A fiber reinforced polymer former for superconducting cables, and methods of producing the same

Abstract

The embodiments described herein relate to apparatuses and methods for mitigating pressure drop in high temperature superconductor (HTS) cables while also addressing challenges associated with traditional HTS cable formers such as structural flexibility and mechanical integrity. The apparatus comprises a former made of a fiber-reinforced polymer composition, configured to define a shape, with a high temperature superconductor material disposed on and around the former. In some embodiments, the fiber-reinforced polymer composition has a ratio of yield strength to Young's modulus of about 0.02 or greater, allowing for formers with diameters of 20 mm or greater to exhibit a bend diameter of 2 m or less.

Description

Agent’s File Ref.: VEIR-008 / 01WO 338760-2059A FIBER REINFORCED POLYMER FORMER FOR SUPERCONDUCTING CABLES, AND METHODS OF PRODUCINGTHE SAMECROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 722,809 filed on November 20, 2024, and entitled “Fiber Reinforced Polymer Former for Superconducting Cables, Methods of Producing the Same” the entire disclosure of which is hereby incorporated by reference herein.TECHNICAL FIELD

[0002] Embodiments described herein generally pertain to apparatuses and methods for mitigating pressure drop in high-temperature superconductor (HTS) cables. In particular, embodiments described herein generally relate to HTS cables in which an HTS material is disposed on and around a fiber-reinforced polymer former, a smooth pipe for coolant flow, helping to reduce pressure variations along the length of the former.BACKGROUND

[0003] In power transmission systems using high-temperature superconductors (HTS), formers play a role in supporting the HTS material and facilitating coolant flow. These formers act as reinforcing structures, providing stability to the cable while creating flow paths that allow coolants, such as liquid nitrogen, to circulate through and regulate the temperature of the HTS materials. Traditionally, the formers are made from corrugated stainless steel or similar materials to provide flexibility and structural support. However, while corrugated or stripwound tubes can accommodate thermal expansion and contraction, they introduce significant resistance to coolant flow. This resistance increases the pressure drop for a given mass flow rate of coolant, which can increase pumping requirements and / or decrease the efficiency of cooling provided by the coolant. Such pressure drops can negatively affect the performance and stability of the HTS cable in power transmission applications. Although polymer formers could provide a smooth surface and flexibility, historically they have been unsuitable for use with superconductors because of their high coefficient of thermal expansion (CTE). This high CTE can lead to significant dimensional changes with temperature fluctuations, potentially327330979 1Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 compromising the structural integrity and performance of the HTS cable. Accordingly, a need exists for formers having relative low resistance to coolant flow with improved thermal expansion properties.SUMMARY

[0004] Embodiments of systems and methods described herein provide a fiber-reinforced smooth former on and around of which an HTS material is disposed. The fiber-reinforced smooth former described herein can mitigate pressure drop within HTS cables without compromising structural flexibility and mechanical integrity during installation and operation.

[0005] Some embodiments described herein relate to an apparatus that includes a former configured to define a shape and an HTS material disposed around the former. The former can be constructed of a fiber-reinforced polymer composition. In some embodiments, the HTS material is in a form of a tape or a wire.

[0006] In some embodiments, the fiber-reinforced polymer composition includes a polymer matrix and a plurality of fibers distributed within the polymer matrix. In some embodiments, the polymer matrix includes a thermosetting polymer. In some embodiments, the polymer matrix includes at least one of polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyetherketoneketone (PEKK), polyetherketone (PEK) or another polymer that is part of the polyaryletherketone (PAEK) family. In some embodiments, the plurality of fibers includes at least one of glass fibers, carbon fibers, aramid fibers, or quartz fibers. In some embodiments, the plurality of fibers is constructed of a material having a tensile modulus greater than 200 GPa, 250 GPa, or 300 GPa. In some embodiments, the plurality of fibers is constructed of a material having a tensile modulus less than 500 GPa. In some embodiments, the plurality of fibers is constructed of a material having a thermal expansion coefficient of about 5X10'6 / °C, or lower, over a temperature range of -273°C to 20°C. In some embodiments, the plurality of fibers has a negative thermal expansion coefficient over a temperature range of -273°C to 20°C.

[0007] In some embodiments, the fiber-reinforced polymer composition has a ratio of yield strength to Young’s modulus of about 0.02 or greater. In some embodiments, the fiber- reinforced polymer composition has a thermal expansion coefficient of about 20x1 O'6 / °C or lower over a temperature range of -273°C to 20°C. In some embodiments, the fiber-reinforced polymer composition has a thermal expansion coefficient of 15x106 / °C or lower over a temperature range of -273 °C to 20°C. In some embodiments, the fiber-reinforced polymer327330979 2Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 composition has a thermal expansion coefficient of within ±3% of a thermal expansion coefficient of the high-temperature superconductor material.

[0008] In some embodiments, the former has a cylindrical shape. In some embodiments, the former having the cylindrical shape has an outer diameter of about 20 mm or greater. In some embodiments, the former has an elastic bend diameter of about 2.0 m or greater.[00091 In some embodiments, the former is in a form of a conduit having an interior surface configured to be physically in contact with the coolant when the coolant is conveyed through the conduit. In some embodiments, the former is thermally insulated from an external environment (e.g., an outdoor environment). In one embodiment, the former has one or more thermally insulating layer(s) disposed on an outer surface of the former and / or on the HTS material. In some embodiments, the former is disposed in a thermally insulating jacket such that an outer surface of the former (or an outer surface of the HTS material containing the former) and the inner surface of the thermally insulating jacket define an annulus through which a coolant can flow. In some embodiments, the coolant is a cryogenic fluid. In some embodiments, the cryogenic fluid selected from at least one of ethane, ethylene, krypton, methane, oxygen, argon, nitrogen, neon, hydrogen, xenon, or helium.

[0010] In some embodiments, the apparatus can include a former that defines a hollow interior configured to transport a cryogenic coolant. In some embodiments, the cryogenic coolant can include at least one of ethane, ethylene, krypton, methane, oxygen, argon, nitrogen, neon, hydrogen, xenon, or helium. In some embodiments, the cryogenic coolant can flow through the hollow interior at a pressure between about 5 bar and about 30 bar greater than atmospheric pressure. In some embodiments, the former can include a surface having an average roughness between about 0.05 pm and about 0.8 pm. In some embodiments, the fiber- reinforced polymer composition can include fibers oriented circumferentially around the former. In some embodiments, the high temperature superconductor material can include a plurality of tapes wound on and around the former in a spiral pattern. In some embodiments, the apparatus can further include a thermally insulating jacket disposed around the former and the high temperature superconductor material such that an annulus is formed between the high temperature superconductor material and an inner surface of the thermally insulating jacket, the annulus being configured to allow coolant flow therethrough. In some embodiments, the thermally insulating jacket can include two concentric corrugated pipes with vacuum disposed therebetween.327330979 3Agent’s File Ref.: VEIR-008 / 01WO 338760-2059

[0011] Some embodiments described herein relate to method of manufacturing an apparatus that includes the former constructed of a fiber-reinforced polymer composition and a HTS material (e.g., an HTS tape) disposed on and around the former. The method can include use of extrusion or pultrusion process to shape the fiber-reinforced polymer composition into a former.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several implementations in accordance with the disclosure and are therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings.

[0013] FIG. 1 is a schematic block diagram of an apparatus including a composite former, according to an embodiment.10014] FIG. 2 is an illustration of an apparatus including a composite former, according to an embodiment.

