Modellering och styrsystemdesign för europeisk balansering av havsbaserad vindkraft och HVDC-förbindelser

This thesis investigates how offshore wind farms connected via high-voltage direct current (HVDC) links can support frequency balancing between two synchronous areas in Europe. A simulation model was developed in MATLAB/Simulink to evaluate four control strategies for managing power imbalances caused by wind forecast errors. The strategies include routing the imbalance to one area, sharing it between both, or managing it locally at the wind farm with a simplified battery model. The model incorporates HVDC constraints, reserve limitations, and optional filtering of the imbalance signal. Simulations using real wind data show that sharing the imbalance between areas results in the most optimal balancing control strategy. Routing all imbalances to a single area often causes HVDC saturation, ramping limitations, or insufficient frequency reserve. While local battery control can smooth short-term imbalances, it is not scalable for longer durations. The results highlight the importance of frequency reserve availability and HVDC transmission headroom for maintaining system stability, especially as offshore wind integration expands through more complex and interconnected grid systems.