Methods, devices, and electronic equipment for determining the compression state of high-voltage cable buffer layers

Abstract

This application discloses a method, apparatus, and electronic device for determining the compression state of a high-voltage cable buffer layer. The method includes: acquiring a curve representing the relationship between the resistivity and pressure of the high-voltage cable buffer layer using a measuring device; determining the inflection interval of the curve, wherein the inflection interval includes the interval where the rate of change of the curve's slope is greater than a preset threshold; determining a target inflection point from the inflection interval, and using the pressure value corresponding to the target inflection point as a critical pressure value; and determining the compression state of the high-voltage cable buffer layer using the critical pressure value. This application solves the technical problem that, due to the long and smooth transition section of the resistivity-pressure curve of the buffer layer, judging whether the high-voltage cable buffer layer is compressed by manual observation results in large errors and a lack of reproducibility.

Description

Technical Field

[0001] This application relates to the field of data processing, and more specifically, to a method, apparatus, and electronic device for determining the compression state of a high-voltage cable buffer layer. Background Technology

[0002] To address the ablation defects in the buffer layer of high-voltage cables, related technologies rely on manual observation of the resistivity-pressure curve of the buffer layer to determine whether it is properly compressed. However, since the transition section of the resistivity-pressure curve of the high-voltage cable buffer layer is long and smooth, manual observation can lead to significant errors due to subjective factors, lacking reliability and reproducibility.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This application provides a method, apparatus, and electronic device for determining the compression state of a high-voltage cable buffer layer, in order to at least solve the technical problem that, due to the long and smooth transition section of the resistivity-pressure curve of the buffer layer, it is difficult to determine whether the high-voltage cable buffer layer is compressed by human observation, resulting in large errors and a lack of reproducibility.

[0005] According to one aspect of the embodiments of this application, a method for determining the compression state of a high-voltage cable buffer layer is provided, comprising: acquiring a curve representing the relationship between the resistivity of the high-voltage cable buffer layer and pressure using a measuring device; determining the inflection interval of the curve, wherein the inflection interval includes an interval where the rate of change of the curve slope is greater than a preset threshold; determining a target inflection point from the inflection interval, and using the pressure value corresponding to the target inflection point as a critical pressure value; and determining the compression state of the high-voltage cable buffer layer using the critical pressure value.

[0006] In some embodiments of this application, determining the inflection interval of the curve includes: obtaining the maximum pressure value of the measurement points in the measurement point set, wherein the measurement points in the measurement point set are used to represent the resistivity of the high-voltage cable buffer layer under different pressure conditions; performing a function operation on the maximum pressure value with a first preset ratio and a second preset ratio respectively to obtain a first pressure value and a second pressure value, wherein the first preset ratio is less than the second preset ratio; taking the measurement point corresponding to the first pressure value as the first starting point of the inflection interval, and taking the measurement point corresponding to the second pressure value as the first ending point of the inflection interval.

[0007] In some embodiments of this application, determining a target inflection point from an inflection interval includes: obtaining the second beginning endpoint and the second end endpoint of the curve; obtaining a first inflection point from the measurement points contained in the inflection interval, wherein the first inflection point is any measurement point within the inflection interval; determining the loss function value of the first inflection point based on the second beginning endpoint of the curve, the second end endpoint of the curve, and the measurement points contained in the inflection interval; and determining the target inflection point from the measurement points contained in the inflection interval based on the loss function value.

[0008] In some embodiments of this application, determining the loss function value of the first inflection point based on the second beginning endpoint of the curve, the second end endpoint of the curve, and the measurement points contained in the inflection interval includes: linearly fitting the first inflection point to the second beginning endpoint and the second end endpoint respectively to obtain a first function and a second function; obtaining the original function value of each measurement point on the curve within the inflection interval, and the first function value corresponding to the first function and the second function value corresponding to the second function for each measurement point; and calculating the loss function value of the first inflection point using the original function value, the first function value, and the second function value.

[0009] In some embodiments of this application, after determining the target inflection point from the measurement points contained in the inflection interval based on the loss function value, the method further includes: comparing the target inflection point with the endpoints of the inflection interval, wherein the endpoints of the inflection interval include the first beginning endpoint and the first end endpoint of the inflection interval; expanding the inflection interval if the target inflection point is an endpoint of the inflection interval; and redetermining the target inflection point using the expanded inflection interval.

[0010] In some embodiments of this application, when the target turning point is the endpoint of a turning interval, expanding the turning interval includes: when the target turning point is the first endpoint of the turning interval, performing a function operation on the pressure value of the first endpoint and a third preset ratio to obtain a third pressure value, and using the measurement point corresponding to the third pressure value as the target first endpoint of the turning interval, wherein the third pressure value is less than the pressure value of the first endpoint; when the target turning point is the first end endpoint of the turning interval, performing a function operation on the pressure value of the first end endpoint and a fourth preset ratio to obtain a fourth pressure value, and using the measurement point corresponding to the fourth pressure value as the target end endpoint of the turning interval, wherein the fourth pressure value is greater than the pressure value of the first end endpoint.

[0011] In some embodiments of this application, determining the compression state of the high-voltage cable buffer layer using a critical pressure value includes: measuring the pressure value of the high-voltage cable buffer layer; comparing the pressure value of the high-voltage cable buffer layer with a critical pressure value; determining that the high-voltage cable buffer layer is in a compressed state when the pressure value of the high-voltage cable buffer layer is greater than the critical pressure value; and determining that the high-voltage cable buffer layer is in a non-compressed state when the pressure value of the high-voltage cable buffer layer is less than or equal to the critical pressure value.

