Hi, adjusting a D6374 motor in an application that requires at least 1500W to move a spindle I managed to break an odrive (non response to calibration even). Controlling the position with trapezoidal trajectory with high accelerations at mid-stroke the odrive gave error in the driver (ERROR_DRV_FAULT) and disabled the motor. After a few repetitions the M1 stopped working and when I changed it to M0 the same thing happened with high accelerations after a few tries. Has anyone experienced something similar breaking the odrive tuning a motor? I have bought a new odrive but I don’t know how to make the adjustment without this happening again, I want to get maximum acceleration without breaking another odrive.
I am looking forward to your answers or experiences. I hope it is not something normal to break an odrive for having misconfigured the motor, it does not seem very robust.
Were you using the ferrite rings?
Also, what was your brake configuration?
You need to be careful when running near the voltage limit. If you try to suddenly stop an inertial load, then a large amount of current will try to charge the DC Bus capacitors, and the ODrive has to turn on the brake resistor to try to reduce this voltage. If it hits 60V even for a millisecond then the 56V ODrive is toast.
Using the ferrites will reduce overall noise (e.g. on current shunts, DC Bus voltage measurement, etc.) and you can also improve robustness by reducing the supply voltage slightly, and reducing the brake resistor threshold voltages “overvoltage_ramp_start” and “overvoltage_ramp_end”. You could also add extra capacitance to the DC bus to slow the time constant at which the voltage rises.
No, I have not used ferrite rings, but if you think they can reduce the chance of driver failure I will order them.
The tests have been done without the brake connected, as the odrive is connected to a lithium battery so I have configured the negative current as the maximum charging current of the battery, is this correct or is it too much negative current? is it better to use the brake even if the battery allows regeneration?
Thank you very much for the quick answer, I still have a lot of things to learn.
Yes, I think that noise on the current sensors could impact overall current control bandwidth/stability, and potentially, noise on the voltage sensor could prevent shutdown when it is needed to prevent damage, so yes.
What voltage are you running at?
Supposing you have a lithium battery with a nominal voltage of 48V and a “fully charged” voltage of 56V, its internal resistance changes depending on state of charge, so if you were to give it 100A of regen at 48V, it might raise the voltage to 54V which ODrive can still handle, but if it is charged to 56V then the regen capability is almost zero - any amount of regen would cause it to go over ODrive’s voltage limit.
I’d recommend that you enable the overvoltage ramp controller, starting at whatever your maximum “charged” voltage is going to be, (say 55V), ending at 57V, and you could set the “overvoltage limit” to 56V.
It will then only turn the brake resistor on when the voltage exceeds 55V, and will be 100% on if it ever reaches 57V, but it will have shut down the gate drives by then.
That way, ODrive will never use the resistor unless it (and the battery) are close to overvoltage.