A method to damp oscillations on the input LC filter of current-type AC-DC PWM converters by using a virtual resistor

A control method to damp oscillations on the input LC filter of current-type AC-DC PWM converters is proposed in this paper. The oscillations on the input LC filter of current-type AC-DC PWM converters are damped by using a virtual resistor that can be connected either in series to or parallel with the filter inductor or capacitor. Because no real resistor is used, the efficiency of the converters is not sacrificed. The required additional sensor and implementation of the virtual resistor in the control algorithm is strongly influenced on how the virtual resistor is connected to the LC filter. We need an additional current sensor if the virtual resistor is connected in series to the filter inductor or capacitor and an additional voltage sensor if connected in parallel. Simulated results are included to verify the proposed method.