Shock and vibration testing of an AMB supported energy storage flywheel

Shock and vibration testing of an Active Magnetic Bearing (AMB) supported energy storage flywheel is presented. The flywheel is under development at the University of Texas-Center for Electromechanics (UT-CEM) for application in a transit bus. The flywheel is gimbal mounted to reduce the gyroscopic forces transmitted to the magnetic bearings during pitching and rolling motions of the bus. The system was placed on a hydraulic terrain simulator and driven through pitch, roll and shock motions equivalent to 150% of maximum expected bus frame values. Although the AMB control approach was originally developed specifically to ensure rotor-dynamic stability, relative rotor/housing motion was typically less than half of the backup bearing clearance under all tested conditions. Test results are presented and compared to analytical predictions for the 35 000 rpm nominal operating speed. The impact of the AMB control algorithm is discussed relative to the input forcing function.