Single-stage high-frequency isolated three-port converter based on interleaved totem-pole structure

To ensure safety, specific applications, such as EV charging, require the galvanic isolation between the various ports. Accordingly, a multi-winding high-frequency (HF) transformer is used to achieve the requisite galvanic isolation for the multi-port converter (MPC). One of the most promising topologies among the multi-winding transformer-coupled MPC family is the triple-active bridge (TAB) converter. The TAB converter is a multi-port converter consisting of three full bridges interconnected through a high-frequency multi-winding transformer. The TAB converter can facilitate bidirectional power flow on each port while simultaneously providing galvanic isolation, which is beneficial for safety and noise isolation. The key contribution of this study lies in two aspects: A totem-pole single-stage AC converter is proposed to replace the conventional two-stage PFC+Inverter structure, significantly reducing component count and complexity. And a new control strategy for the low-voltage side output is proposed, which can avoid the voltage discontinuity phenomenon caused by removing the pre-filter circuit of the step-down converter.