A Detailed Study on Special Electrical Machines

An electrical machine is a device which converts mechanical energy into electrical energy or vice versa. Electrical machines also include transformers which do not actually make conversion between mechanical and electrical form but they convert AC current from one voltage level to another voltage level. As the rotor speed changes the armature supply frequency is also change proportionally so that the armature field always moves (rotates) at the same speed as the rotor. ... Self-control ensures that for all operating points the armature and rotor fields move exactly at the same speed