Gallium Nitride Based High Density Power Factor Corrected AC–DC Converter for Next Generation Power Conversion Solution

Power factor corrected AC–DC converters are required to convert the AC mains voltage to desired DC voltage and minimize the reactive power delivering to the load for various smart cities applications such as data centre, smart grids, electric tractions, etc.. However, both power density and power conversion efficiency are limited with the applications of silicon-based power semiconductors due to reaching their theoretical performance limits. In this work, a high power density and high efficiency digitally controlled totem-pole power-factor-corrected AC–DC converter, based on the application of 3rd generation wide bandgap power semiconductors gallium nitride devices, is introduced to resolve and breakthrough the coupled electrical-thermal challenges for next generation advanced power conversion solution. The converter topology and operation, overall control methodologies, and several advanced gallium nitride devices control features, will be briefly discussed. A 2 kW prototype has been built to practically verify the proposed ideas. Experimental results revealed that the maximum power efficiency and power factor are respectively 99% and 0.99, with a compact solution that only having data centre server power supplies standard height of 1U and a dramatic improvement of power density to 100 W/in(exp 3).