Fractional-order PID and internal model control-based dual-loop load frequency control using teaching-learning optimization

A load frequency controller is essential to counter load disturbances and minimize unscheduled power flow between interlinked areas of a power system. Hence, this paper proposes a fractional-order proportional-integral derivative (FOPID)-based dual-loop control approach for load frequency control of multi-area nonreheated thermal power systems (NRTPS) using teaching-learning optimization (TLO). A stability equation-based predictive model is used with internal model control in the internal loop of the proposed approach, whereas the external loop contains TLO-based FOPID controller. The proposed method is tested on two-area and three-area NRTPSs under various operating conditions. It is validated from the simulation results that the proposed approach improves the system response substantially compared to the well-known existing techniques. The robustness of the proposed method is also demonstrated by performing sensitivity analysis with parametric uncertainties, random load disturbances, generation rate constraints, and governor dead zone.