Consider the Continental Europe synchronous grid. This power system has some DC-DC connections with other countries (for example one with Great-Britain). Suppose now there is a sudden big outage causing the loss of 1-2 GW of generation in Continental Europe grid. This outage leads to a frequency transient. Since Great Britain is connected to the CE grid throug DC-DC links, I imagine that the power transferring on that link would not change during this transient because the two grids are not synchronized, but it seems strange that there is no perturbation on this link even if there is such big outage.
Would the power transfer change? Is there any perturbation on this link?