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  • Title/Summary/Keyword: Stator winding

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Study of PD Location in Generators by PD Pulses Propagation

  • Cheng, Yang-Chun;Li, Cheng-Rong;Wang, Wei
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.5
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    • pp.252-256
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    • 2006
  • When a partial discharge takes place at the stator of a generator, the electrical pulse will propagate along the stator bars and the capacitor chains formed by the end part of the stator winds. On the first path, the pulse propagates as a travel wave at slow speed. On the second path, the pulse propagates at quick speed. Based on the data of the experiments on a real 50 MW steam generator, the author has found the pulses can propagate by magnetic field of the stator winding. It was studied that how to locating the partial discharge by signals coming from the different paths, including the features of signals on the two paths at time domain and frequency domain, the measurement frequency rang of the signals, the blind area, the advantage and disadvantage of this method.

A Study on the SRM Torque Computation According to Different Stator Pole Shapes (스위치드 릴럭턴스 전동기의 스테이터 형상에 따른 토크량 계산에 관한 연구)

  • Jo, Hee;Lee, Jong-Woo;Kim, Kyeong-Hwa
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.693-696
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    • 2011
  • The SRM (Switched Reluctance Motor) is composed of silicon steel plates where the rotor structure is simple and laminated without coil winding or permanent magnet, making it mechanically robust and its maintenance and repair excellent. Applying SRM as traction motor for railway vehicle is given consideration because of its ruggedness capability in severe loading condition and its compact structure. Optimal design of SRM is needed to reduce torque ripple to apply SRM for railway traction drive because SRM has high torque ripple. In this paper, switched reluctance motor with three different stator pole shapes is taken for magnetic analysis using 3d finite element method to apply SRM as traction drive for railway vehicle. It is observed that the model 3 added Tooth Tang Depth and Slot Round to stator shape gives the improved inductance and torque characteristic.

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A Study On The Performances Of A Single-Phase Motor With Non-Quadrature Stator Windings Using Domestic Magnetic Materials. (국산자기재료를 이용한 비대칭자속분포 단상유도기구)

  • Min Ho Park
    • 전기의세계
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    • v.21 no.3
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    • pp.41-47
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    • 1972
  • The requirements of a successful design for single phase induction motors with a high efficiency have, in recent years, led to the use of non-quadrature stator windings motors in which a high starting torque is a prime requisite. The capacitor motor is one of above machines in which various possible forms of asymmetry can be occur. These forms of asymmetry in the stator phase windings, encountered in machine designs, are 1) an asymmetrical disposition in space of their magnetic axes, 2) a difference in their effective number of turns, 3) a difference in the distribution of their coil groups per pole and 4) amounts of capacitance of an auxiary winding. In order to apply the effective performance prediction of these form to motors, mading of lower quality-domestic magnetic materials, the analysis and the experimental investigations of its sample motors are described in this paper. The utility of such a motor is demonstrated and it is shown that the effects- a good efficiency, good power factor and high starting torque-of the motor mechanism with non-quadrature stator phase windings can development disadvantages by using the lower quality-domestis magnetic materials.

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A Novel Design Technique to Improve the Performance of Flux-Reversal Machine (성능 개선을 위한 자속 역전식 기기의 설계 기법)

  • Kim Tae Heoung;Lee Ju;Lee Sang-Don
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.53 no.12
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    • pp.700-708
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    • 2004
  • Flux-reversal machine (FRM) is a new doubly-salient stator-permanent magnet (PM) machine with flux linkage reversal in the stator concentrated windings. It can operate in both motoring and generating modes. In this paper, a novel design technique to improve the performance of FRM is proposed. Proposed techniques have a new stator winding and a magnet arrangement method. The stator and rotor shape with a concave type and a flux barrier are also proposed. According to the experimental results, it is shown that the proposed FRM have an improved performance.

Characteristics of Insulation Failure in High Voltage Motor Stator Windings (고압전동기 고정자 권선의 절연파괴 특성)

  • Kim, Hee-Dong;Kim, Kyeong-Yeol;Park, Deok-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.124-124
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    • 2010
  • Diagnostic tests were performed on six high voltage motors. These tests included ac current, dissipation factor(tan6) and partial discharge(PD) magnitude. The rewind of motor stator insulation at rated voltage is assessed by the results of these tests. After completing the diagnostic tests, the stator windings of motors were subjected to gradually increasing ac voltage, until the insulation punctured. No. 1 and No.2 motors(4.16 kV) failed near rated voltage of 12.3 kV and 14.2 kV, respectively. The breakdown voltage of No.3 and No.4 motors(6.6 kV) was 17.6 kV and 17.8 kV, respectively. These motors are higher that expected for good quality coils in 6.6 kV class motors.

