A new single-stage converter for improving THD

A simple single-stage converter for improving THD is proposed in this paper. The proposed topology combines an additional inductor for boosting and valley-fill rectifier that can do DC-DC conversion and PFC simultaneously. In the proposed circuit, a shape of input current is related to the duty cycle of PWM. The boosting inductor can achieve THD improving. The operation modes and THD of input current are analyzed as applied the boosting inductor, and the optimum value of boosting inductor is determined. A 100 W single-stage converter has been implemented and tested. Experimental results are presented to verify the validity of the proposed converter.