Reactive power control of distribution networks based on optimal capacitor allocation

This study addresses optimal capacitor (caps) allocation in radial distribution networks using the Electric Eel Foraging Optimizer (EEFO) to maximize annual net savings through loss reduction while maintaining voltage within permissible bounds. Power flow is evaluated via the backward/forward sweep, and two strategies are tested on IEEE 33-bus and 69-bus systems: (i) fixed scenarios with one vs. multiple caps under nominal loading, and (ii) treating the number of caps as a decision variable under 24-hour load variation. In Strategy #1 on the 33-bus grid, two caps at buses 11 and 30 totaling 1550 kVar reduced losses by 32.75 % and delivered 203,792.6 SAR/year net savings, outperforming one-, three-, and four-capacitor cases economically despite similar or slightly greater loss reductions with more units. On the 69-bus grid, two caps (550 and 1250 kVar at buses 12 and 61) are most economical (176,440.20 SAR/year) among multi-cap placements, with four units offering marginal extra loss cuts but eroding net savings via higher compensation costs. Under Strategy #2 with daily load variation, EEFO attains the highest net savings on both systems and converges faster than GA and PSO, illustrating a favorable trade-off among voltage support, loss reduction, economic return, and computational efficiency.