Insulation defect evaluation method based on short wave excitation and related device

Abstract

The invention relates to the field of partial discharge detection, and provides an insulation defect evaluation method based on short wave excitation and a related device, and the method comprises the steps: obtaining a partial discharge value set and a partial discharge voltage phase set of a to-be-detected insulator in a partial discharge state; performing defect evaluation on a to-be-detected insulating part according to the partial discharge value set to obtain a first evaluation result; carrying out defect evaluation after the partial discharge quantity value set and the partial discharge voltage phase set are combined to obtain a second evaluation result; and fusing the first evaluation result and the second evaluation result to obtain a defect detection result. The activity of the free charge of the defect of the to-be-detected insulator can be improved during short wave excitation, so that a numerical value can be captured more easily during partial discharge detection. Through the first evaluation and the second evaluation, the deterioration degree and the defect type of the defect are accurately positioned, so that the comprehensive state of the defect of the to-be-detected insulating part is judged, the detection accuracy is improved, and risk management and control are facilitated.

Description

Technical Field

[0001] This application relates to the field of partial discharge detection technology, specifically to an insulation defect assessment method and related apparatus based on shortwave excitation. Background Technology

[0002] Partial discharge detection is a core technology for diagnosing the insulation condition of power equipment. It primarily targets high-voltage equipment such as transformers, cables, and switchgear, detecting localized breakdown discharge phenomena caused by insulation defects such as bubbles, impurities, and aging cracks. This detection method uses sensors to capture electrical signals, ultrasonic signals, and electromagnetic radiation generated by the discharge, and combines this data analysis to pinpoint the type and location of the defect.

[0003] An existing method discloses a method for identifying main longitudinal insulation defects under complex electrical stress on the valve side of a converter transformer. The method includes: first, acquiring partial discharge signals from the valve side of the converter transformer, recording the amplitude and phase of each partial discharge with a period of T, and plotting a partial discharge phase-discharge (PRPD) spectrum when the cumulative number of discharges exceeds N; second, characterizing the PRPD spectrum profile to obtain a PRPD spectrum profile curve to represent the change in maximum discharge amplitude with phase; third, performing frequency domain analysis on the PRPD spectrum profile curve; and fourth, identifying discharges in the main and longitudinal insulation. This method does not preprocess insulation defects, directly using only partial discharge signals as data, resulting in significant errors and low data processing efficiency. Furthermore, relying solely on the PRPD spectrum for defect analysis leads to a single and incomplete evaluation method, and the results are easily affected by noisy data. Summary of the Invention

[0004] This application provides an insulation defect assessment method and related apparatus based on shortwave excitation, which can amplify the signal intensity of the insulation component under test and assess the defect intensity and type separately, thereby improving the accuracy of the defect assessment of the insulation component under test.

[0005] A first aspect of this application provides a method for evaluating insulation defects based on shortwave excitation, the method comprising: Obtain the set of partial discharge values ​​and the set of partial discharge voltage phases of the insulation component under test that is in a partial discharge state; Based on the set of partial discharge values, a defect assessment is performed on the insulation component to be tested to obtain a first assessment result; The defect assessment is performed by combining the set of partial discharge values ​​and the set of partial discharge voltage phases to obtain the second assessment result. The first evaluation result and the second evaluation result are combined to obtain the defect detection result.

[0006] In this example, the set of partial discharge values ​​and the set of partial discharge voltage phases of the insulating component under test in a partial discharge state are obtained. A first evaluation result is obtained by performing a defect assessment on the insulating component under test based on the set of partial discharge values. A second evaluation result is obtained by combining the set of partial discharge values ​​and the set of partial discharge voltage phases and performing a second defect assessment. This allows for an accurate assessment of the degree of degradation and the type of defect. By fusing the first and second evaluation results, a defect detection result is obtained. This determines the overall defect status of the insulating component under test, improving detection accuracy and facilitating risk management.

[0007] In one possible implementation, the set of partial discharge values ​​and the set of partial discharge voltage phases of the insulating component under test in a partial discharge state are obtained, including: Extract the partial discharge pulse signal from the insulating component under test that is in a partial discharge state; The partial discharge pulse signal is converted to obtain the partial discharge voltage phase set; The partial discharge pulse signal is subjected to anti-interference purification to obtain the true partial discharge signal; The partial discharge signal is processed to obtain a set of partial discharge values. In one possible implementation, the step of evaluating the defect of the insulation component to be tested based on the set of partial discharge values ​​to obtain a first evaluation result includes: The partial discharge value set is normalized to obtain a standard partial discharge value set; Based on the absolute threshold of the insulation component to be tested, the set of standard partial discharge values ​​is quantified to obtain a quantitative index. Based on the quantitative indicators, the degree of defect of the insulation component to be tested is evaluated to obtain a first evaluation result.

