A Cross-Coupled Master–Slave Interleaving Method for Boundary Conduction Mode (BCM) PFC Converters

This paper proposes a cross-coupled master-slave interleaving control method for boundary conduction mode (BCM) power factor correction (PFC) converters. The natural period of every switching cycle of each channel is measured and compared to adaptively determine the master and slave converters, where a converter with a longer natural period becomes master operating in BCM, while a converter with a shorter natural period becomes slave operating in discontinuous conduction mode. The proposed method compensates disturbances within one switching cycle, guaranteeing stable 180° out-of-phase interleaving operation against any transient and disturbance. The proposed method has been implemented and tested on a 400 W interleaved BCM boost PFC prototype converter with a dedicated control IC.