Future Electrical Machine Materials: Possibilities, Opportunities and Challenges

This paper studies the opportunities and challenges of employing new materials as replacements for traditional materials in electric machines. Employing new materials such as Carbon NanoTubes (CNT), and Soft Magnetic Composites (SMCs) in electrical machines has demonstrated a promising future in the electrical machine industry. High-speed-frequency permanent magnet (HSFPM) motors manufactured based on traditional material (laminated steel cores and copper windings) can suffer high iron losses and ac losses in winding. Replacing standard laminated steel (0.5 mm thickness) with SMC resulted in improved iron losses at high frequencies. CNT yarn is made of many parallel CNTs, and hence they are similar to Litz wire. This results in considerably reducing winding ac losses due to skin effect and proximity. These materials also bring advantages like the lighter weight of CNT machines (high power density) and SMC's capability of more complex core designs. This paper studies their use in a high frequency and low frequency case study. The results are promising and showing the potential benefits of replacing conventional materials with new materials.