Study of neutral grounding for 22 kV distribution system

To cope with restructuring of electricity market, application of 22 kV 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 (Electromagnetic 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 22 kV distribution line to confirm the accuracy of simulation result. Consequently, we have clarified the permissible range of neutral grounding resistance.