Experimental Vibration Studies on a Solid-Rotor Switched Reluctance Machine

Vibration characteristics of a solid-rotor switched reluctance machine (SRM) are measured in the static as well as dynamic conditions. A series of impulse hammer-based static measurements are carried out on the assembled machine. The impulse hammer tests identify the main resonant frequencies of the rotor assembly, bearing housing and enclosure. For the dynamic vibration tests, the SRM is run at different speeds using single-pulse control and current control. The measured currents are utilized to obtain the electromagnetic radial force on the stator through finite element analysis. The frequency components of the estimated radial force are observed in the vibration spectrum measured in the dynamic tests. The dynamic vibration spectrum also include the resonant frequencies of the SRM subassemblies. The natural frequencies of the rotor assembly are found to influence the vibration spectrum significantly. Harmonics of speed are the other significant components in the measured vibration spectrum at any given speed; the magnitudes of these components increase with rotor speed.