The excitation mode of DC motor is the problem of how to establish the main magnetic field for the excitation windings to supply power and produce excitation magnetic flux. According to the different excitation mode, DC motor can be divided into the following types.
The excitation winding is not connected with the armature winding, and the DC motor powered by other DC power supply to the excitation winding is called the excitation DC motor, and the wiring is shown in Fig. 1. The M in the figure indicates that the motor, if it is a generator, is represented by G. Permanent Magnet DC motor can also be regarded as the DC motor.
The excitation winding of the shunt motor is parallel to the armature winding. As a generator, the end voltage of the motor itself is supplied to the excitation windings; as a shunt motor, the excitation winding and the armature share the same power supply, which is the same as that of his excitation DC motor.
The excitation winding of the series excitation DC motor is connected with the armature winding, and then connected with the DC power supply. The excitation current of the DC motor is the armature current.