WO2016141868A1

WO2016141868A1 - Superconducting tape current transfer capability measurement probe, measurement device, and method

Info

Publication number: WO2016141868A1
Application number: PCT/CN2016/075817
Authority: WO
Inventors: 顾晨; 高琦
Original assignee: 北京原力辰超导技术有限公司
Priority date: 2015-03-10
Filing date: 2016-03-07
Publication date: 2016-09-15
Also published as: CN104820141B; CN104820141A

Abstract

A superconducting tape current transfer capability measurement probe, a measurement device, and a method. The superconducting tape current transfer capability measurement probe comprises a magnetic circuit, a detection winding (5), and a measurement circuit (6) connected to the detection winding (5). The magnetic circuit comprises a magnetic circuit core (1), an excitation winding (3), and an adjustable power source (4) providing the excitation winding (3) with current, the excitation winding (3) and the detection winding (5) being respectively wound on the magnetic circuit core (1), a slit (2) used for accommodating a superconducting tape sample to be measured (7) being arranged on the magnetic circuit core (1), the magnetic circuit core (1) and the slit (2) forming a closed magnetic circuit. The magnetic field amplitude in the slit (2) is adjusted via the excitation winding (3) and the adjustable power source (4) providing the excitation winding (3) with current, and the detection winding (5) and the measurement circuit (6) connected to the detection winding measure the current transfer capability of the superconducting tape sample to be measured (7) which is placed in the slit (2). The device and method measure a local current transfer characteristic of the superconducting tape along the width direction of the tape, and also measure an overall current transfer characteristic of the superconducting tape in an external magnetic field.

Description

Superconducting strip current transmission capability measuring probe, measuring device and method

Technical field

The invention relates to the field of superconducting work, in particular to a superconducting tape current transmission capability measuring probe, a measuring device and a method.

Background technique

Superconducting materials can be widely used in large-scale power installations because of their unobstructed and high current carrying characteristics. It is expected that the era of large-scale use of high-temperature superconducting materials is coming. Current transmission performance is the most basic parameter reflecting the performance of superconducting tape. At present, the "four-lead method" is generally used to measure the critical current to reflect the current transmission performance, that is, load current is applied across the sample to observe the voltage signal. As the current increases, a critical current of the superconducting strip is determined by increasing the observed voltage by generating 1 microvolt per cm of strip length as a quench criterion. This method is simple in principle and is widely used in laboratory-scale short sample measurements with a length of less than 10 cm. As a contact measurement method, the four-lead method has many limitations in the critical current measurement of long superconducting tape. Firstly, the current lead and voltage lead need to be in contact with the strip during the measurement, which may cause mechanical damage to the superconducting strip. Secondly, the test efficiency is also very low, and it is inconvenient to realize continuous and rapid measurement of the 100-meter long strip.

In view of the shortcomings of the four-lead method for continuous measurement of high-temperature superconducting tapes, researchers have developed a magnetic circuit method to detect the current transfer capability of superconducting tapes, such as the patent zl201010033688.5, which uses a double-slit magnetic circuit and The Hall probe realizes the measurement of the current transmission capability of the high-temperature superconducting tape, but this method requires two slits in the magnetic circuit, resulting in a significant decrease in the magnetic field excitation capability, and in particular, in measuring the current transmission capability under an external magnetic field. At that time, it is necessary to detect a small 2-3 orders of magnitude signal under a large background magnetic field, resulting in a large error, which is not conducive to practical applications.

Summary of the invention

In view of the above problems, the present invention has been made in order to provide a superconducting tape current transmission capability measuring probe, measuring apparatus and method that overcome the above problems or at least partially solve or alleviate the above problems.

According to an aspect of the present invention, a superconducting tape current transmission capability measuring probe including a magnetic circuit, a detecting winding, and a measuring circuit connected to the detecting winding is provided The magnetic circuit includes a magnetic circuit core, a field winding, and an adjustable power supply for supplying current to the field winding, the field winding and the detecting winding being respectively wound on the magnetic circuit core, the magnetic circuit a slit for holding a sample of the superconducting tape to be tested, a magnetic core and the slit are opened on the iron core Forming a closed magnetic circuit; adjusting a magnitude of a magnetic field in the slot by the field winding and an adjustable power supply that supplies current to the field winding, the detection winding and a pair of measurement circuits connected to the detection winding The current transfer capability of the superconducting tape sample to be tested in the slit is measured.

Optionally, the material of the magnetic circuit core is a soft magnetic core.

Optionally, the magnetic circuit core is a closed iron core, and the shape is an O-shaped, rectangular or closed polygon.

