Force Analysis of Superconducting Coils in Actively Shielded Air-Core Superconducting Machines

This paper deals with the development of a mathematical model for very high power density actively shielded air-core superconducting (SC) machines. The interacting forces of SC coils in the actively shielded SC machine are studied using a two-dimensional analytical approach. The transfer relation methodology is employed to analyze the fully air-core SC motor that is designed to reduce the weight of the machine with actively shielded coil stator. Magnetic flux and force density distributions obtained by the proposed method are compared with those obtained from finite element analyses. The results can be considered as elements of a library of tools leading toward efficient optimization and mechanical design of actively shielded SC machines.