Pole Pitch Optimization of a Flux Switching Permanent Magnet Linear Machine for Small Scale Wave Energy Harvesting

In this paper, the optimal translator configuration of a small Flux Switching Permanent Magnet Linear Machine (FSPMLM) is investigated for the power take-off in a small scale wave energy converter used to power a drifting sensor platform. The compact size of the armature leads to special design requirements, which are addressed by theoretical consideration of the optimal pole arrangement on the translator. Various pole slot configurations are discussed and the advantages of a pole plurality for a compact design are presented. A shift to the pole pitch is introduced to reduce cogging forces while providing sufficient voltage output. After the creation of a universal description, a FEM simulation is used to validate the theory with an ideal model. Finally, a prototype implementation is used to investigate practical problems and derive concrete design proposals for a small-scale FSPMLM. As a result, a simple design is presented that allows a primary armature of less than 7 cm length and 4cm diameter.