An interleaved high step-down coupled inductor based quadratic DC-DC converter

A high step-down direct current-direct current (DC-DC) buck converter with a coupled-inductor in its topology is presented in this study. The switching pattern of the proposed converter is interleaved; therefore, the voltage stress on the semiconductors and the components is low since the primary high voltage will be divided between the blocking capacitors on the primary side. Thus, the voltage stress on semiconductor elements will be low. As a result, the preselected elements can be chosen with low voltage ratings. In addition, there are cells with coupled inductors utilized in the structure that helps the converter to provide improved voltage gain in its output terminal. Typically, narrow duty cycles are needed to achieve high gain in conventional buck converters, but the proposed converter has obtained a high conversion ratio even with wider duty ratios. Besides, the proposed converter has a constant equation for the voltage gain for the whole range of duty cycles. Theoretical analysis and comparison with other recent converters of similar types have been conducted to demonstrate the proposed converter performance. Furthermore, to verify the theoretical analysis, a 600 W prototype of the proposed converter with 820 V/30 V is implemented, and experimental results are presented.