Three-phase load balancing in distribution systems using index measurementtechnique

By changing open/closed status of sectionalizing and tie-switches, the topo logical structure of distribution feeders is altered for network reconfigur ation in power system. Network reconfiguration can be applied to balance fe eder loads and ease overload conditions in a network by transferring loads from the heavily loaded feeders to the lightly loaded ones. In this paper a n attempt is made to enhance three-phase load balancing by introducing new indices for load balancing. The loading condition of the branches and the o verall system are determined using the proposed indices and the index value s have to be minimum for optimum load balancing. For optimal load balancing condition, the branch load-balancing indices will be nearly equal to each other, and also closely approximate to the overall system load-balancing in dex. In the proposed index measurement technique (IMT), network reconfigura tion for load balancing is done by performing a search over different radia l configurations created by considering branch-exchange type switches. In t he initial stage of the proposed technique, a loop-index is employed to det ermine a loop, which gives maximum improvement in load balancing in the net work. In the final stage, a branch-exchange index is applied to determine t he switching-option in that loop to achieve maximum enhancement in load bal ancing. By using the proposed search scheme, the most appropriate switching -operations for load balancing can be identified. The algorithm has been te sted on a 69-bus radial distribution system and the test results indicate t hat the optimal or near optimal configuration for load balancing can be obt ained by the proposed technique with less computational effort and time. A comparative study is made with the two of the established methods and the p roposed method is found to be better. The numerous load-flow runs have been drastically reduced in the proposed method. The proposed method will be a most useful tool for real-time control of automated distribution system for load balancing. (C) 2001 Published by Elsevier Science Ltd.