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엄주홍(Ju-Hong Eom),이태형(Tae-Hyung Lee),조성철(Sung-Chul Cho) 한국조명·전기설비학회 2008 조명·전기설비학회논문지 Vol.22 No.4
뇌서지 전압이 전파되는 양상은 대상 전원계통과 기기별로 차이를 보인다. 하지만 뇌서지가 유입되는 대상기기를 중심으로 보면 뇌서지 침입경로는 전원선의 두 선간, 전원선과 대지간, 전원선과 PE도체, 중성선과 대지 간 등으로 구분되어진다. 또한 통신기기에서 전원측에서 들어오는 뇌서지 외에 통신선의 선간, 통신선과 대지 간으로 입사 하는 경로가 존재한다. 이 논문은 각각의 경로를 통하여 대상기기에 침입하는 뇌서지에 대해 SPD를 사용한 전원계통의 안전향상 기법 중 독립접지, 공통접지, 바이패스 어레스터를 이용한 접지의 뇌서지 양상을 실증실험을 통하여 분석한 결과를 기술하고 있다. The tendency of lightning surge to propagate is appeared variously depend on the power system and subject equipment of protection. However, looking into the subject equipment with the lightning surge, the invasion route of lightning surge can be divided in between the two lines of power, between the power line and the ground, the power line and the PE conductor, between the neutral line and the ground and the like. In addition, in the event of the communication equipment, there exists the route of lightning surge incoming from between the communication lines, the communication line and the ground in addition to the power lines. In this study, the tendency of propagation of lightning surge penetrated on to the subject equipment is analyzed through the empirical experiment in accordance with the ground method by using the independent ground, common ground and bypass arrester ground for safety improvement in power lines.
Step-up 방식에 의한 송전용 XLPE 모델케이블의 가속열화 수명분석 고찰
엄주홍(Ju Hong Eom),김동규(Dong Kyu Kim),정연하(Yeon Ha Jung),강연욱(Yeon Woog Kang),강지원(Ji Won Kang) 대한전기학회 2021 대한전기학회 학술대회 논문집 Vol.2021 No.10
A new Step-up stress acceleration method, which complements the shortcomings of the constant stress method, was proposed in the stress-life experimental analysis area for power transmission cables, and it was verified that a number of failure data can be obtained and statistical life by stress level is calculated through simulation results.
전류 및 전위 측정선간 상호유도가 접지임피던스에 미치는 영향
嚴柱弘(Ju-Hong Eom),趙成哲(Sung-Chul Cho),李泰炯(Tae-Hyung Lee) 대한전기학회 2008 전기학회논문지 Vol.57 No.7
While a high frequency source is used for measuring the ground impedance, there are several factors having an effect on the measured value. A primary factor of the measurement error is the ac mutual coupling between current and potential test leads. The mutual coupling causes the test current to induce a voltage into the potential test lead that adds to the actual ground potential rise and produces a significant measurement error as the length of the test leads paralleled is prolonged. In order to avoid the mutual coupling, it is recommended that the ground impedance be measured by angled arrangement of test leads. The mutual impedance due to the inductive coupling with an angle of 90° was calculated at 0° by Campbell/Foster Method. With an angle of 180°, the mutual impedance was calculated large value enough to introduce a fairly large margin of error, however, the measured value of ground impedance was close to the value at 90°.
엄주홍,조성철,이태형 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.1
This paper presents the parameters optimization technology for generating the first short stroke lightning current waveform(10/350 μs) which is necessary for the performance tests of components of lightning protection systems, as required under IEC 62305 and the newly amended IEC 62561. The circuit using the crowbar device specified in IEC 62305 was applied to generate the lightning current waveform. To find the proper parameters of the circuit is not easy because the circuit consists of two parts; circuit I, which relates to the front of current waveform, and circuit II, which relates to the tail. A simulation in PSpise was carried out to find main factors related to the front and tail of 10/350 μs. The lightning current generator was developed by utilizing the circuit parameters found in the simulation. In the result of experiments, new parameters of the circuits need to be changed because of the difference between the simulation and the experiment results. Using the iterative method, the optimized parameters of the circuits was determined. Also a multistage-type external coil and a damping resistor were proposed to make the efficiency of generation to enhance. According to the result in this paper, an optimized first short stroke lightning current waveform was obtained.
엄주홍(Ju-hong Eom),조성철(Sung-chul Cho) 한국조명·전기설비학회 2005 한국조명·전기설비학회 학술대회논문집 Vol.2005 No.11월
Surge protective devices can be divided into three categories based on the circuit assembly: a parallel circuit type that considers the surge current amount within the device, a series circuit type that considers the voltage and single circuit type that uses a single element. However, when assembling SPDs, there are many things including function and safety to be taken into consideration because they are directly related to the performance and safety of the device. In this paper, we executed an experimental comparative study of performance and thermal stability of each SPD type using lightning surge generator and thermal image camera.