Magnetically suspended flywheel in gimbal mount - Test bench design and experimental validation

Abstract

This article deals with the design of a test bench and its dynamic testing. The test bench is composed of a rotor levitated by radial active magnetic bearings and axially by a permanent magnet bearing. The rotor housing is mounted in a passive gimbal and the foundation can translate and rotate to emulate a vehicle accelerating, manoeuvring, and subject to outer perturbations such as waves. The work is motivated by a lack of publically available experimental designs and experimental data for magnetically suspended flywheels on moving foundations. The article will describe the test rig design and subcomponents, present experimental results, and afterwards the test rig will be used to experimentally validate a mathematical model governing the dynamics of the system. It is found that the model successfully captures the dynamics of rotor and housing both in a gimballed and non-gimballed flywheel energy storage system when subject to accelerations of the foundation. The simulated maximum housing accelerations are found to deviate 2% from the experiments while the maximum rotor displacements are found to deviate 37%, but only for rotor displacements larger than 100 μm where the linear approximation to the magnetic forces is no longer accurate.