Optionally, the height of the slit is greater than the thickness of the superconducting tape sample to be tested, and the width is greater than the width of the superconducting tape sample to be tested.

According to another aspect of the present invention, a superconducting tape current transmission capability measuring device comprising the superconducting tape current transmission capability measuring probe according to any of the above, a continuous transmission device, a low temperature maintenance device, the continuous transmission device being composed of a first guide wheel and a second guide wheel that cooperate with a pay-off device and a take-up device outside the cryostat device, the first guide wheel and the second guide wheel Separately placed on both sides of the magnetic circuit, the first guide wheel, the slit and the second guide wheel are on the same straight line, and the sample of the superconducting tape to be tested passes from the external pay-off device through the first guide wheel Guided through the slit and then guided to the external wire take-up device through the second guide wheel, the moving direction of the superconducting tape sample to be tested is directed from the first guide wheel to the second guide wheel; the magnetic device is operated when the device is in operation Both the road and the sample of the superconducting tape to be tested are placed in a cryogenic maintenance device.

Optionally, the superconducting tape current transmission capability measuring device further includes an applied magnetic field disposed on the continuous transmission device, wherein the first guide wheel, the applied magnetic field, the slit and the second guide wheel are sequentially disposed in the same On a straight line.

Optionally, the applied magnetic field is applied by an electromagnet or a permanent magnet.

Optionally, the cryogenic maintenance device is a container filled with liquid nitrogen.

According to still another aspect of the present invention, there is provided a method for measuring a superconducting tape current transmission capability based on the above-described superconducting tape current transmission capability measuring device, the method comprising:

Place a sample of the superconducting tape to be tested in the cryogenic maintenance device for cooling;

Passing the cooled sample of the superconducting tape to be tested into the slit through the continuous transmission;

Adjusting the magnitude and/or direction of the magnetic field generated by the field winding by the adjustable power supply for supplying current to the field winding;

The sample of the superconducting tape to be tested is measured in the form of an induced voltage by a detecting winding and a measuring circuit.

The cooled sample of the superconducting tape to be tested is supplied through an electromagnet or a permanent magnet to be placed at least greater than 2 An applied magnetic field that penetrates the magnetic field;

The sample of the superconducting tape to be tested is removed from the applied magnetic field by the continuous transmission device, and enters the slit;

The number of excitation winding turns and the excitation power supply in the superconducting tape current transmission capability measuring device of the present invention need to ensure the ability to generate at least 1 times the amplitude of the penetrating magnetic field of the superconducting tape at the slit, such as a superconducting tape, such as High temperature superconducting wire. The high temperature superconducting tape penetration magnetic field can be estimated by the formula of Jc*d, where Jc is the current density of the superconducting tape and d is the thickness of the superconducting tape.

The superconducting tape current transmission capability measuring device of the invention has three usage methods, which can reflect the current transmission capability of the strip under different conditions.

The first method of use: after the high-temperature superconducting tape is cooled by liquid nitrogen, it enters the slit of the magnetic circuit, and at this time, the excitation winding, that is, the magnetic circuit excitation coil flows, generates a DC magnetic field at the slit, and the magnetic field amplitude is less than or equal to 1 Double penetration of the magnetic field. The high-temperature superconducting tape passes through a DC magnetic field and is magnetized on the strip to generate a circulation. As the amplitude of the external magnetic field increases, the circulation will exhibit an internal-to-inner penetration process. The magnetic field generated by the circulation is opposite to the direction of the applied external magnetic field. This resistance to the application of the external magnetic field causes a change in the magnetic flux of the magnetic circuit, which is detected by the detecting winding in the form of an induced voltage. Since the critical current density of the strip is inconsistent and the amplitude of the external magnetic field is adjusted at the same time, the circulation position can be adjusted to obtain the current transmission capability information at different positions, which is detected by the detecting winding and the measuring circuit in the form of induced voltage. In this configuration, the detection winding and the measurement circuit detect only the change in current transmission capability, and after the system is calibrated, the absolute value of the current transmission capability can be reached.

The second method of use: after the high temperature superconducting tape is cooled by liquid nitrogen, it enters the slit of the magnetic circuit, and at this time, the excitation winding flows, and a DC magnetic field is generated at the slit. In the second method, the magnetic field amplitude is at least Reach 1 times the penetrating magnetic field. When the high-temperature superconducting tape is exposed to more than 1 times the penetrating magnetic field, it will produce a large circulation with a fully penetrating fixed shape, but with the increase of the amplitude of the external magnetic field, the intrinsic Jc (B) of the high-temperature superconducting tape is intrinsic. The effect, although the shape of the full penetration circulation will not change, but the amplitude of the circulation will decrease, loading different external magnetic fields, reflecting the current transmission capacity of the superconducting tape under the magnetic field. This information is detected by the sense winding as an induced voltage. The detection coil detects only the change in current transmission capability. After the system is calibrated, the absolute value of the current transmission capability can be reached.

