High-voltage cable intermediate joint based on multi-layer semi-conductive shielding structure

Abstract

The invention discloses a high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure, which relates to the technical field of power cables, and comprises a conductor connecting pipe, a first joint insulating sleeve, a second joint insulating sleeve, a third joint insulating sleeve and a fourth joint insulating sleeve, the device has the beneficial effects that the conductor connecting pipe, the first joint insulating sleeve and the joint intelligent connecting seat are arranged, and hot air passes through a conveying pipeline, passes through an outlet in the bottom of a positioning insertion rod and is uniformly blown to the top space of the conductor connecting pipe and a surrounding insulating interface area; the temperature of a key area in the connector can be slightly increased, possible poor contact or overload operation is prompted, and fault early warning is achieved; the storage battery and the heating equipment are normally mounted by forming an internal mounting groove in the auxiliary temperature measuring mechanism, and the heating equipment and the storage battery are connected in a reinforced mode through cooperation of a side face positioning plate and a second positioning bolt.

Description

Technical Field

[0001] This invention relates to the field of power cable technology, specifically to a high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure. Background Technology

[0002] High-voltage cable joints are a critical weak link in power transmission networks, and their long-term reliability is directly related to the safety and stability of the entire power grid system.

[0003] Chinese Patent Publication No. CN 204681063 U discloses a high-voltage cable intermediate joint, including an outer sheath, stress-dispersing adhesive wrapped around the outer sheath, a simple shielding layer, a semiconducting layer, an intermediate joint tube, and a conductor connecting tube. The intermediate joint tube and the conductor connecting tube are located inside the outer sheath in a straight line. One end of the intermediate joint tube is close to the end of the conductor connecting tube, and the other end of the intermediate joint tube is connected to the simple shielding layer. A semiconductor self-adhesive tape and a semiconducting layer are provided at the bottom of the conductor connecting tube, with one end of the semiconducting layer close to one end of the semiconductor self-adhesive tape. A core insulation layer is also provided at the top of the conductor connecting tube. A stress tube is also sleeved on the simple shielding layer. A cable steel armor is also provided at the end of the outer sheath, adjacent to the stress tube. Through the above structure, this utility model can disperse the electrical stress at the break point of the cable shielding layer, ensure a uniform electric field distribution in the cable intermediate joint, and make the connection end of the high-voltage cable intermediate joint have good airtightness, aging resistance, and good electrical performance.

[0004] However, the above solution still has the following problems:

[0005] First, the uneven electric field distribution makes it easy for electric field distortion and concentration to occur at conductor connections and insulation restoration points, forming partial discharge initiation points, which, under long-term action, leads to aging and breakdown of the insulation material.

[0006] Secondly, the interface sealing and moisture-proof performance is insufficient, and moisture and humidity in the operating environment can easily penetrate into the joint, which not only reduces the insulation performance, but also causes water tree discharge under the action of electric field, accelerating the insulation damage.

[0007] Lacking effective status perception and intelligent control capabilities, staff cannot monitor key internal conditions such as temperature and humidity in real time. Furthermore, it lacks proactive protection against harsh environments such as low temperature and high humidity, making preventative maintenance difficult. In particular, in areas with large temperature differences between day and night or humid environments, condensation inside the joints is difficult to eradicate, becoming a potential source of failure and failing to meet normal usage requirements.

[0008] Therefore, the present invention needs to design a high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure to solve the above-mentioned problems. Summary of the Invention

[0009] The purpose of this invention is to provide a high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure that integrates intelligent status monitoring and active protection functions, while also possessing superior electric field control and sealing reliability, in order to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure, comprising a conductor connecting tube, and further comprising:

[0011] The first connector insulating sleeve is located on one side of the conductor connecting tube;

[0012] The second connector insulating sleeve is located on the side of the conductor connecting tube away from the first connector insulating sleeve;

[0013] The intelligent connector is located at the top of the conductor connecting tube;

[0014] The conductor connecting tube is equipped with equidistantly distributed side insulating plates and outer shielding plates, with multiple outer shielding plates located on one side of the side insulating plates. The inner wall of the second connector insulating sleeve is equipped with an inner protective layer, and the inner wall of the first connector insulating sleeve is equipped with a waterproof sealing gasket.

