A New High-Frequency High-Efficiency GaN TP PFC with Bidirectional ZVS Cell

Inhalt:
Power factor correction (PFC) circuits generally constitute at least one half size of any power supply. Therefore, there is a great effort both from academia and industry specialists to reduce the size of the PFC stage of a power supply. In order to effectively reduce the size of the EMI filter together with the PFC inductor, switching frequency has to be pushed higher than 400 kHz. This is a very challenging task even with GaN devices under hard-switching. This paper proposes a new PFC converter with soft switching cell, which enables the PFC converter to operate above 400 kHz. The main features of the proposed converter are the simple control structure as it operates in continuous-conduction-mode (CCM), and low components count. When GaN FETs are used, the required resonance inductors become less than 0.5muH allowing them to be implemented as PCB windings, and making it a feasible alternative to ZVS CrM TP PFC.