In order to increase the weighted efficiency of the photovoltaic micro-inverter

a DC/DC converter for the micro-inverter with flexible topology is proposed. The flexible converter includes two operation modes—the improved dual-switches forward mode and the full-bridge mode. The operation principles of the two modes are described

and the design guideline of the key parameters

such as the turns-ratio of transformer and buffering inductor is provided. The power threshold value is determined according to the analysis of switching loss

conduction loss

driving loss and core loss of the converter in two operation modes. A duty ratio pre-calculation control strategy combined with closed-loop fine adjustment is proposed. The experimental results show that the proposed flexible converter has a good performance in addition to a high weighted efficiency.