Direct search algorithm for capacitive compensation in radial distribution systems

In this paper a new algorithm is proposed to determine the optimal sizes of fixed and switched capacitors together with their optimal locations in a radial distribution system so that net savings are maximized and improvement in the voltage profile is achieved. The algorithm searches for all possible locations in the system for a particular size of capacitor and places the capacitor at the bus which gives maximum reduction in active power loss. The optimal sizes are chosen to be standard sizes that are available in the market i.e., discrete sizes of capacitors are considered. The algorithm is tested on standard 69 bus system, 85 bus system and practical 22 bus systems. And the results are compared with results of other methods like particle swarm optimization and genetic algorithm, as available in the literature. The loss reduction obtained in this paper for the two standard test systems is highest compared to the other technique as reported in the literature. Cost analysis is also presented with and without capacitor placement on the three bus systems considering three different loading levels. (c) 2012 Elsevier Ltd. All rights reserved.