A novel robust load frequency controller for a two area interconnected power system using LMI and Compact Genetic Algorithms

This paper proposes a new technique for designing a fixed-structure robust load frequency controller for a two area interconnected power system. The proposed technique uses Linear Matrix Inequality (LMI) method to form an initial solution, and then the global search algorithm, Compact Genetic Algorithm (cGA), is adopted for evaluating the final solution. By combining both techniques, LMI and cGA, a better solution in terms of robust performance can be achieved. Infinity norm from disturbances to states are formulated as the cost function in our optimization. The performance of the designed system is investigated in comparison with the conventional H infinity loop shaping controller, the robust controller designed by LMI method and the reduced order robust controller by Hankel norm model reduction method. As results indicated, stability margin of our proposed controller is better than that of the static controller designed by LMI method and the reduced order robust controller. In addition, order of the proposed controller is much lower than that of conventional robust loop shaping controller, making it easy to implement in practice.