Motor is a device that converts electrical energy into mechanical energy. It generates a rotating magnetic field by means of an electrified coil (i.e. a stator winding) and acts as a rotor (e.g. a squirrel cage closed aluminium frame) to form a magneto-electrodynamic rotating torque. Motor is divided into DC motor and AC motor according to different power supply. Most of the motors in power system are AC motor, which can be synchronous motor or asynchronous motor (the speed of stator magnetic field and rotor rotation is not synchronous). The motor is mainly composed of stator and rotor. The direction of force movement of electrified wire in magnetic field is related to current direction and magnetic induction line (magnetic field direction). The working principle of the motor is that the magnetic field acts on the current force to make the motor rotate.

There are many methods of motor speed regulation, which can meet the requirements of different production machinery speed changes. In general, the output power of the motor varies with the speed of the motor. From the point of view of energy consumption, speed regulation can be roughly divided into two types:

Maintain the input power unchanged. By changing the energy consumption of the speed regulating device, the output power is adjusted to regulate the speed of the motor.

Control the input power of the motor to adjust the speed of the motor. Motor, motor, brake motor, frequency conversion motor, speed regulating motor, three-phase asynchronous motor, high-voltage motor, multi-speed motor, dual-speed motor and explosion-proof motor.