Modular multilevel converter based test bed for mvdc applications — A case study with a 12 kV, 5 MW setup

The Modular Multilevel Converter (MMC) topology has a wide area of possible applications. Features like redundancy at the module level and fault current limiting capability makes it a robust solution for many power applications. Moreover, this topology is very useful as a test equipment for Power Hardware in-the-Loop simulations, especially as a DC grid simulator. This paper describes a recently commissioned MMC based test bed built with four MMCs capable to operate at up to 5 MW power at 6 to 24 kV, depending upon which system configuration is chosen. Test results for the 12 kV configuration are presented along with a detailed description of all the salient control modules. It is concluded that due to its flexibility, this MVDC laboratory can serve the research and development community in addressing and de-risking a broad range of system integration and technology challenges.