Method and device for detecting insulation state of high-voltage cable and electronic equipment

Abstract

The invention provides a high-voltage cable insulation state detection method and device and electronic equipment, and the method comprises the steps: obtaining the structure parameters of a to-be-detected high-voltage cable, the to-be-detected high-voltage cable at least comprises an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structure parameters at least comprise the radius of the insulation defect; a finite element simulation model of the to-be-detected high-voltage cable is constructed according to the structure parameters, defect capacitance of insulation defects and insulation medium capacitance of an insulation layer are calculated according to the finite element simulation model, and the finite element simulation model is used for simulating the structure and the electric field of the to-be-detected high-voltage cable; and determining the real discharge capacity of the to-be-detected high-voltage cable according to the ratio of the defect capacitance to the insulating medium capacitance, and determining that the to-be-detected high-voltage cable is in a non-insulating state under the condition that the real discharge capacity is greater than a preset threshold value. According to the application, the problem that the insulation state of the cable cannot be accurately judged in the prior art is solved, and the effect of accurately judging the insulation state of the cable is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of cable status detection, and in particular to a method, device, computer-readable storage medium, and electronic device for detecting the insulation status of a high-voltage cable. Background Art

[0002] As high-voltage cables age, their insulation materials may gradually degrade due to environmental factors, mechanical stress, or electrical stress, forming defects such as localized air gaps. These gaps can cause partial discharges under voltage, which, in the long term, can accelerate insulation aging and even cause cable failures, disrupting power supply and resulting in significant economic losses and social impacts.

[0003] Partial discharge detection technology is one of the important means of evaluating the insulation condition of power cables. By monitoring partial discharge activity, potential cable defects can be detected early, allowing timely maintenance measures to avoid accidents. The pulse current method is the most commonly used method for partial discharge detection. It indirectly obtains information on the charge of partial discharge by measuring electromagnetic radiation or sound signals around the cable. However, the propagation of partial discharge signals in cables is affected by various factors, including the cable's capacitance effect and high-frequency attenuation of the signal. The capacitance effect can cause the measured apparent discharge to be larger than the actual discharge, while the attenuation of high-frequency signals can weaken discharge information far from the detection point. Both of these factors reduce the accuracy of partial discharge measurements, thereby affecting the judgment of cable health. Summary of the Invention

[0004] The main purpose of this application is to provide a method, device, computer-readable storage medium and electronic device for detecting the insulation status of a high-voltage cable, so as to at least solve the problem in the prior art that the insulation status of the cable cannot be accurately determined.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a method for detecting the insulation state of a high-voltage cable is provided, comprising: obtaining the structural parameters of the high-voltage cable to be detected, wherein the high-voltage cable to be detected includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least the radius of the insulation defect; constructing a finite element simulation model of the high-voltage cable to be detected according to the structural parameters, and calculating the defect capacitance of the insulation defect and the insulating dielectric capacitance of the insulating layer according to the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be detected; determining the actual discharge amount of the high-voltage cable to be detected according to the ratio of the defect capacitance to the insulating dielectric capacitance, and determining that the high-voltage cable to be detected is in a non-insulated state when the actual discharge amount is greater than a preset threshold value.

[0006] Optionally, a target sensor is provided at the grounding point of the high-voltage cable to be detected, and the actual discharge amount of the high-voltage cable to be detected is determined according to the ratio of the defective capacitance to the insulating medium capacitance, including: detecting the apparent discharge amount of the high-voltage cable to be detected by the target sensor; using a partial discharge ultrasonic positioning method to detect the target distance between the target sensor and the insulation defect; and determining the actual discharge amount according to the product of the target distance, the apparent discharge amount and the ratio of the defective capacitance to the insulating medium capacitance.

[0007] Optionally, determining the actual discharge amount according to the product of the target distance, the apparent discharge amount, and the ratio of the defect capacitance to the insulation medium capacitance comprises: using the formula Determine the actual discharge amount, where q r represents the actual discharge amount, q represents the apparent discharge amount, C1 represents the defective capacitance, C2 represents the insulating medium capacitance, f represents the main frequency of the partial discharge signal, and x represents the target distance.

[0008] Optionally, the apparent discharge amount of the high-voltage cable to be tested is determined through a partial discharge test, including: when it is detected that a high-voltage voltage is applied to the high-voltage cable to be tested, recording a current waveform, wherein the current waveform is a waveform of a current generated when a high-voltage voltage is applied to the high-voltage cable to be tested, and the current waveform includes multiple pulses; calculating an equivalent pulse height of the current waveform, and calculating the apparent discharge amount based on the equivalent pulse height, wherein the equivalent pulse height represents the equivalent height of multiple pulses.

[0009] Optionally, the method further includes: when the actual discharge amount is less than or equal to the preset threshold, determining that the high-voltage cable to be detected is in an insulation state.

[0010] Optionally, the high-voltage cable to be tested is a 110kV cross-linked polyethylene power cable.

[0011] According to another aspect of the present application, a device for detecting the insulation status of a cable is provided, comprising: an acquisition unit for acquiring structural parameters of a high-voltage cable to be detected, wherein the high-voltage cable to be detected includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least the radius of the insulation defect; a calculation unit for constructing a finite element simulation model of the high-voltage cable to be detected based on the structural parameters, and calculating the defect capacitance of the insulation defect and the insulating dielectric capacitance of the insulating layer based on the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be detected; a first determination unit for determining the actual discharge amount of the high-voltage cable to be detected based on the ratio of the defect capacitance to the insulating dielectric capacitance, and determining that the high-voltage cable to be detected is in a non-insulated state when the actual discharge amount is greater than a preset threshold value.

[0012] According to another aspect of the present application, a computer-readable storage medium is provided, which includes a stored program, wherein when the program is run, the device where the computer-readable storage medium is located is controlled to execute any one of the methods for detecting the insulation status of a cable.

