Wuhan Ligong Daxue Xuebao (Jiaotong Kexue Yu Gongcheng Ban)/Journal of Wuhan University of Technology (Transportation Science and Engineering)

Reactive power compensation is important to enhance power quality, voltage profile, power factor, and efficiency in electrical networks, resulting in stable, economical, and reliable systems. Shunt capacitors on radial feeders serve as reactive power sources, and determining their ideal placement and size is treated as a constrained optimization problem. Particle swarm optimization (PSO) can address this by minimizing network loss. This study applies PSO to 15-bus and 33-bus radial distribution systems. The forward/backward sweep (FBS) load flow algorithm calculates bus voltages, power flows, and system losses. PSO then determines the optimal capacitor locations and sizes for various capacitor numbers. Results reveal significant network loss reductions with increased capacitor use, as voltage deviation decreases in compensated networks. In the 15-bus case, improvements were 18.4%, 30.4%, and 31.7%, while the 33-bus system showed 18.48%, 25.28%, and 26.87% improvements. Cost savings were analyzed for all cases, identifying the most economical designs.