Insulation interface discharge-based cable accessory fault early warning method and device, terminal equipment and storage medium

Abstract

The application discloses a cable accessory fault early warning method and device based on insulation interface discharge, a terminal equipment and a storage medium, wherein the method calculates the equivalent resistance of the insulation interface discharge of the cable accessory and the energy value acting on the insulation material in the insulation interface discharge process according to the input side voltage, the output side voltage, the quality after the discharge and the initial quality of the cable accessory, so that the preset insulation interface state model accurately evaluates the change of the insulation material state caused by the insulation interface discharge according to the entropy increase law, and then outputs the insulation interface discharge trend characteristic quantity of the cable accessory; finally, when it is determined that the cable accessory has a discharge fault risk according to the discharge trend characteristic quantity, a fault early warning is given. Therefore, the application can accurately evaluate the discharge trend of the insulation interface of the cable accessory, and then accurately evaluate whether the cable accessory has a fault risk, can avoid the tripping, explosion and combustion accidents caused by the discharge fault of the cable accessory, and effectively ensures the safety of the cable.

Description

Technical Field

[0001] This invention relates to the field of power cable fault monitoring technology, and in particular to a method, device, terminal equipment and storage medium for early warning of cable accessory faults based on insulation interface discharge. Background Technology

[0002] Intermediate joints and terminals of power cables are key components connecting power transmission and distribution lines and related power distribution equipment. Power transmission and distribution cable lines typically have one power cable accessory every 500 meters, resulting in a large number of accessories distributed across various laying environments. Silicone rubber (SiR) insulation material, due to its high elasticity, ease of injection molding, and excellent electrical properties, has been widely used in prefabricated cable accessories. However, despite the superior insulation performance of SiR, the complex interface structure formed by the cable accessory and the cable body is prone to discharge phenomena, making the cable accessory a weak point in the power transmission and distribution line.

[0003] Dissection revealed penetrating discharge traces of varying degrees of damage to the cross-linked polyethylene (XLPE)-SiR interfacial insulation of the actual faulty samples. Furthermore, fault recording data showed intermittent ground fault currents at the ampere level for a period prior to the cable accessory fault. Therefore, it can be determined that the interfacial discharge of the XLPE-SiR insulation, leading to the continuous degradation of the XLPE / SiR insulation, is the root cause of the power cable accessory fault.

[0004] Therefore, current methods for predicting faults in power cable accessories typically involve detecting the insulation interface state of the cable accessories. Advanced instruments can be used to characterize this interface state, including Auger electron spectroscopy (AES), electron probe microanalysis (EP), X-ray photoelectron spectroscopy (XPS), scanning secondary ion mass spectrometry (SSIMS), electron energy loss spectroscopy (EELS), X-ray reflectance spectroscopy (GAXP), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Raman spectroscopy, to observe the microstructure, morphology, and thickness of the interface. However, these characterization methods require multiple observations of the sample, resulting in a significant workload. Furthermore, each sample transfer can potentially damage the insulation interface structure, making it difficult to accurately and effectively characterize the XLPE-SiR insulation interface state. This leads to a high degree of inaccuracy in current power cable accessory fault prediction results. Summary of the Invention

[0005] This invention provides a method, device, terminal equipment, and storage medium for early warning of cable accessory faults based on insulation interface discharge. It can accurately assess the discharge trend of the insulation interface of cable accessories, thereby accurately assessing whether there is a fault risk in the cable accessories. It can avoid tripping, explosion, and combustion accidents caused by cable accessory discharge faults, effectively ensuring the safety of cables.

[0006] An embodiment of the present invention provides a cable accessory fault early warning method based on insulation interface discharge, comprising:

[0007] Obtain the input-side voltage, output-side voltage, post-discharge mass, and initial mass of the cable accessory under test;

[0008] Calculate the equivalent discharge resistance when the insulation interface of the cable accessory discharges, based on the input voltage and the output voltage.

[0009] Based on the post-discharge mass and the initial mass, calculate the energy value acting on the insulating material of the cable accessory when the insulation interface of the cable accessory discharges;

[0010] The equivalent discharge resistance and the energy value are input into a preset insulation interface state model so that the insulation interface state model can evaluate the change in the state of the insulation material caused by the discharge at the insulation interface according to the law of entropy increase, and output the discharge trend characteristic quantity of the insulation interface of the cable accessory.