[0013] According to another aspect of the present application, an electronic device is provided, comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include a method for executing any one of the cable insulation status detection methods.

[0014] The technical solution of the present application is applied to obtain the structural parameters of a high-voltage cable to be tested, wherein the high-voltage cable to be tested includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least the radius of the insulation defect; a finite element simulation model of the high-voltage cable to be tested is constructed based on the structural parameters, and the defect capacitance of the insulation defect and the insulation dielectric capacitance of the insulation layer are calculated based on the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be tested; the actual discharge amount of the high-voltage cable to be tested is determined based on the ratio of the defect capacitance to the insulation dielectric capacitance, and when the actual discharge amount is greater than a preset threshold, the high-voltage cable to be tested is determined to be in a non-insulated state. Compared with the prior art, which cannot accurately measure the effect of the capacitance generated by the cable insulation defect on the cable discharge amount, and thus cannot accurately determine the insulation state of the cable, the present application can determine the size of the defect capacitance generated by the insulation defect and the size of the insulation dielectric capacitance, so as to determine the actual discharge amount of the high-voltage cable to be tested based on the ratio of the two, thereby accurately determining the insulation state of the cable. Therefore, it can solve the problem of the inability to accurately determine the insulation state of the cable in the prior art and achieve the effect of accurately determining the insulation state of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings that constitute part of this application are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0016] Figure 1 A hardware structure block diagram of a mobile terminal for performing a method for detecting the insulation status of a high-voltage cable provided in an embodiment of the present application is shown;

[0017] Figure 2 A schematic flow chart of a method for detecting the insulation status of a high-voltage cable provided in an embodiment of the present application is shown;

[0018] Figure 3 A schematic structural diagram of a high-voltage cable provided in an embodiment of the present application is shown;

[0019] Figure 4 The figure shows a structural block diagram of a device for detecting the insulation status of a high-voltage cable provided in an embodiment of the present application.

[0020] The above drawings include the following reference numerals:

[0021] 102. Processor; 104. Memory; 106. Transmission equipment; 108. Input / output equipment; 1. Conductor core layer; 2. Inner semi-conductive layer; 3. Cross-linked polyethylene layer; 4. Outer semi-conductive layer; 5. Buffering and water-blocking layer; 6. Metal sheath layer; 7. PVC outer sheath layer; 8. Air gap defect. DETAILED DESCRIPTION

[0022] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0023] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0024] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0025] As introduced in the background technology, the existing technology cannot accurately measure the impact of the capacitance generated by cable insulation defects on the cable discharge amount, and thus cannot accurately judge the insulation state of the cable. In order to solve the problem of not being able to accurately judge the insulation state of the cable, the embodiments of the present application provide a method, device, computer-readable storage medium and electronic device for detecting the insulation state of a high-voltage cable.

[0026] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0027] The method embodiments provided in the embodiments of the present application can be executed in a mobile terminal, a computer terminal or a similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a method for detecting the insulation status of a high-voltage cable according to an embodiment of the present invention. Figure 1 As shown, the mobile terminal may include one or more ( Figure 1 Only one is shown) a processor 102 (the processor 102 may include but is not limited to a microprocessor MCU or a programmable logic device FPGA and other processing devices) and a memory 104 for storing data, wherein the mobile terminal may also include a transmission device 106 and an input and output device 108 for communication functions. It will be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the mobile terminal. Figure 1 More or fewer components than shown, or with Figure 1 Different configurations shown.

[0028] Memory 104 can be used to store computer programs, such as application software programs and modules, such as the computer program corresponding to the method for detecting the insulation condition of a high-voltage cable in an embodiment of the present invention. Processor 102 executes the computer programs stored in memory 104 to execute various functional applications and data processing, thereby implementing the aforementioned method. Memory 104 may include high-speed random access memory (RAM) and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, memory 104 may further include memory remotely located from processor 102, which can be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof. Transmission device 106 is used to receive or transmit data via a network. Specific examples of such networks may include a wireless network provided by the mobile terminal's telecommunications provider. In one example, transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to enable communication with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0029] In this embodiment, a method for detecting the insulation status of a high-voltage cable running on a mobile terminal, a computer terminal or a similar computing device is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0030] Figure 2 FIG. 1 is a flow chart of a method for detecting the insulation status of a high-voltage cable according to an embodiment of the present application. Figure 2 As shown, the method includes the following steps:

[0031] Step S201, obtaining structural parameters of a high-voltage cable to be inspected, wherein the high-voltage cable to be inspected includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least a radius of the insulation defect;

[0032] Specifically, the structural diagram of the high-voltage cable to be tested is as follows: Figure 3As shown, the system comprises a conductor core layer 1, an inner semiconductive layer 2, a cross-linked polyethylene layer 3, an outer semiconductive layer 4, a buffer water-blocking layer 5, a metal sheath layer 6, a PVC outer sheath layer 7, and an air gap defect 8. The air gap defect 8 is a small circular hole located within the insulation layer, or cross-linked polyethylene layer 3. Since the insulation condition of the cable needs to be tested, it is necessary to first identify the insulation defect and obtain the structural parameters of the high-voltage cable to be tested, such as the radius of the insulation defect, which directly affects the calculation of the defect capacitance. Other structural parameters are shown in Table 1.

