PI gain scheduler for load frequency control using spline techniques

This paper proposes a new gain scheduler for proportional-integral (PI) based load frequency control (LFC) using spline techniques. LFC operation has to comply with the North American Electric Reliability Council (NERC)´s control performance standards. This can be achieved by tuning the control gains of the load frequency controller. Furthermore, excess maneuvering of the generating units can be reduced if the gains are adjusted properly. Various PI gains are generated by a robust control design, where each one yields different control performance. Subsequently, those gains are interpolated and approximated using spline techniques, which finally result in robust gain paths. An appropriate pair of PI gains are scheduled from the gain paths to achieve the LFC objective. Simulation results are shown to illustrate performance of the proposed methods.