[0008] In one possible implementation, the step of performing a defect assessment by combining the set of partial discharge magnitude values ​​and the set of partial discharge voltage phases to obtain a second assessment result includes: Based on the set of partial discharge values ​​and the set of partial discharge voltage phases, a phase-resolved pulsed discharge (PRPD) spectrum is constructed. The PRPD map is fitted to obtain the PRPD curve; Global features are extracted from the PRPD curve, and the global features are identified to obtain the identification result; The defect type of the insulation component to be inspected is evaluated based on the identification result to obtain a second evaluation result. In one possible implementation, the fitting process of the PRPD map to obtain the PRPD curve includes: Based on the PRPD map, the partial discharge voltage phase set is segmented to obtain several partial discharge voltage phase subsets; By performing calculations on several subsets of partial discharge voltage phases, several sets of discharge statistics characteristic values ​​are obtained. The PRPD curve is obtained by fitting the set of characteristic values ​​of several discharge statistics.

[0009] A second aspect of this application provides an insulation defect assessment device based on shortwave excitation, the device comprising: The acquisition unit is used to acquire the set of partial discharge values ​​and the set of partial discharge voltage phases of the insulation component under test that is in a partial discharge state; The first evaluation unit is used to evaluate the defects of the insulation component to be tested based on the set of partial discharge values, and obtain the first evaluation result. The second evaluation unit is used to perform defect evaluation by combining the set of partial discharge values ​​and the set of partial discharge voltage phases to obtain the second evaluation result. The fusion unit is used to fuse the first evaluation result and the second evaluation result to obtain the defect detection result.

[0010] In one possible implementation, the acquisition unit is specifically used for: Extract the partial discharge pulse signal from the insulating component under test that is in a partial discharge state; The partial discharge pulse signal is converted to obtain the partial discharge voltage phase set; The partial discharge pulse signal is subjected to anti-interference purification to obtain the true partial discharge signal; The partial discharge signal is processed to obtain a set of partial discharge values.

[0011] In one possible implementation, the first evaluation unit is specifically used for: The partial discharge value set is normalized to obtain a standard partial discharge value set; Based on the absolute threshold of the insulation component to be tested, the set of standard partial discharge values ​​is quantified to obtain a quantitative index. Based on the quantitative indicators, the degree of defect of the insulation component to be tested is evaluated to obtain a first evaluation result.

[0012] In one possible implementation, the second evaluation unit is specifically used for: Based on the set of partial discharge values ​​and the set of partial discharge voltage phases, a phase-resolved pulsed discharge (PRPD) spectrum is constructed. The PRPD map is fitted to obtain the PRPD curve; Global features are extracted from the PRPD curve, and the global features are identified to obtain the identification result; The defect type of the insulation component to be tested is evaluated based on the identification results to obtain a second evaluation result.

[0013] In one possible implementation, regarding the fitting process of the PRPD map to obtain the PRPD curve, the second evaluation unit is specifically used for: Based on the PRPD map, the partial discharge voltage phase set is segmented to obtain several partial discharge voltage phase subsets; By performing calculations on several subsets of partial discharge voltage phases, several sets of discharge statistics characteristic values ​​are obtained. The PRPD curve is obtained by fitting the set of characteristic values ​​of several discharge statistics.

[0014] A third aspect of this application provides a terminal including a processor, an input device, an output device, and a memory, wherein the processor, input device, output device, and memory are interconnected, wherein the memory is used to store a computer program, the computer program including program instructions, and the processor is configured to invoke the program instructions to execute the step instructions as described in the first aspect of this application.

[0015] A fourth aspect of this application provides a computer-readable storage medium storing a computer program for electronic data interchange, wherein the computer program causes a computer to perform some or all of the steps described in the first aspect of this application.

[0016] A fifth aspect of this application provides a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program operable to cause a computer to perform some or all of the steps described in the first aspect of this application. The computer program product may be a software installation package. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, 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.