[0033] Table 1

[0034] Material Conductivity / (S / m) Relative dielectric constant Radius / mm Conductor core layer <![CDATA[5.998×10 7 ]]> - 14.16 Inner semiconductive layer 0.5 30 15.16 Cross-linked polyethylene layer <![CDATA[1×10 -16 ]]> 2.3 32.16 Outer semiconducting layer 0.5 30 33.16 Buffer water barrier layer <![CDATA[1×10 -8 ]]> 5 39.16 Metal sheath layer <![CDATA[3.774×10 7 ]]> - 41.16 PVC outer sheath <![CDATA[1×10 -14 ]]> 3 45.16

[0035] Step S202: constructing a finite element simulation model of the high-voltage cable to be tested based on the structural parameters, and calculating the defect capacitance of the insulation defect and the insulating dielectric capacitance of the insulating layer based on the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be tested;

[0036] Specifically, the defect capacitance is the capacitance of the air gap defect 8, and the insulating dielectric capacitance is the capacitance between the inner semi-conductive layer 2 and the buffer water-blocking layer 5 excluding the defect portion. The purpose of constructing a finite element simulation model is to simulate the electric field distribution inside the cable, especially the defect capacitance of the insulation defect and the insulating dielectric capacitance of the insulating layer. The capacitance reflects the ability of each layer in the cable to store charge, and the changes in the defect capacitance and the insulating dielectric capacitance indicate the possible location and intensity of the local discharge activity. Based on the structural parameters of the high-voltage cable (including but not limited to the size, shape, material properties, etc. of the conductor core layer, insulation layer, and insulation defects), a simulation model of the cable is constructed using professional simulation software (such as Ansys, Comsol, ANSOFT HFSS, etc.). The cable structure is simplified into a series of finite, analyzable basic units (i.e., "finite elements"), and meshing is performed so that the model can be solved by numerical methods. Through finite element simulation, the defect capacitance of the insulation defects (such as air gaps, microcracks, etc.) and the insulating layer dielectric capacitance connected in series with the defects can be calculated. These calculations are performed by analyzing the changes in the electric field and potential in the cable model and how they affect the charge distribution at different dielectric interfaces (such as conductor-insulation interface and insulation-air interface).

[0037] Step S203: determining the actual discharge amount of the high-voltage cable to be detected based on the ratio of the defective capacitance to the insulating medium capacitance, and determining that the high-voltage cable to be detected is in a non-insulated state when the actual discharge amount is greater than a preset threshold.

[0038] Specifically, in partial discharge measurements, the apparent discharge amount is often directly measured. However, the amount of charge generated during the actual discharge process (i.e., the true discharge amount) may vary due to factors such as signal attenuation and cable capacitance effects. By comparing the ratio of the defect capacitance (C1) to the insulation capacitance (C2), combined with the apparent discharge amount (q) measured by partial discharge, a specific correction formula can be used to calculate the true discharge amount (q) that is closer to the actual value. r ).

[0039] Through this embodiment, the structural parameters of the high-voltage cable to be detected are obtained, wherein the high-voltage cable to be detected includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least the radius of the insulation defect; a finite element simulation model of the high-voltage cable to be detected is constructed according to the structural parameters, and the defect capacitance of the insulation defect and the insulation dielectric capacitance of the insulation layer are calculated according to the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be detected; the real discharge amount of the high-voltage cable to be detected is determined according to the ratio of the defect capacitance and the insulation dielectric capacitance, and when the real discharge amount is greater than a preset threshold, the high-voltage cable to be detected is determined to be in a non-insulated state. Compared with the prior art, which cannot accurately measure the effect of the capacitance generated by the cable insulation defect on the cable discharge amount, and thus cannot accurately determine the insulation state of the cable, the present application can determine the size of the defect capacitance generated by the insulation defect and the size of the insulation dielectric capacitance, so as to determine the real discharge amount of the high-voltage cable to be detected according to the ratio of the two, thereby accurately determining the insulation state of the cable, thereby solving the problem of the inability to accurately determine the insulation state of the cable in the prior art and achieving the effect of accurately determining the insulation state of the cable.

[0040] In a specific implementation, a target sensor is installed at the grounding point of the high-voltage cable to be inspected in step S203. The actual discharge amount of the high-voltage cable to be inspected is determined based on the ratio of the defect capacitance to the insulation dielectric capacitance. This can be achieved by the following steps: step S2031: detecting the apparent discharge amount of the high-voltage cable to be inspected using the target sensor; step S2032: detecting the target distance between the target sensor and the insulation defect using a partial discharge ultrasonic positioning method; and step S2033: determining the actual discharge amount based on the product of the target distance, the apparent discharge amount, and the ratio of the defect capacitance to the insulation dielectric capacitance. This method corrects the apparent discharge amount by taking into account signal attenuation and capacitance differences, namely the ratio of the defect capacitance to the insulation dielectric capacitance, thereby more accurately reflecting the actual discharge amount of partial discharge.

[0041] Specifically, in partial discharge detection, the target sensor is a key component for capturing the ultrasonic signal generated by the discharge. The target distance refers to the specific distance between the target sensor and the insulation defect in the cable. Because the attenuation of the ultrasonic signal during propagation is directly related to the distance, accurately measuring the target distance is crucial for the subsequent correction of the discharge amount. The apparent discharge amount is the energy of the discharge pulse directly measured in the partial discharge test. It is affected by the cable structure, the sensitivity of the measurement system, and the signal propagation path. Although the apparent discharge amount intuitively reflects the existence of partial discharge activity, its value is not equal to the actual discharge amount. The apparent discharge amount data obtained through the partial discharge test is the basis for the correction calculation. The above three key parameters are combined to correct the apparent discharge amount of the partial discharge to obtain a true discharge amount that is closer to the actual situation. The formula involves the signal attenuation caused by the target distance, the basic value of the apparent discharge amount, and the charge distribution difference reflected by the ratio of the defect capacitance (C1) to the insulation medium capacitance (C2), so as to comprehensively calculate the true discharge amount (q r ).

