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1

Transient Peak Currents in Permanent Magnet Synchronous Motors  

E-Print Network (OSTI)

Transient Peak Currents in Permanent Magnet Synchronous Motors for Symmetrical Short Circuits Terms-- Permanent magnet synchronous motor, short circuit, protection measure, transient behavior I 33095 Paderborn, Germany Abstract--To enable constant-power areas with permanent magnet synchronous

Noé, Reinhold

2

Permanent-magnet-less synchronous reluctance system  

DOE Patents (OSTI)

A permanent magnet-less synchronous system includes a stator that generates a magnetic revolving field when sourced by an alternating current. An uncluttered rotor is disposed within the magnetic revolving field and spaced apart from the stator to form an air gap relative to an axis of rotation. The rotor includes a plurality of rotor pole stacks having an inner periphery biased by single polarity of a north-pole field and a south-pole field, respectively. The outer periphery of each of the rotor pole stacks are biased by an alternating polarity.

Hsu, John S

2012-09-11T23:59:59.000Z

3

SUPER HIGH-SPEED MINIATURIZED PERMANENT MAGNET SYNCHRONOUS MOTOR  

E-Print Network (OSTI)

SUPER HIGH-SPEED MINIATURIZED PERMANENT MAGNET SYNCHRONOUS MOTOR by LIPING ZHENG B.S. Shanghai with the design of permanent magnet synchronous motors (PMSM) to operate at super-high speed with high efficiency the motor to have an efficiency reaching above 92%. This achieved efficiency indicated a significant

Wu, Shin-Tson

4

Analytical Method of Torque Calculation for Interior Permanent Magnet Synchronous Machines  

E-Print Network (OSTI)

method for performing the output torque calculations of an interior permanent magnet synchronous motor circuit, inductance, permanent magnet machine, synchronous motors, torque. I. NOMENCLATURE BFE brushless field excitation IPMSM interior permanent magnet synchronous motor FEA finite element analysis mmf

Tolbert, Leon M.

5

Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor  

DOE Patents (OSTI)

A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.

Coffey, Howard T. (Darien, IL)

1993-01-01T23:59:59.000Z

6

Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor  

DOE Patents (OSTI)

A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle levitation. 3 figures.

Coffey, H.T.

1993-10-19T23:59:59.000Z

7

Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor  

DOE Patents (OSTI)

A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.

Coffey, H.T.

1992-12-31T23:59:59.000Z

8

An Improved Sensorless Control System of Permanent Magnet Synchronous Motor  

Science Conference Proceedings (OSTI)

To improve the performance of permanent magnet synchronous motor sensor less control system, the phase offset caused by the low pass filter must be considering. In this paper, to apply the linear control theory to PMSM system. The introduced control ... Keywords: PMSM, Reduced-order Observer, Group Time Delay, Adaptive, Sensorless

Long Tang, Hong-Lin Ou Yang, Chao Meng, Xin-Yuan Li, Xu-Jie Mo

2013-01-01T23:59:59.000Z

9

Adaptive friction compensation for permanent magnet linear synchronous motor  

Science Conference Proceedings (OSTI)

The paper discussed an adaptive friction compensation scheme based on Coulomb friction and a parameter identifier. The model reference adaptive system based on Coulomb friction was designed to compensate the friction on-line. The designed model reference ... Keywords: friction compensation, model reference adaptive control, parameter identification, permanent magnet linear synchronous motor (PMLSM)

Wang Li-Mei; Wu Lin

2009-06-01T23:59:59.000Z

10

Nominal Position Controller for Permanent Magnet Synchronous Motor System  

Science Conference Proceedings (OSTI)

A nonlinear position controller for permanent magnet synchronous motor (PMSM) was designed to achieve position tracing control and robust control. The controller included two parts: the model controller and the robust controller. The former was designed ... Keywords: PMSM, nominal control, sliding mode control

Yuzeng Zhang; Fan Wang; Mingyin Yan

2010-05-01T23:59:59.000Z

11

Nuclear Magnetic Resonance Implementation of a Quantum Clock Synchronization Algorithm  

E-Print Network (OSTI)

The quantum clock synchronization algorithm proposed by I. L. Chuang (Phys. Rev. Lett, 85, 2006(2000)) has been implemented in a three qubit nuclear magnetic resonance quantum system. The effective-pure state is prepared by the spatial averaging approach. The time difference between two separated clocks can be determined by reading out directly through the NMR spectra.

Jingfu Zhang; Guilu Long; Zhiwei Deng; Wenzhang Liu; Zhiheng Lu

2004-06-27T23:59:59.000Z

12

Direct Torque Control for Interior Permanent Magnet Synchronous Motors with Respect to Optimal Efficiency  

E-Print Network (OSTI)

Direct Torque Control for Interior Permanent Magnet Synchronous Motors with Respect to Optimal@lea.upb.de, boecker@lea.upb.de URL: http://wwwlea.upb.de Keywords «Interior permanent magnet synchronous motor to their high torque and power per volume ratio, interior permanent magnet synchronous motors (IPMSM

Noé, Reinhold

13

Model Predictive Control of a Permanent Magnet Synchronous Motor with Experimental Validation  

E-Print Network (OSTI)

Model Predictive Control of a Permanent Magnet Synchronous Motor with Experimental Validation Shan to regulate the speed of a permanent magnet synchronous motor where the design is based on a linearized state rejection, constraints, quadratic programming. 1. Introduction Permanent Magnet Synchronous Motors (PMSMs

14

A Precise Open-Loop Torque Control for an Interior Permanent Magnet Synchronous Motor  

E-Print Network (OSTI)

A Precise Open-Loop Torque Control for an Interior Permanent Magnet Synchronous Motor (IPMSM@lea.upb.de Abstract-Interior permanent magnet synchronous motors (IPMSM) are preferentially chosen as traction drives. INTRODUCTION Interior permanent magnet synchronous motors (IPMSM) provide high power and torque densities

Noé, Reinhold

15

Sensorless Speed Control of Permanent Magnet-Assisted Synchronous Reluctance Motor (PMa-SynRM)  

E-Print Network (OSTI)

An interesting alternative for today's high efficiency variable speed drives is the Permanent Magnet-Assisted Synchronous Reluctance Motor drive, which belongs to the family of brushless synchronous AC motor drives. Generally, the reluctance torque of this motor is significant compared to the Permanent Magnet electrical torque. The advantage of increased reluctance torque is the decreased need of expensive permanent magnet (PM) material, which makes this solution thus cheaper than the respective permanent magnet motor. Also due to its synchronous operation, sensorless rotational control is possible along with higher power factor and better efficiency compared to the induction motor (IM). Therefore, this thesis first deals with the implementation of a vector control strategy for speed control of the PMa-synRM motor that can be applied to a washing machine application. The machine is supplied by a current controlled voltage source PWM inverter to control the instantaneous stator currents which are decided by the reference speed. Secondly, the thesis focuses on the sensorless speed operation of the PMa-SynRM to take advantage of the lower costs as well as increased system reliability which otherwise is not possible using the delicate speed or position sensors. The concept involves estimation of the rotor speed and/or position. There are several speed estimation techniques proposed by researchers and among them the observer based technique is proven and commonly used in the industry. The only requirements of the observer system are a very fast signal processor, specialized and optimized to perform complex mathematical calculations. The feasibility and effectiveness of the control techniques are verified using the experimental results, implemented using the Texas Instruments TMS320F2812 eZDSP controller board and the overall motor drive system in the laboratory.

Chakali, Anil K.

2009-12-01T23:59:59.000Z

16

Design of a High Performance Ferrite Magnet-Assisted Synchronous Reluctance Motor for an  

E-Print Network (OSTI)

Design of a High Performance Ferrite Magnet- Assisted Synchronous Reluctance Motor for an Electric) ferrite-based permanent magnet-assisted synchronous reluctance motor has been designed for an electric the ferrite magnets are safe from irreversible demagnetization. Key performance indicators for the motor

Noé, Reinhold

17

Optimum Control for Interior Permanent Magnet Synchronous Motors (IPMSM) in Constant  

E-Print Network (OSTI)

Optimum Control for Interior Permanent Magnet Synchronous Motors (IPMSM) in Constant Torque and Electrical Drives, Paderborn, Germany Abstract--Interior Permanent Magnet Synchronous Motors (IPMSM) gain weakening range. Operation during flux weakening, however, causes stress to the magnets of the motor

Noé, Reinhold

18

Initial rotor position estimation for low saliency interior permanent-magnet synchronous motor drives.  

E-Print Network (OSTI)

??This work presents an initial rotor position estimation method for low saliency interior permanent-magnet synchronous motor (IPMSM) drives. The method injects signals into the stationary (more)

Yang, Yan.

2010-01-01T23:59:59.000Z

19

Study on Performance Characteristics of Interior Permanent Magnet Synchronous Motor Due to Rotor Configuration.  

E-Print Network (OSTI)

??This research study was conducted in an effort to understand what effects the rotor configuration has on the performance of a permanent magnet synchronous machine, (more)

Kettlewell, James

2013-01-01T23:59:59.000Z

20

Analysis of Slanted Air-gap Structure of Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation  

E-Print Network (OSTI)

Analysis of Slanted Air-gap Structure of Interior Permanent Magnet Synchronous Motor with Brushless permanent magnet synchronous motor (IPMSM) for application in a hybrid electric vehicle. This unique slanted permanent magnet synchronous motor FEA finite element analysis PM permanent magnet II. INTRODUCTION

Tolbert, Leon M.

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Design of optimal digital controller for stable super-high-speed permanent-magnet synchronous  

E-Print Network (OSTI)

Design of optimal digital controller for stable super-high-speed permanent-magnet synchronous motor collaborative design scheme of a super-high-speed permanent-magnet synchronous motor (PMSM) and its digital controller is presented, which provides a low-cost but highly efficient motor system with guaranteed

Wu, Shin-Tson

22

SVPWM-Based Simulation of Direct Torque Control in Permanent Magnet Synchronous Motor  

Science Conference Proceedings (OSTI)

On the basis of analysis of the mathematical model of permanent magnet synchronous motor (PMSM), this paper is to propose a new type direct torque control system based on space vector pulse width modulation (SVPWM) technology aiming at big torque ripple, ... Keywords: permanent magnet synchronous motor, direct torque control, space vector pulse width modulation, MATLAB/Simulink

Huang Xianghui, Sun Nan

2013-10-01T23:59:59.000Z

23

Optimal control in energy conversion of small wind power systems with permanent-magnet-synchronous-generators  

Science Conference Proceedings (OSTI)

This paper presents the results of experimental investigation of a low-power wind energy conversion system (WECS), based on a permanent-magnet synchronous generator (PMSG) connected directly to the turbine. A development system was built in order to ... Keywords: hardware-in-the-loop simulation, maximum power point tracking, optimal control, permanent-magnet synchronous generator, wind system

C. Vlad; I. Munteanu; A. I. Bratcu; E. Ceanga

2008-07-01T23:59:59.000Z

24

Permanent magnet assisted synchronous reluctance motor, design and performance improvement  

E-Print Network (OSTI)

Recently, permanent magnet assisted (PMa)-synchronous reluctance motors (SynRM) have been considered as a possible alternative motor drive for high performance applications. In order to have an efficient motor drive, performing of three steps in design of the overall drive is not avoidable. These steps are design optimization of the motor, identification of the motor parameter and implementation of an advanced control system to ensure optimum operation. Therefore, this dissertation first deals with the design optimization of the Permanent Magnet Assisted Synchronous Reluctance Motor (PMa-SynRM). Various key points in the rotor design of a low cost PMa-SynRM are introduced and their effects are studied. Finite element approach has been utilized to show the effects of these parameters on the developed average electromagnetic torque and the total d-q inductances. As it can be inferred from the name of the motor, there are some permanent magnets mounted in the rotor core. One of the features considered in the design of this motor is the magnetization of the permanent magnets mounted in the rotor core using the stator windings to reduce the manufacturing cost. At the next step, identification of the motor parameters is discussed. Variation of motor parameters due to temperature and airgap flux has been reported in the literatures. Use of off-line models for estimating the motor parameters is known as a computationally intensive method, especially when the models include the effect of cross saturation. Therefore in practical applications, on-line parameter estimation is favored to achieve a high performance control system. In this dissertation, a simple practical method for parameter estimation of the PMa-SynRM is introduced. Last part of the dissertation presents one advanced control strategy which utilized the introduced parameter estimator. A practical Maximum Torque Per Ampere (MTPA) control scheme along with a simple parameter estimator for PMa-SynRM is introduced. This method is capable of maintaining the MTPA condition and stays robust against the variations of motor parameters. Effectiveness of the motor design procedure and the control strategy is validated by presenting simulation and experimental results of a 1.5 kW prototype PMa-SynRM, designed and manufactured through the introduced design method.

Niazi, Peyman

2005-12-01T23:59:59.000Z

25

Control system for an interior permanent magnet synchronous machine  

DOE Patents (OSTI)

A high performance, fully operational, four-quadrant control scheme is used in an interior permanent magnet synchronous machine. The machine operates smoothly with full performance in the constant-torque region as well as in the flux-weakening, constant-power region in both directions of motion. The transition between the constant-torque and constant-power regions is very smooth under all conditions of operation. Control in the constant-torque region is based on a vector or field-oriented technique, with the direct-axis aligned with the total stator flux, whereas constant-power region control is accomplished by orientation of the torque angle of the impressed square-wave voltage through the feedforward vector rotator. In a preferred embodiment, the control system employs a digital distributed microcomputer controller arrangement which relies upon various precisely estimated feedback signals, such as torque, flux, etc. The control scheme includes an outer torque control loop primarily for traction type applications, but also contemplates speed and position control loops for various industrial drives. A 70 hp drive system using a Neodymium-Iron-Boron permanent magnet machine and transistor pulse width modulating inverter has been designed and successfully tested. This control scheme also has application in controlling surface permanent magnet machines. 16 figs.

Bose, B.K.

1988-10-12T23:59:59.000Z

26

Performance improvement of permanent magnet ac motors  

E-Print Network (OSTI)

Multi-phase motors have several advantages over the traditional three-phase motors. In this study, the additional degrees of freedom available in five-phase permanent magnet motors have been used for three purposes: 1) enhancing the torque producing capability of the motor, 2) improving the reliability of the system, and 3) better adjusting of the torque and flux linkages of the five-phase direct torque controlled system. 1) Due to the fact that space and time harmonics of the same orders will contribute positively to output torque, a five-phase permanent magnet motor with quasi-rectangular back-EMF waveform is supplied with combined fundamental and third harmonic of currents. For modeling and analysis of the motor a 0 3 3 1 1 q d q d frame of reference is defined where 1 1q d rotates at the synchronous speed and 3 3q d rotates at the three times synchronous speed. Based on the mathematical model in the 0 3 3 1 1 q d q d frame of reference, it is shown that this system while having a higher torque density with respect to a conventional permanent magnet synchronous machine, is also compatible with vector control algorithm. 2) A resilient current control of the five-phase permanent motor with both sinusoidal and trapezoidal back-EMF waveforms under asymmetrical fault condition is proposed. In this scheme, the stator MMF is kept unchanged during healthy and faulty condition. Therefore, the five-phase permanent magnet motor operates continuously and steadily without additional hardware and just by modifying the control algorithm in case of loss of up to two phases. The feature is of major importance in some specific applications where high reliability is required. 3) High torque and flux ripple are the major drawbacks of a three-phase direct torque controlled system. The number of space voltage vectors directly influences the performance of DTC system. A five-phase drive, while benefiting from other advantages of high order phase drives, has inherently 32 space voltage vectors which permits better flexibility in selecting the switching states and finer adjustment of flux and torque. A sensorless direct torque control of five-phase permanent magnet motor is implemented. Speed information is obtained based on the position of stator flux linkages and load angle. Experiments have been conducted on a 5kW five-phase surface mount permanent magnet motor and a 3kW five-phase interior permanent magnet motor by using TMS320C32 DSP. The results obtained are consistent with theoretical studies and simulation analysis, which further demonstrate the feasibility and practical significance of the five-phase permanent magnet motor drives.

Parsa, Leila

2005-05-01T23:59:59.000Z

27

Study of Various Slanted Air-gap Structures of Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation  

E-Print Network (OSTI)

Study of Various Slanted Air-gap Structures of Interior Permanent Magnet Synchronous Motor of the slanted air-gap structure of an interior permanent magnet synchronous motor with brushless field magnet machine, synchronous motors, torque. I. NOMENCLATURE BFE brushless field excitation IPMSM interior

Tolbert, Leon M.

28

Power-Factor and Torque Calculation with Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with  

E-Print Network (OSTI)

Permanent Magnet Synchronous Motor with Brushless Field Excitation Seong Taek Lee1,2 , Timothy A. Burress1 permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include motor of a hybrid electric vehicle. I. INTRODUCTION The interior permanent magnet synchronous motor

Tolbert, Leon M.

29

A robust forced dynamic sliding mode minimum energy position controller for permanent magnet synchronous motor drives  

Science Conference Proceedings (OSTI)

As a contribution towards improving the environment, a new position controller for vector controlled electric drives employing permanent magnet synchronous motors (PMSM) is presented that achieves approximately 27% less frictional energy loss than a ... Keywords: forced dynamic control, minimum energy manoeuvres, sliding mode control, synchronous motor drives

Stephen J. Dodds; Gunaratnam. Sooriyakumar; Roy Perryman

2008-04-01T23:59:59.000Z

30

A design for improved performance of interior permanent magnet synchronous motor for hybrid electric vehicle  

Science Conference Proceedings (OSTI)

This paper investigates the layout of a magnet shape on the performance of an interior permanent magnet (IPM) synchronous motor. The motor is used in a hybrid electric vehicle. The IPM motor is a pancake shaped motor that has permanent magnets inside the rotor. The motor acts as a rotational electrodynamic machine between the engine and transmission. The main purpose of redesigning the shape of the magnet is to improve the motor performance

Seong Yeop Lim

2006-01-01T23:59:59.000Z

31

Low-power clock synchronization using electromagnetic energy radiating from AC power lines  

Science Conference Proceedings (OSTI)

Clock synchronization is highly desirable in many sensor networking applications. It enables event ordering, coordinated actuation, energy-efficient communication and duty cycling. This paper presents a novel low-power hardware module for achieving global ... Keywords: hardware clock synchronization, sensor networks, synchronization, wireless sensor networks

Anthony Rowe; Vikram Gupta; Ragunathan (Raj) Rajkumar

2009-11-01T23:59:59.000Z

32

Synchronization of an array of spin torque nano oscillators in periodic applied external magnetic field  

E-Print Network (OSTI)

Considering an array of spin torque transfer nano oscillators (STNOs), we have investigated the synchronization property of the system under the action of a common periodically driven applied external magnetic field by numerically analyzing the underlying system of Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equations for the macro-spin variables. We find the novel result that the applied external magnetic field can act as a medium to induce synchronization of periodic oscillations, both in-phase and anti-phase, even without coupling through spin current, thereby leading to the exciting possibility of enhancement of microwave power in a straightforward way.

B. Subash; V. K. Chandrasekar; M. Lakshmanan

2013-04-03T23:59:59.000Z

33

Study on Control of Bearingless Permanent Magnet-Type Motor Synchronous Based on Fuzzy Adaptive Sliding Mode  

Science Conference Proceedings (OSTI)

The bearingless permanent magnet-types synchronous motor is nonlinear and coupling complex system. On the basis of the full formula which express the coupling between suspension and rotor torque, parameters of the motor are discussed to the operation ... Keywords: bearingless permanent magnet-type synchronous motor, fuzzy adaptivity, sliding mode, chattering

Pengfei Li; Xinping Yan; Bo Yang; Huabin Wang

2010-05-01T23:59:59.000Z

34

Abstract--This paper presents an analysis by which the dynamic performances of a permanent magnet synchronous  

E-Print Network (OSTI)

; Permanent magnet synchronous motor; Speed control; Fuzzy; Sliding Mode. I. INTRODUCTION As a resultAbstract-- This paper presents an analysis by which the dynamic performances of a permanent magnet synchronous motor (PMSM) motor is controlled through a hysteresis current loop and an outer speed loop

Paris-Sud XI, Université de

35

A peak power tracker for low-power permanent-magnet-synchronous-generator-based wind energy conversion systems  

Science Conference Proceedings (OSTI)

This paper presents the results of experimental investigation of a low-power wind energy conversion system (WECS), based on a permanent-magnet synchronous generator (PMSG) connected directly to the turbine. A test rig was built in order to carry out ... Keywords: hardware-in-the-loop simulation, maximum power point tracking, optimal control, permanent-magnet synchronous generator, wind system

C. Vlad; I. Munteanu; A. I. Bratcu; E. Ceanga

2008-07-01T23:59:59.000Z

36

A Quick Efficiency-Optimized Scheme for Vector Controlled Permanent Magnet Synchronous Motor Drive  

Science Conference Proceedings (OSTI)

In view of the operation characters of permanent magnet synchronous motor (PMSM) for hybrid electric vehicle (HEV) application, efficiency optimization control strategy is needed to meet the demand of rapidity. A quick efficiency optimized vector control ... Keywords: PMSM, efficiency optimization, HEV, gradient search technique, golden section technique

Xianqing Cao; Liping Fan

2009-07-01T23:59:59.000Z

37

Controlled operation of variable speed driven permanent magnet synchronous generator for wind energy conversion systems  

Science Conference Proceedings (OSTI)

The introduction of distributed generation through renewable sources of energy has opened a challenging area for power engineers. As these sources are intermittent in nature, variable speed electric generators are employed for harnessing electrical energy ... Keywords: permanent magnet synchronous generator, power conditioners, power quality, variable speed generators, wind energy

Rajveer Mittal; K. S. Sandhu; D. K. Jain

2009-02-01T23:59:59.000Z

38

Intelligent control for permanent magnet synchronous motor with improved particle swarm optimization  

Science Conference Proceedings (OSTI)

This paper presents a new intelligent controller for a permanent-magnet synchronous machine in a HEV (hybrid-electric vehicle) application. IPSO (Improved Particle Swarm Optimization) will be used to optimize three proportional parameters ka, ... Keywords: FLC, HEV, IPSO, PMSM, optimization, robustness

Song Zhengqiang; Hou Zhijian; Jiang Chuanwen

2005-09-01T23:59:59.000Z

39

Design of Vertical Transportation System Driven by Permanent Magnet Linear Synchronous Motor Signal Acquisition  

Science Conference Proceedings (OSTI)

Permanent Magnet Linear Synchronous Motor(PMLSM) Vertical Transportation system is a new kind of ropeless hoisting system. In addition to the complications of dynamic state characteristic, the examination of some signals is also very difficult. In this ... Keywords: PMLSM, Signal Acquisition, Hardware Designs, Software

Wang Chang Li; Zhang You Dong; Zhao Liang

2012-08-01T23:59:59.000Z

40

This work presents an improved variant of the Direct Torque Control (DTC) for a Permanent Magnet Synchronous Motor (PMSM). The improved DTC use a higher  

E-Print Network (OSTI)

Magnet Synchronous Motor (PMSM). The improved DTC use a higher number of voltage space vectors;Contents I Introduction 5 Chapter 1 Permanent Magnet Synchronous Motor 6 1.1 Derivation of motor equations Voltage Source Inverter PMSM Permanent Magnet Synchronous Motor 4 #12;I. Introduction Direct Torque

Johansson, Karl Henrik

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Analysis and Design of a High Power Density Axial Flux Permanent Magnet Linear Synchronous Machine Used for Stirling System  

Science Conference Proceedings (OSTI)

a high power density axial flux permanent magnet linear synchronous machine and the stirling system will be introduced. This machine is a tubular axial flux permanent magnet machine. It comprises two parts: stator and mover. With the 2D finite-element ... Keywords: permanent magnet, stirling engine, linear motor

Ping Zheng; Xuhui Gan; Lin Li

2010-09-01T23:59:59.000Z

42

Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films and  

E-Print Network (OSTI)

Time-Resolved Magnetic Flux and AC-Current Distributions in Superconducting YBCO Thin Films magnetic field. We study the interaction behavior of YBCO thin films in an ac transport current and a dc the calibrated field profiles. The current density evolution in YBCO thin films is studied by TRMOI as a function

Lewis, Robert Michael

43

Original article: Bi-criteria optimization design of an interior permanent magnet synchronous machine for a hybrid electric vehicle application  

Science Conference Proceedings (OSTI)

The main focus of this study is to provide a new calculation method of power losses in electrical machine, including copper losses and iron losses at load. This calculation is applied not only for an operating point of the machine but also for thousands ... Keywords: Flux-weakening, Hybrid electric vehicle, Iron loss, Optimization design, Permanent magnet synchronous machine

Phi Hung Nguyen, Emmanuel Hoang, Mohamed Gabsi

2013-04-01T23:59:59.000Z

44

Design of low-power permanent-magnet synchronous motor for use in high-density heat pump  

E-Print Network (OSTI)

An analytical model for the functionality of a permanent-magnet synchronous motor is developed. Taking as input a specific geometry, it predicts steady-state losses of a design at an average rate of 0.85 seconds per analysis, ...

Jenicek, David P. (David Pierre)

2011-01-01T23:59:59.000Z

45

Evaluation of performance and magnetic characteristics of a radial-radial flux compound-structure permanent-magnet synchronous machine used for hybrid electric vehicle  

Science Conference Proceedings (OSTI)

A breed of compound-structure permanent-magnet synchronous machine (CS-PMSM) is used for power-split hybrid electric vehicles(HEVs). It can help to fulfill both the speed and torque control of the internal combustion engine and

Ping Zheng; Ranran Liu; Lin Shen; Lina Li; Weiguang Fan; Qian Wu; Jing Zhao

2008-01-01T23:59:59.000Z

46

Depinning of flux lines and AC losses in magnet-superconductor levitation system  

DOE Green Energy (OSTI)

The AC loss characteristics of a magnet-superconductor system were studied with the magnet fixed to the free end of an oscillating cantilever located near a stationary melt-textured YBCO pellet. Below a threshold AC field amplitude {approx}2Oe, the dissipation of the oscillator is amplitude-independent, characteristic of a linear, non-hysteretic regime. Above threshold,dissipation increases with amplitude, reflecting the depinning and hysteretic motion of flux lines. The threshold AC field is an order of magnitude higher than that measured for the same YBCO material via AC susceptometry in a uniform DC magnetic field, A partial lock-in of flux lines between YBCO ab planes is proposed as the mechanism for the substantial increase of the depinning threshold.

Terentiev, A. N.; Hull, J. R.; De Long, L. E.

1999-11-29T23:59:59.000Z

47

Direct torque control of permanent magnet synchronous motors with non-sinusoidal back-EMF  

E-Print Network (OSTI)

This work presents the direct torque control (DTC) techniques, implemented in four- and six-switch inverter, for brushless dc (BLDC) motors with non-sinusoidal back- EMF using two and three-phase conduction modes. First of all, the classical direct torque control of permanent magnet synchronous motor (PMSM) with sinusoidal back-EMF is discussed in detail. Secondly, the proposed two-phase conduction mode for DTC of BLDC motors is introduced in the constant torque region. In this control scheme, only two phases conduct at any instant of time using a six-switch inverter. By properly selecting the inverter voltage space vectors of the two-phase conduction mode from a simple look-up table the desired quasi-square wave current is obtained. Therefore, it is possible to achieve DTC of a BLDC motor drive with faster torque response while the stator flux linkage amplitude is deliberately kept almost constant by ignoring the flux control in the constant torque region. Third, the avarege current controlled boost power factor correction (PFC) method is applied to the previously discussed proposed DTC of BLDC motor drive in the constant torque region. The test results verify that the proposed PFC for DTC of BLDC motor drive improves the power factor from 0.77 to about 0.9997 irrespective of the load. Fourth, the DTC technique for BLDC motor using four-switch inverter in the constant torque region is studied. For effective torque control in two phase conduction mode, a novel switching pattern incorporating the voltage vector look-up table is designed and implemented for four-switch inverter to produce the desired torque characteristics. As a result, it is possible to achieve two-phase conduction DTC of a BLDC motor drive using four-switch inverter with faster torque response due to the fact that the voltage space vectors are directly controlled.. Finally, the position sensorless direct torque and indirect flux control (DTIFC) of BLDC motor with non-sinusoidal back-EMF has been extensively investigated using three-phase conduction scheme with six-switch inverter. In this work, a novel and simple approach to achieve a low-frequency torque ripple-free direct torque control with maximum efficiency based on dq reference frame similar to permanent magnet synchronous motor (PMSM) drives is presented.

Ozturk, Salih Baris

2008-05-01T23:59:59.000Z

48

Noise reduction control strategy of a permanent magnet synchronous machine for vehicle applications  

E-Print Network (OSTI)

The purpose of this work was to investigate a permanent magnet synchronous machine which will be produced by an industry partner of the Institut fr Stromrichtertechnik und Elektrische Antriebe (ISEA) an institute of the Rheinisch Westflisch Technische Hochschule - Aachen, Germany (RWTH). The machine manufacturer noted certain abnormalities with the frequency spectrum produced by an electric machine that they were developing; this problem was brought to ISEA in order to be investigated. My work continues the work of my supervisor, Dipl.- Ing Matthias Bsing, and seeks to further examine the machine for a much wider range of operating points, determine the relationship between current amplitude, harmonics, control angle and rotor position on radial force components of the machine and therefore stresses on the stator; which are the primary causes of electrical machine noise. Rather than investigate acoustic issues in particular, the study was limited to the study of electromagnetically generated radial force ripple, which is the cause of stator deflection modes and therefore the emission of sound waves. The primary results of this thesis researched the operation of a permanent magnet synchronous machine and described its behavior with regards to force, torque, and force and torque ripple and their spectrums versus numerous parameters, including control angle, secant current and rotor position. Next, the work used provided data, literature and the simulation results for this thesis in order to deconstruct the operation regions of the particular machine and therefore link the causes of particular noise spectral components to the operation of the machine. From this it was possible to identify potential ways to eliminate these areas of noise. Following this, the thesis examined a particular abnormality in the torque and force waveforms produced by the machine and devised actions which could correct this abnormality. After identifying this asymmetry, the work explored how to choose an optimal control strategy for eliminating particular harmonics based on the simulated operating points and a desired command torque. Finally, the research built on the previous work by supplementing the method of current harmonic injection for eliminating radial force harmonics in this machine, with a method of determining an optimal operating point before the injection currents are calculated.

Doolittle, Randy Gene

2008-05-01T23:59:59.000Z

49

A Novel Current Angle Control Scheme in a Current Source Inverter Fed Permanent Magnet Synchronous Motor Drive for Automotive Applications  

DOE Green Energy (OSTI)

This paper describes a novel speed control scheme to operate a current source inverter (CSI) driven surface-mounted permanent magnet synchronous machine (SPMSM) for hybrid electric vehicles (HEVs) applications. The idea is to use the angle of the current vector to regulate the rotor speed while keeping the two dc-dc converter power switches on all the time to boost system efficiency. The effectiveness of the proposed scheme was verified with a 3 kW CSI-SPMSM drive prototype.

Tang, Lixin [ORNL; Su, Gui-Jia [ORNL

2011-01-01T23:59:59.000Z

50

DSP-Based Sensor-less Permanent Magnet Synchronous Motor Driver With Quasi-Sine PWM for Air-Conditioner Rotary Compressor.  

E-Print Network (OSTI)

??This thesis presented a sensor-less permanent magnet synchronous motor (PMSM) driver for controlling air-conditioner rotary compressor speed. In this thesis, a quasi-sine pulse-width modulation (PWM) (more)

Liu, Li-hsiang

2012-01-01T23:59:59.000Z

51

Magnetometry of random AC magnetic fields using a single Nitrogen-Vacancy center  

E-Print Network (OSTI)

We report on the use of a single NV center to probe fluctuating AC magnetic fields. Using engineered currents to induce random changes in the field amplitude and phase, we show that stochastic fluctuations reduce the NV center sensitivity and, in general, make the NV response field-dependent. We also introduce two modalities to determine the field spectral composition, unknown a priori in a practical application. One strategy capitalizes on the generation of AC-field-induced coherence 'revivals', while the other approach uses the time-tagged fluorescence intensity record from successive NV observations to reconstruct the AC field spectral density. These studies are relevant for magnetic sensing in scenarios where the field of interest has a non-trivial, stochastic behavior, such as sensing unpolarized nuclear spin ensembles at low static magnetic fields.

Abdelghani Laraoui; Jonathan S. Hodges; Carlos A. Meriles

2010-09-02T23:59:59.000Z

52

Magnetometry of random AC magnetic fields using a single Nitrogen-Vacancy center  

E-Print Network (OSTI)

We report on the use of a single NV center to probe fluctuating AC magnetic fields. Using engineered currents to induce random changes in the field amplitude and phase, we show that stochastic fluctuations reduce the NV center sensitivity and, in general, make the NV response field-dependent. We also introduce two modalities to determine the field spectral composition, unknown a priori in a practical application. One strategy capitalizes on the generation of AC-field-induced coherence 'revivals', while the other approach uses the time-tagged fluorescence intensity record from successive NV observations to reconstruct the AC field spectral density. These studies are relevant for magnetic sensing in scenarios where the field of interest has a non-trivial, stochastic behavior, such as sensing unpolarized nuclear spin ensembles at low static magnetic fields.

Laraoui, Abdelghani; Meriles, Carlos A

2010-01-01T23:59:59.000Z

53

Calorimetric method of ac loss measurement in a rotating magnetic field  

Science Conference Proceedings (OSTI)

A method is described for calorimetric ac-loss measurements of high-T{sub c} superconductors (HTS) at 80 K. It is based on a technique used at 4.2 K for conventional superconducting wires that allows an easy loss measurement in parallel or perpendicular external field orientation. This paper focuses on ac loss measurement setup and calibration in a rotating magnetic field. This experimental setup is to demonstrate measuring loss using a temperature rise method under the influence of a rotating magnetic field. The slight temperature increase of the sample in an ac-field is used as a measure of losses. The aim is to simulate the loss in rotating machines using HTS. This is a unique technique to measure total ac loss in HTS at power frequencies. The sample is mounted on to a cold finger extended from a liquid nitrogen heat exchanger (HEX). The thermal insulation between the HEX and sample is provided by a material of low thermal conductivity, and low eddy current heating sample holder in vacuum vessel. A temperature sensor and noninductive heater have been incorporated in the sample holder allowing a rapid sample change. The main part of the data is obtained in the calorimetric measurement is used for calibration. The focus is on the accuracy and calibrations required to predict the actual ac losses in HTS. This setup has the advantage of being able to measure the total ac loss under the influence of a continuous moving field as experienced by any rotating machines.

Ghoshal, P. K. [Oxford Instruments NanoScience, Abingdon, Oxfordshire OX13 5QX (United Kingdom); Coombs, T. A.; Campbell, A. M. [Department of Engineering, Electrical Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom)

2010-07-15T23:59:59.000Z

54

Thin superconducting disk with field-dependent critical current: Magnetization and ac susceptibilities  

E-Print Network (OSTI)

Thin superconducting disk with field-dependent critical current: Magnetization and ac of a superconducting thin disk are calculated in the critical-state model assuming a field-dependent critical current for the flux and current distributions Phys. Rev. B 60, 13 112 1999 for a disk placed in a perpendicular

Johansen, Tom Henning

55

AC Losses in the MICE Channel Magnets -- Is This a Curse or a Blessing?  

E-Print Network (OSTI)

for the focusing magnet; Q ACF = Q ACC j caF ?B F d fF V F t?B C d fC V C t chF where Q ACF is the average AC loss for

Green, M.A.; Wu, H.; Wang, L.; Kai, L.L.; Jia, L.X.; Yang, S.Q.

2008-01-01T23:59:59.000Z

56

Gemini Synchronous Inverter  

SciTech Connect

The Gemini Synchronous inverter is a solid state device that, when interposed between a variable-voltage DC power source and an AC power grid, converts the DC to AC at standard line voltages and frequencies. If more power is available from the DC source than is required by the load, the excess flows into the power grid. If less power is available than is required by the load the difference is provided by the power grid in the normal fashion.

Meyer, H.

1976-03-01T23:59:59.000Z

57

Power-Factor Calculation under Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation  

SciTech Connect

This paper introduces a new method for calculating the power factor with consideration of the cross saturation between the direct-axis (d-axis) and the quadrature-axis (q-axis) of an interior permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include the cross-saturation effect by adding the cross-coupled inductance terms. This paper also contains the new method of calculating the cross-coupled inductance values as well as self-inductance values in d- and q-axes. The analyzed motor is a high-speed brushless field excitation machine that offers high torque per ampere per core length at low speed and weakened flux at high speed, which was developed for the traction motor of a hybrid electric vehicle.

Lee, Seong T [ORNL; Burress, Timothy A [ORNL; Hsu, John S [ORNL

2009-01-01T23:59:59.000Z

58

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

Science Conference Proceedings (OSTI)

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

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

2013-04-01T23:59:59.000Z

59

Study of Various Slanted Air-Gap Structures of Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation  

SciTech Connect

This paper shows how to maximize the effect of the slanted air-gap structure of an interior permanent magnet synchronous motor with brushless field excitation (BFE) for application in a hybrid electric vehicle. The BFE structure offers high torque density at low speed and weakened flux at high speed. The unique slanted air-gap is intended to increase the output torque of the machine as well as to maximize the ratio of the back-emf of a machine that is controllable by BFE. This irregularly shaped air-gap makes a flux barrier along the d-axis flux path and decreases the d-axis inductance; as a result, the reluctance torque of the machine is much higher than a uniform air-gap machine, and so is the output torque. Also, the machine achieves a higher ratio of the magnitude of controllable back-emf. The determination of the slanted shape was performed by using magnetic equivalent circuit analysis and finite element analysis (FEA).

Tolbert, Leon M [ORNL; Lee, Seong T [ORNL

2010-01-01T23:59:59.000Z

60

We study the interaction of a high frequency AC current with a magnetic field in an YBCO thin film by using time  

E-Print Network (OSTI)

an applied magnetic field, and a time varying transport current that does not induce any flux inside the thinWe study the interaction of a high frequency AC current with a magnetic field in an YBCO thin film of flux distributions. We find that the total current distribution can be described as the superposition

Lewis, Robert Michael

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Optimal design of a high-speed slotless permanent magnet synchronous generator with soft magnetic composite stator yoke and rectifier load  

Science Conference Proceedings (OSTI)

This paper presents a specific design methodology of a DC generation system using a high-speed slotless generator with surface-mounted magnets and soft magnetic composite (SMC) stator yoke connected to a rectifier. The method is based on an analytical ... Keywords: Eddy currents, High-speed generation system, Optimal design, Permanent magnet machine, Soft magnetic composite material

Ahmed Chebak; Philippe Viarouge; Jrme Cros

2010-10-01T23:59:59.000Z

62

Modeling of PM Synchronous Motors for Control and Estimation Tasks  

E-Print Network (OSTI)

magnet synchronous motors in stationary frame. The model is based on linear magnetics and includes that illustrate uses of di erent models are also presented. 1 Introduction Permanent magnet synchronous motors magnet- ics for saturation e ects on motor inductances, see for example 3 ; symmetry of the stator phases

Stankoviæ, Aleksandar

63

Power-Factor and Torque Calculation under Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation  

SciTech Connect

This paper introduces a new method for calculating the power factor and output torque by considering the cross saturation between direct-axis (d-axis) and quadrature-axis (q-axis) of an interior permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include the cross saturation effect by adding the cross-coupled inductance terms. This paper also contains the new method of calculating the cross-coupled inductance values as well as self-inductance values in d- and q-axes. The analyzed motor is a high-speed brushless field excitation machine that offers high torque per ampere per core length at low speed and weakened flux at high speed, which was developed for the traction motor of a hybrid electric vehicle. The conventional two-axis IPMSM model was modified to include the cross-saturation effect by adding the cross-coupled inductance terms Ldq and Lqd. By the advantage of the excited structure of the experimental IPMSM, the analyzing works were performed under two conditions, the highest and lowest excited conditions. Therefore, it is possible to investigate the cross-saturation effect when a machine has higher magnetic flux from its rotor. The following is a summary of conclusions that may be drawn from this work: (1) Considering cross saturation of an IPMSM offers more accurate expected values of motor parameters in output torque calculation, especially when negative d-axis current is high; (2) A less saturated synchronous machine could be more affected by the cross-coupled saturation effect; (3) Both cross-coupled inductances, L{sub qd} and L{sub dq}, are mainly governed by d-axis current rather than q-axis current; (4) The modified torque equation, can be used for the dynamic model of an IPMSM for developing a better control model or control strategy; and (5) It is possible that the brushless field excitation structure has a common magnetic flux path on both d- and q-axis, and as a result, the reluctance torque of the machine could be reduced.

