• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.888-890
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• 2002

We derived a theory of increasing electromagnetic force acting on arc column for reducing arcing time between electric contacts. A simulation method of arc velocity is presented by calculating blowout force using 3D FEM and drag acting on arc column. This paper is proposed 3 types arc extinguish chamber of different fulx path and is presented electromagnetic force and arc velocity of each model.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.227-227
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• 2009

To prevent such accidents, molded case circuit breakers with improved short-circuit current interrupting capacity are needed. This paper is focused on understanding the interrupting capability with respect to double contact structure and puffer assisted self quenching that are based on the shape of the contact system in the current molded case circuit breaker. The new arc quenching structure for increasing the interrupting capacity of molded case circuit breakers is investigated by simulation and experiment.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.295-296
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• 2011

본 논문에서는 PSCAD/EMTDC 프로그램을 통해 HVDC 제어기를 설계하였다. HVDC 제어기는 컨버터의 운전모드에 따라서 인버터 제어기와 정류기 제어기로 나뉘며, 인버터 제어기는 전류제어기, 전압제어기, 소호각 제어기로 구현하고, 정류기 제어기는 전류제어기 및 전압제어기로 구현하였다. HVDC V-I 특성곡선에 VDCOL을 적용하여 전압에 따른 전류의 의존 특성을 반영하였다. ac 계통 단상 지락 고장, 3상 지락 고장에 대해 시뮬레이션하여 설계한 제어기의 정상상태 및 과도상태시 응답성능을 검증하였다.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.77-79
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• 1996

The model interrupters of $SF_6$ gas electromagnetic contactor whose ratings are 7.2kV, 4.0kA have been designed and manufactured on the basis of theoretical and computational analysis for its development. The eddy current analysis, the magnetic field analysis and the calculation of the rotational force on arcs have been conducted using FLUX2D package. The short circuit current interrupting tests have been conducted for the model interrupters using the simplified synthetic testing facility in KERI. The results show that the model interrupters have sufficient interrupting capability and the new design concept is prefer for good interrupting performance.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.596-599
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• 1991

This paper describes a novel switching algorithm of series connected power semiconductors for high voltage applications. In order to improve the reliability and efficiency of high voltage static power converters, we study on the switching characteristics of series connected power semiconductors and then propose "a servo control of snubber capacitor value" for the dynamic voltage balancing under turn-off state in series connected power semiconductors. Finally, we illustrate the validity of this algorithm by computer simulation and experimental results.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.7
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• pp.356-363
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• 2001

A SRG (Switched Reluctance Generator) has many advantages such as high efficiency, low cost, high-speed capability and robustness compared with other of machine. But the control methods that have been adopted for SRGs are complicated. This paper proposes a simple control method using the PID controller which only controls turn-off angles while keeping turn-on angles of SRG constant. In order to keep the output voltage constant, the turn-off angle for load variations is controlled by using linearity between the generated current and turn-off angle since the reference generated current can be led through the voltage errors between the reference and the actual voltage. The suggested control method enhances the robustness of this system and simplifies the hardware and software by using only the voltage and the speed sensors. The proposed method is verified by experiments.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.263-264
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• 2011

최근 들어 디지털 제품의 급증으로 인해 직류를 사용하는 부하가 증가하고, 직류 배전망에 대한 관심이 높아 지고 있다. 하지만 직류는 교류와 다르게 직류 배전시 부하의 단락 사고가 발생하면 지속적으로 아크전압이 발생하는 문제가 있기 때문에 차단이 어렵다. 인체의 안전과 전력설비 및 기기의 안전성을 확보하기 위해서는 고장전류로부터 계통을 보호하기 위한 차단기술이 필요하다. 본 논문에서는 효과 적인 직류 차단에 대하여 실험적으로 연구하였다.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.669-672
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• 1992

The increasing application of Vacuum Circuit-Breakers (VCB) on utility and industrial systems has prompted and detailed investigation of vacuum switching surge mechanisms and protections. This paper arranges arc-extinguishing principles of magnetic field in vacuum in order to disperse rapidly arc generated from vacuum contacts on switching VCR and plans establishment of protection means to protect high-voltage motor against surge voltage magnitude and transient voltage rate of rise

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2209_2210
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• 2009

송전계통에서 가장 많이 발생하는 고장은 일시고장이며, 이 중 70%~80%가 아크지락 고장이다. 일시 고장시 계통의 빠른 복구를 위한 성공적인 재폐로를 이루기 위해서는 2차아크의 재점호와 소멸시간이 중요한 변수로 작용한다. 따라서 이러한 2차아크의 특성을 분석하고 적절한 소호시점을 알아내는 것이 성공적으로 고장 후 계통을 복구시키기 위해 필요하다. 본 논문에서는 전력 계통의 과도현상 분석 프로그램인 EMTP(Electro Magnetic Transient Program)를 이용하여 765kV 송전계통에서 아크 지락 고장을 시뮬레이션 하고, 송전선로내 고장지점을 다양하게 변화시켜 가며 아크 전압 특성을 분석하였다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1362_1363
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• 2009

In this study, we predicted the thermal breakdown of high-voltage interrupter with the characteristics of thermal plasmas such as temperature, pressure and concentration of the ablated material by using a commercial CFD program. The results showed that the pressure build-up inside the chamber was proportional to the magnitude of arcing current because the quantities of heat energy and ablated mass also increase together with the current during the compression process. And during the decompression process, the reverse flow was not coincided with the magnitude of the applied current due to the compressibility of the gas through backflow channel. The present method is expected to be useful for the design of guideline and interruption capacity on the thermal breakdown of a PASB chamber.