[0015] Reference is made to the accompanying drawings throughout the following detailed description. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative implementations described in the detailed description, drawings, and claims are not meant to be limiting. Other implementations may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and made part of this disclosure.DETAILED DESCRIPTION

[0016] In power transmission systems utilizing high-temperature superconductors (HTS), formers have been used for both supporting the HTS material (e.g., HTS tape or wire) and facilitating coolant flow. These formers reinforce the cable structure, providing stability while optionally creating channels for coolants like liquid nitrogen to circulate and regulate the327330979 4Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 temperature of HTS materials. Typically, formers are made from corrugated stainless steel or similar materials to ensure flexibility and structural integrity. However, while corrugated or strip-wound tubes can absorb thermal expansion and contraction, they significantly increase resistance to coolant flow. This leads to a higher pressure drop at a given mass flow rate of coolant, which can increase pumping requirements and / or decrease the efficiency of cooling provided by the coolant, ultimately affecting the performance and / or stability of the HTS cable in power transmission systems.

[0017] The use of a smooth bore metal former would reduce the pressure drop at a given mass flow through the cable former by up to eight times or greater. However, known smooth metal formers come with their own set of challenges, particularly related to bending. When these formers are bent, there is a risk of plastic deformation, which can permanently deform the former and potentially lead to crimping or rupture. This limitation makes it difficult to achieve the desired bend radius without compromising the integrity of the former.

[0018] The minimum bend diameter of a tube without causing plastic deformation can be determined from the bending curvature relation as:D = (d - E~) / S where (D) is the bend diameter, (d) is the tube diameter, (S) is the yield strength, and (E) is the Young’s modulus. The bend diameter is directly related to the ratio (SZE). For metals such as stainless steel, copper, titanium, and aluminum, (SZE) is generally in the range of 0.002-0.004. Thus, smooth bore metal tubes generally should have either small tube diameters (e.g., 4-8 mm or less) or large bend diameters (e.g., more than 2 m) to avoid plastic deformation. HTS material, such as tapes, which is disposed on and around the former constrains the minimum tube diameter, as HTS tape themselves can crack if bent too sharply or wrapped too tightly, compromising the structural integrity and performance of the HTS cable.

[0019] Given the bending challenges associated with metal formers, the use of polymers has been explored as a potential solution. Polymers offer a significantly lower Young’s modulus for a given strength, allowing for larger tube diameters and smaller bend diameter without the risk of plastic deformation. However, typically polymers exhibit a coefficient of thermal expansion (CTE) that is 5-10 times larger than that of metals like stainless steel. This discrepancy in CTE can cause significant issues when cooling to cryogenic temperatures, as the polymer former would typically shrink much more than the HTS material, leading to structural instability.327330979 5Agent’s File Ref.: VEIR-008 / 01WO 338760-2059

[0020] Accordingly, some embodiments described herein relate to a smooth-surfaced former made of a composite material, such as a fiber-reinforced polymer composition that addresses pressure drop issues within HTS included transmission systems while maintaining a sufficiently small minimum elastic bend diameter (e.g., 2 m or less without causing plastic deformation. This former can be designed to have a low coefficient of thermal expansion (CTE), for example less than 20x1 O'6 / °C, by incorporating fibers, such as glass or carbon fibers, which help in maintaining structural integrity and compatibility with various applications, including cryogenic environments. The composite former exhibits a high str ength-to- Young’s modulus (SZE) ratio (e.g., 0.02 or greater), allowing for larger former tube diameters (e.g., 20 mm or more) and elastic bend diameters suitable for a range of applications, including those requiring pressure containment and resistance to pulling forces during installation.|0021[ Embodiments of apparatuses and methods described herein may provide one or more benefits, including for example: (1) providing smoother fluid flow within the former, leading to efficient coolant transport and enhanced overall system performance; (2) maintaining a sufficiently small elastic bend diameter without causing plastic deformation, leading to enhanced structural integrity and performance; (3) being adaptable to various designs and materials, offering flexibility in configurations to meet specific operational requirements; (4) improving thermal compatibility, particularly in cryogenic applications, by providing formers having sufficiently low thermal expansion coefficients.

[0022] In some embodiment, the apparatus provided herein further includes a HTS material disposed on and around the non-corrugated former. In some embodiments, the HTS material can be in a form of wire and / or tape. Wires or tapes have been developed based HTS materials which may have critical temperatures (Tc) above 77 K, facilitating their use in cryogenic systems cooled by liquid nitrogen. In particular, HTS tapes have been developed in which (a) layer(s) of superconducting material(s) is disposed into a stack of conductive and / or non- conductive layers that form the HTS tape.

[0023] The apparatuses described herein can be suitable for use with HTS tapes including rare-earth barium copper oxide (ReBCO) superconducting materials, which exhibit high- temperature superconducting properties above the critical temperature of 77 K. ReBCO materials typically have the general formula REBa2Cu3O?-x, where RE represents a rare earth element such as yttrium (Y), samarium (Sm), neodymium (Nd), or gadolinium (Gd). Among these, yttrium barium copper oxide (YBCO) is one of the most well-known and widely used327330979 6Agent’s File Ref.: VEIR-008 / 01WO 338760-2059ReBCO materials. The structure of ReBCO is characterized by layers of copper-oxygen planes separated by layers containing the rare earth and barium atoms, which is crucial for their superconducting properties. ReBCO materials exhibit superconductivity at temperatures significantly higher than conventional superconductors, with a critical temperature Tc typically around 90 K. This higher Tc makes ReBCO materials more cost-effective and easier to handle in practical applications. However, the embodiments are not limited to ReBCO and may be applicable to other high-temperature superconductors, such as YBa2Cu3O?-x (YBCO), Bi2Sr2Ca2Cu30io+y, ThBa2Ca2Cu30io+y, and HgBa2Ca2Cu30s+y.

[0024] The apparatuses and methods described herein generally offer multiple benefits by all combinations of the foregoing concepts and additional concepts discussed herein (provided such concepts are not mutually inconsistent) are contemplated as being part of the subject matter disclosed herein. The terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.

[0025] The terminology used herein is for the purpose of describing particular embodiments, implementations, and / or concepts (including any feature(s) or aspect(s) thereof) and is not intended to be limiting. Unless defined otherwise, all technical and / or scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. Any explanation or discussion of or using particular terms is intended to provide context and to facilitate understanding and is not necessarily intended to replace or supersede commonly used or known definitions understood by one skilled in the art unless explicitly stated otherwise. Moreover, various terms may be used to describe similar or substantially the same embodiments, implementations, and / or concepts (including any feature(s) or aspect(s) thereof) and thus, the use of particular terms is not intended to be limiting and / or to the exclusion of other terms unless the terms are mutually exclusive, or the context clearly states otherwise.10026] As used herein, the term “a” or “an” refers to one or more of that entity; for example, “an element” refers to one or more element or at least one element. As such, the terms “a” (or “an”), “one or more” and “at least one” are used interchangeably herein. In addition, reference to “an element” by the indefinite article “a” or “an” does not exclude the possibility that more than one of the elements is present, unless the context clearly requires that there is one and only one of the elements.327330979 7Agent’s File Ref.: VEIR-008 / 01WO 338760-2059

[0027] As used herein, the terms “about” and “approximately” when preceding a numerical value mean a range (e.g., plus or minus 10% of that value). For example, “about 50” can mean 45 to 55, “about 25,000” can mean 22,500 to 27,500, etc., unless such an interpretation would result in a value above or below range of possible values, such as below 0% or above 100% of a possible value. Furthermore, the phrases “less than about / approximately” a value or “greater than about / approximately” a value should be understood in view of the definition of the term “about / approximately” provided herein, as applied to any recited endpoint. Similarly, the term “about / approximately” when preceding a series of numerical values or a range of values (e.g., “about 10, 20, 30” or “about 10-30”) refers to and / or modifies, respectively, all values in the series, and / or the endpoints of the range.