[0012] According to another aspect of the embodiments of this application, a device for determining the compression state of a high-voltage cable buffer layer is also provided, comprising: an acquisition module for acquiring a curve representing the relationship between the resistivity of the high-voltage cable buffer layer and pressure; a first determination module for determining the inflection interval of the curve, wherein the inflection interval includes an interval where the rate of change of the curve slope is greater than a preset threshold; a second determination module for determining a target inflection point from the inflection interval and using the pressure value corresponding to the target inflection point as a critical pressure value; and an execution module for determining the compression state of the high-voltage cable buffer layer using the critical pressure value.

[0013] According to another aspect of the embodiments of this application, an electronic device is also provided, including: a memory and a processor, wherein the memory is used to store program instructions; the processor is connected to the memory and is used to execute the method for determining the compression state of the high-voltage cable buffer layer as described above.

[0014] According to another aspect of the embodiments of this application, a non-volatile storage medium is also provided, the non-volatile storage medium including a stored computer program, wherein the device containing the non-volatile storage medium executes the above-mentioned method for determining the compression state of the high-voltage cable buffer layer by running the computer program.

[0015] According to another aspect of the embodiments of this application, a computer program product is also provided, including computer instructions that, when executed by a processor, implement the method for determining the clamping state of the high-voltage cable buffer layer described above.

[0016] In this embodiment, the measuring device determines the transition interval from the curve of the relationship between the resistivity and pressure of the high-voltage cable buffer layer, and determines the target transition point within the transition interval. The pressure value at the target transition point is used to determine the compression state of the high-voltage cable buffer layer. By accurately determining the target transition point on the curve using the measuring device, the purpose of accurately judging whether high-voltage cables of different voltage levels and different types of buffer layers are compressed can be achieved. This realizes the technical effect of reducing the burning failure of the high-voltage cable buffer layer and effectively improving the conductivity of the high-voltage cable buffer layer. In addition, it solves the technical problem that the transition section of the resistivity-pressure curve of the buffer layer is long and smooth, and the judgment of whether the high-voltage cable buffer layer is compressed by human observation has large errors and lacks reproducibility. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0018] Figure 1 This is a hardware structure block diagram of a computer terminal for a method of determining the compression state of a high-voltage cable buffer layer according to an embodiment of this application.

[0019] Figure 2 This is a flowchart of a method for determining the compression state of a high-voltage cable buffer layer according to an embodiment of this application;

[0020] Figure 3 This is a schematic diagram of the relationship between the resistivity of a high-voltage cable buffer layer and pressure according to an embodiment of this application.

[0021] Figure 4 This is a schematic diagram of the overall process of a method for determining the compression state of a high-voltage cable buffer layer according to an embodiment of this application;

[0022] Figure 5 This is a schematic diagram of a device for determining the compression state of a high-voltage cable buffer layer according to an embodiment of this application. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0025] To better understand the embodiments of this application, the technical terms involved in the embodiments of this application are explained below:

[0026] High-voltage cables: These are power cables used to transmit high voltage (generally above 10kV), mainly for long-distance power transmission.

[0027] Buffer layer: In the structure of high-voltage cables, the buffer layer is usually located between the insulation layer and the metal sheath. It has semi-conductive properties and its main function is to balance the electric field inside the cable, reduce the uneven influence of the electric field on the insulation layer, and at the same time play a role in physical protection and water blocking.

[0028] Resistivity: A physical quantity used to measure the electrical conductivity of a material. It represents the material resistance per unit length and per unit cross-sectional area. For the buffer layer of a high-voltage cable, the change in resistivity is closely related to its degree of moisture absorption and compression condition.

[0029] Pressure: Pressure refers to the force exerted per unit area, a physical quantity used to measure the degree of force on an object. In high-voltage cables, the pressure exerted by the metal sheath on the buffer layer affects the structural compactness and conductivity of the buffer layer.

[0030] With the development of urban power grids and the increasing scarcity of land resources, the application of high-voltage cables is becoming more and more widespread. Their insulation condition directly affects the reliability and stability of the entire power network. However, in recent years, high-voltage cable buffer layer ablation failures have occurred frequently. Ablation marks appear on the semi-conductive buffer water-blocking layer (referred to as the "buffer layer"), and white powder precipitates at the defective areas, gradually deteriorating the main insulation of the cable and ultimately causing insulation breakdown. Buffer layer ablation defects have extremely high latency, a very long development process, and a wide range of effects, seriously impacting the safe operation of urban power transmission networks.

[0031] The ablation defect in the buffer layer is caused by changes in the resistivity of the semi-conductive resistive water in the buffer layer due to moisture (the conductivity of the buffer layer decreases when damp, and the sodium salts generated by the chemical reaction also have low conductivity). This leads to poor contact between the corrugated aluminum sheath and the insulating shield, resulting in localized electric field distortion at the contact points between the corrugated aluminum sheath and the insulating shield, gradually deteriorating the main insulation of the high-voltage cable. Therefore, determining the conductivity of the high-voltage cable buffer layer is extremely important.

[0032] Under pressure, the resistivity of the buffer layer will change significantly due to its loose and porous structure. Test results of the buffer layer-pressure characteristic curve show that it is an "L"-shaped curve with a distinct smooth transition region. Identifying a turning point within this smooth transition region allows for the accurate determination of the critical pressure value at which the resistivity of different types of buffer layers changes from rapid to slow change. By controlling the pressure exerted on the buffer layer by the high-voltage cable's metal sheath, and controlling the buffer layer's resistivity in the region after this turning point (i.e., the region with lower and slower resistivity change), the conductivity of the buffer layer can be effectively improved.

