A method and device for detecting and evaluating the effectiveness of GIS insulation

Abstract

This invention discloses a method and apparatus for evaluating the effectiveness of GIS insulation components. The method designs electromagnetic interference suppression and identification methods based on different types of electromagnetic interference signals; performs partial discharge charging detection based on the electromagnetic interference suppression and identification methods, establishing a GIS insulation component charging detection technology system; and, based on this system, uses a constant voltage method and an ultra-high frequency method to synchronously detect partial discharge signals, obtaining initial detection results. Further detection is then performed on the initial results using an optical tracing method for weak discharge on the insulation component surface defects to obtain target detection results. This invention improves the accuracy and reliability of partial discharge charging detection by developing a targeted improvement scheme for partial discharge charging detection technology.

Description

Technical Field

[0001] This invention relates to the field of anti-interference testing technology for insulating components, specifically to a method and apparatus for evaluating the effectiveness of GIS insulating components. Background Technology

[0002] Currently, anti-interference detection of GIS insulation components has long been a key bottleneck in partial discharge detection. How to achieve the universality and effectiveness of anti-interference algorithms in complex electromagnetic environments and build a technical system for the detection of GIS insulation components has become an urgent need at this stage.

[0003] Therefore, designing a method and device for testing and evaluating the effectiveness of GIS insulation components has become a problem we need to solve. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method and apparatus for evaluating the effectiveness of GIS insulation components, solving the problem of poor effectiveness in anti-interference testing of GIS insulation components.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for detecting and evaluating the effectiveness of GIS insulation components.

[0006] Includes the following steps:

[0007] Based on different types of electromagnetic interference signals, electromagnetic interference suppression and identification methods are designed. Based on the electromagnetic interference suppression and identification methods, partial discharge charging detection and online monitoring are carried out, and a GIS insulation component charging detection technology system is established.

[0008] The process of partial discharge charging detection and online monitoring based on the electromagnetic interference suppression and identification method is as follows: Based on the UHF detection measurement and information extraction method, UHF detection feature analysis is performed to obtain the analysis results. Based on the analysis results, interference suppression measures for partial discharge detection system application in the field under different interference coupling paths and different action modes are constructed. The interference suppression measures include waveform identification interference suppression technology, internal and external signal comparison method, signal multi-cycle analysis method, amplitude ratio clustering anti-interference technology, and multi-element signal separation method of three frequency band centers.

[0009] Based on the aforementioned GIS insulation component live detection technology system, the constant voltage method and ultra-high frequency method are used to synchronously detect partial discharge signals and obtain initial detection results;

[0010] The initial detection results are further detected using an optical tracing method based on weak discharge of surface defects in insulating components to obtain the target detection results.

[0011] Based on the target detection results, the success rate of discharge event capture and the effective spectrum detection rate of the on-site GIS equipment partial discharge UHF online monitoring device are evaluated and estimated, and improvement and rectification measures to enhance the effectiveness of on-site partial discharge detection are given.

[0012] The process of designing electromagnetic interference suppression and identification methods based on different types of electromagnetic interference signals is as follows:

[0013] Actual measurements and statistics were conducted on interference scenarios at substation sites to obtain statistical data. Based on the statistical data, the sources, characteristics, and modes of influence of different types of electromagnetic interference signals at substation sites were obtained.

[0014] For different types of electromagnetic interference signals, electromagnetic interference suppression and identification methods are designed, including those based on waveform characteristics, synchronization, and clustering synthesis.

[0015] The method for separating the multi-element signals at the center of the three frequency bands is as follows:

[0016] Three frequencies are preset as initial settings, and the amplitudes of the three detector outputs after frequency division measurement are detected synchronously and the pulse phase information is recorded simultaneously.

[0017] Three-dimensional data is mapped to a two-dimensional data space to obtain two-dimensional data, and the two-dimensional data is used as a clustering index. At the same time, the discharge amplitude and phase of the discharge pulse are marked to obtain the clustering result.

[0018] Based on the clustering results, discharge mode spectrum (PRPD) is obtained by mapping the discharge amplitude and phase information corresponding to each type of pulse, thereby realizing the separation of multiple discharge sources and subsequent analysis.

[0019] Among them, the constant voltage method and its ultra-high frequency method: obtain the signal of the entire process of partial discharge of typical defect test specimens under long-term voltage to simulate the development process of partial discharge of insulation defects under operating voltage, and establish a multi-dimensional signal feature database of partial discharge of typical defects;

[0020] By analyzing the statistical characteristics of the time domain, frequency domain, pulse sequence time interval, and pulse amplitude of multi-dimensional signal characteristics of partial discharge in analytical defects, the initial, developmental stages and evolution patterns of typical insulation component defects are analyzed from the perspectives of signal intensity distribution, intermittent discharge characteristics, spectral distribution characteristics, and energy distribution of multi-dimensional signals, and an evaluation index for detection effectiveness is constructed.

[0021] Specifically, based on the aforementioned detection effectiveness evaluation index, the partial discharge signal is detected online, and the detection effectiveness is evaluated using the constructed detection effectiveness evaluation index to obtain initial detection results.

[0022] The process of obtaining the evaluation indicators for the effectiveness of the test is as follows:

[0023] Based on the ultra-high frequency method, this study investigates the partial discharge phenomenon of metal particles on the surface of GIS insulators under long-term constant voltage. First, statistical analysis is conducted on the amplitude, discharge frequency, and distribution of discharge density intervals. Two key parameters, effective discharge interval and effective spectrum, are defined. Then, the intermittent characteristics of discharge are quantitatively analyzed using these two key parameters to obtain evaluation indicators for detection effectiveness.