[0028] Where a range of values is provided, it is to be understood that each intervening value (e.g., to the tenth of the unit of the lower limit unless the context clearly dictates otherwise) between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the disclosure. That the upper and lower limits of these smaller ranges can independently be included in the smaller ranges is also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure. All ranges described herein include each individual member or value of the listed range, including the end members or values. Any listed ranges are intended to encompass any and all possible subranges and / or combinations of subranges thereof unless expressly stated otherwise. Any listed range should be recognized as sufficiently describing and enabling the same range being broken down into at least equal subparts unless expressly stated otherwise.

[0029] As used herein, the phrase “and / or,” as used herein, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and / or B”, when used in conjunction with open- ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including327330979 8Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0030] As used herein, the term “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” “not more than one of,” and / or the like will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e., “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the embodiments, shall have its ordinary meaning as used in the field of patent law.

[0031] As used herein, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0032] It should be noted that the term “for example” or “exemplary” as used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations, and / or illustrations of possible embodiments (and such term is not intended to connote that such embodiments are necessarily extraordinary or superlative examples).327330979 9Agent’s File Ref.: VEIR-008 / 01WO 338760-2059

[0033] As used herein, the terms “set” and “plurality” can refer to multiple features or a singular feature with multiple parts. For example, when referring to a set of electrodes, the set of electrodes can be considered as one electrode with multiple portions, or the set of electrodes can be considered as multiple, distinct electrodes. Additionally, for example, when referring to a plurality of electrochemical cells, the plurality of electrochemical cells can be considered as multiple, distinct electrochemical cells or as one electrochemical cell with multiple portions. Thus, a set of portions or a plurality of portions may include multiple portions that are either continuous or discontinuous from each other. A plurality of particles or a plurality of materials can also be fabricated from multiple items that are produced separately and are later joined together (e.g., via mixing, an adhesive, or any suitable method).

[0034] The phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase “based on” describes both “based only on” and “based at least on.

[0035] In the embodiments, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

[0036] As used herein, the terms “high temperature superconductor (HTS) tape” and “high temperature superconductor (HTS) layer” as used herein refer to a tape or layer in which at least a portion of the respective tape or layer contains a high temperature superconductor material. Thus, a “HTS tape” may include one or more regions of superconductor material and optionally one or more regions of non-superconductor material.

[0037] As used herein, the term “conduit” refers to any structure or component that defines or forms a passageway through which materials, such as fluids, gases, or other substances, can be conveyed, transported, or transferred. The conduit can be a tubular member forming a passageway through which something (e.g., fluid) can be conveyed. The conduit may include, but is not limited to, tubular members such as pipes, headers, hoses, vessels, manifolds, tubes, ducts, channels, or similar structures. The conduit may be rigid, flexible, or semi-flexible, and may be constructed from various materials, including metals, polymers, or composites.327330979 10Agent’s File Ref.: VEIR-008 / 01WO 338760-2059

[0038] As used herein, the term “corrugated pipe” refers to a type of conduit with a wall structure featuring corrugations (i.e., ridges and grooves) running along its length. These corrugations may be arranged in a circumferential (annular) or helical (spiral) pattern. The corrugated design typically enhances the flexibility of the pipe compared to non-corrugated pipes.

[0039] As used herein, the term “fluid” refers to gases, liquids, supercritical fluids, and materials that flow.

[0040] As used herein, the term “cryogen” refers to a substance used to achieve and maintain temperatures below -123 °C (150K). These substances have very low boiling points. For example, liquid nitrogen has a boiling point of -196°C (77K), and liquid helium has a boiling point of -269°C (4K). Exemplary cryogens include liquid nitrogen, liquid nitrous oxide, liquid methane, liquid natural gas, or liquid or solid carbon dioxide, chlorodifluoromethane, or Freon®, or any number of other fluids with a high thermal energy transfer capacity and low boiling point, as are commonly known to those skilled in the art. Cryogens can readily induce a temperature differential when applied to an object.

[0041] As used herein, the term “cryogenic liquid” refers to a cryogen in liquid phase.

[0042] As used herein, the term “coolant” refers to any heat transfer medium, particularly a fluid medium, that is suitable for cooling applications. A coolant can be a cryogenic fluid in liquid phase, such as liquid argon or liquid nitrogen.

[0043] As used herein, the term “corrugated surface” refers to any surface having alternating ridges and grooves, creating a wavy, folded, or undulated appearance. This pattern may extend in one direction or multiple directions and can be regular (periodic) or irregular (non-periodic). The corrugated surface may be formed through various processes, such as wrapping, molding, folding, extrusion, or other manufacturing methods.

[0044] As used herein, the term “corrugated pipe” refers to a type of conduit with a wall structure featuring corrugations (i.e., ridges and grooves) running along its length. These corrugations may be arranged in a circumferential (annular) or helical (spiral) pattern. The corrugated design typically enhances the flexibility of the pipe compared to non-corrugated pipes.

[0045] As used herein, the term “smooth pipe” refers to a non-corrugated pipe.327330979 11Agent’s File Ref.: VEIR-008 / 01WO 338760-2059

[0046] FIG. 1 is a block diagram of an apparatus 100 including a former 110 defining a shape, and a high temperature superconductor (HTS) material 120 disposed on and around the former 110. The former 110 is made of a composite material (e.g., polymer-fiber composite). The apparatus 100 can further include a conduit 140 disposed around and spaced apart from the former 110 such that a space (e.g., an annulus) is formed between the former 110 and the conduit 140. The apparatus can further include at least one of an electrically insulating layer 130 or a thermally insulating layer 150 disposed on and / or around the former 110.

[0047] Transmission lines are typically configured to carry electrical power at high voltages, generally above approximately 30kV, to facilitate efficient power transfer over long distances. In certain embodiments, the apparatus 100 may be implemented within a superconducting power transmission system and may function as a transmission line, including but not limited to overhead transmission lines, underground transmission lines, submarine transmission lines, and sea-floor transmission lines. In some embodiments, the apparatus 100 may also be utilized in low-voltage indoor applications (e.g., at voltages below approximately 30kV).

[0048] The former 110 can be a central structural member resembling a bar, tube, and / or pipe defining a shape and providing a mechanical support for the HTS material. In some embodiments, the former 110 may be configured to have any suitable shape and an outer diameter. For example, the former 110 may have a longitudinal dimension with a cross- sectional shape (taken perpendicular to the longitudinal dimension of the former) that is circular, oval, rectangular or of other suitable polygons or closed curves. The shape and outer diameter of the former 110 can be customized to meet various requirements. For example, while a former having a cylindrical shape may be favorable for transmission applications, a former that has a more rectangular shape may be favored by some applications, for example, to simplify winding of certain magnets and other devices. Thus, in some embodiments, the former 110 can have a cylindrical shape (i.e., the former 110 can have a circular axial cross section). In some embodiments, the former 110 can have an elliptical axial cross section. In some embodiments, the former 110 can have a square axial cross section or a rectangular axial cross section. In some embodiments, the former 110 has a cross-sectional diameter of at least about 20 mm, at least about 30 mm, at least about 40 mm, at least about 50 mm, at least about 60 mm, at least about 70 mm, at least about 80 mm, at least about 90 mm, at least about 100 mm, at least about 110 mm, at least about 120 mm, at least about 130 mm, at least about 140 mm, at least about 150 mm, at least about 160 mm, at least about 170 mm, at least about 180327330979 12Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 mm, at least about 190 mm, at least about 200 mm, at least about 210 mm, at least about 220 mm, at least about 230 mm, or at least about 240 mm.

