A multilevel dc-dc converter with high voltage gain and reduced component rating and count

Abstract

This paper proposes a bidirectional multilevel dc-dc converter for applications that require high voltage gain. Some of conventional multilevel dc-dc converters have diverse voltage or current stresses for the switching devices within the circuit, not suitable for modular configuration or for high efficiency demand; some suffer from relatively high power loss or large device count for high voltage gain, even if the device voltage stress could be low. By contrast, the proposed dc-dc converter features low component (switching device and capacitor) power rating, small switching device count and low output capacitance requirement. In addition to its low current stress, the combination of two short symmetric paths of charge pumps further lowers power loss. Therefore, a small and light converter with high voltage gain and high efficiency can be achieved. Simulation and experimental results of a 450-W prototype with a voltage conversion ratio of six validate the principle and features of this topology.