• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.490-491
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• 2008

A photovoltaic power generation system is one of the ideal clean energy sources increasingly replacing fossil fuel, which has many environmental problems such as exhausted gas or air pollution. As a photovoltaic generation system should meet the requirement to be connected to utility, power factor is an important factor for the high quality of power. This paper implements a power factor controller to improve the power quality of utility interactive photovoltaic system. To verify the effectiveness of the implemented power factor controller, the results by Electromagnetic Transients Program (EMTP) are presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.850-852
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• 1996

High impedance fault (HIF) is defined as fault that general overcurrent relay can't detect or interrupt, Especially when HIF occur under 15 kV, energized high voltage conductor results in fire hazard, equipment damage or personal threat. Because most HIF occur arc, HIF detection using arc is to increase. Numerical arc model can be applied in an electromagnetic transients program (EMTP) to reproduce the dynamic and random characteristic of arcs for any insulator arrangement, current and system voltage. It allows the representation of any network configuration to be investigated, so the digital simulation of arc faults through air can be substitute for demanding power arc test.

• 대한전기학회논문지:전력기술부문A
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• 제48권12호
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• pp.1507-1513
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• 1999

This paper describes simulation and experimental results to analyze the dynamic characteristics of STATCOM, which is connected to the ac system for compensation the power factor and improving the voltage stability. The simulation and experimental results confirm that the scaled model for STATCOM can properly compesate the power factor of the load and regulate the bus voltage at the common connection point.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.599-600
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• 2015

This paper presents study of recloser operation in distribution system with Energy Storage System(ESS). However, interconnecting of ESS influence power flow and increasing/decreasing of fault current. Recloser provides stability of system and improves power transmitting ability by reclosing in fault current. The single-line to ground fault current simulated by Electromagnetic Transients Program (EMTP). The simulation is implemented for the three different situations about by using EMTP MODELS.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.216-218
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• 2002

This study is the modeling of resistive type SFCLs. There was numerical modeling and simulation using EMTP in the conventional modeling of SFCL. The numerical modeling was presented an analysis of numerical characteristic of SFCL. And the modeling using EMTP was made up of the study for setting method of specific parameters of a SFCL. This paper proposes the model of resistive type superconducting fault current limiter using EMTDC(Electromagnetic transients for DC analysis program). The simulation schemes that can be applied to the utility network readily and cheaply under various conditions considering the sort of fault, the capacity of systems as well are strongly expected and emphasized among researchers.

• 대한전기학회논문지:전력기술부문A
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• 제48권3호
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• pp.197-202
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• 1999

Electric arc furnaces (EAFs) use bulk electrical energy to create heat in metal refining industries. The electric arc process is a main cause of the degradation of the electric power quality such as voltage flicker due to the interaction of the high demand currents of the load with the supply system impedance. The stochastic models have described the aperiodic physical phenomena of EAFs. An alternative approach is to include deterministic chaos in the characterization of the arc currents. In this parer, a chaotic approach to such modeling is described and justified. At the same time, a DLL(Dynamic Link Library) module, which is a FORTRAN interface with TACS (Transient Analysis of Control Systems), is developed to implement the chaotic load model in the Electromagnetic Transients Program (EMTP). The details of the module and the results of tests performed on the module to verify the model and to illustrate its capabilities are presented in this paper.

• 대한전기학회논문지:전력기술부문A
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• 제53권8호
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• pp.454-460
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• 2004

The effects of surge arresters for protection of transmission systems against direct lightning strokes have already been reviewed using Electromagnetic Transients Program(EMTP). Distribution lines are spanned in much larger area than transmission lines, and therefore, are more susceptible to lightning strokes. We have modelled the 22.9kV underground distribution cable systems that have arresters and grounding wires. And this paper analyzes the overvoltages on underground distribution cable systems when direct lightning strokes strike on the overhead grounding wire using EMTP. Then we investigated that (1) the effects of lightning stroke according to underground distribution cable length (2) voltages at the riser pole and at the cable terminal according to installation of arrester. This study will provide insulation coordination methods for reasonable systems design in 22.9kV underground distribution cable systems.

• KEPCO Journal on Electric Power and Energy
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• 제6권4호
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• pp.393-397
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• 2020

무효전력 보상설비인 분로리액터는 전력계통의 부하 패턴에 따라서 하루에도 수 회 정도 차단기에 의해 운전되거나 정지된다. 분로리액터개폐 시 몇 가지 요인에 의해 발생하는 과전압은 차단기의 절연 성능을 저하시키며, 계통을 구성하는 전력기기에 심각한 전압 스트레스를 유발한다. 분로리액터 개폐 과정에서 발생하는 과도현상을 측정하는 것은 계통을 모의하여 차단기 성능을 검증하는 시험소 수준에서는 가능하나, 실제 계통 운전 중에 발생하는 과도현상을 측정하는 것은 여러 가지 제약으로 어려움이 있다. 따라서 본 논문에서는 실 계통에서 지상 소전류 차단과정에서 가혹한 과도회복전압(TRV: Transient Recovery Voltage)을 유발하는 재발호(reignition)나 전류재단(current chopping) 현상에 대한 해석을 위해 전자계과도해석프로그램(EMTP: Electro-magnetic Transients Program)을 활용한 모델링 과정과 이를 토대로 분로리액터 개폐 과정에서 차단기의 고장을 유발하는 주된 현상에 대해 해석하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1822-1824
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• 1996

Damage and upset of control and communication equipment due to transient overvoltages which occur due primarily to internal switching surge and external lightning surge are an important problems in electromagnetic compatibility(EMC). In this paper, we analyzed operation characteristic of metal oxide varistor widely used low voltage AC line using the electromagnetic transients program(EMTP) and compare it with experimental results and also, we modeled combination generator producing $1.2/50{\mu}s$ open circuit voltage and $8/20{\mu}s$ short circuit current as a source which is critical in calculating operation characteristic. Simulation results showed that most of Transient energy consumes at MOV located in service entrance side than load side, and it showed similar to experimental results. Therefore, entrance side MOV should be selected more energy capacity than that of load side MOV.

• 대한전기학회논문지:전력기술부문A
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• 제53권10호
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• pp.542-549
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• 2004

The conventional fault location algorithms based on the travelling waves have an inherent problem. In cases of the close-up faults occurring near the relaying point and of the faults having zero degree inception angle of voltage signals, the conventional algorithms can not estimate an accurate fault distance. It is because the shapes of travelling waves are near sinusoidal in those cases. A new method solving this problem is presented in this paper. An FIR(Finite Impulse response) filter which makes high frequency components prominent and makes the power frequency component and dc-offset attenuated is used. With this method, the cross-correlation peak is to be very clear when a close-up fault or a fault having near zero-degree inception angle occurs. The cross-correlation peaks can be clearly distinguished and accurate fault location is practically possible consequently. A series of simulation studies using EMTP(Electromagnetic Transients Program) show that the proposed algorithm can calculate an accurate fault distance having maximum 2% or less error.