI]

Consequences of Fault Currents Contributed by Distributed Generation Supplemental Project Report Currents Contributed by Distributed Generation Natthaphob Nimpitiwan Gerald Heydt Research Project Team distributed generation (DG) is growing in the over- all generation mix due in part to state and national

105

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

SciTech Connect (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

106

Current Issues in Vibration-Based Fault Diagnostics and Prognostics Victor Giurgiutiu  

E-Print Network [OSTI]

1 Current Issues in Vibration-Based Fault Diagnostics and Prognostics Victor Giurgiutiu Mechanical Current issues in vibration-based fault diagnostics and prognostics are: (a) fault/damage identification and then classification. Keywords: structural health monitoring, active sensors, vibrations, signal analysis; smart

Giurgiutiu, Victor

107

Restoration and testing of an HTS fault current controller  

SciTech Connect (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

108

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

DOE Patents [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

109

Pinch current limitation effect in plasma focus  

Science Journals Connector (OSTI)

The Lee model couples the electrical circuit with plasma focusdynamics thermodynamics and radiation. It is used to design and simulate experiments. A beam-target mechanism is incorporated resulting in realistic neutron yield scaling with pinch current and increasing its versatility for investigating all Mather-type machines. Recent runs indicate a previously unsuspected “pinch current limitation” effect. The pinch current does not increase beyond a certain value however low the static inductance is reduced to. The results indicate that decreasing the present static inductance of the PF1000 machine will neither increase the pinch current nor the neutron yield contrary to expectations.

S. Lee; S. H. Saw

2008-01-01T23:59:59.000Z

110

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

Science Journals Connector (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

111

Process variation-aware multiple-fault diagnosis of thermometer-coded current-steering DACs  

E-Print Network [OSTI]

detection rate. 8 m/2 m/2x2 thermometer decoder Ci_m/2 Co_1Aware Structural Test of Thermometer Coded Current SteeringFault Diagnosis of Thermometer-Coded Current-Steering DACs

Topaloglu, R O

2007-01-01T23:59:59.000Z

112

Fault Current Contribution from Single-Phase PV Inverters  

SciTech Connect (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

113

Rotor current transient analysis of DFIG-based wind turbines during symmetrical voltage faults  

Science Journals Connector (OSTI)

Abstract The impact of grid voltage fault on doubly fed induction generators (DFIGs), especially rotor currents, has received much attention. So, in this paper, the rotor currents of based-DFIG wind turbines are considered in a generalized way, which can be widely used to analyze the cases under different levels of voltage symmetrical faults. A direct method based on space vector is proposed to obtain an accurate expression of rotor currents as a function of time for symmetrical voltage faults in the power system. The presented theoretical analysis is simple and easy to understand and especially highlights the accuracy of the expression. Finally, the comparable simulations evaluate this analysis and show that the expression of the rotor currents is sufficient to calculate the maximum fault current, DC and AC components, and especially helps to understand the causes of the problem and as a result, contributes to adapt reasonable approaches to enhance the fault ride through (FRT) capability of DFIG wind turbines during a voltage fault.

Yu Ling; Xu Cai; Ningbo Wang

2013-01-01T23:59:59.000Z

114

25 kV Superconducting Fault Current Limiter  

Science Journals Connector (OSTI)

Our technological progress in die field of superconductivity over the last ten years made possible the manufacture of industrial lengths of conductors, consisting of NbTi ultra-fine filaments, embedded in a Cu-30...

T. Verhaege; J. P. Tavergnier; A. Février…

1990-01-01T23:59:59.000Z

115

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

116

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

117

Wind Turbines Condition Monitoring and Fault Diagnosis Using Generator Current Amplitude  

E-Print Network [OSTI]

Wind Turbines Condition Monitoring and Fault Diagnosis Using Generator Current Amplitude in the research of renewable energy sources. In order to make wind turbines as competitive as the classical detection in a Doubly-Fed Induction Generator (DFIG) based wind turbine for stationary and nonstationary

Paris-Sud XI, Université de

118

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

SciTech Connect (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

119

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

120

Upper limits on charm-changing neutral-current interactions  

E-Print Network [OSTI]

parallel decays can be computed with NII =N„e(l+l )8(c l X), where N„ is the number of cc events, e(1+I ) is the detection efficiency for parallel decays, and 8(c l X) is the average semileptonic branching ratio of the charmed hadrons in the continuum...VOLUME 60, NUMBER 16 PHYSICAL REVIEW LETTERS 18 APRIL 1988 Upper Limits on Charm-Changing Neutral-Current Interactions P. Haas, ' M. Hempstead, ' T. Jensen, ' D. R. Johnson, ' H. Kagan, ' R. Kass, ' P. Baringer, R. L. McIlwain, D. H. Miller, C. R...

Baringer, Philip S.

1988-04-18T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

Mechanical fault detection in induction motor drives through stator current monitoring -Theory  

E-Print Network [OSTI]

. Common failures occurring in electrical drives can be roughly classified into: Electrical faults: stator in the load part of the drive) A reliability survey on large electric motors (>200 HP) revealed that most drive including the load, but they show that mechanical fault detection is of great concern in electric

Paris-Sud XI, Université de

122

An investigation of Network Splitting for Fault Level Reduction  

E-Print Network [OSTI]

main methods for fault level reduction namely current limiting reactor, Is-limiter, superconducting term as it is relatively inexpensive and furthermore it has high reliability and flexibility. Modelling in the bus-section. The analysis shows that the fault current is sensitive to closure of the normally open

Watson, Andrew

123

Current parallel I/O limitations to scalable data analysis.  

SciTech Connect (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

124

Photovoltaic ground fault and blind spot electrical simulations.  

SciTech Connect (OSTI)

Ground faults in photovoltaic (PV) systems pose a fire and shock hazard. To mitigate these risks, AC-isolated, DC grounded PV systems in the United States use Ground Fault Protection Devices (GFPDs), e.g., fuses, to de-energize the PV system when there is a ground fault. Recently the effectiveness of these protection devices has come under question because multiple fires have started when ground faults went undetected. In order to understand the limitations of fuse-based ground fault protection in PV systems, analytical and numerical simulations of different ground faults were performed. The numerical simulations were conducted with Simulation Program with Integrated Circuit Emphasis (SPICE) using a circuit model of the PV system which included the modules, wiring, switchgear, grounded or ungrounded components, and the inverter. The derivation of the SPICE model and the results of parametric fault current studies are provided with varying array topologies, fuse sizes, and fault impedances. Closed-form analytical approximations for GFPD currents from faults to the grounded current carrying conductor-known as %E2%80%9Cblind spot%E2%80%9D ground faults-are derived to provide greater understanding of the influence of array impedances on fault currents. The behavior of the array during various ground faults is studied for a range of ground fault fuse sizes to determine if reducing the size of the fuse improves ground fault detection sensitivity. The results of the simulations show that reducing the amperage rating of the protective fuse does increase fault current detection sensitivity without increasing the likelihood of nuisance trips to a degree. Unfortunately, this benefit reaches a limit as fuses become smaller and their internal resistance increases to the point of becoming a major element in the fault current circuit.

Flicker, Jack David; Johnson, Jay

2013-06-01T23:59:59.000Z

125

Verification of an IGBT Fusing Switch for Over-current Protection of the SNS HVCM  

SciTech Connect (OSTI)

An IGBT based over-current protection system has been developed to detect faults and limit the damage caused by faults in high voltage converter modulators. During normal operation, an IGBT enables energy to be transferred from storage capacitors to a H-bridge. When a fault occurs, the over-current protection system detects the fault, limits the fault current and opens the IGBT to isolate the remaining stored energy from the fault. This paper presents an experimental verification of the over-current protection system under applicable conditions.

Benwell, Andrew; Kemp, Mark; Burkhart, Craig; Nguyen, Minh; /SLAC; ,

2010-06-11T23:59:59.000Z

126

Surface current effects on the fetch-limited growth of wave energy Brian K. Haus1  

E-Print Network [OSTI]

Surface current effects on the fetch-limited growth of wave energy Brian K. Haus1 Received 5 the fetch-limited growth of wind wave energy over a region with significant lateral shear of the current. Both the near-surface currents and wave energy and period were mapped over the highly sheared inshore

Miami, University of

127

Enhancing power quality on distribution systems with Fault-Current Limiters  

Science Journals Connector (OSTI)

High levels of power quality are required in electric power systems to ensure safe and continuous operation for most loads. Voltage sags, one of the most critical power quality problems that utilities and customers alike may face, are short voltage-reduction ...

A. Escobar; J. C. Balda; J. Bourne; A. K. Barnes; R. M. Schupbach

2012-01-01T23:59:59.000Z

128

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

SciTech Connect (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

129

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...

Barnett, David Benjamin

2006-08-16T23:59:59.000Z

130

Current limiters based on silicon pillar un-gated FET for field emission application  

E-Print Network [OSTI]

This research investigates the use of vertical silicon ungated field effect transistors (FETs) as current limiters to individuallycontrol emission current in a field emitter and provide a simple solution to three problems ...

Niu, Ying, M. Eng. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

131

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

132

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

SciTech Connect (OSTI)

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

133

A Fault-Tolerant Multiphase Permanent Magnet Generator for Marine Current Turbine Applications  

E-Print Network [OSTI]

on offshore wind turbine systems. Marine current turbines are characterized by a very difficult access current turbine (MCT) are more compact than wind turbines, for the same rated power. Moreover in many aspects to wind turbines, which are already well developed and commercialized. For that reason

Boyer, Edmond

134

Power Limitation Control for a PMSG-Based Marine Current Turbine at High Tidal Speed and  

E-Print Network [OSTI]

Power Limitation Control for a PMSG-Based Marine Current Turbine at High Tidal Speed and Strong Sea Abstract--This paper deals with the control strategies for a fixed-pitch marine current turbine (MCT) when the nominal MPPT tracking speed during high speed marine currents. In the speed control strategy, the turbine

Paris-Sud XI, Université de

135

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

136

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

137

Automated Fault Location In Smart Distribution Systems  

E-Print Network [OSTI]

measured at the power substation during a single phase to ground fault clearance [17] .............................................. 111 Figure 26 Analyzed signal using wavelet transform from phase B current during a fault [17..., but are not limited to, substation and feeder relay, intelligent controllers for capacitor bank switches or reclosers, Automatic Meter Reading (AMR) systems installed at the customer sites, power quality meters installed at strategic locations in the system, low...

Lotfifard, Saeed

2012-10-19T23:59:59.000Z

138

Two-dimensional relativistic space charge limited current flow in the drift space  

SciTech Connect (OSTI)

Relativistic two-dimensional (2D) electrostatic (ES) formulations have been derived for studying the steady-state space charge limited (SCL) current flow of a finite width W in a drift space with a gap distance D. The theoretical analyses show that the 2D SCL current density in terms of the 1D SCL current density monotonically increases with D/W, and the theory recovers the 1D classical Child-Langmuir law in the drift space under the approximation of uniform charge density in the transverse direction. A 2D static model has also been constructed to study the dynamical behaviors of the current flow with current density exceeding the SCL current density, and the static theory for evaluating the transmitted current fraction and minimum potential position have been verified by using 2D ES particle-in-cell simulation. The results show the 2D SCL current density is mainly determined by the geometrical effects, but the dynamical behaviors of the current flow are mainly determined by the relativistic effect at the current density exceeding the SCL current density.

Liu, Y. L.; Chen, S. H., E-mail: chensh@ncu.edu.tw [Department of Physics, National Central University, Jhongli 32001, Taiwan (China); Koh, W. S. [A-STAR Institute of High Performance Computing, Singapore 138632 (Singapore)] [A-STAR Institute of High Performance Computing, Singapore 138632 (Singapore); Ang, L. K. [Engineering Product Development, Singapore University of Technology and Design, Singapore 138682 (Singapore)] [Engineering Product Development, Singapore University of Technology and Design, Singapore 138682 (Singapore)

2014-04-15T23:59:59.000Z

139

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

SciTech Connect (OSTI)

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

140

Detailed study of DFIG-based wind turbines to overcome the most severe grid faults  

Science Journals Connector (OSTI)

Abstract This paper studies the effects of voltage sags caused by faults on doubly-fed induction generators to overcome grid faults. A wide range of sag duration and depth values is considered. It is observed that sag duration influence is periodical. Sag effects depend on duration and depth and on the fault-clearing process as well. Two approaches of the model are compared: the most accurate approach, discrete sag, considers that the fault is cleared in the successive natural fault-current zeros of affected phases, leading to a voltage recovery in several steps; the least accurate approach, abrupt sag, considers that the fault is cleared instantaneously in all affected phases, leading to a one-step voltage recovery. Comparison between both sag models reveals that the fault-clearing process smoothes sag effects. The study assumes that the rotor-side converter can keep constant the transformed rotor current in the synchronous reference frame, thus providing insights into wind turbine fault ride-through capability. The voltage limit of the rotor-side converter is considered to show the situations where the rotor current can be controlled. Finally, a table and a 3D figure summarizing the effects of the most severe grid faults on the rotor-side converter to overcome the most severe faults are provided.

Alejandro Rolán; Joaquín Pedra; Felipe Córcoles

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

Low temperature limiting-current oxygen sensors based on tetragonal zirconia polycrystals  

SciTech Connect (OSTI)

This paper reports that yttria doped tetragonal zirconia polycrystals can overcome the phase transition into the monoclinic phase at about 500{degrees} C and show higher ionic conductivities than cubic stabilized zirconia in spite of the lower defect concentration. This material is applied in oxygen gas sensors under limiting current conditions at intermediate and ambient temperatures. AC and dc conductivities, Tafel behavior, minority charge carrier diffusivity, and the i-V characteristics are reported. The detection limit of the oxygen partial pressure and the response time depend on the thickness of the electrolyte and are related to the oxygen ion conductance and the electronic mobilities, respectively. The sensors may be optimized by the application of thin film electrolytes and of modified configurations with solid oxide bulk conducting diffusion barriers.

Liaw, B.Y.; Weppner, W. (Max-Planck Inst. fur Festkorperforschung, D-7000 Stuttgart 80 (DE))

1991-08-01T23:59:59.000Z

142

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

143

Electrical-Thermal-Structural Coupled Finite Element Model of High Temperature Superconductor for Resistive Type Fault Current Limiters  

Science Journals Connector (OSTI)

A multi-physics finite element model of high-temperature superconductors (HTS) will be presented in this article. The electrical-thermal model is mainly based on Maxwell’s equation and basic heat transfer equa...

J. Sheng; Y. Chen; B. Lin; L. Ying; Z. Jin…

2014-06-01T23:59:59.000Z

144

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

145

Limiter  

DOE Patents [OSTI]

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

146

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...

Akin, Bilal

2009-05-15T23:59:59.000Z

147

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

148

Fault response of inverter interfaced distributed generators in grid-connected applications  

Science Journals Connector (OSTI)

Abstract Inverter-interfaced distributed generation is prominent in some distribution networks because of the growth of PV and other new sources. In order to ensure that protection system design remains effective in this environment, it is essential to be able to accurately represent inverters in fault current calculations. Calculating the fault current contribution is complicated because of the nature of the transition into current limiting mode and because the current produced is a function of control choices as well as physical components. The desire is for a simple source plus impedance model for incorporation into network studies. Based on knowledge of the control strategy and the details of the method of current limiting, linear analytical equivalent models are proposed whose source and impedance values (at fundamental frequency) can be expressed as a function of the inverter's hardware parameters and controller gains. The dependence of the entry into current limit on the nature and location of other generators in the network leads to a proposal for a load flow based fault analysis incorporating the new models. This iteratively determines which inverter experiences current limiting. The proposed inverter fault models and their use in a network fault analysis have been verified against experimental results in a 3-inverter network.

Cornelis A. Plet; Timothy C. Green

2014-01-01T23:59:59.000Z

149

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

SciTech Connect (OSTI)

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

150

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

SciTech Connect (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

151

Three fault ride through controllers for wind systems running in isolated micro-grid and Effects of fault type on their performance: A review and comparative study  

Science Journals Connector (OSTI)

Abstract This paper presents survey about Fault Ride Through (FRT) techniques and controllers which employed with all wind generation system types. After presenting a comprehensive FRT survey, paper proposes three Fault Ride Through (FRT) controllers for keeping stability of Fixed Speed Wind Generation (FSWG) system serving in isolated Micro-Grid (MG). The first controller has been implemented by inserting Superconductor Fault Current Limiter (SFCL) in series with wind generator terminals during fault instant. The second proposed FRT controller is modifying the conventional Pitch Angle Controllers (PAC) to can spill and reduce high percentage of extracted mechanical wind power during and subsequent fault occurrence which in turns help stability improvement and restoration. Third FRT technique is performed by adapting the wind turbine gearbox ratio which forces the wind generation system to run far from the maximum power point. The best performance is obtained with the SFCL controller. Superior results are obtained when the three proposed FRT controllers are employed simultaneously. The three developed FRT controllers are simple, reliable and economical attractive. Effects of fault type on SFCL FRT controller performance are analyzed and investigated in details. The proposed SFCL FRT controller has been tested under single phase, double phase, phase to phase, and three phases to ground faults. Results display that the three phases to ground fault is the most severe type on SFCL FRT performance from stability point of view. On the other hand, double phase to ground fault is the most severe one from fluctuations and oscillations points of view. Parameters of the SFCL must be adjusted based on the three phases to ground fault. If the SFCL FRT controller is designed to can deal with three phases fault, it sure can deal with the other fault types successfully.

Rashad M. Kamel

2014-01-01T23:59:59.000Z

152

Earthquake Fault Studies in Japan  

Science Journals Connector (OSTI)

17 May 1973 research-article Earthquake Fault Studies in Japan K. Kasahara The paper reviews the current status of earthquake fault studies in Japan, taking the work on the off-Honshu tectonics as an example. Within the Japanese tectonic...

1973-01-01T23:59:59.000Z

153

An algorithm for faulted phase and feeder selection under high impedance fault conditions  

E-Print Network [OSTI]

substation. One-line diagram of a distribution system with two feeders. Typical high impedance fault, showing little or no change in phase voltage due to the fault. . Phase voltage and high frequency current component during a staged high impedance... substation. One-line diagram of a distribution system with two feeders. Typical high impedance fault, showing little or no change in phase voltage due to the fault. . Phase voltage and high frequency current component during a staged high impedance...

Benner, Carl Lee

2012-06-07T23:59:59.000Z

154

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

155

Intelligent fault prediction system based on internet of things  

Science Journals Connector (OSTI)

Fault prediction is the key technology to ensure the safe operation of large equipment. Based on the investigation of current and developing research of fault prediction, an intelligent fault prediction system based on internet of things is proposed ... Keywords: Fault prediction, Intelligent computer information processing, Internet of things, Mechanical equipment groups, Predictive maintenance

Xiaoli Xu; Tao Chen; Mamoru Minami

2012-09-01T23:59:59.000Z

156

Charge Transport in one Dimension:Dissipative and Non-Dissipative Space-Charge Limited Currents  

E-Print Network [OSTI]

We consider charge transport in nanopores where the dielectric constant inside the nanopore is much greater than in the surrounding material, so that the flux of the electric fields due to the charges is almost entirely confined to the nanopore. That means that we may model the electric fields due to charge densities in the nanopore in terms of average properties across the nanopore as solutions of one dimensional Poisson equations. We develop basic equations for an M component system using equations of continuity to relate concentrations to currents, and flux equations relating currents to concentration gradients and conductivities. We then derive simplified scaled versions of the equations. We develop exact solutions for the one component case in a variety of boundary conditions using a Hopf-Cole transformation, Fourier series, and periodic solutions of the Burgers equation. These are compared with a simpler model in which the scaled diffusivity is zero so that all charge motion is driven by the electric field. In this non-dissipative case, recourse to an admissibility condition is utilised to obtain the physically relevant weak solution of a Riemann problem concerning the electric field. It is shown that the admissibility condition is Poynting's theorem.

S. R. Holcombe; E. R. Smith

2010-03-23T23:59:59.000Z

157

Space charge limited current conduction in Bi{sub 2}Te{sub 3} thin films  

SciTech Connect (OSTI)

Bi{sub 2}Te{sub 3} is known for its large thermoelectric coefficients and is widely used as a material for Peltier devices. Bi{sub 2}Te{sub 3} thin films with thicknesses in the range 125-300 A have been prepared by Flash Evaporation at a pressure of 10{sup -5} m bar on clean glass substrates at room temperature. An Al-Bi{sub 2}Te{sub 3}-Al sandwich structure has been used for electrical conduction properties in the temperature range 303 to 483 K. I-V characteristics showed Ohmic conduction in the low voltage region. In the higher voltage region, a Space Charge Limited Conduction (SCLC) takes place due to the presence of the trapping level. The transition voltage (V{sub t}), between the Ohmic and the SCLC condition was proportional to the square of thickness. Further evidence for this conduction process was provided by the linear dependence of V {sub t} on t {sup 2} and log J on log t. The hole concentration in the films were found to be n {sub 0} = 1.65 * 10{sup 10} m{sup -3}. The carrier mobility increases with increasing temperature whereas the density of trapped charges decreases with increasing temperature. The barrier height decreases with an increase in temperature. The increase in the trapping concentration V {sub t} is correlated with ascending the degree of preferred orientation of the highest atomic density plane. The activation energy was estimated and the values found to decrease with increasing applied voltage. The zero field value of the activation energy is found to be 0.4 eV.

Sathyamoorthy, R. [PG and Research Department of Physics, Kongunadu Arts and Science College, Coimbatore-029, Tamil Nadu (India)]. E-mail: rsathya_59@yahoo.com; Dheepa, J. [PG and Research Department of Physics, Kongunadu Arts and Science College, Coimbatore-029, Tamil Nadu (India); Velumani, S. [Department of Physics, ITESM-Campus, Monterrey, N.L (Mexico)

2007-08-15T23:59:59.000Z

158

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

159

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:

160

Robust model-based fault diagnosis for chemical process systems  

E-Print Network [OSTI]

diagnosis systems, which use limited information about the process model to robustly detect, discriminate, and reconstruct instrumentation faults. Broadly, the proposed method consists of a novel nonlinear state and parameter estimator coupled with a fault...

Rajaraman, Srinivasan

2006-08-16T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

Low platinum, high limiting current density of the PEMFC (proton exchange membrane fuel cell) based on multilayer cathode catalyst approach  

Science Journals Connector (OSTI)

Abstract Novel multilayer cathode electrodes structures for PEMFC (proton exchange membrane fuel cell) based on sputtering technique were developed to provide high performance with low loading Pt of 0.05 mg/cm² compared to the standard MEA (membrane electrode assembly) cathode (?0.2–0.3 mg/cm²). Different configurations of cathode catalyst layer were made by altering Pt and CN (Carbon–Nafion) ink carefully prepared on gas diffusion layer containing MPL (micro porous layer). The performances of PEMFC containing the multilayer electrodes were compared based on their measured polarization curves. Higher limiting current densities were achieved compared to standard MEA with platinum loading of 0.2 mg/cm² both at the cathode and the anode sides. Limiting current densities over 1.1 A/cm2, 1.2 A/cm2 and 1.4 A/cm2 were reached whereas maximum powers were in the range of 500 mW/cm² at 600 mW/cm². The good performances obtained can be due to the structural improvement which has contributed to a better catalyst utilization compared to conventional methods. A CN loading inferior to 0.24 mg/cm² between each layer is preferred for multilayer electrode.

Daouda Fofana; Sadesh Kumar Natarajan; Jean Hamelin; Pierre Benard

2014-01-01T23:59:59.000Z

162

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...

Mrkic, Jasna

2012-06-07T23:59:59.000Z

163

Software fault avoidance issues  

Science Journals Connector (OSTI)

This article aims to discuss various issues of software fault avoidance. Software fault avoidance aims to produce fault free software through various approaches having the common objective of reducing the number of latent defects in software programs.

