Medium-voltage power cable material and preparation method thereof

Abstract

The invention discloses a medium-voltage power cable material which comprises a modified cable base material, and relates to the technical field of preparation of medium-voltage power cable materials. The high polymer material subjected to nanocrystallization treatment is produced by modifying PTFE (polytetrafluoroethylene), and in the modification process, unsaturated chemical bonds in PTFE (polytetrafluoroethylene) molecules are filled by adding a part of fullerene material; therefore, vinyl fluoride and fluoropropylene can be firstly subjected to graft polymerization with functional groups of PTFE (polytetrafluoroethylene), then fullerene is fused into PTFE (polytetrafluoroethylene), and C-F single bonds of vinyl fluoride and fluoropropylene are intervened and replaced by Cn (n is equal to 20, 60, 70, 76, 80 and the like), so that more stable Cn-F functional groups are formed, and the Cn-F functional groups can be formed. The functional group uniformly disperses charges accumulated in electron holes in the cable to the surface of the modified base material based on the excellent conductivity of fullerene, so that the hole injection problem of electrons formed in the cable material is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of medium-voltage power cable material preparation, and specifically relates to a medium-voltage power cable material and a preparation method thereof. Background Art

[0002] In the prior art, cross-linked polyethylene insulated cables are applicable to distribution networks, industrial installations or other fields requiring large-capacity power consumption, and are used for fixed laying on AC 50Hz, rated voltage 6kV to 35kV power transmission and distribution lines. Their main function is to transmit electrical energy. Cross-linked polyethylene insulated flame-retardant cables have the function of preventing the spread of fire in the cable circuit, can avoid the expansion of fire accidents to reduce losses, and are applicable to places with a high density of cable laying such as subways, tunnels, high-rise buildings, etc.

[0003] According to the description in "Preparation and Insulating Properties of Multilayer Mesoporous Nano-MgO / Low-Density Polyethylene Composites": "During DC power transmission, conductors inject electrons and holes into the insulating layer, and the insulating layer is extremely prone to electron or hole accumulation, forming space charge packets, triggering electric field distortion, and in severe cases, electric breakdown occurs, causing power transmission accidents. Therefore, finding effective ways to suppress space charge accumulation, equalize the electric field distribution in the insulating layer, inhibit the growth of electrical treeing, and extend the service life of cables is a technical bottleneck that urgently needs to be solved in the preparation of high-performance plastic DC cables." and "Numerous studies have shown that adding nanoparticles to cross-linked polyethylene (XLPE) can effectively suppress space charge accumulation, improve breakdown strength and volume resistivity, and inhibit the growth of electrical treeing, thereby improving the electrical properties of insulating materials. This has made nanoparticle / XLPE composites increasingly attractive, and they are known as the third-generation insulating materials. Currently, Japanese scientists have successfully prepared high-voltage DC cables of 250 kV / mm and 500 kV / mm by adding a small amount of nano-MgO to polyethylene and are waiting for commercial applications. The DOW Company in the United States also has commercial nano-modified cable materials. However, there is still no consistent conclusion on the mechanism by which nanoparticles suppress space charge accumulation." Such technical problems exist. Therefore, this application will conduct a preliminary exploration of multilayer mesoporous nano-materials. That is, in the comparative document, after testing the dielectric properties of magnesium oxide, it is injected into polyethylene cables for nano-modification. However, its polarization temperature, time, and thermally stimulated current requirements are relatively strict. As described in it, "Space charge characteristics of LDPE and multilayer mesoporous nano-MgO / LDPE composites under the action of a DC electric field EDC = 70 kV / mm. Prior art research has shown that in pure LDPE under a 70 kV / mm DC electric field, positive space charge appears near the positive electrode, and negative space charge appears near the negative electrode, which belongs to homopolar injection. The space charge accumulated near the positive electrode is mainly caused by the accumulation of holes injected by the electrode, and as the pressurization time (t) prolongs, the space charge gradually accumulates towards the interior of the material. And negative space charge appears near the negative electrode, which is caused by the accumulation of electrons injected by the electrode, and the injection speed is significantly slower than the hole injection at the positive electrode. When carriers are injected from the electrode into the material, they are transported towards the interior of the material in the form of hopping or tunneling effects, etc., ultimately resulting in a large amount of space charge accumulation inside the material. The result is the uneven distribution of the local electric field, and as time prolongs, the degree of electric field distortion will become more serious, increasing the probability of electrical treeing generation, and ultimately leading to insulation failure." This application will adopt targeted solutions to solve the problem. Summary of the Invention