[0018] Figure 1 A flowchart illustrating an insulation defect assessment method based on shortwave excitation is provided for an embodiment of this application. Figure 2 This application provides a schematic diagram of a partial discharge detection circuit. Figure 3 This is a schematic diagram of the structure of a terminal provided in an embodiment of this application; Figure 4 This application provides a schematic diagram of the structure of an insulation defect assessment device based on shortwave excitation. Detailed Implementation

[0019] 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.

[0020] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0021] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0022] To better understand the shortwave excitation-based insulation defect assessment method provided in this application, a brief introduction to existing partial discharge detection methods is given below. Partial discharge detection is a core technology for diagnosing the insulation condition of power equipment, primarily targeting high-voltage equipment such as transformers, cables, and switchgear to detect local breakdown discharge phenomena caused by insulation defects. This detection method uses sensors to capture electrical signals, ultrasonic signals, and electromagnetic radiation generated by the discharge, and combines data analysis to locate the defect type and location. In practice, no preprocessing of insulation defects is performed; only the partial discharge signal is directly used as data, resulting in significant errors and low data processing efficiency. A brief introduction to PRPD spectrum analysis in existing solutions is given below. Phase-resolved pulse discharge spectrum (PRPD spectrum) is an analytical tool for partial discharge detection. By correlating the discharge quantity and number of discharges of the partial discharge signal with the phase angle of the applied voltage, it presents the discharge characteristics in two-dimensional or three-dimensional graphics. By utilizing the correlation between partial discharge and voltage phase, and the unique discharge patterns exhibited by different insulation defects in specific phase intervals, the defect type can be determined.

[0023] To address the aforementioned technical problems, this application provides an insulation defect assessment method based on shortwave excitation, which can amplify the signal intensity of the insulation component under test and assess the defect intensity and type separately, thereby improving the accuracy of the defect assessment of the insulation component under test.

[0024] Please see Figure 1 , Figure 1 This application provides a flowchart illustrating an insulation defect assessment method based on shortwave excitation. Figure 1 As shown, the method includes: 101. Obtain the set of partial discharge values ​​and the set of partial discharge voltage phases of the insulation component under test that is in a partial discharge state.

[0025] When using partial discharge testing to detect defects in insulating components, it is often difficult to obtain electrical signals at the defect location due to the defect's deep interior or minute development. To address this issue, short-wave excitation can be used as a preprocessing method before partial discharge detection.

[0026] A short-wavelength light source with specific parameters is applied to the insulating component under test. The wavelength, intensity, and duration of the light source are set according to standard procedures and the properties of the insulating component. Short-wavelength excitation involves applying the light source to latent defects within the insulating component, such as tiny air gaps or locally aged areas, thereby breaking the defect's original weakly active state. Short-wavelength excitation accelerates the ionization process in the defect area and alters the local electric field distribution, transforming defects with weak and difficult-to-capture discharge signals into active discharge states, facilitating subsequent detection and signal capture. The short-wavelength excitation equipment can be an ultraviolet irradiator or other equipment capable of short-wavelength irradiation; no specific limitations are specified here.

[0027] Shortwave energy penetrates into the defect region inside the insulating component, altering the molecular polarization state around the defect and indirectly adjusting the local electric field distribution. For example, if there are air gaps inside the insulating component under test, the gas molecules within the tiny gaps are more easily ionized under shortwave irradiation, reducing the gap breakdown field strength. This transforms the electric field environment, which was originally unable to produce significant discharge, into a state where stable partial discharge can occur, thus obtaining an excited-state insulating component under test.

[0028] When a partially discharged component is subjected to partial discharge, a momentary voltage change occurs across its terminals, generating a pulse current in the detection circuit. This pulse current, after passing through a sampling resistor, produces a pulse voltage across it. Processing this pulse voltage yields basic information about the partial discharge. By repeatedly performing periodic discharge detection on the excited-state insulating component and converting this basic information, the set of partial discharge magnitudes and the set of partial discharge voltage phases can be obtained.

[0029] 102. Based on the set of partial discharge values, perform a defect assessment on the insulation component to be tested to obtain the first assessment result.

[0030] The initial assessment results are derived from examining the activity of defects in the insulation component under test over time. The activity level of a defect is determined by its degree of degradation. Partial discharge values ​​may be sensitive to changes in external conditions; for example, abrupt changes in partial discharge values ​​may occur when voltage increases or temperature changes. The key to the assessment lies in the potential degree of defect degradation; the results of the initial assessment reflect the extent of the defect's degradation.

[0031] 103. After combining the set of partial discharge values ​​and the set of partial discharge voltage phases, a defect assessment is performed to obtain the second assessment result.

