阅读说明：本技术 高温超导带材螺旋缠绕状态下的临界电流测试装置及方法 (Device and method for testing critical current of high-temperature superconducting strip in spiral winding state ) 是由 张俊生 张午权 于 2020-06-28 设计创作，主要内容包括：本发明公开了一种高温超导带材螺旋缠绕状态下的临界电流测试装置及方法。该装置包括基体、固定平台一、固定平台二以及锁紧组件。基体包括同轴设置且依次连接成一个阶梯轴的定位段一、限位段一、缠绕段、限位段二以及定位段二。缠绕段的外壁上开设有节距不同的多条螺旋凹槽。其中至少一条螺旋凹槽沿着基体轴向的顺时针方向布置,剩余的螺旋凹槽沿着基体轴向的逆时针方向布置。固定平台一包括套接段一和平台段一,固定平台二包括套接段二和平台段二,锁紧组件包括锁紧件一和锁紧件二。本发明能够实现高温超导带材在不同螺旋节距下的临界电流测试功能,实现高温超导带材临界特性规律性的探索,为高温超导带材的应用推广提供可靠的实验测试方法。(The invention discloses a critical current testing device and method for a high-temperature superconducting tape in a spiral winding state. The device comprises a base body, a first fixing platform, a second fixing platform and a locking assembly. The base body comprises a first positioning section, a first limiting section, a winding section, a second limiting section and a second positioning section which are coaxially arranged and sequentially connected into a stepped shaft. The outer wall of the winding section is provided with a plurality of spiral grooves with different pitches. At least one of the spiral grooves is arranged along the clockwise direction of the axial direction of the base body, and the rest of the spiral grooves are arranged along the anticlockwise direction of the axial direction of the base body. The first fixing platform comprises a first sleeving section and a first platform section, the second fixing platform comprises a second sleeving section and a second platform section, and the locking assembly comprises a first locking part and a second locking part. The invention can realize the function of testing the critical current of the high-temperature superconducting tape under different spiral pitches, explore the regularity of the critical characteristics of the high-temperature superconducting tape and provide a reliable experimental test method for the application and popularization of the high-temperature superconducting tape.)

1. A critical current testing device suitable for a high-temperature superconducting tape in a spiral winding state is characterized by comprising:

the base body comprises a first positioning section, a first limiting section, a winding section, a second limiting section and a second positioning section which are coaxially arranged and sequentially connected into a stepped shaft; the cross section of the first limiting section is a regular polygon, and the cross section of the second limiting section is a circle; a plurality of spiral grooves with different pitches are formed in the outer wall of the winding section; at least one spiral groove is arranged along the clockwise direction of the axial direction of the base body, and the rest at least one spiral groove is arranged along the anticlockwise direction of the axial direction of the base body; two ends of the spiral grooves respectively extend to the end faces of two ends of the base body, the bottom surfaces of the same ends of the spiral grooves are positioned on the same cylindrical surface I, and the bottom surfaces of the same ends of the spiral grooves are positioned on the same cylindrical surface II;

the first fixed platform comprises a first sleeving section and a first platform section; the first sleeving connection section is provided with a regular polygon limiting hole matched with the first limiting section, and is sleeved on the first limiting section through the limiting hole; the first platform section and the first sleeving section are integrally formed, the first platform section is arranged on the outer wall of the first sleeving section, and the table top is tangent to the first cylindrical surface;

a second fixed platform which comprises a second sleeving section and a second platform section; the sleeving section is sleeved on the second limiting section; the second platform section and the second sleeving section are integrally formed, the second platform section is arranged on the outer wall of the second sleeving section, and the table top is tangent to the second cylindrical surface; and

the locking assembly comprises at least one locking piece I and at least one locking piece II; the first locking piece is arranged on the first positioning section and used for locking the first fixing platform and the first limiting section relatively along the axial direction of the base body; and the second locking part is arranged on the second positioning section and is used for relatively locking the second fixing platform and the second limiting section along the axial direction of the base body.

