Rare-earth magnet free flux-switching generator for wind turbines in micro-grids: A review

In traditional electricity generation plants, large powerful synchronous, induction, and direct current generators were used. With the proliferation of microgrids focused on electricity generation from renewable energy sources in today's power grids, studies have been conducted on different types of generators. Instead of the traditional generator architecture, generators with brushless structures, particularly those utilizing magnets for excitation, have found broad applications. Flux-switching generators (FSGs) are innovative types owing to their robust structure, active stator design, and high power density capabilities. However, designs have typically relied on rare-earth element magnets. Rare-earth magnets possess negative characteristics such as price uncertainty, the potential risk of scarcity in the future, and limited geographical production, leading to research on FSGs that do not depend on rare-earth magnets. This study comprehensively examines FSGs that do not use rare-earth element magnets. The study delves into the usage areas, operational mechanisms, structural diversities, and counterparts in the literature of these generators.