Research On Distribution Network Reconfiguration With Distributed Generation

Distribution network optimization is an important part of distribution automation.At present,with more and more distributed generations access to the distribution network,its impact on distribution network optimization and reconfiguration can not be ignored.Considering the impact of distributed generations,the state of sectional and tie switches are changed,the topology of distribution network will be changed,which can balance the load and eliminate overload,and reduce the network loss and improve the voltage quality and so on.Therefore,the research of distribution network reconfiguration has been widely valued by electric workers,and becomes a hot topic.The current research on the reconfiguration of distribution network mainly focuses on the static reconfiguration and dynamic reconfiguration.Both are typical complex optimization problems.The intelligent evolutionary algorithms show good performance in solving the problem of distribution network reconfiguration.This thesis mainly completed the following several aspects:(1)Analysis of the equivalent model of distribution network and distributed generations in detail,then calculates the power flow in IEEE33 node using back/forward sweep algorithm,provides the basic data for distribution network reconfiguration.The thesis also studies the influence of location and capacity of distributed generation on distribution network,then gives the simulation examples,the simulation results show that the influence of distributed generation can not be ignored for distribution network reconfiguration.(2)For the distribution network static reconfiguration with distributed generation,this thesis presents a hybrid algorithm which combines DE and PSO,to solve the problem of static reconfiguration of distribution network with multi-type DGs,the algorithm introduces the individual migration strategy and adopts the double populations evolution mechanism,which have a good effect on jumping out of local optimum and accelerating convergence;A simulation example of IEEE33 node is established,the simulation results show that the reconfiguration is beneficial to improving the operation level of the power grid,also,the results show that the algorithm can improve the efficiency and stability.(3)For the dynamic reconfiguration of distribution network with distributed generation,a step-by-step optimization strategy is presented for the dynamic reconfiguration of distribution network.This strategy transforms the dynamic reconfiguration of distribution network into a static reconfiguration problem on several time periods,and uses the DEPSO algorithm to solve the problem.Once again,the effectiveness of the evaluation function is introduced to determine whether the switching operation is adopted in the adjacent reconfiguration periods.The feasibility of the proposed strategy is verified by the IEEE33 node simulation example.