Why damper windings used in synchronous motors?

The two main roles of dampers in Synchronous motor are :

1. Damper windings helps the synchronous motor to start on its own (self starting machine) by providing starting torque
2. By providing damper windings in the rotor of synchronous motor "Hunting of machine"can be suppressed.When there is change in load, excitation or change in other conditions of the systems rotor of the synchronous motor will oscillate to and fro about an equilibrium position. At times these oscillations becomes more violent and resulting in loss of synchronism of the motor and comes to halt