Distribution cable joint state detection device and method

Abstract

The invention relates to the technical field of cable online detection, in particular to a distribution cable joint state detection device and method. Comprising a detection module, the detection module comprises a reader antenna and a control acquisition unit, and the control acquisition unit is configured to control radio frequency energy supply parameters of the reader antenna; the sensing module is mounted outside the cable joint and comprises a radio frequency antenna, a radio frequency-direct current conversion circuit, a power management unit and a sensor group; wherein the radio frequency antenna is connected with the radio frequency-direct current conversion circuit and is used for receiving electromagnetic waves emitted by a reader antenna and converting the electromagnetic waves into electric energy; the power management unit is connected with the radio frequency-direct current conversion circuit and is configured to activate the detection tags in the sensor group in stages according to the energy storage voltage; the detection labels of the sensor group are connected to the corresponding energy storage units based on different voltage requirements, and communicate with the detection module through the radio frequency antenna. The state detection of the cable joint in a battery-free state is realized, and the operation safety level and the emergency disposal capability of a power distribution cable network are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of on-line cable detection, and particularly relates to a device and method for detecting the state of a distribution cable joint. Background Art

[0002] Power cables are laid underground with multiple insulation layers, and the state observability is poor. Internal hidden dangers left by improper product quality and installation technology are difficult to be discovered and investigated in time. Years of operation experience of distribution cables shows that some common latent hidden dangers include: water ingress and moisture absorption, impurities mixed in accessories, internal mechanical stress injuries in the body, cracking of the metal shielding layer, scratches on the outer sheath, incorrect installation dimensions of joints, insufficient clamping force at the joint interface, etc. After these hidden dangers accumulate and develop to a certain extent, they will quickly cause cable failures, mainly characterized by breakdown, and in special cases, they will also cause combustion and explosion, especially for cable joints.

[0003] Cables with water ingress and insulation defects are easily developed into defects and expanded to cause failures quickly under the excitation of reasons such as partial discharge or overvoltage. Moreover, the failures often occur repeatedly on the same line, resulting in most cables unable to reach their designed service life. At present, research has been carried out on the detection devices for the state of high-voltage cable joints at home and abroad. Related detection technologies such as infrared imaging, partial discharge detection, sheath current and other on-line detection technologies are difficult to be effectively applied to distribution cables. The main reason is that distribution cables are mostly laid by direct burial, pipe laying, trench and other methods. Due to the lack of power supply lines in the old cable channels where distribution cables are laid, it is difficult to meet the existing on-line detection technologies.

[0004] Therefore, the prior art mostly adopts passive protection measures to solve cable hidden danger problems, such as installing fireproof / explosion-proof plugs, etc., and it is difficult to detect early latent defects in intermediate joints. There is still no effective solution to the insulation defect problems caused by water ingress and installation technology of cable joints after the distribution cables are put into operation, lacking source and systematic technical solutions, and the ability to discover and dispose of hidden dangers in time is insufficient. Summary of the Invention

[0005] In view of this, the embodiments of the present application provide a device and method for detecting the state of a distribution cable joint to solve the problems that it is difficult for the prior art to detect early latent defects in intermediate joints, there is still no effective solution to the insulation defect problems caused by water ingress and installation technology of cable joints after the distribution cables are put into operation, lacking source and systematic technical solutions, and the ability to discover and dispose of hidden dangers in time is insufficient.

[0006] The first aspect of the embodiments of the present application provides a device for detecting the state of a distribution cable joint, including:

[0007] A detection module, including a reader antenna and a control and acquisition unit, where the control and acquisition unit is configured to control the radio frequency power supply parameters of the reader antenna;

[0008] A sensing module, installed outside the cable joint, includes a radio frequency antenna, a radio frequency - direct current conversion circuit, a power management unit, and a sensor group; wherein:

[0009] The radio frequency antenna is connected to the radio frequency - direct current conversion circuit and is used to receive the electromagnetic wave emitted by the reader antenna and convert it into electrical energy;

[0010] The power management unit is connected to the radio frequency - direct current conversion circuit and is configured to activate the detection tags in the sensor group in stages according to the energy storage voltage;

[0011] The detection tags of the sensor group are connected to the corresponding energy storage units based on different voltage requirements and communicate with the detection module through the radio frequency antenna.

[0012] The second aspect of the embodiments of the present application provides a method for detecting the state of a distribution cable joint, including:

[0013] Transmitting a radio frequency energy signal to the sensing module through the reader antenna of the detection module;

[0014] The sensing module receives the radio frequency energy signal and converts it into electrical energy for storage in the energy storage unit;

[0015] Activating at least one type of detection tag in the sensor group in stages according to the voltage level of the energy storage unit for data collection;

[0016] Transmitting the collected sensor data back to the detection module and generating an alarm signal according to a preset rule.