[0015] The top of the intelligent connector is fixedly connected to a dustproof top plate. The bottom of the intelligent connector is equipped with an auxiliary temperature measuring mechanism located at the top of the conductor connecting tube. A heating device is installed inside the auxiliary temperature measuring mechanism. A positioning rod located on the inner wall of the top of the conductor connecting tube is fixedly connected to the bottom of the auxiliary temperature measuring mechanism. A conveying pipe is installed inside each positioning rod. A fan and a heating wire are installed inside the heating device. The heating wire is located on one side of the fan. A temperature sensor is installed inside the heating device.

[0016] In a preferred embodiment of the present invention, a micro motor is fixedly connected inside the heating device and on the side of the heating wire away from the fan. The output end of the micro motor is fixedly connected to the fan. Removable filter plates are installed on both sides of the heating device. The two removable filter plates are used for air intake and exhaust processing, which facilitates unified cleaning later.

[0017] In a preferred embodiment of the present invention, cables are installed inside the conductor connecting tube, the first connector insulating sleeve, and the second connector insulating sleeve, and equally spaced internal insulating plates are installed inside the first connector insulating sleeve and outside the cable.

[0018] In a preferred embodiment of the present invention, a positioning sensor is fixedly connected to the top of the dustproof top plate. The positioning sensor is used for real-time positioning, which facilitates on-site positioning by remote personnel. The bottom of the intelligent connector is equipped with a slot for mounting the auxiliary temperature measuring mechanism. A bolt hole is provided on one side of the intelligent connector. A third positioning bolt is provided inside the bolt hole. The third positioning bolt and the bolt hole cooperate to reinforce the connection between the intelligent connector and the auxiliary temperature measuring mechanism.

[0019] In a preferred embodiment of the present invention, a first sealing ring is fitted on the outside of the conductor connecting tube and between the outer shielding plate and the side insulating plate, and a second sealing ring is fitted on the outside of the second connector insulating sleeve.

[0020] In a preferred embodiment of the present invention, the conductor connecting tube has a first mounting cavity for cable installation, and both the first connector insulating sleeve and the second connector insulating sleeve have a second mounting cavity for cable installation.

[0021] In a preferred embodiment of the present invention, a storage battery is fixedly connected inside the auxiliary temperature measuring mechanism and on one side of the heating device, and a third mounting cavity is opened inside the intelligent connector seat. The top of the third mounting cavity is threaded with first positioning bolts that are symmetrically distributed and extend to the top of the conductor connecting tube.

[0022] In a preferred embodiment of the present invention, a main control board is fixedly connected inside the positioning sensor, and a control chip is fixedly connected to the outside of the main control board. The positioning sensor, battery, fan, micro motor, heating wire and temperature sensor are all electrically connected to the control chip.

[0023] In a preferred embodiment of the present invention, the auxiliary temperature measuring mechanism has an internal mounting groove for mounting the heating equipment, and the positioning rods each have a sliding groove for mounting the conveying pipes. The top ends of the two conveying pipes extend to the bottom of the heating equipment.

[0024] In a preferred embodiment of the present invention, a side positioning plate that cooperates with the battery positioning is fixedly connected to one side of the heating device, and the side positioning plate is threaded with second positioning bolts that are evenly distributed and extend to the inner wall of the battery.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] This invention comprises a conductor connecting tube, a first joint insulating sleeve, and a smart joint connector. The conductor connection and foundation insulation are as follows: the cable conductors are electrically connected through the conductor connecting tube, which acts as the main insulator, enclosing the connection area and bearing the main working voltage and impulse voltage. On the outside of the conductor connecting tube, side insulating plates and an outer shielding plate are alternately arranged. The side insulating plates are made of ethylene propylene rubber with added carbon black, possessing a certain volume resistivity, serving as insulation and buffering. The different dielectric constants and conductivities of these two materials form a stepped dielectric parameter transition zone. When the main insulation shielding layer of the cable body is interrupted at this point, this multi-layer structure can effectively and smoothly conduct and homogenize the electric field lines, avoiding abrupt changes and concentrations in the electric field. The entire joint shell is then sealed a second time through a first sealing ring and a second sealing ring. First, the heating wire is activated to generate heat; simultaneously, a micro motor drives the fan; hot air is delivered through a conveying pipe, exiting from the bottom of the positioning plug, and evenly blown into the top space of the conductor connecting tube and the surrounding insulation interface area; this slightly raises the temperature of the critical area inside the joint, ensuring it remains above the ambient dew point temperature, thus fundamentally preventing condensation and eliminating the potential for insulation failures caused by moisture; if the monitored temperature exceeds the preset overload alarm threshold, the control chip can send an alarm signal to the maintenance center via the built-in remote communication module, indicating possible poor contact or overload operation, thus providing a fault warning; the battery and heating equipment are properly installed through an internal mounting slot within the auxiliary temperature measuring mechanism, and the heating equipment and battery are reinforced with a side positioning plate and a second positioning bolt. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of a high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to the present invention. Figure 1 ;

