What is the principle of excitation motor?

Principle of excitation motor: The control principle of excitation motor is to apply DC excitation current to excitation winding to generate excitation magnetic field, so that the current of excitation winding generates air gap magnetic field.

The magnitude of excitation winding current is determined by the voltage of DC excitation power supply and the resistance in series with rotor circuit.

When the resistance of rotor circuit is constant, changing the voltage of DC excitation power supply can change the excitation current and the intensity of air gap magnetic field.