• Title/Summary/Keyword: Protection system

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Performance Evaluation of Protection against Electric Shocks for TT and TN Systems (TT, TN접지계통의 감전보호 성능평가)

  • Lee, Bok-Hee;Choi, Young-Chul;Yoo, Jae-Duk;Shin, Hee-Kyung;Yang, Soon-Man;Kim, Tae-Gi;Lee, Zu-Cheul
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.10a
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    • pp.315-318
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    • 2009
  • Electric shock is the accident caused by the current through a person or animal's body. That is characterized by the physiological effects. In this paper, we evaluate performance of protection against electric shocks for TT and TN grounding systems which are used by a low voltage consumer nowadays. The performance of protection against electric shocks for TT grounding system is very excellent in equipotential area of the third class grounding, but the performance is poor outside the equipotential area. The performance of protection against electric shocks for TN grounding system is excellent because the potential difference is less than 50V. Accordingly, the performance of protection for TN grounding system is good as compared with that for TT grounding System.

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Setting Considerations of Distance Relay for Transmission Line with STATCOM

  • Zhang, Wen-Hao;Lee, Seung-Jae;Choi, Myeon-Song
    • Journal of Electrical Engineering and Technology
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    • v.5 no.4
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    • pp.522-529
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    • 2010
  • Distance relay plays an important role in the protection of transmission lines. The application of flexible AC transmission systems (FACTS) devices, such as the static synchronous compensator (STATCOM), could affect the performance of the distance relay because of compensation effect. This paper analyzes the application of distance relay on the protection of a transmission line containing STATCOM. New setting principles for different protection zones are proposed based on this analysis. A typical 500 kV transmission system employing STATCOM is modeled using Matlab/Simulink. The impact of STATCOM on distance protection scheme is studied for different fault types, fault locations, and system configurations. Based on simulation results, the performance of distance relay is evaluated. The setting principle can be verified for the transmission line with STATCOM.

FACTS controller design for improving Power System damping (제동력 향상을 위한 FACTS기기제어)

  • Yoon, Jong-Su;Lee, Gun-Jun;Moon, Gun-Woo;Yoon, Suk-Ho;Choo, Jin-Boo
    • Proceedings of the KIEE Conference
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    • 1997.07c
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    • pp.835-837
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    • 1997
  • This paper presents a control system design for the STATCON of FACTS devices by LQR, LQG control scheme to enhance small-signal stability in the power system, the feature of this FACTS controller is coordinated with generator exciter controller(AVR, PSS) to improve the total power system stability and performance.

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Cathodic Protection Behavior of Coastal Bridge Structure with Sacrificial Anode Cathodic Protection System (희생양극식 음극방식이 적용된 해안 교량 구조물의 방식거동)

  • Ha, Ji-Myung;Jin, Chung-Kuk;Jeong, Jin-A
    • Corrosion Science and Technology
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    • v.11 no.6
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    • pp.242-246
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    • 2012
  • This measurement represents the effectiveness of sacrificial anode cathodic protection (SACP) system in a coastal bridge structure. To verify the cathodic protection (CP) effect, the monitoring sensor (DMS-100) that could measure potential, corrosion rate, current, concrete resistivity, and temperature was embedded. The measurement conducted for three years after CP system was installed. Specifically, due to the fact that fresh water and sea water was repeated in the bridge structure, this bridge structure presented special CP behavior. Measurement factors were CP potential, CP current, concrete resistivity, and depolarization potential. In addition, visual inspection was also carried out. As a result of current and depolarization measurement, CP system was well activated in most piers.

A Study on the Protective Coordination and Automatic Setting Method using Agents in Distribution System with Loop (루프 배전계통에서 Agent를 이용한 보호협조 및 자동정정 방법에 관한 연구)

  • Jin, Young-Taek;Lee, Seung-Jae;Choi, Myeon-Song;Lim, Seong-Il;Kim, Wan-Tae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.8
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    • pp.1107-1114
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    • 2012
  • In this paper, we propose protective coordination and automatic setting method using agents for distribution system with loop. The proposed protection scheme adopts an agent technology assuming communication among protection agents and auto-switch agents. Having exchanged fault-related information with each other, protection agents and auto-switch agents perform the primary and backup protection and fault section isolation, respectively. this proposed scheme using agents for distribution system with loop is implemented by matlab. Because of the various configuration of distribution system, It's difficult to find cooperative agents for each agent. This paper develops a program to automatically set the cooperative route for the agents.