[0028] Figure 2 This is a schematic diagram of the overall structure of a high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to the present invention. Figure 2 ;

[0029] Figure 3 This is an exploded view of the conductor connecting pipe and connector insulating sleeve of a high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to the present invention.

[0030] Figure 4 This is an enlarged schematic diagram of the intelligent connector and auxiliary temperature measuring mechanism of a high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to the present invention.

[0031] Figure 5 This is an enlarged view of the internal structure of an auxiliary temperature measuring mechanism for a high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to the present invention.

[0032] Figure 6 This is an exploded structural diagram of a heating device based on a multi-layer semi-conductive shielding structure for a high-voltage cable intermediate joint according to the present invention.

[0033] Figure 7 This invention relates to a high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure. Figure 6 Enlarged schematic diagram of the structure at point A in the diagram.

[0034] In the picture:

[0035] 1. Conductor connecting tube; 11. Side insulating plate; 12. First sealing ring; 13. Outer shielding plate; 14. First mounting cavity;

[0036] 2. First connector insulating sleeve; 21. Inner insulating plate; 22. Waterproof sealing gasket; 23. Second connector insulating sleeve; 24. Second sealing ring; 25. Inner protective layer; 26. Second mounting cavity;

[0037] 3. Intelligent connector base; 31. Dustproof top plate; 32. Positioning sensor; 33. Third mounting cavity; 34. First positioning bolt; 35. Bolt hole;

[0038] 4. Auxiliary temperature measuring mechanism; 41. Positioning rod; 42. Conveying pipe; 43. Internal mounting slot; 44. Storage battery;

[0039] 5. Heating equipment; 51. Side positioning plate; 52. Second positioning bolt; 53. Fan; 54. Micro motor; 55. Heating wire; 56. Filter plate disassembly device; 57. Temperature sensor. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] Please see Figures 1-7 The present invention provides a technical solution: a high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure, comprising a conductor connecting pipe 1, and further comprising:

[0042] First connector insulating sleeve 2, the first connector insulating sleeve 2 is located on one side of conductor connecting pipe 1;

[0043] The second connector insulating sleeve 23 is located on the side of the conductor connecting tube 1 away from the first connector insulating sleeve 2;

[0044] The intelligent connector 3 is located at the top of the conductor connecting tube 1;

[0045] In this scheme, the outer side of the conductor connecting tube 1 is equipped with equidistantly distributed side insulating plates 11 and outer shielding plates 13. Multiple outer shielding plates 13 are located on one side of the side insulating plates 11. The inner wall of the second joint insulating sleeve 23 is equipped with an inner protective layer 25. The inner wall of the first joint insulating sleeve 2 is equipped with a waterproof sealing gasket 22. The waterproof sealing gasket 22 is made of ethylene propylene rubber or silicone rubber to ensure long-term elastic sealing between the joint interfaces and prevent moisture intrusion. The inner protective layer 25 is made of semi-conductive ethylene propylene rubber with added carbon black to achieve a smooth electrical transition with the cable body shielding layer and uniform electric field distribution. The side insulating plates 11 are made of ethylene propylene rubber or silicone rubber with added carbon black. The outer shielding plates 13 are made of polyurethane or PVC to provide mechanical protection and environmental sealing. The first joint insulating sleeve 2 is made of cross-linked polyethylene XLPE to serve as the main insulation of the joint and withstand working voltage and various overvoltages. The first joint insulating sleeve 2 and the second joint insulating sleeve 23 are made of high-strength insulating engineering plastics such as polyamide or reinforced PBT to provide mechanical support and external insulation protection for internal components.