2. The critical current testing apparatus for a spiral wound high temperature superconducting tape as claimed in claim 1, further comprising:

and the two ends of one high-temperature superconducting strip respectively extend out of the corresponding spiral grooves and are respectively fixed on the first platform section and the second platform section through the first fixing component and the second fixing component.

3. The critical current testing apparatus for a spiral wound high temperature superconducting tape as claimed in claim 2, further comprising:

the first fixing assembly comprises a first fixing frame, a first pressing block and a plurality of first bolts; the first fixed frame is provided with a first fixed part and a second fixed part which are respectively positioned at two opposite sides of the first platform section; the first pressing block is positioned between the first fixing part and the first platform section, and one end of the high-temperature superconducting strip is positioned between the first pressing block and the first platform section; a plurality of first bolts are screwed on the first fixing part, and the insertion ends of the first bolts abut against the first pressing block, so that the first pressing block locks one end of the high-temperature superconducting strip;

the second fixing assembly comprises a second fixing frame, a second pressing block and a plurality of second bolts; the second fixed frame is provided with a third fixed part and a fourth fixed part which are respectively positioned at two opposite sides of the second platform section; the second pressing block is positioned between the third fixing part and the second platform section, and the other end of the high-temperature superconducting strip is positioned between the second pressing block and the second platform section; and a plurality of second bolts are screwed on the third fixing part, and the insertion ends of the second bolts abut against the second pressing block, so that the second pressing block locks the other end of the high-temperature superconducting strip.

4. The critical current testing device suitable for the spiral winding state of the high temperature superconducting tape as claimed in claim 3, wherein the first fixing assembly further comprises a first indium protective layer, and the first indium protective layer is arranged between the first pressing block and one end of the high temperature superconducting tape; the second fixing assembly further comprises a second indium sheet protective layer, and the second indium sheet protective layer is arranged between the second pressing block and the other end of the high-temperature superconducting strip.

5. The critical current testing device for the spiral wound state of the high temperature superconducting tape as claimed in claim 1, wherein two first circular holes are formed on the first platform section, and the two first circular holes are respectively located at one end of the first platform section, which is close to the first locking member; two round holes II are formed in the second platform section and are respectively located at one end, close to the second locking part, of the second platform section.

6. The apparatus for testing critical current suitable for spiral wound high temperature superconducting tape as claimed in claim 1, wherein the locking member is threadedly engaged with the first positioning segment and is capable of rotating to abut against the first engaging segment, so that the first fixing platform is axially locked with one end of the base; and the locking piece II is in threaded sleeve joint with the positioning section II and can rotate to abut against the sleeve joint section II, so that the fixing platform II and the other end of the base body are axially locked.

7. The apparatus for testing critical current of a high temperature superconducting tape in a spiral wound state as claimed in claim 2, wherein the substrate is a substrate made of a glass fiber and epoxy resin composite material, and the high temperature superconducting tape is a high temperature superconducting tape made of an yttrium barium copper oxide material.

8. The critical current testing device for the spiral wound state of a high temperature superconducting tape as claimed in claim 1, wherein the first positioning segment, the first limiting segment, the winding segment, the second limiting segment and the second positioning segment are integrally formed; the cross section of the first limiting section is square, and the side length of the square is equal to the diameter of the cross section of the first positioning section; the winding section is cylindrical, the diameter of the winding section is larger than the side length and the diameter of the limiting section II, and the diameter of the limiting section II is larger than the diameter of the positioning section II.

9. The apparatus for testing critical current suitable for use in a spiral wound hts tape of claim 3, wherein the first and second fixed platforms are made of oxygen-free copper material, the first and second fixed frames are made of stainless steel material, and the first and second compacts are made of glass fiber and epoxy resin composite material.

