Sensing of pole count function
Posted: Sat Apr 25, 2020 11:24 am
Johannes i have an idea... and that is allways risky 
I must admit i got lucky with Outlander motor at guessing the pole count was 10. I know there are a lot more strange motors out there with stranger resolvers...
Since your controler actually needs a motor pole count in relation with resolver pole count isnt there a simple way to find out what that pole count is?
Can you use a bit of old code inside your FOC and only tell the motor to spin up to known Hz in manual mode. You would not neet current sensors at all. This would really be manual mode like in the beginning.
Since Hz would be known we would then need only to measure the motor shaft speed to get RPM which we could then use to get pole cound with this equasion:
n = f (2 / p) 60
n = shaft rotation speed (rev/min, rpm)
f = frequency of electrical power supply (Hz, cycles/sec, 1/s)
p = number of poles
Of course that would have to be done with unloaded motor!
I must admit i got lucky with Outlander motor at guessing the pole count was 10. I know there are a lot more strange motors out there with stranger resolvers...
Since your controler actually needs a motor pole count in relation with resolver pole count isnt there a simple way to find out what that pole count is?
Can you use a bit of old code inside your FOC and only tell the motor to spin up to known Hz in manual mode. You would not neet current sensors at all. This would really be manual mode like in the beginning.
Since Hz would be known we would then need only to measure the motor shaft speed to get RPM which we could then use to get pole cound with this equasion:
n = f (2 / p) 60
n = shaft rotation speed (rev/min, rpm)
f = frequency of electrical power supply (Hz, cycles/sec, 1/s)
p = number of poles
Of course that would have to be done with unloaded motor!