• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.366-370
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• 2005

To meet increasing power demand, 500 kV power systems are under consideration in the regions of some Middle Asian countries. As the power system voltage becomes higher, the cost for the power system insulation increases significantly. 500 kV transmission systems will become the basis of a region's power system and they require much higher system reliability. Consequently, by the methods of limiting overvoltages effectively, a reasonable insulation design and coordination must be accomplished. In particular, the Substations must be constructed to be of outdoor type. In order to determine the various factors for the insulation design, the EMTP (Electro-magnetic transient program) is used for the magnification of transient phenomena of the 500 kV systems in the planned network. In this paper, we will explain the calculation results of lightning overvoltages by the EMTP for lightning protection design for the 500 kV substations. To obtain reliable results, the multi-story tower model and EMTP/TACS model are introduced for the simulation of dynamic arc characteristics.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.714-718
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• 1987

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2283-2284
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• 2008

TCR(Thyristor Controlled Reactor, 싸이리스터 제어 리액터)를 사용한 SVC(Static VAR Compensator, 정지형 무효전력 보상장치)의 모델링을 제시한다. 이 모델링을 전력계통의 전압 제어에 적용하며 EMTP(Electro-Magnetic Transient Program, 전자기적 과도현상 해석 프로그램)를 통하여 시뮬레이션의 결과를 도출하고 EMTP를 통한 모델링을 확인한다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2291-2292
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• 2008

HVDC(High Voltage Direct Current) 송전 시스템은 세계 각국에서 경쟁적으로 개발하고 있으며 계통에의 연계가 점점 증가하고 있다. 전형적인 HVDC 송전 시스템에서는 낮은 고조파 함유율과 높은 전압율 등의 이유로 주로 12-펄스 사이리스터 정류기가 사용된다. 본 논문에서는 12-펄스 정류기를 EMTP(ElectroMagnetic Transient Program)를 이용하여 모델링 하였으며, 고조파 분석을 통하여 모델링의 적절성을 검증하였다.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.945-948
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• 1992

In this paper, switching overvoltages are analyzed for future 765kv power system using EMTP(Electro Magnetic Transient Program) and compared with TNA (Transient Network Analyzer) study results which was previously undertaken during overseas training in 1980 and 1988. The result shows the maximum of 2.10 PU at midpoint of 310Km transmission line which is higher than those of TNA study by 0.4 PU. The deviation of EMTP result from TNA is caused by limitation of nonlinear representation and also frequency dependent modeling in EMTP. Further analysis are required to get more exact switching overvoltage factors for future KEPCO 765KV system not only by EMTP but also TNA.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.10
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• pp.56-62
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• 2014

When fault currents contain decaying DC offset, the peak value of the fault current in the first cycle of the fault period is higher than the fault current during the steady-state period. To reduce the asymmetric fault current, this paper proposes an operation scheme using the series connection of two hybrid type Superconducting Fault Current Limiters (SFCLs) : an auxiliary SFCL and a main SFCL. The proposed method calculates the fault angle by comparing the zero-crossing time with fault detection time. According to the fault angle calculated, an auxiliary SFCL operates to reduce an asymmetric fault current during half a cycle after fault occurrence. After this process, the fault current is limited by a main SFCL. To confirm the usefulness of the proposed method, case studies using Electro-Magnetic Transients Program (EMTP)/Alternative Transient Program (ATP) Draw are perfomed.

• KIEE International Transactions on Power Engineering
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• v.11A no.4
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• pp.9-14
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• 2001

This paper reports a set of digital time-domain simulation studies conducted on 154 kV wound Potential Transformer(PT) int he 154 kV Gas Insulated Substation(GIS). The Electro-Magnetic Transient Program(EMTP) is used to develop the PT model and conduct the transient studies. The accuracy of the PT model is verified through comparison of the EMTP simulation results with those obtained from the field test results. The investigations shows that the developed model can accurately predict PT transient resonance, especially, the phenomenon of ferroresonance. The model is developed not only to determine impact of transients on PT response but also to design ferroresonance suppressor devices of PT. And it can also be used to predict PT transient response on power system monitoring and protection scheme.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.5
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• pp.873-878
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• 2009

When the transmission lines are initially energized for power system restoration, the power system suffers the various overvoltages that can be classified as steady-state, transient, and dynamic overvoltages. For the accurate analyses of these overvoltages, many researchers utilize different simulation tools such as Power System Simulator for Engineering(PSS/E). Although PSS/E provides good solutions in steady-state and dynamic overvoltages, it is not suitable for transient overvoltages. Therefore, transient overvoltages are simulated by using Electro-Magnetic Transients Program(EMTP) developed for the analysis of transients in the power system. Recently, EMTP can be also used to simulate dynamic behavior of the system. In order to analyze the transient overvoltages with steady-state and dynamic overvoltages, the authors adopt EMTP as the simulation tool for the analysis of overvoltages. This paper presents the simulation results for the analyses of various overvoltages, and the possibility of EMTP to be used for these types of analyses.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.7
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• pp.1199-1205
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• 2010

The recent power system is required to a large size of facilities and high power technology according to increasing power demand. However, it could lead to spoiling the beauty of city and environment problem. The miniaturized facilities with large capacity such as GIS have been required in recent power system. The GIS(Gas Insulated Substation) using the SF6 insulation gas enables to miniaturize facilities with large capacity with high insulation performance. However, the substation installed GIS has required to new design model which is different from the conventional substation. The TRV(Transient Recovery Voltage) analysis on simple circuit may applied by differential equation. However, in case of relatively complicated system, EMTP(Electro Magnetic Transients Program) mainly has been used to design and simulate for transient analysis. This paper mainly design the 22.9 kV GIS system and analyze the transient recovery voltage of main circuit breaker using EMTP/RV. It also enables to easily design the other substation installed GIS with same maker and voltage level because the proposed GIS model consists of separated modules such as busbar, circuit breaker, bushing, CT, PT etc. Eventually, it contributes to comfortably compare the interrupting performance of circuit breaker and system TRV corresponding to the substation system configuration.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.997-999
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• 1997

This Paper presents a relay modeling technique to deal with the relay transient characteristics. Existing relay models are based on steady-state concepts. The ninth-order state space mathematical model of the Mho distance relay has been constructed. Computer modeling of a typical distance relay is done within the Transient Analysis of Control System(TACS) subsection of the ElectroMagnetic Transient Program(EMTP).