Fuzzy approach for optimal placement and sizing of capacitor banks in the presence of harmonics

This paper presents a fuzzy-based approach for optimal placement and sizing of fixed capacitor banks in radial distribution networks in the presence of voltage and current harmonics. The objective function includes the cost of power losses, energy losses, and capacitor banks. Constraints include voltage limits, number/size and locations of installed capacitors, and the power quality limits of IEEE-519 standard. Candidate buses for capacitor placement are selected using the sensitivities of constraints and the objective function with respect to reactive power injection at each bus. Using fuzzy set theory, a suitable combination of objective function and constraints is generated as a criterion to select the most suitable bus for capacitor placement. The α-cut process is applied at each iteration to guarantee simultaneous improvements of objective function and satisfying given constraints. Simulation results for the 18 bus IEEE distorted network show the advantages of the proposed method as compared to the maximum sensitivities selection algorithm.