Cable state determination method and device and electronic equipment
By applying multiple filtering windows and weighting to the depolarization current data of the cable, the problem of inaccurate cable condition determination in the prior art is solved, and a more accurate cable condition assessment is achieved.
Patent Information
- Application Number
- CN202511052289.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-29
- Publication Date
- 2025-11-11
AI Technical Summary
Existing technologies determine cable status directly based on depolarization current data or simple mean filtering, leading to inaccurate cable status determination.
By acquiring the depolarization current data sequence of the cable, multiple filtering windows and weights are used to filter each depolarization current data, the target filtered value is determined and the original data is replaced, and the cable status is determined based on the processed data sequence.
It achieves accurate filtering of depolarization current data, improves the accuracy of cable condition determination, and can more realistically reflect the insulation condition and potential problems of the cable.
Smart Images
Figure CN120928075A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power, and more specifically, to a method, apparatus, and electronic device for determining the condition of a cable. Background Technology
[0002] The condition of cables affects the normal transmission of power in a power system, and determining the cable condition is crucial for maintaining the stability of the power system. By applying a DC voltage to the cable, the depolarization current data can be obtained, thus determining the cable condition. However, current technologies either directly rely on the depolarization current data to determine the cable condition, or perform simple mean filtering on the depolarization current data and then determine the condition based on the filtered depolarization current data. The resulting cable condition readings are not accurate enough.
[0003] There is currently no effective solution to the above problems. Summary of the Invention
[0004] This invention provides a cable condition determination method, apparatus, and electronic device to at least solve the technical problem that inaccurate depolarization current filtering in the prior art leads to inaccurate cable condition determination.
[0005] According to one aspect of the present invention, a cable state determination method is provided, comprising: acquiring a depolarization current data sequence of the cable, wherein the depolarization current data sequence includes depolarization current data corresponding to multiple moments of the cable within a predetermined time period; performing the following processing on each depolarization current data in the depolarization current data sequence to obtain a processed depolarization current data sequence: using each depolarization current data in the depolarization current data sequence as a first target depolarization current data; acquiring N filter values corresponding to the first target depolarization current data; determining the weights corresponding to the N filter values respectively; determining a target filter value corresponding to the first target depolarization current data based on the N filter values and the weights corresponding to the N filter values respectively; replacing the first target depolarization current data with the target filter value; and determining the state of the cable based on the processed depolarization current data sequence.
[0006] Optionally, obtaining the N filtered values corresponding to the first target depolarization current data includes: determining N filtering windows corresponding to the first target depolarization current data; and using the N filtering windows to filter the first target depolarization current data to obtain the N filtered values.
[0007] Optionally, determining the N filtering windows corresponding to the first target depolarization current data includes: based on the first target depolarization current data, the first N filtering windows in the depolarization current data sequence... Depolarization current data and subsequent A first filtering window is determined based on the first target depolarized current data, centered on the first target depolarized current data. The window length of the first filtering window is N, where N is an odd number greater than 1. Then, based on the N-1 depolarized current data points within the first filtering window (excluding the first target depolarized current data), the first N-1 depolarized current data points in the depolarized current data sequence are selected. Depolarization current data and subsequent Given a depolarization current data set, N-1 filter windows are determined, each with a window length of N. The N filter windows include the first filter window and the N-1 filter windows themselves.
[0008] Optionally, determining the weights corresponding to the N filter values includes: determining the filtering degree corresponding to each of the N filter values based on the first target depolarization current data and the N filter values corresponding to the first target depolarization current data; obtaining the noise performance degree corresponding to each depolarization current data in each of the N filter windows, and determining the average noise performance degree corresponding to each of the N filter windows, wherein an average noise performance degree is the average noise performance degree corresponding to each of the N depolarization current data in a filter window, and the noise performance degree is used to characterize the degree to which the depolarization current data is affected by noise; and determining the weights corresponding to the N filter values based on the filtering degree corresponding to each of the N filter values and the average noise performance degree corresponding to each of the N filter windows.
[0009] Optionally, obtaining the noise performance level corresponding to each depolarization current data in each of the N filtering windows includes: taking each depolarization current data in each of the N filtering windows as the second target depolarization current data; and obtaining the noise performance level corresponding to the second target depolarization current data based on the second target depolarization current data, the first M depolarization current data and the last M depolarization current data in the depolarization current data sequence.
[0010] Optionally, the step of obtaining the noise performance level corresponding to the second target depolarization current data based on the second target depolarization current data, and the first M and last M depolarization current data in the depolarization current data sequence, includes: obtaining the fitted values corresponding to the first M and last M depolarization current data in the second target depolarization current data sequence, respectively, to obtain 2M+1 first fitted values; based on the 2M+1 first fitted values, and the second target depolarization current data, and the first M and last M depolarization current data in the depolarization current data sequence, determining... A first fitting error is determined corresponding to the second target depolarization current data; interpolation is used to obtain the second target depolarization current data, and reference data corresponding to the first M and last M depolarization current data of the second target depolarization current data in the depolarization current data sequence are obtained to obtain 2M+1 reference data; based on the 2M+1 reference data, fitting values corresponding to the 2M+1 reference data are obtained to obtain 2M+1 second fitting values; based on the 2M+1 first fitting values and the 2M+1 second fitting values, a second fitting error corresponding to the second target depolarization current data is determined; based on the first fitting error and the second fitting error, the noise performance level corresponding to the second target depolarization current data is determined.
