Improved Control Strategy for Inverter Side Current Feedback of LCL Grid-Connected Inverter Under Weak Grid

In view of the inability to achieve unit power factor and the poor stability of the system under weak grids, this paper propose an improved control strategy for inverter side current feedback of LCL grid-connected inverter under weak grid which can using the capacitor voltage to achieve phase-locking, damping and grid-voltage feedback, calculate the reference current to achieve unity power factor correction by the calculation of the capacitance voltage and the inverter side current, and improve the stability of the system by complex filter. The theoretical analysis shows that the proposed improved control strategy has excellent performance under the weak grid and can achieve unit power factor integration. Finally, the correctness and effectiveness of the strategy are verified by simulation and experiment.