Voltage lead arrangement method of uninsulated coil and coil

Abstract

The invention discloses a voltage lead arrangement method of an uninsulated coil and the coil, and relates to the technical field of superconduction. Comprising the following steps: S1, acquiring a superconducting tape and a foil type voltage sensor; s2, winding an uninsulated coil by using a superconducting strip; and S3, inserting a foil type voltage sensor between the superconducting strips of the uninsulated coil which is wound in the S2 to obtain the uninsulated coil provided with the foil type voltage sensor. According to the invention, the voltage in the coil can be measured on the premise of not influencing the turn-to-turn contact performance of the uninsulated coil.

Description

Technical Field

[0001] The invention relates to the field of superconducting technology, and in particular to a voltage lead arrangement method of a non-insulated coil and a coil. Background Art

[0002] The uninsulated coil was first proposed by Hahn et al. of MIT. The insulation between the traditional coil turns is eliminated. Since the superconducting material has zero resistance, and the metal interface between the turns has a higher resistance than the superconducting material, the current will eventually flow in the circumferential direction. In the uninsulated coil, if there are defects in the strip, or local hot spots are generated during quenching, the current can flow through the turns to bypass the defects or hot spots, so as not to cause heat accumulation. In addition, since the insulating material is eliminated, the thermal conductivity between the strip and the metal will be better, and the heat can be taken away in time so as not to induce a larger-scale quench. The size of the coil can also be reduced, greatly improving the engineering current density of the uninsulated coil. Therefore, the uninsulated coil can achieve high current density while having good stability, and has broad prospects in many strong magnetic field applications.

[0003] In the testing technology of uninsulated coils, many sensors are used to monitor whether the coil is quenched. Among them, voltage sensors are typical sensors. When the superconducting material quenches, it will become a conventional conductor with resistance characteristics. A non-zero voltage will appear on the conductor, which is the most effective means to detect quench. In voltage sensors, the current conventional method is to weld voltage leads on the surface or side of the strip. The voltage leads generally use metal wires or metal probes, such as copper wires, manganese copper wires, phosphor bronze wires, copper probes, etc. In order to more accurately understand the operation status of the coil, it is often necessary to arrange multiple distributed voltage sensors for the coil, especially for uninsulated coils. When inter-turn shunt occurs, the local voltage may change, which cannot be detected by the voltage lead of the outermost turn of the coil alone. Jeseok Bang et al. proposed a method of directly welding the voltage lead on the upper surface of the pancake coil (i.e., the side of the strip). However, this method has high requirements for the fixing process. For example, welding will change the inter-turn resistance, and if ordinary tape is used for fixing, the lead will be easily broken.

[0004] Therefore, it is an urgent problem for technical personnel in this field to propose a voltage lead arrangement method and a coil for a non-insulated coil, which can achieve voltage measurement with extremely slight changes in the coil geometry by inserting a foil-shaped conductor between turns during the coil winding process. Summary of the invention

[0005] In view of this, the present invention provides a voltage lead arrangement method for a non-insulated coil and a coil, which can solve the problems existing in the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A method for arranging voltage leads of a non-insulated coil comprises the following steps:

[0008] S1. Obtain superconducting tape and foil voltage sensor;

[0009] S2, using superconducting tape to wind an uninsulated coil;

[0010] S3. Insert the foil type voltage sensor between the superconducting tapes of the non-insulated coil being wound in S2 to obtain the non-insulated coil arranged with the foil type voltage sensor.

[0011] In the above method, optionally, the superconducting tape in S1 is a REBCO superconducting tape, and the foil voltage sensor is a conductive foil.

[0012] In the above method, optionally, in S2: the non-insulated coil is a non-insulated pancake coil.

[0013] In the above method, the specific contents of S3 are optional and include:

[0014] S31, starting from the 1st turn, inserting the foil type voltage sensor when winding to the Nth turn, and fixing the foil type voltage sensor between the Nth turn and the N-1th turn by squeezing the superconducting tape between the two turns;

[0015] S32, repeat S31, and continue to wind the position of the next preset voltage lead point, so that the preset number of foil voltage sensors are fixed by squeezing between two adjacent turns.

[0016] In the above method, optionally, the position of the preset voltage lead point, that is, the placement position of the foil voltage sensor is determined according to the geometric shape of the non-insulated coil, and specifically includes the following contents:

[0017] The uninsulated coil is a circular coil, which is axially symmetrical, and there is no restriction on the placement of the foil voltage sensor;

[0018] If the uninsulated coil is a racetrack-type coil or a D-type coil, foil voltage sensors are placed on the straight section and the curved section respectively to explore the changes in voltage signals at different positions.