[0011] According to another aspect of the present invention, a cable state determination apparatus is provided, comprising: an acquisition module, configured to acquire a depolarization current data sequence of the cable, wherein the depolarization current data sequence includes depolarization current data corresponding to multiple moments of the cable within a predetermined time period; a processing module, configured to perform the following processing on each depolarization current data in the depolarization current data sequence to obtain a processed depolarization current data sequence: taking each depolarization current data in the depolarization current data sequence as a first target depolarization current data; acquiring N filter values corresponding to the first target depolarization current data; determining the weights corresponding to the N filter values respectively; determining a target filter value corresponding to the first target depolarization current data based on the N filter values and the weights corresponding to the N filter values respectively; replacing the first target depolarization current data with the target filter value; and a determination module, configured to determine the state of the cable based on the processed depolarization current data sequence.
[0012] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is executed, it controls the device where the computer-readable storage medium is located to perform the cable status determination method described in any one of the preceding claims.
[0013] According to another aspect of the present invention, an electronic device is provided, comprising: a memory storing an executable program; and a processor for running the program, wherein the program, when running, executes the cable status determination method described in any one of the preceding claims.
[0014] According to another aspect of the present invention, a computer program product is provided, comprising a computer program that, when executed by a processor, implements the steps of any of the cable state determination methods.
[0015] In this embodiment of the invention, by acquiring a depolarization current data sequence of a cable, which includes depolarization current data corresponding to multiple moments of the cable within a predetermined time period; performing the following processing on each depolarization current data in the depolarization current data sequence to obtain a processed depolarization current data sequence: taking each depolarization current data in the depolarization current data sequence as a first target depolarization current data; acquiring N filter values corresponding to the first target depolarization current data; determining the weights corresponding to the N filter values; determining the target filter value corresponding to the first target depolarization current data based on the N filter values and their respective weights; replacing the first target depolarization current data with the target filter value; and determining the state of the cable based on the processed depolarization current data sequence, thereby achieving the purpose of accurately filtering the depolarization current data and realizing the technical effect of accurately determining the cable state based on the depolarization current data. This solves the technical problem of inaccurate depolarization current filtering in the prior art, which leads to inaccurate determination of the cable state. Attached Figure Description
[0016] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:
[0017] Figure 1 This is a flowchart of a cable state determination method according to an embodiment of the present invention;
[0018] Figure 2 This is a schematic diagram of a cable condition detection method based on depolarization current data according to an optional embodiment of the present invention;
[0019] Figure 3This is a structural block diagram of a cable condition determination device according to an embodiment of the present invention. Detailed Implementation
[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.
[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention 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 the invention 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 a 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.
[0022] First, some nouns or terms that appear in the description of the embodiments of this application shall be interpreted as follows:
[0023] Depolarization current: When the DC voltage applied to a cable is suddenly removed or reduced to zero, the charge state inside the system returns to its state before the voltage was applied. The current generated in this process is called depolarization current. In cable insulation testing, depolarization current is one of the key parameters for evaluating the insulation condition of the cable. Methods for measuring depolarization current include polarization and depolarization processes. Polarization involves applying a constant DC voltage to the cable for a period of time, causing polarization of the insulation material, meaning the charge distribution inside the material changes due to the applied voltage. Depolarization involves suddenly removing this DC voltage, allowing the cable insulation material to return to its original state. During this process, a depolarization current is generated as the internal charge of the insulation material attempts to return to equilibrium. The magnitude and shape of the depolarization current can reflect the performance of the cable insulation material, such as insulation aging, moisture content, and charge trapping state. By analyzing the depolarization current, the health condition of the cable can be detected without interfering with normal power supply.
[0024] Mean filtering is a linear filtering technique used in signal processing to smooth data and remove noise. This method achieves its filtering effect by averaging the data in a local area and replacing the data point at the center of that area with the average value. The basic principle of mean filtering is to slide a filter window across the entire data sequence, average the values of all pixels or data points within the window, and then use this average value to replace the data point at the center of the window. The advantages of mean filtering are its simplicity, high computational efficiency, and effectiveness in removing Gaussian noise. However, mean filtering can blur the edges and details of the data sequence, potentially leading to a loss of original signal characteristics for signal processing.
[0025] According to an embodiment of the present invention, an embodiment of a cable state determination method is provided. 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.
[0026] Figure 1 This is a flowchart of a cable state determination method according to an embodiment of the present invention, such as... Figure 1 As shown, the method includes the following steps:
[0027] Step S102: Obtain the depolarization current data sequence of the cable.
[0028] As an optional embodiment, the execution subject of this method can be a terminal or a server for determining cable status. When applied to a terminal, cable status determination can be easily achieved; when applied to a server, the server's abundant computing resources can be utilized, allowing for more accurate cable status determination. The terminal can be of various types, such as a mobile terminal with certain computing capabilities or a fixed computer device with identification capabilities. Similarly, the server can be of various types, such as a local server or a virtual cloud server. Depending on computing power, it can be a single computer device or a computer cluster integrating multiple computer devices.
