Research On Optimization Of Distribution Network Considering Wind Power And Photovoltaic Power

With the development of distributed energy technologies,more and more Distribution Generation(DG)will be connected to the distribution network.Making effective use of new energy is bringing many challenges to the safe and stable operation of the distribution network.On the one hand,the access of the distributed generation will change the original network topology and make the passive network into the active network,and thus having a major impact on the active power loss,power quality,relay protection and system reliability.On the other hand,it brings the advantages of reducing the loss,balancing the distribution load,improving the economy,decreasing the negative impact of the distributed generation network connection,if the distribution network is synchronous optimized and reconstructed while the distributed generation is connected.Therefore,it is of great significance to carry out research on the optimization and reconstruction of distribution network containing DG as the DGs are on a rapid development and massive grid-connection.On this background,this paper studies the optimization and reconstruction of distribution network with DG.Firstly,several schemes of static and dynamic reconstruction of distribution network as well as their advantages and disadvantages are discussed.As for the wind power generation and photovoltaic power generation,different mathematical models are used to describe the output of the power generation units,and the influence on the distribution network is summarized.Combined with the topological analysis method based on graph theory,the distribution network is layered,and the method based on layered model is formed,which simplifies the process of power flow calculation and improves the efficiency.Secondly,a two-stage distribution network reconstruction algorithm is designed by combining the standard harmony search algorithm with the variable neighborhood search algorithm.Primarily,a reasonable and effective approximate solution is found by using the rapidity of the harmonic search algorithm.Then,the optimal solution of the objective function is searched in the neighborhood by means of variable neighborhood search based on approximate solutions.The search range is constantly expanded until the objective function of the solution is no longer reduced,and the reconstruction scheme is finally obtained.To verify the effectiveness of the algorithm,MATLAB is used for simulation,and then the self-designed simulation system is used for verification.The result proves the accuracy and efficiency of the algorithm.Finally,considering the timing characteristics of the distributed generation,an equivalent daily load curve is formed.The K-means clustering algorithm is used to divide the time period to realize the transformation from dynamic reconstruction to static reconstruction based on the network operation index.The IEEE33 node system is adopted to realise the simulation,and results show that the dynamic reconstruction scheme based on k-means clustering algorithm can effectively reduce the power distribution network losses and improve the economy.