Motor's current & speed overshoot when load is released

[Kurzy]

Hey,

So we're trying to modify the motor control SDK to fit our needs.

We currently use the EVSPIN32G4 to evaluate the performance of the motor control SDK with our motor and our requirements.

We're using an SM-PMSM motor, which works in a rated voltage of 24V, max current of 24A and 21 pole-pairs and has Hall sensors installed. We're trying to spin it using Hall sensored-FOC.

The issue we're facing, is that when we release an applied load on the motor at once, the motor's speed rises significantly, followed by a big spike in the current in-take of the motor.

It often leads to over-current or over/under voltage faults.

Is there a way to control that big spike? 

 

Thanks,
Eyal

Hey @Kurzy  

I suppose changing the speed regulator parameters(tuning them) might help!

[Kurzy]

Hey! thanks for the reply.

What parameters exactly should I tweak to get a change in the response to a sudden release in load?
I've tried playing with the PI coefficients for a while. And while I get a fair response when applying a load, I don't see any difference in the response when the load is suddenly released.

Thanks!

Hey @Kurzy 

Do you use the speed mode? when releasing the load, does it take time to set speed of the motor to the desired speed? if yes, it shows your coefficent may be not suitable

changing C1 & C2 in the speed sensing section might also help,

divide C2 by the power of 2s meaning 2, 4 , 8, ... and see if anything changes

regards!