This paper presents a robust control strategy to address the frequency regulation challenges in low-inertia microgrids (MGs) with high penetration of renewable energy sources (RESs). A novel PID-based Virtual Rotor Control with Integral feedback (PID-VRC/I) is proposed to emulate virtual inertia using Electric Vehicles (EVs) and to mitigate the adverse effects of measurement delays caused by the phase-locked loop (PLL). To ensure reliable frequency support during periods when EVs are unavailable, a coordinated demand response (DR) mechanism is integrated as a backup control layer. The DR framework considers flexible loads such as pumps, chillers, compressors, and Uninterruptible Power Supply (UPS) systems, all controlled using a conventional VRC approach while taking into account their communication and response time delays. A modified zebra optimization algorithm (MZOA) is employed to optimize the proposed controller gains. The effectiveness of the proposed control framework is validated through two scenarios using hardware-in-the-loop (HIL) testing on the Real-Time Digital Simulator (RTDS) platform. Results demonstrate that the proposed PID-VRC/I with DR strategy significantly outperforms conventional VRC configurations by reducing frequency deviations, enhancing dynamic response, and minimizing stress on EV systems.

The expanding integration of renewable energy (RE) sources into modern power introduces operational challenges such as frequency instability. This study focuses on Load Frequency Control (LFC) in the context of PV power integration. A Newton–Raphson-Based Optimizer (NRBO) is employed to tune the Proportional–Integral–Derivative (PID) controller parameters for a two-area interconnected power system, with performance compared against the Teach–Learning-Based Optimization (TLBO) method. Furthermore, the study evaluates the performance of a novel cascaded PD–P–PID controller relative to a conventional PID approach. Simulation results reveal notable improvements, including reductions in peak overshoot, undershoot, settling time, and oscillatory behavior. The influence of PV power integration into Area 1 on system frequency and tie-line power is also analyzed. To counteract frequency deviations arising from PV output variability, the paper proposes incorporating an Electric Vehicle (EV) system as an auxiliary frequency regulation resource.

This paper presents an innovative control strategy to enhance the stability of interconnected Microgrids (MGs) with low inertia and high penetration levels of Renewable Energies (REs). The proposed control strategy encompasses a new virtual droop control mechanism that emulates the primary control of synchronous generators for enhanced system stability. Additionally, a weighted Proportional-Integral (PI) controller is used to mitigate the adverse effects of measurement delays caused by Phase-Locked Loop (PLL) dynamics. Furthermore, a feedback integral loop is introduced to improve the efficiency and lifespan of Vanadium Redox Flow Batteries (VRFBs) enabling swift and precise power delivery while reducing steadystate errors. Finally, a new fractional-order virtual inertia control (VIC) is introduced to leverage the fractional derivatives and enhance the system’s frequency response. The presented simulation results demonstrate the effectiveness of the proposed control approach in improving the frequency response and power exchange dynamics across interconnected MGs under various operating scenarios.