I know this topic has been brought up here a couple of times but I am yet to see a permanent solution to the issue. I am running my custom hardware and everything works great with this just one issue present.
Under heavy load (~8-10kw), once the eRPM approaches the transition threshold, there is a some momentary loss of torque and rough switchover. After that, the observer tracks the motor very well and pulls good. The issue is most felt under acceleration, not so much during regen braking. Also, it seems to affect more low kv motors such as hub drives. Any suggestions how to fix this? Thank you.
I had this problem on my surron motor, too. The only solution that helped me was doubling the Current KP in the FOC -> General tab. Hopefully it helps in your case too. Oliver
Link to forum post: VESC help offered for private persons and companies
Website: www.electricfox.de
Thanks, Oliver. I am going to give it a shot and post the results back here.
NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)
Honestly I have just switched over to using sensorless all the time, it seems to actually work much better than I initially realised.
The biggest problem is the switchover erpm from openloop to sensorless. As I found with big motors, you actually can basically set it to 0 and always have the observer tracking the motor which gives insane performance.
That's very cool! Thank you for the tip! I'll give it a shot with my big motors and 15kw in. I did notice that in VESC code sensorless works way better than with other controllers but it would still get lost under load starting from zero. I'll try with 0 setting. I also did try to double KPI setting and it seems like it help a bit but transitions is still noticeable.
NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)
I tried with 0 eRPM open loop setting in sensorless mode and it seems to be tracking well even under load on my inrunner motors.
However, with a large hub motor, that doesn't work as well. The motor is struggling to find the direction it needs to go to.
So, correct sensorless mode operation under load seems to be motor specific. I find that hub motors have most issues with VESC, needs a lot of tuning to get it work right.
For example, without any load in sensored mode, my hub motor would spin up to a certain point and then VESC would either faults at negative overcurrent or just silently gives up without any fault and would stop responding to the throttle until it's power cycled.
NextGen FOC High voltage 144v/34s, 30kw (https://vesc-project.com/node/1477)