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