Experimental Verification of a Voltage Droop Control for Grid Integration of Offshore Wind Farms Using Multi-terminal HVDC

This paper presents an experimental verification of a voltage droop control for a multi-terminal HVDC system for the grid integration of offshore wind farms. The laboratory setup is composed by four voltage-source converter terminals which aim to emulate behavior of the future power grid in the North Sea, where Norway, Germany and the UK are interconnected together with an offshore wind farm. Two main scenarios have been performed to test the robustness of the droop-control strategy: variation in wind power, including changes in the parameters of the droop line, and the sudden disconnection of converter terminal during full wind production. In all performed cases, the implemented system was able to ensure that the voltage stays within its steady state limits and to reach a stable operation point.