Sliding mode load-frequency controller design for dynamic stability enhancement of large-scale interconnected power systems

A robust load-frequency controller, based on sliding mode theory, is addressed for enhancing the dynamic stability of large-scale interconnected power systems with parameter uncertainties. The control configuration of an N-area power system is composed of N local load-frequency controller. It is required that the knowledge about the upper bounds of parameter uncertainties is included in the control design for achieving robust performance and enhancing the stability degree of the power system. The design procedure of the proposed control strategy is to derive an approximating continuous switching control, and to choose a novel switching hyperplane. This design method does not need the solution of the Riccati equation. Simulation results show that the proposed control scheme, which can provide the advantages of dynamic stability enhancement and superior performance, is an effective method for the case where the power system experiences parameter variations and load disturbances.