Research On The Reconfiguration Of Distribution Networks With Distributed Generatio

The access of a lot of distributed generation(DG),such as photovoltaic power generation and wind power generation,has gradually transformed the traditional distribution network into a multi-energy and multi-path system,which improves the reliability of the power supply of the distribution network.However,its flexible access characteristics and the uncertainty and volatility of output will have an adverse impact on the reliability of the distribution network.distribution network reconfiguration(DNR)refers to changing the network topology by opening and closing the block switch and the contact switch,so as to decrease the Active power loss,improve quality of electric energy,balance the active power and reactive power of the network and improve the acceptance capacity of DG.Without a lot of hardware equipment investment can achieve the purpose of optimizing the operation of distribution network.Therefore,it is of great significance to study the distribution network reconstruction with distributed power supply.This paper takes distribution network reconstruction as the research object,and mainly considers the following aspects:Firstly,the paper briefly analyzes the current situation of the development of new energy power in our country in the recent years,and introduces the domestic and foreign research results of solving the uncertainty of output of distributed power,the three-phase unbalance and distribution network reconstruction problem.In order to solve the problem of non-convex and nonlinear power flow constraint of distribution network involved in the reconstruction process,this paper studies the method to solve the non-convex and nonlinear power flow constraint of distribution network,and verifies the effectiveness of the described method by improving the calculation and analysis of IEEE 33 node and IEEE 123 node power distribution system.Secondly,in order to solve the impact of distributed generation supply on three-phase network,this paper establishes a distribution network reconstruction model including the distributed power supply taking into account the three-phase unbalance.The model is based on the three-phase current injection method(TCIM).To reduce the active power loss and three phase unbalance degree as the objective function;The proposed model was converted into mixed integer linear programming(MILP)by using polygonal inner approximation and large M method.Three-phase energy storage(ES)and single-phase static var generator(SVG)are used to further reduce active power loss and three-phase unbalance.By improving the calculation and analysis of IEEE 33 node distribution system,the validity and accuracy of the proposed method are verified.Finally,in view of the uncertainty caused by a large number of distributed generation accessing the distribution network,this paper proposes a distribution network reconstruction model with distributed power sources considering the risk of prediction error.A number of distributed power output scenarios are generated by the Latin hypercube sampling(LHS)and the push-back substitution method.The risks are quantified by introducing the conditional value at risk(CVa R)theory,and an objective function considering the expected loss and risk loss of system operation is established.By improving the calculation and analysis of IEEE 33 node distribution system,the validity and accuracy of the proposed method are verified.