Non-linear sliding mode based load frequency control for power systems using unknown-input-observer

In this paper, a new control strategy is proposed for the load frequency control in interconnected multi-area power systems. An unknown-input-observer based non-linear sliding mode controller is introduced to compensate the effect of unknown load disturbances and parameter uncertainties in the system. The non-linear sliding mode controller stabilizes the system dynamics by utilizing the estimated states and disturbance uncertainties. The closed loop convergence of the observer based controller is verified using Lyapunov stability analysis. The simulation results of the two-area power system show the effectiveness of the proposed controller even in the presence of generator rate constraints.