Research On Distribution Network Planning And Optimal Operation Method Adapted To Distributed Energy Access

With the increasing of distributed energy and electric vehicle charging load in the distribution network,the operation of the distribution network is facing more challenges,such as the voltage overrun problem caused by the access of distributed energy generation,the voltage level fluctuation caused by the access of electric vehicle charging demand into the distribution network,and the increase of network loss of the distribution network.Soft open point(SOP)is a kind of power electronic device which can control the power flow of the distribution network.It can improve the power flow distribution of the distribution network and better adapt to the situation that distributed energy and electric vehicle charging demand are connected to the distribution network.However,although this method is effective,it is relatively expensive to install a large number of soft open pointes.Therefore,it is necessary to study the SOP planning configuration in distribution network,so as to make the limited SOP devices give full play to the best effect.This paper focuses on the soft open point location and sizing optimization in distribution network planning,including the following three parts:Firstly,the distribution network planning model considering SOP device,distributed generation and electric vehicle charging demand is established.The optimization objective of the model includes three parts:distribution network operation loss,distributed energy consumption and electric vehicle charging satisfaction.The SOP device characteristic model and power flow security constraints in distribution network are described analytically in its constraints.Secondly,aiming at the above distribution network planning model,the SOP capacity planning decision-making problem in distribution network is studied.The problem only contains continuous decision variables representing SOP capacity decision-making and distribution network operation state,and the model can be transformed into second-order cone programming for solution.The simulation results based on IEEE 33 bus distribution network verify the effectiveness of the proposed method.Thirdly,the problem of SOP location and capacity hybrid planning in distribution network is further studied.The mixed decision-making problem contains discrete variables representing the location of SOP,which is difficult to be solved directly by mathematical programming.Therefore,this paper adopts a hybrid algorithm of simulated annealing algorithm and cone programming algorithm.Firstly,simulated annealing algorithm is used to quickly search the location decision of SOP device,and then second-order cone programming is used to realize the sizing decision of SOP device,so as to realize the fast and accurate solution of large-scale mixed integer nonlinear optimization problem and meet the calculation requirements of time series optimization.The simulation results based on IEEE 33 bus example show that the above method can effectively improve the problems of network loss increase and voltage instability caused by distributed generation and electric vehicle charging demand access to the distribution network.