[0019] In the above method, optionally, the foil voltage sensor is made of graphite.

[0020] A non-insulated coil with a voltage lead obtained by any of the above methods comprises a non-insulated coil wound by a superconducting tape, wherein foil-type voltage sensors are arranged between the superconducting tapes of the non-insulated coil.

[0021] It can be seen from the above technical solution that compared with the prior art, the present invention discloses a voltage lead arrangement method and coil for a non-insulated coil, which has the following beneficial effects: a high-strength, extremely low-thickness conductive foil is inserted between turns when the coil is wound, and is fixed by extrusion of two adjacent turns. Traditional voltage leads can only be welded to the surface of the strip by soldering and cannot be arranged inside the coil. This foil-type voltage lead can be placed and led out between two strips with an extremely thin thickness by pressure contact, and can measure the voltage inside the coil without affecting the contact performance between the turns of the non-insulated coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0023] Figure 1 It is a flow chart of a method for arranging voltage leads of a non-insulated coil disclosed in the present invention;

[0024] Figure 2 It is a description of the position of the foil voltage sensor disclosed in the present invention when winding the coil;

[0025] Figure 3 The present invention discloses Figure 2 A cross-sectional view of a foil voltage sensor arrangement without an insulating coil;

[0026] Figure 4 The actual picture of the arrangement of the foil-type voltage lead without insulation coil disclosed in the present invention, wherein 4a is the actual picture of the arrangement diagram of the connected wires, and 4b is the actual picture of the arrangement diagram of the unconnected wires;

[0027] Among them, 1-superconducting tape, 2-uninsulated coil, 3-foil voltage sensor. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In this application, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "comprise one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0030] Reference Figure 1-Figure 3 As shown, the present invention discloses a method for arranging voltage leads of a non-insulated coil, comprising the following steps:

[0031] S1, obtaining a superconducting tape 1 and a foil voltage sensor 3;

[0032] S2, using the superconducting tape 1 to wind the non-insulated coil 2;

[0033] S3 . Insert the foil type voltage sensor 3 between the superconducting tapes 1 of the non-insulated coil 2 being wound in S2 , so as to obtain the non-insulated coil 2 on which the foil type voltage sensor 3 is arranged.

[0034] Furthermore, the superconducting tape in S1 is made of REBCO superconducting tape, and the foil voltage sensor 3 is made of conductive foil.

[0035] Among them, REBCO superconducting tape: the second generation of high-temperature superconducting tape, with superconducting properties, can be wound into coils to achieve strong magnetic field applications; non-insulated coil: directly wound using REBCO superconducting tape, without any insulation, to form a pancake-shaped coil; foil voltage sensor: thinner conductive foil, or thinner superconducting tape, with a thickness of about 0.01-0.05mm, selected according to different application scenarios.

[0036] Furthermore, in S2: the non-insulated coil 2 is a non-insulated pancake coil.

[0037] Furthermore, the specific contents of S3 include:

[0038] S31, starting from the 1st turn, insert the foil type voltage sensor 3 when winding to the Nth turn, and fix the foil type voltage sensor 3 between the Nth turn and the N-1th turn by squeezing the superconducting tape between the two turns;

[0039] S32, repeat S31, and continue to wind the position of the next preset voltage lead point, so that the preset number of foil voltage sensors 3 are all fixed by squeezing between two adjacent turns.

[0040] Furthermore, the position of the preset voltage lead point, that is, the placement position of the foil voltage sensor 3 is determined according to the geometric shape of the non-insulated coil 2, and specifically includes the following contents:

[0041] The non-insulated coil 2 is a circular coil, which is axially symmetrical, and the foil type voltage sensor 3 is placed without restriction;

[0042] If the uninsulated coil 2 is a racetrack-shaped coil or a D-shaped coil, foil voltage sensors 3 are placed in the straight section and the curved section respectively to explore the voltage signal changes at different positions.

[0043] Specifically, the number of turns to be placed is determined according to the actual test needs. For example, in this experiment, one turn needs to be placed every 10 turns. In some other experiments, if accurate measurement is required, one turn can be placed every 1 turn. The optimal number of turns is determined according to the actual application.

[0044] Furthermore, the foil type voltage sensor 3 is made of graphite.

