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VESC 75/300 ABS_OVER_CURRENT

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tecnico.solarboat
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VESC 75/300 ABS_OVER_CURRENT

Hi!

We trying to make a motor dyno with two motors and two VESCs 75/300 but the VESC that is controlling the motor is giving ABS_OVER_CURRENT error when a certain torque is reached. The problem is that from the logged data the current values are no where near the maximum current that we have set. 

Attached is the logged data, the MC configuration and the APP configurations.

VESC_Log.zip

On the VESC that is controlling the motor that is working as a generator we are progressively increasing the Brake current so that the applied torque is progressivelly increasing.

TechAUmNu
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Looks like your motor is saturating. What motor are you using?

tecnico.solarboat
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We are using a Lehner 7025 with 14 windings. Datasheet  from the manufacture below. Keep in mind that the current mentioned in the datasheet is battery current. We are getting ABS_OVER_CURRENT at 5 Nm 800 RPMs and roughly 700 W battery power. We should be able to get around 10 Nm and a peak power of 5 kW.

7025-14-44V.pdf

Thank you very much!

tecnico.solarboat
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Which VESC Tool settings limit the motor current? Maybe we are missing something in our configuration.

TechAUmNu
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The datasheet for the motor you linked only goes to 110A. Your logs show it goes crazy about 150-200A, reduce the load on the motor so you can reach a higher duty cycle and you will get a higher power output.
You can't just set the motor current at 400A and expect it to get to 400A. So to stop the ABS_OVER_CURRENT, you need to set the Motor Current Max setting to something more sensible for your motor. From your logs I would set it about 170A.

tecnico.solarboat
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But the currents on the datasheet are battery current  not motor current, according to the manufacturer.

TechAUmNu
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In the test data from the datasheet, they are running at full speed so 100% duty cycle. That means the battery current and motor current are the same. So in this case 110A would be the max motor current they tested at. The chart also shows that the max torque tested as 500Ncm which is 5Nm.

Gerhard
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The RPM-tables of Lehner motors finish at the best efficiency point and is indeed showing battery currents. For sure it is possible to load the motor above 110A. You have to test the maximum current by your own while carefully checking the motor temperatur. I would expect you can load the motor up to 170 A (best efficiency point + 60% overload).