Design and Development of Single-Phase Continuous Conduction Mode Front-End Boost Converter with Variable Duty-Cycle Control to Achieve High Input Power Factor

Abstract

The method of using boost type of converter is accomplished for a single-phase, full-bridge diode recti er. By designing the necessary techniques and methodology, the overall power factor (PF) and total harmonic distortion (THD) would be im- proved according to international electrotechnical commission (IEC) 61000-3-2 stan- dards with input electromagnetic interference (EMI) lter. The cause of having low PF and high THD for a diode-capacitor type of recti ers is related to non-linearity of the input current. Various methods like, buck discontinuous conduction mode (DCM), boost continuous conduction mode (CCM), buck/boost (DCM) schemes are available for power factor correction (PFC) for high frequency pulse width modulated (PWM) non-isolated supply. The boost converter is selected which operates in CCM with average current control, as it has better performance at higher wattage rating. Open-loop tests show considerable improvement in input PF (from 0.6 to 0.9), com- pared to a simple full-bridge recti er. The closed loop is done with PFC integrated circuits (ICs) UCC2809A and LT1248 which results in input PF closed to unity and low THD content. The proposed boost converter scheme is experimentally veri ed under 1 kW load operation. The scheme is simple and compact with less number of power switching devices.