A Single-Phase GaN Totem-Pole Bridgeless PFC with an H-Bridge Active Power Decoupling

Abstract

This research proposes a single-phase power factor correction (PFC) approach employing a GaN Totem-Pole topology with an H-Bridge Active Power Decoupling (APD). The proposed topology assures the achievement of high efficiency with unity power factor and high-power density with minimum losses over a wide range of voltages. Moreover, the GaN Totem-Pole PFC with the H-Bridge APD has shown a significant enhancement on the total energy storage requirement in comparison with the GaN Totem-Pole PFC without the H-Bridge APD. The total energy storage requirement is reduced from 143 J on the Totem-Pole PFC without the H-Bridge APD to around 3.76 J on the Totem-Pole PFC with the H-Bridge APD and the large aluminum electrolytic DC-Link Capacitor (1,880 μF) located at the interface between the converter and the DC load is replaced by the suppressed polypropylene film DC-Link Capacitor (5 μF). The additional H-Bridge APD circuit generates a reactive power that matches and buffers the undesirable low-frequency power ripple caused by the single-phase inherited double-line frequency that exists naturally at the AC side and gets injected into the converter. The topology composes of three GaN high switching frequency legs (100 kHz) and one low (line) frequency leg (60 Hz). The H-Bridge APD circuit consists of two of the high switching frequency legs (100 kHz) with 4 GaN FETs, a decoupling capacitor and an inductor. GaN FETs were used instead of MOSFETs due to their superiorities of having higher switching frequency ensuring lower switching losses, higher efficiency leading to lower conduction losses, lower reverse recovery losses and higher power density.