10. A critical current testing method for a spiral wound high temperature superconducting tape, which is applied to the critical current testing apparatus for a spiral wound high temperature superconducting tape according to any one of claims 1 to 9, comprising the steps of:

respectively winding a plurality of high-temperature superconducting strips in a plurality of spiral grooves, so that two ends of each high-temperature superconducting strip respectively extend out of the corresponding spiral grooves;

placing the high-temperature superconducting tape in a spiral groove with corresponding pitch, wherein the cross section of the first limiting section is square, so that the first fixing platform can be adjusted in a circumferential direction by rotating 90 degrees, the table top of the first fixing platform is overlapped with the bottom surface of the spiral groove with corresponding pitch, and one end of the high-temperature superconducting tape is fixed on the first platform section through the first fixing component;

rotating the second fixing platform to enable the table top of the second fixing platform to be overlapped with the bottom surfaces of the spiral grooves with different pitches, and fixing a plurality of high-temperature superconducting tapes on the second platform section respectively to realize winding of the high-temperature superconducting tapes with different spiral pitches;

placing two ends of the high-temperature superconducting strip on the first platform section and the second platform section respectively, arranging an indium sheet protective layer on the upper layer, arranging an epoxy plate pressing block, screwing a plurality of bolts on two fixing frames respectively positioned above the first platform section and the second platform section, and enabling insertion ends to abut against the epoxy plate pressing block, so that the high-temperature superconducting strip is fixed on the first platform section and the second platform section;

and connecting current to one of the first platform section and the second platform section, enabling the current to flow out of the other one of the first platform section and the second platform section through the high-temperature superconducting tapes with different spiral pitches to form a current loop, connecting the connected current to one of round holes formed in the first platform section or the second platform section through a current lead, pressing and fixing the round holes based on whether the positions of the high-temperature superconducting tapes on the first platform section or the second platform section are on the left side or the right side, selecting a corresponding round hole nearby, and finally realizing the critical current test.

Technical Field

The invention relates to a current testing device in the technical field of high-temperature superconducting application, in particular to a critical current testing device suitable for a high-temperature superconducting tape in a spiral winding state and a critical current testing method suitable for the device in the spiral winding state.

Background

Since 1911 when the phenomenon of superconduction was discovered, the application of superconducting materials has been greatly developed. With the development of superconducting technology, it has great application in the fields of medical treatment, large-scale accelerators, fusion devices, power systems and the like. Compared with the conventional conductor, the superconducting material greatly improves the current-carrying density of the conductor and the coil, reduces the sizes of the conductor and the coil, can realize the zero-resistance characteristic, almost has no resistance in the direct current transmission process, cannot generate joule heat, and greatly improves the transmission efficiency of electric energy.

The superconducting materials are classified into low-temperature superconducting materials and high-temperature superconducting materials according to the use temperature region. The low temperature superconducting materials are most typically NbTi and Nb₃The superconducting transition temperature of the Sn wire is respectively 10K and 18K, and the low-temperature superconducting material has already taken a big step in the field of practical application because the manufacturing process is mature day by day, and is applied to a small number of large devices such as an accelerator device and a fusion device. However, because of the higher requirement of the superconducting working temperature region, the working is required to be carried out in the liquid helium temperature region of 4.2K, and the liquid helium has higher production difficulty and relatively high price. Coils wound by low-temperature superconducting materials are often required to be provided with a liquid helium low-temperature refrigerating device, and high refrigerating cost and severe low-temperature environment requirements become bottlenecks which limit the development of the low-temperature superconducting materials. Therefore, the method has important significance for research and test of the high-temperature superconducting material.

