DRV8353RS-EVM: Sensorless MSPM0G3507 + DRV8353RS

Sorry, I need to consult our expert first.

Hi Dennis,

We provide some documents for the motor control tuning.

Sensored FOC document: https://www.ti.com/lit/ug/slau948/slau948.pdf?ts=1731980945554

Sensorless FOC document: https://www.ti.com/lit/ug/slau927a/slau927a.pdf?ts=1732027085707 

Dennis Brumm said:

But there is no way to change MAX motor current when motor is running.

No, you could not change it when motor is runing.

Actually, when your hardware setting is confirmed (OPA gain and shunt resisitor is done), then this value is keep unchanged. See the documents:

Dennis Brumm said:

that's when I found this opportunity. g_pMC_App->foc.closeLoop.currentReferenceSqrMaxSet.
And that works well.

Not recommend manually change the data in g_pMC_App. This should be taken care by algorithm automatically.

Dennis Brumm said:

For “Sensorless FOC PMSM Motor Control” algoLib is missing

Not sure what happens here, maybe you can share some screenshot here.

B.R.
Sal

Thanks for the answer.

For example: I have a 48V motor with a rated current of 6A. I have to start the motor with 4A and after a certain time (5-10 seconds) set the current to 2A. I use speed control because the load on the motor is unclear and can change constantly.

How can I currently control:

1.With Sensorless FOC PMSM Motor Control I can only set ILIMIT (current limit in closed loop) with 4A (converted to iq)

2. Then start the motor.

3. Rotate the motor (10 seconds).

4. Stop the motor.

5. Adjust ILIMIT to 2A again.

6. Start the motor again.

In my opinion this is too complicated instead of adjusting the current while turning the motor.

But the current version doesn't have that option, so I started looking for a solution myself.

• For “Sensorless FOC PMSM Motor Control” algoLib is missing.

What I meant here is that with “Sensorless FOC PMSM Motor Control” the FOC_Lib.lib library is already compiled and nothing can be adjusted. In principle, you only need three parameters to control the motor: speed (voltage), torque (current) and acceleration. You can adjust speed and acceleration when the motor is rotating, but unfortunately you cannot adjust torque (current).

Wouldn't be bad if such an option appeared in another version.

Hi Dennis,

Dennis Brumm said:

I use speed control because the load on the motor is unclear and can change constantly.

When you are using speed loop, then you don't control the current (or torque) directly, it is controlled by the speed loop output, the iq reference is the PI output of speed loop.

The Ilimit means the maximum output of the speed loop, so you just set it as the maximum value your hardware board / motor can run, then keep it unchanged.

If you want to control the current, you can work in the current loop. Below register could help you:

Make sure your motor has a fixed load, in case when working in current mode, it will result higher speed with light load.

B.R.

Sal

Texas has released Universal FOC Motor Control Library.
That's good.
But when do you get the right parts?
1. The Universal FOC API guide
2. Tuning Document
3. SysConfig 1.22
All links are not working. I've been waiting for a week, but nothing's happening. Can you kindly tell us when we can expect this data?

Hi Dennis,

For Q3, you can manually download the sysconfig and then import to CCS. Or using the latest CCS version which integrated latest sysconfig.

For Q2, let me double check and feedback, it won't take much time I assume.

While most of configuration will be the same to previous, but the observer params should be tunned by user. I nearly directly spin the test motor with no paramter changed.

For Q1, I don't think we are ready to release. Let me double check.

B.R.

Sal