An Efficient and Reliable Bridgeless PFC Decoupling Converter

Single-phase current source (SCS) converters typically necessitate a bulky inductor to mitigate DC current fluctuations. Furthermore, open circuit conditions must be avoided in these systems. Active power decoupling (APD) offers an effective solution by eliminating double-line frequency ripple power without a bulky inductor. However, it introduces additional power losses due to the extra devices. To address this issue, this paper proposes an efficient and reliable bridgeless power factor correction (PFC) APD converter. A diode is incorporated into the converter to construct new current paths. The new paths decrease the number of semiconductor devices to lower conduction losses and provide an inherent freewheeling path for DC current to enhance system reliability. Through a specific modulation strategy, the utilization of new paths is maximized, and switching losses are reduced. This paper begins by describing the operating modes of the proposed converter. It then introduces a specific modulation strategy. A detailed analysis of power losses is presented. Finally, a 360 W prototype is constructed, and experimental results demonstrate an efficiency improvement of 2.5%.