Distribution network cable joint insulation defect live detection digitizer based on electromagnetic coupling

Abstract

The invention discloses a distribution network cable joint insulation defect live-line detection digitization device based on electromagnetic coupling, which belongs to the technical field of cable accessories and comprises an upper sleeve shell unit and a lower sleeve shell unit which are arranged outside a cable joint in a sleeving manner, are arranged up and down and are detachably assembled together, the upper sleeve shell unit is provided with a sensor for monitoring parameters of a cable joint part; the upper sleeve shell unit and the lower sleeve shell unit each comprise a skirt structure, a sealing piece is arranged between the two skirt structures, and the lower sleeve shell unit further comprises a pressure sensing module. According to the invention, the insulation defect of the cable joint of the distribution network can be detected, positioned and analyzed under the condition of live operation, so that the insulation defect of the cable joint can be found in advance, accurate positioning is given, the defect finding and processing efficiency is effectively improved, the power supply reliability of the distribution network is improved, post repair of traditional manual power failure test is realized, and the power supply reliability of the distribution network is improved. And the method is converted to a pre-defect elimination mode of electrified digital inspection operation.

Description

Technical Field

[0001] This invention relates to the field of cable accessories technology, and more specifically, to a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling. Background Technology

[0002] As power distribution lines are continuously constructed, the number of cable faults also increases with the length of the cables. Under conditions such as installation failure, external damage, moisture absorption, and insulation aging and deterioration, cable joints are prone to various defects, which can lead to cable faults.

[0003] Currently, the method of locating faults at cable joints mainly relies on manual string pulling. That is, inspection personnel rely on their senses (mainly sight and hearing) and simple tools to walk along the power lines, carefully observe the line equipment and the surrounding environment, and look for abnormal phenomena caused by the fault to deal with them.

[0004] However, urban cable ring network cabinets are densely packed, and most distribution network cables are laid underground directly or in cable trenches. There are many users and the operating environment is harsh. When a line fault occurs, the traditional method of manually pulling wires to find the fault point at the cable joint cannot accurately select the faulty feeder and locate the faulty section in a timely manner. It is necessary to search section by section, which brings trouble and inconvenience to the timeliness of locating and troubleshooting cable joint faults.

[0005] In view of this, we propose a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling. Summary of the Invention

[0006] Technical problem to be solved: The purpose of this invention is to provide a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling, which solves the technical problems mentioned in the background art above.

[0007] Technical solution: The technical solution of the present invention provides a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling, including an upper housing unit and a lower housing unit that are sleeved on the outside of the cable joint, arranged vertically and detachably assembled together, and the upper housing unit is equipped with a sensor for monitoring parameters of the cable joint. Both the upper and lower housing units include skirt structures, and a sealing element is provided between the two skirt structures. The lower housing unit also includes a pressure-sensitive module. The pressure-sensitive module includes a side housing connected to the side wall of the lower housing unit. The side housing includes a partition mechanism disposed inside it. The partition structure divides the internal space of the side housing into an upper isolation cavity and a lower connecting cavity arranged vertically. The lower connecting cavity is connected to the interior of the lower housing unit. The side housing also includes an alarm structure and a bottom following structure respectively disposed on its top and bottom. The alarm structure includes a static switch part and a dynamic switch part. The bottom following structure includes a bottom sealing diaphragm fixedly sealed at its bottom opening and a pin that is movably inserted into its side wall; The partition mechanism includes an elastic partition, on which a vertically arranged spiked rod assembly is provided. The top end of the spiked rod assembly extends into the alarm structure and is connected to the dynamic switch part, while the bottom spiked part penetrates into the lower bottom following structure and faces the sealing diaphragm. The spiked rod assembly includes a slot structure located on its side wall into which a pin can be inserted. When the spiked rod assembly is in its initial state, the pin is inserted into the slot structure. At this time, the elastic barrier protrudes upward elastically, and the dynamic switch and the static switch do not contact each other.

[0008] As an optional solution to the technical solution of this invention, both the upper and lower housing units also include a shielding cover. The upper housing unit also includes an air injection nozzle that is fixedly connected to the side wall of the shielding housing. The air injection nozzle is equipped with a one-way air inlet valve, and a cap is threaded onto the opening at the end of the air injection nozzle. The sensors include a high-frequency current sensor and a GPS sensor. The high-frequency current sensor is mounted on the shielding housing, with its detection end extending into the shielding housing and facing the cable connector. The GPS sensor is mounted on the outside of the shielding housing.

[0009] As an optional solution of the technical solution in this invention document, the skirt structure includes an end arc-shaped hoop integrally formed at the openings at both ends of the shielding shell and a peripheral skirt integrally formed on the periphery of the side wall of the shielding shell, and the shielding shell and the peripheral skirt are also integrally formed.

[0010] As an optional solution to the technical solution of this invention document, the sealing element includes a skirt sealing gasket and four annular sealing gaskets; Furthermore, two of the annular sealing gaskets are integrally molded on the front and rear ends of the skirt sealing gasket; The skirt edge sealing gasket is connected to one of the peripheral skirt supports; Four annular sealing gaskets are respectively connected to the inside of the four end arc-shaped hoop seats.

