Application Research on Distance Protection in Distribution Network Containing Distributed Power Supply

For that traditional current protection has defects in distribution network which contains distributed power supply,distance protection application in distribution network is suggested to be considered.It can make up shortages of current protection by distance protection based on simulating verification,but its ability to tolerate transition resistance when being applied in medium and low voltage distribution network is poor.For solving this problem,this paper analyzes influence on distance protection by transition resistance when short circuit fault happening on double-side power lines in distribution network while connecting distributed power supply,studies out an algorithm by using sequence component algorithm for measuring fault resistance value by collecting current and voltage phase values of lines which may not be affected by transition resistance.Based on MATLAB simulating verification,it establishes a distribution network model containing wind power units.The simulating result proves that this algorithm can measure fault resistance value correctly and discriminate faults in protection area.Meanwhile,it is of high precision in calculation to remove influence on distance protection by transition resistance well.