Research On Fault Location Technology Of Distribution Network Under Distributed Generation

With the continuous development of the society,the reliability of power supply has been paid more and more attention.At the same time due to the constant transformation of the urban power grid,smart grid,continuous improvement,the rapid rise of a strong smart grid and rapid development of DG,which creates a distribution network becomes more complex,when power failure occurs,how to realize the rapid and accurate positioning is out of order,at the same time for fault isolation and power supply recovery on the fault section is the main task.Accurate fault location is the need of the current smart grid construction,and also the basis of ensuring the reliability of power supply and power quality.Therefore,how to choose an appropriate location method has become a topic of discussion among many scholars.In view of the current development status of distribution network fault location,article firstly introduces the criterion of DG access to distribution network,and then analyzes the influence of DG access to distribution network,including the influence on grid planning,grid operation and traditional positioning methods.Aiming at the shortcomings of the existing positioning methods,puts forward the QPSO algorithm and DE algorithm,with the combination of hybrid optimization algorithm is applied to the fault location in distribution network.Aiming at the shortcomings of the traditional QPSO algorithm in the global search performance and the poor accuracy of the algorithm,the QPSO algorithm is improved by fusing the gaussian distribution function and introducing the identical particle system to enhance the robustness and accuracy of the algorithm.In view of the lack of search ability of mutation operation and the poor search process of crossover operation in DE algorithm,the mutation operation and poor operation are improved appropriately to enhance the search and optimization ability of the algorithm.Finally,the QPSO algorithms and DE algorithms are processed in binary order to make the algorithm suitable for 0-1 fault location of distribution network.Though the hybrid optimization of the two algorithms is carried out to realize complementary advantages,which not only makes up for the lack of convergence in the early stage of QPSO algorithms,but also makes up for the slow convergence in the later stage of DE algorithm.Aiming at the application of hybrid optimization algorithm in distribution network fault location under DG condition,this paper firstly redefines the reference positive direction,redefines the switching coding mode,and optimizes the switching function and fitness function for distribution network fault location,so as to make the algorithm more adaptable to distribution network fault location.Through combined with topology network containing DG positioning algorithm is applied to distribution network,the single fault and multiple faults in distribution network has carried on the simulation,two kinds of cases at the same time for both cases lack of information and information distortion and the corresponding simulation validation,the final results show the feasibility and accuracy of the algorithm.Finally,the experimental results of this paper are compared with particle swarm optimization and traditional QPSO Optimization.The results indicated that this algorithm can find fault points more quickly and needs satisfied of distribution network fault location.