[0011] As an optional solution to the technical solution of this invention document, the side-mounted shell includes a side-mounted shielding shell connected to the side wall of the shielding shell. The partition mechanism includes a baffle plate connected to the inside of the side shielding shell, and the baffle plate divides the internal space of the side shielding shell into an upper isolation cavity and a lower connecting cavity arranged vertically, and the lower connecting cavity is connected to the inside of the shielding shell. The elastic barrier includes a rigid inner seat, an elastic diaphragm is fixedly fitted around the outer periphery of the rigid inner seat, and a first return spring is provided on the top of the rigid inner seat. The baffle plate has a through groove adapted to the elastic diaphragm, and the outer ring wall of the elastic diaphragm is fixedly connected to the through groove.

[0012] As an optional solution to the technical solution of this invention document, the spiked rod assembly includes a driven rod that is inserted and fixed on a rigid inner socket; A guide rod is inserted into the opening at the top of the moving rod; The bottom end of the driven rod is provided with a pointed end; The slot structure is a pin slot set on the side wall of the driven rod.

[0013] As an optional solution of the technical solution in this invention document, the alarm structure also includes an upper insulating cylinder seat connected to the top of the side shielding shell and internally connected to the upper isolation cavity, and the bottom end of the first reset spring is connected to the rigid inner seat, while the top end is connected to the bottom end of the upper insulating cylinder seat. The static switch section includes a static ring terminal and a control circuit board connected inside the upper insulating cylinder base. A wireless signal transmitter is connected to the control circuit board, and the static ring terminal is fixedly connected to the bottom opening of the upper insulating cylinder base. The dynamic switch section includes a dynamic spring; The top of the guide rod passes through the bottom opening of the upper insulating cylinder seat and is fixedly connected to the top wall of the inner cavity of the upper insulating cylinder seat; The rod passes through the opening at the bottom of the upper insulating cylinder from the top and connects with the dynamic spring. When the dynamic spring contacts the static ring terminal, the control circuit board is triggered to turn on the wireless signal transmitter, which then sends out a wireless alarm signal.

[0014] As an optional solution to the technical solution of this invention document, the lower bottom following structure includes a lower bottom cylinder seat connected to the bottom of the side shielding shell and internally connected to the lower connecting cavity; A first bellows is connected to the top opening of the bottom cylinder base, and an inner limiting cover is connected inside the top opening of the first bellows. The top opening of the inner limit cover is sleeved and fixed to the outer periphery of the driven rod; The bottom sealing film is fixedly sealed at the bottom opening of the bottom sealing film, with the pointed end facing the bottom sealing film; The pin part includes a pin rod that is slidably inserted into the side wall of the lower bottom cylinder seat. One end of the pin rod extends into the interior of the lower bottom cylinder seat, and the other end extends out from the side wall of the lower bottom cylinder seat and is connected to a flexible outer cover. The outer edge of the flexible outer cover is fixedly connected to the side wall of the lower bottom cylinder seat. When the spiked rod assembly is in its initial state, the pin in the pin section is inserted into the pin slot in the slot structure. At this time, the elastic diaphragm in the elastic barrier protrudes upward elastically, and the dynamic spring in the dynamic switch section does not contact the static annular terminal in the static switch section.

[0015] As an optional solution to the technical solution of this invention, the lower bottom following structure also includes a flexible pipeline component and an interlayer portion connected to the interior of the lower bottom cylinder. A second corrugated pipe is connected to the openings at both the top and bottom of the interlayer section; The top of the interlayer has several reserved openings, and each reserved opening is connected to a waterproof and breathable membrane; The interlayer is filled with a layer of liquid triggering medium. A passive slide is also slidable inside the interlayer. A second reset spring is connected to one side of the passive slide, and the end of the second reset spring away from the passive slide is connected to the inner wall of the interlayer cavity. A driven tip is connected to the other side of the passive slide; The driven rod passes through the central opening of the interlayer from the bottom end, and the opposite ends of the two second corrugated pipes are both sleeved and fixed to the outer periphery of the side wall of the driven rod. The driven rod has a groove on the side wall of the second bellows located on the upper side. The opening of the groove is sealed with an annular isolation membrane. The groove is filled with a layer of gas-generating particles that work in conjunction with the liquid triggering medium layer. When the spiked rod assembly is in its initial state and the pin in the pin part is inserted into the pin groove in the slot structure, the groove is located above the liquid trigger medium layer, and at this time, under the elastic force of the second reset spring, the driven tip elastically abuts against the side wall of the driven rod.

[0016] As an optional solution of the technical solution in this invention document, the skirt sealing gasket and the two annular sealing gaskets integrally formed with the front and rear ends of the skirt sealing gasket are provided with recessed grooves, and the recessed grooves on the skirt sealing gasket and the recessed grooves on the two annular sealing gaskets are connected to an embedded bladder. One end of the flexible tubing is fixedly connected to the side wall of the lower cylinder seat, and the other end passes through the peripheral skirt seat connected to the seal, then through the skirt sealing gasket and is fixedly connected to the inner bladder. The connection point between the end of the flexible pipe fitting and the side wall of the lower bottom cylinder is located above the interlayer.

