Intelligent test method for porcelain insulator reliability and related device

Abstract

The application is suitable for the technical field of power equipment test, and particularly relates to a porcelain insulator reliability intelligent test method and related device. The method comprises the following steps: firstly, obtaining a detection starting voltage, a detection step voltage and a detection upper limit voltage of a test insulator; then, based on the detection starting voltage, the detection step voltage and the detection upper limit voltage, determining each level detection voltage, applying a detection signal to the test insulator and collecting a leakage current waveform, and obtaining a harmonic ratio based on the leakage current waveform; then, based on the harmonic ratio, determining an electric field elastic critical voltage; again, based on the electric field elastic critical voltage, the detection starting voltage and the detection upper limit voltage, determining a core response characteristic parameter; and finally, obtaining an individual reliability degradation index. Through the above method, the technical defect that the traditional fixed threshold detection method cannot adapt to individual differences can be overcome.

Description

Technical Field

[0001] This application belongs to the field of power equipment testing technology, and in particular relates to intelligent testing methods and related devices for the reliability of porcelain insulators. Background Technology

[0002] Porcelain insulators are the most widely used insulating devices in power systems, and are extensively used in overhead transmission lines, substations and power distribution equipment, serving the dual functions of electrical insulation and mechanical support.

[0003] In the factory quality inspection and in-service condition assessment of insulators, traditional testing methods usually employ withstand voltage tests or leakage current amplitude tests at fixed voltage levels. However, due to manufacturing process deviations and non-uniformity of material microstructure, there are significant individual differences in the internal electric field distribution and dielectric response characteristics of different insulators. This makes it difficult for traditional fixed threshold testing methods to effectively identify individual differences in insulation condition degradation, thus affecting the accuracy and reliability of insulator condition assessment. Summary of the Invention

[0004] This application provides an intelligent testing method and related apparatus for the reliability of porcelain insulators. It can solve the problem that due to manufacturing process deviations and material microstructure inhomogeneity, there are significant individual differences in the internal electric field distribution and dielectric response characteristics of different insulators. This makes it difficult for traditional fixed threshold detection methods to effectively identify individual differences in insulation state degradation, thus affecting the accuracy and reliability of insulator condition assessment.

[0005] In a first aspect, embodiments of this application provide an intelligent testing method for the reliability of porcelain insulators, including: The detection initiation voltage, detection step voltage, and detection upper limit voltage of the tested insulator are obtained; wherein, the detection initiation voltage is the initial voltage value of the progressive detection; the detection step voltage is the voltage increment between two adjacent detection stages; and the detection upper limit voltage is the highest voltage value during the detection process. Based on the detection start voltage, the detection step voltage, and the detection upper limit voltage, the detection voltages at each stage are determined, a detection signal is applied to the insulator under test, and the leakage current waveform is acquired. The harmonic ratio is obtained based on the leakage current waveform; wherein, the harmonic ratio is the ratio of the amplitude of the odd harmonic to the amplitude of the fundamental wave in the leakage current waveform. Based on the harmonic ratio, an electric field elastic critical voltage is determined; wherein, the electric field elastic critical voltage characterizes the detection voltage corresponding to when the rate of change of the harmonic ratio exceeds a preset inflection point sensitivity threshold; the inflection point sensitivity threshold is the critical rate of change for determining the accelerated growth of the harmonic ratio; Based on the electric field elastic critical voltage, the detection initiation voltage, and the detection upper limit voltage, the core response characteristic parameters are determined; wherein, the core response characteristic parameter is the average growth rate of the harmonic ratio with the detection voltage; Based on the core response characteristic parameters and the reference characteristic value, an individual reliability degradation index is obtained; wherein, the individual reliability degradation index characterizes the degree to which the core response characteristic parameters of the tested insulator deviate from the reference characteristic value.

[0006] The technical solutions described in this application embodiment have at least the following technical effects: The intelligent reliability testing method for porcelain insulators provided in this application first obtains the detection initiation voltage, detection step voltage, and detection upper limit voltage of the insulator under test; then, based on the detection initiation voltage, detection step voltage, and detection upper limit voltage, determines the detection voltages at each level, applies a detection signal to the insulator under test, and collects the leakage current waveform, obtaining the harmonic ratio based on the leakage current waveform; next, based on the harmonic ratio, determines the electric field elastic critical voltage; then, based on the electric field elastic critical voltage, detection initiation voltage, and detection upper limit voltage, determines the core response characteristic parameters; finally, based on the core response characteristic parameters and reference characteristic values, obtains the individual reliability degradation index. This application constructs a personalized progressive detection voltage sequence by acquiring the detection initiation voltage, detection step voltage, and detection upper limit voltage of the tested insulator, enabling the detection process to adapt to the differences in electric field response characteristics of different individual insulators. By acquiring the leakage current waveform and extracting the harmonic ratio, the time-domain signal is converted into frequency-domain characteristic parameters, effectively eliminating the interference of random noise on the direct measurement of leakage current amplitude. By determining the electric field elastic critical voltage based on the rate of change of the harmonic ratio, adaptive detection of the starting point of electric field distortion of individual insulators is achieved. By extracting core response characteristic parameters within the effective data range, the overall trend of harmonic ratio change with detection voltage is quantified. Finally, by comparing the core response characteristic parameters with reference characteristic values, the individual reliability degradation index is obtained, realizing the quantitative assessment of the degradation state of individual insulators. Through the above methods, this method can adaptively adjust the evaluation strategy according to the actual response characteristics of different individual insulators, overcoming the technical defects of traditional fixed threshold detection methods that cannot adapt to individual differences.

[0007] Secondly, embodiments of this application provide an intelligent testing system for the reliability of porcelain insulators, applied to a testing apparatus, for implementing the intelligent testing method for the reliability of porcelain insulators as described in any one of the first aspects above. The intelligent testing system for the reliability of porcelain insulators includes: The acquisition unit is used to acquire the detection start voltage, detection step voltage, and detection upper limit voltage of the insulator under test; wherein, the detection start voltage is the initial voltage value of the progressive detection; the detection step voltage is the voltage increment between two adjacent detection stages; and the detection upper limit voltage is the highest voltage value during the detection process. The waveform unit is used to determine the detection voltages at each stage based on the detection start voltage, the detection step voltage, and the detection upper limit voltage, apply a detection signal to the insulator under test, and acquire the leakage current waveform, and obtain the harmonic ratio based on the leakage current waveform; wherein, the harmonic ratio is the ratio of the amplitude of the odd harmonic to the amplitude of the fundamental wave in the leakage current waveform; A critical unit is used to determine the electric field elastic critical voltage based on the harmonic ratio; wherein the electric field elastic critical voltage characterizes the detection voltage corresponding to when the rate of change of the harmonic ratio exceeds a preset inflection point sensitivity threshold; the inflection point sensitivity threshold is the critical rate of change for determining the accelerated growth of the harmonic ratio; The feature unit is used to determine core response feature parameters based on the electric field elastic critical voltage, the detection start voltage, and the detection upper limit voltage; wherein, the core response feature parameter is the average growth rate of the harmonic ratio with the detection voltage; A reliability unit is used to obtain an individual reliability degradation index based on the core response characteristic parameters and a reference characteristic value; wherein the individual reliability degradation index characterizes the degree to which the core response characteristic parameters of the tested insulator deviate from the reference characteristic value.