Lee, Seong T [ORNL; Burress, Timothy A [ORNL; Tolbert, Leon M [ORNL

2009-01-01T23:59:59.000Z

64

High-Performance Control of Two Three-Phase Permanent-Magnet Synchronous Machines in an Integrated Drive for Automotive Applications  

SciTech Connect

The closed-loop control of an integrated dual AC drive system is presented to control two three-phase permanent-magnet motors. A five-leg inverter is employed in the drive system; three of the inverter legs are for a main traction motor, but only two are needed for a three-phase auxiliary motor by utilizing the neutral point of the traction motor. An integrated drive with reduced component count is therefore achieved by eliminating one inverter leg and its gate drivers. A modified current control scheme based on the rotor flux orientation principle is presented. Simulation and experimental results are included to verify the independent control capability of the integrated drive.

Tang, Lixin [ORNL; Su, Gui-Jia [ORNL

2008-01-01T23:59:59.000Z

65

Evaluation of Smart Phone Apps Used to Measure AC Magnetic Fields  

Science Conference Proceedings (OSTI)

There are two specific objectives for this project. The first is to understand the characteristics of the magnetic field sensors used for measuring magnetic fields incorporated in smart phones as well as the integrated circuit in which the sensors are embedded. More specifically, since the design of both the sensor and the integrated circuit in which it is embedded affect the capability of the system to provide accurate magnetic field data, this design should be understood. The second is to learn as much ..

2013-05-01T23:59:59.000Z

66

Sensorless Direct Torque Control For Salient Pole PMSM Based on Extended Kalman Filter Fed By AC/DC/AC Converter  

E-Print Network (OSTI)

, Algeria Abstract -- In this paper, a new sensorless Interior Permanent Magnet Synchronous Motor (IPMSM. Key words-- DTC; sensorless control; extended Kalman filter; Permanent Magnet Synchronous Motor; boost-rectifier. I. INTRODUCTION Permanent magnet synchronous motors (PMSMS) are widely used in many applications

Paris-Sud XI, Université de

67

Synchronous Motor Observability Study and an Improved Zero-speed Position Estimation Design  

E-Print Network (OSTI)

with the Permanent Magnet Synchronous Motor (PMSM) observability analysis for sensor- less control design here for the surface Permanent Magnet Synchronous Motor (PMSM) to overcome position observabilitySynchronous Motor Observability Study and an Improved Zero-speed Position Estimation Design Dalila

Paris-Sud XI, Université de

68

Synchronization and Arbitration in GALS  

Science Conference Proceedings (OSTI)

Synchronizers and arbiters are important components of any Globally Asynchronous, Locally Synchronous network. They contribute to latency, because of the synchronization time required for reliability, and to metastability delay in the arbiters. Simple ... Keywords: Arbitration, Metastability, Synchronization

David Kinniment

2009-08-01T23:59:59.000Z

69

Emergency control of synchronous and nonsynchronous tie lines  

SciTech Connect

It is shown that for power systems using ''weak'' synchronous tie lines (ac lines), by employing backup separation with a mutual angle exceeding the critical value and allocating a portion of the generators to the receiving power system, it is possible to achieve synchronous-tie emergency-control capabilities close to those provided by emergency control of a nonsynchronous tie (a line and dc link as well as a line with electromechanical converters).

Kolonskii, T.V.

1980-01-01T23:59:59.000Z

70

A Study On High Voltage AC Power Transmission Line Electric And Magnetic Field Coupling With Nearby Metallic Pipelines.  

E-Print Network (OSTI)

??In the recent years, there has been a trend to run metallic pipelines carrying petroleum products and high voltage AC power lines parallel to each (more)

Gupta, Abhishek

2006-01-01T23:59:59.000Z

71

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

72

Synchronization and power sharing for droop-controlled inverters in islanded microgrids  

Science Conference Proceedings (OSTI)

Motivated by the recent and growing interest in smart grid technology, we study the operation of DC/AC inverters in an inductive microgrid. We show that a network of loads and DC/AC inverters equipped with power-frequency droop controllers can be cast ... Keywords: Coupled oscillators, Distributed control, Inverters, Kuramoto model, Power-system control, Smart power applications, Synchronization

John W. Simpson-Porco, Florian DRfler, Francesco Bullo

2013-09-01T23:59:59.000Z

73

Advanced synchronous luminescence system  

DOE Patents (OSTI)

A method and apparatus for determining the condition of tissue or otherwise making chemical identifications includes exposing the sample to a light source, and using a synchronous luminescence system to produce a spectrum that can be analyzed for tissue condition.

Vo-Dinh, Tuan (Knoxville, TN)

1997-01-01T23:59:59.000Z

74

Advanced synchronous luminescence system  

DOE Patents (OSTI)

A method and apparatus are disclosed for determining the condition of tissue or otherwise making chemical identifications includes exposing the sample to a light source, and using a synchronous luminescence system to produce a spectrum that can be analyzed for tissue condition. 14 figs.

Vo-Dinh, T.

1997-02-04T23:59:59.000Z

75

Experimental Approach of a High Performance Control of Two PermanentMagnet Synchronous Machines in an Integrated Drive for Automotive Applications  

SciTech Connect

The close-loop digital signal processor (DSP) control of an integrated-dual inverter, which is able to drive two permanent magnet (PM) motors independently, is presented and evaluated experimentally. By utilizing the neutral point of the main traction motor, only two inverter poles are needed for the two-phase auxiliary motor. The modified field-oriented control scheme for this integrated inverter was introduced and employed in real-time control. The experimental results show the inverter is able to control two drives independently. An integrated, component count reduced drive is achieved.

Tang, Lixin [ORNL; Su, Gui-Jia [ORNL

2006-01-01T23:59:59.000Z

76

Programmable synchronous communications module  

SciTech Connect

The functional characteristics of a programmable, synchronous serial communications CAMAC module with buffering in block format are described. Both bit and byte oriented protocols can be handled in full duplex depending on the program implemented. The main elements of the module are a Signetics 2652 Multi-Protocol Communications Controller, a Zilog Z-808 8 bit microprocessor with PROM and RAM, and FIFOs for buffering. (FS)

Horelick, D.

1979-10-01T23:59:59.000Z

77

FIRST 100 T NON-DESTRUCTIVE MAGNET  

DOE Green Energy (OSTI)

The first 100 T non-destructive (100 T ND) magnet and power supplies as currently designed are described. This magnet will be installed as part of the user facility research equipment at the National High Magnetic Field Laboratory (NHMFL) Pulsed Field Facility at Los Alamos National Laboratory. The 100 T ND magnet will provide a 100 T pulsed field of 5 ms duration (above 90% of full field) in a 15 mm diameter bore once per hour. Magnet operation will be non-destructive. The magnet will consist of a controlled power outer coil set which produces a 47 T platform field in a 225 mm diameter bore. Located within the outer coil set will be a 220 mm outer diameter capacitor powered insert coil. Using inertial energy storage a synchronous motor/generator will provide ac power to a set of seven ac-dc converters rated at 64 MW/80 MVA each. These converters will energize three independent coil circuits to create 170 MJ of field energy in the outer coil set at the platform field of 47 T. The insert will then be energized to produce the balance of the 100 T peak field using a 2.3 MJ, 18 kV (charged to 15 kV), 14.4 mF capacitor bank controlled with solid-state switches. The magnet will be the first of its kind and the first non-destructive, reusable 100 T pulsed magnet. The operation of the magnet will be described along with special features of its design and construction.

J. R. SIMS; ET AL

1999-10-01T23:59:59.000Z

78

AC Capabilities  

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

Standards Laboratory Metrology Program AC Electrical Fact Sheet SAND2008-5221P Unlimited Release. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed...

79

Design and operating experience of an ac-dc power converter for a superconducting magnetic energy storage unit  

DOE Green Energy (OSTI)

The design philosophy and the operating behavior of a 5.5 kA, +-2.5 kV converter, being the electrical interface between a high voltage transmission system and a 30 MJ superconducting coil, are documented in this paper. Converter short circuit tests, load tests under various control conditions, dc breaker tests for magnet current interruption, and converter failure modes are described.

Boenig, H.J.; Nielsen, R.G.; Sueker, K.H.

1984-01-01T23:59:59.000Z

80

SLAC synchronous condenser  

SciTech Connect

A synchronous condenser is a synchronous machine that generates reactive power that leads real power by 90{degrees} in phase. The leading reactive power generated by the condenser offsets or cancels the normal lagging reactive power consumed by inductive and nonlinear loads at the accelerator complex. The quality of SLAC`s utility power is improved with the addition of the condenser. The inertia of the condenser`s 35,000 pound rotor damps and smoothes voltage excursions on two 12 kilovolt master substation buses, improving voltage regulation site wide. The condenser absorbs high frequency transients and noise in effect ``scrubbing`` the electric system power at its primary distribution source. In addition, the condenser produces a substantial savings in power costs. Federal and investor owned utilities that supply electric power to SLAC levy a monthly penalty for lagging reactive power delivered to the site. For the 1993 fiscal year this totaled over $285,000 in added costs for the year. By generating leading reactive power on site, thereby reducing total lagging reactive power requirements, a substantial savings in electric utility bills is achieved. Actual savings of $150,000 or more a year are possible depending on experimental operations.

Corvin, C.

1995-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Synchronization and Power Sharing for Droop-Controlled Inverters in Islanded Microgrids  

E-Print Network (OSTI)

Synchronization and Power Sharing for Droop-Controlled Inverters in Islanded Microgrids John W in an inductive microgrid. We show that a network of loads and DC/AC inverters equipped with power-frequency droop model, distributed control. 1 Introduction A microgrid is a low-voltage electrical network, hetero

Bullo, Francesco

82

FIRST 100 T NON-DESTRUCTIVE MAGNET OUTER COIL SET  

DOE Green Energy (OSTI)

The controlled power outer coil set of the first 100 T non-destructive (100 T ND) magnet is described. This magnet will be installed as part of the user facility research equipment at the National High Magnetic Field laboratory (NHMFL) Pulsed Field Facility at Los Alamos National Laboratory. The 100 T ND controlled power outer coil set consists of seven nested, mechanically independent externally reinforced coils. These coils, in combination, will produce a 47 T platform field in a 225-mm diameter bore. Using inertial energy storage a synchronous motor/generator provides ac power to a set of seven ac-dc converters rated at 64 MW/80 MVA each. These converters energize three independent coil circuits to create 170 MJ of field energy in the outer coil set at the platform field of 47 T. Each coil consists of a multi-layer winding of high strength conductor supported by an external high strength stainless steel shell. Coils with the highest magnetic loads will utilize a reinforcing shell fabricated from highly cold worked 301 stainless steel strip. The autofrettage conditioning method will be used to pre-stress the coils and thereby limit conductor and reinforcement strains to the elastic range. The purpose of pre-stressing the coils is to attain a design life of 10,000 full field pulses. The operation and conditioning of the coil set will be described along with special features of its design, magnetic and structural analyses and construction.

J. BACON; A. BACA; ET AL

1999-09-01T23:59:59.000Z

83

Permanent-Magnet-Less Synchronous Reluctance Motors  

also zip-lock assembly features that increase power density and reduce cost. In this invention, a patented, enclosed air gap is introduced between the

84

Permanent-Magnet-Less Synchronous Reluctance System  

Confirmed by Industry . 6 Managed by UT-Battelle for the U.S. Department of Energy ... *** Includes additional cost of 11kg steel and 3kg copper wire (+$40.00) but

85

Synchronous interlocked pipelines  

E-Print Network (OSTI)

In a circuit environment that is becoming increasingly sensitive to dynamic power dissipation and noise, and where cycle time available for control decisions continues to decrease, locality principles are becoming paramount in controlling advancement of data through pipelined systems. Achieving fine grained power down and progressive pipeline stalls at the local stage level is therefore becoming increasingly important to enable lower dynamic power consumption while keeping introduced switching noise under control as well as avoiding global distribution of timing critical stall signals. It has long been known that the interlocking properties of asynchronous pipelined systems have a potential to provide such benefits. However, it has not been understood how such interlocking can be achieved in synchronous pipelines. This paper

Hans M. Jacobson; Prabhakar N. Kudva; Pradip Bose; Peter W. Cook; Stanley E. Schuster

2002-01-01T23:59:59.000Z

86

Available Technologies: Optical Synchronization Systems for ...  

Optical Synchronization Systems for Femtosecond Light Sources . ... The invention enables synchronizing signals to be trasnmitted over standard fiber optic lines to a ...

87

COMPARAISON DES PERFORMANCES DE DEUX MOTEURS LECTRIQUES AUTOPILOTS : LE MOTEUR SYNCHRONE AIMANTS PERMANENTS  

E-Print Network (OSTI)

SELF COMMUTATED ELECTRIC MOTORS : THE PERMANENT MAGNET BRUSHLESS DC MOTOR THE SWITCHED RELUCTANCE MOTOR synchronous brushless motors. These motors are, on one hand, the permanent-magnet brushless DC motor supplied by quasi-square currents, with magnets mounted at rotor surface and trapezoidal e.m.f. waveform, and

Paris-Sud XI, Université de

88

A function based fuzzy controller for VSC-HVDC system to enhance transient stability of AC/DC power system  

Science Conference Proceedings (OSTI)

This paper presents a robust function based optimized fuzzy controller for VSC-HVDC transmission link operating in parallel with an AC transmission line connecting a synchronous generator to infinite bus. A two input one output methodology based optimized ...

Niranjan Nayak; Sangram Kesari Routray; Pravat Kumar Rout

2011-12-01T23:59:59.000Z

89

Synchronous optical pumping of quantum revival beats for atomic magnetometry  

Science Conference Proceedings (OSTI)

We observe quantum beats with periodic revivals due to nonlinear spacing of Zeeman levels in the ground state of potassium atoms, and demonstrate their synchronous optical pumping by double modulation of the pumping light at the Larmor frequency and the revival frequency. We show that synchronous pumping increases the degree of spin polarization by a factor of 4. As a practical example, we explore the application of this double-modulation technique to atomic magnetometers operating in the geomagnetic field range, and find that it can increase the sensitivity and reduce magnetic-field-orientation-dependent measurement errors endemic to alkali-metal magnetometers.

Seltzer, S. J.; Meares, P. J.; Romalis, M. V. [Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States)

2007-05-15T23:59:59.000Z

90

436 IEEE/ASME TRANSACTIONS ON MECHATRONICS, VOL. 9, NO. 2, JUNE 2004 Torque and Velocity Ripple Elimination of AC  

E-Print Network (OSTI)

Elimination of AC Permanent Magnet Motor Control Systems Using the Internal Model Principle Wai-Chuen Gan and velocity ripple elimination in AC permanent magnet (PM) motor control systems. The torque ripples caused-free output response. Index Terms--AC permanent magnet motor, gain scheduled (GS) speed regulators, internal

Qiu, Li

91

Synchronous identification of friendly targets  

DOE Patents (OSTI)

A synchronous communication targeting system for use in battle. The present invention includes a transceiver having a stabilizing oscillator, a synchronous amplifier and an omnidirectional receiver, all in electrical communication with each other. A remotely located beacon is attached to a blackbody radiation source and has an amplitude modulator in electrical communication with a optical source. The beacon's amplitude modulator is set so that the optical source transmits radiation frequency at approximately the same or lower amplitude than that of the blackbody radiation source to which the beacon is attached. The receiver from the transceiver is adapted to receive frequencies approximately at or below blackbody radiation signals and sends such signals to the synchronous amplifier. The synchronous amplifier then rectifies and amplifies those signals which correspond to the predetermined frequency to therefore identify whether the blackbody radiation source is friendly or not.

Telle, John M. (126 Shady Oak Cir., Tijeras, NM 87059); Roger, Stutz A. (5 Kiowa La., Los Alamos, NM 87544)

1998-01-01T23:59:59.000Z

92

Adaptive vibration control using synchronous demodulation with ...  

Adaptive vibration control using synchronous demodulation with machine tool controller motor commutation United States Patent

93

Synchronization in Vehicle Routing---A Survey of VRPs with Multiple Synchronization Constraints  

Science Conference Proceedings (OSTI)

This paper presents a survey of vehicle routing problems with multiple synchronization constraints. These problems exhibit, in addition to the usual task covering constraints, further synchronization requirements between the vehicles, concerning spatial, ... Keywords: coordination, survey, synchronization, trailer, transshipment, vehicle routing

Michael Drexl

2012-08-01T23:59:59.000Z

94

arXiv:1103.2923v1[math.OC]15Mar2011 Estimation of Saturation of Permanent-Magnet  

E-Print Network (OSTI)

arXiv:1103.2923v1[math.OC]15Mar2011 Estimation of Saturation of Permanent-Magnet Synchronous Motors a parametric model of the saturated Permanent-Magnet Synchronous Motor (PMSM) together with an estimation: Permanent magnet synchronous motor, mag- netic circuit modeling, magnetic saturation, energy-based mod

Paris-Sud XI, Université de

95

IEEE TRANSACTIONS ON MAGNETICS, VOL. 41, NO. 10, OCTOBER 2005 3823 Design of a Superhigh-Speed Cryogenic Permanent  

E-Print Network (OSTI)

-Speed Cryogenic Permanent Magnet Synchronous Motor Liping Zheng1, Thomas X. Wu1, Dipjyoti Acharya2, Kalpathy B and simulation of a superhigh-speed permanent magnet synchronous motor (PMSM) that operates in the cryogenic Terms--Cryogenics, permanent magnet synchronous motor (PMSM), superhigh speed, V/f control. I

Wu, Shin-Tson

96

State observer for synchronous motors  

DOE Patents (OSTI)

A state observer driven by measurements of phase voltages and currents for estimating the angular orientation of a rotor of a synchronous motor such as a variable reluctance motor (VRM). Phase voltages and currents are detected and serve as inputs to a state observer. The state observer includes a mathematical model of the electromechanical operation of the synchronous motor. The characteristics of the state observer are selected so that the observer estimates converge to the actual rotor angular orientation and velocity, winding phase flux linkages or currents.

Lang, Jeffrey H. (Waltham, MA)

1994-03-22T23:59:59.000Z

97

Analysis of hunting in Synchronous Hysteresis Motor  

E-Print Network (OSTI)

The Synchronous Hysteresis Motor has an inherent instability when it is used to drive a gyroscope wheel. The motor ideally should spin at a constant angular velocity, but it instead sporadically oscillates about synchronous ...

Truong, Cang Kim, 1979-

2004-01-01T23:59:59.000Z

98

An Introduction to Synchronous Grammars David Chiang  

E-Print Network (OSTI)

An Introduction to Synchronous Grammars David Chiang 21 June 2006 1 Introduction Synchronous International Workshop on Parsing Technologies (IWPT), pages 66­77, 2001. [3] David Chiang. A hierarchical

Chiang, David

99

mat.univie.ac  

E-Print Network (OSTI)

Neumaier@univie.ac.at. Abstract. Results are ...... http://www.mat.univie.ac.at/ neum/glopt/coconut/tests/figures/ ... [11] GAMS World, WWW-document, 2002.

100

AC-DC Difference  

Science Conference Proceedings (OSTI)

... The NIST ac-dc Difference Project provides US industry with the essential link between ac ... Facilities/Tools Used: ... NIST CNST Nanofabrication facility. ...

2012-08-09T23:59:59.000Z

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


101

Modeling Communication with Synchronized Environments  

Science Conference Proceedings (OSTI)

A deterministic behavior of systems composed of several modules is a desirable design goal. Assembling a complex system from components requires also a high degree of re-usability. The compatibility of the selected components may become a problem even ... Keywords: System modeling, action systems, synchronized / interleaved communication

Tiberiu Seceleanu; Axel Jantsch

2008-08-01T23:59:59.000Z

102

Shortest synchronizing strings for Huffman codes  

Science Conference Proceedings (OSTI)

Most complete binary prefix codes have a synchronizing string, that is a string that resynchronizes the decoder regardless of its previous state. This work presents an upper bound on the length of the shortest synchronizing string for such codes. Two ... Keywords: ?ern conjecture, Finite automaton, Huffman code, Synchronizing string

Marek Tomasz Biskup; Wojciech Plandowski

2009-09-01T23:59:59.000Z

103

Networks, smart grids: new model for synchronization  

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

Stories » Stories » Networks, smart grids: new model for synchronization Networks, smart grids: new model for synchronization Researchers developed a surprisingly simple mathematical model that accurately predicts synchronization as a function of the parameters and the topology of the underlying network. May 21, 2013 High voltage transmission lines carry electrical power. High voltage transmission lines carry electrical power. The researchers envision that their method could be applied to assess synchronization and robustness quickly in electrical grids under volatile operating conditions. Networks of individual oscillating nodes often spontaneously synchronize and begin to oscillate at a coherent frequency. From heart cells to flashing fireflies to electric power grids, coupled oscillator networks are

104

Doubly Salient Permanent Magnet Motor Development Review  

Science Conference Proceedings (OSTI)

The research of doubly salient permanent magnet motor (DSPM), arises as the emergence of a novel type mechatronic control of AC drive system. Currently, on the international realm, the studies regarding on this kind of motor mainly focus on calculation ... Keywords: Doubly Salient, Permanent Magnet Motor, AC Variable Speed, Magnetic Materials, Switched Reluctance Motor

Lina Yi, Meng Zhao

2013-09-01T23:59:59.000Z

105

State Laboratory Contacts AC  

Science Conference Proceedings (OSTI)

State Laboratory Contact Information AC. Alabama. Mailing Address, ... PDF. Alaska. Mailing Address, Contact Information. Alaska ...

2013-08-01T23:59:59.000Z

106

Permanent-magnet-less machine having an enclosed air gap  

DOE Patents (OSTI)

A permanent magnet-less, brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by an alternating current. An uncluttered rotor disposed within the magnetic rotating field is spaced apart from the stator to form an air gap relative to an axis of rotation. A stationary excitation core spaced apart from the uncluttered rotor by an axial air gap and a radial air gap substantially encloses the stationary excitation core. Some permanent magnet-less, brushless synchronous systems include stator core gaps to reduce axial flux flow. Some permanent magnet-less, brushless synchronous systems include an uncluttered rotor coupled to outer laminations. The quadrature-axis inductance may be increased in some synchronous systems. Some synchronous systems convert energy such as mechanical energy into electrical energy (e.g., a generator); other synchronous systems may convert any form of energy into mechanical energy (e.g., a motor).

Hsu, John S. (Oak Ridge, TN)

2012-02-07T23:59:59.000Z

107

Permanent-magnet-less machine having an enclosed air gap  

SciTech Connect

A permanent magnet-less, brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by an alternating current. An uncluttered rotor disposed within the magnetic rotating field is spaced apart from the stator to form an air gap relative to an axis of rotation. A stationary excitation core spaced apart from the uncluttered rotor by an axial air gap and a radial air gap substantially encloses the stationary excitation core. Some permanent magnet-less, brushless synchronous systems include stator core gaps to reduce axial flux flow. Some permanent magnet-less, brushless synchronous systems include an uncluttered rotor coupled to outer laminations. The quadrature-axis inductance may be increased in some synchronous systems. Some synchronous systems convert energy such as mechanical energy into electrical energy (e.g., a generator); other synchronous systems may convert any form of energy into mechanical energy (e.g., a motor).

Hsu, John S.

2013-03-05T23:59:59.000Z

108

Screw Type Ac Air Compressor Manufacturers, Screw Type Ac Air ...  

U.S. Energy Information Administration (EIA)

Screw Type Ac Air Compressor, Screw Type Ac Air Compressor Manufacturers & Suppliers Directory - Find here Screw Type Ac Air Compressor Traders, ...

109

magnets  

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

I I Painless Physics Articles BEAM COOLING August 2, 1996 By Leila Belkora, Office of Public Affairs ACCELERATION August 16, 1996 By Dave Finley, Accelerator Division Head RF August 30, 1996 By Pat Colestock, Accelerator Division FIXED TARGET PHYSICS September 20, 1996 By Peter H. Garbincius, Physics Section FIXED TARGET PHYSICS PART DEUX October 16, 1996 By Peter H. Garbincius, Physics Section and Leila Belkora, Office of Public Affaris CROSS SECTION November 1, 1996 By Doreen Wackeroth, Theoretical Physics Edited by Leila Belkora, Office of Public Affaris MAGNETS PART I November 15, 1996 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs MAGNETS PART II January 10, 1997 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs

110

Sun-Synchronous Planetary Exploration  

E-Print Network (OSTI)

Contemporary planetary missions are characterized by favorable landing sites, communication, and duration. The ambition of planetary exploration is to discover the unknown: to explore regions, not just sites; to analyze, not just observe; and to operate effectively and reliably without excessive communication and ground support. New robotics technologies and mission concepts will revolutionize exploration systems and operations. This paper addresses the key enabling technologies for sun-synchronous planetary exploration: environmental modeling, temporal path planning, scaling, and robot configuration. 1.

William Red Whittaker; William red Whittaker; George Kantor; Ben Shamah; David Wettergreen

2000-01-01T23:59:59.000Z

111

AC Losses in the New High-Temperature Superconductors  

Science Conference Proceedings (OSTI)

This report addresses the properties of high-temperature ceramic oxide superconductors in low magnetic fields. It discusses ac losses in the superconducting and normal states, the influence of anisotropy, and a database for monitoring advances in superconductivity. The ac losses of the oxide superconductors were found to be excessive.

1989-03-17T23:59:59.000Z

112

Synchronization of Sub-Picosecond Electron and Laser Pulses  

SciTech Connect

Sub-picosecond laser-electron synchronization is required to take full advantage of the experimental possibilities arising from the marriage of modern high intensity lasers and high brightness electron beams in the same laboratory. Two particular scenarios stand out in this regard, injection of ultra-short electron pulses in short wavelength laser-driven plasma accelerators, and Compton scattering of laser photons from short electron pulses. Both of these applications demand synchronization, which is subpicosecond, with tens of femtosecond synchronization implied for next-generation experiments. Typically, an RF electron accelerator is synchronized to a short pulse laser system by detecting the repetition signal of a laser oscillator, adjusted to an exact subharmonic of the linac RF frequency, and multiplying or phase locking this signal to produce the master RF clock. Pulse-to-pulse jitter characteristic of self-mode-locked laser oscillators represents a direct contribution to the ultimate timing jitter between a high intensity laser focus and electron beam at the interaction point, or a photocathode drive laser in an RF photoinjector. This timing jitter problem has been addressed most seriously in the context of the RF photoinjector, where the electron beam properties are sensitive functions of relative timing jitter. The timing jitter achieved in synchronized photocathode drive laser systems is near, or slightly below one picosecond. The ultimate time of arrival jitter of the beam at the photoinjector exit is typically a bit smaller than the photocathode drive-laser jitter due to velocity compression effects in the first RF cell of the gun. This tendency of the timing of the electron beam arrival at a given spatial point to lock to the RF lock is strongly reinforced by use of magnetic compression.

Rosenzweig, J.B.; Le Sage G.P.

2000-08-15T23:59:59.000Z

113

Networks, smart grids: new model for synchronization  

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

Networks, smart grids: new model for synchronization Networks, smart grids: new model for synchronization Networks, smart grids: new model for synchronization Researchers developed a surprisingly simple mathematical model that accurately predicts synchronization as a function of the parameters and the topology of the underlying network. May 21, 2013 High voltage transmission lines carry electrical power. High voltage transmission lines carry electrical power. The researchers envision that their method could be applied to assess synchronization and robustness quickly in electrical grids under volatile operating conditions. Networks of individual oscillating nodes often spontaneously synchronize and begin to oscillate at a coherent frequency. From heart cells to flashing fireflies to electric power grids, coupled oscillator networks are

114

Synchronization in semiconductor laser rings  

E-Print Network (OSTI)

We examine the dynamics of semiconductor lasers coupled in a ring configuration. The lasers, which have stable output intensity when isolated, behave chaotically when coupled unidirectionally in a closed chain. In this way, we show that neither feedback nor bidirectional coupling is necessary to induce chaotic dynamics at the laser output. We study the synchronization phenomena arising in this particular coupling architecture, and discuss its possible application to chaos-based communications. Next, we extend the study to bidirectional coupling and propose an appropriate technique to optical chaos encryption/decryption in closed chains of mutually coupled semiconductor lasers.

Javier M. Buldu; M. C. Torrent; Jordi Garcia-Ojalvo

2006-10-06T23:59:59.000Z

115

Time synchronization for underwater acoustic sensor networks.  

E-Print Network (OSTI)

??The unique properties of underwater acoustic communications, such as large and time-varying propagation, low and range dependent bandwidth, and adverse operating environment make the synchronization (more)

Khandoker, Tarik-Ul Islam

2012-01-01T23:59:59.000Z

116

A Multi-Level Grid Interactive Bi-directional AC/DC-DC/AC Converter and a Hybrid Battery/Ultra-capacitor Energy Storage System with Integrated Magnetics for Plug-in Hybrid Electric Vehicles  

DOE Green Energy (OSTI)

This study presents a bi-directional multi-level power electronic interface for the grid interactions of plug-in hybrid electric vehicles (PHEVs) as well as a novel bi-directional power electronic converter for the combined operation of battery/ultracapacitor hybrid energy storage systems (ESS). The grid interface converter enables beneficial vehicle-to-grid (V2G) interactions in a high power quality and grid friendly manner; i.e, the grid interface converter ensures that all power delivered to/from grid has unity power factor and almost zero current harmonics. The power electronic converter that provides the combined operation of battery/ultra-capacitor system reduces the size and cost of the conventional ESS hybridization topologies while reducing the stress on the battery, prolonging the battery lifetime, and increasing the overall vehicle performance and efficiency. The combination of hybrid ESS is provided through an integrated magnetic structure that reduces the size and cost of the inductors of the ESS converters. Simulation and experimental results are included as prove of the concept presenting the different operation modes of the proposed converters.

Onar, Omer C [ORNL

2011-01-01T23:59:59.000Z

117

A Self-Learning Solution for Torque Ripple Reduction for Non-Sinusoidal Permanent Magnet  

E-Print Network (OSTI)

1 A Self-Learning Solution for Torque Ripple Reduction for Non-Sinusoidal Permanent Magnet Motor in a permanent-magnet non-sinusoidal synchronous motor. Solutions for calculating optimal currents are deduced are shown to confirm the validity of the proposed neural approach. Index Terms--Permanent Magnet Synchronous

Paris-Sud XI, Université de

118

Control of Two Permanent Magnet Machines Using a Five-Leg Inverter for Automotive Applications  

SciTech Connect

This paper presents digital control schemes for control of two permanent magnet (PM) machines in an integrated traction and air-conditioning compressor drive system for automotive applications. The integrated drive system employs a five-leg inverter to power a three-phase traction PM motor and a two-phase compressor PM motor by tying the common terminal of the two-phase motor to the neutral point of the three-phase motor. Compared to a three-phase or a standalone two-phase inverter, it eliminates one phase leg and shares the control electronics between the two drives, thus significantly reducing the component count of the compressor drive. To demonstrate that the speed and torque of the two PM motors can be controlled independently, a control strategy was implemented in a digital signal processor, which includes a rotor flux field orientation based control (RFOC) for the three-phase motor, a similar RFOC and a position sensorless control in the brushless dc (BLDC) mode for the two-phase motor. Control implementation issues unique to a two-phase PM motor are also discussed. Test results with the three-phase motor running in the ac synchronous (ACS) mode while the two-phase motor either in the ACS or the BLDC mode are included to verify the independent speed and torque control capability of the integrated drive.

Su, Gui-Jia [ORNL; Tang, Lixin [ORNL; Huang, Xianghui [GE Global Research

2006-01-01T23:59:59.000Z

119

Global interactions, information flow, and chaos synchronization  

E-Print Network (OSTI)

We investigate the relationship between the emergence of chaos synchronization and the information flow in dynamical systems possessing homogeneous or heterogeneous global interactions whose origin can be external (driven systems) or internal (autonomous systems). By employing general models of coupled chaotic maps for such systems, we show that the presence of a homogeneous global field, either external or internal, for all times is not indispensable for achieving complete or generalized synchronization in a system of chaotic elements. Complete synchronization can also appear with heterogeneous global fields; it does not requires the simultaneous sharing of the field by all the elements in a system. We use the normalized mutual information and the information transfer between global and local variables to characterize complete and generalized synchronization. We show that these information measures can characterize both types of synchronized states and also allow to discern the origin of a global interaction field. A synchronization state emerges when a sufficient amount of information provided by a field is shared by all the elements in the system, on the average over long times. Thus, the maximum value of the top-down information transfer can be used as a predictor of synchronization in a system, as a parameter is varied.

G. Paredes; O. Alvarez-Llamoza; M. G. Cosenza

2013-07-17T23:59:59.000Z

120

Asynchronous Communication: Exact Synchronization, Universality, and Dispersion  

E-Print Network (OSTI)

Recently, Tchamkerten and coworkers proposed a novel variation of the problem of joint synchronization and error correction. This paper considers a strengthened formulation that requires the decoder to estimate both the ...

Polyanskiy, Yury

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Binarization of synchronous context-free grammars  

Science Conference Proceedings (OSTI)

Systems based on synchronous grammars and tree transducers promise to improve the quality of statistical machine translation output, but are often very computationally intensive. The complexity is exponential in the size of individual grammar rules due ...

Liang Huang; Hao Zhang; Daniel Gildea; Kevin Knight

2009-12-01T23:59:59.000Z

122

Correct-by-Construction Asynchronous Implementation of Modular Synchronous Specifications  

Science Conference Proceedings (OSTI)

In this paper, we introduce a new model for the representation of distributed asynchronous implementations of synchronous specifications. The model covers classical implementations, where a notion of global synchronization is preserved by means of signaling, ... Keywords: Asynchronous systems, Endochronous systems, Globally asynchronous, Kahn processes, Semantics preservation, Synchronous systems, locally synchronous (GALS) architectures

Dumitru Potop-Butucaru; Benot Caillaud

2007-09-01T23:59:59.000Z

123

T-ACS/RoboCrane  

Science Conference Proceedings (OSTI)

Page 1. T-ACS/RoboCrane ... T-ACS (Tactical Auxiliary Crane Ships) T-ACS photo's and drawing courtesy US Navy and/or August Design, Inc. ...

2011-08-25T23:59:59.000Z

124

ACS Symposium Program  

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

the Divisions of Biological Chemistry, Environmental Chemistry, Chemical Education, Geochemistry, and Inorganic Chemistry as part of the ACS Division of Analytical Chemistry...

125

Diagnostics of the Fermilab Tevatron using an AC dipole  

Science Conference Proceedings (OSTI)

The Fermilab Tevatron is currently the world's highest energy colliding beam facility. Its counter-rotating proton and antiproton beams collide at 2 TeV center-of-mass. Delivery of such intense beam fluxes to experiments has required improved knowledge of the Tevatron's beam optical lattice. An oscillating dipole magnet, referred to as an AC dipole, is one of such a tool to non-destructively assess the optical properties of the synchrotron. We discusses development of an AC dipole system for the Tevatron, a fast-oscillating (f {approx} 20 kHz) dipole magnet which can be adiabatically turned on and off to establish sustained coherent oscillations of the beam particles without affecting the transverse emittance. By utilizing an existing magnet and a higher power audio amplifier, the cost of the Tevatron AC dipole system became relatively inexpensive. We discuss corrections which must be applied to the driven oscillation measurements to obtain the proper interpretation of beam optical parameters from AC dipole studies. After successful operations of the Tevatron AC dipole system, AC dipole systems, similar to that in the Tevatron, will be build for the CERN LHC. We present several measurements of linear optical parameters (beta function and phase advance) for the Tevatron, as well as studies of non-linear perturbations from sextupole and octupole elements.

Miyamoto, Ryoichi; /Texas U.

2008-08-01T23:59:59.000Z

126

Superconducting magnetic energy storage for asynchronous electrical systems  

DOE Patents (OSTI)

A superconducting magnetic energy storage coil connected in parallel between converters of two or more ac power systems provides load leveling and stability improvement to any or all of the ac systems. Control is provided to direct the charging and independently the discharging of the superconducting coil to at least a selected one of the ac power systems.

Boenig, Heinrich J. (Los Alamos, NM)

1986-01-01T23:59:59.000Z

127

Propulsion and stabilization system for magnetically levitated vehicles  

DOE Patents (OSTI)

A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and stabilized by a system which includes propulsion windings mounted above and parallel to vehicle-borne suspension magnets. A linear synchronous motor is part of the vehicle guideway and is mounted above and parallel to superconducting magnets attached to the magnetically levitated vehicle.

Coffey, Howard T. (Darien, IL)

1993-06-29T23:59:59.000Z

128

Propulsion and stabilization system for magnetically levitated vehicles  

DOE Patents (OSTI)

A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and stabilized by a system which includes propulsion windings mounted above and parallel to vehicle-borne suspension magnets. A linear synchronous motor is part of the vehicle guideway and is mounted above and parallel to superconducting magnets attached to the magnetically levitated vehicle.

Coffey, H.T.

1992-12-31T23:59:59.000Z

129

ac-driven atomic quantum motor  

E-Print Network (OSTI)

We invent an ac-driven quantum motor consisting of two different, interacting ultracold atoms placed into a ring-shaped optical lattice and submerged in a pulsating magnetic field. While the first atom carries a current, the second one serves as a quantum starter. For fixed zero-momentum initial conditions the asymptotic carrier velocity converges to a unique non-zero value. We also demonstrate that this quantum motor performs work against a constant load.

A. V. Ponomarev; S. Denisov; P. Hanggi

2009-02-03T23:59:59.000Z

130

ac-driven atomic quantum motor  

E-Print Network (OSTI)

We invent an ac-driven quantum motor consisting of two different, interacting ultracold atoms placed into a ring-shaped optical lattice and submerged in a pulsating magnetic field. While the first atom carries a current, the second one serves as a quantum starter. For fixed zero-momentum initial conditions the asymptotic carrier velocity converges to a unique non-zero value. We also demonstrate that this quantum motor performs work against a constant load.

Ponomarev, A V; Hnggi, P

2009-01-01T23:59:59.000Z

131

Electric and Magnetic Field Exposure Levels (0 to 3000 Hz) near Residential Photovoltaic Energy Generation Facilities  

Science Conference Proceedings (OSTI)

Electric and magnetic field levels associated with two residential photovoltaic energy generation facilities were characterized in this study. This measurement evaluation included static (direct current [DC]) magnetic fields and power-frequency alternating current (AC) electric and magnetic fields (up to 3,000 Hz).The major source of DC and AC magnetic fields associated with a residential solar facility is the power inverter that converts DC to AC electricity. In close proximity to one ...

2012-11-01T23:59:59.000Z

132

Synchronous operation of the BLDC motor  

E-Print Network (OSTI)

The brushless de (BLDC) motor is becoming widely used and popular in the small horsepower motor applications. Factors such as simplicity in control, low cost, high efficiency, low frame size, high torque per inertia, high power density and, most importantly, being br-ushless are the reasons that make the BLDC motor very attractive in motor drive applications. In this research a systematic approach to synchronous operation of the brushless DC (BLDC) motor has been investigated and implemented. This thesis establishes principles of synchronous operation of the BLDC motor, develops stable operating conditions, derives the required implementation formulas and introduces some new definitions. The synchronous system follows, open loop, a speed command. The system has been provided by two input references: current and speed. The current reference throughout the operation has been kept constant at the maximum applicable continuous current to obtain maximum torque. Current regulation has been achieved by hysteresis current control. The speed reference has been varied from zero speed to the desired speed linearly. Once speed reaches to the desired speed, it is kept constant at the desired speed. Since the motor operates synchronously and no position information has been used, the motor has to follow exactly the reference speed, otherwise pull out occurs. By this implementation, three operating points of the BLDC motor with synchronous operational system has been presented. One of the three operating points at maximum speed corresponds to maximum load operation.

