Dynamic characteristics and experiment analysis of a single phase permanent magnet linear generator for wave energy conversion

A novel permanent magnet single phase linear generator (PMSPLG) is proposed for direct-drive wave energy conversion. The proposed motor has advantage of simple primary structure. Firstly, the structure and operation principle of the PMSPLG are introduced, and the air-gap field of the generator with Halbach arrays are analyzed. Secondly, based on the rotating electrical machine characteristics, the co-energy method is implemented to derive the cogging force equation. And the 2-D finite element method (FEM) is implemented to investigate the cogging force and the optimized structure of slot pitch and pole pitch is obtained. Additionally, the no-load performance of the generator is investigated at the constant speed and sine variation speed respectively. Lastly, an experimental prototype is used to test the characteristics of the proposed PMSPLG. The analysis and simulation results are validated by the ones of experiment. Due to theoretical analysis results of prototype concordant with the finite-element analysis results, the proposed model and analytical method are correct and effective. This kind of PMSPLG has wide application in the field of wave energy conversion.