Comparison of speed and voltage based critical clearing time of squirrel cage induction generator

This paper compares two types of the critical clearing time (CCT) of squirrel cage induction generator (SCIG). Induction generators have been widely employed in modern renewable power systems. Assessing the stability of power systems, engineers and researchers usually associate with the CCT. In literature two types of CCTs have been frequently quoted for SCIG, one is based on its rotor speed and the other is based on terminal voltage. In this study we compare these two types of CCTs of an SCIG driven by a wind turbine. Scenarios analysis has demonstrated that the voltage based CCT is shorter than the speed based CCT. However, the meanings of these two types of CCTs should be very carefully interpreted.