Capacitor placement in radial distribution systems for loss reduction

Reduction of I-2-R loss in distribution systems is very essential to improve the overall efficiency of power delivery. The (IR)-R-2 loss can be separated into two parts based on the active and reactive components of branch currents. The paper presents a method of minimising the loss associated with the reactive component of branch currents by placing shunt capacitors. This method first determines a sequence of nodes to be compensated by capacitors. The size of the optimal capacitor at the compensated nodes is then determined by optimising the loss saving equation with respect to the capacitor currents. The performance of the proposed method was investigated on two distribution systems consisting of 15 and 33 buses and it was found that a significant loss saving can be achieved by placing optimal capacitors in the system.