Abstract

This paper presents an improved harmony search algorithm for the optimal
reactive/voltage control problem. Optimal reactive/voltage control is a mixed integer, nonlinear
optimization problem which includes both continuous and discrete control variables. The
proposed algorithm is used to find the settings of control variables such as generator voltages, tap
positions of tap changing transformers and the amount of reactive compensation devices to
optimize a certain objective. The objectives are power transmission loss, voltage stability and
voltage profile which are optimized separately. In the presented method, the inequality constraints
are handled by penalty coefficients. The study is implemented on the IEEE 30 Bus system and the
results are compared with other algorithms such as harmony search algorithm (HSA) and particle
swarm optimization (PSO).