• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.6
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• pp.857-863
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• 2015

OF cable with excellent reliability and economic efficiency, has been used as the main cable of underground transmission in Korea. However, as XLPE cable is excellent in view points such as reduction of loss, convenience on the construction/operation, and manufacturing technology, it has been replaced as instead of OF cable. Also, when the aging occurs in some sections of OF cable, the section is replaced as XLPE cable without changing of whole cable line. However, there are some differences like electrical constants between both types of cables. Therefore if underground transmission system will be operated as combined connection composited of both cables, it should be proved that overvoltage is stable in steady and transient state. This paper describes the effectiveness of connection operation in combined OF and XLPE cable. For the evaluation of effectiveness, some important analysis such as sheath component voltage, lightning and switching overvoltage, single line-to-ground fault are carried out in steady and transient state. EMTP/ATPDraw is used for modeling and analysis of system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.823-826
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• 2013

Subscriber Protector is installed in a point of connection between main wire and in-plant cable to protect telecommunication facilities and service users from overvoltage or overcurrent due to the lightning or induction. In Korea, there are regulations for obligation of installation and performance criteria of protectors, but these regulations in force can not cope with diversification of services because it stands on the basis of PSTN service only. In earlier paper, we suggested the improvement way of technical regulation for subscriber protector in customer premises. and in this paper, we propose revised criteria for overvoltage performance of protector in customer premises, and make feasibility of revised criteria through inspection tests.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.6
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• pp.66-71
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• 2003

Electronic equipments made from integrated circuits and small-sized semiconductors is protected by surge protective devices(SPDs) such as ZnO varistors, Zener diode and gas discharge tube from lightning overvoltages. However the clamping voltage of SPDs is greatly influenced by the method of installing the SPDs. In this paper, the protective effects of SPDs according to types of system groundings were experimentally investigated. The separate grounding is a particularly undesirable way to install SPDs. The effectiveness of the common grounding point for ZnO varistors is more pronounced than that for gas discharge tubes. The common grounding at the terminal of SPDs is recommended as a best method of installing SPDs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.2
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• pp.46-53
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• 2007

Extension of the mobile communication and the rapidly developing services connected with wireless multimedia(W-CDMA, DMB, Wibro, and so on) need great many base station transceiver systems, antennas, and many signal transmission line to embody these services. The min communication appliances system is exposed always in danger of transient overvoltage by direct stroke or induced lightning surge flowing in through antenna because the antenna of base station transceiver system or relay equipment is combined with expensive communication network equipments through signal transmission line. Now, gas discharge tube(GDT) or narrow band stub arrestor which is used by the surge protector for communication use is exposing limitations as for lightning surge protective means of the communication facility with high speed and wide frequency band. Therefore, for improving performance of surge arrestor, we applied ceramic filter which can reduce lightning surge invading from antenna effectively, and proved that ceramic filter is effective in residual voltage reduction through the experimental research.

• Proceedings of the KIEE Conference
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• 2001.11a
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• pp.248-250
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• 2001

The surge protector is crucial power apparatus to guarantee the safe operation of power transmission of underground cable which can effectively restrain the overvoltage and inductive lightning stroke in power system. This paper describes the results of a study on the performance of ZnO varistors and surge protector for 154 kV underground cable. And, the influence of water tight and insulating performance was evaluated through such as surge protector of the armored design.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.2
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• pp.120-125
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• 2011

SPDs are increasingly being used against lightning and switching surge according to the applicable revised standard and equipotential grounding system. SPDs are equipped usually with a MOV voltage regulating element. The MOV, however, always is exposed to the danger of thermal runaway resulting from inrushing temporary overvoltage and deterioration. In this paper, the authors made two prototype SPDs built-in Instantaneous trip device and analyzed their limiting voltage through test of the MOV breakdown. As the result of the analysis, the SPDs built-in Instantaneous trip device was proven to be effective for protecting MOV against thermal runaway and Instantaneous trip device react for limiting voltage is considered that is applicable to SPD.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.276-278
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• 2007

This paper describes the analysis to install an arrester for an underground distribution line effectively. Currently, the underground distribution cable is protected by the arrester connected with overhead distribution line. However, riser pole arrester can't protect all parts of cable like the end of the underground distribution cable. To solve this problem, we installed the arrester on each cable and have measured the overvoltage made by lightning surge in each situation. The location to get effective results has been decided from the measured voltage above.

• Proceedings of the KIEE Conference
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• 2008.10a
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• pp.143-144
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• 2008

최근 국내에서 가스절연송전선(GIL: Gas Insulated Transmission Line)의 실계통 도입을 인하여 345kV급 GIL의 개발 및 적용을 위한 연구 및 검토가 수행되고 있다. 이 중의 하나가 가공송전선로 사이의 일부구간을 지중화 하여 GIL로 대치할 경우에 나타날 수 있는 써지에 의한 과전압의 검토이다. 가공선로의 일부구간을 GIL로 대치하는 데 있어서, 변전소 단이 원거리일 경우에는 변전소 내부의 차단기나 단로기 등 개폐 써지에 의한 과전압의 영향은 감쇄효과로 인하여 그다지 크지 않으며, 뇌써지에 의한 과전압이 주요 영향 요소로 작용하고 있다. 따라서, 본 논문은 뇌써지에 의한 GIL-가공선로 구간의 과전압을 검토하기 위하여 GIL과 인접한 가공선로 구간에 낙뢰가 유입된 경우를 가정하여 GIL에 발생되는 과전압 및 보호협조 방안을 분석한다.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.326-328
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• 2005

500kV 개스절연 변전소의 절연협조의 기본은 이상전압의 억제와 동시에 설비의 중요도, 적용형태를 고려하여 설비의 사고확율을 어떤 허용수준이하가 되도록 기기의 절연 강도와 배치를 결정하는 것이다. 일반적으로 변전소 뇌과전압에 영향을 미치는 요소로는 모선 형태 및 구성, 피뢰기의 위치와 설치대수, 피뢰기의 제한 전압-전류특성, 모선의 길이, 피뢰기와 피보호기간의 이격거리 등이 있다. 이 논문에서는 500kV의 개스절연변전소의 기기 절연강도 결정을 위하여 뇌침입시 변전소의 뇌과전압을 EMTP로 모의하여 뇌격의 크기, 뇌격지점, 피뢰기위치와 설치 대수, 등에 따른 최대과전압을 모의하여 BIL(basic inpulse level)을 선정하였다.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.323-325
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• 2005

경제성장에 따른 인구의 집중화 및 도시기능의 고도화에 따라 전력기술분야의 많은 변화를 요구하게 되었다. 좁은 지역에 대용량의 전력을 안정적으로 공급하면서 환경과의 조화를 이루기 위하여 SF6개스를 이용한 개스절연개폐기(GIS)의 이용이 증가하였다. 이 논문에서는 중동국가에서 많이 건설되고있는 400kV 개스절연 변전소의 절연협조를 위하여 일반적으로 변전소 뇌과전압에 영향을 미치는 요소인 모선형태 및 구성, 피뢰기의 위치와 설치대수, 피뢰기의 제한 전압-전류특성, 모선의 길이, 피뢰기와 피보호기간의 이격거리 등을 고려하여 뇌침입시 변전소의 뇌과전압을 EMTP로 모의하여 개스절연변전소의 기기 절연강도를 결정하였다. 결정된 절연강도는 위의 모의결과로 얻어지는 발생예상 전압에 적정한 여유를 두고 IEC규격을 따라 선정하였다.