Composite insulating layer structure and preparation method thereof, and tubular bus and preparation method thereof

Abstract

The invention provides a composite insulating layer structure and a preparation method thereof, and a tubular bus and a preparation method thereof, and the composite insulating layer structure comprises at least two silicone rubber layers which are used for forming a main insulating material; and the epoxy resin layer is arranged between two adjacent silicon rubber layers and is used for fixedly connecting the silicon rubber layers, and the thickness of the epoxy resin layer is less than or equal to 1mm. The composite insulating layer structure is more stable in electrical performance and higher in insulating capacity; different insulating materials are similar to a capacitor after being compounded together due to different dielectric coefficients, and along with the increase of the number of layers, the capacitive reactance is continuously increased, and the insulating property is continuously improved; after the epoxy resin layer is filled between the silicone rubber layers, air and moisture in the whole insulating layer are driven out, and the partial discharge probability is greatly reduced; the epoxy resin layer and the silicone rubber layer form a whole after being cured, so that external moisture and steam cannot invade, and the service life of the insulating material is greatly prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of power generation, transmission, transformation and distribution devices of electric power systems, and in particular to a composite insulation layer structure and a preparation method, a tubular busbar and a preparation method. Background Art

[0002] With the rapid development of my country's economy, the power supply capacity has increased significantly. The rated current of the low-voltage side of the transformer is also increasing. At present, the capacity of a single 110KV and 220KV transformer reaches 120MVA, the voltage on the low-voltage side is 6.3-13.8KV, and the working current is as high as 5000A-11000A. At the same time, my country's thermal power generating units with a single capacity of 125MW and below are gradually shutting down. 200MW, 300MW and 600MW units have become mainstream power generation equipment, with export voltages of 15.75KV, 18KV and 20KV, and export currents of 8625A, 11320A and 19000A, respectively. Tubular busbars are mainly used for large current circuits with currents of more than 4000A. This shape of busbar has a large cross-sectional area, large current carrying capacity, and high bending strength, so it is used in large current carrying capacity and large short-circuit current circuits.

[0003] At present, the insulation of insulated tubular busbar machinery and equipment in use is mostly straight tube-shaped, and the tubular busbar after the insulation layer is made cannot be bent. For example, the Chinese patent "Dry Fully Insulated Tubular Busbar" (CN102237157A) discloses the following technical solution: from the inside to the outside, it includes a hollow conductive tube, a first epoxy resin insulation layer, a first shielding layer, a second epoxy resin insulation layer, a second shielding layer, a third epoxy resin insulation layer, and a third shielding layer, and the third shielding layer is connected to the ground zero potential to form a shielding protection layer. Epoxy resin is used as the insulating layer here, which has the following disadvantages: 1. After the epoxy resin is cured, the epoxy resin insulating layer becomes hard and brittle, and is easily damaged by external forces and difficult to repair; 2. The insulating tubular busbar made of epoxy resin can no longer be bent. To be a certain shape, tubular busbars with different bending angles need to be processed as accessories for use at turns. However, these angled tubular conductors cannot be machined with mechanical equipment for the insulation layer, and the insulation layer can only be wound manually, resulting in unstable product insulation quality. During on-site installation, different bending angles must be selected according to needs, which is obviously not convenient enough and cannot be universal for all bending angles.

[0004] In order to solve the shortcomings of the above-mentioned epoxy resin layer as an insulating layer, the patents "High-temperature-resistant and anti-corrosion high-voltage flexible cable" (CN1929042A) and "Dry-type fully shielded insulated tubular bus" (CN103680685B) use silicone rubber materials to prepare the insulating layer. Although the tubular busbar with this structure can solve the problem of bending, in actual use, the insulating layer made of a single silicone rubber material has the following shortcomings: when the voltage is high and the thickness of the insulating layer is large, the bending part is prone to strain, thereby affecting the effects of the conductor shielding layer, the main insulating layer, and the insulating shielding layer, causing unstable operation and shortening the service life of the insulated tubular busbar. Summary of the invention

[0005] In view of the above defects of the prior art, the present invention provides a composite insulation layer structure and a preparation method, a tubular busbar and a preparation method to solve the technical problem of poor insulation effect of the insulation layer in the prior art.

