Recently, micro-inverter has received great attention due to its excellent performance under local shade condition. However, this kind of inverter needs large DC-DC voltage gain to implement grid-connected power generation for single photovoltaic module. This paper presented a new single switch high voltage gain DC-DC converter, which is consist of a double output voltage Boost converter and a flyback converter. The outputs of both converters are connected in series to supply power for the load, so the proposed converter has high voltage gain. Moreover, the input circuit is shared by the boost converter and the flyback converter in this new converter, which facilitates the converter structure and improves the converter efficiency by recycling the transformer leakage energy. The double output voltage boost converter can reduce the turn ratio of the flyback transformer and it can decrease the leakage inductance of transformer and diode voltage stress. In addition, the clamp capacitor can limit the power device voltage stress and simplify the circuit design. The paper analysis the operation process of presented converter and gives the detailed deduction of relevant formula to guide the converter design. Experimental results verify the presented converter.
DC-DC boost-flyback converter functioning as input stage for one phase low power grid-connected inverter