Approach on the neutral grounding modes of 20kV distribution networks

The neutral grounding mode selection of distribution is one of the concernful problems faced in the modification of distribution. This paper researches and analyzes the three different neutral grounding modes of ungrounded-neutral mode, neutral Peterson coil grounding mode and neutral resistance grounding mode respectively. The selecting schemes of neutral grounding mode to different grid structure of distribution are presented. The calculation and principle of parameters for different grounding modes are introduced; which provides the theoretical basis and guidance to the selections of neutral grounding modes and related facilities in 20 kV distribution modifications.