AC Loss Measurement And Analysis Of HTS Cable Model With Non-magnetic Substrate

High temperature superconducting(HTS) tapes are widely used in many fields as the rapid development of the material science, the cooling technology and so on. Superconducting electrical apparatus, including superconducting fault current limiters, superconducting transmission cables and superconducting transformers have many unique advantages over conventional ones. As the limitation of critical current of one single superconducting tape, many superconducting apparatus, such as superconducting cables usually consist of multiple HTS tapes. However, the AC losses of superconducting cables could affect the stability and economic efficiency. Thus, how to measure AC losses, choose capacity of refrigeration, research relation of electromagnetic field in HTS tapes and reduce AC losses by different arrangements of tapes is very important to the application of superconducting cables.This dissertation does researches about AC losses of superconducting cables both experimentally and numerically. In this dissertation, a pentagonal single layer conductor is prepared first. AC losses are measured and compared to the ones of single wires. Meanwhile, the numerical model is developed to calculate AC losses by finite element method. The calculated results are compared to the measured ones to validate the numerical model. On this basis, we test this superconductor carrying DC offset transport current. Secondly, a pentagonal double layer superconductor is made to find out the influence of magnetic field in layers on AC losses. The double layer conductor is also measured in DC offset current. Finally, a double layer decagon superconducting cable is investigated to find out the influence of different layer current distributions, gap between wires and distance between layers on the AC losses of the cable.The experimental results correspond with the numerical calculated ones in all the above conditions, which indicates we can design experimental models to reduce AC losses under direction of numerical models: For the pentagonal conductors, AC loss of each wire is less than that of a single wire; For multilayer conductors, AC loss could be reduced by narrowing the gap between two neighboring wires and increasing the distance between layers. The conclusion of this dissertation will support the design of HTS cable to optimize the performance and cost.