Voltage Stability Improvement in Optimal Placement of Voltage Regulators and Capacitor Banks Based on FSM and MMOPSO Approach

Installation of Shunt Capacitor Banks (SCBs) and Voltage Regulators (VRs) within distribution system is one of the most effective solutions in reactive power control for improving the voltage profile and reducing power losses along the feeder. However, the presence of the VRs can deteriorate the Voltage Stability Margin (VSM) in distribution feeders. To address this issue, this paper proposes a multi-objective programming model for the simultaneous optimal allocation of VRs and SCBs in the distribution network to improve the voltage profile and to minimize power losses and installation costs. In the proposed model, a Voltage Stability Index (VSI) is considered to prevent voltage instability during SCBs/VRs allocation. A new Modified Multi-Objective Particle Swarm Optimization (MMOPSO) algorithm which includes a dynamic inertia weight and mutation operator is proposed to obtain the optimal solutions as a Pareto set. Thereinafter, a Fuzzy Satisfaction Method (FSM) determines the optimal solution. A practical long radial distribution feeder has been employed to demonstrate the efficiency and efficacy of the proposed model along with a comparison between the proposed MMOPSO and the original MOPSO.