Working principle of synchronous generator rotor

The rotor of a synchronous generator is composed of a rotor core and rotor winding. This rotor winding, also known as the excitation winding, is a DC winding. When we apply direct current to this excitation winding, it will generate a constant magnetic field.
Then, when the prime mover (such as a steam turbine, water turbine, or diesel engine) starts working, it will drag the rotor to rotate. As the rotor rotates, the magnetic field generated by DC excitation will also rotate, just like a rotating magnet.
This rotating magnetic field plays a crucial role! Inside the stator, there are stator windings and stator cores. When the rotor magnetic field rotates, the stator winding will cut off the rotating magnetic field, thereby inducing electromotive force in the stator winding. The phase sequence, frequency, and magnitude of this induced electromotive force are closely related to the rotational state of the rotor magnetic field.
Simply put, the rotor of a synchronous generator is like a rotating magnetic field source, converting mechanical energy into electrical energy through interaction with the stator winding. The key to this process lies in the rotating magnetic field generated by direct current excitation.
I hope this explanation can help you better understand the working principle of synchronous generator rotors! If you have any other questions, feel free to ask me!