Curative or remedial actions are the set of immediate actions intended to
bring the power grid to a safe operating point after a contingency. The
effectiveness of these actions is essential to guarantee curative N-1 security.
Nowadays, curative actions are derived ahead of time, based on the anticipated
future grid state. Due to the shift from steady to volatile energy resources,
the grid state will frequently change and the curative actions would need to be
pre-planned increasingly often. Furthermore, with the shift from large bulk
production to many small decentralized energy sources more devices need to be
actuated simultaneously to achieve the same outcome. Instead of pre-planning,
we propose to calculate these complex curative actions in real-time after the
occurrence of a contingency. We show how the method of Online Feedback
Optimization (OFO) is well suited for this task. As a preliminary demonstration
of these capabilities, we use an (OFO) controller, that after a fault, reduces
the voltage difference over a breaker to enable the operators to reclose it.
This test case is inspired by the 2003 Swiss-Italian blackout, which was caused
by a relatively minor incident followed by ineffective curative actions.
Finally, we identify and discuss some open questions, including closed-loop
stability and robustness to model mismatch