Abstract:
The traditional three-level diode-clamp converter, when it's used as a power correction circuit, has a problem of more active switches. To solve this problem, this paper proposed a family of single-phase three-level pseudo totem-pole PFC (STPT-PFC), the kind of circuits reduce the active switches, and this kind of three-level STPT-PFC has two bridge arms with inductors, which has 5 topologies and work in two modes in positive and negative half cycle, the two bridge rams provide a path for the input current and reduce the current value flowing through the single inductor effectively. Then, this paper analyzes and summarizes the working principle of the STPT-PFC from the aspects of specific current path process, key waveform and modulation pulse distribution. In addition, the designed process and simulation results of the unified pulse width modulation are presented. At the same time, the STPT-PFC can adopt the same modulation scheme when the active switches are the same. So, the modulation method is easily used in the other PFC circuit. Finally, the experimental prototype of the STPT-PFC-Ⅰ circuit is designed and the parameters of this circuit is rated output power 1kW and output voltage 400V. The experimental results verify the correctness of the theoretical analysis and the validity of the unified three-level modulation of the proposed three-level pseudo totem-pole rectifier.