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FOC sensorless doesn't work

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john
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FOC sensorless doesn't work

Hello,

I've been using a Vesc (HW v4.12) for some time now, it worked really well with a brushless motor with HALL sensors.

 I recently decided to change the motor and use a smaller one (also with Hall sensors), but it doesn't work very well.

Now, when in FOC sensored mode, the motor won't switch to sensorless mode when it reaches the "sensorless ERPM" speed. So the default value being 2500ERPM, the motor won't spin faster than that, it will only start to vibrate and make more noises when I tell it to spin faster. Also when below 2500ERPM, the speed control performs very poorly (lots of vibration and oscillation). 

 

Did anyone had this problem too ? and know how to solve it ?

Thank you.

 

 

TechAUmNu
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You need to run motor detection again without the hall sensors enabled. Test it without the hall sensors until it runs smoothly, then re-enable them and the transition should be much smoother.

john
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thank you for your answer.

The thing is it won't work at all in sensorless mode, the detection doesn't even work. 

john
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Sorry, the detection works in FOC sensorless but doesn't in BLDC mode.

When in FOC sensorless, the motor won't spin at more than 400ERPM ( which is the openloop ERPM limit)

TechAUmNu
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Sounds like there is either something wrong with the VESC. Or you have a particularly difficult motor to detect. 

You can try manually tuning the FOC settings if it won't detect it automatically. Start by measuring the resistance and inductance with the button, and enter those values into the fields. Play around with the resistance until the motor spins. Then try changing the other settings to get it running smoother. Can you post a screenshot of your FOC settings and what motor you are trying to use?

john
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Hi

I've tried with two different Vesc and tried to tune the FOC settings manually but without success. The motor only spins in duty mode under 2500ERPMand then start to go crazy above that. I think my motor might be too small for the vesc(motor operates below 3A). 

I've read here (http://vedder.se/forums/viewtopic.php?t=130)  that i might need to replace the shunts with ones with higher resistance. I'm going to change them and see if it gets better.

I don't have access to my Vesc right now, I'll post the screenshots as soon as I can. Thanks for your help

frank
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It would be good to know the motor. manufacturer pole pairs etc.