Reducing torque ripples in permanent magnet synchronous motor

Permanent magnet synchronous motors (PMSMs) are exceptionally promising thanks to their many advantages compared with other types of electrical machines. Indeed, PMSMs are characterized by their important torque density, light weight, high air gap flux density, high acceleration, high efficiency and strong power-to-weight ratio. A surface-mounted PMSM (SPMSM) is used in this work. The SPMSM is built using a 2D finite element method (FEM). Cogging torque, torque ripples and back-EMF are examined during the design process in order to obtain sinusoidal back-EMF and to minimise torque ripples which are one of the major problems with PMSMs. Two procedures are used to reduce the cogging torque of SPMSM: the effect of slot opening and the influence of skewing the stator laminations. Cogging torque factor tc and the torque ripples factor tr have been calculated to compare the two configurations (open slots and closed slots). Then, the configuration with closed slots is utilised with skewing the stator laminations for different angle 0°, 10° and 15°