[0008] Thirdly, embodiments of this application provide an experimental apparatus, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method as described in any of the first aspects above.

[0009] Fourthly, embodiments of this application provide a computer program product that, when run on a testing apparatus, causes the testing apparatus to perform the method described in any one of the first aspects above.

[0010] It is understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 This is a flowchart illustrating an intelligent testing method for the reliability of porcelain insulators provided in an embodiment of this application; Figure 2 This is a schematic diagram of the operation of an intelligent testing method for the reliability of porcelain insulators provided in an embodiment of this application; Figure 3 This is a schematic diagram of the leakage current waveform provided in an embodiment of this application; Figure 4 This is a schematic diagram of the intelligent reliability testing system for porcelain insulators provided in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of the test apparatus provided in the embodiments of this application. Detailed Implementation

[0013] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0014] In related technologies, traditional testing methods for insulator factory quality inspection and in-service condition assessment typically employ withstand voltage tests or leakage current amplitude tests at fixed voltage levels. However, due to manufacturing process deviations and non-uniformity of material microstructure, different insulators exhibit significant individual differences in their internal electric field distribution and dielectric response characteristics. This makes it difficult for traditional fixed-threshold testing methods to effectively identify individual differences in insulation condition degradation, thus affecting the accuracy and reliability of insulator condition assessment.

[0015] To address the aforementioned issues, this application provides an intelligent testing method for the reliability of porcelain insulators. This method includes: acquiring the detection initiation voltage, detection step voltage, and detection upper limit voltage of the tested insulator to construct a personalized progressive detection voltage sequence, enabling the detection process to adapt to the differences in electric field response characteristics of different individual insulators; acquiring leakage current waveforms and extracting harmonic ratios to convert the time-domain signal into frequency-domain characteristic parameters, effectively eliminating the interference of random noise on the direct measurement of leakage current amplitude; determining the electric field elastic critical voltage based on the harmonic ratio change rate to achieve adaptive detection of the insulator's electric field distortion initiation point; quantifying the overall trend of harmonic ratio variation with detection voltage by extracting core response characteristic parameters within the effective data range; and finally obtaining the individual reliability degradation index by comparing the core response characteristic parameters with reference characteristic values, achieving a quantitative assessment of the insulator's degradation state. This method allows for adaptive adjustment of the evaluation strategy according to the actual response characteristics of different individual insulators, overcoming the technical shortcomings of traditional fixed threshold detection methods that cannot adapt to individual differences.

[0016] The intelligent testing method for the reliability of porcelain insulators provided in this application embodiment can be applied to a testing device. In this case, the testing device is the main body for executing the intelligent testing method for the reliability of porcelain insulators provided in this application embodiment. This application embodiment does not impose any restrictions on the specific type of testing device.

[0017] For example, the test device can be implemented using an industrial-grade microprocessor, embedded industrial control computer, digital signal processor, or field-programmable gate array. Its core functions include: storing detection parameters (including detection start voltage, detection step voltage, and detection upper limit voltage); generating control commands for each level of detection voltage based on the above parameters; sending voltage amplitude commands to the high-voltage signal generator; performing spectrum analysis on the leakage current waveform data uploaded by the data acquisition card; calculating the harmonic ratio; determining the electric field elastic critical voltage; extracting core response characteristic parameters; and calculating the individual reliability degradation index. The test device internally includes a central processing unit, a storage unit, a data interface, and a control interface. These units are connected through an internal bus to achieve data interaction and command transmission. The test device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements any of the methods described above.

[0018] The testing device is electrically connected to the control terminal of the high-voltage signal generator via a control bus, used to send voltage amplitude control commands to the high-voltage signal generator. The output terminal of the high-voltage signal generator is connected to the high-voltage terminal of the insulator under test via a high-voltage conductor, used to output a high-voltage AC detection signal of corresponding amplitude to the insulator under test according to the voltage control commands sent by the testing device. The high-voltage signal generator internally includes a voltage regulation module, a power amplification module, and an output transformer, capable of converting the low-voltage control signal sent by the testing device into a high-voltage output signal with adjustable amplitude. Its output voltage range depends on the rated voltage level of the insulator under test and the test requirements.

[0019] Leakage current sensors are connected in series in the grounding circuit of the insulator under test to pick up the leakage current signal from the grounding terminal of the insulator and convert the current signal into a voltage signal that can be acquired by subsequent circuits. Leakage current sensors can be implemented using high-precision non-inductive sampling resistors or through-hole current transformers. The resistance value of the sampling resistor must be selected to balance signal amplitude and power consumption, typically in the kiloohm range. The turns ratio of the current transformer needs to be determined based on the expected range of the leakage current.

[0020] The signal output terminal of the leakage current sensor is electrically connected to the analog input terminal of the data acquisition card via a signal conditioning circuit. The signal conditioning circuit filters, amplifies, and anti-aliasing the voltage signal output by the leakage current sensor. Internally, it includes a filtering module, an amplification module, and an anti-aliasing filtering module. The filtering module removes stray high-frequency noise other than the power frequency and its harmonics. The amplification module amplifies the weak leakage current signal to a voltage range that the data acquisition card can effectively acquire. The anti-aliasing filtering module filters out high-frequency components above the Nyquist frequency before analog-to-digital conversion, preventing spectral aliasing.

[0021] The analog input terminal of the data acquisition card is electrically connected to the output terminal of the signal conditioning circuit, and its digital output terminal is electrically connected to the data interface of the test device via a data bus. The data acquisition card is used to perform analog-to-digital conversion on the conditioned leakage current signal at a preset sampling rate and record the time-domain waveform data. Internally, it includes an analog-to-digital conversion module, a sampling clock, and a buffer unit. The sampling rate must meet the requirements of the Nyquist sampling theorem and is typically set to tens to hundreds of times the power frequency to ensure accurate acquisition of the harmonic components of the leakage current waveform.

