Working principle of brushless motor
In the brushless motor, the commutation work is done by the control circuit in the controller (usually Hall sensor + controller, the more advanced technology is the magnetic encoder).
The brushless motor adopts electronic commutation, the coil does not move, and the magnetic pole rotates. The brushless motor uses a set of electronic equipment to sense the position of the magnetic pole of the permanent magnet through the Hall element. According to this perception, the electronic circuit is used to switch the direction of the current in the coil in time to ensure that the magnetic force in the correct direction is generated to drive the motor. . Eliminates the disadvantages of brushed motors.
These circuits are the motor controllers. The controller of the brushless motor can also realize some functions that the brushed motor cannot, such as adjusting the power switching angle, braking the motor, reversing the motor, locking the motor, and using the brake signal to stop the power supply to the motor. Now the electronic alarm lock of the battery car makes full use of these functions.
The brushless DC motor consists of a motor body and a driver, and is a typical mechatronic product. Because the brushless DC motor runs in a self-controlled manner, it will not add a starting winding to the rotor like a synchronous motor with heavy-load starting under variable frequency speed regulation, nor will it cause oscillation and loss of step when the load changes abruptly.