[0011] When it is determined that there is a risk of discharge fault in the cable accessory based on the discharge trend characteristic, a fault warning is issued.

[0012] Furthermore, the step of calculating the equivalent discharge resistance of the insulation interface of the cable accessory when discharge occurs based on the input-side voltage and the output-side voltage includes:

[0013] The difference between the input voltage and the output voltage is calculated to obtain the discharge equivalent voltage when the insulation interface discharges.

[0014] The discharge current value when the insulation interface discharges is calculated based on the output side voltage and the resistance value of the sampling resistor pre-loaded at the output end of the cable accessory.

[0015] The discharge equivalent resistance is calculated based on the discharge equivalent voltage and the discharge current value.

[0016] Furthermore, the step of calculating the energy value acting on the insulating material of the cable accessory when a discharge occurs at the insulation interface of the cable accessory based on the discharged mass and the initial mass includes:

[0017] The mass change of the insulating material is obtained by calculating the difference between the mass after discharge and the initial mass.

[0018] Based on the mass change value, a search is performed in a preset mass-energy correlation table to determine the energy value corresponding to the mass change value; wherein, the mass-energy correlation table records the energy values ​​corresponding to several mass change values ​​of the insulating material.

[0019] Furthermore, the construction of the mass-energy correlation table includes:

[0020] Obtain experimental samples of the insulating material;

[0021] Discharge tests were conducted on the experimental samples, and several mass changes of the experimental samples after discharge were statistically analyzed.

[0022] Based on the mass change values ​​mentioned above, the energy value of the insulating interface discharge acting on itself of the experimental sample is inverted by thermogravimetric analysis.

[0023] The mass-energy correlation table is constructed based on the mass change value and the energy value.

[0024] Furthermore, the insulation interface state model is as follows:

[0025]

[0026] Where dZ is the discharge trend characteristic quantity; Z A Z represents the discharge tendency before discharge at the insulating interface. B R represents the discharge tendency after the insulating interface discharges; R represents the equivalent resistance of the discharge when the insulating interface discharges; and E represents the energy value.

[0027] Furthermore, the step of issuing a fault warning when determining that the cable accessory has a risk of discharge fault based on the discharge trend characteristic includes:

[0028] Obtain the discharge fault threshold;

[0029] When the discharge trend characteristic quantity is greater than the discharge fault threshold, it is determined that there is a risk of discharge fault in the cable accessory, and a fault warning is issued.

[0030] Another embodiment of the present invention provides a fault early warning device for the insulation interface of cable accessories, comprising:

[0031] The data acquisition module is used to acquire the input side voltage, output side voltage, post-discharge quality, and initial quality of the cable accessory under test.

[0032] The resistance calculation module is used to calculate the discharge equivalent resistance when the insulation interface of the cable accessory discharges, based on the input side voltage and the output side voltage.

[0033] An energy calculation module is used to calculate the energy value acting on the insulating material of the cable accessory when the insulation interface of the cable accessory discharges, based on the mass after discharge and the initial mass.

[0034] The discharge assessment module is used to input the discharge equivalent resistance and the energy value into a preset insulation interface state model, so that the insulation interface state model can assess the change in the state of the insulation material caused by the discharge at the insulation interface according to the law of entropy increase, and output the discharge trend characteristic quantity of the insulation interface of the cable accessory.

[0035] The fault warning module is used to issue a fault warning when it is determined that there is a risk of discharge fault in the cable accessory based on the discharge trend characteristic quantity.

[0036] Furthermore, the step of calculating the equivalent discharge resistance of the insulation interface of the cable accessory when discharge occurs based on the input-side voltage and the output-side voltage includes:

[0037] The difference between the input voltage and the output voltage is calculated to obtain the discharge equivalent voltage when the insulation interface discharges.

[0038] The discharge current value when the insulation interface discharges is calculated based on the output side voltage and the resistance value of the sampling resistor pre-loaded at the output end of the cable accessory.

[0039] The discharge equivalent resistance is calculated based on the discharge equivalent voltage and the discharge current value.

[0040] Another embodiment of the present invention provides a terminal device, including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a cable accessory fault early warning method based on insulation interface discharge as described in any of the embodiments.

[0041] Another embodiment of the present invention provides a storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the storage medium is located to execute a cable accessory fault early warning method based on insulation interface discharge as described in any of the above embodiments.

