Single-stage quasi z-source flyback Power Factor Correction converter

This paper presents a single-stage quasi z-source flyback Power Factor Correction (PFC) AC-DC converter which features high efficiency, unity power factor (PF), and low Total Harmonic Distortion (THD) under wide range input voltage operation. The proposed PFC converter can achieve very low voltage spike on switch by utilizing a common topology, namely quasi z-source topology that has been widely used in many applications. As a result, a low voltage rating Mosfet with low on-resistance Rds(on) can be used to gain a high efficiency. In addition, Continuous Conduction Mode (CCM) operation associated with the variable duty control scheme to regulate the output voltage is also applied to get high PF, low harmonic components in the line current, as well as conduction loss reduction. In this study, the operating principle, circuit analysis, and control method of the proposed PFC converter are provided. Additionally, the design guidelines are also verified by a laboratory prototype with the input voltage of 130-230 V AC, 36 V/180 W output, and 55 kHz switching frequency. Consequently, this topology is suitable for wide input voltage range and low-to-medium power applications where a unity PF, low THD, and high efficiency are required.