Distribution Network Reconfiguration Based On Load Changes

Distribution network reconfiguration problem is a large, mixed integer, nonlinear optimization problem. Under load balancing, the aim of the distribution network reconfiguration is to reduce system power loss and to satisfy capacity constraint and voltage constraint, which is realized by changing status of switches. Network reconfiguration problem can be separated into two sorts: static reconfiguration and dynamic reconfiguration problem. This paper discussed them two:Based on the branch-exchange algorithm, static reconfiguration algorithm was proposed. Based on branch-exchange algorithm, an approximate formula for energy loss reduction was used. And the ideal branch-exchange was determined by the rules of calculating the lowest distance from the optimal transferred loads to the loads transferred. In the course of network reconfiguration, it was avoided to calculate power flow.In the course of dynamic reconfiguration, the selection of network reconfigurations was discussed after time combination. The conclusion was obtained that the more network reconfiguration was necessary by analyzing in theory and example.Based on the above work, a new method of dynamic reconfiguration algorithm with dividing time was presented to consider time varying load. The aim was to determine optimal network structure according to load variation over a specified time period. The whole time period was divided into multi-time intervals. Taking results of static reconfiguration as instruction, the length of each time was divided impersonally. Furthermore, the relatively ideal solution, by building evaluation function and analyzing the loss reduction effect of each time, can be obtained. Constraint of operation numbers of some one switch and all switches can be considered. The program was written out. Examples were given showing the feasibility of the proposed methods.