Optimal Reactive Power Dispatch with Static VAR Compensator Using Harmony Search Algorithms

Abstract

One of the major optimization problems in power systems is the optimal reactive power dispatch (ORPD) problem. ORPD plays an important role for secure and reliable operation of power systems. The main purpose of ORPD is to find the settings of control variables such as voltage rating of generators, reactive power injection of VAr compensators and tap ratios of the tap setting transformers in order to minimize the total active power losses of the network while satisfying a given set of constraints. The whole ORPD problem is considered as a non-linear multi-modal optimization problem with a combination of discrete and continuous variables. Along with the conventional control variables in ORPD the optimal location and the Var settings of SVC are included in the optimization problem for additional active power loss reduction. In this paper, two versions of harmony search algorithms namely basic Harmony Search Algorithm (HSA) and Improved Harmony Search algorithm (IHSA) are applied to solve conventional ORPD, as well as ORPD with the FACTS device Static Var Compensator (SVC), to minimize the total active power loss of the power system. The harmony search algorithms for ORPD, as well as ORPD considering SVC are implemented on IEEE 14 and 57 bus systems. Comparison of simulation results reveals the effectiveness of harmony search algorithms over other well established population based optimization techniques.