[0006] To achieve the above-mentioned purpose and other related purposes, the present invention provides a composite insulation layer structure, including: a silicone rubber layer, used to constitute the main insulation material, and the silicone rubber layer is provided with at least two layers; an epoxy resin layer, arranged between two adjacent silicone rubber layers for fixing the silicone rubber layer, and the thickness of the epoxy resin layer is less than or equal to 1 mm.

[0007] In one embodiment of the present invention, the structure is applied to a tubular member, and both the epoxy resin layer and the silicone rubber layer are tubular.

[0008] To achieve the above-mentioned purpose and other related purposes, the present invention also provides a method for preparing the above-mentioned composite insulating layer structure, comprising the following steps: applying epoxy resin on the surface of an object on which an insulating layer is required to be provided to form a first epoxy resin layer; adhering a first silicone rubber layer on the first epoxy resin layer; applying epoxy resin on the first silicone rubber layer to form a second epoxy resin layer; adhering a second silicone rubber layer on the second epoxy resin layer; and so on, repeating the alternating production to obtain the composite insulating layer structure.

[0009] In one embodiment of the present invention, the structure is applied to a tubular member, and the steps are replaced by: applying epoxy resin on the surface of the tubular member where an insulating layer is required to be provided to form a first epoxy resin layer; sleeve a tubular first silicone rubber layer on the surface of the first epoxy resin layer, and tighten the first silicone rubber layer by heat shrinking or cold shrinking; applying epoxy resin on the surface of the first silicone rubber layer to form a second epoxy resin layer; sleeve a tubular second silicone rubber layer on the surface of the second epoxy resin layer, and tighten the second silicone rubber layer by heat shrinking or cold shrinking; and so on, the composite insulating layer structure can be obtained by repeating the alternating production.

[0010] In one embodiment of the present invention, the step of applying epoxy resin is replaced by applying epoxy resin mixture, wherein the epoxy resin mixture includes epoxy resin and room temperature curing agent, and the weight proportion of the room temperature curing agent is less than or equal to 25%.

[0011] To achieve the above-mentioned purpose and other related purposes, the present invention also provides a tubular busbar, comprising: a conductor; a composite insulation layer, wherein the composite insulation layer is sleeved on the surface of the conductor, and the structure of the composite insulation layer is the composite insulation layer structure as described above.

[0012] In one embodiment of the present invention, the conductor is a copper tube or an aluminum tube or a copper-aluminum bimetallic composite tube.

[0013] In one embodiment of the present invention, a conductor shielding layer is included, the conductor shielding layer is made of a semi-conductive material, the conductor shielding layer is sleeved on the surface of the conductor, and the composite insulating layer is sleeved on the surface of the conductor shielding layer.

[0014] In one embodiment of the present invention, it includes: an insulating shielding layer, which is made of a semi-conductive material and is sleeved on the surface of the composite insulating layer; a metal grounding shielding layer, which is made of a conductive material for grounding and is sleeved on the surface of the insulating shielding layer; and an outer protective sleeve, which is sleeved on the surface of the metal grounding shielding layer.

[0015] To achieve the above-mentioned purpose and other related purposes, the present invention also provides a method for preparing a tubular busbar as described above, comprising the following steps: selecting a tubular conductor and bending it to a suitable angle according to installation requirements; using a semi-conductive material to half-pad the surface of the conductor to form a conductor shielding layer; applying an epoxy resin mixture on the surface of the conductor shielding layer to form a first epoxy resin layer; sleeve a tubular first silicone rubber layer on the surface of the first epoxy resin layer, and tighten the first silicone rubber layer by heat shrinking or cold shrinking; applying an epoxy resin mixture on the surface of the first silicone rubber layer to form a second epoxy resin layer; sleeve a tubular second silicone rubber layer on the surface of the second epoxy resin layer, and tighten the second silicone rubber layer by heat shrinking or cold shrinking; and so on to form a composite insulating layer; using a semi-conductive material to half-pad the surface of the composite insulating layer to form an insulating shielding layer; using a conductive metal material to half-pad the surface of the insulating shielding layer to form a metal grounding shielding layer; using an insulating material to sleeve the surface of the metal grounding shielding layer by heat shrinking or cold shrinking to form an outer protective sleeve.

