Multi-terminal DC transmission system based on modular multilevel converter

A multi-terminal DC (MTDC) transmission system based on an innovative modular multilevel converter (MMC) is presented as a feasible approach to address the concerns regarding reliability and fault ride through capability of multi-terminal dc systems. Furthermore, MTDC using MMC may reduce construction costs and power losses in the converter stations. To demonstrate control flexibility, improved reliability and DC fault ride through capabilities, several scenarios are analyzed in this paper. The authors demonstrate a robust power control using DC voltage droop, and an assessment of the system behavior under temporary and permanent DC faults. The validity of the proposed multi-terminal DC transmission system is confirmed through simulation conducted in Matlab-Simulink.