[0024] The process of online detection of partial discharge signals of insulating components in real time, based on the aforementioned detection effectiveness evaluation index, and evaluating the detection effectiveness against the constructed detection effectiveness evaluation index to obtain initial detection results, is as follows:

[0025] First, based on the evaluation index of detection effectiveness, a long-term overall trend analysis of partial discharge is conducted to obtain an overall statistical trend chart of the average discharge value and discharge repetition rate of ultra-high frequency signals. Based on the overall statistical trend chart, the variation trend of discharge intensity in the initial discharge stage and the long-term development discharge stage, as well as the distribution variance statistics of the average discharge value and discharge repetition rate of ultra-high frequency signals, are analyzed.

[0026] Subsequently, the discharge density distribution characteristics were statistically analyzed. The overlapping times of dense and sparse discharges were counted separately, and the overall proportion of dense and sparse intervals was calculated to obtain quantitative statistical indicators of sparsity in the discharge development process.

[0027] Based on existing detection strategies and the aforementioned sparsity quantification statistical indicators, the rules and quantitative evaluation methods for the formation of effective discharge ranges and effective spectra are statistically analyzed to assess the effectiveness of existing partial discharge devices and obtain initial detection results.

[0028] The process of further detecting the initial detection result using the optical tracing method for weak discharge of surface defects in insulating components to obtain the target detection result is as follows:

[0029] The spatial luminescence characteristics of the discharge region are obtained by using a high-gain industrial high-speed ICCD camera and the ultra-high frequency method. Based on the spatial luminescence characteristics, the morphological evolution process of the discharge luminescence region during long-term constant voltage and the correspondence between the spatial morphological evolution and the ultra-high frequency signal are compared and analyzed.

[0030] The gradual and abrupt changes in discharge morphology under different voltage amplitudes were recorded and statistically analyzed.

[0031] The correlation and difference between ultra-high frequency electrical signals and high-speed ICCD camera optical signals during the initiation and long-term development of discharge of metal particles on the insulator surface were analyzed. The contribution ratio of pulsed discharge and non-pulsed discharge and the evolution direction of discharge development were tracked and recorded. Based on the tracking and recording results, the mechanism of weak discharge of metal particles on the insulator surface was explained.

[0032] The comparative analysis process of the morphological evolution of the discharge luminescence region during long-term constant voltage and the correspondence between the spatial morphological evolution and the ultra-high frequency signal based on the spatial luminescence characteristics is as follows:

[0033] The observation voltage is used to observe the luminescence characteristics of the discharge under the equivalent operating voltage, record the morphological changes of the luminescence region and the variation trend of the discharge luminescence region area, and simultaneously record the UHF signal of the discharge based on the photometry method. The development trend of the UHF signal is synchronously compared and analyzed with the discharge luminescence region to establish the correspondence between the UHF discharge frequency and the discharge luminescence area.

[0034] The process of recording and statistically analyzing the gradual and abrupt changes in discharge morphology under different voltage amplitudes is as follows: the variation law of discharge luminescence region under different voltage amplitudes is obtained by studying and obtaining the variation of discharge luminescence region obtained by long-term observation under different voltage amplitudes, and the luminescence region at the same pressurization time under different voltage amplitudes is compared and analyzed to obtain the variation law of discharge luminescence region under different voltage amplitudes.

[0035] A device for testing and evaluating the effectiveness of GIS insulation components, comprising:

[0036] The design module designs electromagnetic interference suppression and identification methods based on different types of electromagnetic interference signals.

[0037] A module was established to perform partial discharge charge detection and online monitoring based on electromagnetic interference suppression and identification methods, thereby establishing a charge detection technology system for GIS insulating components.

[0038] The initial detection module, based on the GIS insulation component live-line detection technology system, uses constant voltage and ultra-high frequency methods to synchronously detect partial discharge signals and obtain initial detection results.

[0039] The target detection module further detects the initial detection results based on the weak discharge optical tracing method for surface defects of insulating components to obtain the target detection results.

[0040] Compared with existing technologies, this invention has the following beneficial effects: By studying methods to improve the accuracy, anti-interference performance, and reliability of partial discharge detection in GIS, this invention focuses on the 550kV / 1100kV GIS partial discharge detection and diagnostic analysis based on GIS online partial discharge monitoring devices, the study of partial discharge characteristics of internal defects in insulating rods, the formulation of targeted solutions to improve the reliability of partial discharge detection, the study of the intermittent characteristics and detection effectiveness of long-term constant voltage discharge of insulating component defects, the formulation of rectification measures to improve the discharge effectiveness of existing monitoring devices, the study of weak discharge tracking methods for surface defects of insulating components, and the formation of a new optical tracking technology for weak discharge traces, thereby further improving the accuracy and reliability of partial discharge detection. Attached Figure Description

[0041] Figure 1 This is a technical roadmap for the research on UHF systemic interference suppression measures of the present invention.

[0042] Figure 2 This is a technical roadmap for studying the intermittent characteristics and detection effectiveness of long-term constant voltage discharge according to the present invention.

[0043] Figure 3 This is a technical roadmap for the research of the weak discharge optical tracing method of the present invention.