[0022] The collaborative working relationship between the aforementioned hardware modules is as follows: The test device, as the core control unit of the entire system, sends voltage amplitude commands to the high-voltage signal generator via the control bus, controlling it to output high-voltage detection signals of different amplitudes in stages. After the high-voltage signal output by the high-voltage signal generator is applied to the insulator under test, a leakage current is generated in the grounding circuit of the insulator. The leakage current sensor picks up this current signal and converts it into a voltage signal, which is then output to the signal conditioning circuit. The signal conditioning circuit filters, amplifies, and performs anti-aliasing processing on the signal before sending it to the data acquisition card. The data acquisition card performs analog-to-digital conversion on the conditioned analog signal and uploads the time-domain waveform data to the test device via the data bus. After receiving the waveform data, the test device performs steps such as spectrum analysis, harmonic ratio calculation, critical voltage determination, characteristic parameter extraction, and degradation index calculation.

[0023] To better understand the intelligent testing method for the reliability of porcelain insulators provided in the embodiments of this application, the specific implementation process of the intelligent testing method for the reliability of porcelain insulators provided in the embodiments of this application will be described by way of example below.

[0024] Figure 1 A flowchart illustrating the intelligent reliability testing method for porcelain insulators provided in an embodiment of this application is shown. Figure 2 This illustration shows an operational schematic of the intelligent reliability testing method for porcelain insulators provided in an embodiment of this application. The intelligent reliability testing method for porcelain insulators includes: S100: Obtain the detection initiation voltage, detection step voltage, and detection upper limit voltage of the insulator under test. The detection initiation voltage is the initial voltage value of the progressive detection. The detection step voltage is the voltage increment between two adjacent detection stages. The detection upper limit voltage is the highest voltage value during the detection process.

[0025] The initial detection voltage refers to the initial voltage value applied to the insulator under test using a progressive detection voltage. The initial detection voltage is determined based on the rated voltage level of the insulator and the preset configuration of the on-site testing procedures. The initial detection voltage can be obtained by reading a preset testing parameter configuration file or by receiving manual input. The step detection voltage refers to the voltage increment between two adjacent detection voltage levels. The step detection voltage is determined based on the sensitivity requirements of the electric field response characteristics of the insulator under test. The step detection voltage can be obtained by consulting the testing scheme or selecting it from a standard table based on the insulator type. The upper detection voltage limit refers to the maximum detection voltage applied to the insulator under test. The upper detection voltage limit is determined based on the withstand voltage capability of the insulator and the preset configuration of the safety testing procedures. The upper detection voltage can be determined from the insulator's factory withstand voltage value or the on-site safety procedures.

[0026] S200 determines the detection voltages at each stage based on the detection start voltage, detection step voltage, and detection upper limit voltage. It then applies detection signals to the insulator under test and acquires the leakage current waveform, obtaining the harmonic ratio based on the leakage current waveform. The harmonic ratio is the ratio of the amplitude of the odd harmonics to the amplitude of the fundamental wave in the leakage current waveform.

[0027] It can be understood that each level of detection voltage refers to the complete voltage sequence obtained by gradually increasing the detection step voltage from the initial detection voltage until it does not exceed the upper detection voltage limit. The harmonic ratio refers to the ratio of the amplitude of the odd harmonics (such as the 3rd harmonic, 5th harmonic, etc.) extracted after performing spectral analysis on the acquired leakage current waveform to the amplitude of the fundamental frequency (i.e., the 50 Hz power frequency component). This ratio reflects the degree of nonlinear distortion of the leakage current waveform.

[0028] The physical meaning of the harmonic ratio is that the more severe the distortion of the leakage current waveform, the more significant the nonlinear effect inside or on the surface of the insulator, and the higher the proportion of odd harmonics relative to the fundamental frequency. For an ideal linear insulating medium, the leakage current waveform should be a pure sine wave with no harmonic components, and the harmonic ratio should be zero. However, due to material inhomogeneity, surface contamination, and internal micro-defects, the leakage current waveform of a real porcelain insulator always exhibits a certain degree of nonlinear distortion. The harmonic ratio reflects the degree of this distortion and is an effective frequency domain characteristic parameter characterizing the dielectric state of the insulator.

[0029] As an optional embodiment of this application, S200, based on the detection start voltage, detection step voltage, and detection upper limit voltage, determines the detection voltages at each level, applies a detection signal to the insulator under test and acquires the leakage current waveform, and obtains the harmonic ratio based on the leakage current waveform, including: S210, based on the detection start voltage and the detection step voltage, obtain the detection voltage sequence for each stage. Each stage of the detection voltage sequence is a sequence of voltage values ​​starting with the detection start voltage and increasing with the detection step voltage.

[0030] It can be understood that the detection voltage sequence at each stage is a finite arithmetic voltage value sequence, with the first term being the detection start voltage, the tolerance being the detection step voltage, and the last term being the maximum voltage value not exceeding the detection upper limit voltage. The sequence is generated as follows: starting from the first term, each stage increases by one step voltage until it reaches or exceeds the upper limit voltage, and the final voltage sequence covers the entire voltage range from the start voltage to the upper limit voltage.

[0031] In this embodiment, the various levels of the probe voltage sequence are used as an arithmetic progression sequence. The physical significance of this is to ensure a uniform distribution of the probe voltage throughout the entire range, thereby comprehensively and without omission capturing the complete trend of the insulator response as voltage changes. Compared to schemes that randomly select voltage points or select only a few fixed voltage points, the arithmetic progression sequence guarantees the integrity and uniformity of voltage coverage, avoiding the omission of key response features due to uneven voltage sampling. This application does not impose any restrictions on the voltage sequence generation algorithm. For example, the voltage sequence can be generated by cyclic accumulation: starting from the initial voltage, each time a step voltage is added, and the voltage value obtained from each accumulation is added to the sequence until the accumulated value is greater than the upper limit voltage.

[0032] S220 applies detection signals to the insulator under test step by step according to the sequence of detection voltages, and collects the leakage current waveforms corresponding to each detection voltage.

[0033] As can be understood, step-by-step application refers to applying the detection signal sequentially at each voltage level, starting from the first level. Step-by-step acquisition refers to acquiring the leakage current waveform corresponding to each voltage level during the application of that voltage level, thereby establishing a one-to-one correspondence between the detection voltage and the leakage current waveform.

[0034] In this embodiment, a sequential logic of applying and acquiring data at each stage ensures that each detection voltage level has a unique corresponding leakage current waveform record. This one-to-one correspondence between voltage and waveform forms the data basis for subsequent analysis of the harmonic ratio variation trend with voltage. Only by acquiring the corresponding waveform data at each voltage level can the harmonic ratio at each voltage level be calculated, and thus the variation law of the harmonic ratio with voltage be analyzed. This application does not impose restrictions on the order of applying each voltage level. For example, a conventional sequence of gradually increasing voltage from low to high can also be used to ensure the safety of the detection process and avoid the influence of residual charge.

[0035] S230 performs spectrum analysis on the leakage current waveform to obtain the fundamental amplitude and odd harmonic amplitude of the leakage current waveform, and obtains the harmonic ratio based on the fundamental amplitude and odd harmonic amplitude.

