• Title/Summary/Keyword: insulation condition

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Properties of Electrical Performance on Stator Coil of Traction Motor by Accelerated Test (견인전동기 고정자 코일의 전기적 열화특성)

  • Park Hyun-June;Jang Dong-Uk;Kim Gil-Dong
    • Proceedings of the KSR Conference
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    • 2003.10c
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    • pp.623-627
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    • 2003
  • Aging and failure of motor insulation depend on the stresses imposed on it. The insulation life time depends on the severity of the stresses. The electrical aging by transient surge is very important to traction motor in EMU(electric multiple unit). This paper presents the insulation characteristics of stator coil by transient surge from inverter. There are several nondestructive tests available for checking the condition of motor insulation, the probable extent of aging, and the rate of which aging is taking place. So the insulation characteristics of stator coil were each analyzed by measurement of leakage current, dielectric loss($tan{\delta}$), capacitance, polarization index(PI) and partial discharge. The method of diagnosis is able to analyze the aging condition and predict the life of the traction motor in EMU.

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On-line partial discharge measurement techniques of hydro-generator windings (수력 발전기 권선에서의 운전중 부분방전 측정기법)

  • 황동하;김진봉;김용주;박명수;김택수
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.2
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    • pp.294-300
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    • 1996
  • In hydro-generator, a groundwall insulation of stator windings gradually deteriorates due to mechanical, thermal, electrical and environmental stresses. These stresses combine to result in loose windings, delamination of the stator insulation and/or electrical tracking of the endwinding, all of which can lead to stator insulation failures. Conventionally, off-line tests such as partial discharge measurement, DC/AC current and .DELTA.tan.delta. tests has been used for estimation of winding condition. However, off-line test requires large power supply and generator outage. In addition, major cause of insulation problems such as loose wedges and slot dischages may not be found with off-line diagnoses. This paper introduces the on-line partial discharge measurement techniques using frequency spectrum analyzer(FSA) for the generator stator windings. The experimental results from the UIAM #1 hydro-generator confirms a optimistic application of on-line generator diagnosis method as a reliable tool for evaluation of winding condition.

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Assessment of Insulation Condition between Diagnosis and Impregnation for Hydro-Generator (수력발전기의 절연보강 전${\cdot}$후 절연상태 비교평가)

  • Byun il-hwan;Lee Eun-Woong
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.1124-1126
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    • 2004
  • The measurements were performed to assess the insulation deterioration condition of the stator winding of Dae-Cheong hydro-generator ${\sharp}2$ which had been in service after being constructed 1980. After repair of the stator winding insulation. we conducted insulation diagnostic tests which include resistance, polarization index(P. I). AC current, dissipation factor($Tan{\delta}$) and partial discharges ($Q_{max}$). The results of diagnostic tests were compared to the previous records. On the basis of these test results. this paper tried to present the importance of insulation repair for the generator stator winding.

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Assessment of Insulation Condition between Diagnosis and Impregnation for Hydro-Generator (대용량 수차발전기의 절연진단과 절연보수 상관관계 평가)

  • Oh, Bong-Keun;Jung, Jin-Dal;Lee, Kwang-Ho;Kim, Hyun-Il;Kwak, Hee-Jin
    • Proceedings of the KIEE Conference
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    • 2004.05b
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    • pp.39-41
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    • 2004
  • The measurements were performed to assess the insulation deterioration condition of the stator winding of Dae-Cheong hydro-generator #2 which had been in service after being constructed 1980. After repair of the stator winding insulation, we conducted insulation diagnostic tests which include resistance, polarization index(P.I), AC current, dissipation factor($Tan\delta$) and partial discharges ($Q_{max}$). The results of diagnostic tests were compared to the previous records. On the basis of these test results, this paper tried to present the importance of insulation repair for the generator stator winding.

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Analysis of Insulation Characteristic for Small Hydro Generator (소수력발전기 절연특성분석)

  • Oh, Bong-Keun;Chang, Jeong-Ho;Lee, Kwang-Ho;Kang, Dong-Sik
    • 한국신재생에너지학회:학술대회논문집
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    • 2008.05a
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    • pp.142-145
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    • 2008
  • Electrical insulation of small hydro generator stator winding is one of the most important parts in generator facilities. Some stator winding insulation problems can be identified through analysis of insulation diagnostic test. So, Diagnosis of stator winding insulation is an important measure of ensuring the safe operation and extending the remaining life of small hydro generator. This paper presents case studies of insulation failure in generator stator windings and the results of insulation diagnostic test for small hydro generator stator windings. Especially, Conducting the insulation diagnostic test before the generator installed in site is very important process to keep the good insulation condition in service.