[0042] In some other optional implementations, step S2033 determines the actual discharge amount according to the product of the target distance, the apparent discharge amount, and the ratio of the defective capacitance to the insulating medium capacitance, which can be achieved by the following steps: Determine the actual discharge amount, where q r represents the true discharge amount, q represents the apparent discharge amount, C1 represents the defect capacitance, C2 represents the insulation capacitance, f represents the dominant frequency of the partial discharge signal, and x represents the target distance. This method accurately calculates the true discharge amount based on the ratio of the defect capacitance to the insulation capacitance through the above steps, significantly improving the accuracy of partial discharge measurement and reducing measurement errors caused by cable structure and signal propagation characteristics.

[0043] Specifically, The first part considers the proportional relationship between defect capacitance and insulation capacitance. This is because the capacitance at an insulation defect differs from the surrounding insulation capacitance, which redistributes the discharge energy during transmission, affecting the measured apparent discharge amount. By introducing this proportionality factor, errors caused by capacitance differences can be corrected. The second part considers signal attenuation, specifically the effect of the propagation distance x of the high-frequency signal generated by partial discharge in the cable on the apparent discharge amount. Signal attenuation increases with distance, which can also cause deviations between the measured discharge amount and the actual value. Therefore, by multiplying by the attenuation factor, the apparent discharge amount can be further corrected to more closely approximate the actual discharge energy.

[0044] In some other optional implementations, the existing partial discharge ultrasonic positioning method is used to measure the target distance x between the defect in the cable to be tested and the target sensor using an ultrasonic sensor.

[0045] Specifically, the target sensor, as a non-contact detection device, is capable of emitting ultrasonic signals of a specific frequency. These signals propagate in a medium (such as air or cable insulation) and are reflected back to the sensor when encountering insulation defects, allowing the location of the insulation defects to be located. After the sensor receives the reflected signal, the system records the total time from the start of emission to the end of receiving the reflected signal. The propagation speed of ultrasonic waves depends on the properties of the medium, and in different types of cable insulation layers (such as cross-linked polyethylene), the propagation speed of ultrasonic waves may vary and needs to be adjusted according to the acoustic properties of the material. After obtaining the propagation time and propagation speed, the target distance can be calculated.

[0046] In some optional embodiments, step S2032 determines the apparent discharge amount of the high-voltage cable to be tested through a partial discharge test, which can be achieved by the following steps: step S2036: when it is detected that a high voltage voltage is applied to the high-voltage cable to be tested, recording the current waveform, wherein the current waveform is the waveform of the current generated when the high-voltage voltage is applied to the high-voltage cable to be tested, and the current waveform includes multiple pulses; step S2037: calculating the equivalent pulse height of the current waveform, and calculating the apparent discharge amount based on the equivalent pulse height, wherein the equivalent pulse height represents the equivalent height of multiple pulses. This method can effectively quantify the activity of cable partial discharge through accurate current waveform recording and equivalent pulse height calculation, providing strong data support for maintenance and troubleshooting of power cables.

[0047] Specifically, in partial discharge (PD) testing, when a cable is subjected to high voltage, defects in the cable's insulation, such as air gaps or cracks, can cause partial discharge (PD) in these defective areas, generating transient current pulses. The current waveform records the current variations caused by PD in the cable under high voltage and contains information about a series of current pulses. High voltage is applied to the cable and the waveform of the current flowing through it is recorded, including key parameters such as the number, shape, and time interval of the current pulses. The equivalent pulse height (EPH) is a statistical representation of the heights of all pulses in the current waveform and can be considered an indicator of the average energy of a PD event. By calculating the EPH, the apparent discharge of the PD can be further calculated—that is, the PD energy as seen by the measuring device. The recorded current waveform is analyzed to extract the height information of all pulses. Based on the number and distribution of pulses, a representative "equivalent" height is calculated. This equivalent height can be the arithmetic mean, energy mean, or weighted mean of all pulse heights. In actual application, in order to make the operation more standardized, it is also possible to carry out partial discharge tests on the cable under test in accordance with the national standard GB / T 3048.12-2007, collect partial discharge signals, and record the size of the apparent discharge.

[0048] In some optional embodiments, the method further includes step S204: if the actual discharge amount is less than or equal to the preset threshold, determining that the high-voltage cable to be inspected is in an insulated state. By comparing the actual discharge amount with the preset threshold, this method can promptly detect partial discharge phenomena that exceed the normal range, providing an early warning to prevent electrical faults caused by cable insulation aging or damage.

[0049] Specifically, when setting preset thresholds, the cable's operating environment and working conditions, as well as potential interference sources, should be fully considered to ensure the scientific and reasonable nature of the thresholds. Preset thresholds should be regularly updated to account for the potential impact of factors such as cable aging and environmental changes, maintaining the sensitivity and accuracy of the detection system. For different cable types and operating conditions, the preset thresholds may need to be customized to meet specific safety and maintenance requirements. Insulation condition assessment methods based on actual discharge can effectively improve the operational safety of power facilities.

[0050] In some optional embodiments, the high-voltage cable to be tested is a 110kV cross-linked polyethylene power cable. The high-voltage cable used in the method is a 110kV cross-linked polyethylene power cable, which can effectively prevent the danger of insulation breakdown and the like in the cable.

[0051] Specifically, for critical transmission equipment like 110kV cross-linked polyethylene (XLPE) power cables, accurate insulation condition assessment helps maintain safe and stable grid operation and prevent large-scale power outages caused by cable faults. For example, during partial discharge testing of a section of 110kV XLPE power cable, the algorithm, after signal correction, calculates a true discharge value of 30pC, compared to a preset threshold of 50pC. In this case, since the true discharge value is below the threshold, the possibility of a serious insulation problem in the cable can be temporarily ruled out, and the cable can continue to operate. However, if the true discharge value gradually approaches or exceeds the preset threshold in future tests, a further investigation of the cable's insulation condition will be necessary, and appropriate repair measures will be implemented if necessary.

[0052] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the implementation process of the method for detecting the insulation status of a high-voltage cable of the present application will be described in detail below with reference to specific embodiments.

