A modular digital controller architecture for multi-node high power converter applications

Modular voltage source converter has drawn great interest in high power applications. To achieve higher system control reliability and multi-functionality, a modular digital controller architecture is proposed in this paper that will facilitate the concept of modular converter. It can be reconfigured to multiple-node high power converter applications. A hybrid multitap bus and inverse-star structure are adopted in the architecture. Detailed descriptions of the controller structure and function partitioning are described in the paper. Central and local control units are designed individually. A case study on a 13 level cascaded multilevel converter is investigated. Moreover, the data communication protocol and design considerations will be shown. In addition, the hardware circuits and experimental results are shown to verify the structure.