Shock Analysis for a Homopolar, Permanent Magnet Bias Magnetic Bearing System

A transient, nonlinear analysis was developed and used to study the effect of shock machine testing on a gas turbine simulator supported by homopolar, permanent magnet bias magnetic bearings. The magnetic bearing nonlinearities modeled included saturation effects, clearance effects, and integrator and current limits. Free vertical travel of the shock machine anvil table supporting the simulator was also modeled. The magnetic bearing model was coupled to characteristic matrix based models of the rotor and support system and integrated to produce a time simulation of system performance. The results indicate saturation of the magnetic bearing for brief periods following impacts significant enough to exceed design load capacity, followed by recovery to stable operation in less than a second. The analysis was used to evaluate sizing for the magnetic bearing and backup bearing systems and to evaluate the control system strategy.Copyright © 1997 by ASME