Abstract
A two-stage power converter for PV applications is developed in this paper. In the first stage, a multiple-input high step-up dc/dc converter is proposed. The second stage is the five-level dc/dc inverter with boosting functionality. The proposed two-stage converter harnesses the superior features of WBG devices to build a converter with high efficiency and high-power density. The high switching speed of WBG power devices allow both stages operating at high switching frequency, hence, large size film capacitors can be replaced by small size multilayer ceramic capacitors, furthermore, the high operating temperature of WBG devices will help to shrink the cooling size. In additions, a zero current-switching technique is implemented in order to reduce the switching loss and electromagnetic interferences. Prototype with 300 W is built and experimental results are presented with a peak efficiency of 98.3%.