DocumentCode :
1108088
Title :
Applications of bulk high-temperature Superconductors
Author :
Hull, John R. ; Murakami, Masato
Author_Institution :
Energy Technol. Div., Argonne Nat. Lab., IL, USA
Volume :
92
Issue :
10
fYear :
2004
Firstpage :
1705
Lastpage :
1718
Abstract :
Bulk high-temperature superconductors (HTSs) enable the opportunity to develop several unique applications in electrical power that are not feasible with superconducting or normal wires. The large current carrying capacity and low thermal conductivity of the HTSs allows relatively short lengths to carry large currents to low-temperature devices without introducing heat to the device. Such current leads can dramatically reduce the refrigeration requirements for devices such as SMES. The HTSs make a relatively sharp transition to a highly resistive state when the critical current density is exceeded, and this effect has suggested their use for resistive fault current limiters. The bulk HTSs may also take the form of large single-grained superconductors within which circulating currents may flow at large current density without loss. They are capable of developing magnetizations, similar to that of permanent magnets, but with much larger magnetic fields. In this case, they may be used as field-trapping components. Applications in this case include brushless synchronous motors, laboratory magnets, magnetic separation, and magnetron sputtering. The bulk HTSs may also be used as diamagnetic objects in magnetic circuits to provide new types of power devices. One application that uses this effect is an inductive fault current limiters, in which the HTS shields an iron core in an inductive circuit until some current level is exceeded. This transition increases the component from low impedance to high impedance. The diamagnetic property may also be used to create low-loss magnetic bearings for use in efficient energy-storage flywheel devices or sensitive instrumentation. The combination of diamagnetic shielding and field trapping has suggested their use in motor designs analogous to hysteresis motors. Laboratory prototypes for all of these devices have been constructed and tested, and in some cases the devices have been field tested in actual power systems. Improvements in HTS properties, such as flux pinning, mechanical strength, and the ability to grow large grains, have greatly improved the economics of applications that use bulk HTS.
Keywords :
barium compounds; bismuth compounds; calcium compounds; ceramics; critical current density (superconductivity); flywheels; high-temperature superconductors; magnetic levitation; magnetisation; mechanical strength; scanning tunnelling microscopy; sintering; sputtering; strontium compounds; surface cracks; type II superconductors; yttrium compounds; Bi2Sr2Ca1Cu3O10; Bi2Sr2Ca2Cu3O10; HTS shields; SMES; YBa2Cu3O7; brushless synchronous motors; bulk high-temperature superconductors; critical current density; current carrying capacity; diamagnetic objects; diamagnetic properties; diamagnetic shielding; efficient energy-storage flywheel devices; electrical power applications; field trapping; field-trapping components; flux pinning; grain growth; highly resistive state; hysteresis motors; inductive circuit; inductive fault current; iron core; laboratory magnets; laboratory prototypes; large single-grained superconductors; low impedance-high impedance transition; low-loss magnetic bearings; low-temperature devices; magnetic circuits; magnetic separation; magnetization; magnetron sputtering; mechanical strength; permanent magnets; power devices; refrigeration; resistive fault current limiters; sensitive instrumentation; sharp transition; thermal conductivity; Fault current limiters; High temperature superconductors; Hysteresis motors; Impedance; Laboratories; Magnetic flux; Magnetic separation; Superconducting magnetic energy storage; Synchronous motors; Thermal conductivity; Current leads; FCLs; fault-current limiters; flywheel energy storage; high-temperature superconductors; magnetic levitation; magnetic separation; rare-earth compounds; sputtering; superconducting composites; superconducting devices; superconducting rotating machines; trapped-field magnets; yttrium compounds;
fLanguage :
English
Journal_Title :
Proceedings of the IEEE
Publisher :
ieee
ISSN :
0018-9219
Type :
jour
DOI :
10.1109/JPROC.2004.833796
Filename :
1335558
Link To Document :
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