[0044] Figure 4 This is a schematic diagram of the structure of the GIS laboratory physical platform of the present invention.

[0045] Figure 5 This is a schematic diagram of the proposed experimental pressurization method of the present invention.

[0046] Figure 6 This is a statistical diagram of the discharge interval Δt of the present invention.

[0047] Figure 7 This is a statistical chart of the discharge interval Δt count in this invention.

[0048] Figure 8 This is a schematic diagram of the discharge interval Δt timing of the present invention.

[0049] Figure 9 This is a long-term trend chart of the average discharge per second of UHF according to the present invention.

[0050] Figure 10 This is a long-term trend chart of the UHF discharge repetition rate of the present invention.

[0051] Figure 11 This is a trend chart of discharge repetition rate in the dense detail region of the discharge according to the present invention.

[0052] Figure 12 This is a trend chart of discharge repetition rate in the discharge sparse detail region of the present invention.

[0053] Figure 13 This is a schematic diagram of the insulator weak discharge detection platform of the present invention.

[0054] Figure 14 This is a schematic diagram of an experimental model of the defect arrangement method of the present invention.

[0055] Figure 15 This is a physical diagram of the experimental model of the defect arrangement method of the present invention.

[0056] Figure 16 This is a graph showing the relationship between the luminescent area and the ultra-high frequency discharge frequency of the present invention.

[0057] Figure 17 This is a schematic diagram of the light-emitting region during the long-term discharge process of the present invention.

[0058] Figure 18 This is a schematic diagram of the framework of the GIS insulation component effectiveness detection and evaluation device of the present invention. Detailed Implementation

[0059] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0060] A method for evaluating the effectiveness of GIS insulation components includes the following steps:

[0061] like Figure 1 As shown, electromagnetic interference suppression and identification methods are designed based on different types of electromagnetic interference signals. The process is as follows: Actual measurements and statistics are conducted on interference scenarios at substation sites to obtain statistical data. Based on the statistical data, the interference sources, characteristics, and impact modes of different types of electromagnetic interference signals at the substation site are obtained. For different types of electromagnetic interference signals, electromagnetic interference suppression and identification methods based on waveform characteristics, synchronization, and clustering are designed. Partial discharge charging detection and online monitoring are performed based on the electromagnetic interference suppression and identification methods, establishing a GIS insulation component charging detection technology system. The process of partial discharge charging detection and online monitoring based on the electromagnetic interference suppression and identification methods is as follows: Ultra-high frequency detection feature analysis is performed using ultra-high frequency detection measurement and information extraction methods to obtain analysis results. Based on the analysis results, interference suppression measures for the partial discharge detection system applied in the field under different interference coupling paths and different action modes are constructed. These interference suppression measures include waveform identification interference suppression technology, internal and external signal comparison method, signal multi-cycle analysis method, amplitude ratio clustering anti-interference technology, and multi-element signal separation method at the center of three frequency bands.

[0062] Since the partial discharge signal detected by the UHF partial discharge detection system is shielded, filtered and amplified, the signal only retains the peak value, phase and pulse interval information. The effect of using wavelet analysis methods such as time-frequency analysis, digital filtering, adaptive filtering and programmable bandpass filtering to identify and eliminate interference is greatly reduced. Therefore, targeted anti-interference measures should be studied based on the hardware and software characteristics of the UHF detection system in the field.

[0063] (1) Waveform discrimination interference suppression technology:

[0064] Currently, partial discharge signals are generally extracted using signal detection technology. Since the detected waveform of partial discharge signals is in pulse form, while the detected waveform of communication interference signals such as mobile phones is in square wave form, it is proposed to use the characteristic differences of the two signal detected waveforms to remove communication interference signals such as mobile phones.

[0065] (2) Internal and external signal comparison method:

[0066] The internal and external signal comparison method is a method of eliminating external interference signals by comparing the detection signals of the built-in and external sensors that are collected synchronously. For GIS, the sensors of the on-site UHF partial discharge detection system are installed inside the basin or on the outer surface. The GIS shell and insulators themselves play a role in suppressing UHF signals. Therefore, interference signals from outside the GIS shell will be greatly attenuated when they enter the interior. Similarly, the partial discharge signals from inside the shell will also be greatly attenuated when they reach the outside of the shell. The aim is to eliminate external signals by comparing the magnitudes of the internal and external signal amplitudes.

[0067] (3) Multi-period signal analysis method:

[0068] The signal multi-cycle analysis method is used to eliminate continuous periodic pulse interference. Periodic pulse interference occurs in a relatively fixed phase and has a very small amplitude variation within one power frequency cycle. The method aims to use signal multi-cycle analysis to determine whether the pulse signal appears at a fixed phase position and whether the amplitude and waveform remain almost unchanged within several consecutive power frequency cycles, thereby detecting periodic pulse interference signals. Finally, the periodic pulse interference signals are eliminated from the acquired signals.

[0069] (4) Amplitude-ratio clustering anti-interference technology:

[0070] Because the propagation paths and energy attenuation of signals generated at different discharge points to each sensor are different, the amplitude ratio of the synchronization signals generated by the same discharge source received by each sensor will be within a certain range. It is proposed that the pulse separation and discharge spectrum mapping can be achieved by using clustering methods.

