• Title/Summary/Keyword: EMTP MODELS

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A comparison between digital algorithms for estimation of power system frequency (계통 주파수 추정을 위한 디지털 알고리즘 간의 비교)

  • Lee, B.H.;Kim, C.H.
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.276-277
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    • 2006
  • Estimation of power system frequency is an important task because frequency deviation is a good indicator of the system abnormal operating conditions. The algorithms, curve fitting, technique using Taylor series, deviation of phasor angle of fundamental waveform using DFT (Discrete Fourier Transform) and Prony method, are tested under operation of the frequency relaying by using EMTP MODELS. The performance of methods is compared with the simulation results.

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Neutral Current Calculation in One Step Type Pole (1단장주 중성선 전류 계산)

  • Seo, Hun-Chul;Park, Keon-Woo;Kim, Chul-Hwan
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.480-481
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    • 2006
  • This paper presents computation of the neutral torrent using KEPCO's distribution system model which is composed by only one step type poles. The used system model is modelled and simulated by using ATPDraw. And the neutral current is calculated by using EMTP/MODELS.

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A Reclosing Technique considering the Distributed Generation (분산전원을 고려한 재폐로 기법)

  • Seo, Hun-Chul;Kim, Chul-Hwan
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.270-271
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    • 2006
  • This paper presents the reclosing algorithm considering the DG(Distributed Generation). The algorithm consists of angle oscillation's judgment, EEEAC(Emergency Extended Equal-Area Criterion), calculation of optimal reclosing time and reconnection algorithm. The simulation is implemented for the three different DG technologies by using EMTP MODELS.

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Analysis and Model Establishment of OF Cable Underneath a Bridge on Underground Power Cable Systems (지중송전계통에서 OF케이블의 교량 첨가시 모델 수립 및 해석)

  • Lee, Hyun-Suk;Lee, Jong-Beom
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.2245-2246
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    • 2008
  • This paper analyses crossbonded cable system underneath a bridge. The simulation is performed under various system configuration such as cable length, iron frame size, lightning surge. The simulation models are established by EMTP/ATPDRraw. In this paper, the crossboneded cable system underneath a bridge is also analyzed for insulation coordination of iron frame and cables.

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SVC & TCSC Effects Power System in Multi-Machine (다기계통에서의 SVC와 TCSC특성 해석)

  • Sul, Yong-Tae
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.658-660
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    • 1996
  • This paper prescribe the effects of SVC & TCSC in multi-machine power system. EMTP models of two FACTS controllers are proposed to analysis the basic characteristics of SVC & TCSC and the control signal of TCR is determined by rms value which was measured in system. The oscillation model of generator is proposed to analysis the damping effect and the most effective location of TCSC in multi-machine power system is identified by the residues associated with the natural oscillation modes. The 3 generator-9 bus model system is used to demonstrate the applicability of the proposed model.

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A Study on the Out-of-Step Detection Algorithm using Time Variation of Complex Power-Part I : The Variation of Complex Power Trajectory in Complex Plane (복소전력의 변화율을 이용한 동기탈조 검출 알고리즘에 관한 연구-Part I: 복소평면에서의 복소전력의 궤적변화)

  • Kwon O-Sang;Kim Chul-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.54 no.7
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    • pp.345-351
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    • 2005
  • An out-of-step condition results from the loss of the synchronism of the generators. A disturbance in a power system causes the generator angle to oscillate. When there is a severe disturbance such as a heavy current fault loss of major generation or loss of a large block of load, the oscillation can be severe and even increase largely and finally the out-of-step condition may un. During the power swing and out-of-step conditions, the apparent impedance at a relay location changes, and the power flow also changes as the angle difference is varied. This paper presents a method to analyze the trajectory of complex power during a power swing and out-of-step condition. The trajectory of the complex power is analyzed when a power swings and a fault occurs. Moreover, the complex power is analyzed when the ratios between the voltages at both sides and the line impedances are changed. These methods are verified through simulation using the ATP/EMTP MODELS.

