A high step-up voltage gain DC/DC converter for the micro-inverter

Due to the existence of the inductor´s and capacitor´s equivalent series resistance(ESR), traditional Boost converters cannot provide a high voltage gain. Therefore, in some occasions that we need a huge voltage gain such as the photovoltaic grid-connected micro-inverter, traditional Boost converter cannot meet the needs of the voltage conversion. Since the insolated DC/DC converters contain high frequency transformers, they have shortages in volume and conversion efficiency, the non-insolated high step-up voltage gain converters have became the research hotspot. However, traditional non-insolated high step-up voltage gain converters also bring many disadvantages: the converters are large; the voltage stress of the power devices is very high, the voltage gain is still limited. This paper proposes a high step-up voltage gain DC/DC converter, it has following advantages: high voltage gain, low voltage stress, easy to control. A prototype rated at 200W has been established in the lab, and the experimental results verify the correctness of the analysis.