Study On The Fault Location And Power Restoration Algorithm Of Distribution System With DG

The Distributed Generation(Distributed Generation,DG)is complemented and perfected by traditional power,which greatly improves the economical and intelligent level of power distribution network.DG has the advantages of small pollution and renewable,but the characteristic of DG is different from the traditional power supply.As a result,the method of traditional fault location and power restoration cannot meet the demand.Therefore,it is significant to study the fault location and power restoration of distribution network with DG.For this reason,the main schemes of DG accessed to distribution network and the influence are analyzed in this thesis.The stable operation of distribution network and the failure rate are analyzed.The influence of DG access on the stable operation of distribution network is mainly analyzed in terms of harmonic,voltage fluctuation and protection.The influence on the system fault feature is mainly analyzed by using transient signals and steady state.Fault location in the steady-state component is determined through the analysis.On this basis,particle swarm optimization algorithm is used to locate the distribution network with DG.In order to optimize the convergence of the particle swarm optimization algorithm.The convergence of the traditional particle swarm optimization algorithm is improved by preserving the optimal particle and crossing operation of particle.The improved particle swarm optimization algorithm is proved to have better convergence and operation efficiency in the fault location of distribution network with DG,through the simulation analysis of the calculation example.The trend direction is changed and the traditional power flow calculation method are inapplicable,since different DG are connected to the distribution network.Therefore,several DG models,such as photovoltaic power supply and wind generator,are analyzed in detail.Different models are processed by corresponding nodes,the power flow calculation method based on forward and backward substitution method.Power supply recovered after fault location and isolation of distribution network.It can be confirmed the optimal power recovery plan,when the power supply is restored,the primary load is isolated on the island,prioritizing the power supply,and using the improved particle swarm algorithm to search for the remaining networks.Finally,the feasibility of the improved particle swarm optimization algorithm is verified through the simulation analysis of the IEEE33 node system and PG&E69 node system and the actual distribution network in an area.