[0053] This embodiment relates to a specific method for detecting the insulation status of a high-voltage cable, comprising the following steps:

[0054] Step S1: The cable model to be tested is 110kV YJLW02-1×630mm 2 The structural dimensions and material characteristic parameters of cross-linked polyethylene power cable are shown in Table 1 above. The finite element simulation software is used to establish the following Figure 3 In the electromagnetic simulation model shown, the capacitance of the air gap defect with a radius of 1 mm, C1, is calculated as 0.05926 pF using the electrostatic field. The defect is in the middle of the insulating layer, and the capacitance of the insulating medium in series with the air gap, C2, is calculated as 0.004552 pF using the electrostatic field.

[0055] Step S2: using a partial discharge ultrasonic positioning method and a double-terminal time difference positioning method, the propagation distance (target distance) from the cable defect to the sensor is obtained as x = 15 cm;

[0056] Step S3: According to the national standard GB / T 3048.12-2007, a partial discharge test is performed on the cable to be tested, partial discharge signals are collected, and the apparent discharge amount is recorded as q = 50 pC;

[0057] Step S4: Using the formula The actual discharge capacity is calculated to be 700.95 pC, where q r represents the actual discharge amount, q represents the apparent discharge amount, C1 represents the defective capacitance, C2 represents the insulating medium capacitance, f represents the main frequency of the partial discharge signal, which is 20 MHz, and x represents the target distance.

[0058] The embodiments of the present application also provide a device for detecting the insulation status of a cable. It should be noted that the device for detecting the insulation status of a cable in the embodiments of the present application can be used to execute the detection method for the insulation status of a cable provided in the embodiments of the present application. The device is used to implement the above-mentioned embodiments and preferred implementation methods, and the details that have been described will not be repeated here. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware, is also possible and conceivable.

[0059] The following introduces the cable insulation status detection device provided in the embodiment of the present application.

[0060] Figure 4 Schematic diagram of a device for detecting the insulation status of a cable according to an embodiment of the present application. Figure 4 As shown, the device includes:

[0061] An acquiring unit 10 is configured to acquire structural parameters of a high-voltage cable to be inspected, wherein the high-voltage cable to be inspected includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least a radius of the insulation defect;

[0062] Specifically, the structural diagram of the high-voltage cable to be tested is as follows: Figure 3 As shown, the system comprises a conductor core layer 1, an inner semiconductive layer 2, a cross-linked polyethylene layer 3, an outer semiconductive layer 4, a buffer water-blocking layer 5, a metal sheath layer 6, a PVC outer sheath layer 7, and an air gap defect 8. The air gap defect 8 is a small circular hole located within the insulation layer, or cross-linked polyethylene layer 3. Since the insulation condition of the cable needs to be tested, it is necessary to first identify the insulation defect and obtain the structural parameters of the high-voltage cable to be tested, such as the radius of the insulation defect, which directly affects the calculation of the defect capacitance. Other structural parameters are shown in Table 1.

[0063] a calculation unit 20, configured to construct a finite element simulation model of the high-voltage cable to be inspected based on the structural parameters, and calculate the defect capacitance of the insulation defect and the insulating dielectric capacitance of the insulating layer based on the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be inspected;

[0064] Specifically, the purpose of constructing a finite element simulation model is to simulate the electric field distribution within the cable, specifically the defect capacitance of insulation defects and the dielectric capacitance of the insulation layer. Capacitance reflects the charge storage capacity of each layer in the cable, while changes in defect capacitance and dielectric capacitance indicate the possible location and intensity of partial discharge activity. Based on the structural parameters of the high-voltage cable (including but not limited to the size, shape, and material properties of the conductor core, insulation layer, and insulation defects), a simulation model of the cable is constructed using professional simulation software (such as Ansys, Comsol, and ANSOFT HFSS). The cable structure is simplified into a series of finite, analyzable basic units (i.e., "finite elements"), and meshed to enable the model to be solved by numerical methods. Through finite element simulation, the defect capacitance of insulation defects (such as air gaps and microcracks) and the dielectric capacitance of the insulation layer in series with the defects can be calculated. These calculations are performed by analyzing the changes in the electric field and potential in the cable model and how they affect the charge distribution at different dielectric interfaces (such as the conductor-insulation interface and the insulation-air interface).

[0065] The first determination unit 30 is used to determine the actual discharge amount of the high-voltage cable to be detected according to the ratio of the defective capacitance to the insulating medium capacitance, and determine that the high-voltage cable to be detected is in a non-insulated state when the actual discharge amount is greater than a preset threshold.

[0066] Specifically, in partial discharge measurements, the apparent discharge amount is often directly measured. However, the amount of charge generated during the actual discharge process (i.e., the true discharge amount) may vary due to factors such as signal attenuation and cable capacitance effects. By comparing the ratio of the defect capacitance (C1) to the insulation capacitance (C2), combined with the apparent discharge amount (q) measured by partial discharge, a specific correction formula can be used to calculate the true discharge amount (q) that is closer to the actual value. r ).

[0067] Through this embodiment, the structural parameters of the high-voltage cable to be detected are obtained, wherein the high-voltage cable to be detected includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least the radius of the insulation defect; a finite element simulation model of the high-voltage cable to be detected is constructed according to the structural parameters, and the defect capacitance of the insulation defect and the insulation dielectric capacitance of the insulation layer are calculated according to the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be detected; the real discharge amount of the high-voltage cable to be detected is determined according to the ratio of the defect capacitance and the insulation dielectric capacitance, and when the real discharge amount is greater than a preset threshold, the high-voltage cable to be detected is determined to be in a non-insulated state. Compared with the prior art, which cannot accurately measure the effect of the capacitance generated by the cable insulation defect on the cable discharge amount, and thus cannot accurately determine the insulation state of the cable, the present application can determine the size of the defect capacitance generated by the insulation defect and the size of the insulation dielectric capacitance, so as to determine the real discharge amount of the high-voltage cable to be detected according to the ratio of the two, thereby accurately determining the insulation state of the cable, thereby solving the problem of the inability to accurately determine the insulation state of the cable in the prior art and achieving the effect of accurately determining the insulation state of the cable.

