Variable On-time (VOT) Control with Phase Leading Input Current (PLIC) Compensation for 400Hz CRM Boost PFC Converters

This paper establishes the generalized explicit expression of variable on-time (VOT) for CRM boost PFC converters to eliminate the effect of actual resonant processes. In order to minimize the effect of input filter capacitor (IFC) in medium line frequency, the compensation for the phase leading input current (PLIC) can also be implemented using proposed VOT expression. Due to the crossover distortion of the rectified input voltage, different sampling positions of input voltage result in different dead angle and different input current spine. Then this paper selects sampling before the rectifier bridge to reduce the input current THD and a varying parameter control to suppress the input current spine. The experimental results from a 400Hz/115VAC 160W/270VDC CRM boost PFC prototype are presented to verify the effectiveness and advantages of the proposed VOT control.