Feedforward Dual-Mode Repetitive Control for Single-Phase V2G Inverters in Residential Grids

Vehicle-to-grid (V2G) technology enhances the utilization of renewable energy by enabling electric vehicles to inject stored renewable power into the grid. However, in singlephase residential grids, the grid background harmonics and grid frequency variations directly affect the feed-in grid current quality of the V2G inverter system. To address this issue, this paper proposes a novel feedforward dual-mode repetitive control (FDMRC) scheme, which adjusts adaptively the repetitive control (RC) gains according to the harmonics distribution of feed-in grid current. By introducing the feedforward channels into the dual-mode repetitive control, the FDMRC enlarges the open-loop gains at the frequencies of interest, while enhancing the dynamic performance of the system. In addition, the adaptive RC gains improve the harmonics suppression performance of the FDMRC system under varied grid background harmonics. Furthermore, stability analysis and detailed parameters optimization design for the FDMRC system are presented. The experimental platform of a single-phase V2G inverter is established to verify the effectiveness of the proposed FDMRC scheme, and the experimental results demonstrates that the proposed FDMRC scheme possesses enhanced harmonics suppression performance, strong frequency robustness, and fast dynamic performance under the scenarios of varied grid background harmonics and grid frequency variations.