Design, analysis, and fabrication of salient field-pole for a 1-kW-class HTS rotating machine

This paper presents the results of our electromagnetic parametric design, two-dimensional finite element analysis (2-D FEA), final fabrication, and basic test to develop a salient-field pole in rotor for a 1-kW-class high-temperature superconducting rotating machine (HTSRM). The developed machine is a small-scale prototype for an integrated system with an HTS rotating machine and a HTS contactless rotary excitation device, which is connected to the same shaft of the rotating machine and charges the HTS coils of the rotor field winding by pumping fluxes via a non-contact method. To increase economic efficiency during the development stage and the performance of the 1-kW-class HTSRM, various salient-pole structures of the rotor and magnetic materials of both the rotor and stator are considered. Using the time-transient solver of the 2-D FEA, various key design parameters are investigated and compared by considering structural dimensions of the salient-field pole. Then, the final 2-D FEA model is determined based on the parametric-analysis results, and a performance analysis is conducted to determine the various machine characteristics. Finally, the salient-field pole of the 1-kW-class HTSRM was fabricated using four race-track HTS single-pancake coils, and its basic characteristics were measured at 77 K.