Application classification of brushless DC motors

Because the brushless DC motor not only has a series of advantages of AC motor, such as simple structure, reliable operation, convenient maintenance, etc., but also has the characteristics of high operating efficiency, no excitation loss and good speed regulation performance of DC motor, so it is used in various fields of the current national economy. , Such as medical equipment, instrumentation, chemical industry, textile and household appliances, etc. applications are becoming more and more popular.

The applications of brushless DC motors are mainly divided into the following categories:


1. Constant speed drive machinery


In general industrial occasions where speed regulation is not required, most of the three-phase or single-phase AC asynchronous and synchronous motors are often used. With the advancement of power electronic technology, when the power is not more than 10kw and continuous operation, in order to reduce the volume and save Materials to improve efficiency and reduce losses. More and more motors are being replaced by brushless DC motors. Such applications include: automatic doors, elevators, water pumps, fans, etc. In the case of high power, due to the large cost and investment, in addition to the permanent magnet motor, it is necessary to increase the drive and other equipment, so brushless motors are rarely used at present.


2. Adjustable speed drive machinery


Speed needs to be set and adjusted arbitrarily, but a speed control system that does not require high control accuracy. This type of system is divided into two types: one is an open-loop speed regulation system, and the other is a closed-loop speed regulation system (the speed feedback devices at this time mostly use low-resolution pulse encoders or AC and DC speed measurement, etc.). There are three main types of motors commonly used: DC brushed motors, asynchronous motors and DC brushless motors. This has a large number of applications in packaging machinery, food machinery, printing machinery, material handling machinery, textile machinery and transportation vehicles.

At the beginning, the application field of adjustable speed system used more DC motors. With the development of AC speed regulation technology, especially power electronic technology and controller, AC frequency conversion technology has been widely used, and frequency converters and AC motors have penetrated The vast majority of applications of the original DC speed control system. In recent years, due to the increasingly prominent advantages of brushless DC motors such as small size, light weight, high efficiency and energy saving, small and medium power AC frequency conversion systems are gradually being replaced by brushless DC speed control systems, especially in textile machinery, printing machinery and other original Fields where the frequency conversion system is more widely used. And in some application areas that are directly powered by batteries, brushless DC motors are now more used.


3. Precision control


Servo motors have always played a very important role in high-precision control in the field of industrial automation. Different applications have different requirements for the control performance of servo motors. In practical applications, various control forms of servo motors : Torque control/current control, speed control, position control. Brushless DC motors have gradually replaced DC motors and stepper motors in high-speed, high-precision positioning systems due to their good control performance, and become one of the motors of choice for modern servo systems. At present, scanners, cameras, CD drive drives, medical diagnostic CT, computer hard disk drives and CNC lathe drives, etc. have widely adopted brushless DC motor servo systems for precision control.


4. Other applications


Household appliances such as automatic washing machines, CD players, etc.; military applications such as submarines and warships; and the startup of large synchronous motors, etc.