Asymmetrical interleaving strategy for multi-channel PFC

The continuously increasing efficiency and power density requirement of the AC-DC front-end converter posed a big challenge for today´s power factor correction (PFC) circuit design. The multi-channel interleaved PFC is a promising candidate to achieve the goals. In this paper, the multi-channel interleaving impact on the EMI filter design and the output capacitor life time is investigated. By properly choosing the interleaving channel number and the switching frequency, the EMI filter size and cost can be effectively reduced. Further more; multi-channel PFC with asymmetrical interleaving strategy is introduced, and the additional benefit on the EMI filter is identified. At the output side, different interleaving schemes impact on the output capacitor ripple cancellation effect is also investigated and compared.