High temperature superconducting cables and coils

Abstract

A high temperature superconducting (HTS) cable. The HTS cable includes a channel, an HTS material, and an insulating layer. The channel is formed from a conductive material and has a groove extending along the length of the HTS cable. The HTS material is located in the groove such that when the HTS material is in a superconducting state, the HTS material forms a superconducting current path along the cable such that the HTS material is electrically connected to the channel. The insulating layer is located on a surface of the channel. The channel has a plurality of recesses, each recess containing an electrical assembly including a conductive path and / or one or more electrical components, and further including an insulator separating the electrical assembly from the channel. The HTS cable further includes a first electrical connection for each recess providing an electrical connection from the electrical assembly in the recess across or through the insulating layer, and a second electrical connection electrically connecting the channel to the electrical assembly in the recess, such that any conductive path from the first electrical connection through the recess to the second electrical connection passes through the electrical assembly.

Description

[Technical field]

[0001] The present invention relates to high temperature superconductors, and more particularly to the construction of cables containing high temperature superconducting material. [Background technology]

[0002] Superconducting materials are typically classified as "high temperature superconductors" (HTS) and "low temperature superconductors" (LTS). LTS materials, such as Nb and NbTi, are metals or metal alloys whose superconductivity can be described by the BCS theory. All low temperature superconductors have a self-field critical temperature (the temperature above which they cannot become superconducting even in the absence of zero external magnetic field) below about 30 K. The behavior of HTS materials is not described by the BCS theory, and such materials may have a self-field critical temperature above about 30 K (it should be noted, however, that it is the physical differences in composition and superconducting behavior, not the self-field critical temperature, that define HTS and LTS materials). The most commonly used HTS are "copper oxide superconductors", which are ceramics based on copper oxides (compounds containing a copper oxide group) such as BSCCO or ReBCO (where Re is a rare earth element, typically Y or Gd). Other HTS materials include iron pnictides (eg, FeAs and FeSe) and magnesium diborate (MgB2).

[0003] ReBCO is typically manufactured as a tape having the structure shown in Figure 1. Such a tape 100 is generally approximately 100 microns thick and comprises a substrate 101 (typically an electropolished nickel-molybdenum alloy (e.g. Hastelloy® approximately 50 microns thick)) on which a series of buffer layers, known as a buffer stack 102, approximately 0.2 microns thick, is deposited by IBAD, magnetron sputtering, or other suitable technique. An epitaxial ReBCO·HTS layer 103 (deposited by metal oxide chemical vapor deposition (MOCVD) or other suitable technique) overlies the buffer stack and is typically 1 micron thick. A 1-2 micron silver layer 104 is deposited on the HTS layer by sputtering or other suitable technique, and a copper stabilizer layer 105 is deposited on the tape by electroplating or other suitable technique, often completely encapsulating the tape. The silver layer 104 and the copper stabilizer layer 105 are also deposited on the sides of the tape 100 and the substrate 101 so that they extend continuously around the tape 100, allowing electrical connection to be made from either side of the tape 100 to the ReBCO·HTS layer 103. These layers 104, 105 are therefore also referred to as "cladding". Typically, the silver cladding has a uniform thickness of approximately 1-2 microns on both sides and edges of the tape. The silver layer 104 between the HTS layer 103 and the copper layer 105 prevents the HTS material from contacting the copper, which could result in contamination of the HTS material by the copper. Portions of the silver layer 104 and the copper stabilizer layer 105 on both sides of the tape 100 are not shown in FIG. 1 for the sake of clarity. FIG. 1 also does not show the silver layer 104 extending under the substrate 101, as is typically the case. The silver layer 104 provides a low resistance electrical interface to the ReBCO layer 103 and provides a hermetic protective seal around the ReBCO layer 103, while the copper layer 105 allows for external connection to the tape (e.g., allows soldering) and provides a parallel conductive path for electrical stabilization.

[0004] In addition, "peeled" HTS tapes can be produced, which lack the substrate and buffer stack, but have a "perimeter coating", typically of silver, i.e., a layer on both sides and edges of the HTS layer. Tapes with a substrate are referred to as "substrate-attached" HTS tapes.