[0071] (5) Multi-band signal separation method:

[0072] Different discharge sources and different propagation paths will result in different signal spectra at the final sensing end. By detecting the difference in signal amplitude in different frequency bands, the difference information of different discharge sources can be reflected. Then, the effective separation of different discharge sources can be achieved through subsequent clustering algorithms.

[0073] The technical approach used in the three-band center multi-signal separation method is as follows: Three frequencies are set as initial settings: 300MHz, 700MHz, and 1.3GHz, which can be adjusted according to the actual detection results. The amplitudes (V1, V2, V3) of the three detector outputs after frequency division measurement are simultaneously detected, and pulse phase information is recorded. The three-dimensional E(E1, E2, E3) data is mapped to the two-dimensional J(J1, J2) data space to obtain two-dimensional data. This two-dimensional J(J1, J2) data is used as a clustering index, and the discharge amplitude and phase (V, φ) of the discharge pulse are correspondingly labeled to obtain the clustering results. Based on the clustering results, the discharge mode spectrum (PRPD) is obtained by mapping the discharge amplitude and phase information (V, φ) corresponding to each type of pulse, thus realizing the separation of multiple discharge sources and subsequent analysis.

[0074] Based on the aforementioned GIS insulation component live-line testing technology system, the constant voltage method and ultra-high frequency method are used to synchronously detect partial discharge signals to obtain initial detection results. The process is as follows: Signals of the entire partial discharge process of typical defective insulation components under long-term voltage are acquired to simulate the partial discharge development process of insulation component defects under operating voltage, establishing a multi-dimensional signal feature database of typical defect partial discharge; by analyzing the statistical characteristics of the time domain, frequency domain, pulse sequence time interval, and pulse amplitude of the multi-dimensional signal features of typical defect partial discharge, the initial, developmental stages and evolution laws of typical insulation component defects are analyzed from the perspectives of signal intensity distribution, intermittent discharge characteristics, spectral distribution characteristics, and energy distribution of multi-dimensional signals, respectively, to construct detection effectiveness evaluation indicators. The process of obtaining the detection effectiveness evaluation indicators is as follows: Figure 2As shown: Based on the UHF method, this study investigates the partial discharge phenomenon of metal particles on the surface of GIS insulators under long-term constant voltage. First, statistical analysis is performed on the amplitude, discharge frequency, and distribution of discharge density intervals. Two key parameters, effective discharge interval and effective spectrum, are defined. The intermittent characteristics of the discharge are then quantitatively analyzed using these two parameters to obtain a detection effectiveness evaluation index. Based on this index, the partial discharge signal of the insulator is detected online in real time, and its effectiveness is evaluated against the constructed detection effectiveness evaluation index. The process involves: first, analyzing the long-term overall trend of partial discharge based on the detection effectiveness evaluation index to obtain the UHF signal... The overall statistical trend chart of discharge mean and discharge repetition rate is used to analyze the changing trends of discharge intensity in the initial discharge stage and the long-term development discharge stage, as well as the distribution variance statistics of the discharge mean and discharge repetition rate of the UHF signal. Subsequently, the discharge density distribution characteristics are statistically analyzed, and the overlapping moments of dense and sparse discharges are statistically analyzed separately. The overall proportion of dense and sparse intervals is calculated to obtain the sparsity quantitative statistical index in the discharge development process. Based on the existing detection strategy and the sparsity quantitative statistical index, the rules and quantitative evaluation methods for the formation of effective discharge intervals and effective spectra are calculated to evaluate the detection effectiveness of the existing partial discharge device and obtain the initial detection results.

[0075] Among them, the constant voltage method is used to obtain the initial partial discharge voltage U of the sample by applying pressure. i and breakdown voltage U b, The breakdown voltages U are selected at 90%, 80%, and 70% respectively. b The test specimen was pressurized, and the partial discharge signal was synchronously detected using the ultra-high frequency method. The signal of the entire partial discharge process of the typical defect test specimen under long-term voltage was obtained to simulate the partial discharge development process of the insulation component defect under the operating voltage. A multi-dimensional signal feature database of typical defect partial discharge was established. By analyzing the statistical characteristics of the time domain, frequency domain, pulse sequence time interval, and pulse amplitude of the multi-dimensional signal features of typical defect partial discharge, the initial, development stage characteristics and evolution law of typical insulation component defects were analyzed from the perspectives of signal intensity distribution, intermittent discharge characteristics, spectral distribution characteristics, and energy distribution of multi-dimensional signals. The evaluation index of detection effectiveness was studied from the perspective of real-time detection.

[0076] (1) Experimental platform:

[0077] The proposed overall test circuit consists of several main parts: a power frequency pressurization system, a GIS main cavity, a transition cavity, a model cavity, and an ultra-high frequency detection system. The overall test circuit of the test platform is as follows: Figure 4 As shown,

[0078] The overall test circuit consists of several main parts, including a power frequency pressurization system, a GIS main cavity, a transition cavity, a model cavity, an ultra-high frequency partial discharge instrument, and an ultrasonic testing device. Figure 3 As shown, the 220V AC power supply is regulated by an autotransformer and then connected to a power filter. The output is then connected to a power frequency corona-free experimental transformer 1, and after passing through a protection resistor 2 and a coupling capacitor 3, it is connected to a single-phase GIS platform bushing 4. The power filter, experimental transformer, coupling capacitor, and GIS casing are all reliably grounded. A three-way GIS cavity 5 is connected to the single-phase GIS platform bushing 4. One side of the three-way GIS cavity 5 is connected to a 2:1 scaled-down experimental cavity 7 via a transition cavity 6. A quartz glass observation window 8 is located on the outside of the experimental cavity 7. A UHF sensor 9 and an AE ultrasonic sensor 10 used in the experiment are fixed to the outside of the observation window. The signal lines of the UHF sensor 9 and the AE ultrasonic sensor 10 are connected to a subsequent signal acquisition device 11. The signal acquisition device 11 is connected to a PC 12 via a network cable. During the experiment, the PC is used to statistically control the synchronous operation of each signal acquisition device 11 and to store data.

