The electric generators work on the basis of the electromagnetic induction Faraday. The magnetic field is a significant part of the Faraday’s electromagnetic induction. The magnetic field is obtained through DC power source from an Exciter. This exciter is a form of the generator system. It is further discussed below in detail.
The generator produces the electric field at a constant voltage. By controlling the magnetic field, the voltage output of the generator can be controlled.
Excitation system is circled in the below representation of power station-
How is the magnetic field produced and controlled by a large generator?
The magnetic flux is necessary in power generators for the production of the electric power. This magnetic flux is produced by coiling the rotor or the field in a generator. To excite the magnetic field, a rotor is required. The rotor is a rotating electromagnet which requires a DC electric power source for exciting the magnetic field and this power is provided to the rotors by the Exciter.