The high-temperature superconducting material mainly comprises a bismuth-system high-temperature superconducting material and a yttrium-system high-temperature superconducting material, the earliest high-temperature superconducting material is the bismuth-system high-temperature superconducting material, the preparation process mainly comprises a powder sleeve method and a dip coating method, and the preparation process mainly comprises two strip structures of Bi-2212 and Bi-2223. However, when the superconducting material is applied to actual electrical equipment, under the influence of actual working conditions, various stresses, strains and complex electromagnetic environments exist, and these influencing factors can generate large influence on the critical current of the superconducting material, reduce the transmission capability of the superconducting material, and even cause unstable operation and quench of the equipment under certain severe environments. The Bi-based strapping material has obvious anisotropy, and the critical current characteristic is easily influenced by an external magnetic field. Therefore, the second generation yttrium series superconducting tapes become a new hot research direction, and mainly take the YBCO high-temperature superconducting tapes as a representative. Compared with Bi-series high-temperature superconducting tapes, the YBCO tapes have weak anisotropy, higher critical current characteristics and huge application potential particularly in the aspect of direct-current power transmission.

Although the performance of the YBCO high-temperature superconducting tape is improved compared with that of a Bi-based tape, various stress-strain factors still have certain influence on the critical current characteristics of the YBCO high-temperature superconducting tape, for example, the YBCO high-temperature superconducting tape is inevitably subjected to stress strain under bending, torsion and spiral working conditions in the process of winding conductors and coils by the YBCO tape. The stress strain environment can cause the decline of the critical current of the YBCO strip, reduce the current carrying capacity of the YBCO high-temperature superconducting conductor and the coil and influence the stability, the economy and the operating efficiency of high-temperature superconducting power equipment. However, the stress-strain effect in the practical application process cannot be avoided, and the critical current characteristic of the YBCO high-temperature superconducting tape must be mastered to ensure the stable operation of the power device and prevent the occurrence of quench. However, the conventional critical current testing device cannot accurately test the YBCO high-temperature superconducting tape, the test data has large errors due to simple winding, and the testing efficiency is low.

Disclosure of Invention

The invention provides a critical current testing device and method for a high-temperature superconducting strip in a spiral winding state, and aims to solve the technical problems of large error and low efficiency when the existing testing device tests the high-temperature superconducting strip.

The invention is realized by adopting the following technical scheme: a critical current testing device suitable for a high-temperature superconducting tape in a spiral winding state comprises:

the base body comprises a first positioning section, a first limiting section, a winding section, a second limiting section and a second positioning section which are coaxially arranged and sequentially connected into a stepped shaft; the cross section of the first limiting section is a regular polygon, and the cross section of the second limiting section is a circle; a plurality of spiral grooves with different pitches are formed in the outer wall of the winding section; at least one spiral groove is arranged along the clockwise direction of the axial direction of the base body, and the rest at least one spiral groove is arranged along the anticlockwise direction of the axial direction of the base body; two ends of the spiral grooves respectively extend to the end faces of two ends of the base body, the bottom surfaces of the same ends of the spiral grooves are positioned on the same cylindrical surface I, and the bottom surfaces of the same ends of the spiral grooves are positioned on the same cylindrical surface II;

the first fixed platform comprises a first sleeving section and a first platform section; the first sleeving connection section is provided with a regular polygon limiting hole matched with the first limiting section, and is sleeved on the first limiting section through the limiting hole; the first platform section and the first sleeving section are integrally formed, the first platform section is arranged on the outer wall of the first sleeving section, and the table top is tangent to the first cylindrical surface;

a second fixed platform which comprises a second sleeving section and a second platform section; the sleeving section is sleeved on the second limiting section; the second platform section and the second sleeving section are integrally formed, the second platform section is arranged on the outer wall of the second sleeving section, and the table top is tangent to the second cylindrical surface; and

the locking assembly comprises at least one locking piece I and at least one locking piece II; the first locking piece is arranged on the first positioning section and used for locking the first fixing platform and the first limiting section relatively along the axial direction of the base body; and the second locking part is arranged on the second positioning section and is used for relatively locking the second fixing platform and the second limiting section along the axial direction of the base body.

