Research on a three-level PFC circuit with low voltage stress

Three-level and multilevel circuits have the advantages of smaller DC voltage pulsation and reduced circuit loss, and can make DC current waveform closer to sinusoidal, so a four-switch three-level PFC circuit is proposed in this paper. In this paper, four switching tubes are combined to make it have multidirectional switching function, which can not only raise the output voltage to three levels, reduce the voltage stress of switching tubes, but also provide a circuit for inductive charging. At the same time, the circuit can open up to two switches in each mode and share a pulse signal, which simplifies the control complexity in a certain sense. Finally, an experimental platform with rated power of 800 W is built to verify the correctness of the theoretical analysis.