[0005] HTS cables include one or more HTS tapes connected along their length via a conductive material (usually copper). The HTS tapes may be stacked (i.e. arranged so that the HTS layers are parallel) or have other tape arrangements that may vary along the length of the cable. Notable special cases of HTS cables are single HTS tapes and HTS pairs. An HTS pair includes a pair of HTS tapes arranged so that the HTS layers are parallel. If backed tapes are used, the HTS pair can be type 0 (HTS layers facing each other), type 1 (HTS layer of one tape facing the backing of the other tape), or type 2 (backings facing each other). Cables that include more than two tapes can have some or all of the tapes arranged in HTS pairs. Backed HTS tapes can include various arrangements of HTS pairs, most commonly either a stack of type 1 pairs or a stack of type 0 pairs (or equivalently type 2 pairs). HTS cables can include a mix of backed and peeled tapes.

[0006] Superconducting magnets are formed by arranging multiple HTS cables (or individual HTS tapes, which for the purposes of this description can be treated as a single tape cable) into coils, either by winding the HTS cables or by providing sections of coils made from HTS cables and bonding them together. HTS coils fall into three broad classes: · Insulated, having electrically insulating material between the windings (so that current can only flow in the “helical path” through the HTS cable). Non-insulated, the windings are electrically connected radially and not just along the cable. Partially insulated, the windings are radially connected to a controlled resistance, either by using a high resistivity material (compared to copper for example) or by providing intermittent insulation between the coils.

[0007] An uninsulated coil can also be considered as a low resistance case of a partially insulated coil. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] International Publication No. 2021 / 178697 [Patent Document 2] China Patent Publication No. 103794297 [Patent Document 3] International Publication No. 2019 / 150123 [Patent Document 4] China Patent Application Publication No. 110828058 Summary of the Invention

[0009] According to a first aspect, a high temperature superconducting (HTS) cable is provided. The HTS cable includes a channel, an HTS material, and an insulating layer. The channel is formed from a conductive material and has a groove extending along the length of the HTS cable. The HTS material is located within the groove such that when the HTS material is in a superconducting state, the HTS material forms a superconducting current path along the cable such that the HTS material is electrically connected to the channel. An insulating layer is located on a surface of the channel. The channel has a plurality of recesses, each recess containing an electrical assembly including a conductive path and / or one or more electrical components, and further includes an insulator separating the electrical assembly from the channel. The HTS cable further includes, for each recess: a first electrical connection providing an electrical connection from the electrical assembly in the recess across or through the insulating layer; a second electrical connection electrically connecting the channel to an electrical assembly within the recess; Including, Any conductive path from the first electrical connection through the recess to the second electrical connection passes through the electrical assembly.

[0010] According to a second aspect, a high temperature superconducting cable is provided. The HTS cable includes a channel, an HTS material, an insulating layer, and a conductive layer. The channel is formed from the conductive material and has a groove extending along the length of the HTS cable. The HTS material is located within the groove such that when the HTS material is in a superconducting state, the HTS material forms a superconducting current path along the cable such that the HTS material is electrically connected to the channel. The insulating layer is located on a surface of the channel other than the surface where the groove is located. The conductive layer is located on an outer surface of the insulating layer and extends around the insulating layer such that it is in electrical contact with the channel.

[0011] According to a third aspect, a high temperature superconducting (HTS) coil is provided, comprising an HTS cable wound to form a winding of the coil. The HTS cable comprises a channel, an HTS material, and an insulating layer. The channel is formed from a conductive material and has a groove extending along the length of the HTS cable. When the HTS material is located within the groove, such that when the HTS material is in a superconducting state, the HTS material forms a superconducting current path along the cable such that the HTS material is electrically connected to the channel. An insulating layer is located on a surface of the channel. The channel has a plurality of recesses, each recess containing an electrical assembly including a conductive path and / or one or more electrical components, and further comprising an insulator separating the electrical assembly from the channel. The HTS cable further comprises, for each recess: a first electrical connection providing an electrical connection from the electrical assembly in the recess across or through the insulating layer; a second electrical connection electrically connecting the channel to an electrical assembly within the recess; Including, The HTS cable is wound such that the first electrical connection of each winding other than the innermost or outermost winding electrically connects to the channel of an adjacent winding, and any current path from each winding through each recess to the adjacent winding passes through the electrical assembly within the recess.

