A grid-tied flyback-based PV inverter with BCM variable frequency voltage mode control

The modularized micro inverter which can feed small power to the grid directly has the merit of increasing the conversion efficiency and installed flexibility of the renewable power generation system. This paper proposes the control method of the micro inverter derived from the conventional AC-DC boundary conduction mode (BCM) PFC converter. The variable frequency peak-current mode control method and the variable frequency voltage mode control method are proposed for the control of the flyback-based inverter. Modeling of the inverter and quantitative controller design of the variable frequency voltage mode control method is presented. A 120W experimental system with PV module input and 93.9% maximum efficiency is built. A 120W experimental system with PV module for generating power is built. The effectiveness of the proposed method is confirmed with some simulation and measured results.