Optimal Placement and Sizing of Capacitor Banks in Radial Distribution Systems Using the Whale Optimization Algorithm

Capacitor banks (CBs) are widely utilized in electrical distribution networks for reactive power compensation. This study introduces a two-step approach for identifying the optimal location and sizing of CBs in a 34-bus radial distribution network. The proper allocation of CBs in distribution networks provides several benefits such as power loss reduction, boosting net savings, and improving feeders' voltage profiles. The swarm optimization algorithm selected in this study is the Whale Optimization Algorithm (WOA) to find the optimal sizing and allocation of capacitors in the proposed system. The first step in this study will find the fittest buses for capacitors allocation through the loss sensitivity indices and then the second step comes to optimally identify the best locations and sizes of CBs using the whale optimization algorithm. The optimal capacitor placement (OCP) problem considers minimizing the total cost comprising the active power loss cost, the capacitors purchase, and capacitors installation costs. Three cases are studied and compared, the uncompensated case (without reactive power compensation), the fixed capacitors, and the switched capacitors. The results showed the capability of WOA to improve the overall performance in terms of the annual cost, the percentage of energy loss reduction, and the net saving in $/year.