Output Regulation for Load Frequency Control

Most of the existing control schemes for power systems ensure stability only in the presence of constant loads and renewable energy sources. Motivated then by the inadequacy of the existing control strategies for power systems affected by time-varying loads and renewable energy sources, this article proposes two control schemes based on the well-known output regulation control methodology. The first one is designed based on the classical output regulation theory and addresses the so-called load frequency control (LFC) problem in the presence of time-varying uncontrolled power injections. Then, in order to also minimize the generation costs, we use an approximate output regulation method that solves numerically only the partial differential equation of the regulator equation and propose a controller based on this solution, minimizing an appropriate penalty function. An extensive case study shows the excellent performance of the proposed control schemes in realistic and critical scenarios.