A novel active damping control strategy for PWM converter with LCL filter

A novel active damping control strategy for PWM converter with LCL filter is proposed in this paper. There is resonant peak in LCL filter frequency response. Conventional method is connecting a resistor in series with the filter capacitor to resolve the resonant peak, but the power loss will be brought by this passive damping method. The resonant peak could be damped by proper control strategy which is called active damping. A novel design method of filter capacitor current feedback loop is introduced. The filter capacitor current estimate method is adopted so there is no addition sensors needed. The resonant peak is attenuated and the waveform of output current is improved. Finally, the feasibility of the proposed method is verified through experimental results.