A High-Robust Grid-Side Current Feedback Active Damping Design Method for Grid-connected Inverter

Grid-connected inverter with LCL filter is widely employed in renewable energy generation system due to high harmonic suppression ability. However, the resonance issue caused by LCL filter is brought easily. To solve this issue, grid-side current feedback active damping control strategy based on proportional derivative algorithm is employed for cost consideration. Taking digital control delay time into consideration, the active damping method is analyzed in discrete domain. A parameter design method based on dominant pole optimization is proposed, which can not only enhance damping ability but also achieve high robust performance. The validity of the proposed method is finally confirmed by the experimental results.