Load Transfer Analysis And Reliability Calculation Application Based On Power Supply Unit Of Distribution Network

As the key infrastructure of the city,the distribution network is an important link between the power grid and users.It has the characteristics of multiple points,long lines,wide coverage,complex structure,and overlapping management links.The dissertation takes the wiring group of the power supply unit of the distribution network as the research object,in-depth study of the structure of the distribution network on this basis,carries out the load transfer analysis and reliability calculation application research of the wiring group.The main contents of the paper are as follows:First,analyze the topology of the distribution network from the perspective of graph theory,introduce the storage of network topology information and the traversal of the topology,and then introduce the typical power supply structure of the medium voltage distribution network and different power supply modes and failure recovery modes.Finally,the preprocessing of the calculation data of the distribution network is introduced,which lays the foundation for the development of the distribution network load transfer and reliability analysis.Then,simulate multi-scenario failures,determine the power outage area,and use the NSGA-Ⅱ algorithm to achieve efficient load transfer path search.The loop-based real number coding is used to reduce infeasible solutions,combined with fast nondominated sorting to optimize the forwarding plan,and finally through the elite strategy,the sampling space is expanded,so that the optimization process is more evenly distributed in the solution space.Then,a two-stage load transfer analysis method for distribution network based on greedy thinking is proposed,and an optimal stage model with the largest load recovery amount and an optimization stage model with multi-objective operating indicators are established.For non-full capacity transfers,heuristic load shedding strategies and load shedding strategies based on binary notation are proposed,and combined with the NSGA-Ⅱ algorithm to calculate the optimal transfer path.Then,a simple algorithm for finding the minimum path for the power supply feeder of the distribution network is proposed.Based on the minimum path method,capacity judgment and transfer path judgment are added to calculate the reliability index.Further,the result of load shedding strategy of load transfer is combined with the minimum road method.Finally,a test case of a wiring group in the Taizhou distribution network is used to apply the NSGA-Ⅱ algorithm to the analysis of multi-scenario fault load transfer,and consider the load shedding strategy under non-full capacity transfer to calculate the transfer plan.Based on the minimum path method,compare the accuracy of index calculation among several reliability algorithms to verify the feasibility of the algorithm.