Magnetic permeance of doubly‐salient airgap geometry with finite slot depth and tapered teeth

Abstract

Method of unaligned permeance determination for a doubly‐salient rectilinear airgap with infinite slot depth is used in order to cover a wider range of gap geometry. The results are arranged in a more convenient form than is available in the literature. A set of new correction factor curves for finite slot depth and taper are then obtained. These data can directly give the unaligned permeance of a rectilinear slotted geometry for given airgap proportions (t/λ and λ/g, where λ is the tooth pitch, t is the tooth width and g is the airgap length). A wide and useful range of airgap proportions are covered, the aim having been to encompass all geometries likely to be of practical importance.

A new methodology to calculate Carter factor using genetic algorithms

“…Figure 3 illustrates the relationship between the variables d, S c and s [2]. The value of s is used to derive Carter's factor k c , which is defined by (3).…”

“…In an equivalent manner, this means an increase in the effective length of the airgap [2]. For this reason, in the design process of electrical machines, the average induction of the airgap should be corrected to consider the effect of the slots [3]. F. W. Carter was the first to study this effect using conformal transformation.…”