To limit the fault current used surge protective resistance in generator rotor winding to protect the rotor winding heavy damage.
An 'armature winding' is the rotor winding, and the 'field winding' is the stator winding.
AC motor has two main winding components - stator and a rotor. Stator winding is stationary where as rotor winding is on rotating part.
The field winding in the stator is exposed to the full current generated by the rotor's winding.
damper winding help to maintain the magnitude phase shift (on load chages) between rotor an stator flux and kill some parasite currents produced by the leakage flux moving out the rotor winding to the rotor core.
The field winding on a generator is the winding that is electrified to create an electromagnet; it is generally the winding found on the rotor (the rotating part of the generator).
Winding: To wind the coils into the slots on the stator or rotor and connecting them up to form a winding. Re-winding. Is to remove the old winding and doing what I explained above.
Yes, the induction motor has a rotor winding. It is usually one turn, shorted. This is how the magnetic fields generated in the stator induce a current in the rotor, which subsequently generates a torque from the opposing magnetic fields, stator to rotor.
As magnetic field of dc motor is constant. Whenever a current is given to rotor winding there will be a magnetic flux in air gap between rotor and winding so there will be torque in rotor of f=ibl. so due to this torque rotor get rotate and get started.
An induction motor consists of a rotor winding and stator winding. Rotor windings are short circuited and stator winding are given electrical AC supply .Now lets do the physics behind it . As the current starts to flow in the stator winding , magnetic flux start to produce around it . due to it's alternating nature that flux varies and according to farady law emf is induced in the rotor winding .Since the rotor winding is short circuited the current circulates in it .And when a current carrying conductor is placed in magnetic field it experiances a force and hence if start to rotate.
This is how an induction motor normally works, hence the name. The supply voltage is connected to the stator winding(s) and a current is induced in the rotor. A synchronous motor, on the other hand, will have current supplied to the rotor through slip rings and brushes. The rotor current is generally supplied as DC though, or else rectified in the rotor.
The synchronous motor is made self starting by providing a special winding on the rotor poles, known as damper winding or squirrel cage winding. AC supply given to the stator produces a rotating magnetic field which causes the rotor to rotate, therefore, in the beginning synchronous motor provided with damper winding starts as a squirrel cage induction motor. The exciter moves along the rotor. When the motor attains about 95%of synchronous speed, the rotor winding is connected to exciter terminals and the rotor is magnetically locked by the rotating field of the stator and the motor runs as a synchronous motor. While starting a synchronous motor, the field winding must be shorted through a suitable resistance so that the induced voltage is distributed throughout the whole winding and no part is subjected to the high voltage induced in the entire winding.