Dual-Boost Single-Phase PFC Input Current Control Based on Output Current Sensing

This paper presents a new current control method for dual-boost single-phase power-factor-correction (PFC) converters. A dual-boost PFC converter is more efficient than the conventional boost PFC converter by virtue of the elimination of one semiconductor device in the main current path, but is more difficult to control using the existing PFC control method due to the need to sense ac input current and voltage. The proposed current control method is based on sensing of the dc output current, which can be easily accomplished by using a sensing resistor inserted on the negative rail of the dc output. A new pulsewidth-modulation-based multiplier circuit is also developed as a more robust and cost-effective alternative to linear analog multiplier design or mixed-signal implementation. 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 and 400 Hz line is reported to demonstrate its performance for both terrestrial and airborne applications. Conducted electromagnetic interference measurements of the converter are also presented.