Feedforward Droop Control for Reactive Power Balancing in Grid-Forming Inverters With Line Impedance Compensation

초록

This article proposes a novel droop control methodology for grid-forming (GFM) inverters, capable of accurately calculating and compensating voltage drops in the DQ coordinate system for multiple GFM inverters. By employing the proposed impedance tracking method and a feedforward compensation, the proposed methodology effectively mitigates reactive power sharing errors caused by line impedance voltage drops. The control method is specifically designed for multiple GFM inverters with varying line impedances that are not directly connected to the point of common coupling (PCC). The proposed droop controller automatically estimates line impedances and compensates for voltage drop components in the DQ coordinate system, thereby nullifying the influence of line impedances as observed at the output terminals of the GFM inverters. Unlike traditional methods that rely on direct ac voltage application, the proposed approach utilizes DQ synchronous coordinate transformation to ensure stable and accurate reactive power sharing for multiple GFM inverters under both grid-connected and stand-alone conditions. The effectiveness of the proposed control strategy has been validated through simulations and experiments conducted on a 5 kVA prototype, demonstrating its capability to achieve precise reactive power sharing under varying operating conditions. © 1982-2012 IEEE.

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