[0042] The following benefits can be obtained by implementing the present invention:

[0043] This invention discloses a method, device, terminal equipment, and storage medium for cable accessory fault early warning based on insulation interface discharge. The method calculates the equivalent resistance of the insulation interface discharge of the cable accessory, as well as the energy value acting on the insulating material during the insulation interface discharge, based on the input-side voltage, output-side voltage, post-discharge mass, and initial mass of the cable accessory. This allows a preset insulation interface state model to accurately assess the changes in the state of the insulating material caused by the insulation interface discharge, based on the entropy increase law (that is, the greater the energy value acting on the insulating material during the insulation interface discharge, the greater the loss of the insulating material, leading to a lower equivalent resistance of the insulation interface discharge and ultimately a larger discharge amount). The method also considers the influence of voltage on the change in the equivalent resistance of the discharge to accurately assess the changes in the state of the insulating material caused by the insulation interface discharge. This results in the output of insulation interface discharge trend characteristics for the cable accessory. Finally, when the discharge trend characteristics determine that the cable accessory has a discharge fault risk, a fault warning is issued. Therefore, this invention can accurately assess the discharge trend of the insulation interface of cable accessories, thereby accurately assessing whether the cable accessory has a fault risk, avoiding tripping, explosion, and combustion accidents caused by cable accessory discharge faults, and effectively improving cable safety. Attached Figure Description

[0044] Figure 1 This is a flowchart illustrating a cable accessory fault early warning method based on insulation interface discharge, provided by an embodiment of the present invention.

[0045] Figure 2 This is a schematic diagram of the structure of a fault early warning device based on cable accessory insulation interface discharge according to an embodiment of the present invention.

[0046] Figure 3 This is a schematic diagram of the structure of an insulating interface discharge experimental platform provided in an embodiment of the present invention.

[0047] Figure 4 This is a schematic diagram of the structure of an insulating interface sample provided in an embodiment of the present invention.

[0048] Legend:

[0049] 1. Screw; 2. Spring; 3. Acrylic glass; 4. Acrylic glass pressure plate; 5. Silicone rubber; 6. XLPE; 7. Electrode. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0052] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0053] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0054] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0055] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0056] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0057] See Figure 1This is a flowchart illustrating a cable accessory fault early warning method based on insulation interface discharge according to an embodiment of the present invention, including:

[0058] S1. Obtain the input side voltage, output side voltage, post-discharge mass, and initial mass of the cable accessory to be tested;

[0059] In a preferred embodiment of the present invention, a cable accessory with a cross-linked polyethylene (XLPE)-SiR insulation interface is used as the cable accessory to be tested.

[0060] S2. Calculate the equivalent discharge resistance when the insulation interface of the cable accessory discharges, based on the input voltage and the output voltage.

[0061] Preferably, the step of calculating the discharge equivalent resistance when the insulation interface of the cable accessory discharges based on the input-side voltage and the output-side voltage includes:

[0062] S21. Calculate the difference between the input side voltage and the output side voltage to obtain the discharge equivalent voltage when the insulation interface discharges.

[0063] S22. Calculate the discharge current value when the insulation interface discharges, based on the output side voltage and the resistance value of the sampling resistor pre-loaded at the output end of the cable accessory.

[0064] S23. Calculate the discharge equivalent resistance based on the discharge equivalent voltage and the discharge current value.

[0065] In a preferred embodiment of the present invention, Figure 3 Taking the constructed discharge test platform as an example, this paper details the calculation process of the discharge equivalent resistance, and will explain how... Figure 4 The XLPE-Si-R insulating interface sample (including electrodes) Cs shown is connected in series with the sampling resistor r in the high voltage transformer (HVT) circuit. A two-port oscilloscope and a capacitive voltage divider are used to acquire the voltage value in the circuit. Port 1 measures the voltage value u1 on the capacitive voltage divider (CVD1) on the power supply side, and port 2 measures the voltage value u2 on the capacitive voltage divider (CVD2) on the r side.

[0066] The insulation interface discharge current i and the equivalent interface voltage u are calculated using the following formulas. S And the discharge equivalent resistance R:

[0067] i = u2 / r;

[0068] u S =u1-u2;

[0069] R = u S / i.

