The correct analytical expression for the phase inductance of salient pole machines

For the electrical machines with salient pole rotor topology, due to the rotor saliency, the self- and mutual inductance vary sinusoidally with the rotor position. In many literatures analogous to the non-salient pole machines often it is assumed that also for salient pole machines the phase inductance is a function of rotor position, since the self inductance of this type of machines depends on the rotor position. The aim of this paper was to investigate further the performances of this parameter. Deriving a correct formula for the total phase inductance for this type of electric machines shows that this parameter is constant with rotor position, and doesn´t vary as is assumed in many literatures. The new expression for the phase inductance is validated by comparing with finite element method.