The Experts below are selected from a list of 111351 Experts worldwide ranked by ideXlab platform

Ernst Gockenbach - One of the best experts on this subject based on the ideXlab platform.

  • sweep frequency response analysis for diagnosis of low level short Circuit Faults on the windings of power transformers an experimental study
    International Journal of Electrical Power & Energy Systems, 2012
    Co-Authors: Vahid Behjat, Alireza Setayeshmehr, Hossein Borsi, Ali Vahedi, Ernst Gockenbach
    Abstract:

    Abstract This contribution is aimed at obtaining diagnosis criteria for detection of low-level short Circuit Faults throughout sweep frequency response analysis (SFRA) measurements on the transformer windings. Significant advantages would accrue by early detection of low level short Circuit Faults within the transformer, since if not quickly detected, they usually develop into more serious Faults which result in irreversible damage to the transformer and the electrical network, unexpected outages and the consequential costs. A Finite Element Model (FEM) of the tested transformer has been developed to assist in justifying the modifications of the winding frequency response as a result of fault occurrence. Successful operation of the SFRA method in precisely detecting interturn Faults along the transformer windings, even down to a few shorted turns on the winding, is proved through a large number of experiments and measurements. Improving the interpretation of the SFRA measurements needs complementary statistical indicators. The usage of correlation coefficient and spectrum deviation for comparison of the frequency responses obtained through SFRA measurements provides quantitative indicators of the fault presence on the transformer windings and also the fault severity level in the shorted turns.

  • Sweep frequency response analysis for diagnosis of low level short Circuit Faults on the windings of power transformers: An experimental study
    International Journal of Electrical Power and Energy Systems, 2012
    Co-Authors: Vahid Behjat, Alireza Setayeshmehr, Hossein Borsi, Ali Vahedi, Ernst Gockenbach
    Abstract:

    This contribution is aimed at obtaining diagnosis criteria for detection of low-level short Circuit Faults throughout sweep frequency response analysis (SFRA) measurements on the transformer windings. Significant advantages would accrue by early detection of low level short Circuit Faults within the transformer, since if not quickly detected, they usually develop into more serious Faults which result in irreversible damage to the transformer and the electrical network, unexpected outages and the consequential costs. A Finite Element Model (FEM) of the tested transformer has been developed to assist in justifying the modifications of the winding frequency response as a result of fault occurrence. Successful operation of the SFRA method in precisely detecting interturn Faults along the transformer windings, even down to a few shorted turns on the winding, is proved through a large number of experiments and measurements. Improving the interpretation of the SFRA measurements needs complementary statistical indicators. The usage of correlation coefficient and spectrum deviation for comparison of the frequency responses obtained through SFRA measurements provides quantitative indicators of the fault presence on the transformer windings and also the fault severity level in the shorted turns. © 2012 Elsevier Ltd. All rights reserved.

Yanjun Yu - One of the best experts on this subject based on the ideXlab platform.

  • Fault-Tolerant Control of Modular Permanent Magnet Synchronous Motor Under Open-Circuit Faults
    IEEE Access, 2019
    Co-Authors: Feng Chai, Yanjun Yu
    Abstract:

    The paper studies a novel fault-tolerant strategy of the modular permanent magnet synchronous motor under open-Circuit Faults, which is called as the extended open-Circuit fault-tolerant control (EOCFTC) strategy. The faulty modular motor based on the EOCFTC strategy can achieve the high fault-tolerance and maximum output torque capability by making the most of the remaining healthy phases. First, the mathematical model of the modular motor with n modules is described. Then based on the characteristics of the modular motor, a novel winding reconstruction strategy is proposed to deal with multiphase open-Circuit Faults in different modules. All remaining healthy phases are reasonably reconstructed according to the maximum output torque principle. Then these new modules can operate well by employing the armature magnetomotive force (MMF) compensation and the field-orientated control (FOC) strategy. Finally, all cases of open-Circuit Faults and the corresponding processing methods are discussed. The extreme case of open-Circuit Faults is described in detail, which shows the high fault-tolerance of the modular motor with the EOCFTC strategy. The experimental results verify the rationality and feasibility of the EOCFTC strategy on a two-module modular motor.

  • Performance Analysis of Modular In-Wheel Motor with Open-Circuit Faults Considering Temperature Limitation
    2019 22nd International Conference on Electrical Machines and Systems (ICEMS), 2019
    Co-Authors: Yue Tang, Yanjun Yu, Feng Chai
    Abstract:

    In this paper, the fault-tolerant performances of a modular permanent magnet synchronous motor (PMSM) with various open-Circuit Faults are investigated considering temperature limitation. The motor is adopted 16/24 poles/slots and four modules structure. Firstly, the motor system and fault-tolerant principle are shown. Secondly, the fault-tolerant performances of the motor under various open-Circuit Faults are analyzed. These Faults are divided into two cases, the general Faults and extreme Faults. The torque performance, losses and temperature distributions under these Faults are analyzed respectively using various fault-tolerant strategies. The relationship between the overload multiple of the fault-tolerant current and the safe operation time is also discussed. The fault-tolerant strategy with the temperature analysis can give a more reasonable fault-tolerant current and make the output capacity of the motor maximized on the premise of the safe temperature rise.