[0036] In essence, spectrum analysis involves transforming the time-domain leakage current waveform signal into the frequency domain using mathematical transformations to obtain the signal's amplitude distribution at different frequencies. The fundamental frequency amplitude refers to the amplitude component at the fundamental power frequency (50 Hz). Odd-order harmonic amplitudes refer to the amplitude components at odd multiples of the fundamental frequency (such as 150 Hz, 250 Hz, 350 Hz, etc.). Dividing the odd-order harmonic amplitude by the fundamental frequency amplitude yields the harmonic ratio.

[0037] In this embodiment, the conversion logic from time-domain waveform to frequency-domain amplitude and then to ratio constitutes a complete signal processing link. The time-domain waveform is the raw measurement data, containing rich frequency component information; by decomposing the time-domain signal into components of different frequencies through spectrum analysis, the contributions of the fundamental wave and each harmonic can be separated; by calculating the harmonic ratio, the multidimensional spectrum information is compressed into a dimensionless characteristic parameter that can reflect the degree of waveform distortion, which facilitates subsequent quantitative analysis and comparison.

[0038] Existing technologies directly use time-domain amplitude, ignoring the frequency information contained in the waveform. This solution, through frequency domain transformation, can effectively utilize waveform distortion information to extract characteristic parameters that are more sensitive to the nonlinear effects of insulators.

[0039] like Figure 3 As shown, the leakage current waveform is close to a sine wave when the insulator is in the linear response region (e.g., Figure 3 (The waveform on the left side of the middle section) As the voltage increases and enters the nonlinear region, the waveform becomes distorted, exhibiting non-sinusoidal characteristics such as a flat top or sharp peaks (e.g., Figure 3 (The waveform on the right side of the middle section) shows that the harmonic ratio increases accordingly.

[0040] Optionally, spectrum analysis can be implemented using the Fast Fourier Transform (FFT) algorithm. For example, for the acquired discrete-time waveform data, after obtaining the spectrum through FFT, the corresponding amplitudes at frequency points such as 50 Hz, 150 Hz, and 250 Hz are read and used as the fundamental amplitude and the amplitudes of each odd harmonic, respectively. This application does not limit the specific algorithm for spectrum analysis; for example, spectrum analysis can also be implemented using other frequency domain analysis methods such as Discrete Fourier Transform (DFT) and wavelet packet transform.

[0041] By employing the steps S210 to S230 described above, it is helpful to extract frequency domain characteristic parameters with clear physical meaning from the time domain leakage current waveform, eliminate the influence of random noise and electromagnetic interference on the direct measurement of leakage current amplitude, and improve the anti-interference ability and repeatability of frequency domain characteristic parameters.

[0042] S300 determines the electric field elastic critical voltage based on the harmonic ratio. The electric field elastic critical voltage characterizes the detection voltage corresponding to when the rate of change of the harmonic ratio exceeds a preset inflection point sensitivity threshold. The inflection point sensitivity threshold is the critical rate of change that determines the accelerated growth of the harmonic ratio.

[0043] The electric field elastic critical voltage can be understood as the detection voltage value at which the rate of change of the harmonic ratio with increasing detection voltage first exceeds a preset inflection point sensitivity threshold during the step-by-step voltage increase detection process. This critical voltage indicates that the electric field distribution inside or on the surface of the tested insulator begins to undergo significant distortion, and the nonlinear polarization effect of the insulating medium enters an accelerated change phase. The inflection point sensitivity threshold is a preset critical rate of change value, whose value is preset according to the type and voltage level of the tested insulator, and is used to determine whether the rate of change of the harmonic ratio has entered the "accelerated growth" range.

[0044] In this embodiment, the basic principle of inflection point detection is as follows: Before the elastic critical voltage of the electric field, the insulator is in a linear or weakly nonlinear response region. The harmonic ratio increases slowly and almost linearly with the increase of the probe voltage, and the rate of change between adjacent stages is small and stable. When the probe voltage exceeds the elastic critical voltage of the electric field, a significant nonlinear polarization effect begins to appear inside the insulator. Physical processes such as space charge accumulation and enhanced interface polarization lead to an accelerated increase in the distortion of the leakage current waveform, and the rate of change of the harmonic ratio shows a significant jump. By monitoring the rate of change of the harmonic ratio and detecting whether it exceeds the inflection point sensitive threshold, the starting voltage for each individual insulator to enter the nonlinear acceleration region can be objectively determined.

[0045] Existing technologies use fixed voltage thresholds to determine the condition of insulators, which cannot adapt to the differences between individual insulators. This solution adaptively detects the inflection point based on the rate of change of each insulator's harmonic ratio, since the electric field elastic critical voltage may differ for each insulator.

[0046] This application does not impose any restrictions on the specific value of the inflection point sensitivity threshold. Its specific value can be determined based on the type and voltage level of the insulator under test, combined with historical data from factory tests or statistical experience with similar insulators. For example, for 10 kV porcelain insulators, the inflection point sensitivity threshold can be set to a rate of change of the ratio of adjacent harmonics greater than 30%.

[0047] Optionally, one specific method for determining the electric field elastic critical voltage is as follows: For each level of probe voltage (starting from the second level), calculate the rate of change of the current level's harmonic ratio relative to the previous level's harmonic ratio, and compare the current level's rate of change with the previous level's rate of change. When the rate of change significantly increases and exceeds the inflection point sensitivity threshold, the current level probe voltage is taken as the electric field elastic critical voltage. For example, if the rate of change of the 5th level suddenly jumps from about 5% in the previous levels to 35%, exceeding the preset 30% inflection point sensitivity threshold, then the probe voltage corresponding to the 5th level is taken as the electric field elastic critical voltage.

[0048] As an optional embodiment of this application, S300, determining the electric field elastic critical voltage based on the harmonic ratio includes: S310, based on the harmonic ratio values ​​corresponding to each level of detection voltage, obtains the comprehensive change rate of the harmonic ratio values ​​between adjacent levels. When the comprehensive change rate exceeds the inflection point sensitive threshold, the current level detection voltage is taken as the electric field elastic critical voltage.

[0049] It can be understood that the comprehensive rate of change refers to a comprehensive index reflecting the degree of drastic change in the harmonic ratio with voltage for adjacent detection voltage levels in a detection voltage sequence, calculated based on the harmonic ratios of each level. The calculation method is as follows: calculate the first rate of change using the harmonic ratio of the current level to the previous level, calculate the second rate of change using the harmonic ratio of the previous level to the level two levels above, and combine the first and second rates of change (e.g., take the average) to obtain the comprehensive rate of change.

