Hybrid Particle Swarm Optimization for Multi-objective Reactive Power Optimization with Voltage Stability Enhancement

This paper presents a new hybrid particle swarm optimization (HPSO) method for solving multi-objective real power optimization problem. The objectives of the optimization problem are to minimize the losses and to maximize the voltage stability margin. The proposed method expands the original GA and PSO to tackle the mixed –integer nonlinear optimization problem and achieves the voltage stability enhancement with continuous and discrete control variables such as generator terminal voltages, tap position of transformers and reactive power sources. A comparison is made with conventional, GA and PSO methods for the real power losses and this method is found to be effective than other methods. It is evaluated on the IEEE 30 and 57 bus test system, and the simulation results show the effectiveness of this approach for improving voltage stability of the system.