A phenomena that causes most severe transients in three-phase induction motors
SourcetitleElectric Machines and Power Systems
The dynamical behaviour of a 3-phase induction motor supplied through a distribution transformer and during starting period, subjected to a very short time supply disturbance from the primary side of the transformer, while the secondary side is still connected to the machine, has been studied. The analysis has been made by simulating the machine in time domain by using traditional d-q model, including the effect of transformer secondary vinding impedance during the disturbance period. To verify the accuracy of the digital model, the normal starting transient torque-time pattern under free acceleration is computed and compared with the previously measured results. The transient torque-time, speed-time and current-time patterns of two different machines are computed for the phenomenon under investigation and are compared with their counterparts resulting from starting under free acceleration. Also the effect of the supply disturbance time duration on the transient torque peak has been studied. It was found that the phenomenan under investigation results in the most severe transients compared to all the other types of transient phenomenons that are reported in earlier investigations. � 1990 by Hemisphere Publishing Corporation.