Guzelgunler, Yilcan

1998-01-01T23:59:59.000Z

133

The Scheme of Beam Synchronization in MEIC  

Science Conference Proceedings (OSTI)

Synchronizing colliding beams at single or multiple collision points is a critical R&D issue in the design of a medium energy electron-ion collider (MEIC) at Jefferson Lab. The path-length variation due to changes in the ion energy, which varies over 20 to 100 GeV, could be more than several times the bunch spacing. The scheme adopted in the present MEIC baseline is centered on varying the number of bunches (i.e., harmonic number) stored in the collider ring. This could provide a set of discrete energies for proton or ions such that the beam synchronization condition is satisfied. To cover the ion energy between these synchronized values, we further propose to vary simultaneously the electron ring circumference and the frequency of the RF systems in both collider rings. We also present in this paper the requirement of frequency tunability of SRF cavities to support the scheme.

Zhang, Yuhong; Derbenev, Yaroslav S.; Hutton, Andrew M.

2013-06-01T23:59:59.000Z

134

Synchronization and clustering in electroencephalographic signals  

E-Print Network (OSTI)

The degree of synchronization and the amount of dynamical cluster formation in electroencephalographic (EEG) signals are characterized by employing two order parameters introduced in the context of coupled chaotic systems subject to external noise. These parameters are calculated in EEG signals from a group of healthy subjects and a group of epileptic patients, including a patient experiencing an epileptic crisis. The evolution of these parameters shows the occurrence of intermittent synchronization and clustering in the brain activity during an epileptic crisis. Significantly, the existence of an instantaneous maximum of synchronization previous to the onset of a crisis is revealed by this procedure. The mean values of the order parameters and their standard deviations are compared between both groups of individuals.

M. Escalona-Moran; M. G. Cosenza; P. Guillen; P. Coutin

2005-06-07T23:59:59.000Z

135

Impact of Permanent Magnet Field on Inductance Variation of a PMLSM Julien Gomand1  

E-Print Network (OSTI)

of Surface Mounted Permanent Magnet Linear Synchronous Motors are generally presented with constantImpact of Permanent Magnet Field on Inductance Variation of a PMLSM Julien Gomand1 , Ghislain Remy1 Linear drive, Modelling, Estimation technique, Synchronous motor, Harmonics. Abstract Analytical models

Paris-Sud XI, Université de

136

Attenuation of a magnetic field by a superconductor  

Science Conference Proceedings (OSTI)

Observation of magnetic ac field penetration through superconducting tin films has led to the discovery of a 180 phase shift between the magnetic fields on either side of the film under favorable conditions. This result has so far been published ...

K. E. Drangeid; R. Sommerhalder; H. Mller; H. Seitz

1964-01-01T23:59:59.000Z

137

The cost of conservative synchronization in parallel discrete event simulations  

Science Conference Proceedings (OSTI)

This paper analytically studies the performance of a synchronous conservative parallel discrete-event simulation protocol. The class of models considered simulates activity in a physical domain, and possesses a limited ability to predict future behavior. ... Keywords: conservative synchronization

David M. Nicol

1993-04-01T23:59:59.000Z

138

ac and dc current-induced motion of a 360 degrees domain wall  

E-Print Network (OSTI)

he response of 360 [360 degrees]domain walls in narrow magnetic stripes to applied dc and ac currents, investigated by micromagnetic simulation, differs qualitatively from the response of 180 [180 degrees] domain walls. ...

Mascaro, Mark D.

139

Software | M2ACS  

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

Software Algorithm design, high-performance computing and advanced numerical simulations are at the core M2ACS mission. Below is a list of software packages developed or supported...

140

6110AC.DOT  

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

Center RESIDUAL INVENTORY OF MATERIAL OR EQUIPMENT FURNISHED BY OR ACQUIRED FOR SANDIA Contractor: SF 6110-AC (10-96) Supersedes (6-87) issue Contractor No.: Item Description...

Note: This page contains sample records for the topic "magnet ac synchronous" 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.
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141

Laser Array Synchronization - Oak Ridge National Laboratory | ORNL  

Laser Array Synchronization Note: The technology described above is an early stage opportunity. Licensing rights to this intellectual property may

142

Estimation of synchronous machine parameters by standstill tests  

Science Conference Proceedings (OSTI)

In this paper we present the results of a time-domain identification procedure to estimate the linear parameters of a salient-pole synchronous machine at standstill. A new approach is proposed for the estimation of synchronous machine coupled to DC-chopper ... Keywords: Parameter estimation, Standstill tests, Synchronous machine

M. Hasni; O. Touhami; R. Ibtiouen; M. Fadel; S. Caux

2010-10-01T23:59:59.000Z

143

Synchronization and chaos in spin-transfer-torque nano-oscillators coupled via a high speed Op Amp  

E-Print Network (OSTI)

We propose a system of two coupled spin-torque nano-oscillators (STNOs), one driver and another response, and demonstrate {using numerical studies} the synchronization of the response system to the frequency of the driver system. To this end we use a high speed operational amplifier in the form of a voltage follower which essentially isolates the drive system from the response system. We find the occurrence of 1:1 as w ell as 2:1 synchronization in the system, wherein the oscillators show limit cycle dynamics. An increase in power output is noticed when the two oscillators are locked in 1:1 synchronization. Moreover in the cro ssover region between these two synchronization dynamics we show the existence of chaotic dynamics in the slave system. The coupled dynamics under periodic forcing, using a small ac input current in addition to that of the dc part, is also studied. The slave oscillator is seen to retain its qualitative identity in the parameter space in spite of being fed in, at times, a chaotic signal. Such electrically coupled STNOs will be highly useful in fabricating commercial spin-valve oscillators with high power output, when integrated with other spintronic devices.

C. Sanid; S. Murugesh

2013-12-26T23:59:59.000Z

144

Synchronous timing of multi-energy fast beam extraction during a single AGS cycle  

Science Conference Proceedings (OSTI)

Synchronous triggering of fast beams is required because the field of Kicker Magnets must rise within the open space between one beam bunch and the next. Within the Brookhaven AGS, Fast Extracted Beam (FEB) triggering combines nominal timing, based on beam energy with bunch-to-bunch synchronization, based on the accelerating rf waveform. During beam acceleration, a single bunch is extracted at 22 GeV/c and within the same AGS cycle, the remaining eleven bunches are extracted at 28.4 GeV/c. When the single bunch is extracted, a ''hole'', which is left in the remaining circulating beam, can appear in random locations within the second extraction during successive AGS cycles. To overcome this problem, a synchronous rf/12 counting scheme and logic circuitry are used to keep track of the bunch positions relative to each other, and to place the ''hole'' in any desired location within the second extraction. The rf/12 signal is used also to synchronize experimenters triggers.

Gabusi, J.; Naase, S.

1985-01-01T23:59:59.000Z

145

Selection Tests of MnZn and NiZn Ferrites for Mu2e 300 kHz and 5.1 MHz AC Dipoles  

SciTech Connect

Mu2e, a charged lepton flavor violation (CLFV) experiment is planned to start at Fermilab late in this decade. The proposed experiment will search for neutrinoless muon to electron conversions with unprecedented sensitivity, better than 6 x 10{sup -17 }at 90% CL. To achieve this sensitivity the incoming proton beam must be highly suppressed during the window for detecting the muon decays. The current proposal for beam extinction is based on a collimator design with two dipoles running at {approx}300 kHz and 5.1 MHz and synchronized to the proton bunch spacing. The appropriate choice of ferrite material for the magnet yoke is a critical step in the overall design of the dipoles and their reliable operation at such high frequencies over the life of the experiment. This choice, based on a series of the thermal and magnetic measurements of the ferrite samples, is discussed in the paper. Additionally, the first results from the testing at 300 kHz of a prototype AC dipole are presented.

Bourkland, K.; Elementi, L.; Feher, S.; Harding, D.J.; Kashikhin, V.S.; Makarov, A.; Pfeffer, H.; Velev, G.V.; /Fermilab; Mulushev, E.; /Institute of Automatics and Electrometry; Iedmeska, I.; /Moscow, MIPT; Venturini, M.; /Pisa U.

2011-09-09T23:59:59.000Z

146

Ironless Permanent Magnet Motors: Three-Dimensional Analytical Calculation  

E-Print Network (OSTI)

1 Ironless Permanent Magnet Motors: Three-Dimensional Analytical Calculation Romain Ravaud, Guy and the rotor of an ironless permanent magnet motor. The calculations are carried out without using any, torque, magnetic field, PM Synchronous motors ! 1 INTRODUCTION IRONLESS electrical machines are generally

Paris-Sud XI, Université de

147

Interlanguages and synchronic models of computation  

E-Print Network (OSTI)

A novel language system has given rise to promising alternatives to standard formal and processor network models of computation. An interstring linked with a abstract machine environment, shares sub-expressions, transfers data, and spatially allocates resources for the parallel evaluation of dataflow. Formal models called the a-Ram family are introduced, designed to support interstring programming languages (interlanguages). Distinct from dataflow, graph rewriting, and FPGA models, a-Ram instructions are bit level and execute in situ. They support sequential and parallel languages without the space/time overheads associated with the Turing Machine and l-calculus, enabling massive programs to be simulated. The devices of one a-Ram model, called the Synchronic A-Ram, are fully connected and simpler than FPGA LUT's. A compiler for an interlanguage called Space, has been developed for the Synchronic A-Ram. Space is MIMD. strictly typed, and deterministic. Barring memory allocation and compilation, modules are ref...

Berka, Alexander Victor

2010-01-01T23:59:59.000Z

148

Control and Synchronization of Neuron Ensembles  

E-Print Network (OSTI)

Synchronization of oscillations is a phenomenon prevalent in natural, social, and engineering systems. Controlling synchronization of oscillating systems is motivated by a wide range of applications from neurological treatment of Parkinson's disease to the design of neurocomputers. In this article, we study the control of an ensemble of uncoupled neuron oscillators described by phase models. We examine controllability of such a neuron ensemble for various phase models and, furthermore, study the related optimal control problems. In particular, by employing Pontryagin's maximum principle, we analytically derive optimal controls for spiking single- and two-neuron systems, and analyze the applicability of the latter to an ensemble system. Finally, we present a robust computational method for optimal control of spiking neurons based on pseudospectral approximations. The methodology developed here is universal to the control of general nonlinear phase oscillators.

Li, Jr-Shin; Ruths, Justin

2011-01-01T23:59:59.000Z

149

Synchronous Squamous Cell Carcinoma in Multiple Digits  

E-Print Network (OSTI)

Cancers of the perionychium are relatively rare occurrences and are often related to chronic inflammation associated with trauma, infection, exposure to ultraviolet radiation, or other carcinogens. Squamous cell carcinoma is the most common tumor reported of the nail bed. Synchronous squamous cell carcinomas of the perionychium have been rarely reported. We present a case of a 46-year-old woman with synchronous squamous cell carcinomas involving both hands and multiple digits. Treatment modalities include chemotherapeutics, Mohs surgery, and amputation. Early diagnosis of squamous cell carcinoma of the nail bed provides the greatest chance to preserve maximal function of the hand. Onychomycosis may be the presenting symptom of a patient with squamous cell carcinoma and may also be a predisposing factor in patients with occupational risk factors. Suspicion of this disease process can help the clinician establish the diagnosis via biopsy and provide optimal care for these patients. Cancers of the perionychium are relatively rare occurrences and are often related to chronic inflammation associated with trauma, infection, exposure to ultraviolet radiation, or other carcinogens. Squamous cell carcinoma is the most common tumor reported of the nail bed. Synchronous squamous cell carcinomas of the perionychium have been rarely reported. We present a case of a 46-year-old woman with synchronous squamous cell carcinomas involving both hands and multiple digits. CASE REPORT A 46-year-old white female was referred from the dermatology clinic with a biopsy-proven squamous cell carcinoma of the left ring finger perionychium. Physical examination demonstrated erythematous scaly lesions with the absence of a nail plate at the left thumb, index Authors have no financial disclaimers or conflicts to disclose. 70 ABNER ET AT finger, and ring finger as well as the right long finger, without associated lymphadenopathy (Fig 1). She described chronic onychomycosis of the nails attributed to her job as a dishwasher.

Morton L. Kasdan; Bradon J. Wilhelmi; Mda A B

2011-01-01T23:59:59.000Z

150

ACS | Open Energy Information  

Open Energy Info (EERE)

ACS ACS Jump to: navigation, search Name ACS Place Madrid, Spain Zip 28036 Sector Solar Product Madrid based construction company involved in the development of solar thermal projects. Coordinates 40.4203°, -3.705774° 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":40.4203,"lon":-3.705774,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

151

AC | OpenEI  

Open Energy Info (EERE)

AC AC Dataset Summary Description The following data-set is for a benchmark residential home for all TMY3 locations across all utilities in the US. The data is indexed by utility service provider which is described by its "unique" EIA ID ( Source National Renewable Energy Laboratory Date Released April 05th, 2012 (2 years ago) Date Updated April 06th, 2012 (2 years ago) Keywords AC apartment CFL coffeemaker Computer cooling cost demand Dishwasher Dryer Furnace gas HVAC Incandescent Laptop load Microwave model NREL Residential television tmy3 URDB Data text/csv icon Residential Cost Data for Common Household Items (csv, 14.5 MiB) Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Annually Time Period License License Open Data Commons Public Domain Dedication and Licence (PDDL)

152

ETA-AC002  

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

2 2 Revision 2 Effective March 1, 1997 "Control of Test Conduct" Prepared by Electric Transportation Applications Prepared by: _______________________________ Date:__________ Jude M. Clark Approved by: _________________________________________________ Date: _______________ Donald B. Karner Procedure ETA-AC002 Revision 2 2 ©1997 Electric Transportation Applications All Rights Reserved TABLE OF CONTENTS 1.0 Objectives 3 2.0 Purpose 3 3.0 Documentation 3 4.0 Initial Conditions and Prerequisites 4 5.0 Personnel Qualifications 5 6.0 Activity Requirements 6 7.0 Supplemental Activity Requirements 8 8.0 Glossary 9 9.0 References 10 Procedure ETA-AC002 Revision 2 3 ©1997

153

ETA-AC006  

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

6 6 Revision 2 Effective: March 1, 1997 Vehicle Verification Prepared by Electric Transportation Applications Prepared by: _______________________________ Date:__________ Jude M. Clark Approved by: _________________________________________________ Date: ______________ Donald B. Karner ETA-AC006 Revision 2 2 ©1997 Electric Transportation Applications All Rights Reserved TABLE OF CONTENTS 1.0 Objectives 3 2.0 Purpose 3 3.0 Documentation 3 4.0 Initial Conditions and Prerequisites 4 5.0 Verification Requirements 5 6.0 Glossary 11 7.0 References 12 Appendices Appendix A - Manufacturer's Proposal Review Check List 13 Appendix B - Vehicle Receipt Check List 18 ETA-AC006 Revision 2 3

154

Broken Bar Detection in Synchronous Machines Based Wind Energy Conversion System  

E-Print Network (OSTI)

Electrical machines are subject to different types of failures. Early detection of the incipient faults and fast maintenance may prevent costly consequences. Fault diagnosis of wind turbine is especially important because they are situated at extremely high towers and therefore inaccessible. For offshore plants, bad weather can prevent any repair actions for several weeks. In some of the new wind turbines synchronous generators are used and directly connected to the grid without the need of power converters. Despite intensive research efforts directed at rotor fault diagnosis in induction machines, the research work pertinent to damper winding failure of synchronous machines is very limited. This dissertation is concerned with the in-depth study of damper winding failure and its traceable symptoms in different machine signals and parameters. First, a model of a synchronous machine with damper winding based on the winding function approach is presented. Next, simulation and experimental results are presented and discussed. A specially designed inside-out synchronous machine with a damper winding is employed for the experimental setup. Finally, a novel analytical method is developed to predict the behavior of the left sideband amplitude for different numbers and locations of the broken bars. This analysis is based on the magnetic field theory and the unbalanced multiphase circuits. It is found that due to the asymmetrical structure of damper winding, the left sideband component in the stator current spectrum of the synchronous machine during steady state asynchronous operation is not similar to that of the induction machine with broken bars. As a result, the motor current signature analysis (MCSA) for detection rotor failures in the induction machine is usable to detect broken damper bars in synchronous machines. However, a novel intelligent-systems based approach is developed that can identify the severity of the damper winding failure. This approach potentially can be used in a non-invasive condition monitoring system to monitor the deterioration of a synchronous motor damper winding as the number of broken bars increase over time. Some other informative features such as speed spectrum, transient time, torque-speed curve and rotor slip are also found for damper winding diagnosis.

Rahimian, Mina Mashhadi

2011-08-01T23:59:59.000Z

155

A three-sphere swimmer for flagellar synchronization  

E-Print Network (OSTI)

In a recent letter (Friedrich et al., Phys. Rev. Lett. 109:138102, 2012), a minimal model swimmer was proposed that propels itself at low Reynolds numbers by a revolving motion of a pair of spheres. The motion of the two spheres can synchronize by virtue of a hydrodynamic coupling that depends on the motion of the swimmer, but is rather independent of direct hydrodynamic interactions. This novel synchronization mechanism could account for the synchronization of a pair of flagella, e.g. in the green algae Chlamydomonas. Here, we discuss in detail how swimming and synchronization depend on the geometry of the model swimmer and compute the swimmer design for optimal synchronization. Our analysis highlights the role of broken symmetries for swimming and synchronization.

Katja Polotzek; Benjamin M. Friedrich

2012-11-26T23:59:59.000Z

156

Efficient synchronization of structurally adaptive coupled Hindmarsh-Rose neurons  

E-Print Network (OSTI)

The use of spikes to carry information between brain areas implies complete or partial synchronization of the neurons involved. The degree of synchronization reached by two coupled systems and the energy cost of maintaining their synchronized behaviour is highly dependent on the nature of the systems. For non-identical systems the maintenance of a synchronized regime is energetically a costly process. In this work, we study conditions under which two non-identical electrically coupled neurons can reach an efficient regime of synchronization at low energy cost. We show that the energy consumption required to keep the synchronized regime can be spontaneously reduced if the receiving neuron has adaptive mechanisms able to bring its biological parameters closer in value to the corresponding ones in the sending neuron.

A. Moujahid; A. d'Anjou; F. J. Torrealdea

2012-03-05T23:59:59.000Z

157

Nonlinear Synchronization Analysis of Spatiotemporal Heart Data  

Science Conference Proceedings (OSTI)

A high?speed video camera and voltage?sensitive dyes were used to acquire high resolution (8080 pixels) and high?speed (500 ?s/frame) optical signals of ventricular fibrillation in a Langendorff?perfused porcine heart. The resulting spatiotemporal dynamics were recorded before and after the application of a defibrillation shock in order to study the mechanism of defibrillation failure. We calculate nonlinear synchronization index measures to qualify the evolution of different types of activity on the heart surface (focal

Jennifer D. Simonotto; Michael D. Furman; Mark L. Spano; William L. Ditto; Gang Liu; Katherine M. Kavanagh

2003-01-01T23:59:59.000Z

158

2013 Telcordia-NIST-ATIS Workshop on Synchronization in ...  

Science Conference Proceedings (OSTI)

... For the first time, we are in Silicon Valley. ... Strong synchronization is central to LTE, driven by ... interactive Workshop in San Jose California , April 16 ...

159

Projective Synchronization and Control of Unified Chaotic System  

E-Print Network (OSTI)

The problem of projective synchronization(ps) and control are studied in modified unified chaotic system which possess partially linearity property. The desired ratio factor of corresponding subsystem variable could be obtained by state feedback control. Theoretical analysis and numerical simulations are provided to illustrate the projective synchronization and the feasibility of the proposed control method. The effect on projective synchronization caused by channel noise and parameter mismatch are investigated in detail, the results showed that parameter mismatch has more effect on projective synchronization than channel noise does, which may be applied to chaotic secure communications.

Liang Feng; Xiang Jinglin; Chen Shaohua; Shi Jie

2005-05-01T23:59:59.000Z

160

PC-Cluster-Based Real-Time Simulation of an 8 synchronous machines network with HVDC link using  

E-Print Network (OSTI)

AbstractIn this paper, we detail the real-time simulation results of a medium-sized network composed of 8 synchronous machines and an HVDC link. The model is composed of two Kundur-like 4 machines networks connected together with a 12pulse HVDC link. The complete network is modeled with SimPowerSystems with ARTEMIS real-time plug-in and is simulated in real-time on a RT-LAB InfiniBand PC-cluster composed of 3 dual-CPU dual-core Opteron PCs. The network model includes the HVDC control and protection systems as well as the synchronous machine regulators and power stabilizers. It also includes typical fault simulation capability like HVDC DC faults, thyristor misfires and AC faults. This model is excellent to study the complex interactions between an HVDC link and AC network under normal and transient conditions. The real-time simulation is controlled and monitored with a TestDrive interface from Opal-RT. This interface, based on LabView, permits easy monitoring and control of the complete system and enables Python-based scripting for automated tests. The proposed simulator can be interfaced with external equipments and controllers by direct reconfiguration of a FPGA I/O card with Xilinx System Generator blockset.

Christian Dufour; Jean-nicolas Paquin; Vincent Lapointe; Jean Blanger; Loic Schoen

2007-01-01T23:59:59.000Z

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We encourage you to perform a real-time search of NLEBeta
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161

Performance of memory reclamation for lockless synchronization  

E-Print Network (OSTI)

Achieving high performance for concurrent applications on modern multiprocessors remains challenging. Many programmers avoid locking to improve performance, while others replace locks with non-blocking synchronization to protect against deadlock, priority inversion, and convoying. In both cases, dynamic data structures that avoid locking require a memory reclamation scheme that reclaims elements once they are no longer in use. The performance of existing memory reclamation schemes has not been thoroughly evaluated. We conduct the first fair and comprehensive comparison of three recent schemesquiescent-state-based reclamation, epoch-based reclamation, and hazard-pointer-based reclamationusing a flexible microbenchmark. Our results show that there is no globally optimal scheme. When evaluating lockless synchronization, programmers and algorithm designers should thus carefully consider the data structure, the workload, and the execution environment, each of which can dramatically affect the memory reclamation performance. We discuss the consequences of our results for programmers and algorithm designers. Finally, we describe the use of one scheme, quiescentstate-based reclamation, in the context of an OS kernelan execution environment which is well suited to this scheme.

Thomas E. Hart; Paul E. McKenney; Angela Demke Brown; Jonathan Walpole

2007-01-01T23:59:59.000Z

162

AC Propulsion | Open Energy Information  

Open Energy Info (EERE)

founded in 1992 to develop, manufacture, and license system and component technology for electric vehicle drive systems. References AC Propulsion1 LinkedIn Connections...

163

Processus communicants Communication synchrone CSP/CCS/-calcul  

E-Print Network (OSTI)

Processus communicants Communication synchrone CSP/CCS/-calcul Rendez-vous étendu Ada Huitième partie Processus communicants CSP/Ada Systèmes concurrents 2 / 44 #12;Processus communicants Communication synchrone CSP/CCS/-calcul Rendez-vous étendu Ada Principes Synchronisation Désignation

Grigoras, .Romulus

164

Resilient synchronization in robust networked multi-agent systems  

Science Conference Proceedings (OSTI)

In this paper, we study local interaction rules that enable a network of dynamic agents to synchronize to a common zero-input state trajectory despite the malicious influence of a subset of adversary agents. The agents in the networked system influence ... Keywords: adversary, networked multi-agent system, resilience, synchronization

Heath J. LeBlanc; Xenofon D. Koutsoukos

2013-04-01T23:59:59.000Z

165

Improving broadcast efficiency in wireless sensor network time synchronization protocols  

Science Conference Proceedings (OSTI)

In this work we proposed an algorithm to allow nodes in a wireless sensor network to interconnect in a way such that time stamp information can be efficiently distributed for network wide synchronization. The algorithm works by first establishing a level ... Keywords: broadcast optimization, sensor networks, time synchronization

Wenxun Huang; Yujuan Quan; Deming Chen

2012-06-01T23:59:59.000Z

166

An efficient and secure protocol for sensor network time synchronization  

Science Conference Proceedings (OSTI)

The emerging field of wireless sensor networks offers countless possibilities for achieving large scale monitoring in a distributed environment. These networks of resource constrained nodes require time synchronization for various distributed operations, ... Keywords: cross-layer control, passive participation, sensor networks, tempest, time synchronization

Emerson Farrugia; Robert Simon

2006-02-01T23:59:59.000Z

167

Supporting research collaboration through bi-level file synchronization  

Science Conference Proceedings (OSTI)

In this paper, we describe the design and use of Cimetric, a file synchronization application that supports scholarly collaboration. The system design incorporates results of earlier studies that suggest replicating content on a user's personal devices ... Keywords: cloud storage, file synchronization, scholarly collaboration

Catherine C. Marshall; Ted Wobber; Venugopalan Ramasubramanian; Douglas B. Terry

2012-10-01T23:59:59.000Z

168

Enriching music with synchronized lyrics, images and colored lights  

Science Conference Proceedings (OSTI)

We present a method to synchronize popular music with its lyrics at the stanza level. First we apply an algorithm to segment audio content into harmonically similar and/or contrasting progressions, i.e. the stanzas. We map the stanzas found to a sequence ... Keywords: ambience creation, color extraction, images, lyrics synchronization, multimedia, search engines, term identification, world wide web

Gijs Geleijnse; Dragan Sekulovski; Jan Korst; Steffen Pauws; Bram Kater; Fabio Vignoli

2008-02-01T23:59:59.000Z

169

May, Locascio Honored as ACS Fellows  

Science Conference Proceedings (OSTI)

May, Locascio Honored as ACS Fellows. ... May and Locascio will be inducted as fellows during the ACS National Meeting in Denver, Colo., on Aug. ...

2011-08-16T23:59:59.000Z

170

2528 IEEE TRANSACTIONS ON MAGNETICS, VOL. 43, NO. 6, JUNE 2007 A Highly Efficient 200 000 RPM Permanent Magnet Motor System  

E-Print Network (OSTI)

Permanent Magnet Motor System Limei Zhao1, Chan Ham2, Liping Zheng3, Thomas Wu4, Kalpathy Sundaram4, Jay presents the development of an ultra-high-speed permanent magnet synchronous motor (PMSM) that produces effectiveness. Index Terms--Permanent magnet, motor, stability, ultra-high-speed. I. INTRODUCTION DUE

Wu, Shin-Tson

171

Alternative Fuels at AC Transit  

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

Alternative Fuels at AC Transit Alternative Fuels at AC Transit Speaker(s): Jaimie Levin Date: November 1, 2011 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Eve Edelson Mr. Levin will discuss AC Transit's range of environmental technology initiatives, including: zero emission fuel cell transit buses; state-of-the-art, high-capacity, hydrogen fueling stations; solar energy systems; and stationary solid oxide fuel cell power generators. AC Transit has the largest fleet of fuel cell buses in the United States, featuring fuel cell systems with more than 10,000 hours of continuous operation without any failures or power degradation. Their fuel cell fleet has logged more than 400,000 miles of service and carried in excess of one million passengers. Come hear what AC Transit has learned, where they're headed,

172

Nanocrystalline and Nanocomposite Nd-Fe-B Magnets  

Science Conference Proceedings (OSTI)

Mar 2, 2011 ... Funding provided by DOE-EERE-FCVT Office through Ames Lab Contract No. DE-AC02-07CH11358. 5:20 PM Structure and Magnetic...

173

Optimal Magnetic Shield Design with SecondOrder Cone ...  

E-Print Network (OSTI)

... 106-8569 Japan. (tsuchiya@sun312.ism.ac.jp). 1 ... In this paper, a real-world optimal magnetic shielding design problem which arises in the development of...

174

AC resistance measuring instrument  

DOE Patents (OSTI)

An auto-ranging AC resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an AC excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance. After the auto-ranging and auto-compensation functions are complete, the microprocessor calculates the resistance of the load from the selected range resistance, the excitation signal, and the load voltage signal, and displays of the measured resistance on a digital display of the instrument. 8 figs.

Hof, P.J.

1983-10-04T23:59:59.000Z

175

Synchronization of sub-picosecond electron and laser pulses  

SciTech Connect

Sub-picosecond laser-electron synchronization is required to take full advantage of the experimental possibilities arising from the marriage of modern high intensity lasers and high brightness electron beams in the same laboratory. Two particular scenarios stand out in this regard, injection of ultra-short electron pulses in short wavelength laser-driven plasma accelerators, and Compton scattering of laser photons from short electron pulses. Both of these applications demand synchronization, which is sub-picosecond, with tens of femtosecond synchronization implied for next generation experiments. The design of a microwave timing modulator system is now being investigated in more detail. (AIP) {copyright} {ital 1999 American Institute of Physics.}

Rosenzweig, J.B. [UCLA Department of Physics and Astronomy, 405 Hilgard Ave., Los Angeles, California 90095 (United States); Le Sage, G.P. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)

1999-07-01T23:59:59.000Z

176

Synchronization of sub-picosecond electron and laser pulses  

SciTech Connect

Sub-picosecond laser-electron synchronization is required to take full advantage of the experimental possibilities arising from the marriage of modern high intensity lasers and high brightness electron beams in the same laboratory. Two particular scenarios stand out in this regard, injection of ultra-short electron pulses in short wavelength laser-driven plasma accelerators, and Compton scattering of laser photons from short electron pulses. Both of these applications demand synchronization, which is sub-picosecond, with tens of femtosecond synchronization implied for next generation experiments. The design of a microwave timing modulator system is now being investigated in more detail.

Rosenzweig, J. B.; Le Sage, G. P. [UCLA Department of Physics and Astronomy, 405 Hilgard Ave., Los Angeles, California 90095 (United States); Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550 (United States)

1999-07-12T23:59:59.000Z

177

Robust Generator System Using PM Assisted Synchronous Reluctance Generator with Current-fed Drive  

E-Print Network (OSTI)

The growth of embedded generation and portable electrical installations has led to an increased demand for low cost, flexible and reliable generator systems for military and commercial applications. An interior permanent magnet (IPM) machine has high power density due to its reluctance torque and magnetic torque components so it can produce a large constant power-speed range. However, an IPM machine needs demagnetizing current at high-speed during the flux-weakening region and thus develops an inverter shutdown problem in an uncontrolled generator mode operation. In order to overcome the disadvantages of the IPM machine, the permanent magnet assisted synchronous reluctance generator (PMa-SynRG) can be a good solution for low cost, high efficiency reliable generator systems. A PMa-SynRG can produce a high efficiency drive by utilizing the proper amount of magnet and reluctance torque. This work proposes a PMa-SynRG with two flux barriers and permanent magnets embedded in the second layer of the rotor. A neodymium magnet (NdFeB) was used as permanent magnets in the rotor to prevent demagnetization. Finding the minimum amount of magnet is one of the goals of the optimization process. The objectives of this work are to build an optimal design for the 3kW generator and an advanced power electronics converter for the PMa-SynRG drive system. In order to find the optimized 3kW machine, a Lumped Parameter Model (LPM) was used to achieve fast computation, and Differential Evolution Strategy (DES) was used to embed the LPM in an efficient numerical optimization routine to identify optimum designs. Finite Element Analysis (FEA) was used for test performance of optimum designs. On the basis of differences between LPM and FEA, model predictions were used to fine tune the LPM model. For new optimum design converges, numerical optimizations and iterations were performed to produce LPM and FEA predictions. For the drive system, the thyristor based, current-fed drive is much simpler and has lower power losses compared to the pulse width modulation (PWM) drive. Eliminating the requirement for self-controlled switches is a distinct advantage for lower cost. Another feature of the developed current-fed drive is its inherent capability to provide generating action by making the PMa-SynRG operates as a generator, rectifying the phase voltages by means of the three-phase rectifier and feeding the power into the load. These features make the current-fed drive a good candidate for driving any type of synchronous generators including the proposed PMa-SynRG.

Baek, Jeihoon

2009-12-01T23:59:59.000Z

178

Bipolar pulse field for magnetic refrigeration  

DOE Patents (OSTI)

A magnetic refrigeration apparatus includes first and second steady state magnets, each having a field of substantially equal strength and opposite polarity, first and second bodies made of magnetocaloric material disposed respectively in the influence of the fields of the first and second steady state magnets, and a pulsed magnet, concentric with the first and second steady state magnets, and having a field which cycles between the fields of the first and second steady state magnets, thereby cyclically magnetizing and demagnetizing and thus heating and cooling the first and second bodies. Heat exchange apparatus of suitable design can be used to expose a working fluid to the first and second bodies of magnetocaloric material. A controller is provided to synchronize the flow of working fluid with the changing states of magnetization of the first and second bodies. 2 figs.

Lubell, M.S.

1994-10-25T23:59:59.000Z

179

Weights and Measures State Directors AC  

Science Conference Proceedings (OSTI)

State Directors AC. Alaska. Mailing Address, Contact Information. Alaska Division of Measurement Standards/CVE 11900 ...

2013-05-03T23:59:59.000Z

180

Title Offline Trace Synchronization for Smartphone Energy Profiling  

E-Print Network (OSTI)

Energy profiling is a means to effectively understand the power behavior of smartphone applications. However, no tool that effectively combines portability, accuracy and automation has been proposed yet. In this thesis a new approach is proposed, which sets the basis for such a tool by solving a trace synchronization problem. TRAM (TRAce Merger) uses the event trace from a mobile device and the power trace from a measurement device. It synchronizes them offline, maps the mobile device events trace on the corresponding trace from the power measurement tool, and attributes energy consumption to smartphone functionalities. The event and power traces traces from these two systems contain timestamps based on the corresponding local clocks. Taking the aforementioned clocks inaccuracy and deviation into account, we synchronize these traces to extract useful information from their contents. We achieved energy consumption attribution to smartphone functionalities by solving this synchronization problem with milliseconds accuracy.

Ioannis Oikonomidis; Offline Trace; Synchronization Smartphone; Ioannis Oikonomidis; Msc Presentation

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnet ac synchronous" 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

A state estimator including conventional and synchronized phasor measurements  

Science Conference Proceedings (OSTI)

This paper presents an effective weighted least square formulation for the solution of the state estimation problem, considering conventional as well as synchronized phasor measurements. The proposed algorithm is based on a reference-free formulation, ...

George N. Korres; Nikolaos M. Manousakis

2012-03-01T23:59:59.000Z

182

A higher-order extension for imperative synchronous languages  

Science Conference Proceedings (OSTI)

This article presents the very first effective design of higher-order modules in the synchronous programming language Esterel. Higher-order modules, together with the robust separate compilation scheme that implements it, allow us to address a yet unexplored ...

Eric Vecchi; Jean-Pierre Talpin; Sbastien Boisgrault

2010-06-01T23:59:59.000Z

183

Estimation of Surface Insolation Using Sun-Synchronous Satellite Data  

Science Conference Proceedings (OSTI)

A technique is presented for estimating insulation at the Earth's surface using only sun-synchronous satellite data. The technique was tested by comparing the insolation results from year-long satellite datasets with simultaneous ground-measured ...

Wayne L. Darnell; W. Frank Staylor; Shashi K. Gupta; Frank M. Denn

1988-08-01T23:59:59.000Z

184

Repository Synchronization in the OAI Framework Xiaoming Liu  

E-Print Network (OSTI)

Repository Synchronization in the OAI Framework Xiaoming Liu Research Library Los Alamos Research Laboratory Los Alamos, NM, 87544 liu x@lanl.gov Kurt Maly Mohammad Zubair Michael L. Nelson Computer Science

Nelson, Michael L.

185

Cryptographic synchronization recovery by measuring randomness of decrypted data  

DOE Patents (OSTI)

The invention relates to synchronization of encrypted data communication systems and a method which looks for any lack of pattern or intelligent information in the received data and triggers a resynchronization signal based thereon. If the encrypter/decrypter pairs are out of cryptographic synchronization, the received (decrypted) data resembles pseudorandom data. A method and system are provided for detecting such pseudorandom binary data by, for example, ones density. If the data is sufficiently random the system is resynchronized.

Maestas, Joseph H. (Albuquerque, NM); Pierson, Lyndon G. (Albuquerque, NM)

1990-01-01T23:59:59.000Z

186

Stability of Synchronized Chaos in Coupled Dynamical Systems  

E-Print Network (OSTI)

We consider the stability of synchronized chaos in coupled map lattices and in coupled ordinary differential equations. Applying the theory of Hermitian and positive semidefinite matrices we prove two results that give simple bounds on coupling strengths which ensure the stability of synchronized chaos. Previous results in this area involving particular coupling schemes (e.g. global coupling and nearest neighbor diffusive coupling) are included as special cases of the present work.

Govindan Rangarajan; Mingzhou Ding

2002-01-21T23:59:59.000Z

187

Systems and methods for creation of conducting networks of magnetic particles through dynamic self-assembly process  

DOE Patents (OSTI)

Self-assembly of magnetic microparticles in AC magnetic fields. Excitation of the system by an AC magnetic field provides a variety of patterns that can be controlled by adjusting the frequency and the amplitude of the field. At low particle densities the low-frequency magnetic excitation favors cluster phase formation, while high frequency excitation favors chains and netlike structures. For denser configurations, an abrupt transition to the network phase was obtained.

Snezhko, Oleksiy (Woodridge, IL); Aronson, Igor (Darien, IL); Kwok, Wai-Kwong (Downers Grove, IL)

2011-01-25T23:59:59.000Z

188

Ac traction gets on track  

Science Conference Proceedings (OSTI)

This article describes inverter-based ac traction systems which give freight locomotives greater adhesion, pulling power, and braking capacity. In the 1940s, dc traction replaced the steam engine as a source of train propulsion, and it has ruled the freight transportation industry ever since. But now, high-performance ac-traction systems, with their unprecedented levels of pulling power and adhesion, are becoming increasingly common on America`s freight railroads. In thousands of miles of demonstration tests, today`s ac-traction systems have outperformed traditional dc-motor driven systems. Major railroad companies are convinced enough of the benefits of ac traction to have integrated it into their freight locomotives.

O`Connor, L.

1995-09-01T23:59:59.000Z

189

Sensitivity of OFDM Systems to Synchronization Errors and Spatial Diversity  

E-Print Network (OSTI)

In this dissertation, the problem of synchronization for OFDM-based wireless communication systems is studied. In the first part of this dissertation, the sensitivity of both single input single output (SISO) OFDM and multiple input multiple output (MIMO) OFDM receivers to carrier and timing synchronization errors are analyzed. Analytical expressions and numerical results for the power of inter-carrier interference (ICI) are presented. It is shown that the OFDM-based receivers are quite sensitive to residual synchronization errors. In wide-sense stationary uncorrelated scattering (WSSUS) frequency-selective fading channels, the sampling clock timing offset results in rotation of the subcarrier constellation, while carrier frequency offsets and phase jitter cause inter-carrier interference. The overall system performance in terms of symbol error rate is limited by the inter-carrier interference. For a reliable information reception, compensatory measures must be taken. The second part of this dissertation deals with the impact of spatial diversity (usage of multiple transmit/receive antennas) on synchronization. It is found that with multiple transmit and receive antennas, MIMO-OFDM systems can take advantage of the spatial diversity to combat carrier and timing synchronization imperfections. Diversity can favorably improve the synchronization performance. Data-aided and non-data-aided maximum likelihood symbol timing estimators for MIMO-OFDM systems are introduced. Computer simulations show that, by exploiting the spatial diversity, synchronization performance of MIMO-OFDM systems in terms of mean squared error (MSE) of residual timing offset becomes significantly more reliable when compared to conventional SISO OFDM systems. Therefore, spatial diversity is a useful technique to be exploited in the deployment of MIMO-OFDM communication systems. In MIMO systems with synchronization sequences, timing synchronization is treated as a multiple hypotheses testing problem. Generalized likelihood ratio test (GLRT) statistics are developed for MIMO systems in frequency flat channels and MIMO-OFDM systems in frequency selective fading environments. The asymptotic performance of the GLRT without nuisance parameters is carried out. It is shown that the asymptotic performance of the GLRT can serve as an upper bound for the detection probability in the presence of a limited number of observations as well as a benchmark for comparing the performances of different timing synchronizers.