[0032] The second assessment result is derived from constructing a Partial Discharge Voltage Phase Spectrum (PRPD) map by combining the partial discharge voltage phase set and the partial discharge magnitude set, thus determining the defect type. Different types of insulation defects have completely different electric field distribution characteristics and discharge triggering mechanisms. When a discharge occurs, there is a significant difference between the partial discharge voltage phase window and the intensity of a single discharge. This difference can be clearly reflected in the PRPD map. Therefore, different defect types can be identified by utilizing the image differences in the PRPD map. The second assessment result reflects the defect type.

[0033] 104. The first evaluation result and the second evaluation result are combined to obtain the defect detection result.

[0034] The first assessment determines the degree of defect, and the second assessment determines the type of defect. By merging these two assessment results, the examination of the defects in the insulation component under test is completed. Employing different assessment methods and tools across two assessment dimensions improves the accuracy of defect assessment for insulation components.

[0035] In one possible implementation, when using partial discharge (PD) to detect defects in insulating components, it is often difficult to obtain the electrical signal at the defect location due to the defect's deep penetration or minute size. To address this issue, short-wave excitation can be used for preprocessing before PD detection. Secondly, the weak signal generated by a small defect may experience energy loss or signal distortion due to the physical characteristics of the insulating component and the device structure during its propagation from the defect location to the detection end, making the signal even weaker by the time it reaches the sensor.

[0036] To address the issue of weak electrical signals at the aforementioned defects, the insulating component under test can be continuously excited by a short-wavelength light source to obtain the excited state of the insulating component. Partial discharge detection can then be performed on the insulating component to facilitate the subsequent acquisition of the set of partial discharge values ​​and the set of partial discharge voltage phases of the insulating component in a partial discharge state. Specifically, this includes: A1. Extract the partial discharge pulse signal from the insulating component under test that is in a partial discharge state; A2. The partial discharge pulse signal is converted to obtain the partial discharge voltage phase set; A3. Perform anti-interference purification on the partial discharge pulse signal to obtain the true partial discharge signal; A4. Perform calculations and processing on the actual partial discharge signal to obtain a set of partial discharge values.

[0037] Specifically, the partial discharge pulse signal can be extracted from the insulating component under test that is in a partial discharge state.

[0038] Specifically, this embodiment adopts the following possible implementation method: Before performing partial discharge detection, the type of the insulating component to be tested is identified as a GIS equipment insulating basin insulator, made of cross-linked polyethylene, with a rated voltage of 110kV and a maximum operating voltage of 126kV according to IEC 60840 standard. Based on this, the wavelength of the shortwave light source is determined to be in the ultraviolet band of 200~400nm; the intensity is 120mW / cm². To avoid damage to the insulating component due to excessive energy, the action time is set to 240s.

[0039] In laboratory testing, background noise was shielded, and the effective distance between the short-wavelength light source and the insulating component under test was fixed at 20 cm. An optical power meter was used to monitor the light source intensity in real time to avoid excessive local energy concentration. The ultraviolet irradiator was turned on and fully irradiated the insulating component under test according to the calibrated parameters for 240 seconds. After reaching the preset excitation time, the ultraviolet irradiator was turned off, and the component was allowed to stand for 30 seconds to allow the defect discharge state to stabilize. After the standing period, the excited-state insulating component under test was obtained.

[0040] At this point, a detection circuit can be constructed on the excited-state insulating component to be tested, and partial discharge can be performed to generate a partial discharge pulse signal. Please refer to [link / reference]. Figure 2 , Figure 2 This is a schematic diagram of a partial discharge detection circuit. A coupling capacitor, a sampling resistor, a detection terminal, and the insulating component under test form a closed loop, and partial discharge is performed to generate a partial discharge pulse current. The coupling capacitor prevents high voltage from entering the detection circuit and allows the partial discharge pulse current to pass through, entering the sampling resistor; the sampling resistor converts the partial discharge pulse current into the partial discharge pulse signal.

[0041] Partial discharge is applied to the excited-state insulating component under high voltage. If internal defects exist, the electric field strength in the defect area will be significantly higher than that in the surrounding normal insulation area. When the electric field strength reaches the breakdown field strength of the defect medium, local micro-breakdown occurs, generating a partial discharge pulse current. The detection terminal in the detection circuit converts the partial discharge pulse current into a partial discharge pulse signal, thus extracting the partial discharge pulse signal.

