Neutral point grounding modes for 10kV grids in Shanghai Shinan area

With the continuous development of urban construction in Shanghai Shinan area, the 10 kV power grids have developed rapidly. More and more cables have been used, which resulted in the growing of capacitive current. Based on the actual grid situations of Shinan area and the measured capacitive current of nine substations, a basic criterion has been concluded for adjusting the neutral point grounding mode from grounding through arc suppression coil to grounding through low resistance after technically analyzing. The criterion is instructive for selecting the neutral point grounding mode of newly built substations and the rebuilt ones. In the last three years, two substations have been rebuilt to change the neutral point grounding mode based on the criterion. The subsequent actual operation of the two substations has proved the feasibility of the criterion.