[0016] Beneficial effects of the present invention: The present invention proposes a composite insulation layer structure and preparation method, a tubular busbar and preparation method. Compared with a single insulation material, the composite insulation layer structure has more stable electrical properties and higher insulation capacity. Different insulation materials have different dielectric constants, and when they are compounded together, they are similar to a capacitor. As the number of layers increases, it is equivalent to multiple capacitors in series, the capacitive reactance continues to increase, and the insulation performance continues to improve. When the silicone rubber layers are filled with epoxy resin layers, the air and moisture in the entire insulation layer will be forced out, and the probability of local discharge will be greatly reduced. At the same time, after the epoxy resin layer is cured, it forms a whole with the silicone rubber layer, and the density is very high, so that external moisture and water vapor cannot invade, thereby greatly improving the service life of the insulation material. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A schematic structural diagram of a composite insulating layer structure provided by an embodiment of the present invention;

[0019] Figure 2 A schematic structural diagram of a tubular composite insulation layer structure provided by an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of a first tubular busbar structure provided by an embodiment of the present invention;

[0021] Figure 4 is a schematic diagram of a second tubular busbar structure provided by an embodiment of the present invention;

[0022] Figure 5 It is a schematic diagram of a third tubular busbar structure provided by an embodiment of the present invention.

[0023] Explanation of the reference numerals: 100, conductor; 200, conductor shielding layer; 300, composite insulating layer; 310, silicone rubber layer; 311, first silicone rubber layer; 312, second silicone rubber layer; 320, epoxy resin layer; 321, first epoxy resin layer; 322, second epoxy resin layer; 400, insulating shielding layer; 500, metal grounding shielding layer; 600, outer protective cover. DETAILED DESCRIPTION

[0024] The following describes the embodiments of the present invention through specific specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. It should be noted that the following embodiments and the features in the embodiments can be combined with each other without conflict. In addition to the specific methods, equipment, and materials used in the embodiments, according to the technical personnel in this technical field's grasp of the prior art and the records of the present invention, any methods, equipment, and materials of the prior art that are similar or equivalent to the methods, equipment, and materials described in the embodiments of the present invention can also be used to implement the present invention.

[0025] It should be understood that the terms used in the embodiments of the present invention are for describing specific embodiments rather than for limiting the scope of protection of the present invention. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those generally understood by those skilled in the art.

[0026] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions under which the present invention can be implemented, so they have no substantive technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. In addition, the drawings only show the components related to the present invention rather than the number, shape, and size of the components in actual implementation. The type, quantity, and proportion of each component in actual implementation can be changed arbitrarily, and the component layout type may also be more complicated.

[0027] See also Figure 1 An embodiment of the present invention provides a composite insulating layer structure, including: a silicone rubber layer 310, which is used to constitute the main insulating material, and the silicone rubber layer 310 is provided with at least two layers; an epoxy resin layer 320, which is provided between two adjacent silicone rubber layers 310 and is used to fix the silicone rubber layer 310, and the thickness of the epoxy resin layer 320 is less than or equal to 1mm. The epoxy resin layer 320 here plays the role of insulation, adhesion, and filling, so its thickness cannot be too thick, and it should be as thin as possible. After curing, it plays the role of sealing, moisture-proofing, and reinforcing insulation. On the premise of satisfying the above functions and effects, it can be set thinner. The silicone rubber layer 310 is the main insulating material, and its thickness is thicker than the epoxy resin layer 320, but its thickness cannot be too thick. If it is too thick, it will bring about the shortcomings of the single silicone rubber layer 310. Figure 1 In order to clearly see the structure of each layer, different areas of each layer are cut away.

[0028] In actual use, when the composite insulating layer structure is used independently, its bottom layer and top layer are both silicone rubber layers 310; when the composite insulating layer structure needs to be fixedly connected to other components, its bottom layer and / or top layer should be epoxy resin layer 320.

[0029] Compared with a single insulating material, the composite insulating layer structure has more stable electrical properties and higher insulation capacity. Different insulating materials have different dielectric constants, and when they are combined together, they are similar to a capacitor. As the number of layers increases, it is equivalent to multiple capacitors in series, the capacitive reactance continues to increase, and the insulation performance continues to improve. When the silicone rubber layer 310 is filled with the epoxy resin layer 320, the air and moisture in the entire insulating layer will be forced out, and the probability of local discharge will be greatly reduced. At the same time, after curing, the epoxy resin layer 320 forms a whole with the silicone rubber layer 310, and the density is very high, so that external moisture and water vapor cannot invade, thereby greatly improving the service life of the insulating material.

