Research On Reconfiguration's Heuristic Algorithm For Distribution Networks

With the acceleration of urban construction, the loads of urban distribution network have increased and the scale is also expanding gradually. At the same time, consumer's requirement of improving power quality, supply economic and reliability is increasing gradually. To get along with the society's development and market demand, the power system must be kept operating safely and economically. The distribution network connect with consumer directly, the power is distributed to consumer by distribution network, so it is important for distribution network to keep safe and economic operating.Distribution network reconfiguration is an efficient measure of enhancing power network's operating efficiency, supply reliability and power quality. It is a general question covered with many aspects, which can be used to different operating task, such as loss reduction, load balancing, reaction optimization, service restoration, and so on. It is also a complex no-linear, Composite optimization problem on theory.Based on the study of network reconfiguration's basic theories, the distribution network reconfiguration's mathematics model is discussed in this thesis according to the characteristic of distribution network and the current problem. In static reconfiguration, the reconfiguration model in the goal function of loss minimization is established; in dynamic reconfiguration, the comprehensive reconfiguration model that consider switch's handling cost and reconfiguration Efficiency is established.Based on the study of network reconfiguration's method at present, the heuristic algorithm is researched deeply. The thesis discussed the heuristic algorithm's theoretical basis, improved method, calculation steep, and each algorithm's characteristics. Then, the distribution network's power moment mode is established and the power moment method for radial distribution network reconfiguration is proposed, the method's effectiveness is verified by typical distribution systems also.The dynamic reconfiguration is researched in this paper also. The dynamic reconfiguration problem is solved from two respects:one is to determine the optimal reconfiguration times of a day; another is to determine the optimal time interval of every reconfiguration when the reconfiguration times of a day are given. A heuristic algorithm is proposed to divide time also. At the same time, the power moment method is used for each time period's reconfiguration, and the solution procedure become very simple and fast, because the conventional procedures of load flow calculation are reduced. The typical distribution systems'test demonstrate that it can reduce network loss effectively, and it also can be used for establishing switch handle table and scheduling analysis.