[0068] In a specific implementation, the first determination unit includes a detection module, a first determination module, and a second determination module. The detection module is configured to detect the apparent discharge of the high-voltage cable to be inspected using the target sensor. The first determination module is configured to detect the target distance between the target sensor and the insulation defect using a partial discharge ultrasonic positioning method. The second determination module is configured to determine the actual discharge amount based on the product of the target distance, the apparent discharge amount, and the ratio of the defect capacitance to the insulation dielectric capacitance. This device corrects the apparent discharge amount by taking into account signal attenuation and capacitance differences, namely the ratio of the defect capacitance to the insulation dielectric capacitance, thereby more accurately reflecting the actual discharge amount of the partial discharge.

[0069] Specifically, in partial discharge detection, the target sensor is a key component for capturing the ultrasonic signal generated by the discharge. The target distance refers to the specific distance between the target sensor and the insulation defect in the cable. Because the attenuation of the ultrasonic signal during propagation is directly related to the distance, accurately measuring the target distance is crucial for the subsequent correction of the discharge amount. The apparent discharge amount is the energy of the discharge pulse directly measured in the partial discharge test. It is affected by the cable structure, the sensitivity of the measurement system, and the signal propagation path. Although the apparent discharge amount intuitively reflects the existence of partial discharge activity, its value is not equal to the actual discharge amount. The apparent discharge amount data obtained through the partial discharge test is the basis for the correction calculation. The above three key parameters are combined to correct the apparent discharge amount of the partial discharge to obtain a true discharge amount that is closer to the actual situation. The formula involves the signal attenuation caused by the target distance, the basic value of the apparent discharge amount, and the charge distribution difference reflected by the ratio of the defect capacitance (C1) to the insulation medium capacitance (C2), so as to comprehensively calculate the true discharge amount (q r ).

[0070] In some other optional implementations, the second determination module includes a first determination submodule for determining Determine the actual discharge amount, where q r represents the true discharge amount, q represents the apparent discharge amount, C1 represents the defect capacitance, C2 represents the insulation capacitance, f represents the primary frequency of the partial discharge signal, and x represents the target distance. Through the above steps, the device accurately calculates the true discharge amount based on the ratio of the defect capacitance to the insulation capacitance, significantly improving the accuracy of partial discharge measurement and reducing measurement errors caused by cable structure and signal propagation characteristics.

[0071] Specifically, The first part considers the proportional relationship between defect capacitance and insulation capacitance. This is because the capacitance at an insulation defect differs from the surrounding insulation capacitance, which redistributes the discharge energy during transmission, affecting the measured apparent discharge amount. By introducing this proportionality factor, errors caused by capacitance differences can be corrected. The second part considers signal attenuation, specifically the effect of the propagation distance x of the high-frequency signal generated by partial discharge in the cable on the apparent discharge amount. Signal attenuation increases with distance, which can also cause deviations between the measured discharge amount and the actual value. Therefore, by multiplying by the attenuation factor, the apparent discharge amount can be further corrected to more closely approximate the actual discharge energy.

[0072] In some other optional implementations, the existing partial discharge ultrasonic positioning method is used to measure the target distance x between the defect in the cable to be tested and the target sensor using an ultrasonic sensor.

[0073] Specifically, ultrasonic sensors, as a non-contact detection device, can emit ultrasonic signals of a specific frequency. These signals propagate in a medium (such as air or cable insulation) and are reflected back to the sensor when encountering insulation defects. After the ultrasonic sensor receives the reflected signal, the system records the total time from the start of emission to the end of receiving the reflected signal, which can locate the location of the insulation defect. The propagation speed of ultrasonic waves depends on the properties of the medium. In different types of cable insulation layers (such as cross-linked polyethylene), the propagation speed of ultrasonic waves may vary and needs to be adjusted according to the acoustic properties of the material. After obtaining the propagation time and propagation speed, the target distance can be calculated.

[0074] In some optional embodiments, the first determination module includes a recording submodule and a second calculation submodule. The recording submodule is configured to record a current waveform when a high voltage voltage is detected to be applied to the high-voltage cable to be detected, wherein the current waveform is the waveform of the current generated when the high-voltage voltage is applied to the high-voltage cable to be detected, and the current waveform includes multiple pulses. The second calculation submodule is configured to calculate the equivalent pulse height of the current waveform, and calculate the apparent discharge amount based on the equivalent pulse height, wherein the equivalent pulse height represents the equivalent height of multiple pulses. Through precise current waveform recording and equivalent pulse height calculation, the device can effectively quantify the activity of cable partial discharge, providing strong data support for maintenance and troubleshooting of power cables.

[0075] Specifically, in partial discharge (PD) testing, when a cable is subjected to high voltage, defects in the cable's insulation, such as air gaps or cracks, can cause partial discharge (PD) in these defective areas, generating transient current pulses. The current waveform records the current variations caused by PD in the cable under high voltage and contains information about a series of current pulses. High voltage is applied to the cable and the waveform of the current flowing through it is recorded, including key parameters such as the number, shape, and time interval of the current pulses. The equivalent pulse height (EPH) is a statistical representation of the heights of all pulses in the current waveform and can be considered an indicator of the average energy of a PD event. By calculating the EPH, the apparent discharge of the PD can be further calculated—that is, the PD energy as seen by the measuring device. The recorded current waveform is analyzed to extract the height information of all pulses. Based on the number and distribution of pulses, a representative "equivalent" height is calculated. This equivalent height can be the arithmetic mean, energy mean, or weighted mean of all pulse heights.

