• 조명전기설비학회논문지
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• 제25권6호
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• pp.100-107
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• 2011

Since transmission and distribution neutral wires are connected with a substation grounding grid, it is very difficult to measure grounding resistance of isolated substation grounding grid after the substation is energized. It is impractical to isolate the grounding grid from other parallel connections such as distribution line neutrals and overhead ground wires for grounding resistance measurement only. In this paper, we proposed and demonstrated a novel measurement method of grounding resistance of isolated substation grounding grid. For this method, grounding current division factor and conventional FOP(Fall-Of-Potential) profiles were measured at power supplying 154[kV] substation. The obtained FOP profile was processed with the measured grounding current division factor to produce the grounding resistance of isolated grounding grid. Simulated FOP profile agreed well with the measured one showing the validity of the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1490-1492
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• 1999

This paper shows the accuracy of 61.8% rule which is based on the fall-of-potential method in field measurement of earth resistances, and proposes the measurement method which is applicable to the industries. This paper also finds the minimum distance to obtain the horizontal position in the earth resistance curves, and Proposes the standard form for measurement of earth resistance using the fall-of-Potential method.

• 대한전기학회논문지:전력기술부문A
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• 제53권4호
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• pp.234-237
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• 2004

Measuring ground resistance has been a popular method of evaluation of the grounding electrode performance. If some portions of grounding electrodes are lost by corrosion, aging or other reasons, consequent deteriotation of the grounding performance would be resulted. It is one of the reasons why it is required to evaluate the performance of grounding systems regularly. However, in case of the electric facilities with multi-grounded system such as power substations with multi-grounded overhead ground wires and/or distribution line neutrals, it is practically difficult to disconnect neutrals or skywires from the substation grounding mesh for the ground resistance measurement. In this paper, a method for the grounding performance measurement of multi-grounded systems, which is based on the measuring ground current distributions, has been proposed. A field test results has shown the validity of the proposed test method.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권4호
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• pp.234-234
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• 2004

Measuring ground resistance has been a popular method of evaluation of the grounding electrode performance. If some portions of grounding electrodes are lost by corrosion, aging or other reasons, consequent deteriotation of the grounding performance would be resulted. It is one of the reasons why it is required to evaluate the performance of grounding systems regularly. However, in case of the electric facilities with multi-grounded system such as power substations with multi-grounded overhead ground wires and/or distribution line neutrals, it is practically difficult to disconnect neutrals or skywires from the substation grounding mesh for the ground resistance measurement. In this paper, a method for the grounding performance measurement of multi-grounded systems, which is based on the measuring ground current distributions, has been proposed. A field test results has shown the validity of the proposed test method.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.307-312
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• 2002

For accuracy of an experiment, measure changing of grounding resistance by short period after construction and investigated the efficiency of grounding's different methode of parallel connection. We could confirm on measurement's accuracy, error through comparing the theoretical value and measured value. Therefore, reduction ratio can be expected from execution measurement to receive a target resistance value. By the result, we could evaluate the method of rod grounding electrode's proper execution

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2003년도 춘계학술발표대회 개요집
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• pp.143-145
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• 2003

The purpose of research is to measure power and dynamic resistance value through RMS module. Specially designed RMS-DC hardware module was tested. Its output which is obtained every half cycle was compared with that of commercial weld checker. The results show good agreement and the relative error in the measurement was found to be around 5%.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2000년도 학술대회논문집
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• pp.77-81
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• 2000

The purpose of this paper is to describe a new measuring method of ground resistance for the grounding system in energized power equipment and substations. It is very difficult to measure the accurate ground resistance in energized power equipment and substations because of the noise conducted from all external connections to the grounding system and harmonics components caused by unbalanced loads and overloads. The ground resistance that is measured with existing methods includes not only the effect of desired signals but also noise components for the measurement period in grounding system. The measured value of ground resistance can entirely be different from actual value. In this paper, to eliminate 60[Hz] power system interference and harmonic components the low-pass filter method was used in the measurement of ground resistance.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1332-1342
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• 2014

This paper proposes a novel test circuit for SiC transistors. On-state resistance under practical application conditions is an important characteristic for the device reliability and conduction efficiency of SiC transistors. In order to measure the on-state resistance in practical applications, high voltage is needed, and high current is also necessary to ignite performance for the devices. A soft-switching circuit based on synchronous buck topology is developed in this paper. To provide high-voltage and high-current stresses for the devices without additional spikes and oscillations, a resonant circuit has been introduced. Using the novel circuit technology, soft-switching can be successfully realized for all the switches. Furthermore, in order to achieve accurate measurement of on-state resistance under switching operations, an active clamp circuit is employed. Operation principle and design analysis of the circuit are discussed. The dynamic measurement method is illustrated in detail. Simulation and experiments were carried out to verify the feasibility of the circuit. A special test circuit has been developed and built. Experimental results confirm that the proposed circuit gives a good insight of the devices performance in real applications.

• 전기전자학회논문지
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• 제24권4호
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• pp.1129-1135
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• 2020

배터리를 사용함에 따라 노화가 진행되면 배터리의 충전 가능 용량을 나타내는 State of Health(SoH)가 줄어들게 된다. 배터리 모니터링 시스템(BMS)에서 SoH를 추정하는 것이 매우 중요하며, 이를 위해 배터리 내부 저항을 측정하는 방법이 많이 사용된다. 일반적으로 배터리에 특정한 주파수의 전류원을 인가하고 전압응답을 측정하여 내부저항을 연산한다. 충전기가 동작할 경우 전압응답에 충전 고조파 잡음이 발생하여 저항 측정의 정확도가 떨어진다. 본 논문에서는 충전잡음의 영향을 제거하기 위하여 강인한 배터리 내부저항 측정 알고리즘을 제안하였다. 전류원 신호와 전압응답 신호를 일정한 주기 동안 적분하여 잡음을 제거하는 방법으로 우수한 정확도와 안정된 연산결과를 보였다. 무정전 전원장치용 BMS에 적용하여 제안한 방법의 유용함을 입증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.79-81
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• 2000

Measurement used electrical sounding(MacOHM 2115, Japan) for large scale grounding resistance of So-Yang Dam hydroelectric power plant. To applied measurement method is fall of potential method. This result propose to method of efficient administration for grounding system.