Research On The Model For Improving The Resilience And Optimizing The Configuration Of Distribution Networks Under Extreme Weather

The occurrence of extreme weather will have a significant impact on the safe operation of the power system,leading to large-scale power outages in the power grid,which will cause serious economic losses.Aiming at the impact of extreme weather on power grids,the concept of grid resilience is proposed,which represents the ability of power systems to withstand disasters when they are damaged by extreme weather faults.This article focuses on the improvement of distribution network resilience under extreme weather conditions,mainly including the following points:(1)In order to study the influence of extreme weather on the distribution network,the mechanical load effect of typical poles and conductor elements on the distribution network lines is analyzed.Secondly,the probability density function of the two is analyzed by the load effect,and then the failure rate of the circuit element is constructed.Thirdly,the failure rate of distribution network lines is constructed by the failure rate of distribution network components,and the unavailability of lines is calculated by the failure rate of lines.Finally,a typical fault scenario is obtained according to the information entropy theory and the unavailability theory of lines,which provides the background support for the subsequent distribution network fault recovery and elasticity improvement.(2)A fault recovery strategy was proposed for fixed fault scenarios where flexible resources are connected to fixed nodes.By analyzing the optimal power flow model of the distribution network,a fault recovery model for the distribution network was constructed.By comparing the recovery of distribution network faults in different situations,it was verified that the flexible resources in the distribution network have a recovery effect on the load of the affected power system.It was found that under the combination of multiple flexible resources,the recovery effect of the affected distribution network is better than that of a single flexible resource connected to the system.(3)Considering the importance of electrical loads in the distribution network,the input-output method is used to define the total value of loads in the distribution network.By dividing the total value of electrical loads into three categories: primary electrical loads,secondary electrical loads,and tertiary electrical loads.Using the method of distribution network fault reconstruction,considering the load hierarchy in fault recovery,a distribution network fault recovery strategy is constructed based on the idea of first level electrical load being restored first,second level electrical load being restored second,and third level electrical load being restored last.Enable the affected distribution network to recover as many prioritized electricity loads as possible,minimizing economic losses of the affected distribution network.In order to further improve the recovery effect of the affected distribution network,a strategy of collaborative recovery of flexible resource access system and network reconstruction has been adopted,which further enhances the resilience of the power grid.