[0012] The third aspect HTS cable may be the first aspect HTS cable.

[0013] Further embodiments are set out in claims 2 et seq. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram of an HTS cable. [Figure 2A-2B] 2A and 2B show an HTS cable that includes a channel. [Figure 3A] 1 illustrates an exemplary HTS cable. [Figure 3B] 3B illustrates the current flow between the windings of an HTS coil formed from the cable of FIG. 3A. [Figure 4] 3B shows an alternative construction for a cable equivalent to FIG. 3A. [Diagram 5] 1 illustrates a further exemplary HTS cable. [Figure 6A-6C] 6A-6C show an exemplary electrical assembly for use in a cable such as the one shown in FIG. [Figure 7] 1 is a cross section of yet a further exemplary HTS cable. [Figure 8] 8 shows two possible side views of the cable according to FIG. 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] 2A and 2B show an HTS cable. FIG. 2A is an isometric view and FIG. 2B is an end cross section. Only a short section of the HTS cable is shown, which can extend any length in the direction indicated by the arrow in FIG. 2A. The HTS cable includes a channel 201. The channel 201 is an elongated conductive element having a groove 202 along its length, for example having a U-shaped cross section as shown in FIG. 2B. The HTS material 203 is disposed within the channel, i.e., within the groove. The channel may be formed from any conductive material, such as any metal or metal alloy (e.g., high strength copper or high copper alloys, brass, stainless steel, aluminum, optionally electroplated to aid soldering), conductive composite or ceramic materials, or combinations thereof, such as by using different materials in different regions of the channel.

[0016] The HTS material may be an HTS tape as described with reference to Figure 1 and may be arranged as a tape stack or in a complex arrangement. A conductive adhesive, such as solder, resin impregnated with a conductive material, or the like, may be used to secure the HTS material within the channel.

[0017] The conductive material of the channel provides a low resistance alternative current path for sharing current between the HTS materials in the cable, or between the cables in the field coil if used in a non-insulated or partially insulated configuration. Additionally, the channel provides significant thermal mass in close thermal contact with the HTS, helping to mitigate heating caused by the HTS material becoming resistive.

[0018] The channel may also include a high strength material, such as stainless steel, to provide structural reinforcement to resist electromagnetic stresses within the coil pack, and a high thermal conductivity material, such as copper, to compensate for the generally low thermal conductivity of high strength materials.

[0019] 2A and 2B may be used directly to wind an uninsulated HTS field coil, or may be used with an additional layer between the cables (e.g., the partial insulation layer disclosed in WO 2019 / 150123) to an HTS field coil that is partially insulated by a controlled resistance between the windings. However, such partial insulation layers can be relatively bulky and, in combination with a relatively thick channel, may result in a lower than desired current density.

[0020] Thus, the proposed structure provides an HTS cable with integrated elements that, when wound, provide a partially insulated coil with a resistance that is easily controllable by the design of such elements. In addition, the same design allows for the integration of any desired circuitry or components with the HTS cable.

[0021] FIG. 3A shows an HTS cable with an integrated resistor connecting the windings of the resulting HTS coil when the HTS cable is wound. The HTS cable includes a conductive channel 301 with a groove 302 along its length. HTS material 303 is located within the groove as described above. The HTS cable further includes an insulating layer 304 on the underside of the channel (i.e., as would be present between the HTS cable and other windings of the HTS cable when the HTS cable is wound into a coil) and a conductive layer 305 on the underside of the insulating layer. The insulating layer covers the underside of the channel unless otherwise noted. The conductive layer may cover all of the insulating layer or only a portion of it.

[0022] The HTS cable further includes a number of resistors 310 located in recesses 311 in a side of the HTS cable. Each resistor 310 is electrically isolated from the HTS cable by insulation in the recesses and has a first connection 313 that penetrates the insulating layer 304 and electrically connects to the conductive layer 305, and a second connection 314 that electrically connects to the conductive channel 301.

