Combined Differential Evolution Algorithm and Ant System for Optimal Reactive Power Dispatch

Abstract This paper proposes a hybrid approach to solve the optimal reactive power dispatch (ORPD) problem. Traditionally, ORPD is defined as the minimization of active power transmission losses by controlling a number of control variables, which is formulated as a nonlinear constrained optimization problem with continuous and discrete variables. Based on the original differential evolution (DE) algorithm, the proposed approach combines variable scaling mutation and probabilistic state transition rule used in the ant system to deal with the ORPD problem. To verify the performance of the proposed method, the similar evolution approaches such as the evolutionary programming (EP) and particle swarm optimization (PSO) are also implemented using the same study case. Testing on the IEEE 30-bus system indicates that the proposed approach can obtain better results with lower active power transmission losses and better convergence performance than the existing methods.