A Method For Reconstruction Of Power System Network Based On Node Comprehensive Evaluation

With the development and construction of the power grid,the grid scale are in a sustained rapid growth,and the extensive application of DC transmission technology,renewable energy power generation technology and the continuous promotion of electricity market reform,which cause that the dynamic behavior of the grid more and more complex,the operation condition of the grid is more and more rigorous and the threats of blackout faced by power grid keep growing.The reasonable partition recovery strategy can effectively speed up the system recovery progress and reduce the loss of power outage for large scale power grid in advance.The comprehensive evaluation system and evaluation method of nodes are studied in the recovery of power system,and the partition scheme of power network is worked out based on the theory of spectral gap partition.On the basis of partition scheme,according to the comprehensive importance of nodes,a reconfiguration strategy of large-scale backbone network is formulated,which provides a reference plan for large-scale grid restoration after power failure.First,the index of the importance degree of nodes spectrum are defined to evaluate the topological importance of nodes,which is based on the Laplace spectrum theory.The index of importance degree of node power flow is defined based on branch power flow and PageRank algorithm in power grid operation,which is used to evaluate the importance of nodes in power transmission and distribution.The probability of successful delivery of equipment is defined based on the heal th status of equipment,and the node recovery reliability index is defined based on the probability of successful delivery of equipment,which is used to evaluate the probability of the node's successful recovery.The calculation method of the above indexes is given,and the comprehensive evaluation system of the nodes is constructed according to the above indexes.Then,the weight of each index is calculated by the coefficient of variation,and the relative degree of relative proximity of each node is calculated by TOPSIS grey correlation projection method,which is used to measure the comprehensive importance of nodes.Subsequently,the algorithm of Laplace spectral gap partition is studied.Combined with the K-means clustering algorithm,the automatically partition clustering method of grid is proposed based on Laplace spectrum,which can automatically determine the optimal number of partitions,the partition of the nodes,and the order of nodes recovery in the process of skeleton network reconstruction according to the comprehensive importance of each node.Finally,the IEEE118-bus system and the power grid of A province are analyzed and calculated as examples,and the corresponding partition reconfiguration strategy are made.The proposed node evaluation system includes topology,power flow,reliability index of nodes,and the synthetical importance of nodes are calculated by partition,which consider the difference between regions.The proposed partition reconstruction method can recover the important power and load nodes in all regions with priority,which is simple and easy to implement,and has good application prospects in the actual power grid.