Electromagnetic Vibration Analysis and Measurements of Double-Sided Axial-Flux Permanent Magnet Generator With Slotless Stator

This paper examines the effects of the electromagnetic source on the vibration of a double-sided axial permanent magnet generator with a slotless stator depending on the ac and dc-load conditions. The slotless machine has no cogging torque. Most of the vibration originates from the torque ripple and axial force distributions, which result from the current load conditions. The 3-D finite element analysis results are compared with voltage, current, and torque measurements. The order tracking analysis of the vibration test data clearly demonstrates the dependence of the critical harmonics on the load conditions.