[0049] For metals like stainless steel, copper, titanium, and aluminum, the specific stiffness-to- Young’s modulus ratio (SZE) typically falls between 0.002 and 0.004. For instance, if a minimum bend diameter of 2 meters or less is desired, the maximum allowable former diameter may range from approximately 4 to 8 mm. However, such small former diameters are impractical as formers for HTS applications. Formers this small would result in HTS tapes wrapped around and / or coupled to the former having excessive curvature, causing significant strain on the HTS tapes, potentially compromising their mechanical durability and superconducting performance. Additionally, formers with such small diameters would lack the structural strength and surface area needed for effective heat dissipation, tape support, and stability. Therefore, formers with greater diameters are preferred, as they reduce curvature stress, provide better mechanical stability, and ensure the system can carry higher currents while maintaining superconductivity.

[0050] In some embodiments, the former 110 can have a length of at least about 5 m, at least about 10 m, at least about 20 m, at least about 30 m, at least about 40 m, at least about 50 m, at least about 100 m, at least about 200 m, at least about 300 m, at least about 400 m, at least about 500 m, at least about 600 m, at least about 700 m, at least about 800 m, at least about 900 m, at least about 1 km, at least about 1.1 km, at least about 1.2 km, at least about 1.3 km, at least about 1.4 km, or at least about 1.5 km.

[0051] In some embodiments, the former 110 can have a hollow interior (e.g., a conduit), such that the former 110 can transport gas, vapor, and / or liquid coolant fluid therethrough, to assist with cooling of the apparatus 100. In some embodiments, the former 110 can be porous to allow ingress and egress of liquid, vapor, and / or gas coolant. In some embodiments, the former 110 can carry or bear some or all of the tensile force incident upon the apparatus 100.

[0052] n some embodiments, the hollow interior of the former defines a continuous conduit configured to transport a cryogenic coolant at pressures between about 5 bar and about 30 bar above atmospheric pressure. The coolant may flow in a controlled direction through the hollow interior and optionally circulate through an annular space between the former and a thermally insulating jacket.

[0053] In some embodiments, the former 110 can be composed of an electrically insulative composite material. In some embodiments, the former 110 can be composed of a conductive-327330979 13Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 insulative composite material. In some embodiments, the former 110 can be composed of an electrically conductive composite material.

[0054] In some embodiments, the former 110 has at least one smooth surface that is in physical contact with a coolant (e.g., a cryogenic liquid). In some embodiments, the coolant is a cryogenic fluid. In some embodiments, the cryogenic fluid is selected from at least one of ethane, ethylene, krypton, methane, oxygen, argon, nitrogen, neon, hydrogen, xenon, or helium. In some embodiments, the coolant may include, for example, liquid nitrogen, liquid helium, liquid neon, and / or liquid hydrogen. In some embodiments, during operation, an outer and / or an inner surface of the former 110 can be exposed to a low temperature and / or cryogenic coolant. In some embodiments, the at least one smooth surface has an average roughness (Ra) ranging from about 0.05 micrometers to 0.8 micrometers measured by a profilometer. In some embodiments, the former 110 has an outer surface configured to be physically in contact with the HTS material and / or a coolant.

[0055] The smooth former 110 facilitates fluid flow and mitigates pressure drop because it reduces friction and turbulence as a coolant flows over it. This smoother flow minimizes energy losses and helps maintain a consistent and efficient cooling process by reducing the likelihood of localized pressure drops.

[0056] In some embodiments, an interior surface of the former 110 is configured to be physically in contact with the coolant when the coolant is conveyed through the conduit.

[0057] In some embodiments, the former 110 has a minimum elastic bend diameter of about 2.0 m or less. For example, the minimum elastic bend diameter may range from about 0.1 m to about 2.0 m, from about 0.2 m to about 1.8 m, from about 0.3 m to about 1.5 m, from about 0.4 m to about 1.2 m, or from about 0.5 m to about 1.0 m.

[0058] Minimum elastic bend diameter can be determined by the relationship D = d x E / S, where D is the minimum bend diameter, d is the tube diameter, S is the yield strength, and E is the Young's modulus. For common metals such as stainless steel, copper, titanium, and aluminum, the ratio of SZE typically ranges from 0.002 to 0.004. Consequently, smooth bore metal tubes generally must have either small tube diameters (e.g., 4-8 mm or less) or large minimum bend diameters (e.g., more than 2 m) to avoid plastic deformation. Such constraints may make smooth bore metal tubes impractical for certain applications as formers or supports.[0059J In some embodiments, the former 110 is made of a fiber-reinforced polymer composition. In some embodiments, the fiber-reinforced polymer composition comprises a327330979 14Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 polymer matrix and a plurality of fibers distributed within the polymer matrix. In some embodiments, a fiber-reinforced polymer composition includes a polymer matrix with fibers distributed within it. The distribution of these fibers can vary depending on the desired properties and application of the composite material. For example, in some embodiments, the fibers can be uniformly distributed throughout the polymer matrix to provide consistent reinforcement and mechanical strength. In other embodiments, the fibers can be oriented in specific directions to enhance certain properties, such as tensile strength or stiffness, in those directions.

[0060] For instance, when the fiber-reinforced polymer composition is formed into a former 110, the fibers can be concentrated circumferentially around the former 110 to provide enhanced hoop strength and resistance to radial stresses. Additionally, in some embodiments, the fibers can be layered in a cross-ply arrangement to improve the composite’s resistance to delamination and to provide balanced mechanical properties in multiple directions. The specific distribution and orientation of the fibers can be tailored to meet the requirements of different applications, ensuring optimal performance of the fiber-reinforced polymer composition. In some embodiments, a fiber-reinforced polymer composition can be extruded through a die, causing the fibers to preferentially orient along the extruded dimension.

[0061] In some embodiments, the polymer matrix includes thermoplastic polymers, which can include, but are not limited to, polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), polycarbonate (PC), and nylon (polyamide, PA). In some embodiments, the polymer matrix comprises at least one of polyphenylene sulfide (PPS), polyether ether ketone (PEEK), poly etherketoneketone (PEKK), poly etherketone (PEK), or another polymer that is part of the polyaryletherketone (PAEK) family. Thermoplastic polymers are typically used in demanding environments (e.g., cryogenic environments) requiring a certain level of thermal and chemical resistance. Thermoplastic polymers can be melted and reshaped multiple times without undergoing a chemical change, which allows for easier processing and recycling.