[0017] The power distribution cable joint status detection device provided in the first aspect of the embodiments of the present application includes a detection module, which includes a reader antenna and a control and acquisition unit. The control and acquisition unit is configured to control the radio frequency power supply parameters of the reader antenna; a sensing module is installed outside the cable joint and includes a radio frequency antenna, a radio frequency - direct current conversion circuit, a power management unit, and a sensor group. Among them: the radio frequency antenna is connected to the radio frequency - direct current conversion circuit and is used to receive the electromagnetic wave emitted by the reader antenna and convert it into electrical energy; the power management unit is connected to the radio frequency - direct current conversion circuit and is configured to activate the detection tags in the sensor group in stages according to the energy storage voltage; the detection tags of the sensor group are connected to the corresponding energy storage units based on different voltage requirements and communicate with the detection module through the radio frequency antenna. By driving the sensing module through the radio frequency power supply of the detection module and using the power management unit to activate sensors with different voltage requirements in stages according to the energy storage voltage, the cable joint status detection under the battery - free state is realized. The device is installed outside the power distribution cable joint and does not affect the electric field distribution. The sensing module gets rid of the dependence on traditional power wiring through radio frequency energy harvesting technology, is particularly suitable for scenarios with difficult power supply such as underground cable trenches, and significantly improves the deployment flexibility of the device. The staged activation mechanism, according to the working voltage differences of the sensors, preferentially starts the low - voltage sensors and then activates the high - voltage sensors when the energy storage is sufficient. This not only avoids the instantaneous high power consumption problem when multiple sensors work simultaneously but also optimizes the detection timing through distributed sensing, reduces signal crosstalk, and ensures the high - precision acquisition of detection data.

[0018] It can be understood that the beneficial effects of the second aspect above can be referred to the relevant descriptions in the first aspect above and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1 is a connection schematic diagram of the power distribution cable joint status detection device provided by an embodiment of the present application;

[0021] Figure 2 is a structural schematic diagram of the sensing module provided by another embodiment of the present application;

[0022] Figure 3 is a structural schematic diagram of the sensing module provided by another embodiment of the present application;

[0023] Figure 4It is a schematic connection diagram of a sensing module and a cable joint provided by an embodiment of the present application;

[0024] Figure 5 It is a schematic flowchart of a method for detecting the state of a distribution cable joint provided by an embodiment of the present application. Specific embodiments

[0025] In the following description, for the purpose of illustration rather than limitation, specific details such as specific system architectures and technologies are presented in order to thoroughly understand the embodiments of the present application. However, those skilled in the art should clearly understand that the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details from interfering with the description of the present application.

[0026] It should be understood that when used in the specification of the present application and the appended claims, the term "comprising" indicates the presence of the described features, wholes, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0027] It should also be understood that the term "and / or" used in the specification of the present application and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0028] In addition, in the description of the specification of the present application and the appended claims, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0029] The reference to "an embodiment" or "some embodiments" etc. described in the specification of the present application means that a specific feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, the statements "in an embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in another way. The terms "comprising", "including", "having", and their variants all mean "including but not limited to", unless otherwise specifically emphasized in another way.

[0030] As Figure 1 shown, a device for detecting the state of a distribution cable joint provided by an embodiment of the present application includes:

[0031] The detection module 100 includes a reader antenna 102 and a control and acquisition unit 103. The control and acquisition unit 103 is configured to control the radio frequency power supply parameters of the reader antenna 102.

[0032] The sensing module 200 is installed outside the cable joint and includes a radio frequency antenna 201, a radio frequency - direct current conversion circuit 202 (i.e., RF - DC circuit), a power management unit 203, and a sensor group 207. Among them:

[0033] The radio frequency antenna 201 is connected to the radio frequency - direct current conversion circuit 202 and is used to receive the electromagnetic wave emitted by the reader antenna 102 and convert it into electrical energy.

[0034] The power management unit 203 is connected to the radio frequency - direct current conversion circuit 202 and is configured to activate the detection tags in the sensor group 207 in stages according to the energy storage voltage.

[0035] The detection tags of the sensor group 207 are connected to the corresponding energy storage units based on different voltage requirements and communicate with the detection module 100 through the radio frequency antenna 201.

[0036] In application, the detection module can be hung on the channel wall to obtain monitoring data in real - time, or can be held for live detection. The sensing module is fixedly installed outside the cable joint. The power supply consists of a high - power battery pack, which supplies power to the reader antenna, the control and acquisition unit, and the display and alarm unit. The reader antenna provides energy for the radio frequency antenna in the sensing module. The control and acquisition unit controls the power supply time and energy of the reader antenna, and the display and alarm unit displays the signals acquired by the control and acquisition unit.

