An active method to solve the touch current issue of totem-pole bridgeless PFC rectifier

Abstract:
With the application of GaN and SiC, Totem-pole bridgeless PFC (Power Factor Correction) offers higher power density and higher efficiency than the bridged boost PFC. However, a huge spike is commonly observed as touch current (or “leakage current”) in the safety standard test. This paper explains the mechanism of the touch current generation, analyses the equivalent circuits, summarizes possible passive solutions, and proposes an active method to compensate this current spike with OPA (Operational Amplifier). The proposed active method is validated on a 1kW prototype, which significantly reduces the touch current spikes of the prototype and enables the prototype to comply with the stringent safety standard requirements.