Reduction of cogging force in linear generators for wave energy harvesting

Abstract

Due to huge energy potential of sea waves, many technologies have been proposed in the last few years. Some concepts have been developed and sometimes also tested in the open sea. Some prototypes use linear generators to directly convert the vertical motion of buoys into electrical energy. This solution minimizes the numbers of energy conversion steps, increasing the energy efficiency. At the same time, the limited numbers of components could also increase the reliability of the wave energy converter. For this reason, the development of linear generators is considered with great interest. This paper investigated the cogging force, a magnetic force due to the interaction between the magnets and the iron stator. To limit the cogging force, a modified shape of the stator is investigated. Simulations on a specific FEM software are performed, obtaining interesting results.