High-temperature superconducting (HTS) coated conductors (CCs) have become the preferred material for superconducting magnet applications due to their high engineering current density and high mechanical strength. However, due to the low quench zone propagation velocity of CCs, magnets wound with CCs suffer from severe quench risks. Therefore, a rapid, sensitive, and reliable quench detection method is crucial for the safe operation of such HTS magnets. In this paper, we propose a quench detection method based on current redistribution, in which two pieces of HTS CCs are soldered together at each end and insulated in the middle part, which are then parallel co-wound into a double-pancake coil. The two tightly coupled windings and low resistance joints form a very low inductance current loop, resulting in fast current redistribution between the two co-windings even at the inception of quench (with still low quench voltage). We deduced analytical solutions of the current redistribution process under different magnet operational scenarios, including constant current operation, charging and discharging, and proposed quench detection criteria. Corresponding quench tests were performed on a small scale co-wound HTS coil, and the results well verified the analytical solutions and the effectiveness of the quench detection method. Our work may be useful for lowering the risks in HTS magnet quench in various applications.

中文翻译：

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基于电流再分配的并联共绕高温超导线圈失超检测方法

高温超导（HTS）涂层导体（CC）因其高工程电流密度和高机械强度而成为超导磁体应用的首选材料。然而，由于CC的淬火区传播速度较低，用CC缠绕的磁体面临严重的淬火风险。因此，快速、灵敏、可靠的失超检测方法对于此类高温超导磁体的安全运行至关重要。在本文中，我们提出了一种基于电流再分配的失超检测方法，其中两片高温超导CC在两端焊接在一起，中间部分绝缘，然后并联共同缠绕成双薄饼线圈。两个紧密耦合的绕组和低电阻接头形成非常低的电感电流回路，即使在失超开始时（失超电压仍然较低），也会在两个共绕组之间实现快速电流重新分配。我们推导了不同磁体操作场景下的电流重新分布过程的解析解，包括恒流操作、充电和放电，并提出了失超检测标准。在小型共绕高温超导线圈上进行了相应的失超试验，结果很好地验证了解析解和失超检测方法的有效性。我们的工作可能有助于降低各种应用中高温超导磁体失超的风险。