The BLDC/brushless motor has a rotor and a stator. The rotor of the brushless motor is permanent magnet steel, which is connected to the output shaft together with the casing. The stator is a winding coil. The commutation brush used by the brush motor to alternately transform the electromagnetic field is removed, so it is called It is a brushless motor (Brushless motor). To put it simply, by changing the alternating frequency and waveform of the current wave input to the stator coil of the brushless motor, a magnetic field rotating around the geometric axis of the motor is formed around the winding coil. This magnetic field drives the permanent magnet on the rotor to rotate. The motor starts to rotate, and the performance of the motor is related to factors such as the number of magnets, the strength of the magnet flux, and the size of the motor input voltage.
Induction motor is also called "asynchronous motor (asynchronous motor)", that is, the rotor is placed in a rotating magnetic field, under the action of the rotating magnetic field, a rotating torque is obtained, so the rotor rotates. The rotor is a rotatable conductor, usually in the shape of a squirrel cage. The stator is the non-rotating part of the motor, and its main task is to generate a rotating magnetic field. The rotating magnetic field is not realized by mechanical methods. Instead, alternating current is passed through several pairs of electromagnets to cyclically change the magnetic pole properties, so it is equivalent to a rotating magnetic field.
The three-phase induction motor has the advantages of low cost, large temperature range, large output torque adjustment range, and high-speed range efficiency; however, it has large energy consumption, lagging power factor, narrow high-efficiency area, and low light-load power factor. The shortcomings of poor speed performance cannot be ignored.
At the same time, the market has greater demand for brushless motors. Compared with three-phase induction motors, brushless motors have the advantages of high efficiency, wide area, energy saving, small size and light weight.