A wide bandgap device based multilevel switched-capacitor converter

Abstract

This paper presents a new bidirectional multilevel modular switched-capacitor dc-dc converter for high voltage and high conversion ratio application with low capacitor voltage rating. For the high voltage and high conversion ratio application, high voltage capacitor with good performance will not be available either, like the switching devices. For the traditional multilevel modular switched-capacitor dc-dc converter (MMSCC), the switching devices maximum voltage rating is low, but the capacitor voltage rating increases linearly as the conversion ratio increases. Compared with the linear increasing capacitor voltage stress like MMSCC, the proposed circuit maximum capacitor voltage stress is only twice of the low input side voltage. Besides, the proposed circuit also inherits all the good features from the traditional MMSCC, like modular structure, simple control strategy, low device conduction loss, and soft switching. Therefore, it is possible to build a high voltage and high conversion ratio switched-capacitor dc-dc converter with low voltage rating switching device and capacitors to achieve high power density, high efficiency.