A DSP-based controller design for multilevel flying capacitor converters

Multilevel pulse-width-modulated (PWM) converters have a number of applications and undoubtedly state-of-the-art digital control enhances their performance. The flying capacitor voltage-source converter (FC-VSC) topology has a number of unique characteristics when compared with other multilevel topologies such as the cascaded converter and the neutral-point-clamped one. This paper deals with the design of a PWM controller suitable for multilevel flying capacitor (FC) converters using a popular TMS320LF2407 DSP board for implementation. The two cases, namely the three-level and five-level FC controllers are described in detail and special considerations are outlined. Finally, the validity of the controller design is verified experimentally on low power laboratory prototypes.