Run-up and synchronisation of a large synchronous compensator

The synchronising performance of a 125 MVA synchronous compensator with solid salient poles is studied, and it is shown that, by using a 2-axis mathematical model, predictions of the starting and synchronising performance may successfully be made. The conditions for minimum supply-system transients when pulling into step at reduced voltage, and the subsequent transfer to rated voltage are investigated. A proposal is made for an alternative arrangement in which these operations are performed simultaneously, and this is shown to reduce the severity of the supply transients. Previous studies which considered the synchronising of a synchronous motor with a constant load torque are found to be invalid in the compensator application.