• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.28 no.6
• /
• pp.379-383
• /
• 2015

Some insulating materials are organized and analyzed with variables to obtain the optimized profile of encapsulated three phase of epoxy barrier which is applied to gas compartment and supporting conductors for high voltage GIS (gas insulated switchgear). The high voltage GIS is used in electrical power system and operating reliability. In this paper, optimization possibility of barrier shape including both electrical insulation performance and mechanical strength, premised on that condition minimizing volume and light weight should be kept for high voltage GIS, could be achieved by analysis simulation. As a result, filling material which is lower permittivity such as $SiO_2$ instead of $Al_2O_3$ properly to the epoxy material, can be improved to increase the electrical insulation performance and mechanical strength for an optimized profile barrier of a high voltage GIS.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.1
• /
• pp.344-354
• /
• 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.

• Transactions on Electrical and Electronic Materials
• /
• v.16 no.6
• /
• pp.323-327
• /
• 2015

In this paper, parameters related with partial discharge (PD) were analyzed in SF₆ gas under AC and DC voltages. Three electrode systems (protrusion on conductor, protrusion on enclosure, and free particle) were fabricated to simulate PD defects in a gas-insulated switchgear (GIS). All electrode systems were filled with SF₆ gas at 0.5 MPa. PD pulses were detected using an oscilloscope and a data acquisition (DAQ) based on IEC 60270. To analyze the PD characteristics under AC and DC voltages, parameters such as discharge inception voltage (DIV), discharge extinction voltage (DEV), pulse magnitude, repetition rate, and T-F map were compared. From the experimental results, PD was revealed to have different characteristics under AC and DC, and these results may be useful for diagnosis of power facilities operated under HVDC.

• Proceedings of the KIEE Conference
• /
• 2008.11a
• /
• pp.368-369
• /
• 2008

현재 국내 중전기 시장은 시장규모에 비해 다수의 기업이 참여하고 있기 때문에, 국내 중전기 업체간 정쟁은 더욱 심화되고 있다. 따라서 국내 중전기 업체가 더욱 발전해 나아가기 위해서는 해외시장 진출 확대를 위한 수출용 전적기기의 개발이 시급하고, WTO 체제하의 시장 개방화 정책에 따른 국내외시장에서의 User의 요구에 부응하는 전력기기 개발이 절실히 요구되어 당사에서는 국책과제로써 IT 기술을 기반으로 하는 245kV Motor-drive형 초고압 GIS를 개발하게 되었다. 금번에 개발된 절연개폐장치는 변전소 자동화라는 세계적 추세에 맞추어 Bay Controller 및 전자식 변성기(NCIT)를 적용하였고, 자체 참고시험을 통해 확보된 피시품을 가지고 국제공인인증기관인 한국전기연구원(KERI)에서 IEC 국제규격에 준하여 그 성능을 검증하였다.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.438-439
• /
• 2011

Substations in Korea are classified into an outdoor steel structure type, an outdoor GIS(Gas Insulated Switchgear) type, an indoor GIS type, an underground GIS type, and a complex GIS type. Before 1970, substations were built in outdoor steel structure types only. In 1980, an 154kV indoor GIS type substation was built for the first time in Pusan. And the first 345kV indoor GIS type substation, the first 765kV full GIS substation were built in 1984 and in 2002 each. In 1998, 154kV indoor type substations were standardized into regular type and urban type which applied steel frames to structures. In 2002, this was re-standardized into five different types in detail. In 2007, hub substations which had high capacity were built in the region of industrial zone and heavy load areas. And 154kV compact substation was developed and standardized by compacting an indoor GIS type substation in 2009. This paper would present a series of substation type transition and application standards for substation types and facility scales.

