Modeling and stability analysis of active/hybrid common-mode EMI filters for DC/DC power converters

Hybrid electromagnetic interference (EMI) filters (HEFs) which are composed of an active filter and a passive filter, have been proposed to reduce the size and weight of conventional passive EMI filters. However, accurate models that can be used to predict the stability and performance of HEFs have not been developed. To cope with this, this paper presents a modeling technique for a hybrid common-mode (CM) filter. The technique can be applied to the modeling of other HEFs. Critical component models were first developed for the HEF. HEF´s overall model is further developed based on these individual component models. Experimental results validated that the developed model can successfully predict the stability and performance of the hybrid CM filter.