[0017] Beneficial Effects: One or more technical solutions provided in this invention have at least the following technical effects or advantages: 1. When there are insulation defects (such as bubbles or cracks) inside the cable joint, when partial discharge occurs at the defect under operating voltage, the high-frequency current sensor set on the upper housing unit can sensitively couple to the high-frequency electromagnetic field generated by the pulse current when the cable joint has insulation defects, and convert it into a measurable voltage signal and send it to the external main controller. Then, the GPS sensor sends the location information to the main controller, so that this invention can detect and locate insulation defects of distribution network cable joints under live operation, which helps to detect insulation defects of cable joints early, provide accurate location, effectively improve the efficiency of defect detection and handling, improve the reliability of power supply in the distribution network, and realize the transformation from the "traditional manual power outage test" post-repair to the "live digital inspection operation" pre-defect elimination method.

[0018] 2. The housing structure, formed by assembling the upper and lower housing units together, provides external protection for the cable insulation joint. At the same time, the housing structure also forms an electromagnetic shielding layer, which can effectively isolate various electromagnetic interferences (such as radio waves) from the external space of the cable. Furthermore, since external noise is shielded, the signal-to-noise ratio of the signal received by the high-frequency current sensor is high when insulation defects occur at the cable joint. This makes subsequent signal processing and analysis easier and more accurate, greatly reducing the probability of false alarms and missed alarms.

[0019] 3. After the housing structure, formed by assembling the upper housing unit and the lower housing unit, is installed outside the cable insulation joint, insulating gas (such as SF6) at a certain pressure is then injected into the housing through the air injection nozzle on the upper housing unit. The injected insulating gas not only helps maintain the electrical stability of the environment around the cable joint and the sensor probe, avoiding signal fluctuations caused by changes in air humidity, thus keeping the sensor's monitoring conditions in a relatively ideal state, but also ensures that the high-frequency components in the current pulse generated by partial discharge when insulation defects occur at the cable joint are attenuated less during their propagation to the sensor. This allows the high-frequency current sensor to capture a complete waveform that is closer to the original form of the discharge source, which helps improve the accuracy of detecting insulation defects at the cable joint.

[0020] 4. When the seals age due to prolonged use, their sealing performance deteriorates, causing leakage of insulating gas inside the housing structure formed by the upper and lower housing units. This affects the accuracy of cable joint defect detection. As the gas leaks, the air pressure in the lower connecting cavity, which is connected to the housing structure, gradually decreases. This causes the elastic diaphragm in the elastic barrier to gradually reset and drive the spiked rod assembly downward. When the groove on the side wall of the driven rod moves to align with the driven tip, the driven tip punctures the annular isolation membrane under the force of the second reset spring. This causes the gas to react with the liquid trigger medium layer and rapidly release a large amount of gas. After the gas passes through the waterproof and breathable membrane to filter out moisture, it is quickly filled into the embedded bladder through the flexible tubing. The expanded embedded bladder quickly seals the leakage point between the two skirt structures, thus preventing changes in the sensor's detection environment and ensuring accuracy.

[0021] 5. When the enlarged embedded bladder experiences gas leakage due to material aging, leading to a decrease in the sealing performance of the two skirt structural components, the insulating gas inside the shell structure formed by the assembly of the upper and lower shell units leaks, affecting the accuracy of cable joint defect detection. As the gas leaks, the air pressure in the lower connecting cavity, which is connected to the inside of the shell structure, gradually decreases. This causes the elastic diaphragm in the elastic barrier to gradually reset and drive the spiked rod assembly to move downward. During this process, the moving spiked rod assembly drives the dynamic spring in the dynamic switch section to contact the static ring terminal in the static switch section, thereby triggering the control circuit board to control the wireless signal transmitter to send out a wireless alarm signal, reminding staff to perform relevant maintenance and repair work in a timely manner to ensure the reliability of the power distribution network.

[0022] 6. When the embedded bladder leaks insulating gas due to material aging, causing a decrease in the electrical stability of the environment around the cable joint and sensor probe, the leakage of insulating gas causes the elastic diaphragm to further reset and drive the spiked rod assembly to move downward. During this process, the spiked part at the bottom of the spiked rod assembly punctures the sealing diaphragm and contacts the ground. Thus, when insulation defects occur and partial discharge occurs at the cable joint, the grounded spiked rod assembly can instantly and safely conduct these dangerous charges and currents to the ground. This ensures that when maintenance personnel approach or touch the shell structure formed by the upper and lower shell units assembled together, the shell structure always maintains ground potential, thereby effectively avoiding the risk of electric shock to maintenance personnel when repairing cables and improving operational safety. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0024] Figure 2 For the present invention Figure 1 A magnified view of part A in the diagram.

[0025] Figure 3 This is a bottom view of the overall structure of the present invention.

[0026] Figure 4 For the present invention Figure 3 A magnified view of part B in the diagram.

[0027] Figure 5 This is a schematic diagram of the internal structure of the pressure-sensitive module in this invention.

[0028] Figure 6 This is a bottom view of the internal structure of the pressure-sensitive module in this invention.

[0029] Figure 7 This is a partial structural diagram of the bottom following structure in this invention.

[0030] Figure 8 This is a cross-sectional view of the pressure-sensitive module in this invention.

[0031] Figure 9 For the present invention Figure 8 A magnified view of part C in the diagram.

[0032] Figure 10 This is a cross-sectional view of the pressure-sensitive module in this invention.