According to the invention, the high-temperature superconducting tapes are respectively wound in the spiral grooves, and the spiral grooves have different pitches, so that the test requirements of different spiral pitches can be met, and the forward winding mode and the reverse winding mode can effectively reduce the mutual interference between the high-temperature superconducting tapes, reduce the test error and improve the accuracy of the critical current test. Because the bottom surfaces of the same ends of the spiral grooves are all positioned on the same cylindrical surface, after the high-temperature superconducting tape is wound, testers can enable the bottom surfaces of different spiral grooves to coincide with the table top of the first platform section by rotating the second fixed platform, the transition from the spiral to the plane of the high-temperature superconducting tape can be realized, the coincidence characteristic is always kept in the circumferential rotation adjusting process of the second fixed platform, the test operation is very convenient, the test efficiency can be improved, the test requirements of different spiral pitches are met, the technical problems that the error is large and the efficiency is low when the existing test device tests the high-temperature superconducting tape are solved, the current test efficiency is high, the error is small, and the technical effect is simple and convenient to operate.

As a further improvement of the above aspect, the critical current testing apparatus further includes:

and the two ends of one high-temperature superconducting strip respectively extend out of the corresponding spiral grooves and are respectively fixed on the first platform section and the second platform section through the first fixing component and the second fixing component.

Further, the critical current testing apparatus further includes:

the first fixing assembly comprises a first fixing frame, a first pressing block and a plurality of first bolts; the first fixed frame is provided with a first fixed part and a second fixed part which are respectively positioned at two opposite sides of the first platform section; the first pressing block is positioned between the first fixing part and the first platform section, and one end of the high-temperature superconducting strip is positioned between the first pressing block and the first platform section; a plurality of first bolts are screwed on the first fixing part, and the insertion ends of the first bolts abut against the first pressing block, so that the first pressing block locks one end of the high-temperature superconducting strip;

the second fixing assembly comprises a second fixing frame, a second pressing block and a plurality of second bolts; the second fixed frame is provided with a third fixed part and a fourth fixed part which are respectively positioned at two opposite sides of the second platform section; the second pressing block is positioned between the third fixing part and the second platform section, and the other end of the high-temperature superconducting strip is positioned between the second pressing block and the second platform section; and a plurality of second bolts are screwed on the third fixing part, and the insertion ends of the second bolts abut against the second pressing block, so that the second pressing block locks the other end of the high-temperature superconducting strip.

Furthermore, the first fixing assembly further comprises a first indium sheet protective layer, and the first indium sheet protective layer is arranged between the first pressing block and one end of the high-temperature superconducting strip; the second fixing assembly further comprises a second indium sheet protective layer, and the second indium sheet protective layer is arranged between the second pressing block and the other end of the high-temperature superconducting strip.

As a further improvement of the above scheme, two first circular holes are formed in the first platform section and are respectively located at one end, close to the first locking member, of the first platform section; two round holes II are formed in the second platform section and are respectively located at one end, close to the second locking part, of the second platform section.

As a further improvement of the above scheme, the first locking member is sleeved on the first positioning section in a threaded manner and can rotate to abut against the first sleeving section, so that the first fixing platform and one end of the base body are axially locked; and the locking piece II is in threaded sleeve joint with the positioning section II and can rotate to abut against the sleeve joint section II, so that the fixing platform II and the other end of the base body are axially locked.

Furthermore, the substrate is made of glass fiber and epoxy resin composite materials, and the high-temperature superconducting tape is made of yttrium barium copper oxide materials.

As a further improvement of the above scheme, the first positioning section, the first limiting section, the winding section, the second limiting section and the second positioning section are integrally molded; the cross section of the first limiting section is square, and the side length of the square is equal to the diameter of the cross section of the first positioning section; the winding section is cylindrical, the diameter of the winding section is larger than the side length and the diameter of the limiting section II, and the diameter of the limiting section II is larger than the diameter of the positioning section II.

