Investigation of short-term voltage stability problems and countermeasures

This paper discusses a few aspects of short-term voltage instability: modeling of transient overexcitation limiters in synchronous generators; possible outcomes of instability, such as induction motor stalling, induction generator overspeed, generator loss of synchronism leading to a local blackout; eigenvalue tracking and use of eigenvector to characterize the instability mode; and finally use of SVC to counteract short-term voltage instability. Results on two test systems, one of which involves a number of wind farms with induction generators, are included.