[0004] The object of the present invention is to provide a medium-voltage power cable material and its preparation method to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: A medium-voltage power cable material includes a modified cable substrate, and the modified cable substrate includes a copper conductor, a winding insulation, and a modified coating. The modified coating is made of a polymer material that has been nano-processed. Specifically, the polymer material for nano-processing is selected from PTFE (polytetrafluoroethylene) modified production. During the modification process, a part of fullerene material is added to fill the unsaturated chemical bonds inside the PTFE (polytetrafluoroethylene) molecules. Therefore, graft polymerization can be first carried out through vinyl fluoride and fluoropropylene with the functional groups of PTFE (polytetrafluoroethylene). Then, fullerene is incorporated into PTFE (polytetrafluoroethylene), and the C-F single bonds of vinyl fluoride and fluoropropylene are replaced by Cn (n = 20, 60, 70, 76, 80, etc.) to form a more stable Cn-F functional group. Based on the excellent conductivity of fullerene, the charges accumulated in the electron holes in the cable are evenly dispersed on the surface of the modified substrate, thus avoiding the problem of electron hole injection inside the cable material;

[0006] A wrapping layer, the wrapping layer includes a filler and a wrapping tape. The filler is accommodated in the composition space of the cable substrate and the wrapping tape. Specifically, the filler is made of a material that is further modified based on PTFE (polytetrafluoroethylene). The filler will incorporate LDPE (low-density polyethylene) and nano magnesium-aluminum alloy for modification on the basis of using PTFE (polytetrafluoroethylene). Since aluminum has better conductivity than magnesium, the incorporation of nano magnesium-aluminum alloy enables the nano aluminum element to have a better filling rate during the process of space charge transition, so that the filler in the wrapping layer can conduct the electrons in the cable transmission more evenly and quickly, thereby reducing the distribution pressure when the cable substrate exchanges electrons with the filler, enabling the cable substrate to perform charge distribution more efficiently and quickly, and reducing the probability of being broken down by charges during electron transportation. Similarly, the wrapping tape is actually made of multi-mesh hollow metal rings. When the hollow metal rings are sleeved outside the filler, an electromagnetic shielding cage body is actually formed, so that electron exchange can only occur in the cable substrate and the wrapping layer, and at the same time, the problem of breakdown caused by a large number of electrons intervening from the outside is avoided; and

[0007] An outer layer, the outer layer includes a covering ring wrapped outside the wrapping layer. The inside of the covering ring has been subjected to electromagnetic shielding treatment. Similarly, to improve the safety during the use of the cable and completely solve the problem of electron hole injection, carbon nanotubes are sleeved inside the outer layer on the basis of the first electromagnetic shielding of the wrapping layer, so that the electrons that break through the wrapping layer and enter the outer layer can, on the one hand, absorb and reflect the escaping electrons, and on the other hand, convert the absorbed energy into heat that can be dissipated through the outer layer, extending the service life of the cable.

[0008] A medium-voltage power cable material and its preparation method, including

[0009] Step S1: After graft polymerization of PTFE and nanoparticles, a modified cable substrate is generated.

[0010] Step S2: PTEF is fused with LDPE to form a filler.

[0011] Step S3: The filler undergoes sp 3 hybridization, fullerene mixing, and desulfurization treatment.

[0012] Step S4: A steel tape armor and an outer sheath are used to form the outer layer of the covering circle.

[0013] Step S5: The cable substrate, the filler, and the outer layer of the covering circle are assembled to make a cable.