[0033] Figure 11 For the present invention Figure 10 A magnified view of part D in the middle.

[0034] Figure 12 For the present invention Figure 11 A magnified view of part E in the middle.

[0035] Figure 13 This is a schematic diagram of the skirt structure in this invention.

[0036] Figure 14 This is a bottom view of the overall structure of the skirt structure in this invention.

[0037] Explanation of the labels in the diagram: 101. Shielding housing; 102. End arc-shaped clamp; 103. Peripheral skirt; 104. Air inlet; 201. Side-mounted shielding shell; 202. Upper insulating cylinder base; 203. Lower bottom cylinder base; 204. Flexible tubing component; 205. Bottom sealing diaphragm; 206. Baffle plate; 207. Elastic diaphragm; 208. Rigid inner base; 209. Driven rod; 210. Interlayer section; 211. Flexible outer cover; 212. First bellows; 213. End-bottom spike; 214. Control circuit board; 215. Wireless signal transmitter; 216. Dynamic spring; 217. 218. Static annular terminal; 219. Guide inner rod; 220. Second bellows; 221. Pin rod; 222. Inner limit cover; 223. Liquid triggering medium layer; 224. Waterproof and breathable membrane; 225. Passive slide; 226. Driven tip; 227. Gas-generating particle layer; 228. Annular isolation membrane; 229. Annular sealing gasket; 230. Skirt sealing gasket; 231. Embedded bladder; 232. High-frequency current sensor; 233. GPS sensor. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0039] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0040] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or a link; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] Reference Figures 1 to 14This invention provides a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling, comprising an upper housing unit and a lower housing unit that are sleeved on the outside of the cable joint, arranged vertically and detachably assembled together, and a sensor for monitoring parameters at the cable joint is installed on the upper housing unit. Both the upper and lower housing units include skirt structures, and a sealing element is provided between the two skirt structures. The lower housing unit also includes a pressure-sensitive module. The pressure-sensitive module includes a side housing connected to the side wall of the lower housing unit. The side housing includes a partition mechanism disposed inside it. The partition structure divides the internal space of the side housing into an upper isolation cavity and a lower connecting cavity arranged vertically. The lower connecting cavity is connected to the interior of the lower housing unit. The side housing also includes an alarm structure and a bottom following structure respectively disposed on its top and bottom. The alarm structure includes a static switch part and a dynamic switch part. The bottom following structure includes a bottom sealing diaphragm 205 fixedly sealed at its bottom opening and a pin movably inserted into its side wall; The partition mechanism includes an elastic partition, on which a vertically arranged spiked bar assembly is provided. The top end of the spiked bar assembly extends into the alarm structure and is connected to the dynamic switch part, while the bottom spiked part penetrates into the lower bottom following structure and faces the bottom sealing diaphragm 205. The spiked rod assembly includes a slot structure located on its side wall into which a pin can be inserted. When the spiked rod assembly is in its initial state, the pin is inserted into the slot structure. At this time, the elastic barrier protrudes upward elastically, and the dynamic switch and the static switch do not contact each other.

[0042] Reference Figure 1 , Figure 3 , Figure 13 , Figure 14 The present invention provides a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling, wherein both the upper and lower housing units include a shielding cover 101. The upper housing unit also includes an air injection nozzle 104 fixedly connected to the side wall of the shielding housing 101. The air injection nozzle 104 is equipped with a one-way air inlet valve, and a cap is threaded onto the end opening of the air injection nozzle 104. The sensors include a high-frequency current sensor 231 and a GPS sensor 232. The high-frequency current sensor 231 is mounted on the shielding housing 101, and the detection end of the high-frequency current sensor 231 extends into the shielding housing 101 and faces the cable connector. The GPS sensor 232 is mounted on the outside of the shielding housing 101.

[0043] When insulation defects (such as bubbles or cracks) exist inside the cable joint, partial discharge will occur at the defect location under operating voltage. The high-frequency current sensor 231, installed on the upper housing unit, can sensitively couple to the high-frequency electromagnetic field generated by the pulse current when insulation defects occur in the cable joint, and convert it into a measurable voltage signal, which is sent to the external main controller. Then, the GPS sensor 232 sends the location information to the main controller. This invention enables the detection and location analysis of insulation defects in distribution network cable joints under energized operation, which helps to detect insulation defects in cable joints early, provide accurate location, effectively improve the efficiency of defect detection and handling, enhance the reliability of power supply in the distribution network, and realize the transformation from the "traditional manual power outage test" post-event repair to the "live digital inspection operation" pre-event defect elimination method.

[0044] The housing structure, formed by assembling the upper and lower housing units, provides external protection for the cable insulation joint. At the same time, the housing structure also forms an electromagnetic shielding layer, which can effectively isolate various electromagnetic interferences (such as radio waves) from the external space of the cable. Furthermore, because external noise is shielded, the signal-to-noise ratio of the signal received by the high-frequency current sensor 231 is high when an insulation defect occurs at the cable joint. This makes subsequent signal processing and analysis easier and more accurate, greatly reducing the probability of false alarms and missed alarms.