[0037] In the application, in the sensing module: The RF antenna captures electromagnetic waves in a specific frequency band in space and converts them into high-frequency alternating current. The RF-DC voltage multiplier rectification circuit converts this small-amplitude high-frequency alternating current into a DC signal. The first-stage energy storage unit stores the DC electrical energy output by the RF-DC circuit. The power management unit detects the energy on the first-stage energy storage unit. When it reaches W1, the power management unit controls the switch to close, and boosts the output voltage to W2 through the step-up and voltage-stabilizing circuit and stores it in the second-stage energy storage unit. The sensors include a moisture detection tag, a partial discharge detection tag, a vibration detection tag, and a temperature detection tag. The moisture detection tag has a working voltage of V1 and a working current of I1. The temperature detection tag has a working voltage of V2 and a working current of I2. The partial discharge detection tag has a working voltage of V3 and a working current of I3. The vibration detection tag has a working voltage of V4 and a working current of I4. Typically, V1 = V2 and V3 = V4. When the power management unit confirms that the voltage for each detection tag to work is met, the sensor performs a status signal detection and transmits the sensed status signal back to the detection module in numerical form through the RF antenna. The reader antenna in the detection module receives the status signal and performs data display and alarm through the display and alarm unit.

[0038] The embodiment of the present application integrates the RF energy harvesting technology into the design of the sensor to solve the power supply problem of the sensor node. The sensing module is driven by the RF power supply of the detection module. The power management unit activates sensors with different voltage requirements in stages according to the energy storage voltage, realizing the detection of the cable joint status in a battery-free state. The device is installed outside the distribution cable joint without affecting the electric field distribution. The sensing module gets rid of the dependence on traditional power wiring through the RF energy harvesting technology, and is particularly suitable for scenarios with difficult power supply such as underground cable trenches, significantly improving the deployment flexibility of the device. The staged activation mechanism, based on the working voltage differences of the sensors, preferentially starts the low-voltage sensors and then activates the high-voltage sensors when the energy storage is sufficient. This not only avoids the instantaneous high power consumption problem of multiple sensors working simultaneously, but also optimizes the detection timing through distributed sensing, reduces signal crosstalk, and ensures the high-precision acquisition of detection data.

[0039] In one embodiment, the sensing module 200 further includes:

[0040] The first-stage energy storage unit 205 and the second-stage energy storage unit 206, the output end of the RF-DC conversion circuit 202 is connected to the first-stage energy storage unit 205;

[0041] The switch unit 208, connected between the RF-DC conversion circuit 202 and the step-up and voltage-stabilizing circuit 204, and the controlled end of the switch unit 208 is connected to the power management unit 203;

[0042] The step-up and voltage-stabilizing circuit 204, with the input end connected to the switch unit 208 and the output end connected to the second-stage energy storage unit 206;

[0043] The power management unit 203 is configured to monitor the voltage of the first-stage energy storage unit 205. When the voltage reaches the first threshold, it controls the switch unit 208 to close, triggering the boost voltage regulator circuit 204 to supply power to the second-stage energy storage unit 206, and triggering the detection label corresponding to the first-stage energy storage unit 205 to start detection when the voltage of the first-stage energy storage unit 205 reaches the first threshold, or triggering the detection label corresponding to the second-stage energy storage unit 206 to start detection when the voltage of the second-stage energy storage unit 206 reaches the second threshold.

[0044] In the embodiment of the present application, by setting the first-stage energy storage unit and the second-stage energy storage unit, and cooperating with the cascaded control of the boost voltage regulator circuit and the switch unit, the precise power supply adaptation for high- and low-voltage sensors is realized. The temperature and moisture detection labels with low voltage requirements are directly powered by the first-stage energy storage, avoiding the energy consumption loss of the traditional buck circuit; the vibration and partial discharge detection labels with high voltage requirements obtain a stable power supply through the boost circuit, ensuring the signal-to-noise ratio of high-frequency signal acquisition. The intelligent closing control of the switch unit only starts the boost circuit when the energy storage is sufficient, preventing the energy waste caused by the no-load operation of the boost circuit. At the same time, the cascaded trigger logic ensures that the high-power sensors only start after sufficient power supply, avoiding data loss or sensor reset caused by sudden power drop during the detection process.

[0045] In one embodiment, the detection module 100 further includes a power supply 101 and a display and alarm unit 104. The power supply 101 supplies power to the reader antenna 102 and the control and acquisition unit 103, and the display and alarm unit 104 is connected to the control and acquisition unit 103 for displaying sensor data and outputting an alarm signal.

[0046] In the embodiment of the present application, by integrating the power supply and the display and alarm unit in the detection module, the device is provided with the capabilities of portable detection and real-time feedback. The built-in power supply supports independent operation without external power supply in the handheld mode, meeting the mobile inspection requirements in complex environments, especially suitable for scenarios where external power supply cannot be connected in old cable trenches. The display and alarm unit significantly shortens the fault diagnosis time through real-time display of sensor data and acoustic and optical prompts. The maintenance personnel can quickly locate the problem joints without relying on additional equipment. The optimized design of the human-machine interface reduces the operation threshold, and the direct association between the alarm signal and the specific sensor data improves the pertinence and efficiency of emergency handling.

[0047] In one embodiment, the sensor group 207 includes:

[0048] A temperature detection label 2071 and a moisture detection label 2072, connected to the first-stage energy storage unit 205;

[0049] A vibration detection label 2073 and a partial discharge detection label 2074, connected to the second-stage energy storage unit 206.

