A fuzzy-based approach for optimal allocation and sizing of capacitor banks

•We propose a fuzzy optimization approach for capacitor allocation.•In this approach, a membership function for voltage profile constraint has been used.•We propose a new membership function for section active power losses constraint.•Thermal capability of the feeder has been imposed on optimization process.•The proposed approach has been applied to 9-bus and 34-bus distribution systems.

This paper proposes a fuzzy set optimization approach for capacitor allocation in radial distribution system. In this approach, a membership function for voltage profile constraint has been used. Moreover, another membership function incorporating feeder section active power losses and total power losses constraints has been proposed. This membership function indirectly imposes thermal capability of the feeder on the optimization process. The proposed approach has been applied to 9-bus and 34-bus radial distribution systems. The results have been compared with those of two fuzzy approaches in literature. The comparison showed the effectiveness of the proposed approach for optimizing the sizes and locations of the capacitor with running and total cost reduction.