Dc motor control principle, let the dc motor rotation, begin to control department must be based on hall -
Feel to the place of dc motor rotor position sensor, and then according to the stator winding resolution open (
Inverter in the order of the power transistor, makes the AH, BH, CH (
These are called upper arm power transistor)
And AL, BL, CL (
These are called lower arm power transistor)
Sequence, making the current through the dc motor coil consequent (
Or the reverse)
A rotating magnetic field, and the rotor magnet interact with each other, so much can make dc motor chronological/reverse rotation.
When the dc motor rotor rotation to hall -
Feel out another set of sensor signal status, control of open again the next set of power transistor, so much loop dc motor can be in accordance with the unified direction of continuous rotation until the resolution control department to stop the closed power transistor (dc motor rotor
Or just open the arm power transistor)
To dc motor rotor reverse power transistor to open the order instead.
Basically under the accident) of the power transistor can for example: AH, a set of BL - AH, a group CL - BH, CL group - a group BH, AL - CH, a group of AL -> CH, a set of BL, but never can leave AH, AL or BH, BL or CH, CL.
Other due to the electronic components are always switch echo time, thus power transistor in closed and open time will echo time thinking about the parts, or when the upper arm (
Or lower arm)
Has not yet completely closed, under the arm,
Or upper arm)
Is open, the result is the formation of upper and lower arm burned a short-circuit and make a power transistor.
When the dc motor rotation, control department again according to the setting rate of the driver and plus/minus the rate of ordered (
With the hall -
Sensor signal change rate to compare (
Or by the software operation)
By the next group (to resolution
Switch conduction and conduction time length.
Low rate is open long, rate too much shorter, this part of the work are done by PWM.
PWM dc motor speed resolution is fast or slow, the method of how such a PWM is to reach more accurate rate control center.
High speed rate control must consider to the system CLOCK can distinguish rate is enough to have time on the disposal of the software instructions about hall - additionally
Sensor signal change material access method also affect the disposal of the device performance, and concluded that the accuracy and timeliness.
As for the low speed rate control especially due to the back hall - starting at low speed
Sensor signal change more slowly, but capture signal method, the disposal of the time and the characteristics of dc motor based on proper equipment control parameter values can be pretty nervous.
May rate of return changes in encoder transformation for reference, make the signal to distinguish rate added in order to get a better control.
Dc motor can run smoothly and echo is excellent, P.
Control the appropriate or not also cannot be ignored.
The conditions to the dc brushless dc motor is a closed loop control, so back to the credit number is is informing the dc motor speed of the control direction of interval velocity is much, this is the deviation (
Know natural will compensate the deviation, and the method with traditional engineering control such as P.
But control of the morphology and the situation is turbulent and changeable, if you want to control the cement durability are the elements of thinking I'm afraid I can not fully grasp the traditional engineering control, thus vague control, expert system and neural network will also be considered as an intelligent P.
Control of the strain theory.