Research On Distribution Network Reconfiguration Including Wind Power

As a distributed generation, wind power has been widely used in the power system, in order to meet the needs of specific users and ensure the economic and stable operation of the distribution. However, the wind power which is easily influenced by the objective conditions,such as region, weather and wind speed, and the random is large. Also, its unstable active power output will cause the problem of the power flow backwards and the voltage limit of the distirbution network. Therefore, it is necessary to study the distribution network reconfiguration with wind power which can reduce the active power loss and improve the voltage lever of the power system.The paper first introduces the situation of the distribution network reconfiguration and variou kinds of the distributed generation. Power wind which is a relative mature generation technology was selected as the research object, in order to analyzed the influence of wind power access location and capacity to the network loss, the stochastic model was established,and the back/forward sweep method which is based on branch current was used to calculate the change of power trend. According to the complex judgment of the topological radioactivity structure in the reconstruction, a method based on the “optimal-tree” radioactive constrain which can quickly and efficiently carry out the distribution network reconfiguration is proposed. In this method, to simply the network structure, the invalid branch should be deleted and the equivalent should be emerged according to the topology to meet the necessary conditions for radioactive, and then judging the simplified structure to find whether the network meet the radioactive. The “optimal tree” is definited in the simplified structure, the tree breaking results in separate subtree, through the tree traversal to find if there is a closed branch connected to it, so that the global travesal can be converted to partial travesal by a directed tree with a smaller undirected graph travesal. Then, the method to judge the topology radial property based on the “optimal tree” was further added to the method of network reconfiguration based on improved Particle Swarm Optimization. Because of the wind randomness, it is hard to use traditional models to describe the network reconfiguration with wind power, the Wasserstein distance metric was used to generate the optimal scenes of wind power, effectively simulating the random nature of wind power, then, the method based on the“optimal tree” and the improved Particle Swarm Optimization was applied to the distribution network reconfiguration with power wind. Through simulated the IEEE 33-bus system, and comparated with the simulation results of General Algebraic Modeling System solver.Examples analysis showed that the method based on the “optimal tree” radioactive constrains and the improved Particle Swarm Optimization was verificated reasonableness by used in the simulation on the IEEE 69-bus system, also the results showed that the objective function is optimized and can speed up the calculation. Then, the method is applied to the distribution network reconfiguration which consider the randomness of wind power, the result showed that it can effectively reduce the network loss and improve voltage lever. Compared with the other group of intelligence algorithms, the calculation time of the method is greatly reduced though the evolution algebra is more. It can be concluded that the method is effective and stable.