Study On Single And Three-Phase Power Combined Distribution Technology In Urban And Rural Grid

With the development of power grid construction and Reconstruction, the diminishing line loss and economizing power energy has become more impoertant.Compared with the existing of three-phase and four-wire power supply technology in the low-voltage electricity distribution network,the single and three-phase combined distribution technology that in accordance of pinciple with the samll-capacity,more pionts and short radius has the advantages of singnificant reducing losses,high power quality and high reliability in low-voltage electricity distribution. The single-phase power supply system has a broad developping prospects in the resource-saving and envirment-ftiendly society of time.In order to ensure the safety of single and three-phase combined power supply model,some issues about singel and three-phase combined model are investigated in this paper,and the main contents are as follow:1.The operation of single and three-phase combined power supply model is studied.Single-phase and two-wire system,single-phase and three-wire system,single and three-phase combined power supply system are analyzed.The application of single-phase distribution transformormer of structural characteristics and electrical performance are introduced.With analyzing the operation of single and three-phase combined power supply model,the superiority of this power supply model is presented in the paper.2.The condition of application in single and three-phase combined distribution technology is studied.Through establishing the mathematical patterns of single-phase and three-phase distribution mode,the critical conditions of different distribution mode are analyzed.The condition of application in single-phase distribution mode is presented in the paper.3.The connection modes of 10kVdistribution network in urban and rural grid are studied,and the different of connection modes in overhead lines and cable lines are analyzed.The analylsis of different connection modes take an important part in single and three-phase combined distribution technology design.4.Single and three-phase combined distribution technology is designed.The load calculation,line cross-section selection,high-voltage distribution connection, low-voltage distribution modes,capacity and type of single-phase transformer,other subsidiary of distribution equipment,and the safety of single-phase distribution are designed,and the technical and economic analysis are done in this new model of power supply.