Alternating current electric induction motor with auxiliary closed loop toroidal winding

An alternating current electric induction motor which is configured to be fed by a frequency variator, the motor comprising:

• a casing which supports a rotor by means of bearings and which supports a stator with a coaxial ring-shaped core made of a magnetic material, wherein the stator is provided with main windings and an auxiliary closed loop toroidal winding insulated from the main windings and the ring-shaped core, wherein the auxiliary closed loop toroidal winding is not fed by an external power supply or connected to an external charge, and wherein the closed loop toroidal winding counteracts generation of current through the bearings, rotor and casing, and precludes the current generated through the bearings, rotor and casing from damaging the bearings.