[0023] FIG. 3B shows the radial current flow between the first winding 320 and the second winding 330 for a cross section aligned with the recesses of the HTS cable in each winding (note, however, that the recesses do not have to align between windings). The reference numbers for the individual components of the first and second windings are the same as those in FIG. 3A, but with the suffix "a" for the components of the first winding and the suffix "b" for the components of the second winding. When the HTS cable is wound to form the HTS coil, the cable of the first winding 320 is below the cable of the second winding 330, so that the conductive layer 305b of the second winding is in electrical contact with the top surface of the channel 301a of the first winding. The electrical connection between the windings (current flowing from the first winding to the second winding is indicated by the dotted arrow 350) occurs radially through the resistor 310b of the second winding. That is, -First winding HTS material 303a, through the channel 301a of the first winding, through the conductive layer 305b of the second winding, Through the resistor 310b of the second winding via the connection 313b, through the channel 301b of the second winding via the connection 314b, · Leading to the HTS material 303b of the second winding.

[0024] It should be noted that while FIG. 3B shows only two windings, the HTS coil may include any number of windings. Additionally, since the HTS coil may be wound from a single HTS cable, channels 301a and 301b may be different sections of a single channel 301, as well as for insulating layers 304a / b, conductive layers 305a / b, and HTS materials 303a / b.

[0025] This allows the connection resistance between the windings to be easily adjusted when designing the cable by selecting the resistor resistance appropriately. There are additional contributions to the resistance from the conductive material and bonding agents of the channel, and from non-superconducting components, for example, of the HTS tape, but these can be easily determined by calculation or experiment and factored into the design.

[0026] 4, an insulating layer 404 may be provided on top of the channel 401, i.e., the trench 402 containing the HTS material 403 is covered by the insulating layer 404. A conductive layer 405 is then provided on top of the insulating layer 404, and a resistor 410 has one connection 413 that extends upward through the insulating layer and another connection 414 that connects to the channel. It will be appreciated that this alternative arrangement of insulating and conductive layers is possible for all examples presented in this disclosure, even if not specifically illustrated for these examples.

[0027] In addition, the conductive layer 305 / 405 may be omitted and the electrical connections 313 / 413 that penetrate the insulating layer may terminate at a surface of the insulating layer for connection to components located on the opposite side of the insulating layer. Furthermore, the connections 313 / 413 may extend around or across the insulating layer rather than through it.

[0028] The above example shows a simple example using resistors integrated into the channel, but the same principle can be applied to any electrical component. Figure 5 shows a general embodiment of this principle. The HTS cable includes, as in the previous examples, a channel 501, a groove 502, an HTS material 503, an insulating layer 504 and a conductive layer 505. The HTS cable further includes multiple assemblies 510 of electronic components, which are located in recesses 511 on the sides of the channel 501 and are insulated from the channel 501 by insulators (not shown), except as described below.

[0029] As with resistor 310 shown in FIG. 3B, current flowing radially between the turns of the HTS coil wound from the HTS cable of FIG. 5 flows through an assembly 510 of electronic components.

[0030] The assembly has one or more electrical connections 513 through the insulating layer 504 to the conductive layer 505. The assembly also has one or more electrical connections 514 to the channel 501 and / or the HTS material 503, where the current flowing from the electrical connection 513 passes through at least one component of the assembly 510 before flowing through the electrical connection 514, or the current flowing from the electrical connection 514 passes through at least one component of the assembly 510 before flowing through the electrical connection 513. The assembly may include passive devices such as diodes or varistors that react to changes in local conditions within the coil pack, such as voltage between the windings, temperature, or pressure. This allows the components to change electrical resistance in response to fault conditions that may lead to a quench. Alternatively, the assembly may include active components such as semiconductor (field effect transistor) switches controlled by an external voltage. In this case, the assembly may include one or more additional electrical connections 515 to receive inputs for these components. If the assembly includes active components that are actuated by other means (e.g. hydraulic or pressure actuated switches), the assembly may include appropriate inputs for these actuation means. Pressure switches and similar devices have the advantage over diodes or active semiconductor switches in that they have no forward voltage. Pressure switches can be operated externally by changes in gas pressure, or gas pressure can be generated internally by temperature changes by sealing a pressure chamber inside the switch.