[0070] S3. Based on the discharged mass and the initial mass, calculate the energy value acting on the insulating material of the cable accessory when the insulation interface of the cable accessory discharges;

[0071] Preferably, the step of calculating the energy value acting on the insulating material of the cable accessory when a discharge occurs at the insulation interface of the cable accessory based on the discharged mass and the initial mass includes:

[0072] S31. Calculate the difference between the mass after discharge and the initial mass to obtain the mass change value of the insulating material;

[0073] S32. Based on the mass change value, search in a preset mass-energy association table to determine the energy value corresponding to the mass change value; wherein, the mass-energy association table records the energy values ​​corresponding to several mass change values ​​of the insulating material.

[0074] Preferably, the construction of the mass-energy correlation table includes:

[0075] S321. Obtain experimental samples of the insulating material;

[0076] S322. Perform a discharge test on the experimental sample and statistically analyze several mass changes of the experimental sample after discharge.

[0077] S323. Based on the mass change values ​​mentioned above, the energy value of the insulating interface discharge acting on itself of the experimental sample is determined by thermogravimetric analysis.

[0078] S324. Construct the mass-energy correlation table based on the mass change value and the energy value.

[0079] In a preferred embodiment of the present invention, it is assumed that before the interface insulation is completely ablated, the energy value E generated by the discharge at the XLPE-SiR insulation interface is entirely applied to the heat absorption of the phase change material of the interface insulation, and the influence of heat transfer is ignored.

[0080] Based on the above assumptions, thermogravimetric analysis (TG) is proposed to construct the correlation between the degree of phase transformation decomposition and the energy value E of XLPE and SiR insulating materials. By comparing the mass loss after actual insulation interface discharge (considered to be caused by thermal ablation), and combining the thermogravimetric analysis to deduce the thermal ablation endothermic energy value, a comparison table of mass loss value and energy absorption value of XLPE and SiR insulating materials under different evolution states is formulated to determine the energy value E under different insulation interface states, providing input for the calculation of dZ.

[0081] S4. Input the discharge equivalent resistance and the energy value into the preset insulation interface state model so that the insulation interface state model can evaluate the change in the state of the insulation material caused by the discharge of the insulation interface according to the law of entropy increase, and output the discharge trend characteristic quantity of the insulation interface of the cable accessory.

[0082] Preferably, the insulation interface state model is as follows:

[0083]

[0084] Where dZ is the discharge trend characteristic quantity; Z A Z represents the discharge tendency before discharge at the insulating interface. B R represents the discharge tendency after the insulating interface discharges; R represents the equivalent resistance of the discharge when the insulating interface discharges; and E represents the energy value.

[0085] In a preferred embodiment of the present invention, an insulation interface state model is constructed based on the law of entropy increase, defining the state parameter discharge tendency change dZ to quantitatively describe different interface insulation states. According to the insulation interface state model, the capability value E of the insulation interface discharge on the interface insulation effect can be determined. The resulting effect is that the equivalent resistance of the insulation interface autonomously transforms from a high-resistance state (ordered) to a low-resistance state (disordered), therefore dZ is always greater than 0.

[0086] Understandably, the insulation interface state model quantitatively describes the XLPE-SiR insulation interface state under different discharge stages. The discharge tendency change is essentially a definite integral, focusing only on the state of the insulation material before and after discharge, and is independent of process quantities. The final result is a characterization parameter that quantitatively describes the XLPE-SiR insulation interface state, possessing its own physical meaning. The discharge tendency change dZ can provide analytical parameter input for constructing a mapping between the macroscopic characteristics of XLPE-SiR insulation interface discharge and the laws governing microscopic particle motion. Simultaneously, it also provides key state quantity input for cable accessory discharge fault early warning technology.

[0087] S5. When it is determined that there is a risk of discharge fault in the cable accessory based on the discharge trend characteristic quantity, a fault warning is issued.

[0088] Preferably, the step of issuing a fault warning when it is determined that the cable accessory has a risk of discharge fault based on the discharge trend characteristic quantity includes:

[0089] S51. Obtain the discharge fault threshold;

[0090] S52. When the discharge trend characteristic quantity is greater than the discharge fault threshold, it is determined that there is a risk of discharge fault in the cable accessory, and a fault warning is issued.

