TWENTIES - Transmitting wind

Hydropower System Control

Data for system behaviour at storm passage with original (uncoordinated) and coordinated control 

This research presents The storm front event on February 7th -8th, 2011 which was followed by the unexpected failure on HVDC line between Western Denmark and Sweden illustrates the consequences and challenges the power system faced/will face in the future when these events (will) occur. The measured values indicate that the large part of the imbalances caused by storm is compensated by exchanged balancing power, activated from the Nordic Regulation Power List (NOIS list), across the Konti-Skan HVDC link.

System Impacts of storm, 7th – 8th February 2011

  
Frequency deviations during  storm event (left) and HVDC link failure (right)

Conclusions

Comparing the frequency in the Nordic and the Western Danish system shows that the frequency in the Nordic system experienced larger deviations and this due to the following two reasons:

• Western Denmark is synchronised with the Continental European synchronous system, and Continental European system is much larger than the Nordic synchronous system.  Therefore, Continental system has more inertia than the Nordic system.
• There are delays in the control signals caused by the manual control in the Nordic system, whereas the automatic control system in Western Denmark reacted very fast on frequency deviations. This has been improved since the Nordic LFC is running with 100MW and will improve further when the size increase.