Dynamic State Observer-Based Event-Triggered ISM Load Frequency Control of Power Systems With Disturbance Observer
Zeinab Echreshavi, Mohsen Farbood, Mokhtar Shasadeghi
Abstract
This article proposes a new dynamic observer-based event-triggered integral sliding mode control incorporating disturbance observer (DO) for the load frequency control of a multiarea interconnected power system (IPS) considering load disturbances and uncertainties. To improve the system performance and reduce the cost implementation, first a dynamic observer is designed for the IPS to achieve the state estimation. Then, to reduce the chattering effect and improve the robust performance, a DO is designed to obtain the estimated of the unmatched disturbances. To further reduce the chattering effect and computational burden, based on the obtained state estimation and the estimated disturbances, two integral sliding surfaces are proposed. The periodic-time one that is proposed to ensure the robust performance from the initial-time and the time-triggered one that is proposed to obtain the event-triggered control law. Utilizing the Lyapunov theory, the ultimate boundedness stability of the controlled system is studied and sufficient conditions are derived by solving a set of offline linear matrix inequalities. During the system implementation, it is also verified that the controlled system is Zeno-free. Finally, the proposed control strategy is compared with some existing studies and the simulation results demonstrate the effectiveness and the superiority over the existing approaches.