[0050] In the embodiment of the present application, the sensor group is grouped and connected to different energy storage units according to voltage requirements, achieving an accurate match between power consumption characteristics and energy supply strategies. The low-power temperature and moisture detection tags are directly driven by the low-voltage energy storage unit, simplifying the power supply path and reducing circuit losses; the high-power vibration and partial discharge detection tags are powered by the high-voltage energy storage unit to ensure the stability of their operating voltage. The grouped power supply mechanism avoids the influence of the power supply voltage fluctuation of the low-power sensors when the high-power sensors are started through the voltage grading design at the hardware level, ensuring the stability of the synchronous acquisition of multi-sensor data. This design reduces the overall power demand of the RF power supply system while improving the reliability of the collaborative work of the sensors.

[0051] In one embodiment, as Figures 2 to 4 shown, the sensing module 200 includes a sensing device housing 200a and a strap-type mounting structure 200b connected to the sensing device housing. The RF-DC conversion circuit 202, the power management unit 203, the boost voltage regulator circuit 204, the first-stage energy storage unit 205, and the second-stage energy storage unit 206 are disposed in the sensing device housing, and the RF antenna 201 is disposed on the sensing device housing. The cable connector 300 is used to connect the cable 400. The sensing module 200 is mounted outside the cable connector 300 through the strap-type mounting structure. The partial discharge detection tag 2074 is disposed on the inner side surface of the strap-type mounting structure and circumferentially wraps the cable connector to be measured. The temperature detection tag 2071 and the moisture detection tag 2072 are attached to the surface of the sensing device housing, and the vibration detection tag 2073 is embedded inside the sensing device housing.

[0052] In application, combined with the structure of the intermediate joint cylinder, a strap-type mounting structure is designed, and the surface of the partial discharge test electrode is coated with a silicone rubber material to improve the environmental adaptability of the sensor. The temperature detection tag and the moisture detection tag are both directly pasted on the outer shell of the sensing device. The inner side surface of the partial discharge detection tag wraps around the circumference of the joint to be measured, and the outer side surface is closely attached to the silicone rubber strap and the outer shell of the sensing device. The partial discharge detection tag has a thickness of 2 - 3 mm. Therefore, a groove with a depth of 2 - 3 mm is provided at the corresponding position of the bottom of the sensing device housing for embedding the partial discharge detection tag into the groove of the sensing device housing. The vibration detection tag has a thickness of 2 mm and is also embedded inside the sensing device housing. The data detected by each tag of the sensing module 200 is transmitted back through the RF antenna.

[0053] In the embodiment of the present application, the sensing module is tightly wrapped around the cable joint through a strap-type mounting structure. Combining with the circumferential distribution design of the partial discharge detection tags, non-invasive installation and full-circumferential electric field detection capabilities are achieved. The copper strip electrode covered with silicone rubber is in direct contact with the joint surface, avoiding mechanical damage to the cable insulation layer caused by traditional clamping installation, and at the same time ensuring high-sensitivity capture of partial discharge signals. The temperature and moisture detection tags are externally placed on the surface of the housing, directly exposed to the environment around the joint, improving the accuracy of environmental parameter monitoring; the vibration detection tag is embedded inside the housing, effectively isolating external mechanical interference and accurately capturing abnormal vibrations of the joint body. The modular housing encapsulation further enhances the waterproof and dustproof performance, adapting to complex working conditions such as direct burial and pipe laying.

[0054] As Figure 5 shown, a method for detecting the state of a distribution cable joint provided by the present application includes the following steps S101 to S104:

[0055] Step S101: Transmit a radio frequency energy signal to the sensing module through the reader antenna of the detection module;

[0056] Step S102: The sensing module receives the radio frequency energy signal and converts it into electrical energy to be stored in the energy storage unit;

[0057] Step S103: Activate at least one type of detection tag in the sensor group in stages according to the voltage level of the energy storage unit for data acquisition;

[0058] Step S104: Transmit the collected sensor data back to the detection module and generate an alarm signal according to a preset rule.

[0059] In the application, the detection module transmits electromagnetic waves to the sensing module. When the energy storage of the sensing module reaches the working voltage of the sensor, the sensor selectively operates according to the working voltage to sense the state of the distribution cable joint. The detection module receives the detected state information and performs information display and alarm.

[0060] In the embodiment of the present application, the sensing module is driven by radio frequency energy wireless power supply, combined with a voltage grading trigger mechanism, to achieve efficient detection of the cable joint state and low-power operation. The radio frequency power supply technology replaces the traditional battery or wire power supply method, solves the problem of impossible wiring in the cable trench, and significantly reduces the deployment cost and maintenance frequency. The staged activation strategy starts the sensor according to the energy storage state as needed, preferentially collects basic parameters (temperature, moisture), and then activates high-precision sensors (vibration, partial discharge) when the power supply is sufficient, avoiding energy waste caused by ineffective detection. The automatic generation and feedback mechanism of the alarm signal converts the detection data into actionable operation and maintenance instructions, providing real-time decision support for the preventive maintenance of the cable joint and shortening the fault response cycle.

