RECENT DEVELOPMENTS IN HTS POWER CABLE APPLICATIONS

The 1986 discovery of High-Temperature Superconductors (HTS) has great ly revitalized interest in superconducting (SC) cables and transmissio n systems after earlier, liquid helium (LHe)-cooled SC technology prov ed to be technically valid, yet not economically competitive with conv entional systems. The availability of a less costly SC solution, coole d by liquid nitrogen (LN), is the driving force behind various possibl e applications for SC cables in electric power transmission systems. P ractical investigations into SC power transmission applications have b een initiated as a result of the discovery of HTS. These actions are p resently following the parallel courses of materials and technology im provement and an increasingly detailed technical and economical analys is of SC power transmission applications within the system grid. Progr ess in the field of SC materials has been relatively slow of late, a s ituation which has somewhat dampened expectations for dramatically hig her critical temperature (Tc) levels in the near future. Advances in S C wire technology, however, have been very rapid during the last ten y ears; promising new approaches are being developed, while other, more advanced technologies are progressing toward commercialization. This i s particularly true of BSCCO wire technology, which has evolved to mak e available long wire lengths, each with a critical current in excess of 30A. Insofar as power cable applications are concerned, the most re cent advances have been the manufacture of a machine-stranded, 50m lon g, 3300 ampere HTS cable conductor and the detailed specification of s everal prototype HTS cable system installations. Many different HTS ap plication options are being considered, each offering varied and disti nct potential benefits to the electrical power industry. Some of these potential applications are already in development, while others are b eing systematically analyzed for compatibility with associated technic al and economic evaluations.