ABSTRACT
Attraction levitation systems (ALS) use attraction current–controlled electromagnetic force to control the airgap between fix and mobile mild magnetic cores. Applications for ALS range from magnetic bearings and vibrating tables to magnetically levitated vehicles (MAGLEVs). For MAGLEVs, the primary is placed on board and contains permanent magnet (PM)-less or PM-assisted dc controlled current electromagnets and a solid mild iron fix secondary. This chapter focuses on ALS for MAGLEVs, as active magnetic bearing is a field of R&D in itself that deserves a separate treatment. A MAGLEV involves multiple motions. But using secondary and tertiary mechanical suspension systems between the electromagnets and the bogie and between the latter and the passenger cabin, enough decoupling is obtained to allow for separate robust control of each electromagnet. The control system performance for MAGLEVs is related to: electromagnet-guideway collision avoidance; average control power; and ride comfort.