[0014] As a further solution of the present invention: A medium-voltage power cable material, the polymer material includes PTFE (polytetrafluoroethylene). After selecting nanoparticles, grafting treatment is carried out by means of copolymerization. First, by adding a part of fullerene material, the unsaturated chemical bonds inside the PTFE (polytetrafluoroethylene) molecules are filled. Therefore, graft polymerization can be carried out first through the functional groups of vinyl fluoride and fluoropropylene with PTFE (polytetrafluoroethylene). Then, fullerene is incorporated into PTFE (polytetrafluoroethylene), and the C-F single bond of vinyl fluoride and fluoropropylene is intervened and replaced with a Cn-F single bond. The charges accumulated in the electron holes in the cable can be evenly dispersed on the surface of the modified substrate and the problem of charge accumulation can be avoided. The trap characteristics of PTFE (polytetrafluoroethylene) after being modified by TSC (thermally stimulated current) are studied. Specifically, PTFE (polytetrafluoroethylene) can be used as a physical carrier for the TSC capture method due to its excellent chemical resistance, high temperature resistance, and low friction characteristics. During its specific use process, it can capture the escaping charges generated during the operation of the cable. Then, the heat absorbed and converted by the covering circle is used to charge the charges. Then, the current formed by the escaping charges during this process will be captured by TSC (thermally stimulated current). Therefore, the magnitude of this current can be calculated to detect the charge accommodation limit of the modified PTFE (polytetrafluoroethylene), and the cable production process can be further adjusted to improve the dielectric constant and insulation performance of PTFE (polytetrafluoroethylene). At the same time, the verification of the charge characteristic distribution of PTFE (polytetrafluoroethylene) after being modified by PEA (electroacoustic pulse) is used to confirm the modification effect of PTFE (polytetrafluoroethylene).

[0015] As a further solution of the present invention: A medium-voltage power cable material, the filler is made of PTEF composite, the PTEF is subjected to sp3 hybridization treatment after being compounded, 13-18 wt% of graphene elemental material is mixed inside the fullerene, and the filler is subjected to desulfurization treatment after being compounded. Since the filler is placed in the composition space of the cable substrate and the wrapping tape, specifically, the filler is made of a material obtained by further modifying PTFE (polytetrafluoroethylene). Its filler will incorporate LDPE (low-density polyethylene) and nano magnesium-aluminum alloy for modification on the basis of using PTFE (polytetrafluoroethylene). Since aluminum has better conductivity than magnesium, incorporating nano magnesium-aluminum alloy enables the nano aluminum elemental substance to have a better filling rate during the space charge transition, so that the filler in the wrapping layer can conduct the electrons in the cable transmission more evenly and quickly, thereby reducing the distribution pressure during the electron exchange between the cable substrate and the filler, enabling the cable substrate to perform charge distribution more efficiently and quickly, and reducing the probability of being broken down by charges during electron transportation. Similarly, the wrapping tape is actually made of multi-mesh hollow metal rings. When the hollow metal rings are sleeved outside the filler, an electromagnetic shielding cage is actually formed, so that electron exchange can only occur in the cable substrate and the wrapping layer, and at the same time, the problem of breakdown caused by a large number of electrons intervening in the outer layer is avoided.

[0016] As a further solution of the present invention: A medium-voltage power cable material, the covering circle includes a steel tape armor and an outer sheath, the outer sheath is made of polyethylene as a matrix, and 38-42 wt% of barium titanate crystals are incorporated inside the polyethylene matrix. Since barium titanate is a strong dielectric compound material with a high dielectric constant and low dielectric loss, and it has a stable hexagonal crystal system 6 / mmm point group inside, barium titanate transforms into a cubic perovskite structure between 1460 and 130 °C. In this structure, Ti 4+ (titanium ion) is located at the center of the oxygen octahedron formed by O 2- (oxygen ion), and Ba 2+ (barium ion) is in the voids surrounded by eight oxygen octahedrons. At this time, the crystal structure symmetry of barium titanate is extremely high, so there is no dipole moment generated, the crystal has no ferroelectricity, nor piezoelectricity, so it can be used as an excellent covering device.

[0017] As a further solution of the present invention: A medium-voltage power cable material further includes a comprehensive re-inspection device. The comprehensive re-inspection device is provided with an optical detection unit, a strength detection unit, and a composition detection unit, and the optical detection unit, the strength detection unit, and the composition detection unit respectively perform quality inspections on the cable.

[0018] As a further aspect of the present invention: A medium-voltage power cable material, a hardness detector is provided inside the strength detection unit, and a hardness tester for monitoring the Rockwell hardness of the cable material is provided inside the hardness detector.

