Dual-Boost PFC Converter Control Without Input Current Sensing

This paper presents a new current control method for dual-boost power-factor-corrected (PFC) converters which avoids the need for sensing the ac input current. The control method is a generalization to the nonlinear average current control previously developed for boost PFC converters that has demonstrated better control performance and reduced sensitivity to noise. The generalized method for dual-boost PFC converters uses the dc rail return current as feedback signal, which is much easier to sense than any other current. A new PWM-based multiplier circuit is also presented as part of the implementation of the new control method to provide an alternative to linear analog multiplier or a mixed-signal control setup. Control characteristics and performance of the new method are analyzed using averaged models and verified by measurement results from a 500 W prototype. Operation of the converter with both 60 Hz and 400 Hz line is reported to demonstrate its control performance for terrestrial as well as airborne applications. Conducted EMI measurements of the converter are also presented to demonstrate the overall performance of the design.