a novel transverse flux permanent magnet generator for small-scale direct drive wind turbine application: design and analysis

This study focuses on a special topology of transvers flux permanent magnet generator which benefits from low pm cost due to using cheap ferrite pms. in this structure, only one pm per phase is used where leads to easy manufacturing process. in spite of the above mentioned advantages of the topology, there are some disadvantages such as unbalanced voltage, high demagnetisation risk of the pm, and high cogging torque. aiming to solve these problems while maintaining the advantages of the topology, a new structure is proposed. the stator of this structure contains two series connected coils which eliminates all the even order harmonics and balances the voltage waveform. this trick reduces the armature reaction as well as demagnetisation of the pms, significantly. additionally, the rotor teeth of the proposed structure are skewed where leads to a noticeable reduction in cogging torque. the output results of the proposed structure are compared with the original one in terms of harmonic components, cogging torque profile, and pm demagnetisation.