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Start a motor with heavy load

Roberto Giovinetti
Associate III

Hello everybody

I'm using MotorControl Workbench and Motor Control SDK 5.4.1.

I need to control some power tools up to currents of 40A peak. I developed a board similar to IHM08M1 and I'm very satisfied of the power delivered to motors. There's only a "little" problem: I should improve the behavior at heavy loads when motor has to startup, because I noticed that in this case it fails to start. I've a linear ramp of 750ms in which motor moves from 0 rpm to 1650 rpm (15% of nominal speed at free load) and the final current in this phase is the nominal current (so the max current we can give to the motor).

Could be a practical solution create a phase in which current rumps up very quickly to nominal value and desired speed moves from 0 rpm to a little value in a brief time? After that phase I would add a phase in which current is still constant at the maximum value and speed moves from the previous little value to the 15% of nominal speed to exit from open loop mechanism.

Did anybody try a solution like this? Or maybe there's a better way?

Thank you very much for support.

Roberto

1 ACCEPTED SOLUTION

Accepted Solutions

yes, it should improve the torque level at low speed.

Thanks,

Claire

View solution in original post

13 REPLIES 13
Claire O.
ST Employee

Hello Roberto,

are you using sensored or sensorless solution?

Thanks,

Claire

Roberto Giovinetti
Associate III

Hello Claire

I'm using a sensorless solution.

Thanks

Roberto

Claire O.
ST Employee

​ok, this explain your current problem Roberto.

There are no trivial answer to your question ...  our solution is not tuned today to support heavy load at low speed.

But, we are working on this point and some progress are expected this year on this point.

Please stay tuned...

Claire

Roberto Giovinetti
Associate III

Ok, so in your opinion there's no way?

Or maybe I can try to obtain some results If I slighly modify parameters? I can't work on it until my own board is finished, so I'm only thinking about it, at this time.

Roberto

Dear Claire,

just another question: if I use Hall sensor, does this solve the question?

Thank you for support.

Roberto

yes, it should improve the torque level at low speed.

Thanks,

Claire

Dear Claire

Can you tell me if there are some good news about my "problem"? Did Motor Control Suite introduce some improvements for solutions sensorless?

Thank you so much

Roberto

Laurent Ca...
Lead II

Dear Roberto Giovinetti

We will probably make some announcements about sensorless solution support in 2021.

Do not hesitate to contact us again at this time.

Best regards

Laurent C.

SkyWork
Associate III

Hi @Claire OKU​ 

is there any way to solve sensor mode (I using hall sensor to start motor)?

thanks