[0029] As an optional embodiment, the depolarization current data sequence of the cable can be acquired in various ways. For example, a certain DC voltage can be applied to the cable using a detection device. The duration of the voltage can be determined based on the cable characteristics, with the aim of fully polarizing the cable's insulation material and accumulating charge. After a predetermined polarization time, the voltage is removed, allowing the cable to begin the depolarization process. During this stage, the charge accumulated in the cable insulation layer begins to be released, forming a depolarization current. During the cable depolarization process, a current sensor can be used to measure the depolarization current flowing through the cable. The data acquisition frequency can be set according to specific detection requirements, such as once per second, to ensure that detailed information on the changes in depolarization current over time is captured. The depolarization current data collected at each moment is arranged in chronological order to form a depolarization current data sequence. The depolarization current data sequence provides a dynamic record of the cable depolarization process, including depolarization current data corresponding to multiple moments within a predetermined time period.
[0030] Step S104: Perform the following processing on each depolarized current data in the depolarized current data sequence to obtain the processed depolarized current data sequence: take each depolarized current data in the depolarized current data sequence as the first target depolarized current data; obtain N filter values corresponding to the first target depolarized current data; determine the weights corresponding to the N filter values respectively; based on the N filter values and the weights corresponding to the N filter values respectively, determine the target filter value corresponding to the first target depolarized current data; replace the first target depolarized current data with the target filter value.
[0031] As an optional implementation, a corresponding filter value is obtained for each depolarized current data point in the depolarized current data sequence, and the filtered values are used to form a filtered depolarized current data sequence, which can remove noise from the depolarized current data sequence. By obtaining multiple corresponding filter values and their respective weights for each depolarized current data point in the depolarized current data sequence, distortion can be reduced even when the depolarized current data is at the edge of noise, through comprehensive analysis of surrounding data. This can more effectively remove noise while retaining key information needed to determine the cable status, such as the fluctuations and trends of the depolarized current data.
[0032] As an optional implementation, obtaining the N filtered values corresponding to the first target depolarization current data can be done in various ways. For example, N filtering windows corresponding to the first target depolarization current data can be determined; the first target depolarization current data can be filtered using N filtering windows to obtain N filtered values. Each filtering window contains a certain number of data points around the depolarization current data point. The window length and position of the filtering window can be preset according to specific application requirements. By constructing multiple filtering windows for the first target depolarization current data, the noise included in the first target depolarization current data can be understood and processed from multiple perspectives based on the different noise patterns captured by multiple filtering windows and the correlation between depolarization current data, thus more comprehensively evaluating the impact of noise on the first target depolarization current data. Filtering the first target depolarization current data using multiple filtering windows to obtain multiple filtered values can be done in various ways. For example, mean filtering can be used, calculating the average value of all depolarization current data within the filtering window, and using the average value as the filtered value of that filtering window, representing a smoothed estimate of all depolarization current data within the filtering window, reducing the impact of random noise. By acquiring multiple filtered values corresponding to the first target depolarization current data, more accurate filtered values for the first target depolarization current data can be obtained.
[0033] As an optional implementation, various methods can be used to determine the N filtering windows corresponding to the first target depolarization current data. For example, based on the first target depolarization current data, the first N filtering windows in the depolarization current data sequence can be selected from the first target depolarization current data. Depolarization current data and subsequent A first filtering window is determined based on the depolarization current data, centered on the first target depolarization current data. The window length of the first filtering window is N, where N is an odd number greater than 1. Then, based on the N-1 depolarization current data points within the first filtering window (excluding the first target depolarization current data), the first N-1 depolarization current data points in the depolarization current data sequence are analyzed. Depolarization current data and subsequent For each depolarized current data point, N-1 filter windows are defined, with a window length of N. These N filter windows include a first filter window and N-1 additional filter windows. First, the first filter window is determined centered on the first target depolarized current data point, with a window length of N, which is set to an odd number greater than 1. Even-length filter windows may slightly offset the center point during averaging, while odd-length filter windows ensure an equal number of data points on both sides of the center point, resulting in a more symmetrical and accurate mean calculation. To more comprehensively evaluate the noise characteristics of the first target depolarized current data, in addition to the first filter window, N-1 additional filter windows are constructed centered on each depolarized current data point within the first filter window (excluding the first target depolarized current data point). The window length of these additional filter windows is also set to N, consistent with the first filter window, ensuring an equal number of data points within each filter window and standardizing data processing and analysis.
[0034] As an optional embodiment, various methods can be used to determine the weights corresponding to the N filter values. For example, based on the first target depolarization current data and the N filter values corresponding to the first target depolarization current data, the filtering degree corresponding to each of the N filter values is determined; the noise performance degree corresponding to each depolarization current data in each of the N filter windows is obtained, and the average noise performance degree corresponding to each of the N filter windows is determined, wherein an average noise performance degree is the average of the noise performance degrees corresponding to the N depolarization current data in a filter window, and the noise performance degree is used to characterize the degree to which the depolarization current data is affected by noise; based on the filtering degree corresponding to the N filter values and the average noise performance degree corresponding to the N filter windows, the weights corresponding to the N filter values are determined. The filtering degree can characterize the degree of difference between the filter value and the original data point (i.e., the first target depolarization current data). The smaller the difference, the more effectively the filter window can remove the noise around the data point and retain the true signal. For the N filter values corresponding to the first target depolarized current data, by determining the filtering degree corresponding to each of the N filter values, we can determine the noise suppression effect and the degree to which the N filter values preserve the data authenticity. The average noise performance can characterize the overall degree of noise influence on all depolarized current data within the filtering window, that is, the overall noise performance of all depolarized current data within the filtering window. The greater the overall noise performance, the more filtering is needed. Assigning different weights to the N filter values can be based on the filtering degree corresponding to each of the N filter values and the average noise performance corresponding to each of the N filtering windows. A higher filtering degree should correspond to a higher average noise performance. If a filter value deviates from this rule, it indicates that the filter value is not performing well, and its weight can be reduced.