[0046] In this solution, a dustproof top plate 31 is fixedly connected to the top of the intelligent connector 3. An auxiliary temperature measuring mechanism 4 is installed at the bottom of the intelligent connector 3, located at the top of the conductor connecting pipe 1. A heating device 5 is installed inside the auxiliary temperature measuring mechanism 4. A positioning rod 41 located on the inner wall of the top of the conductor connecting pipe 1 is fixedly connected to the bottom of the auxiliary temperature measuring mechanism 4. A conveying pipe 42 is installed inside the positioning rod 41. A fan 53 and a heating wire 55 are installed inside the heating device 5. The heating wire 55 is located on one side of the fan 53. A temperature sensor 57 is installed inside the heating device 5.

[0047] Please see Figures 1-7 In this solution, a micro motor 54 is fixedly connected inside the heating device 5 and on the side of the heating wire 55 away from the fan 53. The output end of the micro motor 54 is fixedly connected to the fan 53. Two detachable filter plates 56 are installed on both sides of the heating device 5. The two detachable filter plates 56 are used for air intake and exhaust treatment, which facilitates unified cleaning later.

[0048] In this scheme, cables are installed inside the conductor connecting pipe 1, the first joint insulating sleeve 2, and the second joint insulating sleeve 23. An internal insulating plate 21 is installed inside the first joint insulating sleeve 2 and outside the cable.

[0049] Please see Figures 1-4In this solution, a positioning sensor 32 is fixedly connected to the top of the dustproof top plate 31. The positioning sensor 32 is used for real-time positioning, which facilitates on-site positioning by remote personnel. The bottom of the intelligent connector 3 is equipped with a slot for installation with the auxiliary temperature measuring mechanism 4. A bolt hole 35 is opened on one side of the intelligent connector 3. A third positioning bolt is provided inside the bolt hole 35. The third positioning bolt and the bolt hole 35 cooperate to reinforce the connection between the intelligent connector 3 and the auxiliary temperature measuring mechanism 4.

[0050] In this design, a first sealing ring 12 is fitted on the outside of the conductor connecting tube 1 and between the outer shielding plate 13 and the side insulating plate 11, and a second sealing ring 24 is fitted on the outside of the second connector insulating sleeve 23. The first sealing ring 12 seals the outside of the conductor connecting tube 1, and the second sealing ring 24 seals the outside of the second connector insulating sleeve 23.

[0051] Please see Figures 1-7 In this scheme, the conductor connecting tube 1 has a first mounting cavity 14 for cable installation, and the first joint insulating sleeve 2 and the second joint insulating sleeve 23 both have a second mounting cavity 26 for cable installation. The two second mounting cavities 26 and the first mounting cavity 14 ensure normal cable installation.

[0052] In this solution, a battery 44 is fixedly connected inside the auxiliary temperature measuring mechanism 4 and located on one side of the heating device 5. The intelligent connector 3 has a third mounting cavity 33 inside. The top of the third mounting cavity 33 is threaded with first positioning bolts 34 that are symmetrically distributed and extend to the top of the conductor connecting pipe 1. By cooperating with the third mounting cavity 33 to properly install the first positioning bolts 34, the intelligent connector 3 and the conductor connecting pipe 1 can be quickly installed and separated, reducing the labor intensity of daily maintenance.

[0053] In this solution, the positioning sensor 32 is internally connected to a main control board, and the main control board is externally connected to a control chip. The positioning sensor 32, battery 44, fan 53, micro motor 54, heating wire 55, and temperature sensor 57 are all electrically connected to the control chip. The control chip is used to control the operation of the positioning sensor 32, battery 44, fan 53, micro motor 54, heating wire 55, and temperature sensor 57, realizing unified management of electrical equipment. The temperature sensor 57 measures environmental parameters, converts them into signals, and sends them to the control chip. The control chip receives the signals, processes them, and generates corresponding control signals according to the preset control algorithm.

[0054] Please see Figures 1-7In this scheme, the auxiliary temperature measuring mechanism 4 has an internal mounting groove 43 for installing the heating device 5, and the positioning rod 41 has a sliding groove for installing the conveying pipe 42. The top end of the two conveying pipes 42 extends to the bottom of the heating device 5. The sliding grooves ensure that the conveying pipe 42 is stably installed inside the positioning rod 41. The battery 44 and the heating device 5 are properly installed by the internal mounting groove 43 inside the auxiliary temperature measuring mechanism 4.

