An Efficiency-Improved Single-Phase PFC Rectifier With Active Power Decoupling

Active power decoupling (APD) technology is an effective solution to store the double-line frequency ripple power in the single-phase system and remove the bulky aluminum electrolytic capacitors. However, APD introduces power loss because of adding extra switches operating at high frequency, which hurts the system efficiency inevitably. Addressing this issue, this article proposes an improved boost power factor correction (PFC) rectifier with a buck-type APD cell. An auxiliary circuit, composed of a resonant inductor and a diode, is added. With the developed modulation strategy, zero voltage switching of the switches both in the PFC and APD circuits is achieved, which improves the system efficiency significantly. This article first describes operating modes and then analyzes the soft-switching condition of each switch. Finally, a 300 W prototype is built and the experimental result shows that the efficiency is increased by 4%.