A variable structure-based controller with fuzzy tuning for load-frequency control

This paper presents a variable structure-based approach to the load frequency control problem in electric power generation systems. This approach combines the salient features of both variable structure and fuzzy systems to achieve high-performance and robustness. Fuzzy tuning is proposed for this purpose to continuously adjust the controller parameters according to the area control error. Simulation results indicate that the control scheme is able to substantially enhance control performance in single-area and multi-area interconnected systems with non-reheat or reheat turbines. Furthermore, it is shown that the responses of the system employing the proposed controllers are quite insensitive to parameter changes and speed governor deadband, with or without generation rate constraints. The control strategy requires low computational cost and is amenable for practical implementation.