Intelligent Cascade Control With Virtual Inertia for Frequency Stability of Time-Delayed Power System Under DoS Attack

Abstract

This work puts forward an intelligent cascade control approach for frequency regulation of a low-inertia interconnected power system (IPS) under denial-of-service (DoS) attack and time delay (TD). The considered IPS incorporates a thermal power plant, solar and wind-based renewable energy source (RES), and a virtual synchronous generator (VSG) based composite energy storage unit. The proposed cascade controller combines a fuzzy-proportional-derivative plus integral (F-PD+I) controller in the outer loop and a PI controller in the inner loop. A dynamic model of the considered IPS with all practical nonlinearities and physical constraints is deduced in this work. Moreover, a physics-inspired optimization termed as Fick’s law algorithm (FLA) is used to obtain the parameters of the proposed control approach. Extensive simulation with parametric uncertainty-based robustness assessment replicates the effectiveness of the proposed approach for enhancing the dynamic stability of IPS. Comparative assessment with existing control structure demonstrates that the proposed cascaded control scheme effectively mitigates the impact of cyberattack and load frequency control (LFC) challenges in the considered low-inertia IPS. Finally, an IEEE-118 bus system is employed to test the proposed control over a more realistic power system structure.