Research On A County Power Grid Reconstruction

In the process of electric energy transmission,a large amount of loss will be generated,and the reasonable operation mode can not only reduce the network loss,but also improve the power quality of power supply.Based on the expanded power grid of a county in Central Plains(hereinafter referred to as M county)in China,this paper carries out network reconstruction research aimed at reducing network loss and increasing node voltage.First of all,it introduces the basic situation of M county’s geographic location,power grid construction and so on.By sorting and analyzing the data of the M county power grid,based on the planning data of the M county power grid,the 110 kV busbars are merged into a root node,and the sectional switches and tie switches and the transmission lines and distribution between The transformer is equivalent to an edge,and the load is equivalent to a node.According to the structural characteristics of the network,a tree-like undirected graph is used to describe the topology of the network.After calculation,it is found that the original network operation mode has higher network loss and lower node voltage,which is not the optimal operation mode.Secondly,the 35 kV power grid after M county expansion was optimized and reconstructed.The self-loop nodes in the network are treated with virtual nodes and virtual branches.Under the two conditions of reducing network loss and considering network loss and average node voltage,respectively,the quantum particle swarm algorithm is used to give the optimal network Operation mode.The calculation results show that compared with the original network,the optimal operation mode can not only reduce the network loss,but also increase the average node voltage.Finally,a fault recovery model of distribution network aimed at restoring load power supply is established.The N-1 situation of 21 branches in the network was analyzed,and the results showed that the power supply could be quickly restored byadjusting the network structure when 13 lines failed;when the remaining 8 lines failed,they would not meet the stable operating conditions of the grid Or the reconstruction conditions cannot be quickly restored through network reconstruction,which will cause local power supply to be interrupted for a long time.It gives practical guidance for the operation,maintenance and construction of M county power grid.