Designing of coupled inductor in interleaved critical conduction mode boost PFC converter

Boost converter in critical conduction mode (CRM) can be used for power factor correction in low power level and it also can be used in medium or high power application by using interleaving technical which can reduce the input current ripple and output capacitor rms current. In this paper, the two inductors of two-phase interleaved Boost converter in CRM is inverse coupled for copper volume reduction. The coupling effect on switching frequency is analyzed, and the design procedure including inductance, turns number and air gap is introduced step by step. Based on minimum switching frequency larger than 30 kHz, the turns number of each winding can be reduced by coupling compare with the non-coupled case.