Measurement of AC Loss of Double-Layer Shielded YBCO Cable Model With Different Voltage Leads

In this article, a model of double-layer shielded YBCO cable is measured and analyzed by six different voltage leads. Under the current distribution of different layers, the loss characteristics measured by VO-lead, S-lead, and CO-lead are studied, respectively, and the relationship between the losses measured by different voltage leads is demonstrated. The experimental results show that the loss measured by S-lead is very small compared with the loss measured by VO-lead in the YBCO cable model, especially in go–return mode. The loss of the outer shield varies with the change of the magnetic field’s magnitude and direction, while the loss of the inner conductor is basically not affected by the magnetic field of the shield. Under the two current transportation modes, the loss of the CO-lead is the addition or subtraction of the S-lead and VO-lead. The loss in go–go mode is obviously bigger than that in go–return mode, which is due to the different direction of magnetic field produced by the conductor and shield. In addition, the comparative analysis with the BSCCO cable model more fully illustrates the ac loss characteristics of the double-layer wire shielded YBCO cable model. The YBCO wire has obvious advantages in reducing the ac loss of high-temperature superconducting cables.