Digitally Controlled Bridgeless Totem-Pole Power Factor Corrector

Abstract

This paper presents the steps of designing, controlling, and implementing a 3kW Gallium-Nitride (GaN)-based bridgeless totem-pole power factor corrector (PFC) for single-phase 230V rectifier applications. The bridgeless design of such a converter combined with zero-recovery switching loss of GaN transistors enables more efficient design operation compared to traditional Si-based solutions. Thermally efficient design with forced-air cooling for the switching devices increased the power density beyond 100W/inch3 while keeping the power switches temperatures less than the thermal limits. Continuous Conduction Mode (CCM) was adopted in this work for better converter stability and was analyzed thoroughly along with the losses breakdown for each part of the converter. The digital control model of the converter was discussed in detail accompanied by the hardware design steps for the converter. Experimental results proved a maximum efficiency of 98.9% during 2.4kW operation and 98.6% during 3kW (full load) operation with minimum Total Harmonics Distortion (THD) of AC input current of 2.78% at rated current (13A) when converting the AC input voltage (230V) to 400 VDC.