Influence of Critical Current Density Distribution on Transport AC Losses for Round Superconducting Wire

The AC loss per cycle per unit length of a round superconducting wire has been theoretically analyzed based on the critical state model and numerically calculated from the power-law model. By using Bean's critical state model, it is found that the distribution of critical current density J (c) which increases from the center to the edge along a radial direction lowers the loss value. And the sharper the J (c) varies, the more significant the loss reduction. After considering the coupling of thermoelectric interaction, the results show that the temperature in superconducting wires gradually increases and finally becomes stable. The temperature of stable state has a dependence on the J (c) distribution and the rise of temperature has an important effect on the AC loss behavior.