Research On Planning Methods To Enhance Distribution Network Resilience Under High Penetration Of Renewable Energy Conditions

The development of power technology has led to the rapid development of modern society and economy,promoting the progress of human society.With the overall development of the power system,various potential dangers have also increased,unpredictable natural disasters and man-made attacks can lead to varying degrees of power outages in the distribution network,and although these contingencies cannot be completely avoided,the resilience of the grid should be enhanced to increase resistance to destructive forces as well as to The resilience of the system.Building resilient grids and increasing grid resilience is becoming a global development strategy.In the context of the global transformation of the energy mix,new energy sources are taking up an increasingly high proportion of the energy supply,and the high penetration of new energy sources provides new opportunities and challenges for the development of resilient grids.On the one hand,the access to new energy sources acts as a back-up energy source,providing energy and backup power during normal operation of the distribution network,as well as providing stable energy support during network disturbance failures,and providing strong support for the resilience of the distribution network.But on the other hand,the non-uniformity of wind and solar resources in space and time makes the output of wind and PV random,volatile and intermittent,and the increasing share of new energy sources makes the impact of this uncertainty non-negligible.The deployment of energy storage devices is also a measure to improve the resilience of the distribution network,and energy storage is able to respond quickly to power outages in the distribution network.With the increasing scale of new energy installations,energy storage is also an important technical tool to support the development of renewable energy.Taking into account the role of energy storage in improving the resilience of the distribution network and suppressing the fluctuation of new energy output,its application in the power system will be even richer.Based on the above research background,this paper firstly determines the analysis method for distribution network resilience assessment,selects extreme snow and ice weather as a typical extreme weather,establishes a line fault model through ice cover load characteristics and component strength characteristics,and proposes a fault scenario selection method based on system information entropy,selects the scenario with the highest entropy probability as a typical fault scenario,and defines the disturbance absorption rate of the distribution network after the disturbance occurs as a resilience assessment The disturbance absorption rate of the distribution network is defined as the resilience assessment indicator.On this basis,measures to improve the resilience of the distribution network are investigated,and a grid planning method and an energy storage planning and allocation method are proposed respectively to consider the resilience of the distribution network.In the grid planning,a grid planning method is proposed based on probabilistic currents that can improve the resilience of the distribution network,quantify the uncertainty and reduce the uncertainty impact on the system while maintaining a high penetration rate in order to maximise the resilience,solve the problem using an improved particle swarm algorithm,and compare the proposed algorithm with the traditional Monte Carlo simulation method to verify that the method can effectively improve the grid resilience and reduce the planning cost.In the energy storage planning,lithium battery energy storage is selected as the planning object,the total investment in energy storage allocation and the distribution grid resilience index are chosen as the objectives of the two-stage planning,and the energy storage planning model is established and simulated by arithmetic cases.It also provides a brief outlook on the directions still to be researched to improve grid resilience under high penetration new energy conditions.