[0019] As a further aspect of the present invention: A medium-voltage power cable material, a micro spectrometer is provided inside the composition detection unit, and the micro spectrometer is used for the composition detection of the cable material.

[0020] As a further aspect of the present invention: A medium-voltage power cable material, an IPC detector is provided inside the optical detection unit, and the IPC detector is used for the comprehensive detection of the cable material.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. The polymer material subjected to nanometer treatment in this application is produced by modifying PTFE (polytetrafluoroethylene). During the modification process, a part of fullerene material is first added to fill the unsaturated chemical bonds inside the PTFE (polytetrafluoroethylene) molecules. Therefore, graft polymerization can be first carried out between vinyl fluoride and fluoropropylene and the functional groups of PTFE (polytetrafluoroethylene), and then fullerene is incorporated into PTFE (polytetrafluoroethylene), and the C-F single bonds of vinyl fluoride and fluoropropylene are intervened and replaced with Cn (n = 20, 60, 70, 76, 80, etc.), so as to form a more stable Cn-F functional group. Based on the excellent electrical conductivity of fullerene, the charges accumulated in the electron holes in the cable are evenly dispersed on the surface of the modified substrate, thus avoiding the problem of electron hole injection inside the cable material.

[0023] 2. The filler in this application is made of a material further modified based on PTFE (polytetrafluoroethylene). The filler will be modified by fusing LDPE (low-density polyethylene) and nano magnesium-aluminum alloy on the basis of using PTFE (polytetrafluoroethylene). Since aluminum has better electrical conductivity than magnesium, the incorporation of nano magnesium-aluminum alloy makes the nano aluminum element have a better filling rate during the space charge transition, so that the filler in the wrapping layer can conduct the electrons in the cable transmission more evenly and faster, thus reducing the distribution pressure when the cable substrate exchanges electrons with the filler, enabling the cable substrate to distribute charges more efficiently and quickly, and reducing the probability of being broken down by charges during electron transportation. Similarly, the wrapping tape is actually made of multi-mesh hollow metal rings. When the hollow metal rings are sleeved outside the filler, an electromagnetic shielding cage is actually formed, so that electron exchange can only occur in the cable substrate and the wrapping layer, while avoiding the problem of breakdown caused by a large number of electrons intervening in the outer layer.

[0024] 3. The interior of the wrapping ring of this application is subjected to electromagnetic shielding treatment. Similarly, to enhance the safety during the use of the cable and completely solve the problem of electron hole injection, on the basis of performing electromagnetic shielding on the wrapping layer, carbon nanotubes are sleeved inside the outer layer. In this way, the electrons that penetrate the wrapping layer and enter the outer layer can, on the one hand, absorb and reflect the escaping electrons, and on the other hand, convert the absorbed energy into heat that can be dissipated through the outer layer, thereby extending the service life of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic flow chart in a medium-voltage power cable material and its preparation method of the present invention;

[0026] Figure 2 It is one of the schematic diagrams of the overall structure in a medium-voltage power cable material and its preparation method of the present invention;

[0027] Figure 3 It is another schematic diagram of the overall structure in a medium-voltage power cable material and its preparation method of the present invention;

[0028] Figure 4 It is a medium-voltage power cable material and its preparation method of the present invention Figure 2 The enlarged view of part A in it;

[0029] Figure 5 It is a schematic diagram of the structure of the comprehensive test stand in a medium-voltage power cable material and its preparation method of the present invention;

[0030] In the figure: 1. Comprehensive test stand; 2. Optical detection unit; 3. Strength detection unit; 4. Composition detection unit; 5. Inlet roller; 6. Bunching ring frame; 7. Coil; 8. Support leg; 9. Driving wheel frame; 10. Servo motor; 11. Driving friction wheel; 12. Driven friction wheel; 13. Commutator; 14. Ball screw nut pair; 15. Outlet roller; 16. Arc-proof groove. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected", "set" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The following describes the embodiments according to the overall structure of the present invention.

