Analytical investigation of efficiency and operating range of different Modular Multilevel Converters

In the last years, Modular Multilevel Converters (MMC) have become state of the art for HVDC, but future applications for Multi-Terminal-DC-Grids, Wind Parks, Large Drives and others are under development [1], [2], [3], [4]. For most of these future systems, fully electronic failure management — including electronic current limitation at AC- and DC-Side — and a very wide operating range will become key requirements. The most suitable submodule topologies and a novel “Double Zero”-Submodule (DZ-SM) are investigated and compared in a generalized way. The analytic computations reveal the advantages of the novel DZ-SM, especially when SiC-Power devices are available.