[0062] In some embodiments, the polymer matrix includes thermosetting polymers, which can include, but are not limited to, epoxy resins, phenolic resins, polyimides, bismaleimides (BMI), cyanate esters, vinyl esters, and polyurethanes. In some embodiments, the polymer matrix includes a combination of thermoplastic and thermosetting polymers, leveraging the unique properties of both types to achieve desired properties (e.g., thermal coefficient, elastic bend radius, yield strength) for specific applications.327330979 15Agent’s File Ref.: VEIR-008 / 01WO 338760-2059

[0063] In some embodiments, the fiber-reinforced composition comprises from about 5 wt.% to about 40 wt.%, from about 10 wt.% to about 40 wt.% , or from about 20 wt.% to about 40 wt.% of the plurality of fibers based on the total weight of the fiber-reinforced polymer composition. In some embodiments, the fiber-reinforced composition includes from at least about 5 wt.%, at least about 10 wt.%, at least about 15 wt.%, at least about 20 wt.%, at least about 22 wt.%, at least about 24 wt.%, at least about 26 wt.%, at least about 28 wt.%, at least about 30 wt.%, at least about 32 wt.%, at least about 34 wt.%, at least about 36 wt.%, at least about 38 wt.%, or at least about 40 wt.% of the plurality of fibers based on the total weight of the fiber-reinforced polymer composition. In some embodiments, the fiber-reinforced composition can include no more than about 40 wt.%, no more than about 38 wt.%, no more than about 36 wt.%, no more than about 34 wt.%, no more than about 32 wt.%, no more than about 30 wt.%, no more than about 28 wt.%, no more than about 26 wt.%, no more than about 24 wt.%, or no more than about 22 wt.% of the plurality of fibers based on the total weight of the fiber-reinforced polymer composition. Combinations of the above-referenced fiber contents are also possible (e.g., at least about 5 wt.% and no more than about 40 wt.%, or at least about 20 wt.% and no more than about 30 wt.%), inclusive of all values and ranges therebetween.10064] In some embodiments, the plurality of fibers comprises at least one of glass fibers, carbon fibers, aramid fibers (e.g., Kevlar), quartz fibers, or basalt fibers. In order for the fibers to provide a reinforcement effect to the polymer matrix material, the plurality of fibers should exhibit a tensile modulus within a specific range. In some embodiments, the plurality of fibers is constructed of a material having a tensile modulus between 250 GPa and 500 GPa. For example, the plurality of fibers can be constructed of a material having a tensile modulus of at least about 250 GPa, at least about 275 GPa, at least about 300 GPa, at least about 325 GPa, at least about 350 GPa, at least about 375 GPa, at least about 400 GPa, at least about 425 GPa, at least about 450 GPa, or at least about 475 GPa. The tensile modulus of the fibers can impart enhanced mechanical strength to the former 110.|0065| The coefficient of thermal expansion (CTE) measures how much a material expands or contracts with temperature changes. When materials with different CTEs are bonded, temperature variations can cause differential expansion or contraction, leading to mechanical stresses, deformation, or even failure. Producing a composite material as described herein with a CTE that closely matches that of the high-temperature superconducting (HTS) material can help minimize these stresses, improving the overall structural integrity and performance of the system. When the apparatus 100 is subjected to cryogenic temperatures, it may undergo327330979 16Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 significant thermal contraction. The reduction in diameter of the former can cause additional challenges. Both the former and the HTS material will contract as they cool, but potentially at different rates. This difference can lead to mechanical stress and potential damage if the thermal expansion properties of the former and the HTS material are not well-matched. Accordingly, in some embodiments, the former 110 can be selected to exhibit a contraction similar to or matching the thermal contraction of the HTS material 120. Choosing materials with similar thermal contraction properties for both the former and the HTS material helps maintain structural integrity and functionality.

[0066] Traditionally, formers have been made from corrugated stainless steel or Hastelloy. Using only a polymer matrix in a former presents challenges due to the inherent properties of polymers, which typically exhibit a much higher CTE compared to metals like stainless steel or Hastelloy. This discrepancy means that when the system is cooled to cryogenic temperatures, the polymer former would shrink significantly more than the HTS material it supports. This differential shrinkage can lead to mechanical stresses and potential damage to the HTS material, compromising its performance and structural integrity.]0067] By incorporating fibers with lower CTE (e.g., 10* 10 / °C or lower) into a polymer matrix, a bulk polymer material can be engineered to have a low CTE, matching that of stainless steel or Hastelloy. In some embodiments, the plurality of fibers has a thermal expansion coefficient of about 10* 10 / °C or lower over a temperature range of -273°C to 20°C. In some embodiments, the plurality of fibers has a thermal expansion coefficient of about 5* 10 / °C or lower over a temperature range of -273 °C to 20°C. In some embodiments, the plurality of fibers has a thermal expansion coefficient of no more than about 10* 10 / °C, no more than about 9* 10 / °C, no more than about 8* 10 / °C, no more than about 7* 10 / °C, no more than about 6* 10 / °C, no more than about 5* 10 / °C, no more than about 4* 10 / °C, no more than about 3* 106 / °C, no more than about 2* 10 / °C, or no more than about 1*106 / °C, over a temperature range of -273°C to 20°C. This thermal expansion coefficient provides dimensional stability to the apparatus 100 under varying thermal conditions. In some embodiments, the plurality of fibers can have a negative thermal expansion coefficient over a temperature range of -273°C to 20°C. Without bound by theory, fibers having a lower thermal expansion coefficient than that of the polymer matrix can counteract the expansion of the polymer matrix, further enhancing the dimensional stability of the former 110.

[0068] In some embodiments, the fibers can have a thickness of at least about 1 nm, at least about 50 nm, at least about 100 nm, at least about 150 nm, at least about 200 nm, at least about327330979 17Agent’s File Ref.: VEIR-008 / 01WO 338760-2059250 nm, at least about 300 nm, at least about 350 nm, at least about 400 nm, at least about 450 nm, at least about 500 nm, at least about 600 nm, at least about 700 nm, at least about 800 nm, at least about 900 nm, at least about 1 pm, at least about 2 pm, at least about 5 pm, at least about 10 pm, at least about 20 pm, at least about 50 pm, or at least about 100 pm. Combinations of the above-referenced thicknesses are also possible (e.g., at least about 300 nm and no more than about 100 pm), inclusive of all values and ranges therebetween. The thickness of fibers can affect overall performance characteristics of the apparatus 100. Selecting the appropriate fiber thickness depends on the specific mechanical, thermal, or functional requirements of the apparatus 100.

[0069] As used herein, the term “fiber thickness” refers to the mean diameter or width of individual fibers included in the fiber-reinforced polymer composition.

[0070] In some embodiments, the fibers can have an average length (i.e., average length of the plurality of fibers included in the fiber-reinforced polymer composition) in a range of about 1 nm to about 100 pm.[00711 In some embodiments, the fiber-reinforced polymer composition has a ratio of yield strength (S) to Young’s modulus (E) (SZE) of at least about 0.005, at least about 0.01, at least about 0.015, at least about 0.02, at least about 0.025, at least about 0.03, at least about 0.035, at least about 0.04, at least about 0.045, at least about 0.05, at least about 0.055, at least about 0.06, at least about 0.065, at least about 0.07, at least about 0.075, at least about 0.08, at least about 0.085, at least about 0.09, and at least about 0.1. The SZE ratio helps predict the ability of the former 110 to bend without permanent deformation. A higher SZE ratio means the material is more likely to bend elastically (spring back to its shape after bending), which is important for maintaining the tube's structural integrity. Conversely, a lower SZE ratio means the material is more prone to plastic deformation.

[0072] In some embodiments, the fiber-reinforced polymer composition has a thermal expansion coefficient of no more than 20x10 / °C, no more than 18x106 / °C, no more than 16x106 / °C, no more than 14x106 / °C, no more than 12x106 / °C, no more than 10x106 / °C, no more than 8x 10 / °C, no more than 6x 10 / °C, no more than 4x 10 / °C, no more than 2x106 / °C, and no more than 1 xl 06 / °C over a temperature range of -273°C to 20°C.

