• 한국초전도ㆍ저온공학회논문지
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• 제7권2호
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• pp.35-38
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• 2005

One of the most serious problems in KEPCO system operation is higher fault current than the SCC(Short Circuit Capacity) of circuit breaker. There are many alternatives to reduce the increased fault current such as isolations of bus ties, enhancement of SCC of circuit breaker, applications of HVDC-BTB(Back to Back) and FCL(fault current limiter). But, these alternatives have some drawbacks in viewpoints of system stability and cost. As the superconductivity technology has been developed, the resistance type HTS-FCL(High Temperature Superconductor Fault Current Limiter) can be one of the most attractive alternatives to solve the fault current problem. To evaluate the accurate transient performance of resistance type HTS-FCL, it is needed that the dynamic simulation model considering transient characteristics during quenching and recovery state. Under this background, this paper presents the EMTDC model for resistance type HTS-FCL considering the nonlinear characteristic of final resistance value when quenching and recovery phenomena by fault current injection and clearing occurs.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 D
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• pp.1035-1037
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• 1997

This paper deals with the mathematical modeling of battery energy storage systems interconnected with the distribution system. This battery model takes account of self-discharge, battery storage capacity, internal resistance and overvoltage. The model components are decided by using an approximation technique and experimental results. This model can be used to evaluate battery performance of battery energy storage systems interconnected with distribution system.

• 전기학회논문지
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• 제60권4호
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• pp.733-738
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• 2011

As increase of nonlinear loads and renewable energy generators (REGs) being connected to power distribution system via inverters, the concern on harmonic problems have increased. Recently, the harmonics evaluation method considering TDD (Total Demand Distortion) is used to analyze the effect of harmonics from inverters on power distribution quality. Harmonic current sources are typically used for simulation of nonlinear load. Most inverter type for REGs is voltage source inverter (VSI). So, harmonic voltage sources are more suitable to analyze impact of renewable energy generator on harmonics problem in power distribution system. In this paper, we presented the circuit model to analyze interaction between harmonics from nonlinear load and REGs. We verified that the harmonic analysis using the proposed circuit model is more appropriate than the harmonics evaluation method considering TDD through case study using PSCAD/EMTDC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.247-248
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• 2015

Wind turbines causes instabilities on the grid as their penetration increase. To mitigate harmful effects from wind turbines, transmission system operator(TSO) set up some requirements to obligate for wind generation operator for grid connection. So wind farm management system(WFMS) has important role to follow requirement from TSO, WFMS calculates available real power by considering wake effects, and dispatches real power order to each wind turbine in wind farm to optimize for decreasing load fatigue. To verify operation of WFMS, real-time simulator(RTS) is necessary. This paper deals with RTS configuration to verify WFMS operation. RTS includes wind farm model and power flow code. Normally, wind farm equivalent simple model makes wind turbines in wind farm to one wind turbine mode which cannot verify power flow in wind farm and WFMS operation. Thus, this paper makes wind farm model using simple wind turbine model with transfer function. Matlab is used for make power flow code and wind farm model to impose RTS and those model is certified by PSCAD/EMTDC.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.60-62
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• 2005

This paper describes a feasibility analysis result of STATCOM application for the Jeiu-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-Haenam 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.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 추계학술대회 논문집
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• pp.11-12
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• 2014

This paper introduces a scaled hardware model for the 10kVA, 1kV, 11-level MMC (Modular Multilevel Converter), which was manufactured in the lab based on computer simulations with PSCAD/EMTDC. Various experiments were conducted to verify the major operation algorithms of MMC. The hardware scaled-model developed in the lab can be utilized for analyzing the operation analysis and performance evaluation of MMC according to the modulation pattern and redundancy operation scheme.

• KIEE International Transactions on Power Engineering
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• 제3A권4호
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• pp.206-213
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• 2003

The main purpose of this paper is to present a simulation model for assessing the impacts of a variable speed wind turbine (VSWT) on the distribution network and perform a simulation analysis of voltage profiles along the wind turbine installed feeder using the presented model. The modeled wind energy conversion system consists of a fixed pitch wind turbine, a synchronous generator, a rectifier and a voltage source inverter (VSI). Detailed study on the voltage impacts of a variable speed wind turbine is conducted in terms of steady state and dynamic behaviors. Various capacities and different modes of variable speed wind turbines are simulated and investigated. Case studies demonstrate how feeder voltages are influenced by capacity and control modes of wind turbines and changes in wind speed under different network conditions. Modeling and simulation analysis is based on PSCAD/EMTDC a software package.

• 전기학회논문지
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• 제58권12호
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• pp.2402-2409
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• 2009

This paper proposed a simple and helpful analysis model of voltage variation in order to predict the voltage variation at PCC (Point of Common Coupling), when a wind turbine is connected in an isolated grid. The PCC voltage flucuates when the wind turbine outputs active power to an isolated grid. This voltage variation is proportional to the product of the line impedance from the ideal generator to the PCC and the wind turbine output current. And It is different according as where wind turbine is connected. To solve the problem of voltage variation, this paper proposed the reactive power control. To verify the proposed analysis model, this paper utilized PSCAD/EMTDC Simulation and the field measurement data of the voltage variation during the wind power generation.

• 대한전기학회논문지:전력기술부문A
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• 제53권6호
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• pp.309-315
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• 2004

The wind power is known as the most promising future energy source to obtain the electricity Induction generator is a simple energy conversion unit in the wind power generation system but it consumes the reactive power from the interconnected power system. Switched capacitor banks are normally used to compensate the reactive power, which bring about the transient overvoltage. This paper proposes a method for compensating the reactive power with STATCOM. A detail simulation model for analyzing the interaction between the wind power system and the commercial power system was developed using EMTDC software. The developed simulation model can be effectively utilized to plan the reactive power compensation for newly designed wind power system.

• 전기학회논문지
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• 제59권2호
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• pp.248-254
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• 2010

This paper deals with implementation of the laboratory-scale microgrid using energy storage system. Also, this paper develops a simulation model of the microgrid with same parameters on the laboratory-scale microgrid using PSCAD/EMTDC. The experimental results show good agreement with the simulation results. This shows the validity of the simulation model. A valve regulated lead acid (VRLA) battery is used to store energy. Energy storage system with fast response is able to maintain power quality of sensitive load within the microgrid.