We're trying to get a 3 phase, 18 pole pair, <150V <5A motor going. When we try to start with evspin32f0601s1, it slowly stutters forward with a regular forward-back motion at about 10 RPM. Looks like it might be going 2 poles forward, then one pole back? I'm using bemf, resistance and inductance values provided by the manufacturer.
evspin32f0601s1 - We were planning to use this one, but can't get it to spin up at all beyond that 10 RPM halting movement
evspin32f0251s1 - spins up, but needs tuning (gets jittery and power draw spikes at a few hundred RPM, and RPM caps out pretty low)
Tested 2 motors and 2 f0601 control boards with same results, and it works on the f025 board, so pretty sure we've ruled out hardware issues with control board, motor, or wiring. I tried messing with a bunch of parameters just in case in MC Workbench, mostly with little to no effect.
The only thing I can think of that's different between the two boards is the bemf resistor divider, which has a bigger ratio for the 600V boards. I didn't think that would keep it from working at all though, since none of the documentation hinted that changing those resistors was a normal/necessary step. Also, I guess 18 pole pairs is a lot more than usual... is that going to throw off any of the default hardware or parameter setup?
If it's just the bemf measurement at low speeds that's the issue, then I think (?) all I have to do is:
- modify the divider network (e.g. replace R6+R7 so their total resistance around 1/8 the current value, and likewise with R20/1, R46/7)
- Change the divider constant in MC Workbench
- ...?
https://www.st.com/resource/en/user_manual/um2595-evspin32f0601s1-3phase-inverter-based-on-stspin32f0601-stmicroelectronics.pdf
