In many high-temperature superconducting (HTS) applications, HTS coated conductors carry DC currents under external AC magnetic fields. There are two AC loss mechanisms in this situation: magnetization loss due to the external magnetic field and dynamic loss due to the interaction between the DC current and the external magnetic field. The sum of these two loss components is referred to as total loss. In this work, the total loss in a 4 mm wide REBCO coated conductor is measured under perpendicular AC magnetic fields up to 105 mT at 77 K, 70 K, and 65 K, with reduced DC current level, i (I _dc/I _c0), from 0.025 to 0.98, where I _dc is the transport DC current value and I _c0 is the self-field critical current of the coated conductor at each temperature. The experimental results show a good quantitative agreement with an analytical equation for each loss component, as well as 2D finite element modelling (FEM) results from H -formulation. For any given temperature, we observe that the total loss is mostly dominated by magnetization loss at i< 0.2, while dynamic loss makes a comparable, even greater contribution to total loss at i > 0.5. Electromagnetic analysis from the FEM modelling shows the evolution process of total loss, where the dynamic loss region and magnetization loss region vary across the conductor width at high magnetic fields or high DC current level. The simulation results also reveal the superposition of (positive) DC current and the anti-parallel (negative) shielding current, which occurs at high DC current level. The superposition drives the current density of one conductor edge to subcritical stage, and it leads to one-sided loss generation in each half-cycle. Our results provide a valuable reference for total loss behaviours in REBCO coated conductors.

在许多高温超导 (HTS) 应用中，HTS 涂层导体在外部交流磁场下承载直流电流。在这种情况下有两种交流损耗机制：外部磁场引起的磁化损耗和直流电流与外部磁场相互作用引起的动态损耗。这两个损耗分量的总和称为总损耗。在这项工作中，在 77 K、70 K 和 65 K 下高达 105 mT 的垂直交流磁场下测量了 4 mm 宽 REBCO 涂层导体的总损耗，并降低了直流电流水平i ( I _dc / I _c0 )，从 0.025 到 0.98，其中I _dc是传输直流电流值，I _c0是涂层导体在每个温度下的自场临界电流。实验结果与每个损耗分量的解析方程以及来自H公式的二维有限元建模 (FEM) 结果显示出良好的定量一致性。对于任何给定的温度，我们观察到总损耗主要由i < 0.2 时的磁化损耗决定，而动态损耗在i 时对总损耗的贡献相当甚至更大 > 0.5。FEM 建模的电磁分析显示了总损耗的演变过程，其中动态损耗区域和磁化损耗区域在高磁场或高直流电流水平下随导体宽度变化。仿真结果还揭示了（正）直流电流和反平行（负）屏蔽电流的叠加，这发生在高直流电流水平。叠加将一个导体边缘的电流密度驱动到亚临界阶段，并导致在每个半周期内产生单侧损耗。我们的结果为 REBCO 涂层导体的总损耗行为提供了有价值的参考。