Fault Locating Method For Power Distribution Network Considering Distributed Power Generation

With the rapid development of my country’s national economy and technological level,the existing power distribution network system is becoming more and more difficult to meet the demand for green,reliable,safe and economical power supply.The rapid development of intelligent power distribution technology with distribution network automation as the core is of great significance for improving power supply reliability and power quality.With the increasing depletion of primary energy,the proportion of distributed renewable energy power generation will continue to increase.Distributed power sources can make full use of clean energy such as wind,photovoltaics,and tidal energy.They have high environmental protection,flexibility,safety,and have been rapidly developed in my country.However,when distributed power is connected into the medium voltage distribution network system,it may affect the correct operation of the relay protection device of the distribution network,and may also reduce the accuracy of the traditional distribution network fault location method.Therefore,as the network structure of the medium-voltage distribution network becomes more and more complex,and the scale of distributed power grid connection is gradually expanded,it is necessary to study the suitable fault location technology of the distribution network containing distributed power sources on the basis of distribution network automation.This article has carried out in-depth research in this field,and the main work is as follows:(1)The concept,structure,function of distribution network automation,as well as the classification and working principle of feeder automation are firstly reviewed.Principle of grid connection of distributed power,influence of distributed power access position on the fault location of the distribution network are then discussed.(2)A fault location method for distribution network based on improved matrix algorithm is proposed.This method improves the generation and calculation process of the network description matrix D,the fault information matrix G,and the fault judgment matrix P,reduces the amount of calculation,and improves the positioning efficiency and accuracy.This method can accurately determine the fault interval of the distributed distribution network system,and is also suitable for the special situation where the fault interval is at the end of the system.(3)A fault location method for distribution network based on packet differential evolution particle swarm optimization is proposed.First,The principles and shortcomings of the particle swarm optimization,and the differential evolution are analyzed.Then,a packet differential evolution particle swarm optimization is proposed by introducing the grouping algorithm.On this basis,the fault location interval model of the distribution network is constructed,so the location accuracy is improved by introducing misjudgment items.Then,the solution process on the packet differential evolution particle swarm optimization is given.Finally,the accuracy and practicability of the proposed method are verified through case studies.(4)Based on the distribution network automation master station of Yuci District,Jinzhong City,a fault location software based on packet differential evolution particle swarm optimization is developed.Composition of the main distribution network automation station is introduced.Interface and functions of the distribution network positioning software are elaborated.Furthermore,taking the Qiaodong Line of Yuci District as an example,the feasibility of applying the algorithm to actual projects is verified.