A Current-Sharing Strategy for Single-Phase Inverter Parallel System Based on Multi-Loop Cooperative Control

Droop control is widely utilized in parallel inverter control within microgrids. However, conventional droop control strategy struggle to achieve reactive power sharing and circulating current suppression among multiple parallel inverters due to mismatched output impedances. To address this issue, this paper proposes a current-sharing strategy for single-phase parallel inverters based on multi-loop cooperative control. The proposed control strategy comprises a voltage-current loop, a droop control loop, a virtual impedance loop, and a reactive power tracking loop. Under the multi-loop cooperative control framework, the virtual impedance can be adaptively adjusted to compensate for output impedance discrepancies, thereby achieving reactive power balance and output current sharing in the parallel system. Finally, the effectiveness and feasibility of the control strategy were verified through experimental results.