Design and Evaluation of a Permanent Magnet Generator for Wave Power Applications

Licentiate thesis, 2015

In this thesis, the performance of a wave energy converter (WEC) consisting of a single point absorber wave device coupled with a radial flux permanent magnet generator is investigated. The available wave power and the energy potential are studied for a specified wave climate and the electric power output is determined through an analytical buoy movement simulation. Based on the ideal buoy size determined for the selected wave climate and the resulting generator power, different rotor designs of a suitable permanent magnet machine are investigated. By implementing different generator designs into the WEC, the efficiency maps of the WEC generators are investigated. Furthermore, for a better understanding of the economical feasibility of the system, life cycle cost (LCC) analysis is performed on the different generator designs. The inset design is further improved by replacing the initial materials with better performance materials. Despite the cost increase due to using higher performance materials, an important finding was that the capitalised losses account for the majority of the LCC. Therefore, the improved magnet and iron materials are well motivated, since such a design results in a lower LCC.