• Title/Summary/Keyword: power distribution line

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Current Control Method of Distribution Static Compensator Considering Non-Linear Loads (비선형 부하를 고려한 배전용 정지형 보상기의 전류제어 기법)

  • Kim, Dong-Geun;Choi, Jong-Woo;Kim, Heung-Geun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.7
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    • pp.1342-1348
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    • 2009
  • DSTATCOM(distribution static compensator) is one of the custom power devices, and protects a distribution line from unbalanced and harmonic current caused by non-linear and unbalanced loads. Researches about DSTATCOM are mainly divided two parts, one is the calculation of compensated current and the other part is the current control. This paper proposes a proportional-resonant-repetitive current controller. Improved performance of instantaneous power compensation has been shown by simulations and experiments.

The Analysis of Underground Power Line Communication Channel Characteristics by Measurements (지중전력선 통신채널 측정에 의한 특성해석)

  • Shin, Dong-Hwan;Choi, Jeong-Yeon;Lee, Seung-Jun;Woo, Hui-Gon;Shin, Jai-Ho;Eom, Ki-Hwan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.86-89
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    • 2009
  • In this paper, a broadband power line communication modem and network technology to develop tests with actual characteristics of the underground power line communication channel to be interpreted. Length and structure of the underground distribution line due to underground distribution line to the broadband powerline communication channels to measure the amount of attenuation on the signal generator, spectrum analyzer, such as contactless coupler was used to configure the channel measurement system. Demonstration tests in the test line as a single line by selecting the longest high-voltage lines where the two-channel measurement and signal attenuation on the noise level was measured. Measuring results degrade communication performance can be quite sure that was the presence of impulse noise, long lines, the line length was confirmed by the high-frequency attenuation appears.

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A Strategy for Balanced Power Regulation of Energy Storage Systems in a Distribution System during Closed-Loop Operation

  • Han, Yoon-Tak;Oh, Joon-Seok;Cha, Jae-Hun;An, Jae-Yun;Hyun, Seung-Yoon;Lee, Jong-Kwan;Seo, In-Yong;Kim, Jae-Eon
    • Journal of Electrical Engineering and Technology
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    • v.12 no.6
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    • pp.2208-2218
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    • 2017
  • To resolve overload in a distribution system, a distribution system operator (DSO) often performs a load transfer using normally open tie points and switches in the distribution line. During this process, the distribution system is momentarily operated in closed-loop operation. A closed-loop current in the distribution system can cause a power failure due to excess breaking current in the circuit breakers and reclosers. Therefore, it is necessary to calculate the closed-loop current exactly. However, if there are a large number of distributed generation (DG) systems in the distribution system, such as energy storage systems (ESS), they might obstruct the closed-loop operation based on bidirectional power flow. For quick and precise operation of a closed-loop system, the ESS has to regulate the power generation while satisfying closed-loop operation in the worst cases. We propose a strategy for balanced power regulation of an ESS. Simulations were carried out using PSCAD/EMTDC, and the results were compared with calculation results.

Ultrasonic Source Localization and Visualization Technique for Fault Detection of a Power Distribution Equipment (배전설비 결함 검출을 위한 초음파 음원 위치추정 및 시각화 기법)

  • Park, Jin Ha;Jung, Ha Hyoung;Lyou, Joon
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.4
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    • pp.315-320
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    • 2015
  • This paper describes the implemenation of localization and visualization scheme to find out an ultrasonic source caused by defects of a power distribution line equipment. To increase the fault detection performance, $2{\times}4$ sensor array is configured with MEMS ultrasonic sensors, and from the sensor signals aquired, the azimuth and elevation angles of the ultrasonic source is estimated based on the delay-sum beam forming method. Also, to visualize the estimated location, it is marked on the background image. Experimental results show applicability of the present technique.

