• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.215-218
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• 2007

In this paper, we have analyzed the effects from the change of separation distance between grounding equipment at end of telecommunication line and the inducting facilities in power inducting situation. In the result of measurement, we can see that as the separation distance between grounding equipment ant end of telecommunication line and the inducting facility become longer, the induced noise level and PIF level is decreased. From the another experiment results about the effect of changing the impedance size in both ends of telecommunication line, however, we already knew that as the ground impedance at either end of the telecommunication line become grower, the noise level is increased, and as the ground impedance at either end of the telecommunication line become smaller, the noise level is decreased. Hence we can not define the relationship exactly between separation distance from inducting facility to inducted facility and the induced noise level because when the grounding equipment is moved, its impedance size is changed too. In conclusion, changing the separation distance between grounding equipment at end of telecommunication line and the inducting facilities have not influence on the induced noise level.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.470-480
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• 2008

After 1th line was built in 1974, the history of subway in Korea has been expended to 9th line which is under construction. It is time to prepare nation wide subway grounding system urgently according to the domestic electric standard that aligns to world wide standard by WTO/TBT treat (1995). Newly added grounding system to the fundamentally different system caused many problems. PSD(platform screen door) and other newly added equipment are also need grounding system. By the electrical code(established by Korea Electric Association), low voltage equipment(including grounding system) under 1,000V AC are in the process of change into IEC 60374. IEC 60364 standard will be added to the electrical code(established by Korea Electric Association) in 2007 and amended and after 3-5 years later, it will become a complete IEC 60364. So the purpose of this study is to compare the domestic rail road grounding system and suggest the standardized grounding system for the newly built subway.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 추계학술대회 논문집
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• pp.343-346
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• 2009

The grounding system of low voltage power systems is TT grounding system in Korea. In order to follow the international standard, TN grounding system is adopted. However, the performance of grounding systems has not been evaluated. This paper deals with the experimental results of protection ability of grounding system when lightning surge invades to the neutral line of low voltage power system. As a result, the TT grounding system is most frail for the lightning surge and it does not protect the electrical devices. On the other hand, the TN grounding system perfectly protects the electrical equipment and prevents the electric shock for human through the equipotential bonding. In case of TN system with supplement grounding, it is very important to lower the supplement grounding resistance to protect the electrical equipment and electric shock for human.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.313-318
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• 2002

Purpose of the grounding system design are establish a safe environment for personnel as well as the general public in the vicinity of the power system equipment, and establish a low resistance connection to earth such that protective devices detect and isolate faults quickly and potential rise of the grounding system does not exceed a value which could damage electrical equipment. This paper deals with the grounding system design for the electric facilities. In this paper, emphasize the necessity of the computer programs for the grounding system designs. Especially, earth soil models for the grounding system design are must used two-layered soil model.

• 전기학회논문지
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• 제62권9호
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• pp.1308-1312
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• 2013

In this paper, carried out for optimal ground system for ensuring safety for electricity used to power equipment in the 20 kHz frequency. Now the grounding system of the mesh electrode, electrode rods are installed for power plant safety and protection against electric shock. However, the electrical equipment grounding system in the 20 kHz were considering the increasing grounding impedance due to the high frequency and the magnetic shielding. But until now, there has been little research on the grounding system. To solve this problem, In this paper was proposed optimal grounding system due to the experiment using a mesh electrode, rod electrode, aluminum plate electrodes. Measurement results, grounding resistance was depending on the material of the electrode grounding resistance. In addition, the leakage current (induced) appeared to be affected depending on the type of electrode.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2001년도 학술대회논문집
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• pp.173-180
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• 2001

Electric power facilities must have effective grounding to provide means to carry electric current into the earth under fault conditions and to prevent damage of equipment, Ignition, and electrocution of presonnel. nuts paper present an algorithm called the Pattern Search method for the optimal parameters selection of the grounding system. Computer simulation results used the CDEGS grounding analysis program verifying the effects of the grounding system design parameters obtained from this method show that the grounding systems are adequately designed.

