• 제목/요약/키워드: Grounding systems

검색결과 231건 처리시간 0.021초

3가지 접지방식에 대한 접지특성비교 (The Comparison on Grounding Characteristics for 3 Grounding Systems)

  • 신동호;김용;백수현;이은영;김필수;조대훈
    • 대한전기학회논문지:전력기술부문A
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    • 제49권6호
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    • pp.289-297
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    • 2000
  • This paper presents a comparison on the resistance and characteristics of transient response of grounding systems under surge currents using frequency domain electromagnetic field analysis software package and field test. Analysis is done by computer model, based on electromagnetic field theory approach, that accurately takes into account frequency dependent characteristics of the system. The transient performance of three grounding systems is analyzed by comparison of frequency dependent impedance and the maximal transient GPR. A double exponential lighting surge current is injected at one corner of the grounding systems. The transient GPRs a rod grounding systems are higher than mesh or electrolytic grounding systems. Af field test, the results of resistance measurement and time-variant of ground resistance slightly reduce electorlytic grounding systems less than rod and mesh grounding systems.

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접지계의 경년변화 특성에 관한 연구 (A Study on the Secular Change Characteristics of Grounding Systems)

  • 김재이
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제54권5호
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    • pp.224-226
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    • 2005
  • In this paper, the secular changes of buried grounding electrodes was investigated; the electrodes are such facilities as grounding grid, grounding connector, grounding terminal and grounding rod etc.. The corrosiveness of removed substation grounding electrodes after commercial operation more than 50 years was measured and its conductivity deterioration trend was analyzed. The measuring results using three experimental methods were compared, finally the consideration for safe and economic grounding design were shown. As the result, it shows the maintenance necessity of grounding systems.

A Study on Lightning Overvoltage Characteristics of Grounding Systems in Underground Distribution Power Cables

  • Jung, Chae-Kyun;Jung, Yeon-Ha;Kang, Ji-Won
    • Journal of Electrical Engineering and Technology
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    • 제9권2호
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    • pp.628-634
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    • 2014
  • This paper investigates the transient characteristics of grounding systems used in under-ground distribution power cables. Recently, two kinds of grounding system are used for underground distribution cables in Korea. The first one is conventional multi-point grounding system, the other is newly proposed non-bundled common grounding system. The non-bundled common grounding system has an advantage the decreasing the power loss due to decrease of the shield circulation current. In this paper, the lightning overvoltage induced in neutral wire (in case of non-bundled common grounding system, overvoltage between opened neural wires and grounding in each phase) of these two kinds of grounding systems are estimated and compared by field tests and EMTP simulations. The EMTP simulation methods are firstly verified by comparison of measurement and simulation. Finally, the insulation level against lightning is expected by EMTP simulation results using verified model.

서지전류에 대한 과도접지임피던스의 특성 (Characteristics of Transient Grounding Impedance under Surge Currents)

  • 이덕희;박종순
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권11호
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    • pp.717-723
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    • 1999
  • The transient characteristics of grounding systems play a major role in the protection of power equipments, electronic circuits and info-communication facilities against surges which arise from lightning or ground faults. Electronic devices are very weak against lightning surges injected from grounding systems and can be damaged. The malfunction and damage of electronic circuits bring about bad operation performances, a lot of economical losses, and etc. Therefore, in order to obtain the effective protection measure of electronic devices from overvoltages and lightning surges, the analysis of the transient grounding impedances in essential. One of this work is to examine the transient behaviors of grounding impedances under steplike currents for various grounding systems. And the other of this work is to evaluate the transient behaviors of a grid with rods under impulse currents and to investigate the effect of grounding lead wire. Transient grounding impedances of a grid with rods under impulse current waves have been measured as a parameter of the length of the grounding leads. Z-t, Z-i and V-i curves of transient grounding impedance under impulse current waveforms have been measured and analyzed. It was found that the grounding impedance gives the inductive, resistive and capacitive aspects under steplike current. Transient grounding impedance characteristics were very different with shapes, geometries of ground electrodes. Also, they were dependent on the waveform and magnitude of impulse current.

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무선중계소 접지계의 과도특성 해석 (An Analysis of Transient Characteristics on Grounding Systems in the Radio Relay Station)

  • Wang Kim
    • 전자공학회논문지A
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    • 제30A권9호
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    • pp.1-5
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    • 1993
  • The surge impedance of grounding systems must be accurately computed for a safe grounding design. Specifically, the case of radio relay station in a mountaintop region is required special design method using transient analyses. To approach these design objectives, this paper presents an algorithm to compute the surge impedance of two or more grounding systems using the Laplace Transform technique and deals with the analysis of the transient characteristics on grounding systems. Also, simulation results are compared with the measured data to prove the validity of the algorithm.

