Design, simulation and optimization of transverse flux disk generator for wind turbines

Transverse flux machines (TFM); along with the new topology recommendations made, it has become an important option in low speed-high torque applications such as electrical vehicles and direct drive wind turbines. High torque density can be easily obtained with TFMs but the biggest drawbacks are low power factors and high cogging torque. However, the new models developed have reduced the leakage in recent years. Significant improvements have been made by increasing the use of magnets. TFMs can compete with radial and axial flux machines. With this study it is aimed to introduce the models examined in the literature related with TFMs which have not been discussed academically in our country and to create an awareness by explaining their advantages and disadvantages. TFMs are classified according to their structure (single-sided and double-sided) and magnet position (surface-mounted, embedded). In conventional TFMs of linear and circular (radial, axial) type, predominantly disc type or disc type model can be developed. ANSYS Maxwell program was used for dimension analysis for 250 W machine design. Machines with inner radius of 70 mm, 65 mm, 60 mm, 55 mm and 50 mm were examined. As a result of back emf analysis, the induced voltages were close to each other. Cogging torque analysis was performed to determine the exact size of the machine and when the rotor had an internal radius of 55 mm, the cogging torque was lower. As a result of the analysis, it was decided that the inner radius of the rotor should be 55 mm. In this thesis, a novel three phase transverse flux disc generator model is introduced. The working principle of the model and the electrical circuit model are explained. Using the finite element method, the back-emf force change was obtained according to the rotor inner radius of the proposed generator model. As another electromagnetic analysis, cogging torque was examined. The cogging torque one of the general drawbacks of transverse flux machines, it was reduced from 6 Nm to 0,38 Nm. To achive this a three phase disc model was used and 0,5° magnet skewing was applied to each disc structure.