Study of neutral grounding method for 22kV distribution system

Analysis of voltage and current distribution in case of ground fault using power frequency model

Abstract

To cope with restructuring of electricity market, application of 22kV distribution system to areas with high load density, is promising. In this paper, we have studied the neutral grounding method considering low voltage rise and induced voltage to communication line in case of ground fault. We have performed EMTP(Electro-Magnetic Transients Program) simulation on several distribution system models with variation of line length and assembling representing actual distribution systems. We have also compared the simulation result with measurement performed on line imitating actual 22kV distribution line to confirm the accuracy of simulation result. Consequently, we have clarified the permissible range of neutral grounding resistance.