Uncertainty Evaluation for DC Critical Current Determined by Using Power-Law Fit to Current-Voltage Curve Applicable to Superconducting Wires and Power Cables

We evaluate the uncertainty associated with the critical current measurement of high-temperature superconducting power cables in which a power-law fit of a voltage-current characteristic is used to determine the critical current. We calculate the uncertainty contribution of each factors involved in the critical current measurement and find that the largest contribution to the combined standard uncertainty comes from the process of the power-law fit. This analysis can be applied to the uncertainty evaluation on the critical current measurement of superconducting wires.