Research On Fault Location Method Of Distribution Network With Distributed Power Supply

With the development of power technology,distributed generation(Distributed generation,DG)technology has been developed rapidly.Distributed power supply has been widely used in various fields because of its green,efficient and low pollution characteristics.When the distributed power supply is connected to the distribution network,the traditional single power supply fault location method can not be applied,which will lead to the problem that the fault section can not be correctly determined and the staff maintenance will be affected.In view of the appeal problem,this thesis analyzes the research status of distribution network and its automation system at present,and two main methods for fault section location of distribution network at this stage: direct algorithm and indirect algorithm.The advantages and disadvantages of specific methods are analyzed.According to the function of feeder terminal equipment and the characteristics of distributed power supply connected to the network,the main methods of locating the traditional single radiation power supply section are analyzed.When the distributed power supply is connected to the grid from the bus position and from the feeder position to the grid,It will have a certain impact on the over-current information of feeder terminal equipment FTU.In order to solve the problem of segment location in distributed power distribution network,a fault section location method based on improved pigeon swarm algorithm is proposed.Pigeon swarm algorithm has the advantages of fast convergence and simple parameters,but it is easy to fall into local optimization in the process of iteration,and the number of pigeons will decrease rapidly in the process of landmark factor iteration.And the problem that affects the diversity of population.Aiming at the characteristics of DG merging into distribution network and the shortcomings of basic pigeon swarm algorithm,a pigeon swarm algorithm based on pigeon swarm algorithm and improved simulated annealing algorithm is proposed in this thesis.Seven different test functions are adopted,which are based on the pigeon swarm algorithm and improved by simulated annealing algorithm.The improved pigeon swarm algorithm is compared with the basic pigeon swarm algorithm.According to its iterative convergence curve and test results,the good convergence performance of the improved pigeon swarm algorithm is verified.The improved pigeon swarm algorithm is applied to the fault section location of distribution network with DG.Firstly,an improved switching function with the positive direction of the main power supply of the system is constructed to simplify the problem of determining the main power supply in the traditional multi-direction.Secondly,the improved evaluation function is established to prevent misjudgment.Finally,the model is established by Matlab,and theconvergence performance of the improved pigeon swarm algorithm is determined under the condition of single point fault,multi-point fault and information distortion,and the practical,fast and fault-tolerant ability of the method is verified by comparing the genetic algorithm.There are35 graphs,6 tables and 59 references in this thesis.