Research On The Fault Effect And Countermeasure Of Neufral Point Grounding In A 10kV Same Mother Back Line

With the development of social economy,the distribution network from the previous pure overhead network mode is developing into today's overhead and cable hybrid wode or pure cable network mode.Its wiring is more complex,and line corridors are becoming more complex.Especially,the cable line,the main line is mose couplex for the laying of cable trench the power distribution network.Economically developed areas,such as the Pearl River Delta,cable trench cable,dense,small space,there is no other cable isolation measures,from the point of failure of the group has occurred.Therefore,how to reduce the population failure from the root cause is the starting point and the practical significance of this study.The most direct influence of different grounding modes of substation on the power cable line are the length of the fault and whether the fault can be removed in time.This paper starts from the analysis of the different neutral point grounding,and the situation of the isolated light over the neutral point in different situations.Then,these puts forward some countermeasures.Firstly,this time is analyzes the common problems and characteristics of the common mother line and multiple return cable from the perspective of the practical case.Because of its wide influence,long duration and serious impact on the reliability of power supply.Analysis of arc over-voltage is even camp where a main reason,and to further explore the neutral point of the transformer station grounding arc over voltage line cable fire station,this paper puts forward the research topic of this paper,and discusses how to solve the problem.Secondly,the line of the substation and station simulation model and built carefully using PSCAD software,the simulation parameters are very close to site operation,simulation of grounding modes and different time arc over voltage in different neutral point are camiedon.Then best fitful neutral point grounding station connection are analy and decided.Based on the fault cutting time and accuracy,the paper studies the relationship between the different neutral point grounding mode and line protection action device.In case of line fault,the efficiency and sensitivity of the protection action are analyzed,and the time and the target value of the fault line are analyzed.It is proposed to adopt the neutral point grounding mode and the matching requirement of the station and the outside of the station.Finally,based on the above research and simulation,this paper summarizes the neutral point grounding mode,which is suitable for different power distribution line,to guide the design and construction requirements of power facilities,to achieve the goal of safety production,reduce the large area power outages and improve the reliability of power supply.