Study of frequency dependence of AC transport current losses in HTS conductors subject to DC background field

To study a mechanism of AC transport current losses in HTS wires, the authors measured the AC transport current losses of two kinds of HTS wires subject to DC background magnetic field by changing frequency of currents. The tested wires are a multifilamentary Bi2223/Ag sheathed tape and YBCO thin film conductors. The measurement results show that the losses in the Bi/Ag sheathed tape and YBCO conductors deviate from the Norris model in different ways and are only weakly dependent on frequencies of transport currents. In this paper, measured results are presented and the loss characteristics are explained based on a numerical model which they made in a previous work to analyze the AC transport current losses.