• International Journal of Safety
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• 제9권2호
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• pp.1-5
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• 2010

In order to analyze the potential rise of ground surface of grounding grid installed in buildings, the grounding simulator has been designed and fabricated as substantial and economical measures. This paper describes the study of touch and step voltages with grounding grid where earth leakage current is injected. To assess risk voltage of grounding grid, the grounding simulator and CDEGS program were used to obtain measured data and theoretical results of this study. The grounding simulator was composed of an electrolytic tank, AC power supply, a movable potentiometer, and test grounding electrodes. The potential rise was measured by grounding simulator, and the touch and step voltages were computed by CDEGS program. As a consequence, the touch voltage and step voltage above the grounding grid were very low, but were significantly increased near the edge of grounding grid.

• Journal of Electrical Engineering and Technology
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• 제7권2호
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• pp.225-229
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• 2012

This paper proposes a reduced-scale simulator that can replace numerical analytic methods for the estimation of potential distribution caused by ground faults in various grounding systems. The simulator consists of a hemispherical electrolytic tank, a three-dimensional potential probe, a grounding electrode, and a data acquisition module. The potential distribution is measured using a potentiometer with a position-tracing function when a test current flows to the grounding electrode. Using the simulator, we could clearly analyze the potential distribution for a reduced- scale model by one-eightieth of the buried depth and length of the grounding rod and grounding grid. Once both the shape of the grounding electrode and the fault current are known, the actual potential distribution can be estimated.

• International Journal of Safety
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• 제8권2호
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• pp.9-14
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• 2009

This paper describes analysis of risk voltage for grounding electrode where earth leakage current is injected. To assess risk voltage of grounding electrode, the grounding simulator and CDEGS program were used to obtain measured data and theoretical results of this study. The grounding simulator was composed of a hemispherical water tank, AC power supply, a movable potentiometer, and test grounding electrodes. The shapes of grounding electrode model was ground rod. The potential rise was measured by grounding simulator, and the touch and step voltages were computed by CDEGS program. As a consequence, the potential rise of ground rod abruptly decreases with increasing the distance from the grounding electrode to the point to be tested. The touch voltage above the ground rod was low, but the step voltage was high. The measured results were compared with the computer calculated data and were known in good agreement.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.351-354
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• 2006

This paper deals with the potential interferences between ground rod and counterpoise. The ground potential rise and coefficient of potential interference were measured by using the hemispherical water tank grounding simulator and calculated from CDEGS program as functions of the configuration and size of grounding electrodes and the distance between grounding electrodes. The ground potential un and potential interference coefficient strongly depend on the distance between grounding electrodes, the arrangement and size of grounding electrodes.

• 전기학회논문지P
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• 제60권4호
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• pp.214-219
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• 2011

The substation grounding design,"IEEE Guide for Safety in AC Substation Grounding (ANSI / IEEE Std 80)"has been widely used. Substation grounding design and substation grounding resistance of grounding network site to predict the voltage at the risk of a very important task, which is a ground fault current due to the influx of the ground network and due to rise in the Earth's potential can be applied to human dangerous Voltage within safe tolerances be configured to be the ground because the network. IEEE Std. 80 for the substation construction safety equipment on the ground securing the ground electrode and the mesh around the boundary potential distribution in terms of risk analysis by the touch voltage and the reference was to clean up the definition and the basic steps of the voltage of the voltage limits the risk of peripheral grounding electrode Suppression by the simulator through a new secure from dangerous voltage design techniques were presented.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.440-445
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• 2007

This paper deals with assessment of risk component for electrical safety and investigation on the spot of computer room in elementary middle high school. The investigation was carried out side by side for floor, outlet, panel board, earth leakage circuit breaker at computer room In order to assess electrical safety at computer room, grounding simulator and power quality monitor have been used. Potential rise has been measured and analyzed for ground rod and grounding grid by using the simulator. Phase and neutral-line current have been monitored in real time. As a consequence, it is desirable for us to install conductive tile at floor of computer room Grounding grid had better than ground rod for electrical safety. Neutral-line current was produced by unbalanced phase current.

