Intelligent monitoring protection device and method suitable for distribution network cable intermediate joint

Abstract

The invention discloses an intelligent monitoring protection device and method suitable for an intermediate joint of a distribution network cable, and belongs to the technical field of cable protection. The intelligent monitoring protection device comprises a ventilation type expansion fire-resistant explosion-proof net and an intelligent monitoring device; a ventilation type expansion fire-resistant explosion-proof net is coated on a cable joint and is used for protecting a distribution network cable intermediate joint; the intelligent monitoring device comprises a temperature monitoring device and a partial discharge monitoring device, and the intelligent monitoring device is arranged on the outer side of the ventilation type expansion fire-resistant explosion-proof net; partial discharge and temperature rise generated under the abnormal operation condition of the distribution network cable intermediate joint are monitored through the intelligent monitoring device, and the method is used for hidden danger identification of early fire of the cable. According to the invention, a novel net structure design is used, the temperature during normal operation of the cable is not influenced, explosion energy generated when the cable fails can be quickly released, explosives are prevented from splashing, the harm to the surrounding environment and personnel is reduced, meanwhile, the effects of fire prevention, flame retardance, heat insulation and the like are achieved, and the fire protection capability of the cable is improved.

Description

Technical Field

[0001] The present invention belongs to the field of cable protection, and in particular, relates to an intelligent monitoring and protection device and method suitable for an intermediate joint of a distribution network cable. Background Art

[0002] During the long-term operation of power cables, the temperature of cable joints rises and insulation breaks down due to reasons such as humid environment, aging of insulation, and poor accessory manufacturing, which leads to cable explosion and fire accidents. Cable failures often occur at cable joints, and cable fires and explosions caused by cable joint failures account for about 70% of the total number of cable accidents. In the context of safe operation of power grids, the problem of increasing number of cable joints caused by the continuous extension of power cable laying lengths has put forward higher requirements for explosion protection and fire safety levels at cable joints.

[0003] The existing cable joint protection methods mainly improve the flame retardant and fireproof ability of the cable by applying fire retardant paint on both sides of the cable joint or wrapping it with flame retardant tape, and installing explosion-proof blankets or explosion-proof boxes at the joints to improve the explosion-proof ability of the cable. Although the above methods can prevent the protection problems of the cable intermediate joints, there are still many limitations, which may include the following problems:

[0004] Fire retardant coatings and flame retardant tapes are extremely inconvenient to use in places with high cable density and small space, and are time-consuming and labor-intensive, affecting the construction period. Moreover, they can only be flame retardant and cannot achieve the purpose of explosion-proofing the intermediate joints of cables.

[0005] The explosion-proof sealant injected inside the explosion-proof box causes poor heat dissipation performance and heavy weight. The internal space is relatively closed, and heat is easy to accumulate, which may affect the normal operation and maintenance of the cable joint. The explosion energy cannot be released quickly, which easily causes the shell to deform, and the explosion-proof requirements are difficult to meet. At the same time, the rigid protective device may be broken due to the strong impact force generated by the explosion of the cable joint. The resulting fragments will injure other cables and maintenance personnel around it, posing a safety risk.

[0006] Since the explosion-proof blanket is a multi-layer protective structure, similar to the explosion-proof box, it will also have the problem of poor heat dissipation performance after wrapping, which affects the normal operation of the cable joint, and is difficult to disassemble and maintain in the later stage. It cannot be used with the cable well bending and other problems, and lacks flexibility and applicability. Prior art document 1 (CN 218966332 U) discloses a warning filter-type fire and explosion blanket wrapped on a high-voltage cable joint, including a fire and explosion blanket body, the diagonal and four sides of the fire and explosion blanket body are sewn with sewing threads, and the fire and explosion blanket body includes an absorption fiber layer. This prior art establishes an internal and external interactive double-coating heat dissipation system so that heat does not accumulate inside the fire and explosion blanket, so as to achieve the purpose of rapid heat dissipation, and adds a fiber absorption layer and establishes a surface temperature change warning coating. However, it has too many layers, is heavy, and the inner layer also uses 304 stainless steel, which is not easy to bend, is not easy to apply at the cable corner, and is not convenient to install; secondly, the nano coating is easy to fall off when applied on the silicone layer, and has poor weather resistance.

[0007] In summary, due to the limitations of materials and processes, the existing fire-proof and explosion-proof products of cable intermediate joints have a long construction period in cable tunnels or cable trenches, are inconvenient to install, and lack flexibility and applicability.

