Electrical machine inductances also can be evaluated
with all the windings excited by the energy perturbation
or current perturbation method [6]-[9]. The method solves
multiwinding inductances with one matrix equation, and
provides detailed inductance variations as a function of
rotor position, leading to an accurate determination of
machine inductances. However, the method requires FE
field solutions under current perturbations for each machine
winding. It therefore demands more effort and computing
time in solving multiple field solutions, especially
for machine designs in which geometric variations must
be examined.