The third method of use: after the high-temperature superconducting strip is cooled by liquid nitrogen, it first passes through an applied magnetic field of at least 2 times the penetrating magnetic field, and the applied magnetic field can be applied by an electromagnet or by a permanent magnet. After the superconducting tape is subjected to a magnetic field of more than 2 times and then the external magnetic field is removed, a fully penetrating superconducting circulation is left. At this time, the high-temperature superconducting tape enters the superconducting tape current transmission capability measuring device of the present invention. The slit detects the overall current transmission capability of the high-temperature superconducting tape under a zero applied magnetic field by using a detecting winding and a measuring circuit.

The beneficial effects of the invention are:

The invention provides a superconducting tape current transmission capability measuring probe, a measuring device and a method, and only requires a single-slit magnetic circuit to realize non-contact non-destructive measurement of the superconducting tape current transmission capability, and adopts a single slit. The excitation signal is stronger, and the external magnetic field measurement can be applied to the superconducting tape by the application of the external magnetic field, and the overall current transmission characteristic of the superconducting tape under the external magnetic field can be measured after filtering the external magnetic field signal, effectively The ground improves measurement accuracy while reducing system complexity.

The above description is only an overview of the technical solutions of the present invention, and the above-described and other objects, features and advantages of the present invention can be more clearly understood. Specific embodiments of the invention are set forth below.

DRAWINGS

Various other advantages and benefits will become apparent to those skilled in the art from a The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting. Throughout the drawings, the same reference numerals are used to refer to the same parts. In the drawing:

1 is a schematic structural view of a superconducting tape current transmission capability measuring probe according to an embodiment of the present invention;

2 is a schematic structural view of a superconducting tape current transmission capability measuring device according to an embodiment of the present invention;

3 is a schematic view showing a circulation flow formed on a superconducting tape by using the first test method in the embodiment of the present invention;

4 is a schematic view showing a circulation flow formed on a superconducting tape by using a second test method in an embodiment of the present invention;

Fig. 5 is a schematic view showing a circulation flow formed on a superconducting tape by a third test method in an embodiment of the present invention.

detailed description

The embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are intended to be illustrative of the invention and are not to be construed as limiting.

The singular forms "a", "an", "the" It is to be understood that the phrase "comprise" or "an" Integers, steps, operations, components, components, and/or groups thereof.

Those skilled in the art will appreciate that all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs, unless otherwise defined. It should also be understood that terms such as those defined in a general dictionary should be understood to have meaning consistent with the meaning in the context of the prior art, and will not be idealized or overly formal unless specifically defined. To explain.

The embodiment of the invention provides a superconducting tape current transmission capability measuring probe, which can continuously detect the critical current of the high temperature superconducting tape without loss. As shown in FIG. 1, the probe includes a magnetic circuit, and the magnetic circuit includes a magnetic core 1. In the embodiment of the present invention, the magnetic core has a C-shaped structure. The magnetic circuit core 1 of the magnetic circuit is made of soft magnetic material. In the embodiment, the C-type magnetic routing permalloy is formed in the form of a toroidal magnetic circuit, wherein the inner radius of the annular magnetic circuit is 50 mm, the outer radius of the annular magnetic circuit is 60 mm, and the annular magnetic circuit is formed. The thickness is 10mm. The window width d of the slit 2 on the magnetic circuit is larger than the width of the high temperature superconducting tape 7 to be tested, and the slit window height a is larger than the thickness of the high temperature superconducting tape 7 to be tested, in the embodiment a=5 mm, d=10 mm. In the embodiment of the invention, the magnetic circuit further comprises a field winding 3 and an adjustable excitation power source 4 matching the field winding, and the number of field winding turns is set to 240 匝. The C-type magnetic core is also wound with a detecting winding 5 and a measuring circuit 6 that cooperates with the detecting winding, and the detecting winding is set to 1000 匝.

Another embodiment of the present invention further provides a superconducting tape current transmission capability measuring device, as shown in FIG. 2, the superconducting tape current transmission capability measuring device measures the superconducting tape current transmission capability The probe is combined with the continuous transmission device 8 and the low temperature maintenance device 9 as shown in FIG. 2 to realize continuous measurement of the high-temperature superconducting long-band current transmission characteristic, wherein the low-temperature maintenance device 9 can be realized by a liquid nitrogen tank.

