Differential Model EMI Filter Analysis for Interleaved Boost PFC Converters Considering Optimal Phase Shifting

Interleaved Power Factor Correction (PFC) has become a most popular topology from efficiency and power density point of view over single-switch boost PFC. The dependency of the Differential Model (DM) Electromagnetic Interference (EMI) noise magnitude on input current ripple leads to investigate the influence of the interleaved technique on EMI noise. Hence, this paper provides a comprehensive investigation for the design of DM EMI filter a single-phase interleaved PFC targeting to minimize component size. It is shown how different operation modes (continuous and discontinuous conduction mode) and switching frequency may influence the required filter attenuation and, consequently, the EMI filter size. Furthermore, the impact of the number of interleaved stages and optimal phase shifting on the required filter attenuation is analyzed. Finally, the influence of optimal phase shifting achieve an overall minimum EMI filter corner frequency is discussed. Experimental results from a 2 kW interleaved single-phase boost PFC converter validate the effectiveness of the proposed optimal phase shifting method.