Design and Analysis of a Novel Primary-Permanent-Magnet Transverse-Flux Linear Generator for Free-Piston Energy Converter

Owing to the high temperature and closed environment in the free-piston energy converter, the secondary permanent magnet of the machine is easily demagnetized. Therefore, a tubular primary-permanent-magnet transverse-flux linear generator (PPM-TFLG) with flux-reversal structure is proposed in this paper. Firstly, the basic structure and operational principle of the PPM-TFLG is presented. Then, the three-dimensional (3D) equivalent magnetic circuit model (EMCM) and finite-element model (FEM) are given to investigate electromagnetic characteristics of the PPM-TFLG. The influence of key parameters on electromagnetic thrust and thrust ripple is investigated and its electromagnetic performance is compared with other typical TFLMs. Finally, the research results confirm the feasibility of the proposed machine.