[0091] This embodiment provides a cable accessory fault early warning method based on insulation interface discharge. Based on the input-side voltage, output-side voltage, post-discharge mass, and initial mass of the cable accessory, the equivalent resistance of the insulation interface discharge and the energy value acting on the insulating material during the insulation interface discharge are calculated. A preset insulation interface state model is then used to accurately assess the changes in the state of the insulating material caused by the insulation interface discharge, based on the entropy increase law. This principle states that the greater the energy value acting on the insulating material during the insulation interface discharge, the greater the loss to the insulating material, leading to a lower equivalent resistance of the insulation interface discharge and ultimately a larger discharge amount. The method also considers the influence of voltage on the change in the equivalent resistance of the discharge to accurately assess the changes in the state of the insulating material caused by the insulation interface discharge. This results in the output of insulation interface discharge trend characteristics for the cable accessory. Finally, when the discharge trend characteristics determine that the cable accessory has a discharge fault risk, a fault warning is issued. Therefore, this invention can accurately assess the discharge trend of the insulation interface of cable accessories, thereby accurately assessing whether the cable accessory has a fault risk, avoiding tripping, explosion, and combustion accidents caused by cable accessory discharge faults, and effectively improving cable safety.

[0092] See Figure 2 This is a schematic diagram of a fault early warning device based on cable accessory insulation interface discharge according to an embodiment of the present invention, comprising:

[0093] The data acquisition module is used to acquire the input side voltage, output side voltage, post-discharge quality, and initial quality of the cable accessory under test.

[0094] The resistance calculation module is used to calculate the discharge equivalent resistance when the insulation interface of the cable accessory discharges, based on the input side voltage and the output side voltage.

[0095] An energy calculation module is used to calculate the energy value acting on the insulating material of the cable accessory when the insulation interface of the cable accessory discharges, based on the mass after discharge and the initial mass.

[0096] The discharge assessment module is used to input the discharge equivalent resistance and the energy value into a preset insulation interface state model, so that the insulation interface state model can assess the change in the state of the insulation material caused by the discharge at the insulation interface according to the law of entropy increase, and output the discharge trend characteristic quantity of the insulation interface of the cable accessory.

[0097] The fault warning module is used to issue a fault warning when it is determined that there is a risk of discharge fault in the cable accessory based on the discharge trend characteristic quantity.

[0098] Preferably, the step of calculating the discharge equivalent resistance when the insulation interface of the cable accessory discharges based on the input-side voltage and the output-side voltage includes:

[0099] The difference between the input voltage and the output voltage is calculated to obtain the discharge equivalent voltage when the insulation interface discharges.

[0100] The discharge current value when the insulation interface discharges is calculated based on the output side voltage and the resistance value of the sampling resistor pre-loaded at the output end of the cable accessory.

[0101] The discharge equivalent resistance is calculated based on the discharge equivalent voltage and the discharge current value.

[0102] It should be noted that the device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can be specifically implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0103] Those skilled in the art will clearly understand that, for convenience and brevity, the specific working process of the device described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0104] Another preferred embodiment of the present invention provides a terminal device including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements a fault warning method based on cable accessory insulation interface discharge as described in any of the above embodiments.

[0105] The terminal device can be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0106] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal device, connecting all parts of the terminal device via various interfaces and lines.

[0107] The memory can be used to store the computer program. The processor implements various functions of the terminal device by running or executing the computer program stored in the memory and calling data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function, etc.; the data storage area may store data created based on the use of the mobile phone, etc. In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, RAM, plug-in hard disk, smart memory card (SMC), secure digital card (SD) card, flash memory card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0108] Another preferred embodiment of the present invention provides a storage medium, which is a computer-readable storage medium, in which a computer program is stored. When executed by a processor, the computer program can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable file, or some intermediate form. The computer-readable medium can include any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0109] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for early warning of cable accessory faults based on insulation interface discharge, characterized in that, include: Obtain the input-side voltage, output-side voltage, post-discharge mass, and initial mass of the cable accessory under test; Calculate the equivalent discharge resistance when the insulation interface of the cable accessory discharges, based on the input voltage and the output voltage. Based on the post-discharge mass and the initial mass, calculate the energy value acting on the insulating material of the cable accessory when the insulation interface of the cable accessory discharges; The equivalent discharge resistance and the energy value are input into a preset insulation interface state model so that the insulation interface state model can evaluate the change in the state of the insulation material caused by the discharge at the insulation interface according to the law of entropy increase, and output the discharge trend characteristic quantity of the insulation interface of the cable accessory. When it is determined that there is a risk of discharge fault in the cable accessory based on the discharge trend characteristic, a fault warning is issued.

