US 2020/0200841 A1Published application

Method for evaluating the electrical properties of a hts superconductor

AssigneeBruker HTS GmbH

InventorsAlexander USOSKIN, Ulrich BETZ, Klaus SCHLENGA

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Abstract

A measurement current (i) is injected into an active part (4) of an HTS superconductor. The active part is cooled, but not reservoirs (1, 2) from/to which the superconductor is wound. Only a fraction of the active part is exposed to a magnetic field for testing the electrical properties of the superconductor. Buffer devices (20a, 20b) prevent current sharing from outside the active part. The measurement current is injected where the residual magnetic field is at least 3 times lower than the magnetic field for testing, and/or the local critical current at the current injection locations is at least three times higher than the critical current at the magnetic field for testing. The electrical properties, e.g. the critical current, are tested by determining an integral of a voltage drop (U) across the active part, e.g. between two voltage pick-up elements (15a, 15b), as a function of measurement time (τ).

Claims25

Dependent claims

A method for evaluating electrical properties of a high temperature superconductor(HTS), comprising:

exposing the HTS superconductor to a cryogenic environment of a temperature Tenv,
passing the HTS superconductor through a characterization zone while applying a magnetic field to the HTS superconductor in the characterization zone,
wherein the characterization zone comprises a central region and two peripheral regions through which the HTS superconductor passes,
and supplying the HTS superconductor with a measuring current (i) by two current exchange elements, wherein each of the current exchange elements contacts the HTS superconductor in a respective one of the peripheral regions,
wherein the HTS superconductor is continuously translated from a first reservoir through the characterization zone to a second reservoir,
wherein the HTS superconductor is exposed to the cryogenic environment only in a cryogenic zone, wherein the cryogenic zone includes the characterization zone and wherein the first and second reservoirs are located outside the cryogenic zone,
wherein the HTS superconductor passes two buffer zones where two decoupling sections are formed in the HTS superconductor, with a first decoupling section established between the first reservoir and the characterization zone, and a second decoupling section established between the characterization zone and the second reservoir,
wherein the magnetic field is selected such that a maximum magnetic flux density at the HTS superconductor in the central region is Bcentr, with Bcentr≥1.5 Tesla, and a maximum magnetic flux density at the HTS superconductor at the current exchange elements is Bperi, such that, at the temperature Tenv of the HTS superconductor established by the cryogenic environment in the characterization zone, for a critical current Icentrcrit of the HTS superconductor in the central region and a critical current Ipericrit of the HTS superconductor at the current exchange elements, the following applies:
Ipericrit≥3*Icentrcrit,
and wherein in each buffer zone the HTS superconductor is treated such that
the HTS superconductor becomes normally conducting within the decoupling section, or
a local critical current Ibuffercrit of the HTS superconductor in the decoupling section is reached with Ibuffercrit≤1/50*Icentrccrit.

9 more elements

A method for measuring electrical properties of a high temperature superconductor (HTS), comprising:

continuously translating a HTS superconductor from a first reservoir through a first buffer zone, a characterization zone and a second buffer zone to a second reservoir,
while translating the HTS superconductor, exposing the HTS superconductor to a cryogenic environment of a temperature Tenv only in a cryogenic zone,
wherein the cryogenic zone includes the characterization zone, and the characterization zone comprises a central region and two peripheral regions through which the HTS superconductor passes, and
wherein the first reservoir and the second reservoir are located outside the cryogenic zone,
while translating the HTS superconductor, supplying the HTS superconductor with a measuring current (i) with two current exchange elements,
wherein each of the current exchange elements contacts the HTS superconductor in a respective one of the peripheral regions, and
wherein respective decoupling sections are formed in the HTS superconductor when the HTS superconductor passes each of the two buffer zones, with a first of the decoupling sections being established between the first reservoir and the characterization zone, and a second of the decoupling sections being established between the characterization zone and the second reservoir, and
while translating the HTS superconductor, applying a magnetic field to the HTS superconductor in the characterization zone,
wherein the magnetic field is set such that a maximum magnetic flux density at the HTS superconductor in the central region is Bcentr, with Bcentr≥1.5 Tesla, and a maximum magnetic flux density at the HTS superconductor at the current exchange elements is Bperi, and such that, at the temperature Tenv of the HTS superconductor established by the cryogenic environment in the characterization zone, for a critical current Icentrcrit of the HTS superconductor in the central region and a critical current Ipericrit of the HTS superconductor at the current exchange elements:
Ipericrit≥3*Icentrcrit, and
while translating the HTS superconductor, treating the HTS superconductor in each of the buffer zones such that either:
the HTS superconductor becomes normally conducting within the decoupling section, or
a local critical current Ibuffercrit of the HTS superconductor in the decoupling section is reached with Ibuffercrit≤1/50*Icentrcrit.

10 more elements

Dependencies are inferred from the claim text.