Optimal VAR control for real power loss minimization and voltage stability improvement using Hybrid Multi-Swarm PSO

This paper presents a recently developed Hybrid Multi-Swarm Particle Swarm Optimization (HMPSO) algorithm for multi-objective optimal reactive power control (ORPC) for minimizing real power loss and improving voltage stability. Optimal reactive power control in electrical power system is a single objective or a multi-objective, non-linear, constrained optimization problem that can be solved by applying any optimization technique. HMPSO is a recently develop devolutionary computing based optimization algorithm, in which the existing swarm is divided into several sub-swarms. For each sub-swarm, PSO algorithm is implemented as the search engine. In addition to this, differential evolution (DE) algorithm is applied to improve the personal best of each particle. To find the Pareto optimal set for the ORPC problem, the weighted sum method has been used. Consequently, to extract the best compromise solution out of the Pareto-optimal set, fuzzy based mechanism has been used. Effectiveness of the HMPSO algorithm for solving ORPC problem has been established by applying it on the IEEE 30-bus system.