• 한국화재소방학회논문지
• /
• 제11권4호
• /
• pp.25-31
• /
• 1997

In this study, EMTP(Electromagnetic Transients Program) which is one of the most well-known computer simulation methods is used to collect the data for a power plant fault. EMTP is the program for an interpretation of the phenomena of electric transients, and is designed to manifest the data of the electric current and voltage etc. at the time of a power plant fault. By EMTP, I analyze the properties of the heat energy which are transferred from the electrics when a power plant fault brings out. In terms of the results of this study, it is able to measure the heat energy at a power plant fault (power transformer) and to be acquired of the related data. And moreover, these data are expected to be used as a standard for the protection of the fire owing to a high voltage power transformer fault.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
• /
• pp.2182-2183
• /
• 2005

A pulse generator of one stage magnetic pulse compression modulator was simulated by electromagnetic transients program (EMTP). The pulse generator was expected to generate ${\sim}80kV$ peak voltage, ${\sim}140ns$ pulse width and about $70{\sim}75%$ energy delivery efficiency from initial charge capacitor $(0.2{\mu}F)$ to dummy load $(25{\Omega})$. From this simulation, the scheme of pulse circuit could be estimated as a practically reasonable design.

• Journal of Electrical Engineering and Technology
• /
• 제11권3호
• /
• pp.592-601
• /
• 2016

This paper presents the modeling of insulated-gate bipolar transistor (IGBT) in electromagnetic transients program (EMTP) simulation for the reliable calculation of switching and conduction losses. The conventional approach considering the physical property of switching devices requires many attribute parameters and large computation efforts. In contrast, the proposed method uses the curve fitting and interpolation techniques based on typical switching waveforms and a user-defined component with variable resistances to capture the dynamic characteristics of IGBTs. Therefore, the simulation time can be efficiently reduced without losing the accuracy while avoiding the extremely small time step, which is required in simulation by the conventional method. The EMTP based simulation includes turn-on and turn-off transients of IGBT, saturation state, forward voltage of free-wheeling diode, and reverse recovery characteristics, etc. The effectiveness of proposed modeling for the EMTP simulation is verified by the comparison with experimental results obtained from practical implementation in hardware.

• 한국철도학회논문집
• /
• 제19권4호
• /
• pp.436-444
• /
• 2016

철도차량용 주변압기 고압권선은 고압인통선에 유기되는 이상전압과 내부공진을 발생 시킬 수 있는 다양한 주파수 대역의 고유주파수를 가진다. 공장시험은 다양한 파형과 지속시간을 지닌 이상전압의 여자가능성을 판단하는데 한계가 있다. 본 연구는 전자계과도해석프로그램(이하 EMTP)을 이용하여 고압권선 모델을 설계하고 초기 전압분포와 전압-주파수 관계 측면에서 내부공진특성을 모의분석한다. 턴 단위의 집중매개변수는 변압기 형상정보부터 계산되며, 각 레이어 단위로 합산된 서브모델은 네트워크 모델로 결합되어 EMTP의 라이브러리를 통해 구현한다. 사례연구는 주파수 변동에 따른 레이어 단위의 전압-주파수 관계 특성과 시계열 영역에서 전압 확대 및 분포 양상을 보여준다.

• 대한전기학회논문지
• /
• 제45권1호
• /
• pp.67-73
• /
• 1996

Subsynchronous resonance(SSR) causes a torsional shaft torque on the generator. Damages resulting from the uncontrolled SSR have resulted in the breakdown in the shaft and costs for replacement power. This paper is to determine the feasibility of controlling SSR by the fast modulation of series compensation capacitors. The presence of subsynchronous currents in the system was detected by a subsynchronous relay which was modeled by the transient analysis of control systems(TACS) in electromagnetic transients program (EMTP). The capacitor segments were switched by bi-directional thyristor switches. These were modeled into EMTP. The strategy to switch the capacitors were modeled as a closed loop system. The paper proves that effective control of SSR can be obtained only by the detuning of the system and the removal or blocking of subsynchronous energy from the system. (author). refs., figs., tabs.

