The integrated DC brushless motor not only has features of simple structure, reliable operation and convenient maintenance of the AC motor but also has many advantages such as high operation efficiency, no excitation loss and good speed regulation performance of the DC motor, it is widely used in various fields of the national economy.
For more than a century, as a mechanical and electrical energy conversion device, the motor has been applied in various fields of the national economy and people's daily life. Its main types are synchronous motor, asynchronous motor, and DC motor. Because the traditional DC motor uses the brush to change the direction mechanically, there is relative mechanical friction, which brings the weakness of noise, cremation, radio interference, and short life. Besides, the disadvantages of high manufacturing cost and difficult maintenance greatly limit its application range, which makes most of the current industrial and agricultural production use three-phase asynchronous motor.
Because of the disadvantages of the traditional DC motor, as early as the 1930s, some people began to develop an integrated DC brushless motor with electronic commutation instead of brush mechanical commutation. After decades of effort, it was finally realized in the early 1960s. Since the 1970s, with the rapid development of the power electronics industry, many high-performance semiconductor power devices, such as GTR, MOSFET, IGBT, IPM, etc., and the advent of high-performance permanent magnet materials have laid a solid foundation for the wide application of integrated DC BLDCM.
The basic composition of the integrated DC bold permanent magnet motor is composed of a motor body, position sensor, and an electronic switch circuit. Its sub winding is generally made of multi-phase (three-phase, four-phase, five-phase, etc.), and the rotor is composed of permanent magnetic steel according to a certain number of poles.
Working principle of integrated DC Brushless Motor
The armature of a common DC motor is on the rotor, while the stator produces a fixed magnetic field. To make the DC motor rotate, it is necessary to change the direction of the current in the armature winding through the commutator and the brush, so that the directions of the two magnetic fields are always perpendicular to each other, to generate a constant torque to drive the motor to rotate continuously.
To remove the brush, the integrated DC brushless motor puts the armature on the stator, and the rotor is made into a permanent magnet, which is just the opposite of the ordinary DC motor. However, even if this change is not enough, because the armature on the stator can only produce the constant magnetic field after passing through the DC, the motor still can not rotate. To turn the motor, it is necessary to make the windings of each phase of the stator armature exchange electricity continuously, to make the stator magnetic field constantly change with the position of the rotor, keep the space angle of the stator magnetic field and the permanent magnetic field of the rotor all the time, and generate torque to push the rotor to rotate. The integrated DC BLDCM is a typical mechatronics product, which is composed of a motor body and driver.