Analysis on Critical Current Density of an HTS Conductor With Quasi-Isotropic and High Engineering Current Density

A high-temperature superconducting (HTS) conductor with quasi-isotropic and high engineering current density is proposed. The HTS conductor consists of inner quasi-isotropic strand and outer power cable. The inner quasi-isotropic strand, equivalent to a former, is a twisted quasi-isotropic conductor made from four components stacked by the second generation (2G) HTS wire with symmetrical arrangement. The outer conductor is made by winding the 2G wire on the inner conductor that is equivalent a power cable. Simply speaking, the HTS conductor is a power cable with replacing the copper former by HTS quasi-isotropic strand so that its engineering critical current is high. The HTS conductor has quasi-isotropic critical current density, since it is a combination of a quasi-isotropic strand and an isotropic power cable. The engineering current density is improved by changing twisting pitch of inner quasi-isotropic conductor and pitch of outer power cable, the conductor is also of benefit to mechanical flexibility and quasi-isotropic critical current density. Additionally, the critical current density of inner quasi-isotropic strand is higher than the one in self-field by considering the effect of longitudinal magnetic fled taking into account.