[0033] In an embodiment of the present invention, a medium-voltage power cable material includes a modified cable substrate, and the modified cable substrate includes a copper conductor, a winding insulation, and a modified coating. The modified coating is made of a polymer material that has been nano-processed. Specifically, the nano-processed polymer material is selected from the modified production of PTFE (polytetrafluoroethylene). During the modification process, first, a part of fullerene material is added to fill the unsaturated chemical bonds inside the PTFE (polytetrafluoroethylene) molecules. Therefore, graft polymerization can be carried out first through vinyl fluoride and fluoropropylene with the functional groups of PTFE (polytetrafluoroethylene). Then, fullerene is incorporated into PTFE (polytetrafluoroethylene), and the C-F single bonds of vinyl fluoride and fluoropropylene are replaced by Cn (n = 20, 60, 70, 76, 80, etc.) to form a more stable Cn-F functional group. Based on the excellent electrical conductivity of fullerene, the charges accumulated in the electron holes in the cable are evenly dispersed on the surface of the modified substrate, thus avoiding the problem of hole injection of electrons inside the cable material.

[0034] The wrapping layer, the wrapping layer includes a filler and a wrapping tape, the filler is contained in the composition space of the cable substrate and the wrapping tape. Specifically, the filler is made of a material further modified based on PTFE (polytetrafluoroethylene). The filler will fuse LDPE (low density polyethylene) and nano magnesium aluminum alloy for modification on the basis of using PTFE (polytetrafluoroethylene). Since aluminum has better conductivity than magnesium, the incorporation of nano magnesium aluminum alloy enables the nano aluminum element to have a better filling rate during the space charge transition, so that the filler in the wrapping layer can conduct the electrons in the cable transmission more evenly and quickly, thus reducing the distribution pressure during the electron exchange between the cable substrate and the filler, enabling the cable substrate to perform charge distribution more efficiently and quickly, and reducing the probability of being broken down by charges during electron transportation. Similarly, the wrapping tape is actually made of multi-mesh hollow metal rings. When the hollow metal rings are sleeved outside the filler, an electromagnetic shielding cage is actually formed, so that electron exchange can only occur in the cable substrate and the wrapping layer, and at the same time, the problem of breakdown caused by a large number of electrons intervening from the outer layer is avoided; and

[0035] The outer layer, the outer layer includes a covering circle wrapped outside the wrapping layer. The inside of the covering circle has been subjected to electromagnetic shielding treatment. Similarly, to improve the safety during the use of the cable and completely solve the problem of electron hole injection, carbon nanotubes are sleeved inside the outer layer on the basis of the first electromagnetic shielding of the wrapping layer, so that the electrons that break through the wrapping layer and enter the outer layer can, on the one hand, absorb and reflect the escaping electrons, and on the other hand, convert the absorbed energy into heat that can be dissipated through the outer layer, extending the service life of the cable.

[0036] Other embodiments of the present invention: A medium-voltage power cable material. After selecting nanoparticles for the polymer material including PTFE (polytetrafluoroethylene), grafting treatment is carried out by means of copolymerization. First, by adding a part of fullerene material, the unsaturated chemical bonds inside the PTFE (polytetrafluoroethylene) molecules are filled. Therefore, graft polymerization can be carried out first through vinyl fluoride and fluoropropylene with the functional groups of PTFE (polytetrafluoroethylene). Then, fullerene is incorporated into PTFE (polytetrafluoroethylene), and the C-F single bonds of vinyl fluoride and fluoropropylene are intervened and replaced with Cn-F single bonds. The charges accumulated in the electron holes in the cable can be evenly dispersed on the surface of the modified substrate to avoid the problem of charge accumulation. The trap characteristics of PTFE (polytetrafluoroethylene) after being modified by TSC (thermally stimulated current) are studied. Specifically, PTFE (polytetrafluoroethylene) can be used as a physical carrier for the TSC capture method due to its excellent chemical resistance, high temperature resistance and low friction characteristics. During its specific use process, it can capture the escaping charges generated during the operation of the cable, and then charge the charges through the heat absorbed and converted by the coating ring. Then, the current formed by the escaping charges during this process will be captured by TSC (thermally stimulated current). Therefore, the magnitude of this current can be calculated to detect the charge accommodation limit of the modified PTFE (polytetrafluoroethylene), and the cable production process can be further adjusted to improve the dielectric constant and insulation performance of PTFE (polytetrafluoroethylene). At the same time, the verification of the charge characteristic distribution of PTFE (polytetrafluoroethylene) after being modified by PEA (electroacoustic pulse) is used to confirm the modification effect of PTFE (polytetrafluoroethylene).

