• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1214-1215
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• 2011

현재 HVDC 및 FACTS와 같은 전력전자소자 기반 전력기기의 최신 개발은 능동형 스위치소자의 발전 및 설치 환경의 변화로 인하여 VSC Topology로 이동되고 있다. 하지만 VSC Toplolgy의 스위칭 손실등의 문제로 대용량 전력기기의 경우 MMC(Modular Multilevel Converter) 적용이 가속화되고 있다. 이에 본 논문에서는 MMC Topology의 특징, 구동 원리, 시뮬레이션 과정을 소개한다. Modulation 및 Quantization 그리고 Sorting Algorithm을 통해 7-level, 151-level 삼상 MMC Topology을 시뮬레이션을 수행하였다.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.31-32
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• 2017

모듈형 멀티레벨 컨버터(Modular Multilevel Converter, MMC) 토플로지는 HVDC 송전을 위한 전력변환 시스템 또는 전기추진 선박과 같은 대용량 시스템에 주로 사용된다. 본 논문은 MMC 시스템의 출력 전류 센서에서 전류 검출 과정 시, 발생 가능한 오차 성분의 영향을 분석하였다. 또한 전류 센서의 오차 성분을 일반화 하고, 이를 시뮬레이션을 통해 타당성을 검증하였다.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.216-217
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• 2011

HVDC System의 핵심 구성요소인 대용량 전력변환장치의 신뢰도를 확보하기 위해서는 시스템 설치 전에 전력변환장치를 구성하는 각 Thyrister Valve의 동작성능 검증이 매우 중요하다. 이러한 검증은 모든 Thyrister Valve를 대상으로 한 전수검사를 기본으로 하므로 Thyrister Valve의 성능시험장치 개발이 필요하다. 이 논문에서는 Full Power 시험과 유사한 특성을 얻기 위한 시험장치의 용량을 최소화하기 위하여 STC(Synthetic Test Circuit)기법을 사용한 2kV, 200A급의 STC를 Simplorer6.0프로그램을 이용하여 구현하였으며, STC의 동작특성을 모의 하였다.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.331-332
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• 2006

This paper proposes the fuel cell power plants as alternative energy sources for distributed generation in Jeju Island, Korea. This will help to increase the fuel efficiency, at least double the current thermal power plants, decrease environmental pollution, virtually to none, increase the reliability of power supply, reducing the dependency of the HVDC link, and provide quality power to the growing infrastructure in meeting the requirements for the free-trade international island.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.4
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• pp.641-644
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• 2007

The electro-mechanical mercury relay is used as an auxiliary relay of power facility because it is superior to operating time and no-bounce. So the KEPCO had used the mercury relay for operating HVDC(High Voltage Direct Current) system. But it has many problems with facility operation by occurrence of mercury evaporation, held contact point and malfunction according to long term use, furthermore it is forbidden to produce for fear of environmental pollution in 2002. This paper presents the no-mercury relay development, comparison test and application.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.6
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• pp.906-915
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• 1994

Line-Current harmonics resulting from ac to dc power conversion interfere with power system operation and reduce power factor, hence resulting in increasing power source unnecessarily. This study describes a 3 phase phase-controlled converter eliminating low frequency harmonics in the output by inserting notches. Notch points are calculated by Newton-raphson method, The impacts of the choppings on ac and dc sides are analyzed in the steady state. Potential applications of the study are dc motor controls, high power dc power supplies for telecommunications, static var compensators and HVDC.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.343-344
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• 2015

전력산업은 친환경 신재생 에너지 자원의 증대, 국가간 에너지 교류 등 고성능 대용량 전력전자 응용분야 기기의 필요성이 지속적으로 확대되고 있다. 신규 AC 송전선로 건설이 민원 등의 사유로 건설에 장시간 소요되고, 건설단가의 지속적 증가 및 전력전자 설비의 가격하락(HVDC, FACTS 등 특수설비의 국산화 추진) 등으로 AC 송전선로 신규건설 보다는 송전선로 조류제어로 전력계통 유연성 향상이 필요하게 되었으며, 향후 융통전력의 한계, 전력수요 포화 및 Smart Grid 시대를 대비하여 기존 송전선로의 이용을 극대화하는 방향으로 계통계획의 방향 전환이 더욱 급속도로 진행될 전망이다. 본 논문에서는 최첨단 무효전력보상장치 소개와 계통안정화를 위한 전력계통 영향분석을 통해 직 병렬 FACTS의 필요성을 소개하고자 한다.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.396-397
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• 2015

With the increasing utilization of high-voltage, direct current (HVDC) transmissions in modern power systems, the DC grid is becoming a hot topic in academic and practical systems. In the DC grid, one of the urgent problems is the fast clearance of the DC fault in the DC network. One preferred method is to isolate the faulty point from the DC network in a short time. The DC circuit breaker is to interrupt the overcurrent after DC faults occur. In this paper, a self-excited resonant DC circuit breaker is an easy and cheap equipment to interrupt the DC fault current. The Mayr's arc model is utilized to simulate the self-excited DC circuit breaker in a DC test system in PSCAD/EMTDC.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1067.1-1067.4
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• 2000

During the last three decades power electronics has gone through energetic technical evolution. The technical needs from wide area such as in industrial, commercial, consumer, aerospace and environmental applications have driven the environment favorably for the power electronics. In the future, two extreme technology-expansion trends are expected: one into low power, and the other into very high power. The former is based on the high frequency and the circuit miniature using VLSI circuit and surface mounting aiming for the system-on-chip (SOC) technology. The latter includes the application areas of power utility such as HVDC, FACTS and SVC and large science area of electrophsycal apparatus such as thermonuclear fusion, acclerators, and electric guns. This paper describes the technology status of some major elements which are available today and the key roles of the power electronics from view points of applications. The author would like to take this opportunity to raise discussions about the future technology development trend of power electronics in our country with the fellow power electronics engineers.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.109-111
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• 1996

This paper describes real time dynamic tests on the digital distance relay using new digital test system including RTDS(Real Time Digital Simulator) in KEPRI. The RTDS is developed by the Manitoba HVDC Reserch Centre and consists of specialized hardware and software which allows transients simulation of electrical power systems in real time. From high impedance fault test, it is known that the characteritics of distance reach is influenced by load flow. A detailed discussion of relay test using the RTDS simulator, high impedance faults and test results are included in the paper.