A Study on the Optimal Position of Lightning Arrester on Joint Operation of Neutral Wire and Overhead Grounding Wire through Lightning Surge Analysis in Combined Distribution System

혼합배전계통에서 뇌과전압 해석을 통한 중성선과 가공지선 혼용 운전시 적정 피뢰기 위치에 관한 연구

This paper studies the validity about a joint operation of neutral wire and overhead grounding wire in combined distribution systems. The overhead grounding wire and neutral wire are currently installed separately and grounded by common. However there is no any ineffectiveness or electrical problem in case of the proposed system, such system can be operated at real distribution system. Therefore this paper describes the suitability of a joint operation through lightning surge analysis on combined distribution systems and analyzes the optimal position of lightning arrester on joint operation of neutral wire and overhead grounding wire. Lightning surge analysis is carried out by EMTP/ATPDraw to obtain the overvoltage of overhead line and underground cable in various conditions such as location and current types of lightning stroke. Over voltage gained by the analysis show that the insulation strength of the joint operation case is not stable compare with the current operation case.