Goutam Kumar Saha

2006-11-01T23:59:59.000Z

164

Flow loop studies of the relationship between limiting currents and CO{sub 2}/H{sub 2}S corrosion of carbon steel  

SciTech Connect (OSTI)

Corrosion measurements on AISI 1010 carbon steel were performed in a glass/titanium flow loop, containing a single-phase test fluid of distilled water, 3% in NaCl saturated with CO{sub 2} or a CO{sub 2}/H{sub 2}S gas mixture. The tests were run at temperatures from 25 to 90 C and flow velocities ranged from 0.25 to 2.5 m/s. Corrosion rates were calculated from LPR and tafel extrapolations. Steady-state corrosion currents were compared to cathodic limiting diffusion currents obtained under corresponding conditions. The limiting currents were calculated from potentiodynamic sweeps carried out on platinum. Limiting current plateaus were easily seen at pH values below 5, but vanished with increasing pH. Results show a linear correlation between the measured corrosion rates and the limiting currents, both with and without H{sub 2}S present. With further research and development on this field, the limiting diffusion current technique can be used in predicting corrosivity of CO{sub 2}/H{sub 2}S-containing media and other aqueous environments, as well as for `in-situ` corrosion monitoring.

Kvarekvn, J. [MARINTEK, Sandefjord (Norway). Lab. for Materials Application

1998-12-31T23:59:59.000Z

165

Proactive Fault Tolerance for HPC with Xen Virtualization  

SciTech Connect (OSTI)

with thousands of processors. At such large counts of compute nodes, faults are becoming common place. Current techniques to tolerate faults focus on reactive schemes to recover from faults and generally rely on a checkpoint/restart mechanism. Yet, in today's systems, node failures can often be anticipated by detecting a deteriorating health status. Instead of a reactive scheme for fault tolerance (FT), we are promoting a proactive one where processes automatically migrate from ?unhealthy? nodes to healthy ones. Our approach relies on operating system virtualization techniques exemplied by but not limited to Xen. This paper contributes an automatic and transparent mechanism for proactive FT for arbitrary MPI applications. It leverages virtualization techniques combined with health monitoring and load-based migration. We exploit Xen's live migration mechanism for a guest operating system (OS) to migrate an MPI task from a health-deteriorating node to a healthy one without stopping the MPI task during most of the migration. Our proactive FT daemon orchestrates the tasks of health monitoring, load determination and initiation of guest OS migration. Experimental results demonstrate that live migration hides migration costs and limits the overhead to only a few seconds making it an attractive approach to realize FT in HPC systems. Overall, our enhancements make proactive FT a valuable asset for long-running MPI application that is complementary to reactive FT using full checkpoint/ restart schemes since checkpoint frequencies can be reduced as fewer unanticipated failures are encountered. In the context of OS virtualization, we believe that this is the rst comprehensive study of proactive fault tolerance where live migration is actually triggered by health monitoring.

Nagarajan, Arun Babu [North Carolina State University; Mueller, Frank [North Carolina State University; Engelmann, Christian [ORNL; Scott, Stephen L [ORNL

2007-01-01T23:59:59.000Z

166

Influence of the backward-pump process on photon-number squeezing in a constant-current-driven heterojunction LED: Transition from thermionic emission to diffusion limits  

Science Journals Connector (OSTI)

Physical mechanisms which limit the squeezing bandwidth in a heterojunction light-emitting diode (LED) have been extensively studied both theoretically and experimentally. It is proven that our experimental results of pump-current dependence of the squeezing bandwidth in the constant-current-driven heterojunction LED at room temperature cannot be explained by previous theoretical predictions. We present a theoretical framework, including the effects of a microscopic backward-pump (BP) process, generally applicable to a heterojunction LED. Parameters describing the relative significance of the BP process are determined by the measurements of current-versus-voltage characteristic and differential resistance of the LED, independent of the noise measurements. As a consequence, the experimental results can be explained by our model in a unified manner over a whole range of injection current, and it is clarified that the pump situation of the LED moves continuously from thermionic emission to diffusion limits with increasing pump current.

Masahide Kobayashi; Masamichi Yamanishi; Hiroyuki Sumitomo; Yutaka Kadoya

1999-12-15T23:59:59.000Z

167

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

SciTech Connect (OSTI)

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

168

Thermal anomalies indicate preferential flow along faults in unconsolidated sedimentary aquifers  

E-Print Network [OSTI]

Thermal anomalies indicate preferential flow along faults in unconsolidated sedimentary aquifers V in unconsolidated siliciclastic aquifers off-set by normal-faults in the Lower Rhine Embayment, Germany. High plane. Most current models of fault hydrology in unconsolidated sedimentary sequences assume faults

Bense, Victor

169

Why don't you see what I mean? Prospects and limitations of current automatic sign recognition research  

E-Print Network [OSTI]

of Groningen. Currently: Information and Communication Theory Group, Delft University of Technology Center for Language and Cognition Groningen, University of Groningen Artificial Intelligence, University of Groningen

170

buffer Layer Growth, the Thickness Dependence of Jc in Coated Conductors, Local Identification of Current Limiting Mechanisms and Participation in the Wire Development Group  

SciTech Connect (OSTI)

The primary thrusts of our work were to provide critical understanding of how best to enhance the current-carrying capacity of coated conductors. These include the deconstruction of Jc as a function of fim thickness, the growth of in situ films incorporating strong pinning centers and the use of a suite of position-sensitive tools that enable location and analysis of key areas where current-limiting occurs.

Larbalestier, David; Hellstron, Eric; Abraimov, Dmytro

2011-12-17T23:59:59.000Z

171

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

172

Fault diagnosis and management system for switched reluctance motor drives  

Science Journals Connector (OSTI)

An effective detection and diagnosis of faults is desirable for online condition monitoring, assessment, product quality assurance and improved operational efficiency of Switched Reluctance Motor (SRM) drives. The proposed fault diagnosis and management system uses the measured phase voltages, currents and speed of the motor. In this article, a Matlab/Simulink model-based fault diagnosis system is developed and simulated for SRM drive. The simulation results show that the SRM drive is capable of operating under faulty conditions.

S. Vijayan; S. Paramasivam

2008-01-01T23:59:59.000Z

173

Fault Location and Incipient Fault Detection in Distribution Cables.  

E-Print Network [OSTI]

??A set of fault location algorithms for underground medium voltage cables, two incipient fault detection schemes for distribution cables and a state estimation method for… (more)

Xu, Zhihan

2011-01-01T23:59:59.000Z

174

DAFT: decoupled acyclic fault tolerance  

Science Journals Connector (OSTI)

Higher transistor counts, lower voltage levels, and reduced noise margin increase the susceptibility of multicore processors to transient faults. Redundant hardware modules can detect such errors, but software transient fault detection techniques are ... Keywords: multicore, speculation, transient fault

Yun Zhang; Jae W. Lee; Nick P. Johnson; David I. August

2010-09-01T23:59:59.000Z

175

Space-charge-limited currents in n-i-n devices incorporating glow-discharge and hot-wire deposited a-Si:H  

SciTech Connect (OSTI)

Space-charge-limited currents have been examined in a wide variety of n-i-n devices. If the devices were completely symmetric, the current-voltage characteristics would be identical for positive and negative bias, but in several devices differences between the two polarities were observed. In order to understand in which part of the device these differences originate, the influence of the contacts and interfaces on the JV characteristics were examined by using different metal top contacts, different n-layers and different i-layers. Ag and Al top contacts gave minor differences between the polarities, whereas with Cr contacts no differences were observed. Incorporation of a defect layer in the i-layer results in asymmetric JV curves. They have observed a small asymmetry in an experimental device, and a large symmetry using AMPS modeling. N-i-n devices appear to be a sensitive probe for interface defects.

Molenbroek, E.C.; Van der Werf, C.H.M.; Feenstra, K.F.; Rubinelli, F.; Schropp, R.E.I.

1997-07-01T23:59:59.000Z

176

Dealing with Faults in Wireless Sensor Networks Lilia Paradis and Qi Han  

E-Print Network [OSTI]

, fault detection, fault diagnosis, fault tolerance 1 Introduction Continuing advances in computational number of such sensing devices with severely limited processing, storage and communication capabilities are fragile, 2 #12;and they may fail due to depletion of batteries or destruction by an external event

177

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

1986-01-01T23:59:59.000Z

178

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

179

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

180

Fault Detection and Diagnosis for Brine to Water Heat Pump Systems.  

E-Print Network [OSTI]

?? This research project is part of a wider project called Smart Fault Detection and Diagnosis for HeatPump Systems currently under development by the Royal… (more)

Vecchio, Daniel

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

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

SciTech Connect (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

182

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

183

Optimal fault location  

E-Print Network [OSTI]

for the pre-selected time out to pass and initiate reclosing again. If after selected number of attempts of reclosing, fault is still present, breaker lockout is taking place. There will be no more attempts to reclose automatically the breaker again....2: Trip and reclose sequences on a single breaker In the case of breaker lockout the assumption taken by the operators is that fault is permanent. Special order is issued to the maintenance for the breaker to be closed back in 4 again once...

Knezev, Maja

2009-05-15T23:59:59.000Z

184

Optimal fault location  

E-Print Network [OSTI]

for the pre-selected time out to pass and initiate reclosing again. If after selected number of attempts of reclosing, fault is still present, breaker lockout is taking place. There will be no more attempts to reclose automatically the breaker again....2: Trip and reclose sequences on a single breaker In the case of breaker lockout the assumption taken by the operators is that fault is permanent. Special order is issued to the maintenance for the breaker to be closed back in 4 again once...

Knezev, Maja

2008-10-10T23:59:59.000Z

185

Limited Lawn & Limited Commercial  

E-Print Network [OSTI]

Limited Lawn & Ornamental Limited Commercial Landscape Maintenance Review and Exams Limited for Commercial Landscape Maintenance Application: http://www.flaes.org/ pdf/lndspckt.pdf Limited Certification.floridatermitehelp.org or request by phone at 850-921-4177. Limited Lawn & Ornamental/Limited Commercial Landscape Maintenance

Watson, Craig A.

186

Limited Lawn & Limited Commercial  

E-Print Network [OSTI]

Limited Lawn & Ornamental Limited Commercial Landscape Maintenance Review and Exams Limited-921-4177. Limited Lawn & Ornamental/Limited Commercial Landscape Maintenance: Ornamental and Turf Pest Control (SM 7&O/Structural only). See web locations below for applications. Limited Certification for Commercial Landscape

Jawitz, James W.

187

Row fault detection system  

DOE Patents [OSTI]

An apparatus, program product and method check for nodal faults in a row of nodes by causing each node in the row to concurrently communicate with its adjacent neighbor nodes in the row. The communications are analyzed to determine a presence of a faulty node or connection.

Archer, Charles Jens (Rochester, MN); Pinnow, Kurt Walter (Rochester, MN); Ratterman, Joseph D. (Rochester, MN); Smith, Brian Edward (Rochester, MN)

2012-02-07T23:59:59.000Z

188

The application of satellite time references to HVDC fault location  

SciTech Connect (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

189

Quaternary faults of the central Rocky Mountains, Colorado: A new seismotectonic evaluation  

SciTech Connect (OSTI)

Quaternary faults in the central Rocky Mountain of CO exhibit normal displacement, are generally parallel to the strike of pre-existing Larmide structures, and typically occur in the hanging walls of Laramide thrust faults. These observations are consistent with models in which Mesozoic thrust faults are being reactivated as normal faults in the contemporary extensional tectonic setting. To assess the seismogenic potential of these faults, the authors evaluated the recency of fault movement and style of deformation via aerial reconnaissance, interpretation of aerial photography and field mapping of selected sites. The 82-km-long Red Rocks-Climarron fault zone shows evidence of late Quaternary displacement and may be capable of producing an M[>=]6.75 earthquake based on its total fault length and inferred fault width. Earthquake hypocenters indicate that the thickness of the seismogence crust in CO is similar to much of the western US (ca. 15 km). In additional to tectonic deformation, numerous faults and lineaments have been identified in the Paradox Basin and along the southern Grand Hogback monocline that are active due to diapiric movement of halite. In particular, active deformation along the Grand Hogback is limited to portions of the structure underlain by a 3-km-deep Pennsylvania halite basin. Because Quaternary deformation along and near these large Laramide structures is due to the movement of halite rather than deep-seated tectonism, the maximum size of a potential earthquake is limited by the down-dip width and lateral extent of fault planes within brittle rocks overlying the halite. The authors infer that the maximum depth of brittle faulting due to diapiric halite flow is 6 km, and the earthquakes larger than M 5 are unlikely to occur on faults associated with the Grand Hogback and salt anticlines of the Paradox Basin. The 1984 Carbondale earthquake swarm (M[<=]3.2) may have been the result of such faulting.

Unruh, J.R.; Noller, J.S.; Lettis, W.R. (William Lettis and Association, Inc., Oakland, CA (United States)); Wong, I.G.; Sawyer, T.L.; Bott, J.D.J. (Woodward-Clyde Federal Services, Oakland, CA (United States))

1993-04-01T23:59:59.000Z

190

The Portland Hills Fault: uncovering a hidden fault in Portland, Oregon using high-resolution geophysical methods  

Science Journals Connector (OSTI)

The Portland metropolitan area historically is the most seismically active region in Oregon. At least three potentially active faults are located in the immediate vicinity of downtown Portland, with the Portland Hills Fault (PHF) extending directly beneath downtown Portland. The faults are poorly understood, and the surface geologic record does not provide the information required to assess the seismic hazards associated with them. The limited geologic information stems from a surface topography that has not maintained a cumulative geologic record of faulting, in part, due to rapid erosion and deposition from late Pleistocene catastrophic flood events and a possible strike-slip component of the faults. We integrated multiple high-resolution geophysical techniques, including seismic reflection, ground penetrating radar (GPR), and magnetic methods, with regional geological and geophysical surveys to determine that the Portland Hills Fault is presently active with a zone of deformation that extends at least 400 m. The style of deformation is consistent with at least two major earthquakes in the last 12–15 ka, as confirmed by a sidehill excavation trench. High-resolution geophysical methods provide detailed images of the upper 100 m across the active fault zone. The geophysical images are critical to characterizing the structural style within the zone of deformation, and when integrated with a paleoseismic trench, can accurately record the seismic history of a region with little surface geologic exposure.

Lee M. Liberty; Mark A. Hemphill-Haley; Ian P. Madin

2003-01-01T23:59:59.000Z

191

Complex Faulting in the Yuha Desert: Implications for Fault Interaction  

E-Print Network [OSTI]

Dibblee. Geology of the Imperial Valley region, California,and tectonics of the Imperial Valley region, California. Innent faults surrounding the Imperial Valley region, southern

Kroll, Kayla Ann

2012-01-01T23:59:59.000Z

192

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

193

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

194

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

Boyer, Edmond

195

Intelligent fault diagnosis of power transmission line; -.  

E-Print Network [OSTI]

??This dissertation presents the application of recent intelligent newlinetechniques for fault diagnosis in electrical power transmission line Fault newlinesection identification classification and location are the… (more)

Malathi, V

2014-01-01T23:59:59.000Z

196

Transition-fault test generation  

E-Print Network [OSTI]

large to store in the memory of the tester. The proposed methods of test generation utilize stuck-at-fault tests to create transition-fault test sets of a smaller size. Greedy algorithms are used in the generation of both the stuck...

Cobb, Bradley Douglas

2013-02-22T23:59:59.000Z

197

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

198

Hot Pot Detail - Evidence of Quaternary Faulting  

SciTech Connect (OSTI)

Compilation of published data, field observations and photo interpretation relevant to Quaternary faulting at Hot Pot.

Lane, Michael

2013-06-27T23:59:59.000Z

199

Hot Pot Detail - Evidence of Quaternary Faulting  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

Compilation of published data, field observations and photo interpretation relevant to Quaternary faulting at Hot Pot.

Lane, Michael

200

Fault Tolerant MapReduce-MPI using User Level Failure Mitigation...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

different models to achieve fault tolerance in MR-MPI: checkpoint-restart and detect-resume. The checkpoint-restart model is implemented using the current MPI standard. It allows...

Note: This page contains sample records for the topic "fault current limiter" 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

Earth-Fault Relay Equipment  

Science Journals Connector (OSTI)

... proving the reliability of the equipment. By Observing the operation of the relays at each substation with faults at selected points, the complete scheme can be put into operation with ...

1944-04-15T23:59:59.000Z

202

Electric Currents Electric Current  

E-Print Network [OSTI]

coefficient of resistivity Electric Power: = = = Also, = . So, = = 2 = 2 Unit of Power(P): Watt (WChapter 18 Electric Currents #12;Electric Current: Flow of electric charge Current is flow of positive charge. In reality it's the electron moves in solids- Electron current. #12;Ohm's Law : Resistance

Yu, Jaehoon

203

Development of secondary faults between en echelon, oblique-slip faults: examples from basement controlled, small-fault systems in the Llano Uplift of central Texas  

E-Print Network [OSTI]

between and oriented oblique to the bounding faults. With increasing displacement on the bounding faults, the system of secondary faults evolves from an Elementary to a Compound, to an Advanced geometry, which includes the formation of secondary... to the primary faults. Synthetic faults form interior to and ahead of the bounding faults, increasing the effective overlap. Displacements on antithetic faults are directly related to changes in displacement on associated bounding faults. Additionally...

Hedgcoxe, Howard Reiffert

2012-06-07T23:59:59.000Z

204

Termination of a Major Normal Fault | Open Energy Information  

Open Energy Info (EERE)

Termination of a Major Normal Fault: Major normal fault terminations or tip-lines sometimes split into multiple closely-spaced faults that result in increased...

205

Parametic Study of the current limit within a single driver-scaletransport beam line of an induction Linac for Heavy Ion Fusion  

SciTech Connect (OSTI)

The High Current Experiment (HCX) at Lawrence Berkeley National Laboratory is part of the US program that explores heavy-ion beam as the driver option for fusion energy production in an Inertial Fusion Energy (IFE) plant. The HCX is a beam transport experiment at a scale representative of the low-energy end of an induction linear accelerator driver. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge-dominated heavy-ion beams at high intensity (line charge density {approx}0.2 {micro}C/m) over long pulse durations (4 {micro}s) in alternating gradient focusing lattices of electrostatic or magnetic quadrupoles. This experiment is testing transport issues resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and steering, envelope matching, image charges and focusing field nonlinearities, halo and, electron and gas cloud effects. We present the results for a coasting 1 MeV K{sup +} ion beam transported through ten electrostatic quadrupoles. The measurements cover two different fill factor studies (60% and 80% of the clear aperture radius) for which the transverse phase-space of the beam was characterized in detail, along with beam energy measurements and the first halo measurements. Electrostatic quadrupole transport at high beam fill factor ({approx}80%) is achieved with acceptable emittance growth and beam loss. We achieved good envelope control, and re-matching may only be needed every ten lattice periods (at 80% fill factor) in a longer lattice of similar design. We also show that understanding and controlling the time dependence of the envelope parameters is critical to achieving high fill factors, notably because of the injector and matching section dynamics.

Prost, Lionel Robert

2007-02-14T23:59:59.000Z

206

Evaluation Of Fault-Tolerant Policies Using Simulation  

SciTech Connect (OSTI)

Various mechanisms for fault-tolerance (FT) are used today in order to reduce the impact of failures on application execution. In the case of system failure, standard FT mechanisms are checkpoint/restart (for reactive FT) and migration (for pro-active FT). However, each of these mechanisms create an overhead on application execution, overhead that for instance becomes critical on large-scale systems where previous studies have shown that applications may spend more time checkpointing state than performing useful work. In order to decrease this overhead, researchers try to both optimize existing FT mechanisms and implement new FT policies. For instance, combining reactive and pro-active approaches in order to decrease the number of checkpoints that must be performed during the application 's execution. However, currently no solutions exist which enable the evaluation of these FT approaches through simulation, instead experimentations must be done using real platforms. This increases complexity and limits experimentation into alternate solutions. This paper presents a simulation framework that evaluates different FT mechanisms and policies. The framework uses system failure logs for the simulation with a default behavior based on logs taken from the ASCI White at Lawrence Livermore National Laboratory. We evaluate the accuracy of our simulator comparing simulated results with those taken from experiments done on a 32-node compute cluster. Therefore such a simulator can be used to develop new FT policies and/or to tune existing policies.

Tikotekar, Anand A [ORNL; Vallee, Geoffroy R [ORNL; Naughton, III, Thomas J [ORNL; Scott, Stephen L [ORNL

2007-01-01T23:59:59.000Z

207

Small-scale faulting in the Upper Cretaceous of the Groningen block (The Netherlands): 3D seismic interpretation, fault plane analysis and regional paleostress  

Science Journals Connector (OSTI)

Over the last years, field-based studies have shown that fault surfaces can exhibit a considerable self-affine topography. It is reasonable to assume that similar undulations are also present in fault interpretations from 3D reflection seismic data, however both the interpretation uncertainty and geophysical resolution limits hinder their analysis. This study analyses a set of small-scale, non-reactivated faults in the Upper Cretaceous Chalk Group (Upper Ommelanden Formation) of the NW-part of the Groningen Block, the Netherlands, in a high quality Pre Stack Depth Migrated 3D seismic data set. The studied faults are fully contained inside the Chalk Group, in an area located between the major tectonic-bounding faults of the NW Groningen Block. Over 200 faults, with offsets in the order of 30–50 m, were interpreted across an area of ca. 150 km2, showing a clear preferential orientation for strike, dip and dip-direction. Detailed interpretations and 3D fault plane analyses show undulations on the fault plane. We show that these undulations are not an interpretation or gridding artefact, and interpret these to indicate direction of fault slip. These results were used to calculate a paleostress tensor, using all faults to calculate a single stress tensor for the entire study area by Numerical Dynamic Analysis. Based on the orientation, position and a thickness analysis, it is interpreted that these faults formed due to the tectonic reactivation of salt structures in the Latest Cretaceous. The calculated paleostress state shows a general NW–SE-extension, with a vertical maximum principle stress, and a stress ratio of about 0.3, indicating that the studied faults are not the result of dewatering. This interpretation agrees both with a nearby salt-tectonic reconstruction, as well as field-based paleostress results from the UK, Belgium and France. A first look at other surveys from the Dutch sector indicates that similar faults are present in other areas, with different orientations. We propose that a dedicated analysis of these faults across on- and offshore Europe would allow extending the stress map of the Late Cretaceous into areas where the Chalk is not outcropping.

Heijn van Gent; Stefan Back; Janos L. Urai; Peter Kukla

2010-01-01T23:59:59.000Z

208

Quaternary faults of west Texas  

SciTech Connect (OSTI)

North- and northwest-striking intermontane basins and associated normal faults in West Texas and adjacent Chihuahua, Mexico, formed in response to Basin and Range tectonism that began about 24 Ma ago. Data on the precise ages of faulted and unfaulted Quaternary deposits are sparse. However, age estimates made on the basis of field stratigraphic relationships and the degree of calcic soil development have helped determine that many of the faults that bound the basin margins ruptured since the middle Pleistocene and that some faults probably ruptured during the Holocene. Average recurrence intervals between surface ruptures since the middle Pleistocene appear to be relatively long, about 10,000 to 100,000 yr. Maximum throw during single rupture events have been between 1 and 3 m. Historic seismicity in West Texas is low compared to seismicity in many parts of the Basin and Range province. The largest historic earthquake, the 1931 Valentine earthquake in Ryan Flat/Lobo Valley, had a magnitude of 6.4 and no reported surface rupture. The most active Quaternary faults occur within the 120-km-long Hueco Bolson, the 70-km-long Red Light Bolson, and the > 200-km-long Salt Basins/Wild Horse Flat/Lobo Valley/Ryan Flat.

