DC brushless motor

The brushless DC motor has the same working principle and application characteristics as the general DC motor, but its composition is different. In addition to the motor itself, the former also has an additional commutation circuit, and the motor itself and the commutation circuit are closely integrated. The motor itself of many low-power motors is integrated with the commutation circuit. From the appearance, the DC brushless motor is exactly the same as the DC motor.

The motor itself of the brushless DC motor is an electromechanical energy conversion part. In addition to the two parts of the motor armature and the permanent magnet excitation, it also has a sensor. The motor itself is the core of the DC brushless motor. It is not only related to performance indicators, noise and vibration, reliability and service life, but also involves manufacturing costs and product costs. Due to the use of permanent magnet magnetic field, the brushless DC motor can get rid of the traditional design and structure of the general DC motor, meet the requirements of various application markets, and develop towards the direction of saving copper and materials and making it easy to manufacture. The development of permanent magnet magnetic field is closely related to the application of permanent magnet materials. The application of the third-generation permanent magnet materials promotes brushless DC motors to move towards high efficiency, miniaturization and energy saving.

In order to achieve electronic commutation, there must be a position signal to control the circuit. In the early days, electromechanical position sensors were used to obtain position signals, and electronic position sensors or other methods have been gradually used to obtain position signals. The easiest method is to use the potential signal of the armature winding as the position signal.

To realize the control of the motor speed, there must be a speed signal. The speed signal is obtained by a similar method of obtaining the position signal. The simplest speed sensor is a combination of a frequency-measuring tachogenerator and an electronic circuit.