The brushless DC motor has the advantages of low temperature rise, low noise, large torque, high speed, high efficiency (stable operation, high reliability, good stability), low energy consumption (multi-stage deceleration loss is eliminated, and the comprehensive power saving rate is as high as 20% - 60%), no spark (no spark, especially suitable for explosive places), long service life (can be used continuously for 30000 hours), etc.

Brushless DC motors are widely used in micro machines in all walks of life, such as circulating fans, humidifiers, dehumidifiers, air fresheners, cooling and heating fans, soap dispensers, cell phones, smart door locks, textile machinery, laser processing machinery, engraving machines, printing machinery, medical equipment, automatic packaging machines, robots, automatic production lines, CNC lathes, measuring instruments, electronic manufacturing equipment, etc.

Brushless motor is also called DC variable frequency motor (BLDC) in some fields. It adopts electronic commutation (Hall sensor), and the coil (armature) does not move the magnetic pole. At this time, the permanent magnet can be outside the coil or inside the coil., Therefore, there are outer rotor brushless motor and inner rotor brushless motor. The brushless motor has the same structure as permanent magnet synchronous motor.

However, a single brushless motor is not a complete power system. The brushless system is basically controlled by the brushless controller, that is, through an ESC to achieve continuous operation. It is a brushless electronic speed controller (ESC), which determines its performance. There are generally two kinds of driving current of brushless motor, one is square wave, the other is sine wave. Sometimes the former is called DC brushless motor, and the latter is called AC servo motor. To be exact, it is an AC servo motor.

For example, when the rotor is in a certain position, the elements 2 and 3 N poles near the hall will be activated, and the controller will turn on two coils to magnetize the coil B S pole and C N pole to attract the rotor to rotate. When the rotor is turned to the next position, only Hall element 2 is activated and the controller will open coils a and C. The former is magnetized to the S pole.

he latter is magnetized to the N pole and continues to pull the rotor to rotate, constantly changing the energization of the coil, so that the rotor can be continuously transmitted. This is how the brushless DC motor works.