• Title/Summary/Keyword: Over current relay(OCR)

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Operating Characteristics of Protection Coordination Devices in Distribution System interconnected with Distributed Generation (분산전원이 연계된 배전계통에서 보호협조기기의 운용특성에 관한 연구)

  • Kim, So-Hee;Ji, Seong-Ho;Kim, Sun-Young;Rho, Dae-Seok
    • Journal of the Korea Convergence Society
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    • v.2 no.2
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    • pp.35-45
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    • 2011
  • Recently, with the increasement of the interest about global warming, pollutions, and so on, a number of distributed generations(DGs) such as photovoltaic(PV) and wind power(WP), are interconnected with distribution systems. However, installing of DGs makes power flow changes such as directions, one-direction to bi-direction, and increasing/decreasing of fault current. Therefore, it may cause the critical problems. This paper proposes an evaluation algorithm for bi-directional protection coordination and presents an evaluation system for protection coordination based on this algorithm. Additionally, the result shows that the existing method may cause critical problems, and also the effectiveness of proposed method is verified.

A study on Optimal Operation of Protection Coordination Devices Evaluation System in Distribution System with Distributed Sources (분산전원이 연계된 배전계통에 보호협조기기 평가시스템의 최적운용에 관한 연구)

  • Ji, Sungho;Song, Bangwoon;Kim, Byungki;Rho, Daeseok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.6
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    • pp.2971-2978
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    • 2013
  • Recently, with the world-wide issues about global warming and CO2 reduction, a number of distributed generations(DGs) such as photovoltaic(PV) and wind power(WP), are interconnected with the distribution systems. However, DGs can change the direction of the power flow from one-direction to bi-direction, and also change the direction and amount of fault current of existing distribution systems. Therefore, it may cause the critical problems on the power quality and protection coordination. This paper proposes an operation algorithm for bi-directional protection coordination using and apply it for the evaluation system for protection coordination. From the simulation results It is found that the proposed method is more effective and convenient than existing method.

A study on An Optimal Protection System for Power Distribution Networks by Applying Multi-Agent System (Multy-agent system을 애용한 배전계통 최적 보호시스템 연구)

  • Jung, K.H.;Min, B.W.;Lee, S.J.;Choi, M.S.;Kang, S.H.
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.299-301
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    • 2003
  • In this paper, a protection system using Multi-Agent concept for power distribution network is proposed. Multi agent system consist of Feeder agent, OCR(Over Current Relay) agent, Recloser agent and Switch agent. An agent calculates and corrects its parameter by itself through communication with neighboring agents and its own intelligence algorithm. Simulations in a simple distribution network show the effectiveness of the suggested protection system. Multi-Agent System, protection of distribution network, Communication.

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Optimal Operation Algorithm of Protection Devices in Distribution Systems With PV System (대용량 태양광전원이 연계된 배전선로에 있어서 보호협조기기의 최적 운용알고리즘)

  • Kwon, Soon-hwan;Lee, Hu-dong;Nam, Yang-hyun;Rho, Dae-seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.5
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    • pp.17-26
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    • 2018
  • If a photovoltaic (PV) system is installed in a primary feeder interconnected with the PV system, bi-directional power flow can occur, and then, the magnitude and direction of the fault current can change, depending on the fault location and point of common coupling (PCC) of the PV system, and the time current curve (TCC) cannot be properly coordinated between protection devices. Also, it is difficult to obtain a proper time interval for protection devices because the conventional setting approach is applied, even though the PV system is installed and operating. Therefore, this paper presents three operation modes considering the operational conditions of the PV system to obtain setting values for protection devices. Based on the mode, this paper proposes an algorithm to calculate the optimal protection coordination time interval according to the introduction capacity of the PV system. In addition, this paper performs modelling of a distribution system with the PV system and protection devices by using Off-DAS S/W, and analyzes the characteristics of the time interval between the protection devices, such as substation relays, reclosers, customer relays, and PV customer relays. The simulation results confirmed that the proposed operational modes and setting-value algorithms are useful and effective for protection coordination in a distribution system for a PV system.