• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.3
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• pp.229-235
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• 2012

This paper dealt with the fabrication of a partial discharge (PD) analyzer for insulation diagnosis of power facilities like transformers, cables and gas-insulated switchgears. An analytic algorithm for the phase (${\phi}$), the magnitude (q), and the pulse count (n) of PD pulse was designed and a time-frequency (TF) map algorithm was applied in the system to eliminate noises by analyzing the time and the frequency component of signals. All the algorithms were operated by a LabView graphical program. The detection circuit consists of a coupling capacitor, a detection impedance, and a low noise amplifier. A plane-plane and a point-plane electrode system were fabricated to simulate different types of insulation defects. In the experiment, we could easily understand the characteristics of PD pulses using the prototype PD analyzer.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1465-1466
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• 2006

The monitoring and diagnosing technique for lightning arresters is important to assure the reliability of power supply in GIS-substation. In this paper, we described the implementation of an expert system for GIS arrester facilities. The proposed system consists of a data acquisition module (DAM), a wireless communication module, and a personal computer. The DAM detects system voltages, total leakage currents and its harmonic components, and includes an algorithm to calculate the resistive leakage current by the principle that the magnitudes of resistive leakage current are equal at the same level of the system voltage applied to the arrestor. Also, we designed a surge event detection circuit which can acquire the date, the polarity, and the amplitude of surge events. All the acquired data are transmitted after correction by many algorithms to the remote station through the ZigBee protocol. The expert system is based on the Jave Expert System Shell (JESS) and make more reliable decision by using an exclusive inference process.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.30 no.1
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• pp.96-101
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• 2016

In this paper, We investigate the number of 795 transformer in the private electrical facilities and analyze the annual load factor. The results show that the annual load factor of transformer is 20.16% in manufacturing industry, education services(school) is 9.59%, retail and wholesale services is 19.68%, resort and leisure industry is 10.93%, office building is 13.10%, and apartment houses is 14.69%. Education services, resort and leisure industry are being operated with a very low annual load factor. The relatively small capacity of less than 500kVA transformer also been analyzed that is being operated with a low load factor. Therefore, In order to minimize the power loss of the transformer, it is advisable to complement the Transformer Efficiency Management system to be designed the efficiency is good transformer when the load is low. Analysis results will be used as the basis for the provision of transformer efficiency management system and be used High-efficiency transformers promotion system.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1110-1111
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• 2007

These days, the concerns about maintenance and repair of electric facilities for stable and reliable electric power supply are increasing day by day. Because, we can have enormous damages economically and socially from a problem of the facilities, no matter how it is a small one. Especially, electric facilities in our country had been built abruptly from 40 years ago, so it can be thought that here are great amount of old facilities that must be repaired or replaced with new one, and the number would be increased time by time. On this situation, many researchers are studying the efficient and reliable method of maintenance for electric facilities and the results are applied on the facilities gradually by growing interests of operators and managers of the facilities. In this paper, the IED(Intelligent Electronic Devices) for Diagnosis system of electric machines are described. It takes analog data from a sensing device and operates digital processor to get a optimum digital data for diagnosis system. Now, this device is applied on several high voltage substations to diagnose and maintain GIS. Brief schematic of total diagnosis system and the construction of the IED are included in this paper.

• Journal of the Korean Institute of Gas
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• v.25 no.4
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• pp.57-62
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• 2021

In this study, risk assessment was conducted in case of leakage of storage facilities (tube trailer) using the HyKoRAM program developed through international joint research. The high-pressure gas facilities in the hydrogen filling station are divided into four main categories: storage facilities (tube trailers), processing facilities (compressors), compressed gas facilities, and filling facilities (dispensers). Among them, the design specifications of the tube trailer, which is a storage facility, and the surrounding environmental conditions were reflected to construct an accident scenario with previously occurring accidents and potential accidents. Through this, we identify the risks of storage facilities at hydrogen refueling stations and suggest measures to improve the safety of hydrogen charging stations.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.2 no.4
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• pp.28-41
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• 2003

A micros-strip ring patch antenna with ultra wide band characteristics is presented. The proposed antenna is designed by a modified form of the annular ring patch antenna with modified microstrip feedline. The designed antenna gives 5.6GHz bandwidth with regular radiation pattern from 4.4GHz to 12.0GHz for -10dE return loss or VSWR of less than 2.0 in simulation, which is also excellently agreed with the measured data.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.237-242
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• 1998

Salt accumulation is frequently experienced in soils under protected cultivation. Since protected cultivation does not have rainfall and resulting infiltration, salt accumulation in the soils is inevitable. In this study, analyzed were chemical charecteristics of soils under protected cultivation to investigate the factors which may contribute the salt accumulation. Soil samples were collected from 99 protected cultivation facilities around An-sung Gun, Gyungki-Do and analyzed for electrical conductivity, pH, organic matter con-tents. The results showed that there was no significant trend of changes in electrical conductivity and pH along cultivation years. the only factor influencing salt accumulation was irrigation type. Soils in facilities using drip irrigation showed higher electrical conductivity than those using diversion-hose type irrigation.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.223-227
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• 2004

False-tripping of MCCB(Molded Case Circuit Breaker) and ELB(Earth Leakage Circuit Breaker), using to protect overload and ground-fault accidents in power system raise direct and indirect losses like as information loss, facilities damage, slipup of goods production in industry place. Cause of false-tipping of MCCB and ELB is various and cause analysis of false-tripping is mostly made up by inference because trip is not reappeared. This paper investigated and analyzed causes and influences of false-tripping of MCCB and ELB by making up a question to safety managers of two hundred and eighteen electrical facilities for private use. Also, the necessity of experimental study on the effect of harmonics on false-tipping of MCCB and ELB was presented.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.1 no.1
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• pp.65-72
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• 2002

본 논문에서는 인터넷 가전제어를 위한 전력선 통신망 채널 특성 추정 기법을 제시하였고 실 거주 댁내 전력선 통신망의 채널 특성을 실측하여 통신 신뢰도를 평가하였다. 전력선 통신 기능을 내장한 동일 모델의 네트워크 가전제품 4종(에어컨, 냉장고, 세탁기, 전자렌지)을 실 거주 가정 100가구에 설치하여 전력선 통신망의 통신 신뢰도를 평가하였다. 통신 신뢰도의 평가 결과 통신 신뢰도가 90%이상이 나타나는 것을 확인하였다. 이것은 PLC모뎀이 장착된 가전제품의 활용과 고밀도 아파트 주거 지역에서 인터넷 가전제어를 위한 서비스가 상업적으로 이용할 수 있는 근거를 뒷받침한다고 할 수 있다.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.15-18
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• 2009

In recent years electric devices and telecommunication facilities were often damaged by surge generated lightning discharge. When the service was interrupted by failure of electrical devices due to surge the social loss is very enormous. Therefore in order to protect electrical systems against lightning, SPDs(Surge protective device) have been used But damaged SPDs often make some troubles like fire and interrupt of service. In this work, 3rd harmonic leakage current defection method was applied as the diagnosis of SPD degradation and the effectiveness of this method was verified by field survey.