HVDC grids are seen as a key driver for the future development of the energy system with high shares of renewables. The technology is quickly evolving, and HVDC is increasingly important in today's power system. HVDC, and particularly VSC HVDC behaves in a fundamentally different manner compared to other equipment due to its controllability. In order to move towards HVDC grids, new models and tools are needed to correctly study the behavior of the system and its interaction with the DC grid. These models are needed in the different time domains of the power system: from system planning and operations, AC DC system interactions, very fast transients at the DC side and real-time system modeling. The challenges in each of the time domains will be covered, together with selected results, including models for testing DC grid protection using HIL.
Dirk Van Hertem, KU Leuven