[0073] In some embodiments, the fiber-reinforced polymer composition has a thermal expansion coefficient of about 20x106 / °C or lower over a temperature range of -273 °C to 20°C. In some embodiments, the fiber-reinforced polymer composition has a thermal327330979 18Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 expansion coefficient of about 5x106 / °C or lower over a temperature range of -273°C to 20°C. In some embodiments, the fiber-reinforced polymer composition has a thermal expansion coefficient within ±3% of a thermal expansion coefficient of the high-temperature superconductor material 120.[00741 The HTS material 120 can include any of the high-temperature superconducting materials that exhibit superconducting properties above the temperature of liquid nitrogen, 77 K. Such materials may include, for example, YBa2Cu3O?-x, Bi2Sr2Ca2Cu30io+y, Ti2Ba2Ca2Cu30io+y, and HgBa2 Ca2Cu3 Os+y. One class of materials includes REBa2Cu3O?-x, wherein RE is a rare earth element. Of the foregoing, YBa2Cu3O?-x, also generally referred to as YBCO, may be advantageously utilized.

[0075] In some embodiments, the HTS material 120 can include at least one of a high- temperature superconducting (HTS) wire or a high-temperature superconducting (HTS) tape, disposed around an outside surface of the former 110, such that the superconducting material conforms to the shape of the former 110. The HTS tapes described herein include a substrate and a high temperature superconducting (HTS) material disposed on the substrate. In some embodiments, the substrate is a flexible substrate that provides mechanical support to the HTS material. In some embodiments, the HTS tapes can include a plurality of layers stacked on top of each other. In some embodiments, one or more layer(s) from the plurality of layers can include a HTS layer. The plurality of layers can further include a buffer layer, a stabilizing layer, a capping layer, or any other layer to ensure optimum performance of the HTS tapes. For example, the stabilizer layer and / or capping layer can be implemented to provide a low resistance interface for electrical stabilization to aid in prevention of superconductor burnout in practical use. In some embodiments, the HTS tape cam include a substrate, an HTS layer disposed on the substrate, and a stabilizing layer (e.g., copper, or silver layer) disposed on the HTS layer.

[0076] In some embodiments, the HTS wires or tapes can be wound around the former 110. In some embodiments, the HTS wires or tapes can be wound around the former 110 in a spiral pattern. In some embodiments, the HTS wires or tapes can be wound around the former 110 in a non-spiral pattern. In some embodiments, the HTS wires or tapes can be wound around the former 110 in a single layer. In some embodiments, the number of layers of the HTS wires or tapes, the width of the HTS wires or tapes, the angle and direction of winding can be selected or adjusted based on a desired application. For example, these parameters can be adjusted to minimize AC losses and / or to minimize self-inductance of the HTS wires or tapes . Similarly,327330979 19Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 a number of layers with desired winding angles may be selected to produce desired mechanical and / or electrical characteristics of the HTS wires or tapes . In some embodiments, the HTS wires or tapes can be wound around the former 110 in about 2 layers, about 3 layers, about 4 layers, about 5 layers, about 6 layers, about 7 layers, about 8 layers, about 9 layers, or about 10 layers, inclusive of all values and ranges therebetween.

[0077] In some embodiments, the apparatus 100 can include a conduit 140 disposed around and spaced apart from the former 110 such that a coolant flow is formed between the former 110 and the conduit 140. If the HTS material 120 include one or more cryogenically cooled superconductors, the coolant can be a liquid cryogen (e.g., liquid nitrogen, liquid helium, liquid neon, liquid methane, or liquid air).

[0078] In some embodiments, the conduit 140 can be formed to minimize the amount of heat from the surrounding environment that reaches the HTS material 120. In some embodiments, the conduit 140 can be load bearing in addition to or as an alternative to the former 110, such that the conduit 140 provides mechanical support for the apparatus 100. In some embodiments, an additional tube can be placed inside the conduit 140 to provide mechanical support. Alternatively, or in addition, a cable, a metal rope, a solid rod, or any combination thereof can be placed inside the conduit 140 to provide mechanical support.

[0079] The conduit 140 can have any shape of cross section, including for example circular, navette, triangle, square, polygon, regular shape, etc. In some embodiments, the shape of cross section of conduit 140 is circular. The conduit 140 can be made of any material suitable for use at cryogenic temperatures and operating pressures. For example, the conduit 140 can be made of at least one of a metal, an alloy, a polymer, or a composite (e.g., fiber reinforced polymers). In some embodiments, the conduit 140 can include cryogenically compatible polymers, such as fiber-reinforced epoxy composites, and ultra-high molecular weight polyethylene. In some embodiments, the conduit 140 can include stainless steel, aluminum, copper, or Hastelloy alloy.

[0080] In some embodiments, the conduit 140 is configured to allow a fluid to flow therethrough (e.g., between the HTS material 120 and the conduit 140) at a pressure (e.g., between about 5 bar and about 15 bar, or between about 25 bar and about 30 bar) greater than atmospheric pressure. In some embodiments, the conduit is configured to allow a fluid to flow therethrough at a specified temperature (e.g., about 77 K).327330979 20Agent’s File Ref.: VEIR-008 / 01WO 338760-2059

[0081] In some embodiments, the conduit 140 can be flexible and capable of withstanding pre-determined bending stresses without failure. For example, the conduit 140 can endure a two-way bending strain of more than about 0.1%, more than about 0.2%, more than about 0.3%, more than about 0.4%, more than about 0.5%, or more than about 1% with a bend diameter of more than 5 mm for an inner diameter of more than 50 mm. In some embodiments, the conduit 140 can be suitable for applications requiring flexibility in environments where cryogenic fluids are conveyed, particularly under constrained bending conditions. In some embodiments, the conduit 140 may be a corrugated pipe, which increases its flexibility compared to a non-corrugated pipe.

[0082] In some embodiments, the apparatus 100 can include an electrically insulating layer 130, which may be disposed on and / or around the HTS material 120, and optionally around the conduit 140 when present within the apparatus 100. In some embodiments, the apparatus 100 includes an electrically insulating layer 130 (e.g., insulating tapes) disposed on and around the HTS material 120. electrically insulating layer 130. In some embodiments, the electrically insulating layer 130 can serve to isolate the HTS material 120 from surrounding elements, preventing electrical short circuits, and providing desired functioning of the apparatus 100. In some embodiments, the electrically insulating layer 130 may be in the form of flexible tapes, which can be wrapped around the HTS material 120. In some embodiments, the electrically insulating layer 130 may be made from various insulating materials, such as plastic polymers, glass fiber, or other non-conductive composites, depending on the thermal and mechanical requirements of the desired application. In some embodiments, the electrically insulating layer 130 can be in a form of coating or film, configured to withstand the operational temperatures and environmental conditions of the apparatus 100.

