HTS cable and its anticipated effects on power transmission networks

High temperature superconductive cable (HTS cable) has unique characteristic of low impedance to current flow. Unlike conventional power cables, HTS cable offers higher power transfer with minimum losses and more compact designs of power applications yet better power flow absorption in the networks at the same voltage levels. In attempts to closely study the effect of HTS cable on power networks, several pilot projects were carried out around the world. Promising results were achieved in terms of cable capacity and reliability. However, the big challenge of this technology is the high cost of superconductive materials in addition to the cost associated with cable-cooling which is required for its normal operation temperature (-208/spl deg/C for present HTS cables). A new cable design which utilises the cryogenic electrical insulator have been developed, in parallel with developing highly reliable cable cooling technology with a long service life aiming for longer service intervals. These are expected to reduce the cost of HTS cable technology significantly in the short term; and in the mid term industry scale production will certainly further reduce the cost of HTS cable. This paper will present the technology involved in HTS cable and its anticipated effects on power transmission networks.