Integration of Vienna Rectifier and SC-PFM for Soft-Switching Current Sensorless PFC With Simplified Control

This article presents a study on the interleaved Vienna Rectifier with pulse-frequency modulation (IVR-PFM), an integration of the Vienna Rectifier and the switching cell with pulse-frequency modulation (SC-PFM), for three-phase three-wire applications. The IVR-PFM retains key advantages of the SC-PFM, including soft switching, voltage-follower behavior, and simplified control without current sensing. Unlike converters in discontinuous conduction mode (DCM), the IVR-PFM achieves continuous input current with peak currents in active components only slightly exceeding the input current–behavior associated with continuous conduction mode (CCM). Control requires only output voltage feedback and a simple outer-loop PI controller, eliminating the need for processor-intensive control algorithms such as dq0 or $\alpha\beta$ transformations, space vector pulse width modulation (SVPWM), phase-locked loops (PLLs), and cosine generation. The article also analyzes the commutation behavior, input current ripple, zero-crossing dynamics, and natural voltage balancing between the dual output capacitors. Experimental results from a 3 kW prototype, operating from a 220 V line input to an 800 V output, confirm the converter’s performance under varying load conditions and validate the proposed analytical models.