[0079] (2) Pressurization method:

[0080] According to the description in GB 7674-2008 "Gas-insulated metal-enclosed switchgear of 72.5kV and above", and based on the conversion relationship between phase voltage and line voltage, as well as the 2:1 scaling ratio of the experimental chamber 7, the effective value of the rated operating voltage of the experimental chamber 7 in this embodiment is obtained and denoted as U0. According to the author's previous experiments, a 10mm long aluminum strip can cause partial discharge before the rated voltage of 36.3kV after being polished at the tip.

[0081] The voltage boosting method was as follows: starting from 0, the voltage was rapidly boosted to the partial discharge inception voltage (PDIV), and the PDIV value was recorded. Then, the voltage was continuously boosted in steps to 1.2 times the PDIV value, at which point the boosting was stopped. A long-term constant voltage experiment was conducted at this voltage value. The voltage boosting method is as follows: Figure 5 As shown.

[0082] (3) Data analysis methods:

[0083] A single partial discharge signal has a high degree of randomness, so it is difficult to extract key feature information of partial discharge from a single discharge waveform or single-cycle data. Comprehensive analysis of data over a period of time to construct statistical spectrum and trend spectrum is a more effective strategy for partial discharge signal feature analysis.

[0084] In this embodiment, the statistical graphs to be constructed for the analysis of long-term constant pressure experimental data include: the statistical trend graph of the mean amplitude (Vave-t), the statistical trend graph of the number of discharges (Nt), and the statistical distribution graph of the discharge interval (HΔt-t), etc.

[0085] ① Statistical trend chart of the mean amplitude of Vave-t / statistical trend chart of the number of discharges of Nt:

[0086] Using data within time period t during the experiment as the statistical object, according to V ave =V total / N t and Calculate the average discharge amplitude Vave and the number of discharges Nt within the time period t. Plot time t on the x-axis and the statistics Vave and Nt on the y-axis, and display the results in a bar chart to obtain a statistical graph showing the trend of the average discharge amplitude and the number of discharges over the test time.

[0087] ② Statistical distribution diagram of HΔt-t discharge interval:

[0088] Studies on the long-term constant voltage of metal particles on the insulator surface have revealed that the discharge gradually changes from an initial intense and continuous discharge to an intermittent and discontinuous discharge. Discharge does not occur in every statistical time period. To visually represent this intermittent discharge pattern, the interval Δt between two adjacent discharges is statistically analyzed. Figure 6 As shown, histogram statistics were then performed on the distribution characteristics of the interval Δt throughout the entire observation period, resulting in a statistical distribution chart of NΔt-t discharge intervals. The horizontal axis represents the value of Δt, and the vertical axis represents the number (or percentage) of that Δt value in all recorded sequences Δt. Figure 7 As shown; after obtaining the NΔt-t distribution plot, the horizontal axis remains unchanged, and the vertical axis represents the percentage of individuals within a given time period. This is calculated by multiplying the statistically calculated interval Δt by the corresponding N, and then dividing by the sum of all Δt×N values ​​throughout the entire detection process. An example of the calculation result is shown below. Figure 8 As shown; its calculation function is:

[0089] (4) Evaluation indexes and methods for detection effectiveness:

[0090] First, based on the aforementioned effectiveness evaluation indicators, a long-term overall trend analysis of partial discharge is performed. Using seconds as the statistical unit, an overall statistical trend chart of the average discharge value and discharge repetition rate (number of discharges per second) of the UHF signal is obtained, as shown below. Figure 9-10 As shown, based on the overall statistical trend chart, the variation trend of the discharge intensity in the initial discharge stage and the long-term development discharge stage, as well as the distribution variance statistics of the mean discharge value and discharge repetition rate of the ultra-high frequency signal are analyzed.

[0091] Subsequently, statistical analysis of the discharge density distribution characteristics was performed, separating the interleaved times of dense and sparse discharges for statistical analysis, such as... Figure 11-12 As shown; the overall proportion of dense and sparse discharge regions is statistically analyzed to obtain quantitative statistical indicators of sparsity in the discharge development process;

[0092] Finally, based on existing detection strategies and the aforementioned sparsity quantification statistical indicators, the rules and quantitative evaluation methods for the formation of effective discharge intervals and effective spectra are statistically analyzed. Measures to improve the detection effectiveness of existing partial discharge devices are proposed. For partial discharge detection systems that rely on individual 1-second data collection to determine PD events have a very low false negative rate for surface metal foreign objects; a long-term data accumulation method should be adopted. Based on a set of typical test results, when the cumulative discharge detection time is increased to 50 seconds, the online monitoring PD event capture probability can be increased to 49.68%, and when the cumulative time is 210 seconds (point B), the PD event capture probability can be increased to 75.12%.