[0033] In related technologies, there is no clear technical solution for determining whether the buffer layer of a high-voltage cable is compressed. Most methods rely on human observation. However, the resistivity-pressure characteristic curve of the buffer layer has a long and smooth transition section, and human observation is prone to significant errors due to subjective factors, lacking reliability and repeatability. To address these technical problems, this application provides a corresponding solution, which is detailed below.

[0034] The method for determining the compression state of the high-voltage cable buffer layer provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Figure 1 A hardware block diagram of a computer terminal for determining the compression state of a high-voltage cable buffer layer is shown. Figure 1 As shown, the computer terminal 10 may include one or more processors (shown as 102a, 102b, ..., 102n in the figure) (the processor may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.), a memory 104 for storing data, and a transmission module 106 for communication functions connected via wired and / or wireless networks. In addition, it may also include: a display, a keyboard, a cursor control device, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the I / O interface), a network interface, and a BUS bus. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the aforementioned electronic device. For example, computer terminal 10 may also include... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0035] It should be noted that the aforementioned one or more processors and / or other data processing circuits are generally referred to herein as "data processing circuits". These data processing circuits may be implemented wholly or partially as software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuits may be a single, independent processing module, or may be wholly or partially integrated into any other element in the computer terminal 10. As involved in the embodiments of this application, the data processing circuits serve as processor control (e.g., selection of a variable resistor termination path connected to an interface).

[0036] The memory 104 can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the method for determining the compression state of the high-voltage cable buffer layer in this embodiment. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 104, thereby realizing the above-mentioned method for determining the compression state of the high-voltage cable buffer layer. The memory 104 may include high-speed random access memory, 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 instances, the memory 104 may further include memory remotely located relative to the processor, and these remote memories can be connected to the computer terminal 10 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0037] The transmission module 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the communication provider of the computer terminal 10. In one example, the transmission module 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission module 106 may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0038] The display may be, for example, a touchscreen liquid crystal display (LCD) that allows the user to interact with the user interface of the computer terminal 10.

[0039] It should be noted here that, in some optional embodiments, the above... Figure 1 The computer terminal shown may include hardware elements (including circuitry), software elements (including computer code stored on a computer-readable medium), or a combination of both hardware and software elements. It should be noted that... Figure 1 This is only one instance of a specific particular instance, and is intended to illustrate the types of components that may exist in the aforementioned computer terminal.

[0040] Under the above operating environment, this application provides an embodiment of a method for determining the compression state of a high-voltage cable buffer layer. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0041] Figure 2 This is a flowchart illustrating a method for determining the compression state of a high-voltage cable buffer layer according to an embodiment of this application, as shown below. Figure 2 As shown, the method includes the following steps:

[0042] Step S202: The measuring device acquires a curve representing the relationship between the resistivity of the high-voltage cable buffer layer and the pressure.

[0043] In step S202, the measuring device refers to an instrument or system capable of measuring the resistivity of the high-voltage cable buffer layer under different pressures. In some embodiments, the measuring device may include, but is not limited to, a pressure sensor, a resistance meter, a computer control system, etc. For example, the measuring device may be a device containing a pressure chamber and a resistance measuring circuit. The pressure chamber can apply pressure through a hydraulic system or a pneumatic system, and the resistance measuring circuit can measure the resistance value of the buffer layer under different pressures, thereby calculating the resistivity.

[0044] In some embodiments, the curve relating the resistivity of the high-voltage cable buffer layer to pressure can be obtained through the following steps: sampling the buffer layer of the high-voltage cable, performing buffer layer resistivity tests under different pressure conditions, obtaining a set of measurement points reflecting the buffer layer resistivity-pressure relationship, performing polynomial fitting on the measurement points in the measurement point set, and obtaining a smooth buffer layer resistivity-pressure characteristic curve.

[0045] The relationship between resistivity and pressure can be visualized by the distribution of measurement points in a coordinate system. For example, by using the horizontal axis to represent pressure and the vertical axis to represent resistivity, it can be shown how the resistivity of the buffer layer changes with increasing pressure.

[0046] Step S204: Determine the turning interval of the curve, wherein the turning interval includes the interval where the rate of change of the curve slope is greater than a preset threshold.

[0047] In step S204, the transition interval refers to the region in the resistivity-pressure relationship curve of the buffer layer where the resistivity change changes from rapid to slow (i.e., the region where the rate of change of resistivity with respect to pressure changes significantly). The rate of change of the curve slope refers to the difference between the slope of a point on the resistivity-pressure relationship curve of the buffer layer and the slope of adjacent points; the rate of change of this difference can be used to quantify the degree of slope change in the transition interval. The preset threshold is a pre-set value for the rate of change of the curve slope, used to distinguish between transition intervals and non-transition intervals, and can be determined based on historical data, experience, or statistical analysis methods.

[0048] In some embodiments, the turning point interval can be determined by the rate of change of the curve slope and a preset threshold:

[0049] (1) Calculate the slope of the curve: that is, calculate the slope of the curve at each point, for example, by using the differential of the curve.

[0050] (2) Calculate the slope change rate: that is, calculate the difference between the slopes of adjacent points to obtain the slope change rate. For example, the slope change rate sequence can be obtained by calculating the difference between the slope sequences.