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국제 규격 접지시스템의 국내 적용을 위한 시뮬레이션 기반의 안전도 평가 방안 (Method for Safety-Decision to Apply International Standard Grounding Systems to Domestic Power System by Computer Simulation)

  • 이순;김정훈;박정욱
    • 전기학회논문지
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    • 제57권3호
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    • pp.344-353
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    • 2008
  • To apply the appropriate new grounding system to domestic power system, safety has to be guaranteed under the given circumstances. It is not possible to decide the safety of grounding systems by the experimental test because safety experiments directly relate to the human life and the installed electric machines. Therefore, the computer simulation program to decide the safety of grounding systems based on the IEC standard systems, has to be developed. This paper proposes the computer simulation based method to decide the safety of grounding system with the concepts of touch voltage, step voltage, human resistivity, and applied electric current according to the several conditions of human body located in the corresponding grounding systems. The proposed method is implemented by Matlab/Simulink and Visual C++ programming tools for its visualization.

서지 전류에 의한 접지계의 과도응답 특성 및 접지저항 비교 (A Comparison on the Resistance and characteristics of Transient response of Grounding Systems under Surge Currents)

  • 신동호;김용;정철희;조대훈;김필수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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    • pp.222-225
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    • 1999
  • This paper presents the surges response of the grounding systems using frequency domain electromagnetic field analysis software package. The frequency and time domain performance of a building grounding systems subjected to a lighting strike is described and discussed. The computed scalar potentials is presented graphically as a function of spatial coordinates. A double exponential lighting surge current is injected at one corner or the building grounding systems. Time-variant response of rod, mesh and kit grounding systems under impulse currents have been obtained. This paper deals with the results of studies on the time variation of ground resistance in three grounding systems.

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노이즈 저감을 위한 접지시스템 진단 엔지니어링 (Diagnosis Engineering of Grounding System to Reduce Noise Signals)

  • 조대훈;이기식
    • 전기학회논문지
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    • 제65권7호
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    • pp.1290-1294
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    • 2016
  • In this study, we investigate the sources of system malfunctions by measuring and diagnosing various surges and noise signals from grounding systems for electrical and electronic systems and installations in order to ensure the reliability and stability of the system operations. We measured performance or structural problems detected in the grounding systems currently in operation and analyzed the measured data in order to eliminate noise currents and interferences causing the systems to malfunction and be damaged. Based on the analysis results, we proposed improving grounding systems and the wiring arrangements most appropriate for the grounding systems and carried out the installations as per the proposed engineering. We verified that the proposed engineering made the status of system operations improved by measuring the ground noise signals during the system operations and comparing them before and after improvements being carried out.

서울메트로 접지시스템의 경년변화에 따른 개선 접지 기준 (A Study on the Unification of The Grounding System of SeoulMetro due to Ageing)

  • 민병훈;김균식;정용기
    • 한국철도학회논문집
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    • 제9권4호
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    • pp.394-400
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    • 2006
  • Since Seoulmetro built the first line of electric railway at seoul 1974, the passengers of railway have been increased rapidly, and electric railway requires more electric power for the greater capacity of transport. It is important that we prevent the accidents related with the subway, because all systems of subway are constructed in artificial underground structure. Since the previous versions of the earth system were built to meet the old standards of the electric facility for the lightning, some accidents related with the DC earth fault are causing secondary damages to the electric equipments. So, the old grounding system must be improved, and new standards of grounding system are required. We compare the grounding systems of the domestic railway corporations and the accidents that are related with the grounding systems. And we give ideas to improve the grounding systems and present standards which are suitable to electric railway.

축소모델 기법을 이용한 대규모 접지계의 특성분석 (Characteristic Analysis elf Large Grounding system by Using Reduced Scale Model Method)

  • 장석훈;이재복;명성호;조연규;김점식
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제53권3호
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    • pp.162-167
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    • 2004
  • The scale model grounding systems to study the behavior of grounding system in uniform soils have been designed and fabricated. Constructional details and instrumentation have been discussed. To verify the accuracy of the results obtained from the experimental tests, they have been compared with computer calculation results. Also, in order to assess the effectiveness of bonding two grounding systems, grounding grid conductors which were downsized as a scale factor of 100:1 were analyzed by using the scale model method. A profile of GPR(Grounding Potential Rise) of each case was measured. The scale model grounding system presented in this paper can be valuable tool to analyze the ground potential profile and ground resistance of practical grounding system.