Research On Fault Diagnosis Of Distribution Network With Distributed Generation In The City

The application of the smart grid is to improve the processing capacity of the distribution network,including the ability to accurately and quickly locate the faulty section through modern technical means after a fault occurs.This paper takes the city's distribution network as the research object,and the area has gradually adopted fault location based on centralized intelligence of Feeder Automation(FA).However,the fault location still exists such as the impact of Distributed Generation(DG)access,feeder terminal units low online rate leads to problems such as low accuracy of fault investigation and judgment.Traditional fault location methods will no longer be applicable.This paper will study the fault segment location of distribution networks with DG based on Particle Swarm Optimization(PSO)algorithm.Firstly,the influence of photovoltaic power generation on distribution network faults is studied.Because the DG in the city is mainly photovoltaic grid-connected,it is necessary to analyze the output response of photovoltaic power in the event of a short circuit.Using PSCAD software to build a single-stage three-phase photovoltaic power grid simulation model,the fault current characteristics are obtained by simulation.Taking a certain feeder as an example,the influence of the presence or absence of photovoltaic connection on the short-circuit current when the distribution network fails is simulated and analyzed.Due to the influence of DG access,traditional fault location methods are difficult to apply,and other methods are needed for fault location research.Secondly,the fault location method of distribution network with DG is studied.According to the characteristics of Binary Particle Swarm Optimization(BPSO)algorithm,which has certain fault tolerance and can solve the optimization problem composed of 0 and 1,it is applied to the fault location of distribution network.So as to apply to the fault location of unidirectional and multidirectional distribution networks,based on the fault location model with BPSO algorithm determines the coding method and objective function of the fault information,and improves the expected function of the switch.Through MATLAB software simulation analysis,the fault location model based on BPSO algorithm can effectively locate faults in a distribution network with DG.Finally,the BPSO algorithm is improved,and its convergence and convergence speed performance are analyzed.For PSO algorithm,it is easy to fall into the local optimum and may not be able to converge.Using the Estimation of Distribution(ED)algorithm can make good use of the characteristics of global information and mix the two algorithms.The improved fault location model Estimation of Distribution-Binary Particle Swarm optimization(ED-BPSO)algorithm is obtained.A multi-node complex distribution network model with DG is established,and two algorithms are simulated and analyzed.The upshot show that the BPSO algorithm and the ED-BPSO algorithm can be used to locate fault sections of complex distribution networks with DG,and have certain accuracy and fault tolerance.The performance of the two algorithms is analyzed.The fault location model based on the ED-BPSO algorithm has higher accuracy and faster convergence,and is more suitable for fault location of distribution network with DG.In summary,in the case that DG access affects the automatic fault location of the distribution network,faults based on the BPSO algorithm can accurately and quickly locate faults in radiation and multi-source distribution networks,and the improved ED-BPSO algorithm has higher accuracy and faster.It will provide theoretical basis and guidance for fault location of distribution network with DG.