[0051] (3) Set a preset threshold: For example, conduct multiple experiments, analyze the distribution of the slope change rate, and select a significant change point in the slope change rate distribution as the preset threshold.

[0052] (4) Compare the slope change rate with the preset threshold: Compare the slope change rate sequence calculated in step (2) with the preset threshold, find the points where the slope change rate is greater than the preset threshold, and the set of these points defines the range of the turning interval.

[0053] (5) Determine the turning point: The starting and ending points of the turning point can be determined by points where the rate of change of the slope is greater than a preset threshold. For example, start from the point where the rate of change of the slope of the last curve is greater than the preset threshold and search to the left until the point where the rate of change of the slope is first lower than the preset threshold is found to determine the starting point of the turning point; start from the point where the rate of change of the slope of the last curve is greater than the preset threshold and search to the right until the point where the rate of change of the slope is first lower than the preset threshold is found to determine the ending point of the turning point.

[0054] To more accurately pinpoint the inflection point of the change in the compression state of the buffer layer, the inflection interval can be determined through the following steps: obtaining the maximum pressure value of the measurement points in the measurement point set, wherein the measurement points in the measurement point set are used to represent the resistivity of the high-voltage cable buffer layer under different pressure conditions; performing function calculations on the maximum pressure value with a first preset ratio and a second preset ratio respectively to obtain a first pressure value and a second pressure value, wherein the first preset ratio is less than the second preset ratio; taking the measurement point corresponding to the first pressure value as the first endpoint of the inflection interval, and taking the measurement point corresponding to the second pressure value as the first end endpoint of the inflection interval.

[0055] (1) Obtain the maximum pressure value of the measurement points in the measurement point set: that is, find the maximum pressure value that the buffer layer can withstand from all the corresponding data of resistivity and pressure of the high voltage cable buffer layer obtained by measurement. In some embodiments, this can be achieved by sorting the data or directly searching for the maximum pressure value in the dataset.

[0056] (2) Calculate the first pressure value and the second pressure value: The first preset ratio is a preset ratio used to determine the starting point of the turning interval (e.g., 10%), and its value is less than the second preset ratio, so as to determine the starting point of the turning interval; the second preset ratio is a preset ratio used to determine the ending point of the turning interval (e.g., 30%), and its value is greater than the first preset ratio, so as to determine the ending point of the turning interval. The function operation can be linear operation, exponential operation, logarithmic operation, power operation, etc.

[0057] In some embodiments, the maximum pressure value can be multiplied by a first preset ratio to obtain a first pressure value, and the maximum pressure value can be multiplied by a second preset ratio to obtain a second pressure value.

[0058] (3) Determine the beginning and end points of the transition interval: In some embodiments, a measurement point with pressure equal to the first pressure value can be found in the dataset and the point is determined as the first beginning point of the transition interval. A measurement point with pressure equal to the second pressure value can be found in the dataset and the point is determined as the first end point of the transition interval.

[0059] Step S206: Determine the target turning point from the turning interval, and take the pressure value corresponding to the target turning point as the critical pressure value.

[0060] In step S206, the target inflection point refers to the key point within the inflection range that accurately reflects the transition of the buffer layer from a non-compressed state to a compressed state. The critical pressure value refers to a standard value that can be used for the manufacture, testing, and maintenance of high-voltage cables. In some embodiments, when the pressure on the high-voltage cable buffer layer exceeds the critical pressure value, the buffer layer is considered to be compressed, while when the pressure is less than or equal to the critical pressure value, the buffer layer is in a non-compressed state.

[0061] In some embodiments, the target inflection point is a unique point calculated from the measurement points contained in the inflection interval. For example, the target inflection point can be obtained by calculating the rate of change of the slope at each point within the inflection interval, and finding the point with the smallest rate of change of slope. Alternatively, statistical methods can be used to analyze the set of points within the inflection interval to find the local minimum of the rate of change of slope. After determining the target inflection point, the critical pressure value can be obtained by reading the abscissa (pressure value) of the target inflection point on the curve.

[0062] To more accurately locate the target inflection point, the target inflection point can be calculated using a loss function. Specifically: obtain the second starting endpoint and the second ending endpoint of the curve; obtain the first inflection point from the measurement points contained in the inflection interval, where the first inflection point is any measurement point within the inflection interval; determine the loss function value of the first inflection point based on the second starting endpoint, the second ending endpoint of the curve, and the measurement points contained in the inflection interval; and determine the target inflection point from the measurement points contained in the inflection interval based on the loss function value.

[0063] The second initial endpoint refers to a starting point on the smooth curve obtained after curve fitting, located at the end with lower pressure. In some embodiments, the second initial endpoint can be a point outside the measurement point set, for example, an endpoint of the curve after data processing or fitting. The second final endpoint is opposite to the second initial endpoint and refers to the ending point on the smooth curve obtained after curve fitting, located at the end with higher pressure.

[0064] In some embodiments, the loss function value of the first inflection point can be calculated using the following steps: linearly fitting the first inflection point to the second beginning endpoint and the second end endpoint respectively to obtain the first function and the second function; obtaining the original function value of each measurement point on the curve within the inflection interval, and the first function value corresponding to the first function and the second function value corresponding to the second function for each measurement point; and calculating the loss function value of the first inflection point using the original function value, the first function value, and the second function value.

