Ripple Minimization Method for a Modified Non-Inverting Buck–Boost DC–DC Converter

This paper presents an improved switching strategy developed for the Modified Non-Inverting Step-Down/Up (MNI-SDU) DC–DC converter. Unlike previously studied switching strategies, the proposed approach changes the firing sequence and then the equivalent circuits without increasing the switching frequency. This switching technique alters the equations used to select the converter’s capacitors, enabling a different voltage ripple in the capacitors while maintaining the same capacitance as in the previous operation. The proposed switching technique is introduced with a theoretical explanation, and the feasibility of the proposed method is verified through experimental results on a 570 W prototype. The results indicate that the new operation reduces capacitor capacitance and achieves over 58% voltage ripple reduction for both capacitors, while preserving desired operation, specified capacitances, and voltage regulation. The proposed strategy provides a compact and effective solution for high-performance power converters in battery-regulated and renewable-energy systems.