[0045] The choice of foil is not limited to graphite, copper, aluminum, stainless steel, etc. Any conductive material that meets the requirements of high strength and thin thickness can be the choice of foil voltage lead. At the same time, there is no theoretical upper limit on the number of foil insertions, and they can be arranged at any position of the coil as needed. Reasonable arrangement of foil voltage leads can better measure and monitor the coil.

[0046] Specifically, this method has very high requirements for the foil. In order to measure voltage, the foil needs to be made of conductive material. First of all, the foil is required to be very thin, not to affect the winding of the uninsulated coil, not to cause obvious gaps between adjacent turns, to ensure that the two adjacent turns still have good contact and have a sufficiently small inter-turn resistance, so the thickness of the foil needs to be controlled below 0.05mm. In addition, the foil must have good friction. Since the foil is fixed by the friction generated by the extrusion between the turns, if the friction is too small, the foil may slip out of the gap between the turns. Finally, the foil must have high strength. Generally, foils with a thickness of less than 0.02mm are very fragile even if they are made of metal materials, and are easy to tear and break, so high-strength foil materials need to be selected.

[0047] In a specific embodiment, the foil is made of high-purity material to make a 0.01-0.05 mm graphite sheet.

[0048] In another specific embodiment, the foil is a copper sheet with a thickness of 0.03-0.05 mm, an aluminum sheet with a thickness of 0.02-0.05 mm, or a stainless steel sheet with a thickness of 0.01-0.05 mm.

[0049] See also Figure 2 As shown, the present invention also discloses a non-insulated coil with a voltage lead obtained by any of the above methods, comprising a non-insulated coil 2 wound by a superconducting tape 1, and a foil voltage sensor 3 is arranged between the superconducting tapes 1 of the non-insulated coil 2.

[0050] In a specific embodiment, see Figure 4 The figure shows a non-insulated coil with a voltage lead obtained by winding using the scheme of the present invention, wherein: Figure 4 a is a physical picture of the layout of the connecting wires. Figure 4 b is a physical picture of the layout diagram without connected wires.

[0051] A high-strength, extremely low-thickness conductive foil is inserted between turns when the coil is wound and fixed by squeezing two adjacent turns. Traditional voltage leads can only be soldered to the surface of the strip and cannot be arranged inside the coil. This foil-type voltage lead can be placed and led out between two strips in an extremely thin thickness by pressure contact, and can measure the voltage inside the coil without affecting the contact performance between turns of the uninsulated coil.

[0052] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can refer to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can refer to the partial description of the method embodiment. The system and system embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without creative work.

[0053] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for arranging voltage leads without an insulation coil, characterized in that: The following steps are involved: S1. Obtain superconducting tape and foil voltage sensor; S2, using superconducting tape to wind an uninsulated coil; S3. Insert the foil type voltage sensor between the superconducting tapes of the non-insulated coil being wound in S2 to obtain the non-insulated coil arranged with the foil type voltage sensor.

2. The method for arranging voltage leads of a non-insulated coil according to claim 1, characterized in that: The superconducting tape in S1 uses REBCO superconducting tape, and the foil voltage sensor uses conductive foil.

3. The method for arranging voltage leads of a non-insulated coil according to claim 1, characterized in that: In S2: the non-insulated coil is a non-insulated pancake coil.

4. The method for arranging voltage leads of a non-insulated coil according to claim 3, characterized in that: The specific contents of S3 include: S31, starting from the 1st turn, inserting the foil voltage sensor when winding to the Nth turn, and fixing the foil voltage sensor between the Nth turn and the N-1th turn by squeezing the superconducting tape between the two turns; S32, repeat S31, and continue to wind the position of the next preset voltage lead point, so that the preset number of foil voltage sensors are fixed by squeezing between two adjacent turns.

5. The method for arranging voltage leads of a non-insulated coil according to claim 4, characterized in that: The location of the preset voltage lead point, i.e. the placement position of the foil voltage sensor, is determined based on the geometry of the uninsulated coil, including the following: The uninsulated coil is a circular coil, which is axially symmetrical, and there is no restriction on the placement of the foil voltage sensor; If the uninsulated coil is a racetrack-type coil or a D-type coil, foil voltage sensors are placed on the straight section and the curved section respectively to explore the changes in voltage signals at different positions.

6. The method for arranging voltage leads of a non-insulated coil according to claim 1, characterized in that: Foil voltage sensors use graphite sheets.

7. An uninsulated coil with a voltage lead obtained by the method according to any one of claims 1 to 6, characterized in that: The invention comprises a non-insulated coil wound by a superconducting tape, and foil type voltage sensors are arranged between the superconducting tapes of the non-insulated coil.

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