Investigation of the eccentricity effect on the quasi-Halbach magnetized PM T-LSM features

The paper is devoted to the investigation of the effect of the mover eccentricity on the features of tubular-linear synchronous machines (T-LSMs) with quasi-Halbach magnetized PMs. The investigation is initiated by the analytical prediction of air gap flux density distribution considering the two cases (i) coaxial mover with respect to the stator and (ii) the presence of an eccentricity of the mover with respect to the stator. Then, the radial magnetic forces applied to the mover are formulated and their variation with respect to the eccentricity is investigated. The study is achieved by the formulation of the synchronising component of the electromagnetic force in terms of eccentricity. 3D finite element analysis is carried out and enables the validation of the analytically-predicted results.