“All stable processes we shall predict. All unstable processes we shall control”

-John van Neumann, mathematician and computer scientist.

Stability is an important aspect of the electricity grid. Ideally, we want that unexpected events do not have a big impact on how the grid operates. In this lecture, the term stability is explained with respect to a power system. The different ancillary services should help to make a power system stable. Also, different examples will be discussed in which stability plays a role.