Turbo Alternators

Turbo Alternators are alternators coupled to turbines.  Turbo alternators run at high speeds and develop large quantities of power usually of the order of hundreds of Megawatts.  The rotor of the Turbo alternator is usually made of many pieces connected together.  Turbo generators usually have cylindrical rotors.  The speed of the rotor is around 3000 rpm (50 Hz) or 3600 (60 Hz). 

Turbo alternators are extremely sensitive machines as they operate at very high speed.  The slots for the rotor windings are milled on the rotor shaft.  The rotor of the turbo alternator does not have damper windings as the prime mover used is usually a turbine which provides a consistent and steady torque unlike the diesel engine which provides pulsating torque.   The wedges used to secure the rotor winding to the slots are made of steel and function as a damper winding as well. 

Cooling is a major issue in Turbo generator, given the enormous amount of heat generated.  Air, Hydrogen and water have been employed to transfer the heat away from the generator.