Flux-linkage model including cross-saturation for a bearingless synchronous reluctance motor

This paper deals with magnetic modeling of a bearingless synchronous reluctance motor. The motor under consideration includes two separate sets of three-phase windings, one for torque production and the other one for radial-force production. This paper demonstrates by means of finite-element analysis, that it is unrealistic to assume the two three-phase windings to be decoupled from one another. Instead, it is shown that especially the torque-producing winding currents affect to the operation of the radial-force producing winding. A simple nine-parameter explicit-function based magnetic model is proposed to model the cross-saturation between the two winding sets. The effectiveness of the proposed magnetic model is demonstrated by applying it together with model-based torque and radial-force controllers.