[0008] In addition, the lack of an effective early warning monitoring system for cable joints makes it difficult to monitor their operating status in real time. At the equipment site, due to the complex environment, power supply and communication are often challenging, resulting in the inability to obtain equipment status information in a timely manner. At the same time, relying on manual inspections to detect temperature and equipment status is not only inefficient, but also difficult to achieve full coverage due to the limited frequency of personnel inspections, increasing the risk of equipment failure.

[0009] Therefore, there is an urgent need for a new type of fire-resistant and explosion-proof cable joint product that meets the fire and explosion prevention requirements and is easy to install and construct. At the same time, it can effectively identify early fire hazards in cables and prevent the spread of cable fires, providing support for the safe operation of power grids under the construction of new power systems. Summary of the invention

[0010] In order to solve the deficiencies in the prior art, the present invention provides an intelligent monitoring and protection device and method suitable for the intermediate joints of distribution network cables, which meets the requirements of fire prevention and explosion prevention, is easy to install and construct, and can effectively identify early fire hazards of cables and prevent the spread of cable fires.

[0011] The present invention adopts the following technical solution.

[0012] The first aspect of the present invention discloses an intelligent monitoring and protection device suitable for an intermediate joint of a distribution network cable, comprising a ventilated expansion fire-resistant explosion-proof net and an intelligent monitoring device;

[0013] The ventilated expansion fire-resistant explosion-proof net comprises, by weight percentage, 5% to 25% of a fiber mesh skeleton structure material and 75% to 95% of a fire-resistant expansion matrix material;

[0014] The ventilated expanded fire-resistant explosion-proof net is wrapped on the cable joint to protect the middle joint of the distribution network cable;

[0015] The intelligent monitoring device comprises: a temperature monitoring device and a partial discharge monitoring device, and the intelligent monitoring device is arranged outside the ventilation type expansion fireproof explosion-proof net;

[0016] Intelligent monitoring devices are used to monitor partial discharge and temperature rise caused by abnormal operation of the intermediate joints of the distribution network cables, which can be used to identify hidden dangers of early cable fires.

[0017] Preferably, the reinforcing fiber skeleton structure comprises flame-retardant aramid 1414 fiber with a warp and weft strength of ≥200N / mm and a fineness of 500D to 3000D;

[0018] On the reinforcing fiber skeleton structure, the fire-resistant expansion matrix material is evenly attached to each fiber by dipping or coating, and woven into a mesh structure with a mesh size of 4mm×4mm to 10mm×10mm.

[0019] Preferably, on the reinforced fiber mesh skeleton structure, a 10 mm fire-resistant expansion matrix material is attached by molding at intervals of 5 mm to 10 mm to form a plurality of concave and convex grid areas;

[0020] The fire-resistant expansion matrix material is prepared from the following weight percentages: 25% to 35% of resin matrix, 20% to 40% of composite expansion agent, 20% to 50% of halogen-free flame retardant, 0.6% to 1.8% of cross-linking agent, 4% to 8% of plasticizer, 0.5% to 1.5% of composite lubricant, and 0.6% to 2.0% of composite stabilizer. The sum of the weights of the components is 100%, and after being evenly mixed, the material is prepared and formed by a twin-screw extruder.

[0021] Preferably, the resin matrix is ​​at least one of cross-linked polyvinyl chloride and ethylene-vinyl acetate copolymer;

[0022] The composite expansion agent is at least one of expanded graphite 802 and expanded graphite ADT351, and the expansion ratio is ≥300 times;

[0023] The halogen-free flame retardant is at least one of magnesium hydroxide, aluminum hydroxide, diethyl aluminum hypophosphite, toluene diphenyl phosphate, melamine thiocyanate and melamine;

[0024] The cross-linking agent is at least one of dicumyl peroxide, di-tert-butyl peroxide and 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane;

[0025] The plasticizer is at least one of dioctyl adipate, dioctyl sebacate and diisononyl adipate;

[0026] The composite lubricant is at least one of talc, hydrotalcite, carbon black and clay;

[0027] The composite stabilizer is at least one of barium stearate, calcium stearate and barium laurate.

[0028] Preferably, the temperature monitoring device is a passive temperature sensor probe, and the partial discharge monitoring device is a passive ground wave TEV partial discharge monitoring device.

