ηρ-Pareto optimization and comparative evaluation of inverter concepts considered for the GOOGLE Little Box Challenge

In recent years, driven by worldwide growing environmental awareness the research in power electronics was focusing on the development of highly efficient but mostly bulky converter systems e.g. for interfacing renewable energy to the grid. The GOOGLE Little Box Challenge was impulse to give the power density again more attention by motivating engineers worldwide to design a single-phase solar inverter system at the cutting edge of what is technically possible. In this paper a comparative evaluation of inverter concepts considered by a team of ETH Zurich, FH-IZM and Fraza company for the GOOGLE Little Box Challenge is given. Based on the lessons learned from the participation in the competition, for the considered inverter concepts the achievable efficiency, power density and the optimal modulation scheme are identified with a multi-objective ηρ-Pareto optimization. This provides a sound basis for the redesign of the existing system pushing the forefront of power density even further.