[0065] The first and second functions are two linear functions obtained by linearly fitting the first inflection point to the second beginning and end points, respectively. They describe the trend of the buffer layer resistivity changing with pressure before and after the inflection point. The original function values ​​are the actual measured values ​​on the buffer layer resistivity-pressure curve, for example, the resistivity values ​​at the measurement points. The first and second function values ​​include the function values ​​corresponding to each measurement point before and after the first inflection point on the first and second functions, respectively. Loss functions include Mean Squared Error (MSE) and Root Mean Squared Error (RMSE).

[0066] To facilitate understanding of the process of determining the target inflection point, a specific embodiment will be used as an example below. Figure 3 This is a schematic diagram illustrating the relationship between the resistivity of a high-voltage cable buffer layer and pressure according to an embodiment of this application. Figure 3 As shown, the horizontal axis represents pressure (unit: Pa), and the vertical axis represents resistivity (unit: Ω·m). The curve showing the relationship between resistivity and pressure is an "L"-shaped curve C1.

[0067] (1) Determine the turning interval (i.e., the turning segment): Select the point D(X) corresponding to the position where the pressure of the curve is 10% of the maximum value. l Y l The first endpoint of the inflection interval is E(X2, Y2), and the first tail endpoint of the inflection interval is E(X2, Y2), where the curve pressure is 30% of the maximum value.

[0068] (2) Obtain the first turning point: Obtain any point B(X) from the measurement points contained in the turning interval. c.i ,Y c.i This serves as the first turning point.

[0069] (3) Perform linear fitting between the first inflection point and the second beginning and end points respectively: B(X) c.i ,Y c.i ) and the first endpoint A(X) of curve C1 c.1 ,Y c.1 ), tail endpoint C(X) c.end ,Y c.end Connect the lines to obtain linear segments L1 (segment AB, i.e., the first function) and L2 (segment BC, i.e., the second function), and their calculation formula is:

[0070]

[0071] Y l =[Y l.1 ][Y l.2 (3)

[0072] Among them, Y l.1 Let X be the resistivity value (i.e., the first function value) at a point on the linear segment L1. n Y represents the deformation distance value of the original data points. l.2 Y is the resistivity value (i.e., the second function value) at a point on the linear segment L2. l Let be the resistivity value at a point on the linear segment.

[0073] (4) Calculate the loss function value at the first inflection point: At each measurement point within the inflection interval (a total of n measurement points), calculate the RMSE of the function value at the measurement point and the function values ​​of the linear segments L1 and L2. The specific calculation formula is as follows:

[0074]

[0075] Among them, Y n.j This is the resistivity value of a point on the original curve (i.e., the original function value of the measurement point on the curve).

[0076] (5) Traverse the measurement points contained in the turning interval and calculate the RMSE of each measurement point as a turning point.

[0077] (6) Determine the target inflection point from the measurement points contained in the inflection interval based on the loss function value: In some embodiments, the inflection point (X) corresponding to the minimum RMSE value can be selected. c.i ,Y c.i (This serves as the target turning point.)

[0078] (7) Take the pressure value in the coordinate value corresponding to the target turning point as the critical pressure value.

[0079] After determining the target inflection point from the measurement points contained in the inflection interval based on the loss function value, the following steps can be performed: compare the target inflection point with the endpoints of the inflection interval, wherein the endpoints of the inflection interval include the first beginning endpoint and the first end endpoint of the inflection interval; if the target inflection point is an endpoint of the inflection interval, expand the inflection interval; and redetermine the target inflection point using the expanded inflection interval.

[0080] In some embodiments, the coordinates of the target turning point can be compared with the coordinates of the endpoints of the turning interval to determine whether the target turning point is the endpoint of the turning interval.

[0081] When the target turning point is the endpoint of the turning interval, the turning interval can be expanded in the following way: When the target turning point is the first endpoint of the turning interval, the pressure value of the first endpoint is calculated by performing a function operation with a third preset ratio to obtain a third pressure value. The measurement point corresponding to the third pressure value is taken as the target first endpoint of the turning interval, wherein the third pressure value is less than the pressure value of the first endpoint. When the target turning point is the first tail endpoint of the turning interval, the pressure value of the first tail endpoint is calculated by performing a function operation with a fourth preset ratio to obtain a fourth pressure value. The measurement point corresponding to the fourth pressure value is taken as the target tail endpoint of the turning interval, wherein the fourth pressure value is greater than the pressure value of the first tail endpoint.

[0082] To conserve computational resources, in some embodiments, the third preset ratio and the fourth preset ratio can be the same, and the function operation includes exponential operation, logarithmic operation, power operation, etc. The third pressure value is used to extend the first endpoint of the turning interval along the curve in a preset direction, and the fourth pressure value is used to extend the first tail endpoint of the turning interval along the curve in a preset direction, where the preset direction is the direction of expanding the turning interval. When the target turning point is the first endpoint of the turning interval, only the first endpoint can be extended, or both the first and first tail endpoints can be extended simultaneously. When the target turning point is the first tail endpoint of the turning interval, only the first tail endpoint can be extended, or both the first and first tail endpoints can be extended simultaneously.

[0083] In some embodiments, if the target turning point falls into the first endpoint, the maximum pressure can be reduced by 2% (i.e., the third preset ratio) based on the original pressure value of the first endpoint; if the target turning point falls into the first end endpoint, the maximum pressure can be increased by 2% (i.e., the fourth preset ratio) based on the original pressure value of the first end endpoint.

[0084] The expanded turning interval is taken as the turning interval. The measurement points contained in the turning interval are re-determined. The above steps for determining the target turning point are repeated until the target turning point does not fall into the endpoint of the turning interval. The pressure value in the corresponding coordinate value of the target turning point is taken as the critical pressure value.

