Development of high-frequency "airgap" windings for high-power density electrical machines

This thesis proposes the development of high-frequency airgap windings for a 1 MW permanent magnet electric machine designed for aerospace applications. A centerpiece of the design is focused on increasing the power density of the machine to 8 hp/lb, a factor of two greater than the state-of-the-art electric machines, while maintaining 96% efficiency. In essence this design specification demands increasing the electrical loading per lowest weight, which can be achieved by employing high-frequency armature currents together with a high pole count. This work will aim to design and implement an armature winding design made out of Litz wire that minimizes the extent of increased AC losses due to higher operating frequencies while simultaneously remaining a manufacturable solution. The approach will be based on identifying a numerical model that aids in selecting a specific conductor topology that minimizes copper losses, while a more refined finite element model will be used to verify these results. To verify the methods used to compute losses, the results of a caliometric experiment will be presented to validate the design approach. Ultimately, a manufacturing process will be demonstrated to conclude the development phase of the winding by presenting several hardware trials that implement the proposed conductor topology that resulted from the previous analysis