[0045] After the housing structure, formed by assembling the upper housing unit and the lower housing unit, is installed outside the cable insulation joint, a certain pressure of insulating gas (such as SF6) is then injected into the housing through the air injection nozzle 104 on the upper housing unit. The injected insulating gas not only helps maintain the electrical stability of the environment around the cable joint and the sensor probe, avoiding signal fluctuations caused by changes in air humidity, and keeping the sensor's monitoring conditions in a relatively ideal state, but also allows the high-frequency components in the current pulse generated by partial discharge when insulation defects occur at the cable joint to be attenuated less during propagation to the sensor. This enables the high-frequency current sensor 231 to capture a complete waveform that is closer to the original form of the discharge source, which helps improve the accuracy of detecting insulation defects in cable joints.

[0046] Reference Figure 13 and Figure 14 This invention provides a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling. The skirt structure includes an end arc-shaped clamp 102 integrally formed at the openings at both ends of a shielding shell 101 and a peripheral skirt 103 integrally formed on the periphery of the side wall of the shielding shell 101. The shielding shell 101 and the peripheral skirt 103 are also integrally formed. The shielding shell 101, the end arc-shaped clamp 102, and the peripheral skirt 103 are all made of insulating material.

[0047] Reference Figure 13 and Figure 14 The present invention provides a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling, wherein the sealing element includes a skirt sealing gasket 229 and four annular sealing gaskets 228. Furthermore, two of the annular sealing gaskets 228 are integrally formed on the front and rear ends of the skirt sealing gasket 229; The skirt edge sealing gasket 229 is connected to one of the peripheral skirt supports 103; Four annular sealing gaskets 228 are respectively connected to the interior of the four end arc-shaped clamps 102.

[0048] Reference Figures 1 to 6 , Figures 8 to 10 The present invention provides a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling, wherein the side housing includes a side shielding shell 201 connected to the side wall of the shielding shell 101; The partition mechanism includes a baffle 206 connected inside the side shielding shell 201, and the baffle 206 divides the internal space of the side shielding shell 201 into an upper isolation cavity and a lower connecting cavity arranged vertically, and the lower connecting cavity is connected to the inside of the shielding cover 101. The elastic barrier includes a rigid inner seat 208, an elastic diaphragm 207 is fixedly fitted around the outer periphery of the rigid inner seat 208, and a first return spring is provided on the top of the rigid inner seat 208. The baffle plate 206 has a through groove adapted to the elastic diaphragm 207, and the outer ring wall of the elastic diaphragm 207 is fixedly connected to the through groove.

[0049] Reference Figures 8 to 10 The present invention provides a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling. The spiked rod assembly includes a driven rod 209 that is inserted and fixed on a rigid inner socket 208. A guide rod 218 is movably inserted into the opening at the top of the movable rod 209; The bottom end of the moving rod 209 is provided with a bottom spike 213; The slot structure is a pin slot set on the side wall of the driven rod 209.

[0050] Reference Figure 8 and Figure 9 This invention provides a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling. The alarm structure also includes an upper insulating cylinder seat 202 connected to the top of the side shield shell 201 and internally connected to the upper isolation cavity. The bottom end of the first reset spring is connected to the rigid inner seat 208, and the top end is connected to the bottom end of the upper insulating cylinder seat 202. The static switch unit includes a static ring terminal 217 and a control circuit board 214 connected inside the upper insulating cylinder base 202. A wireless signal transmitter 215 is connected to the control circuit board 214. The static ring terminal 217 is fixedly connected to the bottom opening of the upper insulating cylinder base 202. The dynamic switch unit includes a dynamic spring 216; The top end of the guide inner rod 218 passes through the bottom opening of the upper insulating cylinder seat 202 and is fixedly connected to the top wall of the inner cavity of the upper insulating cylinder seat 202. The moving rod 209 passes through the opening at the bottom of the upper insulating cylinder seat 202 from the top and connects with the dynamic spring piece 216. When the dynamic spring 216 contacts the static ring terminal 217, the trigger control circuit board 214 controls the wireless signal transmitter 215 to turn on, and then the wireless signal transmitter 215 sends a wireless alarm signal to the external main controller. The main controller mentioned in this article is a common existing technology such as a computer that plays a control role, and will not be described in detail here.

[0051] Reference Figure 8 and Figure 10 This invention provides a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling. The lower bottom following structure includes a lower bottom cylinder seat 203 connected to the bottom of the side shielding shell 201 and internally connected to the lower connecting cavity. The side shielding shell 201, the upper insulating cylinder seat 202, and the lower bottom cylinder seat 203 are all made of insulating material. The side shielding shell 201, the upper insulating cylinder seat 202, and the lower bottom cylinder seat 203 can also shield and isolate various electromagnetic interferences from the external space outside the shell structure formed by assembling the upper shell unit and the lower shell unit. A first bellows 212 is connected to the top opening of the bottom cylinder seat 203, and an inner limit cover 221 is connected inside the top opening of the first bellows 212. The top opening of the inner limit cover 221 is sleeved and fixed to the outer periphery of the driven rod 209; The bottom sealing film 205 is fixedly sealed at the bottom opening of the bottom sealing film 205, and the bottom spike 213 faces the bottom sealing film 205; The pin part includes a pin rod 220 that is slidably inserted into the side wall of the lower bottom cylinder seat 203. One end of the pin rod 220 extends into the interior of the lower bottom cylinder seat 203, and the other end extends out from the side wall of the lower bottom cylinder seat 203 and is connected to a flexible outer cover 211. The outer edge of the flexible outer cover 211 is fixedly connected to the side wall of the lower bottom cylinder seat 203. When the spiked rod assembly is in its initial state, the pin 220 in the pin part is inserted into the pin groove in the slot structure. At this time, the elastic diaphragm 207 in the elastic barrier protrudes upward elastically, and the dynamic spring 216 in the dynamic switch part and the static annular terminal 217 in the static switch part do not contact each other.

