Other Parts Discussed in Thread: DRV8323
Tool/software:
I have over time accumulated some questions while learning and messing around with motor control.
I am fairly new into the motor control game, so there might be some incorrect statements.
We are using the TMS320F28054M with the smarte gate driver DRV8323 to control my sensorless BLDC motor with the following specs:
| DC Bus Rated voltage | 24V (14V actually inputted to motor) |
| Rated Current | 13A |
| Rated Torque | 0.65 Nm |
| Rated Speed | 6000 rpm |
| Number of Poler | 14 |
| Voltage Constant | 285 rpm/V |
| Rated Power | 313.5 W |
| Rated Efficiency | 85 % |
FW is pretty much proj_lab10b.c from TI labs with custom changes/additions not related to motor control.
Overall I am controlling wheels and are having two different shaking issues:
1. random occurrences of shaking while standing still (Using the TI software, the stator resistance (RS) is measured on each boot).
2. Shaking/flaky behavior at low RPM speeds (sub 100 rpm).
In the pursuit of understanding more the following questions have risen:
How does the stator resistance affect the control algorithms?
1. If the RS value is (due to a glitch or for whatever reason), measured higher than the actual resistance value in wiring + motor
2. If the RS value is measured lower than the actual value in wiring + motor.
3. Does the resistance in the wires leading up to the the motor matter, or is it just the resistance in the windings in the motor? Can the resistance in the wires be ignored (leading to question 2).
How know the actual RPM range the motor can handle smoothly?
- Is there a way to calculate or determine the minimum RPM my motor can handle? Any default/standard information about it?
- Any tests that can be used to reliably determine the minimum RPM?
- Is my motor supposed to be able to handle sub 100 rpm smoothly and changes in control algorithm is necessary?
Thanks in advance, all help is appreciated!