[0083] In some embodiments, the apparatus 100 can include a thermally insulating layer 150 disposed on and / or around the HTS material 120, and optionally around the conduit 140 when present within the apparatus 100. In some embodiments, the thermally insulating layer 150 can have a thermal conductivity of less than 5 Watt / m° C, less than 2.5 Watt / m° C, less than 1.0 Watt / m° C, less than 0.5 Watt / m°, less than 0.1 Watt / m° C, less than 0.05 Watt / m° C, less than 0.04 Watt / m° C, less than 0.03 Watt / m° C, or less than 0.02 Watt / m° C.(0084] In some embodiments, the thermally insulating layer 150 can include at least one of polyurethane foam, bitumen, cement, clay, concrete, ceramic filled corian, cork, cotton wool insulation, diatomaceous earth, epoxy, fiberglass, foam glass, glass pearls or beads, glass wool, gypsum, magnesite, magnesia insulation, mineral insulation, nylon, perlite, foamed plastic327330979 21Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 insulation, expanded polystyrene, porcelain, PTFE, PVC, Pyrex glass, sand, silica aerogel, Styrofoam, urethane foam, vermiculite or vinyl ester.

[0085] In some embodiments, the thermally insulating layer 150 can provide structural reinforcement for the apparatus 100. In some embodiments, the thermally insulating layer 150 can aid in preventing damage from impacts to the apparatus 100. In some embodiments, the optional conduit 140 and / or the former 110 can be disposed within the thermally insulating layer 150 such that vacuum or another material (e.g., carbon dioxide (CO2), an inert gas, etc.) can be disposed within a space between the optional conduit and / or the former 110.

[0086] In some embodiments, the thermally insulating layer 150 can include a thermally insulating jacket disposed on and optionally spaced apart from the optional conduit 140 and / or the former 110. The thermally insulating jacket is configured to reduce an amount of heat from the surroundings that reaches the inner surface of the former 110. The thermally insulating jacket, itself, can include, for example, two concentric pipes (e.g., metal pipes) spaced from one another, with vacuum or another material (e.g., carbon dioxide (CO2), an inert gas, etc.) disposed between the two pipes. As another example, the thermally insulating jacket may include two concentric pipes, rendered flexible by corrugation or other means, spaced from one another, with vacuum or another material (e.g., an inert gas) disposed between the two flexible pipes. In some embodiments, the concentric pipes that forms the thermally insulating jacket can be made from at least one of a metal or an alloy. In some embodiments, the concentric pipes that forms the thermally insulating jacket can be made from a metal. In some embodiments, the concentric pipes that forms the thermally insulating jacket can be made from at least one of metal, an alloy, polymer, or a composite (e.g., fiber reinforced composite).

[0087] FIG. 2 illustrates an apparatus 200 for being implemented in a superconducting power transmission line / system, according to an embodiment. The apparatus 200 includes a former 210 defining a cylindrical shape, made of a fiber-reinforced composite composition, and HTS wires or tapes 220 wound around the former 210. The former 210 is hollow configured to transport gas, vapor, or liquid coolant (e.g., cryogen), facilitating the cooling of the apparatus 200. This hollow structure forms a flow space 211 within the former 210, allowing coolant fluids to flow through its core. The apparatus further includes a conduit 240 which is disposed around and spaced apart from the former 210 and HTS material 220 such that an annular space 212 defining a coolant flow space is formed. A thermally insulated jacket constructed of two concentric corrugated metal pipes 244, 246 spaced from one another, with327330979 22Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 vacuum 248 disposed therebetween surrounds the conduit 240. This configuration can mitigate heat ingress from the environment while maintaining flexibility under cryogenic conditions.

[0088] In some embodiments, the apparatus 200 can be implemented within a superconducting power transmission line / system. In some embodiments, at least one of the coolant flow spaces 211 or 212 can be filled with a flowing liquid coolant. In some embodiments, the liquid coolant can be a liquid cryogen (e.g., liquid nitrogen, liquid helium, liquid neon, liquid methane, or liquid air). In some embodiments, during operation of apparatus 200, a liquid cryogen can flow through the flow space 211 in one direction and through annular space 212 in another. The two directions may be either opposite or the same. In some embodiments, the liquid cryogen may include nitrogen.]0089[ In some embodiments, the former 210, the HTS material 220, and the conduit 240, can be the same or substantially similar to the former 110, the HTS material 120, and the conduit 140, as described above with reference to FIG. 1. Thus, certain aspects of the former 210, the HTS material 220, and the conduit 240 are not described in greater detail herein.

[0090] In some embodiments, the conduit 240 can be formed to minimize the amount of heat from the surrounding environment that reaches cryogen within the conduit 240 and / or the HTS wires or tapes 220. In some embodiments, the conduit 240 and / or the former 210 can be load bearing, such that the conduit 240 and / or the former 210 provides mechanical support for the apparatus 200. In some embodiments, an additional tube, a cable, a metal rope, a solid rod, or any combination thereof (not shown) can be placed inside the conduit 240 to provide mechanical support.

[0091] In some embodiments, the conduit 240 has an inner diameter (ID) of at least about 50 mm, at least about 60 mm, at least about 70 mm, at least about 80 mm, at least about 90 mm, at least about 100 mm, at least about 110 mm, at least about 120 mm, at least about 140 mm, or at least about 140 mm. In some embodiments, the conduit 240 has an inner diameter (ID) of no more than about 150 mm, no more than about 140 mm, no more than about 140 mm, no more than about 120 mm, no more than about 110 mm, no more than about 100 mm, no more than about 90 mm, no more than about 80 mm, no more than about 70 mm, or no more than about 60 mm. Combinations of the above-referenced inner diameters are also possible (e.g., at least about 50 mm and no more than about 150 mm or at least about 80 mm and no more than about 120 mm), inclusive of all values and ranges therebetween.327330979 23Agent’s File Ref.: VEIR-008 / 01WO 338760-2059

[0092] In some embodiments, the conduit 240 has an outer diameter (OD) of at least about 75 mm, at least about 80 mm, at least about 90 mm, at least about 100 mm, at least about 110 mm, at least about 120 mm, at least about 130 mm, at least about 140 mm, at least about 150 mm, at least about 160 mm, at least about 170 mm, at least about 180 mm, at least about 190 mm, at least about 200 mm, at least about 210 mm, at least about 220 mm, at least about 240 mm, or at least about 240 mm. In some embodiments, the conduit 240 has an outer diameter (OD) of no more than about 250 mm, no more than about 230 mm, no more than about 240 mm, no more than about 220 mm, no more than about 210 mm, no more than about 200 mm, no more than about 190 mm, no more than about 180 mm, no more than about 170 mm, no more than about 160 mm, no more than about 150 mm, no more than about 140 mm, no more than about 130 mm, no more than about 120 mm, no more than about 110 mm, no more than about 100 mm, no more than about 90 mm, or no more than about 80 mm. Combinations of the above-referenced inner diameters are also possible (e.g., at least about 75 mm and no more than about 250 mm or at least about 150 mm and no more than about 200 mm), inclusive of all values and ranges therebetween.

[0093] In some embodiments, provided herein is a method of forming a former made of a fiber-reinforced composite material. The composite material may include fibers such as carbon, glass, or aramid, embedded in a polymer matrix. In some embodiments, the fibers may be distributed throughout the polymer matrix. In some embodiments, the fibers can be oriented in specific directions to optimize mechanical strength and thermal stability, allowing the former to withstand the operational stresses and temperatures associated with high-temperature superconducting (HTS) applications.

[0094] In some embodiments, the fiber-reinforced polymer composition can be obtained by first preparing a polymer solution, wherein the polymer precursor may be dissolved in a suitable solvent. The reinforcing fibers, which may include carbon, glass, aramid, or natural fibers, can then be dispersed into the polymer solution using methods such as mechanical stirring, ultrasonication, or high shear mixing to achieve uniform or non-uniform distribution. Subsequently, the solvent can be evaporated, resulting in a mixture of fibers and polymer. The mixture can be then cured by applying heat or a chemical curing agent, thereby solidifying the polymer matrix that includes fibers distributed throughout the polymer matrix.

