Improved Magnetic Modelling of EMS Maglev Levitators

The paper presents an improved model of the magnetic circuit of two kinds of EMS Maglev levitators (one with coils only and the other one of the hybrid kind, with coils and permanent magnets): this model allows to obtain sensible enhancements both in evaluating the operating quantities, and in the levitation control. The introduced improvements concern the evaluation of the air-gap quantities (fluxes and forces) and the es-timation of the leakage parameters (coil and permanent magnet leakage fluxes): - the evaluation of the air-gap quantities is performed by means of mathematical expressions, deduced by the analytical investigation of the fields (method of the conformal transformations, in particular the Schwartz and Christoffel transformation); the results of these mathematical expressions have been validated by FEM analyses; - the evaluation of the leakage parameters is operated on the basis of the actual field distribution, obtained by FEM analyses. The obtained improvements are shown: - by evaluating fluxes and forces in different operating conditions, and comparing these values with the re-sults obtained by the classical modelling; - by showing some levitation tests measurements, discussing the enhancements obtained by the use of the improved modelling.