Abstract – Modular Multilevel Converter Systems for HVDC Applications

The modular multilevel converter (MMC) introduced in the early 2000s has gained widespread acceptance as a state-of-the-art solution for medium to high voltage and power applications, including MVDC, HVDC, and FACTS. Its salient features include high modularity and scalability, low harmonics generation and high conversion efficiency. To date, real world applications of MMCs include grid integration of offshore wind turbines, multiterminal HVDC, and (shortly) the world’s first HVDC grid.

At present, explosive levels of research into the development of new HVDC converter systems that can reap the benefits of the original dc-ac MMC concept are being witnessed. Examples include dc-dc converters, HVDC tapping stations, dc line power flow controllers and multiport dc-dc-ac hubs. This presentation will give an overview of next generation MMC systems with a focus on HVDC applications, including some topologies recently proposed at the University of Alberta.