Fuzzy optimal placement of capacitors in the presence of nonlinear loads in unbalanced distribution networks using BF-PSO algorithm

This paper presents a new method to optimize locating and the size of fixed and switching capacitor banks based on bacterial foraging (BF) oriented by particle swarm optimization (PSO) algorithm (BF-PSO). The algorithm is proposed for radial and meshed networks in the presence of unbalanced and nonlinear loads. The objective function considers the minimization of the total energy loss costs and capacitor installation cost, network total harmonic distortion (THD) index, and the deviation of the voltage fundamental component from the permitted value. Since these parameters do not have similar units and variation ranges, a membership degree is assigned to each parameter by using fuzzy sets. The IEEE 123-Bus distribution network is used to test the proposed method. The simulation results of the proposed algorithm are compared with PSO, BF and genetic algorithms to show the efficiency of this method to reduce the system costs.