Modeling and Analysis of a Tubular Oscillating Permanent-Magnet Actuator

An improved analytical model is developed to predict the electromagnetic performance of a single-phase tubular oscillating permanent-magnet actuator. The analytically predicted thrust force, flux linkage, and back-electromotive-force coefficient of an actuator equipped with a quasi-Halbach magnetized mover are compared with the results deduced from finite-element analyses and measurements. In addition, the influence of mover back iron is investigated, the loss of the prototype actuator is estimated, and the optimal design parameters, viz., the optimum ratio of the axial lengths of the radially and axially magnetized ring magnets and the optimum mover-diameter-to-stator-diameter split ratio, are identified.