Bi-Directional Single-Stage Interleaved Totem-Pole AC-DC Converter with High Frequency Isolation for On-Board EV Charger

In this paper a new single-stage electrolytic capacitor-less ac-dc converter with high frequency isolation and low components count is introduced. The proposed converter is constructed using two interleaved CCM boost circuits in the grid side and non-regulating full bridge in the DC side. An optimized switching is implemented on the two interleaved boost circuits resulting in a ripple-free grid current without a ripple cancellation network; hence small filter inductors are used. A simple and reliable closed-loop control system is easily implemented, since the phase-shift angle is the only independent variable. Moreover, current imbalance is avoided in the presented topology despite the CCM operation without current control loop in each phase. The proposed charger charges the battery with a sinusoidal-like current instead of a constant direct current. ZVS turn on of all switches is achieved throughout the operation in both directions of power flow without any additional components.