• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.9
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• pp.434-440
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• 2005

This paper describes an optimized Scheme of reactive-power compensation for the low short-circuit-ratio AC system interconnected with the HVDC system. An HVDC system interconnected with tile low SCR AC system is vulnerable to the ac voltage variation, which brings about the commutation failure of the converter. This problem can be solved using optimized compensation of reactive power. In this study, a benchmark system for HVDC system interconnected with low SCR AC system is derived using PSS/E simulation. Then an optimized srheme for reactive power compensation was derived using integer programming. The feasibility of proposed scheme was analyzed through silnulations with PSS/E and PSCAD/EMTDC. The proposed scheme can compensate the reactive power accurately and minimize the number of switching for harmonic filters and shunt reactors.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.3
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• pp.247-257
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• 2006

This paper shows the comparison of operating characteristics between squirrel cage induction generator and DFIG(Double Fed Induction Generator). Because squirrel cage induction generator consume the reactive power due to magnetizing reactance, the capacitor is need to compensate the reactive power. Otherwise, two back-to-back PWM voltage-fed inverters connected between the stator and the rotor allow sub/super synchronous operation with low distortion currents. In this paper, the response characteristics of squirrel cage induction generator and DFIG, were analyzed and investigated using PSCAD/EMTDC.

• Progress in Superconductivity and Cryogenics
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• v.6 no.1
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• pp.28-31
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• 2004

Since the discovery of the high temperature superconductors, many researches have been performed for the practical applications of superconductivity technologies in various fields. As results. significant progress has been achieved. Especially, Superconducting Fault Current Limiter (SFCL) offers an attractive means to limit fault current in power systems. In order to verify the effectiveness of the SFCL, in this paper, the analysis of fault current and voltage stability assessment in a distribution system are performed by the PSCAD/EMTDC-based simulation method in which a component for resistive type ot SFCL is presented. Through the simulation. the advantage of SFCL application is shown, and the effective parameters of the SFCL are also recommended.

• Progress in Superconductivity and Cryogenics
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• v.5 no.1
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• pp.60-65
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• 2003

An effective modeling and simulation scheme of a resistive type Superconducting fault Current Limiter (SFCL) using PSCAD/EMTDC is proposed in this paper. In case of High Temperature Superconducting (HTS) resistive type fault current limiter current limiting is implemented by the ultra-fast transition characteristics from the superconducting (non-resistive) state to the normal (resistive) state by overstepping the critical current density. The states can generally be divided into three sub-states: the superconducting state the quench state and the recovery state respectively. In order to provide alternative application schemes of a resistive type SFCL, an effective modeling and simulation method of the SFCL is necessary. For that purpose, in this study, an actual experiment based component model is developed and applied for the simulation of the real resistive type SFCL using PSCAD/EMTDC. The proposed simulation scheme can be implemented to the grid system readily under various system conditions including sort of faults and the system capacity as well. The simulation results demonstrate the effectiveness of the proposed model and simulation scheme.

• 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.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.66 no.4
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• pp.267-273
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• 2017

In recent years, there is an increasing demand for DC microgrid because the digital load due to DC increases and the efficiency of the distribution system increases due to loss of conversion losses and conversion stages due to reactive power compared to AC distribution. Currently, with the support of the KEPRI, the development of an electronic large-capacity circuit breaker for DC distribution protection, which has been underway since 2016, is proceeding. In this paper, as a part of this project, we modeled the DC microgrid connected with PV using PSCAD. The converter station, AC/DC converter control, PV and MPPT controller are designed. In order to evaluate the performance of the modeled DC microgrid, it is examined whether the voltage is adjusted according to the load variation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.4
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• pp.138-143
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• 2004

This paper analyzed harmonics from high speed railway traction to high speed railway substation and provide a reduction method of harmonics using the passive filter. A substation supplies the electric power to a train or can supply the electric power to several trains. According to the number of trains covered by a substation, characteristics of harmonics are investigated. These harmonics affect transformer heating and inductive interference. In order to get rid of the damage from the harmonics, this paper presented minimizing method of harmonics. The proposed method is verified in simulation using the PSCAD/EMTDC.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.406-407
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• 2011

The closed-loop distribution system is more flexible and more reliable than radial system. If any type fault occurs, the reliability of system can be better by providing electrical energy through another distribution line. However, it needs protection device coordination of different type. Typically, it is available by using directional overcurrent relay (67). This paper gives a solution about loop protection relay modeling which can be used by the simulation tools.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.2
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• pp.184-191
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• 2006

This paper deals with the HVDC system fault analysis and the tuning of the control parameter. This paper is based on the actual cable fault which was caused by the overvoltage due to commutation failure. In order to analyze the fault, the detailed PSCAD/EMTDC model which the sampling time is $50{\mu}s$, was made. Finally, the control parameter of HVDC system was tuned.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.8
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• pp.401-409
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• 2005

This paper describes a feasibility analysis result of STATCOM application for the Jeju-Haenam HVDC system. The Jeju-Haenam HVDC system is one of the typical HVDC system interconnected with the low short-circuit-ratio AC system, which is vulnerable to the commutation failure due to the AC voltage variation. STATCOM has been considered as an effective reactive-power compensator to increase short-circuit-ratio of the interconnected AC system. In this study, a simulation model of Jeju-Hacnam HVDC system with STATCOM was developed using PSCAD/EMTDC. The developed simulation model was utilized to analyze the dynamic performance analysis of Jeju-Haenam HVDC system with STATCOM. The analysis results show that STATCOM can improve the dynamic performance of Jeju-Haenam HVDC system, such as load-change recovery performance and fault recovery performance.