  • Radial Force and Vibration Calculation for Modular Permanent Magnet Synchronous Machine With Symmetrical and Asymmetrical Open-Circuit Faults
    IEEE Transactions on Magnetics, 2018
    Co-Authors: Zaixin Song, Feng Chai, Yanjun Yu, Yue Tang
    Abstract:

    This paper studies the radial force and vibration performance of the modular three-phase permanent magnet synchronous machine under typical two-phase open-Circuit Faults: symmetrical and asymmetrical. First of all, the expressions of armature magnetomotive force are formalized in normal and fault conditions; thus, the air-gap magnetic fields and radial force density can be analyzed theoretically. Second, the theoretical analysis is verified by running the finite-element simulation of a four-unit modular machine. The relationship between the fault types and radial force harmonic contents is also discussed with the help of 2-D fast Fourier transform. This is followed by the transient and harmonic structural analysis, with the exciting forces imposed on the stator system in order to get the acceleration response. The simulation results are validated by vibration measurement experiments of a similar small-sized modular motor. This investigation can instruct the designer to lower the modular machine's vibration under different fault conditions.

J M Nagashima - One of the best experts on this subject based on the ideXlab platform.

  • IPM synchronous machine drive response to symmetrical and asymmetrical short Circuit Faults
    IEEE Transactions on Energy Conversion, 2003
    Co-Authors: B A Welchko, T M Jahns, W L Soong, J M Nagashima
    Abstract:

    A closed-form solution is presented for the steady-state response of interior permanent magnet (IPM) synchronous machines to symmetrical short Circuits including the effects of q-axis magnetic saturation. Machine response to single-phase asymmetrical short Circuits is also investigated. Experimental data are presented to verify predicted behavior for both types of short Circuits. It is shown that single-phase asymmetrical short Circuit Faults produce more severe fault responses with high pulsating torque and a significant threat of rotor demagnetization. A control strategy that purposely transitions such Faults into symmetrical three-phase short Circuits can minimize the fault severity and associated demagnetization risks. Implications for the design of IPM machines with improved fault tolerance are discussed.

  • ipm synchronous machine drive response to symmetrical and asynunetrical short Circuit Faults
    IEEE Power & Energy Magazine, 2002
    Co-Authors: B A Welchko, T M Jahns, W L Soong, J M Nagashima
    Abstract:

    A closed-form solution is presented for the steady-state response of interior permanent magnet (IPM) synchronous machines to symmetrical short Circuits including the effects of q-axis magnetic saturation. Machine response to single-phase asymmetrical short Circuits is also investigated. Experimental data are presented to verify predicted behavior for both types of short Circuits. It is shown that single-phase asymmetrical short Circuit Faults produce more severe fault responses with high pulsating torque and a significant threat of rotor demagnetization. A control strategy that purposely transitions such Faults into symmetrical three-phase short Circuits can minimize the fault severity and associated demagnetization risks. Implications for the design of IPM machines with improved fault tolerance are discussed.

Vahid Behjat - One of the best experts on this subject based on the ideXlab platform.

  • sweep frequency response analysis for diagnosis of low level short Circuit Faults on the windings of power transformers an experimental study
    International Journal of Electrical Power & Energy Systems, 2012
    Co-Authors: Vahid Behjat, Alireza Setayeshmehr, Hossein Borsi, Ali Vahedi, Ernst Gockenbach
    Abstract:

    Abstract This contribution is aimed at obtaining diagnosis criteria for detection of low-level short Circuit Faults throughout sweep frequency response analysis (SFRA) measurements on the transformer windings. Significant advantages would accrue by early detection of low level short Circuit Faults within the transformer, since if not quickly detected, they usually develop into more serious Faults which result in irreversible damage to the transformer and the electrical network, unexpected outages and the consequential costs. A Finite Element Model (FEM) of the tested transformer has been developed to assist in justifying the modifications of the winding frequency response as a result of fault occurrence. Successful operation of the SFRA method in precisely detecting interturn Faults along the transformer windings, even down to a few shorted turns on the winding, is proved through a large number of experiments and measurements. Improving the interpretation of the SFRA measurements needs complementary statistical indicators. The usage of correlation coefficient and spectrum deviation for comparison of the frequency responses obtained through SFRA measurements provides quantitative indicators of the fault presence on the transformer windings and also the fault severity level in the shorted turns.