[0037] Other embodiments of the present invention: A medium-voltage power cable material, wherein the filler is made of PTEF composite. The PTEF is subjected to sp3 hybridization treatment after being compounded. 13-18 wt% of graphene elemental material is mixed inside the fullerene. The filler is subjected to desulfurization treatment after being compounded. Since the filler is placed in the composition space of the cable substrate and the wrapping tape, specifically, the filler is made of a material obtained by further modifying PTFE (polytetrafluoroethylene). The filler will incorporate LDPE (low-density polyethylene) and nano magnesium-aluminum alloy for modification on the basis of using PTFE (polytetrafluoroethylene). Since aluminum has better conductivity than magnesium, the incorporation of nano magnesium-aluminum alloy enables the nano aluminum elemental substance to have a better filling rate during the process of space charge transition, so that the filler in the wrapping layer can conduct the electrons in the cable transmission more evenly and faster, thereby reducing the distribution pressure during the electron exchange between the cable substrate and the filler, enabling the cable substrate to perform charge distribution more efficiently and quickly, and reducing the probability of being broken down by charges during electron transportation. Similarly, the wrapping tape is actually made of multi-mesh hollow metal rings. When the hollow metal rings are sleeved outside the filler, an electromagnetic shielding cage is actually formed, so that electron exchange can only occur in the cable substrate and the wrapping layer, and at the same time, the problem of breakdown caused by a large number of electrons intervening from the outer layer is avoided.

[0038] Other embodiments of the present invention: A medium-voltage power cable material, wherein the covering layer includes a steel tape armor and an outer sheath. The outer sheath is made based on polyethylene. 38-42 wt% of barium titanate crystals are incorporated inside the polyethylene matrix. Since barium titanate is a strong dielectric compound material with a high dielectric constant and low dielectric loss, and it has a stable hexagonal crystal system 6 / mmm point group inside, barium titanate transforms into a cubic perovskite structure between 1460 and 130 °C. In this structure, Ti 4+ (titanium ion) is located at the center of the oxygen octahedron formed by O 2- (oxygen ion), and Ba 2+ (barium ion) is in the voids surrounded by eight oxygen octahedrons. At this time, the crystal structure symmetry of barium titanate is extremely high, so no dipole moment is generated, the crystal has no ferroelectricity, nor piezoelectricity, so it can be used as an excellent covering device.

[0039] Other embodiments of the present invention: A medium-voltage power cable material further includes a comprehensive re-inspection device. An optical detection unit, a strength detection unit, and a composition detection unit are provided in the comprehensive re-inspection device. The optical detection unit, the strength detection unit, and the composition detection unit respectively perform quality inspections on the cable. Specifically, a hardness detector is provided in the strength detection unit, and a hardness tester for monitoring the Rockwell hardness of the cable material is provided inside the hardness detector. A micro spectrometer is provided in the composition detection unit, and the micro spectrometer is used for the cable material to perform composition detection. An IPC detector is provided in the optical detection unit, and the IPC detector is used for the cable material to perform comprehensive detection;

[0040] A medium-voltage power cable material and its preparation method include

[0041] Step S1: Graft polymerization of PTFE and nanoparticles to generate a modified cable substrate;

[0042] Step S2: Fuse PTEF and LDPE to form a filler;

[0043] Step S3: The filler undergoes sp 3 Hybridization, fullerene mixing, and desulfurization treatment;

[0044] Step S4: Use steel tape armor and an outer sheath to form the outer layer of the covering circle;

[0045] Step S5: Assemble the cable substrate, the filler, and the outer layer of the covering circle to make a cable.

