Research On An Optimal Configuration Method For Dynamic Voltage Restorers In Distribution Network

Voltage sag interrupts industrial process and even causes causalities,which leads to substantial economic losses.Dynamic voltage restorer(DVR)becomes popular as a costeffective solution for mitigating voltage sags.The mitigation effectiveness and investment depend on the size and placement of DVRs.Unelaborate configuration of DVRs leads to unacceptable mitigation result and overinvestment.Meanwhile,customers hope to strike a balance between mitigation effectiveness and investment when they are making decisions on mitigation schemes.With the advent of various load in distribution network,the configuration of DVRs becomes more difficult.Therefore,the research focuses on the optimal sizing and placement of DVRs from three aspects: description of the price per k VA of DVR,customer's mitigation expectation and calculation efficiency.The main work is as follows,(1)To reflect the impact of the nonlinear relationship between the price per kVA of DVR and its capacity,the optimal configuration model for DVRs in distribution network based on the function of the price per k VA of DVR was established.The price per k VA of DVR was fitted by a continuous function by means of investigating the actual price of DVRs with different capacity.The optimal configuration model of DVRs was then proposed based on the function.The model contributed to avoiding the negative effect on the result owing to adopt constant unit price and discrete unit price.(2)To balance the mitigation effectiveness and investment,the optimal configuration model for DVRs based on the mitigation effectiveness index was established.The mitigation effectiveness index(MEI)was proposed and the relationship between voltage to be compensated and customers' mitigation demand was determined.The optimization model was proposed based on the index.Schemes under different MEI were compared in detail,which offered guidance for customers to select mitigation schemes which achieved a balance between mitigation effectiveness and investment.(3)The size and locations of DVRs were determined simultaneously when solving the DVRs configuration problem.A multiple population genetic algorithm(MPGA)with hybrid encoding method was proposed to solve the optimal size and placement of DVRs,which improved the accuracy and efficiency of the algorithm,comparing with adopting plain encoding method.The proposed method investigated the configuration of DVRs from three aspects,which provided effective support for customers to make decisions on mitigation schemes.