[0030] See also Figure 2 In a specific embodiment of the present invention, the structure is applied to a tubular member, such as a tubular busbar, and the epoxy resin layer 320 and the silicone rubber layer 310 are both tubular and nested together layer by layer.

[0031] An embodiment of the present invention provides a method for preparing the above-mentioned composite insulating layer structure, comprising the following steps: applying epoxy resin on the surface of an object on which an insulating layer is to be provided to form a first epoxy resin layer 321, and the application should be as uniform as possible, so that the first epoxy resin layer 321 formed will be better; adhering a first silicone rubber layer 311 on the first epoxy resin layer 321, and when adhering, it is best to press the first epoxy resin layer 321 and the first silicone rubber layer 311 together with the aid of external force to improve the viscosity of the two and fully discharge the air and moisture therein; applying epoxy resin on the first silicone rubber layer 311 to form a second epoxy resin layer 322; adhering a second silicone rubber layer 312 on the second epoxy resin layer 322; and so on, repeating the alternating production to obtain the composite insulating layer structure.

[0032] In a specific embodiment of the present invention, the structure is applied to a tubular member, and the steps are replaced as follows: epoxy resin is applied to the surface of the tubular member on which an insulating layer is required to be provided to form a first epoxy resin layer 321, and the application should be as uniform as possible; the tubular first silicone rubber layer 311 is sleeved on the surface of the first epoxy resin layer 321, and the first silicone rubber layer 311 is tightened by heat shrinkage or cold shrinkage. It is difficult to tighten the silicone rubber layer 310 on the tubular member by pressing, so in this embodiment, heat shrinkage or cold shrinkage is used to tighten it; epoxy resin is applied to the surface of the first silicone rubber layer 311 to form a second epoxy resin layer 322; the tubular second silicone rubber layer 312 is sleeved on the surface of the second epoxy resin layer 322, and the second silicone rubber layer 312 is tightened by heat shrinkage or cold shrinkage; and so on, the composite insulating layer structure can be obtained by repeated alternating production. In this embodiment, we use a tubular silicone rubber layer 310 (referred to as silicone tube) to make the composite insulation layer structure. When selecting the silicone tube, it is recommended that the thickness be 1 to 2 mm. If it is too thick, it is difficult to achieve sleeve insertion, cold shrinkage or heat shrinkage. If it is too thin, the insulation performance is poor and it is easy to break when shrinking. Therefore, it is not recommended to use too thin. The thickness of the composite insulation layer 300 can be adjusted according to different voltage levels. If you want it to be thicker, just put on more layers of silicone tubes and increase the thickness of the silicone rubber layer 310. Therefore, there is no need to strictly define the thickness of a single-layer silicone tube, and you only need to consider the difficulty of processing.

[0033] As for the thickness of other forms of silicone rubber layer 310, the specific thickness should be considered based on many factors: first, the processing technology of the silicone rubber layer 310 itself needs to be considered, and its thickness should be set to facilitate processing; second, the insulation performance needs to be considered because the silicone rubber layer needs to be used as the main insulating material; third, the process of combining the silicone rubber layer 310 with the epoxy resin layer 320 needs to be considered, and its thickness should be convenient for combining with the epoxy resin layer 320.

[0034] In a specific embodiment of the present invention, the step of applying epoxy resin is replaced by applying epoxy resin mixture, and the epoxy resin mixture includes epoxy resin and room temperature curing agent, and the weight proportion of room temperature curing agent is less than or equal to 25%. Adding a certain weight ratio of room temperature curing agent to epoxy resin can accelerate the curing speed of epoxy resin layer 320 and shorten the preparation time of composite insulation layer structure. Generally speaking, the curing time of epoxy resin changes with the change of ambient temperature, and the curing time will be longer if no curing agent is added. Curing agent includes room temperature curing agent and high temperature curing agent. High temperature curing requires the product to be placed in a drying oven for heating, which is troublesome and costly. Therefore, in this embodiment, room temperature curing agent is added to epoxy resin mixture. When adding room temperature curing agent, the more it is added, the shorter the curing time. Therefore, when considering the proportion of room temperature curing agent, it is necessary to consider the time of making composite insulation layer structure. The curing time must be greater than the production time to avoid curing during the production process, and the composite bonding effect cannot be achieved. At the same time, too much room temperature curing agent cannot be added, which will affect the insulation effect of the epoxy resin. Therefore, in this embodiment, it is preferred to add 25% of room temperature curing agent, or less.

