We report on the testing of a 1 m long and 0.5 m wide racetrack coil wound from 4.5 km of MgB₂ tape-shaped superconductors with a copper strip soldered to the nickel matrix. The cross-section of the coil corresponds to what is needed for the field windings of a 10 MW direct drive wind turbine generator pole, but where the straight section has been shortened. Ten double pancake sub-coils were wet-wound, with epoxy as the only electrical insulation, and assembled. The entire coil was cooled down to 14 K, and the direct current was ramped up. Voltage measurements were made over the double pancake coils. For eight of the ten double pancake coils, excessive voltages appeared at currents much lower than the design current. These voltages may either be attributed to the wire quality or to the winding process. A quench was observed at 149 A, which is in reasonable agreement with the predicted load line of the coil obtained by scaling wire transport measurements at 1 T and 20 K with hysteretic magnetization measurements in the range 1-5 T and 5-20 K.

我们报告了由 4.5 公里的 MgB ₂缠绕而成的 1 m 长和 0.5 m 宽跑道线圈的测试带状超导体，铜带焊接在镍基体上。线圈的横截面对应于 10 MW 直接驱动风力涡轮发电机极的励磁绕组所需的横截面，但直线部分已缩短。十个双薄饼子线圈湿绕，环氧树脂作为唯一的电绝缘，并组装。整个线圈冷却到 14 K，直流电流逐渐升高。在双薄饼线圈上进行电压测量。对于十个双扁平线圈中的八个，在远低于设计电流的电流下出现过高电压。这些电压可能归因于导线质量或绕组工艺。在 149 A 观察到猝灭，