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A Study on the Electrical Properties of the Conduction-cooled HTS SMES System (전도냉각형 고온초전도 에너지저장장치의 전기적 특성)

  • Choi, Jae-Hyeong;Kwag, Dong-Soon;Cheon, Hyeon-Gweon;Kim, Hae-Jong;Kim, Sang-Hyun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.2
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    • pp.135-141
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    • 2007
  • The conduction-cooled HTS SMES is operated in cryogenic and high vacuum condition. Thus, Insulation design at cryogenic temperature and high vacuum is a key and an important element that should be established to accomplish miniaturization that is a big advantage of HTS SMES. However, the behaviors of insulators for cryogenic conditions in vacuum are virtually unknown. Therefore, we need active research and development of insulation concerning application of the conduction-cooled HTS SMES. Therefore, in this study, we experimented about insulation characteristic high vacuum and cryogenic similar to driving condition of SMES system. Also, investigated about insulation characteristic of suitable some materials to insulator for conduction-cooled HTS SMES. As this results, we possessed basis data for insulation materials selection and insulation design for development of 600 kJ class conduction-cooled HTS SMES.

Insulating Properties between Cryocooler and Magnet for the Conduction-Cooled HTS SMES System (전도냉각형 고온초전도 SMES의 냉동기와 마그네트 간의 절연 특성)

  • Choi Jae-Hyeong;Kwag Dong-Soon;Cheon Hyeon-Gweon;Kim Hae-Jong;Seong Ki-Chul;Kim Sang-Hyun
    • Progress in Superconductivity and Cryogenics
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    • v.8 no.3
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    • pp.45-48
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    • 2006
  • The conduction-cooled HTS SMES is operated in cryogenic and high vacuum condition. Thus. Insulation design at cryogenic temperature and high vacuum is a key and an important element that should be established to accomplish compact design is a big advantage of HTS SMES. However, the behaviors of insulators for cryogenic conditions in vacuum are virtually unknown. Therefore, active research and development of insulation concerning application of the conduction cooled HTS SMES was needed. In this study, the insulation characteristics at experimented high vacuum and cryogenic similar to running condition of SMES system. Also, investigated about insulation characteristics of suitable some materials to insulator for conduction-cooled HTS SMES. As these results. the basis data was obtained for insulation materials selection and insulation design for development of 600kJ class conduction-cooled HTS SMES.

Characteristics of Insulation Resistance of Cable according to Temperature Rise and Over-Current for Process of the Melting Furnace (용해로의 공정상 온도상승 및 과전류에 따른 케이블의 절연저항 특성)

  • Suk Bong Ko;Doo-Hyun Kim;Sung-Chul Kim
    • Journal of the Korean Society of Safety
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    • v.39 no.2
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    • pp.22-27
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    • 2024
  • The purpose of this study is to explore the trend in insulation resistance values according to temperature and overcurrent by conducting an investigation on the actual condition and experiments on the electrical wiring during the melting furnace process. In addition, the Arrhenius equation is used to determine whether temperatures in the furnace operating process can be applied to the actual field. In the investigation of the actual condition, the insulation resistance started to decrease seven years after replacement, even though cables in oil pump A were replaced in 2010. Both the experimental and theoretical values of the insulation resistance obtained using the Arrhenius equation decreased with an increase in temperature. Errors in insulation resistance (MΩ) values between tests and the Arrhenius equation ranged from ±2 to ±10, demonstrating a high similarity. Results revealed that when the insulation resistance cannot be measured in a manufacturing workplace (quarterly analysis), it can be estimated by partially applying the Arrhenius equation.

Assessment of Insulation Condition in Gas Turbine Generator Stator Windings (가스터빈 발전기 고정자 권선의 절연상태 평가)

  • Kim, Hee-Dong;Yang, Gyu-Hyun;Ju, Young-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.8
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    • pp.1423-1428
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    • 2010
  • The results of off-line and on-line diagnostic tests performed on the stator winding of an air-cooled gas turbine(G/T) generator are reported in this paper. Off-line diagnostic tests included measurements of the ac current, dissipation factor(tan${\delta}$), and partial discharge(PD). Six epoxy-mica capacitors were installed in the three phases of G/T generator for performing on-line diagnostic testing with the turbine generator analyzer(TGA). The TGA showed that the normalized quantity number(NQN) and the PD magnitude($Q_m$) were high in phase A of the stator winding. Internal discharges were generated in phases B and C, and slot discharge occurred in phase A. According to the trend analyses of the NQN and $Q_m$ values available for insulation condition assessment for G/T generator stator windings, it was concluded that phases B and C were in good condition, whereas phase A has been significantly deteriorated.

Fault Prediction & Reliability Estimation of the Traction Motor by the Complex Accelerating Degradation and Condition Diagnosis (견인전동기의 복합가속열화 상태진단에 의한 고장예측 및 신뢰성 평가)

  • 왕종배;김명룡
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.763-766
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    • 2000
  • In this paper, stator form-winding sample coils based on silicone resin and polyimide were made for fault prediction and reliability estimation on the 200 Class insulation system of traction motors. The complex accelerative degradation was performed by periods during 10 cycles, which was composed of thermal stress, fast rising surge voltage, vibration, water immersion and overvoltage applying. After aging of 10 cycles, condition diagnosis test such as insulation resistance & polarization index, capacitance & dielectric loss and partial discharge properties were investigated in the temperature range of 20∼160$^{\circ}C$. Relationship among condition diagnosis test was analyzed to find an dominative degradation factor and an insulation state at end-life point.

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