[0035] See also Figure 3 An embodiment of the present invention provides a tubular busbar, comprising: a conductor 100; a composite insulation layer 300, wherein the composite insulation layer 300 is sleeved on the surface of the conductor 100, and the structure of the composite insulation layer 300 is the composite insulation layer structure as described above. In the tubular busbar structure, the conductor 100 and the composite insulation layer 300 are necessary basic structures. In this structure, the advantages of the composite insulation layer structure are also applicable to the tubular busbar. Compared with the tubular busbar with a single insulation layer, the tubular busbar using the composite insulation layer 300 as the insulation layer has a greatly improved withstand voltage, a greatly reduced probability of partial discharge, and a greatly reduced dielectric loss value.

[0036] In a specific embodiment of the present invention, the conductor 100 is a copper tube or an aluminum tube or a copper-aluminum bimetallic composite tube. Compared with the soft conductor 100 made of thin copper wires twisted in the patent "High-temperature and corrosion-resistant high-voltage flexible cable" CN1929042A, the conductor 100 made of a copper tube or an aluminum tube or a copper-aluminum bimetallic composite tube is more ideal. The specific preparation method of the conductor 100 can refer to the scheme in "Dry-type fully shielded insulated tubular busbar" CN103680685B, which will not be repeated in this case. When preparing the conductor 100, it is necessary to select a copper tube or an aluminum tube or a copper-aluminum bimetallic composite tube of corresponding specifications according to the size of the rated current. The tube diameter is 30 to 300 mm and the tube wall thickness is 3 to 20 mm.

[0037] In a specific embodiment of the present invention, a conductor shielding layer 200, an insulating shielding layer 400, a metal grounding shielding layer 500 and an outer protective cover 600 may also be included. The structures and functions of these layers are as follows.

[0038] Conductor shielding layer 200: The conductor shielding layer 200 is made of a semi-conductive material, such as a semi-conductive cloth or a semi-conductive self-adhesive tape. The conductor shielding layer 200 is sleeved on the surface of the conductor 100, and the composite insulating layer 300 is sleeved on the surface of the conductor shielding layer 200. In order to improve the safety of operation, when the voltage is higher than 1 kV or above, the conductor shielding layer 200 is sleeved on the surface of the conductor 100 to play a role in uniform electric field.

[0039] Insulating shielding layer 400: The insulating shielding layer 400 is made of a semi-conductive material like the conductive shielding layer 200. The insulating shielding layer 400 is sleeved on the surface of the composite insulating layer 300 and mainly plays the role of insulating shielding.

[0040] Metal grounding shielding layer 500: The metal grounding shielding layer 500 is made of conductive material and is used for grounding to ensure safe operation under high voltage. It is sleeved on the surface of the composite insulating layer 300 or the insulating shielding layer 400. It can be made of highly conductive materials such as copper foil, aluminum foil or copper tape.

[0041] The outer protective sleeve 600 is sleeved on the outer surface of the metal grounding shielding layer 500 to prevent the metal grounding shielding layer 500 from forming a loop current due to multi-point grounding, and protect the metal grounding shielding layer 500 from being corroded by external moisture, dust, etc. It can be composed of the high-voltage busbar tube in "Dry Fully Shielded Insulated Tubular Bus" CN103680685B.

[0042] The above layers can be freely combined under reasonable circumstances, together with the above most basic conductor 100+composite insulation layer structure, to form the following solution. For a more concise description, the following only describes the layers in order from the inside to the outside.

[0043] Solution 1, conductor 100+composite insulating layer 300, such as Figure 3 As shown;

[0044] Solution 2, conductor 100+conductor shielding layer 200+composite insulating layer 300, such as Figure 4 shown.