[0095] In some embodiments, the fiber-reinforced polymer composition can be obtained by extruding a polymer resin including fibers through a die. This process can align the fibers327330979 24Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 in the direction of extrusion, enhancing the mechanical properties of the resulting material. The polymer resin may be selected from thermoplastic or thermosetting polymers.

[0096] In other embodiments, the fiber-reinforced polymer composition can be produced using a tape-like material that is laid up in layers, similar to the construction of a carbon fiber wing, allowing for control over the orientation and distribution of the fibers within the polymer matrix.

[0097] In some embodiments, pultrusion can be used to produce the fiber-reinforced polymer composition. This method involves pulling continuous fibers through a resin bath and then through a heated die, where the resin cures to form a solid composite material.

[0098] Additionally, in some embodiments, the fiber-reinforced polymer composition can be achieved through laser welding of fiber-containing tapes. This technique can involve welding multiple tapes together to form a cohesive structure.

[0099] In some embodiments, the former may be formed using the fiber-reinforced polymer composition through methods such as filament winding, or resin transfer molding, depending on the desired shape and dimensions of the former. Once the fiber-reinforced composite former is fabricated, the HTS material can be applied. In some embodiments, the HTS material is wrapped around or disposed onto the surface of the former in a controlled manner, providing uniform coverage and alignment. This can be achieved through methods such as tape winding. The HTS material may include layers of superconducting tape, typically consisting of materials like yttrium barium copper oxide (YBCO), which exhibit high electrical conductivity and minimal resistance at operational temperatures. The wrapping process ensures that the HTS material adheres securely to the former while maintaining its superconducting properties.101.00] In certain embodiments, the method may include additional steps to further secure and protect the HTS material. For example, a protective insulating layer, such as a thermally or electrically insulating coating, may be applied over the HTS material to safeguard it from environmental factors such as moisture, mechanical stress, or thermal cycling. This layer can be applied using techniques like spraying, dip-coating, or laminating, depending on the material and the desired protective characteristics. These additional steps provide the structural integrity and long-term performance of the HTS material in operational environments.[01011 Various concepts may be embodied as one or more methods, of which at least one example has been provided. The acts performed as part of the method may be ordered in any327330979 25Agent’s File Ref.: VEIR-008 / 01WO 338760-2059 suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments. As such, some of these features may be mutually contradictory, in that they cannot be simultaneously present in a single embodiment. Similarly, some features are applicable to one aspect of the innovations, and inapplicable to others.

[0102] In addition, the disclosure may include other innovations not presently described. Applicant reserves all rights in such innovations, including the right to embodiment such innovations, file additional applications, continuations, continuations-in-part, divisionals, and / or the like thereof. As such, it should be understood that advantages, embodiments, examples, functional, features, logical, operational, organizational, structural, topological, and / or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the embodiments or limitations on equivalents to the embodiments.327330979 26

Claims

Agent’s File Ref.: VEIR-008 / 01WO 338760-2059CLAIMS1. An apparatus comprising: a former constructed of a fiber-reinforced polymer composition; and a high temperature superconductor material disposed on and around the former.

2. The apparatus of claim 1, wherein the fiber-reinforced polymer composition has a ratio of yield strength to Young’s modulus of about 0.02 or greater.

3. The apparatus of claims 1 or 2, wherein the fiber-reinforced polymer composition has a thermal expansion coefficient of about 20x1 O'6 / °C or lower over a temperature range of about -273°C to about 20°C.

4. The apparatus of claim 3, wherein the fiber-reinforced polymer composition has a thermal expansion coefficient of about 5x106 / °C or lower over a temperature range of about - 273°C to about 20°C.

5. The apparatus of any one of the preceding claims, the fiber-reinforced polymer composition has a thermal expansion coefficient within ±3% of a thermal expansion coefficient of the high-temperature superconductor material.

6. The apparatus of any one of the preceding claims, wherein the former has a cylindrical shape.

7. The apparatus of claim 6, wherein the former has an outer diameter of about 20 mm or greater.

8. The apparatus of claim 6, wherein the former has an outer diameter of about 30 mm or greater.

9. The apparatus of any one of the preceding claims, wherein the former has a minimum elastic bend diameter of about 2.0 m or lower.327330979 27Agent’s File Ref.: VEIR-008 / 01WO 338760-205910. The apparatus of any one of the preceding claims, wherein the former is in a form of a conduit configured to allow a coolant to flow therethrough at a pressure greater than atmospheric pressure.

11. The apparatus of any one of the preceding claims, wherein the former and high temperature superconductor material are disposed in a thermally insulating jacket such that a space is created between the high temperature superconductor material and an inner surface of the thermally insulating jacket, the space being configured to allow a coolant to flow therethrough.

12. The apparatus of any one of the preceding claims, wherein the fiber-reinforced polymer composition comprises a polymer matrix and a plurality of fibers distributed within the polymer matrix.

13. The apparatus of claim 12, wherein the fiber-reinforced composition includes about 10 to about 30% fiber by weight.

14. The apparatus of claim 12, wherein the polymer matrix is a thermosetting polymer.

15. The apparatus of claim 12, wherein the polymer matrix includes at least one of polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyetherketoneketone (PEKK), or poly etherketone (PEK).

16. The apparatus of claim 12, wherein the polymer matrix includes a polyaryletherketone (PAEK).

17. The apparatus of claim 12, wherein the plurality of fibers is constructed of a material having a thermal expansion coefficient below about 5x1 O'6 / °C over a temperature range of about -273°C to about 20°C.

18. The apparatus of claim 12, wherein the plurality of fibers is constructed of a material having a negative thermal expansion coefficient over a temperature range of about -273 °C to about 20°C.327330979 28Agent’s File Ref.: VEIR-008 / 01WO 338760-205919. The apparatus of claim 12, wherein the plurality of fibers includes at least one of glass fibers, carbon fibers, aramid fibers, or quartz fibers.

20. The apparatus of claim 12, wherein the plurality of fibers is constructed of a material that has a tensile modulus between about 250 GPa and about 500 GPa.

21. The apparatus of any one of the preceding claims, wherein the former defines a hollow interior configured to transport a cryogenic coolant.

22. The apparatus of claim 21, wherein the cryogenic coolant comprises ethane, ethylene, krypton, methane, oxygen, argon, nitrogen, neon, hydrogen, xenon, or helium.

23. The apparatus of claims 21 or 22, wherein the coolant flows through the hollow interior at a pressure between about 5 bar and about 30 bar greater than atmospheric pressure.

24. The apparatus of any one of the preceding claims, wherein the former has a surface with an average roughness between about 0.05 pm and about 0.8 pm.

25. The apparatus of any one of the preceding claims, wherein fibers in the fiber-reinforced polymer composition are oriented circumferentially around the former.

26. The apparatus of any one of the preceding claims, wherein the high temperature superconductor material comprises a plurality of high temperature superconductor tapes wound on and around the former in a spiral pattern.

27. The apparatus of any one of the preceding claims, further comprising: a thermally insulating jacket disposed around the former and the high temperature superconductor material such that an annulus is formed between the high temperature superconductor material and an inner surface of the thermally insulating jacket, the annulus being configured to allow a coolant to flow therethrough.

28. The apparatus of claim 27, wherein the thermally insulating jacket comprises two concentric corrugated pipes with vacuum disposed therebetween.327330979 29

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