• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.199-201
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• 2000

This paper describes the theory and experimental result of scaled model of STATCOM. The STATCOM, a solid-state voltage source inverter coupled with a transformer, is tied to a transmission line. A STATCOM inject an almost sinusoidal current of variables magnitude, at the pont of connection. This injected current is almost in quadrature with the line voltage, thereby emulating an inductive or capacitive reactance at the point of connection with the transmission line.

• 조명전기설비학회논문지
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• 제22권12호
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• pp.36-46
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• 2008

본 논문은 대전력시험설비를 이용한 특고압 가스 절연 부하 개폐기의 대전력 시험회로의 구성과 통합형 시험 방법에 관하여 연구하였다. 대전력시험설비는 전기기기의 전기적 및 기계적인 성능을 검증하는 설비로서 단락발전기, 보호차단기, 투입스위치, 임피던스, 고압변압기, 저압변압기, 측정 및 보호시스템 등으로 구성되며, 이 시스템을 이용하여 단시간전류시험, 전류개폐용량시험, 단락투입 및 차단시험 등을 실시한다. 특고압 가스 절연 부하 개폐기의 규격으로는 국내 배전계통에 적용되는 ES(한국전력공사 표준규격) 5925-0002가 있으며, 국제 규격으로는 IEC 60265-1, 62271-1 및 IEEE C 37.74 등이 있다. 본 논문에서는 여러 규격에 각각 규정되어 있는 시험 절차, 시험회로 구성 및 시험 방법 등을 통합하여 600[MVA]급 대전력 시험설비에 적용하였다.

• Journal of Power Electronics
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• 제5권2호
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• pp.99-103
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• 2005

In this paper, a novel circuit topology of a three-winding coupling inductor-assisting a high-frequency PWM boost chopper type DC-DC power converter with a high boost voltage conversion ratio and low switch voltage stress is proposed for the new energy interfaced DC power conditioner in solar photovoltaic and fuel cell generation systems. The operating principle in a steady state is described by using its equivalent circuits under the practical condition of energy processing of a lossless capacitive snubber. The newly-proposed power MOSFET boost chopper type DC-DC power converter with the three-winding coupled inductor type transformer and a single lossless capacitor snubber is built and tested for an output power of 500W. Utilizing the lower voltage and internal resistance power MOSFET switch in the proposed PWM boost chopper type DC-DC power converter can reduce the conduction losses of the active power switch compared to the conventional model. Therefore, the total actual power conversion efficiency under a condition of the nominal rated output power is estimated to be 81.1 ％, which is 3.7％ higher than the conventional PWM boost chopper DC power conversion circuit topology.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.239-241
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• 2000

This paper describes a modeling of a FACTS(Flexible AC Transmission System) device, namely, SSSC(Static Synchronous Series Compensator) model. The SSSC, a solid-state voltage source inverter coupled with a transformer, is connected in series with a transmission line. SSSC provides controllable compensating voltage, which is in quadrature with the line current, over an capacitive and an inductive range, independently of the magnitude of the line current. This SSSC model is obtained from the injection model for series connected VSC(Voltage Source Converter) by adding a constraint that the injected voltage should be in quadrature with the line current. The paper discusses the basic operating and performance characteristics of the SSSC, and power flow control in power system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1793-1795
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• 2004

지금까지 변전소나 개폐소에서 전류, 전압을 계측하는 수단으로서 주로 철심과 권선으로 구성되어진 변류기(CT), 계기용 변압기(PT, PD)가 사용되어 왔다 최근, 2차측의 계측기나 보호 Relay의 Digital화가 진전되어, 또한 이것을 Digital Network으로 종합한 Intelligent 변전소의 구축이 검토되어짐에 따라 Digital Network에 대응한 신형 CT, VD가 요구되어 지고 있다. 상기와 같은 요구로 인해 당사에서는 CT는 검출부에 Rogowski Coil을 적용하며 그 후단에 적분기를 설치하였으면, VD는 검출부에 중간 전극을 이용해서 분압하는 방식인 Capacitive Voltage Divider를 사용하고 증폭기를 삽입하여, 각각 요구되는 전압 신호를 얻었다. 이러한 신형 CT/VD의 적용으로 종래의 CT/PT가 차지하는 공간이 필요 없게 되어 컴팩트한 GIS의 구조가 능하게 되어 있다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 춘계학술대회논문집
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• pp.467-472
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• 2005

In this paper, design and control of the novel SEPIC-Flyback converter(SF converter) is developed as a possible converter for fuel cell system. This output characteristic of SF converter is similar to Buck-Boost converter in that it can step-up or step-down the voltage. With the small signal equivalent circuit modeling of SF converter, control-to-output transfer function is obtained. SF converter couples up the inductive type converter to capacitive type converter with one transformer, which has less ripple current than its respective one does. To verify the validity of the proposed converter, 500W, 100kHz converter is designed and tested. ZVS switching and active clamping are also tested in practice.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.456-457
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• 2006

We have carried out the construction of the 154kV intelligent substation with KEPRI. The Intelligent substation is built in Gochang testing facility of KEPCO and consists of electronic instruments for GIS(gas insulated switchgear), digital control panel, remote monitoring and diagnosis system, and digital relay system. Rogowski coil type CT(RCT) and capacitive voltage divider(CVD) are introduced compared with the instrument transformer of conventional type. Digital control Panel(DCP) replaces the LCP(local control panel) which is drived for mechanical operation. For the monitoring of the condition of GIS and TR, various sensors are used. In this Paper, we mention the synopsis and report the progress state of project.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.33-35
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• 2005

We perform intelligent substation construction of 154kV class with KEPRI. The intelligent substation is build in Gochang 765kV testing facility and consists of electronic instruments, digital control panel, remote monitoring and diagnosis system and digital relay system. Rogowski coil type CT(RCT) and capacitive voltage divider(CVD) are applicable for instrument transformer of conventional type. Digital control panel(DCP) replaces local panel which is drived by mechanical operation. For monitoring condition of GIS and TR, various sensors are used. In this paper, we report the synopsis and the progress state of project.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
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• pp.129-130
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• 2005

We perform intelligent substation construction of 154kV class with KEPRI. The intelligent substation is build in Gochang 765kV testing facility and consists of electronic instruments, digital control panel, remote monitoring and diagnosis system, and digital relay system. Rogowski coil type CT(RCT) and capacitive voltage divider(CVD) are applicable for instrument transformer of conventional type. Digital control panel(DCP) replaces local panel which is drived by mechanical operation. For monitoring rendition of GIS and TR, various sensors are used. In this paper, we report the synopsis and the progress state of project.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.524-526
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• 2004

We perform intelligent substation construction of 154kV class with KEPRI. The intelligent substation is build in Gochang 765kV testing facility and consists of electronic instruments, digital control panel, remote monitoring and diagnosis system, and digital relay system. Rogowski coil type CT(RCT) and capacitive voltage divider(CVD) are applicable for instrument transformer of conventional type. Digital control panel(UP) replaces local panel which is drived by mechanical operation. For monitoring condition of GIS and TR, various sensors are used. In this paper, we report the synopsis and the progress state of project.