Comparison of Active Power Decoupling Methods for High-Power-Density Single-Phase Inverters Using Wide-Bandgap FETs for Google Little Box Challenge

Abstract

This paper presents a comparison between mitigation techniques for double line frequency ripples in single-phase microinverters based on wide-bandgap FETs. A topology based on an auxiliary dc-ac stage is adopted based on optimizing both power density and efficiency to achieve the pressing needs of the next generation of microinverters as announced by Google's little box challenge. An accurate yet simple control algorithm is proposed that provides a ripple-free dc current. Experimental results demonstrate the effectiveness of the presented topology and control algorithm in achieving a high-power-density microinverter rated at 2 kW.