[0045] Solution 3: conductor 100+composite insulation layer 300+insulation shielding layer 400.

[0046] Solution 4: conductor 100+conductor shielding layer 200+composite insulating layer 300+insulating shielding layer 400.

[0047] On the basis of the above four solutions, a separate outer protective sleeve 600 can be added to obtain four new solutions, or a metal grounding shielding layer 500 + outer protective sleeve 600 can be added at the same time to obtain four new solutions. Among them, the safest tubular busbar structure should include all the above layers, that is, conductor 100 + conductor shielding layer 200 + composite insulation layer 300 + insulation shielding layer 400 + metal grounding shielding layer 500 + outer protective sleeve 600, such as Figure 5 However, in actual use, other solutions can also be selected according to the application to reduce costs.

[0048] An embodiment of the present invention provides a method for preparing the above-mentioned tubular busbar, comprising the following steps: selecting a tubular conductor 100, bending it to a suitable angle according to installation requirements; using a semi-conductive material to half-wrap around the surface of the conductor 100 to form a conductor shielding layer 200; applying an epoxy resin mixture on the surface of the conductor shielding layer 200 to form a first epoxy resin layer 321; sleeve a tubular first silicone rubber layer 311 on the surface of the first epoxy resin layer 321, and tighten the first silicone rubber layer 311 by heat shrinking or cold shrinking; applying an epoxy resin mixture on the surface of the first silicone rubber layer 311. A second epoxy resin layer 322 is formed; a tubular second silicone rubber layer 312 is sleeved on the surface of the second epoxy resin layer 322, and the second silicone rubber layer 312 is tightened by heat shrinkage or cold shrinkage; and so on, a composite insulating layer 300 is formed; a semi-conductive material is used to half-pad the surface of the composite insulating layer 300 to form an insulating shielding layer 400; a conductive metal material is used to half-pad the surface of the insulating shielding layer 400 to form a metal grounding shielding layer 500; an insulating material is sleeved on the surface of the metal grounding shielding layer 500 by heat shrinkage or cold shrinkage to form an outer protective cover 600.

[0049] In the patent CN1929042A "High-temperature-resistant and anti-corrosion high-voltage flexible cable", the high-voltage cable itself is soft and can be bent, but the bending is limited by the thickness of the cable itself. Even if the cable is soft, its bending radius still needs to reach 6 times the outer diameter of the cable, which is not applicable in many occasions.

[0050] In the patent CN103680685B of "Dry Fully Shielded Insulated Tubular Busbar", the first semi-conductive shielding layer, the insulating layer, and the second semi-conductive shielding layer are co-extruded by an extruder, and then vulcanized and formed on the conductive core to form a shielded insulating conductor. After the shielded insulating conductor is processed, it can be bent according to the installation requirements on site. Compared with the cable in the previous section, the tubular busbar itself is not very soft and can also be bent, which is a great improvement. However, the bending part is prone to damage, which will affect the effect of the conductor shielding layer 200, the insulating layer, and the insulating shielding layer 400, resulting in unstable operation and shortening the service life of the tubular busbar.

[0051] The preparation method of the tubular busbar in the above embodiment is different. All layers outside the conductor 100 can be processed by winding, coating, heat shrinking or cold shrinking according to conductors of different shapes. It has great advantages: first, the other layers outside the conductor 100 are processed after the conductor 100 is bent, so the protection effect of each layer will not be affected in any way; second, when bending the conductor 100, the bending angle can be larger, so the application range is wider; third, in the case of bending, too thick silicone tubes are difficult to install, and too thin silicone tubes cannot meet the insulation requirements. Only by adopting the structure of the composite insulation layer, the thinner silicone tube is convenient to install on the outside of the bent conductor 100, and the multi-layer silicone tube can meet the insulation requirements. Epoxy resin coating is set between the silicone tubes to force out the air gap between the silicone tubes, reducing the probability of partial discharge, and the pressure resistance and safety are greatly improved.

[0052] In the specific processing, the tubular busbar is prefabricated in the factory according to the installation requirements. The current process can produce the composite insulation layer 300 in different shapes, without the risk of straightening the tube first and then bending it. In short, both straight and bent tubes can be processed, and the process can be guaranteed, and the insulation performance is not affected by the shape.

