Why is torque falling at low speed?
I'm running the motor in torque and speed modes with a hall sensors.
The only problem I have is that something internal to the FOC software adjusts the torque down at (very) low and zero speed. I assume this is done to avoid the motor overheating.
Example:
I align and start the motor, it quickly spins up with lots of torque.
I apply some friction to the motor and it still maintains a high torque level.
I apply more and more friction, the speed falls as I apply more friction. At some point when the speed gets low the power draw gradually falls.
I force the motor to a complete stop, the power draw is almost zero. Almost zero torque obviously.
I let go of the motor, it spins up again.
At very low speeds when the torque (for some reason) drops, the motor is very unstable and jumps erratically back and forth.
So my questions are pretty simple:
- What is affecting my torque at low/zero speeds?
- How do I increase torque at low/zero speeds?
How do I achieve smooth speed control ant low speeds <100rpm? I have adjusted the Kp and Ki gains with no success.
Is the ST-SPIN32F0 capable of performingproperly at low speeds?