[0029] Preferably, the temperature monitoring device and the partial discharge monitoring device are integrated into one body and powered by a battery.

[0030] Preferably, the intelligent monitoring device uploads the monitoring data to a background monitoring center via wireless communication.

[0031] The second aspect of the present invention discloses an intelligent monitoring and protection method applicable to the intermediate joint of the distribution network cable, based on the intelligent monitoring and protection device applicable to the intermediate joint of the distribution network cable, comprising the following steps:

[0032] Check the circumference of the cable, design the specifications of the protective device according to the on-site cable parameters, wrap the protective device on the middle joint of the cable, and turn on the intelligent detection device;

[0033] Cut the fire-resistant and explosion-proof modules so that they fully cover the cable connectors and overlap the edges by 15%;

[0034] Place the intelligent monitoring module at the cable joint and secure it with a cable tie;

[0035] After the installation is complete, turn on the intelligent monitoring module switch, the device will monitor at the set frequency, and upload the monitoring information to the monitoring host to achieve monitoring and protection.

[0036] The third aspect of the present invention discloses an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is loaded into the processor, it implements an intelligent monitoring and protection method applicable to intermediate joints of distribution network cables.

[0037] The fourth aspect of the present invention discloses a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the intelligent monitoring and protection method applicable to the intermediate joint of the distribution network cable.

[0038] Compared with the prior art, the beneficial effects of the present invention include at least:

[0039] 1. The ventilated expanded fire-resistant explosion-proof net suitable for the intermediate joint of the distribution network cable of the present invention uses a new mesh structure design, which does not affect the temperature of the normal cable operation, and can also quickly release the explosion energy generated when the cable fails, effectively preventing the splash of explosives and reducing the harm to the surrounding environment and personnel. At the same time, it achieves fire prevention, flame retardancy, heat insulation and other effects, and improves the fire protection capability of the cable.

[0040] 2. The ventilated expanded fireproof explosion-proof net for the intermediate joint of the distribution network cable of the present invention can be cut and coated on site according to actual needs, which greatly simplifies the construction process. This design avoids complicated installation steps, making the overall installation and use more convenient, while also reducing construction costs and time and improving engineering efficiency.

[0041] 3. In the monitoring device for the intermediate joints of distribution network cables of the present invention, the use of cable joint partial discharge sensors and temperature online monitoring equipment can detect hidden dangers in cable operation early, reduce the difficulty of personnel inspections, and improve the operation and inspection level of the distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the intelligent monitoring and protection device for the cable intermediate joint of the present invention;

[0043] Figure 2 is a schematic diagram of the intelligent monitoring device of the present invention;

[0044] In the figure: 1. Fiber mesh skeleton structure; 2. Ventilation mesh; 3. Refractory expansion matrix grid-like area; 4. Intelligent monitoring device. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only embodiments of a part of the present invention, rather than all embodiments. Based on the spirit of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0046] like Figure 1-2 As shown, embodiment 1 of the present invention provides an intelligent monitoring and protection device suitable for intermediate joints of distribution network cables, wherein the intelligent monitoring and protection device for intermediate joints of cables comprises: a ventilated expanding fire-resistant explosion-proof net and an intelligent monitoring device (4), wherein the intelligent monitoring device (4) is arranged on the outside of the ventilated expanding fire-resistant explosion-proof net.

[0047] The ventilation type expanded fire-resistant explosion-proof net is composed of the following components by weight percentage: 5% to 25% of a reinforced fiber mesh skeleton structure material and 75% to 95% of a fire-resistant expanded matrix material.

[0048] The intelligent monitoring device (4) is composed of the following devices: a temperature monitoring device and a partial discharge monitoring device.

[0049] By monitoring the characteristic parameters such as partial discharge and temperature rise generated when the intermediate joints of the distribution network cables are in abnormal operation, early fire hazards of the cables can be identified. By covering the cable joints with expandable fire-resistant explosion-proof nets, the impact of fire and explosion accidents at the cable joints can be reduced to prevent the fire from spreading.

[0050] In a preferred but non-limiting embodiment of the present invention, the reinforcing fiber skeleton structure (1) is composed of flame-retardant aramid 1414 fibers with a warp and weft strength of ≥200 N / mm and a fineness of 500D to 3000D.

[0051] On the reinforcing fiber skeleton structure, the fire-resistant expansion matrix material is evenly attached to each fiber by dipping or coating, and is woven into a mesh structure.

