Comparison of Superconducting Joint Methods for Motor-drive Applications

Superconducting materials offer the electrical benefits of zero resistance, high current carrying capacity, and high efficiency. These benefits will be crucial for the design of future advanced power electronic motor-drives and electric machines for emerging applications such as electrified aviation. Despite these benefits, there are significant challenges associated with working with these materials. One such difficulty is the task of joining superconductors together, and the focus of this study is the evaluation of different methods for joining superconductors for these emerging applications. The objective of this evaluation is to discover the superconducting joint method with the least electrical resistance. Several joints were constructed with superconducting materials using different fabrication techniques such as soldering and epoxy. The resistances of each joint type were measured and compared, using different measurement techniques with varied precision, including the well-known four-probe method. The study found that SnPb solder reasonably preserved the low resistance quality of superconductors, and performed consistently across multiple iterations, and therefore appears to be the best method to use in practical applications.