The superconducting tape current transmission capability measuring device provided by the embodiment of the invention is particularly suitable for measuring the current transmission capability of the flat high-temperature superconducting tape. The device has three measuring methods, which can reflect the current transmission of the strip under different conditions. ability.

In one embodiment of the invention, the first method is used to measure the current transfer capability of the high temperature superconducting tape at different width locations. The method is as follows: after the high temperature superconducting tape 7 is cooled by liquid nitrogen, it enters the slit 2, and at this time, the C-type magnetic circuit excitation coil flows, and a DC magnetic field is generated at the slit 2. In this embodiment, the DC magnetic field amplitude The value is always less than 1 times the penetrating magnetic field. The high-temperature superconducting tape passes through the DC magnetic field to produce the self-inward and penetrating circulation 11 as shown in Fig. 3. The larger the amplitude of the external magnetic field is, the deeper the penetration depth is, and the DC magnetic field is as large as 1 times. When it happens, it just happens to achieve complete penetration.

The magnetic field generated by the circulation is opposite to the direction of the applied external magnetic field. This resistance to the application of the external magnetic field causes a change in the magnetic flux of the magnetic circuit, which is detected by the detecting winding 5 and the measuring circuit 6 in the form of an induced voltage. Since the critical current density of the strip is inconsistent and the amplitude of the external magnetic field is adjusted at the same time, the position of the circulating current from the outside to the inside can be adjusted, and the current transmission capability information at different positions can be obtained, and the information is detected by the detecting winding. After the system is calibrated, the absolute value of the current transfer capability can be reached.

In another embodiment of the invention, the second method of use is used to measure the overall current transfer capability of the high temperature superconducting tape under different magnetic fields. The method of use is as follows: after the high temperature superconducting tape 7 is cooled by liquid nitrogen, it enters the slit 2, and at this time, the C-type magnetic circuit excitation coil flows, and a DC magnetic field is generated at the slit 2, and in the second method, the magnetic field The amplitude is at least 1 time above the penetrating magnetic field. When the high-temperature superconducting tape is exposed to more than 1 times the penetrating magnetic field, a full-penetration circulation will occur. As shown in Fig. 4, the full-flow shape of the circulation will not change as the amplitude of the external magnetic field 12 increases. However, affected by the intrinsic Jc(B) of the high-temperature superconducting tape, the amplitude of the circulation will decrease and the different external magnetic fields will be loaded, reflecting the overall current transmission capacity of the superconducting strip under different magnetic fields. It will be detected by the detecting winding 5 and the measuring circuit 6 in the form of an induced voltage, and after the system is calibrated, the absolute value of the current carrying capability can be reached.

Further, the superconducting tape current transmission capability measuring device further includes an applied magnetic field disposed on the continuous transmission device, the first guide wheel, the applied magnetic field, the slit and the second guide wheel are sequentially disposed on the same straight line Wherein the applied magnetic field is applied by an electromagnet or a permanent magnet.

In a further embodiment of the invention, a third measurement method is employed to measure the overall current transfer capability of the high temperature superconducting tape just under zero external magnetic field. The method is as follows: after the high-temperature superconducting strip 7 is cooled by liquid nitrogen, it is first subjected to a sufficiently large applied magnetic field, and the applied magnetic field can be applied by an electromagnet or a permanent magnet, and in this embodiment, as shown in FIG. 2 The illustrated permanent magnet 10 applies an external magnetic field. In the embodiment of the present invention, a sufficiently large applied magnetic field generally refers to a magnetic field of at least 2 times the size of the high temperature superconducting tape penetrating magnetic field. After the superconducting tape is applied with a magnetic field of more than 2 times, the external magnetic field is removed, and a super-permeating circulation of the fully penetrating state remains on the strip, as shown in FIG. The strip carrying the completely penetrating state circulation passes through the slit 2 and magnetizes the magnetic circuit. Since the critical current density of the strip is different, the circulation current is different. Like the first method, the coil 5 and the measuring circuit are detected. 6 Detected in the form of induced voltage, after the system is calibrated, the absolute value of the current transfer capability can be reached.

The above embodiment only enumerates a superconducting tape current transmission capability measuring device based on a C-type magnetic circuit structure probe, and the actual probe can also be various, such as an O-shaped, rectangular or closed polygon with slits, as long as it is The use of a field winding to apply a tunable magnetic field to a sample in a slit while detecting a sample circulating signal using a detecting winding is a variation in accordance with the spirit of the present invention and is intended to be encompassed within the scope of the invention.