[0061] In one embodiment, at least one type of detection tag in the sensor group is activated in stages according to the voltage level of the energy storage unit for data collection, including:

[0062] When the first-level voltage of the energy storage unit reaches the first threshold, the first type of detection tag is activated;

[0063] When the second-level voltage of the energy storage unit reaches the second threshold, the second type of detection tag is activated;

[0064] Wherein the first threshold is lower than the second threshold, and the working voltage requirement of the first type of detection tag is lower than that of the second type of detection tag.

[0065] Through the hierarchical activation mechanism based on the voltage level of the energy storage unit in the embodiments of the present application, precise control of sensor power supply and resource optimization are achieved. The first threshold triggers the immediate detection of low-voltage sensors to ensure that basic parameters can be obtained at the initial stage of power supply; the second threshold ensures that high-voltage sensors are started after sufficient energy storage to avoid high-frequency signal distortion caused by insufficient voltage. The voltage grading logic is strictly matched with the power consumption characteristics of the sensors, which not only ensures the rationality of the detection timing but also prevents false triggering problems caused by voltage fluctuations. Through the collaborative design of hardware and algorithms, stable power supply triggering accuracy can still be maintained in a complex electromagnetic environment.

[0066] In one embodiment, the energy storage unit includes a first-level energy storage unit and a second-level energy storage unit, and the method further includes:

[0067] The power management unit monitors the voltage of the first-level energy storage unit, and when it reaches the first threshold, controls the switch unit to close, triggering the boost voltage regulator circuit to supply power to the second-level energy storage unit;

[0068] And, when the voltage of the first-level energy storage unit reaches the first threshold, trigger the detection tag corresponding to the first-level energy storage unit to start detecting, or when the voltage of the second-level energy storage unit reaches the second threshold, trigger the detection tag corresponding to the second-level energy storage unit to start detecting.

[0069] Through the closed-loop control of the boost voltage regulator circuit by the power management unit in the embodiments of the present application, coordinated power supply and dynamic regulation of the two-level energy storage unit are achieved. The intelligent closing operation of the switch unit only starts the boost circuit when the energy storage is sufficient, avoiding excessive consumption of the first-level energy storage during the boost process and ensuring the continuous power supply of low-voltage sensors. After the voltage of the first-level energy storage reaches the standard, the low-power consumption sensors are immediately triggered to work, and the high-power consumption sensors are seamlessly started after the second-level energy storage is established, forming an efficient power supply timing chain. This method ensures the continuity and data integrity of the detection process through hardware-level power supply path control. Especially in intermittent radio frequency power supply scenarios (such as intermittent power supply during handheld detection), a stable detection rhythm can still be maintained to avoid data breakpoints.

[0070] In one embodiment, generating an alarm signal according to a preset rule includes:

[0071] If the detected value of the temperature detection tag is greater than the preset temperature threshold, generate a joint thermal defect alarm signal;

[0072] If the detected value of the moisture detection tag is greater than the preset moisture threshold, generate a joint water immersion alarm signal;

[0073] If the detected value of the vibration detection tag is greater than the preset vibration amplitude threshold, generate a joint abnormal vibration alarm signal;

[0074] If the detected value of the partial discharge detection tag is greater than the preset discharge amount threshold, generate a joint insulation defect alarm signal.

[0075] In one embodiment, it further includes:

[0076] If the single detected value of the moisture detection tag is greater than the preset moisture threshold, generate a joint water immersion alarm signal. If the consecutive multiple detected values of the moisture detection tag are greater than the preset moisture threshold, generate a severe joint water immersion alarm signal;

[0077] If the single detected value of the vibration detection tag is greater than the preset vibration amplitude threshold, generate a joint abnormal vibration alarm signal. If the consecutive multiple detected values of the vibration detection tag are greater than the preset vibration amplitude threshold, generate a severe joint mechanical damage alarm signal;

[0078] If the single detected value of the partial discharge detection tag is greater than the preset discharge amount threshold, generate a joint insulation defect alarm signal. If the consecutive multiple detected values of the partial discharge detection tag are greater than the preset discharge amount threshold, generate a severe joint insulation defect alarm signal.

[0079] In application, judge the severity of the defects of the distribution cable joint for temperature, vibration, moisture and partial discharge. When it is judged that there are defects, alarm the state of the cable joint. When the judgment result is no defect or mild defect, continue to wait for the next judgment. The alarm criteria specifically include:

[0080] Criterion A: T≥Ts. When the single detected temperature T exceeds the set severity threshold Ts, it indicates that there are severe thermal defects in the cable joint. Typically, Ts is 60°C.

[0081] Criterion B: S≥Ss. When the single detected moisture value S exceeds the set severity threshold Ss, it indicates that the cable joint is flooded. When S≥Ss for more than 30 consecutive days, send an alarm for the severe state of joint water immersion. Typically, Ss is 30.

[0082] Criterion C: Z ≥ Zs. When the vibration amplitude Z detected in a single measurement exceeds the set severity threshold Zs, it indicates abnormal vibration of the cable joint. When Z ≥ Zs for more than 30 consecutive times, an alarm for severe mechanical damage of the joint is issued. Typically, Zs is 0.1g.

