Virtual inertia and intelligent control assisted frequency regulation of time-delayed power system under DoS attacks

This work proposes an intelligent fractional order fuzzy-proportional derivative plus fractional order-integral (FOF-PD + FOI) control and virtual inertia (VI) control (VIC) for frequency regulation of renewable penetrated interconnected power system (IPS) under denial of service (DoS) attacks and time delays (TDs). The considered IPS is based on thermal power plants in each area with a wind power plant in area-1 and a solar power plant in area-2, moreover, the impact of DoS attacks is considered in the VIC loop. All the physical constraints and non-linearities are also considered. To harvest the power from solar and wind, a perturb and observe (P&O) maximum power point tracking (MPPT) scheme as well as a variable speed wind turbines' slow dynamic behaviour based MPPT respectively are implemented. To obtain the optimal parameters of the proposed controller, a physics-informed optimization termed Archimedes optimization algorithm (AOA) is used. The proposed FOF-PD + FOI controller's supremacy is tasted over PI, PID and fuzzy-PD + I (F-PD + I) controllers in terms of steady state, dynamic performances and with/without renewable energy sources (RESs) while considering the proposed VIC. To replicate the robust operation of AOA-tuned FOF-PD + FOI controller and VIC, variations in virtual inertia of both areas as well as variations in grid parameters are considered. Furthermore, root locus-based stability evaluation is performed to show the stable operation of the designed control architecture. Finally, the proposed controller is tested over New England IEEE-39 bus-based multi-machine large-scale IPS by considering DoS attacks and TDs.