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I examine present and future applications of superconductors. The host of requirements that must be satisfied for a successful commercial application are described and discussed briefly. The substantial role of materials in applications, the large number of requirements on successful commercial superconducting wire, and the trends in superconducting material development are discussed. [ABSTRACT FROM AUTHOR]

A small high-temperature superconductor (HTS) coil was designed and tested at the General Electric Global Research Center to evaluate the overcurrent capability for the HTS generator rotor. The superconducting rotor coil is a layer-wound racetrack coil using the BSCCO 2223 conductor. Overcurrent simulation tests have been done to simulate the fault operation condition for the generator based on previous analysis work. The obtained data are used to evaluate the performance of the HTS material in generator applications. [ABSTRACT FROM AUTHOR]

When a synchronous generator connected to the power grid experiences a fault, it is required to stay on line, ride through the fault, and be able to carry full rated field current when the fault is cleared. The peak current during these events could be 2 times higher than the normal operating current. This may cause an HTS rotor coil to go into normal state and generate Joule heating. If the fault event is short enough and the heat dumped can be carried away by the cooling system, the coil may recover to the superconducting state at the end of the fault. Otherwise, the coil may thermally run away, or ‘quench’. To investigate the quench behavior of the HTS rotor coil of the 100 MVA generator at GE Global Research Center, a 1.5 MVA prototype coil was developed and tested to quench under different conditions. The experiment design, set up, tests and test results are presented in this paper. [ABSTRACT FROM AUTHOR]

High-temperature superconducting (HTS) coils are generally stable against transient thermal disturbances. Protection against spontaneous quenches is not a main design issue for an HTS coil. However, HTS coils used in many electric devices such as motors, generators, transformers, and current limiters will operate under over-current fault conditions, which may result in a coil quench and thermal runaway. Those electric devices should be able to ride through some grid fault conditions and remain functional. This requires a certain over-current capability of the HTS coils. This paper discusses the over-current requirements from grid faults and the thermal transient responses of a BSCCO coil. It presents the analysis results of the coil subjected to over-current pulses at different operating conditions. The study also investigates the thermal runaway current and its relationship with the over-current pulse. [ABSTRACT FROM AUTHOR]