[0083] Criterion D: P ≥ Ps. When the partial discharge amplitude P detected in a single measurement exceeds the set severity threshold Ps, it indicates an insulation defect in the cable joint. When P ≥ Ps for more than 20 consecutive times within one day, an alarm for severe insulation defect of the joint is issued. Typically, Ps is 100 pC.

[0084] The overall criterion is: S = A or B or C or D.

[0085] In the embodiment of the present application, by setting independent alarm thresholds for temperature, moisture, vibration, and partial discharge parameters, accurate identification and classification alarm of multi-dimensional defects of cable joints are realized. The temperature threshold directly reflects the overheating risk of the joint, the moisture threshold identifies the hidden danger of long-term immersion in water, the vibration threshold captures the signs of mechanical damage, and the partial discharge threshold warns of the insulation deterioration process. The multi-parameter combined criterion breaks through the limitations of traditional single detection indicators. For example, relying solely on temperature detection may miss the hidden danger of partial discharge, while the proposed solution significantly improves the accuracy of fault diagnosis through cross-verification of multi-dimensional data. The strong correlation between the alarm signal and the specific detection parameter helps the operation and maintenance personnel quickly locate the defect type (such as distinguishing overheating from immersion in water), shortening the response cycle from detection to disposal.

[0086] In the embodiment of the present application, through the combined strategy of single-exceedance alarm and continuous-exceedance graded alarm, dynamic risk assessment and graded response of cable joint defects are realized. The single alarm is used for immediate risk warning (such as sudden mechanical impact causing vibration to exceed the standard), and the continuous alarm indicates the continuous deterioration trend of the defect (such as long-term immersion in water causing the moisture parameter to accumulate and exceed the standard), providing a quantitative basis for the formulation of operation and maintenance strategies. This method effectively distinguishes occasional interference (such as instantaneous temperature fluctuations) from real defects (such as continuous partial discharge) through data accumulation analysis in the time dimension, reducing the false alarm rate. The graded alarm mechanism further optimizes the allocation of operation and maintenance resources, ensuring that severe defects are prioritized for disposal (such as insulation defect alarm triggering emergency power outage), and improving the overall safety level and operation reliability of the cable network.

[0087] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0088] It should be noted that for the information interaction, execution process, etc. between the above-mentioned devices / units, since they are based on the same concept as the method embodiment of the present application, for their specific functions and the technical effects brought, reference can be specifically made to the method embodiment part, and details will not be elaborated here.

[0089] In one embodiment, the detection module is held for live detection, and the sensing module is installed on the distribution cable joint.

[0090] In this embodiment, the sensors include 4 types: temperature, moisture, partial discharge, and vibration. The typical parameters of the sensors are as follows: The working temperature range of the moisture detection tag is from 40°C to +85°C, meeting the typical working temperature and operating conditions of the distribution cable. It is made of flexible materials, with dimensions of 80×20×2 mm, a rated voltage of 1V, and in the measurement mode: 500 μA; The partial discharge detection tag uses a capacitive sensor, with a copper strip as the material, a width dimension of 80 mm, a thickness of 1.5 mm, and a length matching the circumferential length at the intermediate joint. The measurement range of the partial discharge amount is 0 - 10000 pC, the sensitivity is 5 pC, and in the measurement mode under a working voltage of 2.5V: 850 μA; The vibration detection tag is an acceleration sensor based on the piezoelectric principle, and in the measurement mode of this acceleration sensor under a working voltage of 2.5V: 150 μA, with a user-selectable bandwidth of 200 Hz to 3200 Hz, a working temperature range of -40°C to 105°C, a vibration detection range of 0 - 0.5g, and a resolution of 1 mg within the sensitivity range of ±0.5g; The temperature detection tag uses a sensing element based on the thermosensitive principle, with a working temperature range of -40°C to +85°C, a short-term maximum temperature of +125°C, a sensor size of 50×60×4 mm, a rated voltage of 1V, and in the measurement mode: 500 μA.

[0091] When working, start the power supply of the detection module, control the acquisition unit to select and acquire four signals of temperature, moisture, partial discharge, and vibration of the distribution cable joint. Then control the reader antenna to emit electromagnetic waves at 983 MHz. After the RF antenna receives this electromagnetic wave of a specific frequency, it converts it into high-frequency alternating current. The RF–DC voltage-doubling rectifier circuit converts this high-frequency alternating current with a small amplitude into a DC signal. The first-stage energy storage unit stores the DC electrical energy output by the RF–DC circuit. The power management unit detects the energy on the first-stage energy storage unit. When it reaches W1, the output voltage is stabilized to 2.5 V through the step-up and voltage-stabilizing circuit and stored in the second-stage energy storage unit. When the power management unit detects that the energy of the second-stage energy storage unit reaches W2, each detection tag conducts detection. In this embodiment, the working voltage of the temperature and moisture detection tags is 1 V, and the total working current is 1 mA. Therefore, W1 is 1 mW. The working voltage of the vibration and partial discharge detection tags is 2.5 V, and the total working current is 1 mA. W1 is 2.5 mW. When the power management unit confirms that the energy required for each detection tag to work is met, which is 3.5 mW in this embodiment, each detection tag conducts detection. Among them, the temperature detection tag senses the heating state of the distribution cable joint, the moisture detection tag senses the moisture ingress state of the distribution cable joint, the vibration detection tag senses the vibration state of the distribution cable joint, and the partial discharge detection tag senses the internal insulation defect state of the distribution cable joint. The obtained state signals are sent back to the reader antenna through the RF antenna and are displayed and alarmed by the display and alarm unit according to the alarm criterion. In this embodiment, the sensor detection data and the display and alarm state of the display and alarm unit are shown in Table 1.