[0055] In this solution, a side positioning plate 51 is fixedly connected to one side of the heating device 5 to limit the position of the battery 44. The side positioning plate 51 is threaded with second positioning bolts 52 that are evenly distributed and extend to the inner wall of the battery 44. The heating device 5 and the battery 44 are reinforced and connected by the side positioning plate 51 and the second positioning bolts 52.

[0056] Please see Figures 1-7 The working principle of this invention is as follows:

[0057] This invention comprises a conductor connecting tube 1, a first connector insulating sleeve 2, and a connector intelligent connector base 3. In use:

[0058] Working principle of electric field optimization and insulation sealing:

[0059] Conductor connection and base insulation: The cable conductors are electrically connected through conductor connection tube 1. On its outside, the first joint insulation sleeve 2 and the second joint insulation sleeve 23 are made of cross-linked polyethylene XLPE, which serve as the main insulator, wrapping the connection area and bearing the main working voltage and impulse voltage.

[0060] Electric field averaging mechanism of multilayer semiconducting shielding structure: This is one of the core innovations of this invention. Side insulating plate 11 and outer shielding plate 13 are alternately arranged on the outside of conductor connecting tube 1.

[0061] The side insulation plate 11 is made of ethylene propylene rubber with added carbon black, which has a certain volume resistivity and plays a role in insulation and buffering.

[0062] The outer shielding plate 13 is made of polyurethane or PVC, which has a lower resistivity and serves as a semi-conductive shielding layer.

[0063] The different dielectric constants and conductivity of these two layers of materials form a stepped dielectric parameter transition zone. When the main insulation shielding layer of the cable body is interrupted here, this multi-layer structure can effectively and smoothly conduct and homogenize electric field lines, avoiding abrupt changes and concentrations in the electric field.

[0064] Double sealing and moisture-proof mechanism:

[0065] Interface sealing: At the interface between the first joint insulating sleeve 2 and the cable insulation, a waterproof sealing gasket 22 made of ethylene propylene rubber is provided to provide an initial elastic compression seal.

[0066] Structural sealing: The entire connector shell is sealed twice by the first sealing ring 12 and the second sealing ring 24. The semi-conductive ethylene propylene rubber inner protective layer 25 on the inner wall of the second connector insulating sleeve 23 not only realizes the electric field transition, but its rubber elastomer also helps to enhance the sealing of the interface, forming a multi-layer moisture barrier from the inside to the outside.

[0067] Working principle of intelligent monitoring and active protection:

[0068] Status perception center: The control chip is used to control the operation of positioning sensor 32, battery 44, fan 53, micro motor 54, heating wire 55 and temperature sensor 57, realizing unified management of power equipment. Temperature sensor 57 measures environmental parameters, converts them into signals and sends them to the control chip. The control chip receives the signals and processes them, and generates corresponding control signals according to the preset control algorithm. Positioning sensor 32 provides geographical location information, which facilitates asset management and precise positioning.

[0069] Temperature monitoring and intelligent temperature control: This is another core innovation of this invention;

[0070] Monitoring: Temperature sensor 57 installed inside heating equipment 5 monitors the ambient temperature of key parts of the joint in real time and transmits the data to the control chip;

[0071] Decision-making and execution: The control chip has a built-in algorithm that automatically activates the active anti-condensation mode when the monitored temperature is lower than the preset condensation risk threshold, such as being lower than a certain difference from the ambient dew point temperature.

[0072] First, the heating element 55 is activated to generate heat;

[0073] Simultaneously, the micro motor 54 is activated to drive the fan 53 to operate;

[0074] Hot air is delivered through the delivery pipe 42 and through the outlet at the bottom of the positioning rod 41 to the top space of the conductor connecting pipe 1 and the surrounding insulation interface area.

[0075] It can slightly raise the temperature of critical areas inside the joint, keeping it always above the ambient dew point temperature, thereby fundamentally preventing condensation and eliminating potential insulation failures caused by moisture.

