Asynchronous Electric Machine

an AC electric machine in which the speed of rotation of the rotor is not equal to the speed of rotation of the magnetic field of the stator. The machine is used primarily as a motor and rather rarely as a generator. An asynchronous electric machine can also operate in a braking mode if its rotor is run in the direction opposite to the rotation of the magnetic field; this property of the machines is utilized, for example, in AC electric traction.