Multi-phase Coupled and Integrated Inductors for Bi-directional On-board Charger

摘要

Coupled inductor has been widely adopted in VR applications for many years because of its benefits such as reducing current ripple or improving transient performance. Previously, the negative coupled inductor has been applied to interleaved MHz totem-pole CRM PFC converter for server power supply. In this paper, the positive coupled inductor concept is applied to interleaved totem-pole CRM PFC converter for 6.6kW on board battery charger. The difference between negative coupling and positive coupling will be discussed. The benefit of positive coupling for battery charger will be presented, such reducing switching frequency range and reducing input DM noise. Hence the positive coupled inductor can improve the performance of PFC converter. In addition, balance technique is applied to help minimize CM noise. Previously, balance technique has been developed for interleaved boost PFC converter with independent inductors. This presentation will introduce how to achieve balance with coupled inductor. Last but not least, the inductor will be integrated into PCB winding with a little sacrifice on loss. With the inductor integration, the converter can avoid labor intensive production and achieve fully automatic manufacture.