[0042] The partial discharge pulse signal can be converted into the partial discharge voltage phase set. One possible implementation is as follows: the occurrence of the partial discharge pulse needs to correspond to the phase change of the voltage to ensure the accuracy of the conversion. Therefore, the partial discharge pulse signal and the voltage reference signal need to be acquired simultaneously. The voltage reference signal can be acquired through a voltage transformer to identify the moment when the sine wave crosses 0V from negative to positive, denoted as t0. The peak time of the partial discharge pulse signal is recorded as T0. Then, the phase conversion of a single partial discharge voltage can be performed using the formula: θ=2 Multiple periodic discharge detections generate multiple partial discharge voltage phases. By calculating each partial discharge voltage phase using the formula described above, the set of partial discharge voltage phases can be obtained.

[0043] The partial discharge (PD) pulse signal can be purified to obtain the true PD signal. One possible implementation is as follows: Since there is a large amount of interference at the PD detection site, and these interference signals may resemble the PD pulse in shape, they can easily interfere with subsequent analysis. A fixed phase interval can be used: 0~90° for the positive half-cycle and 180~270° for the negative half-cycle. The actual signal generally has a discharge peak in both the positive and negative half-cycles, while interference signals are usually irregular or have a uniform phase distribution. Therefore, only signals with specific phases need to be retained to obtain the true PD signal. Simultaneously, since the rising edge, falling edge, and pulse width of the true PD signal have fixed characteristics, software can be used for feature comparison to eliminate interference signals with inconsistent shapes. After the anti-interference purification, the true PD signal is obtained.

[0044] The partial discharge signal can be processed to obtain a set of partial discharge values; one possible implementation is as follows: The partial discharge value is essentially a calculated result of the equivalent charge. The partial discharge pulse current appearing in the detection circuit needs to be converted into charge through integration. For the actual partial discharge signal I... (t) Integrating over the pulse duration Δt yields the total charge q, which can be expressed by the formula: q = Before integrating the true partial discharge signal, the signal attenuation caused by the detection circuit needs to be calibrated. A standard charge generator capable of outputting a known charge q0 is connected to the detection circuit to capture the standard signal at the detection end. After processing the standard signal as described above, the calibration coefficient K is obtained. The partial emission value can then be calculated using the formula: Q = K· Multiple periodic discharge detections generate multiple partial discharge values. By calculating each partial discharge value using the formula described above, a set of partial discharge values ​​can be obtained.

[0045] In one possible implementation, the step of evaluating the defect of the insulation component to be tested based on the set of partial discharge values ​​to obtain a first evaluation result includes: B1. Normalize the set of partial discharge values ​​to obtain a standard set of partial discharge values; B2. Based on the absolute threshold of the insulation component to be tested, the standard partial discharge value set is quantified to obtain a quantitative index; B3. Based on the quantitative indicators, assess the degree of defect of the insulation component to be tested to obtain the first assessment result.

[0046] The partial discharge value set can be normalized to obtain a standard partial discharge value set. One possible implementation is as follows: The storage format of the partial discharge value set is unified; it can be an array, list, or CSV column, and no particular limitation is made here. All partial discharge values ​​are uniformly numerical data, excluding strings, null values, and logical values. The phase range of the partial discharge voltage corresponding to all partial discharge values ​​is unified, and outliers are removed. After the above operations, the partial discharge value set is normalized, resulting in a standard partial discharge value set.

[0047] The standard partial discharge value set can be quantified based on the absolute threshold of the insulating component to be tested to obtain a quantitative index. One possible implementation is as follows: The absolute threshold of the insulating component to be tested can be the execution standard of the equipment to which the insulating component belongs. Taking the GIS equipment insulator basin as an example, the execution standard is EC62271-303, and the absolute threshold is 5pC. The standard partial discharge value set can be quantified according to "average discharge quantity", "maximum discharge quantity", and "pulse frequency", without limitation. The result of the quantization is then integrated with the absolute threshold of the insulating component to be tested as the quantitative index.

[0048] The degree of defect in the insulating component under test can be assessed based on the quantitative indicators to obtain a first assessment result. One possible implementation is as follows: the quantitative indicators are used to jointly assess the degree of defect in the insulating component under test, rather than a single assessment. The quantitative indicators can be based on the following rules, which are not limited here: if the partial discharge values ​​are all stable below the absolute threshold and the fluctuation range is less than the average value of the set of partial discharge values, the insulating component under test is assessed as having stable defects. If the partial discharge values ​​all exceed the absolute threshold and continue to increase over time, with intermittent increases at the rated voltage of the insulating component under test, the insulation state of the insulating component under test is assessed as deteriorating and defects are beginning to develop. If the partial discharge values ​​all exceed twice the absolute threshold and continue to increase over time, exceeding the average value of the set of partial discharge values, the insulation state of the insulating component under test is assessed as poor, and defects will affect the insulation effect. After assessment by the quantitative indicators, the degree of defect in the insulating component under test is obtained as the first assessment result.

