Impact of modified differential evolution strategy on reactive power dispatch problem

Reactive power dispatch (RPD) is a non-linear, mixed integer optimization problem which optimizes grid congestion by minimizing the real power losses and voltage deviation for a fixed economic power dispatch. This paper proposes an efficient and reliable soft-computing technique based on differential evolution (DE) method to solve the RPD problem. Classical DE sometimes suffers from the problem of slow convergence. In this paper a new modified DE is employed to settle the RPD control variables. RPD optimizes power system losses by controlling the reactive power control variables such as generator voltages, transformer tap-settings and other sources of reactive power like capacitor banks and provides better system voltage control. Thus, it improves voltage profile, system security, power transfer capability and overall system operation. As a test case standard IEEE 118-bus system is considered. Simulation results based on the proposed approach are compared with other reported evolutionary techniques in the literature. The results prove the potential of the proposed approach and show its effectiveness and robustness to solve the RPD problem.