I. Introduction
High-Performance rotating machines commonly use composite rotor materials to maximize energy density. Since the mechanical strength of composite materials typically degrades significantly with increasing temperature, it is essential to limit anticipated rotor temperature excursions. This has led to the use of evacuated enclosures to reduce rotor surface heating due to air friction. Accordingly, magnetic bearings are finding increased use in high speed machines because of lower losses and the ability to operate in vacuum environments. However, losses in magnetic bearing systems can vary widely, depending on factors such as bearing actuator design and bearing system control implementation [1]. Inside-out configuration flywheel alternator.