New improved estimation method for airgap self and mutual inductance in electric machines

The accurate estimation of the phase inductance is essential for proper machine design and efficient control strategy development. Within this paper two different analytical estimation methods for the airgap self inductance are compared and improved by introducing the airgap mutual inductance. Moreover, a more accurate new expression is proposed where the stator slotting is included. A validation has been carried out with FEM simulations in FLUX2D^® where the new method offers 20% more accurate results than those achieved with other methods proposed in the literature.