Industrial applicability

The invention provides a superconducting tape current transmission capability measuring probe, a measuring device and a method, and only requires a single-slit magnetic circuit to realize non-contact non-destructive measurement of the superconducting tape current transmission capability, and adopts a single slit. The excitation signal is stronger, and at the same time, the external magnetic field measurement can be applied to the superconducting tape by the application of the external magnetic field, and the overall current transmission characteristic of the superconducting tape under the external magnetic field can be measured after filtering the external magnetic field signal.

The above embodiments are merely illustrative of the present invention and are not intended to be limiting of the invention, and various modifications and changes can be made without departing from the spirit and scope of the invention. Equivalent technical solutions are also within the scope of protection of the present invention.

Claims

A superconducting tape current transmission capability measuring probe, characterized in that the superconducting tape current transmission capability measuring probe comprises a magnetic circuit, a detecting winding and a measuring circuit connected to the detecting winding; the magnetic circuit The magnetic circuit core, the field winding, and an adjustable power supply for supplying current to the field winding, the field winding and the detecting winding are respectively wound on the magnetic circuit core, and the magnetic circuit core is opened a slit for accommodating a sample of the superconducting tape to be tested, the magnetic core and the slit forming a closed magnetic circuit; the narrowing is adjusted by the exciting winding and an adjustable power supply for supplying current to the field winding The magnitude of the magnetic field in the slot, the probe winding and a measurement circuit coupled to the probe winding measure the current transfer capability of the superconducting tape sample to be tested placed in the slit.
The superconducting tape current transmission capability measuring probe according to claim 1, wherein the material of the magnetic circuit core is a soft magnetic core.
The superconducting tape current transmission capability measuring probe according to claim 1 or 2, wherein the magnetic circuit core is a closed iron core and has an O-shape, a rectangular shape or a closed polygon shape.
The superconducting tape current transmission capability measuring probe according to claim 1 or 2, wherein the height of the slit is larger than the thickness of the superconducting tape sample to be tested, and the width is larger than the superconducting tape sample to be tested. The width.
A superconducting tape current transmission capability measuring device, comprising: the superconducting tape current transmission capability measuring probe according to any one of claims 1-4, continuous a transmission device, a low temperature maintenance device, the continuous transmission device is composed of a first guide wheel and a second guide wheel that cooperate with a pay-off device and a take-up device outside the cryostat device, and the first guide wheel and the second guide wheel respectively Placed on both sides of the magnetic circuit, the first guide wheel, the slit and the second guide wheel are on the same straight line, and the sample of the superconducting tape to be tested is guided from the external take-up device through the first guide wheel Passing through the slit and then guiding to the external wire take-up device through the second guide wheel, the moving direction of the superconducting tape sample to be tested is directed from the first guide wheel to the second guide wheel; the magnetic circuit is operated when the device is in operation And the superconducting tape samples to be tested are placed in the cryogenic maintenance device.
The superconducting tape current transmission capability measuring apparatus according to claim 5, further comprising an applied magnetic field provided on said continuous transmission, said first guide wheel, an applied magnetic field, a slit and a second The guide wheels are arranged in sequence on the same line.
The superconducting tape current transmission capability measuring apparatus according to claim 6, wherein said applied magnetic field is applied by an electromagnet or a permanent magnet.
The superconducting tape current transmission capability measuring apparatus according to any one of claims 5 to 7, wherein the low temperature maintaining means is a container containing liquid nitrogen.
A method for measuring a superconducting tape current transmission capability of a superconducting tape current transmission capability measuring device according to claim 5 or 8, wherein the method comprises:

Place a sample of the superconducting tape to be tested in the cryogenic maintenance device for cooling;

Passing the cooled sample of the superconducting tape to be tested into the slit through the continuous transmission;

Adjusting the magnitude and/or direction of the magnetic field generated by the field winding by the adjustable power supply for supplying current to the field winding;

The sample of the superconducting tape to be tested is measured in the form of an induced voltage by a detecting winding and a measuring circuit.
A method for measuring a superconducting tape current transmission capability of a superconducting tape current transmission capability measuring device according to any one of claims 6-8, characterized in that the method comprises:

Place a sample of the superconducting tape to be tested in the cryogenic maintenance device for cooling;

The cooled sample of the superconducting tape to be tested is supplied by an electromagnet or a permanent magnet to an applied magnetic field of at least 2 times the penetrating magnetic field;

The sample of the superconducting tape to be tested is removed from the applied magnetic field by the continuous transmission device, and enters the slit;

The sample of the superconducting tape to be tested is measured in the form of an induced voltage by a detecting winding and a measuring circuit.