a lot of people say brushless motor with a brush motor has a different, indeed, physical carbon brush brushless motor is cancelled, improved the quick wear of carbon brush brush motor, and conflict and carbon brush noise and high speed spark problems at work. But since there is no physical module of carbon brush this turn, so the brushless motor digital signal control and join the brushless drive to control has become a necessary condition.
brushless dc drive contains the power module and control module, power supply module three-phase power to power a brushless motor, the control module is based on power frequency signal transformation input.
power supply module can directly to dc input (Normally for 12 v / 24 v / 48 v)Or in an alternating current input (220 V)Will have to by the converter first, if the input is an alternating current into direct current. Both input dc or ac input to turn to motor coil must be before the dc voltage by the inverter into three phase voltage to drive motor.
the supply PWM control module (Pulse width modulation)Resolution of motor and inverter power for opportunity. Brushless dc motor is generally expected to use when the load change rate can be stable in value and will not change speed control, so the brushless motor with can induced magnetic field sensor (Generally for hall sensor)Together, as the speed closed loop control, also as the basis of phase sequence control. Dongguan model aircraft motor manufacturer but it only used for speed control and not as a positioning control. Positioning control and demand with servo motor encoder. Most of the brushless motor and servo motor are same closed-loop structure.
to make brushless motor rolling up, primary control module must be based on the sensor sensing brushless motor rotor's position now, and then according to the resolution of the stator winding open (Or closed)Inverter in the order of the power transistor, the inverter of the AH, BH, CH (These are called upper arm power transistor)And AL, BL, CL (These are called lower arm power transistor)To is in the current flowing through the motor coil in a sequence (Or reverse)A rotating magnetic field, and interact with the rotor magnet, so can make the motor is/the scroll. When the induction motor rotor scroll to sensor out another set of signals of bearing, control module and then open the next set of power transistor, so cycle, brushless motors can be in the same direction until continuous rolling manipulation module resolution to brushless motor suspension closed power transistor (Or just open the arm power transistor)； To brushless motor reverse rolling power transistor open order instead.