Further, the first fixing platform and the second fixing platform are both platforms made of oxygen-free copper materials, the first fixing frame and the second fixing frame are both frames made of stainless steel materials, and the first pressing block and the second pressing block are both pressing blocks made of glass fiber and epoxy resin composite materials.

The invention also provides a critical current testing method suitable for the high-temperature superconducting tape in the spiral winding state, which is applied to any critical current testing device suitable for the high-temperature superconducting tape in the spiral winding state, and comprises the following steps:

respectively winding a plurality of high-temperature superconducting strips in a plurality of spiral grooves, so that two ends of each high-temperature superconducting strip respectively extend out of the corresponding spiral grooves;

placing the high-temperature superconducting tape in a spiral groove with corresponding pitch, wherein the cross section of the first limiting section is square, so that the first fixing platform can be adjusted in a circumferential direction by rotating 90 degrees, the table top of the first fixing platform is overlapped with the bottom surface of the spiral groove with corresponding pitch, and one end of the high-temperature superconducting tape is fixed on the first platform section through the first fixing component;

rotating the second fixing platform to enable the table top of the second fixing platform to be overlapped with the bottom surfaces of the spiral grooves with different pitches, and fixing a plurality of high-temperature superconducting tapes on the second platform section respectively to realize winding of the high-temperature superconducting tapes with different spiral pitches;

placing two ends of the high-temperature superconducting strip on the first platform section and the second platform section respectively, arranging an indium sheet protective layer on the upper layer, arranging an epoxy plate pressing block, screwing a plurality of bolts on two fixing frames respectively positioned above the first platform section and the second platform section, and enabling insertion ends to abut against the epoxy plate pressing block, so that the high-temperature superconducting strip is fixed on the first platform section and the second platform section;

and connecting current to one of the first platform section and the second platform section, enabling the current to flow out of the other one of the first platform section and the second platform section through the high-temperature superconducting tapes with different spiral pitches to form a current loop, connecting the connected current to one of round holes formed in the first platform section or the second platform section through a current lead, pressing and fixing the round holes based on whether the positions of the high-temperature superconducting tapes on the first platform section or the second platform section are on the left side or the right side, selecting a corresponding round hole nearby, and finally realizing the critical current test.

Compared with the existing testing device, the critical current testing device and method of the high-temperature superconducting tape in the spiral winding state have the following beneficial effects:

1. according to the critical current testing device applicable to the spiral winding state of the high-temperature superconducting strip, all sections of a base body are connected to form a stepped shaft, a first fixing platform and a second fixing platform are respectively arranged at two ends of the base body to form current testing access ports, and the first fixing platform and the second fixing platform are fixed with the base body through a locking assembly, so that the testing device is of an integral structure, and the device can be conveniently operated. The spiral grooves on the base body of the device can be used for winding a plurality of high-temperature superconducting strips, and because the pitches of the high-temperature superconducting strips are different, the situation that the strips are inevitably subjected to stress strain under bending, twisting and spiral working conditions in the process of winding conductors and coils can be simulated, the test requirements of different spiral pitches are met, the mutual interference between the high-temperature superconducting strips can be effectively reduced by the two winding modes of forward rotation and reverse rotation, the test error is reduced, and the accuracy of critical current test is improved. Because the bottom surfaces of the same ends of the spiral grooves are all positioned on the same cylindrical surface, after the high-temperature superconducting tape is wound, testers can enable the bottom surfaces of different spiral grooves to coincide with the table surfaces of the first platform section and the second platform section by rotating the first fixing platform and the second fixing platform, transition from a spiral to a plane of the high-temperature superconducting tape can be realized, the coincidence characteristic is always kept in the circumferential rotation adjusting process of the second fixing platform, the testing operation is very convenient, the testing efficiency can be further improved, the testing requirements of different spiral pitches are met, the exploration of the regularity of the critical characteristic of the high-temperature superconducting tape is realized, and a reliable experimental testing method is provided for application and popularization of the high-temperature superconducting tape.