[0035] As an optional embodiment, the noise performance level corresponding to each depolarized current data in each of the N filtering windows can be obtained in various ways. For example, each depolarized current data in each of the N filtering windows can be used as the second target depolarized current data; based on the second target depolarized current data, the noise performance level corresponding to the first M and last M depolarized current data in the depolarized current data sequence can be obtained. For each depolarized current data in each of the N filtering windows, i.e., the second target depolarized current data, the noise performance level can be evaluated in conjunction with its surrounding data, i.e., the first M and last M depolarized current data. The value of M can be preset according to specific application requirements and noise levels to obtain an appropriate neighborhood range, thereby accurately determining the noise performance level corresponding to the second target depolarized current data.
[0036] As an optional embodiment, when obtaining the noise performance level corresponding to the second target depolarization current data based on the second target depolarization current data, specifically the first M and last M depolarization current data in the second target depolarization current data sequence, various methods can be employed. For example, obtaining the fitted values corresponding to the first M and last M depolarization current data in the second target depolarization current data sequence, respectively, yields 2M+1 first fitted values; based on these 2M+1 first fitted values, and the second target depolarization current data, specifically the first M and last M depolarization current data in the second target depolarization current data sequence, the first fitting error corresponding to the second target depolarization current data is determined; and an interpolation method is used to obtain the second target depolarization current... The data consists of the first M depolarization current data points and the last M reference data points of the second target depolarization current data in the depolarization current data sequence, resulting in 2M+1 reference data points. Based on these 2M+1 reference data points, fitted values are obtained for each of them, resulting in 2M+1 second fitted values. Based on these 2M+1 first fitted values and 2M+1 second fitted values, the second fitting error corresponding to the second target depolarization current data is determined. Based on the first and second fitting errors, the noise performance level corresponding to the second target depolarization current data is determined.
[0037] The fitting process can be performed using least squares or other appropriate statistical methods to fit 2M+1 depolarization current data points, including the second target depolarization current data, to obtain a fitted value for each depolarization current data point, i.e., the first fitted value. This first fitted value reflects the value that the depolarization current data should have under ideal or smoothed conditions, and this smoothness is jointly determined by the surrounding depolarization current data. The first fitting error characterizes the degree to which the depolarization current data deviates from its theoretical value under the fitted model and can be used to quantify the direct impact of noise. Interpolation methods, such as linear interpolation, can be used to temporarily remove any depolarization current data point from the sequence and fill this gap with the interpolated value, i.e., the reference data. Similarly, the reference data obtained from the 2M+1 depolarization current data points, including the second target depolarization current data, can be fitted using least squares or other appropriate statistical methods to obtain a second fitted value. The second fitting error obtained from the first and second fitted values reflects how the characteristics of the surrounding data points affect the fitted value of the target point after excluding the interference of the target point itself, and can be used to quantify the indirect impact of noise. By combining these two types of fitting errors, the noise level of the second target depolarization current data, i.e., its noise performance, can be estimated more accurately and comprehensively.
[0038] Step S106: Determine the state of the cable based on the processed depolarization current data sequence.
[0039] As an optional implementation, the data is based on a processed depolarization current data sequence, specifically a filtered depolarization current data sequence. By determining multiple filter values and weighted filtering processes, each depolarization current data point is assigned a filter value closer to its true value. Therefore, the processed depolarization current data sequence, composed of filtered values, is smoother and exhibits fewer abnormal fluctuations, thus more accurately reflecting the current change characteristics of the cable during the depolarization process. By analyzing the changing trends and characteristics of the depolarization current data in the processed depolarization current data sequence, the insulation condition of the cable and other potential problems can be determined. For example, under normal circumstances, the depolarization current gradually decays over time. If the initial depolarization current data value in the processed depolarization current data sequence is significantly higher than the normal range for similar cables, and the decay rate does not meet expectations, this may indicate insulation defects or aging problems in the cable. When comparing the processed depolarization current data sequence with the normal range for similar cables, a threshold can be set for comparison. For example, if it exceeds the normal range by a certain percentage (e.g., 30%), it indicates that the cable's insulation performance may be degraded, indicating a potential fault. For cables that may be faulty, further statistical analysis can be performed on the processed depolarization current data sequence, such as calculating the average rate of change and fluctuation range of the current value, to more precisely determine the operating status and potential problems of the cable.
[0040] Through the above steps, a depolarization current data sequence of the cable can be obtained. This sequence includes depolarization current data corresponding to multiple moments within a predetermined time period. The following processing is performed on each depolarization current data in the sequence to obtain a processed depolarization current data sequence: each depolarization current data is used as the first target depolarization current data; N filter values corresponding to the first target depolarization current data are obtained; the weights corresponding to the N filter values are determined; based on the N filter values and their corresponding weights, a target filter value corresponding to the first target depolarization current data is determined; the target filter value is used to replace the first target depolarization current data; and the cable state is determined based on the processed depolarization current data sequence. This achieves the goal of accurately filtering the depolarization current data, thus realizing the technical effect of accurately determining the cable state based on the depolarization current data. This solves the technical problem of inaccurate depolarization current filtering in existing technologies, which leads to inaccurate cable state determination.