[0076] In high temperature warning mode: if the monitored temperature exceeds the preset overload alarm threshold, the control chip can send an alarm signal to the operation and maintenance center through the built-in remote communication module, indicating that there may be poor contact or overload operation, thus realizing fault warning;

[0077] Energy and mechanical structure: The storage battery 44 provides an independent power supply, and the auxiliary temperature measuring mechanism 4 is inserted into a predetermined position through the positioning rod 41 and fixed by bolts and intelligent connector 3, realizing modular installation and rapid maintenance;

[0078] The bottom of the intelligent connector 3 is equipped with a slot for mounting the auxiliary temperature measuring mechanism 4. A bolt hole 35 is provided on one side of the intelligent connector 3, and a third positioning bolt is provided inside the bolt hole 35. The third positioning bolt and the bolt hole 35 work together to reinforce the connection between the intelligent connector 3 and the auxiliary temperature measuring mechanism 4. The first sealing ring 12 provides a sealing effect on the outside of the conductor connecting pipe 1, and the second sealing ring 24 provides a sealing effect on the outside of the second connector insulating sleeve 23. The third mounting cavity 33 is used to install the first positioning bolt 34, thereby enabling quick installation and separation of the intelligent connector 3 and the conductor connecting pipe 1, reducing the labor intensity of daily maintenance. The sliding groove ensures that the conveying pipe 42 is stably installed inside the positioning rod 41. The internal mounting groove 43 inside the auxiliary temperature measuring mechanism 4 is used to install the battery 44 and the heating equipment 5. The side positioning plate 51 and the second positioning bolt 52 work together to reinforce the connection between the heating equipment 5 and the battery 44.

[0079] Example: A smart intermediate joint for 66kV cross-linked polyethylene (XLPE) insulated cables

[0080] 1. Structural parameters:

[0081] Conductor connecting tube 1: Made of copper crimp tube, outer diameter 50mm;

[0082] Multi-layer semi-conductive shielding structure: A total of 3 sets of side insulating plates 11 + outer shielding plates 13 composite layers are provided;

[0083] Side insulation plate 11: Silicone rubber with added carbon black, 3mm thick, volume resistivity 10. 10 Ω·cm;

[0084] Outer shielding plate 13: Semi-conductive polyurethane, 2mm thick, volume resistivity 10. 4 Ω·cm;

[0085] Each composite layer is tightly bonded and completely covers the main insulation recovery area of ​​conductor connecting tube 1;

[0086] First and second joint insulation sleeves: prefabricated cross-linked polyethylene XLPE insulation components are used, and the inner semi-conductive shielding layer is smoothly overlapped with the cable body shielding layer, with an overlap length of not less than 30mm.

[0087] Waterproof sealing gasket 22: formed by on-site injection curing of liquid silicone rubber to ensure an interface pressure greater than 0.4MPa;

[0088] 2. Intelligent temperature control system parameters:

[0089] Temperature sensor 57: PT100 platinum resistance thermometer, measurement accuracy ±0.5℃;

[0090] Heating equipment 5: Heating wire 55, power 80W; Fan 53, air volume 5CFM;

[0091] Control logic:

[0092] The control chip collects temperature sensor data T1 57 times per minute;

[0093] Meanwhile, the control chip can acquire the ambient dew point temperature T2 by either having a built-in barometric pressure sensor or receiving remote meteorological data.

[0094] Anti-condensation mode activation conditions: When T1-T2≤2℃, it is determined that there is a risk of condensation. The intelligent control module immediately starts the heating wire 55 and fan 53 to deliver warm air through the delivery pipe 42.

[0095] Stopping condition: Heating shall be stopped when T1-T2≥5℃;

[0096] Over-temperature alarm conditions: When T1≥75℃, considering that the long-term allowable operating temperature of the conductor is 90℃, the control chip sends a first-level alarm signal to the monitoring background through the 4G / NB-IoT communication module, which can be integrated into the smart connector 3; when T1≥85℃, a second-level emergency alarm signal is sent.

[0097] Battery 44: Lithium thionyl chloride battery pack, capacity 12V10Ah, can support the intelligent system standby for more than 5 years without external power supply, and supports continuous heating operation for more than 72 hours.

[0098] 3. Assembly and Effects:

[0099] During on-site installation, the first step is to crimp the cable conductors and grind the main insulation.

[0100] Insert the multi-layer semi-conductive shielding structure assembly in sequence and tighten it with a torque wrench to ensure that each layer is in close contact.

