Protection, Control and Modeling of Offshore Hvdc Grids For Transmission To Onshore

Decarbonization targets have been set globally, leading to decommissioning of CO2 producing generation plant and replacement by renewable sources of power generation. Utility-scale offshore renewable power is to be transmitted to onshore HVAC grids in a reliable, quality, and cost-efficient way. This paper reports on development of multi-terminal HVDC offshore grid topologies where industrialized technologies are deployed. Master power controller and protection philosophies with different DC circuit breaker deployment levels are presented, analyzed, and compared. Real-time simulated models implementing the HVDC grid topology as well as the protection philosophy are demonstrated for HVDC offshore grids and results presented with hardware-in-the-loop protection relays.