[0093] The initial detection result is further detected using an optical tracing method based on weak discharge of surface defects in insulating components to obtain the target detection result. The process is as follows: Figure 3 As shown, the spatial luminescence characteristics of the discharge region are obtained by using a high-gain industrial high-speed ICCD camera and UHF method. Based on the spatial luminescence characteristics, the morphological evolution of the discharge luminescence region during long-term constant voltage and the correspondence between the spatial morphological evolution and the UHF signal are compared and analyzed. The process is as follows: observe the luminescence characteristic change trend of the discharge under the equivalent operating voltage, record the morphological change of the luminescence region and the change trend of the discharge luminescence region area, and simultaneously record the UHF signal of the discharge based on the photometry method. The development trend of the UHF signal is synchronously compared and analyzed with the discharge luminescence region to establish the correspondence between the UHF discharge frequency and the discharge luminescence area.

[0094] The process of recording and statistically analyzing the gradual and abrupt changes in discharge morphology under different voltage amplitudes is as follows: The study obtains the variation law of the discharge luminous region under different voltage amplitudes; by recording the changes in the discharge luminous region obtained from long-term observations under different voltage amplitudes, a comparative analysis is conducted on the luminous regions at the same pressurization time for different voltage amplitudes to obtain the variation law of the discharge luminous region under different voltage amplitudes; the gradual and abrupt changes in discharge morphology under different voltage amplitudes are recorded and statistically analyzed; the correlation and difference analysis of ultra-high frequency electrical signals and high-speed ICCD camera optical signals during the initiation and long-term development of discharge from metal particles on the insulator surface is performed; the contribution ratio of pulsed discharge and non-pulsed discharge during the discharge process and the evolution direction during the discharge development process are tracked and recorded; and the mechanism explanation of the weak discharge of metal particles on the insulator surface is provided based on the tracking and recording results.

[0095] (1) Test platform:

[0096] A simulation model of the UHV GIS basin insulator structure was constructed. The electric field distribution under rated voltage was obtained through simulation calculations. Based on the principle of equivalent electric field distribution (i.e., Emax and Eave are the same), a scaled-down model was established, and test chamber 7 was designed and fabricated accordingly. The basin insulator was made into a disc-shaped sample using transparent epoxy resin, and linear metal particles of different sizes were adhered to it. Test chamber 7 is shown in the figure. Figure 13 As shown.

[0097] To gain a deeper understanding of the changes in the discharge space region during the long-term constant voltage process of metal particles on the surface of insulating components, a high-gain industrial high-speed ICCD camera was used to conduct synchronous observation of the discharge space luminescence process. The spatial luminescence process caused by discharge energy and the morphological evolution of the discharge luminescence region under different voltage amplitudes were systematically studied.

[0098] To facilitate lens installation and adjustment when observing the luminous area, an aluminum strip is attached to the surface of the insulator near the high-voltage conductor, with one end of the strip pressed under the shielding cover to ensure good contact. The defect arrangement is as follows: Figure 14-15 As shown.

[0099] During the experimental observation, a high-speed ICCD camera was used, with the camera lens facing the defect location.

[0100] During the long-term constant voltage process, the high-speed ICCD camera signal is connected to the back-end computer via a network cable. Image acquisition is performed using the accompanying Lightfield software, with a single image exposure time set to 5 seconds. Since the project involves a 168-hour long-term constant voltage uninterrupted test, the uninterrupted storage of the high-speed ICCD camera signal places a huge burden on storage space for the research work. Furthermore, the image information of the luminescent areas in the images stored in close proximity is very similar, and the uninterrupted storage method also contains a large amount of redundant information. In order to optimize the storage strategy, the high-speed ICCD camera signal adopts a periodic intermittent storage method, saving 10 minutes every 4 hours.

[0101] (2) Measurement system:

[0102] The high-speed ICCD camera is the key equipment in this embodiment. It is used to measure the dynamic development trajectory of the surface, capture images of intermittent discharge current beams along the surface, and measure the emission characteristics of the discharge plasma. The Princeton PI-MAX4 high-speed ICCD camera is planned to be selected. This camera has superior performance in terms of sensitivity, speed, gain, and time resolution imaging control. It also has faster gating, intelligent remote control, and flexible experimental settings and operations. It supports dynamic acquisition at a resolution of 1024*256 and can perform time resolution on single excitation experiments. The gating accuracy between subframes reaches the order of 500 ps, ​​which is sufficient to meet the research requirements of this embodiment.

[0103] (3) Research Methods:

[0104] ① The development and changes of the luminescent region during long-term constant pressure development:

[0105] The study observes the changing trends of luminescence characteristics during discharge at the equivalent operating voltage (U0), recording the morphological changes of the luminescent region and the variation trends of the luminescent region area. To correlate the changes in discharge characteristics with luminescence characteristics, the UHF signal of the discharge can be recorded simultaneously with the photometry method. The development trend of the UHF signal (rising range, oscillation range, falling range, and stable range) is then synchronously compared and analyzed with the luminescent region of the discharge. The aim is to establish a correspondence between UHF discharge frequency and luminescent area. Figure 16 As shown.

