• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1768-1769
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• 2003

가스절연개폐장치(Gas-insulated Switchgear, GIS)의 예방진단 기술의 한 방법으로, 극 초단파(Ultrahigh frequency) 부분방전(Partial discharge) 센서를 사용하여 결함의 유무를 판별할 수 있다. 그러나 UHF PD 센서에는 부분방전신호 이외에 외부 잡음의 유입 가능성이 크다. 따라서 본 논문에서는 PD 센서 주변 잡음을 측정하기 위하여 $0{\sim}2$ GHz 의주파수영역에서 산지, 도심 지역의 변전소의 위치에 따른 외부 잡음을 측정하였다. 주파수 대역별로 FM 방송, TV 방송, 이동전화, 등의 신호를 판별하였다.

• Journal of information and communication convergence engineering
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• 제21권3호
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• pp.233-238
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• 2023

This study presents a method for identifying partial discharge defects in an eco-friendly gas insulated system using a backpropagation algorithm. Four partial discharge (PD) electrode systems, namely, a free-moving particle, protrusion on the conductor, protrusion on the enclosure, and voids, were designed to simulate PD defects that can occur during the operation of eco-friendly gas-insulated switchgear. The PD signals were measured using an ultrahigh-frequency sensor as a nonconventional method based on IEC 62478. To identify the types of PD defects, the PD parameters of single PD pulses in the time and frequency domains and the phase-resolved partial discharge patterns were extracted, and a back-propagation algorithm in the artificial neural network was designed using a virtual instrument based on LabVIEW. The backpropagation algorithm proposed in this paper has an accuracy rate of over 90% for identifying the types of PD defects, and the result is expected to be used as a reference database for asset management and maintenance work for eco-friendly gas-insulated power equipment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.482-483
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• 2006

배전급 가스절연개폐기(이하 개폐기)에서 발생하는 고장을 예방하기 위해서는 개폐기 내부에서 발생하는 부분방전 신호로부터 방전의 원인을 추정하는 것이 중요하다. 본 논문에서는 개폐기 내부의 결함을 다양하게 모의하여 방전원에 대한 신호 패턴을 분류하고 방전 원인별로 특성을 분석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.447-448
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• 2015

In order to looking for method of detecting inner fault of a 154kV GIT(Gas Insulated Transformer), it was considered that diagnosis partial discharge(PD) in UHF band and that analyze the ingredients of SF6 insulating gas. UHF PD diagnosis that is optimized to GIS was considered unsuitable through checking of inner part of a transformers which PD is detected excessively. The method analyzing the content of six kinds of gas(SOF2, SO2F2, etc)was decided through analysis of chemical degradation and combination process and discharge experiment. With the result applying this method to analyze the content of insulated gas of eighty five Gas Insulated Transformers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마
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• pp.50-54
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• 2000

Recently, the HFPD measurement testing is widely used in partial discharge measurement of HV machines because HFPD measurement testing receives less influence of external noise and has a merit of good sensitivity. Also HFPD testing is able to offer the judgement standard of degradation level of HV machine and can detect discharge signals in live-line. Therefore it is very useful method compare to previous conventional PD testing method and effective diagnosis method in power transformer that requires live-line diagnosis. But partial discharges have very complex characteristics of discharge pattern so it is required continuous research to development of precise analysis method. In recent, the study of partial discharge is carrying out discover of initial defect of power equipment through condition diagnosis and system development of degradation diagnosis using HFPD(High Frequency Partial Discharge) detection. In this study, simulated transformer is manufactured and HFPD occurred from transformer is measured with broad band antenna in real time, the degradation grade of transformer is analyzed through produced patterns in simulated transformer according to applied voltages.

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.344-354
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• 2015

In order to study the development of partial discharge (PD) under typical protrusion defects in gas-insulated switchgear, we applied step voltages on the defect and obtained the ${\varphi}-u$ and ${\varphi}-n$ spectrograms of ultra-high frequency (UHF) PD signals in various PD stages. Furthermore, we extracted seven kinds of features to characterize the degree of deterioration of insulation and analyzed their values, variation trends, and change rates. These characteristics were inconsistent with the development of PD. Hence, the differences of these features could describe the severity of PD. In addition, these characteristics could provide integrated characteristics regarding PD development and improve the reliability of PD severity assessment because these characteristics were extracted from different angles. To explain the variation laws of these seven kinds of parameters, we analyzed the relevant physical mechanism by considering the microphysical process of PD formation and development as well as the distortion effect generated by the space charges on the initial field. The relevant physical mechanism effectively allocated PD severity among these features for assessment, and the effectiveness and reliability of using these features to assess PD severity were proved by testing a large number of PD samples.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권1호
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• pp.5-9
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• 2003

The waveforms of partial discharges (PDs) imply physical and structural properties of PD sources, so analyzing them give us information on the kind of PD sources and the location. Waveforms of PD as a time series function have variable amplitudes but sustain a certain uniform shape, which shows well the characteristics of the waveforms and frequency region. They can also be used as parameters having time and frequency information of PD signals and applied to classification of multiple PDs sources via Artificial Neural Network with back propagation (BP) learning.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1888-1890
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• 2004

현대사회에 들어서면서, 전력수요의 중가와 전력기기산업의 고집적화에 따라 사고시에 발생하는 파급효과가 대형화되는 추세에 있다. 따라서 이를 미연에 방지하기 위한 연구가 각 분야에 걸쳐 활발하게 진행되고 있다. 이에 당사에서는 초고압 계통에서 사용되는 SF6가스 절연 GIS(Gas Insulated Switchgear) 및 Oil-Transformer에서의 부분방전 측정/분석을 위하여 UHF/AE를 이용한 on-line/portable 측정 시스템을 개발하였다. 본 논문에서는 개발/상용화 되어 field에서 사용되고 있는 시스템의 전반에 대하여 설명한다. 또한 철재 선진사와 공동 진행중인 Risk Assessment에 대하여 언급하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1835-1837
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• 2004

The UHF electromagnetic waves excited by PD pulses propagate along the GIS busbar not only TEM mode, but also TE and TM mode. Generally the waves detected by the UHF sensors are those of high order modes and such waves can only propagate the higher than cut-off frequency. In this paper, computed cut-off frequency of 362[kV] GIS by each modes and simulated electromagnetic field of each propagation modes by FEM(Finite Element Method) program. Frequency band of each TEmn/TMmn modes were determinated by simulation results and were discussed optimal position of UHF sensor from this results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기설비전문위원
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• pp.86-89
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• 2006

대상 전력기기와 위치가 정해지지 않은 상태에서 UHF 부분방전 센서의 성능 측정시, 유효높이는 유용한 파라메터이며 이를 용이하게 측정하기 위해서 표준전계 발생장치가 필요하다. 표준전계를 발생을 위해 평행판 전송선로 형태의 TEM Line을 설계 제작하였으며, 제작된 TEM Line의 특성을 살펴보았고, 표준프로브법을 이용하여 TEM Line의 내부 전계를 보정하기위한 실험을 실시하였다.