[0050] In this embodiment, inflection point determination is performed using a comprehensive rate of change rather than a single-level rate of change, which improves the robustness and accuracy of the determination. A single-level rate of change is easily affected by fluctuations in single-point measurements or random noise, resulting in outliers. The comprehensive rate of change, by fusing information from both levels, acts as a smoothing and filtering mechanism, reducing the possibility of misjudging random fluctuations as the electric field elastic critical voltage.

[0051] Existing technologies do not involve the calculation of the rate of change or the detection of inflection points. This solution, by comprehensively considering the rate of change, can objectively and stably detect the starting point of each individual insulator entering the nonlinear region.

[0052] In one possible implementation, S310, based on the harmonic ratio values ​​corresponding to each level of the detection voltage, obtains the comprehensive rate of change of the harmonic ratio values ​​between adjacent levels. When the comprehensive rate of change exceeds the inflection point sensitivity threshold, the current level detection voltage is taken as the electric field elastic critical voltage, including: S311, based on the harmonic ratio of the Nth level and the harmonic ratio of the N-1th level, the first rate of change is obtained.

[0053] It can be understood that the first rate of change refers to the quotient obtained by subtracting the harmonic ratio of the Nth harmonic from the harmonic ratio of the (N-1)th harmonic and then dividing by the harmonic ratio of the (N-1)th harmonic, which is used to characterize the magnitude of change of the current harmonic relative to the previous harmonic.

[0054] S312, based on the harmonic ratios of the N-1 and N-2 levels, the second rate of change is obtained.

[0055] It can be understood that the second rate of change refers to the quotient obtained by subtracting the N-2 harmonic ratio from the N-1 harmonic ratio and then dividing by the N-2 harmonic ratio. It is used to characterize the change of the previous level relative to the level before that, and serves as a reference for the first rate of change.

[0056] S313: Based on the first rate of change and the second rate of change, a comprehensive rate of change is obtained. When the comprehensive rate of change exceeds the inflection point sensitivity threshold, the current stage detection voltage is taken as the electric field elastic critical voltage. The comprehensive rate of change is the average of the first rate of change and the second rate of change.

[0057] It can be understood that the composite rate of change refers to the arithmetic mean of the first and second rates of change. The composite rate of change is used to smooth the random fluctuations of single-level rates of change. The composite rate of change is obtained by averaging the first and second rates of change.

[0058] Existing technologies directly compare individual measurements with fixed thresholds, lacking mechanisms to suppress measurement fluctuations. This scheme uses the average of two levels of change rates to comprehensively determine the inflection point, resulting in stronger anti-interference capabilities and measurement robustness.

[0059] For example, assuming the harmonic ratio of level N-2 is 0.05, the harmonic ratio of level N-1 is 0.06, and the harmonic ratio of level N is 0.09, then the first rate of change = (0.09-0.06) / 0.06 = 50%, the second rate of change = (0.06-0.05) / 0.05 = 20%, and the combined rate of change = (50%+20%) / 2 = 35%. If the inflection point sensitivity threshold is preset to 30%, then the combined rate of change of 35% exceeds the threshold, and the detection voltage corresponding to level N is taken as the electric field elastic critical voltage. This application does not impose any restrictions on the calculation method of the combined rate of change.

[0060] By adopting the above steps S311 to S313, it is helpful to eliminate misjudgment of the rate of change caused by single-point noise or measurement fluctuations, improve the robustness and accuracy of the detection of the inflection point of the electric field elastic critical voltage, and avoid misjudging random fluctuations as the electric field elastic critical voltage.

[0061] S400 determines the core response characteristic parameters based on the electric field elastic critical voltage, the detection initiation voltage, and the detection upper limit voltage. Among them, the core response characteristic parameter is the average growth rate of the harmonic ratio with the detection voltage.

[0062] It can be understood that the core response characteristic parameter refers to a comprehensive quantitative index extracted through statistical regression or trend analysis based on the numerical sequence of the harmonic ratio changing with the probe voltage within the voltage range from the probe initiation voltage to the electric field elastic critical voltage, or within the complete voltage range from the probe initiation voltage to the probe upper limit voltage. The core response characteristic parameter is used to reflect the overall dependence and trend of the harmonic ratio on the probe voltage change. In the embodiments of this application, the extraction of the core response characteristic parameter is based on the following principle: before the electric field elastic critical voltage, the insulator is in a linear or weakly nonlinear response region, and the change law of the harmonic ratio with voltage reflects the intrinsic dielectric properties of the insulator. By performing trend analysis (such as linear regression) within this effective data range, the average growth rate of the harmonic ratio with voltage can be extracted, which can quantify the response characteristics of an individual insulator before entering the nonlinear region. The larger the average growth rate, the higher the sensitivity of the insulator to voltage increase, and the more significant the individual differences in its dielectric response.

[0063] This application does not impose any restrictions on the specific extraction algorithm for the core response feature parameters. For example, the regression slope of univariate linear regression can be used as the core response feature parameter, or the cumulative growth amount or other trend quantification indicators can be used.

[0064] As an optional embodiment of this application, in step S400, based on the electric field elastic critical voltage, the detection initiation voltage, and the detection upper limit voltage, the core response characteristic parameters are determined, including: S410, based on the voltage levels between the detection start voltage and the electric field elastic critical voltage, obtains the number of critical effective voltage levels.

[0065] The critical effective voltage level can be understood as the total number of detection voltage levels between the detection initiation voltage level and the electric field elastic critical voltage level. The critical effective voltage level is used to determine whether the number of data points within the interval meets the sample size requirements for statistical analysis. The critical effective voltage level is obtained by counting the voltage levels within the interval.

[0066] For example, the preset minimum effective data point threshold in the preset data point conditions is determined based on the sample size requirements of the statistical regression analysis. To ensure the statistical significance of univariate linear regression analysis, the preset minimum effective data point threshold is at least level 3.

[0067] S420: When the critical effective voltage level meets the preset data point conditions, the core response characteristic parameters are obtained based on the harmonic ratio sequence corresponding to the critical effective voltage level.

[0068] As can be understood, the preset data point condition means that the critical effective voltage level is not less than a preset minimum effective data point threshold. The preset minimum effective data point threshold is the minimum sample size required for statistical regression analysis. The preset data point condition is used to determine whether the critical effective voltage level is sufficient to support statistical regression analysis. The preset data point condition is achieved by comparing the critical effective voltage level with the minimum effective data point threshold.

[0069] In one possible implementation, S420, when the critical effective voltage level meets the preset data point conditions, the core response characteristic parameters are obtained based on the harmonic ratio sequence corresponding to the critical effective voltage level, including: S421, when the critical effective voltage level meets the preset data point conditions, the changing trend parameters are obtained based on the harmonic ratio sequence.