• 전자공학회논문지T
• /
• 제36T권3호
• /
• pp.79-84
• /
• 1999

기존의 포트란-77로 작성된 EMTP(전자기 과도현상 해석 프로그램)는 폐쇄적인 구조로 되어 있을 뿐 아니라, 낮은 수준의 데이터 관리에서부터 실제적인 수치적 풀이에 이르기까지 그 기능을 만족하기 위하여 많은 양의 코드수를 사용하기 때문에, 수치적인 풀이의 프로그램화는 희석되어지고, 시각화는 거의 불가능하다. 그래서, 프로그램 모듈의 관리나 개발에 있어서 많은 어려움이 있다. 본 논문에서는 매트랩과 비주얼 C++을 사용하여 EMTP의 재개발을 위해 적합한 새로운 디자인 아이디어를 제안하고, 윈도우 환경에서 구동하는 새로운 EMTP 패키지의 개발을 제시한다. 이 패키지는 전기회로에서 과도현상의 해석을 위한 매트랩 계산 엔진과 그래픽 사용자 인터페이스 기능을 가진다.

• Journal of Electrical Engineering and Technology
• /
• 제11권3호
• /
• pp.602-608
• /
• 2016

Because of the random characteristics of lightning, the Monte Carlo method is applied to estimate the flashover rate due to lightning, however, the simulations using previous methods are difficult to both beginner and expert in power corporations. Therefore, this paper proposes the new and easy method to simulate the flashover rate by connection of electromagnetic transients program (EMTP) and MATLAB. The magnitude of a lightning strike is based on a curve measured in the field, while the classification of direct and indirect lightning depends on the striking distance. In a Korean distribution system, the flashover rate induced by lightning is simulated using proposed method. Simulations of the footing resistance according to the existence of an overhead ground wire (OHGW) are performed and the simulation results are discussed. The simulation results are compared with findings obtained with the IEEE Flash 2.0 program.

• Transactions on Electrical and Electronic Materials
• /
• 제15권3호
• /
• pp.117-124
• /
• 2014

The calculation of short-circuit currents is important for power systems operation and restoration, and for determining the means to protect human lives and properties. In this paper, a part of a power system network, around the D$\breve{e}$tmarovice power station in Czech Republic, was simulated by the well known program EMTP-ATPDraw (Electromagnetic Transients Program-Alternative Transient Program), and short-circuit currents and voltages were calculated at different points in the electric network and presented as a time function by the PlotXY program. Calculations were done just for phase-to-ground, and for the three-phase short-circuit at the Kun$\check{c}$ice substation. The results were important for determining the characteristics of the equipment required to withstand or break the short-circuit current; for this reason, the calculations were repeated using earth-fault resistances only for the case of busbar KUN shown in Figs. 5 and 6.

• 한국조명전기설비학회지:조명전기설비
• /
• 제11권3호
• /
• pp.88-96
• /
• 1997

본 논문은 배전시스템에서의 파라미터에 따른 과도현상을 분석하였다. 재투입에 의한 순간전압강하와 개폐서지를 분석하였으며, 이를 위해서 22.9[kV] 배전시스템의 실 데이터를 이용하여 다중접지된 모델 시스템을 구성하였다. EMTP 시뮬레이션을 통하여 주상변압기 2차측 수용가에서의 재투입 영향을 분석하였으며, 사고선로와 인근선로에서의 과도현상을 나타냈었다. 또한 사고위치, 부하크기, 부하역률, 캐패시터뱅크의 크기, 재투입 위상각에 대한 파라미터 분석을 하였고, 이들 요소와 재투입에 의한 과도 현상과의 관계를 나타내었다.

• 전기학회논문지
• /
• 제57권6호
• /
• pp.932-937
• /
• 2008

The transformer inrush current can cause a voltage drop by source impedance. This current can impact sensitive loads by the voltage drop. Therefore, it is necessary to take measures to limit this inrush current. This study, described in this paper, analyzes the power quality affected by transformer inrush current using the X power system in Korea. The Electromagnetic Transients Program(EMTP) is used to analyze the transient phenomenon. We discuss a method to model the hysteresis curve of the transformer in EMTP. We carried out various simulations to analyze the power quality during transformer energization. The analysis results of voltage drop by the inrush current occurrence when certain requirements are met are presented.