Current distribution and stability of LTS/HTS hybrid superconducting conductors

Abstract

Current distribution and stability of a hybrid LTS/HTS superconductor, consisting of multifilamentary NbTi/Cu and Bi2223/Ag tapes, were numerically analyzed according to power-law models. The results showed that most of current passed through the LTS and the current increased in the HTS with temperature rise when the transport current was below the critical current of the hybrid conductor. The quench propagation velocity of the hybrid conductor was smaller but its minimum quench energy was larger than those of LTS conductors, indicating that the stability of the hybrid superconducting conductor was effectively improved and a high engineering current density was simultaneously achieved. Finally, a hybrid sample, made by soldering Bi2223/Ag tape onto NbTi/Cu conductor, was prepared and tested successfully at helium temperature. The experimental results qualitatively agreed with the simulated ones. distribution, hybrid conductor, minimum quench energy, quench propagation velocity, n value, stability Citation:Guan X J, Wang Y S, Zhou W W. Current distribution and stability of LTS/HTS hybrid superconducting conductors. Sci China Tech Sci

Numerical analysis on the current-sharing temperature of LTS/HTS hybrid conductor

“…Assume that the length of the hybrid conductor in Figure 1 is infinite and the magnetic field is uniform; it is approximately reasonable to neglect the current distribution effects induced by the joints and the couple current effect. We use the model which has been partially tested by experiment [4], where the LTS/HTS hybrid conductor can be considered to be approximately parallel circuit consisting of LTS, HTS, and metal matrix, shown in Figure 2.…”

“…I T is the total transport current of hybrid conductor; I H , I L , and I M are the transport currents through HTS, LTS, and matrices, respectively. In adiabatic condition, according to the power law model, the above parameters satisfy the following equations [4]:…”

Research focuses and advance technologies of smart grid in recent years

“…The current distribution in a hybrid conductor consisting of low temperature superconductivity (LTS) and HTS was investigated by numerical simulation method based on the power-law models [59]. Results show that the current in the HTS increases with the temperature arise as long as the current is under the critical value.…”

Some new results of electric power science

“…Ref. [35,36] focused on superconductor. Xin et al [35] gave the experiments with multilayer high temperature superconductor (HTS) cable samples to reveal a new phenomenon that alternating current had a tendency to flow in the inner and outer layers of the cables.…”

“…In ref. [36] current distribution and stability of a hybrid LTS/HTS superconductor, consisting of multi-filamentary NbTi/Cu and Bi2223/Ag tapes, were numerically analyzed according to power-law models. To satisfy the requirements for accurate dynamic complicated signal parameter estimation and its high speed implementation in embedded terminals, refs.…”