Research On Fault Location Method Of Distribution Network With Distributed Generation

The distribution network directly connects with the users,and its safe and stable operation is very significant for the reliable power supply of the power system.With more and more distributed generation are connected into the distribution network in recent years,it has changed from the single-source radial network to multi-source complex network,and correspondingly,the direction of tendency has become more complex,which leads to the decrease of accuracy of traditional distribution network fault location method.It is very necessary to research a fault location method which is suitable for distributed generation switching and has high fault tolerance and reliability.In this thesis,based on the current fault location method studied at home and abroad,a fault location method based on the combination of the beetle antennae search algorithm and the improved genetic algorithm is proposed.Firstly,the concept and access criterion of distributed generation are briefly introduced.The influence of distributed generation on fault current is analyzed from two aspects of distributed generation access bus and feeder line.The detailed analysis is carried out from three situations:the distributed generation is located in the upstream and downstream of the fault feeder and is not in the same feeder as the fault section.The model of distribution network is built based on PSCAD/EMTDC simulation platform,which verifies the influence of distributed generation access on distribution network.Secondly,in order to solve the problem that the genetic algorithm is easy to converge too early and cannot accurately locate the fault in complex distribution network,this thesis optimizes the traditional genetic algorithm in the aspects of genetic operator and self-adaptability,and the fault location is carried out by combining the high-quality initial population generated by the beetle antennae search algorithm with the improved genetic algorithm.The global searching ability and convergence performance of the proposed algorithm are tested by three classical testing functions.Based on the test results and the iterative convergence curve,the good convergence and optimization ability of the proposed algorithm are verified.Finally,the improved algorithm is used to solve the fault location problem of distribution network of distributed generation.The positive direction of distribution network with distributed generation and the code method of each switch node are redefined,and the switch function and fitness function suitable for distributed generation switching are constructed.Taking IEEE33 node distribution network model as an example,the single fault,multiple fault and the distortion of switch information are simulated and analyzed,and the stability and fault tolerance of the algorithm are compared from three aspects: the quantity of power supply,the number of faults and the information distortion.The simulation results show that the proposed algorithm has fast convergence speed,good fault tolerance,high accuracy and short running time,which can meet the basic requirements of fault section location of distribution network with distributed generation.The paper has 35 figures,8 tables and 76 references.