This digest proposes a current control method for bridgeless totem-pole power factor correction (BTPPFC) converters without a grid voltage sensor. The grid voltage is pre-estimated through a Discontinuous Conduction Mode (DCM) start-up technique before executing closed-loop current control. The estimated grid voltage is used as feedforward into the current controller just before activation of the closed-loop current control, enabling a seamless. The PR (proportional-resonant) controller is utilized both for current control and grid angle estimation. The error between the estimated and actual grid angles is below 0.3ยบ at steady state. The validity of the proposed grid voltage sensorless current control method is verified by experiments with a 3.2 kW SiC MOSFET-based totem-pole PFC converter.
