Calculation Method of d-Axis Inductance Considering Magnetic Saturation and Cross Coupling Effects Under Load Conditions

In determining the characteristics of motors with salient polarity, the
$d$
- and q-axis inductances are important. These parameters are also critical for accurate equivalent circuit analysis. Conventional inductance calculation methods, which typically use constant no load flux linkage values induced by permanent magnets, often result in discontinuities in the d-axis inductance at current phase angles near 90 degrees, compromising the analysis precision. This paper introduces a novel, continuous d-axis inductance calculation method that accounts for magnetic saturation and cross coupling effects, enhancing the accuracy of such analyses. Furthermore, it includes a comparative study of the
$d$
- and q-axis inductance values and the magnetic flux of permanent magnets.