The working process of the DC generator rotor winding after turning 90°. When the winding turns 90°, the two winding sides are on the physical neutral plane of the magnetic field, and the brushes are not in contact with the commutator segments. No current flows through the winding, F=0, and the torque disappears. The power generation process of a generator is an energy conversion process. For example, the energy of water flowing drives the water turbine to rotate, and the water turbine drives the generator to rotate and outputs induced electromotive force, which converts the energy of the water flow in the reservoir into electrical energy.

The basic working process of a generator is the process of converting various mechanical energy that drives the generator rotor to rotate into electrical energy through electromagnetic induction.

1. Working principle of DC generators

When the DC generator is working, the action of external mechanical force drives the conductor coil to rotate in the magnetic field and continuously cuts the magnetic induction line to generate induced electromotive force. Figure 1 shows the working principle of a typical DC generator

The working process at the moment when the rotor winding of a DC generator starts to rotate. When external mechanical force drives the winding to rotate, the coils ab and cd respectively perform the action of cutting the magnetic induction wire. According to the principle of electromagnetic induction, current is generated inside the winding. The direction of the current can be judged by the right-hand rule as: the induced current flows through the coil dc→cb→ba, commutator 1, brush A, ammeter, brush B, and commutator 2 form a loop.