• 대한전자공학회논문지SD
• /
• 제46권3호
• /
• pp.96-102
• /
• 2009

본 논문에서는 600V/200A 또는 1200V/150A와 같은 고전력 절연 게이트 소자를 구동 및 보호하기 위한 파워 IC에 대한 연구에 대해서 살펴보았다. 고전력 소자의 구동을 위해서 최대 Sourcing 전류 4A, 최대 Sinking 전류 8A로 설계하였으며, 과전류 보호회로로는 전력소자의 드레인(콜렉터) 전압을 측정하여, Desaturation을 검출하는 방식을 사용하였다. 또한 과전류 보호시 기생 인덕턴스에 의해 발생할 수 있는 과전압을 억제하기 위해서 soft-shutdown 기능을 추가하였다. 제안된 게이트 구동 IC는 동부하이텍의 고전압 BCDMOS 공정인 0.35um BDA350 공정과 PDK를 사용하여 설계 및 제작하여 검증하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
• /
• pp.219-221
• /
• 1999

HVDC(High Voltage Direct Current) transmission system was constructed between Cheju island and mainland Haenam and has been operating commercially since 1998. But research activities in this area are not so much. That is caused by the facts that HVDC is large scale system and it is not so easy to implement and to test. Though such simulation tools as RTDS(Real Time Digital Simulator) and EMTDC can be useful, these have limitations for actual control and protective system design. Therefore scaled-down HVDC model was developed for the purpose of researches at operating technique, control and protection methods. The design of this model was based on real Cheju-Haenam HVDC system. And additionally faults simulator such as ground fault, short-circuit and change of impedance in transmission line is equipped for analysis of these faults. Control system of the model was implemented fully digitally. So it is very easy for the researchers to develope control and protection algorithm and to test the performance.

• 한국멀티미디어학회논문지
• /
• 제19권2호
• /
• pp.352-359
• /
• 2016

This paper presents high efficiency 5A synchronous DC-DC buck converter. The proposed DC-DC buck converter works from 4.5V to 18V input voltage range, and provides up to 5A of continuous output current and output voltage adjustable down to 0.8V. This chip is packaged MCP(multi-chip package) with control chip, top side P-CH switch, and bottom side N-CH switch. This chip is designed in a 25V high voltage CMOS 0.35um technology. It has a maximum power efficiency of up to 94% and internal 3msec soft start and fixed 500KHz PWM(Pulse Width Modulation) operations. It also includes cycle by cycle current limit function, short and thermal shutdown protection circuit at 150℃. This chip size is 2190um*1130um includes scribe lane 10um.

• Journal of Power Electronics
• /
• 제9권6호
• /
• pp.835-844
• /
• 2009

In this paper a new buck-boost type DC-DC converter is presented. Its voltage gain is positive, all active elements operate under soft-switching condition independent of loading, magnetic isolation and self output short-circuit protection exist, and very fast dynamic operation is achievable by a simple bang-bang controller. This converter also exhibits appropriate PFC characteristics since its input current is inherently proportional to the source voltage. When the voltage source is off-line, it is sufficient to add an inductor after the rectifier, then near unity power factor is achievable. All essential guidelines to design the converter as a DC-DC and a PFC regulator are presented. Simulation and experimental results verify the developed theoretical analysis.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1992년도 하계학술대회 논문집 B
• /
• pp.762-764
• /
• 1992

This Paper presents some experimental result of current limiting and short circuit interruption behavior of thin copper film, 12${\mu}m$, 25${\mu}m$, 40${\mu}m$, 50${\mu}m$ on alumina substrate. and a fuse-link having elements of copper film provided with high-precision small hols with electrolytical process. Construction, fabrication, as well as the test circuitry built especially for the develoment of this fuse-links are explained below.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
• /
• pp.313-315
• /
• 2005

Recently There has been growing interest in new renewable energy systems with high-energy efficiency due to the increasing energy consumption and environmental pollution problems. But an insertion of new distributed generation to existng power distribution systems can cause several problems such as voltage variations, harmonics, protective coordination, increasing fault current etc, because of reverse power. This paper was applied to fault location defecting a method as each Relay sensing fault current value and carried out short-circuit analysis by MATLAB and PSCAD/EMTDC programs and identity the faulted section o f22.9[kV] distribution system interconnected a large number of distributed generation. The existing protection system of 22.9[kV] power distribution system analyzed and the study on protective coordination recloser and Sectionalzer accomplished

• 대한전기학회논문지:전력기술부문A
• /
• 제53권7호
• /
• pp.397-404
• /
• 2004

This paper describes a study of transient characteristics in 765kV untransposed transmission lines. As the 765(kV) system can carry bulk power, some severe fault on the system nay cause large system disturbance. The large shunt capacitance and small resistance of 765kv transmission line make various difficulties for its protection. These problems including current difference between sending and receiving terminals on normal power flow, low order harmonic current component in fault current and current transformer saturation due to the long DC time constant of the circuit etc. must be investigated and solved. The analysis of transient characteristics at sending terminal has been carried out for the single phase to ground fault and 3-phase short fault, etc. The load current, charging current in normal condition and line flows, fault current, THD(Total Harmonic Distortion) of harmonics, time constants have been analysed for the 765kV untransposed transmission line systems.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2006년도 추계학술대회 논문집
• /
• pp.878-884
• /
• 2006

Grounding fault and short of the DC power supply systems are detected and protected by high-speed circuit breaker, linked breaking device, ground relay and fault selective device, all of which are installed and operated in substaions. however, there have been many cases in which the protective devices did not detect grounding of of the over head catenary systems on concrete support for an extended period of time. Such cases often cause severe damages to the supports with high grounding resistances. If grounding accidents occur repetitively, the earth current and the rise of earth potential can damage not only passenger and staff but also electric facilities and equipment, necessitating high cost and endeavor to restore. The following study points out various problems that can be occurred occur as a result of high impedance grounding accident, and proposes a new system which can protect and intercept them.

• 전기의세계
• /
• 제27권5호
• /
• pp.5-12
• /
• 1978

1.Power utilities and CRIEPI are very active in almost all aspects of power systems research. 2.About 50% of research activity of CRIEPI is made under the joint work with power utilities. 3.Research motivation of manufactures are mainly stimulated by the need of power utilities and manufacturers are closely collaborating with power utilities. 4.Main effort of universities is concentrated upon the theoretical aspects of network analysis and the means of stability improvement. Univer sities are doing research rather independently of industry unless inexceptional cases. 5.Universities are making a significant contribution to the exploration of new horizon of power systems engineering, namely, in the research on the social impact on the future of power system. 6.Current main interest of power systems reserch is centered around the stability problem and power system operation and control. Research activity in power system planning is rather low as compared to that in these two major fields. A similar statement holds for the analysis of electromagnetic transients and short circuit analysis. However a new research field is sprouting in the area of power system protection.

• 대한전기학회논문지:전력기술부문A
• /
• 제48권5호
• /
• pp.538-544
• /
• 1999

One of the most important requirements for the development of computerized relay setting system is its openness to abbommodate the various changes like new panel additions. This paper describes the relay settein-coordination system(PROSET2000), which has an open system architecture and adopts the dbject oriented programming paradigm. Its main features include the intelligent fault type identification, automatic running of the short circuit analysis, ren-time rulebase modification, automatic documentation, ect.