[0085] Step S208: Determine the compression state of the high-voltage cable buffer layer using the critical pressure value.

[0086] In step S208, the compressed state refers to the resistivity of the buffer layer of the high-voltage cable being stable within a preset range. When the buffer layer is in the compressed state, the buffer layer material is fully compressed and the porosity is reduced, which can effectively prevent electric field distortion and local overheating.

[0087] In some embodiments, the measured actual pressure value can be compared with the critical pressure value determined in step S206. Specifically: the pressure value of the high-voltage cable buffer layer is measured; the pressure value of the high-voltage cable buffer layer is compared with the critical pressure value; if the pressure value of the high-voltage cable buffer layer is greater than the critical pressure value, it is determined that the high-voltage cable buffer layer is in a compressed state; if the pressure value of the high-voltage cable buffer layer is less than the critical pressure value, it is determined that the high-voltage cable buffer layer is in a non-compressed state. For example, if the measured pressure of the high-voltage cable buffer layer is 150 kPa, and the critical pressure value is 120 kPa, then it can be determined that the buffer layer is in a compressed state.

[0088] Through steps S202 to S208, the measuring device determines the transition range from the curve of the relationship between the resistivity and pressure of the high-voltage cable buffer layer, and determines the target transition point within the transition range. The pressure value at the target transition point is used to determine the compression state of the high-voltage cable buffer layer. By accurately determining the target transition point on the curve using the measuring device, the purpose of accurately judging whether high-voltage cables of different voltage levels and different types of buffer layers are compressed can be achieved. This realizes the technical effect of reducing the burning failure of the high-voltage cable buffer layer and effectively improving the conductivity of the high-voltage cable buffer layer. In addition, it solves the technical problem that the transition section of the resistivity-pressure curve of the buffer layer is long and smooth, and the judgment of whether the high-voltage cable buffer layer is compressed by human observation has large errors and lacks reproducibility.

[0089] Figure 4 This is a schematic flowchart illustrating the overall process of a method for determining the compression state of a high-voltage cable buffer layer according to an embodiment of this application. Figure 4 As shown, it includes the following steps:

[0090] S402, Test the resistivity-pressure characteristic curve of the buffer layer of the cable under test: Sample the buffer layer of the high-voltage cable. The sample needs to be representative and consistent. Under a series of preset pressure conditions, measure the resistivity of the buffer layer and record the corresponding values ​​of each pressure and resistivity to form the original dataset.

[0091] S404, Data fitting yields characteristic curves: Using polynomial fitting or other curve fitting methods, the original data points are connected into a smooth curve, namely the buffer layer resistivity-pressure characteristic curve C1.

[0092] S406, Select the transition segment (i.e., the transition interval): Based on the shape of the curve, select the area where the pressure value is between 10% and 30% of the maximum value of the curve as the transition segment S2. This is the area where the resistivity change rate begins to change significantly.

[0093] S408, assuming the inflection point is used to calculate the linear segment data: within the inflection segment S2, each point is selected cyclically as the inflection point, and connected with the first and last endpoints of the curve to form linear segments L1 and L2. The resistivity values ​​of each point on L1 and L2 are calculated.

[0094] S410, RMSE calculation of linear segment data and original data: At each measurement point within the transition interval (a total of n measurement points), RMSE calculation is performed on the function value of the measurement point and the function values ​​of linear segments L1 and L2.

[0095] S412, obtain the point on the fitted curve corresponding to the minimum RMSE: traverse all points within the transition segment S2, and find the transition point (X) that minimizes the RMSE. c.i ,Y c.i The target turning point is obtained by comparing it with the endpoint of the turning segment. If the target turning point falls into the endpoint of the turning segment, step S414 is executed; otherwise, step S416 is executed.

[0096] S414, Expand the turning point: If the assumed turning point happens to fall at the endpoint of the turning point S2, it means that the point is not the optimal turning point. The range of the turning point can be adjusted according to the preset rules, and the target turning point can be re-determined (i.e., repeat steps S410 and S412 until the target turning point no longer falls at the endpoint of the turning point).

[0097] S416, outputs the x-coordinate of the inflection point as the critical pressure value P. t In some embodiments, the critical pressure value P t This is the x-coordinate of the target inflection point, indicating the critical pressure value at which the buffer layer transitions from a non-compressed to a compressed state.

[0098] S418, Test the pressure P on the buffer layer of the cable under test: Measure the pressure P on the actual high-voltage cable buffer layer under production, testing, or operating conditions, and determine whether P is greater than P0. t .

[0099] S420, in some embodiments, if the actual measured pressure P is greater than the critical pressure value P t This indicates that the buffer layer is in a compressed state, which helps maintain good conductivity and prevents ablation.

[0100] S422, if the actual measured pressure P is less than or equal to the critical pressure value P t This indicates that the buffer layer has not been sufficiently compressed, posing a risk of insulation degradation.

[0101] Figure 5 This is a structural diagram of a device for determining the compression state of a high-voltage cable buffer layer according to an embodiment of this application, as shown below. Figure 5 As shown, the device includes:

[0102] The acquisition module 50 is used to acquire a curve representing the relationship between the resistivity of the high-voltage cable buffer layer and the pressure.

[0103] The first determining module 52 is used to determine the turning interval of the curve, wherein the turning interval includes the interval where the rate of change of the curve slope is greater than a preset threshold.

[0104] The second determining module 54 is used to determine the target turning point from the turning interval and take the pressure value corresponding to the target turning point as the critical pressure value.