Collins, E.W.; Raney, J.A. (Univ. of Texas, Austin, TX (United States). Bureau of Economic Geology)

1993-04-01T23:59:59.000Z

209

Effect of faulting on ground-water movement in the Death Valley region, Nevada and California  

SciTech Connect (OSTI)

This study characterizes the hydrogeologic system of the Death Valley region, an area covering approximately 100,000 square kilometers. The study also characterizes the effects of faults on ground-water movement in the Death Valley region by synthesizing crustal stress, fracture mechanics,a nd structural geologic data. The geologic conditions are typical of the Basin and Range Province; a variety of sedimentary and igneous intrusive and extrusive rocks have been subjected to both compressional and extensional deformation. Faulting and associated fracturing is pervasive and greatly affects ground-water flow patterns. Faults may become preferred conduits or barriers to flow depending on whether they are in relative tension, compression, or shear and other factors such as the degree of dislocations of geologic units caused by faulting, the rock types involved, the fault zone materials, and the depth below the surface. The current crustal stress field was combined with fault orientations to predict potential effects of faults on the regional ground-water flow regime. Numerous examples of fault-controlled ground-water flow exist within the study area. Hydrologic data provided an independent method for checking some of the assumptions concerning preferential flow paths. 97 refs., 20 figs., 5 tabs.

Faunt, C.C.

1997-12-31T23:59:59.000Z

210

Design of Rotor-side Controller Using Adaptive Time-frequency Method for DFIG Bearing Fault Detection  

Science Journals Connector (OSTI)

To ensure the reliable operation and power quality of wind power systems, the fault-tolerant control for DFIG is studied in this paper. Based on measured motor currents data, an adaptive statistical time-frequency method is then used to detect the fault ... Keywords: Doubly-fed induction generator, monitoring, wind turbine, rotor side inverter

Suratsavadee K. Korkua

2013-07-01T23:59:59.000Z

211

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

SciTech Connect (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

212

PREEARTHQUAKE AND POSTEARTHQUAKE CREEP ON THE IMPERIAL FAULT AND THE BRAWLEY FAULT ZONE1  

E-Print Network [OSTI]

(Goulty and others, 1978). The 1979 Imperial Valley earthquake was associated with surface faultingPREEARTHQUAKE AND POSTEARTHQUAKE CREEP ON THE IMPERIAL FAULT AND THE BRAWLEY FAULT ZONE1 By STEPHEN, and 2 years ofsurveys from two nail files suggests that creep events on the Imperial fault 2 to 5 months

Tai, Yu-Chong

213

Control strategies of doubly fed induction generator-based wind turbine system with new rotor current protection topology  

Science Journals Connector (OSTI)

A protection scheme of a doubly fed induction generator (DFIG) based wind turbine system during faults is crowbar activation. With this protection the rotor side converter (RSC) is temporarily disconnected and its vector control over the stator active and reactive power is lost leading to poor power quality at the point of common coupling (PCC). This paper presents a new protection scheme for transient rotor current to improve the performance of DFIG during grid disturbance. The new scheme consisting of a crowbar and series circuit is connected between the rotor windings and RSC to enhance the low voltage ride-through capability of DFIG. The proposed scheme successfully limits the transient rotor current and dc-link voltage and a disconnection of RSC from the rotor windings is avoided during fault. Additionally RSC and grid-side converter controllers are modified to improve the voltage at PCC. Simulations on matlab/Simulink verify the effectiveness of the proposed scheme.

Jackson John Justo; Kyoung-Soo Ro

2012-01-01T23:59:59.000Z

214

Fault tolerant supercomputing: a software approach  

Science Journals Connector (OSTI)

Adding fault tolerance to embedded supercomputing applications is becoming an issue of great significance, especially as these applications support critical parts of our everyday life in the modern "Information Society". To this end, a software middleware ... Keywords: embedded parallel and distributed systems, fault-tolerant communication, high performance computing, maintainability, separation of design concerns, software fault tolerance, user-specified recovery strategies

E. Verentziotis; T. Varvarigou; D. Vergados; G. Deconinck

2001-01-01T23:59:59.000Z

215

Fault-tolerant TCP mechanisms  

E-Print Network [OSTI]

While fault-tolerance is supported by a variety of critical services that can be accessed over the Internet, they are not robust in that they are oblivious of the impact of their tolerant mechanisms on the service they deliver. Throughputs and fail...

Satapati, Suresh Kumar

2012-06-07T23:59:59.000Z

216

Method of detecting the direction of arcing faults on power distribution feeders  

E-Print Network [OSTI]

of overcurrent relays, which Journal model is IEEE transactions on Power Delivery is required for distribution system reliability. The traveling wave directionality al- gorithms also require fairly substantial change in voltage for proper operation... is of significant magnitude to cause a current reversal in the case of a reverse fault [18]. 2. Traveling Wave Relaying The need for more accurate and fast detection of fault and direction of very high voltage transmission lines, was the base of invention...

Fernando, W. Anand Krisantha

2012-06-07T23:59:59.000Z

217

Landsat TM processing in the investigation of active fault zones, South Lajas Valley Fault Zone and Cerro Goden Fault Zone as an example  

E-Print Network [OSTI]

unrecognized east- west trending fault crossing an alluvial fan on the southern side of the Lajas Valley, SWLandsat TM processing in the investigation of active fault zones, South Lajas Valley Fault Zone and geophysical data, to delineate the lateral extent of two fault zones, the South Lajas Valley Fault Zone (SLVFZ

Gilbes, Fernando

218

Verification of inferred faults by resistivity analysis. Technical progress report, July 17-October 31, 1981  

SciTech Connect (OSTI)

The major purpose of this effort is to detect new faults which may indicate fracture systems with potential for gas production from the black shales. The method is to gather surface geophysical data, principally resistivity, to test Landsat lineaments as faults. A second purpose is to develop an economical method of confirming remotely sensed lineaments as faults or fractures which can be applied in this region and perhaps be extended to the eastern part of the United States. To attain the goal of this work, the planned approach was to use high-powered (3KW) resistivity measurements in a dipole-dipole configuration to penetrate deeply - a rather expensive procedure. Toward this end it was decided to make a preliminary investigation using a scintillation counter in addition to a low-current resistivity measuring instrument. The scintillation counter gave more definite indication of known faults than did the resistivity measurements. The South Graham, North Graham, and the fault at Highways 403-269, Kentucky were all indicated on one traverse by scintillation measurements, but only the North Graham fault was indicated by resistivity, and the resistivities profile was not conclusive. The reason for the inconclusive resistivity result may have been the fact that the fault zones in this region are often thin, sometimes a matter of a few inches.

Jackson, P.L.

1981-01-01T23:59:59.000Z

219

Fault-Tolerant Control Performance Comparison of 3-and 5-Phase PMSG  

E-Print Network [OSTI]

-cost and maintenance [4-5]. As marine current turbines are similar in many aspects to wind turbine technologies, their theoretical and experimental studies are essentially based on wind turbine experiences. Therefore, criticalFault-Tolerant Control Performance Comparison of 3- and 5-Phase PMSG for Marine Current Turbine

Paris-Sud XI, Université de

220

Neotectonics of Panama. I. Major fault systems  

SciTech Connect (OSTI)

The direction and rate of relative plate motion across the Caribbean-Nazca boundary in Panama is poorly known. This lack of understanding can be attributed to diffuse seismicity; lack of well constrained focal mechanisms from critical areas; and dense tropical vegetation. In order to better understand the relation of plate motions to major fault systems in Panama, the authors have integrated geologic, remote sensing, earthquake and UTIG marine seismic reflection data. Three areas of recent faulting can be distinguished in Panama and its shelf areas; ZONE 1 of eastern Panama consists of a 70 km wide zone of 3 discrete left-lateral strike-slip faults (Sanson Hills, Jaque River, Sambu) which strike N40W and can be traced as continuous features for distances of 100-150 km; ZONE 2 in central Panama consists of a diffuse zone of discontinuous normal(.) faults which range in strike from N40E, N70E; ZONE 3 in western Panama consists of a 60 km wide zone of 2 discrete, left-lateral(.) strike-slip faults which strike N60W and can be traced as continuous features for distances of 150 km; ZONE 3 faults appear to be continuous with faults bounding the forearc Teraba Trough of Costa Rica. The relation of faults of ZONE 3 to faults of ZONE 2 and a major fault bounding the southern Panama shelf is unclear.

Corrigan, J.; Mann, P.

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

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

222

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

E-Print Network [OSTI]

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...

Andoh, Kwame Sarpong

2012-06-07T23:59:59.000Z

223

Simulation of Sensor Fault Diagnosis for Wind Turbine Generators DFIG and PMSM Using Kalman Filter  

Science Journals Connector (OSTI)

Abstract The fault detection and isolation of generators used in wind turbines gathering interest as to maximize the reliability and avail of distributed energy systems with recent unmatched growth in construction of offshore wind farms. In particular it is interested in performing fault detection and isolation (FDI) of incipient faults affecting the measurements of the three-phase signals (currents) in a controlled DFIG and PMSG. Although different authors have dealt with FDI for sensors in induction machines and in DFIGs, most of them rely on the machine model with constant parameters. However, the parameter uncertainties due to changes in the operating conditions will produce degradation in the performance of such FDI systems. The robust techniques to detect faults are exist but there is a need of extra sensor. This paper proposed a systematic methodology for the design of sensor FDI systems with the following characteristics: i) capable of detecting and isolating incipient additive (bias) faults, ii) robust against changes in the references/disturbances affecting the controlled DFIG and PMSG as well as modeling/parametric uncertainties, iii) residual generation system based on a multi-observer strategy to enhance the isolation process, The designed sensor FDI systems have been validated using measured voltages, as well as simulated data from a controlled DFIG. First the state space models of DFIG and PMSM explained followed by kalman filter introduction and current sensor fault detection using a bank of kalman filter named dedicated Observer Scheme and generalized Observer scheme to detect simultaneous and multiple faults was theorized and simulated using MATLAB simulation tool .The simulation results were summarized with and without Sensor fault.

R. Saravanakumar; M. Manimozhi; D.P. Kothari; M. Tejenosh

2014-01-01T23:59:59.000Z

224

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

SciTech Connect (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

225

Research on Fault Analysis and Fault-Tolerant Control of EV/HEV Powertrain  

E-Print Network [OSTI]

presents research works in the topics of fault analysis and fault tolerant control of an electric vehicle mechanism (transition strategy) at sensor fault occurrence. Index Terms--Electric vehicle, induction motor-tolerant AC motor drives in industrial applications [9-10- 41]. II. ELECTRIC VEHICLE POWERTRAIN COMPONENTS

Brest, Université de

226

Structural Heterogeneity and Permeability in Faulted Eolian Sandstone: Implications for Subsurface Modeling of Faults  

Science Journals Connector (OSTI)

...fault that could be hydraulically significant in a reservoir...Reynolds and E. D. Dolly, eds., Mesozoic paleogeography...Jones, 1998, Fault-controlled communication in the...Reynolds and E. D. Dolly, eds., Mesozoic paleogeog-raphy...Jones, 1998, Fault-controlled communication in theSleipner...

Zoe K. Shipton; James P. Evans; Kim R. Robeson; Craig B. Forster; Stephen Snelgrove

227

Accurate resistive bridge fault modeling, simulation, and test generation  

E-Print Network [OSTI]

Resistive bridging faults in CMOS combinational circuits are studied in this work. Bridging faults are modeled using HSPICE circuit simulation of the various types of bridging faults that can occur in CMOS combinational circuits. The results...

Sar-Dessai, Vijay Ramesh

2012-06-07T23:59:59.000Z

228

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...

Burrell, Richard Dennis

2012-06-07T23:59:59.000Z

229

Off-fault Damage Associated with a Localized Bend in the North Branch San Gabriel Fault, California  

E-Print Network [OSTI]

and microstructural study focused on structural domains before, within, and after the fault bend on both sides of the fault. Subsidiary fault fabrics are similar in all domains outside the bend, which suggests a steady state fracture density and orientation...

Becker, Andrew 1987-

2012-08-15T23:59:59.000Z

230

Investigation of active faulting at the Emigrant Peak fault in Nevada using shallow seismic reflection and ground penetrating radar  

E-Print Network [OSTI]

The objective of this study was to assess fault displacement, off-fault deformation, and alluvial fan stratigraphy at the Emigrant Peak fault zone (EPFZ) in Fish Lake Valley, Nevada utilizing shallow seismic reflection (SSR) and ground penetrating...

Christie, Michael Wayne

2007-12-18T23:59:59.000Z

231

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 ...

Ripunjoy Phukan

2013-10-04T23:59:59.000Z

232

A novel KICA–PCA fault detection model for condition process of hydroelectric generating unit  

Science Journals Connector (OSTI)

Abstract Fault detection and diagnosis of hydroelectric generating unit (HGU) have significant importance to the security of hydropower plant and the power system. In recent years, many fault detection methods based on spectral characteristic of vibration signals have been published. However, some faults cannot be effectively recognized just with spectral features for condition process monitoring of HGU. Thus, this study presents a novel fault detection model based on kernel independent component analysis and principal component analysis (KICA–PCA) monitoring model for condition process of HGU. Each of the condition processes is equivalent to a multivariate statistical process monitoring (MSPM). KICA–PCA model of the specific MSPM is trained by normal condition process data at first. Then, confidence limits of two monitoring indices (Hotelling’s T2 statistic and SPE statistic) of the trained KICA–PCA model are used to monitor the same condition process and detect fault online. Moreover, the proposed monitoring model is applied to a real condition process of HGU. Compared to ICA–PCA and PCA monitoring model, the proposed model has superior performance in fault detection.

Wenlong Zhu; Jianzhong Zhou; Xin Xia; Chaoshun Li; Jian Xiao; Han Xiao; Xinxin Zhang

2014-01-01T23:59:59.000Z

233

Development of a bridge fault extractor tool  

E-Print Network [OSTI]

Bhat, B. Tech, Indian Institute of Technology, Bombay Co-Chairs of Advisory Committee: Dr. D. M. H. Walker Dr. Jiang Hu Bridge fault extractors... Bhat, B. Tech, Indian Institute of Technology, Bombay Co-Chairs of Advisory Committee: Dr. D. M. H. Walker Dr. Jiang Hu Bridge fault extractors...

Bhat, Nandan D.

2005-02-17T23:59:59.000Z

234

FaultLocal Distributed Mending (Extended Abstract)  

E-Print Network [OSTI]

As communication networks grow, existing fault handling tools that involve global measures such as global time­outs or reset procedures become increasingly unaffordable, since their cost grows with the size of the network. Rather, for a fault handling mechanism to scale to large networks, its cost must depend only

Kutten, Shay

235

Physiochemical Evidence of Faulting Processes and Modeling of Fluid in Evolving Fault Systems in Southern California  

SciTech Connect (OSTI)

Our study targets recent (Plio-Pleistocene) faults and young (Tertiary) petroleum fields in southern California. Faults include the Refugio Fault in the Transverse Ranges, the Ellwood Fault in the Santa Barbara Channel, and most recently the Newport- Inglewood in the Los Angeles Basin. Subsurface core and tubing scale samples, outcrop samples, well logs, reservoir properties, pore pressures, fluid compositions, and published structural-seismic sections have been used to characterize the tectonic/diagenetic history of the faults. As part of the effort to understand the diagenetic processes within these fault zones, we have studied analogous processes of rapid carbonate precipitation (scaling) in petroleum reservoir tubing and manmade tunnels. From this, we have identified geochemical signatures in carbonate that characterize rapid CO2 degassing. These data provide constraints for finite element models that predict fluid pressures, multiphase flow patterns, rates and patterns of deformation, subsurface temperatures and heat flow, and geochemistry associated with large fault systems.

Boles, James [Professor

2013-05-24T23:59:59.000Z

236

Sensitivity Study of Physical Limits on Ground Motion at Yucca Mountain  

E-Print Network [OSTI]

Sensitivity Study of Physical Limits on Ground Motion at Yucca Mountain by Benchun Duan and Steven at Yucca Mountain, Nevada, and assess sensitivities due to uncertainties in fault geometry, off-fault rock ground-motion parameters (e.g., Bommer, 2002; Bommer et al., 2004). The 1998 PSHA for Yucca Mountain

Duan, Benchun

237

Analysis of transmission system faults in the phase domain  

E-Print Network [OSTI]

the zero, positive and negative sequences. d) Calculate the post-fault line current ij 2 2 2 ij j ij z VI ?= (2.15) where ij is the primitive impedance element between nodes i and j. After all these sequence quantities... in Figure 5. The data of this system is listed in Tables 1, 2, and 3. Figure 5. System diagram for the 3-bus system Table 1 Generator data (3 Bus system) Generator impedance(p.u.) # Gen. connection P N Z 1 Y-grounded 0.05j 0.05j 0.15j 2...

Zhu, Jun

2004-11-15T23:59:59.000Z

238

Selected growth and interaction characteristics of seafloor faults in the central Mississippi Canyon Offshore Continental Shelf (OCS) area, northern Gulf of Mexico  

E-Print Network [OSTI]

for dealing with potentially active seafloor faults is avoidance?placing the seafloor facility, structure foundation, pilings, or pipeline in such a way that the potential for damage to the infrastructure is well within design limits for the design lifetime...

Wegner, Scott Ashley

2006-08-16T23:59:59.000Z

239

TRANSIENT PROCESSOR/BUS FAULT TOLERANCE FOR EMBEDDED SYSTEMS  

E-Print Network [OSTI]

TRANSIENT PROCESSOR/BUS FAULT TOLERANCE FOR EMBEDDED SYSTEMS With hybrid redundancy and data the schedule length overhead. Keywords: real-time embedded systems, safety-critical systems, transient faults, ecological, and/or financial disasters) that could result from a fault, these systems must be fault

Girault, Alain

240

Quantification of Priority-OR gates in temporal fault trees  

Science Journals Connector (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

Note: This page contains sample records for the topic "fault current limiter" 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

Fault-Tolerance Verification of the Fluids and Combustion Facility of  

E-Print Network [OSTI]

installations. Currently, the FCF safety specification requires one-component fault-tolerance. In future is critical. It is becoming all the more important as budget constraints increase while safety requirements. The system is subjected to various kinds of radiation and airborne contaminants [5]. Protection of the space

Nesterenko, Mikhail

242

Stacking and twin faults in close-packed crystal structures: exact description of random faulting statistics for the full range of faulting probabilities  

Science Journals Connector (OSTI)

A model of independent random faulting in face-centered-cubic and hexagonal close packing considering single deformation faults or twin faulting is revisited. The approach allows the analysis, within the random model, of the whole range of faulting probabilities. Several descriptions of the underlying faulting process are presented which allows the derivation of different properties of the faulted sequences. The probability of finding two layers of the same type layers apart is derived. It is shown that previous generalizations did not account for mixed terms in the final probability expressions.

Estevez-Rams, E.

2008-08-14T23:59:59.000Z

243

A New Intelligent Fusion Method of Multi-Dimensional Sensors and Its Application to Tribo-System Fault Diagnosis of Marine Diesel Engines  

Science Journals Connector (OSTI)

Marine diesel engines, a critical component to provide ... to ensure their safety operation. Vibration and wear debris analysis are currently the most popular ... , a new fault diagnosis technique for the marine ...

Zhixiong Li; Xinping Yan; Zhiwei Guo; Peng Liu; Chengqing Yuan…

2012-07-01T23:59:59.000Z

244

Observations and modeling of shallow fault creep along the San Andreas Fault System  

E-Print Network [OSTI]

refraction survey of the Imperial Valley region, California,earthquake, in The Imperial Valley, California, EarthquakeSlip on faults in the Imperial Valley triggered by the 4

Wei, Meng

2011-01-01T23:59:59.000Z

245

Dose Limits  

Broader source: Energy.gov [DOE]

Dose Limits ERAD (Question Posted to ERAD in May 2012) Who do you define as a member of the public for the onsite MEI? This question implies that there may be more than one maximally exposed individual (MEI), one on-site and one off-site, when demonstrating compliance with the Public Dose Limit of DOE Order 458.1. Although all potential MEIs should be considered and documented, as well as the calculated doses and pathways considered, the intent of DOE Order 458.1 is in fact to ultimately identify only one MEI, a theoretical individual who could be either on-site or off-site.

246

Injection Technologies for Fault Attacks on Microprocessors  

Science Journals Connector (OSTI)

The fault injection technique we will analyze in detail in Sect. 16.3, is the constant under-powering of a computing device. By running the chip with a depleted power supply, the attacker is able to insert transi...

Alessandro Barenghi; Guido M. Bertoni; Luca Breveglieri…

2012-01-01T23:59:59.000Z

247

Supporting fault-tolerant communication in networks  

E-Print Network [OSTI]

We address two problems dealing with fault-tolerant communication in networks. The first one is designing a distributed storage protocol tolerant to Byzantine failure of servers. The protocol implements a multi-writer multi-reader register which...

Kanjani, Khushboo

2009-05-15T23:59:59.000Z

248

Development of a Hydrologic Characterization Technology for Fault Zones Final Report  

E-Print Network [OSTI]

Hydrologic Characterization Technology of Fault Zones, Phaseof Characterization Technology for Fault Zones, LBNL-1635E,Characterization on Technology of Fault Zones – Phase II

Karasaki, Kenzi

2014-01-01T23:59:59.000Z

249

E-Print Network 3.0 - andreas fault zone Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Chester Summary: accommodated along large plate-boundary faults like the San Andreas transform fault in California. These faults... depend in part on the structure of the tabular...

250

E-Print Network 3.0 - active fault zone Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Earth Structure (2nd Edition), 2004 Summary: 292010 Oceanic Transform Faults and Fracture Zones Transform Fault: Active displacement. Fracture Zone: Fossil... fault, no active...

251

E-Print Network 3.0 - automatic fault management Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

2000 Tutorial on Summary: Management 5. Fault Tolerant Applications 6. Fault Tolerant Hello Server Example 12;Tutorial on Fault... Systems, Inc, 2000 Who Has Control? ...

252

Effect of wind generation system types on Micro-Grid (MG) fault performance during both standalone and grid connected modes  

Science Journals Connector (OSTI)

Abstract Recently, there are three wind generation (WG) system types. The first type is called Fixed Speed Wind Generation (FSWG) system, which employs squirrel cage induction generators. Double Fed Induction Generator (DFIG) is utilized in the second type. The third type is called Full Converter Wind Generation (FCWG) system, which is interfaced with Micro-Grid (MG) through a back to back converter. During fault occurrence, each WG has its performance and characteristics which are determined by the generator physical characteristics and the MG earthing system configuration. For some WG types, the fault current depends also on the control algorithm of the power converter. The main target of this paper is to investigate and estimate how the fault performance of MG during both standalone and grid-connected modes is influenced by the type of WG. It is found during standalone mode that the type of the employed WG has a dominant impact on the MG performance under fault disturbance. On the contrary, the type of the employed WG has a negligible effect on the MG fault performance during grid-connected mode. This is because the main grid contributes most of the fault current. Effects of earthing system type on MG performance are highlighted.

Rashad M. Kamel

2014-01-01T23:59:59.000Z

253

Statistical Fault Detection for Parallel Applications with AutomaDeD  

SciTech Connect (OSTI)

Today's largest systems have over 100,000 cores, with million-core systems expected over the next few years. The large component count means that these systems fail frequently and often in very complex ways, making them difficult to use and maintain. While prior work on fault detection and diagnosis has focused on faults that significantly reduce system functionality, the wide variety of failure modes in modern systems makes them likely to fail in complex ways that impair system performance but are difficult to detect and diagnose. This paper presents AutomaDeD, a statistical tool that models the timing behavior of each application task and tracks its behavior to identify any abnormalities. If any are observed, AutomaDeD can immediately detect them and report to the system administrator the task where the problem began. This identification of the fault's initial manifestation can provide administrators with valuable insight into the fault's root causes, making it significantly easier and cheaper for them to understand and repair it. Our experimental evaluation shows that AutomaDeD detects a wide range of faults immediately after they occur 80% of the time, with a low false-positive rate. Further, it identifies weaknesses of the current approach that motivate future research.

