Effect of Slot Number on Performances of a Single-Side Axial-Flux Permanent Magnet Generator

The use of permanent magnet generators (PMGs) for the application in the wind power generation is increasingly being used. Commonly NdFeB permanent magnets are applied in order to get the higher flux density in the airgap because of high coercivity and remanence. Good and bad performances of the PMGs are affected not only by the permanent magnets but also by the number of slots in the stator core and the permanent magnet configuration on the rotor. Four different slot numbers of 6 slots, 9 slots, 12 slots and 15 slots combined with three different configurations of 8 permanent magnet poles in each configuration are modeled and analyzed by the assist of the Ansys Maxwell software to know their effect on the performances of a single-side axial flux permanent magnet generator. The results show that the surface permanent magnet configuration provides the highest internal generated voltage, output power and efficiency followed by inset rotor with surface permanent magnet configuration and embedded tangential permanent magnet configuration. The results also show that the generator with 12 slots combined with the 8 poles surface permanent magnet configuration gives the highest efficiency of 93.479% compared to 6 slots, 9 slots and 15 slots.