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Current sign varies between motors

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vadimz
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Last seen: 1 year 11 hours ago
Joined: 2018-08-29 17:30
Posts: 17
Current sign varies between motors

Observing a very strange behavior running VESC6 with small motors (TMotor MN4010, Faulhaber BX4)

When running idle without load, the motors showing different current signs - positive on MN4010, negative on BX4. Negative current and negative power implies generator mode, which is definitely not the case here - motor is running idle at constant RPM without any external torque source.

 

So any ideas what might be going on here ?

 

This happens both with encoder and sensorless commutation - checked for suspected phase errors. Phase current sensors (shunts and amplifiers) also checked for accuracy.

Also seeing the same behavior on HW4.10 with latest FW5.03.

And when the load is applied, the current in both motors goes up, crossing zero in the case of BX4.

 

MN4010_vesc.png

FHBX4_vesc.jpg