[0076] In some optional embodiments, the device further includes a second determination unit configured to determine that the high-voltage cable under inspection is in an insulated state when the actual discharge amount is less than or equal to a preset threshold. By comparing the actual discharge amount with the preset threshold, the device can promptly detect partial discharge phenomena that exceed the normal range, providing an early warning to prevent electrical faults caused by aging or damage to the cable insulation.

[0077] Specifically, when setting preset thresholds, the cable's operating environment and working conditions, as well as potential interference sources, should be fully considered to ensure the scientific and reasonable nature of the thresholds. Preset thresholds should be regularly updated to account for the potential impacts of factors such as cable aging and environmental changes, maintaining the sensitivity and accuracy of the detection system. For different cable types and operating conditions, the preset thresholds may need to be customized to meet specific safety and maintenance requirements. An insulation condition assessment device based on actual discharge can effectively improve the operational safety of power facilities.

[0078] In some optional embodiments, the high-voltage cable to be detected is a 110kV cross-linked polyethylene power cable. The high-voltage cable used in the device is a 110kV cross-linked polyethylene power cable, which can effectively prevent the danger of insulation breakdown and the like of the cable.

[0079] Specifically, for critical transmission equipment like 110kV cross-linked polyethylene (XLPE) power cables, accurate insulation condition assessment helps maintain safe and stable grid operation and prevent large-scale power outages caused by cable faults. For example, during partial discharge testing of a section of 110kV XLPE power cable, the algorithm, after signal correction, calculates a true discharge value of 30pC, compared to a preset threshold of 50pC. In this case, since the true discharge value is below the threshold, the possibility of a serious insulation problem in the cable can be temporarily ruled out, and the cable can continue to operate. However, if the true discharge value gradually approaches or exceeds the preset threshold in future tests, a further investigation of the cable's insulation condition will be necessary, and appropriate repair measures will be implemented if necessary.

[0080] The cable insulation status detection device includes a processor and a memory. The acquisition unit, calculation unit, and first determination unit are all stored as program units in the memory. The processor executes the program units stored in the memory to implement the corresponding functions. The modules are all located in the same processor; alternatively, the modules can be located in different processors in any combination.

[0081] The processor contains a kernel, which retrieves the corresponding program unit from the memory. One or more kernels can be set, and the insulation status of the cable can be accurately determined by adjusting the kernel parameters.

[0082] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0083] An embodiment of the present invention provides a computer-readable storage medium, which includes a stored program. When the program is executed, the device where the computer-readable storage medium is located is controlled to execute the method for detecting the insulation status of a high-voltage cable.

[0084] Specifically, the method for detecting the insulation status of a high-voltage cable includes:

[0085] Step S201, obtaining structural parameters of a high-voltage cable to be inspected, wherein the high-voltage cable to be inspected includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least a radius of the insulation defect;

[0086] Step S202: constructing a finite element simulation model of the high-voltage cable to be tested based on the structural parameters, and calculating the defect capacitance of the insulation defect and the insulating dielectric capacitance of the insulating layer based on the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be tested;

[0087] Step S203: determining the actual discharge amount of the high-voltage cable to be detected based on the ratio of the defective capacitance to the insulating medium capacitance, and determining that the high-voltage cable to be detected is in a non-insulated state when the actual discharge amount is greater than a preset threshold.

[0088] An embodiment of the present invention provides an electronic device, including a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, at least the following steps are performed:

[0089] Step S201, obtaining structural parameters of a high-voltage cable to be inspected, wherein the high-voltage cable to be inspected includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least a radius of the insulation defect;

[0090] Step S202: constructing a finite element simulation model of the high-voltage cable to be tested based on the structural parameters, and calculating the defect capacitance of the insulation defect and the insulating dielectric capacitance of the insulating layer based on the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be tested;

[0091] Step S203: determining the actual discharge amount of the high-voltage cable to be detected based on the ratio of the defective capacitance to the insulating medium capacitance, and determining that the high-voltage cable to be detected is in a non-insulated state when the actual discharge amount is greater than a preset threshold.

[0092] The devices in this article can be servers, PCs, PADs, mobile phones, etc.

[0093] The present application also provides a computer program product, including a computer program, which, when executed by a processor, implements the steps of the method described in each embodiment of the present application:

[0094] Step S201, obtaining structural parameters of a high-voltage cable to be inspected, wherein the high-voltage cable to be inspected includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least a radius of the insulation defect;

[0095] Step S202: constructing a finite element simulation model of the high-voltage cable to be tested based on the structural parameters, and calculating the defect capacitance of the insulation defect and the insulating dielectric capacitance of the insulating layer based on the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be tested;

[0096] Step S203: determining the actual discharge amount of the high-voltage cable to be detected based on the ratio of the defective capacitance to the insulating medium capacitance, and determining that the high-voltage cable to be detected is in a non-insulated state when the actual discharge amount is greater than a preset threshold.

[0097] Obviously, those skilled in the art will appreciate that the various modules or steps of the present invention described above can be implemented using a general-purpose computing device, can be centralized on a single computing device, or can be distributed across a network of multiple computing devices. They can be implemented using program code executable by the computing device, and thus, can be stored in a storage device and executed by the computing device. In some cases, the steps shown or described herein can be performed in a different order than that shown, or can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0098] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0099] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0100] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0101] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0102] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0103] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0104] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0105] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0106] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0107] 1) In the method for detecting the insulation state of a high-voltage cable of the present application, the structural parameters of the high-voltage cable to be detected are obtained, wherein the high-voltage cable to be detected includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least the radius of the insulation defect; a finite element simulation model of the high-voltage cable to be detected is constructed according to the structural parameters, and the defect capacitance of the insulation defect and the insulation dielectric capacitance of the insulation layer are calculated according to the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be detected; the actual discharge amount of the high-voltage cable to be detected is determined according to the ratio of the defect capacitance and the insulation dielectric capacitance, and when the actual discharge amount is greater than a preset threshold, the high-voltage cable to be detected is determined to be in a non-insulated state. Compared with the prior art, which cannot accurately measure the effect of the capacitance generated by the cable insulation defect on the cable discharge amount, and thus cannot accurately determine the insulation state of the cable, the present application can determine the size of the defect capacitance generated by the insulation defect and the size of the insulation dielectric capacitance, so as to determine the actual discharge amount of the high-voltage cable to be detected according to the ratio of the two, thereby accurately determining the insulation state of the cable. Therefore, it can solve the problem of the inability to accurately determine the insulation state of the cable in the prior art and achieve the effect of accurately determining the insulation state of the cable.

