Study On Reconfiguration Of Active Distribution Network With Distributed Generations

Distribution network reconfiguration is under the condition of satisfying certain constraints, by changing the opening or closing the switch network to change distribution system topology structure and operation status, in order to reduce the network loss, improve power quality target of an optimization run means. With the large amount of access of distributed generation in distribution network, the distribution network has become an active network from the passive network, the unidirectional power flow has become a trend. The large fluctuation of DG output of high permeability has brought the power quality of distribution network and the network loss. The control method of the traditional distribution network side is not enough to deal with the impact of high permeability DG.Firstly, the power flow calculation model of active distribution network with distributed generation is established in this paper. Using this model, the influence of distributed generation on the loss of active distribution network is analyzed.Secondly, in the aspect of active distribution network static reconfiguration, this paper presents a multi-objective distribution network reconfiguration model with multi-type distributed power supply. Pareto optimal criterion and Multi-Objective Binary Particle Swarm Optimization (MOBPSO) algorithm are used in the reconfiguration process. The algorithm is improved in three aspects:the ring-based coding method to reduce the probability of infeasible solutions; the dynamic change of inertia factor and the asynchronous change of learning factor to improve the algorithm’s adaptive ability; Combination of niche sharing mechanism and proportional operator selection are proposed to update the particles. According to the decision maker’s bias, this paper finally gives an evaluation mechanism, which can select the appropriate reconstruction scheme from the optimal solution. Numerical results show that the improved MOBPSO algorithm can improve the efficiency and stability of the optimization. This paper’s model, the improved algorithm cooperating with the evaluation mechanism can provide an effective reconfiguration scheme for decision maker. In addition, this paper studies the effect of different power output and access mode on the reconfiguration of active distribution network and analyzes the causes of the above effects, and summarizes the changes of the reconstruction results.In the end, the paper presents a dynamic reconfiguration method based on the squeeze strategy. According to the set reconstruct times by operator, the optimization section is operated by "enumerating" actions to determine the reconstruction time and corresponding solutions, then the reconstruction time and corresponding solutions are operated by squeeze actions. Through the above two steps can obtain the final optimization programs. Using IEEE33 nodes distribution system containing distributed generation as an example, the simulation results indicate the feasibility, effectiveness and global convergence of the method.