Bronevetsky, G; Laguna, I; Bagchi, S; de Supinski, B R; Ahn, D; Schulz, M

2010-03-23T23:59:59.000Z

254

Bearing fault severity estimation using time-based descriptors for rotating electric machines  

Science Journals Connector (OSTI)

This paper evaluates the bearing fault severity in rotating electric machines based on the time-based descriptors derived from machine vibration signal. Time-based descriptors are independent of bearing dimensions and machine dynamics. To establish the relationship between the time-based descriptor and bearing fault severity, a wide range of defective bearings are examined on an experimental set-up and the factors contributing to the value of time-based descriptor are determined. The application of this technique to the bearing faults such as rolling element, inner-race and outer-race fault, has confirmed that time-based descriptor successfully measures the severity of faults. The significance of time-based descriptors has been evaluated and tested by developing online bearing failure situation via shaft current. Since the time-based descriptors are independent of dimensions and characteristic frequencies of the bearing, the severity estimation is less sensitive to operating conditions for data acquisition. The laboratory investigations on 10-hp cage induction motor are presented.

Rajesh Patel; S.P. Gupta; Vinod Kumar

2014-01-01T23:59:59.000Z

255

The detection of high impedance faults using random fault behavior  

E-Print Network [OSTI]

not be desirable if the proper operation of the detector required expensive additions or modifications to the existing power system. Such additions may include communication capabilities between substations which currently does not exists. An acceptable... not be desirable if the proper operation of the detector required expensive additions or modifications to the existing power system. Such additions may include communication capabilities between substations which currently does not exists. An acceptable...

Carswell, Patrick Wayne

2012-06-07T23:59:59.000Z

256

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

SciTech Connect (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

257

"giant faults" does not lead to total failure, because the displacement equivalent to the fault  

E-Print Network [OSTI]

"giant faults" does not lead to total failure, because the displacement equivalent to the fault changes in physical properties by cold working seen in Fig. 1 are attributed to this accumulated nanoscale as supporting material on Science Online. 5. T. W. Duerig, A. R. Pelton, in Materials Properties Handbook

Rubloff, Gary W.

258

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.

259

Modelling and simulation of faults in synchronous generators for robust numerical protection  

Science Journals Connector (OSTI)

When an internal fault occurs in a synchronous generator, the symmetry between the parallel paths of the winding is broken and different currents flow in them, due to unsymmetrical magnetic linkage between the stator windings. The aim of this paper is to present a simulation model to investigate the effect of internal fault on the parallel path currents of a large synchronous generator using direct phase quantities. This model is based on a modified winding function approach where the machine inductances are calculated directly from the machine winding distribution using machine electrical parameters instead of the geometrical ones. The simulation results for different cases of internal faults in salient-pole and non-salient-pole synchronous machines have been obtained. Salient-pole synchronous generator has wave winding distribution while the non-salient-pole generator has lap winding arrangement. Due to different stator winding arrangements, the two machines have been simulated individually. By using the simulated fault data, a suitable numerical protection scheme for synchronous generators can be developed.

Amrita Sinha; D.N. Vishwakarma; R.K. Srivastava

2012-01-01T23:59:59.000Z

260

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

Note: This page contains sample records for the topic "fault current limiter" 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

A hybrid fault tolerance technique in grid computing system  

Science Journals Connector (OSTI)

In order to achieve high level of reliability and availability, the grid infrastructure should be a foolproof fault tolerant. Fault tolerance plays a key role in order to assert availability and reliability of...

Kalim Qureshi; Fiaz Gul Khan; Paul Manuel; Babar Nazir

2011-04-01T23:59:59.000Z

262

Scalable, Fault-tolerant Management in a Service Oriented Architecture  

E-Print Network [OSTI]

Scalable, Fault-tolerant Management in a Service Oriented Architecture Harshawardhan Gadgil: Scalable, Fault-tolerance, Service Oriented Management, Architecture 1. Introduction With the explosion. The service-oriented architecture provides a simple and flexible framework for building sophisticated

263

IVF: characterizing the vulnerability of microprocessor structures to intermittent faults  

Science Journals Connector (OSTI)

With the advancement of CMOS manufacturing process to nano-scale, future shipped microprocessors will be increasingly vulnerable to intermittent faults. Quantitatively characterizing the vulnerability of microprocessor structures to intermittent faults ...

Songjun Pan; Yu Hu; Xiaowei Li

2010-03-01T23:59:59.000Z

264

Design and analysis of a fault tolerant network processor  

E-Print Network [OSTI]

This thesis investigates the effect of transient faults on a processor and proposes on-chip fault tolerant design techniques to improve its reliability. The target processor is a general 32-bit, four stage pipeline, dual context RISC style design...

Desai, Shaishav A

2012-06-07T23:59:59.000Z

265

Dining philosophers with masking tolerance to crash faults  

E-Print Network [OSTI]

We examine the tolerance of dining philosopher algorithms subject to process crash faults in arbitrary conflict graphs. This classic problem is unsolvable in asynchronous message-passing systems subject to even a single crash fault. By contrast...

Idimadakala, Vijaya K.

2009-05-15T23:59:59.000Z

266

100 Area electrical distribution fault and coordination report  

SciTech Connect (OSTI)

This report documents three-phase and line-to-ground fault values and time overcurrent coordination curves for the electrical utility distribution system located in the 100 Areas. Activities that may improve the coordination of the distribution system have also been identified. An evaluation of system coordination was performed. The results of this evaluation are listed in Appendix B. There are protective devices within the 100 Area distribution system that do not coordinate with one another throughout the Areas. There is also a mis-application of reclosing relays at the 100B Area. The impact of the mis-coordination and incorrect application of reclosing relays is that system selectivity is reduced. Equipment will still be protected against damaging currents, however more equipment will be de-energized than necessary during fault conditions. It is the opinion of the author of this report that the cases of mis-coordination listed above, and in Appendix B, do not significantly degrade the system protection system nor the reliability of the 100 Area distribution system. Therefore, immediate response to correct these problems is not recommended. However, a planned methodology, outlined in an Activity Plan, to correct these problems should be developed and implemented in the near future.

Webber, J.J. [ICF Kaiser Hanford Co., Richland, WA (United States)

1994-09-23T23:59:59.000Z

267

Detachment Faulting & Geothermal Resources- Pearl Hot Spring, NV  

Broader source: Energy.gov [DOE]

Detachment Faulting & Geothermal Resources - Pearl Hot Spring, NV presentation at the April 2013 peer review meeting held in Denver, Colorado.

268

A method for quantitative fault diagnosability analysis of stochastic linear descriptor models  

Science Journals Connector (OSTI)

Analyzing fault diagnosability performance for a given model, before developing a diagnosis algorithm, can be used to answer questions like ''How difficult is it to detect a fault f"i?'' or ''How difficult is it to isolate a fault f"i from a fault f"j?''. ... Keywords: Fault detection and isolation, Fault diagnosability analysis, Model-based diagnosis

Daniel Eriksson; Erik Frisk; Mattias Krysander

2013-06-01T23:59:59.000Z

269

Bridge Fault Simulation Strategies for CMOS Integrated Circuits Brian Chess  

E-Print Network [OSTI]

Bridge Fault Simulation Strategies for CMOS Integrated Circuits Brian Chess Tracy Larrabee \\Lambda the Primitive Bridge Function, a char­ acteristic function describing the behavior of bridged com­ ponents, we present a theorem for detecting feedback bridge faults. We discuss two different methods of bridge fault

Larrabee, Tracy

270

UNSUPERVISED CLUSTERING FOR FAULT DIAGNOSIS IN NUCLEAR POWER PLANT COMPONENTS  

E-Print Network [OSTI]

1 UNSUPERVISED CLUSTERING FOR FAULT DIAGNOSIS IN NUCLEAR POWER PLANT COMPONENTS Piero Baraldi1 on transients originated by different faults in the pressurizer of a nuclear power reactor. Key Words: Fault of Nuclear Power Plants (NPPs) [Cheon et al., 1993; Kim et al., 1996; Reifman, 1997; Zio et al., 2006a; Zio

Boyer, Edmond

271

Stacking fault energy and microstructure effects on torsion texture evolution  

Science Journals Connector (OSTI)

...research-article Stacking fault energy and microstructure effects...2000, , Rosario, Argentina 3 Department of Geology...The stacking fault energy (SFE) of the metal...torsion| Stacking fault energy and microstructure e...CONICET-UNR) 2000, Rosario, Argentina 3Department of Geology...

2000-01-01T23:59:59.000Z

272

Continuity conditions for a fault consisting of obliquely aligned cracks  

E-Print Network [OSTI]

by the ambient stress, and other regions that are open and ¯uid- or air-®lled (e.g. Nagy 1992). The fault may as a ¯uid conduit or a seal depending on the fault zone complexity or microstructural details (Jones & Knipe 1996). Therefore, prediction of the fault seal potential is important. One way to characterize

Cambridge, University of

273

COMPLETE FAULT ANALYSIS FOR LONG TRANSMISSION LINE USING  

E-Print Network [OSTI]

COMPLETE FAULT ANALYSIS FOR LONG TRANSMISSION LINE USING SYNCHRONIZED SAMPLING Nan Zhang Mladen 77843-3128, U.S.A. Abstract: A complete fault analysis scheme for long transmission line represented fault analysis tool for transmission lines is very useful for on-line confirmation and off-line trouble

274

Structure of the eastern Red Rocks and Wind Ridge thrust faults, Wyoming: how a thrust fault gains displacement along strike  

E-Print Network [OSTI]

STRUCTURE OF THE EASTERN RED ROCKS AND WIND RIDGE THRUST FAULTS, WYOMING: HOW A THRUST FAULT GAINS DISPLACEMENT ALONG STRIKE A Thesis by BRENT STANLEY HUNTSMAN Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1983 Major Subject: Geology STRUCTURE OF THE EASTERN RED ROCKS AND WIND RIDGE THRUST FAULTS, WYOMING: HOW A THRUST FAULT GAINS DISPLACEMENT ALONG STRIKE A Thesis by BRENT STANLEY HUNTSMAN...

Huntsman, Brent Stanley

1983-01-01T23:59:59.000Z

275

From mechanical modeling to seismic imaging of faults: A synthetic workflow to study the impact of faults on seismic  

Science Journals Connector (OSTI)

Abstract Although typically interpreted as 2D surfaces, faults are 3D narrow zones of highly and heterogeneously strained rocks, with petrophysical properties differing from the host rock. Here we present a synthetic workflow to evaluate the potential of seismic data for imaging fault structure and properties. The workflow consists of discrete element modeling (DEM) of faulting, empirical relations to modify initial acoustic properties based on volumetric strain, and a ray-based algorithm simulating prestack depth migration (PSDM). We illustrate the application of the workflow in 2D to a 100 m displacement normal fault in a kilometer size sandstone-shale sequence at 1.5 km depth. To explore the effect of particle size on fault evolution, we ran two DEM simulations with particle assemblages of similar bulk mechanical behavior but different particle size, one with coarse (1–3 m particle radii) and the other with fine (0.5–1.5 m particle radii) particles. Both simulations produce realistic but different fault geometries and strain fields, with the finer particle size model displaying narrower fault zones and fault linkage at later stages. Seismic images of these models are highly influenced by illumination direction and wave frequency. Specular illumination highlights flat reflectors outside the fault zone, but fault related diffractions are still observable. Footwall directed illumination produces low amplitude images. Hanging wall directed illumination images the shale layers within the main fault segment and the lateral extent of fault related deformation. Resolution and the accuracy of the reflectors are proportional to wave frequency. Wave frequencies of 20 Hz or more are necessary to image the different fault structure of the coarse and fine models. At 30–40 Hz, there is a direct correlation between seismic amplitude variations and the input acoustic properties after faulting. At these high frequencies, seismic amplitude variations predict both the extent of faulting and the changes in rock properties in the fault zone.

Charlotte Botter; Nestor Cardozo; Stuart Hardy; Isabelle Lecomte; Alejandro Escalona

2014-01-01T23:59:59.000Z

276

Tokamak halo currents  

SciTech Connect (OSTI)

A halo current flows for part of its path through the plasma edge and for part through the chamber walls and can be as large as tenths of the plasma current. The primary interest in halo currents is the large force that they can exert on machine components. Two discordant constraints are central to the theory: (1) Halo currents must produce the magnetic field distribution required to maintain plasma force balance—a distribution that depends on the two angular coordinates of a torus. (2) Halo currents must flow along the magnetic field lines in the plasma, which implies a dependence on a linear combination of the two angular coordinates—only one angular coordinate is free. The physics basis of these two constraints is explained as is their application to the calculation of the properties of halo currents, such as their broad toroidal spectrum. Existing codes could be used to (1) provide detailed comparisons with experiments to validate that the critical elements of physics are adequately included, (2) allow more complete predictions for future machines such as ITER, and (3) design shunts and resistive elements to ensure halo currents follow paths that are the least damaging to the machine. The physics of halo currents implies that it may be possible to feedback stabilize resistive wall modes beyond the ideal-wall limit.

Boozer, Allen H. [Department of Applied Physics and Applied Mathematics Columbia University, New York, New York 10027 (United States)] [Department of Applied Physics and Applied Mathematics Columbia University, New York, New York 10027 (United States)

2013-08-15T23:59:59.000Z

277

Seismoelectric Imaging of a Shallow Fault System Employing Fault Guided Waves  

E-Print Network [OSTI]

Independent sets of reflection seismic and seismoelectric data were collected, processed, and interpreted with the aim of generating and studying guided waves within a fault zone. While seismic surveys have recently been utilized to investigate...

Cohrs, Frelynn Joseph Reese

2012-07-16T23:59:59.000Z

278

Cooperative Fault Tolerant Distributed Computing  

SciTech Connect (OSTI)

HARNESS was proposed as a system that combined the best of emerging technologies found in current distributed computing research and commercial products into a very flexible, dynamically adaptable framework that could be used by applications to allow them to evolve and better handle their execution environment. The HARNESS system was designed using the considerable experience from previous projects such as PVM, MPI, IceT and Cumulvs. As such, the system was designed to avoid any of the common problems found with using these current systems, such as no single point of failure, ability to survive machine, node and software failures. Additional features included improved inter-component connectivity, with full support for dynamic down loading of addition components at run-time thus reducing the stress on application developers to build in all the libraries they need in advance.

Fagg, Graham E.

2006-03-15T23:59:59.000Z

279

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

SciTech Connect (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

280

Fault-tolerant search of container codes  

Science Journals Connector (OSTI)

This paper describes a method to locate and recognize container code characters. This method is aimed to make more fault-tolerant a system based on tophat transformation, segmentation algorithms, filters and classifiers. Our aim is to be able to find ... Keywords: character recognition, computer vision, segmentation

Juan Rosell; Gabriela Andreu; Alberto Pérez

2006-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

Fault-tolerant search of container codes  

Science Journals Connector (OSTI)

This paper describes a method to locate and recognize container code characters. This method is aimed to make more fault-tolerant a system based on tophat transformation, segmentation algorithms, filters and classifiers. Our aim is to be able to find ... Keywords: character recognition, computer vision, segmentation

Juan Rosell; Gabriela Andreu; Alberto Pérez

2006-09-01T23:59:59.000Z

282

Sensor Fault Diagnosis Using Principal Component Analysis  

E-Print Network [OSTI]

and the assumption of white Gaussian noise, the effect of noise on the isolability is studied, and the minimum magnitude of isolable fault in each sensor is found based on the distribution of noise in the measurement system. Next, for the decision process a...

Sharifi, Mahmoudreza

2010-07-14T23:59:59.000Z

283

Adaptive performance support for fault diagnosis  

Science Journals Connector (OSTI)

This paper introduces a strategy, a user model, and a methodology for utilising adaptive hypermedia in performance support domain and specifically for fault diagnosis. This utilisation is implemented by employing task-specific and user-centred hypermedia ... Keywords: adaptive hypermedia, diagnostic expert systems, performance support systems, semantic data modelling, user modelling

Ammar M. Huneiti

2008-07-01T23:59:59.000Z

284

FPGA Interconnect Delay Fault Testing Erik Chmelar  

E-Print Network [OSTI]

A satisfactory FPGA testing method meets several crite- ria. First, the routing resources must be explicitlyFPGA Interconnect Delay Fault Testing Erik Chmelar Center for Reliable Computing Stanford is a scalable manufactur- ing test method for all SRAM-based FPGAs, able to detect multiple interconnect delay

Stanford University

285

Radon emanation on San Andreas Fault  

Science Journals Connector (OSTI)

... RADON is constantly emanated from the Earth into its atmosphere, normally in minute amounts. ... is constantly emanated from the Earth into its atmosphere, normally in minute amounts. Radon emanation is known to be anomalously large on active faults and to show temporal variations ...

Chi-Yu King

1978-02-09T23:59:59.000Z

286

All row, planar fault detection system  

DOE Patents [OSTI]

An apparatus, program product and method for detecting nodal faults may simultaneously cause designated nodes of a cell to communicate with all nodes adjacent to each of the designated nodes. Furthermore, all nodes along the axes of the designated nodes are made to communicate with their adjacent nodes, and the communications are analyzed to determine if a node or connection is faulty.

Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D; Smith, Brian Edward

2013-07-23T23:59:59.000Z

287

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

288

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

289

Proceedings of the 2008 International Conference on Electrical Machines Paper ID 1434 DFIG-Based Wind Turbine Fault Diagnosis  

E-Print Network [OSTI]

Generator (DFIG), Discrete Wavelet Transform (DWT), fault diagnosis. I. INTRODUCTION Wind energy conversion. Currently largest onshore wind turbine and offshore installations. © Nordex: N80 ­ 2.5 MW (Norway) Gear). Fig. 1. Worldwide growth of wind energy installed capacity [1]. 978-1-4244-1736-0/08/$25.00 ©2008 IEEE

Boyer, Edmond

290

Design and production of efficient current leads for 1500-A, 50-Hz service in a 77-4 K temperature gradient  

SciTech Connect (OSTI)

Two arrays of BSCCO 2223 bars were designed and produced for use in current leads for a power utility fault-current limiter operating at 4 K. Each conduction-cooled array, consisting of four parallel bars arranged within a 100-mm-diameter boundary, delivered 1,500 A peak, 50-Hz AC through a 77-4 K temperature gradient while dissipating < 0.2 W. The sinter-forged bars displayed DC critical current densities of 950--1,300 A/cm{sup 2} at 77 K and > 5,000 A/cm{sup 2} at 4 K. Magnetic field sensitivity was relatively low. Thermal conductivity tests showed values higher than literature values for polycrystalline BSCCO 2223 made by other processes.

Balachandran, U.; Youngdahl, C.A.; Lanagan, M.T. [and others

1994-10-01T23:59:59.000Z

291

Geometry and development of relay ramps in normal fault systems  

SciTech Connect (OSTI)

Normal fault zones play a major role in the development of basins and in the migration and trapping of hydrocarbons. The mapping of normal fault systems using seismic data requires careful correlation of faults on adjacent sections, a procedure that often leads to the interpretation of faults as having long, continuous, sinuous traces. Recent work involving detailed mapping of fault traces, first by using land exposures but more recently using three-dimensional seismics, has demonstrated that faults are usually made up of many overstepping segments, linked by areas of complex deformation, termed transfer zones or relay ramps. Relay ramps occur between normal fault segments that overstep in map view. The geometry and evolution of exposure-scale relay ramps are described from the Somerset coast, England, and are compared with larger scale ramps from elsewhere. Relay ramps can be classified into four groups based on the degree of interaction and linkage between the overstepping segments; these groups are interpreted as being evolutionary stages. In stage 1, the segments do not interact. Stage 2 involves the reorientation of bedding between two interacting faults to produce a relay ramp. In stage 3, connecting fractures start to break the relay ramp. Stage 4 is when the relay ramp is destroyed to produce a single fault that has an along-strike bend. These evolutionary stages can develop through time, but they can also be seen spatially. A branch line between normal faults or an along-strike bend may represent a stage 4 relay, with progressively earlier stages occurring updip or downdip. Characteristic variability in displacement-distance profiles for fault segments and linked faults accompanies the interaction and linkage processes. Displacement transfer by relay ramps is accompanied by steep displacement gradients along fault segments at oversteps. Relay ramps often contribute to a minimum in total fault displacement at a linkage point. 47 refs., 16 figs.

Peacock, D.C.P. (Univ. of Southampton (United Kingdom) Univ. of Plymouth, Devon (United Kingdom)); Sanderson, D.J. (Univ. of Southampton (United Kingdom))

1994-02-01T23:59:59.000Z

292

Current Status  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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).

293

REQUEST BY INTERMAGNETICS GENERAL CORPORATION FOR AN ADVANCE  

Broader source: Energy.gov (indexed) [DOE]

all the tangible assets of Petitioner's HTS power-related activities, including HTS transformer, fault current controller, fault current limiter and second generation wire....

294

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

295

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

296

Morphometric and geometric characterization of normal faults on Mars  

Science Journals Connector (OSTI)

Abstract Using three different approaches (fault plane fitting, 3D crater rim palinspatic restorations and fault scarps morphometric analysis) we investigate the geometry and degradation history of Martian normal faults in two distinct areas. The three independent methods produce similar results, indicating that the average dip angle of the normal faults on these two locations is probably below the value that is usually assumed for Mars (?60°). Our best estimate for this average dip angle is 46.8 ± 9.8 ° , which is a value comparable with the mean dip angle inferred on Earth for seismically active normal faults. This lower average dip angle implies that all the rift strain estimates performed until now might be underestimated. From the comparative analysis of the two faulted regions (Phlegethon Catena and Claritas Fossae), we show that local and regional dip variabilities may exist on Mars. This reinforces the idea that the amount of extension associated with Martian rifts must be reconsidered. We also demonstrate the advantages of performing a comparative morphometric analysis of fault scarps. This approach enables the reconstruction of the faults scarps degradation history and can be used to evaluate how environmental conditions changed through time. After modeling the degradation of the fault scarps at the two sites we conclude that the observed morphometric variations are mainly due to the different faulting ages in an environment characterized by low scarp degradation rates ( 4 × 10 ? 3 m 2 / kyr ) over the last 3 Ga.

David A. Vaz; Mauro G. Spagnuolo; Simone Silvestro

2014-01-01T23:59:59.000Z

297

Calculating the probability of injected carbon dioxide plumes encountering faults  

SciTech Connect (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

298

Sensitivity Study of Physical Limits on Ground Motion at Yucca Mountain  

E-Print Network [OSTI]

1 Sensitivity Study of Physical Limits on Ground Motion at Yucca Mountain Benchun Duan1 and Steven investigate physical3 limits at Yucca Mountain, Nevada, and assess sensitivities due to uncertainties in fault (e.g.,28 Bommer, 2002; Bommer et al., 2004).29 The 1998 PSHA for Yucca Mountain, a potential high

Duan, Benchun

299

Analysis of field-oriented controlled induction motor drives under sensor faults and an overview of sensorless schemes  

Science Journals Connector (OSTI)

Abstract To obtain high dynamic performance on induction motor drives (IMD), variable voltage and variable frequency operation has to be performed by measuring speed of rotation and stator currents through sensors and fed back them to the controllers. When the sensors are undergone a fault, the stability of control system, may be designed for an industrial process, is disturbed. This paper studies the negative effects on a 12.5 hp induction motor drives when the field oriented control system is subjected to sensor faults. To illustrate the importance of this study mine hoist load diagram is considered as shaft load of the tested machine. The methods to recover the system from sensor faults are discussed. In addition, the various speed sensorless schemes are reviewed comprehensively.