Zhou, Yi

2010-12-01T23:59:59.000Z

190

Measurements of AC Losses and Current Distribution in Superconducting Cables  

Science Conference Proceedings (OSTI)

This paper presents our new experimental facility and techniques to measure ac loss and current distribution between the layers for High Temperature Superconducting (HTS) cables. The facility is powered with a 45 kVA three-phase power supply which can provide three-phase currents up to 5 kA per phase via high current transformers. The system is suitable for measurements at any frequency between 20 and 500 Hz to better understand the ac loss mechanisms in HTS cables. In this paper, we will report techniques and results for ac loss measurements carried out on several HTS cables with and without an HTS shielding layer. For cables without a shielding layer, care must be taken to control the effect of the magnetic fields from return currents on loss measurements. The waveform of the axial magnetic field was also measured by a small pick-up coil placed inside a two-layer cable. The temporal current distribution between the layers can be calculated from the waveform of the axial field.

Nguyen, Doan A [Los Alamos National Laboratory (LANL); Ashworth, Stephen P [Los Alamos National Laboratory (LANL); Duckworth, Robert C [ORNL; Carter, Bill [AMSC; Fleshler, Steven [AMER Superconductor Corp, Devens, MA 01434

2011-01-01T23:59:59.000Z

191

Synchronization in Complex Oscillator Networks and Smart Grids  

SciTech Connect

The emergence of synchronization in a network of coupled oscillators is a fascinating topic in various scientific disciplines. A coupled oscillator network is characterized by a population of heterogeneous oscillators and a graph describing the interaction among them. It is known that a strongly coupled and sufficiently homogeneous network synchronizes, but the exact threshold from incoherence to synchrony is unknown. Here we present a novel, concise, and closed-form condition for synchronization of the fully nonlinear, non-equilibrium, and dynamic network. Our synchronization condition can be stated elegantly in terms of the network topology and parameters, or equivalently in terms of an intuitive, linear, and static auxiliary system. Our results significantly improve upon the existing conditions advocated thus far, they are provably exact for various interesting network topologies and parameters, they are statistically correct for almost all networks, and they can be applied equally to synchronization phenomena arising in physics and biology as well as in engineered oscillator networks such as electric power networks. We illustrate the validity, the accuracy, and the practical applicability of our results in complex networks scenarios and in smart grid applications.

Dorfler, Florian [Los Alamos National Laboratory; Chertkov, Michael [Los Alamos National Laboratory; Bullo, Francesco [Center for Control, Dynamical Systems and Computation, University of California at Santa Babara, Santa Barbara CA

2012-07-24T23:59:59.000Z

192

Synchronization in Complex Oscillator Networks and Smart Grids  

E-Print Network (OSTI)

The emergence of synchronization in a network of coupled oscillators is a fascinating topic in various scientific disciplines. A coupled oscillator network is characterized by a population of heterogeneous oscillators and a graph describing the interaction among them. It is known that a strongly coupled and sufficiently homogeneous network synchronizes, but the exact threshold from incoherence to synchrony is unknown. Here we present a novel, concise, and closed-form condition for synchronization of the fully nonlinear, non-equilibrium, and dynamic network. Our synchronization condition can be stated elegantly in terms of the network topology and parameters, or equivalently in terms of an intuitive, linear, and static auxiliary system. Our results significantly improve upon the existing conditions advocated thus far, they are provably exact for various interesting network topologies and parameters, they are statistically correct for almost all networks, and they can be applied equally to synchronization phenomena arising in physics and biology as well as in engineered oscillator networks such as electric power networks. We illustrate the validity, the accuracy, and the practical applicability of our results in complex networks scenarios and in smart grid applications.

Florian Drfler; Michael Chertkov; Francesco Bullo

2012-07-31T23:59:59.000Z

193

220,000-r/min, 2-kW Permanent Magnet Motor Drive for Turbocharger Toshihiko Noguchi, Yosuke Takata *  

E-Print Network (OSTI)

220,000-r/min, 2-kW Permanent Magnet Motor Drive for Turbocharger Toshihiko Noguchi, Yosuke Takata-speed permanent-magnet synchronous motor drive, which is embedded in a turbocharger of an internal permanent magnet. Also, it is indispensable to reduce the motor inductance less than 10 (µH) because dc bus

Fujimoto, Hiroshi

194

Microsoft Word - HgAcBr  

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

(AC-Br) (DARCO Hg- LH, Norit Americas Inc.) and brominated activated carbon fibers (ACF-Br) (Illinois State Geological Survey and University of Illinois). The AC-Br sorbents...

195

ACS_RRA_2001.PDF  

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

Qualitative and Semi-quantitative Qualitative and Semi-quantitative Analysis Of Semi-volatile Organics from Ambient Air Fine-particulate Matter, PM 2.5 Richard Anderson, Don Martello, Brian R. Strazisar and Curt M. White richard.anderson@netl.doe.gov ACS-222 / RRA' / ST-10 / 8-28-2001 Different Missions * EPA - Protect the public health * DOE - Assist the private sector in supplying clean, abundant, and affordable energy ACS-222 / RRA' / ST-10 / 8-28-2001 PM 2.5 Regulatory Process * 1997 National Ambient Air Quality Standards (NAAQS) for PM 2.5 based on "health effects" - Mean annual concentration < 15 µg/m 3 - Maximum concentration < 65µg/ m 3 ACS-222 / RRA' / ST-10 / 8-28-2001 Why Is DOE Concerned About PM 2.5 ? * Coal-based power systems contribute to PM 2.5 - Primary particles * Ultra-fine fly-ash (Spherical Alumino-silicates,SAS), carbon soot

196

Study of power transfer capability of dc systems incorporating ac loads and a parallel ac line  

Science Conference Proceedings (OSTI)

Concepts of maximum power transfer of dc systems and associated ac voltage variations, particularly at inverter stations having low short-circuit ratios, have been extended to include various ac load models and an ac line in parallel with the dc line. The operating capabilities are shown to vary from those predicted from either a Thevenin ac source model or the corresponding short-circuit ratio. The study used an ac/dc load flow program.

Reeve, J.; Uzunovic, E. [Univ. of Waterloo, Ontario (Canada)

1997-01-01T23:59:59.000Z

197

Detection of synchronization from univariate data using wavelet transform  

E-Print Network (OSTI)

A method is proposed for detecting from univariate data the presence of synchronization of a self-sustained oscillator by external driving with varying frequency. The method is based on the analysis of difference between the oscillator instantaneous phases calculated using continuous wavelet transform at time moments shifted by a certain constant value relative to each other. We apply our method to a driven asymmetric van der Pol oscillator, experimental data from a driven electronic oscillator with delayed feedback and human heartbeat time series. In the latest case, the analysis of the heart rate variability data reveals synchronous regimes between the respiration and slow oscillations in blood pressure.

Alexander E. Hramov; Alexey A. Koronovskii; Vladimir I. Ponomarenko; Mikhail D. Prokhorov

2007-05-24T23:59:59.000Z

198

Time Synchronization in Hierarchical TESLA Wireless Sensor Networks  

SciTech Connect

Time synchronization and event time correlation are important in wireless sensor networks. In particular, time is used to create a sequence events or time line to answer questions of cause and effect. Time is also used as a basis for determining the freshness of received packets and the validity of cryptographic certificates. This paper presents secure method of time synchronization and event time correlation for TESLA-based hierarchical wireless sensor networks. The method demonstrates that events in a TESLA network can be accurately timestamped by adding only a few pieces of data to the existing protocol.

Jason L. Wright; Milos Manic

2009-08-01T23:59:59.000Z

199

Femtosecond Synchronization of Laser Systems for the LCLS  

SciTech Connect

The scientific potential of femtosecond x-ray pulses at linac-driven free-electron lasers such as the Linac Coherent Light Source is tremendous. Time-resolved pump-probe experiments require a measure of the relative arrival time of each x-ray pulse with respect to the experimental pump laser. An optical timing system based on stabilized fiber links has been developed for the LCLS to provide this synchronization. Preliminary results show synchronization of the installed stabilized links at the sub-20-femtosecond level. We present details of the implementation at LCLS and potential for future development.

Byrd, John; /LBL, Berkeley; Doolittle, Lawrence; /LBL, Berkeley; Huang, Gang; /LBL, Berkeley; Staples, John; /LBL, Berkeley; Wilcox, Russell; /LBL, Berkeley; Arthur, John; /SLAC; Frisch, Josef; /SLAC; White, William; /SLAC

2012-08-24T23:59:59.000Z

200

Superconducting magnetic energy storage for asynchronous electrical systems  

DOE Patents (OSTI)

It is an object of the present invention to provide superconducting magnetic energy storage for a plurality of asynchronous electrical systems. It is a further object of the present invention to provide load leveling and stability improvement in a plurality of independent ac systems using a single superconducting magnetic energy storage coil.

Boenig, H.J.

1984-05-16T23:59:59.000Z

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Magnetic force microscopy method and apparatus to detect and image currents in integrated circuits  

DOE Patents (OSTI)

A magnetic force microscopy method and improved magnetic tip for detecting and quantifying internal magnetic fields resulting from current of integrated circuits. Detection of the current is used for failure analysis, design verification, and model validation. The interaction of the current on the integrated chip with a magnetic field can be detected using a cantilevered magnetic tip. Enhanced sensitivity for both ac and dc current and voltage detection is achieved with voltage by an ac coupling or a heterodyne technique. The techniques can be used to extract information from analog circuits.

Campbell, Ann. N. (13170-B Central SE #188, Albuquerque, NM 87123); Anderson, Richard E. (2800 Tennessee NE, Albuquerque, NM 87110); Cole, Jr., Edward I. (2116 White Cloud NE, Albuquerque, NM 87112)

1995-01-01T23:59:59.000Z

202

Nonlinear control and synchronization of multiple Lagrangian systems with application to tethered formation flight spacecraft  

E-Print Network (OSTI)

This dissertation focuses on the synchronization of multiple dynamical systems using contraction theory, with applications to cooperative control of multi-agent systems and synchronization of interconnected dynamics such ...

Chung, Soon-Jo, 1976-

2007-01-01T23:59:59.000Z

203

Product Form Steady-State Distribution for Stochastic Automata Networks with Domino Synchronizations  

Science Conference Proceedings (OSTI)

We present a new kind of synchronization which allows Continuous Time Stochastic Automata Networks (SAN) to have a product form steady-state distribution. Unlike previous models on SAN with product form solutions, our model allows synchronization between ...

Jean-Michel Fourneau

2008-08-01T23:59:59.000Z

204

A preliminary comparison of synchronous venues for distance learning: traditional videoconferencing vs. web-based conferencing  

Science Conference Proceedings (OSTI)

Synchronous venues are often preferred in distance learning settings as they most closely approximate the face-to-face experience. This paper examines two synchronous venues: videoconferencing and web-based conferencing. Both are compared, ...

Norman A. Garrett

2011-07-01T23:59:59.000Z

205

Ship routing and scheduling with cargo coupling and synchronization constraints  

Science Conference Proceedings (OSTI)

The purpose of this paper is to introduce and solve a planning problem faced by shipping companies operating in a special segment of tramp shipping called project shipping. Project shipping differs from other more traditional tramp segments because the ... Keywords: Path-flow, Ship routing and scheduling, Synchronization

Henrik Andersson; Jon M. Duesund; Kjetil Fagerholt

2011-11-01T23:59:59.000Z

206

Efficient circuit partitioning to extend cycle simulation beyond synchronous circuits  

Science Conference Proceedings (OSTI)

Cycle simulation techniques, such as levelized compiled code, can ordinarily be applied only to synchronous designs. They usually cannot be applied to designs containing circuit features like combinational paths, multiple clock domains, generated clocks, ... Keywords: logic simulation, cycle simulation, circuit partitioning, levelized compiled code

Charles J. DeVane

1997-11-01T23:59:59.000Z

207

Temporal coding with synchronization and acceleration as complementary mechanisms  

Science Conference Proceedings (OSTI)

Temporal coding requires an appropriate combination of synchronizing and desynchronizing mechanisms. We study temporal coding with a desynchronizing mechanism, referred to as acceleration, that causes the units of the network to oscillate with higher ... Keywords: Autoassociative memory, Complex-valued neural networks, Oscillatory networks, Pattern recognition, Temporal coding

Thomas Burwick

2008-03-01T23:59:59.000Z

208

New Synchronous Orbits Using the Geomagnetic Lorentz Force Brett Streetman  

E-Print Network (OSTI)

New Synchronous Orbits Using the Geomagnetic Lorentz Force Brett Streetman and Mason A. Peck the interaction between the Earth's geomagnetic field and an electrostatic charge built up on a satellite [2 causes an interaction between the geomagnetic field and the vehicle in the form of the Lorentz force

Peck, Mason A.

209

New Synchronous Orbits Using the Geomagnetic Lorentz Force  

E-Print Network (OSTI)

New Synchronous Orbits Using the Geomagnetic Lorentz Force Brett Streetman and Mason A. Peck makes use of the interaction between the Earth's geomagnetic field and an electrostatic charge built up an interaction between the geomagnetic field and the vehicle in the form of the Lorentz force. The magnitude

Peck, Mason A.

210

New advances in designing energy efficient time synchronization schemes for wireless sensor networks  

E-Print Network (OSTI)

Time synchronization in wireless sensor networks (WSNs) is essential and significant for maintaining data consistency, coordination, and performing other fundamental operations, such as power management, security, and localization. Energy efficiency is the main concern in designing time synchronization protocols for WSNs because of the limited and generally nonrechargeable power resources. In this dissertation, the problem of time synchronization is studied in three different aspects to achieve energy efficient time synchronization in WSNs. First, a family of novel joint clock offset and skew estimators, based on the classical two-way message exchange model, is developed for time synchronization in WSNs. The proposed joint clock offset and skew correction mechanisms significantly increase the period of time synchronization, which is a critical factor in the over-all energy consumption required for global network synchronization. Moreover, the Cramer-Rao bounds for the maximum likelihood estimators are derived under two different delay assumptions. These analytical metrics serve as good benchmarks for the experimental results thus far reported. Second, this dissertation proposes a new time synchronization protocol, called the Pairwise Broadcast Synchronization (PBS), which aims at minimizing the number of message transmissions and implicitly the energy consumption necessary for global synchronization of WSNs. A novel approach for time synchronization is adopted in PBS, where a group of sensor nodes are synchronized by only overhearing the timing messages of a pair of sensor nodes. PBS requires a far smaller number of timing messages than other well-known protocols and incurs no loss in synchronization accuracy. Moreover, for densely deployed WSNs, PBS presents significant energy saving. Finally, this dissertation introduces a novel adaptive time synchronization protocol, named the Adaptive Multi-hop Timing Synchronization (AMTS). According to the current network status, AMTS optimizes crucial network parameters considering the energy efficiency of time synchronization. AMTS exhibits significant benefits in terms of energy-efficiency, and can be applied to various types of sensor network applications having different requirements.

Noh, Kyoung Lae

2007-08-01T23:59:59.000Z

211

Current Controller with Defined Dynamic Behavior for an Interior Permanent Magnet  

E-Print Network (OSTI)

Current Controller with Defined Dynamic Behavior for an Interior Permanent Magnet Synchronous Motor saturation and changing motor parameters. In this paper a current control scheme is presented that ensures combustion vehicles already provide. Today's modern HEV and EV mostly include interior permanent magnet

Noé, Reinhold

212

Pulsating Torque Reduction for Permanent Magnet Bojan Grcar, Peter Cafuta, Gorazd Stumberger  

E-Print Network (OSTI)

Pulsating Torque Reduction for Permanent Magnet AC Motors Bojan Grcar, Peter Cafuta, Gorazd on the motor design (skewing, shifting the magnet position, special windings, etc.) [5], [6] are in general,MA Abstract-- Control methods for pulsation of torque reduction for the surface-mounted permanent magnet

Stankoviæ, Aleksandar

213

Fault Modeling and Analysis for Resistive Bridging Defects in a Synchronizer  

Science Conference Proceedings (OSTI)

This paper presents fault modeling and analysis for bridging defects in a synchronizer that is implemented by two D flip-flops. Bridging defects are injected into any two nodes of the synchronizer, and HSPICE is used to perform circuit analysis. The ... Keywords: Bridging defect, Fault modeling, Synchronizer

Hyoung-Kook Kim; Wen-Ben Jone; Laung-Terng Wang

2010-06-01T23:59:59.000Z

214

Coordinating, integrating, and synchronizing disaster response : use of an emergency response synchronization matrix in emergency planning, exercises, and operations.  

SciTech Connect

The Chemical Stockpile Emergency Preparedness (CSEP) Program is a wide-ranging activity in support of a national initiative involving the U.S. Army Chemical Materiel Command (CMA), the Federal Emergency Management Agency (FEMA), 9 states, and 37 counties. Established in 1988, the CSEP Program enhances emergency planning for the unlikely event of a release of hazardous chemical weapons agent from one of the Army's chemical weapons storage installations currently storing chemical weapons. These obsolete weapons are scheduled to be destroyed; meanwhile, however, they pose a threat to installation workers and residents of the surrounding communities. Argonne's CSEP Program includes a variety of components that serve the needs of multiple program participants. Among the major activities are: (1) Development of the Emergency Planning Synchronization Matrix to facilitate integration of multi-jurisdictional emergency plans: (a) Coordinating, Integrating, and Synchronizing Disaster Response: Use of an Emergency Response Synchronization Matrix in Emergency Planning, Exercises, and Operations. A graphical depiction of the entire emergency response process via a synchronization matrix is an effective management tool for optimizing the design, exercise, and real-life implementation of emergency plans. This system-based approach to emergency planning depicts how a community organizes its response tasks across space and time. It gives responders the opportunity to make real-time adjustments to maximizing the often limited resources in protecting area residents. An effective response to any natural or technological hazard must involve the entire community and must not be limited by individual jurisdictions and organizations acting on their own without coordination, integration, and synchronization. An emergency response to an accidental release of chemical warfare agents from one of this nation's eight chemical weapons stockpile sites, like any other disaster response, is complex. It requires the rapid coordination, integration, and synchronization of multiple levels of governmental and nongovernmental organizations from numerous jurisdictions, each with varying response capabilities, into a unified community response. The community response actions occur in an area extending from an on-site storage location to points 25 or more miles away. Actions are directed and controlled by responding local governments and agencies situated within the response area, as well as by state and federal operations centers quite removed from the area of impact. Time is critical and the protection action decision-making process is greatly compressed. To ensure an effective response with minimal confusion, given the potential catastrophic nature of such releases, the response community must carefully synchronize response operations.

Hewett, P. L., Jr.; Mitrani, J. E.; Metz, W. C.; Vercellone, J. J.; Decision and Information Sciences

2001-11-01T23:59:59.000Z

215

M2ACS | M2ACS Web Space  

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

Welcome to the Multifaceted Mathematics for Complex Energy Systems (M2ACS) Welcome to the Multifaceted Mathematics for Complex Energy Systems (M2ACS) project webspace We are a multi-institution project whose aim is to fully explore the opportunities in applied mathematics brought about by multi-disciplinary focus - involving optimization, dynamical systems, stochastic analysis, discrete mathematics, scalable algorithms - on the DOE Grand Challenge of energy systems. The central research concept is the one of multi-faceted mathematics - whereby new mathematics is discovered by sustained investigation of the multiple facets presented by the grand challenge subproblems, such as nonconvexity, stochasticity, integrality, spatio-temporal variability - from the perspective of all the mathematics discipline area involved. Our project involves 22 principal investigators from 3 national

216

Cell body rocking is a dominant mechanism for flagellar synchronization in a swimming algae  

E-Print Network (OSTI)

The unicellular green algae Chlamydomonas swims with two flagella, which can synchronize their beat. Synchronized beating is required to swim both fast and straight. A long-standing hypothesis proposes that synchronization of flagella results from hydrodynamic coupling, but the details are not understood. Here, we present realistic hydrodynamic computations and high-speed tracking experiments of swimming cells that show how a perturbation from the synchronized state causes rotational motion of the cell body. This rotation feeds back on the flagellar dynamics via hydrodynamic friction forces and rapidly restores the synchronized state in our theory. We calculate that this `cell body rocking' provides the dominant contribution to synchronization in swimming cells, whereas direct hydrodynamic interactions between the flagella contribute negligibly. We experimentally confirmed the coupling between flagellar beating and cell body rocking predicted by our theory. We propose that the interplay of flagellar beating and hydrodynamic forces governs swimming and synchronization in Chlamydomonas.

Veikko Geyer; Frank Jlicher; Jonathon Howard; Benjamin M Friedrich

2013-05-03T23:59:59.000Z

217

Introduction to the Report "Interlanguages and Synchronic Models of Computation."  

E-Print Network (OSTI)

A novel language system has given rise to promising alternatives to standard formal and processor network models of computation. An interstring linked with a abstract machine environment, shares sub-expressions, transfers data, and spatially allocates resources for the parallel evaluation of dataflow. Formal models called the a-Ram family are introduced, designed to support interstring programming languages (interlanguages). Distinct from dataflow, graph rewriting, and FPGA models, a-Ram instructions are bit level and execute in situ. They support sequential and parallel languages without the space/time overheads associated with the Turing Machine and l-calculus, enabling massive programs to be simulated. The devices of one a-Ram model, called the Synchronic A-Ram, are fully connected and simpler than FPGA LUT's. A compiler for an interlanguage called Space, has been developed for the Synchronic A-Ram. Space is MIMD. strictly typed, and deterministic. Barring memory allocation and compilation, modules are ref...

Berka, Alexander Victor

2010-01-01T23:59:59.000Z

218

Manipulating Synchronous Optical Signals with a Double $?$ Atomic Ensemble  

E-Print Network (OSTI)

We analyze a double $\\Lambda $ atomic configuration interacting with two signal beams and two control beams. Because of the quantum interference between the two $\\Lambda $ channels, the four fields are phase-matched in electromagnetically induced transparency. Our numerical simulation shows that this system is able to manipulate synchronous optical signals, such as generation of optical twin signals, data correction, signal transfer and amplification in the atomic storage.

Zhuan Li; De-Zhong Cao; Kaige Wang

2004-10-06T23:59:59.000Z

219

The synchronous active neutron detection system for spent fuel assay  

SciTech Connect

The authors have begun to develop a novel technique for active neutron assay of fissile material in spent nuclear fuel. This approach will exploit the unique operating features of a 14-MeV neutron generator developed by Schlumberger. This generator and a novel detection system will be applied to the direct measurement of the fissile material content in spent fuel in place of the indirect measures used at present. The technique they are investigating is termed synchronous active neutron detection (SAND). It closely follows a method that has been used routinely in other branches of physics to detect very small signals in the presence of large backgrounds. Synchronous detection instruments are widely available commercially and are termed {open_quotes}lock-in{close_quotes} amplifiers. The authors have implemented a digital lock-in amplifier in conjunction with the Schlumberger neutron generator to explore the possibility of synchronous detection with active neutrons. This approach is possible because the Schlumberger system can operate at up to a 50% duty factor, in effect, a square wave of neutron yield. The results to date are preliminary but quite promising. The system is capable of resolving the fissile material contained in a small fraction of the fuel rods in a cold fuel assembly. It also appears to be quite resilient to background neutron interference. The interrogating neutrons appear to be nonthermal and penetrating. Although a significant amount of work remains to fully explore the relevant physics and optimize the instrument design, the underlying concept appears sound.

Pickrell, M.M.; Kendall, P.K.

1994-10-01T23:59:59.000Z

220

AOCS Official Method Ac 1-45  

Science Conference Proceedings (OSTI)

Sampling AOCS Official Method Ac 1-45 Methods Methods and Analyses Analytical Chemistry Methods Downloads DEFINITION SCOPE Applicable to soybeans. 7BEE304BFEC99451

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Method of driving liquid flow at or near the free surface using magnetic microparticles  

DOE Patents (OSTI)

The present invention provides a method of driving liquid flow at or near a free surface using self-assembled structures composed of magnetic particles subjected to an external AC magnetic field. A plurality of magnetic particles are supported at or near a free surface of liquid by surface tension or buoyancy force. An AC magnetic field traverses the free surface and dipole-dipole interaction between particles produces in self-assembled snake structures which oscillate at the frequency of the traverse AC magnetic field. The snake structures independently move across the free surface and may merge with other snake structures or break up and coalesce into additional snake structures experiencing independent movement across the liquid surface. During this process, the snake structures produce asymmetric flow vortices across substantially the entirety of the free surface, effectuating liquid flow across the free surface.

Snezhko, Oleksiy (Woodridge, IL); Aronson, Igor (Darien, IL); Kwok, Wai-Kwong (Evanston, IL); Belkin, Maxim V. (Woodridge, IL)

2011-10-11T23:59:59.000Z

222

Superconducting Magnets  

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

magnet technology has allowed physicists to attain higher energies in circular accelerators. One can obtain higher magnetic fields because there is no resistance in a...

223

Electric and Magnetic Field Exposure Levels (0 to 3 GHz) in Occupational Environments near Photovoltaic Energy Generation Facilities  

Science Conference Proceedings (OSTI)

Electric and magnetic field levels associated with photovoltaic energy generation facilities were measured and characterized in this study. This evaluation included the measurement of static (direct current [DC]) magnetic fields, power-frequency alternating current (AC) electric and magnetic fields (up to 3,000 Hz), and radio-frequency (RF) electric and magnetic fields (up to 3,000 MHz) at two electric utility solar generation facilities.The major sources of DC magnetic fields within a ...

2012-11-07T23:59:59.000Z

224

A Nonlinear Transient Approach for Morton Synchronous Rotordynamic Instability and Catcher Bearing Life Predictions  

E-Print Network (OSTI)

This dissertation deals with three research topics; i) the catcher bearings life prediction method, ii) the Morton effect, and iii) the two dimensional modified Reynolds equation. Firstly, catcher bearings (CB) are an essential component for rotating machine with active magnetic bearings (AMBs) suspensions. The CB's role is to protect the magnetic bearing and other close clearance component in the event of an AMB failure. The contact load, the Hertzian stress, and the sub/surface shear stress between rotor, races, and balls are calculated, using a nonlinear ball bearing model with thermal growth, during the rotor drop event. Fatigue life of the CB in terms of the number of drop occurrences prior to failure is calculated by applying the Rainflow Counting Algorithm to the sub/surface shear stress-time history. Numerical simulations including high fidelity bearing models and a Timoshenko beam finite element rotor model show that CB life is dramatically reduced when high-speed backward whirl occurs. Secondly, the theoretical models and simulation results about the synchronous thermal instability phenomenon known as Morton Effect is presented in this dissertation. A transient analysis of the rotor supported by tilting pad journal bearing is performed to obtain asymmetric temperature distribution of the journal by solving variable viscosity Reynolds equation, energy equation, heat conduction equation, and equations of motion for rotor. The tilting pad bearing is fully nonlinear model. In addition, thermal mode approach and staggered integration scheme are utilized in order to reduce computation time. The simulation results indicate that the temperature of the journal varies sinusoidally along the circumferential direction and linearly across the diameter, and the vibration envelope increased and decreased, which considers as a limit cycle that is stable oscillation of the envelope of the amplitude of synchronous vibration. Thirdly, the Reynolds equation plays an important role to predict pressure distribution in the fluid film for the fluid film bearing analysis. One of the assumptions on the Reynolds equation is that the viscosity is independent of pressure. This assumption is still valid for most fluid film bearing applications, in which the maximum pressure is less than 1 GPa. In elastohydrodynamic lubrication (EHL) which the lubricant is subjected to extremely high pressure, however, the pressure independent viscosity assumption should be reconsidered. With considering pressure-dependent viscosity, the 2D modified Reynolds equation is derived in this study. The solutions of 2D modified Reynolds equation is compared with that of the classical Reynolds equation for the plain journal bearing and ball bearing cases. The pressure distribution obtained from modified equation is slightly higher pressures than the classical Reynolds equations.

Lee, Jung Gu

2012-05-01T23:59:59.000Z

225

The interphase power controller: A new concept for managing power flow within AC networks  

SciTech Connect

The paper presents a new concept for controlling the flow of power within AC networks. The application is based on the series connection of impedances between different phases of the two (synchronous) subnetworks to be interconnected, hence its name: the Interphase Power Controller (IPC). The IPC acts as a current source with the following characteristics: the power flow is nearly constant (within 10%) for a wide range ([+-]25[degree]) of angle between the two subnetworks; there is no significant short-circuit contribution from one network to the other; severe contingencies on one side of the IPC have negligible impact on the voltage of the other side; no harmonics are generated (because there is no control action). Other operating conditions (reduced power, reactive power generation or absorption) are possible by switching impedance components. In all cases, the IPC comprises only conventional elements (transformer, capacitors, reactors, and circuit breakers).

Brochu, J.; Pelletier, P.; Beauregard, F.; Morin, G. (Citeq, Varennes, Quebec (Canada))

1994-04-01T23:59:59.000Z

226

Magnetic field survey at PG&E photovoltaic sites  

DOE Green Energy (OSTI)

Public awareness has aroused concerns over the possible effects of magnetic fields on human health. While research continues to determine if magnetic fields do, in fact, affect human health, concerned individuals are requesting data on magnetic field sources in their environments to base personal decisions about limiting their exposure to these sources. Timely acceptance and implementation of photovoltaics (PV), particularly for distributed applications such as PV rooftops, windows, and vehicles, may be hampered by the lack of PV magnetic field data. To address this situation, magnetic flux density was measured around equipment at two PVUSA (Photovoltaics for Utility Scale Applications) project sites in Kerman and Davis, California. This report documents the data and compares the PV magnetic fields with published data on more prevalent magnetic field sources. Although not comprehensive, electric and magnetic field (EMF) data taken at PVUSA indicate that 60-Hz magnetic fields (the EMF type of greatest public concern) are significantly less for PV arrays than for household applications. Therefore, given the present EMF research knowledge, PV array EMF may not merit considerable concern. The PV system components exhibiting significant AC magnetic fields are the transformers and power conditioning units (PCUs). However, the AC magnetic fields associated with these components are localized and are not detected at PV system perimeters. Concern about transformer and PCU EMF would apply to several generation and storage technologies.

Chang, G.J.; Jennings, C.

1994-08-01T23:59:59.000Z

227

Bringing practical lock-free synchronization to 64-bit applications  

Science Conference Proceedings (OSTI)

Many lock-free data structures in the literature exploit techniques that are possible only because state-of-the-art 64-bit processors are still running 32-bit operating systems and applications. As software catches up to hardware, "64-bit-clean" lock-free ... Keywords: 64-bit architectures, 64-bit-clean software, compare-and-swap (CAS), freelists, load-linked/store-conditional (LL/SC), lock-free, memory management, multiprocessors, nonblocking synchronization, population-oblivious, queues, space-adaptive

Simon Doherty; Maurice Herlihy; Victor Luchangco; Mark Moir

2004-07-01T23:59:59.000Z

228

Magnet Coil Shorted Turn Detector  

Science Conference Proceedings (OSTI)

The Magnet Coil Shorted Turn Detector has been developed to facilitate the location of shorted turns in magnet coils. Finding these shorted turns is necessary to determine failure modes that are a necessary step in developing future production techniques. Up to this point, coils with shorted turns had the insulation burned off without the fault having been located. This disassembly process destroyed any chance of being able to find the fault. In order to maintain a flux balance in a coupled system such as a magnet coil, the current in a shorted turn must be opposed to the incident current. If the direction of the current in each conductor can be measured relative to the incident current, then the exact location of the short can be determined. In this device, an AC voltage is applied to the magnet under test. A small hand held B-dot pickup coil monitors the magnetic field produced by current in the individual magnet conductors. The relative phase of this pickup coil voltage is compared to a reference signal derived from the input current to detect a current reversal as the B-dot pickup coil is swept over the conductors of the coil under test. This technique however, is limited to only those conductors that are accessible to the hand held probe.

Dinkel, J.A.; Biggs, J.E.

1994-03-01T23:59:59.000Z

229

Design and analysis of modern three-phase AC/AC power converters for AC drives and utility interface  

E-Print Network (OSTI)

Significant advances in modern ac/ac power converter technologies and demands of industries have reached beyond standard ac/ac power converters with voltage-source inverters fed from diode rectifiers. Power electronics converters have been matured to stages toward compact realization, increased high-power handling capability, and improving utility interface. Modern ac/ac power converter topologies with various control strategies have been introduced for the further improvements, such as matrix converters, current-fed converters, PWM rectifiers, and active power filters. In this dissertation, several new converter topologies are proposed in conjunction with developed control schemes based on the modern ac/ac converters which enhance performance and solve the drawbacks of conventional converters. In this study, a new fault-tolerant PWM strategy is first proposed for matrix converters. The added fault-tolerant scheme would strengthen the matrix converter technology for aerospace and military applications. A modulation strategy is developed to reshape output currents for continuous operation, against fault occurrence in matrix converter drives. This study designs a hybrid, high-performance ac/ac power converter for high power applications, based on a high-power load commutated inverter and a mediumpower voltage source inverter. Natural commutation of the load commutated inverter is actively controlled by the voltage source inverter. In addition, the developed hybrid system ensures sinusoidal output current/voltage waveforms and fast dynamic response in high power areas. A new topology and control scheme for a six-step current source inverter is proposed. The proposed topology utilizes a small voltage source inverter, to turn off main thyristor switches, transfer reactive load energy, and limit peak voltages across loads. The proposed topology maximizes benefits of the constituent converters: highpower handling capability of large thyristor-based current source inverters as well as fast and easy control of small voltage source inverters. This study analyzes, compares, and evaluates two topologies for unity power factor and multiple ac/ac power conversions. Theoretical analyses and comparisons of the two topologies, grounded on mathematical approaches, are presented from the standpoint of converter kVA ratings, dc-link voltage requirements, switch ratings, semiconductor losses, and reactive component sizes. Analysis, simulation, and experimental results are detailed for each proposed topology.

Kwak, Sangshin

2006-05-01T23:59:59.000Z

230

Copper laser modulator driving assembly including a magnetic compression laser  

DOE Patents (OSTI)

A laser modulator (10) having a low voltage assembly (12) with a plurality of low voltage modules (14) with first stage magnetic compression circuits (20) and magnetic assist inductors (28) with a common core (91), such that timing of the first stage magnetic switches (30b) is thereby synchronized. A bipolar second stage of magnetic compression (42) is coupled to the low voltage modules (14) through a bipolar pulse transformer (36) and a third stage of magnetic compression (44) is directly coupled to the second stage of magnetic compression (42). The low voltage assembly (12) includes pressurized boxes (117) for improving voltage standoff between the primary winding assemblies (34) and secondary winding (40) contained therein.

Cook, Edward G. (Livermore, CA); Birx, Daniel L. (Oakley, CA); Ball, Don G. (Livermore, CA)

1994-01-01T23:59:59.000Z

231

Spatiotemporal phase synchronization in a large array of convective oscillators  

E-Print Network (OSTI)

In a quasi-1D thermal convective system consisting of a large array of nonlinearly coupled oscillators, clustering is the way to achieve a regime of mostly antiphase synchronized oscillators. This regime is characterized by a spatiotemporal doubling of traveling modes. As the dynamics is explored beyond a spatiotemporal chaos regime with weak coupling, new interacting modes emerge through a supercritical bifurcation. In this new regime, the system exhibits coherent subsystems of antiphase synchronized oscillators, which are stationary clusters following a spatiotemporal beating phenomena. This regime is the result of a stronger coupling. We show from a phase mismatch model applied to each oscillator, that these phase coherent domains undergo a global phase instability meanwhile the interactions between oscillators become nonlocal. For each value of the control parameter we find out the time-varying topology (link matrix) from the contact interactions between oscillators. The new characteristic spatiotemporal scales are extracted from the antiphase correlations at the time intervals defined by the link matrix. The interpretation of these experimental results contributes to widen the understanding of other complex systems exhibiting similar phase chaotic dynamics in 2D and 3D.

M. A. Miranda; J. Burguete

2009-11-10T23:59:59.000Z

232

Repetitive Transcranial Magnetic Stimulation to the Primary Motor Cortex Interferes with  

E-Print Network (OSTI)

Repetitive Transcranial Magnetic Stimulation to the Primary Motor Cortex Interferes with Motor- cranial magnetic stimulation (rTMS) to test the idea that this ``motor learning by observing'' is based representations of novel motor skills can be ac- quired through visual observation. We used repetitive trans

Miall, Chris

233

AC Loss Measurements with a Cryocooled Sample  

SciTech Connect

A new cryostat cooled by a closed-cycle Cryomech GB-37 cryocooler for superconductor measurements at temperatures down to 20 K is described. The sample is conductively coupled to the cold stage so as to minimize vibration and thermal stresses. AC losses have been measured calorimetrically in several HTSC coils that have been wound to simulate sub-scale transformer winding pairs. Stable temperatures down to 20 K were reached on these coils, allowing measurements at practical levels of ac current and I{sub c}. By using short ac current pulses, losses on individual turns could be resolved. Results are reported mainly to showcase the apparatus, measurement procedure and analytical approach.

Schwenterly, S.W.

2001-02-15T23:59:59.000Z

234

Stability analysis of permanent magnet synchronous generator used in micro-cogeneration systems  

Science Conference Proceedings (OSTI)

This paper has a dual purpose: on the one hand the technical-economic analysis of cogeneration microplants (also emphasizing the producers' preferences for certain classes of electric generators in terms of using the same type of prime mover, respectively ... Keywords: electrical generators, m-CHP, renewable energies, stirling engine

Ion Voncil?; Nicolae Badea

2010-10-01T23:59:59.000Z

235

Design of a Permanent Magnet Synchronous Motor according to FreedomCAR specifications.  

E-Print Network (OSTI)

??Electric mobility is becoming in recent years a growing reality due to increase of the demand and cost of oil and the enviromental impact of (more)

Carraro, Enrico

2012-01-01T23:59:59.000Z

236

Dynamic environment coupling induce synchronized states in coupled time-delayed electronic circuits  

E-Print Network (OSTI)

We experimentally demonstrate the occurrence of various synchronized states in coupled piece-wise linear time-delayed electronic circuits using dynamic environment coupling where the environment has its own intrinsic dynamics via feedback from the circuits. We carry out these experiments in two different coupling configurations, namely mutual and subsystem coupling configurations. Depending upon the coupling strength and the nature of feedback, we observe a transition from nonsynchronization to complete synchronization via phase synchronization and from nonsynchronization to inverse synchronization via inverse-phase synchronization between the circuits in hyperchaotic regime. Snapshots of the time evolution, phase projection plots and localized sets of the circuits as observed experimentally from the oscilloscope, along with supporting numerical simulations confirm the existence of different synchronized states. Further, the transition to different synchronized states can be verified from the changes in the largest Lyapunov exponents, Correlation of Probability of Recurrence and Correlation Coefficient as a function of the coupling strength. We present a detailed linear stability analysis and obtain conditions for different synchronized states.

