Mathematical Analysis Model of Double-Stator Field Modulation HTS Machine Based on General Airgap Field Modulation Theory

TheSuperconducting (SC) machines have the merits of higher power and torque density due to the fact of higher electrical or magnetic loading. Especially, the field modulation SC machine (FMSCM) recently attracts more and more attention from scholars, since this kind of SC machines successfully overcome the drawbacks of the traditional SC synchronous machines, such as the rotating seal of the coolant and the electrical brush-slip-ring for current transfer. However, the research method of the FMSCM mainly adopts the finite element analysis (FEA). Although the FEA can provide accurate results, the time consumption is huge, particularly at the initial design of the large capacity FMSCM, the time cost will be unacceptable. Aiming at solving this problem, this paper attempts to establish the mathematical analysis model of a double-stator field modulation HTS machine (DSFM-SCM) using a new theory of electrical machine, i.e., general airgap field modulation theory, for the first time. Both the FEA and experiments are carried out on the DSFM-SCM, to verify the effectiveness of the proposed mathematical analysis model. Although there is discrepancy between the proposed analytical method and FEA, it can basically meet the requirement at the initial design, and sufficiently exhibit the modulation effect of geometric structure, reflecting the essential mechanism of the DSFM-SCM. In addition, it is worth noting that the establishment process of analytical model of the DSFM-SCM can provide reference for the other FMSCMs.