[0101] Install the insulating sleeves of the first and second connectors and complete the sealing;

[0102] Finally, the intelligent connector 3 with integrated intelligent temperature control system is aligned with the slot through the positioning rod 41 and fixed with the first positioning bolt 34 and the third positioning bolt.

[0103] Test results: In a laboratory environment simulating a day-night temperature difference cycle of 25℃-5℃ and a relative humidity of 95%, the traditional connector showed obvious condensation on the cold end surface, while the humidity in the key area inside the connector of the present invention remained below 70%, with no condensation. Partial discharge test showed that at 1.7 times the rated phase voltage, the apparent discharge of the connector of the present invention was less than 5pC, which is significantly better than the existing connectors, which are usually required to be less than 10pC.

[0104] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure, comprising a conductor connecting pipe (1), characterized in that, Also includes: The first connector insulating sleeve (2) and the second connector insulating sleeve (23) are located on both sides of the conductor connecting pipe (1) respectively, and together constitute the main insulator of the connector; The conductor connecting tube (1) is alternately fitted with at least one set of composite shielding layers consisting of a side insulating plate (11) and an outer shielding plate (13). The volume resistivity of the side insulating plate (11) is higher than that of the outer shielding plate (13). The two are used together to achieve a step-like smooth transition of the electric field at the joint. The intelligent connector (3) is located at the top of the conductor connecting tube (1); The intelligent control module and auxiliary temperature measuring mechanism (4) are integrated into the intelligent connector (3); the auxiliary temperature measuring mechanism (4) includes a heating device (5), a temperature sensor (57) embedded therein, and a positioning plug (41) and a delivery pipe (42) extending to the vicinity of the conductor connecting pipe (1); the temperature sensor (57) and the heating device (5) are electrically connected to the intelligent control module to monitor the internal temperature of the connector and perform active anti-condensation heating.

2. The high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to claim 1, characterized in that: A micro motor (54) is fixedly connected inside the heating device (5) and on the side of the heating wire (55) away from the fan (53). The output end of the micro motor (54) is fixedly connected to the fan (53). Removable filter plates (56) are installed on both sides of the heating device (5).

3. The high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to claim 2, characterized in that: Cables are installed inside the conductor connecting tube (1), the first connector insulating sleeve (2), and the second connector insulating sleeve (23). An internal insulating plate (21) is installed inside the first connector insulating sleeve (2) and outside the cable.

4. The high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to claim 2, characterized in that: A positioning sensor (32) is fixedly connected to the top of the dustproof top plate (31), and a bolt hole (35) is provided on one side of the intelligent connector (3).

5. The high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to claim 1, characterized in that: A first sealing ring (12) is fitted on the outside of the conductor connecting tube (1) and between the outer shielding plate (13) and the side insulating plate (11), and a second sealing ring (24) is fitted on the outside of the second connector insulating sleeve (23).

6. The high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to claim 4, characterized in that: The conductor connecting tube (1) has a first mounting cavity (14) for cable installation, and the first connector insulating sleeve (2) and the second connector insulating sleeve (23) both have a second mounting cavity (26) for cable installation.

7. The high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to claim 4, characterized in that: A battery (44) is fixedly connected inside the auxiliary temperature measuring mechanism (4) and on one side of the heating device (5). A third mounting cavity (33) is opened inside the connector intelligent connector (3). The top of the third mounting cavity (33) is threaded with first positioning bolts (34) that are symmetrically distributed and extend to the top of the conductor connecting pipe (1).

8. The high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to claim 7, characterized in that: The positioning sensor (32) has a main control board fixedly connected inside, and a control chip is fixedly connected to the outside of the main control board. The positioning sensor (32), battery (44), fan (53), micro motor (54), heating wire (55) and temperature sensor (57) are all electrically connected to the control chip.

9. The high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to claim 8, characterized in that: The auxiliary temperature measuring mechanism (4) has an internal mounting groove (43) for installation with the heating device (5), and the top ends of the two conveying pipes (42) extend to the bottom of the heating device (5).

10. The high-voltage cable intermediate joint based on a multi-layer semi-conductive shielding structure according to claim 8, characterized in that: The heating device (5) is fixedly connected to a side positioning plate (51) that is used to limit the position of the battery (44). The side positioning plate (51) is threaded with second positioning bolts (52) that are evenly distributed and extend to the inner wall of the battery (44).

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