[0106] ② The influence of voltage amplitude on the development of the discharge luminescence region:

[0107] This study investigates the variation patterns of the discharge luminescence region under different voltage amplitudes. By recording the changes in the discharge luminescence region over a long period under different voltage amplitudes, and comparing and analyzing the luminescence regions at the same applied pressure time for different voltage amplitudes, the study aims to obtain the variation patterns of the discharge luminescence region under different voltage amplitudes. Figure 17 As shown in the figure, the black square area is the camera shooting area, and the white area is the light-emitting area caused by the discharge. By using the relative relationship between the diameter of the white light-emitting area in the camera shooting area and the length of the high-voltage conductor and metal particles, the area of ​​the light-emitting area at each shooting time point can be calculated.

[0108] ③ Investigation into the mechanism of weak discharge of metal particles on the surface of insulators:

[0109] This study analyzes the correlation and differences between ultra-high frequency electrical signals and high-speed ICCD camera optical signals during the initiation and development of discharge from metal particles on the insulator surface. The contribution ratios of pulsed and non-pulsed discharges and their evolutionary direction during discharge development are recorded. Based on existing theories of pulsed and glow discharges, the mechanism of weak discharge from metal particles on the insulator surface is explained.

[0110] Based on the target detection results, the success rate of discharge event capture and the effective spectrum detection rate of the on-site GIS equipment partial discharge UHF online monitoring device are evaluated and estimated, and improvement and rectification measures to enhance the effectiveness of on-site partial discharge detection are given.

[0111] A device for testing and evaluating the effectiveness of GIS insulation components, comprising:

[0112] The design module designs electromagnetic interference suppression and identification methods based on different types of electromagnetic interference signals.

[0113] A module was established to perform partial discharge charge detection and online monitoring based on electromagnetic interference suppression and identification methods, thereby establishing a charge detection technology system for GIS insulating components.

[0114] The initial detection module, based on the GIS insulation component live detection technology system, uses constant voltage and ultra-high frequency methods to synchronously detect partial discharge signals.

[0115] The target detection module further detects the initial detection results based on the weak discharge optical tracing method for surface defects of insulating components to obtain the target detection results;

[0116] The evaluation and estimation module evaluates and estimates the success rate of discharge event capture and the effective spectrum detection rate of the on-site GIS equipment partial discharge UHF online monitoring device based on the target detection results, and provides improvement and rectification measures to enhance the effectiveness of on-site partial discharge detection.

[0117] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for evaluating the effectiveness of a GIS insulating member, characterized by Includes the following steps: Based on different types of electromagnetic interference signals, electromagnetic interference suppression and identification methods are designed. Based on the electromagnetic interference suppression and identification methods, partial discharge charging detection and online monitoring are carried out, and a GIS insulation component charging detection technology system is established. The process of partial discharge charging detection and online monitoring based on the electromagnetic interference suppression and identification method is as follows: Based on the UHF detection measurement and information extraction method, UHF detection feature analysis is performed to obtain the analysis results. Based on the analysis results, interference suppression measures for partial discharge detection system application in the field under different interference coupling paths and different action modes are constructed. The interference suppression measures include waveform identification interference suppression technology, internal and external signal comparison method, signal multi-cycle analysis method, amplitude ratio clustering anti-interference technology, and multi-element signal separation method of three frequency band centers. Based on the aforementioned GIS insulation component live detection technology system, the constant voltage method and ultra-high frequency method are used to synchronously detect partial discharge signals to obtain initial detection results; The initial detection results are further detected using an optical tracing method based on weak discharge of surface defects in insulating components to obtain the target detection results. Based on the target detection results, the success rate of discharge event capture and the effective spectrum detection rate of the on-site GIS equipment partial discharge UHF online monitoring device are evaluated and estimated, and improvement and rectification measures are given to enhance the effectiveness of on-site partial discharge detection. The method for separating the multi-element signals at the center of the three frequency bands is as follows: Three frequencies are preset as initial settings, and the amplitudes of the three detector outputs after frequency division measurement are detected synchronously and the pulse phase information is recorded simultaneously. Three-dimensional data is mapped to a two-dimensional data space to obtain two-dimensional data, and the two-dimensional data is used as a clustering index. At the same time, the discharge amplitude and phase of the discharge pulse are marked to obtain the clustering result. Based on the clustering results, discharge mode spectrum (PRPD) is obtained by mapping the discharge amplitude and phase information corresponding to each type of pulse, thereby realizing the separation of multiple discharge sources and subsequent analysis.

2. The method of evaluating the effectiveness of a GIS insulation according to claim 1, characterized in that: The process of designing electromagnetic interference suppression and identification methods based on different types of electromagnetic interference signals is as follows: Actual measurements and statistics were conducted on interference scenarios at substation sites to obtain statistical data. Based on the statistical data, the sources, characteristics, and modes of influence of different types of electromagnetic interference signals at substation sites were obtained. For different types of electromagnetic interference signals, electromagnetic interference suppression and identification methods are designed, including those based on waveform characteristics, synchronization, and clustering synthesis.

3. The method of claim 2, wherein: Constant pressure method and its ultra-high frequency method: The signal of the partial discharge process of typical defect test specimens under long-term voltage is obtained to simulate the partial discharge development process of insulation defects under operating voltage, and a multi-dimensional signal feature database of typical defect partial discharge is established. By analyzing the statistical characteristics of the time domain, frequency domain, pulse sequence time interval, and pulse amplitude of multi-dimensional signal characteristics of partial discharge in analytical defects, the initial, developmental stages and evolution patterns of typical insulation component defects are analyzed from the perspectives of signal intensity distribution, intermittent discharge characteristics, spectral distribution characteristics, and energy distribution of multi-dimensional signals, and an evaluation index for detection effectiveness is constructed.

