Benefits of 2G HTS over 1G HTS wire:
Projected lower cost
Superior performance in magnetic field
Superior mechanical properties
Initially SuperPower's development of HTS electric power device components was based on the use of 1G HTS wire. With 2G HTS available in sufficient quantities since 2006 and with impressive performance characteristics and mechanical properties, device development work (cables, fault current limiters, motors, generators and other) is continuing based on the use of 2G HTS wire.
SuperPower has been at the forefront in the development and scale-up to commercial manufacturing of second-generation high temperature superconducting (2G HTS) wire since the late 1990s. Prior to this time, the HTS Group, as part of the former Intermagnetics General Corporation, began its work in first-generation (1G) HTS shortly after the discovery of high temperature superconductors in 1986. When Intermagnetics itself was formed in 1971, the early materials development work was focused on low temperature superconductors.
Superconductors come in two types, low-temperature (LTS) and high-temperature (HTS). The temperature that defines each is the level to which the conductors need to be cooled in order to become "superconducting." SuperPower has developed the capability to produce wire (tape) from forms of ceramic HTS materials that have transition temperatures of around 77K (or -320ºF), and thereby are called high-temperature superconductors. These temperatures are considerably warmer than the metal alloy LTS currently being used in magnetic resonance imaging (MRI) magnets.
Low Temperature Superconductors (LTS)
Low Temperature Superconductors were discovered in 1911 (see “What is Superconductivity? ”). LTS materials need to be cooled to about 4 K, which is achieved with liquid helium. Clinical MRI was the first major commercial application of superconductivity and remains as the major market today.
High Temperature Superconductors (HTS)
The discovery of ceramic-based high temperature superconductors in 1986 in Switzerland opened the possibility of applying superconductivity to electric power devices. The 'high' in HTS refers to the ability to achieve the superconducting state at temperatures attainable using inexpensive liquid nitrogen, approximately 77K. The reduced cooling needs of HTS offer performance advantages to electric power devices that did not exist with LTS.
HTS Components and Devices
- First-Generation Superconductors (1G HTS)
The most commonly used materials in early HTS were bismuth-based, specifically Bi-2212 and Bi-2223. These materials have come to be known as first generation (1G) superconductors and have been used to demonstrate a variety of HTS power devices including transmission cable , transformers , fault current controllers , motors and generators. Performance benefits of these HTS devices compared to conventional, non-superconducting devices, have been demonstrated for all these applications.
- Second-Generation Superconductors (2G HTS)
More recently, rare earth-based HTS materials ((RE)BCO) have been developed. Rare earth elements include, but are not limited to, Yttrium, Samarium and Gadolinium. This 2G conductor (or wire) offers both performance benefits (operates at higher temperatures and background magnetic fields) and cost benefits. In early 2000 SuperPower signed a Cooperative Research and Development Agreement (CRADA) with Los Alamos National Laboratory (LANL) to transfer technology related to producing 2G superconductors and has scaled up the process for long length manufacturing.
HTS wire is the enabling component for a variety of energy technology, transportation, medical, industrial and military applications.
SuperPower has concentrated its efforts on the following devices:
HTS Transmission Cable >
HTS Transformer & SFCL Transformer >
Superconducting Fault Current Limiters (SFCL) >
HTS Motors and Generators >
High Field Magnets >
Superconducting Magnetic Energy Storage >
HTS Current Leads >