AC Loss Characteristics of Copper-Stabilized YBCO Coated Conductor

Influence of copper layer and mechanical stress on AC losses in copper stabilized YBCO coated conductor (CC) was investigated. The uni-axial tensile stress was applied to the sample CC in liquid nitrogen at atmospheric pressure, and the AC losses (transport, magnetization and total AC losses) were measured by an electric method. Influence of the copper layer was investigated by investigating frequency dependence of the AC losses. The experimental results show that there are some influences of the copper layer. However, the influence of the copper layer is not significant from the stand point of practical applications. As to the stress dependences, experimental results show that, when stress dependences of the transport current and magnetization losses are expressed by properly normalized values using stress dependent critical currents, the loss curves fall close to unified curves, respectively and that the stress dependence of the AC losses can be estimated by knowing stress dependent critical current and AC losses in CCs without stresses.