• Journal of Electrical Engineering and Technology
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• 제3권4호
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• pp.559-565
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• 2008

This study designed a new type of loop antenna that is able to detect partial discharges based on microstrip line technology. In the diagnosis of power cables, partial discharge signals are generally produced at a frequency range less than 100MHz because high frequency PD signals are lost along a propagation path in such cables. The new type of loop antenna sensor has been studied using simulation software known as CST microwave studio version 5.0. In partial discharge measurement experiments, a commercial HFCT sensor was used as a reference sensor. Several experiments were made over HFCT and loop antenna sensors for detecting partial discharges on 22.9kV MV XLPE cable. In this study, we showed the loop antenna designed in this study that can be applied as a commercial HFCT sensor.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1790-1791
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• 2011

In this paper, the diagnosis system for detecting and localizing the neutral wire defect in an energized XLPE power cable is proposed. The neutral wire defect is detectd and localized by the time-frequency domain reflectometry. To extract the reflected signal from the neutral wire defect, the adaptive RLS filtering is introduced. To verify the proposed method, the experiments for detecting and localizing neutral wire defect in active XLPE power cable is conducted.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1385_1386
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• 2009

In this paper, we examined the faulted cable joint through the external form analysis, material analysis, experimental verification and it's cause diagnosis system. It was not observed the voild, sharp material from the external form analysis and material variation. From the experimental verification, the thickness decrease of an insulator decreased ac breakdown strength suddenly and the breakdown traces of the insulator that was damaged by knife displayed elliptic shape. Thus, the faulted cable is assumed to accident that become dielectric breakdown by the deterioration of insulation performance that can happen when work.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.35-40
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• 1997

As demand of electric power are growing and transmission line limited owing to enlargement of the downtown area The eonfidence of underground transmission cable which shows gradual growth are high. It is found whether insulating ability is good or not. In this paper, The exper iment result is shown that the fall of insulating ability and take preventive measure through the analysis of tans, water content, dielectric breakdown voltage, total acid number, volume resistivity , and gas in the oil in an accordance with the characteristic change of oil used very much for insulating oil of cable.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권4호
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• pp.161-165
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• 2006

In this paper, we developed HPF (high pass filter) consists of lumped LC components to decrease the noises that are detected in PD (partial discharge) measuring test, and adapted it to field test. We tested it under laboratory circumstances like the fields, and measured the phase change properties of detected signal in UHF sensor with Lemke Probe and oscilloscope (TDS-3054, Tektronix). As a result, we obtained available data showing the decrease of noises in the experiments with the developed HPF from the joint box of 22.9kV distribution line. The result can be adapted to prevent the degeneration of the XLPE power cable, and to observe and diagnosis the underground power transmission cable at the ultra-high voltage.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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• pp.1511-1512
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• 2006

In this paper, we measured PD signals from artificial surface defects and corona discharges under laboratory circumstances like the fields using both HFCT-sensor and UHF-sensor for MV grade XLPE cable with AMP, spectrum analyzer and oscilloscope. Also, detected signals were analyzed via PRPDA system in this paper. As a result, in this case of HFCT-sensor, the amount of background noise are larger than as compared to UHF-sensor. There is needed some hardware or software or software algorithm removing background noise effectively for diagnosis the underground power transmission cable in the case of HFCT-sensor.

• 한국전기전자재료학회논문지
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• 제27권12호
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• pp.877-882
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• 2014

It has been confirmed that the inner defect of transformer and the perfect diagnosis for aging are closely related to safe electric power transmission system and that the detection of accident and diagnosis technique turn out to be very important issues. Since electric power machinery consists of various kinds of components, however, it is very difficult to make a diagnosis for aging by one parameter. Thus, diagnosis for aging is feasible only through the combination of various parameters. Recently, various expert systems have been developed and applied to diagnosis for aging, but they are not yet reliable enough to apply to the real system. In this paper, XLPE which is ultra high voltage cable insulator material were chosen to investigate the influence of void on insulator material using partial discharge. Obtained data have been processed by PRPD (phased resolved partial discharge) distribution function and K-means. And statistical and cluster distribution of partial discharge have been analysed and investigated.

• 한국공간구조학회논문집
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• 제9권3호
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• pp.67-74
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• 2009

가진력의 영향을 평가하기 위해 이용되는 압전소자와 물체의 변형량을 분석하기 위해 사용되는 광섬유 센서와 변형 게이지는 각종 시험과 실험에 널리 사용되고 있다. 본 연구에서는 케이블 시스템에서 발생한 손상을 검토하기 위해 압전소자와 광섬유센서를 이용하였다. 케이블 시스템은 압축이나 휨이 발생하지 않고 막구조에서 단지 인장력을 분담한다. 그러나 기존의 안전진단법을 이용하여 케이블 시스템의 손상을 판단하는 것은 전체구조의 특이한 구조거동 등으로 검토하기 어렵다. 인장부재에서 케이블의 풀림과 할렬이 발생하면 진동을 유발하기 때문에 압전소자를 케이블의 손상을 검토하기 위해 이용하였으며, 이를 광섬유 센서를 이용한 실험의 결과와 비교하였다. 본 연구는 인장응력 하에 케이블 시스템의 손상을 검토하는 방법을 제안하기 위한 실험적 연구이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.2140_2141
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• 2009

We used the eddy current sensor for a 22.9kV distribution power line insulation cable diagnosis. The insulation cable which is used in the 22.9kV distribution power line is having element wire from 6 to 18. Consequently, currently to ECT applications it has a limit in the distribution power line. We about under producing to apply in pick-up coil forms and the differential total coil form where becomes sum of zero in order to have. From measurement result, partial broken cable was confirmed 500 mV~980 mV changes from normal state.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권4호
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• pp.247-252
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• 1999

In this paper, in order to investigate availability of the OW-PD measurement method which has been proposed as an alternative of AC-PD measurement method to an after laying test and/or diagnosis for the power cable system, partial discharges owing to the needle-type defect integrated into the cable have been measured using AC and OW(Oscillating Wave) voltages. In the AC-PD measurement, the magnitude, phase and pulse number of partial discharges have been changed with the duration of voltage application, which can be analyzed through the relation with the process of the electrical tree initiation and propagation. In addition, the characteristics of partial discharges using OW voltage are appeared to be similar to those in case of AC-PD measurement and to be different with the shapes of electrical tree. From these results, it is concluded that the OW-PD measurement method is available to the tests for the cable system.