Multi Objective Differential Evolution approach for voltage stability constrained reactive power planning problem

Abstract

This paper presents the application of Multi Objective Differential Evolution (MODE) algorithm to solve the Voltage Stability Constrained Reactive Power Planning (VSCRPP) problem. Minimization of total cost of energy loss and reactive power production cost of capacitors and maximization of voltage stability margin are taken as the objectives in the Reactive Power Planning (RPP) problem. The L-index of the load buses is taken as the indicator of voltage stability. In the proposed approach, generator bus voltage magnitudes, transformer tap settings and reactive power generation of capacitor bank are taken as the control variables and are represented as the combination of floating point numbers and integers. The MODE emphasizes the non dominated solutions and simultaneously maintains diversity in the non dominated solutions. DE/randSF/1/bin strategy scheme of Differential Evolution with self tuned parameter which employs binomial crossover and difference vector based mutation is used for the VSCRPP problem. A fuzzy based mechanism is employed to get the best compromise solution from the pareto front to aid the decision maker. The proposed reactive power planning model is implemented on two test systems, IEEE 30 bus and IEEE 57 bus test systems. The simulation results of the proposed optimization approach show that MODE is better in maintaining diversity and optimality of solutions.