[0041] To evaluate the cable condition in a power system, the polarization / depolarization current method can be used. This method is a dielectric response method that applies a DC voltage to the cable under test and monitors the current changes during polarization and depolarization to determine the cable's insulation condition. To more accurately determine the cable condition, the current data during depolarization needs to be denoised to obtain more accurate current data, thus enabling a more accurate cable condition assessment. The mean filtering algorithm selects a filtering window centered on any depolarization current data point and uses the mean of the data within the window as the filter value for that depolarization current data. However, the acquisition of depolarization current data is easily affected by environmental noise or interference from the current sensor itself, resulting in noise in the acquired data. If a depolarization current data point is on the edge of a noise point, the filtering result may be severely affected because noise points often differ significantly from adjacent data points. Therefore, directly using the average value may lead to data distortion, thus affecting the accuracy of the final cable condition determination. Meanwhile, there are some obvious fluctuations in the depolarized current data due to insulation defects or aging problems in the cable. This is similar to the data changes caused by noise, which makes it difficult for mean filtering to distinguish noise and normal data. As a result, the depolarized current data after noise removal using traditional mean filtering has the problem of under-filtering or filtered waves, which affects the accuracy of cable condition detection.
[0042] To address the issue of inaccurate filtering results when the depolarized current data is located at the edge of noise during denoising using the mean filtering algorithm, an optional implementation method is provided, combining the above embodiments and alternative embodiments. In this optional implementation method, a cable condition detection method based on depolarized current data is proposed. The final filtered value is obtained by weighted averaging of the filtered values of the depolarized current data across multiple windows, thereby improving the denoising effect of mean filtering on the depolarized current data and ultimately enhancing the accuracy of cable condition detection. Figure 2 This is a schematic diagram of a cable condition detection method based on depolarization current data according to an optional embodiment of the present invention, as shown below. Figure 2 As shown, the method includes the following processing.
[0043] S1 collects depolarization current data.
[0044] A constant DC voltage is applied to the cable under test by the testing equipment for a period of time. After the voltage is stopped, the cable under test is short-circuited and discharged. The depolarization current data is collected at each sampling time using a current sensor. The sequence of depolarization current data at all sampling times is taken as the depolarization current data sequence.
[0045] S2, based on the surrounding data of each depolarization current data, obtain the noise performance level of each depolarization current data.
[0046] It should be noted that the depolarization current data is easily affected by environmental noise or problems with the current sensor itself during the acquisition process, which can lead to noise in the depolarization current data. Such noise can cause irregular changes in the data. Therefore, the degree of noise performance of each depolarization current data can be calculated by utilizing the regularity of the changes in the depolarization current data in its surrounding data.
[0047] When obtaining the noise level of each depolarization current data, the following methods can be used: Perform curve fitting on the surrounding data of the depolarization current data. If the fitting error of the surrounding data is large, it indicates that the change of the depolarization current data is more irregular, and the noise level of the depolarization current data is greater. Replace the depolarization current data with the surrounding data using the linear interpolation method to obtain reference data. If the difference in the average area enclosed by the two fitted curves formed by the surrounding data and the reference data is larger, it indicates that the noise level of the depolarization current data is greater.
[0048] For example, the i-th depolarization current data, the M data points preceding the i-th depolarization current data, and the M data points following the i-th depolarization current data are used as the surrounding data of the i-th depolarization current data. Here, M can be preset to 15, or it can be preset to other values depending on the specific implementation.
[0049] The least squares method is used to fit the surrounding data of the i-th depolarization current data, obtaining the fitted value for each surrounding data of the i-th depolarization current data. The least squares method finds the best function match for the data by minimizing the sum of squared errors, thus achieving the fitting of the surrounding data of the i-th depolarization current data.
[0050] Based on the surrounding data of the i-th depolarization current data, the i-th depolarization current data is replaced using the linear interpolation method to obtain reference data for the i-th depolarization current data. Then, the surrounding data of the i-th depolarization current data are replaced using the linear interpolation method to obtain reference data for the surrounding data of the i-th depolarization current data. Finally, the least squares method is used to fit the reference data to obtain the fitted value for each reference data point. The linear interpolation method can be used to estimate the value of an unknown data point between two known data points. Specifically, by assuming that the change in data between two known points is linear, the value of the unknown data point can be estimated.
[0051] The noise level of the i-th depolarization current data is shown below:
[0052]
[0053] In the formula, Z i N represents the noise level of the i-th depolarization current data; i I represents the number of surrounding data points for the i-th depolarization current data; i,n f represents the value of the nth surrounding data of the i-th depolarization current data; i,n g represents the fitted value of the nth surrounding data for the i-th depolarization current data; i,n The fitted value of the nth reference data represents the i-th depolarization current data. The larger the value, the larger the fitting error of the surrounding data of the i-th depolarization current data, and the greater the noise performance of the i-th depolarization current data. The value represents the difference in the average area enclosed by the two fitted curves formed by the surrounding data and the reference data for the i-th depolarization current data. The larger the value, the greater the noise level of the i-th depolarization current data.
