Brushless DC motor itself has the characteristics of fast response, large starting torque, from zero speed to rated speed, which can provide rated torque. But this advantage of Brushless DC motor is also its disadvantage, because in order to produce the performance of constant torque under rated load, the armature magnetic field and rotor magnetic field must be kept at 90 degrees, which depends on its own Carbon brush and commutator. The carbon brush and commutator will produce certain sparks and carbon powder when the motor is running, so it will cause damage to its components. In addition, it is also subject to greater restrictions in the use of occasions.

　　Brushless DC motor is widely used in many scenes of our work, such as automobile, tools, industrial control, automation, aerospace and so on. In short, brushless DC motor can be divided into the following three uses:

　　   1, continuous load application: This is mainly for some areas that require a certain speed but do not have high speed accuracy requirements, which are widely used, such as electric fan, water pump, hair dryer and other applications commonly used in our home. The cost of this kind of application is relatively low, and it can be mostly open-loop control.

　　   2. Application of variable load: this application is mainly aimed at the application that needs to change the speed within a certain range, so the requirements for motor speed characteristics and dynamic response time characteristics are higher. For example, our household dryer and compressor are very clear examples. In the automotive industry, the cost of oil pump control, electric controller, engine control, etc. is relatively high.

　　   3. Positioning application: in most industrial control and automatic control applications, it belongs to this category, so what effect can be achieved in this kind of application? Brushless DC motor can complete energy transmission in this kind of application, so it has special requirements for speed dynamic response and torque, and it also has high requirements for its controller. Some photoelectric equipment and some synchronous equipment may be used in speed measurement. Process control, mechanical control, transportation control and many other aspects belong to this kind of application.

　　   brushless DC motor has small volume, light weight, high bearing capacity, long service life, stable operation and low noise. Brushless DC motor is more suitable for lifting and transportation, engineering machinery, metallurgy, mining, petrochemical, construction machinery, light industry and textile, medical equipment, instrumentation, automobile, ship, weapons, aerospace and many other industrial sectors.