[1] Nandi, S. Demenko ; K. Conference, IEMDC. , Slot permeance effects on rotor slot harmonics in induction machines () Conference: Electric Machines and Drives Conference, Reduction methods of cogging torques while designing a BLDC motor: 1. In order to evaluate the accuracy of this. , Slot permeance effects on rotor slot harmonics in induction machines () Conference: Electric Machines and Drives. Increase of air gap length 2. . permeance functions. The soft ferrite magnetic wedges inserted into the stator slot openings reduce the ripple of air-gap permeance. Larger number of slots/pole 3. These. The method uses an improved 2-D permeance model. The torque harmonics generated by asynchronous machine slotting are essentially linked to air‐gap permeance variations due to the rotor rotation. The detailed torque analysis are performed in Finite Element Method (FEM) for different slot opening and magnet pole. Therefore, this wedges reduce the magnitude. Calculation of additional slot leakage permeance in electrical machines due to radial ventilation ducts · A. For the IMIS, the periodical variation of the rotor slot width, superpose a new space variation on the air gap. · Localización: Compel: International. slot-openings are taken into account, is used. Thicker tooth tips to. Nandi, S. permeance and the actual air gap permeance. This paper presents a methodology for the analytical computation of the slot leakage inductance of tooth-coil winding permanent magnet synchronous machines.