• 조명전기설비학회논문지
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• 제20권5호
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• pp.92-98
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• 2006

본 논문은 봉상접지전극 주변에서 접지전극간 전위간섭에 대해 다루었다. 접지전극 상호간의 전위간섭을 저감하는 기법을 제안하기 위해서 실규모 접지전각에서 발생될 수 있는 대지전위와 전위간섭을 이론적 해석과 축소모델 실험을 이용하여 실험적으로 분석하였다. 반구형 수조모의접지 실험장치로 접지전극 상호간 이격거리에 따른 전위 상승과 전위간섭계수를 측정하고, CDEGS 소프트웨어를 이용하여 이들 현상을 해석하였다. 그 결과 전위상승과 전위간섭계수는 접지전극의 이격거리에 강하게 의존하였으며, 실측결과는 이론적 계산결과와 잘 일치는 결과를 얻었다.

• 한국항해항만학회지
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• 제33권1호
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• pp.43-50
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• 2009

최근 해양사고가 날로 증가되고 있으며, 특히, 인적과실로 인한 충돌사고의 비중은 70%에 이르고 있다. 본 연구에서는 실시간 충돌 위험도 표시 시스템을 개발하였는데, 충돌위험도를 사전에 인지함으로써 비상상황에 효과적으로 대처하고, 인적과실로 인한 충돌위험도를 줄이고자 하였다. 충돌위험도 추정을 위해, 선박들 간에 충돌위험도를 평가하는 퍼지알고리즘을 이용한 방법과 항해사가 느끼는 환경스트레스를 이용하여 충돌위험도를 평가하는 방법의 두 가지를 비교 검토하였다. 실시간 충돌위험도 추정 알고리즘을 검증하기 위해 선박운항 시뮬레이터에 설치하고 다양한 시뮬레이션을 수행하였다.

• 한국산학기술학회논문지
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• 제7권6호
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• pp.1078-1085
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• 2006

시설물이나 장비로 surge wave가 유입되는 것을 방지하기 위해서는 접지시스템의 접지저항을 수 $\Omega$ 정도로 낮추어야 하지만 시공비를 낮추기 위하여 적절한 접지저항 값을 결정하는 것이 중요한 문제이다. 본 연구에서는 접지저항 simulator를 이용하여 최적화된 경제적 접지저항(임피던스) 값을 설정하였으며 수용성 알칼리족 원소와 활성탄소를 주성분으로 하는 새로운 접지충진제를 개발하여 접지품질을 개선하기 위한 전기적 특성을 평가하였다.

• 해양환경안전학회지
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• 제24권3호
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• pp.346-351
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• 2018

The proportion of collision in the total marine accidents is high. The main causes of collisions are navigation rule violation, safety speed violation, neglected watch-keeping and improper collision avoidance action. There are two main ways of avoiding collision situations during maritime navigation: the method of altering course and reducing ship's speed. The purpose of this study is to analyze the result of the collision avoidance action of the reserve officer in case of encountering a multiple number of ships using the ship handling simulator. Full-mission ship handling simulator was used to experiment the situation scenarios that encountered multiple ships. After the experiment, the questionnaire about the experiment was investigated. A total of 50 subjects were participated in the experiment. Experimental results showed that the number of the experimenters who used the engine was 11 and the number of the experimenters who did not use the engine was 39. In the case of using the engine, there were 0 collision accident, 1 grounding accident, and 10 no accidents. However, when the engine was not used, there were 28 collision accidents, 2 grounding accidents, and 9 no accidents. The causes of these results can be found in the survey results. 74 % of the non used engine participants said they were hesitate to use the engine. As can be seen from these results, the reserve officer are hesitant to use the engine and need a way to get correct of it. Maritime course subject can emphasize the importance of using ship's engines and case study also can be it. So, It is considered that various case study scenario will need to developed by various tools in the future.