• Title/Summary/Keyword: PD monitoring

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Development of Insulation Diagnosis System by On-Line Partial Discharge Measurement of Generator Stator Windings (발전기 고정자 권선의 운전중 부분방전 측정에 의한 절연진단 시스템 개발)

  • Shin, Byoung-Chol;Hwang, Don-Ha;Kim, Yong-Joo;Kim, Jeong-Woo
    • Proceedings of the KIEE Conference
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    • 1999.11d
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    • pp.1025-1027
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    • 1999
  • Recently, many researches on a diagnosis of stator winding insulation of large generators are reported. They mostly utilize a trend analysis of Partial Discharge (PD). In this paper, a novel on-line monitoring system for an insulation diagnosis is proposed. This system obtains the parameters such as Maximum Partial Discharge Magnitude (QM), Normalized Quantity Number (NQN) and Dynamic Stagnation Voltage (DSV) by continuous on-line monitoring of winding insulation. It is capable of diagnosing the insulation condition by analyzing the trend of PD and utilizing the database built by the system.

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Development of On-line PD Monitoring System for High Voltage Power Cable System (초고압 선로 부분방전 On-line 모니터링 시스템 개발)

  • Kim, Choong-Sik;Lee, Chang-Young;Kim, Won-Nyeon
    • Proceedings of the KIEE Conference
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    • 2005.07e
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    • pp.58-60
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    • 2005
  • 초고압 선로에 대한 풍부한 진단 경험과 축적된 Know-how를 바탕으로 선로의 이상유무를 원격으로 진단, 감시하는 On-line PD Monitoring System을 개발하였다. 초고압 선로의 이상 유무를 활선상태에서 정밀하게 진단할 수 있는 전기적인 측정방법으로 부분방전이 유일하다. 그러나 부분방전 신호는 미약하고 주위 노이즈와 구분이 어렵기 때문에 측정 뿐만 아니라 분석하기가 어렵다. 부분방전 측정 장비는 이러한 노이즈를 효과적으로 제거하고 측정된 신호를 의미있는 정보로 가공하여 사용자에게 제공해 주어야 한다. 본 논문에서는 이러한 조건들을 충족하는 고성능의 원격 진단시스템에 관하여 서술하였다.

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On-Line Insulation Diagnosis Techniques for Stator Winding of Rotating Machines (회전기 고정자 권선에서의 운전 중 절연열화 진단기법)

  • 윤대희;황돈하;신병철;김용주;이광식
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2000.11a
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    • pp.89-93
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    • 2000
  • Recently many research activities on the diagnosis of stator winding insulation of large rotating machines have been reported. Capacitive couplers are widely used as sensors for on-line partial discharge (PD) measurement of high voltage rotating machines. This paper presents laboratory test to compare Stator Slot Coupler (SSC), Resistance Temperature Detector (RTD), 80 [pF] coupler and 500 [pF] coupler for on-line PD measurement of rotating machines. And a novel on-line monitoring system for an insulation diagnosis is proposed.

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Application of SA-SVM Incremental Algorithm in GIS PD Pattern Recognition

  • Tang, Ju;Zhuo, Ran;Wang, DiBo;Wu, JianRong;Zhang, XiaoXing
    • Journal of Electrical Engineering and Technology
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    • v.11 no.1
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    • pp.192-199
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    • 2016
  • With changes in insulated defects, the environment, and so on, new partial discharge (PD) data are highly different from the original samples. It leads to a decrease in on-line recognition rate. The UHF signal and pulse current signal of four kinds of typical artificial defect models in gas insulated switchgear (GIS) are obtained simultaneously by experiment. The relationship map of ultra-high frequency (UHF) cumulative energy and its corresponding apparent discharge of four kinds of typical artificial defect models are plotted. UHF cumulative energy and its corresponding apparent discharge are used as inputs. The support vector machine (SVM) incremental method is constructed. Examples show that the PD SVM incremental method based on simulated annealing (SA) effectively speeds up the data update rate and improves the adaptability of the classifier compared with the original method, in that the total sample is constituted by the old and new data. The PD SVM incremental method is a better pattern recognition technology for PD on-line monitoring.

Fabrication and Characterization of Portable Electronic Nose System using Gas Sensor Array and Artificial Neural Network (가스센서 어레이와 인공 신경망을 이용한 소형 전자코 시스템의 제작 및 특성)

  • 홍형기;권철한;윤동현;김승렬;이규정
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.99-102
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    • 1997
  • An electronic nose system is an instrument designed far mimicking human olfactory system. It consists generally of gas (odor) sensor array corresponding to olfactory receptors of human nose and artificial neural network pattern recognition technique based on human biological odor sensing mechanism. Considerable attempts to develop the electronic nose system have been made far applications in the fields of floods, drinks, cosmetics, environment monitoring, etc. A portable electronic nose system has been fabricated by using oxide semiconductor gas sensor array and pattern recognition technique such as principal component analysis (PCA) and back propagation artificial neural network The sensor array consists of six thick film gas sensors whose sensing layers are Pd-doped WO$_3$ Pt-doped SnO$_2$ TiO$_2$-Sb$_2$O$_3$-Pd-doped SnO$_2$ TiO$_2$-Sb$_2$O$_{5}$-Pd-doped SnO$_2$+Pd filter layer, A1$_2$O$_3$-doped ZnO and PdCl$_2$-doped SnO$_2$. As an application the system has been used to identify CO/HC car exhausting gases and the identification has been successfully demonstrated.d.