[0054] S3, obtain all filtering windows for each depolarized current data and the filtering degree of each filtering window for each depolarized current data.
[0055] When acquiring all filtering windows for each depolarization current data, a window parameter 'a' can be preset, for example, 'a' can be set to 3. In the depolarization current data sequence, the window formed by the 'a' polarization current data before and the 'a' polarization current data after the i-th depolarization current data is denoted as a filtering window for the i-th depolarization current data.
[0056] The preceding a polarization current data points and the following a polarization current data points of the i-th depolarization current data are both denoted as the comparison polarization current data of the i-th depolarization current data. For any comparison polarization current data point of the i-th depolarization current data, the window formed by the preceding a polarization current data points and the following a polarization current data points is denoted as a filtering window of the i-th depolarization current data. Thus, all filtering windows of the i-th depolarization current data are obtained. When a is 3, the total number of filtering windows for the i-th depolarization current data is 7.
[0057] The mean value of the data in each filter window of each depolarized current data is used as the filter value for each filter window of each depolarized current data.
[0058] The absolute value of the difference between the filtered value of each filter window for each depolarized current data and the value of each depolarized current data is used as the filtering degree of each filter window for each depolarized current data.
[0059] S4. Based on the average noise performance of all data in each filter window of each depolarized current data and the filtering degree of each filter window of each depolarized current data, obtain the weight of each filter window of each depolarized current data.
[0060] It's important to note that within the multiple filtering windows of each depolarized current data set, the higher the average noise level of all data within any filtering window, the more filtering is needed in that window, and therefore, the higher the filtering level of that window should be. In other words, the average noise level of all data within each filtering window of each depolarized current data set should exhibit a positive correlation with the filtering level of each filtering window. If any filtering window deviates from this positive correlation, it indicates poor filtering performance, and the weight of that filtering window should be reduced. Therefore, the weight of each filtering window for the depolarized current data set can be determined based on the average noise level of all data within each filtering window and the filtering level of each filtering window.
[0061] When obtaining the weight of each filtering window for each depolarized current data based on the mean noise level of all data in each filtering window of each depolarized current data and the filtering degree of each filtering window of each depolarized current data, the following method can be used: Construct a two-dimensional Cartesian coordinate system with the filtering degree as the x-axis and the mean noise level as the y-axis. Map the filtering degree of each filtering window of the i-th depolarized current data and the mean noise level of all data in each filtering window of the i-th depolarized current data to the two-dimensional Cartesian coordinate system to obtain several filtering window data points for the i-th depolarized current data. The filtering window data points can be represented in the form of two-dimensional coordinates, such as (x, y).
[0062] The least squares method is used to perform linear regression on all the filtered window data points of the i-th depolarization current data to obtain the linear regression curve of the i-th depolarization current data.
[0063] The reciprocal of the distance between the k-th filter window data point of the i-th depolarized current data and the linear regression curve of the i-th depolarized current data is denoted as the distance factor of the k-th filter window of the i-th depolarized current data.
[0064] The weights for each filter window for each depolarization current data are obtained as follows:
[0065]
[0066] In the formula, h i,k The weights of the k-th filter window represent the values of the i-th depolarization current data; d i,j The distance factor representing the k-th filter window of the i-th depolarization current data; d i,sum This represents the sum of distance factors for all filter windows of the i-th depolarized current data. The larger the value of the distance factor of the k-th filter window of the i-th depolarized current data, the more positively correlated the mean noise performance of all data in the k-th filter window of the i-th depolarized current data is with its filtering degree.
[0067] S5: Obtain the filtered value for each depolarized current data according to the weight of each filtering window for each depolarized current data.
[0068] The sum of the products of the weights of each filtering window and the filter value for each depolarization current data point is used as the filter value for each depolarization current data point. The filter value for each depolarization current data point is obtained as follows:
[0069]
[0070] In the formula, R i h represents the filtered value of the i-th depolarization current data.i,k B represents the weight of the k-th filter window for the i-th depolarization current data; i F represents the number of filter windows for the i-th depolarization current data; i,k The filter value represents the filter value of the k-th filter window for the i-th depolarization current data.
[0071] S6. Based on the filtered value of each depolarization current data, obtain the filtered depolarization current data sequence, and determine the state of the cable based on the filtered depolarization current data sequence.
[0072] For example, the values in the filtered depolarized current data sequence are compared with the normal range of similar cables. If the initial value is more than 30% higher than the normal range of similar cables, it is determined that the cable has insulation defects or aging problems.
[0073] By constructing multiple filtering windows for each depolarized current data point, and then weighting the filter values of each filtering window for each depolarized current data point to obtain the filter value for each depolarized current data point, it is possible to consider each depolarized current data point at different positions in multiple filtering windows. This allows for a more comprehensive assessment of the surrounding conditions of each depolarized current data point, thereby more effectively removing noise while retaining detailed information. This significantly improves the noise reduction effect of mean filtering on depolarized current data, and thus enables more accurate detection of cable conditions.
[0074] According to an embodiment of the present invention, a cable condition determination device is provided. Figure 3 This is a structural block diagram of a cable condition determination device according to an embodiment of the present invention, such as... Figure 3 As shown, the device includes: an acquisition module 302, a processing module 304, and a determination module 306. The device will be described below.
