Hybrid ZCD-Based Critical Conduction Mode Totem-pole PFC
Gibum Yu, Xingyu Chen, Rahul Rajendran, Qiang Li · 2024
This paper proposes the novel hybrid zero current detector (ZCD) method for critical conduction mode (CRM) based totem-pole power factor correction (PFC). In the conventional ZCD-based method, the large undesired negative current is generated due to the ZCD circuit's propagation delay and the MCU's processing delay. The proposed hybrid ZCD method guarantees CRM operation using a ZCD circuit and compensates for this ZCD delay using the synchronized rectifier (SR) on-time calculation. Therefore, the undesired negative current is eliminated, and the inductor current ripple is reduced, leading to higher efficiency at a higher switching frequency. A 6.6kW two-channel interleaved totem-pole PFC with the hybrid ZCD is built and verified by the experiment.