Wind-solar-battery In Grid Connection Planning Based On Staged Coordination Optimization Strategy

With the increasing shortage of fossil energy and the increasing environmental pollution caused by traditional thermal power generation,renewable energy power generation has become the future development trend of the power industry.Distributed generation(DG)such as wind and photovoltaic power is flexible in control and has little pollution to the environment,which can realize the local consumption of electric energy.However,the output of DG has the characteristics of intermittency and volatility.As the penetration rate of DG in the power grid gradually increases,there are a large number of wind power and photovoltaic curtailment.The connection of energy storage batteries to the distribution network can effectively suppress the fluctuation of the wind and photovoltaic power and improve the ability of utilization.Therefore,in order to coordinate and optimize the configuration of wind-solar-storage,this dissertation carries out the following work:First5 establish a wind and photovoltaic power probability output model,consider the energy storage to suppress the fluctuation of wind and light,establish a charge and discharge model of the energy storage battery,and analyze the influence of the wind power,photovoltaic and energy storage battery on the distribution network.Second,proposes a wind-solar-storage stage-type coordinated optimization strategy.The first stage is based on the premise of system stability,and the installation location and capacity of the wind and photovoltaic power are determined according to the load active power loss sensitivity.The second stage is to optimize the installation location of energy storage batteries with the minimum network loss as the target on the basis of wind and solar site selection and volume determination,and then comprehensively consider the investment cost,voltage stability and wind and photovoltaic curtailment rate to establish a multi-objective optimization model,and use simulated annealing-particle swarm optimization algorithn to optimize the energy storage capacity.The third stage takes the typical scheme of energy storage optimization as an example to use the probability flow method to evaluate the network loss and voltage.Finally,the actual distribution system in a place in Northeast China is used to simulate and analyze to verify the correctness and effectiveness of the phased coordination optimization strategy.This dissertation studies the timing characteristics of renewable energy sources such as wind and photovoltaic power.The proposed energy storage optimization strategy provides different optimization schemes for decision makers according to different emphases,which is of guiding significance for practical projects and provides important support for the decision of coordinated control and optimal configuration of wind-solar-storage.