[0049] Taking the basin-type insulator of GIS equipment as an example, the standard is EC 62271-303, and the absolute threshold is 5pC. If the partial discharge value is stable between 3 and 5pC, and the fluctuation range is less than or equal to 1pC, the defect in the basin-type insulator of the GIS equipment is assessed as stable. If the partial discharge value consistently exceeds 5pC and increases slowly, and a sudden change in the partial discharge value occurs at 1.2 times the rated voltage, the defect in the basin-type insulator of the GIS equipment is assessed as beginning to develop, and monitoring is required. If the partial discharge value consistently exceeds 10pC and increases rapidly, with an increase rate exceeding an average of 7.5pC every three hours, the insulation condition of the basin-type insulator of the GIS equipment is assessed as poor, requiring immediate action.

[0050] In one possible implementation, the step of performing a defect assessment by combining the set of partial discharge magnitude values ​​and the set of partial discharge voltage phases to obtain a second assessment result includes: C1. Construct a phase-resolved pulsed discharge (PRPD) spectrum based on the set of partial discharge values ​​and the set of partial discharge voltage phases. C2. Fit the PRPD map to obtain the PRPD curve; C3. Extract global features from the PRPD curve, identify the global features, and obtain the identification result; C4. Evaluate the defect type of the insulation component to be tested based on the identification results to obtain a second evaluation result.

[0051] Specifically, a phase-resolved pulsed discharge (PRPD) map can be constructed based on the partial discharge quantity set and the partial discharge voltage phase set. One possible implementation method is as follows: the Y-axis represents the partial discharge quantity set, indicating the amount of charge released in a single partial discharge; the X-axis represents the partial discharge voltage phase set, indicating the sinusoidal AC voltage phase angle at the time of partial discharge, and the image is distributed in a scattering form.

[0052] The PRPD map can be fitted to obtain the PRPD curve. One possible implementation is as follows: Curve fitting is performed using a cubic polynomial: y = aφ³ + bφ² + cφ + d. Least squares fitting is then applied to the statistical points to minimize the error between the fitted value and the actual statistical value. The residuals between the actual and fitted values ​​are considered good if their absolute value is less than 10% of the statistical value. If the residuals are concentrated in a certain phase interval, the fitting model needs to be readjusted, selecting a higher-order polynomial or other mathematical fitting model. After the above fitting process, the PRPD curve is obtained.

[0053] The process involves extracting global features from the PRPD curve, identifying these global features, and obtaining identification results. One possible implementation is as follows: the extracted global features include symmetry, data point density, distribution range, curve curvature, peak and valley values, etc., which are not limited here. The global features are identified according to the typical spectral morphology of the PRPD curve, and the identification results are used to determine the defect type, thus obtaining the second evaluation result.

[0054] Taking a small air gap defect as an example, the partial discharge voltage phase is concentrated in the positive half-cycle (0~90°) and the negative half-cycle (180~270°). The partial discharge quantity is above 10pC and is concentrated in the phase range. The pulse density is uniform in the phase range, and the characteristics of the positive and negative half-cycles are basically symmetrical. At this time, the PRPD curve shows a "double cluster distribution", that is, there is a dense cluster of discharge points in each of the positive and negative half-cycles, and the shape is close to an ellipse. At this time, the defect is evaluated as a small air gap.

[0055] In one possible implementation, the fitting process of the PRPD map to obtain the PRPD curve includes: D1. Based on the PRPD spectrum, the partial discharge voltage phase set is segmented to obtain several partial discharge voltage phase subsets; D2. Perform calculations on several partial discharge voltage phase subsets to obtain several sets of discharge statistical characteristic values. D3. Fit the set of characteristic values ​​of several discharge statistics to obtain the PRPD curve.