[0031] Components with variable resistance allow the coil to operate at high or low interwinding resistance, which advantageously allows the coil to be energized quickly (the component has a high resistance, minimizing the current driven between the windings by the induced voltages that develop across the windings due to current changes) and then switched to a state of low interwinding resistance, stabilizing the coil against disturbances when the currents in the windings are stable.

[0032] Advantageously, the interwinding resistance can also be adjusted in real time. For example, when quickly dumping energy from the magnet after detecting a quench or a condition that would cause a quench, the higher the interwinding resistance, the greater the percentage of the damping current that is driven to the external damping resistor, reducing the amount of magnet energy dumped into the coil pack, which in turn reduces the terminal coil temperature, thus avoiding transient stresses caused by rapid thermal expansion of different parts of the coil structure.

[0033] The assembly 510 may include any desired components to achieve the required electrical interaction in the radial direction between the windings of the HTS coil when the HTS cable is wound. For example, the assembly may include resistors, diodes, varistors, thermistors, and other temperature-dependent resistors such as cartridges containing vanadium oxide or other compounds, transistors (e.g., MOSFETs), thyristors, capacitors, switches (e.g., hydraulic or pressure-activated switches), superconducting elements (e.g., superconducting elements that are more sensitive to temperature changes than the HTS material), circuits or integrated circuits that include combinations of the above components. One possible circuit or integrated circuit is an RC filter connected to the gate voltage of a switch (e.g., a transistor or thyristor) that allows for triggering a change from a high resistance state to a low resistance state. Other circuit designs are of course possible. As a further example, each electrical assembly may include a conductive path, for example a conductive path whose material, cross-sectional area and length are selected to provide the required resistance to act as a resistor. A current path having a length greater than any dimension of the recess may be achieved by providing a current path that is not linear.

[0034] A number of assemblies are placed in respective recesses along the HTS cable. These assemblies may be electrically connected to each other, for example, to allow coordinated control of switching within the assemblies. The spacing between these assemblies is determined by the required bulk electrical properties of the HTS cable; i.e., for resistive assemblies, the greater the spacing between the recesses, the higher the average resistance per unit length of the entire HTS cable. The spacing between the recesses may vary along the HTS cable, for example, to provide an HTS coil with variable interwinding resistance along different arcs of the coil when the cable is wound. The assemblies may vary in their structural or electrical properties; for example, different assemblies may have different resistances, or several types of assemblies may be alternated in a repeating pattern.

[0035] The assembly is required to fit without structural compromise into the channel material on either side of the groove, the width of the channel material on either side of the groove typically being between 3mm and 15mm, and the height of the channel material typically being between 3mm and 25mm, allowing sufficient space for electrical components given the miniaturization of such components.

[0036] Some example assemblies are shown as circuit diagrams in Figures 6A to 6C. In each case, an upper rail 601 represents the connection to the channel, and a lower rail 602 represents the connection through an insulating layer.

[0037] Figure 6A represents the example shown in Figure 3A, where the electrical components in the recesses are resistors 611. This results in a fixed resistance per recess, and the inter-turn resistance per unit length of the HTS cable when wound into an HTS coil can be controlled by varying the resistance of resistor 611 or the spacing of the recesses.

[0038] FIG. 6B shows an example with resistor 631 and diode 632 connected in series in the recess. This can also be implemented without the resistor if the resistance of the diode and the electrical connection to the diode are sufficient. The diode limits the flow of current through the resistor in only one direction below its forward voltage. This voltage can be increased by placing multiple diodes in series. A back-to-back pair of diodes extends this idea to allow current to flow in either direction. As an extension of this principle, two sets of such assemblies may be provided, where the first set allows current to flow radially outward through the coil and the second set allows current to flow radially inward, allowing independent control of the resistance in each direction.

[0039] 6C shows an example with a resistor 631 and a MOSFET transistor 632 connected in series. The gate of the MOSFET is connected to a control input 633, which may be connected to an external controller. This allows the radial current flow in the HTS coil wound from the HTS cable to be electronically controlled, for example allowing the HTS coil to behave similarly to an insulated coil during ramping (resulting in reduced ramp times) and to behave as a partially insulated coil during operation (resulting in increased resistance to quenching).

