A Novel Cost Effective Variable On-Time Control of Digital Boost PFC Converter in Boundary Conduction Mode

This paper proposes a novel variable on-time (VOT) control in boundary conduction mode (BCM) for boost power factor correction (PFC) converter. Compared with other VOT controls, the proposed control is easy to implement in hardware and can achieve high power factor (PF) and low total harmonic distortion (THD). To achieve high efficiency, the system is operated under the zero-voltage switching (ZVS) and valley switching (VS) for reducing switching loss. The digital controller is implemented in FPGA and applies to a 200W boost PFC with universal AC input to verify the feasibility of the proposed control method. The maximum efficiency is 92%, the maximum PF is 0.998, and the THD is 3.7%.