6. Classification for AC motors

The dominant position of the cage induction motor in electric drives is well known.

This position is due to the fact that it is a robust, easy-to-use and competitively priced motor. Its only challengers are, on the one hand, the wound-rotor induction motor fitted with a ring which can be connected to an external circuit (variable resistor or converter) and, on the other hand, the wound-rotor synchronous motor for high-power applications at constant speed.

When considering the field of variable-speed electric drives, the advantages of the asynchronous cage motor are not as obvious, since we now have to consider the frequency inverter-motor combination, in which case the synchronous motor in its many variants becomes very competitive. However, with the weight of habit, the numerical predominance of variable-speed electric drives using asynchronous...