Inner-Outer Loop based Robust Active Damping for LCL Resonance in Grid-Connected Inverters using Grid Current Feedback

In this paper, the active damping of LCL filter resonance of a grid-tied inverter is studied. We show the tradeoffs involved in designing a hierarchical inner-outer control system by analyzing the control-relevant properties at multiple loop-breaking points. We demonstrate how a novel inner-outer control design technique can help obtain reasonable properties simultaneously at the error and plant input/controls. Specifically, we show how...