• Proceedings of the KIEE Conference
• /
• 1992.07b
• /
• pp.626-628
• /
• 1992

GCB(Gas Circuit Breaker) and GIS(Gas Insulated Switchgear) using $SF_6$ are worldwidely applied over 72.5KV classes. It Is known that $SF_6$ gas has the most superior characteristics among the extingushing and insulating media. Our Company has produced GCB and GIS from early 1980's and at present, we are producing 362KV 40KA class which is the highest voltage in our country. According to change KEPCO's standards (ESB standards), our company has redeveloped and tested for all productions type from 1989. During redeveloping, we largely contribute raise reliability of power system, through all the more improvement for performance and quality of manufactures. One of them, we developed 170KV 50KA GCB with common three-pole operating mechanism and sucessfully completed test of KERI under KEPCO presence, at first in our country. Thus, we announce the outline of it.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1400_1401
• /
• 2009

In this paper describes the comparisons of the surface flashover characteristics according to the change of the insulation media by experimental GIS(Gas Insulated Switchgear) chamber in accordance with change of pressure(P) and electrode distance(d). The using insulation medias are $SF_6$, Dry-Air, I-Air(Imitation Air, $N_2$ : $O_2$ = 79[%] : 21[%]), $N_2:O_2$ mixture gas and pure $N_2$. In this study, in order to compare the properties $SF_6$ and order insulation gas, we investigated the properties of the various insulation media with a knife to knife electrode under ac high voltage application. The gas pressure was changed from 1 to 5[atm]. as a result, it was found that dielectric strength is $SF_6$ > I-Air > Dry-Air and the best environmental preservation gas is Dry-Air.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.58 no.4
• /
• pp.516-520
• /
• 2009

Atmosphere Plasmas of Gas Discharge (APGD) have been used in plasma sources for material processing such as etching, deposition, surface modification, etc. This study is to investigate and understand the fundamental plasma discharge properties. Especially, $SF_6/N_2$ mixed gas would be used in power transformer, GIS (Gas insulated switchgear) and so on. In this paper, we developed a one dimensional fluid simulation model with capacitively coupled plasma chamber at the atmosphere pressure (760 [Torr]). 38 kinds of $SF_6/N_2$ plasma particles which are an electron, two positive ions (${SF_5}^+$, ${N_2}^+$), five negative ions (${SF_6}^-$, ${SF_5}^-$, ${SF_4}^-$, ${F_2}^-$, ${F_1}^-$), thirty excitation and vibrational particles for $N_2$ were considered in this computation. The $N_2$ gases of 20%, 50%, 80% were mixed in $SF_6$ gas. As the amount of $N_2$ gas was increased, the properties of electro-negative plasma moved toward the electro-positive plasma.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.20 no.9
• /
• pp.103-109
• /
• 2006

This research is contents about output characteristic of optic current sensor that use faraday effect. optic current sensor used in an experiment is consisted of three parts.(1) Source of light used laser diode of 1310[nm].(2) Sensor section manufactured circularly according to gas insulated switchgear. And $9/125[{\mu}m]$ standard single mode optical fiber for communication was installed winding 20 [turn] on sensor section core surroundings of diameter 31 [cm].(3) Electrical signal of PD(Photo detector) is collected using NI company's 16bit DAQ board via terminal block. Collected data analyzed by different three signal processing methods. NI company's $Labview^{TM}$ was used to signal processing software. As a result, In signal processing of optic current sensor, we could know that noise greatly more influences the error generation than fluctuation of light intensity. also, 1 class CT(current transformer) manufacture that have error rate less than 1[%] was available by removing these

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.64 no.9
• /
• pp.1374-1379
• /
• 2015

Time Domain Reflectometry(TDR) using microwave bands, including broadband spectrum that occurs at the range of rates that start between partial discharge position it easier to make the techniques that could be measured. Partial discharge in the Gas Insulated Switchgear(GIS), the dielectric constant in the band more than GHz different the insulating material if you want to organize, and the insulating material regardless of how partial discharge position in the SF6 gas Partial Discharge by applying the heritability estimated its position, but the position error occurred about 23 percent of the existing way, correct in not suitable location tracking the outbreak PD. This technique the rate of other dielectric that make up the power apparatus heterology is measured at the function to slow the progression of the electromagnetic waves apart by calculating the partial discharge as the location, A simple way to track. Dielectric using other methods proposed new structure can calculate the speed of heritability PD is occurring can measure.