A novel simplified variable on-time method for CRM boost PFC converter

The critical conduction mode (CRM) Boost PFC converter utilizes the resonance to realize soft-switching, however, leading to high THD and poor power quality. In this paper, a novel simplified variable on-time control method is proposed based on given theoretical support. By means of approximation and the Taylor's series, the expression of the variable on-time curves could be derived as the sum of a dc component and an inverse sinusoidal component. Proposed simplified method could be easily implemented by an analog circuit with low system cost, compared with the existing complex digital control method. Then an adaptive control strategy for proposed simplified method is further investigated by numerical analysis. And the proposed novel simplified VOT method is verified with the experimental results very well.