[0056] Specifically, based on the PRPD spectrum, the partial discharge voltage phase set can be segmented to obtain several partial discharge voltage phase subsets; these subsets can then be calculated to obtain several sets of discharge statistical characteristic values; these characteristic values ​​can be the total number of partial discharges and the average partial discharge value. One possible implementation is as follows: divide 0~360° into 36~72 subsets, each corresponding to 5~10°, and calculate the frequency and discharge statistics within each phase subset. Divide 360° into 72 subsets, each representing 5°. The 10th subset (45~50°) contains 10 partial discharge values, with a total discharge value of 500pC. Therefore, the total number of partial discharges in this subset is 10, and the average partial discharge value is 50pC. The coordinates of the fitted curve at the midpoint of the 10th subset at 47.5° can then be used. Following the above calculation method, several sets of discharge statistical characteristic values ​​are calculated for each subset. The above mainly describes the solutions of the embodiments of this application from the perspective of the method execution process. It is understood that, in order to achieve the above functions, the terminal includes the corresponding hardware structure and / or software modules for executing each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments provided herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware 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.

[0057] This application embodiment can divide the terminal into functional units according to the above method example. For example, each function can be divided into a separate functional unit, or two or more functions can be integrated into one processing unit. The integrated unit can be implemented in hardware or as a software functional unit. It should be noted that the unit division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0058] For those consistent with the above, please refer to Figure 4 , Figure 4 This application provides a schematic diagram of the structure of an insulation defect assessment device based on shortwave excitation. Figure 4 As shown, the device includes: The acquisition unit 301 is used to acquire the set of partial discharge values ​​and the set of partial discharge voltage phases of the insulation component under test that is in a partial discharge state; The first evaluation unit 302 is used to perform defect evaluation on the insulation component to be tested based on the set of partial discharge values, and obtain a first evaluation result. The second evaluation unit 303 is used to perform defect evaluation by combining the set of partial discharge values ​​and the set of partial discharge voltage phases to obtain the second evaluation result. The fusion unit 304 is used to fuse the first evaluation result and the second evaluation result to obtain the defect detection result.

[0059] In one possible implementation, the acquisition unit 301 is used for: Extract the partial discharge pulse signal from the insulating component under test that is in a partial discharge state; The partial discharge pulse signal is converted to obtain the partial discharge voltage phase set; The partial discharge pulse signal is subjected to anti-interference purification to obtain the true partial discharge signal; The partial discharge signal is processed to obtain a set of partial discharge values.

[0060] In one possible implementation, the first evaluation unit 302 is used to: The partial discharge value set is normalized to obtain a standard partial discharge value set; Based on the absolute threshold of the insulation component to be tested, the set of standard partial discharge values ​​is quantified to obtain a quantitative index. Based on the quantitative indicators, the degree of defect of the insulation component to be tested is evaluated to obtain a first evaluation result.

[0061] In one possible implementation, the second evaluation unit 303 is used for: Based on the set of partial discharge values ​​and the set of partial discharge voltage phases, a phase-resolved pulsed discharge (PRPD) spectrum is constructed. The PRPD map is fitted to obtain the PRPD curve; Global features are extracted from the PRPD curve, and the global features are identified to obtain the identification result; The defect type of the insulation component to be tested is evaluated based on the identification results to obtain a second evaluation result.

[0062] In one possible implementation, regarding the fitting process of the PRPD map to obtain the PRPD curve, the second evaluation unit 303 is specifically used for: Based on the PRPD map, the partial discharge voltage phase set is segmented to obtain several partial discharge voltage phase subsets; By performing calculations on several subsets of partial discharge voltage phases, several sets of discharge statistics characteristic values ​​are obtained. The PRPD curve is obtained by fitting the set of characteristic values ​​of several discharge statistics.

[0063] This application also provides a computer storage medium storing a computer program for electronic data exchange, which causes a computer to perform some or all of the steps of any of the shortwave excitation-based insulation defect assessment methods described in the above method embodiments.

[0064] This application also provides a computer program product; please refer to [link / reference]. Figure 3 , Figure 3 This is a schematic diagram of a terminal structure. The computer program product includes a non-transitory computer-readable storage medium storing a computer program that causes a computer to perform some or all of the steps of any of the shortwave excitation-based insulation defect assessment methods described in the above method embodiments.

[0065] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0066] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0067] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments 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 system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0068] 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.

[0069] Furthermore, the functional units in the various embodiments of the application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software program module.

[0070] If the integrated unit is implemented as a software program module and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned memory 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.

[0071] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage device, which may include: a flash drive, a read-only memory, a random access memory, a magnetic disk, or an optical disk, etc.