A Study on Thermal Analysis of Dual Beam Laser Welding of Thin Metal Sheet (박판의 이중 빔 레이저 용접에서 열유동 해석에 관한 연구)

  • 김재웅
    • Journal of Welding and Joining
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    • v.15 no.4
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    • pp.99-108
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    • 1997
  • Analytical model for the temperature distribution and the cooling rate of weld in dual beam laser welding is presented for investigating the possibility of controling the cooling rate. The model is based on the solutions to the problem of heat flow due to the distributed and line heat sources for preheating and welding respectively in plates with finite thickness. The effects of beam power, beam distribution parameter, interbeam distance, and welding speed on the resulting temperature distribution and cooling rate are presented. The cooling rates of dual beam laser weld at the weld centerline under the investigated conditions are reduced to as one third of those of welds which were produced by single beam laser. And it appeared that the cooling rate of dual beam laser weld is strongly dependent on the process parameters of preheating laser beam power and welding speed.

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Stress intensity factor and stress distribution near crack tip for infinite body containing regid inclusion with crack shape (균열형상의 강체함유물을 포함하는 무한체에 대한 균열선단 부근의 응력분포와 응력세기계수)

  • Lee, Kang-Young;Kim, Jong-Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.3
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    • pp.680-683
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    • 1998
  • In case of the infinite body containing a rigid inclusion with line crack shape, stress intensity factor is determined and the relation between stress intensity factor and stress distribution near a crack tip is developed. Also, the relation between stress intensity factor and Kolosoff stress function is developed. Finally, these results are compared with those that the crack surface is under no traction.

Analysis of System Performance on DSTATCON Installation using EMTDC (EMTDC를 이용한 DSTATCON 설치 효과 분석)

  • Yoo, I.D.;Choi, Y.J.;Hong, S.W.;Lee, H.S.;Jeon, Y.S.;Lee, K.S.
    • Proceedings of the KIEE Conference
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    • 1998.07c
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    • pp.943-945
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    • 1998
  • This paper presents a method of modeling of DSTATCON (Distribution-line Static Condenser) for installation in a specific plant and analyze the effectiveness of the DSTATCON from the viewpoints of voltage regulation and harmonic mitigation in a distribution line. For the reliable modeling, detailed information on distribution system and loads is performed by field measurements. The DSTATCON has been modeled according to the control algorithm of real controller. The effectiveness of the DSTATCON installation is verified by simulation using EMTDC.

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A Method to Allocate Real Power Losses of Transmission Lines using Loss Distribution factors (손실배분계수를 이용한 송전선로 유효전력 손실의 배분법)

  • Ro, Kyoung-Soo
    • Proceedings of the KIEE Conference
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    • 1999.07c
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    • pp.1259-1261
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    • 1999
  • The paper proposes a simple method to calculate the portion of real power losses allocated to individual loads. The method is implemented by loss distribution factors, and analyses the share of loads in transmission line losses. Effectiveness of the algorithm is verified by a computer simulation. The results can be used to compute the cost of ancillary services under deregulated environment in electric power industries.

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An Investigation of the nominal rating current for breakers in distribution system due to the increased capacity of power transformer (주변압기 용량증설에 따른 배전계통의 차단기 정격차단전류 검토)

  • Cho, Seong-Soo;Han, Sang-Ok
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.396-397
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    • 2008
  • In order to evaluate the nominal rating of breakers in distribution system due to the increased capacity of power transformer from 60 to 100 MVA, the fault currents are calculated in the condition of 3-phase fault and single line-to-ground fault. Consequently, under the condition of the parallel operation of transformers the fault currents were exceed the nominal rating current of breakers in some areas.

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Study for Influence of grid-connected PV System on The Distribution System. (계통연계형 태양광발전시스템의 배전계통에 미치는 영향)

  • 정영석;강기환;유권종;송진수
    • Proceedings of the KIPE Conference
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    • 1998.07a
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    • pp.100-102
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    • 1998
  • In recent years, for the viewpoint of environment and electric power demand for stable secure, new energy such as photovoltaic system (PV) become increasingly popular. In case of interconnecting PV to the commercial electric company, two problems will occur when operating in isclation with the other general consumers. One is doing harm to the power quality. And the other is the security problem caused by charching a part of commercial system line that has to be no voltage. In this paper, a simple modelling of distribution system and grid-connected PV system and simulation result were proposed.

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