Dual-Battery Reconfigurable Converter-Assisted Vehicle-to-Grid System for Adaptive Microgrid Frequency Stabilization: A Simulation Study

Abstract: This paper presents a unified MATLAB/Simulink co-simulation framework integrating a reconfigurable dual- battery contactor-based converter (CBC) architecture with a Vehicle-to-Grid (V2G) energy management layer within a renewable-integrated community microgrid. Unlike conventional V2G investigations that model each EV as a fixed- voltage equivalent, the proposed CBC enables real-time series/parallel reconfiguration of two 36 V battery packs to deliver up to 72 V effective bus voltage during severe under-frequency events, while an integrated voltage-balancing stage suppresses inter-pack circulating currents by 93.7%. A Fractional-Order Super-Twisting Sliding Mode Controller (FO-STSMC, α = 0.85) governs the frequency regulation outer loop with Lyapunov-guaranteed finite-time convergence, and a cascaded Multi-Variable Compensating (MVC) notch filter maintains grid-current total harmonic distortion (THD) below 2.8%. A state-of-charge (SoC)-stratified dispatch algorithm coordinates 100 EVs across five behavioural profiles over a 24-hour simulation. Across 30 Monte Carlo scenarios with randomised fleet SoC spread, load variability, and renewable irradiance, the proposed system demonstrates a 47.7% frequency nadir improvement and 55.7% recovery time reduction versus the no-V2G baseline under worst-case disturbance conditions, with zero traction SoC violations and 18.7% daily diesel fuel saving.

Keywords: Contactor-based converter; dual-battery EV; fractional-order super-twisting SMC; microgrid frequency regulation; multi-variable compensating filter; SoC management; V2G aggregator; vehicle-to-grid.