A Study on the Design and Control of a 6.6-kW Three-Phase Interleaved Totem-Pole PFC for OBC Applications

This paper presents the design, control, and experimental verification of a 6.6-kW three-phase interleaved Totem-Pole power factor correction (PFC) converter for on-board charger (OBC) applications. Three parallel PFC phases are operated with PWM carrier phase shifts of 0°, 120°, and 240° to distribute the input current and reduce the synthesized input-current ripple. SiC MOSFETs are employed for high-frequency switching operation. A digital control system consisting of output-voltage and input-current control loops, a Second-Order Generalized Integrator Phase-Locked Loop (SOGI-PLL), a notch filter, and duty feed-forward was implemented for stable DC-link voltage regulation and input-current control. A 6.6-kW prototype operating with a 220-Vrms input and a 400 V DC-link voltage was developed. Compared with the two-phase interleaved configuration under the same Boost inductance and switching frequency conditions, the three-phase interleaved configuration reduced the maximum input-current ripple from 3.4 A to 2.28 A, corresponding to a reduction of approximately 32.9%, while increasing the ripple frequency from 140 kHz to 210 kHz. The threephase interleaved configuration exhibited an input-current THD up to 3.871 percentage points lower than that of the two-phase configuration while maintaining a comparable power factor. At rated load, the developed converter achieved an input-current THD of 5.438%, a power factor of 0.996, and an efficiency of 97.978%.