考虑自场影响的高温超导励磁绕组临界电流计算方法

High-temperature superconducting (HTS) tapes are widely used in the design of excitation windings due to excellent current-carrying capacity and low power dissipation. This paper proposes a method for calculating the critical current of the HTS excitation winding considering the self-field effect. First, due to the suppressive effect of the self-field on the critical current, a ratio analysis is performed to correct the experimental data provided by the manufacturer. Then, an improved formula is developed that accounts for the different suppression effects of parallel and perpendicular magnetic fields, and thus accurately describes the magnetic field and angular dependence of the critical current. Next, taking a 10 kW double-stator HTS machine (DS-HTSM) as an example, the effective critical current of the HTS windings is calculated based on the A-V formulation and homogenization method to determine the upper limit of the operating current. Furthermore, influenced by the armature reaction magnetic field, the AC losses of the HTS windings are evaluated under rated operating conditions by applying the full boundary magnetic field simulation method. Finally, modular Bi-2223 HTS magnets are fabricated, and experimental measurements of the critical current are conducted to confirm the validity of the proposed method.