[0075] Acquisition module 302 is used to acquire the depolarization current data sequence of the cable, wherein the depolarization current data sequence includes depolarization current data corresponding to multiple moments of the cable within a predetermined time period; Processing module 304, connected to the acquisition module 302, is used to perform the following processing on each depolarization current data in the depolarization current data sequence to obtain a processed depolarization current data sequence: taking each depolarization current data in the depolarization current data sequence as the first target depolarization current data; acquiring N filter values corresponding to the first target depolarization current data; determining the weights corresponding to the N filter values respectively; determining the target filter value corresponding to the first target depolarization current data based on the N filter values and the weights corresponding to the N filter values respectively; replacing the first target depolarization current data with the target filter value; Determination module 306, connected to the determination module 306, is used to determine the state of the cable based on the processed depolarization current data sequence.
[0076] It should be noted that the above-mentioned acquisition module 302, processing module 304 and determination module 306 correspond to steps S102 to S106 in the embodiments. The multiple modules and the corresponding steps implement the same instances and application scenarios, but are not limited to the content disclosed in the above embodiments.
[0077] As an optional embodiment, the processing module 304 includes a first determining unit and a filtering unit. The first determining unit is used to determine N filtering windows corresponding to the first target depolarization current data; the filtering unit, connected to the first determining unit, is used to filter the first target depolarization current data using the N filtering windows to obtain N filtered values.
[0078] As an optional embodiment, the first determining unit includes: a first determining subunit and a second determining subunit. The first determining subunit is used to determine the first target depolarization current data in the depolarization current data sequence based on the first target depolarization current data. Depolarization current data and subsequent A first filtering window is determined based on the first target depolarized current data, centered on the first target depolarized current data. The window length of the first filtering window is N, where N is an odd number greater than 1. A second determining subunit, connected to the first determining subunit, is used to determine the first filtering window based on the N-1 depolarized current data (excluding the first target depolarized current data) within the first filtering window, and to determine the first N-1 depolarized current data in the depolarized current data sequence based on the center. Depolarization current data and subsequent Given a depolarization current data set, determine N-1 filter windows. The window length of each of the N-1 filter windows is N, where the N filter windows include a first filter window and the N-1 filter windows.
[0079] As an optional embodiment, the processing module 304 further includes: a second determining unit, a third determining unit, and a fourth determining unit. The second determining unit is used to determine the filtering degree corresponding to each of the N filter values based on the first target depolarization current data and the N filter values corresponding to the first target depolarization current data. The third determining unit, connected to the second determining unit, is used to obtain the noise performance degree corresponding to each depolarization current data in each of the N filter windows, and determine the average noise performance degree corresponding to each of the N filter windows, wherein an average noise performance degree is the average noise performance degree corresponding to each of the N depolarization current data in a filter window, and the noise performance degree is used to characterize the degree to which the depolarization current data is affected by noise. The fourth determining unit, connected to the third determining unit, is used to determine the weight corresponding to each of the N filter values based on the filtering degree corresponding to each of the N filter values and the average noise performance degree corresponding to each of the N filter windows.
[0080] As an optional embodiment, the third determining unit includes: an assuming subunit and an acquiring subunit. The assuming subunit is used to take each depolarization current data in each of the N filtering windows as the second target depolarization current data; the acquiring subunit, connected to the assuming subunit, is used to acquire the noise performance level corresponding to the second target depolarization current data based on the first M and last M depolarization current data in the depolarization current data sequence of the second target depolarization current data.
[0081] As an optional embodiment, the above-mentioned acquisition subunit includes: a first acquisition subunit, a first determination subunit, a second acquisition subunit, a third acquisition subunit, a second determination subunit, and a third determination subunit. Specifically, the first acquisition subunit is used to acquire the second target depolarization current data, and the fitted values corresponding to the first M and last M depolarization current data of the second target depolarization current data in the depolarization current data sequence, respectively, to obtain 2M+1 first fitted values; the first determination subunit, connected to the first acquisition subunit, is used to determine the first fitting error corresponding to the second target depolarization current data based on the 2M+1 first fitted values and the second target depolarization current data, and the first M and last M depolarization current data of the second target depolarization current data in the depolarization current data sequence; the second acquisition subunit, connected to the first determination subunit, is used to acquire the second target depolarization current data using an interpolation method, and the depolarization current data sequence... The reference data corresponding to the first M and last M depolarization current data of the second target depolarization current data in the column are respectively obtained to obtain 2M+1 reference data. The third obtaining sub-unit is connected to the above-mentioned second obtaining sub-unit and is used to obtain the fitting values corresponding to the 2M+1 reference data based on the 2M+1 reference data to obtain 2M+1 second fitting values. The second determining sub-unit is connected to the above-mentioned third obtaining sub-unit and is used to determine the second fitting error corresponding to the second target depolarization current data based on the 2M+1 first fitting values and the 2M+1 second fitting values. The third determining sub-unit is connected to the above-mentioned second determining sub-unit and is used to determine the noise performance level corresponding to the second target depolarization current data based on the first fitting error and the second fitting error.
[0082] According to an embodiment of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is executed, it controls the device where the computer-readable storage medium is located to execute the cable status determination method described in any one of the above embodiments.
[0083] According to an embodiment of the present invention, an electronic device is provided, comprising: a memory storing an executable program; and a processor for running the program, wherein the program executes the cable status determination method described in any one of the preceding embodiments.
