Future HVDC-grids employing modular multilevel converters and hybrid DC-breakers

The necessary shift from fossil fuels to regenerative sources imposes a great challenge for future power transmission. A large, meshed HVDC-Grid is proposed by several experts as the best and most efficient solution. For meshed DC-Grids, however, new and essential requirements - especially regarding availability and reliability - have to be researched very thoroughly. Fast and reliable handling of DC-faults must be ensured without disturbing the energy flow in the whole grid. The following paper deals with the key components (Modular Multilevel Converters and DC-Breakers) in large meshed HVDC-Grids. A comparison between suitable submodule topologies with DC-fault handling abilities is presented alongside with a new topology for a hybrid DC-Breaker.