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Alex Chen
Alex Chen
Associate II
May 11, 2021
Question

How to start motor using FOC from zero speed?

  • May 11, 2021
  • 7 replies
  • 4853 views

Hi all,

I am using STM32F303RB with iHM08M1 to control a BLDC motor.

I want to startup my motor from zero speed using FOC, but the motor shakes at the beginning.

I have tried to increase Vq, but the motor will have a big vibration if Vq is set to high, but if I set it smaller the motor shakes.

Does someone can share how to startup a motor from zero speed using FOC? Or please give me some hints?

Thank you.

Alex

This topic has been closed for replies.

7 replies

Claire O.
Claire O.
Technical Moderator
May 11, 2021

​Hello Alex,

Did you try with a sensored or with a sensorless solution?

Thanks,

Claire

Alex Chen
Alex ChenAuthor
Associate II
May 12, 2021

Hi Claire,

We are using sensored solution.

Thanks.

Alex

Alex Chen
Alex ChenAuthor
Associate II
May 13, 2021

Hi Claire,

​

Do you have any suggestions or what I can try next?

Thank you.

Alex​

Alex Chen
Alex ChenAuthor
Associate II
May 17, 2021

Hello, @Claire OKU​ ​ 

​

For startup from zero speed using FOC and sensored solution, do you have any suggestions?

I have tried many ways but the motor shakes.

Thank you.

Alex

Alex Chen
Alex ChenAuthor
Associate II
May 19, 2021

Hello, @Claire OKU​ ,

Any updates or suggestions?

Thank you.

Alex Chen
Alex ChenAuthor
Associate II
May 24, 2021

Hi @Claire OKU​ ,

This problem is urgent. We need to startup the motor from zero speed with FOC.

Could you please help us? Thank you.

Alex

AErma.2
AErma.2
Visitor II
May 24, 2021

Good Day. For start in FOC control system have to set Iq( active current_) to level that produce lager torque then for example load or friction.

In any case FOC will work correctly only if motor rotor flux aligned with D axis in software. If you are using Absolute positon sensor u have to check that in give correct ELECTRICal engle to foc algorirms. If that not right motor will stall on current o bounce.

Alex Chen
Alex ChenAuthor
Associate II
June 3, 2021

Hi AErma,

Thank you for the reply.

You mentioned "FOC will work correctly only if motor rotor flux aligned with D axis".

Please correct me if I am wrong. When FOC starts, I set Vd to a value (for example, 6000)

and Vq = 0 for a short period, then I set Vd = 0 and Vq = 6000. Is it correct? But I still have some "shaking"

at the beginning when speed is zero.

Any suggestion?

Thanks.

LSHEN.1
LSHEN.1
Associate
June 5, 2021

Hi Alex:

Did you run the motor profiler at first to get some motor parameters?

and what's the sensor you use for this motor? If you use Hall sensors, sometimes

you have to change the order of the halls.

Good luck

Steve LIn

Alex Chen
Alex ChenAuthor
Associate II
June 10, 2021

Hi Steven,

​

Thanks for the reply.

Yes, We have run the motor profiler to get the motor parameters and we use hall sensors.

Because the motor runs very smoothly without any shaking after the motor gets some speed (after leaving the still state),

so we think the order of the hall sensors should be correct.

Thank you.

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