Modern power systems are very complex and critical to electrical engineering services. The interconnections between various areas, nonlinear dynamics, and huge inertia of the components, make the problem very complex. Any load deviation in one area will affect the others, too. So, in this paper, a robust control strategy is utilized to offer minimal and non-oscillatory frequency swings in response to load deviation. The paper also explores and compares the use of covariance matrix adaptation evolution strategy (CMA-ES) based algorithm for the design of optimal robust controller. The controller has been expressed as the aggregate function of a multi-objective optimization problem. The results obtained show that the robust controller designed using CMA-ES offers a satisfactory response when compared to classical and other controllers obtained using time-based performance indices.
