• 제목/요약/키워드: Fall-of-potential method Ground resistance

검색결과 27건 처리시간 0.023초

접지임피던스 측정시 보조전극의 배치 기준 연구 (Placement Standard Research of Auxiliary Probes when Measuring Ground Impedance)

  • 김동우;길형준;김동욱;이기연;문현욱
    • 전기학회논문지
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    • 제60권10호
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    • pp.1984-1991
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    • 2011
  • Among ground impedance measurement methods, the fall-of-potential method is the most thorough and reliable method. In the fall-of-potential method, ground electrode and auxiliary probes are placed in a straight line, and then, auxiliary potential probe is moved away from the ground electrode. The point at which plotted resistance curve flattens out is taken as right position of auxiliary potential probe. However, in some cases, it is hard to place ground electrode and auxiliary probes in a straight line. Therefore, we provided alternative placement method in this research. The method can be easily applicable to placing auxiliary probes. Also, this paper analyzed and compared ground impedance measurement standards of large grounding systems. Based on the analysis, practical measurement method using an earth tester was proposed. The proposed methods presented in this paper will be useful when determining locations of auxiliary probes in alternative positions, and the methods can be applied practically and easily.

봉상접지전극의 접지임피던스의 주파수의존성의 분석 (Analysis of the Frequency Dependent Characteristics of Ground Impedance of a Ground Rod)

  • 이복희;엄주홍
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제53권8호
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    • pp.426-432
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    • 2004
  • This paper presents a systematic approach of measurement, modeling and analysis of grounding system impedance in the field of lightning protection system and intelligent power equipments. The measurement and analysis system of ground impedance is based on a computer aided technique. The magnitude and phase of ground impedance were determined by the novel measurement and analysis using the revised fall-of-potential method. The ground impedances of the ground rod of 50 m long are considerably dependent on the frequency. The ground impedance is mainly resistive in the frequency range of 3-20 kHz. At higher frequencies, the reactive components of the ground impedances are no longer negligible and the inductance of the ground rod was found to be the core factor deciding the ground impedance. Although the steady-state ground resistance of the ground rod of 50 m was less than that of the ground rod of 10 m, the ground impedances of the ground rod of 50 m over the frequency range of more than 60 kHz were much greater than those of the ground rod of 10 m. Furthermore, the equivalent circuit model based on the measured data was proposed. and the calculated results were in approximately agreement with the measured data.

전위강하법에 의한 접지저항측정에 미치는 전위보조전극 위치의 영향 (Effects of the Position of Potential Probe on Ground Resistance Measurements Using the Fall-of-Potential Method)

  • 이복희;어주홍;김성원
    • 조명전기설비학회논문지
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    • 제15권2호
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    • pp.97-104
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    • 2001
  • 본 논문에서는 전위강하법에 의한 접지저항 측정시 전위보조전극 위치의 영향에 대하여 기술하였다. 전위강하법에서 접지저항은 이론적으로 전위보조전극을 피측정 접지전극과 전류보조전극이 이루는 일직선상에 위치시킬때 61.8[%]법칙을 적용하여 측정한다. 하지만 측정현장의 사정상 전위보조전극의 위치를 피측정 접지전극과 전류 보조전극이 이루는 일직선과 어느 정도의 각도를 가지도록 시설하여 접지저항을 측정하게 될 경우에 측정오차가 발생하게 되고 보정이 필요하다. 본 연구에서의 측정대상 전극은 길이 2.4 [m]의 봉형 접지전극으로 하였으며, 피측정 접지전극, 전위보조전극, 전류보조전극이 일직선상에 놓이지 않은 상태에서 접지저항을 측정하면 측정값은 항상 (-)의 오차를 나타내었고, 이들 전극이 이루는 각도가 증가함에 따라 측정 오차도 증가하였다.

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대체 보조전극을 이용한 접지저항 측정 신뢰성 분석 (Trust Analysis of Ground Resistance Measurements by the Substitute Auxiliary Electrode)

  • 이상익;유재근;전정채;전현재
    • 전기학회논문지P
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    • 제56권2호
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    • pp.109-114
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    • 2007
  • This paper summarize about the auxiliary electrode measured a ground resistance. The method to measure a ground resistance is the fall-of-potential method to using an auxiliary electrode. And an auxiliary electrode must be set up on the ground. Today it is so difficult to set up the auxiliary electrode on the ground because of many concrete building and many paved roads. So this paper is regarding a trust analysis of the ground resistance measurement by the substitute auxiliary electrode. It substituted a iron structure around the building, a neutral line multiplex ground to earth, a wire net for auxiliary electrode. This information is confirmed bv compared with the measurement value.

접지극의 공용화를 통한 접지저항 저감효과 분석 (Analysis of Ground Resistance Reduction Effect by Common use of Ground Poles)

  • 흥성택;이은춘;신강욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 A
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    • pp.440-442
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    • 2004
  • The ground resistance of middle scale ground pole was measured by using the 'fall of potential method' suggested by IEEE However, the measured resistance value was lower than the minimum value required To solve this problem. ground pole was set to be used commonly. In this research. ground resistance was measured using the newly suggested method and the results were analyzed to see if they satisfied the domestic regulation The results of this research will be applied to the management works as well as the establishment of new plan.

