Power Loss Comparison in a BOOST PFC Circuit Considering the Reverse Recovery of the Forward Diode
The nature of diode reverse recovery is analyzed in this paper, and the reverse recovery loss is evaluated in a BOOST PFC converter using a silicon (Si) or silicon carbide (SiC) diode in the forward branch. Mathematical models of the forward conduction and reverse recovery losses are established to assess the influence of Si and SiC diodes. To characterize and quantify the losses related to diode reverse recovery, an 85~265V AC to 400V DC, 2kW BOOST PFC prototype is built with switching frequencies of 65kHz. It is found that the reverse-recovery inherent in a Si diode cannot be neglected. The switching loss is substantially smaller when the diode is a SiC one. In order to investigate further, a double pulse test rig is established, with the switch and the diode being either Si or SiC. The experimental results demonstrate that with a SiC diode, not only the diode conduction losses but also the transistor turn-on loss is greatly reduced.