[0072] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is 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. A method for assessing insulation defects based on shortwave excitation, characterized in that, The method includes: Obtain the set of partial discharge values ​​and the set of partial discharge voltage phases of the insulation component under test that is in a partial discharge state; Based on the set of partial discharge values, a defect assessment is performed on the insulation component to be tested to obtain a first assessment result; The defect assessment is performed by combining the set of partial discharge values ​​and the set of partial discharge voltage phases to obtain the second assessment result. The first evaluation result and the second evaluation result are combined to obtain the defect detection result.

2. The insulation defect assessment method based on shortwave excitation according to claim 1, characterized in that, Obtain the set of partial discharge values ​​and the set of partial discharge voltage phases for the insulation component under test that is in a partial discharge state, including: Extract the partial discharge pulse signal from the insulating component under test that is in a partial discharge state; The partial discharge pulse signal is converted to obtain the partial discharge voltage phase set; The partial discharge pulse signal is subjected to anti-interference purification to obtain the true partial discharge signal; The partial discharge signal is processed to obtain a set of partial discharge values.

3. The insulation defect assessment method based on shortwave excitation according to claim 2, characterized in that, The step of evaluating the defects of the insulation component to be tested based on the set of partial discharge values ​​to obtain a first evaluation result includes: The partial discharge value set is normalized to obtain a standard partial discharge value set; Based on the absolute threshold of the insulation component to be tested, the set of standard partial discharge values ​​is quantified to obtain a quantitative index. Based on the quantitative indicators, the degree of defect of the insulation component to be tested is evaluated to obtain a first evaluation result.

4. The insulation defect assessment method based on shortwave excitation according to claim 3, characterized in that, The defect assessment is performed by combining the set of partial discharge values ​​and the set of partial discharge voltage phases to obtain a second assessment result, including: Based on the set of partial discharge values ​​and the set of partial discharge voltage phases, a phase-resolved pulsed discharge (PRPD) spectrum is constructed. The PRPD map is fitted to obtain the PRPD curve; Global features are extracted from the PRPD curve, and the global features are identified to obtain the identification result; The defect type of the insulation component to be tested is evaluated based on the identification results to obtain a second evaluation result.

5. The insulation defect assessment method based on shortwave excitation according to claim 4, characterized in that, The process of fitting the PRPD map to obtain the PRPD curve includes: Based on the PRPD map, the partial discharge voltage phase set is segmented to obtain several partial discharge voltage phase subsets; By performing calculations on several subsets of partial discharge voltage phases, several sets of discharge statistics characteristic values ​​are obtained. The PRPD curve is obtained by fitting the set of characteristic values ​​of several discharge statistics.

6. An insulation defect assessment device based on shortwave excitation, characterized in that, The device includes: The acquisition unit is used to acquire the set of partial discharge values ​​and the set of partial discharge voltage phases of the insulation component under test that is in a partial discharge state; The first evaluation unit is used to evaluate the defects of the insulation component to be tested based on the set of partial discharge values, and obtain the first evaluation result. The second evaluation unit is used to perform defect evaluation by combining the set of partial discharge values ​​and the set of partial discharge voltage phases to obtain the second evaluation result. The fusion unit is used to fuse the first evaluation result and the second evaluation result to obtain the defect detection result.

7. The insulation defect assessment device based on shortwave excitation according to claim 6, characterized in that, The acquisition unit is specifically used for: Extract the partial discharge pulse signal from the insulating component under test that is in a partial discharge state; The partial discharge pulse signal is converted to obtain the partial discharge voltage phase set; The partial discharge pulse signal is subjected to anti-interference purification to obtain the true partial discharge signal; The partial discharge signal is processed to obtain a set of partial discharge values.

8. The insulation defect assessment device based on shortwave excitation according to claim 7, characterized in that, The first evaluation unit is specifically used for: The partial discharge value set is normalized to obtain a standard partial discharge value set; Based on the absolute threshold of the insulation component to be tested, the set of standard partial discharge values ​​is quantified to obtain a quantitative index. Based on the quantitative indicators, the degree of defect of the insulation component to be tested is evaluated to obtain a first evaluation result.

9. A terminal, characterized in that, The device includes a processor, an input device, an output device, and a memory, which are interconnected. The memory stores a computer program, which includes program instructions. The processor is configured to invoke the program instructions to execute the shortwave excitation-based insulation defect assessment method as described in any one of claims 1-5.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, the computer program including program instructions that, when executed by a processor, cause the processor to perform the insulation defect assessment method based on shortwave excitation as described in any one of claims 1-5.

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