2. The cable accessory fault early warning method based on insulation interface discharge as described in claim 1, characterized in that, The step of calculating the equivalent discharge resistance of the cable accessory's insulation interface when discharge occurs based on the input voltage and the output voltage includes: The difference between the input voltage and the output voltage is calculated to obtain the discharge equivalent voltage when the insulation interface discharges. The discharge current value when the insulation interface discharges is calculated based on the output side voltage and the resistance value of the sampling resistor pre-loaded at the output end of the cable accessory. The discharge equivalent resistance is calculated based on the discharge equivalent voltage and the discharge current value.

3. The cable accessory fault early warning method based on insulation interface discharge as described in claim 1, characterized in that, The step of calculating the energy value acting on the insulating material of the cable accessory when a discharge occurs at the insulation interface of the cable accessory, based on the discharged mass and the initial mass, includes: The mass change of the insulating material is obtained by calculating the difference between the mass after discharge and the initial mass. Based on the mass change value, a search is performed in a preset mass-energy correlation table to determine the energy value corresponding to the mass change value; wherein, the mass-energy correlation table records the energy values ​​corresponding to several mass change values ​​of the insulating material.

4. The cable accessory fault early warning method based on insulation interface discharge as described in claim 3, characterized in that, The construction of the mass-energy correlation table includes: Obtain experimental samples of the insulating material; Discharge tests were conducted on the experimental samples, and several mass changes of the experimental samples after discharge were statistically analyzed. Based on the mass change values ​​mentioned above, the energy value of the insulating interface discharge acting on itself of the experimental sample is inverted by thermogravimetric analysis. The mass-energy correlation table is constructed based on the mass change value and the energy value.

5. The cable accessory fault early warning method based on insulation interface discharge as described in claim 1, characterized in that, The state model of the insulation interface is as follows: Wherein, dZ is the discharge trend characteristic quantity; Z A Z represents the discharge tendency before discharge at the insulating interface. B R represents the discharge tendency after the insulating interface discharges; R represents the equivalent resistance of the discharge when the insulating interface discharges; and E represents the energy value.

6. The cable accessory fault early warning method based on insulation interface discharge as described in claim 1, characterized in that, The step of issuing a fault warning when determining that the cable accessory has a risk of discharge fault based on the discharge trend characteristic includes: Obtain the discharge fault threshold; When the discharge trend characteristic quantity is greater than the discharge fault threshold, it is determined that there is a risk of discharge fault in the cable accessory, and a fault warning is issued.

7. A fault early warning device based on cable accessory insulation interface discharge, characterized in that, include: The data acquisition module is used to acquire the input side voltage, output side voltage, post-discharge quality, and initial quality of the cable accessory under test. The resistance calculation module is used to calculate the discharge equivalent resistance when the insulation interface of the cable accessory discharges, based on the input side voltage and the output side voltage. An energy calculation module is used to calculate the energy value acting on the insulating material of the cable accessory when the insulation interface of the cable accessory discharges, based on the mass after discharge and the initial mass. The discharge assessment module is used to input the discharge equivalent resistance and the energy value into a preset insulation interface state model, so that the insulation interface state model can assess the change in the state of the insulation material caused by the discharge at the insulation interface according to the law of entropy increase, and output the discharge trend characteristic quantity of the insulation interface of the cable accessory. The fault warning module is used to issue a fault warning when it is determined that there is a risk of discharge fault in the cable accessory based on the discharge trend characteristic quantity.

8. A fault early warning device based on cable accessory insulation interface discharge as described in claim 7, characterized in that, The step of calculating the equivalent discharge resistance of the cable accessory's insulation interface when discharge occurs based on the input voltage and the output voltage includes: The difference between the input voltage and the output voltage is calculated to obtain the discharge equivalent voltage when the insulation interface discharges. The discharge current value when the insulation interface discharges is calculated based on the output side voltage and the resistance value of the sampling resistor pre-loaded at the output end of the cable accessory. The discharge equivalent resistance is calculated based on the discharge equivalent voltage and the discharge current value.

9. A terminal device, characterized in that, The method includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements a cable accessory fault early warning method based on insulation interface discharge as described in any one of claims 1 to 6.

10. A storage medium, characterized in that, The storage medium includes a stored computer program, wherein, when the computer program is executed, it controls the device where the storage medium is located to perform a cable accessory fault early warning method based on insulation interface discharge as described in any one of claims 1 to 6.

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