Resilient Ratio Control Assisted Virtual Inertia for Frequency Regulation of Hybrid Power System Under DoS Attack and Communication Delay

Due to the presence of Denial-of-Service (DoS) attacks and communication time delay (CTD), frequency regulation of a thermal and wind plants-based hybrid power system (HPS) with wind power fluctuations and load variations may not be guaranteed, and in the worst situation overall system may be destabilized. This paper addresses a robust proportional-integral (PI) controller to compensate for the impact of CTD and for the first time, an intelligent fuzzy logic-assisted ratio control-based virtual inertia (VI) is implemented for handling the DoS attacks. The controller's design is carried out using physics-inspired optimization called Fick's law optimization (FLO), where Kharitonov's theorem is used to obtain the maximum and minimum bounds of the controller. The effectiveness of proposed control design is assessed by considering the various practical scenarios such as cyber-attacks, parametric uncertainties, varying CTD, stochastic wind power fluctuations, industrial and domestic loads, step load perturbations and the presence of system nonlinearities such as generator dead band (GDB), valve limits and generator rate constraint (GRC). Moreover, for the stability assessment of the proposed control design, maximum sensitivity <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$( {{{{\bm{M}}}_{\bm{S}}}} )$</tex-math></inline-formula> based stability evaluation is employed. Finally, the controller performance is also evaluated upon a multi-machine interconnected IEEE-39 bus system.