[0046] Other embodiments of the present invention: Please refer to Figure 2 , Figure 3 , Figure 4 and Figure 5 , a medium-voltage power cable material includes a comprehensive re-inspection device. The comprehensive re-inspection device takes the comprehensive test stand 1 as the main body, and an optical detection unit 2, a strength detection unit 3, and a composition detection unit 4 are provided inside the comprehensive test stand 1. Input / output holes for the cable to pass through are opened on both sides of the comprehensive test stand 1. The composition detection unit 4 is arranged on one side of the comprehensive test stand 1 close to the input hole, and is used to use the micro spectrometer provided in the composition detection unit 4 to perform composition detection on the cable material after the cable enters the comprehensive test stand 1, so as to verify the material composition of the cable in the above embodiments and check whether there are packaging or manufacturing errors inside the cable;

[0047] In addition, the optical detection unit 2 is arranged on the side of the component detection unit 4 away from the comprehensive test stand 1. After the cable passes through the component detection of the component detection unit 4, it will pass through the optical detection unit 2 for the outer shape detection of the cable. Specifically, flaw detection and chromaticity detection are carried out through the IPC detector arranged in the optical detection unit. Because there is a camera in the IPC detector that can perform point cloud processing on the captured images. After the camera converts the images into point clouds, crack detection can be carried out through the point cloud group formed by the point cloud arrangement (if there are cracks, obvious straight lines will be shown on the point cloud group). And the chromaticity information shown by the point cloud group can also be used to detect abnormal point clouds, so as to detect whether the outer shape and color of the cable are uniform and whether there are any defects;

[0048] Meanwhile, the strength detection unit 3 is arranged at a position close to the output hole of the comprehensive test stand 1. After the cable passes through the detection of the component detection unit 4, the hardness of the cable material can be monitored through the hardness tester arranged inside the strength detection unit 3 for Rockwell hardness monitoring of the cable material, so as to ensure the good state of the cable product and avoid the problem of the cable being defective and leaving the factory.

[0049] Moreover, a driving mechanism for the optical detection unit 2 to perform circumferential detection on the cable is arranged on one side of the comprehensive test stand 1. The driving mechanism includes a servo motor 10, a driving friction wheel 11 and a driven friction wheel 12. The output end of the servo motor 10 is fixedly connected to the driving friction wheel 11, and the servo motor 10 is fixedly installed on one side of the comprehensive test stand 1 through the driving wheel frame 9. Therefore, by driving the driving friction wheel 11 to rotate through the servo motor 10 and driving the optical detection unit 2 to rotate through the driving friction wheel 11, the IPC detector inside the optical detection unit 2 can perform circumferential optical detection on the cable. And an anti-drop arc groove 16 for supporting the optical detection unit 2 during movement is provided inside the comprehensive test stand 1, which can avoid the problem of the optical detection unit 2 falling off during rotation.

[0050] In addition, ball screw nut pairs 14 are respectively arranged on both sides of the driven friction wheel 12 through a commutator 13, and the two ball screw nut pairs 14 are respectively bridged with the strength detection unit 3 and the component detection unit 4. Therefore, during the working process, the positions of the strength detection unit 3 and the component detection unit 4 can be adjusted through the ball screw nut pairs 14 to detect different positions of the cable.

[0051] Meanwhile, an inlet roller 5 and an outlet roller 15 are respectively arranged near the input hole and the output hole of the comprehensive test stand 1, so that the cable can be conveyed linearly in the comprehensive test stand 1, avoiding the problem of inaccurate detection due to the cable being bent.

[0052] Finally, a coil holder 6 for loading the coil 7 is arranged on one side of the comprehensive test stand 1, which can provide a good input detection environment for the cable.

[0053] The working principle of the present invention is as follows: the polymer material subjected to nano-processing in the present application is produced by modifying PTFE (polytetrafluoroethylene). In the modification process, a portion of fullerene material is first added to fill the unsaturated chemical bonds inside the PTFE (polytetrafluoroethylene) molecule. Therefore, graft polymerization can be first performed by vinyl fluoride and propylene fluoride with the functional groups of PTFE (polytetrafluoroethylene). Then, fullerene is integrated into PTFE (polytetrafluoroethylene), and the CF single bonds of vinyl fluoride and propylene fluoride are replaced by Cn (n=20, 60, 70, 76, 80, etc.), thereby forming a more stable Cn-F functional group. Based on the excellent conductive properties of fullerene, the functional group uniformly disperses the charges accumulated in the electron holes in the cable to the surface of the modified substrate, thereby avoiding the hole injection problem of electrons formed inside the cable material.

