A control method to damp oscillation in the input LC filter

A control method to damp oscillation in the input LC filter of AC-DC PWM converters is proposed in this paper. The oscillation in the input LC filter of AC-DC PWM converters is damped by using a virtual resistor that can be connected either in series to or parallel with 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 by 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 and experimental results are included to verify the proposed method.