4. The method of evaluating the effectiveness of the GIS insulation according to claim 3, characterized in that: Based on the aforementioned detection effectiveness evaluation index, the partial discharge signal is detected online, and the detection effectiveness is evaluated using the constructed detection effectiveness evaluation index to obtain initial detection results.

5. The method of evaluating the effectiveness of the GIS insulation according to claim 4, characterized in that: The process of obtaining the evaluation indicators for the effectiveness of the test is as follows: Based on the ultra-high frequency method, this study investigates the partial discharge phenomenon of metal particles on the surface of GIS insulators under long-term constant voltage. First, statistical analysis is conducted on the amplitude, discharge frequency, and distribution of discharge density intervals. Two key parameters, effective discharge interval and effective spectrum, are defined. Then, the intermittent characteristics of discharge are quantitatively analyzed using these two key parameters to obtain evaluation indicators for detection effectiveness.

6. The method for effectiveness detection and evaluation of GIS insulation components according to claim 5, characterized in that: The process of evaluating the detection effectiveness by real-time online detection of partial discharge signals of insulating components based on the aforementioned detection effectiveness evaluation index is as follows: First, based on the evaluation index of detection effectiveness, a long-term overall trend analysis of partial discharge is conducted to obtain an overall statistical trend chart of the average discharge value and discharge repetition rate of ultra-high frequency signals. Based on the overall statistical trend chart, the variation trend of discharge intensity in the initial discharge stage and the long-term development discharge stage, as well as the distribution variance statistics of the average discharge value and discharge repetition rate of ultra-high frequency signals, are analyzed. Subsequently, the discharge density distribution characteristics were statistically analyzed. The overlapping times of dense and sparse discharges were counted separately, and the overall proportion of dense and sparse intervals was calculated to obtain quantitative statistical indicators of sparsity in the discharge development process. Based on existing detection strategies and the aforementioned sparsity quantification statistical indicators, the rules and quantitative evaluation methods for the formation of effective discharge ranges and effective spectra are statistically analyzed to assess the effectiveness of existing partial discharge devices and obtain initial detection results.

7. The method for effectiveness detection and evaluation of GIS insulation components according to claim 6, characterized in that: The process of further detecting the initial detection results using the weak discharge optical tracing method for surface defects of insulating components to obtain the target detection results is as follows: The spatial luminescence characteristics of the discharge region are obtained by using a high-gain industrial high-speed ICCD camera and the ultra-high frequency method. Based on the spatial luminescence characteristics, the morphological evolution process of the discharge luminescence region during long-term constant voltage and the correspondence between the spatial morphological evolution and the ultra-high frequency signal are compared and analyzed. The gradual and abrupt changes in discharge morphology under different voltage amplitudes were recorded and statistically analyzed. The correlation and difference between ultra-high frequency electrical signals and high-speed ICCD camera optical signals during the initiation and long-term development of discharge of metal particles on the insulator surface were analyzed. The contribution ratio of pulsed discharge and non-pulsed discharge and the evolution direction of discharge development were tracked and recorded. Based on the tracking and recording results, the mechanism of weak discharge of metal particles on the insulator surface was explained.

8. The method for effectiveness detection and evaluation of GIS insulation components according to claim 7, characterized in that: The comparative analysis process of the morphological evolution of the discharge emission region during long-term constant voltage process and the correspondence between the spatial morphological evolution and the ultra-high frequency signal based on the spatial luminescence characteristics is as follows: The observation voltage is used to observe the luminescence characteristics of the discharge under the equivalent operating voltage, record the morphological changes of the luminescence region and the variation trend of the discharge luminescence region area, and simultaneously record the UHF signal of the discharge based on the photometry method. The development trend of the UHF signal is synchronously compared and analyzed with the discharge luminescence region to establish the correspondence between the UHF discharge frequency and the discharge luminescence area. The process of recording and statistically analyzing the gradual and abrupt changes in discharge morphology under different voltage amplitudes is as follows: the variation law of discharge luminescence region under different voltage amplitudes is obtained by studying and obtaining the variation of discharge luminescence region obtained by long-term observation under different voltage amplitudes, and the luminescence region at the same pressurization time under different voltage amplitudes is compared and analyzed to obtain the variation law of discharge luminescence region under different voltage amplitudes.

9. A device for detecting and evaluating the effectiveness of GIS insulation components, used to perform the method for detecting and evaluating the effectiveness of GIS insulation components according to any one of claims 1-8, characterized in that... include: The design module designs electromagnetic interference suppression and identification methods based on different types of electromagnetic interference signals. A module was established to perform partial discharge charge detection and online monitoring based on electromagnetic interference suppression and identification methods, thereby establishing a charge detection technology system for GIS insulating components. The initial detection module, based on the GIS insulation component live-line detection technology system, uses constant voltage and ultra-high frequency methods to synchronously detect partial discharge signals and obtain initial detection results. The target detection module further detects the initial detection results based on the weak discharge optical tracing method for surface defects of insulating components to obtain the target detection results; The evaluation and estimation module evaluates and estimates the success rate of discharge event capture and the effective spectrum detection rate of the on-site GIS equipment partial discharge UHF online monitoring device based on the target detection results, and provides improvement and rectification measures to enhance the effectiveness of on-site partial discharge detection.

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