Thrust fluctuation modeling and its minimization of a double tubular Halbach permanent-magnet motor

This paper extends an analysis developed for double tubular Halbach permanent-magnet motors to account for the thrust fluctuation associated with the primary design parameters of linear motors. Established by equivalent magnetic circuit method (EMC), the air-gap magnetic field distribution, provides an accurate means of predicting the cogging force that results from end effects. Comparison shows that the analytical model and finite element analysis (FEA) result match well. The analytical model provides an effective means for evaluating the influence of mechanical design parameters on the cogging force waveform, also facilitate its minimization. The employment of slotted core with windings and choosing proper cogging design helps to improve the thrust output.