A general active damping method based on capacitor voltage detection for grid-connected inverter

In this paper, a general active damping method based on capacitor voltage detection for stable control of LCL-filter grid-connect inverter is proposed. Three active damping methods are derived from the general form. Root locus and bode diagrams are used to analysis these three active damping methods. And in the case of different control delay, robustness of three active damping methods are compared. Integrated the advantages and disadvantages of each method, and eventually come to a relatively better active damping method. Finally, each active damping method is verified by simulation and experiment.