I found this piece of text in the getting started guide:
•The current limit: odrv0.axis0.motor.config.current_lim [A]. The default current limit, for safety reasons, is set to 10A. This is quite weak, and good for making sure the drive is stable. Once you have tuned the drive, you can increase this to 75A to get some performance. Note that above 75A, you must change the current amplifier gains. You do this by requesting a different current range. i.e. for 90A on M0: ‘odrv0.axis0.motor.config.requested_current_range = 90’ [A], then save the configeration and reboot as the gains are written out to the DRV (MOSFET driver) only during startup. ◦Note: The motor current and the current drawn from the power supply is not the same in general. You should not look at the power supply current to see what is going on with the motor current. Ok so tell me how it actually works then…
The current in the motor is only connected to the current in the power supply sometimes and other times it just cycles out of one phase and back in the other. This is what the modulation magnitude is (sometimes people call this duty cycle, but that’s a bit confusing because we use SVM not straight PWM). When the modulation magnitude is 0, the average voltage seen across the motor phases is 0, and the motor current is never connected to the power supply. When the magnitude is 100%, it is always connected, and at 50% it’s connected half the time, and cycled in just the motor half the time.
The largest effect on modulation magnitude is speed. There are other smaller factors, but in general: if the motor is still it’s not unreasonable to have 50A in the motor from 5A on the power supply. When the motor is spinning close to top speed, the power supply current and the motor current will be somewhat close to each other.
My question is, when I set the maximum current, with the command,
Is this the maximum current to the motor or is this the maximum current that gets drawn from the power supply?
Also, Is there a way to know what the current to the motor is by knowing the current to the Odrive controller (input current)?