[0092] Table 1 First Detection Data of Sensors

[0093]

[0094] In one embodiment, the working mode of the detection module and the sensor indicators in this embodiment are the same as those in the previous embodiment.

[0095] When working, start the power supply of the detection module, control the acquisition unit to select and acquire the temperature and moisture of the distribution cable joint. The power management unit detects the energy on the first-stage energy storage unit. When it reaches W1 of 1 mW, the temperature and moisture detection tags conduct detection. The obtained state signals are sent back to the reader antenna through the RF antenna and are displayed and alarmed by the display and alarm unit. In this embodiment, the sensor detection data and the display and alarm state of the display and alarm unit are shown in Table 2.

[0096] Table 2 Second Detection Data of Sensors

[0097] sensor temperature moisture data 32℃ 30 display alarm unit display status no thermal defect connector water ingress

[0098] When working, the power supply of the detection module is started. The control acquisition unit can also select to acquire the vibration and partial discharge of the distribution cable joint. The power management unit detects the energy on the first-stage energy storage unit. When it reaches W1 of 1 mW, the switch is turned on, and the step-up and voltage-stabilizing circuit works. The second-stage energy storage unit starts to store energy. When it reaches W2, the vibration and partial discharge detection label is triggered for detection. The obtained status signal is sent back to the reader antenna through the radio frequency antenna and is displayed and alarmed by the display and alarm unit.

[0099] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the above-mentioned functional units and unit divisions are used as examples for illustration. In practical applications, the above-mentioned functions can be allocated to different functional units and units according to needs, that is, the internal structure of the device is divided into different functional units or units to complete all or part of the functions described above. Each functional unit and unit in the embodiment can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of each functional unit and unit are only for the convenience of mutual distinction and do not limit the protection scope of this application. The specific working processes of the units and units in the above-mentioned system can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated here.

[0100] The embodiment of the present application provides a computer program product, including a computer program. When the computer program product runs on an electronic device, it enables the electronic device to execute and implement the steps in the foregoing method embodiments.

[0101] When an integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, to implement all or part of the processes in the above method embodiments of this application, a computer program can be used to instruct relevant hardware to complete. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the above method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc. The computer-readable medium can at least include: any entity or device that can carry the computer program code to the device / electronic device, recording medium, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal, and software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk, or an optical disc, etc. In some jurisdictions, according to legislation and patent practice, the computer-readable medium cannot be an electrical carrier signal and a telecommunication signal.

[0102] In the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0103] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0104] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of units or units is only a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical, mechanical or other form.

[0105] The unit described as a separation component may or may not be physically separated, and the component displayed as a unit may or may not be a physical unit, that is, it may be located in one place or may be distributed across multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0106] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included within the protection scope of the present application.

Claims

1. A distribution cable joint status detection device, characterized in that Comprising: A detection module (100), including a reader antenna (102) and a control and acquisition unit (103), wherein the control and acquisition unit (103) is configured to control the radio frequency power supply parameters of the reader antenna (102); A sensing module (200), installed outside the cable joint, including a radio frequency antenna (201), a radio frequency - DC conversion circuit (202), a power management unit (203), and a sensor group (207); wherein: The radio frequency antenna (201) is connected to the radio frequency - DC conversion circuit (202), and is used for receiving the electromagnetic wave emitted by the reader antenna (102) and converting it into electric energy; The power management unit (203) is connected to the radio frequency - DC conversion circuit (202), and is configured to activate the detection tags in the sensor group (207) in stages according to the energy storage voltage; The detection tags of the sensor group (207) are connected to the corresponding energy storage units based on different voltage requirements, and communicate with the detection module (100) through the radio frequency antenna (201).

2. The power distribution cable joint state detection device according to claim 1, wherein The sensing module (200) further includes: A first - stage energy storage unit (205) and a second - stage energy storage unit (206), the output end of the radio frequency - DC conversion circuit (202) is connected to the first - stage energy storage unit (205); A switch unit (208), connected between the radio frequency - DC conversion circuit (202) and the boost and voltage - regulating circuit (204), and the controlled end of the switch unit (208) is connected to the power management unit (203); A boost and voltage - regulating circuit (204), with the input end connected to the switch unit (208) and the output end connected to the second - stage energy storage unit (206); The power management unit (203) is configured to monitor the voltage of the first - stage energy storage unit (205), when the voltage reaches a first threshold, control the switch unit (208) to close, trigger the boost and voltage - regulating circuit (204) to supply power to the second - stage energy storage unit (206), and when the voltage of the first - stage energy storage unit (205) reaches the first threshold, trigger the detection tags corresponding to the first - stage energy storage unit (205) to start detection, or when the voltage of the second - stage energy storage unit (206) reaches a second threshold, trigger the detection tags corresponding to the second - stage energy storage unit (206) to start detection.