[0052] The size of the ventilation mesh (2) is 4mm×4mm to 10mm×10mm.

[0053] On the reinforced fiber mesh skeleton structure, a 10 mm thick fire-resistant expansion matrix material is attached at intervals of 5 mm to 10 mm by a molding method to form a plurality of concave and convex grid areas (3).

[0054] The fire-resistant expansion matrix material is prepared from the following weight percentages: 25% to 35% of resin matrix, 20% to 40% of composite expansion agent, 20% to 50% of halogen-free flame retardant, 0.6% to 1.8% of cross-linking agent, 4% to 8% of plasticizer, 0.5% to 1.5% of composite lubricant, and 0.6% to 2.0% of composite stabilizer. The sum of the weights of the components is 100%, and after being uniformly mixed, the material is formed by a twin-screw extruder to form a fire-resistant expansion matrix grid-shaped region (3).

[0055] The resin matrix is ​​at least one of cross-linked polyvinyl chloride and ethylene-vinyl acetate copolymer.

[0056] The composite expansion agent is at least one of expanded graphite 802 and expanded graphite ADT351, and the expansion ratio is ≥300 times.

[0057] The halogen-free flame retardant is at least one of magnesium hydroxide, aluminum hydroxide, diethyl aluminum hypophosphite, toluene diphenyl phosphate, melamine thiocyanate and melamine.

[0058] The crosslinking agent is at least one of dicumyl peroxide, di-tert-butyl peroxide and 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane.

[0059] The plasticizer is at least one of dioctyl adipate, dioctyl sebacate and diisononyl adipate.

[0060] The composite lubricant is at least one of talc, hydrotalcite, carbon black and clay.

[0061] The composite stabilizer is at least one of barium stearate, calcium stearate and barium laurate.

[0062] The temperature monitoring device is a passive temperature sensor probe.

[0063] The partial discharge monitoring device is a passive ground wave TEV partial discharge monitoring device.

[0064] Embodiment 2 of the present invention provides an intelligent monitoring and protection method applicable to the intermediate joint of the distribution network cable, based on the intelligent monitoring and protection device applicable to the intermediate joint of the distribution network cable, comprising the following steps:

[0065] Step 1: Check the circumference of the cable, design the specifications of the protective device according to the on-site cable parameters, wrap the protective device on the middle joint of the cable, and turn on the intelligent detection device;

[0066] Step 2: Cut the fire-resistant and explosion-proof module to a suitable size to ensure that it can fully cover the cable connector and the edge overlaps by 15%;

[0067] In a preferred but non-limiting embodiment of the present invention, the wrapping is installed by wrapping, the fire-resistant and explosion-proof module is laid at the cable joint, the throat clamp is installed, and the tightness is appropriately adjusted;

[0068] Step 3: Select a suitable location at the cable joint to place the intelligent monitoring module and fix it with a cable tie;

[0069] Step 4. After the installation is completed, turn on the intelligent monitoring module switch and the device starts working. The equipment will monitor the local discharge, temperature and other related data at the set frequency, and upload the monitoring information to the monitoring host to achieve monitoring and protection.

[0070] Embodiment 3 of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the computer program is loaded into the processor, an intelligent monitoring and protection method for intermediate joints of distribution network cables according to Embodiment 2 is implemented.

[0071] Embodiment 4 of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements an intelligent monitoring and protection method for intermediate joints of distribution network cables according to Embodiment 2.

[0072] The present invention will be further described below in conjunction with specific embodiments.

[0073] Embodiment 1:

[0074] The invention discloses an intelligent monitoring and protection device suitable for the intermediate joint of a distribution network cable, comprising the following components (percentage by weight): 75% of 1500D aramid 1414 fiber and 25% of a fire-resistant expansion matrix.

[0075] The fire-resistant expansion matrix comprises the following components (by weight): 30% cross-linked polyvinyl chloride, 30% expanded graphite 802, 30% aluminum hydroxide, 1.5% dicumyl peroxide, 5% dioctyl adipate, 1.5% talc and 2% barium stearate.

[0076] Embodiment 2:

[0077] The invention discloses an intelligent monitoring and protection device suitable for the intermediate joint of a distribution network cable, comprising the following components (percentage by weight): 70% of 500D aramid 1414 fiber and 30% of a fire-resistant expansion matrix.

