Analysis of an E-Core Interior Permanent Magnet Linear Oscillating Actuator

This paper presents the design, analysis and experimental validation of a single-phase tubular E-core interior permanent magnet (IPM) linear oscillating actuator (LOA). Firstly, the topology is described and its electromagnetic performance, in terms of the air-gap flux density, flux-linkage, back-emf coefficient and thrust force-displacement characteristic, is analyzed by finite element analyses. It shows that it is simple to manufacture compared to E-core SPM actuators and solves the problem of significant leakage flux in C-core actuators. In addition, the E-core IPM actuator is capable of producing reluctance force due to the salient mover structure, which enhances the spring stiffness and is conducive to the oscillation, although has no contribution to the output power. The influence of the magnet pole ratio and split ratio on the performance of the IPM LOA is investigated, and the optimal parameters have been identified with reference to the peak value and flatness of the excitation force-displacement characteristic. Finally, the predicted thrust force characteristics are validated by measurements on a prototype actuator.