CM EMI Evaluation of Totem-Pole and HERIC Single-Phase PFC Converters

The totem-pole PFC stage is a commonly used and widely accepted topology in industry. With the newest emerging power semiconductor technologies, such as the M-BDS, different concepts like the HERIC PFC converter are becoming increasingly more attractive and provide numerous benefits. The presence of a bidirectional switch in the HERIC converter results in a symmetric structure and avoids a problem of the totempole topology, the unfolding. This leads to improved performance in terms of conducted common-mode emissions and to lower control complexity. This paper presents a detailed analysis of both topologies, examining and comparing their performance in terms of conducted electro-magnetic interferences. The influence of the design aspects of the magnetic components, i.e., the gridside boost inductor, is considered, highlighting that the conducted emissions can be effectively mitigated by a proper balancing and coupling strategy. The measurement-based evaluation utilizes a hardware demonstrator that can be operated as HERIC or totempole-PFC stage and fully demonstrate the effectiveness of the proposed solution, with CM noise reductions of up to 30 dB.