A PSO-based approach to optimal capacitor placement with harmonic distortion consideration

This paper presents a particle swarm optimization (PSO) based approach to achieve optimal capacitor placement in radial distribution systems. Harmonic distortion effects, discrete nature of capacitors, and different load levels are all taken into consideration in the problem formulation. Mathematically, the capacitor placement problem is a non-linear and non-differentiable mixed integer optimization problem with a set of equality and inequality operating constraints. Most conventional optimization techniques are incapable to solve this hard combinatorial problem, whereas PSO algorithm is very suitable. The proposed solution method employs PSO to search for optimal locations, types, and sizes of capacitors to be placed and optimal numbers of switched capacitor banks at different load levels. Computation procedures of applying the method to the capacitor placement problem are given in detail. The proposed approach has been implemented and tested on a distorted IEEE 9-bus test system with promising results.