[0040] In general, if an assembly of electronic components includes active components such as transistors or other components that change state due to an applied voltage, a control input may be included that may be connected to an external controller or may be connected to other recessed electronic components to allow propagation of the control input along the HTS cable.

[0041] When the exemplary HTS cable described above is wound into a coil, the conductive layer 305 / 405 / 505 (or electrical connection 313 / 413 / 513 if no conductive layer is present) contacts the opposing surface of the channel 301 / 401 / 501. Thus, electrical current can flow radially between the windings of the resulting HTS coil via the electrical components 310 / 410 / 510 in the recesses in the channel.

[0042] The insulating layer between the windings may also be configured as a flexible printed circuit board containing sense wires that act as sense wires to obtain the non-inductive component of the voltage across all windings by subtracting the induced voltage developed across the open circuit sense from the point-to-point voltage across the coil (which is the vector sum of the inductive and non-inductive components) when the current in the coil is changing.

[0043] While the figures show recesses on only one side of the cable, it should be understood that this is for illustrative purposes only and that recesses may be located on both sides of the cable. Additionally, where the description refers to an "upper" or "lower" surface, or any particular orientation is implied, it should be understood that this is for ease of understanding in the description, and that HTS cables may be provided in any orientation (indeed, they are commonly wound in coils where the absolute orientation has no particular practical meaning). Similarly, while the figures show recesses with straight sides that extend the full height of the channel, it should be understood that the recesses may be of any size to accommodate the required electrical components therein, and may extend only a portion of the channel's height, provided limitations regarding electrical connection to and insulation from the channel are met. In general, the figures should be considered schematic diagrams designed to highlight certain concepts, rather than faithful representations of actual physical devices. Although some cross-hatching and block filling are used in the figures to distinguish certain materials (i.e., HTS materials and insulators), the presence or absence of cross-hatching and block filling for a given element does not imply that the element is made of the same material as other elements with the same presence or absence of cross-hatching or block filling, unless otherwise stated. In particular, the channel and conductive layer or layers may be made of different conductive materials.

[0044] 7 shows a cross-section of an alternative structure for an HTS cable. As with the previous examples, the HTS cable includes a channel 701, a groove 702, and an HTS material 703 within the groove. The HTS cable further includes an insulating layer 704 that covers the bottom and sides of the channel, and a conductive layer 705 (e.g., copper or stainless steel, or both elements) that covers the insulating layer 704 and extends to the top of the channel 701.

[0045] When wound, this design allows current to flow between the windings through the conductive layer 705, with resistance depending on the thickness and material of the layer. Figure 8 is a side view of an example structure according to Figure 7. To further control the resistance, the conductive layer 705 may have multiple notches 801 on its side to create a set of current paths 802 with a higher resistance than would be achieved by a complete conductive layer. These notches may limit the width of the conductive path, as shown on the left side of the figure, or may define complex conductive paths to allow a longer length of conductive path (and therefore resistance) than would be possible with a straight conductive path, as shown on the right side.

[0046] In this disclosure, an "insulator" takes its ordinary definition, i.e., an insulator through which electric current does not flow freely and has a resistivity greater than that of a conductor or semiconductor, e.g., greater than 10 5 ohms / meter or 10 10 A material that has a resistivity greater than ohms per meter. Conductive materials include metals, metal alloys, and carbon (amorphous or graphite forms). The inter-winding voltage in an HTS coil is generally low enough that breakdown or breakdown voltage does not need to be a factor.

Claims

1. 1. A high temperature superconducting (HTS) cable, comprising: a channel (701) formed from a conductive material, the channel (701) having a groove extending along the length of the HTS cable; an HTS material (703) located in the groove, wherein when the HTS material is in a superconducting state, the HTS material forms a superconducting current path along the HTS cable, and the HTS material is electrically connected to a channel; an insulating layer (704) located on a surface of the channel other than the surface on which the grooves are located; a conductive layer (705) located on the outer surface of the insulating layer, the conductive layer (705) extending around the insulating layer to make electrical contact with the channel; Including, The conductive layer (705) is arranged such that when the HTS cable is wound to form a plurality of windings of an HTS coil, a current can flow between the plurality of windings through the conductive layer (705).

