INFLUENCE OF SLOTS AND ROTOR POLES COMBINATIONS ON NOISE AND VIBRATIONS OF MAGNETIC ORIGINS IN `U'-CORE FLUX-SWITCHING PERMANENT MAGNET MACHINES

This paper deals with the computation of vibrations and noise of electromagnetic origin for 'U'-shaped stator core flux switching permanent magnet (FSPM) machines. The investigation concerns a family of FSPM stator/rotor configurations with 12 slots and 10, 11, 13, and 14 rotor poles. More precisely, the study focuses on the influence of different number of rotor poles on the sound power level of U-core FSPM machines. Electromagnetic forces acting on the stator frame inner surface are calculated with the Maxwell stress tensor thanks to 2-D finite element (FE) simulations. The local magnetic force density serves then as a boundary condition to the 3-D finite element vibrational simulations of the whole stator frame with housing. Finally, obtained displacements help the authors to conduct the acoustic computations using a dedicated 3-D FE analysis model. The obtained vibro-acoustic spectra help electric machines designers to make appropriate choice of stator/rotor pole combination with respect to specifications at early stages of the design process.