R. Suresh; K. Srinivasan; D. V. Senthilkumar; K. Murali; M. Lakshmanan; J. Kurths

2013-04-04T23:59:59.000Z

237

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

Science Conference Proceedings (OSTI)

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

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

2006-06-01T23:59:59.000Z

238

Synchronization and cell search algorithms in 3GPP long term evolution systems (FDD mode)  

Science Conference Proceedings (OSTI)

In this paper initial downlink synchronization (sync) and cell identification algorithms for the 3rd generation partnership project (3GPP) long term evolution (LTE) systems are presented. The frequency division duplex (FDD) mode is used in the downlink ... Keywords: 3GPP LTE, MIMO, OFDM, cell search, frequency and time synchronization

Abdo N. Gaber; Loay D. Khalaf; Ahmad M. Mustafa

2012-02-01T23:59:59.000Z

239

A Multiple View Approach to Support Common Ground in Distributed and Synchronous Geo-Collaboration  

Science Conference Proceedings (OSTI)

In this paper we investigate strategies to support knowledgesharing in distributed, synchronous collaboration. Our goalis to propose, justify, and assess a multiple view approachto support common ground in geo-collaboration within multi-roleteams. We ... Keywords: Multiple views, common ground, distributed and synchronous geo-collaboration

Gregorio Convertino; Craig H. Ganoe; Wendy A. Schafer; Beth Yost; John M. Carroll

2005-07-01T23:59:59.000Z

240

Strata: wait-free synchronization with efficient memory reclamation by using chronological memory allocation  

Science Conference Proceedings (OSTI)

A locking is the typical mechanism to coordinate the race between multiple threads. But it downgrades the overall system performance due to the waiting time for the locked data to be unlocked. Wait-free synchronization is the one of the schemes to cope ... Keywords: memory management, wait-free synchronization

Eunhwan Shin; Inhyuk Kim; Junghan Kim; Young Ik Eom

2011-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Automatic two way synchronization between server and multiple clients for HVAC system  

Science Conference Proceedings (OSTI)

The authors study different two way synchronization methods between a server and distributed clients. Client-server architectures are used to control multiple instances from center. Hard-coded embedded controllers are replaced by embedded controllers ... Keywords: HVAC, data synchronization, embedded systems, multi-agent systems, online file storage, thick client

Anton Tyukov; Adriaan Brebels; Maxim Shcherbakov

2011-12-01T23:59:59.000Z

242

The synchronous force control of a double-axial pneumatic actuating system  

Science Conference Proceedings (OSTI)

This paper presents the design of the synchronous force controller of a double-axial pneumatic actuating system. This system is ideally decomposed into two independent subsystems, and the coupling effect is considered as the noise effect. So, each ... Keywords: STC, double-axial pneumatic system, synchronous force control

Ying-Tsai Wang; Ming-Kun Chang

1999-07-01T23:59:59.000Z

243

Media synchronization and QoS packet scheduling algorithms for wireless systems  

Science Conference Proceedings (OSTI)

Wireless multimedia synchronization is concerned with distributed multimedia packets such as video, audio, text and graphics being played-out onto the mobile clients via a base station (BS) that services the mobile client with the multimedia packets. ... Keywords: distributed algorithms, media synchronization, mobile multimedia, packet scheduling algorithm, quality of service (QoS), wireless communications

Azzedine Boukerche; Harold Owens, II

2005-02-01T23:59:59.000Z

244

Highly Efficient Synchronization Based on Active Memory Operations Lixin Zhang Zhen Fang and John B. Carter  

E-Print Network (OSTI)

Austin, TX 78758 Salt Lake City, UT 84112 zhangl@us.ibm.com zfang, retrac@cs.utah.edu Abstract. In this paper, we present a mechanism that allows atomic synchronization operations to be executed on the home mem- ory controller of the synchronization variable. By perform- ing atomic operations near where

Carter, John B.

245

Optimizing the Synchronization Operations in Message Passing Interface One-Sided Communication  

Science Conference Proceedings (OSTI)

One-sided communication in Message Passing Interface (MPI) requires the use of one of three different synchronization mechanisms, which indicate when the one-sided operation can be started and when the operation is completed. Efficient implementation ... Keywords: MPI, one-sided communication, remote-memory access, synchronization

Rajeev Thakur; William Gropp; Brian Toonen

2005-05-01T23:59:59.000Z

246

Winans of XSD Elected to ACS Fellowship  

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

2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed Winans of XSD Elected to ACS Fellowship JULY 8, 2009 Bookmark and Share Randy Winans Randall E. Winans, Chemical and...

247

AOCS Official Method Ac 4-91  

Science Conference Proceedings (OSTI)

Catalyst AOCS Official Method Ac 4-91 Methods Methods and Analyses Analytical Chemistry Methods Downloads DEFINITION This method determines total nitrogen content and protein as 6.25 times the nitrogen content o

248

AOCS Official Method Ac 3-44  

Science Conference Proceedings (OSTI)

Oil AOCS Official Method Ac 3-44 Methods Methods and Analyses Analytical Chemistry Methods Downloads DEFINITION This method determines the substances extracted from ground soybean seeds by petroleum ether under

249

AOCS Official Method Ac 5-41  

Science Conference Proceedings (OSTI)

Free Fatty Acids AOCS Official Method Ac 5-41 Methods Methods and Analyses Analytical Chemistry Methods Downloads DEFINITION This method determines the free fatty acids in oil removed from the seed by petroleum

250

AOCS Official Method Ac 2-41  

Science Conference Proceedings (OSTI)

Moisture and Volatile Matter AOCS Official Method Ac 2-41 Methods Methods and Analyses Analytical Chemistry Methods Downloads DEFINITION This method determines the moisture and any material that is volatile unde

251

Optimal Filtering of AC Output Anemometers  

Science Conference Proceedings (OSTI)

The output of pulsed and AC output anemometers suffer from discretization noise when such anemometers are sampled at fast rates (>1 Hz). This paper describes the construction of an optimal filter designed to reduce this noise. By comparing the ...

J. C. Barnard; L. L. Wendell; V. R. Morris

1998-12-01T23:59:59.000Z

252

AC distribution system for TFTR pulsed loads  

DOE Green Energy (OSTI)

This paper outlines the AC distribution system associated with the Tokamak Fusion Test Reactor and discusses the significant areas related to design, protection, and equipment selection, particularly where there is a departure from normal utility and industrial applications.

Carroll, R.F.; Ramakrishnan, S.; Lemmon, G.N.; Moo, W.I.

1977-01-01T23:59:59.000Z

253

New approach to the fault location problem using synchronized sampling  

E-Print Network (OSTI)

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

Mrkic, Jasna

1994-01-01T23:59:59.000Z

254

Synchronized states in chaotic systems coupled indirectly through a dynamic environment  

E-Print Network (OSTI)

We consider synchronization of chaotic systems coupled indirectly through a common environmnet where the environment has an intrinsic dynmics of its own modulated via feedback from the systems. We find that a rich vareity of synchronization behavior, such as in-phase, anti-phase,complete and anti- synchronization is possible. We present an approximate stability analysis for the different synchronization behaviors. The transitions to different states of synchronous behaviour are analyzed in the parameter plane of coupling strengths by numerical studies for specific cases such as Rossler and Lorenz systems and are characterized using various indices such as correlation, average phase difference and Lyapunov exponents. The threshold condition obtained from numerical analysis is found to agree with that from the stability analysis.

V. Resmi; G. Ambika; R. E. Amritkar

2009-10-13T23:59:59.000Z

255

Synchronization of Fractional-order Chaotic Systems with Gaussian fluctuation by Sliding Mode Control  

E-Print Network (OSTI)

This paper is devoted to the problem of synchronization between fractional-order chaotic systems with Gaussian fluctuation by the method of fractional-order sliding mode control. A fractional integral (FI) sliding surface is proposed for synchronizing the uncertain fractional-order system, and then the sliding mode control technique is carried out to realize the synchronization of the given systems. One theorem about sliding mode controller is presented to prove the proposed controller can make the system synchronize. As a case study, the presented method is applied to the fractional-order Chen-L\\"u system as the drive-response dynamical system. Simulation results show a good performance of the proposed control approach in synchronizing the chaotic systems in presence of Gaussian noise.

Yong Xu; Hua Wang

2013-09-04T23:59:59.000Z

256

An Energy-efficient Clock Synchronization Protocol for Wireless Sensor Networks  

E-Print Network (OSTI)

The behavior of Wireless Sensor Networks (WSN) is nowadays widely analyzed. One of the most important issues is related to their energy consumption, as this has a major impact on the network lifetime. Another important application requirement is to ensure data sensing synchronization, which leads to additional energy consumption as a high number of messages is sent and received at each node. Our proposal consists in implementing a combined synchronization protocol based on the IEEE 1588 standard that was designed for wired networks and the PBS (Pairwise Broadcast Synchronization) protocol that was designed for sensor networks, as none of them is able to provide the needed synchronization accuracy for our application on its own. The main goals of our new synchronization protocol are: to ensure the accuracy of local clocks up to a tenth of a microsecond and to provide an important energy saving. Our results obtained using NS-2 (Network Simulator) show that the performance of our solution (IEEE 1588-PBS) matches...

Albu, Roxana; Thierry, Gayraud; Pascal, Berthou

2010-01-01T23:59:59.000Z

257

Magnetic Storms  

Science Conference Proceedings (OSTI)

... magnetic reversal. As there is no predictive science of geomagnetism, we currently lack even simple forecasts. Our scientific ...

2010-10-05T23:59:59.000Z

258

Magnetic Imaging  

Science Conference Proceedings (OSTI)

... data-storage and permanent magnets with increased energy products, in ... Optimization of future materials, including improved yields, requires an ...

2012-10-02T23:59:59.000Z

259

Magnetic Properties  

Science Conference Proceedings (OSTI)

...Since the discovery of high-temperature superconductors in 1986 (Ref 10), the demonstration of magnetic flux exclusion

260

Original article: Lumped-parameter-based thermal analysis of a doubly radial forced-air-cooled direct-driven permanent magnet wind generator  

Science Conference Proceedings (OSTI)

A lumped-parameter-based thermal analysis of a direct-driven permanent magnet wind generator with double radial forced-air cooling is presented. In the proposed thermal model, the thermal conduction and convection as well as the heating of the cooling ... Keywords: Air cooling, Permanent magnet synchronous generator, Thermal analysis, Thermal resistance networks

Janne Nerg, Vesa Ruuskanen

2013-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Field tests of a circuit breaker synchronous control  

Science Conference Proceedings (OSTI)

A circuit breaker synchronous control interface which controls the point-on-wave at which shunt reactor circuit breakers open or close has been developed and tested on Hydro-Quebec`s 735-kV power system. It takes into account the influence of outdoor temperature on the breaker closing and opening times. It is also equipped with a reignition and a high-inrush-current detection system. Opening tests at different preset arcing times were conducted and the arcing time range where there are no re-ignitions in air-blast breakers was established. The tests showed that the interface is a valuable device for the elimination of re-ignitions associated with the interruption of small inductive currents. Closing tests have shown that the interface is also useful for the limitation of high inrush currents by selecting an appropriate point-on-wave for circuit breaker closing.

Rajotte, R.J.; Charpentier, C.; Breault, S.; Le, H.H.; Huynh, H. [Hydro-Quebec, Montreal, Quebec (Canada); Desmarais, J. [Snemo Ltd., Brossard, Quebec (Canada)

1995-07-01T23:59:59.000Z

262

An adaptive synchronization protocol for parallel discrete event simulation  

SciTech Connect

Simulation, especially discrete event simulation (DES), is used in a variety of disciplines where numerical methods are difficult or impossible to apply. One problem with this method is that a sufficiently detailed simulation may take hours or days to execute, and multiple runs may be needed in order to generate the desired results. Parallel discrete event simulation (PDES) has been explored for many years as a method to decrease the time taken to execute a simulation. Many protocols have been developed which work well for particular types of simulations, but perform poorly when used for other types of simulations. Often it is difficult to know a priori whether a particular protocol is appropriate for a given problem. In this work, an adaptive synchronization method (ASM) is developed which works well on an entire spectrum of problems. The ASM determines, using an artificial neural network (ANN), the likelihood that a particular event is safe to process.

Bisset, K.R.

1998-12-01T23:59:59.000Z

263

VEHICLE SPECIFICATIONS  

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

4-Cylinder Displacement: 1.4 L Fuel Tank Capacity: 9.3 gal Fuel Type: Premium gasoline Motor Type: 12-pole permanent magnet AC synchronous Max. PowerTorque: 111 kW370 Nm Max....

264

Synchronization in hyperchaotic time-delayed electronic oscillators coupled indirectly via a common environment  

E-Print Network (OSTI)

The present paper explores the synchronization scenario of hyperchaotic time-delayed electronic oscillators coupled indirectly via a common environment. We show that depending upon the coupling parameters a hyperchaotic time-delayed system can show in-phase or complete synchronization, and also inverse-phase or anti-synchronization. This paper reports the first experimental confirmation of synchronization of hyperchaos in time-delayed electronic oscillators coupled indirectly through a common environment. We confirm the occurrence of in-phase and inverse-phase synchronization phenomena in the coupled system through the dynamical measures like generalized autocorrelation function, correlation of probability of recurrence, and the concept of localized sets computed directly from the experimental time-series data. We also present a linear stability analysis of the coupled system. The experimental and analytical results are further supported by the detailed numerical analysis of the coupled system. Apart from the above mentioned measures, we numerically compute another quantitative measure, namely, Lyapunov exponent spectrum of the coupled system that confirms the transition from the in-phase (inverse-phase) synchronized state to the complete (anti-) synchronized state with the increasing coupling strength.

Tanmoy Banerjee; Debabrata Biswas

2013-03-21T23:59:59.000Z

265

Three phase AC motor controller  

DOE Patents (OSTI)

A motor controller for a three phase AC motor (10) which is adapted to operate bidirectionally from signals received either from a computer (30) or a manual control (32). The controller is comprised of digital logic circuit means which implement a forward and reverse command signal channel (27, 29) for the application of power through the forward and reverse power switching relays (16, 18, 20, 22). The digital logic elements are cross coupled to prevent activation of both channels simultaneously and each includes a plugging circuit (65, 67) for stopping the motor upon the removal of control signal applied to one of the two channels (27, 29) for a direction of rotation desired. Each plugging circuit (65, 67) includes a one-shot pulse signal generator (88, 102) which outputs a single pulse signal of predetermined pulsewidth which is adapted to inhibit further operation of the application of power in the channel which is being activated and to apply a reversal command signal to the other channel which provides a reversed phase application of power to the motor for a period defined by the pulse-width output of the one-shot signal generator to plug the motor (10) which will then be inoperative until another rotational command signal is applied to either of the two channels.

Vuckovich, Michael (Elizabeth, PA); Wright, Maynard K. (Bethel Park, PA); Burkett, John P. (South Huntington Township, Westmoreland County, PA)

1984-03-20T23:59:59.000Z

266

ac electric-field-induced resonant energy transfer between cold Rydberg atoms  

E-Print Network (OSTI)

An oscillating electric field at 1.356 GHz was used to promote the resonant energy transfer process: $43d_{5/2}+43d_{5/2} \\to 45p_{3/2}+41f$ between translationally cold $^{85}$Rb Rydberg atoms. The ac Stark shifts due to this dressing field created degeneracies between the initial and final two-atom states of this process. The ac field strength was scanned to collect spectra which are analogous to dc electric-field-induced resonant energy transfer spectra. Different resonances were observed for different magnetic sublevels involved in the process. Compared to earlier work performed at higher frequencies, the choice of dressing frequency and structure of the spectra may be intuitively understood, by analogy with the dc field case.

Petrus, J A; Martin, J D D; 10.1088/0953-4075/41/24/245001

2009-01-01T23:59:59.000Z

267

Global generalized synchronization in networks of different time-delay systems  

E-Print Network (OSTI)

We show that global generalized synchronization (GS) exists in structurally different time-delay systems, even with different orders, with quite different fractal (Kaplan-Yorke) dimensions, which emerges via partial GS in symmetrically coupled regular networks. We find that there exists a smooth transformation in such systems, which maps them to a common GS manifold as corroborated by their maximal transverse Lyapunov exponent. In addition, an analytical stability condition using the Krasvoskii-Lyapunov theory is deduced. This phenomenon of GS in strongly distinct systems opens a new way for an effective control of pathological synchronous activity by means of extremely small perturbations to appropriate variables in the synchronization manifold.

D. V. Senthilkumar; R. Suresh; M. Lakshmanan; J. Kurths

2013-01-31T23:59:59.000Z

268

Using Genetic Algorithms to Optimize ACS-TSP  

Science Conference Proceedings (OSTI)

We propose the addition of Genetic Algorithms to Ant Colony System (ACS) applied to improve performance. Two modifications are proposed and tested. The first algorithm is a hybrid between ACS-TSP and a Genetic Algorithm that encodes experimental variables ...

Marcin L. Pilat; Tony White

2002-09-01T23:59:59.000Z

269

Robust Clock Synchronization Methods for Wireless Sensor Networks  

E-Print Network (OSTI)

Wireless sensor networks (WSNs) have received huge attention during the recent years due to their applications in a large number of areas such as environmental monitoring, health and traffic monitoring, surveillance and tracking, and monitoring and control of factories and home appliances. Also, the rapid developments in the micro electro-mechanical systems (MEMS) technology and circuit design lead to a faster spread and adoption of WSNs. Wireless sensor networks consist of a number of nodes featured in general with energy-limited sensors capable of collecting, processing and transmitting information across short distances. Clock synchronization plays an important role in designing, implementing, and operating wireless sensor networks, and it is essential in ensuring a meaningful information processing order for the data collected by the nodes. Because the timing message exchanges between different nodes are affected by unknown possibly time-varying network delay distributions, the estimation of clock offset parameters represents a challenge. This dissertation presents several robust estimation approaches of the clock offset parameters necessary for time synchronization of WSNs via the two-way message exchange mechanism. In this dissertation the main emphasis will be put on building clock phase offset estimators robust with respect to the unknown network delay distributions. Under the assumption that the delay characteristics of the uplink and the downlink are asymmetric, the clock offset estimation method using the bootstrap bias correction approach is derived. Also, the clock offset estimator using the robust Mestimation technique is presented assuming that one underlying delay distribution is mixed with another delay distribution. Next, although computationally complex, several novel, efficient, and robust estimators of clock offset based on the particle filtering technique are proposed to cope with the Gaussian or non-Gaussian delay characteristics of the underlying networks. One is the Gaussian mixture Kalman particle filter (GMKPF) method. Another is the composite particle filter (CPF) approach viewed as a composition between the Gaussian sum particle filter and the KF. Additionally, the CPF using bootstrap sampling is also presented. Finally, the iterative Gaussian mixture Kalman particle filter (IGMKPF) scheme, combining the GMKPF with a procedure for noise density estimation via an iterative mechanism, is proposed.

Lee, Jae Han

2010-08-01T23:59:59.000Z

270

Magnetic Materials  

Science Conference Proceedings (OSTI)

Oct 27, 2009 ... Extreme magnetic fields (>2 tesla), especially when combined with temperature, are being shown to revolutionize materials processing and...

271

Improved braking torque generation capacity of an eddy current brake with time varying magnetic fields: A numerical study  

Science Conference Proceedings (OSTI)

Eddy current brakes (ECB) are electrically controlled and non-contact actuators used as assistive brakes in vehicles. ECBs exhibit insufficient generated braking torque at low speeds. In order to overcome this, the use of AC magnetic fields with fixed ... Keywords: Automotive applications, Brake-by-wire, Eddy current brakes, Finite element analysis, Time-varying magnetic field

Kerem Karakoc; Edward J. Park; Afzal Suleman

2012-10-01T23:59:59.000Z

272

7AC Technologies, Inc. | Department of Energy  

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

7AC 7AC Technologies, Inc. America's Next Top Energy Innovator Challenge 498 likes 7AC Technologies, Inc. National Renewable Energy Laboratory Air conditioning is a very large contributor to U.S. and world energy consumption. Heating and cooling costs for commercial and industrial buildings exceed 25 percent of U.S. primary energy consumption (cooling alone accounts for 4.5 Quads out of 40 Quads) and typically accounts for almost half of a building's operating costs. Air conditioning is also a significant cause of grid instability with cycling compressor motors turning on and off, and causing load issues on hot summer days. Conventional air conditioners improve efficiency only marginally every year and retrofitting older rooftop units does not result in significant energy

273

7AC Technologies, Inc. | Department of Energy  

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

7AC 7AC Technologies, Inc. America's Next Top Energy Innovator Challenge 498 likes 7AC Technologies, Inc. National Renewable Energy Laboratory Air conditioning is a very large contributor to U.S. and world energy consumption. Heating and cooling costs for commercial and industrial buildings exceed 25 percent of U.S. primary energy consumption (cooling alone accounts for 4.5 Quads out of 40 Quads) and typically accounts for almost half of a building's operating costs. Air conditioning is also a significant cause of grid instability with cycling compressor motors turning on and off, and causing load issues on hot summer days. Conventional air conditioners improve efficiency only marginally every year and retrofitting older rooftop units does not result in significant energy

274

Princeton Plasma Physics Lab - AC power  

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

ac-power The electricity that runs the ac-power The electricity that runs the Laboratory's experiments and facilities. "AC" stands for the alternating current that comes from large power stations. The term compares with "DC," for "direct current," which comes from sources like batteries. en Offshore Wind and Vehicle to Grid Power http://www.pppl.gov/events/offshore-wind-and-vehicle-grid-power

Professor Willett Kempton, of the University of Delaware, presents "Offshore Wind and Vehicle to Grid Power" as part of the Andlinger Center's 2013-2014 Highlight Seminar Series.

275

7AC Technologies, Inc. | Department of Energy  

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

7AC 7AC Technologies, Inc. America's Next Top Energy Innovator Challenge 498 likes 7AC Technologies, Inc. National Renewable Energy Laboratory Air conditioning is a very large contributor to U.S. and world energy consumption. Heating and cooling costs for commercial and industrial buildings exceed 25 percent of U.S. primary energy consumption (cooling alone accounts for 4.5 Quads out of 40 Quads) and typically accounts for almost half of a building's operating costs. Air conditioning is also a significant cause of grid instability with cycling compressor motors turning on and off, and causing load issues on hot summer days. Conventional air conditioners improve efficiency only marginally every year and retrofitting older rooftop units does not result in significant energy

276

16,000-rpm Interior Permanent Magnet Reluctance Machine with Brushless Field Excitation  

SciTech Connect

The reluctance interior permanent magnet (RIPM) motor is currently used by many leading auto manufacturers for hybrid vehicles. The power density for this type of motor is high compared with that of induction motors and switched reluctance motors. The primary drawback of the RIPM motor is the permanent magnet (PM) because during high-speed operation, the fixed PM produces a huge back electromotive force (emf) that must be reduced before the current will pass through the stator windings. This reduction in back-emf is accomplished with a significant direct-axis (d-axis) demagnetization current, which opposes the PM's flux to reduce the flux seen by the stator wires. This may lower the power factor and efficiency of the motor and raise the requirement on the alternate current (ac) power supply; consequently, bigger inverter switching components, thicker motor winding conductors, and heavier cables are required. The direct current (dc) link capacitor is also affected when it must accommodate heavier harmonic currents. It is commonly agreed that, for synchronous machines, the power factor can be optimized by varying the field excitation to minimize the current. The field produced by the PM is fixed and cannot be adjusted. What can be adjusted is reactive current to the d-axis of the stator winding, which consumes reactive power but does not always help to improve the power factor. The objective of this project is to avoid the primary drawbacks of the RIPM motor by introducing brushless field excitation (BFE). This offers both high torque per ampere (A) per core length at low speed by using flux, which is enhanced by increasing current to a fixed excitation coil, and flux, which is weakened at high speed by reducing current to the excitation coil. If field weakening is used, the dc/dc boost converter used in a conventional RIPM motor may be eliminated to reduce system costs. However, BFE supports a drive system with a dc/dc boost converter, because it can further extend the constant power speed range of the drive system and adjust the field for power factor and efficiency gains. Lower core losses at low torque regions, especially at high speeds, are attained by reducing the field excitation. Safety and reliability are increased by weakening the field when a winding short-circuit fault occurs, preventing damage to the motor. For a high-speed motor operating at 16,000-revolutions per minute (rpm), mechanical stress is a challenge. Bridges that link the rotor punching segments together must be thickened for mechanical integrity; consequently, increased rotor flux leakage significantly lowers motor performance. This barrier can be overcome by BFE to ensure sufficient rotor flux when needed.

Hsu, J.S.; Burress, T.A.; Lee, S.T.; Wiles, R.H.; Coomer, C.L.; McKeever, J.W.; Adams, D.J.

2007-10-31T23:59:59.000Z

277

Definitions of Managed Objects for Synchronous Optical Network (SONET) Linear Automatic Protection Switching (APS) Architectures  

Science Conference Proceedings (OSTI)

This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in TCP/IP based internets. In particular, it defines objects for managing networks using Synchronous Optical Network (SONET) linear Automatic ...

J. Kuhfeld; J. Johnson; M. Thatcher

2003-03-01T23:59:59.000Z

278

Integrating the Army Geospatial Enterprise : synchronizing geospatial-intelligence to the dismounted soldier  

E-Print Network (OSTI)

The Army's Geospatial Enterprise (AGE) has an emerging identity and value proposition arising from the need to synchronize geospatial information activities across the Army in order to deliver value to military decision ...

Richards, James E., S.M. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

279

Identifying and Validating Irregular Mutual Exclusion Synchronization in Explicitly Parallel Programs (Research Note)  

Science Conference Proceedings (OSTI)

Existing work on mutual exclusion synchronization is based on a structural definition of mutex bodies. Although correct, this structural notion fails to identify many important locking patterns present in some programs. In this paper we present a novel ...

Diego Novillo; Ronald C. Unrau; Jonathan Schaeffer

2000-08-01T23:59:59.000Z

280

Single-phase Converter-less Excitation Synchronous Stand-along Wind Power Generator System.  

E-Print Network (OSTI)

??In this thesis, a single-phase converter-less excitation synchronous stand-along wind power generator system is proposed. In order to simplify the system and improve the system (more)

Lin, Chin-wei

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Channel Modeling and Time Delay Estimation for Clock Synchronization Among Seaweb Nodes  

SciTech Connect

From simulations, tracking of the impulse response is feasible. Potential to benefit other functions such as ranging between two nodes. Potential to combine the features of different protocols to create a new and more realistic clock-synchronization protocol.

Gagnon, P; Rice, J; Clark, G A

2012-07-08T23:59:59.000Z

282

Genetic Programming Based Approach for Synchronization with Parameter Mismatches in EEG  

Science Conference Proceedings (OSTI)

Effects of parameter mismatches in synchronized time series are studied first for an analytical non-linear dynamical system (coupled logistic map, CLM) and then in a real system (Electroencephalograph (EEG) signals). The internal system parameters derived ...

Dilip P. Ahalpara; Siddharth Arora; M. S. Santhanam

2009-04-01T23:59:59.000Z

283

Data Assimilation as Synchronization of Truth and Model: Experiments with the Three-Variable Lorenz System  

Science Conference Proceedings (OSTI)

The potential use of chaos synchronization techniques in data assimilation for numerical weather prediction models is explored by coupling a Lorenz three-variable system that represents truth to another that represents the model. By adding ...

Shu-Chih Yang; Debra Baker; Hong Li; Katy Cordes; Morgan Huff; Geetika Nagpal; Ena Okereke; Josue Villafae; Eugenia Kalnay; Gregory S. Duane

2006-09-01T23:59:59.000Z

284

Transcriptome and Proteome Dynamics of a Light-Dark Synchronized Bacterial Cell Cycle  

E-Print Network (OSTI)

Growth of the ocean's most abundant primary producer, the cyanobacterium Prochlorococcus, is tightly synchronized to the natural 24-hour light-dark cycle. We sought to quantify the relationship between transcriptome and ...

Chisholm, Sallie (Penny)

285

Impact of Sun-Synchronous Diurnal Sampling on Tropical TOA Flux Interannual Variability and Trends  

Science Conference Proceedings (OSTI)

Satellite observations of the earths radiation budget (ERB) are a critical component of the climate observing system. Recent observations have been made from sun-synchronous orbits, which provide excellent spatial coverage with global ...

Patrick C. Taylor; Norman G. Loeb

2013-04-01T23:59:59.000Z

286

A Parameterization for Longwave Surface Radiation from Sun-Synchronous Satellite Data  

Science Conference Proceedings (OSTI)

A parameterization has been developed for computing downward, upward, and net longwave radiation at the earth's surface using meteorological data from NOAA's operational sun-synchronous satellites. The parameterization was developed using a ...

Shashi K. Gupta

1989-04-01T23:59:59.000Z

287

Downward Longwave Surface Radiation from Sun-Synchronous Satellite Data: Validation of Methodology  

Science Conference Proceedings (OSTI)

An extensive study has been carried out to validate a satellite technique for estimating downward longwave radiation at the surface. The technique, mostly developed earlier, uses operational sun-synchronous satellite data and a radiative transfer ...

Wayne L. Darnell; Shashi K. Gupta; W. Frank Staylor

1986-07-01T23:59:59.000Z

288

Improved File Synchronization Techniques for Maintaining Large Replicated Collections over Slow Networks  

Science Conference Proceedings (OSTI)

We study the problem of maintaining large replicated collectionsof files or documents in a distributed environment withlimited bandwidth. This problem arises in a number of importantapplications, such as synchronization of data betweenaccounts or devices, ...

Torsten Suel; Patrick Noel; Dimitre Trendafilov

2004-03-01T23:59:59.000Z

289

AC H I E V I NG  

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

AC AC H I E V I NG The Department's strategic plan flow is highlighted in the cascade below beginning with the mission statement which flows to the strategic themes. The strategic themes connect to the broader strategic goals and are linked to the annual performance goals in the performance budget through the multi-year program plans. The multi-year program plans allow DOE to strategize over a five-year period how each program will implement the strategic goals of the Department. Annual performance goals and assessment of performance against prior-year

290

Synchronizing carrier frequencies of co-channel amplitude-modulated broadcast  

DOE Patents (OSTI)

Systems and methods are described for carrier-frequency synchronization for improved AM and TV broadcast reception. A method includes synchronizing a carrier frequency of a broadcast signal with a remote reference frequency. An apparatus includes a reference signal receiver; a phase comparator coupled to the reference signal receiver; a voltage controlled oscillator coupled to the phase comparator; and a radio frequency output coupled to the voltage controlled oscillator.

Smith, Stephen F. (London, TN); Moore, James A. (Powell, TN)

2007-05-15T23:59:59.000Z

291

Security analysis of communication system based on the synchronization of different order chaotic systems  

E-Print Network (OSTI)

This work analyzes the security weakness of a recently proposed communication method based on chaotic modulation and masking using synchronization of two chaotic systems with different orders. It is shown that its application to secure communication is unsafe, because it can be broken in two different ways, by high-pass filtering and by reduced order system synchronization, without knowing neither the system parameter values nor the system key.

G. Alvarez; L. Hernandez; J. Munoz; F. Montoya; Shujun Li

2005-06-27T23:59:59.000Z

292

Magnetic nanotubes  

DOE Patents (OSTI)

A magnetic nanotube includes bacterial magnetic nanocrystals contacted onto a nanotube which absorbs the nanocrystals. The nanocrystals are contacted on at least one surface of the nanotube. A method of fabricating a magnetic nanotube includes synthesizing the bacterial magnetic nanocrystals, which have an outer layer of proteins. A nanotube provided is capable of absorbing the nanocrystals and contacting the nanotube with the nanocrystals. The nanotube is preferably a peptide bolaamphiphile. A nanotube solution and a nanocrystal solution including a buffer and a concentration of nanocrystals are mixed. The concentration of nanocrystals is optimized, resulting in a nanocrystal to nanotube ratio for which bacterial magnetic nanocrystals are immobilized on at least one surface of the nanotubes. The ratio controls whether the nanocrystals bind only to the interior or to the exterior surfaces of the nanotubes. Uses include cell manipulation and separation, biological assay, enzyme recovery, and biosensors.

Matsui, Hiroshi (Glen Rock, NJ); Matsunaga, Tadashi (Tokyo, JP)

2010-11-16T23:59:59.000Z

293

Superconducting Magnets  

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

Mit Hilfe der Technologie supraleitender Magnete lassen sich in Mit Hilfe der Technologie supraleitender Magnete lassen sich in Ringbeschleunigern höhere Energien erreichen. Weil supraleitende Spulen keinen elektrischen Widerstand aufweisen, können damit stärkere Magnetfelder erzeugt werden. In normal leitenden Elektromagneten wird - wegen des elektrischen Widerstands der Drähte - die Spule aufgeheizt. Auf diese Weise geht sehr viel Energie in Form von Wärme verloren, was die Energiekosten dieser Magnete in die Höhe treibt. Supraleitende Spulen erlauben es, Magnete grosser Feldstärke unter günstigen Bedingungen zu betreiben und damit die Energiekosten zu senken. Durch den Einbau supraleitender Spulen in den Ringbeschleuniger von Fermilab konnte dessen Energie verdoppelt werden.Auch der im Bau befindliche "Large Hadron Collider" am CERN wird supraleitende Magnete

294

On Synchronization: Comments on the paper "Synchronization in scale-free dynamical networks: robustness and fragility", IEEE Trans. Circuits Syst. I 49 (1) (2002) 54-62  

E-Print Network (OSTI)

Synchronization problem for linear coupled networks is a hot topic in recent decade. However, until now, some confused concepts and results still puzzle people. To avoid further misleading researchers, it is necessary to point out these misunderstandings, correct these mistakes and give precise results.

Tianping Chen

2013-06-20T23:59:59.000Z

295

Nuclear Magnetic Resonance Laboratory  

Science Conference Proceedings (OSTI)

Nuclear Magnetic Resonance Laboratory. ... A 600 MHz Nuclear Magnetic Resonance Spectrometer. Analytical Data Compilation Reference Materials. ...

2012-10-01T23:59:59.000Z

296

Learning About Magnets!  

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

the the National High Magnetic Field Laboratory Learning About Name A magnet is a material or object that creates a magnetic fi eld. This fi eld is invisible, but it creates a force that can "attract" or "repel" other magnets and magnetic materials, like iron or nickel. What is a Magnet? This bar magnet is a permanent magnet. Permanent magnets can be found in the Earth as rocks and metals. Magnets have

297

Characterization of the Effects of a Sun-Synchronous Orbit Slot Architecture on the Earth's Orbital Debris Environment.  

E-Print Network (OSTI)

?? Low Earth orbit represents a valuable limited natural resource. Of particular interest are sun-synchronous orbits; it is estimated that approximately 44% of low Earth (more)

Noyes, Connor David

2013-01-01T23:59:59.000Z

298

Study and Development of Anti-Islanding Control for Synchronous Machine-Based Distributed Generators: November 2001--March 2004  

SciTech Connect

This report summarizes the study and development of new active anti-islanding control schemes for synchronous machine-based distributed generators, including engine generators and gas turbines.

Ye, Z.

2006-03-01T23:59:59.000Z

299

A new measure of phase synchronization for a pair of time series and seizure focus localization  

E-Print Network (OSTI)

Defining and measuring phase synchronization in a pair of nonlinear time series are highly nontrivial. This can be done with the help of Fourier transform, when it exists, for a pair of stored (hence stationary) signals. In a time series instantaneous phase is often defined with the help of Hilbert transform. In this paper phase of a time series has been defined with the help of Fourier transform. This gives rise to a deterministic method to detect phase synchronization in its most general form between a pair of time series. Since this is a stricter method than the statistical methods based on instantaneous phase, this can be used for lateralization and source localization of epileptic seizures with greater accuracy. Based on this method a novel measure of phase synchronization, called syn function, has been defined, which is capable of quantifying neural phase synchronization and asynchronization as important parameters of epileptic seizure dynamics. It has been shown that such a strict measure of phase synchronization has potential application in seizure focus localization from scalp electroencephalogram (EEG) data, without any knowledge of electrical conductivity of the head.

Kaushik Majumdar

2006-12-13T23:59:59.000Z

300

Neutrino magnetic moment in a magnetized plasma  

E-Print Network (OSTI)

The contribution of a magnetized plasma to the neutrino magnetic moment is calculated. It is shown that only part of the additional neutrino energy in magnetized plasma connecting with its spin and magnetic field strength defines the neutrino magnetic moment. It is found that the presence of magnetized plasma does not lead to the considerable increase of the neutrino magnetic moment in contrast to the results presented in literature previously.

N. V. Mikheev; E. N. Narynskaya

2010-11-08T23:59:59.000Z

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Magnetostrictive materials and method for improving AC characteristics in same  

DOE Patents (OSTI)

The present invention provides Terfenol-D alloys ("doped" Terfenol) having optimized performances under the condition of time-dependent magnetic fields. In one embodiment, performance is optimized by lowering the conductivity of Terfenol, thereby improving the frequency response. This can be achieved through addition of Group III or IV elements, such as Si and Al. Addition of these types of elements provides scattering sites for conduction electrons, thereby increasing resistivity by 125% which leads to an average increase in penetration depth of 80% at 1 kHz and an increase in energy conversion efficiency of 55%. The permeability of doped Terfenol remains constant over a wider frequency range as compared with undoped Terfenol. These results demonstrate that adding impurities, such as Si and Al, are effective in improving the ac characteristics of Terfenol. A magnetoelastic Gruneisen parameter, .gamma..sub.me, has also been derived from the thermodynamic equations of state, and provides another means by which to characterize the coupling efficiency in magnetostrictive materials on a more fundamental basis.

Pulvirenti, Patricia P. (Chicago, IL); Jiles, David C. (Ames, IA)

2001-08-14T23:59:59.000Z

302

Motor technology for mining applications advances  

SciTech Connect

AC motors are steadily replacing DC motors in mining and mineral processing equipment, requiring less maintenance. The permanent magnet rotor, or the synchronous motor, has enabled Blador to introduce a line of cooling tower motors. Synchronous motors are soon likely to take over from the induction motor. 1 photo.

Fiscor, S.

2009-08-15T23:59:59.000Z

303

AC Solar Inc | Open Energy Information  

Open Energy Info (EERE)

Logo: AC Solar Inc Name AC Solar Inc Address P.O. Box 128 Place Florence, Colorado Zip 81226 Sector Solar Product Solar and wind sales for residential Website http://www.acsolar.com/ Coordinates 38.381551°, -105.112265° 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":38.381551,"lon":-105.112265,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

304

An FPGA Based Multiprocessing CPU for Beam Synchronous Timing in CERN's SPS and LHC  

E-Print Network (OSTI)

The Beam Synchronous Timing system (BST) will be used around the LHC and its injector, the SPS, to broadcast timing meassages and synchronize actions with the beam in different receivers. To achieve beam synchronization, the BST Master card encodes messages using the bunch clock, with a nominal value of 40.079 MHz for the LHC. These messages are produced by a set of tasks every revolution period, which is every 89 us for the LHC and every 23 us for the SPS, therefore imposing a hard real-time constraint on the system. To achieve determinism, the BST Master uses a dedicated CPU inside its main Field Programmable Gate Array (FPGA) featuring zero-delay hardware task switching and a reduced instruction set. This paper describes the BST Master card, stressing the main FPGA design, as well as the associated software, including the LynxOS driver and the tailor-made assembler.

Ballester, F J; Gras, J J; Lewis, J; Savioz, J J; Serrano, J

2003-01-01T23:59:59.000Z

305

Transmission of information and synchronization in a pair of coupled chaotic circuits: an experimental overview  

E-Print Network (OSTI)

We propose a rationale for experimentally studying the intricate relationship between the rate of information transmission and synchronization level in active networks, applying theoretical results recently proposed. We consider two non-identical coupled Chua's circuit with non-identical coupling strengths in order to illustrate the proceeding for experimental scenarios of very few data points coming from highly non-coherent coupled systems, such that phase synchronization can only be detected by methods that do not rely explicitely on the calculation of the phase. A relevant finding is to show that for the coupled Chua's circuit, the larger the level of synchronization the larger the rate of information exchanged between both circuits. We further validate our findings with data from numerical simulations, and discuss an extension to arbitrarily large active networks.

M. S. Baptista; S. P. Garcia; S. K. Dana; J. Kurths

2008-02-21T23:59:59.000Z

306

Control of synchronization in coupled neural systems by time-delayed feedback  

E-Print Network (OSTI)

We discuss the synchronization of coupled neurons which are modelled as FitzHugh-Nagumo systems. As smallest entity in a larger network, we focus on two diffusively coupled subsystems, which can be interpreted as two mutually interacting neural populations. Each system is prepared in the excitable regime and subject to independent random fluctuations. In order to modify their cooperative dynamics, we apply a local external stimulus in form of an extended time-delayed feedback loop that involves multiple delays weighted by a memory parameter and investigate if local control applied to a subsystem can allow one to steer the global cooperative dynamics. Depending on the choice of this new control parameter, we investigate different measures to quantify the influence on synchronization: ratio of interspike intervals, power spectrum, interspike interval distribution, and phase synchronization intervals. We show that the control method is more robust for increasing memory parameter.

Philipp Hoevel; Markus A. Dahlem; Eckehard Schoell

2008-09-04T23:59:59.000Z

307

A low-power circuit for piezoelectric vibration control by synchronized switching on voltage sources  

E-Print Network (OSTI)

In the paper, a vibration damping system powered by harvested energy with implementation of the so-called SSDV (synchronized switch damping on voltage source) technique is designed and investigated. In the semi-passive approach, the piezoelectric element is intermittently switched from open-circuit to specific impedance synchronously with the structural vibration. Due to this switching procedure, a phase difference appears between the strain induced by vibration and the resulting voltage, thus creating energy dissipation. By supplying the energy collected from the piezoelectric materials to the switching circuit, a new low-power device using the SSDV technique is proposed. Compared with the original self-powered SSDI (synchronized switch damping on inductor), such a device can significantly improve its performance of vibration control. Its effectiveness in the single-mode resonant damping of a composite beam is validated by the experimental results.

