Power Flow Calculation With Distributed Generation Distribution Network Based On Newton Raphson Method

With the rapid development of the national economy,now the secure,high qualified and economical operation of distribution network became the basic requirement for the power grid operation.The aggravation of environmental pollution and energy crisis has accelerated the application progress of distributed generation(DG)technology and pomoted the extensive application of distributed energy.But the integration of distributed generation affects the power quality and relay protection of the distribution network.The accidents in the power grid can be prevented by power flow calculation.The paper introduces the models of various distributed generation and the corresponding handing of the type of grid connected nodes.The principles of several common traditional power flow calculation,such as Gauss Seidel method,Newton Raphson method,direct method and forward back generation method,are compared and analysed.According to the characteristics of distribution network,the improved Newton Ralphson calculation based on the modified Jacobi matrix is adopted in this paper to analyze and simulate the application of distributed generation in distributed network.The system that 6 nodes with small impedance branch is simulated by using the Matlab software.The simulation results show that the improved Newton Raphson method keeps a good convergence on the problem that small impedance branch processing.The improved Newton Raphson method is used to simulate the IEEE30 node.The distribution network of 6kV is added to the thirteenth node.The simulation data shows that the improved Newton Raphson method can be used to deal with a variety of distributed generation,and the calculation has a better convergence and adaptability to the network with distributed generation.Finally,the simulation data that the influence of the distribution generation with different type,different position and different capacity on the voltage and network loss that in the application of distributed generation in distribution network is analyzed.