A Novel Control Scheme of Three-Phase Single-Switch Quasi-CRM Boost Rectifier

A three phase single switch boost rectifier, operating in a quasi-critical conduction mode of the inductor current, can achieve the power factor correction and meet the IEC 61000-3-2. However, the switching frequency is variable in a line cycle, and the design of the inductor and electromagnetic interference filter as well as the power component selection is deteriorated. In this paper, a novel constant frequency control method is proposed for the converter by modulating the on-time of the switch. Compared with the traditional variable frequency control, the proposed control scheme achieves a constant switching frequency in a line cycle, which simplifies the design of the power devices, especially the magnetic components. Furthermore, the switching frequency and the rms value of the inductor current are also reduced, which contributes to a higher efficiency.