[0108] 2) In the detection device for the insulation state of a high-voltage cable of the present application, the structural parameters of the high-voltage cable to be detected are obtained, wherein the high-voltage cable to be detected includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least the radius of the insulation defect; a finite element simulation model of the high-voltage cable to be detected is constructed according to the structural parameters, and the defect capacitance of the insulation defect and the insulation dielectric capacitance of the insulation layer are calculated according to the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be detected; the actual discharge amount of the high-voltage cable to be detected is determined according to the ratio of the defect capacitance and the insulation dielectric capacitance, and when the actual discharge amount is greater than a preset threshold, the high-voltage cable to be detected is determined to be in a non-insulated state. Compared with the prior art, which cannot accurately measure the effect of the capacitance generated by the cable insulation defect on the cable discharge amount, and thus cannot accurately determine the insulation state of the cable, the present application can determine the size of the defect capacitance generated by the insulation defect and the size of the insulation dielectric capacitance, so as to determine the actual discharge amount of the high-voltage cable to be detected according to the ratio of the two, thereby accurately determining the insulation state of the cable. Therefore, it can solve the problem of the inability to accurately determine the insulation state of the cable in the prior art and achieve the effect of accurately determining the insulation state of the cable.

[0109] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for detecting the insulation status of a high-voltage cable, characterized in that: include: Acquire structural parameters of a high-voltage cable to be inspected, wherein the high-voltage cable to be inspected includes at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters include at least a radius of the insulation defect; Constructing a finite element simulation model of the high-voltage cable to be inspected according to the structural parameters, and calculating the defect capacitance of the insulation defect and the insulating dielectric capacitance of the insulating layer according to the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be inspected; The actual discharge amount of the high-voltage cable to be detected is determined according to the ratio of the defective capacitance to the insulating medium capacitance, and when the actual discharge amount is greater than a preset threshold, the high-voltage cable to be detected is determined to be in a non-insulated state.

2. The method for detecting the insulation status of a cable according to claim 1, wherein: A target sensor is provided at the grounding point of the high-voltage cable to be detected, and a true discharge amount of the high-voltage cable to be detected is determined according to the ratio of the defect capacitance to the insulation medium capacitance, including: Detecting the apparent discharge amount of the high-voltage cable to be detected by the target sensor; Using a partial discharge ultrasonic positioning method to detect the target distance between the target sensor and the insulation defect; The actual discharge amount is determined according to a product of the target distance, the apparent discharge amount, and a ratio of the defect capacitance to the insulation medium capacitance.

3. The method for detecting the insulation status of a cable according to claim 2, wherein: Determining the actual discharge amount according to the product of the target distance, the apparent discharge amount, and the ratio of the defect capacitance to the insulation medium capacitance includes: By formula Determine the actual discharge amount, where q r represents the actual discharge amount, q represents the apparent discharge amount, C1 represents the defective capacitance, C2 represents the insulating medium capacitance, f represents the main frequency of the partial discharge signal, and x represents the target distance.

4. The method for detecting the insulation status of a cable according to claim 2, wherein: The apparent discharge amount of the high-voltage cable to be tested is determined by a partial discharge test, including: When it is detected that a high voltage voltage is applied to the high-voltage cable to be detected, a current waveform is recorded, wherein the current waveform is a waveform of a current generated when the high voltage voltage is applied to the high-voltage cable to be detected, and the current waveform includes a plurality of pulses; The equivalent pulse height of the current waveform is calculated, and the apparent discharge amount is calculated according to the equivalent pulse height, wherein the equivalent pulse height represents the equivalent height of multiple pulses.

5. The method for detecting the insulation status of a cable according to claim 1, wherein: The method further comprises: When the actual discharge amount is less than or equal to the preset threshold, it is determined that the high-voltage cable to be detected is in an insulation state.

6. The method for detecting the insulation status of a cable according to claim 1, wherein: The high-voltage cable to be tested is a 110kV cross-linked polyethylene power cable.

7. A device for detecting the insulation status of a cable, characterized in that: include: an acquiring unit, configured to acquire structural parameters of a high-voltage cable to be inspected, wherein the high-voltage cable to be inspected comprises at least an insulation layer and an insulation defect, the insulation defect is located in the insulation layer, and the structural parameters comprise at least a radius of the insulation defect; a calculation unit, configured to construct a finite element simulation model of the high-voltage cable to be inspected based on the structural parameters, and calculate the defect capacitance of the insulation defect and the insulating dielectric capacitance of the insulating layer based on the finite element simulation model, wherein the finite element simulation model is used to simulate the structure and electric field of the high-voltage cable to be inspected; The first determining unit is used to determine the actual discharge amount of the high-voltage cable to be detected according to the ratio of the defective capacitance to the insulating medium capacitance, and determine that the high-voltage cable to be detected is in a non-insulated state when the actual discharge amount is greater than a preset threshold.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the method for detecting the insulation status of a cable according to any one of claims 1 to 6.

9. An electronic device, characterized in that: include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include a method for executing the cable insulation status detection method according to any one of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the method for detecting the insulation status of a cable according to any one of claims 1 to 6 is implemented.

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