Distributed Generation Optimal Placement In Distribution System Considering Network Reconfiguration

Nowadays,the mode of'centralized generation and long distance transmission'shows its demerits,which reflect to the significant role that Distributed Generation(DG)plays.When DGs are connected to the distribution system,the location,capacity of those DGs,as well as the network topology structure affects the power flow and operating status of the distribution system,thus DG placement and network reconfiguration have important influence on the efficient and economic operation of distribution network.So the research about the integration of DG placement and network reconfiguration plays an guiding role in distribution network planning and operation.This paper first briefly introduces several kinds of DG.Based on the operation mode and control mechanism of different DG,DG is modeled as PQ,PQ(V),PI,PV types.The power flow calculation model is therefore established.Considering that the topology of distribution system may not maintain the same after different reconfiguration,node-branch incidence matrix is employed to generate the calculation sequence table.The simulation analyzes property of the power flow calculation.As for DG placement,which is a difficult mixed integer programming,the mathematical model is built with the targets are active power loss and voltage stability.To solve this,an intelligent optimization algorithm using electromagnetism-like mechanism(ELM)is used to effectively find the optimum.The simulation results shows the better performance in global optimization,thereafter the influence of network structure is analyzed.Finally,this paper gives the mathematical modeling of the integrated optimization problem which contains topology reconfiguration and distributed power allocation in the active power distribution network,and then introduces the related questions of topological constraint in the model.This paper introduces the related knowledge of graph theory,and according to the basic loop and connecting-branch-exchange operation.The coding and decoding method is thus designed to illustrate the topological structure of the network.Through the simulation in Passive distribution network,the results prove the correctness and feasibility of the coding and decoding method.After several plans of the simulation in the active power distribution network,the simultaneous optimization of topology reconfiguration and DG placement shows the best result.The method proposed by this paper is compared with other methods,the results show that the method has better global optimization performance.