[0084] According to an embodiment of the present invention, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the cable state determination method described above.
[0085] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.
[0086] In the above embodiments of the present invention, 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.
[0087] 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.
[0088] 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.
[0089] Furthermore, the functional units in the various embodiments of the present invention 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.
[0090] 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 the present invention, 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 the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.
[0091] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for determining the state of a cable, characterized in that, include: Obtain the depolarization current data sequence of the cable, wherein the depolarization current data sequence includes depolarization current data of the cable at multiple times within a predetermined time period; The following processing is performed on each depolarized current data in the depolarized current data sequence to obtain a processed depolarized current data sequence: Each depolarized current data in the depolarized current data sequence is used as a first target depolarized current data; N filter values corresponding to the first target depolarized current data are obtained; the weights corresponding to the N filter values are determined; based on the N filter values and their respective weights, a target filter value corresponding to the first target depolarized current data is determined; the first target depolarized current data is replaced with the target filter value. The state of the cable is determined based on the processed depolarization current data sequence.
2. The method according to claim 1, characterized in that, The step of obtaining the N filtered values corresponding to the first target depolarization current data includes: Determine N filtering windows corresponding to the first target depolarization current data; The first target depolarization current data is filtered using the N filtering windows to obtain the N filtered values.
3. The method according to claim 2, characterized in that, The step of determining the N filtering windows corresponding to the first target depolarization current data includes: Based on the first target depolarization current data, the first target depolarization current data in the depolarization current data sequence Depolarization current data and subsequent A depolarization current data is used to determine a first filtering window, wherein the first filtering window is centered on the first target depolarization current data, and the window length of the first filtering window is N, where N is an odd number greater than 1; Taking N-1 depolarization current data points within the first filtering window (excluding the first target depolarization current data) as centers, and based on these centers, the preceding data points in the depolarization current data sequence are... Depolarization current data and subsequent Given a depolarization current data set, N-1 filter windows are determined, each with a window length of N. The N filter windows include the first filter window and the N-1 filter windows themselves.
4. The method according to claim 2, characterized in that, Determining the weights corresponding to the N filter values includes: Based on the first target depolarization current data and the N filter values corresponding to the first target depolarization current data, the filtering degree corresponding to the N filter values is determined respectively; Obtain the noise performance level corresponding to each depolarized current data in each of the N filtering windows, and determine the average noise performance level corresponding to each of the N filtering windows. The average noise performance level is the average noise performance level corresponding to each of the N depolarized current data in a filtering window. The noise performance level is used to characterize the degree to which the depolarized current data is affected by noise. Based on the filtering degree corresponding to the N filter values and the average noise performance degree corresponding to the N filter windows, the weights corresponding to the N filter values are determined.
5. The method according to claim 4, characterized in that, The step of obtaining the noise performance level corresponding to each depolarization current data in each of the N filtering windows includes: Each depolarization current data in each of the N filtering windows is used as the second target depolarization current data; Based on the second target depolarization current data, the noise performance level corresponding to the second target depolarization current data is obtained from the first M and last M depolarization current data in the depolarization current data sequence.
6. The method according to claim 5, characterized in that, The step of obtaining the noise performance level corresponding to the second target depolarization current data based on the second target depolarization current data, including the first M and last M depolarization current data in the depolarization current data sequence, includes: Obtain the second target depolarization current data, and obtain the fitting values corresponding to the first M and last M depolarization current data of the second target depolarization current data in the depolarization current data sequence, respectively, to obtain 2M+1 first fitting values; Based on the 2M+1 first fitted values and the second target depolarization current data, the first M depolarization current data and the last M depolarization current data of the second target depolarization current data in the depolarization current data sequence are used to determine the first fitting error corresponding to the second target depolarization current data. Interpolation is used to obtain the second target depolarization current data. The first M depolarization current data and the last M depolarization current data of the second target in the depolarization current data sequence are respectively the reference data, resulting in 2M+1 reference data. Based on the 2M+1 reference data, obtain the fitting values corresponding to the 2M+1 reference data respectively, and obtain 2M+1 second fitting values; Based on the 2M+1 first fitted values and the 2M+1 second fitted values, the second fitting error corresponding to the second target depolarization current data is determined; Based on the first fitting error and the second fitting error, the noise performance level corresponding to the second target depolarization current data is determined.
7. A cable condition determination device, characterized in that, include: The acquisition module is used to acquire the depolarization current data sequence of the cable, wherein the depolarization current data sequence includes depolarization current data of the cable at multiple times within a predetermined time period; The processing module is configured to perform the following processing on each depolarized current data in the depolarized current data sequence to obtain a processed depolarized current data sequence: taking each depolarized current data in the depolarized current data sequence as a first target depolarized current data; obtaining N filter values corresponding to the first target depolarized current data; determining the weights corresponding to the N filter values respectively; determining the target filter value corresponding to the first target depolarized current data based on the N filter values and the weights corresponding to the N filter values respectively; and replacing the first target depolarized current data with the target filter value. A determination module is used to determine the state of the cable based on the processed depolarization current data sequence.
8. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored executable program, wherein, when the executable program is executed, it controls the device containing the computer-readable storage medium to perform the cable status determination method according to any one of claims 1 to 6.
9. An electronic device, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, executes the cable status determination 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, it implements the steps of the method according to any one of claims 1 to 6.