[0054] The filler of the present application is made of a material that is further modified based on PTFE (polytetrafluoroethylene). The filler is modified by fusing LDPE (low-density polyethylene) and nano-magnesium-aluminum alloy on the basis of PTFE (polytetrafluoroethylene). Since aluminum has better electrical conductivity than magnesium, the addition of nano-magnesium-aluminum alloy enables nano-aluminum element to have a better filling rate during space charge transition, so that the filler in the sheath can conduct electrons in cable transmission more evenly and faster, thereby reducing the distribution pressure when the cable substrate and the filler exchange electrons, so that the cable substrate can distribute charges more efficiently and quickly, and reduce the probability of being broken down by charges during electron transportation. Similarly, the wrapping tape is actually made of a hollow metal ring with multiple meshes. When the hollow metal ring is sleeved on the outside of the filler, it actually forms an electromagnetic shielding cage, so that the electron exchange can only be carried out in the cable substrate and the sheath, while avoiding the problem of breakdown caused by a large number of electrons intervening in the outer layer.

[0055] The interior of the sheath of the present application has been subjected to electromagnetic shielding treatment. Similarly, in order to improve the safety of the cable during use and completely solve the problem of electron hole injection, carbon nanotubes are inserted into the inner part of the outer layer on the basis of electromagnetic shielding of the sheath, so that the electrons that penetrate the sheath and enter the outer layer can absorb and reflect the escaping electrons on the one hand, and convert the absorbed energy into heat that can be dissipated through the outer layer on the other hand, thereby extending the service life of the cable.

[0056] What is described above is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A medium voltage power cable material, characterized in that: It includes a modified cable substrate, which includes a copper conductor, a winding insulation and a modified coating, and the modified coating is made of a polymer material that has been subjected to nano-processing; A wrapping layer, the wrapping layer comprising a filler and a wrapping tape, the filler being accommodated in a space formed by the cable base material and the wrapping tape; and The outer layer comprises a covering ring wrapped around the outer side of the wrapping layer, and the interior of the covering ring is subjected to electromagnetic shielding treatment.

2. A medium voltage power cable material according to claim 1, characterized in that: The polymer material includes PTFE which is grafted with nanoparticles by copolymerization, the trap characteristics of the modified PTFE are studied by TSC, and the charge characteristic distribution of the modified PTFE is verified by PEA.

3. A medium voltage power cable material according to claim 2, characterized in that: The filler is made of PTEF composite, and the PTEF is sp 3 Hybridization treatment: 13-18wt% of graphene single material is mixed inside the fullerene, and the filler is desulfurized after compounding.

4. A medium voltage power cable material according to claim 3, characterized in that: The covering ring comprises a steel belt armor and an outer sheath, wherein the outer sheath is made of a polyethylene matrix, and 38-42 wt % of barium titanate crystals are mixed inside the polyethylene matrix.

5. A medium voltage power cable material according to claim 4, characterized in that: It also includes a comprehensive re-inspection device, in which an optical detection unit, a strength detection unit and a component detection unit are arranged. The optical detection unit, the strength detection unit and the component detection unit respectively perform quality inspection on the cable.

6. A medium voltage power cable material according to claim 5, characterized in that: The strength detection unit is provided with a hardness detector, and the hardness detector is provided with a hardness meter for Rockwell hardness monitoring of the cable material.

7. A medium voltage power cable material according to claim 6, characterized in that: The component detection unit is provided with a micro-spectrometer, and the micro-spectrometer is used for component detection of cable materials.

8. A medium voltage power cable material according to claim 7, characterized in that: An IPC detector is provided in the optical detection unit, and the IPC detector is used for comprehensive detection of cable materials.

9. A medium voltage power cable material and a preparation method thereof according to claim 8, characterized in that: include Step S1: PTFE and nanoparticles are grafted and polymerized to generate a modified cable substrate; Step S2: PTEF is fused with LDPE to prepare a filler; Step S3: Filling is passed through sp 3 Hybridization, fullerene blending and desulfurization treatment; Step S4: using the steel belt armor and the outer sheath to form the outer layer of the sheath; Step S5: The cable base material, filler and outer layer of the sheath are assembled to form a cable.

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