Advances in both superconducting technologies and the necessary power electronics interface have made SMES a viable technology for high power utility and defense applications. The power industry's demands for more flexible, reliable and fast active power compensation devices make the ideal opportunity for SMES applications. However, in order to make this technology attractive to the deregulated utility market, it is necessary for industry to provide cost-effective systems. The information presented herein is taken from results to date of a DARPA Technology Reinvestment Program SMES Commercialization Demonstration. This program is currently in the design and risk reduction phase. Completion is expected in 2001. This system will provide +/-l O O M W peak and +/-50MW oscillatory power with lOOMJ of stored energy. The base line for the coil design assumes a cable-in-conduit conductor (CICC), with rated voltage of 24 kV, and operating at nominal temperature of 4.5 K This paper reviews the possible utility industry applications and discusses a number of technical issues and trade-offs resulting from the design optimization process for SMES utility applications.The conductor design options, system configuration, currentfvoltage levels and insulation issues for a low temperature superconducting coil are discussed. The power electronics interfaces (system configuration, circuit topology and devices and switching technologies) are also discussed. Finally, consideration is given to the impact of the new business environment, potential markets and overall cost.

The use of a high-T, YBaCuO superconducting film as a switch element of a rectifier was investigated. It was shown that a film can work as a controlled switch at a frequency up to 20 Hz, at current "4 A and voltage "4 V with current-stimulated quench. Film performance in the switch mode was calculated and theories and experiments were compared. Based on high-T, films it is possible to develop superconducting rectifiers that can work at the temperature of liquid nitrogen.

The critical current in a NbTi tape measured in different directions of magnetic field and the current reduction due to the self field. The tape is extra sensitive for the component of the magnetic field perpendicular to the surface. Without external field this component of the self field reduces the critical current far below its intrinsic value. A one dimensional rodel can describe the reduction of critical current due to the self field in a thin tape.-

No abstract

YBCO single crystals 1-2-3 were grown from a melted mixture of YBa2Cu3O7-y-BaO-CuO using the method of horizontally directed cooling in the zone melting equipment. This method makes it possible to grow high quality single crystals with dimensions up to 3*2*0.15 mm3, which may then be extracted simply from the crucible. Differences in superconducting properties, parameters of crystal structure and the microstructure were found in single crystals grown in Al2O3 and ZrO2 crucibles. It is possible that these differences are connected with the different stability of the crucibles used and consequently with the presence of impurities in the melted charge during the single crystal growth process.