What is the effect of the motor damping winding?

Two effects, one is the role of damping the power system to play the role of damping, the second is the stator winding negative sequence current generated by the reverse rotation of the magnetic field generated in the rotor induced current to provide access. The damping windings consist of damped teeth and damp strips forming a squirrel cage similar to an asynchronous motor. The principle is very simple is that once the stator magnetic field and the rotor magnetic field has a relative movement, will be generated in the squirrel cage induced current, the formation of additional magnetic field (from the damping effect).