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Low RPM motor stutter?

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ebikerevolution
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Low RPM motor stutter?

Hey there,

Still trying to figure out the best control method for my eBike. From stand-still, applying slight throttle creates a motor stutter. Is the motor not receiving enough amperage from the battery? I'm using Current control on ADC app input. 

All information is appreciated!

TechAUmNu
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If you are using current control, you will probably want to blip the throttle quite high to get moving as you need to break the static friction and get the motor spinning properly. If you only give it slight throttle then it won't have enough torque to keep turning properly and will stutter or cog.

ebikerevolution
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Even when I give it high throttle from a stand-still, the stuttering just gets worse. I have to get a rolling start then give it throttle for the motor to start working. 

Any ideas?

TechAUmNu
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Try adjusting deadtime compensation in advanced settings under FOC. Try 0.08 - 0.3

ebikerevolution
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@TechAUmNu Hmm... does this apply if I'm using a BLDC motor?

district9prawn
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If using sensored bldc check hall table. For sensorless try playing with bemf coupling as that can make startup quite rough if it is off. Increasing startup boost could also help. 

ebikerevolution
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Hm... I'm using Sensorless and have tried messing with BEMF coupling and startup boost and they haven't really fixed the problem. It's definitely improved it though!

I would just like to increase the torque at low RPMs using sensorless BLDC + Current control. What other routes should I look into?

 

Thanks for the help.

Tibor Kalman Za...
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The Throttle transmitter cable - if too long - can collect interfering signals, for example from a strong magnetic field generated by the engine power lines. Try rearranging the throttle cable remotely.

 

Tibor Kalman Za...
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- Of course I think he uses a wired throttle on an e-bike .

I noticed a similar error on the e-scooter The rearrangement of the cables is sagging. 
Also check if the second analog input is activated. If so and there is no device on it, the "floating" outlet can cause similar symptoms. Cancel unused ports in the software. 
Eg Throttle mod: only current 
If, for example, analog port 2 is not used, no power and 2nd port brake set