Shen, Hui; Ji, Hongli; Zhu, Kongjun; Balsi, Marco; Giorgio, Ivan; dell'Isola, Francesco

2010-01-01T23:59:59.000Z

308

Magnetization Characterization Laboratory  

Science Conference Proceedings (OSTI)

... use of magnetic materials for motors, generators, transformers ... all depend on the specific magnetic characteristics of ... For example, a magnet used in ...

2012-10-23T23:59:59.000Z

309

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network (OSTI)

Scale Superconducting Magnetic Energy Storage Plant", IEEEfor SlIperconducting Magnetic Energy Storage Unit", inSuperconducting Magnetic Energy Storage Plant, Advances in

Hassenzahl, W.

2011-01-01T23:59:59.000Z

310

MAGNETIC GRID  

DOE Patents (OSTI)

An electronic grid is designed employing magnetic forces for controlling the passage of charged particles. The grid is particularly applicable to use in gas-filled tubes such as ignitrons. thyratrons, etc., since the magnetic grid action is impartial to the polarity of the charged particles and, accordingly. the sheath effects encountered with electrostatic grids are not present. The grid comprises a conductor having sections spaced apart and extending in substantially opposite directions in the same plane, the ends of the conductor being adapted for connection to a current source.

Post, R.F.

1960-08-01T23:59:59.000Z

311

FeCo and FeNi-based Nanocomposite Magnets for Energy ...  

Science Conference Proceedings (OSTI)

Symposium, Magnetic Materials for Energy Applications ... AC power conversion applications in hybrid vehicles will be discussed. In Co-rich ... First to Second Order Magnetocaloric Transition: on Correct Analysis of Experimental Data ... Recent Advances in Non-oriented Electrical Steel for EV/HEV Traction Motor.

312

A laser-excited synchronous fluorescence spectrometer for benzo(a)pyrene  

Science Conference Proceedings (OSTI)

A laser-based synchronous scanning fluorimeter was developed for detecting polycyclic aromatic hydrocarbons (PAHs). Although extensive sample cleanup and separation are usually required, fluorescence has long been used for determination of PAHs. Amount of sample pretreatment can often be reduced when synchronous fluorescence (SF) is used, and the sensitivity of SF can be increased by the high power and narrow profile of a laser source. A small, portable, pulsed dye laser was used in this study. The instrument and its application to the determination of the carcinogen benzo(a)pyrene are described.

Huebedr, D.M.; Iruela Del Olmo, M.; Stevenson, C.L.; Vo-Dinh, T.

1995-09-01T23:59:59.000Z

313

Time Synchronization Attack in Smart Grid-Part I: Impact and Analysis  

E-Print Network (OSTI)

Many operations in power grids, such as fault detection and event location estimation, depend on precise timing information. In this paper, a novel Time Synchronization Attack (TSA) is proposed to attack the timing information in smart grid. Since many applications in smart grid utilize synchronous measurements and most of the measurement devices are equipped with global positioning system (GPS) for precise timing, it is highly probable to attack the measurement system by spoofing the GPS. The effectiveness of TSA is demonstrated for three applications of phasor measurement unit (PMU) in smart grid, namely transmission line fault detection, voltage stability monitoring and event locationing. The validity of TSA is demonstrated by numerical simulations.

Zhang, Zhenghao; Dimitrovski, Aleksandar D; Li, Husheng

2012-01-01T23:59:59.000Z

314

Surge Protection in Low-Voltage AC Power Circuits  

Science Conference Proceedings (OSTI)

Surge Protection in Low-Voltage AC Power Circuits: An 8-part Anthology ... converting old and yellowing papers into 21st Century electronic files, and ...

2013-05-20T23:59:59.000Z

315

AC vs DC Wizard Version 1.0  

Science Conference Proceedings (OSTI)

AC vs DC Wizard compares the use of HVDC to HVAC in both new and existing overhead lines and in new underground cable ...

2012-12-04T23:59:59.000Z

316

AC-to-DC Power Transmission Line Conversion  

Science Conference Proceedings (OSTI)

System planners have grown more interest in the prospect of converting ac transmission lines to dc as transfer constraints become more severe and they increasingly recognize dc as a means to improve ac system performance. Two factors have influenced the economic case for conversion. The first is development of a new (tripole) dc configuration that allows dc to make full use of all three ac phase positions without the need for earth return. The second is the realization that converting an ac line to dc ma...

2010-11-10T23:59:59.000Z

317

Road to AC Voltage Standard Leads to Important Junction  

Science Conference Proceedings (OSTI)

Road to AC Voltage Standard Leads to Important Junction. ... Grumman in the mid-1990s.*** A number of innovations since then have led to the first ...

2013-08-13T23:59:59.000Z

318

Simultaneous distribution of AC and DC power - Energy ...  

... Alternating Current) as well as the elimination of equipment normally used to reconvert AC back to DC for components of HVAC systems, ...

319

Brushless machine having ferromagnetic side plates and side magnets  

Science Conference Proceedings (OSTI)

An apparatus is provided having a cylindrical stator and a rotor that is spaced from a stator to define an annular primary air gap that receives AC flux from the stator. The rotor has a plurality of longitudinal pole portions disposed parallel to the axis of rotation and alternating in polarity around a circumference of the rotor. Each longitudinal pole portion includes portions of permanent magnet (PM) material and at least one of the longitudinal pole portions has a first end and an opposing second end and a side magnet is disposed adjacent the first end and a side pole is disposed adjacent the second end.

Hsu, John S

2012-10-23T23:59:59.000Z

320

Questions about Magnets  

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

off just the north (or just the south) end of a magnet? Are magnets stronger than gravity? Hold a magnet in the air. Place a nail against it. The magnet holds the nail up...

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Synchronous Ultra-Wide Band Wireless Sensors Networks for oil and gas exploration  

E-Print Network (OSTI)

Synchronous Ultra-Wide Band Wireless Sensors Networks for oil and gas exploration Stefano Savazzi1 of new oil and gas reservoir. Seismic exploration requires a large number (500 ÷ 2000 nodes, MAC and network layer to develop wireless sensors networks tailored for oil (and gas) exploration

Savazzi, Stefano

322

Unconditionally secure message transmission in arbitrary directed synchronous networks tolerating generalized mixed adversary  

Science Conference Proceedings (OSTI)

In this paper, we re-visit the problem of unconditionally secure message transmission (USMT) from a sender S to a receiver R, who are part of a distributed synchronous network, modeled as an arbitrary directed graph. Some ... Keywords: error probability, information theoretic security, mixed adversary

Kannan Srinathan; Arpita Patra; Ashish Choudhary; C. Pandu Rangan

2009-03-01T23:59:59.000Z

323

HiRe: using hint & release to improve synchronization of speculative threads  

Science Conference Proceedings (OSTI)

Thread-Level Speculation (TLS) is a promising technique for improving performance of serial codes on multi-cores by automatically extracting threads and running them in parallel. However, the speculation efficiency as well as the performance gain of ... Keywords: dependence prediction, multi-core architecture, synchronization, thread-level speculation

Liang Han; Xiaowei Jiang; Wei Liu; Youfeng Wu; James Tuck

2012-06-01T23:59:59.000Z

324

Effects of applying STR for group learning activities on learning performance in a synchronous cyber classroom  

Science Conference Proceedings (OSTI)

This study aimed to apply Speech to Text Recognition (STR) for individual oral presentations and group discussions of students in a synchronous cyber classroom. An experiment was conducted to analyze the effectiveness of applying STR on learning performance. ... Keywords: Computer-mediated communication, Distance education and telelearning, Improving classroom teaching, Pedagogical issues, cooperative/collaborative learning

Tony C. T. Kuo; Rustam Shadiev; Wu-Yuin Hwang; Nian-Shing Chen

2012-01-01T23:59:59.000Z

325

Digital multimode buck converter control with loss-minimizing synchronous rectifier adaptation  

E-Print Network (OSTI)

AbstractThis paper develops a multimode control strategy which allows for efficient operation of the buck converter over a wide load range. A method for control of synchronous rectifiers as a direct function of the load current is introduced [1]. The function relating the synchronous-rectifier timing to the load current is optimized on-line with a gradient power-loss-minimizing algorithm. Only low-bandwidth measurements of the load current and a power-loss-related quantity are required, making the technique suitable for digital controller implementations. Compared to alternative loss-minimizing approaches, this method has superior adjustment speed and robustness to disturbances, and can simultaneously optimize multiple parameters. The proposed synchronous-rectifier control also accomplishes an automatic, optimal transition to discontinuous-conduction mode at light load. Further, by imposing a minimum duty-ratio, the converter automatically enters pulse-skipping mode at very light load. Thus, the same controller structure can be used in both fixed-frequency pulsewidth modulation and variable-frequency pulse-skipping modes. These techniques are demonstrated on a digitally-controlled 100-W buck converter. Index TermsAdaptive control, dead-time, digital control, gradient methods, multimode control, optimization methods, pulse skipping, pulsewidth modulated (PWM) power converters, pulsewidth modulation (PWM), synchronous rectifier (SR), variable frequency control. Fig. 1. Buck converter with SR (M), and the corresponding MOSFET control signals.

Angel V. Peterchev; Seth R. S

2006-01-01T23:59:59.000Z

326

Experimental evaluation of topology control and synchronization for in-building sensor network applications  

Science Conference Proceedings (OSTI)

While multi-hop networks consisting of 100s or 1000s of inexpensive embedded sensors are emerging as a means of mining data from the environment, inadequate network lifetime remains a major impediment to real-world deployment. This paper describes several ... Keywords: energy conservation, performance evaluation, synchronization, topology control, wireless sensor networks

W. Steven Conner; Jasmeet Chhabra; Mark Yarvis; Lakshman Krishnamurthy

2005-08-01T23:59:59.000Z

327

The Synchronous Boltzmann Machine for learning and hard-combinatoric search  

E-Print Network (OSTI)

The Synchronous Boltzmann Machine for learning and hard-combinatoric search Ursula X. Iturrarán that part of the theory related to energy minimisation only permits one unit at a time to update its state Boltzmann machine is in hard combinatoric search. The main difficulty is that, for a given search problem

Jones, Antonia J.

328

Using synchronous peer tutoring system to promote elementary students' learning in mathematics  

Science Conference Proceedings (OSTI)

The face-to-face computer-supported collaborative learning has emerged as an important strategy to elementary students' learning. Few studies have explicitly incorporated the structured peer tutoring to the synchronous environment in mathematics. This ... Keywords: Applications in subject areas, Computer-mediated communication, Cooperative/collaborative learning, Elementary education, Teaching/learning strategies

Mengping Tsuei

2012-05-01T23:59:59.000Z

329

Modulus-based synchronous two-stage multisplitting iteration methods for linear complementarity problems  

Science Conference Proceedings (OSTI)

In order to solve large sparse linear complementarity problems on parallel multiprocessor systems, we construct modulus-based synchronous two-stage multisplitting iteration methods based on two-stage multisplittings of the system matrices. These iteration ... Keywords: Convergence, Linear complementarity problem, Matrix multisplitting, Modulus method, Successive relaxation, Two-stage iteration

Zhong-Zhi Bai; Li-Li Zhang

2013-01-01T23:59:59.000Z

330

Synchronization and Transient Stability in Power Networks and Non-Uniform Kuramoto Oscillators  

E-Print Network (OSTI)

Motivated by recent interest for multi-agent systems and smart power grid architectures, we discuss the synchronization problem for the network-reduced model of a power system with non-trivial transfer conductances. Our key insight is to exploit the relationship between the power network model and a first-order model of coupled oscillators. Assuming overdamped generators (possibly due to local excitation controllers), a singular perturbation analysis shows the equivalence between the classic swing equations and a non-uniform Kuramoto model. Here, non-uniform Kuramoto oscillators are characterized by multiple time constants, non-homogeneous coupling, and non-uniform phase shifts. Extending methods from transient stability, synchronization theory, and consensus protocols, we establish sufficient conditions for synchronization of non-uniform Kuramoto oscillators. These conditions reduce to and improve upon previously-available tests for the standard Kuramoto model. Combining our singular perturbation and Kuramoto analyses, we derive concise and purely algebraic conditions that relate synchronization and transient stability of a power network to the underlying system parameters and initial conditions.

Florian Dorfler; Francesco Bullo

2009-10-29T23:59:59.000Z

331

Hybrid Electric Vehicle with Permanent Magnet Traction Motor: A Simulation Model  

E-Print Network (OSTI)

A simulation model for a hybrid electric vehicle is developed. Permanent magnet synchronous motor is considered for the drive part of the hybrid electric vehicle which comprises three energy sources: (i) a fuel cell, (ii) a battery bank, and (iii) a super capacitor. Rotor-oriented speed controller is designed, and also verified by simulation results, to achieve trajectory tracking requirements of the hybrid electric vehicle within the inverter voltage and current limits.

Levent U. Gkdere; Khalid Benlyazid; Enrico; Enrico Santi; Charles W. Brice; Roger A. Dougal

1999-01-01T23:59:59.000Z

332

magnets2  

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

II II Painless Physics Articles BEAM COOLING August 2, 1996 By Leila Belkora, Office of Public Affairs ACCELERATION August 16, 1996 By Dave Finley, Accelerator Division Head RF August 30, 1996 By Pat Colestock, Accelerator Division FIXED TARGET PHYSICS September 20, 1996 By Peter H. Garbincius, Physics Section FIXED TARGET PHYSICS PART DEUX October 16, 1996 By Peter H. Garbincius, Physics Section and Leila Belkora, Office of Public Affaris CROSS SECTION November 1, 1996 By Doreen Wackeroth, Theoretical Physics Edited by Leila Belkora, Office of Public Affaris MAGNETS PART I November 15, 1996 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs MAGNETS PART II January 10, 1997 By Hank Glass, Technical Support Section Edited by Donald Sena, Office of Public Affairs

333

Electrostatic coalescence system with independent AC and DC hydrophilic electrodes  

DOE Patents (OSTI)

An improved electrostatic coalescence system is provided in which independent AC and DC hydrophilic electrodes are employed to provide more complete dehydration of an oil emulsion. The AC field is produced between an AC electrode array and the water-oil interface wherein the AC electrode array is positioned parallel to the interface which acts as a grounded electrode. The emulsion is introduced into the AC field in an evenly distributed manner at the interface. The AC field promotes drop-drop and drop-interface coalescence of the water phase in the entering emulsion. The continuous oil phase passes upward through the perforated AC electrode array and enters a strong DC field produced between closely spaced DC electrodes in which small dispersed droplets of water entrained in the continuous phase are removed primarily by collection at hydrophilic DC electrodes. Large droplets of water collected by the electrodes migrate downward through the AC electrode array to the interface. All phase separation mechanisms are utilized to accomplish more complete phase separation.

Hovarongkura, A. David (Arlington, VA); Henry, Jr., Joseph D. (Morgantown, WV)

1981-01-01T23:59:59.000Z

334

AC impedance analysis of Au/porous silicon contacts  

Science Conference Proceedings (OSTI)

In this paper we present the AC impedance analysis of Au/porous silicon contacts in order to investigate their conduction mechanisms. The porous silicon layer was obtained by electrochemical etching of the p-Si wafer. The measurements were made between ... Keywords: AC electrical conductivity, Electrical equivalent circuit, Porous silicon

F. Fonthal; T. Trifonov; A. Rodriguez; L. F. Marsal; J. Pallars

2006-11-01T23:59:59.000Z

335

www.mmu.ac.uk/careers Careers & Employability Service  

E-Print Network (OSTI)

;www.mmu.ac.uk/careers Identifying courses · www.prospects.ac.uk/search_courses.htm · www: Courses to allow you to enter certain professions Courses that build your skills in a new area Examples · MRes (taught prep for further research) These usually involve lectures for the first two terms

336

Measurement of coupling resonance driving terms with the AC dipole  

Science Conference Proceedings (OSTI)

Resonance driving terms for linear coupled betatron motion in a synchrotron ring can be determined from corresponding spectral lines of an excited coherent beam motion. An AC dipole is one of instruments to excite such a motion. When a coherent motion is excited with an AC dipole, measured Courant-Snyder parameters and betatron phase advance have apparent modulations, as if there is an additional quadrupole field at the location of the AC dipole. Hence, measurements of these parameters using the AC dipole require a proper interpretation of observed quantities. The situation is similar in measurements of resonance driving terms using the AC dipole. In this note, we derive an expression of coupled betatron motion excited with two AC dipoles in presence of skew quadrupole fields, discuss an impact of this quadrupole like effect of the AC dipole on a measurement of coupling resonance driving terms, and present an analytical method to determine the coupling resonance driving terms from quantities observed using the AC dipole.

Miyamoto, R.

2010-10-01T23:59:59.000Z

337

Turk J Elec Eng & Comp Sci, Vol.18, No.5, 2010, c TUBITAK doi:10.3906/elk-0906-55  

E-Print Network (OSTI)

estimation methods will be determined based on the motor type (induction or interior permanent magnet induction and interior permanent magnet synchronous motors will be presented. The study helps the motion investigation of shaft transducerless speed and position control of ac induction and interior permanent magnet

Hava, Ahmet

338

Magnetic Reconnection  

SciTech Connect

We review the fundamental physics of magnetic reconnection in laboratory and space plasmas, by discussing results from theory, numerical simulations, observations from space satellites, and the recent results from laboratory plasma experiments. After a brief review of the well-known early work, we discuss representative recent experimental and theoretical work and attempt to interpret the essence of significant modern findings. In the area of local reconnection physics, many significant findings have been made with regard to two- uid physics and are related to the cause of fast reconnection. Profiles of the neutral sheet, Hall currents, and the effects of guide field, collisions, and micro-turbulence are discussed to understand the fundamental processes in a local reconnection layer both in space and laboratory plasmas. While the understanding of the global reconnection dynamics is less developed, notable findings have been made on this issue through detailed documentation of magnetic self-organization phenomena in fusion plasmas. Application of magnetic reconnection physics to astrophysical plasmas is also brie y discussed.

Masaaki Yamada, Russell Kulsrud and Hantao Ji

2009-09-17T23:59:59.000Z

339

Superconductor with Improved Flux Pinning and Reduced AC ...  

Superconductor with Improved Flux ... involve ramped magnetic or oscillating magnetic fields or require that the HTS wire carry alternating current ...

340

ESS 2012 Peer Review - Magnetic Composites for Flywheel Energy Storage - Jim Martin, SNL  

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

subsidiary subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. Photos placed in horizontal position with even amount of white space between photos and header Photos placed in horizontal position with even amount of white space between photos and header Magnetic composites for flywheel energy storage September 27, 2012 James E. Martin Project description  The bearings currently used in energy storage flywheels dissipate a significant amount of energy. Magnetic bearings would reduce these losses appreciably.  Magnetic bearings require magnetic materials on an inner annulus of the flywheel for magnetic levitation.  This magnetic material must be able to withstand a 2% tensile deformation, yet

Note: This page contains sample records for the topic "magnet ac synchronous" 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

RESEARCH ON THE EFFECTS OF MAGNETIC FIELDS ON THERMIONIC POWER GENERATION. Progress Report No. 1  

SciTech Connect

Research concerned with a theoretical and experimental study of magneto- thermionic power generation is reported. This concept promises a number of advantsges over conventional thermionic generators. Low pressure Cs diodes suffer from an undesirable size limitation, because selfinduced magnetic fields reduce current transmission and hence, efficiency. Although this effect does not arise in the small devices tested to date, it becomes important in building larger generators. Analysis indicates that this problem can be virtually eliminnted by the application of a longitudinal magnetic field. An experimental and theoretical study was initiated to verify the predicted magnetic field effects, and to examine their possible use in a-c generation. (auth)

Schock, A.; Kunen, A.E.

1961-10-01T23:59:59.000Z

342

AC versus DC distribution systems- Did we get it right?  

DOE Green Energy (OSTI)

We presently enjoy a predominantly ac electrical distribution system, the engineering basis for which was designed over 100 years ago. While ac distribution systems have served us well, we should periodically pause to assess what opportunities we have accepted or been denied by the overwhelming predominance of ac electrical power distribution systems. What opportunities could be obtained by engineering dc distribution into at least portions of our present system? What advantages of the present ac distribution system should be recognized and protected? This paper will focus on distribution within premise and low-voltage distribution systems. Specifically, we will address the conversion efficiency costs of adopting various premise ac and dc distribution system topologies. According to a simple predictive model formulated in this paper, premise residential dc distribution will incur unfavorable total conversion efficiency compared with existing ac premise distribution. However, if a residence is supplied by a fuel cell or another dc generator, the total conversion efficiency within a residential dc distribution system could be similar to, or even better than, that for ac distribution.

Hammerstrom, Donald J.

2007-06-28T23:59:59.000Z

343

Superconducting magnet  

DOE Patents (OSTI)

A superconducting magnet designed to produce magnetic flux densities of the order of 4 to 5 Webers per square meter is constructed by first forming a cable of a plurality of matrixed superconductor wires with each wire of the plurality insulated from each other one. The cable is shaped into a rectangular cross-section and is wound with tape in an open spiral to create cooling channels. Coils are wound in a calculated pattern in saddle shapes to produce desired fields, such as dipoles, quadrupoles, and the like. Wedges are inserted between adjacent cables as needed to maintain substantially radial placement of the long dimensions of cross sections of the cables. After winding, individual strands in each of the cables are brought out to terminals and are interconnected to place all of the strands in series and to maximize the propagation of a quench by alternating conduction from an inner layer to an outer layer and from top half to bottom half as often as possible. Individual layers are separated from others by spiraled aluminum spacers to facilitate cooling. The wound coil is wrapped with an epoxy tape that is cured by heat and then machined to an interference fit with an outer aluminum pipe which is then affixed securely to the assembled coil by heating it to make a shrink fit. In an alternate embodiment, one wire of the cable is made of copper or the like to be heated externally to propagate a quench.

Satti, John A. (Naperville, IL)

1980-01-01T23:59:59.000Z

344

Magnet innovations for linacs  

Science Conference Proceedings (OSTI)

It is possible to produce large magnetic fields at the aperture of permanent magnet quadrupoles, even when the magnetic aperture is very small. That, combined with their compactness, makes permanent magnet quadrupoles very powerful components of small aperture linacs. Results will be presented about past and present work on both fixed and variable strength permanent magnets suitable for use in and around linacs.

Halbach, K.

1986-06-01T23:59:59.000Z

345

Method and means for generating a synchronizing pulse from a repetitive wave of varying frequency  

DOE Patents (OSTI)

An event that occurs repetitively at continuously changing frequencies can be used to generate a triggering pulse which is used to synchronize or control. The triggering pulse is generated at a predetermined percentage of the period of the repetitive waveform without regard to frequency. Counts are accumulated in two counters, the first counting during the "on" fraction of the period, and the second counting during the "off" fraction. The counts accumulated during each cycle are compared. On equality the trigger pulse is generated. Count input rates to each counter are determined by the ratio of the on-off fractions of the event waveform and the desired phase relationship. This invention is of particular utility in providing a trigger or synchronizing pulse during the open period of the shutter of a high-speed framing camera during its acceleration as well as its period of substantially constant speed.

DeVolpi, Alexander (Lisle, IL); Pecina, Ronald J. (Westchester, IL); Travis, Dale J. (Lockport, IL)

1976-01-01T23:59:59.000Z

346

Tests with a microcomputer based adaptive synchronous machine stabilizer on a 400MW thermal unit  

Science Conference Proceedings (OSTI)

Field tests have been conducted on a microcomputer-based adaptive synchronous machine stabilizer. The adaptive control algorithm tracks the system operating conditions using a least squares identification technique with variable forgetting factor and the control is calculated by a self-searching pole-shift method. An outline of the control algorithm and the results of field tests on a 400MW thermal generating unit are described in this paper.

Malik, O.P.; Hope, G.S.; Hancock, G.C. (Univ. of Calgary, Alberta (Canada)); Mao, C.X. (Huazhong Univ. of Science and Technology, Wuhan (China)); Prakash, K.S. (Bharat Heavy Electricals, Banglore (India))

1993-03-01T23:59:59.000Z

347

Bad seeds sprout perilous dynamics: stochastic thermostat induced trajectory synchronization in biomolecules  

SciTech Connect

Molecular dynamics simulations starting from different initial conditions are commonly used to mimic the behavior of an experimental ensemble. We show in this article that when a Langevin thermostat is used to maintain constant temperature during such simulations, extreme care must be taken when choosing the random number seeds used in order to prevent statistical correlation among the MD trajectories. While recent studies have shown that stochastically thermostatted trajectories evolving within a single potential basin with identical random number seeds tend to synchronize, we show that there is a synchronization effect even for complex, biologically relevant systems. We demonstrate this effect in simulations of Alanine trimer and pentamer and in a simulation of a temperature-jump experiment for peptide folding of a 14-residue peptide. Even in replica-exchange simulations, in which the trajectories are at different temperatures, we find partial synchronization occurring when the same random number seed is employed. We explain this by extending the recent derivation of the synchronization effect for two trajectories in a harmonic well to the case in which the trajectories are at two different temperatures. Our results suggest several ways in which mishandling selection of a pseudo random number generator initial seed can lead to corruption of simulation data. Simulators can fall into this trap in simple situations such as neglecting to specifically indicate different random seeds in either parallel or sequential restart simulations, utilizing a simulation package with a weak pseudorandom number generator, or using an advanced simulation algorithm that hasn't been programmed to distribute initial seeds.

Voter, A F [Los Alamos National Laboratory; Sindhikara, Daniel J [UNIV OF FLORIDA; Kim, Seonah [UNIV OF CALIFORNIA; Roitberg, Adrian E [UNIV OF FLORIDA

2009-01-01T23:59:59.000Z

348

Method and system for controlling a synchronous machine over full operating range  

DOE Patents (OSTI)

System and method for controlling a synchronous machine are provided. The method allows for calculating a stator voltage index. The method further allows for relating the magnitude of the stator voltage index against a threshold voltage value. An offset signal is generated based on the results of the relating step. A respective state of operation of the machine is determined. The offset signal is processed based on the respective state of the machine.

Walters, James E. (Carmel, IN); Gunawan, Fani S. (Westfield, IN); Xue, Yanhong (Westfield, IN)

2002-01-01T23:59:59.000Z

349

Turbine-Generator Topics for Power Plant Engineers: Synchronous Generator Voltage Regulator Basics  

Science Conference Proceedings (OSTI)

This material is intended for the new engineer, the control room operator, management, or the non-engineer. The basics of a synchronous generator excitation system; the fundamentals of the voltage regulator; and its controls and functions are discussed. The typical exciter types are covered, but not in detail. There is also basic information on voltage regulator maintenance issues. Put simply, the excitation system is made up of three basic component systems. The voltage regulator monitors the synchronou...

2012-02-16T23:59:59.000Z

350

Particle swarm optimisation for power quality improvement of a 12-pulse rectifier-chopper fed LCI-synchronous motor drive  

Science Conference Proceedings (OSTI)

This paper investigates the optimised passive filter combination for power quality improvement of a 12-pulse rectifier-chopper fed load commutated inverter LCI based synchronous motor SM drive. The search of optimised component values of passive filter ...

Sanjeev Singh; Bhim Singh

2012-03-01T23:59:59.000Z

351

Gamma band synchronization and the formation of representations in visual word processing: Evidence from repetition and homophone priming  

Science Conference Proceedings (OSTI)

The formation of an object's cortical representation seems to rely on synchronized neuronal activity within the gamma band frequency range (gamma band activity [GBA]). In this study, we investigated whether electroencephalogram (EEG) GBA, and its phase ...

Atsushi Matsumoto; Tetsuya Iidaka

2008-11-01T23:59:59.000Z

352

Magnetics and the body  

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

no magnetic "charges"), such as from electromagnets. Magnetic fields are measured in Tesla (T) or Gauss (G). The Tesla is a very large unit (1 T 10,000 G). Most large magnets...

353

Learning About Magnets!  

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

the National High Magnetic Field Laboratory Learning About Name A magnet is a material or object that creates a magnetic fi eld. This fi eld is invisible, but it creates a force...

354

ALS superbend magnet system  

E-Print Network (OSTI)

ALS Superbend Magnet System J. Zbasnik , S. T. Wang ,of a High-Field Magnet for the ALS, Transactions AppliedRefrigeration options for the ALS Superbend dipole magnets,

2000-01-01T23:59:59.000Z

355

Effects of nuclear electromagnetic pulse (EMP) on synchronous stability of the electric power system  

SciTech Connect

The effects of a nuclear electromagnetic pulse (EMP) on the synchronous stability of the electric power transmission and distribution systems are evaluated. The various modes of coupling of EMP to the power system are briefly discussed, with particular emphasis on those perturbations affecting the synchronous stability of the transmission system. A brief review of the fundamental concepts of the stability problem is given, with a discussion of the general characteristics of transient analysis. A model is developed to represent single sets as well as repetitive sets of multiple faults on the distribution systems, as might be produced by EMP. The results of many numerical stability calculations are presented to illustrate the transmission system's response from different types of perturbations. The important parameters of both multiple and repetitive faults are studied, including the dependence of the response on the size of the perturbed area, the fault density, and the effective impedance between the fault location and the transmission system. Both major load reduction and the effect of the opening of tie lines at the time of perturbation are also studied. We conclude that there is a high probability that EMP can induce perturbations on the distribution networks causing a large portion of the transmission network in the perturbed area to lose synchronism. The result would be an immediate and massive power failure. (auth)

Manweiler, R.W.

1975-11-01T23:59:59.000Z

356

ATLAS: A Small, Light Weight, Time-Synchronized Wind-Turbine Data Acquistion System  

DOE Green Energy (OSTI)

Wind energy researchers at Sandia National Laboratories have developed a small, lightweight, time- synchronized, robust data acquisition system to acquire long-term time-series data on a wind turbine rotor. A commercial data acquisition module is utilized to acquire data simultaneously from multip!e strain-gauge, analog, and digital channels. Acquisition of rotor data at precisely the same times as acquisition of ground data is ensured by slaving the acquisition clocks on the rotor- based data unit and ground-based units to the Global Positioning Satellite (GPS) system with commercial GPS receiver units and custom-built and programmed programmable logic devices. The acquisition clocks will remain synchronized within two microseconds indefinitely. Field tests have confirmed that synchronization can be maintained at rotation rates in excess of 350 rpm, Commercial spread-spectrum radio modems are used to transfer the rotor data to a ground- based computer concurrently with data acquisition, permitting continuous acquisition of data over a period of several hours, days or even weeks.

Berg, D.E.; Robertson, P.; Zayas, J.

1998-11-09T23:59:59.000Z

357

Bursting synchronization in networks with long-range coupling mediated by a diffusing chemical substance  

E-Print Network (OSTI)

Many networks of physical and biological interest are characterized by a long-range coupling mediated by a chemical which diffuses through a medium in which oscillators are embedded. We considered a one-dimensional model for this effect for which the diffusion is fast enough so as to be implemented through a coupling whose intensity decays exponentially with the lattice distance. In particular, we analyzed the bursting synchronization of neurons described by two timescales (spiking and bursting activity), and coupled through such a long-range interaction network. One of the advantages of the model is that one can pass from a local (Laplacian) type of coupling to a global (all-to-all) one by varying a single parameter in the interaction term. We characterized bursting synchronization using an order parameter which undergoes a transition as the coupling parameters are changed through a critical value. We also investigated the role of an external time-periodic signal on the bursting synchronization properties of the network. We show potential applications in the control of pathological rhythms in biological neural networks.

R. L. Viana; A. M. Batista; C. A. S. Batista; J. C. A. de Pontes; F. A. dos S. Silva; S. R. Lopes

2011-09-15T23:59:59.000Z

358

Adaptive vibration control using synchronous demodulation with machine tool controller motor commutation  

DOE Patents (OSTI)

A control system and method for actively reducing vibration in a spindle housing caused by unbalance forces on a rotating spindle, by measuring the force-induced spindle-housing motion, determining control signals based on synchronous demodulation, and provide compensation for the measured displacement to cancel or otherwise reduce or attenuate the vibration. In particular, the synchronous demodulation technique is performed to recover a measured spindle housing displacement signal related only to the rotation of a machine tool spindle, and consequently rejects measured displacement not related to spindle motion or synchronous to a cycle of revolution. Furthermore, the controller actuates at least one voice-coil (VC) motor, to cancel the original force-induced motion, and adapts the magnitude of voice coil signal until this measured displacement signal is brought to a null. In order to adjust the signal to a null, it must have the correct phase relative to the spindle angle. The feedback phase signal is used to adjust a common (to both outputs) commutation offset register (offset relative to spindle encoder angle) to force the feedback phase signal output to a null. Once both of these feedback signals are null, the system is compensating properly for the spindle-induced motion.

Hopkins, David James (Livermore, CA)

2008-05-13T23:59:59.000Z

359

Reactive Power Laboratory: Synchronous Condenser Testing&Modeling Results - Interim Report  

Science Conference Proceedings (OSTI)

The subject report documents the work carried out by Oak Ridge National Laboratory (ORNL) during months 5-7 (May-July 2005) of a multi-year research project. The project has the overall goal of developing methods of incorporating distributed energy (DE) that can produce reactive power locally and for injecting into the distribution system. The objective for this new type of DE is to be able to provide voltage regulation and dynamic reactive power reserves without the use of extensive communication and control systems. The work performed over this three-month period focused on four aspects of the overall objective: (1) characterization of a 250HP (about 300KVAr) synchronous condenser (SC) via test runs at the ORNL Reactive Power Laboratory; (2) development of a data acquisition scheme for collecting the necessary voltage, current and power readings at the synchronous condenser and on the distribution system; (3) development of algorithms for analyzing raw test data from the various test runs; and (4) validation of a steady-state model for the synchronous condenser via the use of a commercial software package to study its effects on the ORNL 13.8/2.4kV distribution network.

Henry, SD

2005-09-27T23:59:59.000Z

360

Magnet power system for the Microwave Tokamak Experiment (MTX)  

SciTech Connect

The system configuration, layout, and general philosophy for the MTX magnet power system is described. The vast majority of the magnet power equipment was quite successfully used on the ALCATOR-C experiment at the Massachusetts Institute of Technology. The AC power for the magnet system at MIT was obtained from a 225MVA alternator. The power for the system at LLNL is obtained directly from the local utility's 230 kV line. This installation, therefore, necessitates the addition of a great deal of equipment in ranges from new switchgear in the substation to using existing switchgear obtained from MIT as contractors for intershop electrical isolation as well as safety isolation for personnel entry into the experimental area. Additionally, some discussion is made of the unique layout of this facility and the tradeoffs made to accommodate them. 2 refs., 6 figs.

Jackson, M.C.; Musslewhite, R.C.

1987-10-07T23:59:59.000Z

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Helical Magnets Project | Superconducting Magnet Division  

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

RHIC, the basic construction unit is a superconducting dipole magnet producing a four tesla dipole field that rotates through 360 degrees in a length of 2.4 meters. The magnets...

362

Magnetization of neutron matter  

SciTech Connect

In this paper, we compute magnetization of neutron matter at strong magnetic field using the lowest order constrained variational (LOCV) technique.

Bigdeli, M. [Department of Physics, Zanjan University, P.O. Box 45195-313, Zanjan (Iran, Islamic Republic of)

2011-09-21T23:59:59.000Z

363

SUPERCONDUCTING MAGNETIC ENERGY STORAGE  

E-Print Network (OSTI)

Superconducting 30-MJ Energy Storage Coil", Proc. 19 80 ASC,Superconducting Magnetic Energy Storage Plant", IEEE Trans.SlIperconducting Magnetic Energy Storage Unit", in Advances

Hassenzahl, W.

2011-01-01T23:59:59.000Z

364

Magnetic Materials Group Homepage  

Science Conference Proceedings (OSTI)

... and simulation to become the driving force in ... develop a real-time magnetic domain imaging ... data-storage and permanent magnets with increased ...

2012-12-03T23:59:59.000Z

365

NSLS II: Magnetism  

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

spatial ordering of the magnetic moments that is superimposed on the crystal lattice. Why these atomic magnetic moments survive and how they arrange in the solid is the...

366

Regenerator for Magnetic Refrigerants  

Ames Laboratory researchers have developed a new magnetic material that can be used at low temperatures (sub liquid hydrogen) for magnetic refrigerators.

367

Designing AC power grids using integer linear programming  

Science Conference Proceedings (OSTI)

Recent developments have drawn focus towards the efficient calculation of flows in AC power grids, which are difficult to solve systems of nonlinear equations. The common linearization approach leads to the well known and often used DC formulation, which ...

Arie M. C. A. Koster; Stephan Lemkens

2011-06-01T23:59:59.000Z

368

acs_JY_jp-2011-008094 1..7  

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

C 2011, 115, 10245-10251 ARTICLE pubs.acs.orgJPCC Fast Proton Hopping Detection in Ice I h by Quasi-Elastic Neutron Scattering Itay Presiado, Jyotsana Lal, Eugene...

369

M2ACS: Multifaceted Mathematics for Complex Energy Systems Project...  

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

M2ACS: Multifaceted Mathematics for Complex Energy Systems Project Enables efficient and safe incorporation of renewable energy in the U.S. energy system; shown here is the...

370

A New, Iterative, Synchronous-Response Algorithm for Analyzing the Morton Effect  

E-Print Network (OSTI)

The present work proposes a new computational algorithm for analyzing Morton Effect using a Successive Iterative Synchronous Response Algorithm (SISRA). Previous studies on the Morton Effect were based on Eigen or Nyquist analysis for stability studies and predicted only an onset speed of instability. The outcome of SISRA is the convergence of response to a steady state orbit in a finite number of iterations. A progressive increase in the response with increasing running speed indicates the former instability. SISRA predicts both the synchronous response for the speed range of concern plus the speed where the response becomes divergent. SISRA is implemented in a Timochenko-beam-based finite-element rotordynamics software suite. SISRA analyzes the Morton Effect as a synchronous response problem with excitations from: (1) mechanical imbalance, (2) induced thermal bent shaft moments, and (3) mechanical imbalance that is induced by thermal bow. A general elliptical orbit can be decomposed into the sum of forward and backward circular orbits. As input, SISRA requires that, at a specified speed, equilibrium position, and orbit: (1) the predicted maximum differential temperature, and (2) the angle between hot spot (position of maximum temperature) and position of minimum film thickness. Two examples from the published literature are considered. SISRA predicted higher vibration levels, even before the motion diverges due to Morton Effect. In some cases, the synchronous response of the system due to Morton Effect is orders of magnitude greater than the response due only to mechanical imbalance. The combined effects of: (1) mechanical imbalance with induced thermal bent shaft moments, and (2) mechanical imbalance with thermally induced mechanical imbalance are also studied. The impact of induced thermal bent shaft moments is found to be greater than the mechanical imbalance induced by thermal bow. A parametric investigation on the impact of the changes of (1) bearing length to diameter ratio, (2) reduced viscosity of the lubricant, (3) bearing radial clearance to radius ratio and (4) overhung mass magnitude is performed to consider their respective impacts on synchronous response. Based on the available input data and the cases considered, reducing viscosity and reducing the overhung mass are found to be the best remedies to alleviate problems arising from the Morton Effect.