D Arun Dominic; Thanga Raj Chelliah

2014-01-01T23:59:59.000Z

300

An adaptive algorithm for the detection of high impedance faults on power distribution systems  

E-Print Network [OSTI]

OF LITERATURE III TRAINING ALGORITHMS 12 A. Overview . B. Level 1 Training Algorithm (TRL1) C. Level 2 Training Algorithm (TRL2) IV ONLINE ALGORITHM 12 13 18 21 A. Extensions to TRL2 B. ONLINE algorithm V IMPLEMENTATION AND RESULTS 21 24 27 VI A... spectrum of the current or the phase relationship between the current and the voltage. TRL1, the level 1 training algorithm, produces a set of level 1 centroids from the training data, each having a fault or normal class label. During on-line processing...

McCall, Kurt Eric

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

Relaxed fault detection and isolation: An application to a nonlinear case study  

Science Journals Connector (OSTI)

Given a number of possibly concurrent faults (and disturbances) that may affect a nonlinear dynamic system, it may not be possible to solve the standard fault detection and isolation (FDI) problem, i.e., to detect and isolate each single fault from all ... Keywords: Fault detection and isolation, Fault sets, Geometric conditions, Nonlinear systems, Robot manipulators

Raffaella Mattone; Alessandro De Luca

2006-01-01T23:59:59.000Z

302

Energy Currents  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

303

Energy Currents  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

304

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

305

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

306

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

307

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

308

LMFBR fuel-design environment for endurance testing, primarily of oxide fuel elements with local faults  

SciTech Connect (OSTI)

The US Department of Energy LMFBR Lines-of-Assurance are briefly stated and local faults are given perspective with an historical review and definition to help define the constraints of LMFBR fuel-element designs. Local-fault-propagation (fuel-element failure-propagation and blockage propagation) perceptions are reviewed. Fuel pin designs and major LMFBR parameters affecting pin performance are summarized. The interpretation of failed-fuel data is aided by a discussion of the effects of nonprototypicalities. The fuel-pin endurance expected in the US, USSR, France, UK, Japan, and West Germany is outlined. Finally, fuel-failure detection and location by delayed-neutron and gaseous-fission-product monitors are briefly discussed to better realize the operational limits.

Warinner, D.K.

1980-01-01T23:59:59.000Z

309

Dynamic Resistance of YBCO-Coated Conductors in Applied AC Fields with DC Transport Currents and DC Background Fields  

SciTech Connect (OSTI)

In order to predict heat loads in future saturable core fault-current-limiting devices due to ac fringing fields, dynamic resistance in YBCO-coated conductors was measured at 77 K in peak ac fields up to 25 mT at 60 Hz and in dc fields up to 1 T. With the sample orientation set such that the conductor face was either parallel or perpendicular to the ac and dc applied fields, the dynamic resistance was measured at different fractions of the critical current to determine the relationship between the dc transport current and the applied fields. With respect to field orientation, the dynamic resistance for ac fields that were perpendicular to the conductor face was significantly higher than when the ac fields were parallel to the conductor face. It was also observed that the dynamic resistance: (1) increased with increasing fraction of the dc transport current to the critical current, (2) was proportional to the inverse of the critical current, and (3) demonstrated a linear dependence with the applied ac field once a threshold field was exceeded. This functional behavior was consistent with a critical state model for the dynamic resistance, but discrepancies in absolute value of the dynamic resistance suggested that further theoretical development is needed.

Duckworth, Robert C [ORNL] [ORNL; Zhang, Yifei [ORNL] [ORNL; Ha, Tam T [ORNL] [ORNL; Gouge, Michael J [ORNL] [ORNL

2011-01-01T23:59:59.000Z

310

Mechanical properties and fabric of the Punchbowl fault zone, California  

E-Print Network [OSTI]

, and 50 to 125'C, in the presence of pore fluids. The fault zone and surrounding rock consists of (1) the main gouge zone, separated from (2) the undeformed host-rack, by (3) an irregular zone of damaged host-rock. The subsidiary fault fabric... orientations of discrete shear surfaces within the gouge 52 14 Photographs of subsidiary faults within the damaged zone of the Punchbowl Formation. . . . . . 57 15 Photomicrographs showing the progressive increase in deformation of the Punchbowl Formation...

Chester, Frederick Michael

2012-06-07T23:59:59.000Z

311

Fault Detection and Diagnosis Method for VAV Terminal Units  

E-Print Network [OSTI]

: Air density [kg/m3] NOMENCLATURE REFERENCES 1) IEA Annex 25, Building Optimization and Fault Diagnosis Source Book, Eds. J. Hyvarinen and S. Karki, Technical Research Center of Finland, 1996 2) Harunori Yoshida: Typical Faults of Air Conditioning..., IEA Annex 34 ?Detection and Diagnosis Methods in Real Building?, Eds. A. Dexter and J. Pakanen, Section C.2, pp.143-148, 2001 6) Harunori Yoshida, Sanjay Kumar, Yasunori Morita: Online Fault Detection and Diagnosis in VAV Air Handling Unit by RARX...

Miyata, M.; Yoshida, H.; Asada, M.; Wang, F.; Hashiguchi, S.

2004-01-01T23:59:59.000Z

312

The northwest extension of the Meers Fault in southwestern Oklahoma  

E-Print Network [OSTI]

unmapped terrace deposits, a trench, and creek banks along an extended N60W trending line in Kiowa County, Oklahoma, strongly suggests that the Meers Fault has an active northwest extension of about 30km which bifurcates in the Sugar Creek area... Fault Study Area The study area covers about 100 square miles and it is located about 20 mi N45W of Lawton, Oklahoma, primarily in Kiowa and Comanche counties (TSN, R14W and R15W) (Figure 7). The Meers Fault is the south-bounding fault of the complex...

Cetin, Hasan

2012-06-07T23:59:59.000Z

313

Active Fault Controls At High-Temperature Geothermal Sites- Prospectin...  

Open Energy Info (EERE)

the level of unrecognized active faults present in these areas. Analysis of low-sun-angle aerial photography acquired over the Needle Rocks, Astor Pass, Empire, and Lee...

314

Controls on Fault-Hosted Fluid Flow: Preliminary Results from...  

Open Energy Info (EERE)

Results from the Coso Geothermal Field, CA Abstract cap rock, permeability, fault, fracture, clay, Coso Authors Davatzes, N.C.; Hickman and S.H. Published Geothermal Resource...

315

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

Open Energy Info (EERE)

Valley Geothermal Area Regions (0) Retrieved from "http:en.openei.orgwindex.php?titleHigh-ResolutionAeromagneticSurveytoImageShallowFaults,DixieValleyGeothermalField...

316

Application of machine learning technique in wind turbine fault diagnosis.  

E-Print Network [OSTI]

??In this study, a machine learning technique called anomaly detection is employed for wind turbine bearing fault detection. Basically, the anomaly detection algorithm is used… (more)

Purarjomandlangrudi, Afrooz

2014-01-01T23:59:59.000Z

317

Application of fuzzy SOFM neural network and rough set theory on fault diagnosis for rotating machinery  

Science Journals Connector (OSTI)

This paper presents a new method that applies fuzzy logic, rough set theory and SOFM neural network to rotating machinery fault diagnosis. In this method, firstly, relationships between the fault causations and fault symptoms are established by fuzzy ...

Dongxiang Jiang; Kai Li; Gang Zhao; Jinhui Diao

2005-05-01T23:59:59.000Z

318

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

Science Journals Connector (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

319

The structure and evolution of small-displacement strike-slip faults in porous sandstone  

E-Print Network [OSTI]

relationship between the progressive addition of subsidiary fault segments (deformation bands) and earlier-formed linkage structures. The along-strike variability and distribution of fault structure are documented and used to assess the role of early fault...

Schafer, Kirk Wyatt

2012-06-07T23:59:59.000Z

320

Research on Fault Diagnosis of Marine Diesel Engine Based on Integrated Similarity  

Science Journals Connector (OSTI)

In order to guarantee the normal operation of marine, an effective fault diagnosis model need to ... to determine the reason causing the fault of marine diesel engine. According to the problem of fault diagnosis ...

Yanyou Chai; Xiuyan Peng; Liufeng Xu; Jiuyu Shi

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

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

E-Print Network [OSTI]

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...

Kuhle, Nathan John

2012-06-07T23:59:59.000Z

322

Fault tolerant control of homopolar magnetic bearings and circular sensor arrays  

E-Print Network [OSTI]

Fault tolerant control can accommodate the component faults in a control system such as sensors, actuators, plants, etc. This dissertation presents two fault tolerant control schemes to accommodate the failures of power amplifiers and sensors in a...

Li, Ming-Hsiu

2006-04-12T23:59:59.000Z

323

Neural Network-Based Classification of Single-Phase Distribution Transformer Fault Data  

E-Print Network [OSTI]

The ultimate goal of this research is to develop an online, non-destructive, incipient fault detection system that is able to detect incipient faults in transformers and other electric equipment before the faults become catastrophic...

Zhang, Xujia

2006-08-16T23:59:59.000Z

324

Curiosity's Fault Tolerant Wakeup and Shutdown Design  

Science Journals Connector (OSTI)

Abstract Curiosity spends roughly 70% of the day “sleeping”, in order to recharge the batteries from the nuclear power source. The system is designed to ensure the Rover goes to sleep and wakes back up to continue science and engineering activities. Additionally, the design is robust to off-nominal situations that may need additional actions performed by both hardware and software to ensure the Rover can communicate with the Earth. This paper describes nominal and off-nominal behavioral patterns, fault tolerance features designed into the Rover system (hardware and software), several off-nominal scenarios that are accommodated by the design, and some lessons learned from this development effort.

Tracy A. Neilson; James A. Donaldson

2014-01-01T23:59:59.000Z

325

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

SciTech Connect (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

326

E-Print Network 3.0 - automated fault extraction Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

with extracted... automation, fault diagnosis, asset management, as well as power system modeling and simulation. 12;... 1 F Voltage Sag Data Utilization for Distribution Fault...

327

Fault Identification in Doubly Fed Induction Generator Using FFT and Neural Networks  

Science Journals Connector (OSTI)

This paper presents a fault identification system for doubly fed induction generator (DFIG). It considers cases of single phase ... with the PP to fault identification in the DFIG.

Marcelo Patrício de Santana…

2012-01-01T23:59:59.000Z

328

Fault degradation assessment of water hydraulic motor by impulse vibration signal with Wavelet Packet Analysis and Kolmogorov–Smirnov Test  

Science Journals Connector (OSTI)

The machinery fault diagnosis is important for improving reliability and performance of systems. Many methods such as Time Synchronous Average (TSA), Fast Fourier Transform (FFT)-based spectrum analysis and short-time Fourier transform (STFT) have been applied in fault diagnosis and condition monitoring of mechanical system. The above methods analyze the signal in frequency domain with low resolution, which is not suitable for non-stationary vibration signal. The Kolmogorov–Smirnov (KS) test is a simple and precise technique in vibration signal analysis for machinery fault diagnosis. It has limited use and advantage to analyze the vibration signal with higher noise directly. In this paper, a new method for the fault degradation assessment of the water hydraulic motor is proposed based on Wavelet Packet Analysis (WPA) and KS test to analyze the impulsive energy of the vibration signal, which is used to detect the piston condition of water hydraulic motor. WPA is used to analyze the impulsive vibration signal from the casing of the water hydraulic motor to obtain the impulsive energy. The impulsive energy of the vibration signal can be obtained by the multi-decomposition based on Wavelet Packet Transform (WPT) and used as feature values to assess the fault degradation of the pistons. The kurtosis of the impulsive energy in the reconstructed signal from the Wavelet Packet coefficients is used to extract the feature values of the impulse energy by calculating the coefficients of the WPT multi-decomposition. The KS test is used to compare the kurtosis of the impulse energy of the vibration signal statistically under the different piston conditions. The results show the applicability and effectiveness of the proposed method to assess the fault degradation of the pistons in the water hydraulic motor.

H.X. Chen; Patrick S.K. Chua; G.H. Lim

2008-01-01T23:59:59.000Z

329

Creep along the Imperial Fault, southern California, from GPS measurements  

E-Print Network [OSTI]

on a fault. [4] Located southwest of the Salton Sea (Figure 1), the Imperial Valley has experienced numerousCreep along the Imperial Fault, southern California, from GPS measurements Suzanne N. Lyons, Yehuda Positioning System (GPS) 46 geodetic monuments established by Imperial College, London, in a dense grid (half

Sandwell, David T.

330

Fault Tolerant Oxygen Control of a Diesel Engine Air System  

E-Print Network [OSTI]

Fault Tolerant Oxygen Control of a Diesel Engine Air System Rainer Nitsche Matthias Bitzer control problem of a Diesel engine air system having a jammed Exhaust Gas Recirculation (EGR) valve of the air system. Keywords: Fault tolerant control, Diesel engine, Air system, Model-based trajectory

Paris-Sud XI, Université de

331

The faults that move during earthquakes do not always come  

E-Print Network [OSTI]

often live near active faults, because where there is a fault there is usually a water supply. And that means these places become part of major trade routes, like the Silk Roads across Asia from Xi urban building. What is even more frighten- ing is that in many parts of the world poor

Cipolla, Roberto

332

Fault detection and diagnosis capabilities of test sequence selection  

E-Print Network [OSTI]

Review Fault detection and diagnosis capabilities of test sequence selection methods based on the FSM model T Ramalingam*, Anindya Dast and K ThuIasiraman* Different test sequence selection methods resolution in diagnosing the fault. The test sequence selection methods are then compared based on the length

Thulsiraman, Krishnaiyan

333

Observations on the capability of the Criner fault, southern Oklahoma  

E-Print Network [OSTI]

of the Criner fault arises because of its proximity to the Meers fault, which is documented to have been reactivated within the last 1200 years. Such findings contradict the prevailing view that the inner continent of North America is a stable tectonic regime...

Williamson, Shawn Collin

2012-06-07T23:59:59.000Z

334

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

335

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

336

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

337

ALLIANCE: An architecture for fault tolerant, cooperative control of heterogeneous mobile robots  

SciTech Connect (OSTI)

This research addresses the problem of achieving fault tolerant cooperation within small- to medium-sized teams of heterogeneous mobile robots. The author describes a novel behavior-based, fully distributed architecture, called ALLIANCE, that utilizes adaptive action selection to achieve fault tolerant cooperative control in robot missions involving loosely coupled, largely independent tasks. The robots in this architecture possess a variety of high-level functions that they can perform during a mission, and must at all times select an appropriate action based on the requirements of the mission, the activities of other robots, the current environmental conditions, and their own internal states. Since such cooperative teams often work in dynamic and unpredictable environments, the software architecture allows the team members to respond robustly and reliably to unexpected environmental changes and modifications in the robot team that may occur due to mechanical failure, the learning of new skills, or the addition or removal of robots from the team by human intervention. After presenting ALLIANCE, the author describes in detail experimental results of an implementation of this architecture on a team of physical mobile robots performing a cooperative box pushing demonstration. These experiments illustrate the ability of ALLIANCE to achieve adaptive, fault-tolerant cooperative control amidst dynamic changes in the capabilities of the robot team.

Parker, L.E.

1995-02-01T23:59:59.000Z

338

Fault detection and diagnosis within a wind turbine mechanical braking system using condition monitoring  

Science Journals Connector (OSTI)

Renewable energy sources have a key role to play in the global energy mix as a means of reducing the impact of energy production on climate change. Wind energy is the most developed of all renewable energy technologies with more than 200 GW of globally installed capacity as of 2011. Analyses of wind farm maintenance costs show that up to 40% of the outlay is related to unexpected component failures that lead to costly unscheduled amendments. Wind farm operators are constantly looking for new technological developments in condition monitoring that can contribute to the minimisation of wind turbine maintenance expenditure. Early fault detection through condition monitoring can help prevent major breakdowns as well as significantly decrease associated costs. Moreover it enables the optimisation of maintenance schedules, reduces downtime, increases asset availability and enhances safety and operational reliability. Faults in the braking system are of particularly concern since they can result in catastrophic failure of the wind turbine. The present study investigates online condition monitoring based on voltages and currents for mechanical wind turbine brake system fault diagnosis.

M. Entezami; S. Hillmansen; P. Weston; M.Ph. Papaelias

2012-01-01T23:59:59.000Z

339

Use of Fault Tree Analysis for Automotive Reliability and Safety Analysis  

SciTech Connect (OSTI)

Fault tree analysis (FTA) evolved from the aerospace industry in the 1960's. A fault tree is deductive logic model that is generated with a top undesired event in mind. FTA answers the question, ''how can something occur?'' as opposed to failure modes and effects analysis (FMEA) that is inductive and answers the question, ''what if?'' FTA is used in risk, reliability and safety assessments. FTA is currently being used by several industries such as nuclear power and chemical processing. Typically the automotive industries uses failure modes and effects analysis (FMEA) such as design FMEAs and process FMEAs. The use of FTA has spread to the automotive industry. This paper discusses the use of FTA for automotive applications. With the addition automotive electronics for various applications in systems such as engine/power control, cruise control and braking/traction, FTA is well suited to address failure modes within these systems. FTA can determine the importance of these failure modes from various perspectives such as cost, reliability and safety. A fault tree analysis of a car starting system is presented as an example.

Lambert, H

2003-09-24T23:59:59.000Z

340

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

Note: This page contains sample records for the topic "fault current limiter" 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.


341

The effects of lithology and initial fault angle in physical models of fault-propagation folds  

E-Print Network [OSTI]

(1998). . . . 12 10 Principal stress directions within a layer moving through a ramp region of a thrust by Wiltschko (1979). . 14 Potential secondary fault trajectories interpreted from maximum shear stresses in theoretical models by Rodgers... Sandstone Data: Lead Configuration B. . 10 Layer Thickness Measurements ? Clay Configuration A . . . 91 11 Limb Dips: Configuration A Clay Models. . . 113 12 Fold Measurements: Configuration A Clay Models . . . 113 13 Sandstone Data: Clay Configuration...

McLain, Christopher Thomas

2012-06-07T23:59:59.000Z

342

Climate Prediction: The Limits of Ocean Models  

E-Print Network [OSTI]

We identify three major areas of ignorance which limit predictability in current ocean GCMs. One is the very crude representation of subgrid-scale mixing processes. These processes are parameterized with coefficients whose ...

Stone, Peter H.

343

Western limits of the Seattle fault zone and its interaction with the Olympic Peninsula, Washington  

E-Print Network [OSTI]

deformation zone. Newly acquired high- resolution seismic reflection and marine magnetic data suggest A.P. Lamb1 , L.M. Liberty1 , R.J. Blakely2 , T.L. Pratt3 , B.L. Sherrod3 , and K. van Wijk1 1

Boise State University

344

Structured Adaptive Model Inversion control with fault tolerance and actuator position limits  

E-Print Network [OSTI]

). The adaptation mechanism is mostly synthesized by the use of Lyapunov stability theory [6]. Thc basic theory of MRAC is well developed due to significant contributions by Narendra, K. S. , [3] and Annaswamy, Sastry, S. , and Bodson, [4] M. , Iannou, R A...

Tandale, Monish Deepak

2012-06-07T23:59:59.000Z

345

Ergodicity in natural earthquake fault networks  

Science Journals Connector (OSTI)

Numerical simulations have shown that certain driven nonlinear systems can be characterized by mean-field statistical properties often associated with ergodic dynamics [C. D. Ferguson, W. Klein, and J. B. Rundle, Phys. Rev. E 60, 1359 (1999); D. Egolf, Science 287, 101 (2000)]. These driven mean-field threshold systems feature long-range interactions and can be treated as equilibriumlike systems with statistically stationary dynamics over long time intervals. Recently the equilibrium property of ergodicity was identified in an earthquake fault system, a natural driven threshold system, by means of the Thirumalai-Mountain (TM) fluctuation metric developed in the study of diffusive systems [K. F. Tiampo, J. B. Rundle, W. Klein, J. S. Sá Martins, and C. D. Ferguson, Phys. Rev. Lett. 91, 238501 (2003)]. We analyze the seismicity of three naturally occurring earthquake fault networks from a variety of tectonic settings in an attempt to investigate the range of applicability of effective ergodicity, using the TM metric and other related statistics. Results suggest that, once variations in the catalog data resulting from technical and network issues are accounted for, all of these natural earthquake systems display stationary periods of metastable equilibrium and effective ergodicity that are disrupted by large events. We conclude that a constant rate of events is an important prerequisite for these periods of punctuated ergodicity and that, while the level of temporal variability in the spatial statistics is the controlling factor in the ergodic behavior of seismic networks, no single statistic is sufficient to ensure quantification of ergodicity. Ergodicity in this application not only requires that the system be stationary for these networks at the applicable spatial and temporal scales, but also implies that they are in a state of metastable equilibrium, one in which the ensemble averages can be substituted for temporal averages in studying their spatiotemporal evolution.

K. F. Tiampo; J. B. Rundle; W. Klein; J. Holliday; J. S. Sá Martins; C. D. Ferguson

2007-06-22T23:59:59.000Z

346

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

347

Radiated seismic energy based on dynamic rupture models of faulting and Ralph J. Archuleta1  

E-Print Network [OSTI]

Radiated seismic energy based on dynamic rupture models of faulting Shuo Ma1 and Ralph J. Archuleta energy from three hypothetical crustal events, 30° dipping reverse fault, 60° dipping normal fault, and 0.34 MPa for the reverse, normal, and strike-slip faults, respectively. The energy distribution

Archuleta, Ralph

348

SLIP ALONG THE SAN ANDREAS FAULT ASSOCIATED WITH THE EARTHQUAKE1  

E-Print Network [OSTI]

Imperial Valley earthquake occurred along other than the Imperial fault and the Brawley fault zone. More in the static- strain field that accompanied the earthquake. At about the same time in the 1979 Imperial Valley, similar behavior of the Imperial fault before 1979 suggests that this section ofthe San Andreas fault may

Tai, Yu-Chong

349

On-Line Fault Detection and Compensation of Hydraulic Driven Machines Using Modelling Techniques  

E-Print Network [OSTI]

On-Line Fault Detection and Compensation of Hydraulic Driven Machines Using Modelling Techniques C purpose of hydraulic driven machines as well as for the compensation of incipient faults where applicable: Modelling, Simulation, Hydraulic motors, Fault detection, Fault Compensation 1. Introduction Model

Thawonmas, Ruck

350

Dynamic neural network-based fault diagnosis of gas turbine engines  

Science Journals Connector (OSTI)

In this paper, a neural network-based fault detection and isolation (FDI) scheme is presented to detect and isolate faults in a highly nonlinear dynamics of an aircraft jet engine. Towards this end, dynamic neural networks (DNN) are first developed to ... Keywords: Aircraft jet engine, Bank of filters, Computational intelligence, Dynamic neural networks, Fault detection and isolation, Fault diagnosis, Multiple model schemes

S. Sina Tayarani-Bathaie; Z. N. Sadough Vanini; K. Khorasani

2014-02-01T23:59:59.000Z

351

Improving and Evaluating Differential Fault Analysis on LED with Algebraic Techniques  

E-Print Network [OSTI]

Improving and Evaluating Differential Fault Analysis on LED with Algebraic Techniques Xinjie Zhao.zhang,zshi,chm10010}@engr.uconn.edu Abstract--This paper proposes a fault analysis technique on LED by combining- ential fault analysis (ADFA). In ADFA on LED, we use DFA to deduce the possible fault differences

Shi, Zhijie Jerry

352

In situ measurement of the hydraulic diffusivity of the active Chelungpu Fault, Taiwan  

E-Print Network [OSTI]

.1. Boreholes of the Taiwan Chelungpu-Fault Drilling Project [6] The pair of boreholes used for this experiment shaking in the regions of large slip if the fault was sufficiently sealed. We investigate in situ in situ on an active large-scale fault. Hydraulic tests in deep bore- holes intersecting the Nojima fault

353

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

SciTech Connect (OSTI)

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

354

Geometry and scaling relations of a population of very small rift-related normal faults  

E-Print Network [OSTI]

normal faults within the Solite Quarry of the Dan River rift basin range in length from a few millimetres AND SCALING RELATIONS The small normal faults are present in quarries of the Virginia Solite Corporation outcrops and quarried boulders (Fig. 2). The fault traces are typically straight, although the fault tips

355

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

356

Visualization of stacking faults in fcc crystals in plastic deformations  

E-Print Network [OSTI]

Using molecular dynamics simulation, we investigate the dynamics of stacking faults in fcc crystals in uniaxial stretching in a Lennard-Jones binary mixture composed of 4096 particles in three dimensions. We visualize stacking faults using a disorder variable $D_j(t)$ for each particle $j$ constructed from local bond order parameters based on spherical harmonics (Steinhardt order parameters). Also introducing a method of bond breakage, we examine how stacking faults are formed and removed by collective particle motions. These processes are relevant in plasticity of fcc crystals.