3. The power distribution cable joint state detection device according to claim 1, characterized in that, The detection module (100) further includes a power supply (101) and a display and alarm unit (104), the power supply (101) supplies power to the reader antenna (102) and the control and acquisition unit (103), and the display and alarm unit (104) is connected to the control and acquisition unit (103), and is used for displaying sensor data and outputting an alarm signal.

4. The power distribution cable joint state detection device according to claim 1, wherein The sensor group (207) includes: A temperature detection tag (2071) and a moisture detection tag (2072), connected to the first - stage energy storage unit (205); A vibration detection tag (2073) and a partial discharge detection tag (2074), connected to the second - stage energy storage unit (206).

5. The power distribution cable joint state detection device according to claim 2, characterized in that The sensing module (200) includes a sensing device housing and a strap-type mounting structure connected to the sensing device housing. The radio frequency - DC conversion circuit (202), power management unit (203), boost voltage regulation circuit (204), first-stage energy storage unit (205), and second-stage energy storage unit (206) are disposed within the sensing device housing. The radio frequency antenna (201) is disposed on the sensing device housing. The sensing module (200) is wrapped and mounted outside the cable joint through the strap-type mounting structure. The partial discharge detection tag (2074) is disposed on the inner side of the strap-type mounting structure and circumferentially wraps the cable joint to be measured. The temperature detection tag (2071) and the moisture detection tag (2072) are attached to the surface of the sensing device housing, and the vibration detection tag (2073) is embedded inside the sensing device housing.

6. A method for detecting the state of a distribution cable joint, characterized in that, including: Transmitting a radio frequency energy signal to the sensing module through the reader antenna of the detection module; The sensing module receives the radio frequency energy signal and converts it into electrical energy for storage in the energy storage unit; Activating at least one type of detection tag in the sensor group for data collection according to the voltage level of the energy storage unit in stages; Transmitting the collected sensor data back to the detection module and generating an alarm signal according to a preset rule.

7. The method for detecting the state of a distribution cable joint according to claim 6, wherein, The activating at least one type of detection tag in the sensor group for data collection according to the voltage level of the energy storage unit in stages includes: When the first-stage voltage of the energy storage unit reaches a first threshold, activating the first type of detection tag; When the second-stage voltage of the energy storage unit reaches a second threshold, activating the second type of detection tag; Wherein the first threshold is lower than the second threshold, and the working voltage requirement of the first type of detection tag is lower than that of the second type of detection tag.

8. The method for detecting the state of a distribution cable joint according to claim 7, wherein The energy storage unit includes a first-stage energy storage unit and a second-stage energy storage unit, and the method further includes: The power management unit monitors the voltage of the first-stage energy storage unit, and when it reaches the first threshold, controls the switch unit to close, triggering the boost voltage regulation circuit to supply power to the second-stage energy storage unit; And when the voltage of the first-stage energy storage unit reaches the first threshold, triggering the detection tag corresponding to the first-stage energy storage unit to start detection, or when the voltage of the second-stage energy storage unit reaches the second threshold, triggering the detection tag corresponding to the second-stage energy storage unit to start detection.

9. The method for detecting the state of a distribution cable joint according to claim 6, wherein, The generating an alarm signal according to a preset rule includes: If the detected value of the temperature detection tag is greater than the preset temperature threshold, generating a joint thermal defect alarm signal; If the detected value of the moisture detection tag is greater than the preset moisture threshold, generating a joint water immersion alarm signal; If the detected value of the vibration detection tag is greater than the preset vibration amplitude threshold, generating a joint abnormal vibration alarm signal; If the detected value of the partial discharge detection tag is greater than the preset discharge amount threshold, generating a joint insulation defect alarm signal.

10. The method for detecting the state of a distribution cable joint according to claim 9, characterized in that, further including: If the single detected value of the moisture detection tag is greater than the preset moisture threshold, generating a joint water immersion alarm signal, and if the consecutive multiple detected values of the moisture detection tag are greater than the preset moisture threshold, generating a joint severe water immersion alarm signal; If the single detection value of the vibration detection tag is greater than the preset vibration amplitude threshold, an abnormal vibration alarm signal for the joint is generated. If the consecutive multiple detection values of the vibration detection tag are greater than the preset vibration amplitude threshold, a severe alarm signal for mechanical damage of the joint is generated; If the single detection value of the partial discharge detection tag is greater than the preset discharge amount threshold, an alarm signal for insulation defect of the joint is generated. If the consecutive multiple detection values of the partial discharge detection tag are greater than the preset discharge amount threshold, a severe alarm signal for insulation defect of the joint is generated.

Images