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대체 보조전극을 이용한 접지저항 측정값 비교 (Comparison of Ground Resistance Measurement Value by the Substitute Auxiliary Electrode)

  • 이상익;유재근;전정채;전현재
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 춘계학술대회 논문집 전기설비전문위원
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    • pp.85-87
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    • 2007
  • This paper summarize about the auxiliary electrode measured a ground resistance The method to measure a ground resistance is the fall-of-potential method to using an auxiliary electrode. And an auxiliary electrode must be set up on the ground. Today it is so difficult to set up the auxiliary electrode on the ground because of many concrete building and many paved roads. So this paper is regarding of the ground resistance measurement by the substitute auxiliary electrode. It substituted a iron structure around the building, a wire net for auxiliary electrode. This information is confirmed by compared with the measurement value.

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변이율을 활용한 접지저항 측정 기술 (Ground Resistance Measurement Technology Utilizing the Variation Rate)

  • 이상무
    • 조명전기설비학회논문지
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    • 제19권3호
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    • pp.51-56
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    • 2005
  • 접지의 성능을 결정하는 기본 요소인 접지저항을 측정하는 것은 성능평가를 위한 중요한 기술이 된다. 접지저항의 정확한 측정을 위하여는 측정 환경상 고려하여야 할 주요한 변수들이 있는데 실제의 측정 현장에서 이러한 변수들을 알고 측정하기는 곤란한 것이 현실이다. 본 논문에서는 3점전위강하법상의 전류전극에 이르기까지 나타나는 전위차 특성 곡선에 대하여 측정 환경 변수의 특성을 내포하고 있는 변이율이라는 개념을 도입하여 미지의 측정 환경 변수중에서도 가능한 접지저항의 참값에 근접한 측정을 지향하는 방법을 제의한 것이다. 이 이론은 이미 기검증된 논문들의 결과 내용을 분석함으로써 귀납적인 결론을 유도한 것이다.

접지선 전류를 시험 전류원으로 활용한 접지저항 측정기법에 관한 연구 (The Measurement of the Grounding Resistance Using the Ground Current of the Distribution System)

  • 강문호
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2004년도 학술대회 논문집
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    • pp.293-295
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    • 2004
  • Public utilities adopt the grounding rules ; class I, class II, class III and special class III, and install the grounding electrodes in distribution facilities. To keep the safety of the human and the facilities, Public utilities also manage the value of ground resistance in distribution system biennially. At present the Hook-On meter is normally used to measure the ground resistance although it has ${\pm}5[%]$ measuring error and it can not measure the exact value when the current is over 1[A]. In addition it is very difficult to use the fall-of-potential method in distribution system. In this paper we propose the new measurement method using ground current of distribution system as the current source.

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배전계통에 사용되는 봉형 접지전극의 접지 특성 분석 (Grounding Characteristics Analysis of the Rod-Type Grounding Electrodes used for Electric Distribution Systems)

  • 김경철;정지원
    • 조명전기설비학회논문지
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    • 제25권6호
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    • pp.49-56
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    • 2011
  • Grounding system insures a reference potential point for electric devices and also provides a low impedance path for fault currents or transient currents in the earth. The ground impedance as function of frequency is necessary for determining its performance since fault currents could contain a wide range of frequencies. In this paper, the grounding resistance, grounding impedance and transient grounding impedance are measured by using 3-point fall-of-potential method in order to analyse grounding characteristics of the copper and concrete rod grounding electrodes. An equivalent transfer function model of the ground impedance and transient grounding impedance are identified from the measured values by using ARMA method and evaluated by comparing the conventional grounding impedance.

접지저항 측정에 있어서 전류전극의 최소 이격거리 (Minimized Distance of the Current Electrode in the Measurement of Ground Resistance)

  • 이상무;강영흥;양준규
    • 조명전기설비학회논문지
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    • 제20권10호
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    • pp.68-73
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    • 2006
  • 접지저항을 측정하는데 있어서 전류전극의 이격거리는 일반적으로 접지전극으로부터 전류전극에 이르기까지의 직선 구간상에서의 전압강하의 변화 곡선에 소위 평탄 구간이 존재하도록 이격하는 것으로 알려져 있다. 그러나 이러한 전류전극 이격 기준의 문제점은 그와 같은 조건을 만족하기에는 현실적으로 곤란한 측정 현장이 있다는 것이다. 이러한 문제의 보완을 위하여 본 논문은 실험적 측정 데이터를 활용, 분석하여 전류전극 이격거리의 최소 규격을 제시하였다. 분석 결과에 의하면 봉상접지에 대하여는 봉 길이의 2배 이상을, 메쉬접지에 대하여는 한 변 길이의 2배 이상 이격하여야 함을 알 수 있다.