Takeshi Kawasaki; Akira Onuki

2011-11-27T23:59:59.000Z

357

Fault-tree construction and calculations on a microcomputer  

E-Print Network [OSTI]

Figure 17 - Program Overview Screen Figure 18 ? Main Menu Screen Figure 19 ? Invalid Command Screen Figure 20 - First Usage of Disk Screen Figure 21 ? Fault-tree Name Screen Figure 22 - Invalid Fault-tree Name Screen Fi gure 23 ? TOP EVENT Label... to do? Fi gure 19. Inval i d Command Screen 53 CREATE - This command allows the user to build a new fault tree. After a CREATE command is entered, the system wi 1 1 display the screen in Figure 20. This question is asked in order to determine...

Beckmann, Jeffery Linn

1985-01-01T23:59:59.000Z

358

Evaluation of a Decoupling-Based Fault Detection and Diagnostic Technique - Part I: Field Emulation Evaluation  

E-Print Network [OSTI]

), evaporator fouling (Evapfoul), liquid-line restriction (Llrestr), low refrigerant charge (Reflow), and refrigerant high charge (Refhigh). Except for refrigerant charge and compressor leakage faults for which five fault levels were introduced, four fault... for these tests. The method could detect low refrigerant charge and loss of compressor performance at the lowest levels introduced and all other faults at the second level. All of the faults could be reliably diagnosed before a 5% degradation in capacity...

Li, H.; Braun, J.

2006-01-01T23:59:59.000Z

359

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

360

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

Note: This page contains sample records for the topic "fault current limiter" 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

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

362

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

363

Geophysical investigation of concealed faults near Yucca Mountain, southwest Nevada  

SciTech Connect (OSTI)

Detailed gravity and ground magnetic data collected along surveyed traverses across Midway Valley, on the eastern flank of Yucca Mountain, Nevada reveal that these methods can be used to delineate concealed faults. These studies are part of an effort to evaluate faulting in the vicinity of the proposed surface facilities for a potential nuclear waste repository at Yucca Mountain. The largest gravity and magnetic anomaly in the vicinity of Midway Valley is associated with the Paintbrush fault on the west flank of Alice Ridge. Geophysical data infer a vertical offset of about 200 m (650 ft). Another prominent gravity and magnetic anomaly is associated with the Bow Ridge fault in the western part of Midway Valley.

Ponce, D.A. [Geological Survey, Menlo Park, CA (United States)

1993-12-31T23:59:59.000Z

364

Unknown Input Observers and Fault Tolerant Control Allocation Andrea Cristofaro  

E-Print Network [OSTI]

objectives [3] [13] [17] , such as power or fuel consumption minimization. On the other hand, usually in order to make relevant faults observable. The case study of an overactuated marine vessel supports

Johansen, Tor Arne

365

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

366

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. (George Janbing), 1979-

2007-01-01T23:59:59.000Z

367

Understanding Fault Characteristics And Sediment Depth For Geothermal...  

Open Energy Info (EERE)

Fault Characteristics And Sediment Depth For Geothermal Exploration Using 3D Gravity Inversion In Walker Valley, Nevada Jump to: navigation, search OpenEI Reference LibraryAdd to...

368

Characteristics of Wind Turbines Under Normal and Fault Conditions: Preprint  

SciTech Connect (OSTI)

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

369

Lossless fault-tolerant data structures with additive overhead  

E-Print Network [OSTI]

We develop the first dynamic data structures that tolerate ? memory faults, lose no data, and incur only an O(? ) additive overhead in overall space and time per operation. We obtain such data structures for arrays, linked ...

Christiano, Paul F.

370

Performance analysis of fault-tolerant nanoelectronic memories  

E-Print Network [OSTI]

important that defect and fault-tolerant schemes be incorporated into the design of nanotechnology related devices. In this dissertation, we focus on the study of a novel and promising class of computer chip memories called crossbar molecular switch memories...

Coker, Ayodeji

2009-05-15T23:59:59.000Z

371

Detecting and Tolerating Byzantine Faults in Database Systems  

E-Print Network [OSTI]

This thesis describes the design, implementation, and evaluation of a replication scheme to handle Byzantine faults in transaction processing database systems. The scheme compares answers from queries and updates on multiple ...

Vandiver, Benjamin Mead

2008-06-30T23:59:59.000Z

372

Detecting and tolerating Byzantine faults in database systems  

E-Print Network [OSTI]

This thesis describes the design, implementation, and evaluation of a replication scheme to handle Byzantine faults in transaction processing database systems. The scheme compares answers from queries and updates on multiple ...

Vandiver, Benjamin Mead, 1978-

2008-01-01T23:59:59.000Z

373

A fault detection service for wide area distributed computations.  

SciTech Connect (OSTI)

The potential for faults in distributed computing systems is a significant complicating factor for application developers. While a variety of techniques exist for detecting and correcting faults, the implementation of these techniques in a particular context can be difficult. Hence, we propose a fault detection service designed to be incorporated, in a modular fashion, into distributed computing systems, tools, or applications. This service uses well-known techniques based on unreliable fault detectors to detect and report component failure, while allowing the user to tradeoff timeliness of reporting against false positive rates. We describe the architecture of this service, report on experimental results that quantify its cost and accuracy, and describe its use in two applications, monitoring the status of system components of the GUSTO computational grid testbed and as part of the NetSolve network-enabled numerical solver.

Stelling, P.

1998-06-09T23:59:59.000Z

374

A Fault Detection and Diagnosis Method for HVAC Systems  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

375

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

376

Fault simulation of combinational circuits based on critical path tracing  

E-Print Network [OSTI]

FAULT SIMULATION Ol' COMBINATIONAI, CIRCUITS BASED ON CRITICAL PATH TRACING A Thesis by CHARLES JAMES BURNETT Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1992 Major Subject: Electrical Engineering FAULT SIIUIULATION OF COMBINATlONAL CIRCUITS BASED ON CRITICAL PATH TRACINC A Thesis CHARLES JAMES BURNETT Approved as to style and content by: Don E. Ross (Chair of Committee...

Burnett, Charles James

1992-01-01T23:59:59.000Z

377

Neural net application to transmission line fault detection and classification  

E-Print Network [OSTI]

NEURAL NET APPLICATION TO TRANSMISSION LINE FAULT DETECTION AND CLASSIFICATION A Thesis by IGOR RIKALO Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approve as to style... Applicanon to Transmission Line Fault Detection and Classification. (December 1994) Igor Rikalo, B. S. University of Sarajevo Chair of Advisory Committee: Dr. Mladen Kezunovic Today, in electric power systems, a large amount of data is made readily...

Rikalo, Igor

2012-06-07T23:59:59.000Z

378

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

379

In-situ stress and fracture permeability in a fault-hosted geothermal reservoir at Dixie Valley, Nevada  

SciTech Connect (OSTI)

As part of a study relating fractured rock hydrology to in-situ stress and recent deformation within the Dixie Valley Geothermal Field, borehole televiewer logging and hydraulic fracturing stress measurements were conducted in a 2.7-km-deep geothermal production well (73B-7) drilled into the Stillwater fault zone. Borehole televiewer logs from well 73B-7 show numerous drilling-induced tensile fractures, indicating that the direction of the minimum horizontal principal stress, S{sub hmin}, is S57{degrees}E. As the Stillwater fault at this location dips S50{degrees}E at {approximately}53{degrees}, it is nearly at the optimal orientation for normal faulting in the current stress field. Analysis of the hydraulic fracturing data shows that the magnitude of S{sub hmin} is 24.1 and 25.9 MPa at 1.7 and 2.5 km, respectively. In addition, analysis of a hydraulic fracturing test from a shallow well 1.5 km northeast of 73B-7 indicates that the magnitude of S{sub hmin} is 5.6 MPa at 0.4 km depth. Coulomb failure analysis shows that the magnitude of S{sub hmin} in these wells is close to that predicted for incipient normal faulting on the Stillwater and subparallel faults, using coefficients of friction of 0.6-1.0 and estimates of the in-situ fluid pressure and overburden stress. Spinner flowmeter and temperature logs were also acquired in well 73B-7 and were used to identify hydraulically conductive fractures.

Hickman, S. [Geological Survey, Menlo Park, CA (United States); Barton, C.; Zoback, M. [Stanford Univ., CA (United States)] [and others

1997-12-31T23:59:59.000Z

380

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

SciTech Connect (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

Note: This page contains sample records for the topic "fault current limiter" 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

A fuzzy-based reliability approach to evaluate basic events of fault tree analysis for nuclear power plant probabilistic safety assessment  

Science Journals Connector (OSTI)

Abstract Fault tree analysis has been widely utilized as a tool for nuclear power plant probabilistic safety assessment. This analysis can be completed only if all basic events of the system fault tree have their quantitative failure rates or failure probabilities. However, it is difficult to obtain those failure data due to insufficient data, environment changing or new components. This study proposes a fuzzy-based reliability approach to evaluate basic events of system fault trees whose failure precise probability distributions of their lifetime to failures are not available. It applies the concept of failure possibilities to qualitatively evaluate basic events and the concept of fuzzy sets to quantitatively represent the corresponding failure possibilities. To demonstrate the feasibility and the effectiveness of the proposed approach, the actual basic event failure probabilities collected from the operational experiences of the David–Besse design of the Babcock and Wilcox reactor protection system fault tree are used to benchmark the failure probabilities generated by the proposed approach. The results confirm that the proposed fuzzy-based reliability approach arises as a suitable alternative for the conventional probabilistic reliability approach when basic events do not have the corresponding quantitative historical failure data for determining their reliability characteristics. Hence, it overcomes the limitation of the conventional fault tree analysis for nuclear power plant probabilistic safety assessment.

Julwan Hendry Purba

2014-01-01T23:59:59.000Z

382

Vibrant fault diagnosis for hydroelectric generator units with a new combination of rough sets and support vector machine  

Science Journals Connector (OSTI)

The fault diagnosis for hydroelectric generator unit (HGU) is significant to prevent dangerous accidents from occurring and to improve economic efficiency. The faults of HGU involve overlapping fault patterns which may denote a kind of faults in the ... Keywords: Fault diagnosis, Hydroelectric generator unit, Rough sets, Support vector machine

Xiaoyuan Zhang; Jianzhong Zhou; Jun Guo; Qiang Zou; Zhiwei Huang

2012-02-01T23:59:59.000Z

383

Provenance evidence for major post–early Pennsylvanian dextral slip on the Picuris-Pecos fault, northern New Mexico  

Science Journals Connector (OSTI)

...Pf-Pajarito fault, GMf-Glorieta Mesa fault, SdCff-Sangre de Cristo frontal...TCf-Tijeras-Canoncito fault, Cf-Chupadera fault, Tf-Tecolote fault, SHf-Sand...2009, Tectonics of the Chupadera Mesa region, central New Mexico: New...

Steven M. Cather; Adam S. Read; Nelia W. Dunbar; Barry S. Kues; Karl Krainer; Spencer G. Lucas; Shari A. Kelley

384

The LMFBR fuel-design environment for endurance testing, primarily of oxide fuel elements with local faults  

SciTech Connect (OSTI)

The U.S. Department of Energy LMFBR Lines-of-Assurance are briefly stated and local faults are given perspective with an historical review and definition to help define the constraints of LMFBR fuel-element designs. Local-fault-propagation (fuel-element-failure propagation and blockage propagation) perceptions are reviewed. Fuel pin designs and major LMFBR parameters affecting pin performance are summarized. The interpretation of failed-fuel data is aided by a discussion of the effects of nonprototypicalities. The fuel-pin endurances expected in the United States, USSR, France, UK, Japan, and West Germany are outlined. Finally, fuel-failure detection and location by delayed-neutron and gaseous-fission product monitors are briefly discussed to better realize the operational limits.

Warinner, D.K.

1983-07-01T23:59:59.000Z

385

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

SciTech Connect (OSTI)

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

386

Characterizing fault-plume intersection probability for geologic carbon sequestration risk assessment  

SciTech Connect (OSTI)

Leakage of CO{sub 2} out of the designated storage region via faults is a widely recognized concern for geologic carbon sequestration. The probability of such leakage can be separated into the probability of a plume encountering a fault and the probability of flow along such a fault. In the absence of deterministic fault location information, the first probability can be calculated from regional fault population statistics and modeling of the plume shape and size. In this study, fault statistical parameters were measured or estimated for WESTCARB's Phase III pilot test injection in the San Joaquin Valley, California. Combining CO{sub 2} plume model predictions with estimated fault characteristics resulted in a 3% probability that the CO{sub 2} plume will encounter a fault fully offsetting the 180 m (590 ft) thick seal. The probability of leakage is lower, likely much lower, as faults with this offset are probably low-permeability features in this area.

Jordan, Preston D.; Oldenburg, Curtis M.; Nicot, Jean-Philippe

2008-11-01T23:59:59.000Z

387

Line-Fault Ride-Through (LFRT) Capabilities of DFIG Wind Turbine Connected to the Power System  

Science Journals Connector (OSTI)

Abstract With increased penetration of wind power into electrical grids, DFIG wind turbines are largely deployed due to their variable speed feature and hence influencing system dynamics. According to grid codes issued by utilities, tripping of wind turbines following power system faults is not allowed. Besides, to provide voltage support to the grid, reactive current supply is necessary. This paper studies the power flow (PF) of two different networks, the first is a transmission network and the second is a distribution one, A wind Doubly-Fed Induction Generator (DFIG) turbine is injected to these different networks. A line fault right through (LFRT) is applied on each network and the power flow results are given and compared, then a new solution is proposed to connect the wind turbine to the distribution network with a down transformer to not disconnect the wind turbine during the LFRT, the power system analysis toolbox (PSAT) is used in this work.

A. Khattara; M. Bahri; A. Aboubou; M. Becherif; M.Y. Ayad

2013-01-01T23:59:59.000Z

388

Localized rotation of principal stress around faults and fractures determined from borehole breakouts in hole B of the Taiwan Chelungpu-fault Drilling Project (TCDP)  

Science Journals Connector (OSTI)

To reveal details of stress perturbations associated with faults and fractures, we investigated the faults and large fractures accompanied by stress-induced borehole breakouts or drilling-induced tensile fractures in hole B of the Taiwan Chelungpu-fault Drilling Project (TCDP). Then, we determined the relationship between the faults and fractures and stress orientation changes. We identified faults and fractures from electrical images of the borehole wall obtained by downhole logging but also from photographs and descriptions of retrieved core samples, and measured the variations in the principal horizontal stress orientation ascertained from borehole breakouts observed on the electrical images in the vicinity of the faults and fractures. Identification of geological structures (faults, fractures, and lithologic boundaries) by electrical images only is difficult and may sometimes yield incorrect results. In a novel approach, therefore, we used both the electrical images and core photographs to identify geological structures. We found four patterns of stress orientation change, or no change, in the vicinity of faults and fractures in TCDP hole B: (i) abrupt (discontinuous) rotation in the vicinity of faults or fractures; (ii) gradual rotation; (iii) suppression of breakouts at faults, fractures, or lithologic boundaries; and (iv) no change in the stress orientation. We recognized stress fluctuations, that is, heterogeneous mesoscale (? 10 cm) stress distributions with respect to both stress orientation and magnitude. In addition, we found that stress state changes occurred frequently in the vicinity of faults, fractures, and lithologic boundaries.

Weiren Lin; En-Chao Yeh; Jih-Hao Hung; Bezalel Haimson; Tetsuro Hirono

2010-01-01T23:59:59.000Z

389

Prediction of marine diesel engine performance under fault conditions  

Science Journals Connector (OSTI)

The diesel engine, due to its superior efficiency when compared to other thermal engines, is widely used for propulsion of marine vessels. Since in such applications the power concentration is critical, most marine diesel engines are of the turbocharged type. Turbocharging has a serious effect on engine performance due to the interaction between the turbocharger and the engine. This interaction makes the detection of engine faults extremely difficult since a specific fault affects the turbocharger and through it the engine. For this reason various methods have been proposed for the detection of engine faults. The present author has in the past presented a method for marine diesel diagnosis by processing measured engine data using a simulation model. In the present work a completely different approach is followed; an attempt is made to use a simulation model to predict marine diesel engine performance under various fault conditions. The method is applied to a newly built vessel powered by a slow speed two stroke marine diesel engine. Using the engine shop trial data obtained under propeller law the simulation model constants are determined, using an automatic method that has been developed. The comparison of results obtained with the data from the official shop trials confirms the accuracy of the model and its ability to predict almost all operating parameters of the engine. The model is then used to produce results by simulating various engine faults or faults of its subsystems. From this analysis their impact on various measurable engine parameters is determined. It is interesting to see that in the case of turbocharged engines some faults have a different effect when compared to naturally aspirated ones. Also, it is revealed that without the use of modeling in many cases it is relatively difficult to determine the actual cause for an engine malfunction, since the observed effects on engine performance are similar. The proposed method is promising and assists the engineer to understand the actual effect of various faults on engine performance. Also it can be used as a training tool since it is easy to simulate various engine faults, a procedure which is extremely difficult, if not impossible, to perform on the field.

Dimitrios T Hountalas

2000-01-01T23:59:59.000Z

390

Accident Fault Trees for Defense Waste Processing Facility  

SciTech Connect (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

391

Grain-scale Comminution and Alteration of Arkosic Rocks in the Damage Zone of the San Andreas Fault at SAFOD  

E-Print Network [OSTI]

is cut by numerous subsidiary faults that display extensive evidence of repeating episodes of compaction, shear, dilation, and cementation. The subsidiary faults are grouped into three size classes: 1) small faults, 1 to 2 mm thick, that record an early...

Heron, Bretani

2012-02-14T23:59:59.000Z

392

Limited Test Ban Treaty  

National Nuclear Security Administration (NNSA)

Detection System (USNDS), which monitors compliance with the international Limited Test Ban Treaty (LTBT). The LTBT, signed by 108 countries, prohibits nuclear testing in the...

393

Current Solicitations - Hanford Site  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Home Prime Contracts Current Solicitations Small Business Other Sources DOE RL Contracting Officers DOE RL Contracting Officer Representatives Current Solicitations Email...

394

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

395

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":""}]}

396

Analysis of electrical signatures in synchronous generators characterized by bearing faults  

E-Print Network [OSTI]

Synchronous generators play a vital role in power systems. One of the major mechanical faults in synchronous generators is related to bearings. The popular vibration analysis method has been utilized to detect bearing faults for years. However...

Choi, Jae-Won

2009-05-15T23:59:59.000Z

397

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

SciTech Connect (OSTI)

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

398

Advanced fault diagnosis techniques and their role in preventing cascading blackouts  

E-Print Network [OSTI]

This dissertation studied new transmission line fault diagnosis approaches using new technologies and proposed a scheme to apply those techniques in preventing and mitigating cascading blackouts. The new fault diagnosis approaches are based on two...

Zhang, Nan

2007-04-25T23:59:59.000Z

399

Fault tree analysis of spontaneous combustion of sulphide ores and its risk assessment  

Science Journals Connector (OSTI)

A logic fault tree of mine spontaneous combustion of sulphide ores was built by the fault tree analysis (FTA) based on a lot of mechanism investigation of sulphide ore spontaneous combustion in more than ten m...

Chao Wu

1995-11-01T23:59:59.000Z

400

The Auto-tuning of ASC and Fault Online Selection Device in Intelligent Substation  

Science Journals Connector (OSTI)

In this chapter, the characteristic of single-phase earth fault in the 10kV isolated neutral distribution network is studied. The application of the auto-tuning of arc suppression coil (ASC) and fault line select...

Haibo Bu; Zhihong Zhang; Fazhang Li…

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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

E-Print Network 3.0 - aircraft fault detection Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of a one step diagnostic system to detect faults. It has been... considered in the FMEA, and it can only detect faults defined in the component library but it does have......

402

Characterization of the structure of faults in the Eocene Carrizo Formation near Gause, Milam County, Texas  

E-Print Network [OSTI]

-scale graben accommodating NW-SE extension. The Carrizo Fm. consists primarily of friable to weakly lithified quartz sandstones with several horizons with interbedded siltstones and shales. Five faults and fault zones occur in the quarry with displacements...

Yilmaz, Ramazan

2012-06-07T23:59:59.000Z

403

Effects of un-transposed UHV transmission line on fault analysis of power systems  

Science Journals Connector (OSTI)

The conventional fault analysis method based on symmetrical components supposes that the three-phase parameters of un-transposed transmission line are symmetrical in case of fault. The errors caused by the method...

Anning Wang ???; Qing Chen ? ?; Zhanping Zhou ???

2008-06-01T23:59:59.000Z

404

Observation and scaling of microearthquakes from the Taiwan Chelungpu-fault borehole seismometers  

Science Journals Connector (OSTI)

......Chelungpu-fault borehole seismometers...Chelungpu-fault Drilling Project Borehole Seismometers...Despite the large coseismic slip...stress drops of larger events including...Taiwan Chelungpu drilling project (TCDP...seven-level vertical borehole seismic array......

Yen-Yu Lin; Kuo-Fong Ma; Volker Oye

2012-07-01T23:59:59.000Z

405

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

Open Energy Info (EERE)

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...

406

Basement faults and seismicity in the Appalachian Basin of New York State  

Science Journals Connector (OSTI)

Landsat lineaments identified by Earth Satellite Corporation (EARTHSAT, 1997) can be groundtruthed across the Appalachian Basin of New York State (NYS). Both fracture intensification domains (FIDs) and faults are observed in outcrop along the lineaments. Confirmation of deep structure associated with the surface structure is provided by both well log analyses and seismic reflection data (primarily proprietary). Additional faults are proposed by comparing the lineament locations with gravity and magnetic data. The result is a web of basement faults that crisscross New York State. By overlaying epicenter locations on the fault/lineament maps, it is possible to observe the spatial correlation between seismic events and the faults. Every seismic event in the Appalachian Basin portion of NYS lies on or near a known or suspected fault. It thus appears that not only are there more faults than previously suspected in NYS, but also, many of these faults are seismically active.

Robert D Jacobi

2002-01-01T23:59:59.000Z

407

The 2002 Denali Fault Earthquake, Alaska: A Large Magnitude, Slip-Partitioned Event  

Science Journals Connector (OSTI)

...the Trans Alaska Pipeline at the Denali fault crossing was engineered...dextral slip. The pipeline, designed to...slip at the fault crossing (12), withstood...13 Alyeska Pipeline Service Company (APSC), Design Basis DB-180...

Donna Eberhart-Phillips; Peter J. Haeussler; Jeffrey T. Freymueller; Arthur D. Frankel; Charles M. Rubin; Patricia Craw; Natalia A. Ratchkovski; Greg Anderson; Gary A. Carver; Anthony J. Crone; Timothy E. Dawson; Hilary Fletcher; Roger Hansen; Edwin L. Harp; Ruth A. Harris; David P. Hill; Sigrún Hreinsdóttir; Randall W. Jibson; Lucile M. Jones; Robert Kayen; David K. Keefer; Christopher F. Larsen; Seth C. Moran; Stephen F. Personius; George Plafker; Brian Sherrod; Kerry Sieh; Nicholas Sitar; Wesley K. Wallace

2003-05-16T23:59:59.000Z

408

Power system fault analysis based on intelligent techniques and intelligent electronic device data  

E-Print Network [OSTI]

This dissertation has focused on automated power system fault analysis. New contributions to fault section estimation, protection system performance evaluation and power system/protection system interactive simulation have been achieved. Intelligent...

