This paper provides a new vision of loss measurement and modelling for superconducting coils, with both the short-time test and long-time test, as the behaviour of the AC loss in superconductors is actually a dynamic process with the temperature and time dependence, particularly for the medium-to-high frequency AC operation. A single-pancake High temperature superconducting (HTS) coil was tested in a power electronic circuit (DC-AC inverter). The operating current was from 15 A to 50 A, and the operating frequency was from 1 kHz to 5 kHz. The AC loss measurements were carried out using the function of fully decoupling power by a commercial power analyzer. This method was able to measure the real-time AC loss, and the loss measuring process is much easier than the conventional electrical and magnetic method. As expected, for short-time loss tests, the experiment, the FEM H-formulation model, and the conventional analytical model agree with each other. However, the AC losses in long-time tests are found having power-law relations with the operating time (above kHz level). As the accumulated heat in the HTS coil as well as the interrelation between the critical current and temperature, the real-time AC losses are strongly time-dependent. A new time-dependent analytical model is developed, for the purpose of accurately modelling the real-time loss in the HTS coil. The new analytical model well matches the AC loss tests over both the long and short testing time. The experimental method and new analytical model offer a new sight at the AC loss of superconducting coil for both the short-time and long-time operation in a power electronic circuit, which is able to explore more reasonable guidelines of safe operating area (SOA) during the practical AC operation of superconducting applications.

本文提供了超导线圈损耗测量和建模的新视角，包括短时测试和长时间测试，因为超导体中交流损耗的行为实际上是一个具有温度和时间依赖性的动态过程，特别是用于中高频交流操作。在电力电子电路（DC-AC 逆变器）中测试了单饼高温超导 (HTS) 线圈。工作电流为 15 A 至 50 A，工作频率为 1 kHz 至 5 kHz。交流损耗测量是通过商用功率分析仪使用完全去耦功率的功能进行的。这种方法能够实时测量交流损耗，损耗测量过程比传统的电磁法要容易得多。正如预期的那样，对于短时损失测试，H-公式模型，与常规分析模型相互吻合。然而，在长时间测试中发现交流损耗与操作时间（高于 kHz 水平）具有幂律关系。由于高温超导线圈中的累积热量以及临界电流和温度之间的相互关系，实时交流损耗具有很强的时间依赖性。开发了一种新的瞬态分析模型，目的是对 HTS 线圈中的实时损耗进行准确建模。新的分析模型很好地匹配了长短测试时间的交流损耗测试。该实验方法和新的分析模型为电力电子电路中短时和长时间工作的超导线圈交流损耗提供了新的视角，