Cluster Voltage Balancing Control for Modular Multilevel Converter with Cluster Phase-Shifted Nearest Level Control

This paper proposes the cluster voltage balancing control for Modular Multilevel Converter (MMC)-High Voltage Direct Curret (HVDC) system with Cluster Phase-Shifted Nearest Level Control (CPS-NLC). The CPS-NLC is a type of modulation method, which splits arm submodules into several clusters for distribution of digital controller computational burden. The benefit of CPS-NLC is enhancement of controller scalability, reliability, and cost effectiveness. The cluster of CPS-NLC needs additional voltage balancing control for stable operation. This paper analyzes the dynamics of voltage of cluster and proposes the cluster voltage balancing control. The proposed cluster voltage control is verified by PSCAD/EMTDC simulation.