• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.10
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• pp.2000-2004
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• 2009

In general, for the condition monitoring of a power transformer using the UHF PD measuring technique, detection of any partial discharge, identifying the defect in the transformer and locating the insulation defect are necessary. In this paper one of the most frequent detects which can result in turn to turn fault in power transformer was examined for identifying the defect. In order to model the defect, as a discharge source, a partial discharge cell was used for experimental activity. Magnitude of electromagnetic wave signals and corresponding amount of apparent discharge were measured simultaneously against phase of applied voltage to the discharge cell. Frequency range and phase resolved partial discharge signals were measured and analyzed. The results will be contributed to build the defect database of power transformer and to decrease the occurrence of transformer faults.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.9
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• pp.1392-1401
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• 2017

In this study, the design methodology of pattern classification is introduced for avoiding faults through partial discharge occurring in the power facilities and local sites. In order to classify some partial discharge types according to the characteristics of each feature, the model is constructed by using the Radial Basis Function Neural Networks(RBFNNs) and Particle Swarm Optimization(PSO). In the input layer of the RBFNNs, the feature vector is searched and the dimension is reduced through Principal Component Analysis(PCA) and PSO. In the hidden layer, the fuzzy coefficients of the fuzzy clustering method(FCM) are tuned using PSO. Raw datasets for partial discharge are obtained through the Motor Insulation Monitoring System(MIMS) instrument using an Epoxy Mica Coupling(EMC) sensor. The preprocessed datasets for partial discharge are acquired through the Phase Resolved Partial Discharge Analysis(PRPDA) preprocessing algorithm to obtain partial discharge types such as void, corona, surface, and slot discharges. Also, when the amplitude size is considered as two types of both the maximum value and the average value in the process for extracting the preprocessed datasets, two different kinds of feature datasets are produced. In this study, the classification ratio between the proposed RBFNNs model and other classifiers is shown by using the two different kinds of feature datasets, and also we demonstrate the proposed model shows superiority from the viewpoint of classification performance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.8
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• pp.1436-1441
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• 2016

Currently, partial discharge diagnosis in the field of prevention applied technology and diagnostic equipment is a possible strong limit to remove the noise generated by external or internal I still have one unreliable diagnosis. This technology is the noise removal from signal the time lag analysis algorithms technique is applied by a fundamental. Increasing the reliability in terms of technology spectrum frequence of analysis method for by applying the acquisition through the position of the frequency content and sources of traffic lights partial discharge of the acquisition of signal analysis to judge whether a way diagnosis the environment of the scene, and conditions. Partial discharge signal and make the discharge while building blocks were found through the Analysis. Spectrum frequence of Analysis and wide discharge part, to be more precise, in line with the various functions, including the analysis technique band. Diagnosis and comes up with advanced technology that can detect the presence of a position. This method is portable single device developed for maintenance and mobility and ease and convenience of getting caught by discharge of the pattern analysis and position detection method suitable for a new diagnosis will suggest.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.8
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• pp.394-400
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• 2001

This paper describes an application of the on line partial discharge measurement method in operating transformer. In the operating transformer, the partial discharge signal may be superimposed by radio intereference voltage(RIV) and pulse shaped noise signals generated by external corona. The partial discharge quantity showed about 3,800pC due to very high sinusoidal interferences at the measuring impedance terminal of the transformer bushing tap. In order to reject these noises, this paper applied RIV filter, band-pass filters and noise gating method. The resulting measuring sensitivity was improved from 3,800pC to 160pC.

• KIEE International Transactions on Electrophysics and Applications
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• v.2C no.5
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• pp.239-245
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• 2002

In this work, in order to realize the possible defects at the cable joint interface, four different types of artificial defects are provided : conducting, insulating substances, void and scratches. The analysis related to the PD patterns has been performed by means of conventional Phase Resolved Partial Discharge Analysis (PRPDA) and Chaotic Analysis of Partial Discharge (CAPD) as well which was proposed by our previous communication. As a result, it could be pointed out that each defect has shown particular characteristics in its pattern respectively and that the nature of defect causing partial discharge could be identified more distinctively when the CAPD is combined with the conventional statistic method, PRPDA.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.102-102
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• 2010

A purpose of this paper is to recognize partial discharge pattern for cable insulation. The classification of PD sources was widely studied for two decades. this research sought to use the partial discharge detection method, and to diagnose the interface of cable, which is deemed vulnerable of cable systems. A research abalyzed faults that can occur in the interface of cable joint as well as accident mechanisms, manufactured test 22.9kV CNC cable, invented artificial faults and carried out partial discharge detection experiments. As a result, various PD pattern along defect measured and distinguished.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1778-1780
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• 1996

In this paper, we describe the partial discharge measurement with measuring impedance to have two wide frequency band transformers(filters) in the oil-paper and air insulation. The measuring impedance consists of high and low limiting frequency transformers. This measuring impedance could be measured the partial discharge current wave. We have the results that the amplitude partial discharge pulse ratio of low limiting frequency tranformer to high limiting frequency one is varied in the condition(in oil-paper insulation and air) to generate partial discharge.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1026-1031
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• 2016

Neat Epoxy, nano alumina composites, micro alumina composites and multi-nano alumina composites were prepared and experiment were performed to measure their partial discharge resistant characteristics. The partial discharge resistance obtained for the microcomposites, nanocomposites and multi-nanocomposites are compared with those of unfilled epoxy and with GDE amount for surface modifier. It was observed that compare multi-nano alumina composites to micro alumina composites, the partial discharge resistance to degradation gets improved considerably. The improvement in the degradation resistance is attributed to the interface intension between the nano alumina composites and GDE, micro alumina and epoxy neat.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.283-286
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• 1996

A signal generated by partial discharge in low density Polyethylene (LDPE) and cross- linked polyethylene (XLPE) has been detected by ultrasonic sensors. The observed signal is analysed with the quantity of partial discharge, number of peaks, and energy ($\Sigma$y$^2$). It was found that signals between LDPE and XLPE are quite different and that the signal of XLPE has very long duration time and rising time, and that the quantity of partial discharge of XLPE is saturated. It was also found that tree retardant XLPE (TR-XLPE) has lower quantity of partial discharge, number of peaks, and energy than naturalal XLPE.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2277-2279
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• 1999

We have investigated the characteristic analysis of ultrasonic in case of occurring partial discharge in experimental steel chamber. This study presents the discriminative method of partial discharge by optimum threshold value. We have carried out the experiments of measuring partial discharge numbers between ultrasonic sensor and transducer with changing distance and barrier inside steel chamber. After the measured data were trasformed A/D conversion by GPIB, we used the optimum method of threshold value for counting numbers of partial discharge.