Development of Distributive Independent IDPACS(Integrated Digital Protection And Control System) (분산 독립형 변전소 종합 보호 제어 시스템 개발)

  • Koh, Jae-Hak;Cho, Kyung-Lae;Ahn, Bog-Chan;Won, Hoi-Kwang;Lee, Kwon-Han;Cho, Nam-Gook;Shin, Hee-Seung
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.919-921
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    • 1996
  • Recently, a growing demands on electricity require a high performance and reliable operation in the area of protection, control and monitoring of power plants and substations which may not provides with conventional systems. This paper describes a novel IDPACS (Integrated Digital Protection And Control System) in which we integrate all protection, control and monitoring function of the substations. The simulation results show that the proposed system provides fast response and reliable operation of power plant with superb performance on protection and control system.

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Development of Protection Coordination Algorithm for Smart Distribution Management System using Communication Method based on IEC61850 (IEC61850 기반의 통신방식을 이용한 스마트 배전운영시스템용 보호협조 알고리즘 개발)

  • Chu, Cheol-Min;Yun, Sang-Yun;Kwan, Seung-Chul;Chu, Kyung-Yong;Jin, Young-Kyu;Choi, Myeon-Song
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.10
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    • pp.1412-1419
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    • 2012
  • In this paper, we propose the protection coordination algorithm using communication methode based on IEC 61850. The communication protocol in power distribution management system has been issued by IEC standard, IEC61850 of them, which was made for substation automation system, has researched to apply into power distribution system, even though the standard is not a suitable for the system. In smart distribution management system' launched in 2009, the communication network based on the ethernet network for IEC 61850 has been designed to apply the self-healing concept, which is to perform the system protection through the communication between remote terminal units(RTU) according to the standard. However, it is first time to apply the scheme in the real. Thus, this paper proposed the protection algorithm and consideration for applying communication method and introduced the result of demonstration.

The Field Test of a Mitigation Method from DC Subwaysystem for Underground Pipeline

  • Bae, Jeong-Hyo;Ha, Tae-Hyun;Ha, Yoon-Cheol;Lee, Hyun-Goo;Kim, Dae-Kyeong
    • Corrosion Science and Technology
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    • v.6 no.6
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    • pp.308-310
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    • 2007
  • The owner of underground metallic structures (gas pipeline, oil pipeline, water pipeline, etc) has a burden of responsibility for the corrosion protection in order to prevent big accidents like gas explosion, soil pollution, leakage and so on. So far, Cathodic Protection(CP) technology have been implemented for protection of underground systems. The stray current from DC subway system in Korea has affected the cathodic protection (CP) design of the buried pipelines adjacent to the railroads. In this aspect, KERI has developed a various mitigation method, drainage system through steel bar under the rail, a stray current gathering mesh system, insulation method between yard and main line, distributed ICCP(Impressed Current Cathodic System), High speed response rectifier, restrictive drainage system, Boding ICCP system. We installed the mitigation system at the real field and test of its efficiency in Busan and Seoul, Korea. In this paper, the results of field test, especially, distributed ICCP are described.

Real-Time HD Watermarking System in DTV environment

  • Hahm Sangjin;Lee Keunsik;Park Keunsoo
    • Journal of Broadcast Engineering
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    • v.10 no.2
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    • pp.131-138
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    • 2005
  • High-quality digital broadcasting contents are susceptible to illegal copy and unauthorized redistribution, which makes broadcasters difficult to protect valuable media assets. So, broadcasters and content providers need the technology for copyright protection of professional digital content. Digital watermarking technology is one of the most actively developed solutions for the copyright protection. This paper suggests the requirements of watermarking technology in DTV(Digital TV) environment for copyright protection and shows the developed real-time watermark embedding/detecting system for HD(High Definition)/SD(Standard Definition) video and experimental results of the system against watermark attack tests. Our watermarking system meets the watermarking requirements of invisibility, robustness and security of DTV environment.

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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