Power Flow Calculation Of Distribution Network With Distributed Power Based On Improved Newton-Raphson Method

Power flow calculation is the basis of power system stability calculation and fault analysis.The accuracy of power flow calculation has a very important impact on the safe operation,reasonable planning and economic optimization of power grid.With the rapid development of distributed power technology,its flexible location,small pollution and other characteristics perfectly fit the development trend of today’s power system.However,when the distributed generation is incorporated into the power grid,a large number of power electronic equipment,capacitors and inductors will be introduced into the network,which will change the topology of the network and affect the power flow distribution.After the introduction of distributed generation,there will be PI,PV,PQ(V)and other node types in the traditional power grid,which may lead to a small number of looped networks in the traditional power grid structure,making the forward push back algorithm based on the traditional radial network not applicable,and the distribution network itself will have a sick system with too large impedance ratio when it is overloaded,which will also make the traditional power flow calculation unable to converge.Therefore,it is necessary to improve the existing power flow calculation method to solve the problem of power flow calculation when the distributed generation is incorporated into the distribution network.This paper analyzes the working principle of all kinds of distributed power,establishes the mathematical model of distributed power,determines the node type and grid connection mode in the distribution network,and deeply studies the influence of all kinds of distributed power on power flow calculation after grid connection.For Newton method,the grid connection of distributed generation will change the voltage distribution in the grid,which makes it difficult to select the initial value of Newton method and makes the power flow calculation unable to converge.For the forward and backward generation method,PV nodes will be introduced into the grid connection of distributed powergeneration,which may cause the radial distribution network to generate ring network,which will make the forward and backward generation method unavailable.If you want to apply the forward and backward generation method to the power flow calculation with distributed power generation,you must break the ring network into a radial grid and also need to deal with PV nodes,which is more cumbersome.Newton’s method is more mature in the principle of dealing with the ring network and PV nodes,so from all aspects,it has higher value to improve on the basis of the traditional Newton’s method.By homotopy algorithm,the traditional Newton method is improved,and the convergence range of the traditional Newton algorithm is expanded,so that it can be applied to the power flow calculation with distributed generation,and at the same time it can solve the problem of ill conditioned system non convergence of distribution network.Finally,simulation examples of this algorithm through MATLAB,combined with the simulation results,it can be concluded that the improved algorithm in this paper can reliably converge when performing power flow calculation on distribution networks with distributed power sources,and can also solve the problem of power flow calculation caused by ill-conditioned systems.Compared with the traditional power flow calculation algorithm,the algorithm has higher calculation accuracy,fewer iterations,and faster calculation speed.