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A Study on Saturation Modeling of Synchronous Generator using Operating Data (운용 데이타를 이용한 동기발전기 포화 모델링에 관한 연구)

  • Kim, Kyung-Yul;Yoo, Ill-Do;Seo, Jang-Cheol;Moon, Seung-Ill
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.106-109
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    • 1995
  • This paper presents a new saturation modeling technique of synchronous generators using the operating data. With the stator voltages, currents and the field current directly measured on the field winding at different steady state operating conditions, it can estimate tile saturated stator mutual inductances, stator resistance and the field-stator equivalent turns ratio. Effects of the measurement noises on tile estimated parameters are also investigated.

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Development of the On-line Partial Discharge Measuring Sensor and System on Stator Windings for Hydro Generator (수력발전기 고정자권선용 운전중 부분방전 측정 센서 및 시스템 개발)

  • Kang, D.S.;Sun, J.H;Hwang, D.H.;Yun, Y.H.;Seo, I.S.;Shin, B.C.;Klm, H.I.;Lee, K.H.
    • Proceedings of the KIEE Conference
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    • 2005.11c
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    • pp.103-106
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    • 2005
  • A lot of R&D on the diagnosis of stator winding insolation for large rotating machines has been carried out since the 1970s. The on-line partial discharge measurement has proved to be an effective technique in the evaluation of the state of stator insulation in high voltage rotating machines. The purpose of this paper is to describe the method of the on-line partial discharge measurement on stator windings for hydro- generator with ceramic sensor and measuring system. We developed ceramic coupling sensor, partial discharge measuring system, terminal box and index parameters.

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Study on the Reduction of Vibration, Acoustic Noise of SRM by DC Excitation Commutation Method (SRM의 직류여자 전류방식에 의한 진동, 소음의 저감 대책에 관한 연구)

  • Hwang, Yeong-Mun;Jeong, Tae-Uk;O, Seong-Gyu;Chu, Yeong-Bae
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.1
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    • pp.1-8
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    • 2000
  • Switched reluctance motor(SRM) has simple magnetic structure, and requires simple power electronic driving circuit. It is very useful for wide range adjustable speed drive system. But, SRM drive generates large vibration and acoustic noise because it is commutated individually by step pulse m.m.f of each phase pole. In the vibration and acoustic noise characteristics. The considerable vibration and noise is induced by radial deforming of stator, so the frequency of dominant vibration and noise is coincident with the frequency of natural mode frequency of mechanical structure. This radial vibration force is generated in the phase commutation region. This paper suggests the new electromagnetic structure of SRM with auxiliary commutation winding which is excited by direct current. This phase and commutation winding are coupled magnetically between one phase winding and the other. Therefore, the switch-off phase current is absorbed by the another phase winding. By this interaction of phase and commutation winding in commutation mechanism, vibration and noise is reduced. And this reduction effect is examined by the test of prototype machine. As a result, SRM with DC exciting commutation winding is very useful to reduce vibration and acoustic noise.

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High-Speed BLDC Motor Design for Suction Fan and Impact on the Loss caused by Core Welding

  • Hong, Hyun-Seok;Kim, In-Gun;Lee, Ho-Joon;Go, Sung-Chul;Lee, Ju
    • Journal of Electrical Engineering and Technology
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    • v.12 no.1
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    • pp.126-133
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    • 2017
  • This paper deals with the effects of welding, which is done to fix the stator stack, on a motor in case of fabricating a prototype motor that is manufactured in a small quantity. In the case of a small motor, the stator is designed and fabricated with the segmented core as a way to raise the fill factor of winding wire to the utmost within a limited size. In case of fabrication by welding both inside and outside of the stator in order to fix the segmented-core stator, the effects of stack are ignored, and the eddy current loss occurs. This paper performed the no-load test on an IPM-type BLDC motor for driving the suction fan of a vacuum cleaner, which was manufactured by using a segmented-core stator. As a result of the test, it was found that input power more than expected was supplied. To analyze the effects of welding by using the finite element analysis method and verify them experimentally, a stator was re-manufactured by bonding, and input power supplied during the no-load test was compared.

Judgement Criterion of Insulation Deterioration in 4.16kV and 6.6kV Motor Stator Windings (4.16kV 및 6.6kV 전동기 고정자 권선의 절연열화 판정기준)

  • Kim, Hee-Dong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.4
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    • pp.788-794
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    • 2009
  • To assess the condition of stator insulation, nondestructive tests were performed on twenty five coil groups and twenty six motors. The stator windings has nominal ratings of 6.6kV and are classified into five coil groups ;one group with healthy insulation and four groups with four different types of artificial defects. After completing nondestructive tests, the AC voltage applied to the stator windings was gradually increasing until insulation failure in order to obtain the breakdown voltage. No.1, No.2 and No.6 of 6.6kV motors failed near rated voltage of 14kV, 8.7kV and 14kV, respectively. The breakdown voltage of three motors was lower that expected for good quality coils(14.2kV) in 6.6kV motors. No.3 and No.6 of 4.16kV motors failed near rated voltage of 5.6kV and 4.2kV, respectively. Almost all of failures were located in a line-end coil at the exit from the core slot. The breakdown voltages and the types of defects showed strong relation to the stator insulation tests such as in the case of AC current, dissipation factor(tanδ) and partial discharge magnitude.