Derivation and application of sensitivities to assess transient voltage sags caused by rotor swings

The paper introduces an approach to investigate voltage sags, which are caused by large generator rotor swings following a transient disturbance. Therefore, the method exploits sensitivities derived from the algebraic network equations. These provide information on the impact of a generator on the voltage magnitude at a load bus and the effect of load variation on the generator’s power injection.

It is shown that these sensitivities give valuable information to identify critical generator–load pairs and locations for applying preventive control measures.