High-temperature superconducting (HTS) coated conductors (CCs) are widely regarded as a promising candidate to enable very high power density motors. These machines operate at high rotational speeds, with some designs going up to 12 000 rpm. HTS CCs are applied to the field windings of these motors to increase the magnetic loading and hence the power density. Even though the superconducting field windings operate with a DC current, due to the magnetic field environment, losses are present. This paper examines the dynamic and total loss characteristics of YBCO-coated conductors in the frequency range relevant to high-speed motors for electric aircraft propulsion. A multi-layer model was created using the H -formulation and the losses for each layer were highlighted. For the first time, it was shown that the DC transport current region in the HTS layer shrinks as the frequency of the applied field increases due to the increased magnetisation current around the edges of the CC, which reduces the dynamic loss per cycle as the frequency increases. To fully understand the loss distribution in the HTS CC, the total loss in the conductor was investigated. For an applied magnetic field of 100 mT and 800 Hz, more than 30% of the total loss occurs in the copper layer due to the decreased penetration depth of the magnetic field and the skin effect. Results show that to accurately model and understand the losses in superconducting field windings, a multi-layer model should be used, since a significant proportion of loss shifts towards the copper stabilizers. Over all, it was shown that both the dynamic loss as well as magnetisation loss play a crucial role in the estimation of the loss in superconducting field windings.

中文翻译：

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电动飞机推进电机励磁绕组中高温超导涂层导体的损耗特性

高温超导 (HTS) 涂层导体 (CC) 被广泛认为是实现超高功率密度电机的有希望的候选者。这些机器以高转速运行，有些设计高达 12 000 rpm。HTS CC 应用于这些电机的励磁绕组以增加磁负载，从而增加功率密度。即使超导励磁绕组以直流电流运行，但由于磁场环境的原因，仍存在损耗。本文研究了 YBCO 涂层导体在与用于电动飞机推进的高速电机相关的频率范围内的动态和总损耗特性。使用 H 公式创建了一个多层模型，并突出显示了每一层的损失。首次，结果表明，由于 CC 边缘周围磁化电流的增加，HTS 层中的 DC 传输电流区域会随着外加场频率的增加而缩小，这会随着频率的增加而降低每个周期的动态损耗。为了充分了解 HTS CC 中的损耗分布，研究了导体中的总损耗。对于 100 mT 和 800 Hz 的外加磁场，由于磁场穿透深度降低和趋肤效应，总损耗的 30% 以上发生在铜层中。结果表明，为了准确建模和理解超导磁场绕组中的损耗，应使用多层模型，因为损耗的很大一部分会转移到铜稳定器上。全面的，