[0053] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A composite insulating layer structure, characterized in that: include: A silicone rubber layer, used to form a main insulating material, wherein the silicone rubber layer is provided with at least two layers; The epoxy resin layer is arranged between two adjacent silicone rubber layers to fix the silicone rubber layers, and the thickness of the epoxy resin layer is less than or equal to 1 mm.

2. The composite insulating layer structure according to claim 1, characterized in that: The structure is applied to a tubular member, and both the epoxy resin layer and the silicone rubber layer are tubular.

3. A method for preparing the composite insulating layer structure according to claim 1, characterized in that: The steps include: Apply epoxy resin on the surface of the object on which the insulating layer is to be provided to form a first epoxy resin layer; adhering a first silicone rubber layer to the first epoxy resin layer; Applying epoxy resin on the first silicone rubber layer to form a second epoxy resin layer; adhering a second silicone rubber layer to the second epoxy resin layer; By analogy, the composite insulating layer structure can be obtained by repeating the alternating production.

4. The method for preparing a composite insulating layer structure according to claim 3, characterized in that: The structure is applied to a tubular member, and the steps are replaced by: Apply epoxy resin on the surface of the tubular member where the insulation layer is required to be provided to form a first epoxy resin layer; Sleeve a tubular first silicone rubber layer on the surface of the first epoxy resin layer, and tighten the first silicone rubber layer by heat shrinking or cold shrinking; Apply epoxy resin on the surface of the first silicone rubber layer to form a second epoxy resin layer; Sleeve a tubular second silicone rubber layer on the surface of the second epoxy resin layer, and tighten the second silicone rubber layer by heat shrinking or cold shrinking; By analogy, the composite insulating layer structure can be obtained by repeating the alternating production.

5. The method for preparing a composite insulating layer structure according to claim 3 or 4, characterized in that: The step of applying epoxy resin is replaced by applying epoxy resin mixture, wherein the epoxy resin mixture includes epoxy resin and room temperature curing agent, and the weight proportion of the room temperature curing agent is less than or equal to 25%.

6. A tubular busbar, characterized in that: include: conductor; A composite insulating layer, wherein the composite insulating layer is sleeved on the surface of the conductor, and the structure of the composite insulating layer is the composite insulating layer structure as claimed in claim 1.

7. The tubular busbar according to claim 6, characterized in that: The conductor is a copper tube or an aluminum tube or a copper-aluminum bimetallic composite tube.

8. The tubular busbar according to claim 6, characterized in that: It comprises a conductor shielding layer, which is made of a semi-conductive material and is sleeved on the surface of the conductor; and the composite insulating layer is sleeved on the surface of the conductor shielding layer.

9. The tubular busbar according to claim 6, characterized in that: include: An insulating shielding layer, wherein the insulating shielding layer is made of a semi-conductive material and is sleeved on the surface of the composite insulating layer; A metal grounding shielding layer, made of a conductive material and used for grounding, and sleeved on the outer surface of the insulating shielding layer; The outer protective sleeve is sleeved on the outer surface of the metal grounding shielding layer.

10. A method for preparing the tubular busbar according to claim 6, characterized in that: The steps include: Select a tubular conductor and bend it to a suitable angle according to installation requirements; A semi-conductive material is used to half-wrap around the surface of the conductor to form a conductor shielding layer; Apply epoxy resin mixture on the surface of the conductor shielding layer to form a first epoxy resin layer; sleeve a tubular first silicone rubber layer on the surface of the first epoxy resin layer, and tighten the first silicone rubber layer by heat shrinking or cold shrinking; apply epoxy resin mixture on the surface of the first silicone rubber layer to form a second epoxy resin layer; sleeve a tubular second silicone rubber layer on the surface of the second epoxy resin layer, and tighten the second silicone rubber layer by heat shrinking or cold shrinking; and so on to form a composite insulating layer; A semi-conductive material is used to half-wrap around the outer surface of the composite insulating layer to form an insulating shielding layer; A conductive metal material is used to wrap around the outer surface of the insulating shielding layer to form a metal grounding shielding layer; An insulating material is used to be sleeved on the surface of the metal grounding shielding layer by cold shrinkage or heat shrinkage to form an outer protective sleeve.

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