[0052] After the insulating gas (such as SF6) at a certain pressure is injected into the housing through the air injection nozzle 104 on the upper housing unit, the operator then pulls out the pin 220 that was originally inserted in the slot structure. Subsequently, the elastic diaphragm 207 bulges upward under the action of air pressure and drives the driven rod 209 in the spike rod assembly to move upward. At this time, the dynamic spring 216 in the dynamic switch section and the static ring terminal 217 in the static switch section do not contact each other.

[0053] Reference Figures 8 to 14 The present invention provides a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling. The lower bottom following structure also includes a flexible pipe component 204 and an interlayer portion 210 connected inside the lower bottom cylinder seat 203, wherein the flexible pipe component 204 is a flexible pipe. The top and bottom openings of the interlayer 210 are both connected to a second corrugated pipe 219; The top of the interlayer 210 has several reserved openings, and each reserved opening is connected to a waterproof and breathable membrane 223. The interlayer 210 is filled with a liquid triggering medium layer 222. A passive slide 224 is also slidable inside the interlayer 210. A second return spring is connected to one side of the passive slide 224, and the end of the second return spring away from the passive slide 224 is connected to the inner wall of the interlayer 210. The liquid triggering medium layer 222 is a liquid layer formed by liquid water. A driven tip 225 is connected to the other side of the passive slide 224; The driven rod 209 passes through the center opening of the interlayer 210 from the bottom end, and the opposite ends of the two second corrugated pipes 219 are both sleeved and fixed to the outer periphery of the side wall of the driven rod 209. The driven rod 209 has a groove on the side wall of the part inside the second bellows 219 located on the upper side. The opening of the groove is sealed with an annular isolation membrane 227. The groove is filled with a gas-generating particle layer 226 that works in conjunction with the liquid triggering medium layer 222. The gas-generating particle layer 226 is made of an effervescent disintegrant. When the spiked rod assembly is in its initial state and the pin 220 in the pin part is inserted into the pin groove in the slot structure, the groove is located above the liquid trigger medium layer 222, and at this time, under the elastic force of the second reset spring, the driven tip 225 elastically abuts against the side wall of the driven rod 209.

[0054] Reference Figure 3 , Figure 8 , Figure 13 as well as Figure 14 The present invention provides a digital device for live detection of insulation defects in distribution network cable joints based on electromagnetic coupling. The skirt sealing gasket 229 and the two annular sealing gaskets 228 integrally formed with the front and rear ends of the skirt sealing gasket 229 are provided with recessed grooves, and the recessed grooves on the skirt sealing gasket 229 and the recessed grooves on the two annular sealing gaskets 228 are connected to an embedded bladder 230. One end of the flexible tubing component 204 is fixedly connected to the side wall of the lower bottom cylinder seat 203, and the other end passes through the peripheral skirt seat 103 connected to the seal, then through the skirt sealing gasket 229 and is fixedly connected to the inner bladder 230. The connection point between the end of the flexible pipe component 204 and the side wall of the lower bottom cylinder seat 203 is located above the interlayer 210.

[0055] When the seal ages due to prolonged use, its sealing performance deteriorates, causing leakage of insulating gas inside the housing structure formed by the upper and lower housing units. This affects the accuracy of cable joint defect detection. As the gas leaks, the air pressure in the lower connecting cavity, which is connected to the inside of the housing structure, gradually decreases. This causes the elastic diaphragm 207 in the elastic barrier to gradually reset and drive the spiked rod assembly to move downwards. When the groove on the side wall of the driven rod 209 moves to the position of the driven rod... When the moving tip 225 is aligned, under the action of the second reset spring, the driven tip 225 punctures the annular isolation membrane 227, causing 226 to come into contact with the liquid trigger medium layer 222 and react, rapidly releasing a large amount of gas. After the gas passes through the waterproof and breathable membrane 223 to filter out moisture, it is then quickly filled into the inner bladder 230 by the flexible tubing component 204. The expanded inner bladder 230 quickly seals the leakage point between the two skirt structures, thereby preventing the sensor's detection environment from changing and affecting the detection accuracy.

[0056] When the enlarged embedded bladder 230 leaks gas due to material aging, the sealing performance of the two skirt structures decreases, causing the insulating gas inside the shell structure formed by the upper and lower shell units to leak. This affects the accuracy of cable joint defect detection. As the gas leaks, the air pressure in the lower connecting cavity connected to the inside of the shell structure gradually decreases. This causes the elastic diaphragm 207 in the elastic barrier to gradually reset and drive the spiked rod assembly to move downward. During this process, the movable spiked rod assembly drives the dynamic spring 216 in the dynamic switch section to contact the static ring terminal 217 in the static switch section, thereby triggering the control circuit board 214 to control the wireless signal transmitter 215 to send out a wireless alarm signal, reminding staff to perform relevant maintenance and repair work in a timely manner to ensure the reliability of power supply in the power distribution network.

