A new virtual LC filter concept and its applications

This paper proposes a new virtual LC filter to minimize the low-frequency output ripples of static power converters. The proposed virtual LC filter can be considered as an additional controller that simulates the roles of a passive LC filter that is connecting in series to the output side of converter. The LC filter is tuned at the ripple frequency. As the filter is virtual, we have no physical and cost limitations. The filter can be designed in such a way so that only the undesired ripple is affected by the filter. Several experimental results are included to show the effectiveness of the proposed virtual LC filter in reducing the low-frequency current ripples produced by static power converters.