Improved calculation of the slot leakage inductance of different slot shapes

The slot leakage inductance calculation is an important element of the electric machine's design. The empirical definitions are described in the literature and widely used until today. The crucial parameter is the slot permeance factor which defines the influence of slot dimensions on the leakage inductance. The traditional approach to the slot leakage inductance calculation is used in this paper, but improved flux line length and active slot area calculation are presented. The main objective of the paper is the definition of relatively simple relation to the calculation of the slot permeance factor and comparison with the finite element calculation and literature-based equations. Therefore, an overview of different slot types is presented in this paper, and obtained results are in general more reliable than literature-related relations based on the finite element validation.