A Hybrid Communication Topology for Modular Multilevel Converter

摘要

Modular multilevel converter with large number of modules is a potential topology for many applications such as high-voltage DC (HVDC) and solid state transformers (SST). However, the communication between the controller and the modules becomes complex if the number of modules is high. If conventional star topology communication where the controller has direct connection to all the modules is used, the wiring can be cumbersome and the cost can be high. Another possible solution is ring topology communication. Because the modules are connected in series and each module imposes some delay, ring topology has a limited communication speed. In this paper, we proposed a hybrid communication topology to combine star and ring topology. The proposed communication topology reduces the cycle time by 30% compared to ring topology for MMC with 30 modules while increases negligible cost.