On Facilitating the Modular Multilevel Converter Power Scalability Through Branch Paralleling

Modular multilevel converter current scalability challenge can be significantly alleviated by connecting its branches in parallel. In case a predefined submodule design is to be used with the aim of serving a certain span of applications, methods of achieving desired current scalability of the modular multilevel converter rely upon numerous hardware adaptations. Contrary to that, for the same goal to be achieved, paralleling of the branches eliminates the need for a major redesign of the existing converter parts. Consequently, superior operational flexibility can be achieved with most of the effort being concentrated in the control domain, allowing for less costly solutions to be realized. This paper provides a thorough control analysis of the modular multilevel converter operating with an arbitrary number of parallel connected branches.