Jun 21, 2017
DC brushless motor is a synchronous motor, which means that the motor rotor speed by the motor stator rotation of the magnetic field speed and the number of rotor number. DC brushless motor has the advantages of traditional DC motor, while eliminating the carbon brush, slip ring structure; stepless speed regulation, wide speed range, overload capacity; high reliability, DC Brush Motor good stability, strong adaptability, maintenance and Easy maintenance and so on. DC brushless motor commutation circuit by the drive and control of two parts, these two parts are not easy to separate, especially low-power circuit is often integrated into a single dedicated ASIC.
DC motor has a fast response, DC Brush Motor a large starting torque, from zero speed to rated speed with rated torque can provide the performance, but the advantages of DC motor is also its shortcomings, because the DC motor to produce a constant load under constant load Moment performance, the armature magnetic field and the rotor magnetic field to be constant to maintain 90 °, which will rely on carbon brush and commutator. Carbon brushes and commutators produce sparks when the motor rotates, and the toner is limited in addition to damage to the components.
Brushless DC motor consists of the main body of the motor and the drive, the motor stator windings made of three symmetrical star connection, with three-phase asynchronous motor is very similar. DC Brush Motor The rotor of the motor is glued to the magnetized permanent magnet. In order to detect the polarity of the motor rotor, a position sensor is installed in the motor. The driver is composed of power electronic devices and integrated circuits. The function is to accept the start, stop and brake signals of the motor to control the start, DC Brush Motor stop and braking of the motor. The position sensor signal and the forward and reverse signals are used to control the reverse Variable speed command and speed feedback signal, used to control and adjust the speed; to provide protection and display, and so on.
DC brushless motor mainly by the motor body, DC Brush Motor the location of the sensor and electronic switch circuit composed of three parts. The motor body is structurally similar to a permanent magnet synchronous motor, but there are no cage windings and other starter devices. (Three-phase, four-phase, five-phase), the rotor by the permanent magnet by a certain number of pole pairs (2p = 2,4, ...) composition.
When a certain phase of the stator winding is energized, the current interacts with the magnetic field generated by the magnetic pole of the rotor permanent magnet to generate torque, drives the rotor to rotate, and then converts the rotor magnet position into an electrical signal by the position sensor to control Electronic switch circuit, so that the stator phase winding in a certain order conduction, DC Brush Motor the stator phase current with the rotor position changes in a certain order commutation. As the electronic switching circuit conduction sequence is synchronized with the rotor angle, which played a commutation of the mechanical commutator.
DC brushless motor electronic switch circuit is used to control the motor and stator on each phase winding power and the order of time, mainly by the power switch unit and the position sensor signal processing unit composed of two parts. Power logic switch unit and position sensor signal processing unit composed of two parts. Power logic switch unit is the core of the control circuit, DC Brush Motor its function is to power the power to a certain logical relationship to the DC brushless motor stator on the phase of the winding, so that the motor to produce continuous torque. And the order and time of conduction of each phase winding depends primarily on the signal from the position sensor. But the signal generated by the sensor is generally not directly used to control the power logic switch unit. In summary, the composition of the main components of the brushless DC motor include: 1, the main motor: the main stator, the main rotor.
2, electronic switch lines: power logic switch, position signal processing
3, the position sensor: sensor stator, sensor rotor