Abstract:

GaN devices are widely used in totem-pole bridgeless PFC circuits due to their excellent switching performance.In the inductor current critical continuous mode (CRM), Totem-Pole bridgeless PFC can achieve soft switching of the switching tube across the full input voltage range through the reasonable control.In view of the problem of complex control timing for the control mode based on the traditional current zero-crossing detection (ZCD) circuit, a soft switching control strategy based on the current state detection circuit is proposed to reduce the complexity of control.The design pressure of the EMI filter is reduced by adopting an interleaved parallel structure, and the power inductances of the two-phase circuit are integrated by using decoupling magnetic integration technology.Finally, a 3 000 W GaN-based interleaved bridgeless totem-pole PFC rectifier is built.The effectiveness of the proposed circuit design scheme is verified by experiments.

Key words: GaN devices, interleaved totem-pole bridgeless PFC, integrated inductors, iTHD