Saha, Rohit

2010-12-01T23:59:59.000Z

371

Development of an AC Module System: Final Technical Report  

DOE Green Energy (OSTI)

The GreenRay Inc. program focused on simplifying solar electricity and making it affordable and accessible to the mainstream population. This was accomplished by integrating a solar module, micro-inverter, mounting and monitoring into a reliable, 'plug and play' AC system for residential rooftops, offering the following advantages: (1) Reduced Cost: Reduction in installation labor with fewer components, faster mounting, faster wiring. (2) Maximized Energy Production: Each AC Module operates at its maximum, reducing overall losses from shading, mismatch, or module downtime. (3) Increased Safety. Electrical and fire safety experts agree that AC Modules have significant benefits, with no energized wiring or live connections during installation, maintenance or emergency conditions. (4) Simplified PV for a Broader Group of Installers. Dramatic simplification of design and installation of a solar power system, enabling faster and more efficient delivery of the product into the market through well-established, mainstream channels. This makes solar more accessible to the public. (5) Broadened the Rooftop Market: AC Modules enable solar for many homes that have shading, split roofs, or obstructions. In addition, due to the smaller building block size of 200W vs. 1000W, homeowners with budget limitations can start small and add to their systems over time. Through this DOE program GreenRay developed the all-in-one AC Module system with an integrated PV Module and microinverter, custom residential mounting and performance monitoring. Development efforts took the product from its initial concept, through prototypes, to a commercial product sold and deployed in the residential market. This pilot deployment has demonstrated the technical effectiveness of the AC Module system in meeting the needs and solving the problems of the residential market. While more expensive than the traditional central inverter systems at the pilot scale, the economics of AC Modules become more and more favorable as the product matures and is made in high volumes. GreenRay's early customers have been highly enthusiastic about the AC Module system benefits.

Suparna Kadam; Miles Russell

2012-06-15T23:59:59.000Z

372

System and method for determining stator winding resistance in an AC motor using motor drives  

DOE Patents (OSTI)

A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

Lu, Bin; Habetler, Thomas G; Zhang, Pinjia

2013-02-26T23:59:59.000Z

373

tutimura@mist.i.u-tokyo.ac.jp kaneko@ipl.t.u-tokyo.ac.jp  

E-Print Network (OSTI)

://www.misojiro.t.u-tokyo.ac.jp/~tutimura/sem5/ 2004 6 9 ­ p.1/20 · · · · ­ p.2/20 · · · ­ p.3/20 · Java AWT/Swing (Java2D) · Tcl/Tk, Perl Graphics public void paint(Graphics g){ Graphics2D g2 = (Graphics2D)g; .... } ­ p.5/20 Tcl/Tk, Perl/Tk, Ruby/Tk · Tk GUI · Tcl, Perl, Ruby · Tcl/Tk John Ousterhout · Windows, X11, Mac · ­ p.6/20 OpenGL · 3

Murota, Kazuo

374

Demodulation circuit for AC motor current spectral analysis  

DOE Patents (OSTI)

A motor current analysis method for the remote, noninvasive inspection of electric motor-operated systems. Synchronous amplitude demodulation and phase demodulation circuits are used singly and in combination along with a frequency analyzer to produce improved spectral analysis of load-induced frequencies present in the electric current flowing in a motor-driven system.

Hendrix, Donald E. (Oak Ridge, TN); Smith, Stephen F. (Knoxville, TN)

1990-12-18T23:59:59.000Z

375

Control aspects of the Tacoma superconducting magnetic energy storage project  

SciTech Connect

On February 16, 1983, a 10 MW/30 MJ superconducting magnetic energy storage unit was energized at the Bonneville Power Administration (BPA) substation in Tacoma, Washington. The unit was retired a year later, after extensive tests directed toward its experimental use as a small-signal stabilizer for the Pacific AC Intertie. This paper addresses the control aspects of the project. These include the response characteristics of the unit, a-priori modeling of power system response, tradeoffs in control-law design, measured power system dynamics, and projection of unit effectiveness as a stabilizer.

Hauer, J.F.; Boenig, H.J.

1987-05-01T23:59:59.000Z

376

Neuro-Fuzzy Controller of a Sensorless PM Motor Drive For Washing Machines  

E-Print Network (OSTI)

algorithms to enable direct drive from permanent magnet (PM) synchronous motors[3]. #12;Among AC drives, the permanent magnet (PM) motors have became popular, due to its high torque to current ration, large powerNeuro-Fuzzy Controller of a Sensorless PM Motor Drive For Washing Machines Kasim M. Al

377

Analysis of the Concentric Planetary Magnetic Gear  

E-Print Network (OSTI)

In the field of electric machine design, a trend in many applications has been to design machines with increasing torque density. When machines fail to meet torque density requirements or are simply incapable of matching load torque, gears are commonly used. Magnetic gears have been proposed as a means of increasing torque density within electromechanical systems, while avoiding problems associated with traditional mechanical gears. While the idea behind magnetic gears goes back to early patents, their study and use in industry has been very limited to date. This study looks into variations of the gear which could lead to more industrial use. The effect of pole count upon torque ripple is investigated with finite element analysis (FEA). The analysis is extended to new magnetic layouts which borrow from permanent magnet machine design. One of the most critical components of the gear, the stator pole pieces, are also investigated for variations which aid in construction while maintaining the performance of the gear. As a means of supplementing analysis of the gear, winding function theory (WFT) is used to analyze the gear. Winding function theory has enjoyed success with induction, synchronous, and even switched reluctance machines in the past. This study is the first of its kind to apply winding function theory to a device devoid of windings altogether. It is shown that this method is capable of generating the stall torque and steady-state torque ripple waveforms which have been commonly attempted with FEA. While magnetic gears enjoy distinct advantages over mechanical gears such as inherent overload protection, they are not as torsionally stiff as their mechanical counterparts. As such, the use of damper windings for the purpose of stiffening the gear against transient oscillations is also investigated. Several competing designs are investigated for their performance, and a final design is studied which is capable of arresting transient oscillations in less than a second. In addition, a prototype has been fabricated and will be used to verify the analysis undertaken. The prototype is used to verify variations of the stator pole pieces as well as the inner rotor magnetic layout. A dynamometer has been assembled to test the performance of the prototype. A new design is also proposed for future work.

Frank, Nicolas Walter

2011-05-01T23:59:59.000Z

378

Control for stabilizing the alignment position of the rotor of a synchronous motor  

DOE Patents (OSTI)

A method and apparatus for damping oscillations in the rotor load angle of a synchronous motor to provide stable rotational alignment in high precision applications. The damping method includes sensing the angular position of the rotor and utilizing the position signal to generate an error signal in response to changes in the period of rotation of the rotor. The error signal is coupled to phase shift amplifiers which shift the phase of the motor drive signal in a direction to damp out the oscillations in the rotor load angle.

Donley, Lawrence I. (Lemont, IL)

1988-01-01T23:59:59.000Z

379

Control for stabilizing the alignment position of the rotor of the synchronous motor  

DOE Patents (OSTI)

A method and apparatus is described for damping oscillations in the rotor load angle of a synchronous motor to provide stable rotational alignment in high precision applications. The damping method includes sensing the angular position of the rotor and utilizing the position signal to generate an error signal in response to changes in the period of rotation of the rotor. The error signal is coupled to phase shift amplifiers which shift the phase of the motor drive signal in a direction to damp out the oscillations in the rotor load angle.

Donley, L.I.

1985-03-12T23:59:59.000Z

380

Larval ecology and synchronous reproduction of two crustacean species : Semibalanus balanoides in New England, USA and Gecarcinus quadratus in Veraguas, Panama  

E-Print Network (OSTI)

The environmental cues for synchronous reproduction were investigated for two highly abundant, ecologically important crustacean species: the temperate acorn barnacle, Semibalanus balanoides, and the tropical terrestrial ...

Gyory, Joanna

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Nanocomposite Magnets: Transformational Nanostructured Permanent Magnets  

SciTech Connect

Broad Funding Opportunity Announcement Project: GE is using nanomaterials technology to develop advanced magnets that contain fewer rare earth materials than their predecessors. Nanomaterials technology involves manipulating matter at the atomic or molecular scale, which can represent a stumbling block for magnets because it is difficult to create a finely grained magnet at that scale. GE is developing bulk magnets with finely tuned structures using iron-based mixtures that contain 80% less rare earth materials than traditional magnets, which will reduce their overall cost. These magnets will enable further commercialization of HEVs, EVs, and wind turbine generators while enhancing U.S. competitiveness in industries that heavily utilize these alternatives to rare earth minerals.

None

2010-10-01T23:59:59.000Z

382

HTS Magnet Program | Superconducting Magnet Division  

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

HTS Magnet Program HTS Magnet Program High Temperature Superconductors (HTS) have the potential to revolutionize the field of superconducting magnets for particle accelerators, energy storage and medical applications. This is because of the fact that as compared to the conventional Low Temperature Superconductors (LTS), the critical current density (Jc ) of HTS falls slowly both: as a function of increasing field, and as a function of increasing temperature These unique properties can be utilized to design and build: HTS magnets that produce very high fields (20 - 50 T) HTS magnets that operate at elevated temperatures (20 - 77 K) This is a significant step forward over the convention LTS magnets which generally operate at a temperature of ~4 K and with field usually limited

383

Plant and operational features of the BPA 30 MJ superconducting magnetic energy storage system  

DOE Green Energy (OSTI)

A 30 MJ superconducting magnetic energy storage (SMES) system was designed and developed for application in the Western US Power System to damp power oscillations that limit high voltage ac transmission. The system is in place at the Bonneville Power Administration (BPA) Tacoma Substation and has been in an experimental use for over a year. Extended operations of the unit have been undertaken with success. The physical, electrical, and operational features of the SMES system are given.

Rogers, J.D.; Hauer, J.F.

1984-01-01T23:59:59.000Z

384

AC Loss Measurements on a 2G YBCO Coil  

SciTech Connect

The Oak Ridge National Laboratory (ORNL) is collaborating with Waukesha Electric Systems (WES) to continue development of HTS power transformers. For compatibility with the existing power grid, a commercially viable HTS transformer will have to operate at high voltages in the range of 138 kV and above, and will have to withstand 550-kV impulse voltages as well. Second-generation (2G) YBCO coated conductors will be required for an economically-competitive design. In order to adequately size the refrigeration system for these transformers, the ac loss of these HTS coils must be characterized. Electrical AC loss measurements were conducted on a prototype high voltage (HV) coil with co-wound stainless steel at 60 Hz in a liquid nitrogen bath using a lock-in amplifier technique. The prototype HV coil consisted of 26 continuous (without splice) single pancake coils concentrically centered on a stainless steel former. For ac loss measurement purposes, voltage tap pairs were soldered across each set of two single pancake coils so that a total of 13 separate voltage measurements could be made across the entire length of the coil. AC loss measurements were taken as a function of ac excitation current. Results show that the loss is primarily concentrated at the ends of the coil where the operating fraction of critical current is the highest and show a distinct difference in current scaling of the losses between low current and high current regimes.

Rey, Christopher M [ORNL; Duckworth, Robert C [ORNL; Schwenterly, S W [ORNL

2011-01-01T23:59:59.000Z

385

Comparison of iterative methods for AC analysis in PISCES-IIB  

Science Conference Proceedings (OSTI)

The implementation of an improved small-signal AC simulation capability in the general-purpose device simulator PISCES-IIB is described. The preconditioned generalized conjugate residual (GCR) algorithm has been implemented, which allows AC simulations ...

D. R. Apte; M. E. Law

2006-11-01T23:59:59.000Z

386

Prime Contract DE-AC36-99GO10337 Modification M075 SF30 Page...  

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

changes to contract DE-AC36-99GO10337: A. Section J, ATTACHMENT 5 "APPLICABLE DIRECTIVES (List B)" of Contract DE-AC36- 99GO10377 is deleted and replaced in its entirety to...

387

DOE 10 CFR Part 431 EERE-2010-BT-TP-0036 RIN 1904-AC-38 Submission...  

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

0 CFR Part 431 EERE-2010-BT-TP-0036 RIN 1904-AC-38 Submission of Comments by Howe Corporation DOE 10 CFR Part 431 EERE-2010-BT-TP-0036 RIN 1904-AC-38 Submission of Comments by Howe...

388

Docket No. EERE-2011-BT-NOA-0067 and RIN Number 1904-AC52 Ex...  

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

1-BT-NOA-0067 and RIN Number 1904-AC52 Ex parte Communication Docket No. EERE-2011-BT-NOA-0067 and RIN Number 1904-AC52 Ex parte Communication This memorandum for the record...

389

Tamper resistant magnetic stripes  

DOE Patents (OSTI)

This invention relates to a magnetic stripe comprising a medium in which magnetized particles are suspended and in which the encoded information is recorded by actual physical rotation or alignment of the previously magnetized particles within the flux reversals of the stripe which are 180.degree. opposed in their magnetic polarity. The magnetized particles are suspended in a medium which is solid, or physically rigid, at ambient temperatures but which at moderately elevated temperatures, such as 40.degree. C., is thinable to a viscosity permissive of rotation of the particles therein under applications of moderate external magnetic field strengths within acceptable time limits.

Naylor, Richard Brian (Albuquerque, NM); Sharp, Donald J. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

390

Lensless Imaging of Magnetic Nanostructures  

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

Magnetic Nanostructures Print Magnetism is useful for many devices and techniques, from electric motors and computer hard drives to magnetic resonance imaging used in medicine....

391

Power control of a wind farm with active stall wind turbines and AC grid connection  

E-Print Network (OSTI)

turbines with AC connection. The control of other wind farm concepts such as wind farms with DFIG wind

392

Noise-sustained oscillation and synchronization of excitable media with stirring  

SciTech Connect

Constructive effects of noise have been well studied in spatially extended systems. In most of these studies, the media are static, reaction-diffusion type, and the constructive effects are a consequence of the interplay between local excitation due to noise perturbation and propagation of excitation due to diffusion. Many chemical or biological processes occur in a fluid environment with mixing. In this paper, we investigate the interplay among noise, excitability, diffusion and mixing in excitable media advected by a chaotic flow, in a 2-d Fitz Hugh-Nagumo model described by the reaction-advection-diffusion equations. Without stirring, noise can only generate non-coherent excited patches of the static media. In the presence of stirring, we can observe three dynamical and pattern formation regimes: (i) Non-coherent excitation, when mixing is not strong enough to achieve synchronization of independent excitations developed at different locations; (ii) Coherent global excitation, when noise-perturbation survives the mixing to generate a synchronized excitation of the whole domain; and (iii) Homogenization, when strong enough stirring dilutes quickly those noise-induced local excitations. In the presence of an external sub-threshold periodic forcing, the period of-the noise-sustained oscillations can be locked by the forcing period with different ratios. Our results may be verified in experiments and find applications in population dynamics of oceanic ecological systems.

Neufeld, Z. (Zoltan); Zhou, C. (Changsong); Kurths, J. (Jrgen),; Kiss, I. Z.

2004-01-01T23:59:59.000Z

393

Breathing HRV by the Concept of AC Ventilation  

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

Breathing HRV by the Concept of AC Ventilation Breathing HRV by the Concept of AC Ventilation Speaker(s): Hwataik Han Date: July 10, 2007 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Thomas McKone Heat recovery ventilators are frequently used to save heating/cooling loads of buildings for ventilation. There are several types of HRV's, including a parallel plate type, a rotary type, a capillary type, and a heat pipe type. The breathing HRV is a heat recovery ventilator of a new kind using the concept of alternating-current ventilation. The AC ventilation is the ventilation with the airflow directions reversed periodically. It has an advantage of using a single duct system, for both supply and exhaust purposes. In order to develop a breathing HRV system, the thermal recovery performance should be investigated depending on many parameters, such as

394

Timing Synchronization and Node Localization in Wireless Sensor Networks: Efficient Estimation Approaches and Performance Bounds  

E-Print Network (OSTI)

Wireless sensor networks (WSNs) consist of a large number of sensor nodes, capable of on-board sensing and data processing, that are employed to observe some phenomenon of interest. With their desirable properties of flexible deployment, resistance to harsh environment and lower implementation cost, WSNs envisage a plethora of applications in diverse areas such as industrial process control, battle- field surveillance, health monitoring, and target localization and tracking. Much of the sensing and communication paradigm in WSNs involves ensuring power efficient transmission and finding scalable algorithms that can deliver the desired performance objectives while minimizing overall energy utilization. Since power is primarily consumed in radio transmissions delivering timing information, clock synchronization represents an indispensable requirement to boost network lifetime. This dissertation focuses on deriving efficient estimators and performance bounds for the clock parameters in a classical frequentist inference approach as well as in a Bayesian estimation framework. A unified approach to the maximum likelihood (ML) estimation of clock offset is presented for different network delay distributions. This constitutes an analytical alternative to prior works which rely on a graphical maximization of the likelihood function. In order to capture the imperfections in node oscillators, which may render a time-varying nature to the clock offset, a novel Bayesian approach to the clock offset estimation is proposed by using factor graphs. Message passing using the max-product algorithm yields an exact expression for the Bayesian inference problem. This extends the current literature to cases where the clock offset is not deterministic, but is in fact a random process. A natural extension of pairwise synchronization is to develop algorithms for the more challenging case of network-wide synchronization. Assuming exponentially distributed random delays, a network-wide clock synchronization algorithm is proposed using a factor graph representation of the network. Message passing using the max- product algorithm is adopted to derive the update rules for the proposed iterative procedure. A closed form solution is obtained for each node's belief about its clock offset at each iteration. Identifying the close connections between the problems of node localization and clock synchronization, we also address in this dissertation the problem of joint estimation of an unknown node's location and clock parameters by incorporating the effect of imperfections in node oscillators. In order to alleviate the computational complexity associated with the optimal maximum a-posteriori estimator, two iterative approaches are proposed as simpler alternatives. The first approach utilizes an Expectation-Maximization (EM) based algorithm which iteratively estimates the clock parameters and the location of the unknown node. The EM algorithm is further simplified by a non-linear processing of the data to obtain a closed form solution of the location estimation problem using the least squares (LS) approach. The performance of the estimation algorithms is benchmarked by deriving the Hybrid Cramer-Rao lower bound (HCRB) on the mean square error (MSE) of the estimators. We also derive theoretical lower bounds on the MSE of an estimator in a classical frequentist inference approach as well as in a Bayesian estimation framework when the likelihood function is an arbitrary member of the exponential family. The lower bounds not only serve to compare various estimators in our work, but can also be useful in their own right in parameter estimation theory.

Ahmad, Aitzaz 1984-

2012-12-01T23:59:59.000Z

395

VOLTAGE COLLAPSE AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS  

E-Print Network (OSTI)

VOLTAGE COLLAPSE AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS by Claudio A. Ca AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC/DC SYSTEMS by Claudio A. Ca~nizares A dissertation submitted . . . . . . . . . . . . . 4 1.3.2 AC/DC Transient Energy Functions . . . . . . . . . . . . . . 6 2 System Modelling 8 2

Cañizares, Claudio A.

396

H? robust control of DC-AC interfaced microsource in microgrids  

Science Conference Proceedings (OSTI)

This paper focuses on the direct current -- alternating current (DC-AC) interfaced microsource based H robust control strategies in microgrids. It presents detail of a DC-AC interfaced microsource model which is connected to the ... Keywords: DC-AC interfaced microsource, H? robust control, Microgrid, f-v droop characteristic, smooth switching

Chun-Xia Dou; Fang Zhao; Xing-Bei Jia; Dong-Le Liu

2013-02-01T23:59:59.000Z

397

LHC Magnet Program | Superconducting Magnet Division  

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

Magnet Program Magnet Program The Superconducting Magnet Division is building a number of dipole magnets for the Large Hadron Collider (LHC), which is now under construction at CERN in Geneva, Switzerland. Scheduled to begin operation in 2007, this machine will collide beams of protons with the unprecedented energy of 7 TeV per beam to explore the nature of matter at its most basic level (RHIC can collide beams of protons with energies of 0.25 TeV, but is mostly used to collide heavy ions with energies of 0.1 TeV per nucleon). The magnets are being built as part of the US program, recommended by the High Energy Physics Advisory Panel (HEPAP) and approved by Congress, to contribute to the construction and, later, use of that frontier machine by the US high energy physics community. Fermi National Accelerator Laboratory (FNAL) and

398

Active magnetic regenerator  

SciTech Connect

The disclosure is directed to an active magnetic regenerator apparatus and method. Brayton, Stirling, Ericsson, and Carnot cycles and the like may be utilized in an active magnetic regenerator to provide efficient refrigeration over relatively large temperature ranges.

Barclay, John A. (Los Alamos, NM); Steyert, William A. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

399

ALS superbend magnet performance  

E-Print Network (OSTI)

ALS Superbend Magnet Performance S. Marks, J. Zbasnik, W.the Advanced Light Source (ALS), with the fourth magnet as ahe Advanced Light Source (ALS) at the Lawrence Berkeley

2001-01-01T23:59:59.000Z

400

DE-AC05-06OR23100 Section H  

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

DE-AC05-06OR23100 DE-AC05-06OR23100 Section H - Page 1 of 29 PART I - SCHEDULE SECTION H SPECIAL CONTRACT REQUIREMENTS H.1 CONSECUTIVE NUMBERING (MAY 1997)......................................................................... 4 H.2 MODIFICATION AUTHORITY (MAY 1997) ....................................................................... 4 H.3 OVERSIGHT OF CONTRACTOR (OCT 2004)..................................................................... 4 H.4 SMALL BUSINESS SUBCONTRACTING PLAN (SEPT 1999)............................................ 5 H.5 SAFEGUARDS AND SECURITY AWARENESS PROGRAM (MAY 1997)........................ 5 H.6 QUALITY ASSURANCE SYSTEM ALTERNATE I (JUL 2004).......................................... 5 H.7 CONFIDENTIALITY OF INFORMATION (MAY 1997)...................................................... 6 H.8 INDIRECT

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Superconducting magnet of Aurora  

Science Conference Proceedings (OSTI)

The AURORAsuperconducting magnet system is composed of a cylindrical single?body magnet and a refrigeration system for superconducting coils. The magnet generates B z =1 T on the central orbit at the 150 MeV electron beam injection energy and B z =4.3 T at the 650 MeV storage energy. The diameter of the central orbit is 1 m. Iron poles and yokes are used for shielding the magnetic field

T. Takayama; SHI Accelerator Research Group

1989-01-01T23:59:59.000Z

402

Magnetic Materials Staff  

Science Conference Proceedings (OSTI)

... Materials Science and Engineering Division Staff Directory; MML Organization. Contact. Magnetic Materials Group Robert Shull, Group Leader. ...

2012-10-09T23:59:59.000Z

403

Minimum Magnetic Energy Theorem  

E-Print Network (OSTI)

The Thomson's Theorem states that static charge distributions in conductors show up at the conducting surfaces in an equipotential configuration, so that the electrostatic energy is a minimum. In this work we study an analogue statement for magnetic systems: in a given set of conductors, the stored magnetic field energy reaches the minimum value for superficial current distributions so that the magnetic vector potential is tangent to the conductors surfaces. This is the counterpart of Thomson's theorem for the magnetic field.

Fiolhais, M C N

2008-01-01T23:59:59.000Z

404

Magnetic Nanoparticle Metrology  

Science Conference Proceedings (OSTI)

... T2 relaxation times, hysteretic energy loss, etc ... Optimization of magnetic nanoparticle synthesis for ... competition between lattice energies and dipolar ...

2012-12-03T23:59:59.000Z

405

Irreversible magnetic switch  

DOE Patents (OSTI)

This invention is comprised of an irreversible magnetic switch containing a ferromagnetic amorphous metal having a predetermined crystallization temperature in its inductor magnetic path. With the incorporation of such material, the magnetic properties after cooling from a high temperature excursion above its crystallization temperature are only a fraction of the original value. The difference is used to provide a safety feature in the magnetic switch.

Karnowsky, M.M.; Yost, F.G.

1991-12-31T23:59:59.000Z

406

Magnetic nanohole superlattices  

DOE Patents (OSTI)

A magnetic material is disclosed including a two-dimensional array of carbon atoms and a two-dimensional array of nanoholes patterned in the two-dimensional array of carbon atoms. The magnetic material has long-range magnetic ordering at a temperature below a critical temperature Tc.

Liu, Feng

2013-05-14T23:59:59.000Z

407

Tunable Magnetic Regenerator/Refrigerant  

Magnetic regenerators utilize the magnetocaloric effect--the ability of a magnetic field to reduce the magnetic part of a solid materials entropy, generating heat, and then removing the magnetic field, permitting the reduction of temperature with the ...

408

Magnetic damping for maglev  

DOE Green Energy (OSTI)

Magnetic damping is one of the important parameters to control the response and stability of maglev systems. An experimental study is presented to measure the magnetic damping using a direct method. A plate attached to a permanent magnet levitated on a rotating drum was tested to investigate the effect of various parameters on magnetic damping such as conductivity, gap, excitation frequency, and oscillation amplitude. The experimental technique is capable of measuring all magnetic damping coefficients, some of which can not be measured by an indirect method.

Chen, S.S.; Zhu, S.; Cai, Y.; Rote, D.M. [Argonne National Lab., IL (United States). Energy Technology Div.

1994-12-31T23:59:59.000Z

409

Magnetically attached sputter targets  

DOE Patents (OSTI)

An improved method and assembly for attaching sputtering targets to cathode assemblies of sputtering systems which includes a magnetically permeable material is described. The magnetically permeable material is imbedded in a target base that is brazed, welded, or soldered to the sputter target, or is mechanically retained in the target material. Target attachment to the cathode is achieved by virtue of the permanent magnets and/or the pole pieces in the cathode assembly that create magnetic flux lines adjacent to the backing plate, which strongly attract the magnetically permeable material in the target assembly. 11 figures.

Makowiecki, D.M.; McKernan, M.A.

1994-02-15T23:59:59.000Z

410

Allianz Climate Solutions ACS GmbH | Open Energy Information  

Open Energy Info (EERE)

Allianz Climate Solutions ACS GmbH Allianz Climate Solutions ACS GmbH Jump to: navigation, search Name Allianz Climate Solutions (ACS) GmbH Place Munich, Germany Zip 80802 Product Munich-based subsidiary of insurance and asset management provider Allianz SE. ACS acts as investment manager, service provider and advisor of climate solutions for Allianz Group and external customers. Coordinates 48.136415°, 11.577531° 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":48.136415,"lon":11.577531,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

411

Ac loss calorimeter for three-phase cable  

SciTech Connect

A calorimeter for measuring ac losses in meter-long lengths of HTS superconducting power transmission line cables is described. The calorimeter, which is based on a temperature difference technique, has a precision of 1 mW and measures single, two-phase (coupling), and three-phase losses. The measurements show significant coupling losses between phases.

Daney, D.E.; Boenig, H.J.; Maley, M.P.; McMurry, D.E.; DeBlanc, B.G. [Los Alamos National Lab., NM (United States). Superconductivity Technology Center

1996-10-01T23:59:59.000Z

412

www.eprg.group.cam.ac.uk EPRGWORKINGPAPER  

E-Print Network (OSTI)

quarter of the EU's natural gas consumption, or 6.5% of the bloc's primary energy supply (Nol, 2008; Nol supply function has been applied in natural gas market modelling (e.g., Egging and Gabriel (2006), Eggingwww.eprg.group.cam.ac.uk EPRGWORKINGPAPER Abstract Strategic Eurasian Natural Gas Model for Energy

Aickelin, Uwe

413

$a-c$ test of holography vs quantum renormalization group  

E-Print Network (OSTI)

We show that a "constructive derivation" of the AdS/CFT correspondence based on the quantum local renormalization group in large N quantum field theories consistently provides the a-c holographic Weyl anomaly in d=4 at the curvature squared order in the bulk action. The consistency of the construction further predicts the form of the metric beta function.

Yu Nakayama

2014-01-21T23:59:59.000Z

414

www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY  

E-Print Network (OSTI)

in forward markets, due to the high associated storage costs of natural gas and hard coal. Furthermore are self-hedged to the extent that power, natural gas and carbon prices naturally co-move. In particular hard coal and natural #12;www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY gas

Kraft, Markus

415

www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY  

E-Print Network (OSTI)

www.eprg.group.cam.ac.uk EPRGWORKINGPAPERNON-TECHNICALSUMMARY Nuclear Energy in the Enlarged Russia and Ukraine. Interrrupted heating in European cities on cold winter nights adds a new dimension in central and eastern Europe for nuclear power. This working paper notes that with the addition of 12 new

Aickelin, Uwe

416

Carbon Management Plan www.nottingham.ac.uk/sustainability  

E-Print Network (OSTI)

Carbon Management Plan 2010-2020 www.nottingham.ac.uk/sustainability #12;1 Carbon Management Plan 2010-2020 Contents Introduction 2 UK Carbon Policy 3 University Carbon Baselines 4 Recent Performance Trends and KPIs 5 University Targets 8 Strategic Themes 9 Carbon Saving Projects 12 2010-2012 Projects 13

Li, Jingpeng

417

Alternating two-way AC-tree automata  

Science Conference Proceedings (OSTI)

We explore the notion of alternating two-way tree automata modulo the theory of finitely many associative-commutative (AC) symbols. This was prompted by questions arising in cryptographic protocol verification, in particular in modeling group key agreement ... Keywords: Alternating tree automata, Associative-commutative, Branching vector addition systems with states, Cryptographic protocols, Resolution, Tree automata, Two-way tree automata

Kumar Neeraj Verma; Jean Goubault-Larrecq

2007-06-01T23:59:59.000Z

418

Thermal Unit Commitment Including Optimal AC Power Flow Constraints  

E-Print Network (OSTI)

Thermal Unit Commitment Including Optimal AC Power Flow Constraints Carlos Murillo{Sanchez Robert J algorithm for unit commitment that employs a Lagrange relaxation technique with a new augmentation. This framework allows the possibility of committing units that are required for the VArs that they can produce

419

www.abdn.ac.uk/energy Energy Institute in  

E-Print Network (OSTI)

Student energy Summit As the oil and gas industry gathers in Aberdeen for this year's offshore europe and regulatory frameworks of energy supply. It will also address the political, environmental, socialwww.abdn.ac.uk/energy RED Revolution Energy Institute in the Energy Capital Pioneering

Pym, David J.

420

http://www.kyoto-u.ac.jp/ja 22 22  

E-Print Network (OSTI)

://www.kyoto-u.ac.jp/en Integrated Human Studies Integrated Human Studies Letters Letters Education Educational Sciences Law Economics Economics and Management Science Science Medicine Medical Science (6) Human Health Sciences Pharmaceutical Sciences Pharmaceutical Sciences Pharmacy (6) Engineering Global Engineering, Architecture

Takada, Shoji

Note: This page contains sample records for the topic "magnet ac synchronous" 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

http://www.soken.ac.jp/ School of Physical Sciences  

E-Print Network (OSTI)

http://www.soken.ac.jp/ 2012 2013 School of Physical Sciences Department of Structural Molecular Science Department of Functional Molecular Science Department of Astronomical Science Department of Fusion Science Department of Space and Astronautical Science School of High Energy Accelerator Science Department

Kinosita Jr., Kazuhiko

422

http://www.kyoto-u.ac.jp/ja 22 22  

E-Print Network (OSTI)

://www.kyoto-u.ac.jp/en Integrated Human Studies Integrated Human Studies Letters Letters Education Educational Sciences Law Economics Economics and Management Science Science Medicine Medical Science (6) Human Health Sciences Pharmaceutical Sciences Sciences for Drug Discovery Pharmacy (6) Engineering Global Engineering, Architecture

Takada, Shoji

423

http://www.soken.ac.jp/ School of Physical Sciences  

E-Print Network (OSTI)

20132013 20142014 & http://www.soken.ac.jp/ School of Physical Sciences Department of Structural Molecular Science Department of Functional Molecular Science Department of Astronomical Science Department of Fusion Science Department of Space and Astronautical Science School of High Energy Accelerator Science

Kinosita Jr., Kazuhiko

424

Time Synchronization Attack in Smart Grid-Part II: Cross Layer Detection Mechanism  

E-Print Network (OSTI)

A novel time synchronization attack (TSA) on wide area monitoring systems in smart grid has been identified in the first part of this paper. A cross layer detection mechanism is proposed to combat TSA in part II of this paper. In the physical layer, we propose a GPS carrier signal noise ratio (C/No) based spoofing detection technique. In addition, a patch-monopole hybrid antenna is applied to receive GPS signal. By computing the standard deviation of the C/No difference from two GPS receivers, a priori probability of spoofing detection is fed to the upper layer, where power system state is estimated and controlled. A trustworthiness based evaluation method is applied to identify the PMU being under TSA. Both the physical layer and upper layer algorithms are integrated to detect the TSA, thus forming a cross layer mechanism. Experiment is carried out to verify the effectiveness of the proposed TSA detection algorithm.

Zhang, Zhenghao; Dimitrovski, Aleksandar D; Li, Husheng

2012-01-01T23:59:59.000Z

425

Using Worldfip for Synchronization and Time Stamping in the LHC Accelerator  

E-Print Network (OSTI)

Time is one of the key topics in the construction of particle accelerators for which very accurate synchronization and high resolution time stamping are required. Nowadays, accelerator control systems may profit of the same industrial components than automotive industries and oil refineries are using: PLCs and Fieldbuses. WorldFIP, one of the three fieldbuses that have been selected at CERN, is the only one that is intrinsically deterministic. Therefore, in addition to the general control and monitoring functions that any fieldbus may provide, its determinism brings in the unique capability of transmitting time related data for setting to the same value the clocks of the equipment. With the use of the GPS, any equipment located around the Large Hadron Collider (LHC) accelerator may thus be exactly in phase with the Universal Time. Thanks to its judicious design, WorldFIP supports also many other very interesting features like Web or video transmission. Current developments around this powerful fieldbus will a...

Brun, R; Sicard, Claude Henri

2003-01-01T23:59:59.000Z

426

Reducing power consumption while synchronizing a plurality of compute nodes during execution of a parallel application  

DOE Patents (OSTI)

Methods, apparatus, and products are disclosed for reducing power consumption while synchronizing a plurality of compute nodes during execution of a parallel application that include: beginning, by each compute node, performance of a blocking operation specified by the parallel application, each compute node beginning the blocking operation asynchronously with respect to the other compute nodes; reducing, for each compute node, power to one or more hardware components of that compute node in response to that compute node beginning the performance of the blocking operation; and restoring, for each compute node, the power to the hardware components having power reduced in response to all of the compute nodes beginning the performance of the blocking operation.

Archer, Charles J. (Rochester, MN); Blocksome, Michael A. (Rochester, MN); Peters, Amanda A. (Rochester, MN); Ratterman, Joseph D. (Rochester, MN); Smith, Brian E. (Rochester, MN)

2012-01-10T23:59:59.000Z

427

A geometrically-conservative, synchronized, flux-corrected remap for arbitrary Lagrangian-Eulerian computations with nodal finite elements  

Science Conference Proceedings (OSTI)

This article describes a conservative synchronized remap algorithm applicable to arbitrary Lagrangian-Eulerian computations with nodal finite elements. In the proposed approach, ideas derived from flux-corrected transport (FCT) methods are extended to ... Keywords: Arbitrary Lagrangian-Eulerian methods, Compatible discretizations, Geometric conservation law, Meteorological flows, Nodal finite element method, Remap, Shock hydrodynamics

A. LPez Ortega; G. Scovazzi

2011-07-01T23:59:59.000Z

428

Abstract--This paper presents a comparative stability analysis of conventional synchronous generators and wind farms based on  

E-Print Network (OSTI)

generators and wind farms based on double feed induction generators (DFIG). Based on an appropriate DFIG wind on system stability of replacing conventional generation by DFIG-based wind generation on the IEEE 14-bus that the oscillatory behavior associated with the dominant mode of the synchronous generator is improved when the DFIG

Cañizares, Claudio A.

429

A ``triple sea-ice state'' mechanism for the abrupt warming and synchronous ice sheet collapses during Heinrich events  

E-Print Network (OSTI)

changes. This weak coupling can lead to a ``nonlinear phase locking'' of the different ice sheets whichA ``triple sea-ice state'' mechanism for the abrupt warming and synchronous ice sheet collapses. [1] Abrupt, switch-like, changes in sea ice cover are proposed as a mechanism for the large

Sayag, Roiy

430

SLAC collider injector, RF-drive synchronization and trigger electronics, and 15-AMP thermionic-gun development  

SciTech Connect

The rf drive system for the Collider Injector Development (EL CID) including laser timing, subharmonic buncher drive and phasing, and accelerator rf drive is described. The rf synchronized master trigger generation scheme for the collider is outlined. Also, a 15 amp peak, 200 kV short pulse gun being developed at SLAC as a backup to the Sinclair laser gun is described.

Koontz, R.; Miller, R.; McKinney, T.; Wilmunder, A.

1981-02-01T23:59:59.000Z

431

Direct Coherency Identification of Synchronous Generators in Taiwan Power System Based on Fuzzy c-Means Clustering  

Science Conference Proceedings (OSTI)

This paper is to investigate the application of fuzzy c-means clustering to the direct identification of coherent synchronous generators in power systems. Because of the conceptual appropriateness and computational simplicity, this approach is essentially ... Keywords: cluster analysis, coherency identification, coherency measure, fuzzy c-means, power system dynamic equivalent

Shu-Chen Wang; Pei-Hwa Huang; Chi-Jui Wu; Yung-Sung Chuang

2007-10-01T23:59:59.000Z

432

Explicit spatial scattering for load balancing in conservatively synchronized parallel discrete-event simulations  

SciTech Connect

We re-examine the problem of load balancing in conservatively synchronized parallel, discrete-event simulations executed on high-performance computing clusters, focusing on simulations where computational and messaging load tend to be spatially clustered. Such domains are frequently characterized by the presence of geographic 'hot-spots' - regions that generate significantly more simulation events than others. Examples of such domains include simulation of urban regions, transportation networks and networks where interaction between entities is often constrained by physical proximity. Noting that in conservatively synchronized parallel simulations, the speed of execution of the simulation is determined by the slowest (i.e most heavily loaded) simulation process, we study different partitioning strategies in achieving equitable processor-load distribution in domains with spatially clustered load. In particular, we study the effectiveness of partitioning via spatial scattering to achieve optimal load balance. In this partitioning technique, nearby entities are explicitly assigned to different processors, thereby scattering the load across the cluster. This is motivated by two observations, namely, (i) since load is spatially clustered, spatial scattering should, intuitively, spread the load across the compute cluster, and (ii) in parallel simulations, equitable distribution of CPU load is a greater determinant of execution speed than message passing overhead. Through large-scale simulation experiments - both of abstracted and real simulation models - we observe that scatter partitioning, even with its greatly increased messaging overhead, significantly outperforms more conventional spatial partitioning techniques that seek to reduce messaging overhead. Further, even if hot-spots change over the course of the simulation, if the underlying feature of spatial clustering is retained, load continues to be balanced with spatial scattering leading us to the observation that spatial scattering can often obviate the need for dynamic load balancing.

Thulasidasan, Sunil [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory; Eidenbenz, Stephan [Los Alamos National Laboratory; Romero, Philip [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

433

Explicit spatial scattering for load balancing in conservatively synchronized parallel discrete-event simulations  

SciTech Connect

We re-examine the problem of load balancing in conservatively synchronized parallel, discrete-event simulations executed on high-performance computing clusters, focusing on simulations where computational and messaging load tend to be spatially clustered. Such domains are frequently characterized by the presence of geographic 'hot-spots' - regions that generate significantly more simulation events than others. Examples of such domains include simulation of urban regions, transportation networks and networks where interaction between entities is often constrained by physical proximity. Noting that in conservatively synchronized parallel simulations, the speed of execution of the simulation is determined by the slowest (i.e most heavily loaded) simulation process, we study different partitioning strategies in achieving equitable processor-load distribution in domains with spatially clustered load. In particular, we study the effectiveness of partitioning via spatial scattering to achieve optimal load balance. In this partitioning technique, nearby entities are explicitly assigned to different processors, thereby scattering the load across the cluster. This is motivated by two observations, namely, (i) since load is spatially clustered, spatial scattering should, intuitively, spread the load across the compute cluster, and (ii) in parallel simulations, equitable distribution of CPU load is a greater determinant of execution speed than message passing overhead. Through large-scale simulation experiments - both of abstracted and real simulation models - we observe that scatter partitioning, even with its greatly increased messaging overhead, significantly outperforms more conventional spatial partitioning techniques that seek to reduce messaging overhead. Further, even if hot-spots change over the course of the simulation, if the underlying feature of spatial clustering is retained, load continues to be balanced with spatial scattering leading us to the observation that spatial scattering can often obviate the need for dynamic load balancing.

Thulasidasan, Sunil [Los Alamos National Laboratory; Kasiviswanathan, Shiva [Los Alamos National Laboratory; Eidenbenz, Stephan [Los Alamos National Laboratory; Romero, Philip [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

434

Low loss conductor for ac or dc power transmission  

DOE Patents (OSTI)

A compact, easy to fabricate, noninductive, low surface magnetic field superconductor transmission line that has minimal stay fields is described.

