RPM calculation from eangvel

(Okholm) #1

I’m a little confused about the meaning of electric angular velocity (eangvel), electric frequency and RPM.

I would expect the relationship between eangvel and RPM to be:

RPM = eangvel / (2 * pi) / N_poles * 60.

In our testsystem (Xyxa) the eangvel_min is set to 400 rad/sec, the number of poles is 14. Using the above equation I. would expect the minium RPM should be 272.8 rev/min, yet the minium RPM seems to be twice that: 545.6 rev/min. The electric frequency is however as I would expect 400/(2*pi) = 63.66.

Based on the trust I have seen with this setup then I believe the mechanical RPM numbers are correct.

Do you know where this factor 2 error comes from?