Fractional order control for vanadium redox flow battery to enhance LFC performance, resiliency, and robustness in a nonlinear RES-integrated liberalized cyber-physical energy system

• An extensive literature review on the various RFB models used in LFC is presented, and the flaws are discussed. • A novel FOCs approach for a dedicated RFB model is proposed for a nonlinear liberalized cyber-physical hybrid power system. • Performance of the offered RFB-LFC approach is evaluated across various scenarios. • Resiliency of the proposed FOCs-based RFB-LFC approach is evaluated under concurrent MTTD and cyberattacks. • Robustness of the presented FOCs-based RFB-LFC approach is evaluated by conducting sensitivity analysis. Vanadium redox flow battery (VRFB) is well-suited for addressing load frequency control (LFC) due to its significant merits as a grid-scale storage. While previous studies have explored RFBs to address LFC, existing RFB models have notable flaws, which are reviewed comprehensively. Earlier RFB control models either fail to capture the unique dynamics of RFB or are fixed-parameter, yielding unreliable results and limited effectiveness in enhancing LFC performance. To significantly aid LFC, the lack of an efficient control method for VRFB’s unique dynamics is a critical gap that requires further investigation. This paper introduces resilient control strategies that incorporate fractional order controllers (FOCs) into the actual dynamics of VRFBs. Applying FOCs to VRFBs is a new idea. A nonlinear renewable energy source (RES)-integrated liberalized cyber-physical power system is benchmarked to yield actionable insights and dependable results. Numerical stability metrics and dynamic examinations, conducted under a competitive scenario and different non-contracted loads as contract violations, indicate that implementing tilt integral derivative (TID)- and fractional order proportional integral derivative (FOPID)-based VRFB-LFC yield considerable enhancements in damping measures compared with the former control approaches. Examinations of various false data injection (FDI)-type cyberattacks and communication time delays (CTDs) demonstrate that the FOC-based control strategy is quite resilient to cybersecurity threats and larger CTDs. It is shown that the retuned FOC-based VRFB-LFC is resilient against concurrently applied cybersecurity threats and CTDs, even under the maximum tolerable time delay. Sensitivity analyses indicate that the FOCs-based VRFB-LFC remains robust to variations in the key system parameter of synchronizing coefficient and loading.