[0078] The fire-resistant expansion matrix comprises the following components (by weight): 25% cross-linked polyvinyl chloride, 25% expanded graphite ADT351, 40% magnesium hydroxide, 1% 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane, 4% diisononyl adipate, 1.5% clay and 2% barium laurate.

[0079] Embodiment three:

[0080] An intelligent monitoring and protection device suitable for the middle joint of a distribution network cable comprises the following components (percentage by weight): 80% of 3000D aramid 1414 fiber and 20% of a fire-resistant expansion matrix.

[0081] The fire-resistant expansion matrix comprises the following components (by weight): 35% of ethylene-vinyl acetate copolymer, 30% of expanded graphite 802, 25% of aluminum hydroxide, 1.3% of dicumyl peroxide, 7% of dioctyl adipate, 0.5% of talc and 1.2% of barium stearate.

[0082] Comparative Example:

[0083] Take the common explosion-proof blanket sold on the market as a comparative example.

[0084] Application Example 1: With reference to GB 16807-2009 "Fireproof Intumescent Seals", GB 8624 "Classification of Combustion Performance of Building Materials and Products", GB / T 8627-2007 "Test Method for Smoke Density of Combustion or Decomposition of Building Materials" and GB / T 3917.3 "Tear Properties of Textile Fabrics", chemical properties, physical and mechanical properties, and fire retardant properties were tested.

[0085] Among them, vertical combustion V-0 is the highest level, horizontal combustion HB is the highest level, and the oxygen index is ≥32%.

[0086] The results are shown in the table below:

[0087]

[0088] Application Example 2: The temperature rise of the cable of the embodiment and the comparative example is monitored, and the change of the current carrying capacity of the cable is tested. With reference to TICW 8-2012 "Extruded Insulated Fire-Resistant Power Cable with Rated Voltage 6kV to 35kV", the intelligent monitoring and protection device is coated on the middle joint of the cable, and the cable is applied with U0=8.7kV voltage, and a propane torch is used to continuously supply fire for 90 minutes. Within 1 hour after the test, a test voltage of 3.5 times U0 is applied for a period of time to observe whether it breaks down.

[0089] The results are shown in the table below:

[0090]

[0091] Application Example 3: Referring to the test of short circuit accident and explosion at the middle joint of the distribution network cable, a short circuit current test of 12.5kV and 20kA was carried out. The results show that in the early stage of the short circuit of the cable, embodiments 1, 2 and 3 can issue early warning information in time through the intelligent monitoring device. At the same time, after the internal electrical short circuit explosion, it is guaranteed that there is no splash of explosives, and the surfaces of the cables placed on the adjacent two sides are not damaged. The ventilated expansion fire-resistant explosion-proof net can withstand the pressure shock generated during the test. After the test, it remains intact as a whole, no detachment occurs, and there is no obvious damage or melting on the surface. At the same time, when a fire and explosion occurs at the cable joint in the experiment, the foamed flame retardant material expands rapidly at about 150°C, and all the heat dissipation holes are closed, achieving the effect of suffocating the fire.

[0092] Compared with the prior art, the beneficial effects of the present invention include at least:

[0093] 1. The ventilated expanded fire-resistant explosion-proof net suitable for the intermediate joint of the distribution network cable of the present invention uses a new mesh structure design, which does not affect the temperature of the normal cable operation, and can also quickly release the explosion energy generated when the cable fails, effectively preventing the splash of explosives and reducing the harm to the surrounding environment and personnel. At the same time, it achieves fire prevention, flame retardancy, heat insulation and other effects, and improves the fire protection capability of the cable.

[0094] 2. The ventilated expanded fireproof explosion-proof net for the intermediate joint of the distribution network cable of the present invention can be cut and coated on site according to actual needs, which greatly simplifies the construction process. This design avoids complicated installation steps, making the overall installation and use more convenient, while also reducing construction costs and time and improving engineering efficiency.

[0095] 3. In the monitoring device for the intermediate joints of distribution network cables of the present invention, the use of cable joint partial discharge sensors and temperature online monitoring equipment can detect hidden dangers in cable operation early, reduce the difficulty of personnel inspections, and improve the operation and inspection level of the distribution network.