[0070] It can be understood that the trend parameter refers to the regression slope obtained by fitting a univariate linear regression within the effective voltage range, with the probe voltage as the independent variable and the harmonic ratio as the dependent variable. The trend parameter is used to quantify the average growth rate of the harmonic ratio as the probe voltage increases. In the embodiments of this application, a typical implementation of the trend parameter is the univariate linear regression slope. By performing least-squares linear fitting on the voltage-harmonic ratio data points within the effective data range, the regression slope obtained is the trend parameter, and its physical meaning is the increase in the harmonic ratio per unit voltage. However, in actual measurements, individual abnormal data points may cause the fitted slope to deviate from the physically reasonable range (e.g., excessively large positive or even negative values). In this case, directly using the slope as the core response feature parameter will lead to unclear physical meaning. By limiting the trend parameter to a physically reasonable range determined based on the insulator material and structural characteristics through reasonableness verification, the influence of abnormal data can be effectively filtered out.

[0071] S422, the rationality of the changing trend parameters is verified to obtain the core response characteristic parameters.

[0072] As can be understood, rationality verification refers to comparing the fitted trend parameters with a preset physical rationality interval. If the trend parameters are within the physical rationality interval, they are directly adopted; if they exceed the physical rationality interval, they are corrected to the boundary value of the physical rationality interval according to a preset truncation rule to ensure that the core response feature parameters are physically interpretable. Rationality verification is completed by comparing the trend parameters with the upper and lower limits of the physical rationality interval. If the regression slope is within the physical rationality interval, the regression slope is directly used as the core response feature parameter; if the regression slope is less than the lower limit of the physical rationality interval, the lower limit of the physical rationality interval is used as the core response feature parameter; if the regression slope is greater than the upper limit of the physical rationality interval, the upper limit of the physical rationality interval is used as the core response feature parameter.

[0073] This application does not impose any restrictions on the specific numerical range of the physically reasonable interval; its value is determined based on the voltage level and type of the insulator under test. For example, for a 10 kV porcelain insulator, the reasonable range of the harmonic ratio's increase in slope with voltage can be set to 0.01 to 0.10 per kV. If the fitted slope is 0.12, and it falls within this range, it is directly used as the core response characteristic parameter; if the fitted slope is -0.02, which is less than the lower limit of the interval (0.01), then 0.01 is used as the core response characteristic parameter; if the fitted slope is 0.15, which is greater than the upper limit of the interval (0.10), then 0.10 is used as the core response characteristic parameter.

[0074] By adopting the above steps S421 to S422, it is helpful to ensure the physical rationality and statistical significance of the extracted core response feature parameters, avoid fitting distortion due to individual abnormal data points, and improve the credibility of the core response feature parameters.

[0075] S430, when the critical effective voltage level does not meet the preset data point conditions, the core response characteristic parameters are obtained based on the harmonic ratio sequence corresponding to each voltage level between the detection start voltage and the detection upper limit voltage.

[0076] It is understandable that when the critical effective voltage level is less than the preset minimum effective data point threshold, the data extraction interval is expanded to the complete range from the detection start voltage to the detection upper limit voltage to ensure sufficient sample size to support statistical calculations. This data interval expansion is achieved by changing the effective interval to all voltage levels, and regression analysis is also used to obtain the core response characteristic parameters.

[0077] By adopting the above steps S410 to S430, it is helpful to adaptively select the optimal effective data interval under different data conditions, ensure the statistical reliability and stability of the core response feature parameter extraction, and avoid distortion of the core response feature parameters due to insufficient data.

[0078] S500, based on the core response characteristic parameters and reference characteristic values, yields the individual reliability degradation index. The individual reliability degradation index characterizes the degree to which the core response characteristic parameters of the tested insulator deviate from the reference characteristic values.

[0079] The Individual Reliability Degradation Index (IRI) is a dimensionless composite index obtained by comparing the core response characteristic parameters of the tested insulator with a reference characteristic value, calculating the relative deviation between the two and taking into account the baseline characteristics of the reference characteristic value itself. The IRI is used to quantitatively assess the degree of degradation of the tested insulator's current state compared to a reference state. The IRI can be obtained by first calculating the relative deviation and relative satisfaction, and then coupling the relative deviation and relative satisfaction (e.g., by multiplication or weighted summation).

[0080] As an optional embodiment of this application, in step S500, based on the core response characteristic parameters and reference characteristic values, an individual reliability degradation index is obtained, including: S510, based on the core response characteristic parameters of the tested insulator and the reference characteristic value, obtains the relative deviation.

[0081] The reference characteristic value refers to the statistically representative value of the core response characteristic parameters extracted from a standard insulator sample group of the same type, voltage level, and healthy state as the insulator under test, under the same detection parameter conditions. The reference characteristic value serves as a benchmark for judging the degradation of the insulator under test. The reference characteristic value can be obtained by testing multiple healthy samples and taking the average or median of the core response characteristic parameters of the healthy samples. The relative deviation is the absolute value of the quotient obtained by subtracting the reference characteristic value from the core response characteristic parameter and then dividing by the reference characteristic value. The relative deviation is used to quantify the degree to which the response characteristics of the insulator under test deviate from the benchmark state. The relative deviation is calculated using the difference ratio. The reference characteristic value can be obtained by selecting at least three insulator samples of the same type and voltage level as the insulator under test, which have been confirmed to be in a healthy state through factory testing. In a healthy state, the leakage current harmonic response of the insulator is within the normal fluctuation range, and there are no abnormal responses caused by manufacturing defects or operational aging. For each healthy sample, the core response characteristic parameters of each sample are extracted using the exact same detection parameters as the insulator under test. The arithmetic mean or median of the core response characteristic parameters for each healthy sample is used as the reference characteristic value. When there are at least 5 healthy samples, the arithmetic mean is preferred; when there are 3 to 4 healthy samples, the median is preferred to reduce the impact of extreme values.

[0082] S520, based on reference eigenvalues ​​and preset benchmark parameters, obtains the relative satisfaction level.

[0083] It can be understood that preset benchmark parameters refer to the baseline levels of core response characteristic parameters preset according to insulator design standards and operational requirements. Preset benchmark parameters can be obtained from industry standards or design specifications. Relative satisfaction is the quotient obtained by comparing the reference characteristic value with the preset benchmark parameter; relative satisfaction is used to quantify the degree to which the reference characteristic value meets the preset benchmark level. Relative satisfaction is calculated through a ratio.

[0084] S530, based on relative deviation and relative satisfaction, yields the individual reliability degradation index.

[0085] It can be understood that the individual reliability degradation index is a comprehensive index obtained by coupling relative deviation and relative satisfaction through multiplication or weighted summation. The individual reliability degradation index takes into account both the degree of deviation of the tested insulator from the standard reference and the margin level of the standard reference itself relative to the baseline. The individual reliability degradation index can be obtained through coupling calculation.