[0105] Execution module 56 is used to determine the compression state of the high-voltage cable buffer layer using the critical pressure value.

[0106] In the aforementioned device for determining the compression state of the high-voltage cable buffer layer, the first determining module is further used to obtain the maximum pressure value of the measurement points in the measurement point set, wherein the measurement points in the measurement point set are used to represent the resistivity of the high-voltage cable buffer layer under different pressure conditions; the maximum pressure value is used to perform a function operation with a first preset ratio and a second preset ratio respectively to obtain a first pressure value and a second pressure value, wherein the first preset ratio is less than the second preset ratio; the measurement point corresponding to the first pressure value is used as the first starting point of the transition interval, and the measurement point corresponding to the second pressure value is used as the first ending point of the transition interval.

[0107] In the aforementioned device for determining the compression state of the high-voltage cable buffer layer, the second determining module is further configured to acquire the second beginning endpoint and the second end endpoint of the curve; acquire the first turning point from the measurement points contained in the turning interval, wherein the first turning point is any measurement point within the turning interval; determine the loss function value of the first turning point based on the second beginning endpoint of the curve, the second end endpoint of the curve, and the measurement points contained in the turning interval; and determine the target turning point from the measurement points contained in the turning interval based on the loss function value.

[0108] In the aforementioned device for determining the compression state of the high-voltage cable buffer layer, the second determining module is further used to perform linear fitting between the first turning point and the second beginning endpoint and the second end endpoint respectively to obtain the first function and the second function; obtain the original function value of each measurement point on the curve within the turning interval, as well as the first function value corresponding to the first function and the second function value corresponding to the second function for each measurement point; and calculate the loss function value of the first turning point using the original function value, the first function value, and the second function value.

[0109] In the device for determining the compression state of the high-voltage cable buffer layer, the second determining module is further used to compare the target turning point with the endpoint of the turning interval, wherein the endpoint of the turning interval includes the first beginning endpoint of the turning interval and the first end endpoint of the turning interval; when the target turning point is the endpoint of the turning interval, the turning interval is expanded; and the target turning point is re-determined using the expanded turning interval.

[0110] In the aforementioned device for determining the compression state of the high-voltage cable buffer layer, the second determining module is further configured to, when the target turning point is the first endpoint of the turning interval, perform a function calculation on the pressure value of the first endpoint and a third preset ratio to obtain a third pressure value, and use the measurement point corresponding to the third pressure value as the target first endpoint of the turning interval, wherein the third pressure value is less than the pressure value of the first endpoint; when the target turning point is the first end endpoint of the turning interval, perform a function calculation on the pressure value of the first end endpoint and a fourth preset ratio to obtain a fourth pressure value, and use the measurement point corresponding to the fourth pressure value as the target end endpoint of the turning interval, wherein the fourth pressure value is greater than the pressure value of the first end endpoint.

[0111] In the aforementioned device for determining the compressed state of the high-voltage cable buffer layer, the execution module is also used to measure the pressure value of the high-voltage cable buffer layer; compare the pressure value of the high-voltage cable buffer layer with the critical pressure value; determine that the high-voltage cable buffer layer is in a compressed state when the pressure value of the high-voltage cable buffer layer is greater than the critical pressure value; and determine that the high-voltage cable buffer layer is in a non-compressed state when the pressure value of the high-voltage cable buffer layer is less than or equal to the critical pressure value.

[0112] It should be noted that, Figure 5The device shown for determining the compression state of the high-voltage cable buffer layer is used to perform... Figure 2 The method for determining the compression state of the high-voltage cable buffer layer shown is therefore... Figure 2 The relevant explanations in the method for determining the compression state of the high-voltage cable buffer layer also apply to... Figure 5 The device for determining the compression state of the high-voltage cable buffer layer shown is not described in detail here.

[0113] This application also provides an electronic device, which includes a memory and a processor. The memory is used to store program instructions, and the processor is connected to the memory to execute the steps of determining the compression state of the high-voltage cable buffer layer in the various embodiments of this application.

[0114] For example, a processor performs the following functions by executing program instructions stored in memory:

[0115] The measuring equipment acquires a curve representing the relationship between the resistivity of the high-voltage cable buffer layer and the pressure; determines the inflection interval of the curve, wherein the inflection interval includes the interval where the rate of change of the curve slope is greater than a preset threshold; determines the target inflection point from the inflection interval, and takes the pressure value corresponding to the target inflection point as the critical pressure value; and uses the critical pressure value to determine the compression state of the high-voltage cable buffer layer.

[0116] This application also provides a non-volatile storage medium, which includes a stored computer program, wherein the device containing the non-volatile storage medium executes the steps of the method for determining the compression state of the high-voltage cable buffer layer in various embodiments of this application by running the computer program.

[0117] This application also provides a computer program product, including computer instructions, which, when executed by a processor, implement the steps of the method for determining the compression state of the high-voltage cable buffer layer in various embodiments of this application.

[0118] This application also provides a computer program that, when executed by a processor, implements the steps of the method for determining the compression state of the high-voltage cable buffer layer in various embodiments of this application.

[0119] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0120] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0121] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0122] The units described as separate components may or may not be physically separate. 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 units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0123] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0124] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard drive, magnetic disk, or optical disk.

