A modified harmony search algorithm for solving load-frequency control of non-linear interconnected hydrothermal power systems

In this paper, a new method is presented to solve the load-frequency control of non-linear power systems. In the proposed methodology, a two-area interconnected hydrothermal power system is considered to optimal adjustment parameters of Proportional-Integral-Derivative (PID) controller. In order to illustrate the usefulness of the newly proposed method, the obtained results are compared with the determined results of genetic algorithm. The cost function of problem is also proposed based on the Integral of Time-multiplied Absolute value of the Error (ITAE) in the optimization process along with frequency bias factor to improve system response. The proposed controller is optimized by a new music- inspired algorithm, named modified harmony search algorithm (MHSA). The MHSA is a recently developed optimization algorithm which imitates the music improvisation process. In this process, the Harmonists improvise their instrument pitches searching for the perfect state of harmony. The newly developed method has been implemented on a two-area interconnected hydrothermal system with three different scenarios to show the feasibility and effectiveness of the proposed method. Simulation results demonstrated the sufficiency of the newly developed method in the load-frequency control, when compared with other methods; and therefore, it can be beneficial for the real-world power systems. (C) 2015 Elsevier Ltd. All rights reserved.