Dynamic investigation of Georges phenomenon related to three-phase wound-rotor induction motor

Abstract

The squirrel cage induction motors have dominated the industry due to their wellknown advantages, but in some application wound-rotor induction motor (WRIM) is still more used. The capability of the large WRIMs in developing a high starting torque at low starting currents by the means of adding external resistances in series with the rotor windings makes them ideal for some applications. Besides limiting the starting current, this resistance can also be used in controlling the motor speed. These advantages make the WRIMs suitable for large power industrial application such as cranes, pumps, conveyors and hoists [1]. Asymmetrical operation of induction machine results in unbalanced air gap flux, consequently unbalanced supply currents, increased losses, increased torque pulsations