[0125] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for determining the compression state of a high-voltage cable buffer layer, characterized in that, include: The measuring equipment acquires a curve representing the relationship between the resistivity of the high-voltage cable buffer layer and the pressure. Determine the turning interval of the curve, wherein the turning interval includes the interval where the rate of change of the curve slope is greater than a preset threshold; Determine the target turning point from the turning interval, and take the pressure value corresponding to the target turning point as the critical pressure value; The compression state of the high-voltage cable buffer layer is determined using the critical pressure value. The step of determining the target inflection point from the inflection interval includes: obtaining the second beginning endpoint and the second end endpoint of the curve; obtaining a first inflection point from the measurement points contained in the inflection interval, wherein the first inflection point is any measurement point within the inflection interval; determining the loss function value of the first inflection point based on the second beginning endpoint of the curve, the second end endpoint of the curve, and the measurement points contained in the inflection interval; and determining the target inflection point from the measurement points contained in the inflection interval based on the loss function value. The loss function value is determined by: linearly fitting the first inflection point to the second beginning endpoint and the second end endpoint respectively to obtain a first function and a second function; obtaining the original function value of each measurement point in the inflection interval on the curve, and the first function value of each measurement point corresponding to the first function and the second function value corresponding to the second function; and calculating the loss function value of the first inflection point using the original function value, the first function value, and the second function value.

2. The method according to claim 1, characterized in that, Determining the inflection interval of the curve includes: Obtain the maximum pressure value of the measurement points in the measurement point set, wherein the measurement points in the measurement point set are used to represent the resistivity of the high-voltage cable buffer layer under different pressure conditions; The maximum pressure value is calculated by performing a function operation with the first preset ratio and the second preset ratio respectively to obtain the first pressure value and the second pressure value, wherein the first preset ratio is less than the second preset ratio; The measurement point corresponding to the first pressure value is taken as the first endpoint of the transition interval, and the measurement point corresponding to the second pressure value is taken as the first end endpoint of the transition interval.

3. The method according to claim 1, characterized in that, After determining the target inflection point from the measurement points included in the inflection interval based on the loss function value, the method further includes: The target turning point is compared with the endpoints of the turning interval, wherein the endpoints of the turning interval include the first beginning endpoint and the first end endpoint of the turning interval. If the target turning point is the endpoint of the turning interval, the turning interval is expanded; The target inflection point is redefined using the expanded inflection interval.

4. The method according to claim 3, characterized in that, When the target turning point is the endpoint of the turning interval, the turning interval is expanded, including: When the target turning point is the first endpoint of the turning interval, the pressure value of the first endpoint is calculated by a function with a third preset ratio to obtain a third pressure value. The measurement point corresponding to the third pressure value is taken as the target starting point of the turning interval, wherein the third pressure value is less than the pressure value of the first endpoint. When the target turning point is the first end point of the turning interval, the pressure value of the first end point is calculated by performing a function operation with a fourth preset ratio to obtain a fourth pressure value. The measurement point corresponding to the fourth pressure value is taken as the target end point of the turning interval, wherein the fourth pressure value is greater than the pressure value of the first end point.

5. The method according to claim 1, characterized in that, Determining the compression state of the high-voltage cable buffer layer using the critical pressure value includes: Measure the pressure value of the high-voltage cable buffer layer; The pressure value of the high-voltage cable buffer layer is compared with the critical pressure value; If the pressure value of the high-voltage cable buffer layer is greater than the critical pressure value, it is determined that the high-voltage cable buffer layer is in a compressed state. If the pressure value of the high-voltage cable buffer layer is less than or equal to the critical pressure value, the high-voltage cable buffer layer is determined to be in a non-compressed state.

6. A device for determining the compression state of a high-voltage cable buffer layer, applied to a measuring device, comprising: The acquisition module is used to acquire curves representing the relationship between the resistivity of the high-voltage cable buffer layer and the pressure. The first determining module is used to determine the turning interval of the curve, wherein the turning interval includes the interval where the rate of change of the curve slope is greater than a preset threshold. The second determining module is used to determine a target inflection point from the inflection interval, and to take the pressure value corresponding to the target inflection point as a critical pressure value. Determining the target inflection point from the inflection interval includes: obtaining the second beginning endpoint and the second end endpoint of the curve; obtaining a first inflection point from the measurement points contained in the inflection interval, wherein the first inflection point is any measurement point within the inflection interval; determining a loss function value for the first inflection point based on the second beginning endpoint, the second end endpoint of the curve, and the measurement points contained in the inflection interval; determining the target inflection point from the measurement points contained in the inflection interval based on the loss function value; the loss function value is determined by: linearly fitting the first inflection point to the second beginning endpoint and the second end endpoint respectively to obtain a first function and a second function; obtaining the original function value of each measurement point within the inflection interval on the curve, and the first function value corresponding to the first function and the second function value corresponding to the second function for each measurement point; and calculating the loss function value of the first inflection point using the original function value, the first function value, and the second function value. An execution module is used to determine the compression state of the high-voltage cable buffer layer using the critical pressure value.

7. An electronic device, characterized in that, include: A memory and a processor, wherein the memory is used to store program instructions; the processor is connected to the memory and is used to execute the method for determining the compression state of the high-voltage cable buffer layer as described in any one of claims 1 to 5.

8. A non-volatile storage medium, characterized in that, The non-volatile storage medium includes a stored computer program, wherein the device containing the non-volatile storage medium executes the method for determining the compression state of the high-voltage cable buffer layer as described in any one of claims 1 to 5 by running the computer program.

9. A computer program product comprising computer instructions, characterized in that, When the computer instructions are executed by the processor, they implement the method for determining the compression state of the high-voltage cable buffer layer as described in any one of claims 1 to 5.

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