Discrimination Method of Internal and External Fault of Current Differential Relay using Instantaneous Value of Current in Case of Fault with One end CT Saturation (편단 CT 포화 고장 발생시 양단 전류 순시치를 이용한 전류차동계전기의 내·외부 고장위치 판별방안)

  • Lee, Myoung-Hee;Choi, Hae-Sul;Kim, Chul-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.12
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    • pp.1801-1806
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    • 2012
  • This paper presents a simple and practical method which enables to prevent malfunction of protection relay due to differential current caused by one end CT saturation in case of external fault. This method uses difference of magnitude(instantaneous value) between the both end current just before the occurrence of differential current without a separate method to CT staturation detection. One end CT saturation is simulated by current transformer model using type-96 component and the presented method is verified by using EMTP MODELS with respect to internal and external fault with one end CT staturation. The presented method distinguished rightly bewteen external and internal fault with one end CT saturation. This information can be used to prevent malfunction of current differential protection relay in case of external fault. And this method is not affected by sampling rate and has no calculation burden, so it will be applicable to differential current protection relay with ease.

Electric Arc furnaces: Chaotic Load Models and Transient Analysis

  • Jang, Gil-Soo;Venkata, S.S.;Kwon, Sae-Hyuk
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.923-925
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    • 1998
  • Electric arc furnaces (EAFs) are a main cause of 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 physical phenomena of EAFs. An alternative approach is to include deterministic chaos in the characterization of the arc currents. In this paper, 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.

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A Study on the Out-of-Step Detection Algorithm using Time Variation of Complex Power-Part II : Out-of-Step Detection Algorithm using a Trajectory of Complex Power (복소전력의 변화율을 이용한 동기탈조 검출 알고리즘에 관한 연구-Part II: 복소전력의 궤적 변화를 이용한 동기탈조 검출 알고리즘)

  • Kim Chul-Hwan;Heo Jeong-Yong;Kwon O-Sang
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.54 no.5
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    • pp.217-225
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    • 2005
  • In a power system, an out-of-step condition causes a variety of risk such as serious damage to system elements, tripping of loads and generators, mal-operation of relays, etc. Therefore, it is very important to detect the out-of-step condition and take a proper measure. Several out-of-step detection methods have been employed in relays until now. Most common method used for an out-of-step detection is based on the transition time through the blocking impedance area in R-X diagram. Also, the R-R dot out-of-step relay, the out-of-step prediction method and the adaptive out-of-step relay using the equal area criterion (EAC) and Global Positioning Satellite (GPS) technology have been developed. This paper presents the out-of-step detection algorithm using the time variation of the complex power. The complex power is calculated and the mechanical power of the generator is estimated by using the electrical power, and then the out-of-step detection algorithm which is based on the complex power and the estimated mechanical power, is presented. This algorithm may detect the instant when the generator angle passes the Unstable Equilibrium Point (UEP). The proposed out-of-step algorithm is verified and tested by using Alternative Transient Program/Electromagnetic Transient Program (ATP/EMTP) MODELS.

A Characteristic Analysis of Superconducting Fault Current Limiter in Power Systems (초전도 한류기 동작 특성에 따른 계통 영향 분석)

  • Rhee, Sang-Bong;Kim, Chul-Hwan;Kim, Kyu-Ho;Hyun, Ok-Bae
    • Proceedings of the KIEE Conference
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    • 2007.11b
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    • pp.207-209
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    • 2007
  • For proper application of the superconducting fault current limiter(SFCL), the prior investigation of fundamental characteristics and its effects to the distribution systems are needed. The Current limiting behavior of SFCL is dominated by quenching and recovery characteristics. So, we have developed an EMTP/ATPDraw model of resistive type SCFL using MODELS language. The operating characteristics and current limiting behaviors of SFCL in distribution systems have been simulated and investigated.

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