2. According to the critical current testing device suitable for the high-temperature superconducting tape in the spiral winding state, the matrix can be made of glass fiber and epoxy resin composite materials, effective insulation can be formed, and meanwhile, input current is guaranteed to form a loop through the high-temperature superconducting tape. The fixed platform is made of an oxygen-free copper material, so that current is transmitted to the high-temperature superconducting strip through the oxygen-free copper to form a loop, the resistance is low, the influence on the test can be reduced, and the critical current test precision is improved.

3. This critical current testing arrangement suitable for under high temperature superconducting tape spiral winding state, its locking component's retaining member one and retaining member two carry on spacingly through the mode of spiro union to fibre section one and spacing section two, just so can easily adjust the position of fixed platform one and fixed platform two, only need loosen the retaining member when needs change the spiral pitch and can realize the rotation to fixed platform, test convenient and fast more.

4. According to the critical current testing device applicable to the spiral winding state of the high-temperature superconducting strip, the bolt of the fixing assembly can be pressed on the pressing block in a threaded connection mode, and the pressing block can further limit the high-temperature superconducting strip between the pressing block and the fixing platform, so that the end part of the high-temperature superconducting strip can be fixed, and the current can be conveniently and subsequently transmitted to the high-temperature superconducting strip through the fixing platform. An indium sheet protective layer capable of protecting the high-temperature superconducting strip is arranged between the high-temperature superconducting strip and the pressing block, so that the high-temperature superconducting strip is protected from being damaged while being compressed, damage to a test product is avoided, and the accuracy of the test is improved.

5. According to the critical current testing device applicable to the high-temperature superconducting strip in the spiral winding state, the platform section of the fixing platform is provided with the two round holes, so that the relatively close holes are determined as current lead access positions according to the spiral direction of the strip, the current leads at two ends of the base body are accessed, the current is transmitted to the high-temperature superconducting strip through the fixing platform to form a loop, meanwhile, the low resistivity of the oxygen-free copper material can effectively reduce joule heat, and the reliability of current transmission is guaranteed.

6. The critical current testing method applicable to the high-temperature superconducting tape in the spiral winding state has the same beneficial effects as the critical current testing device applicable to the high-temperature superconducting tape in the spiral winding state, and the detailed description is omitted here.

Drawings

Fig. 1 is a schematic structural diagram of a critical current testing apparatus suitable for use in a state where a high-temperature superconducting tape is spirally wound according to embodiment 1 of the present invention.

Fig. 2 is a schematic view of a base of the current testing apparatus of fig. 1.

FIG. 3 is a schematic diagram showing the uniform distribution and short axis of the grooves in the cross section of the starting end of the substrate in FIG. 2.

FIG. 4 is a schematic cross-sectional groove distribution and short axis view of the substrate termination end of FIG. 2.

Fig. 5 is a schematic view showing that the fixing platforms of the current testing apparatus of fig. 1 are assembled at both ends of the base body and the strip is embedded in the groove.

FIG. 6 is a schematic diagram showing the upper plane of the mounting platform of the current testing apparatus of FIG. 1 coinciding with the bottom surface of the groove on the end face of the base body G10.

Fig. 7 is a schematic view of a fixing frame of the current testing apparatus of fig. 1 fixing a strip joint.

Description of the symbols:

1 base body 14 spacing section two

2 high-temperature superconducting strip 15 positioning section two

3 fixed platform one 16 socket joint section one

4 fixed platform two 17 platform section one

5 locking piece one 18 socket joint section two

6 locking piece two 19 platform section two

7 InP protective layer one 20 fixed frame two

8 pressing blocks one and 21 pressing blocks two

9 bolt one 22 bolt two

10 fixed frame one 23 indium sheet protective layer two

11 positioning section one 24 round hole one

12 spacing section one 25 round hole two

13 winding section 26 spiral groove

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.