Three-phase Load Balancing in Distribution Systems Using Index Measurement Technique

By changing open/closed status of sectionalizing and tie-switches, the topological structure of distribution feeders is altered for network reconfiguration in power system. Network reconfiguration can be applied to balance feeder loads and ease overload conditions in a network by transferring loads from the heavily loaded feeders to the lightly loaded ones. In this paper an attempt is made to enhance three-phase load balancing by introducing new indices for load balancing. The loading condition of the branches and the overall system are determined using the proposed indices and the index values 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 index. In the proposed index measurement technique (IMT), network reconfiguration for load balancing is done by performing a search over different radial configurations created by considering branch-exchange type switches. In the initial stage of the proposed technique, a loop-index is employed to determine a loop, which gives maximum improvement in load balancing in the network. In the final stage, a branch-exchange index is applied to determine the switching-option in that loop to achieve maximum enhancement in load balancing. By using the proposed search scheme, the most appropriate switching-operations for load balancing can be identified. The algorithm has been tested on a 69-bus radial distribution system and the test results indicate that the optimal or near optimal configuration for load balancing can be obtained by the proposed technique with less computational effort and time. A comparative study is made with the two of the established methods and the proposed 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. © 2001 Published by Elsevier Science Ltd.