Luo, Xu

2007-09-17T23:59:59.000Z

409

On strong fault tolerance (or strong Menger-connectivity) of multicomputer networks  

E-Print Network [OSTI]

As the size of networks increases continuously, dealing with networks with faulty nodes becomes unavoidable. In this dissertation, we introduce a new measure for network fault tolerance, the strong fault tolerance (or strong Menger...

Oh, Eunseuk

2004-11-15T23:59:59.000Z

410

On the Prevalence of Sensor Faults in Real-World Deployments  

E-Print Network [OSTI]

A. Great Duck Island (GDI) data set We looked at datafor different sensors in the GDI data set. The Hybrid (I)faults Fig. 9. SHORT Faults in GDI data set rule and the HMM

Sharma, Abhishek; Golubchik, Leana; Govindan, Ramesh

2007-01-01T23:59:59.000Z

411

Remote Fault Detection of Building HVAC System Using a Global Optimization Program  

E-Print Network [OSTI]

the simulation program in conjunction with synthetic measured data to identify faults in the building operation. This fault detection approach has successfully identified all of the faulty parameters with noise levels of 1%, 3% and 6%. It successfully detected...

Lee, S. U.; Claridge, D. E.

2004-01-01T23:59:59.000Z

412

The effect of fault relayand clay smearing on groundwater flow patterns in the Lower Rhine  

E-Print Network [OSTI]

in the unconsolidated sediments of the Lower Rhine Embayment. Hydraulic head maps show that many individual faults form unconsolidated sediments at shal- low depth is likely to be di¡erent from that of faults at depths where rocks

Bense, Victor

413

Thermo-and hydro-mechanical processes along faults during rapid slip  

E-Print Network [OSTI]

Thermo- and hydro-mechanical processes along faults during rapid slip James R. Rice & Eric M micro-contacts, and (2) Thermal pressurization of fault-zone pore fluid. Both have characteristics which

Dunham, Eric M.

414

Origin of Tokamak Density Limit Scalings  

Science Journals Connector (OSTI)

The onset criterion for radiation driven islands [P.?H. Rebut and M. Hugon, Plasma Physics and Controlled Nuclear Fusion Research 1984: Proc. 10th Int. Conf. London, 1984, (IAEA, Vienna, 1985), Vol. 2] in combination with a simple cylindrical model of tokamak current channel behavior is consistent with the empirical scaling of the tokamak density limit [M. Greenwald, Nucl. Fusion 28, 2199 (1988)]. Many other unexplained phenomena at the density limit are consistent with this novel physics mechanism.

D. A. Gates and L. Delgado-Aparicio

2012-04-20T23:59:59.000Z

415

Tarmat behavior calculated for reservoir with sealing fault  

SciTech Connect (OSTI)

The Minagish Oolite oil reservoir in Kuwait is one of many Middle East reservoirs characterized by the presence of a tarmat (heavy to tar-like crude) at the oil-water contact. Since a waterflood project is planned for the Minagish Oolite, which contains a radial pattern of faults, a study was made to consider tarmat behavior upon water injection below it when the injection well is located near a sealing fault. The study resulted in a technique to predict the time of tarmat breakdown, response time at the nearest observation well, and differential pressure at the tarmat anywhere in the reservoir.

Osman, M.E.S.

1986-08-01T23:59:59.000Z

416

Tectonic history and setting of a seismogenic intraplate fault system that lacks microseismicity: The Saline River fault system, southern United States  

Science Journals Connector (OSTI)

Abstract Although the northwest-striking Saline River fault system of southeastern Arkansas is not defined by microseismicity, it is associated with sand blows and shows evidence of Pleistocene and Holocene surface ruptures, suggesting a significant seismogenic potential. This fault system is within the northern Gulf of Mexico interior coastal plain, a region only recently recognized as containing seismogenic faults. To better characterize this active fault system, we reconstructed its post-Paleozoic history using petroleum and coal industry wire-line well log and seismic reflection subsurface data. The Saline river fault system initiated as a series of northwest-striking grabens during Triassic/Jurassic uplift and incipient Gulf of Mexico rifting along the basement Alabama–Oklahoma transform margin of the North American Proterozoic craton. During post-rift subsidence, these grabens were buried by Gulf sediments until mid-Cretaceous uplift and igneous activity resulted in minor extensional reactivation of graben faults. Faulting style changed from extension to transpression during the Late Cretaceous due to compression of eastern North America as the North Atlantic rapidly widened and due to thermal weakening of the Alabama–Oklahoma transform lithospheric discontinuity as it obliquely crossed a mantle hot spot. In the Late Cretaceous, graben faults experienced contractional reactivation and steep, deeply-rooted transpressional faults developed within and parallel to the graben system. These transpressional faults locally displace Eocene, Pleistocene, and Holocene sediments. Fault activity continues on the Saline River fault system due to thin crust along the Alabama–Oklahoma transform and to high heat flow, which act together to weaken the crust and promote seismogenic tectonism. The fault system may lack appreciable microseismicity because the aftershock sequence of the last large earthquake has had time to dissipate.

Randel Tom Cox; J. Luke Hall; Chris S. Gardner

2013-01-01T23:59:59.000Z

417

Weighted local and global regressive mapping: A new manifold learning method for machine fault classification  

Science Journals Connector (OSTI)

This article studies if machine faults can be effectively determined in a reduced dimensional space. When faults occur in machines, machine vibration signals will deviate from its normal signal pattern. Such changes can be reflected in the features constructed ... Keywords: Fault classification, Feature extraction, Unsupervised learning, Vibrations

Xiaohang Jin, Fang Yuan, Tommy W. S. Chow, Mingbo Zhao

2014-04-01T23:59:59.000Z

418

Performance of Graceful Degradation for Cache Faults Hyunjin Lee Sangyeun Cho Bruce R. Childers  

E-Print Network [OSTI]

Performance of Graceful Degradation for Cache Faults Hyunjin Lee Sangyeun Cho Bruce R. Childers to thermal hot spots) and may man- ifest themselves as operational faults at the micro- Bruce Childers that is dependent on the fault and the frequency of access to an address that would normally be held in the disabled

Cho, Sangyeun

419

Bearing Fault Detection in DFIG-Based Wind Turbines Using the First Intrinsic Mode Function  

E-Print Network [OSTI]

Bearing Fault Detection in DFIG-Based Wind Turbines Using the First Intrinsic Mode Function Y for bearing fault detection in DFIG-based wind turbines. The proposed method uses the first Intrinsic Mode Terms--Wind turbine, Doubly Fed Induction Generator (DFIG), fault detection, bearings, signal processing

Boyer, Edmond

420

IPR: In-Place Reconfiguration for FPGA Fault Tolerance and Rupak Majumdar2  

E-Print Network [OSTI]

IPR: In-Place Reconfiguration for FPGA Fault Tolerance Zhe Feng1 , Yu Hu1 , Lei He1 and Rupak Angeles ABSTRACT We describe In-Place Reconfiguration (IPR) for LUT-based FPGAs, an algorithm the propagation of faults seen at a pair of comple- mentary inputs. Based on IPR, we develop a fault

He, Lei

Note: This page contains sample records for the topic "fault current limiter" 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

Fault Sensitivity Analysis and Reliability Enhancement of Analog-to-Digital Converters  

E-Print Network [OSTI]

proposing a sensitivity analysis methodology for -particle induced transients and then suggesting redesign- sients is introduced which improves the accuracy of the sensitivity analysis. The fault simulations show, Fault Sensitivity, Analog-to- Digital Converters, Alpha particles, Reliability, Transient Faults I

Koren, Israel

422

Dynamic rupture through a branched fault2 configuration at Yucca Mountain and resulting3  

E-Print Network [OSTI]

Dynamic rupture through a branched fault2 configuration at Yucca Mountain and resulting3 ground analyses. This is motivated by the normal faults in the vicinity10 of Yucca Mountain, NV, a potential site fault12 located approximately 1 km west of the crest of Yucca Mountain, is the13 most active

Dmowska, Renata

423

The Research of the Intelligent Fault Diagnosis System Optimized by GA for Marine Diesel Engine  

Science Journals Connector (OSTI)

The marine diesel engine is a complex system, which has the important function to guarantee the marine security. There is strong coupling relationship among the mapping process of fault diagnosis. An approach of intelligent fault diagnosis based on fuzzy ... Keywords: Fuzzy neural network, Genetic algorithm, Fault diagnosis, Marine diesel engine

Peng Li; Qi Jin; Haixia Gong

2008-12-01T23:59:59.000Z

424

Interseismic deformation and geologic evolution of the Death Valley Fault Zone  

E-Print Network [OSTI]

Interseismic deformation and geologic evolution of the Death Valley Fault Zone Cecilia Del Pardo,1 Valley Fault Zone (DVFZ), located in southeastern California, is an active fault system with an evolved motion and long-term stress accumulation rates to better understand the nature of both past and present

Blewitt, Geoffrey

425

Core-log integration studies in hole-A of Taiwan Chelungpu-fault Drilling Project  

Science Journals Connector (OSTI)

......Chelungpu-fault Drilling Project Yun-Hao...Chelungpu-fault Drilling Project (TCDP...involved in the large displacements...electrical borehole images and dipole-shear...energetics of a large earthquake from...Chelungpu-fault Drilling Project, Nature...Stress-induced borehole elongation......

Yun-Hao Wu; En-Chao Yeh; Jia-Jyun Dong; Li-Wei Kuo; Jui-Yu Hsu; Jih-Hao Hung

2008-09-01T23:59:59.000Z

426

Heat signature on the Chelungpu fault associated with the 1999 Chi-Chi, Taiwan earthquake  

E-Print Network [OSTI]

for a large earthquake. Temperature measurements in a borehole that intersects the Chelungpu fault at a depth-fault temperature change observed for any previous large earthquakes that can be attributed to the frictional, 1999 Chi-Chi earth- quake, the Taiwan Chelungpu-fault Drilling Project (TCDP) bored two holes which

Ma, Kuo-Fong

427

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

428

Yield Modeling and Analysis of a Clockless Asynchronous Wave Pipeline with Pulse Faults  

E-Print Network [OSTI]

Yield Modeling and Analysis of a Clockless Asynchronous Wave Pipeline with Pulse Faults T. Feng fault model and its modeling and analysis methods in a clockless asynchronous wave pipeline fault rate model for establishing a sound theoretical foundation for clockless wave pipeline design

Ayers, Joseph

429

Fault Diagnosis Of A Water For Injection System Using Enhanced Structural Isolation  

Science Journals Connector (OSTI)

A water for injection system supplies chilled sterile water as a solvent for pharmaceutical products. There are ultimate requirements for the quality of the sterile water, and the consequence of a fault in temperature or in flow control within the process ... Keywords: Fault Diagnosis, Fault Isolation, Matching, Structural Analysis

Morten Laursen; Mogens Blanke; Dilek Dü?TegöR

2008-12-01T23:59:59.000Z

430

Optical limiting materials  

DOE Patents [OSTI]

Optical limiting materials. Methanofullerenes, fulleroids and/or other fullerenes chemically altered for enhanced solubility, in liquid solution, and in solid blends with transparent glass (SiO.sub.2) gels or polymers, or semiconducting (conjugated) polymers, are shown to be useful as optical limiters (optical surge protectors). The nonlinear absorption is tunable such that the energy transmitted through such blends saturates at high input energy per pulse over a wide range of wavelengths from 400-1100 nm by selecting the host material for its absorption wavelength and ability to transfer the absorbed energy into the optical limiting composition dissolved therein. This phenomenon should be generalizable to other compositions than substituted fullerenes.

McBranch, Duncan W. (Santa Fe, NM); Mattes, Benjamin R. (Santa Fe, NM); Koskelo, Aaron C. (Los Alamos, NM); Heeger, Alan J. (Santa Barbara, CA); Robinson, Jeanne M. (Los Alamos, NM); Smilowitz, Laura B. (Los Alamos, NM); Klimov, Victor I. (Los Alamos, NM); Cha, Myoungsik (Goleta, CA); Sariciftci, N. Serdar (Santa Barbara, CA); Hummelen, Jan C. (Groningen, NL)

1998-01-01T23:59:59.000Z

431

E-Print Network 3.0 - aneurysms current status Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Plaza, Reed 4238 Summary: of this workshop is to discuss the significance of aneurysm modeling and simulation, identify current limitations... for 10 min Session II: Current...

432

Antiproton Limits on Decaying Gravitino Dark Matter  

E-Print Network [OSTI]

We report on constraints on the lifetime of decaying gravitino dark matter in models with bilinear R-parity violation derived from observations of cosmic-ray antiprotons with the PAMELA experiment. Performing a scan over a viable set of cosmic-ray propagation parameters we find lower limits ranging from $8\\times 10^{28}$s to $6\\times 10^{28}$s for gravitino masses from roughly 100 GeV to 10 TeV. Comparing these limits to constraints derived from gamma-ray and neutrino observations we conclude that the presented antiproton limits are currently the strongest and most robust limits on the gravitino lifetime in the considered mass range. These constraints correspond to upper limits on the size of the bilinear R-parity breaking parameter in the range of $10^{-8}$ to $8\\times 10^{-13}$.

Grefe, Michael

2014-01-01T23:59:59.000Z

433

Limited Commercial Maintenance (LCLM) Limited Lawn & Ornamental (LLO)  

E-Print Network [OSTI]

, Limited Commercial Landscape Maintenance, Ornamental & Turf, Private Ag, or General Standards CORE for Limited Commercial Landscape Maintenance (LCLM), you must attend all day to earn the 6 CEUs required. Limited Commercial Maintenance (LCLM) Limited Lawn & Ornamental (LLO) Training & Exams Date

Florida, University of

434

Fault prediction in aircraft engines using Self-Organizing Maps  

E-Print Network [OSTI]

Fault prediction in aircraft engines using Self- Organizing Maps Marie Cottrell1 , Patrice Gaubert1. Aircraft engines are designed to be used during several tens of years. Their maintenance is a challenging and costly task, for obvious security reasons. The goal is to ensure a proper operation of the engines

Paris-Sud XI, Université de

435

Modeling Fault Propagation in Telecommunications Networks for Diagnosis Purposes  

E-Print Network [OSTI]

Modeling Fault Propagation in Telecommunications Networks for Diagnosis Purposes A. Aghasaryan , C@lipn.univ-paris13.fr Abstract: This paper describes a formalism to model the behavior of telecommunications net. Keywords: network management, modeling, UML, distributed diagnosis. 1 Introduction Telecommunications

Pencolé, Yannick

436

Fault Tolerance in Data Gathering Wireless Sensor Networks  

Science Journals Connector (OSTI)

......total 30% node faults. FIGURE 8. Energy efficiency. better than LEACH when link error...Efficiency In this section, we analyze the energy efficiency (in Fig. 8) and time efficiency...May 1213, pp. 474479. The Printing House, Inc. [14] Huang, S. K., Ssu......

Guangyan Huang; Yanchun Zhang; Jing He; Jinli Cao

2011-06-01T23:59:59.000Z

437

Influence of plastic deformation on bimaterial fault rupture directivity  

E-Print Network [OSTI]

Influence of plastic deformation on bimaterial fault rupture directivity Nora DeDontney,1 Elizabeth of the role of the stress state on the distribution of plastic deformation and the direction of preferred in determining the location of plastic deformation. For different orientations, plastic deformation can

Dmowska, Renata

438

Fault Detection Effectiveness of Spathic Test Data Jane Huffman Hayes  

E-Print Network [OSTI]

Fault Detection Effectiveness of Spathic Test Data Jane Huffman Hayes Computer Science Department This paper presents an approach for generating test data for unit-level, and possibly integration-level, testing based on sampling over intervals of the input probability distribution, i.e., one that has been

Hayes, Jane E.

439

Invited Talk: Mitigating the Effects of Internet Timing Faults  

E-Print Network [OSTI]

Invited Talk: Mitigating the Effects of Internet Timing Faults Across Embedded Network Gateways and the Internet. The usual approach to making such a connection is to install a gateway node which translates from Internet protocols to embedded field bus network protocols. Such connections raise obvious security

Koopman, Philip

440

Autonomous FPGA Fault Handling through Competitive Runtime Reconfiguration  

E-Print Network [OSTI]

environments of mechanical/acoustical stress during launch, high doses of ionizing radiation, and thermal due to radiation- induced stuck-at-faults, thermal fatigue, oxide breakdown, electromigration-available [Xilinx04]. Meanwhile NASA terrestrial applications routinely employ FPGAs for tasks ranging from launch

DeMara, Ronald F.

Note: This page contains sample records for the topic "fault current limiter" 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

Acoustic condition monitoring of wind turbines: Tip faults  

Science Journals Connector (OSTI)

As a significant and growing source of the world’s energy wind turbine reliability is becoming a major concern. At least two fault detection techniques for condition monitoring of wind turbine blades have been reported in early literature i.e. acoustic emissions and optical strain sensors. These require off-site measurement. The work presented here offers an alternative non-contact fault detection method based on the noise emission from the turbine during operation. An investigation has been carried out on a micro wind turbine under laboratory conditions. 4 severity levels for a fault have been planted in the form of added weight at the tip of one blade to simulate inhomogeneous debris or ice build up. Acoustic data is obtained at a single microphone placed in front of the rotor. Two prediction methods have been developed and tested on real data: one based on a single feature - rotational frequency spectral magnitude; and another based on a fuzzy logic interference using two inputs - spectral peak and rotational peak variation with time. Results show that the single spectral peak feature can be used to determine fault severity in ranges. The implementation of the fuzzy logic using a further input feature is shown to significantly improve the detection accuracy.

Daniel J. Comboni; Bruno Fazenda

2012-01-01T23:59:59.000Z

442

On Fault Coverage of Tests for Finite State Specifications  

E-Print Network [OSTI]

On Fault Coverage of Tests for Finite State Specifications A. Petrenko and G. v. Bochmann-Ville, Montréal (Québec), H3C 3J7, Canada Abstract Testing is a trade-off between increased confidence in the correctness of the implementation under test and constraints on the amount of time and effort that can

von Bochmann, Gregor

443

Diverse neural net solutions to a fault diagnosis problem \\Lambda  

E-Print Network [OSTI]

system solution to a problem of fault diagnosis in a four­stroke marine diesel engine; that of early detection of faulty combustion in an engine cylinder. Recognition of faulty combustion usually requires the intervention of a skilled marine engineer, to undertake the time­ consuming and fallible process of comparing

Sharkey, Amanda

444

Fault-tolerant architecture for quantum computation using electrically controlled  

E-Print Network [OSTI]

ARTICLES Fault-tolerant architecture for quantum computation using electrically controlled an architecture for quantum computation using electrically controlled semiconductor spins by extending the Loss in the solid state. Here, we develop a scalable architecture for solid-state quantum computation based

Loss, Daniel

445

Fracture surface energy of the Punchbowl fault, San Andreas system  

E-Print Network [OSTI]

Fracture surface energy of the Punchbowl fault, San Andreas system Judith S. Chester1 , Frederick M. Chester1 & Andreas K. Kronenberg1 Fracture energy is a form of latent heat required to create weakening1­3 . Fracture energy has been estimated from seismological and experimental rock deformation data4

Chester, Frederick M.

446

Algorithm-dependent fault tolerance for distributed computing  

SciTech Connect (OSTI)

Large-scale distributed systems assembled from commodity parts, like CPlant, have become common tools in the distributed computing world. Because of their size and diversity of parts, these systems are prone to failures. Applications that are being run on these systems have not been equipped to efficiently deal with failures, nor is there vendor support for fault tolerance. Thus, when a failure occurs, the application crashes. While most programmers make use of checkpoints to allow for restarting of their applications, this is cumbersome and incurs substantial overhead. In many cases, there are more efficient and more elegant ways in which to address failures. The goal of this project is to develop a software architecture for the detection of and recovery from faults in a cluster computing environment. The detection phase relies on the latest techniques developed in the fault tolerance community. Recovery is being addressed in an application-dependent manner, thus allowing the programmer to take advantage of algorithmic characteristics to reduce the overhead of fault tolerance. This architecture will allow large-scale applications to be more robust in high-performance computing environments that are comprised of clusters of commodity computers such as CPlant and SMP clusters.

P. D. Hough; M. e. Goldsby; E. J. Walsh

2000-02-01T23:59:59.000Z

447

Module Placement for Fault-Tolerant Microfluidics-Based Biochips  

E-Print Network [OSTI]

Module Placement for Fault-Tolerant Microfluidics-Based Biochips FEI SU and KRISHNENDU CHAKRABARTY Duke University Microfluidics-based biochips are soon expected to revolutionize clinical diagnosis, DNA sequencing, and other laboratory procedures involving molecular biology. Most microfluidic biochips today

Chakrabarty, Krishnendu

448

Fault Tolerance on Interleaved inverter with Magnetic couplers  

E-Print Network [OSTI]

Fault Tolerance on Interleaved inverter with Magnetic couplers K.Guépratte, D.Frey, P-O.Jeannin, H Electrical Engineering (G2Elab), Thales Systemes Aeroportes Abstract- The paper focuses on a new control strategy for improving the availability of power electronic converters based on interleaved structures

Paris-Sud XI, Université de

449

Defects and Faults in Quantum Cellular Automata at Nano Scale  

E-Print Network [OSTI]

Defects and Faults in Quantum Cellular Automata at Nano Scale Mehdi Baradaran Tahoori, Mariam considerable research on quantum dot cellular automata (QCA) as a new computing scheme in the nano, quantum dot cellular automata (QCA) not only gives a solution at nano scale, but also it offers a new

450

Proceedings of the 18th Fault-Tolerant Computing Symposium  

E-Print Network [OSTI]

Proceedings of the 18th Fault-Tolerant Computing Symposium Tokyo, Japan, pp. 234-239, June 1988 performed on this erroneous information are ``undone'' using a hardware mechanism for fast rollback of a few and confine the damage caused by the error to the failed module, it is often necessary to check the outputs

Tamir, Yuval

451

This document contains 3087 words. FAULT-TOLERANT COMPUTING  

E-Print Network [OSTI]

or physical damage. An extensive methodology has been developed in this field over the past thirty years the annual IEEE International Symposium on Fault-Tolerant Computing (FTCS) and the papers in its Digests with protective redundancy so that, if the module fails, others can assume its function. Special mechanisms

Rennels, David A.

452

A static voltage-current characteristic for the low current DC arc  

E-Print Network [OSTI]

systems has failed to detect arcing faults numerous times with disastrous consequences. The fault leaves a charred furrow, known as the ''arc track'', through Kapton cable insulation. Tests by NASA and others have confirmed that the average circuit...

Moores, Gregory Lee

2012-06-07T23:59:59.000Z

453

Anomalous - viscosity current drive  

DOE Patents [OSTI]

An apparatus and method for maintaining a steady-state current in a toroidal magnetically confined plasma. An electric current is generated in an edge region at or near the outermost good magnetic surface of the toroidal plasma. The edge current is generated in a direction parallel to the flow of current in the main plasma and such that its current density is greater than the average density of the main plasma current. The current flow in the edge region is maintained in a direction parallel to the main current for a period of one or two of its characteristic decay times. Current from the edge region will penetrate radially into the plasma and augment the main plasma current through the mechanism of anomalous viscosity. In another aspect of the invention, current flow driven between a cathode and an anode is used to establish a start-up plasma current. The plasma-current channel is magnetically detached from the electrodes, leaving a plasma magnetically insulated from contact with any material obstructions including the cathode and anode.

