I. Introduction
Switched reluctance machines are inherently susceptible to noise and vibration by the nature of their torque production. There are many papers that address the noise and nodal vibrations in switched reluctance machines (SRMs), some of which are listed in [1] to [4]. However, these assume balanced windings and a centered rotor. Tavner and Penman [5] review the nodal vibrations that can occur in an electrical machine and calculate the natural vibrations in a stator core; however, they treat the stator as a thin ring with resonant frequencies which are far from those found in a real motor. There are several papers that address this in more detail when applied to a switched reluctance machine [6]–[8]. Rao [9] gives an excellent description of the processes that create vibrations and related these to the forces.