J. Kellers

Publications (2)2.08 Total impact

• Source

  Available from: amsc.com

  Article: Industrial high temperature superconductors: perspectives and milestones

  L.J. Masur, J. Kellers, Feng Li, S. Fleshler, E.R. Podtburg
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  ABSTRACT: High Temperature Superconductors (HTS) are widely considered for large power applications used by industrial end-users and electric utilities. The prominent application areas include power transmission cables, electric motors, generators, current limiters, and transformers. The promising design concepts rely on HTS to be a flexible composite conductor, robust enough to handle an industrial environment. Currently, the most advanced manufacturing method for flexible composite conductor is the Bi-2223-OPIT, used by many organizations. Significant advances in HTS technology have been made, with average critical current performance above 115 A at 77 K which is equivalent to an engineering current density of 13.8 kA/cm². During the past 18 months, American Superconductor increased its HTS wire manufacturing capacity from 250 km to 500 km per year to meet the increased demand for development and demonstrations. While this level of quality and quantity enables impressive demonstrations of prototype power applications, it does not fully meet the requirements of commercial economic viability. Therefore, to further decrease wire price to $50/kA-m, American Superconductor is currently siting a new facility dedicated to the manufacturing of Bi-OPIT-2223 wire in quantities of 10000 km per year. Initial applications for this wire are power transmission cables, industrial motors and electrical generators. This paper will report on the performance and reliability testing of Bi-2223 tapes. We will discuss the electrical, tensile, compression, and fatigue testing results of tapes manufactured for specific key projects. Also, we will review mass availability of High Temperature Superconductors and we will report on technological and price/performance limitations to be overcome to increase the applicability of HTS in research and industrial devices and equipment.
  IEEE Transactions on Appiled Superconductivity 04/2002; · 1.04 Impact Factor
• Article: HTS SMES magnet design and test results

  S.S. Kalsi, D. Aized, B. Conner, G. Snitchier, J. Campbell, R.E. Schwall, J. Kellers, T. Stephanblome, A. Tromm, P. Winn
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  ABSTRACT: This paper describes design, construction, and testing of a 5 kJ superconducting magnetic energy storage (SMES) magnet. This magnet was built by American Superconductor Corporation (ASC) for Gesellschaft fur Innovative Energieumwandlung und Speicherung (EUS) of Germany. The magnet consists of a solenoidal coil constructed from a silver-sheathed BiPb₂Sr₂Ca₂Cu₂O (Bi-2223) conductor which was reacted before winding. The coil is epoxy impregnated and cooled with single stage Gifford McMahon (G-M) cryocoolers for operation at 100 A (DC) with substantial AC components due to the frequent variation of current (ramp-up and ramp-down.) The magnet was tested in early spring of 1996 and was shipped to EUS in mid June. The successful operation of this magnet illustrates that the technology of cooling HTS magnets with G-M type cryocooler is now fully established. The long-term operation of this magnet at EUS will verify the reliability of HTS magnet system in critical applications and will open future applications for HTS in the area of SMES and other magnets
  IEEE Transactions on Appiled Superconductivity 07/1997; · 1.04 Impact Factor