[0086] In one possible implementation, S530, based on relative deviation and relative satisfaction, derives an individual reliability degradation index, including: S531, normalize the relative deviation to obtain the standardized deviation coefficient.

[0087] As can be understood, the standardized deviation coefficient refers to a dimensionless coefficient that transforms the relative deviation to the [0,1] interval. The standardized deviation coefficient is used to eliminate the dimensional effects caused by differences in voltage levels or reference values. For example, normalization can be obtained using the known Min-Max normalization formula, where Max is the maximum value of the relative deviation and Min is the minimum value of the relative deviation.

[0088] S532, weighting is applied to the relative satisfaction level to obtain the weighted satisfaction coefficient. The weighting rules are preset according to the voltage level of the insulator under test.

[0089] The weighted satisfaction coefficient is understood to be the product of the weight value obtained by looking up the corresponding weight value from the preset weight configuration table based on the voltage level of the tested insulator and multiplying the weight value by the relative satisfaction level. The weighted satisfaction coefficient is used to differentiate the importance of insulators of different voltage levels in the calculation of the individual reliability degradation index. The weighted satisfaction coefficient is obtained by multiplying the weight value obtained from the table by the relative satisfaction level. Please refer to Table 1.

[0090] Table 1 S533 calculates the individual reliability degradation index by coupling the standardized deviation coefficient with the weighted satisfaction coefficient.

[0091] The coupling operation can be understood as the process of obtaining the individual reliability degradation index by multiplying or otherwise combining the standardized deviation coefficient and the weighted satisfaction coefficient. The individual reliability degradation index is the product of the standardized deviation coefficient and the weighted satisfaction coefficient; a larger index value indicates more severe reliability degradation of the tested insulator. The individual reliability degradation index is obtained by multiplying the standardized deviation coefficient and the weighted satisfaction coefficient.

[0092] By adopting the above steps S531 to S533, it is helpful to achieve the standardization and comparability of the individual reliability degradation index of insulators at different voltage levels, so that the insulator evaluation results are not affected by the voltage level differences, and it is convenient to formulate a unified maintenance decision threshold.

[0093] By employing the steps S510 to S530 described above, it is helpful to systematically compare the high-frequency response characteristics of the tested insulator with the health standard reference. At the same time, the margin information of the reference characteristic value itself is introduced to avoid misjudgment of the insulator degradation state due to fluctuations in the reference characteristic value itself, thereby improving the comprehensiveness and accuracy of the insulator degradation degree assessment.

[0094] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0095] Corresponding to the intelligent testing method for the reliability of porcelain insulators described in the above embodiments, this application also provides an intelligent testing system for the reliability of porcelain insulators, wherein each unit of the system can realize each step of the intelligent testing method for the reliability of porcelain insulators. Figure 4 The diagram shows a structural block diagram of the intelligent reliability testing system for porcelain insulators provided in the embodiments of this application. For ease of explanation, only the parts related to the embodiments of this application are shown.

[0096] Reference Figure 4 The system includes: The acquisition unit is used to acquire the detection initiation voltage, detection step voltage, and detection upper limit voltage of the insulator under test. The detection initiation voltage is the initial voltage value of the progressive detection. The detection step voltage is the voltage increment between two adjacent detection stages. The detection upper limit voltage is the highest voltage value during the detection process.

[0097] The waveform unit is used to determine the detection voltages at each stage based on the detection start voltage, detection step voltage, and detection upper limit voltage, apply detection signals to the insulator under test, and acquire the leakage current waveform. The harmonic ratio is then obtained based on the leakage current waveform. The harmonic ratio is the ratio of the amplitude of the odd harmonics to the amplitude of the fundamental wave in the leakage current waveform.

[0098] A critical element is used to determine the elastic critical voltage of the electric field based on the harmonic ratio. The elastic critical voltage characterizes the detection voltage corresponding to when the rate of change of the harmonic ratio exceeds a preset inflection point sensitivity threshold. The inflection point sensitivity threshold is the critical rate of change at which the harmonic ratio accelerates its increase. The feature unit is used to determine the core response characteristic parameters based on the electric field elastic critical voltage, the detection start voltage, and the detection upper limit voltage. Among them, the core response characteristic parameter is the average growth rate of the harmonic ratio with the detection voltage.

[0099] The reliability unit is used to obtain the individual reliability degradation index based on the core response characteristic parameters and the reference characteristic value. The individual reliability degradation index characterizes the degree to which the core response characteristic parameters of the tested insulator deviate from the reference characteristic value.

[0100] It should be noted that the information interaction and execution process between the above-mentioned units are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, which will not be repeated here.

[0101] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units is merely an example. In practical applications, the above functions can be assigned to different functional units as needed, that is, the internal structure of the system can be divided into different functional units to complete all or part of the functions described above. The functional units in the embodiments 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. Furthermore, the specific names of the functional units are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0102] This application also provides a testing apparatus. Figure 5 This is a schematic diagram of the structure of an experimental apparatus provided in one embodiment of this application. Figure 5 As shown, the test apparatus 6 of this embodiment includes: at least one processor 60 ( Figure 5 Only one is shown in the image), at least one memory 61 ( Figure 5 (Only one is shown in the image) and a computer program 62 stored in the at least one memory 61 and executable on the at least one processor 60. When the processor 60 executes the computer program 62, it causes the test device 6 to perform the steps in any of the above embodiments of the intelligent test method for the reliability of porcelain insulators, or causes the test device 6 to perform the functions of the units in the above embodiments of the system.

[0103] Exemplarily, the computer program 62 may be divided into one or more units, which are stored in the memory 61 and executed by the processor 60 to complete this application. The one or more units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 62 in the experimental apparatus 6.

[0104] The test device 6 can be an intelligent insulator withstand voltage tester, a high-voltage electrical test and control terminal, a portable insulator reliability testing device, an industrial-grade high-voltage test control computer, a substation intelligent testing terminal, an insulator leakage current tester, an embedded high-voltage test control system, a cloud-linked high-voltage detection server, or other industrial test devices with functions such as voltage regulation, signal application, data acquisition, waveform analysis, parameter calculation, and intelligent discrimination. The test device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method described in any of the above aspects. The test device 6 may include, but is not limited to, a processor 60 and a memory 61. Those skilled in the art will understand that... Figure 5 This is merely an example of test apparatus 6 and does not constitute a limitation on test apparatus 6. It may include more or fewer components than shown, or combine certain components, or different components, such as input / output devices, network access devices, buses, etc.

[0105] The processor 60 can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor.

[0106] In some embodiments, the memory 61 may be an internal storage unit of the experimental apparatus 6, such as a hard disk or memory of the experimental apparatus 6. In other embodiments, the memory 61 may be an external storage device of the experimental apparatus 6, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the experimental apparatus 6. Further, the memory 61 may include both internal storage units and external storage devices of the experimental apparatus 6. The memory 61 is used to store operating systems, applications, bootloaders, data, and other programs, such as the program code of the computer program. The memory 61 can also be used to temporarily store data that has been output or will be output.

