Research on Data-Driven Approaches for Life Prediction of YBCO Tapes Under Overcurrent

Superconducting power devices have many advantages. In recent years, prototypes of various superconducting power devices based on high-temperature superconducting wires have been successfully developed, and some prototypes have also been tested on the power grid, which has accelerated the development of superconducting power technology. However, the reliability of superconducting devices under overcurrent has not yet been supported by research, which is part of the important reason that restricts large-scale promotion of them. In this article, the critical current degradation and life distribution characteristics of yttrium barium copper oxide (YBCO) tapes under overcurrent were analyzed. The overcurrent test adopted a sinusoidal alternating current with an amplitude of 480 A (4–5 times the critical current) and a frequency of 50 Hz. The duration of each overcurrent was 0.44 s. The critical current of the sample was measured in liquid nitrogen using the 10 ⁻⁴ V·m ⁻¹ criterion. The results show that there is an approximately exponential relationship between the critical current degradation rate of YBCO tapes and the number of overcurrent cycles. The life of YBCO tapes under overcurrent can be considered to obey the two-parameter Weibull distribution. Two different remaining useful life of YBCO tape prediction models based on data-driven methods were built. It is verified through cross-checking that the relative prediction errors of the two methods are 8.4% and 5.3%, respectively. And the validity of the models was verified through uncertainty analysis and the comparison with two traditional statistical methods.