[0057] When the embedded bladder 230 leaks insulating gas due to material aging, causing a decrease in the electrical stability of the environment around the cable joint and sensor probe, the leakage of insulating gas causes the elastic diaphragm 207 to further reset and drive the spiked rod assembly to move downward. During this process, the end spikes 213 in the spiked rod assembly pierce the sealing diaphragm 205 and contact the ground. Thus, when insulation defects occur and partial discharge occurs at the cable joint, the grounded spiked rod assembly can instantly and safely conduct these dangerous charges and currents to the ground. This ensures that when maintenance personnel approach or touch the housing structure formed by the upper housing unit and the lower housing unit assembled together, the housing structure always maintains the ground potential, thereby effectively avoiding the risk of electric shock to maintenance personnel when repairing cables and improving operational safety.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A digital device for live-line detection of insulation defects in distribution network cable joints based on electromagnetic coupling, characterized in that: It includes an upper housing unit and a lower housing unit that are fitted over the cable joint, arranged vertically, and detachably assembled together. The upper housing unit is equipped with a sensor for monitoring parameters at the cable joint. Both the upper and lower housing units include skirt structures, and a sealing element is provided between the two skirt structures. The lower housing unit also includes a pressure-sensitive module. The pressure-sensitive module includes a side shell component connected to the side wall of the lower shell unit. The side shell component includes a partition mechanism disposed inside it. The partition structure divides the internal space of the side shell component into an upper isolation cavity and a lower connecting cavity arranged vertically. The lower connecting cavity is connected to the interior of the lower shell unit. The side housing also includes an alarm structure and a bottom following structure respectively disposed on its top and bottom, wherein the alarm structure includes a static switch part and a dynamic switch part; The bottom following structure includes a bottom sealing film (205) fixedly sealed at its bottom opening and a pin movably inserted into its side wall; The partition mechanism includes an elastic partition, on which a vertically arranged spiked rod assembly is provided. The top end of the spiked rod assembly extends into the alarm structure and is connected to the dynamic switch part, while the bottom spiked part penetrates into the lower bottom following structure and faces the bottom sealing diaphragm (205). The spiked rod assembly includes a slot structure located on its side wall into which a pin can be inserted. When the spiked rod assembly is in its initial state, the pin is inserted into the slot structure. At this time, the elastic barrier protrudes upward elastically, and the dynamic switch and the static switch do not contact each other.

2. The digital device for live-line detection of insulation defects in distribution network cable joints based on electromagnetic coupling according to claim 1, characterized in that: The upper and lower housing units also include a shielding cover (101). The upper housing unit also includes an air injection nozzle (104) fixedly connected to the side wall of the shielding cover (101). The air injection nozzle (104) is provided with a one-way air inlet valve, and a cap is threadedly fitted at the end opening of the air injection nozzle (104). The sensors include a high-frequency current sensor (231) and a GPS sensor (232). The high-frequency current sensor (231) is mounted on the shielding housing (101), and the detection end of the high-frequency current sensor (231) extends into the shielding housing (101) and faces the cable connector. The GPS sensor (232) is mounted on the outside of the shielding housing (101).

3. The digital device for live-line detection of insulation defects in distribution network cable joints based on electromagnetic coupling according to claim 2, characterized in that: The skirt structure includes an end arc-shaped hoop (102) integrally formed at the openings at both ends of the shielding shell (101) and a peripheral skirt seat (103) integrally formed on the periphery of the side wall of the shielding shell (101), and the shielding shell (101) and the peripheral skirt seat (103) are also integrally formed.

4. The digital device for live-line detection of insulation defects in distribution network cable joints based on electromagnetic coupling according to claim 3, characterized in that: The seal includes a skirt gasket (229) and four annular gaskets (228); Furthermore, two of the annular sealing gaskets (228) are integrally formed on the front and rear ends of the skirt sealing gasket (229); The skirt edge sealing gasket (229) is connected to one of the peripheral skirt supports (103); The four annular sealing gaskets (228) are respectively connected to the interior of the four end arc-shaped clamps (102).

5. The digital device for live-line detection of insulation defects in distribution network cable joints based on electromagnetic coupling according to claim 4, characterized in that: The side housing includes a side-mounted shielding shell (201) connected to the side wall of the shielding shell (101). The partition mechanism includes a partition (206) connected inside the side shielding shell (201), and the partition (206) divides the internal space of the side shielding shell (201) into an upper isolation cavity and a lower connecting cavity arranged vertically, and the lower connecting cavity is connected to the inside of the shielding cover (101). The elastic barrier includes a rigid inner seat (208), on which an elastic diaphragm (207) is fixedly sleeved and fixedly fitted, and a first return spring is provided on the top of the rigid inner seat (208). The baffle plate (206) has a through groove adapted to the elastic diaphragm (207), and the outer ring wall of the elastic diaphragm (207) is fixedly connected to the through groove.

6. The digital device for live-line detection of insulation defects in distribution network cable joints based on electromagnetic coupling according to claim 5, characterized in that: The spiked rod assembly includes a driven rod (209) that is inserted and fixed to a rigid inner socket (208). A guide rod (218) is inserted into the opening at the top of the moving rod (209). The driven rod (209) has a bottom spike (213) at its bottom end. The slot structure is a pin slot provided on the side wall of the driven rod (209).