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Development and Site Evaluation of the On-line Partial Discharge Measuring System on the 13 kV Class Stator Windings for Hydro Generator (13 kV급 수력발전기 고정자 권선용 On-line 부분방전 측정 시스템 개발 및 현장적용 평가)

  • Sun, Jong-Ho;Hwang, Don-Ha;Yun, Young-Ho;Shin, Byoung-Chol;Oh, Bong-Keun;Kang, Dong-Sik
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.4
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    • pp.189-198
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    • 2006
  • In order to improve the reliability of stator windings for hydro generators, it is necessary to detect the defective point and life assessment of the high voltage windings. Especially the on-line partial discharge (PD) test provides the ability to monitor effects, such as slot discharge, internal discharge, and end-winding discharge without interrupting generators, this method has been proven the major testing technology in high voltage rotating machines nowadays. The purpose of this paper is to describe the method of the on-line PD measurement on stator windings for hydro-generator with 13 [kV] class ceramic coupler (CC), on-line PD measuring system, terminal box, and index parameters. Also, the developed PD measuring system and 13 [kV] class CC were installed Daechung-dam generator #2. It was found that this installed sensor and system had good electrical characteristics to detect PD activity during the operating condition with its detection frequency band is between several and several tens MHz.

Assessment of 23 kV Capacitive Coupler for On-line Partial Discharge Measurements

  • Jeong, J.Y.;Kang, D.S.;Sun, J.H.;Heo, J.C.;Park, C.H.
    • Journal of Electrical Engineering and Technology
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    • v.4 no.1
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    • pp.123-130
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    • 2009
  • The partial discharge (PD) measurement is a very effective method to assess the winding insulation condition of high-voltage machines, since most of the insulation failure processes are directly or indirectly caused by PD. On-line PD measurements, which can detect insulation defects of winding in the early stages on rotating machines in operation, have been accepted as the most important technique. The epoxy mica capacitive coupler is currently and extensively used for on-line detection of PD pulses of high-voltage rotating machines. To evaluate the feasibility of developing a capacitive coupler that is easier to manufacture at a lower cost compared to epoxy mica couplers, a 100pF capacitive coupler made of ceramic material is designed, fabricated and tested for on-line PD measurements of 23 kV electrical machines. A series of electrical tests and accelerated aging tests are performed on the ceramic coupler to evaluate the performance requirements, long-term reliability and thermal stability for in field application. The test results show that the newly developed ceramic coupler provides equal and improved performance at a lower cost compared to epoxy mica couplers, and estimated voltage life is anticipated to surpass 100 years.

A Study of Performance Characteristics for Electronic Personal Dosimeters in Photon and Electron Radiation Field (광자 및 베타 방사선에 대한 전자개인선량계의 성능특성연구)

  • Kim, Hyun-Ki;Kim, Bong-Hwan;Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.22 no.2
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    • pp.85-95
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    • 1997
  • TLD and film badges have been traditionally used as formal dosimeters in personal monitoring and are still most widely used. Recently, electronic personal dosimeters based upon Si diode or miniature G-M tube were developed and are getting attractions due to their merits of active nature ; indication of dose rates and the commutative dose, and facilitation of record keeping and radiological control. Response characteristics of the electronic dosimeters including reproducibility, accuracy, linearity, energy and angular dependencies, detection threshold, and response time were examined for three commercial types ; EPD2, STEPHEN6000, and PD-3i. The results were compared with the relevant requirements of IEC standards and Ontario Hydro standards to conclude that their general performances were good. Some specific deficiencies, e.g. incapability of shallow dose measurement of STEPHEN6000, and PD-3i, however, should be corrected to be used as a formal dosimeter.

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Application of Joint Electro-Chemical Detection for Gas Insulated Switchgear Fault Diagnosis

  • Li, Liping;Tang, Ju;Liu, Yilu
    • Journal of Electrical Engineering and Technology
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    • v.10 no.4
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    • pp.1765-1772
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    • 2015
  • The integrity of the gas insulated switchgear (GIS) is vital to the safety of an entire power grid. However, there are some limitations on the techniques of detecting and diagnosing partial discharge (PD) induced by insulation defects in GIS. This paper proposes a joint electro-chemical detection method to resolve the problems of incomplete PD data source and also investigates a new unique fault diagnosis method to enhance the reliability of data processing. By employing ultra-high frequency method for online monitoring and the chemical method for detecting SF6 decomposition offline, the acquired data can form a more complete interpretation of PD signals. By utilizing DS evidence theory, the diagnostic results with tests on the four typical defects show the validity of the new fault diagnosis system. With higher accuracy and lower computation cost, the present research provides a promising way to make a more accurate decision in practical application.

Flashover Prediction of Polymeric Insulators Using PD Signal Time-Frequency Analysis and BPA Neural Network Technique

  • Narayanan, V. Jayaprakash;Karthik, B.;Chandrasekar, S.
    • Journal of Electrical Engineering and Technology
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    • v.9 no.4
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    • pp.1375-1384
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    • 2014
  • Flashover of power transmission line insulators is a major threat to the reliable operation of power system. This paper deals with the flashover prediction of polymeric insulators used in power transmission line applications using the novel condition monitoring technique developed by PD signal time-frequency map and neural network technique. Laboratory experiments on polymeric insulators were carried out as per IEC 60507 under AC voltage, at different humidity and contamination levels using NaCl as a contaminant. Partial discharge signals were acquired using advanced ultra wide band detection system. Salient features from the Time-Frequency map and PRPD pattern at different pollution levels were extracted. The flashover prediction of polymeric insulators was automated using artificial neural network (ANN) with back propagation algorithm (BPA). From the results, it can be speculated that PD signal feature extraction along with back propagation classification is a well suited technique to predict flashover of polymeric insulators.