0
\$\begingroup\$

I am struggling with the calculation of the motor flux for a RPX22-042V24 PMSM. I know back EMF, Torque constant and several other values from the datasheet. But I found different ways to calculate the flux and I am not sure if its correct to use back EMV in V/kRPM or V/RPM.

With the equation at the end of this page I get a flux of 4.15 mWb. Does this value make sense for this parameter?

\$\endgroup\$
2
  • \$\begingroup\$ I found two ways for calculating the magnetic flux of a motor, but the results are very different. Maybe someone knows why? Option 1: According to the formula in the end of this page de.mathworks.com/help/sps/ug/… flux1=Kt/N=16.6mNm/A/4pole pairs=4.15mWb with Kt = torque constant Option 2: According to the formula from the SPMSM page de.mathworks.com/help/mcb/ref/surfacemountpmsm.html flux2=(2/3)*Kt/N=(2/3)*16.6 mNm/A/4pole pairs=2.77mWb The flux's unit is in both cases correct but whats the reason for the factor2/3 \$\endgroup\$
    – hanss
    Commented Sep 19, 2023 at 10:20
  • \$\begingroup\$ This was helpful, do you have any literature where we can establish a relation between Motor speed and phase current at constant load? \$\endgroup\$
    – AK47
    Commented Apr 17 at 6:15

1 Answer 1

0
\$\begingroup\$

If anybody faces the same problem:

In my case the datasheet's values must be converted from line to line to phase values and the formula for flux1 is for a BLDC. For a PMSM the formula for flux2 = (2/3)*Kt/N=(2/3)*16.6 mNm/A/4pole pairs suits better. The other one (via back-EMF) proposed in the link can also be used with a slightly different result.

https://de.mathworks.com/help/mcb/ref/surfacemountpmsm.html

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.