Efficiency Optimization of a Two-stage Microinverter with Grid Support functions

This paper describes the efficiency optimization of a grid supporting two-stage microinverters consisting of an LLC converter and a full-bridge inverter. Multiple combinations of switching devices and magnetics are compared to maximize the California energy commission (CEC) efficiency. The numerical loss breakdowns of each component are performed, and the simulations are supplemented to confirm the results. To verify the design strategy in this paper, a 400W microinverter is built and tested. Both the simulation and the experiments on the microinverter validate the effectiveness of the optimization strategy presented in this paper.