Innovative 3-D Printed Coil and Cooling Designs for Weight-Sensitive Energy-Saving Electrical Machine

The performance of electrical machines is often limited by manufacturability challenges. With the emergence of additive manufacturing (AM) technology, new design solutions that were previously impossible using conventional production techniques are becoming applicable. This work addresses novel design possibilities in the manufacturing of machine windings. Using AM technology, a series of 3-D-printed coils are designed and prototyped for high-power density electrical machines. The power losses of these new coils are measured and compared with the conventional windings. The 3-D coil designs combine higher performance and easier manufacturability. Moreover, a new thermal management concept is introduced using novel AM-shaped profile coils with direct cooling channels featuring ridged surfaces. The cooling tubes have small grooves or ridges on their surface that create a series of indents, which help increase their surface area and improve their cooling efficiency. The dimensions of the proposed heat exchanger are optimized to achieve a good balance between the current density and the cooling performance. The investigation includes identifying suitable materials for both the coils and the heat exchanger that can enhance the electromagnetic and thermal performance of the electrical machine while achieving a lightweight structure. Finally, the experimental results demonstrate the effectiveness of the proposed approach in achieving significant improvements in performance and weight reduction. Compared to the conventional copper coils, the new design has twice the current carrying capacity with only 53% weight.