Effect of slot depth on the permeance of aligned teeth in a doubly-salientrectilinear toothed structure

Effect of slot depth on the evaluation of permeance in the aligned position for identically slotted rectilinear tooth geometry can be carried out usin g conformal transformations. Consequent increase of permeance is related to the airgap proportion ratios; tooth-width to tooth-pitch, t/lambda; tooth- pitch to airgap dimension, lambda/g; and slot-depth to slot-d/s; through tw o intermediate parameters. Efficient search routine is used to find a suita ble combination of these two parameters corresponding to given proportions of tooth and slot. For lambda/g larger than 80 and d/s between 0.3 and 1, t he effect of slot depth is negligible, but for lambda/g equal to or less th an 80 a family of permeance correction factor curves is obtained which may be wed to correct for finite slot depth in permeance calculations based on infinitely deep slots. This effect is important in stepping and switched re luctance motors, particularly those with multiple teeth per stator pole.