Working Principle Of Motor

Electromagnetic induction and Lorentz force

The working principle of the motor is based on electromagnetic induction and Lorentz force. The main components of the motor include the stator and the rotor. The stator is the stationary part of the motor, usually composed of coils, which generates a magnetic field when powered on; the rotor is the rotating part, located in the magnetic field. When the current passes through the rotor coil, according to the principle of Lorentz force, the magnetic field will exert a force on the current, thereby driving the rotor to rotate.

Working principles of different types of motors

1. DC motor only: powered by a DC power supply, the stator is usually composed of permanent magnets or electromagnets, and the rotor is composed of coils. When the DC current passes through the rotor coil, the coil is acted upon by a force in the magnetic field, thereby generating rotation. The advantages of DC motors are good speed regulation performance and large starting torque, which are suitable for occasions where precise speed control is required.

2. AC motor: powered by an AC power supply, both the stator and the rotor generate a magnetic field through AC power. When three-phase AC current passes through the stator coil, a rotating magnetic field is generated, which drives the rotor to rotate. The advantages of AC motors are simple structure and low maintenance cost, which are suitable for industrial fields.

3. Stepper motor: The rotation angle and speed of the motor are controlled by controlling the number and frequency of pulses. Each time an electric pulse is input, the motor rotates one angle and moves forward one step.

4. Permanent magnet motor: Permanent magnets are used to provide a magnetic field, and torque is generated by the movement of current in the magnetic field.

Energy conversion process

The working process of the motor is actually a process of energy conversion. When electrical energy is input into the motor, the current in the stator winding generates a magnetic field. This process is the conversion of electrical energy into magnetic energy. Then, the rotor rotates through the interaction of the magnetic field, and the magnetic energy is converted into mechanical energy, thereby driving the load to operate. At the same time, during the operation of the motor, some energy losses will inevitably occur, such as copper loss, iron loss and mechanical loss, which will lead to reduced efficiency of the motor.