Real-time frequency regulation in AC microgrid using electric vehicles with V2G and G2V support: Simulation and hardware-in-the-loop validation

This paper presents a frequency regulation strategy for an AC microgrid comprising a fleet of electric vehicles (EVs) capable of bidirectional power flow through vehicle-to-grid (V2G) and grid-to-vehicle (G2V) modes. The proposed approach ensures frequency stability by dynamically switching EV operation modes based on state-of-charge (SOC), grid frequency, and load conditions. EVs with a SOC of less than 50% run in charging mode, while those with a SOC of more than 90% supply power to the microgrid during times of high demand to support ancillary frequencies. Bidirectional power exchange between EV batteries and the microgrid is made possible by a three-level t-type three-phase bidirectional converter (TLT3PBC). Under varied load disturbances, the suggested control architecture keeps the microgrid frequency within a predetermined range of 0.999–1.001 p.u. To assess system performance during load connection and disconnection events, simulation experiments are carried out in MATLAB/Simulink. Additionally, a microcontroller that implements the control algorithm and a real-time simulator for the microgrid plant are used for hardware-in-the-loop (HIL) validation. The results show that under dynamic operating conditions, coordinated V2G/G2V operation efficiently reduces frequency deviations, increases microgrid resilience, and improves system stability. In future smart microgrids, the suggested method emphasizes the potential of aggregated EV resources as distributed energy storage for real-time frequency regulation.