Comparison of Electromagnetic and Dynamic Characteristics of Linear Oscillating Actuators With Rare-Earth and Ferrite Magnets

Linear oscillating actuators (LOAs) are electric machines that perform linear reciprocating motion. Generally, single-phase short-stroke LOAs that employ rare-earth permanent magnets (PMs) are used. However, they are expensive and are affected by unstable material supply. Therefore, we proposed a ferrite PM LOA to replace rare-earth PM LOAs. In this paper, the structure and operation principle of a conventional rare-earth PM LOA and the ferrite PM LOA are examined. In addition, for the purpose comparison, the models of both LOAs are designed to generate the same back electromotive force and electromagnetic stroke region at equal volumes. Inductance values are analyzed, and load analysis is performed considering a mechanical system. Tuning capacitors are used to compensate for the high inductance of the ferrite PM LOA. In addition, it is confirmed that the performances of the ferrite PM LOA and rare-earth PM LOA are similar.