Full Scale Applications of Permanent Magnet Electromagnetic Energy Converters From Nd2Fe14B to Ferrite

University dissertation from Uppsala : Acta Universitatis Upsaliensis

Abstract: This thesis presents research regarding a full scale linear ferrite permanent magnet generator, installed in a wave energy conversion system. The ferrite based magnetic circuit, supplementing the previous utilized Nd2Fe14B-magnet design, is designed with an electromagnetic numerical simulation tool, where the model is derived from Maxwell’s equations. The full scale design is, known to the author, the first developed linear ferrite based machine. The material change in the magnetic circuit required different mechanical solutions of the generator. The fundamental, primary theory and reasoning behind the new mechanical design is here presented, where sustainability, economy and production have been in focus and affected the final design. Two versions of the generator have been assembled and deployed at the projects experimental site on the Swedish west coast, and three more are under construction, planned to be installed during the autumn of 2013.  Further, the thesis presents an electric conversion circuit based on the electric resonance phenomena. Full scale experimental results present a successfully achieved electric resonance between the linear wave energy generator and external circuit.Finally, research regarding a two pole permanent magnet motor for an electrical vehicle is presented. Detailed analytical and numerical calculations are utilized to investigate the losses in the machine over a wide frequency interval. The results indicate the possibility of an increased efficiency of electrical motors in electrical vehicle system and argue for elimination of the gearbox. The system total efficiency and mechanical stability can thereby be increased.   The work concerning the wave energy converter is a part of a larger project, the Lysekil Wave Power Project, developed by a research group at Uppsala University, whereas the work concerning the electric motor so far has been carried out as an individual project. However, a future goal is to integrate the research on the electric motor for electric vehicles with ongoing research regarding a flywheel based electric driveline for an All Electric Propulsion System.