A Differential Mode Noise Estimation and Filter Size Comparison in Totem-Pole PFC Converters

The switching frequency of a power converter has the greatest impact for achieving higher power density. Higher switching frequency reduces the size of the passives such as inductors but not necessarily the size of electro-magnetic interference (EMI) filter as conducted EMI is measured beyond 150kHz. This paper proposes differential mode (DM) noise estimation methods for the totem-pole (TP) power-factor-correction (PFC) converters consisting of multi-leg multi-phase and three-level continuous-conduction-mode (CCM) PFCs as well as multi-phase interleaved critical-conduction-mode (CrM) PFCs. The filter size among different PFC topologies is compared and the impact of the switching frequency selections on the DM filter size is analyzed.