How to start motor using FOC from zero speed?

[Alex Chen]

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

[Claire O.]

​Hello Alex,

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

Thanks,

Claire

[Alex Chen]

Hi Claire,

We are using sensored solution.

Thanks.

Alex

[Alex Chen]

Hi Claire,

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

Thank you.

Alex​

[Alex Chen]

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]

Hello, @Claire OKU​ ,

Any updates or suggestions?

Thank you.

[Alex Chen]

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]

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]

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]

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