High-Efficiency Interleaved Totem-Pole PFC Converter With Voltage Follower Characteristics

Abstract

High power density, efficiency, control simplification, and robustness are highly demanded for power factor correction (PFC) converters. This paper proposes a totem-pole rectifier based on the switching cell with switching frequency modulation (SC-SFM). The SC-SFM features interleaved operation, soft commutation, and resistive characteristics with continuous conduction in the input inductor. The converter operates without needing sensors and a control loop for the current. Unlike conventional solutions or some sensorless converters, the converter does not require a fast control loop to shape the current since the current naturally follows the input voltage. Only one output voltage sensor and one input half-line cycle detector are required to achieve unitary power factor and regulated DC output voltage. A detailed analysis of the converter operation, including the operating principle, mathematical analysis, a small signal model, and control method, is presented, including the differences in operation from the conventional PFC rectifier with the diode bridge. Experimental results evaluate a 1-kW prototype with different switch technologies (IGBT, SiC, and GaN).