A Critical Current Calculation Method of HTS Excitation Winding Considering the Effect of Self-Field

This paper proposes an optimized method to calculate the critical current of high-temperature superconducting (HTS) excitation winding. Considering the self-field effect generated by the internal transport current within the superconducting tape on the critical current, the experimental data provided by the material manufacturer are corrected. Afterwards, a new formula for $J_{c}(B_{loc},\theta)$ is proposed to describe the strong anisotropy of Bi-2223 tape. Here $B_{loc}$ represents the local flux density of the superconducting tape. Additionally, the actual cross-section shape of Bi-2223 tapes is elliptical. To validate the reliability and accuracy of the simulation results, two numerical models are established with both rectangular and elliptical cross-section based on the A-V formula and $E-J$ power law. The object of study is a 10kW double-stator HTS machine (DS-HTSM), homogenization model is used to establish the finite-element analysis (FEA) model of the HTS magnet and calculates its critical current. Finally, the effectiveness of the proposed optimized calculation method is verified by current-carrying test of the HTS magnet.