Thrust Ripple Suppression of Long Primary Double Sided Linear Induction Motor with Wedge Secondary

Based on the distribution of air gap flux density and current density of secondary along the longitudinal direction of long primary double sided linear induction machine (LPDLIM) with plates secondary, a wedge secondary for suppressing the thrust ripple is studied. The wedge structure of the secondary exit end changes the distribution of air gap flux density and secondary current density, thus reducing the thrust ripple of the motor. The influence of wedge size on thrust and force ripple performance is researched. The calculation results indicate that the wedge secondary can effectively reduce the thrust ripple due to longitudinal end effect and improve the thrust density of the LPDLIM, although the output thrust is reduced. The comparison and analysis with the calculation results of the plate and wedge secondary DLIM show that the wedge secondary can effectively suppress the force ripple of LPDLIM with any length secondary.