A nontrivial factor in determining current distribution in an ac HTS cable-proximity effect

Abstract

A superconductor has zero resistance at the superconducting state. This unique property creates many exceptional phenomena, of which some are known and the others are not. Our experiments with multilayer high temperature superconductor (HTS) cable samples revealed a new phenomenon that alternating current had a tendency to flow in the inner and outer layers of the cables. We attribute the cause of this phenomenon to the electromagnetic interaction in an infinite electrical conductivity medium and term it "super-proximity-effect". This effect will greatly affect the performance of a multilayer superconducting cable and other superconducting devices which are involved with alternating current transportation. HTS cables, proximity-effect, superconductivity, electromagnetic interaction Citation:Xin Y, Gong W Z, Zhang J Y. A nontrivial factor in determining current distribution in an ac HTS cable-proximity effect. Sci China Tech Sci, 2010, 53: 922−928,

Current distribution among layers of single phase HTS cable conductor

“…Based on spiral pitch, current flowing and winding direction of each layer, the magnetic field induced in each layer has two components: azimuthal component B ih at in outer region and axial component B iz at in inner region for cable axis [11,12]. The magnetic field of layer i is decided by currents of other layers and itself.…”

Research focuses and advance technologies of smart grid in recent years

“…Experiments show that alternating current mainly flows in the inner and outer layers of the cable. This phenomenon has significant importance to the design of the multilayer superconductor that used in power electricity transmission [58].…”

Some new results of electric power science

“…[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.…”