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Foc Mode: high revs causing unusual behaviour

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Michael Schäfer
Last seen: 4 years 8 months ago
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Joined: 2017-05-24 12:14
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Foc Mode: high revs causing unusual behaviour


the wiring of the regulator went well so I did a test drive with my scooter yesterday.

With load the motor spins up nicely most of the time and torques it's way to the desired speed.

When I reach top speed the motor starts rumbling and stuttering and i have to start from zero again... what can be the cause for that?

Do I have to shield the cables to avoid interferences maybe?


One other thing: when cranking up the throttle too fast the vesc just stops... Probably it hits the max levels of ampere for motor or battery. Can this behaviour be programmed to be linear? Simply keep the desired max and not shutting off?


Thanks again for your input



Roger Wolff
Last seen: 1 year 11 months ago
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Joined: 2017-05-24 12:27
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I have the impression that your parameters are "slightly off". I'm guessing you had them detected. Maybe you can try to detect them again. Or, considering that R and L are often very reliably detected, lambda may be off by a bit. Try a bit lower or higher. 


If your controller suddenly shuts off, it probably had a "fault". When it happens, go home and without turning off the controller, connect it to the computer and type "faults" in the terminal. You're probably seeing overcurrent faults. Either you have the "max motor current" set too high compared to the "absolute max" or... same as above: some parameter is not correctly set. 


josh's picture
Last seen: 2 years 5 months ago
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I had something like this with 4.12 HW. I recall adjusting the observer gain by a factor of two or cutting it in half. That fixed the issue for me, but I would wait for Vedder to give a response. Perhaps post a video of the effect.


Last seen: 1 week 5 days ago
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Maybe you should try to do the detection without the drive train being attached. You should also detect the motor, using the voltage you finally use. This is the cleanest way to detect your motor. Frank
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Which motor, battery voltage and settings are you using? The more details you can provide the easier it is to help.
Last seen: 8 months 1 day ago
Joined: 2022-04-29 13:36
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Hi everyone! Run in to the same issue, under the high load and high rmp the motor start making weird sound and shuts down, no fault messages are displayed. 

Some logs screenshots below.


Screenshot 2022-10-11 at 23.08.23.png


electricfox's picture
Last seen: 4 hours 57 min ago
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Joined: 2019-01-01 17:11
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From what I see by the limited information you give you can try reducing "Duty Cycle Current Limit Start" to 90% for example.

Also Maximum duty Cycle should be set at 95%, not higher. Maybe you can provide more info in a new Thread providing more information about motor, setup, etc.