• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.466-467
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• 2006

Several synthetic testing methods have widely been used for the performance evaluation of ultra high-voltage circuit breaker. Among these synthetic method, in the paper, capacitance switching testing method which can meet the test requirements and increase the testing capacity has been proposed. This method is made up of two separated sources of short-circuit generator for current source and L-C resonance circuit for voltage source. By using this method, KERI will perform the performance evaluation of capacitive current switching performance for the 800kV GCB(Gas Circuit Breaker).

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.737-738
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• 2008

대전력 시험 시스템은 전력 계통의 지락 사고 및 단락 사고시 발생되는 사고 전류가 각종 전기 기기에 인가되었을 때 그 기기의 성능을 시험하는 설비로서 발전기, 보호 스위치, 투입 스위치, 임피던스, 변압기, 측정 시스템 및 보호 시스템 등으로 구성되어 있다. 이러한 설비는 계통의 상용 전원을 이용하는 방법과 발전기와 같은 별도의 전원 발생 장치를 이용하는 방법이 있다. 상용 전원을 이용한 방법은 저전압 소전류의 설비에 적용하고, 발전기를 이용한 방법은 배전급 기기를 포함한 고전압 대전류의 설비에 적용하며, 보통 대전력 시험 설비라고 하면 발전기를 이용한 시험 설비를 말한다. 본 논문에서는 국내에서 배전급 기기에 대하여 단락 발전기를 이용한 대전력 시험 시스템 국산화 추진시 발전기, 보호 차단기 및 투입 스위치의 요건과 용량을 산정하는 방법을 살펴본다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.7
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• pp.362-368
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• 2006

This paper presents the results of a small capacitive current interruption test for the three types of interrupter which are called 'serial type', 'parallel/separated type' and 'puffer type' according to the arrangement of the thermal expansion chamber and the puffer cylinder. After the preconditioning test the small current interruption capability of the 'puffer type' decreased, on the contrary, that of the hybrid interrupters increased. A number of reignition have been occurred in the 'serial type' hybrid interrupter and the change of small current interruption capability after preconditioning test is mainly influenced by the structure of interrupter. Finally it has been proved that the 'parallel/separated type' hybrid interrupter has the best interruption performance through the verification tests.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.106-108
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• 2002

Capacitive current switching test for circuit breaker and load breaker switch requires special attention because, after current interruption, the capacitive load contains an electrical charge and can cause dielectric restrike and re-ignition of the switching devices. therefore dielectric strength of capacitor load bank shall be able to withstand 4Vt (Vt : test voltage) and charging voltage discharged within 1 min. In this paper presents both characteristic of capacitive current switching tests and design of capacitor load bank.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.8
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• pp.396-402
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• 2006

Even the case DC circuit Breaker have good quality for interruption of high current like heavy load current, short-circuit current, the verification for small current breaking capability of circuit breaker should be performed. It comes from the reason DC small current breaking failure can be lead to break out second heavy fault condition and in the long run substation shutdown. In this paper, we can find the characteristics of DC small current and international test standard discription about small current breaking and one of the proper solution to get over it.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.8
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• pp.384-391
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• 2001

The insulation strength between contacts after current interruption to the transient recovery voltage i.e., the dielectric recovery strength should be estimated for the evaluation of the small capacitive current interruption capability. Many authors have used theoretical and semi-experimental approaches to evaluate the transient breakdown voltage after the current interruption. Moreover, an empirical equation, which is obtained from a series of tests, has been used to estimated the dielectric recovery strength. Un this paper, the theoretical method which is generated from the streamer theory has been applied to real circuit breakers in order to evaluated the interruption capability. The results of analysis have been compared with the test results and the reliability has been investigated.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.164-166
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• 1998

This paper presents the results of the measured pressure-rise and the analyzed results of the cold gas flow-field in a 72.5kV 20kA gas circuit breaker for the electrical railway system. The analysis of cold gas flow field and the calculation of electric field strength have been performed in 3 types of interrupters and the low current interruption capability has been estimated for each of the gas circuit breaker considering the opening speed, the nozzle shape and the stroke length.

• Proceedings of the KIPE Conference
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• 2019.11a
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• pp.118-119
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• 2019

본 논문은 유연전극의 플라즈마 반응을 위한 고효율 전원장치에 대한 연구이다. 유연전극은 저온 플라즈마 방전으로, 수 kV의 AC형태의 고전압 및 소전력 구동 사양이 요구된다. 상용전원을 사용하는 유연전극용 고전압 전원장치는 AC-DC, DC-AC로 변환이 가능한 2단 구조를 갖는다. 1단은 낮은 전력에서 높은 효율을 달성 할 수 있는 CrM(Critical Conduction Mode) PFC와 전부하 영역 소프트 스위칭을 통해 고효율 달성이 용이한 LLC 공진 컨버터를 사용하였다. 유연전극은 사양에 따라 커패시턴스가 달라진다. 따라서, 본 논문에서는 유연전극 사양에 따른 공진 주파수의 최적화를 통해서 유연전극의 플라즈마 반응 및 특성 시험을 위해 고효율 전원장치를 구성하였다. 실험을 통해서 유연전극용 고효율 전원장치를 검증하였다.

• Proceedings of the KIEE Conference
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• summer
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• pp.974-976
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• 2004

현대 정보사회는 교통수단의 발달과 더불어, 휴대용 기기의 급속적인 발전을 가져왔다. 따라서, 휴대용 기기의 전원에 관한 많은 연구가 진행되고 있다. 그러나 여전히 시간적 제약을 받는 배터리에 대부분의 휴대용 기기가 의존하고 있다. 이에 본 연구에서는 사람들이 동작하는 동안 항상 버려지는 체중에 의한 에너지를 이용한 발전장치를 설계하였다. 이 발전장치는 외력을 주었을 때, 대전압${\cdot}$소전류를 발생하는 평판형 압전소자의 특성을 이용한 장치이다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.10
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• pp.528-533
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• 2006

To analyze the small current interruption performance for the gas circuit breakers, the gas density and electric field intensity should be calculated. In this paper, the FVFLIC method is used for the gas flow analysis and the FEM for the electric field analysis. Then, the dielectric withstanding voltage is evaluated by the empirical formulation or Streamer theory. By comparing the calculated dielectric strength with the test result, it is found that both methods show good prediction capability for the small current interruption performance. Especially, when both methods predict the same interrupting performance, the prediction is in accordance with the experimental result.