• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.616-619
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• 2004

Lightning surge damages of low voltage equipments in building are increasing due to increase in electrical and communication networks in the information-oriented society. And electronic equipments contained electrical circuits with semiconductor are very weak against lightning surge. The surge protective devices for electronic circuit in electronic equipments and AC power lines are becoming more widely. To achieve effective method of surge protection, there are needs for correlation between lightning surge protective effect of electronic equipment and installation method of surge protective device. This paper describes as a result of experiments for correlation between lightning surge protective effect and installation method of surge protective device.

• Proceedings of the KIEE Conference
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• 2005.11a
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• pp.90-92
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• 2005

Lightning surge damages of low voltage equipments in building are increasing due to increase in electrical and communication networks in the information-oriented society. And electronic equipments contained electrical circuits with semiconductor are very weak against lightning surge. The surge protective devices for electronic circuit in electronic equipments and AC power lines are becoming more widely. To achieve effective method of surge protection, there are needs for correlation between lightning surge protective effect of electronic equipment and installation method of surge protective device. This paper describes as a result of experiments for correlation between lightning surge protective effect and installation of surge protective device and Earth Leakage Breaker.

• Proceedings of the KIEE Conference
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• 2004.11d
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• pp.40-42
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• 2004

Electronic equipments made from electrical circuits with small-sized semiconductor are very weak against lightning surge. So, electronic equipments is protected by SPD(surge protective devices) such as Zno varistor. The SPD protect electronic circuit in electronic equipments and AC power lines from the lightning surge. Therefore to achieve effective method of surge protection, there are needs for correlation between lightning surge protective effect and installation method of surge protective device. Therefore this paper describes as a result of experiments for correlation between lightning surge protective effect and installation method of surge protective device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.658-661
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• 2004

Lightning surge damages of low voltage equipments in building are increasing due to increase in electrical and communication networks in the information-oriented society And electrical circuits with semiconductor are very weak against lightning surge. To achieve effective method of surge protection on low voltage lines, there are needs for the relationship between propagation aspects of lightning surge and arrangement of indoor wire. This paper describes the experimental study on the relationship between them. This result may be raw data for establishment of surge protection system.

• Proceedings of the KIEE Conference
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• 2005.11c
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• pp.80-82
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• 2005

Lightning surge damages of low voltage equipments in building are increasing due to increase in electrical and communication networks in the information-oriented society. And electrical circuits with semiconductor are very weak against lightning surge. To achieve effective method of surge protection on low voltage lines, there are needs for the relationship between propagation aspects of lightning surge and arrangement of indoor wire. This paper describes the experimental study on the relationship between them. This result may be raw data for establishment of surge protection system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.8
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• pp.96-101
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• 2012

A surge protection device of the metal oxide varistor(MOV) has been commonly used for preventing electrical damage in many electronic equipments. The MOV has a property that leakage current is increased and might be permanently damaged when it is exposed continuously to the electrical stresses such as lightening surges. In this paper, we propose a novel surge protection circuit adopting a silicon controlled rectifier(SCR) in the traditional protection circuits using the MOV device simultaneously. When lightning surges are injected to the proposed circuit, the MOV lets the surge pulses bypassing through the ground at first up to the level that SCR begins to operate. Above the threshold level of turning on the SCR, the SCR operates bypasses large surge currents to the ground. Proposed circuit was verified with a leakage current experiment and PSpice circuit simulations under the repeated surge injection environment.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.289-292
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• 2008

This paper describes the electrical characteristics of the ZnO surge arrester according to the variation of surrounding conditions. To investigate the characteristics of degraded ZnO surge arrester, 8/20 [${\mu$s], 2.5 [kA] impulse currents were applied to the ZnO surge arrester to be test. To present the effect of the surrounding con야tions, the leakage currents of ZnO surge arrester were measured to the surrounding temperature and wet conditions. As a result, the increase of ambient temperature causes the increase of resistive leakage current of ZnO surge arrester. Also, in the wet test, the outside leakage current through the ZnO surge arrester housing is much larger than the intrinsic leakage current.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.279-281
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• 1996

This paper deals with the two stage surge protection device by using varistor and LC low pass filter. Recently varistor alone has been used with overvoltage protection devices for the AC power mains and has same problems associated with high remnant voltage and noise. In this work, in order to improve the cutoff performance of surge protection device, the lightning surge protection device having two stage hybrid circuit for an AC single phase mains was designed and fabricated. Operation characteristics and surge clamping performance of the surge protection device in an $8/20{\mu}s$ surge current are investigated. As a consequence, it is found that the proposed two stage surge protective device for AC power mains has a variety of advantages such as a smaller clamping voltage, high frequency noise reduction and large clamping capacity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.2
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• pp.130-134
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• 2020

Metal oxide varistors (MOVs) protect circuits and devices from transient overvoltages in electric power systems. However, a MOV continuously deteriorates owing to manufacturing defects or repetitive protective operations from transient overvoltages. A deteriorated MOV may result in a short circuit or a line-ground accident. Previous studies focused on the analysis of deterioration mechanisms and condition diagnosis techniques for MOVs owing to their recent growth of use. An accelerated deterioration experiment under the same conditions in which a MOV operates is essential. In this study, we designed and fabricated a surge generator that can apply a surge current to a MOV connected to AC mains. The coupling network operates at a low impedance against the surge current from the surge generator and transfers the surge current to the MOV under test. It also acts as a high impedance against AC mains for the AC voltage not to be applied to the surge generator. The decoupling network operates at a high impedance against the surge current and blocks the surge current from AC mains. It also acts as a low impedance against AC mains for the AC voltage to be applied to the MOV under test. The prototype surge generator can apply the 8/20 us up to 15 kA on AC voltages in the approximate range of 110~450 V, and it fully operates on a LabVIEW-based program.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.2
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• pp.190-195
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• 2013

Vacuum circuit breaker(VCB) has been widely used for interruption of load current and fault current for high voltage motor in the industrial field. Its arc extinguishing capability is excellent compared to other breakers. But it has the potential to cause multi reignition surge by high extinguishing capability. Surge voltage is generated by the opening and closing of VCB. Multi reignition surge of VCB is steep-fronted waveform. It may have a detrimental effect on the motor winding insulation. So, most of users install a protection device to limit steep-front waveform at the motor terminal or breaker side. So, most of users install a protection device at the motor terminal or breaker side. This protective device is surge absorber(SA) such as ZnO and RC type. In this study, we analyzed whether there is any effect when two type SA is applied to the VCB multi reignition surge. We confirmed that ZnO SA is slightly more effective than RC SA for reduction of multi reignition surge.