• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1213-1214
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• 2015

서지보호장치(Surge Protective Device)가 국내에 본격적으로 설치된 것은 산업화의 발전으로 인해 현장 전력시스템의 복잡성과 다양성 및 급격히 변화하고 있는 우리나의 기후변화 때문일 것이다. 전원계통의 전원용서지보호장치(Poser Systems Surge Protective Devices) 및 통신계통의 통신용서지보호장치(Telecommunication Surge Protective Devices)의 설치는 해마다 증가하고 있다. 이에 따른 제품개발도 급속도로 이루어지고 있으며, 과거 몇년 전만해도 서지보호장치에 대한 표준과 시험설비의 이해와 부족으로 인해 표준에 의한 제품검증이 어려웠으나 2013년 제정된 KS 표준(KS C IEC 61643-11)으로 상당수 제조자가 관련인증을 취득하고 있다. 이 논문에서는 KS표준에서 정의하고 있는 열안전성시험에 대한 방법과 결과판정 및 새로운 기준을 제시하고자 한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.156-159
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• 2002

This paper presents an experimental study of the surge response characteristics for the primary winding of a pole transformer and ultimately aims at devising countermeasures against the surge in operating transformer. After applying the impulse voltage to the primary of the 30 kVA pole transformer with single bushing, the voltage waveforms were measured at each tap lead and compared with one another. As a result, the voltage peak of the surge propagating in the primary was decreased in magnitude at a constant rate and somewhat delayed compared to the peak of the applied surge as the tap leads were getting closer to the grounding terminal. The voltage measured at the secondary was not delayed in time, different from that at the primary, and it was about 1/6 according to the turn ratio.

• 전기의세계
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• v.28 no.11
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• pp.45-51
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• 1979

Finte element methods are developed for the initial distribution problems which contain the surge potential circuits of high voltage transformer windings. The initial distribution of surge voltages in transformer windings are useful to the work to a practical engineering basis. However, the conventional methods of analyzing them so far are much complicated for practical designs. In this paper, the ability to solve surge potential field problems underlies the development of descreting methods to a lodal capacitive distribution-coefficients for determing the surge voltage relationship among a set of transformer coils. A practical example-the modeling of an antioscillation shield coil winding and hisercap winding is used to illustrate and evaluate these methods.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.1
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• pp.1-7
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• 2005

This paper describes the lightning surge analysis model of extra high voltage GIS using EMTP. Various lightning current parameters were investigated in order to confirm the impact on the lightning surge analysis such as lightning current amplitude, waveform, size of GIS, tower footing resistance and surge arresters. The multi-story tower model and EMTP/TACS model were introduced for the simulation of dynamic arc characteristics. The margin between the maximum overvoltage and BIL of the GIS was about 10 percent and the margin between the maximum overvoltage and BIL of the transformer was 21 percent.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1688-1690
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• 2002

The unpredictable threat of lightning surge is ever increasing in today's low-voltage power supplies. Thus Surge protection devices for AC mains are more widely used. The false-tripping of the earth leakage breaker (ELB) can be caused by the installation of surge protection devices with MOV. In order to examine the cause of malfunction, the malfunction characteristics of ELBs applied by lightning surge were investigated experimentally. As a result, all of them brought about malfunctions under 7 kV of the impulse voltage. The suitable position of MOV and use of zener diode were suggested to eliminate the problems.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2080-2082
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• 1999

This paper describes the analysis results for the protection of lightning surge at 154 kV substation. We found that the surge arrester is needed at the inlet structure. The maximum overvoltage is 975 kV at the circuit breaker without the surge arrester at the inlet structure. This value can be lower than 600 kV by installing the surge arrestor at the inlet structure. In addition to the incoming surge from transmission line, the shield wire should be considered to prevent the shielding failure by the direct lightning stroke.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05b
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• pp.170-174
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• 2005

The purpose of this study is to design the digital surge counter for lightning arresters. The used detecting method for surges is using the signal of both ends of ZnO varistor. The electronic detecting parts of the digital counter are arranged in outside of main processer for protecting it from noise. The detecting parts change detected signals into small signals. The countermeasures for noises are (1) Shielding (2) Reinforcement of power circuits (3) Cables & Circ1e core (4) Watch-doc & control of input signals.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.15-17
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• 1994

As VCB has many advantages which is an excellent interruption capability, compact structure, easy maintenance and light weight, it has been widely used as a load breaker. But steep-fronted surge voltage due to high frequency extinguishing capability in switching has been occurred. If it impinges into induction motor, it acts on the electrical stress, and causes to deteriorate winding insulation. In this research, in order to protect motor insulation from the steep-fronted reignition surge, the occurring condition, the cause of the reignition surge and the influence of circuit parameters which have been an effect on the occurrence of reignition and multiple reignition surge has been also analyzed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.383-386
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• 1999

Surge arrestor is used for protection of facilities and lines. Recently lots of arresters fatted prematurely In the distribution lines. It is important to know that what the cause of the failures is. This paper presents characteristics of the aged and new 18kV surge arrester. In order to analyse characteristics, we measured leakage current using specialty made leakage current measurement system and also investigated Tan $\delta$ of the arrester and microstructure of the elements. Through the investigation we found that the characteristics among the ZnO elements in an arrester were a little different, It means that the surge arreste can have non-uniform electric field due to the characteristic difference of The each element. Owing to this concentration of the electric field, the localized aging might be proceeded.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.88-91
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• 2003

A fuel spiking test was performed to measure the surge margin of gas turbine engines. The surge marin was mainly determined by the compressors and fuel spiking was used to change the operating point in the compressor characteristic map while speed remained constant. To access the surge margin region different spiking signals were applied by modulations of time(frequency) and fuel flow rate(amplitude). The test results showed good agreements with expected fuel spiking patterns and possibility of further studies.