[0096] The present disclosure may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An intelligent monitoring and protection device suitable for the intermediate joint of distribution network cables, characterized in that: Including ventilation type expansion fire-resistant explosion-proof net and intelligent monitoring device; The ventilated expansion fire-resistant explosion-proof net comprises, by weight percentage, 5% to 25% of a fiber mesh skeleton structure material and 75% to 95% of a fire-resistant expansion matrix material; The ventilated expanded fire-resistant explosion-proof net is wrapped on the cable joint to protect the middle joint of the distribution network cable; The intelligent monitoring device comprises: a temperature monitoring device and a partial discharge monitoring device, and the intelligent monitoring device is arranged outside the ventilation type expansion fireproof explosion-proof net; Intelligent monitoring devices are used to monitor partial discharge and temperature rise caused by abnormal operation of the intermediate joints of the distribution network cables, which can be used to identify hidden dangers of early cable fires.

2. According to claim 1, an intelligent monitoring and protection device suitable for the intermediate joint of a distribution network cable is characterized in that: The reinforcing fiber skeleton structure comprises flame-retardant aramid 1414 fiber with a warp and weft strength of ≥200N / mm and a fineness of 500D to 3000D; On the reinforcing fiber skeleton structure, the fire-resistant expansion matrix material is evenly attached to each fiber by dipping or coating, and woven into a mesh structure with a mesh size of 4mm×4mm to 10mm×10mm.

3. The intelligent monitoring and protection device for the intermediate joint of the distribution network cable according to claim 2 is characterized in that: On the reinforced fiber mesh skeleton structure, a 10 mm fire-resistant expansion matrix material is attached at intervals of 5 mm to 10 mm by a molding method to form a plurality of concave and convex grid areas; The fire-resistant expansion matrix material is prepared from the following weight percentages: 25% to 35% of resin matrix, 20% to 40% of composite expansion agent, 20% to 50% of halogen-free flame retardant, 0.6% to 1.8% of cross-linking agent, 4% to 8% of plasticizer, 0.5% to 1.5% of composite lubricant, and 0.6% to 2.0% of composite stabilizer. The sum of the weights of the components is 100%, and after being evenly mixed, the material is prepared and formed by a twin-screw extruder.

4. The intelligent monitoring and protection device for the intermediate joint of the distribution network cable according to claim 3 is characterized in that: The resin matrix is ​​at least one of cross-linked polyvinyl chloride and ethylene-vinyl acetate copolymer; The composite expansion agent is at least one of expanded graphite 802 and expanded graphite ADT351, and the expansion ratio is ≥300 times; The halogen-free flame retardant is at least one of magnesium hydroxide, aluminum hydroxide, diethyl aluminum hypophosphite, toluene diphenyl phosphate, melamine thiocyanate and melamine; The cross-linking agent is at least one of dicumyl peroxide, di-tert-butyl peroxide and 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane; The plasticizer is at least one of dioctyl adipate, dioctyl sebacate and diisononyl adipate; The composite lubricant is at least one of talc, hydrotalcite, carbon black and clay; The composite stabilizer is at least one of barium stearate, calcium stearate and barium laurate.

5. The intelligent monitoring and protection device for the intermediate joint of the distribution network cable according to claim 1 is characterized in that: The temperature monitoring device is a passive temperature sensor probe, and the partial discharge monitoring device is a passive ground wave TEV partial discharge monitoring device.

6. The intelligent monitoring and protection device for the intermediate joint of the distribution network cable according to claim 5 is characterized in that: The temperature monitoring device and the partial discharge monitoring device are integrated into one body and powered by a battery.

7. The intelligent monitoring and protection device for the intermediate joint of the distribution network cable according to claim 1 is characterized in that: The intelligent monitoring device uploads the monitoring data to the background monitoring center via wireless communication.

8. An intelligent monitoring and protection method for intermediate joints of distribution network cables, based on an intelligent monitoring and protection device for intermediate joints of distribution network cables according to any one of claims 1 to 7, characterized in that: The following steps are involved: Check the circumference of the cable, design the specifications of the protective device according to the on-site cable parameters, wrap the protective device on the middle joint of the cable, and turn on the intelligent detection device; Cut the fire-resistant and explosion-proof modules so that they fully cover the cable connectors and overlap the edges by 15%; Place the intelligent monitoring module at the cable joint and secure it; After the installation is complete, turn on the intelligent monitoring module switch, the device will monitor at the set frequency, and upload the monitoring information to the monitoring host to achieve monitoring and protection.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the computer program is loaded into the processor, it implements the intelligent monitoring and protection method applicable to the intermediate joint of the distribution network cable according to claim 8.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by the processor, an intelligent monitoring and protection method applicable to intermediate joints of distribution network cables according to claim 8 is implemented.

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