Multilevel modular DC/DC converter for regenerative braking using supercapacitors

Abstract

[eng] Regenerative braking is present in many electric traction applications such as electric and hybrid vehicles, lifts and railways. The regenerated energy can be stored for future use, increasing the efficiency of the system. This paper outlines the benefits of the modular multilevel converter (MMC) in front of the cascaded or series connection of converters to achieve high voltage from low voltage storage elements such as supercapacitors. The paper compares three different solutions and shows that the MMC can benefit from weight and volume reduction of the output inductance when shifted frequency is increased, and reduces the magnitude of the voltage applied to the inductor, reducing its size and volume.