Sampson, W.B.; Garber, M.

1973-03-13T23:59:59.000Z

435

High Field Magnet R&D |Superconducting Magnet Division  

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

High Field Magnet R&D High Field Magnet R&D The Superconducting Magnet Division is developing advanced magnet designs and magnet-related technologies for high field accelerator magnets. We are currently working on magnets for three inter-related programs: High Field Magnets for Muon Collider Papers, Presentations Common Coil Magnets Papers, Presentations Interaction Region Magnets Papers, Presentations High Temperature Superconductor (HTS) Magnets Papers, Presentations This is part of a multi-lab superconducting magnet development program for new accelerator facilities that would be part of the U.S. High Energy Physics program. These programs (@BNL, @FNAL, @LBNL) are quite complimentary to each other, so that magnet designs and technologies developed at one laboratory can be easily transferred to another. The BNL

436

Cool Magnetic Molecules  

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

Cool Magnetic Molecules Cool Magnetic Molecules Cool Magnetic Molecules Print Wednesday, 25 May 2011 00:00 Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

437

Pulse magnetic welder  

DOE Patents (OSTI)

A welder is described for automated closure of fuel pins by a pulsed magnetic process in which the open end of a length of cladding is positioned within a complementary tube surrounded by a pulsed magnetic welder. Seals are provided at each end of the tube, which can be evacuated or can receive tag gas for direct introduction to the cladding interior. Loading of magnetic rings and end caps is accomplished automatically in conjunction with the welding steps carried out within the tube.

Christiansen, D.W.; Brown, W.F.

1984-01-01T23:59:59.000Z

438

Magnetic latching solenoid  

DOE Patents (OSTI)

This invention discloses a D.C. magnetic latching solenoid that retains a moving armature in a first or second position by means of a pair of magnets, thereby having a zero-power requirement after actuation. The first or second position is selected by reversing the polarity of the D.C. voltage which is enough to overcome the holding power of either magnet and transfer the armature to an opposite position. The coil is then de-energized.

Marts, Donna J. (Idaho Falls, ID); Richardson, John G. (Idaho Falls, ID); Albano, Richard K. (Idaho Falls, ID); Morrison, Jr., John L. (Idaho Falls, ID)

1995-01-01T23:59:59.000Z

439

Booster main magnet power supply, present operation and potential future upgrades  

SciTech Connect

The Brookhaven Booster Main Magnet Power Supply (MMPS) is a 24 pulse thyristor control supply, rated at 5500 Amps, +/-2000 Volts, or 3000 Amps, +/-6000 Volts. The power supply is fed directly from the power utility and the peak magnet power is 18 MWatts. This peak power is seen directly at the incoming ac line. This power supply has been in operation for the last 18 years. This paper will describe the present topology and operation of the power supply, the feedback control system and the different modes of operation of the power supply. Since the power supply has been in operation for the last 18 years, upgrading this power supply is essential. A new power supply topology has been studied where energy is stored in capacitor banks. DC to DC converters are used to convert the dc voltage stored in the capacitor banks to pulsed DC voltage into the magnet load. This enables the average incoming power from the ac line to be constant while the peak magnet power is pulsed to +/- 18 MWatts. Simulations and waveforms of this power supply will be presented.

Bajon, E.; Bannon, M.; Marneris, I.; Danowski, G.; Sandberg, J.; Savatteri, S.

2011-03-28T23:59:59.000Z

440

Nanostructrured Magnetic Materials  

Science Conference Proceedings (OSTI)

Aug 8, 2013 ... The demand for OFF-ON becomes increasingly important as ... The residual magnetic flux density and maximum energy product of the...

Note: This page contains sample records for the topic "magnet ac synchronous" 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

Magnetically leviated superconducting bearing  

DOE Patents (OSTI)

A magnetically levitated superconducting bearing includes a magnet (2) mounted on a shaft (12) that is rotatable around an axis of rotation and a Type II superconductor (6) supported on a stator (14) in proximity to the magnet (2). The superconductor (6) is positioned so that when it is cooled to its superconducting state in the presence of a magnetic field, it interacts with the magnet (2) to produce an attractive force that levitates the magnet (2) and supports a load on the shaft (12). The interaction between the superconductor (6) and magnet(2) also produces surface screening currents (8) that generate a repulsive force perpendicular to the load. The bearing also has means for maintaining the superconductor at a temperature below its critical temperature (16, 18). The bearing could also be constructed so the magnet (2) is supported on the stator (14) and the superconductor (6) is mounted on the shaft (12). The bearing can be operated by cooling the superconductor (6) to its superconducting state in the presence of a magnetic field.

Weinberger, Bernard R. (Avon, CT); Lynds, Jr., Lahmer (Glastonbury, CT)

1993-01-01T23:59:59.000Z

442

Rare Earth Magnets  

Science Conference Proceedings (OSTI)

Mar 6, 2013 ... Performance and Endurance of Nd-Fe-B Sintered Magnets in E-Motor Application Conditions: Martina Moore1; Ralph Sueptitz1; Margitta...

443

Rare Earth Magnets  

Science Conference Proceedings (OSTI)

Aug 8, 2013 ... Current high performance permanent magnets (PM) for traction motors of (hybrid) electric vehicles use substantial amount of Dy in Nd-Fe-B...

444

Magnetic Materials and Properties  

Science Conference Proceedings (OSTI)

Aug 5, 2013 ... Following vacuum distillation of the Mg-RE alloy, 98% pure RE metals can be recovered, which are then used to synthesize permanent magnet...

445

Various Magnet Options for a Delta Launched Version of ASTROMAG  

E-Print Network (OSTI)

be shielded from the sun by the solar panels. As a result ofa sun synchronous orbit and an earth trailing solar orbit.a sun synchronous orbit and an earth trailing solar orbit

Green, M.A.

2011-01-01T23:59:59.000Z

446

Magnetism Highlights| Neutron Science | ORNL  

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

Magnetism Magnetism SHARE Magnetism Highlights 1-5 of 5 Results ARCS maps collaborative magnetic spin behavior in iron telluride December 01, 2011 - Researchers have long thought that magnetism and superconductivity are mutually exclusive. The former typically involves localized atomic electrons. The latter requires freely propagating, itinerant electrons. Unexpected Magnetic Excitations in Doped Insulator Surprise Researchers October 01, 2011 - When doping a disordered magnetic insulator material with atoms of a nonmagnetic material, the conventional wisdom is that the magnetic interactions between the magnetic ions in the material will be weakened. Neutron Analysis Reveals Unique Atomic-Scale Behavior of "Cobalt Blue" September 01, 2011 - Neutron scattering studies of "cobalt blue," a

447

BEPC-II Magnet Project | Superconducting Magnet Division  

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

BEPC-II Magnet Project BEPC-II Magnet Project Project Overview The BEPC-II magnets are Interaction Region magnets to be used as part of an upgrade to the Beijing Electron Positron Collider. Two magnets will be produced, both of which will be inserted within the solenoidal detector at one of the collision points. Since the best use of the quadrupole focusing in this case requires placing the magnet as close to the collision point as possible, these magnets will be used within the magnetic field of the detector. This constrains the materials that can be used for construction to only non-magnetic materials. It also places severe demands on the structure of the magnet and it's holding supports due to the reaction forces between the solenoid and the magnet. To create the coil pattern for the final magnet, the coils will be

448

DE-AC05-06OR23100  

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

Section B - Page 1 of 10 Section B - Page 1 of 10 PART I - THE SCHEDULE SECTION B SUPPLIES OR SERVICES AND PRICES/COSTS B.1 ITEMS BEING ACQUIRED (ALTERNATE I) (OCT 2004) ................................... 3 B.2 ESTIMATED COST, BASE FEE, AND AWARD FEE (NOV 2004) ...................... 3 B.3 OPTION TO EXTEND THE CONTRACT (NOV 2004) .......................................... 6 B.4 OBLIGATION OF FUNDS (CPAF) (NOV 2004) ...................................................... 8 B.5 DETERMINATION OF AWARD FEE EARNED (NOV 2004) .............................. 9 DE-AC05-06OR23100 Section B - Page 2 of 10 Blank Page DE-AC05-06OR23100 Section B - Page 3 of 10 PART I - THE SCHEDULE SECTION B SUPPLIES OR SERVICES AND PRICES/COSTS B.1 ITEMS BEING ACQUIRED (ALTERNATE I) (OCT 2004)

449

SNL software manual for the ACS Data Analytics Project.  

SciTech Connect

In the ACS Data Analytics Project (also known as 'YumYum'), a supercomputer is modeled as a graph of components and dependencies, jobs and faults are simulated, and component fault rates are estimated using the graph structure and job pass/fail outcomes. This report documents the successful completion of all SNL deliverables and tasks, describes the software written by SNL for the project, and presents the data it generates. Readers should understand what the software tools are, how they fit together, and how to use them to reproduce the presented data and additional experiments as desired. The SNL YumYum tools provide the novel simulation and inference capabilities desired by ACS. SNL also developed and implemented a new algorithm, which provides faster estimates, at finer component granularity, on arbitrary directed acyclic graphs.

Stearley, Jon R.; McLendon, William Clarence, III; Rodrigues, Arun F.; Williams, Aaron S.; Hooper, Russell Warren; Robinson, David Gerald; Stickland, Michael G.

2011-10-01T23:59:59.000Z

450

On-Chip AC self-test controller  

DOE Patents (OSTI)

A system for performing AC self-test on an integrated circuit that includes a system clock for normal operation is provided. The system includes the system clock, self-test circuitry, a first and second test register to capture and launch test data in response to a sequence of data pulses, and a logic circuit to be tested. The self-test circuitry includes an AC self-test controller and a clock splitter. The clock splitter generates the sequence of data pulses including a long data capture pulse followed by an at speed data launch pulse and an at speed data capture pulse followed by a long data launch pulse. The at speed data launch pulse and the at speed data capture pulse are generated for a common cycle of the system clock.

Flanagan, John D. (Rhinebeck, NY); Herring, Jay R. (Poughkeepsie, NY); Lo, Tin-Chee (Fishkill, NY)

2009-09-29T23:59:59.000Z

451

AC/AB Stacking Boundaries in Bilayer Graphene  

Science Conference Proceedings (OSTI)

Boundaries, including phase boundaries, grain boundaries, and domain boundaries, are known to have an important influence on material properties. Here, dark-field (DF) transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) imaging are combined to provide a full view of boundaries between AB and AC stacking domains in bilayer graphene across length scales from discrete atoms to the macroscopic continuum. Combining the images with results obtained by density functional theory (DFT) and classical molecular dynamics calculations, we demonstrate that the AB/AC stacking boundaries in bilayer graphene are nanometer-wide strained channels, mostly in the form of ripples, producing smooth low-energy transitions between the two different stackings. Our results provide a new understanding of the novel stacking boundaries in bilayer graphene, which may be applied to other layered two-dimensional materials as well.

Lin, Junhao [ORNL; Fang, Wenjing [Massachusetts Institute of Technology (MIT); Zhou, Wu [ORNL; Lupini, Andrew R [ORNL; Idrobo Tapia, Juan C [ORNL; Kong, Jing [Massachusetts Institute of Technology (MIT); Pennycook, Stephen J [ORNL; Pantelides, Sokrates T [ORNL

2013-01-01T23:59:59.000Z

452

Control of the LHC 400 MHz RF System (ACS)  

E-Print Network (OSTI)

The LHC ACS RF system is composed of 16 superconducting cavities, eight per ring. Each ring has two cryomodules, each containing four cavities. Each cavity is powered by a 300 kW klystron. The klystrons are grouped in fours, the klystrons in each group sharing a common 58 kV power converter and HV equipment bunker. The ACS RF control system is based on modern industrial programmable controllers (PLCs). A new fast interlock and alarm system with inbuilt diagnostics has been developed. Extensive use of the FIPIO Fieldbus drastically decreases the cabling complexity and brings improved signal quality, increased reliability and easier maintenance. Features of the implementation, such as system layout, communication and the high-level software interface are described. Operational facilities such as the automatic switch on procedure are described, as well as the necessary specialist tools and interfaces. A complete RF chain, including high voltage, cryomodule and klystron is presently being assembled in order to ch...

Arnaudon, L; Maesen, P; Prax, M

2004-01-01T23:59:59.000Z

453

System and method for determining stator winding resistance in an AC motor  

Science Conference Proceedings (OSTI)

A system and method for determining stator winding resistance in an AC motor is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor. The circuit includes at least one contactor and at least one switch to control current flow and terminal voltages in the AC motor. The system also includes a controller connected to the circuit and configured to modify a switching time of the at least one switch to create a DC component in an output of the system corresponding to an input to the AC motor and determine a stator winding resistance of the AC motor based on the injected DC component of the voltage and current.

Lu, Bin (Kenosha, WI); Habetler, Thomas G. (Snellville, GA); Zhang, Pinjia (Atlanta, GA); Theisen, Peter J. (West Bend, WI)

2011-05-31T23:59:59.000Z

454

EVOLUTION OF RELATIVE MAGNETIC HELICITY AND CURRENT HELICITY IN NOAA ACTIVE REGION 11158  

SciTech Connect

Both magnetic and current helicities are crucial ingredients for describing the complexity of active-region magnetic structure. In this Letter, we present the temporal evolution of these helicities contained in NOAA active region 11158 during five days from 2011 February 12 to 16. The photospheric vector magnetograms of the Helioseismic and Magnetic Imager on board the Solar Dynamic Observatory were used as the boundary conditions for the coronal field extrapolation under the assumption of nonlinear force-free field, from which we calculated both relative magnetic helicity and current helicity. We construct a time-altitude diagram in which altitude distribution of the magnitude of current helicity density is displayed as a function of time. This diagram clearly shows a pattern of upwardly propagating current helicity density over two days prior to the X2.2 flare on February 15 with an average propagation speed of {approx}36 m s{sup -1}. The propagation is synchronous with the emergence of magnetic flux into the photosphere, and indicative of a gradual energy buildup for the X2.2 flare. The time profile of the relative magnetic helicity shows a monotonically increasing trend most of the time, but a pattern of increasing and decreasing magnetic helicity above the monotonic variation appears prior to each of two major flares, M6.6 and X2.2, respectively. The physics underlying this bump pattern is not fully understood. However, the fact that this pattern is apparent in the magnetic helicity evolution but not in the magnetic flux evolution makes it a useful indicator in forecasting major flares.

Jing, Ju; Liu, Chang; Lee, Jeongwoo; Xu, Yan; Deng, Na; Wang, Haimin [Space Weather Research Laboratory, New Jersey Institute of Technology, Newark, NJ 07102 (United States); Park, Sung-Hong [Korea Astronomy and Space Science Institute, Daejeon, 305-348 (Korea, Republic of); Wiegelmann, Thomas, E-mail: ju.jing@njit.edu, E-mail: chang.liu@njit.edu, E-mail: yx2@njit.edu, E-mail: na.deng@njit.edu, E-mail: haimin@flare.njit.edu, E-mail: freemler@kasi.re.kr, E-mail: leej@njit.edu, E-mail: wiegelmann@linmpi.mpg.de [Max Planck Institut fuer Sonnensystemforschung (MPS), Max-Planck-Strasse 2, 37191 Katlenburg-Lindau (Germany)

2012-06-10T23:59:59.000Z

455

Passive magnetic bearing configurations  

Science Conference Proceedings (OSTI)

A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.

Post, Richard F. (Walnut Creek, CA)

2011-01-25T23:59:59.000Z

456

EXOTIC MAGNETS FOR ACCELERATORS.  

SciTech Connect

Over the last few years, several novel magnet designs have been introduced to meet the requirements of new, high performance accelerators and beam lines. For example, the FAIR project at GSI requires superconducting magnets ramped at high rates ({approx} 4 T/s) in order to achieve the design intensity. Magnets for the RIA and FAIR projects and for the next generation of LHC interaction regions will need to withstand high doses of radiation. Helical magnets are required to maintain and control the polarization of high energy protons at RHIC. In other cases, novel magnets have been designed in response to limited budgets and space. For example, it is planned to use combined function superconducting magnets for the 50 GeV proton transport line at J-PARC to satisfy both budget and performance requirements. Novel coil winding methods have been developed for short, large aperture magnets such as those used in the insertion region upgrade at BEPC. This paper will highlight the novel features of these exotic magnets.

WANDERER, P.

2005-09-18T23:59:59.000Z

457

Performance testing of the AC propulsion ELX electric vehicle  

DOE Green Energy (OSTI)

Performance testing of the AC Propulsion ELX electric vehicle is described. Test data are presented and analyzed. The ELX vehicle is the first of a series of electric vehicles of interest to the California Air Resources Board. The test series is being conducted under a Cooperative Research and Development Agreement (CRADA) between the US Department of energy and the California Air Resources Board. The tests which were conducted showed that the AC Propulsion ELX electric vehicle has exceptional acceleration and range performance. when the vehicle`s battery was fully charged, the vehicle can accelerate from 0 to 96 km/h in about 10 seconds. Energy consumption and range tests using consecutive FUDS and HWFET Driving cycles (the all-electric cycle) indicate that the energy economy of the AC Propulsion ELX electric vehicle with regenerative braking is 97 W{center_dot}h/km, with a range of 153 km (95 miles). Computer simulations performed using the SIMPLEV Program indicate that the vehicle would have a range of 327 km (203 miles) on the all-electric cycle if the lead acid batteries were replaced with NiMH batteries having an energy density of 67 W{center_dot}h/kg. Comparisons of FUDS test data with and without regenerative braking indicated that regenerative braking reduced the energy consumption of the ELX vehicle by approximately 25%.

Kramer, W.E.; MacDowall, R.D.; Burke, A.F.

1994-06-01T23:59:59.000Z

458

Assessment of US electric vehicle programs with ac powertrains  

Science Conference Proceedings (OSTI)

AC powertrain technology is a promising approach to improving the performance of electric vehicles. Four major programs are now under way in the United States to develop ac powertrains: the Ford/General Electric single-shaft electric propulsion system (ETX-II), the Eaton dual-shaft electric propulsion system (DSEP), the Jet Propulsion Laboratories (JPL) integrated ac motor drive and recharge system, and the Massachusetts Institute of Technology (MIT) variable reluctance motor (VRM) drive. The JPL program is sponsored by EPRI; the other three programs are funded by the US Department of Energy. This preliminary assessment of the four powertrain programs focuses on potential performance, costs, safety, and commercial feasibility. Interviews with program personnel were supplemented by computer simulations of electric vehicle performance using the four systems. Each of the four powertrains appears superior to standard dc powertrain technology in terms of performance and weight. The powertrain technologies studied in this assessment are at varying degrees of technological maturity. One or more of the systems may be ready for incorporation into an advanced electric vehicle during the early 1990s. Each individual report will have a separate abstract. 5 refs., 37 figs., 29 tabs.

Kevala, R.J. (Booz, Allen and Hamilton, Inc., Bethesda, MD (USA). Transportation Consulting Div.)

1990-02-01T23:59:59.000Z

459

Electric power high-voltage transmission lines: Design options, cost, and electric and magnetic field levels  

SciTech Connect

This report provides background information about (1) the electric and magnetic fields (EMFs) of high-voltage transmission lines at typical voltages and line configurations and (2) typical transmission line costs to assist on alternatives in environmental documents. EMF strengths at 0 {+-} 200 ft from centerline were calculated for ac overhead lines, and for 345 and 230-kV ac underground line and for a {+-}450-kV dc overhead line. Compacting and height sensitivity factors were computed for the variation in EMFs when line conductors are moved closer or raised. Estimated costs for the lines are presented and discussed so that the impact of using alternative strategies for reducing EMF strengths and the implications of implementing the strategies can be better appreciated.

Stoffel, J.B.; Pentecost, E.D.; Roman, R.D.; Traczyk, P.A.

1994-11-01T23:59:59.000Z

460

Non-Federal Participation in AC Intertie Final Environmental Impact Statement Volume2:Appendices  

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

Non-Federal Participation in AC Intertie Final Non-Federal Participation in AC Intertie Final Environmental Impact Statement Volume2:Appendices Bonneville DOE/eis- 0145 POWER ADMINISTRATION January 1994 Non-Federal Participation in AC Intertie Draft Environmental Impact Statement Table of Contents Appendix A Life-of-Facilities Capacity Ownership Proposal A1 Appendix B Long-Term Intertie Access Policy B1 Appendix C Glossary C1 Appendix D Biological Assessment ad Supporting Materials

Note: This page contains sample records for the topic "magnet ac synchronous" 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.


461

Nonlinear modal interaction in HVDC/AC power systems with dc power modulation  

Science Conference Proceedings (OSTI)

In this paper investigation of nonlinear modal interaction using the normal form of vector fields technique is extended to HVDC/AC power systems with dc power modulation. The ac-dc interface equations are solved to form a state space model with second order approximation. Using the normal form technique, the system`s nonlinear dynamic characteristics are obtained. The proposed approach is applied to a 4-generator HVDC/AC test power system, and compare with the time domain solution.

Ni, Y.X. [Tsinghua Univ., Beijing (China); Vittal, V.; Kliemann, W.; Fouad, A.A. [Iowa State Univ., Ames, IA (United States)

1996-11-01T23:59:59.000Z

462

Power upgrading of transmission line by combining AC-DC transmission  

Science Conference Proceedings (OSTI)

Long extra high voltage (EHV) ac lines cannot be loaded to their thermal limits in order to keep sufficient margin against transient instability. With the scheme proposed in this project, it is possible to load these lines very close to their thermal ... Keywords: extra high voltage (EHV)transmission, flexible ac transmission system (FACTS), power system computer-aided design(PSCAD), simultaneous ac-dc power transmission

Jarupula Somlal

2010-07-01T23:59:59.000Z

463

UNIXUNIXUNIXUNIX((((OpenSSHOpenSSHOpenSSHOpenSSH)))) (gw.ps.nifs.ac.jp) RSA  

E-Print Network (OSTI)

pdf SSH SSH SSH UNIXUNIXUNIXUNIX((((OpenSSHOpenSSHOpenSSHOpenSSH)))) ssh (gw.ps.nifsTerm: New connection TCP/IP gw.ps.nifs.ac.jp %ssh (-i ) (-l ) gw.ps.nifs.ac.jp The authenticity of host 'gw.ps.nifs.ps.nifs.ac.jp,133.75.37.11' (RSA) to the list of known hosts. Enter passphrase for key '/home

Ito, Atsushi

464

Charging and Transport of Aerosols near AC Transmission Lines: A Literature Review  

Science Conference Proceedings (OSTI)

It has been hypothesized that the charging of airborne pollutant particles by alternating current (AC) transmission lines results in enhanced deposition and retention of these particles in the respiratory tract. This report provides an overview of the effect of AC transmission line corona on ion formation and the transfer of charge to aerosols. A literature review identified gaps in the information required to model the charging of aerosols by AC transmission lines and their dispersal downwind, so that e...

2003-12-08T23:59:59.000Z

465

AC to DC Line Conversion: DConvert Program Version 1.0  

Science Conference Proceedings (OSTI)

The past several years have seen renewed interest in the prospect of converting ac lines to dc operation interest spurred both by the ongoing need to make greater use of existing transmission assets and advances in HVDC converter technology. EPRI has sponsored two major studies dealing with the conversion prospect. The first, 8220Tools for Assessing Conversion of AC Power Transmission Lines to DC,(Product ID # 1020651) and the second, 8220Dc Capability of AC Transmission Lines,(Product ID #1013979). Cont...

2010-10-26T23:59:59.000Z

466

Superconducting Magnet Division  

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

3 - 6/13/06 3 - 6/13/06 Superconducting Magnet Division S&T Committee Program Review June 22-23, 2006 Conference Room A, Bldg. 725, BNL DRAFT AGENDA Thursday, June 22 0830 Executive Session to address the charge S. Aronson (25 min) 0855 Welcome S. Aronson (5 min) 0900 Superconducting Magnet Division Status & M. Harrison (45 + 15 min) Issues - mission statement, core competencies, themes, program, problems, etc. 1000 Themes - Nb3Sn, HTS, Direct wind, Accelerator integration, P. Wanderer (20 + 10 min) rapid cycling Core Competencies 1030 Superconducting Materials A. Ghosh (20 + 5 min) 1055 Break 1110 Magnetic Design R. Gupta (20 + 5 min) 1135 Magnet Construction M. Anerella (20 + 5 min) 1200 Magnet Testing G. Ganetis (20 + 5 min)

467

Cool Magnetic Molecules  

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

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

468

Cool Magnetic Molecules  

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

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

469

Cool Magnetic Molecules  

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

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

470

Cool Magnetic Molecules  

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

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

471

Cool Magnetic Molecules  

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

Cool Magnetic Molecules Print Cool Magnetic Molecules Print Certain materials are known to heat up or cool down when they are exposed to a changing magnetic field. This is known as the magnetocaloric effect. All magnetic materials exhibit this effect, but in most cases, it is too small to be technologically useful. Recently, however, the search for special molecules with a surprisingly large capacity to keep cool has heated up, driven by environmental and cost considerations as well as by recent improvements in our ability to design, assemble, and probe the structure and chemistry of small molecules. An international collaboration of researchers from Spain, Scotland, and the U.S. has utilized ALS Beamline 11.3.1 (small-molecule crystallography) to characterize the design of such "molecular coolers." The work targets the synthesis of molecular cluster compounds containing many unpaired electrons ("nanomagnets") for applications involving enhanced magnetic refrigeration at very low temperatures.

472

Magnet pole tips  

DOE Patents (OSTI)

An improved magnet which more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.

Thorn, Craig E. (Wading River, NY); Chasman, Chellis (Setauket, NY); Baltz, Anthony J. (Coram, NY)

1984-04-24T23:59:59.000Z

473

Magnet pole tips  

DOE Patents (OSTI)

An improved magnet more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.

Thorn, C.E.; Chasman, C.; Baltz, A.J.

1981-11-19T23:59:59.000Z

474

Magnetization of neutron star matter  

E-Print Network (OSTI)

The magnetization of neutron star matter in magnetic fields is studied by employing the FSUGold interaction. It is found that the magnetic susceptibilities of the charged particles (proton, electron and muon) can be larger than that of neutron. The effects of the anomalous magnetic moments (AMM) of each component on the magnetic susceptibility are examined in detail. It is found that the proton and electron AMM affect their respective magnetic susceptibility evidently in strong magnetic fields. In addition, they are the protons instead of the electrons that contribute most significantly to the magnetization of the neutron star matter in a relative weak magnetic field, and the induced magnetic field due to the magnetization can be appear to be very large. Finally, the effect of the density-dependent symmetry energy on the magnetization is discussed.

Dong, Jianmin; Gu, Jianzhong

2013-01-01T23:59:59.000Z

475

Soft x-ray circular dichroism and scattering using a modulated elliptically polarizing wiggler and double synchronous detection  

Science Conference Proceedings (OSTI)

We have constructed an experimental station (beamline) at the National Synchrotron Light Source to measure circular dichroism (CD) using soft x-rays (250 {le} hv {le} 900 eV) from a time modulated elliptically polarizing wiggler. The polarization of the soft x-ray beam switches periodically between two opposite polarizations, hence permitting the use of phase-sensitive (lock-in) detection. While the wiggler can be modulated at frequencies up to 100 Hz, switching transients limit the actual practical frequency to {approx}25 Hz. With analog detection, switching transients are blocked by a chopper synchronized to the frequency and phase of the wiggler. The CD is obtained from the ratio of the signal recovered at the frequency of polarization modulation, f, to the average beam intensity, which is recovered by synchronous detection at frequency 2f.

Sutherland, J.C.; Polewski, K.; Monteleone, D.C. [and others

1998-01-23T23:59:59.000Z

476

New codes and standards for utility - interconnection of AC PV modules  

DOE Green Energy (OSTI)

Photovoltaic (PV) modules that provide only ac power give new dimensions to the use of, and utility interface of, PV systems because all of the dc issues are virtually eliminated. These AC PV modules offer the important advantage that customers may now purchase a PV system without hiring a design engineer. A qualified electrician will be able to install a complete PV system that performs as expected and meets local electrical codes. Simple installations of additional AC PV modules will be possible once the proper branch circuit wiring and protection have been installed. Codes and standards are currently being written to address the utility-interconnect issues for AC PV modules and other interactive inverters. An industry-supported Task Group has recently written and submitted proposals for changes to bring Article 690 of the 1999 National Electrical Code{reg_sign} (NEC{reg_sign}) up to the state-of-the-art for PV devices such as AC PV modules. This paper summarizes the proposed code changes and standards related to the evolving AC PV module technology in the United States. Topics such as the need for dedicated branch circuits for AC PV modules in residential applications are discussed and analyzed. Requirements for limiting the number of AC modules on a branch circuit and the listing requirements that make safe installations are discussed. Coordination of all standards activities for AC module installations, the building-integrated perspectives, and utility-interface issues is discussed.

Bower, W.

1997-10-01T23:59:59.000Z

477

Table AC1. Total Households Using Air-Conditioning Equipment, 2005 ...  

U.S. Energy Information Administration (EIA)

Table AC1. Total Households Using Air-Conditioning Equipment, 2005 Million U.S. Households Type of Air-Conditioning Equipment (millions) Central System

478

Table AC6. Average Consumption for Air-Conditioning by Equipment ...  

U.S. Energy Information Administration (EIA)

Central System 5 Table AC6. Average Consumption for Air-Conditioning by Equipment Type, 2005 Million British Thermal Units (Btu) per Household

479

Table AC7. Average Expenditures for Air-Conditioning by Equipment ...  

U.S. Energy Information Administration (EIA)

Central System 5 Table AC7. Average Expenditures for Air-Conditioning by Equipment Type, 2005 Dollars per Household Type of Air-Conditioning Equipment

480

ACCELERATED AGING STUDY OF MACHINE WINDING INSULATION UNDER AC AND HIGH FREQUENCY PULSE VOLTAGE APPLICATION.  

E-Print Network (OSTI)

?? It is common practice to perform accelerated aging with 60 Hz ac to determine the lifetime characteristics of insulation used in the machine. Comparable (more)

Chalise, Sajal Raj

2010-01-01T23:59:59.000Z

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481

Impact of inverter station on torsional dynamics of parallel HVdc-ac power system  

SciTech Connect

This paper investigates the impact of an inverter station on the torsional dynamics of a turbine-generator set which is located at the rectifier side of a parallel HVdc-ac power system. The studies show that depending on the stiffness of the inverter ac bus and electrical coupling between the inverter and rectifier ac buses, the inverter closed loop control can have noticeable contribution to the instability of torsional dynamics. This adverse torsional impact is observed in the study results even when the inverter ac bus is fairly strong (ESCR larger than 5.0).

Iravani, M.R.; Zhao, Z.; Hamouda, R.M. (Univ. of Toronto, Ontario (Canada). Dept. of Electrical Engineering)

1993-08-01T23:59:59.000Z

482

Non-Federal Participation In Ac Intertie Final Environmental Impact Statement  

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

Non-Federal Participation In Ac Intertie Non-Federal Participation In Ac Intertie Final Environmental Impact Statement Volume 1: Environmental Analysis Bonneville DOE/eis-0145 POWER ADMINISTRATION January 1994 Non-Federal Participation in AC Intertie Final Environmental Impact Statement (DOE/EIS - 0145) Responsible Agency: U.S. Department of Energy, Bonneville Power Administration (BPA) Title of Proposed Action: Non-Federal Participation in AC Intertie States and Other Areas Involved: Washington, Oregon, Idaho, Montana, California, Nevada, Utah, New Mexico, Arizona, Wyoming, British Columbia Abstract: BPA is considering action in two areas: (1) non-Federal access to

483

The Price of Synchrony: Resistive Losses due to Phase Synchronization in Power Networks  

E-Print Network (OSTI)

We investigate the total resistive losses incurred in returning a power network of identical generators to a synchronous state following a transient stability event or in maintaining this state in the presence of persistent stochastic disturbances. We formulate this cost as the input-output $H^2$ norm of a linear dynamical system with distributed disturbances. We derive an expression for the total resistive losses that scales with the size of the network as well as properties of the generators and power lines, but is independent of the network topology. This topologically invariant scaling of what we term the price of synchrony is in contrast to typical power system stability notions like rate of convergence or the region of attraction for rotor-angle stability. Our result indicates that highly connected power networks, whilst desirable for higher phase synchrony, do not offer an advantage in terms of the total resistive power losses needed to achieve this synchrony. Furthermore, if power flow is the mechanism used to achieve synchrony in highly-distributed-generation networks, the cost increases unboundedly with the number of generators.

Bassam Bamieh; Dennice F. Gayme

2012-09-21T23:59:59.000Z

484

Data:360311ac-6ca0-4146-89ac-db323120f125 | Open Energy Information  

Open Energy Info (EERE)

11ac-6ca0-4146-89ac-db323120f125 11ac-6ca0-4146-89ac-db323120f125 No revision has been approved for this page. It is currently under review by our subject matter experts. Jump to: navigation, search Loading... 1. Basic Information 2. Demand 3. Energy << Previous 1 2 3 Next >> Basic Information Utility name: Northern States Power Co - Minnesota Effective date: 2012/05/01 End date if known: Rate name: LIMITED OFF PEAK SERVICE Transmission Transformed (Commercial & Industrial) Sector: Commercial Description: Available to any customers for controlled loads that will be energized only for the time period between 10:00 p.m. to 6:30 a.m. daily. DETERMINATION OF CUSTOMER BILLS Customer bills shall reflect energy charges (if applicable) based on customer's kWh usage, plus a customer charge (if applicable), plus demand charges (if applicable) based on customer's kW billing demand as defined. INTERIM RATE ADJUSTMENT A 4.49% Interim Rate Surcharge will be applied to rate components specified in the "Interim Rate Surcharge Rider." In addition, customer bills under this rate are subject to the following adjustments and/or charges. FUEL CLAUSE Bills are subject to the adjustments provided for in the Fuel Clause Rider. RESOURCE ADJUSTMENT Bills are subject to the adjustments provided for in the Conservation Improvement Program Adjustment Rider, the State Energy Policy Rate Rider, the Renewable Development Fund Rider, the Transmission Cost Recovery Rider, the Renewable Energy Standard Rider and the Mercury Cost Recovery Rider.

485

Magnetic Thin Films and Devices  

Science Conference Proceedings (OSTI)

... metal atoms that form small magnets with Curie ... a toggle operation of the magnetic state of ... A high-frequency probe driving a microwave waveguide ...

2010-10-05T23:59:59.000Z

486

Experiment Hazard Class 9 - Magnets  

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

hazard classification applies to all experiments involving magnets, magnetic fields, and electric fields. Other hazard classifications such as electrical safety and their...

487

Permanent Magnets for Energy Applications  

Science Conference Proceedings (OSTI)

Mar 13, 2012 ... Magnetic Materials for Energy Applications II: Permanent Magnets for ... to 500% in the last 12 months, the most unstable being the price of Dy.

488

Nanostructured Materials for Magnetic Refrigeration  

Science Conference Proceedings (OSTI)

... of Nd-Fe-B Magnets to the Megawatt Scale Generator for the Wind Turbine ... Low Loss, High Power Density Magnetics in Inductor/Transformer Cores for Army ...

489

Search Publications | Superconducting Magnet Division  

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

Rapid Cycling Magnets Helical Magnets HERA upgrade LHC IR Dipoles RHIC Publications Search Publications Selected Cryogenic Data Notebook Proceedings of the 1968 Summer Study on...

490

Table 1. Design specifications of ultra-high speed PM motor. Supply voltage (V) 12  

E-Print Network (OSTI)

Analysis of Ultra-High Speed Permanent-Magnet Motor Masaru Kano, and Toshihiko Noguchi Department@vos.nagaokaut.ac.jp Abstract This paper describes a design of an ultra-high speed (UHS) permanent-magnet (PM) synchronous motor, a surface permanent-magnet (SPM) motor (150,000 r/min, 1.5 kW) fed by a low voltage battery (12 V

Fujimoto, Hiroshi

491

Low loss conductor for ac or dc power transmission  

DOE Patents (OSTI)

The patent describes a compact, easy to fabricate, noninductive, low surface magnetic field superconductor transmission line that has minimal stray fields.

Sampson, W.B.; Garber, M.

1973-03-13T23:59:59.000Z

492

Construction and calibration of a 12 T pulsed magnet integrated with a 4 K closed-cycle refrigerator  

SciTech Connect

A low cost 12 T pulsed magnet system has been integrated with a closed-cycle helium refrigerator for performing magnetotransport measurements. Minimal delay between pulses and ac current excitation with software lock-in to reduce noise enables quick but accurate measurements to be performed at temperatures of 4-300 K up to 12 T. An additional pulsed magnet operating with a liquid nitrogen cryostat extends the range up to 19 T. The instrument has been calibrated against a commercial superconducting magnet by comparing quantum Hall effect data in a p-channel SiGe/Si heterostructure, and common issues arising out of pulsed magnet usage have been addressed. The versatility of the system is demonstrated through magnetotransport measurements in a variety of samples such as heterostructures, narrow gap semiconductors, and those exhibiting giant magnetoresistance.

Murthy, O. V. S. N.; Venkataraman, V. [Department of Physics, Indian Institute of Science, Bangalore 560012 (India)

2007-11-15T23:59:59.000Z

493

Magnetically Driven Accretion  

E-Print Network (OSTI)

We carried out 2.5-dimensional resistive magnetohydrodynamic simulations to study the effects of magnetic diffusivity on magnetically driven mass accretion and jet formation. The initial state is a constant angular-momentum torus threaded by large-scale vertical magnetic fields. Since the angular momentum of the torus is extracted due to magnetic braking, the torus medium falls toward the central region. The infalling matter twists the large-scale magnetic fields and drives bipolar jets. We found that (1) when the normalized magnetic diffusivity, ? ? ?/(r0VK0), where VK0 is the Keplerian rotation speed at a reference radius r = r0, is small (? ? 10 ?3), mass accretion and jet formation take place intermittently; (2) when 10 ?3 ? ? ? 10 ?2, the system evolves toward a quasi-steady state; and (3) when ? ? 10 ?2 the accretion/mass 1 outflow rate decreases with ? and approaches 0. The results of these simulations indicate that in the center of a galaxy which has a super-massive ( ? 10 9 M?) black hole, a massive ( ? 10 8 M?) gas torus and magnetic braking provide a mass accretion rate which is sufficient to explain the activity of AGNs when ? ? 5 10?2.

Takuhito Kuwabara; Kazunari Shibata; Takahiro Kudoh

2000-01-01T23:59:59.000Z

494

How ready is `capture ready'? May 2008 SCCS for WWF -1(44) -www.geos.ed.ac.uk/sccs Nils.Markusson@ed.ac.uk S.Haszeldine@ed.ac.uk  

E-Print Network (OSTI)

@mines.edu. § Division of Economics, University of Stirling. i.a.lange@stir.ac.uk. ¶ Dyson School of Applied Economics. Such a correlation may be explained in part through engineering aspects of plant operations. For instance, increasing

Haszeldine, Stuart

495

Modeling and simulation of a wind farm in the presence of power electronic devices for the enhancement of transient stability  

Science Conference Proceedings (OSTI)

A comprehensive comparative study is made of a pitch control system and shunt flexible AC transmission system (FACTS) devices in order to improve large wind farm operation. Transient stability analysis of a large wind farm in the presence of superconducting ... Keywords: Wind farm, pitch controller, simulation, static synchronous compensator (STATCOM), static var compensator (SVC), superconducting magnetic energy storage (SMES), transient stability

Peyman Farhang, Saeid Jalilzadeh, Ahad Kazemi

2013-06-01T23:59:59.000Z

496

Magnetic field generator  

DOE Patents (OSTI)

A magnetic field generating device provides a useful magnetic field within a specific retgion, while keeping nearby surrounding regions virtually field free. By placing an appropriate current density along a flux line of the source, the stray field effects of the generator may be contained. One current carrying structure may support a truncated cosine distribution, and it may be surrounded by a current structure which follows a flux line that would occur in a full coaxial double cosine distribution. Strong magnetic fields may be generated and contained using superconducting cables to approximate required current surfaces.

Krienin, Frank (Shoreham, NY)

1990-01-01T23:59:59.000Z