• 조명전기설비학회논문지
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• 제25권5호
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• pp.54-60
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• 2011

This paper presents characteristics of frequency-dependent grounding impedance and transient grounding impedance for the carbon compound grounding electrode used in the installation of computerized electronic equipment and lightning protection system. The frequency-dependent grounding impedances were measured by applying sinusoidal currents in the frequency range from 100 [Hz] to 10[MHz], and the transient grounding impedances were examined by subjecting the impulse current with the front-time between 1~80[${\mu}s$]. As a result, the ground resistance of the carbon compound grounding electrode is less than that of another type grounding electrodes. The transient grounding impedance is relatively low and the conventional grounding impedance is rather lower than the ground resistance. The frequency-dependent grounding impedance of the carbon compound grounding electrode is capacitive and the grounding impedance is decreased with increasing the frequency of injected currents. Therefore in the case that the carbon compound grounding electrode is jointly used with large-scaled grounding electrodes, it is possible to reduce the high frequency grounding impedance of the integrated grounding electrode system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.588-595
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• 2008

최근 기상환경 변화로 인해 낙뢰의 발생횟수가 증가하고 뇌전류의 세기가 점점 강해지고 있다. 접지 시스템은 시공당시에 어떻게 시공하느냐에 따라 그 성능이 좌우된다. 특히 매설접지선을 이용한 공용접지 방식은 시공 이후에 접지저항 측정으로는 관리하기가 곤란하므로 신설 및 보강시 정확한 설계와 철저한 시공이 이루어지도록 해야 한다. 철도신호설비의 접지시스템 배선방식은 독립접지 구간과 공용접지 구간에 따라 다르게 구성될 수 있다. 이렇게 다양한 환경아래에서 운용되는 신호설비에 대해서 표준접지방식을 제시하기란 매우 어려운 일이다. 각 개소별 정확한 현상파악 없이 일괄적으로 접지시스템에 대한 표준을 정한다면 해당구간에서의 주위 환경이 철도신호설비에 미치는 영향을 고려할 수 없기 때문이다. 따라서 본 논문에서는 철도신호설비의 접지시스템 구성현황을 검토하여 독립접지와 공용접지 구간별 개선방안을 제시하고자 한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.699-704
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• 2005

In the station of the railway and the subway various illumination equipment and a general power equipment for a passenger convenience, the signal equipment and the communication equipment which is necessary to the train operation provided. At the all of like this equipment from the electric room which is established in each station by changing from high voltage to low voltage and it supplies from the illumination transformer, the power transformer and the signal transformer. If it supplies to the equipment from the high voltage to the low voltage, it must be established to contact protection device in between the high voltage coil and the low voltage coil. Also it must do the grounding faulting device at the low voltage lines, the earthing devices at apparatus for the protection of an electric shock and an electric fire by the electric relation law. Compared the related regulations between the facilities which require protective functions such as grounding fault or earthing in public utilities like subway stations, and the facilities which do not require line earthing or protective functions such as electricity supplied for signalling the train. Also, will describe a countermeasure for the accident from a grounding fault.

• 전기학회논문지P
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• 제57권4호
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• pp.444-450
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• 2008

There are several ways to bond to building grounding systems for reducing GPR(ground potential rise) and EMI resulting from power system faults or lightning stroke to building. In order to verify effective bonding practice, the GPR and voltage of equipment due to the direct stroke to building are calculated with ATP-EMTP model for transformer, transmission line and MOV(Metal oxide varistor). The simulated model shows a satisfactory accuracy compared with experimental result for the $8/20{\mu}s$ simulated current pulse. It is observed that separate grounding can cause dangerous voltage to the building equipment and the performance of surge protective device can improve when it is installed to the protected equipment in distance as short as possible.