Research On Neutral Grounding Mode Reform Of Hefei 10kV Distribution Network

With the rapid development of Hefei urban and distribution network construction,the distribution network structure of Hefei city has undergone great changes.The rapid increase of cable rate leads to a large increase in capacitive current of the system,which puts forward new requirements for the grounding mode of distribution network.It is necessary for Hefei 10 k V distribution network to adopt the current mode of small current grounding operation,and carry out the research on the strategy of neutral grounding.This paper first analyzes the domestic and international distribution network neutral grounding mode and the development trend of Hefei city based on the current situation of the distribution network neutral point grounding via arc suppression coil capacity is not easy,using low resistance grounding and modification of the existing grounding mode of arc suppression coil dispersion compensation in two ways,from two aspects of technology and the economy with the two programs were compared,obtained the neutral point for Hefei city 10 k V distribution network with low resistance grounding mode.Research on Strategy of distribution network neutral interval theory of low resistance grounding transformation based on the comprehensive consideration of the impact of closed loop operation mode may appear neutral grounding via low resistance and in the process of transformation of the distribution network reliability and economic factors,the reliability index turned into economic index,and to the economy the best index of total target,choose the life cycle cost of the lowest neutral point grounding reconstruction as the target program.The whole life cycle assessment model of substation neutral point grounding transformation project is established,aiming at the analysis of the model,providing scientific decision-making basis for neutral grounding transformation.In view of the gradual development of substation transformation,the power supply sub area in Shushan,Hefei is selected as the research object.Based on the above mentioned neutral point grounding mode,the life cycle theory is reconstructed,and the transformation sequence of the substation to be rebuilt is clearly defined.The research results provide a theoretical basis and reference for the neutral point grounding transformation of distribution network in other cities in China.