In brushless motors, the commutation work is completed by the control circuit in the controller (usually a Hall sensor + controller, and the more advanced technology is a magnetic encoder).
Brushless motors use electronic commutation, the coil does not move and the magnetic pole rotates. Brushless motors use a set of electronic equipment to sense the position of the permanent magnet poles through Hall elements. Based on this perception, electronic circuits are used to timely switch the direction of the current in the coil 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 motor controllers. The controller of a brushless motor can also implement some functions that a brushed motor cannot, such as adjusting the power switching angle, braking the motor to reverse rotation, locking the motor, and using the brake signal to stop powering the motor. Nowadays, the electronic alarm lock of battery vehicles makes full use of these functions.
The brushless DC motor is composed of a motor body and a driver and is a typical electromechanical integration product. Since the brushless DC motor operates in a self-controlled manner, it does not have an additional starting winding on the rotor like a synchronous motor that starts under heavy load under variable frequency speed regulation, and it will not produce oscillation or loss of synchronization when the load changes suddenly.
