A Kind of Bydirectional Active EMI Filter Based on Double-Side Sensing Network

Power converters based on the controlling of switching devices can achieve power conversion with high efficiency. This kind of converter occupies several advantages but will introduce sever electromagnetic interference(EMI) as side effect. To block the propagation of EMI noise, it is widely used to add passive filter or active EMI filter(AEF) into the converters. With small size and decent noise attenuation ability of AEF, it has the tendency to cover the usage of passive filter. But different from passive filter, with the limitation of controlling method of AEF, it doesn’t have the ability to attenuate the noise from both sides. Nowadays, the cascade of power converters is becoming more and more common, this feature will limit the applications of AEF. To cope with this problem, this paper proposes a kind of bydirectional AEF with double-side sensing method. Based on the theoretical analysis and experiments, it can be found that this topology can well attenuate the noise signals from both sides and the insertion loss is pretty decent.