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Roberto Giovinetti
Associate III
December 12, 2019
Solved

Start a motor with heavy load

  • December 12, 2019
  • 8 replies
  • 2681 views

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

This topic has been closed for replies.
Best answer by Claire O.

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

Thanks,

Claire

8 replies

Claire O.
Technical Moderator
January 17, 2020

Hello Roberto,

are you using sensored or sensorless solution?

Thanks,

Claire

Roberto Giovinetti
Associate III
January 17, 2020

Hello Claire

I'm using a sensorless solution.

Thanks

Roberto

Claire O.
Technical Moderator
January 17, 2020

​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
January 21, 2020

Dear Claire,

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

Thank you for support.

Roberto

Claire O.
Claire O.Answer
Technical Moderator
January 23, 2020

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

Thanks,

Claire

Roberto Giovinetti
Associate III
January 17, 2020

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

Laurent Ca...
Senior III
September 22, 2020

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
January 27, 2021

Hi @Claire OKU​ 

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

thanks

Claire O.
Technical Moderator
January 28, 2021

​Hello Skywork,

Sorry I am not sure I understood your question. Do you have problem with hall sensor ? Or do you want to remove them?

Thanks and best regards,

Claire

SkyWork
Associate III
January 31, 2021

Hello @Claire OKU​ 

I have the similar issue under FOC + hall sensor situation, I will meet that the motor will shake when climbing the hill with heavy loading

Is there any method to improve this situation

thanks

SkyWork
Associate III
February 1, 2021

Hello @Claire OKU​ 

I means that I using hall sensor + FOC to drive the BLDC motor, but I still have issue under heavy load startup situation

Is there anyway to solve this issue

thanks

Laurent Ca...
Senior III
June 15, 2021

The question has been set only to the "STM32 Motor Control" topic (the question is only about the STM32 MC SDK). 

Best regards