[0107] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0108] This application provides a computer program product that, when run on a testing device, causes the testing device to perform the steps in any of the above-described method embodiments.

[0109] 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, all or part of the processes in the methods of the above embodiments of this application can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer-readable storage medium may include: read-only memory (ROM), random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0110] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0111] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0112] In the embodiments provided in this application, it should be understood that the disclosed intelligent testing method, system, and apparatus for the reliability of porcelain insulators can be implemented in other ways. For example, the embodiments of the intelligent testing system and apparatus for the reliability of porcelain insulators described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, 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 may be electrical, mechanical, or other forms.

[0113] 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 network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0114] The above provides a detailed description of an intelligent testing method and related apparatus for the reliability of porcelain insulators provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An intelligent testing method for the reliability of porcelain insulators, characterized in that, include: The detection initiation voltage, detection step voltage, and detection upper limit voltage of the tested insulator are obtained; wherein, the detection initiation voltage is the initial voltage value of the progressive detection; the detection step voltage is the voltage increment between two adjacent detection stages; and the detection upper limit voltage is the highest voltage value during the detection process. Based on the detection start voltage, the detection step voltage, and the detection upper limit voltage, the detection voltages at each stage are determined, a detection signal is applied to the insulator under test, and the leakage current waveform is acquired. The harmonic ratio is obtained based on the leakage current waveform; wherein, the harmonic ratio is the ratio of the amplitude of the odd harmonic to the amplitude of the fundamental wave in the leakage current waveform. Based on the harmonic ratio, an electric field elastic critical voltage is determined; wherein, the electric field elastic critical voltage characterizes the detection voltage corresponding to when the rate of change of the harmonic ratio exceeds a preset inflection point sensitivity threshold; the inflection point sensitivity threshold is the critical rate of change for determining the accelerated growth of the harmonic ratio; Based on the electric field elastic critical voltage, the detection initiation voltage, and the detection upper limit voltage, the core response characteristic parameters are determined; wherein, the core response characteristic parameter is the average growth rate of the harmonic ratio with the detection voltage; Based on the core response characteristic parameters and the reference characteristic value, an individual reliability degradation index is obtained; wherein, the individual reliability degradation index characterizes the degree to which the core response characteristic parameters of the tested insulator deviate from the reference characteristic value.

2. The method as described in claim 1, characterized in that, The process of determining various detection voltages based on the detection start voltage, the detection step voltage, and the detection upper limit voltage, applying detection signals to the tested insulator, and acquiring leakage current waveforms includes: Based on the detection start voltage, the detection step voltage, and the detection upper limit voltage, a detection voltage sequence at each level is obtained; wherein, the detection voltage sequence at each level is a sequence of voltage values ​​that starts with the detection start voltage and increases with the detection step voltage. According to the sequence of detection voltages at each level, detection signals are applied to the insulator under test step by step, and the leakage current waveforms corresponding to each detection voltage are collected.

3. The method as described in claim 1, characterized in that, The process of obtaining the harmonic ratio based on the leakage current waveform includes: The leakage current waveform is subjected to spectral analysis to obtain the fundamental amplitude and odd harmonic amplitude of the leakage current waveform, and the harmonic ratio is obtained based on the fundamental amplitude and the odd harmonic amplitude.

4. The method as described in claim 1, characterized in that, The determination of the electric field elastic critical voltage based on the harmonic ratio includes: Based on the harmonic ratio values ​​corresponding to each level of detection voltage, the comprehensive rate of change of the harmonic ratio values ​​between adjacent levels is obtained. When the comprehensive rate of change exceeds the inflection point sensitivity threshold, the current level detection voltage is taken as the electric field elastic critical voltage.

5. The method as described in claim 4, characterized in that, The method involves obtaining the comprehensive rate of change of harmonic ratios between adjacent levels based on the harmonic ratios corresponding to each level of detection voltage. When the comprehensive rate of change exceeds the inflection point sensitivity threshold, the current level detection voltage is taken as the electric field elastic critical voltage. The first rate of change is obtained based on the harmonic ratio of the Nth level and the harmonic ratio of the (N-1)th level. Based on the harmonic ratio values ​​of the N-1 and N-2 levels, the second rate of change is obtained; Based on the first rate of change and the second rate of change, a comprehensive rate of change is obtained. When the comprehensive rate of change exceeds the inflection point sensitivity threshold, the current level detection voltage is taken as the electric field elastic critical voltage. The comprehensive rate of change is the average of the first rate of change and the second rate of change.

6. The method as described in claim 1, characterized in that, The determination of core response characteristic parameters based on the electric field elastic critical voltage, the detection initiation voltage, and the detection upper limit voltage includes: Based on the voltage levels between the detection initiation voltage and the electric field elastic critical voltage, the number of critical effective voltage levels is obtained; When the critical effective voltage level meets the preset data point conditions, the core response characteristic parameters are obtained based on the harmonic ratio sequence corresponding to the critical effective voltage level. When the critical effective voltage level does not meet the preset data point condition, the core response characteristic parameters are obtained based on the harmonic ratio sequence corresponding to each voltage level between the detection start voltage and the detection upper limit voltage.

7. The method as described in claim 6, characterized in that, When the critical effective voltage level satisfies the preset data point condition, the core response characteristic parameters are obtained based on the harmonic ratio sequence corresponding to the critical effective voltage level, including: When the critical effective voltage level meets the preset data point condition, the change trend parameter is obtained based on the harmonic ratio sequence; The rationality of the aforementioned trend parameters is verified to obtain the core response characteristic parameters.

8. The method as described in claim 1, characterized in that, The individual reliability degradation index, obtained based on the core response characteristic parameters and reference characteristic values, includes: The relative deviation is obtained based on the core response characteristic parameters of the tested insulator and the reference characteristic value; wherein, the reference characteristic value is a benchmark value used to judge the degree of deviation of the core response characteristic parameters of the tested insulator. Based on the reference feature value and the preset benchmark parameter, the relative satisfaction level is obtained; Based on the relative deviation and the relative satisfaction, the individual reliability degradation index is obtained.

9. The method as described in claim 8, characterized in that, The individual reliability degradation index, derived based on the relative deviation and the relative satisfaction, includes: The relative deviation is normalized and corrected to obtain the standardized deviation coefficient; The relative satisfaction level is weighted to obtain a weighted satisfaction coefficient; wherein the weighting rule is preset according to the voltage level of the tested insulator. The standardized deviation coefficient and the weighted satisfaction coefficient are coupled to calculate the individual reliability degradation index.

10. An experimental apparatus, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method as described in any one of claims 1 to 9.

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