Design perspectives of a low acoustic noise switched reluctance machine

Stator vibrations due to magnetic radial force are the dominant source of acoustic noise in the switched reluctance machine (SRM). The intensity of this noise is related to stator mode frequencies, operating speed and magnetomotive force (amp-turns) of the machine. The higher the dominant mode frequencies, the lower is the noise intensity. The factors related to noise generation in the SRM are functions of machine geometry, configuration and material properties. A set of guidelines to select configuration, geometry, internal dimensions and stator pole shapes to reduce acoustic noise is presented with supporting simulations. The proposed design considerations have been applied to a 4-phase, 8/6 (1-repetition) and a 3-phase, 12/8 (2-repetition) 1.0 kW SRM with low acoustic noise requirement. The static and magneto-dynamic finite element analysis (FEA) have been made to compare the results of the two low-noise SRM designs