Research On Distribution Network Reconfiguration Methods With Distributed Generation

By changing the switch state of the distribution network switch to reconfigure the distribution network,the topology of the distribution network can be optimized,and the voltage quality and power supply reliability of the distribution network can be improved.With the increasing access of distributed generation(DG)to distribution network,the power flow of distribution network has changed.The traditional distribution network reconfiguration method is no longer applicable to the distribution network with distributed generation.Therefore,it is of great theoretical and practical value to study the distribution network with distributed generation.Based on graph theory and CIM topology package,the topology model,topology diagram and reconfiguration diagram of distribution network are established.Then,a time division method based on improved K-means clustering algorithm is proposed,and the time interval of reconstruction is divided according to the load data set.The calculation results show that the algorithm can effectively divide the time intervals of different lengths according to the load characteristics.Taking a typical substation with single-segment connection of two main transformers as an example,according to the theory of economic operation of transformers,the economic operation mode of transformers and bus bars on the inlet and outlet sides of substations is determined.Combined with the distribution network reconfiguration based on single voltage level,it provides a theoretical method for realizing unified distribution network reconfiguration optimization.According to the given optimization model,combined with the reconfiguration period division method,the distribution network reconfiguration feasible solution set generation method,the substation economic operation and the power flow calculation method with distributed generation,the dynamic reconfiguration optimization algorithm of the unified distribution network with DG is obtained.The multi-objective function and constraints in the reconstruction model are processed by the constrained Pareto multi-objective processing technique.On the basis of the reconstruction map,the feasible solution set generation method of distribution network reconfiguration is used to ensure that the generated reconfiguration feasible scheme meets the radiation constraints.Taking the actual distribution network in a certain area as an example,the proposed algorithm is verified by the prototype program.The example calculation shows that the proposed method and algorithm can dynamically reconstruct the distribution network.By comparing the objective function values before and after reconstruction,it can be seen that the distribution network reconfiguration optimization algorithm with distributed generation proposed in this thesis achieves the purpose of optimizing the distribution network and can converge quickly and reliably.