Because brushless DC motors have a series of advantages such as simple structure, reliable operation and convenient maintenance of AC motors, as well as high operating efficiency, no excitation loss and good speed regulation performance of DC motors, they are used in various fields of the national economy , Such as medical equipment, instrumentation, chemicals, textiles and household appliances, and other applications are becoming increasingly popular.
The applications of brushless DC motors are mainly divided into the following categories:
1.Adjustable speed drive machinery
Speed needs to be arbitrarily set and adjusted, but the speed regulation system with low control accuracy is not required. This type of system is divided into two types: one is an open-loop speed control system, and the other is a closed-loop speed control system (at this time, the speed feedback devices mostly use low-resolution pulse encoders or AC and DC speed measurement). 和 There are three main types of motors commonly used: DC brushed motors, DC brushless motors, and 。 Asynchronous motor . 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 of adjustable speed system was mostly DC motors. With the development of AC speed regulation technology, especially power electronics technology and controllers, AC frequency conversion technology has been widely used. Inverters and AC motors have penetrated into Most areas of the original DC speed control system application. In recent years, due to the advantages of small size, light weight and high efficiency and energy saving of brushless DC motors, medium and small power AC frequency conversion systems are gradually being replaced by brushless DC speed regulation systems, especially in textile machinery, printing machinery, etc. There are many applications for frequency conversion systems. In some application areas directly powered by batteries, DC brushless motors are now more used.
2.Constant speed drive machinery
In general industrial areas, where speed regulation is not required, most of them use three-phase or single-phase AC asynchronous and synchronous motors. With the advancement of power electronics technology, in the case of continuous operation with power less than 10kw, in order to reduce volume and save Materials, improve efficiency and reduce losses, more and more motors are being replaced by brushless DC motors, such applications are: automatic doors, elevators, water pumps, fans, etc. However, in the case of large power, due to the large cost and investment, in addition to the permanent magnet motor, it is necessary to add drivers and other equipment, so brushless motors are currently rarely 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. Because of its good control performance, brushless DC motors have gradually replaced DC motors and stepper motors in high-speed and high-precision positioning systems, becoming one of the motors selected by modern servo systems. At present, brushless DC motor servo systems are widely used in scanners, cameras, CD drives, medical diagnostic CT, computer hard drives, and CNC lathe drives for precise control.
Household appliances such as automatic washing machines, CD players, etc .; military applications such as submarines, warships; and the start of large synchronous motors.