2. 2. The HTS cable of claim 1, wherein the conductive layer includes a plurality of notches (801) and a plurality of current paths (802) between the notches, each current path (802) connecting a surface of the channel in which the groove resides to an opposite surface of the conductive layer.

3. 1. A high temperature superconducting (HTS) cable, comprising: a channel (301, 401, 501) formed from a conductive material, the channel having a groove (302, 402, 502) extending along the length of the HTS cable; an HTS material (303, 403, 503) located in the groove, wherein when the HTS material is in a superconducting state, the HTS material forms a superconducting current path along the HTS cable, and the HTS material is electrically connected to a channel; and an insulating layer (304, 404, 504) located on the surface of the channel; Including, the channel has a plurality of recesses (311, 411, 511), each recess containing an electrical assembly (310, 410, 510) including conductive paths and / or one or more electrical components, each recess further containing an insulator separating the electrical assembly from the channel; The HTS cable further comprises, for each recess: a first electrical connection (313, 413, 513) providing an electrical connection from the electrical assembly in the recess across or through the insulating layer; a second electrical connection (314, 414, 514) electrically connecting the channel to the electrical assembly within the recess; Including, Any conductive path from the first electrical connection to the second electrical connection through the recess passes through the electrical assembly.

4. 4. The HTS cable of claim 3, further comprising a conductive layer (505) located on a surface of the insulating layer facing the channel, the conductive layer including one or more conductive elements in electrical contact with the first electrical connection.

5. The one or more electrical components include: resistor, transistors, Thyristor, switch, pressure or hydraulic actuated switches, integrated circuits, capacitors, Diodes, and Barista 4. The HTS cable of claim 3, comprising one or more of:

6. 4. The HTS cable of claim 3, wherein the channel is formed from copper, stainless steel, or a combination thereof.

7. The recessed portion is evenly spaced along the length of the channel; or 4. The HTS cable of claim 3, wherein the spacing between adjacent recesses varies along the length of the channel.

8. 4. The HTS cable of claim 3, wherein each recess contains an electrically equivalent arrangement of the one or more electrical components.

9. 4. The HTS cable of claim 3, wherein the plurality of recesses comprises a plurality of sets of recesses, and within each set of recesses, each recess of the set contains an electrically equivalent arrangement of the one or more electrical components.

10. 10. The HTS cable of claim 9, wherein the recesses form a pattern in which the arrangement of the recesses in each set repeats periodically along the channel.

11. 4. The HTS cable of claim 3, wherein each electrical assembly includes one or more active components.

12. 12. The HTS cable of claim 11, including a control input for each recess, wherein a voltage applied to said control input causes a change of state of at least one active component within said recess.

13. 13. The HTS cable of claim 12, wherein the control input for each recess connects to the electrical assembly of the other recess via a conductive path that is electrically isolated from the channel.

14. 10. A high temperature superconducting (HTS) coil comprising an HTS cable wound to form windings of the HTS coil, the HTS cable being the HTS cable of claim 1.

15. 10. A high temperature superconducting (HTS) coil, comprising an HTS cable wound to form windings of the HTS coil, the HTS cable being the HTS cable of claim 3.

16. A high temperature superconducting (HTS) coil, an HTS cable wound to form the windings of the HTS coil; The HTS cable comprises: a channel formed from a conductive material, the channel having a groove extending along the length of the HTS cable; an HTS material located in the groove, wherein when the HTS material is in a superconducting state, the HTS material forms a superconducting current path along the HTS cable, and the HTS material is electrically connected to a channel; and an insulating layer located on a surface of the channel; Including, the channel has a plurality of recesses, each recess containing an electrical assembly including a conductive path and / or one or more electrical components, each recess further containing an insulator separating the electrical assembly from the channel; The HTS cable further comprises, for each recess: a first electrical connection providing an electrical connection from the electrical assembly in the recess across or through the insulating layer; a second electrical connection electrically connecting the channel to the electrical assembly within the recess; Including, an HTS coil, wherein the HTS cable is wound such that the first electrical connection of each winding other than the innermost or outermost winding electrically connects to the channel of an adjacent winding, and any current path from each winding to an adjacent winding through each recess passes through the electrical assembly within the recess.

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