7. The digital device for live-line detection of insulation defects in distribution network cable joints based on electromagnetic coupling according to claim 6, characterized in that: The alarm structure also includes an upper insulating cylinder seat (202) connected to the top of the side shield shell (201) and internally connected to the upper isolation cavity, and the bottom end of the first reset spring is connected to the rigid inner seat (208), while the top end is connected to the bottom end of the upper insulating cylinder seat (202). The static switch unit includes a static ring terminal (217) and a control circuit board (214) connected inside the upper insulating cylinder base (202). A wireless signal transmitter (215) is connected to the control circuit board (214). The static ring terminal (217) is fixedly connected to the bottom opening of the upper insulating cylinder base (202). The dynamic switch includes a dynamic spring (216). The top end of the guide inner rod (218) passes through the bottom opening of the upper insulating cylinder seat (202) and is fixedly connected to the top wall of the inner cavity of the upper insulating cylinder seat (202); The top of the driven rod (209) passes through the bottom opening of the upper insulating cylinder seat (202) and is connected to the dynamic spring sheet (216); When the dynamic spring (216) contacts the static ring terminal (217), the trigger control circuit board (214) controls the wireless signal transmitter (215) to turn on, and then the wireless signal transmitter (215) sends out a wireless alarm signal.

8. The digital device for live-line detection of insulation defects in distribution network cable joints based on electromagnetic coupling according to claim 7, characterized in that: The lower bottom following structure includes a lower bottom cylinder seat (203) connected to the bottom of the side shield shell (201) and internally connected to the lower connecting cavity. The bottom cylinder seat (203) is connected to the top opening of the first corrugated pipe (212), and the top opening of the first corrugated pipe (212) is connected to the inner limiting cover (221). The top opening of the inner limiting cover (221) is sleeved and fixed to the outer periphery of the driven rod (209); The bottom sealing film (205) is fixedly sealed at the bottom opening of the bottom sealing film (205), and the bottom spike (213) faces the bottom sealing film (205). The pin part includes a pin rod (220) that is slidably inserted into the side wall of the lower bottom cylinder seat (203). One end of the pin rod (220) extends into the interior of the lower bottom cylinder seat (203), and the other end extends out from the side wall of the lower bottom cylinder seat (203) and is connected to a flexible outer cover (211). The outer edge of the flexible outer cover (211) is fixedly connected to the side wall of the lower bottom cylinder seat (203). When the spiked rod assembly is in the initial state, the pin rod (220) in the pin part is inserted into the pin groove in the slot structure. At this time, the elastic diaphragm (207) in the elastic barrier protrudes upward elastically, and the dynamic spring piece (216) in the dynamic switch part and the static ring terminal (217) in the static switch part do not contact each other.

9. The digital device for live-line detection of insulation defects in distribution network cable joints based on electromagnetic coupling according to claim 8, characterized in that: The lower bottom following structure also includes a flexible tubing component (204) and a sandwich section (210) connected to the interior of the lower bottom cylinder (203). The top and bottom openings of the interlayer (210) are connected to a second corrugated pipe (219). The top of the interlayer (210) has several reserved openings, and each reserved opening is connected to a waterproof and breathable membrane (223). The interlayer (210) is filled with a liquid triggering medium layer (222), and a passive slide (224) slides inside the interlayer (210). A second reset spring is connected to one side of the passive slide (224), and the end of the second reset spring away from the passive slide (224) is connected to the inner wall of the interlayer (210). A driven tip (225) is connected to the other side of the passive slide (224); The bottom end of the driven rod (209) passes through the central opening of the interlayer (210), and the opposite ends of the two second corrugated pipes (219) are both sleeved and fixed to the outer periphery of the side wall of the driven rod (209); The driven rod (209) has a groove on the side wall of the part inside the second bellows (219) located on the upper side. The opening of the groove is sealed with an annular isolation membrane (227). The groove is filled with a gas-generating particle layer (226) that works in conjunction with the liquid triggering medium layer (222). When the spiked rod assembly is in its initial state and the pin rod (220) in the pin part is inserted into the pin groove in the slot structure, the groove is located above the liquid trigger medium layer (222), and at this time, under the elastic force of the second reset spring, the driven tip (225) elastically abuts against the side wall of the driven rod (209).

10. The digital device for live-line detection of insulation defects in distribution network cable joints based on electromagnetic coupling according to claim 9, characterized in that: The skirt sealing gasket (229) and the two annular sealing gaskets (228) integrally formed with the front and rear ends of the skirt sealing gasket (229) are provided with recessed grooves, and the recessed grooves on the skirt sealing gasket (229) and the recessed grooves on the two annular sealing gaskets (228) are connected to an embedded bladder (230). One end of the flexible tubing component (204) is fixedly connected to the side wall of the lower bottom cylinder seat (203), and the other end passes through the peripheral skirt seat (103) connected to the seal, then passes through the skirt sealing gasket (229) and is fixedly connected to the inner bladder (230). The connection point between the end of the flexible pipe component (204) and the side wall of the lower bottom cylinder seat (203) is located above the interlayer (210).

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