Stix, Thomas H. (Princeton, NJ); Ono, Masayuki (Princeton Junction, NJ)

1988-01-01T23:59:59.000Z

454

Controlled-source electromagnetic mapping of a faulted sandstone aquifer in central Texas  

E-Print Network [OSTI]

across a fault (Randolph 1991), due to permeability reduction in the deformation zone, but in some cases can be enhanced along the fault slip plane (Antonellini and Aydin 1994), i. e. parallel to the fault. A knowledge of subsurface fault distributions... the electromagnetic response. Seaborne et al. (1979) interpreted the anomalies as the edge effect of thin horizontal sheets of low resistivity beds, as opposed to the high conductivity response of the material in a fault zone. In a similar study, Hazell er al...

Gorman, Erin Margaret

2012-06-07T23:59:59.000Z

455

High-Current Accelerators  

E-Print Network [OSTI]

F i g . 13 F i g . 14 A 48 ACCELERATOR F i g . 25 F i g . 16supply. Extrapolation of accelerator energy and current9 . A-48 high-current accelerator, low-velocity end. Fig.

Lawrence, Ernest O.

1955-01-01T23:59:59.000Z

456

Development of Asset Fault Signatures for Prognostic and Health Management in the Nuclear Industry  

SciTech Connect (OSTI)

Proactive online monitoring in the nuclear industry is being explored using the Electric Power Research Institute’s Fleet-Wide Prognostic and Health Management (FW-PHM) Suite software. The FW-PHM Suite is a set of web-based diagnostic and prognostic tools and databases that serves as an integrated health monitoring architecture. The FW-PHM Suite has four main modules: Diagnostic Advisor, Asset Fault Signature (AFS) Database, Remaining Useful Life Advisor, and Remaining Useful Life Database. This paper focuses on development of asset fault signatures to assess the health status of generator step-up generators and emergency diesel generators in nuclear power plants. Asset fault signatures describe the distinctive features based on technical examinations that can be used to detect a specific fault type. At the most basic level, fault signatures are comprised of an asset type, a fault type, and a set of one or more fault features (symptoms) that are indicative of the specified fault. The AFS Database is populated with asset fault signatures via a content development exercise that is based on the results of intensive technical research and on the knowledge and experience of technical experts. The developed fault signatures capture this knowledge and implement it in a standardized approach, thereby streamlining the diagnostic and prognostic process. This will support the automation of proactive online monitoring techniques in nuclear power plants to diagnose incipient faults, perform proactive maintenance, and estimate the remaining useful life of assets.

Vivek Agarwal; Nancy J. Lybeck; Randall Bickford; Richard Rusaw

2014-06-01T23:59:59.000Z

457

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

458

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

459

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;

460

Abstract--The reliability and quality of power distribution systems are usually affected by many different distribution faults.  

E-Print Network [OSTI]

1 Abstract--The reliability and quality of power distribution systems are usually affected by many different distribution faults. Tree-caused faults are one of the major fault causes. In this paper, four to analyze the characteristics of tree-caused distribution faults. This paper also uses statistical

Chow, Mo-Yuen

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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.


461

Security Clearances; Limitations  

Broader source: Energy.gov (indexed) [DOE]

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.

462

Modeling tip zones to predict the throw and length characteristics of faults  

SciTech Connect (OSTI)

A map of faults in a 60 km{sup 2} area of the southern North Sea has been produced from three-dimensional seismic data. The faults shown on the map obey power-law cumulative-frequency distributions for throw (power-law exponent, D, {approx} 2.7) and length (D {approx} 1.1). Simulations have been carried out to correct for sampling biases in the data and to make predictions of the throw the data and to make predictions of the throw and length scaling characteristics of the faults. The most important bias is caused by poor resolution of the small displacement tip zones of faults. The raw data show considerable scatter in their length: throw ratios, but they more closely fit a linar relationship if a length of 500 m is added to each fault, thereby making up for the zones near the fault tips with throws ({approx} 15 m) below seismic resolution. Further variability in the data may be caused by such geological factors as fault interaction. Tip lengths have been extended to simulate the actual fault pattern in the study area. Maps produced by this procedure can be used to estimate the true connectivity of the fault network. Extending the faults results in greater connectivity than shown by the raw data, which may cause greater compartmentalization of the rock mass. This greater compartmentalization has implications for hydrocarbon exploitation if the faults are sealing. A problem with the model, however, is that it does not deal effectively with the interaction of subparallel, noncoplanar faults. To test the reliability of the procedure, we analyzed exposure-scale faults in Somerset, United Kingdom, where the tips are well constrained. Both length-throw relationships and map-pattern connectivity for the simulated fault networks agree closely with the actual data.

Pickering, G.; Sanderson, D.J.; Bull, J.M. [Univ. of Southampton (United Kingdom)] [and others

1997-01-01T23:59:59.000Z

463

Behavior of Repeating Earthquake Sequences in Central California and the Implications for Subsurface Fault Creep  

SciTech Connect (OSTI)

Repeating earthquakes (REs) are sequences of events that have nearly identical waveforms and are interpreted to represent fault asperities driven to failure by loading from aseismic creep on the surrounding fault surface at depth. We investigate the occurrence of these REs along faults in central California to determine which faults exhibit creep and the spatio-temporal distribution of this creep. At the juncture of the San Andreas and southern Calaveras-Paicines faults, both faults as well as a smaller secondary fault, the Quien Sabe fault, are observed to produce REs over the observation period of March 1984-May 2005. REs in this area reflect a heterogeneous creep distribution along the fault plane with significant variations in time. Cumulative slip over the observation period at individual sequence locations is determined to range from 5.5-58.2 cm on the San Andreas fault, 4.8-14.1 cm on the southern Calaveras-Paicines fault, and 4.9-24.8 cm on the Quien Sabe fault. Creep at depth appears to mimic the behaviors seen of creep on the surface in that evidence of steady slip, triggered slip, and episodic slip phenomena are also observed in the RE sequences. For comparison, we investigate the occurrence of REs west of the San Andreas fault within the southern Coast Range. Events within these RE sequences only occurred minutes to weeks apart from each other and then did not repeat again over the observation period, suggesting that REs in this area are not produced by steady aseismic creep of the surrounding fault surface.

Templeton, D C; Nadeau, R; Burgmann, R

2007-07-09T23:59:59.000Z

464

Photon and graviton mass limits  

SciTech Connect (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

465

Systems analysis approach to probabilistic modeling of fault trees  

SciTech Connect (OSTI)

A method of probabilistic modeling of fault tree logic combined with stochastic process theory (Markov modeling) has been developed. Systems are then quantitatively analyzed probabilistically in terms of their failure mechanisms including common cause/common mode effects and time dependent failure and/or repair rate effects that include synergistic and propagational mechanisms. The modeling procedure results in a state vector set of first order, linear, inhomogeneous, differential equations describing the time dependent probabilities of failure described by the fault tree. The solutions of this Failure Mode State Variable (FMSV) model are cumulative probability distribution functions of the system. A method of appropriate synthesis of subsystems to form larger systems is developed and applied to practical nuclear power safety systems.

Bartholomew, R.J.; Qualls, C.R.

1985-01-01T23:59:59.000Z

466

BGE_Comments_CurrentComms.pdf  

Broader source: Energy.gov (indexed) [DOE]

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

467

Current Testbed Research  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Current Testbed Research Previous Testbed Research Proposal Process Terms and Conditions Dark Fiber Testbed Performance (perfSONAR) Software & Tools Development Partnerships...

468

Current Research Portfolio  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Resources News & Events Expand News & Events Skip navigation links Smart Grid Demand Response Energy Efficiency Emerging Technologies Current Research Portfolio Behavior Based...

469

Ion current interface.  

E-Print Network [OSTI]

?? Abstract Abstract The reason to measure the ion current in a combustion engine is to extract combustion parameters in order to achieve closed loop… (more)

Johansson, Morgan

2005-01-01T23:59:59.000Z

470

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

471

QUANTIFYING UNCERTAINTIES IN GROUND MOTION SIMULATIONS FOR SCENARIO EARTHQUAKES ON THE HAYWARD-RODGERS CREEK FAULT SYSTEM USING THE USGS 3D VELOCITY MODEL AND REALISTIC PSEUDODYNAMIC RUPTURE MODELS  

SciTech Connect (OSTI)

This project seeks to compute ground motions for large (M>6.5) scenario earthquakes on the Hayward Fault using realistic pseudodynamic ruptures, the USGS three-dimensional (3D) velocity model and anelastic finite difference simulations on parallel computers. We will attempt to bound ground motions by performing simulations with suites of stochastic rupture models for a given scenario on a given fault segment. The outcome of this effort will provide the average, spread and range of ground motions that can be expected from likely large earthquake scenarios. The resulting ground motions will be based on first-principles calculations and include the effects of slip heterogeneity, fault geometry and directivity, however, they will be band-limited to relatively low-frequency (< 1 Hz).

Rodgers, A; Xie, X

2008-01-09T23:59:59.000Z

472

Fault Detection, Diagnostics and Optimmization using BIG Data Analytics  

E-Print Network [OSTI]

111, Duke Street, Suite 3800 Montreal (Quebec) H3C 2M1 CANADA Tel : +1-514-866-5159 Fax : +1-514-866-2047 Fault Detection, diagnostics and optimization using BIG data analytics Presenter: IFCS Inc., Quebec, CANADA The past decade has seen... Joule AnalytiX management framework Unified Collector ? Syslog Events/SNMP ? Diagnostic Agent for Building Operations ? Performance Data ? System Health Data ? Feedback from BMS ? Johnson Controls ? Delta Controls ? Trane ? Siemens...

Bonifay, X.

2013-01-01T23:59:59.000Z

473

An expert system for fault detection and diagnosis  

E-Print Network [OSTI]

Major Subject: Electrical Engineering AN EXPERT SYSTEM FOR I AIJLT DETECTION AND DIAGNOSIS A Thesis by PREDRAG SPASOJEVIC Approv d as to style and content by; (, . I Mladen Kezunovic (Chair of ommitt R. Don Russell Ali Abur (Member) / /$t...:l~. , ~ 1 /z Karan L. Watson (Member) Wil iam M. Li y (Member . W. Howze (Head of Department) August 1992 ABSTRACT An Expert System 1' or Fault Detection and Diagnosis. (August 1992) Preclrag Spasojevic, Dipl. Ing. , University of Sarajevo Chair...

Spasojevic, Predrag

1992-01-01T23:59:59.000Z

474

Experimental characterization of faults on low-voltage systems  

E-Print Network [OSTI]

INTRODUCTION . Page II EXISTING DETECTION SCHEMES AND RESEARCH OBJECTIVES 8 Existing Detection Schemes Research Objectives III THEORY OF ARCS AND ARCING FAULTS 8 15 17 Formation of Spark Arc Chracteristics 17 18 IV FIELD TEST INSTRUMENTATION... EQUIPMENT . , V DESCRIPTION OF TESTS VI FIELD TESTS - GENERAL . . 30 VII DATA ANALYSIS, OBSERVATION AND SUMMARY . . 43 Time Domain Analysis . Frequency Domain Analysis Comparison with 15 kV Systems . Summary of Results . 44 56 67 72 REFERENCES...

Ahmed, Jubayer

1992-01-01T23:59:59.000Z

475

Heat flux limiting sleeves  

DOE Patents [OSTI]

A heat limiting tubular sleeve extending over only a portion of a tube having a generally uniform outside diameter, the sleeve being open on both ends, having one end thereof larger in diameter than the other end thereof and having a wall thickness which decreases in the same direction as the diameter of the sleeve decreases so that the heat transfer through the sleeve and tube is less adjacent the large diameter end of the sleeve than adjacent the other end thereof.

Harris, William G. (Tampa, FL)

1985-01-01T23:59:59.000Z

476

Automatic fault detection on BIPV systems without solar irradiation data  

E-Print Network [OSTI]

BIPV systems are small PV generation units spread out over the territory, and whose characteristics are very diverse. This makes difficult a cost-effective procedure for monitoring, fault detection, performance analyses, operation and maintenance. As a result, many problems affecting BIPV systems go undetected. In order to carry out effective automatic fault detection procedures, we need a performance indicator that is reliable and that can be applied on many PV systems at a very low cost. The existing approaches for analyzing the performance of PV systems are often based on the Performance Ratio (PR), whose accuracy depends on good solar irradiation data, which in turn can be very difficult to obtain or cost-prohibitive for the BIPV owner. We present an alternative fault detection procedure based on a performance indicator that can be constructed on the sole basis of the energy production data measured at the BIPV systems. This procedure does not require the input of operating conditions data, such as solar ...

Leloux, Jonathan; Luna, Alberto; Desportes, Adrien

2014-01-01T23:59:59.000Z

477

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).

478

Time-varying effects and averaging issues in models for current-mode control  

E-Print Network [OSTI]

This paper investigates issues in modeling of current-mode control in converters. The effects of the current-sampling intrinsic to current-mode control are analyzed, and inadequately recognized limitations of linear ...

Perreault, David J.

479

Gas monitor update review of progress in the development of a microelectronic in-situ transformer fault gas analyzer  

SciTech Connect (OSTI)

This report summarizes the ongoing work of Micromonitors, Inc., on behalf of the Electric Power Research Institute (EPRI) under research project RP2445-03. Purpose of the work is to develop, test and commercialize a microelectronic, in-situ mineral oil transformer fault gas analyzer, based on patented metal-insulator-semiconductor (MIS) sensor technology. The work entails fabrication and testing of an array of MIS devices sensitive to hydrogen, carbon monoxide, acetylene and ethylene. Current experimental prototypes are comprised of an array of three sensors mounted on an alumina substrate with an integrated heater to control temperature. The sensor package is configured in a probe assembly with attached analog circuitry. Analog-to-digital conversion and digital processing occur in a separate NEMA 4X enclosure. Gas concentrations are calculated using a matrix-based algorithm installed in a Motorola MC68HC11 microprocessor. The {alpha}-phase of the field demonstration of Micromonitors` analyzer was initiated in October, 1993, at the Bonneville Power Administration (BPA) Alvey Substation and culminated with installations at BPA`s Celilo Converter Station in September, 1994. We report on the performance of the field units, all 12 of which are currently operating. The development of improved resolution of the four fault gases is reviewed.

Pledger, W.A.; Pyke, S.C. [Micromonitors, Inc., Sisters, OR (United States)

1996-03-01T23:59:59.000Z

480

Polarized electron beams at milliampere average current  

SciTech Connect (OSTI)

This contribution describes some of the challenges associated with developing a polarized electron source capable of uninterrupted days-long operation at milliAmpere average beam current with polarization greater than 80%. Challenges will be presented in the context of assessing the required level of extrapolation beyond the performance of today's CEBAF polarized source operating at ~ 200 uA average current. Estimates of performance at higher current will be based on hours-long demonstrations at 1 and 4 mA. Particular attention will be paid to beam-related lifetime-limiting mechanisms, and strategies to construct a photogun that operate reliably at bias voltage > 350kV.

Poelker, Matthew [JLAB

2013-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "fault current limiter" 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.


481

Ultracapacitor current collector  

DOE Patents [OSTI]

An ultracapacitor having two solid, nonporous current collectors, two porous electrodes separating the collectors, a porous separator between the electrodes and an electrolyte occupying the pores in the electrodes and separator. At least one of the current collectors comprises a conductive metal substrate coated with a metal nitride, carbide or boride coating.

Jerabek, Elihu Calfin (Glenmont, NY); Mikkor, Mati (Ann Arbor, MI)

2001-10-16T23:59:59.000Z

482

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

483

A Circuit Level Fault Model for Resistive Bridges ZHUO LI, XIANG LU, WANGQI QIU, WEIPING SHI and D. M. H. WALKER  

E-Print Network [OSTI]

A Circuit Level Fault Model for Resistive Bridges ZHUO LI, XIANG LU, WANGQI QIU, WEIPING SHI and D. M. H. WALKER Texas A&M University Delay faults are an increasingly important test challenge. Modeling bridge faults as delay faults helps delay tests to detect more bridge faults. Traditional bridge

Walker, Duncan M. "Hank"

484

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

485

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"

486

A High-Resolution Aeromagnetic Survey to Identify Buried Faults at Dixie Valley, Nevada  

SciTech Connect (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

487

Interpretive geophysical fault map across the central block of Yucca Mountain, Nevada  

SciTech Connect (OSTI)

Geophysical data collected along 29 traverses across the central block of Yucca Mountain in southwest Nevada reveal anomalies associated with known fault sand indicate a number of possible concealed faults beneath the eastern flank of Yucca Mountain. Geophysical interpretations indicate that Midway Valley is characterized by several known and previously unknown faults, that the existence of the Yucca Wash fault is equivocal, and that the central part of the eastern flank of Yucca Mountain is characterized by numerous low-amplitude anomalies that probably reflect numerous small-scale faults. Gravity and magnetic data also reveal several large-amplitude anomalies that reflect larger-scale faulting along the margins of the central block.

Ponce, D.A.

1996-12-31T23:59:59.000Z

488

An integrated technique for fault location and section identification in distribution systems  

Science Journals Connector (OSTI)

Abstract This paper proposes an integrated impedance and transient-based formulation for fault location in distribution systems. The technique uses an extended apparent impedance analysis in order to estimate the fault distance, taking into account the unbalanced operation, intermediate loads, laterals, and time-varying load profile of distribution systems. The fault distance information is used in calculating characteristic frequencies associated to each possible fault location. A transient analysis is proposed to evaluate the spectral content of the fault-generated traveling wave, thus identifying its most significant frequency components. Based on the time–frequency correlation it is possible to eliminate the multiple estimates obtained from the impedance-based method, thus resulting in a single fault location. Aiming to verify the application of the proposed methodology, simulations were carried out in the ATP/EMTP Software considering a real distribution feeder with 3472 buses.

D.S. Gazzana; G.D. Ferreira; A.S. Bretas; A.L. Bettiol; A. Carniato; L.F.N. Passos; A.H. Ferreira; J.E.M. Silva

2014-01-01T23:59:59.000Z

489

Effect of HVDC line faults on transient torsional torques of turbine-generator shafts  

SciTech Connect (OSTI)

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

490

A brightness exceeding simulated Langmuir limit  

SciTech Connect (OSTI)

When an excitation of the first lens determines a beam is parallel beam, a brightness that is 100 times higher than Langmuir limit is measured experimentally, where Langmuir limits are estimated using a simulated axial cathode current density which is simulated based on a measured emission current. The measured brightness is comparable to Langmuir limit, when the lens excitation is such that an image position is slightly shorter than a lens position. Previously measured values of brightness for cathode apical radii of curvature 20, 60, 120, 240, and 480 ?m were 8.7, 5.3, 3.3, 2.4, and 3.9 times higher than their corresponding Langmuir limits, respectively, in this experiment, the lens excitation was such that the lens and the image positions were 180 mm and 400 mm, respectively. From these measured brightness for three different lens excitation conditions, it is concluded that the brightness depends on the first lens excitation. For the electron gun operated in a space charge limited condition, some of the electrons emitted from the cathode are returned to the cathode without having crossed a virtual cathode. Therefore, method that assumes a Langmuir limit defining method using a Maxwellian distribution of electron velocities may need to be revised. For the condition in which the values of the exceeding the Langmuir limit are measured, the simulated trajectories of electrons that are emitted from the cathode do not cross the optical axis at the crossover, thus the law of sines may not be valid for high brightness electron beam systems.

Nakasuji, Mamoru [2-15-11, Serigaya-chou, Kounan-ku, Yokohama-shi, Kanagawa-ken (Japan)] [2-15-11, Serigaya-chou, Kounan-ku, Yokohama-shi, Kanagawa-ken (Japan)

2013-08-15T23:59:59.000Z

491

Distributed Bayesian Algorithms for Fault-Tolerant Event Region Detection in Wireless Sensor Networks  

E-Print Network [OSTI]

We propose a distributed solution for a canonical task in wireless sensor networks---the binary detection of interesting environmental events. We explicitly take into account the possibility of sensor measurement faults and develop a distributed Bayesian algorithm for detecting and correcting such faults. Theoretical analysis and simulation results show that 85-95 percent of faults can be corrected using this algorithm, even when as many as 10 percent of the nodes are faulty.

Bhaskar Krishnamachari; Sitharama Iyengar

2004-01-01T23:59:59.000Z

492

Slip rate variations on normal faults during glacial–interglacial changes in surface loads  

Science Journals Connector (OSTI)

... Here we use finite-element models to investigate why four parallel normal faults—the Wasatch, West Valley, Oquirrh and Stansbury faults in the eastern Basin and Range Province, Utah—have experienced ... We now test whether the Late Pleistocene/Holocene increase in slip rates of the Wasatch, West Valley, Oquirrh and Stansbury normal faults may be due to isostatic rebound caused by the ...

Ralf Hetzel; Andrea Hampel

2005-05-05T23:59:59.000Z

493

Structural character of the northern segment of the Paintbrush Canyon fault, Yucca Mountain, Nevada  

SciTech Connect (OSTI)

Detailed mapping of exposed features along the northern part of the Paintbrush Canyon fault was initiated to aid in construction of the computer-assisted three-dimensional lithostratigraphic model of Yucca Mountain, to contribute to kinematic reconstruction of the tectonic history of the Paintbrush Canyon fault, and to assist in the interpretation of geophysical data from Midway Valley. Yucca Mountain is segmented into relatively intact blocks of east-dipping Miocene volcanic strata, bounded by north-striking, west-dipping high-angle normal faults. The Paintbrush Canyon fault, representing the easternmost block-bounding normal fault, separates Fran Ridge from Midway Valley and continues northward across Yucca Wash to at least the southern margin of the Timber Mountain Caldera complex. South of Yucca Wash, the Paintbrush Canyon Fault is largely concealed beneath thick Quaternary deposits. Bedrock exposures to the north reveal a complex fault, zone, displaying local north- and west-trending grabens, and rhombic pull-apart features. The fault scarp, discontinuously exposed along a mapped length of 8 km north of Yucca Wash, dips westward by 41{degrees} to 74{degrees}. Maximum vertical offset of the Rhyolite of Comb Peak along the fault measures about 210 m in Paintbrush Canyon and, on the basis of drill hole information, vertical offset of the Topopoah Spring Tuff is about 360 m near the northern part of Fran Ridge. Observed displacement along the fault in Paintbrush Canyon is down to the west with a component of left-lateral oblique slip. Unlike previously proposed tectonic models, strata adjacent to the fault dip to the east. Quaternary deposits do not appear displaced along the fault scarp north of Yucca Wash, but are displaced in trenches south of Yucca Wash.

Dickerson, R.P. [Science Applications International Corp., Golden, CO (United States); Spengler, R.W. [Geological Survey, Denver, CO (United States)

1994-12-31T23:59:59.000Z

494

Credits Current Catalog Description  

E-Print Network [OSTI]

Introduction to Probability and Statistics with applications in Computer Science. Counting, permutations and combinations. Probability, conditional probability, Bayes theorem. Standard probability distributions. Measures of central tendency and dispersion. Central Limit Theorem. Regression and correlation. Hypothesis testing. Random number generation. Random

unknown authors

495

Direct-Current Resistivity At Dixie Valley Geothermal Field Area (Laney,  

Open Energy Info (EERE)

2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity 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

496

Direct-Current Resistivity Survey At Stillwater Area (Laney, 2005) | Open  

Open Energy Info (EERE)

Stillwater Area (Laney, 2005) Stillwater Area (Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Direct-Current Resistivity Survey At Stillwater Area (Laney, 2005) Exploration Activity Details Location Stillwater 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

497

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.

498

E-Print Network 3.0 - automatical adaptive fault Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Abstract. In robotics, exogenous fault detection is the process ... Source: Birattari, Mauro - Computer and Decision Engineering Department, Universit Libre de Bruxelles; Libre...