Brushless motor consists of motor body and driver. Because the brushless motor runs in automatic control mode, it is not necessary to add starting winding to the rotor with variable frequency speed regulation, and it will not oscillate or out of step due to sudden load change.
Brushless motor uses semiconductor switching devices to realize electronic commutation, that is, electronic switching devices replace traditional contact commutator and brush. Brushless motor consists of permanent magnet rotor, multipole winding stator and position sensor.
According to the change of the rotor position, the position sensor commutates the stator winding current in a certain order, that is, it detects the position of the rotor magnetic pole relative to the stator winding and generates a position detection signal. The signal conversion circuit controls the power switch circuit and switches the winding current according to a certain logical relationship. The working voltage of the stator winding is provided by the electronic switch circuit controlled by the output of the position sensor.
Structure Analysis of Brushless Motor
In structure, there are similarities between brushless motor and brush motor, and there are also rotors and stators, but the structure is opposite to brush motor. The rotor of the brush motor is coil winding, which is connected with the power output shaft, and the stator is permanent magnet steel. The rotor of a brushless motor is made of permanent magnet steel, which is connected with the output shaft together with the shell, and the stator is a winding coil, so it is called a brushless motor, and there is no commutating brush for alternately changing the electromagnetic field.
Simply put, by changing the alternating frequency and waveform of the current wave input to the stator coil of brushless motor, a magnetic field rotating around the geometric axis of the motor is formed around the winding coil, which drives the permanent magnet steel sheet on the rotor to rotate and the motor to rotate. The performance of the motor is related to the number of magnetic steel, the magnetic flux intensity of magnetic steel, the input voltage of the motor and other factors, and has a great relationship with the control performance of the brushless motor.
Because the input is direct current, the electronic governor needs to convert the current into three-phase alternating current, and the control signal needs to be received from the remote controller receiver to control the speed of the motor to meet the needs of the model.