Research On Self-healing Strategy Of Distribution Network Containing Renewable Enery

With the development of economic, the contradiction between gradual exhaustion of fossil contradiction energy reserves and increasing demand for electricity supply is becoming more and more outstanding. The distributed generation(DG) technology is becoming more and more mature and has become a hot research topic. To a certain extent, the proposion of the distributed generation alleviates the problems brought about by low power supply reliability. However, after a great of DGs being connected into the distribution network, the distribution network operation and control mode and the self-healing capabilities of smart grid should have a new start. It has certain realistic significance and practical value for preventing grid cascade accident to research reliable self-healing strategy which will regulate the distribution grid operation state. This paper divided the operating condition of power grid into two conditions: fault condition and normal condition, then self-healing strategy for different conditions was researched. The main research results were summarized as follows:Based on the above analysis, the wind power model and photovoltaic output model are established, and then drawing power distribution curve based on wind velocity and photovoltaic power curve. The method of probabilistic power flow based on Monte Carlo simulation in distribution network is proposed.Under fault condition, a self-healing control strategy based on the combining graph theory law and particle swarm optimization(PSO) has been put forward. The method of probabilistic power flow based on Monte Carlo simulation can solve the problem caused by output characteristics of DG.Choosing optimal supply route, searching for optimal load-shedding in different points.By the above operation, the optimization results about system loss and load recovery will be obtained. The effectiveness of the proposed method is verified by calculation results of IEEE 33-bus system.Under normal condition, the new energy will be used more economical and efficient by the management about load demand side. To achieve the goal, a self-healing control strategy based on improved particle swarm optimization(PSO) has been put forward. Determining the system losses as the objective function, optimizating the new energy's output, and then the self-healing control strategy about distributed generation will be accomplished.At the same time, the superiority about distribution network containing new energy will be appeared by the comparing between system parameters. The effectiveness of the proposed method is verified by calculation results of IEEE 33-bus system.