  • Sweep frequency response analysis for diagnosis of low level short Circuit Faults on the windings of power transformers: An experimental study
    International Journal of Electrical Power and Energy Systems, 2012
    Co-Authors: Vahid Behjat, Alireza Setayeshmehr, Hossein Borsi, Ali Vahedi, Ernst Gockenbach
    Abstract:

    This contribution is aimed at obtaining diagnosis criteria for detection of low-level short Circuit Faults throughout sweep frequency response analysis (SFRA) measurements on the transformer windings. Significant advantages would accrue by early detection of low level short Circuit Faults within the transformer, since if not quickly detected, they usually develop into more serious Faults which result in irreversible damage to the transformer and the electrical network, unexpected outages and the consequential costs. A Finite Element Model (FEM) of the tested transformer has been developed to assist in justifying the modifications of the winding frequency response as a result of fault occurrence. Successful operation of the SFRA method in precisely detecting interturn Faults along the transformer windings, even down to a few shorted turns on the winding, is proved through a large number of experiments and measurements. Improving the interpretation of the SFRA measurements needs complementary statistical indicators. The usage of correlation coefficient and spectrum deviation for comparison of the frequency responses obtained through SFRA measurements provides quantitative indicators of the fault presence on the transformer windings and also the fault severity level in the shorted turns. © 2012 Elsevier Ltd. All rights reserved.

Feng Chai - One of the best experts on this subject based on the ideXlab platform.

  • Fault-Tolerant Control of Modular Permanent Magnet Synchronous Motor Under Open-Circuit Faults
    IEEE Access, 2019
    Co-Authors: Feng Chai, Yanjun Yu
    Abstract:

    The paper studies a novel fault-tolerant strategy of the modular permanent magnet synchronous motor under open-Circuit Faults, which is called as the extended open-Circuit fault-tolerant control (EOCFTC) strategy. The faulty modular motor based on the EOCFTC strategy can achieve the high fault-tolerance and maximum output torque capability by making the most of the remaining healthy phases. First, the mathematical model of the modular motor with n modules is described. Then based on the characteristics of the modular motor, a novel winding reconstruction strategy is proposed to deal with multiphase open-Circuit Faults in different modules. All remaining healthy phases are reasonably reconstructed according to the maximum output torque principle. Then these new modules can operate well by employing the armature magnetomotive force (MMF) compensation and the field-orientated control (FOC) strategy. Finally, all cases of open-Circuit Faults and the corresponding processing methods are discussed. The extreme case of open-Circuit Faults is described in detail, which shows the high fault-tolerance of the modular motor with the EOCFTC strategy. The experimental results verify the rationality and feasibility of the EOCFTC strategy on a two-module modular motor.

  • Performance Analysis of Modular In-Wheel Motor with Open-Circuit Faults Considering Temperature Limitation
    2019 22nd International Conference on Electrical Machines and Systems (ICEMS), 2019
    Co-Authors: Yue Tang, Yanjun Yu, Feng Chai
    Abstract:

    In this paper, the fault-tolerant performances of a modular permanent magnet synchronous motor (PMSM) with various open-Circuit Faults are investigated considering temperature limitation. The motor is adopted 16/24 poles/slots and four modules structure. Firstly, the motor system and fault-tolerant principle are shown. Secondly, the fault-tolerant performances of the motor under various open-Circuit Faults are analyzed. These Faults are divided into two cases, the general Faults and extreme Faults. The torque performance, losses and temperature distributions under these Faults are analyzed respectively using various fault-tolerant strategies. The relationship between the overload multiple of the fault-tolerant current and the safe operation time is also discussed. The fault-tolerant strategy with the temperature analysis can give a more reasonable fault-tolerant current and make the output capacity of the motor maximized on the premise of the safe temperature rise.

  • Analysis and Suppression of Vibration in Modular Fault-Tolerant PMSM Under Single-Phase Short-Circuit Faults
    2019 22nd International Conference on Electrical Machines and Systems (ICEMS), 2019
    Co-Authors: Shibo Li, Feng Chai, Lei Chen, Zaixin Song, Yue Tang
    Abstract:

    This paper investigates the effects of single-phase short-Circuit Faults (SCF) on the electromagnetic (EM) force and vibration compared with the normal condition of the motor. Firstly, this paper introduces the structure of the modular motor. Secondly, optimize the modular motor structure to suppress the short-Circuit current and ensure that the motor can run under the fault. Finally, the magnetomotive force (MMF) compensation fault-tolerant strategy is introduced, and based on the Maxwell stress tensor method, the theoretical analysis results of the radial force under the fault and magnetomotive force compensation are presented and FEA results are given to verify the theoretical analysis.

  • Radial Force and Vibration Calculation for Modular Permanent Magnet Synchronous Machine With Symmetrical and Asymmetrical Open-Circuit Faults
    IEEE Transactions on Magnetics, 2018
    Co-Authors: Zaixin Song, Feng Chai, Yanjun Yu, Yue Tang
    Abstract:

    This paper studies the radial force and vibration performance of the modular three-phase permanent magnet synchronous machine under typical two-phase open-Circuit Faults: symmetrical and asymmetrical. First of all, the expressions of armature magnetomotive force are formalized in normal and fault conditions; thus, the air-gap magnetic fields and radial force density can be analyzed theoretically. Second, the theoretical analysis is verified by running the finite-element simulation of a four-unit modular machine. The relationship between the fault types and radial force harmonic contents is also discussed with the help of 2-D fast Fourier transform. This is followed by the transient and harmonic structural analysis, with the exciting forces imposed on the stator system in order to get the acceleration response. The simulation results are validated by vibration measurement experiments of a similar small-sized modular motor. This investigation can instruct the designer to lower the modular machine's vibration under different fault conditions.