GIS equipment partial discharge determination method and system

Abstract

The invention relates to the technical field of discharge detection, in particular to a GIS equipment partial discharge judgment method and system.The method comprises the steps that sensor data of multiple adjacent channels of GIS equipment is read, and PRPD maps are drawn respectively; judging each PRPD map feature, if the number of signal channels with similar typical map features is greater than or equal to 2, speculating a discharge source position in a pre-constructed equipment three-dimensional structure model by combining attenuation characteristics of two channels with the maximum amplitude, and if positioning succeeds, judging an amplitude rule of each channel based on the positioned discharge source position, so as to obtain an amplitude rule of each channel; and if the attenuation law is met and the amplitude gradient exists between the channels, finally determining that the partial discharge signal exists in the equipment. According to the method, the limitation of single channel signal judgment can be overcome, the probability of false alarm is greatly reduced, and more powerful guarantee is provided for stable operation of GIS equipment.

Description

Technical Field

[0001] This invention relates to the field of discharge detection technology, and more specifically to a method and system for determining partial discharge in GIS equipment. Background Technology

[0002] GIS equipment, with its advantages of small footprint, excellent insulation performance, high operational reliability, and minimal susceptibility to external environmental influences, has become a core component of ultra-high voltage and extra-high voltage substations. However, during manufacturing, transportation, installation, and long-term operation, GIS equipment inevitably develops some potential defects, such as internal metal particles, poor contact of conductive rods, and surface contamination of insulating components. These defects can lead to localized electric field concentration within the equipment, resulting in partial discharge. If partial discharge problems are not detected and addressed in a timely manner, the defects may eventually lead to insulation breakdown of the GIS equipment, causing serious equipment failure, widespread power outages, and significant losses to social production and residents' lives, while also incurring high equipment repair and replacement costs.

[0003] Ultra-high frequency (UHF) monitoring technology, as a primary means of early warning of potential defects in GIS equipment, has been widely applied in the condition monitoring and operation and maintenance of GIS equipment. Currently, the system determines whether partial discharge has occurred mainly based on the partial discharge signal spectrum characteristics collected by a single channel sensor. However, due to the complex electromagnetic environment at the site, Currently, partial discharge line monitoring systems primarily rely on single-channel sensor signals to determine the status of partial discharge. If the signal from a particular channel matches the defect characteristics and exceeds the alarm threshold, the system will issue an alarm signal. However, the operating environment at substation sites is extremely complex, with numerous sources of electromagnetic interference. Signals collected by a single sensor are easily affected by external interference, leading to significant errors in the judgment results. False alarms and missed alarms frequently occur, posing a significant threat to the stable operation of GIS equipment.

[0004] Therefore, how to overcome the limitations of single-channel signal judgment and significantly reduce the probability of false alarms is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a method and system for determining partial discharge in GIS equipment, which can overcome the limitations of single-channel signal judgment, significantly reduce the probability of false alarms, and provide a stronger guarantee for the stable operation of GIS equipment.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for determining partial discharge in GIS equipment, comprising the following steps: S1. Read sensor data from adjacent multiple channels of the GIS device and draw PRPD maps respectively; S2. Judge the characteristics of each PRPD spectrum. If the number of signal channels with similar typical spectrum characteristics is ≥2, then execute S3; otherwise, return to S1. S3. Combining the attenuation characteristics of the two channels with the largest amplitude, infer the location of the power supply in the pre-built three-dimensional structural model of the device. If the location is successful, execute S4; otherwise, return to S1. S4. Based on the located discharge source position, judge the amplitude pattern of each channel. If it conforms to the attenuation pattern and there is an amplitude gradient between channels, then it is finally determined that there is a partial discharge signal inside the device; otherwise, return to S1.

[0007] Furthermore, the method for determining PRPD map features is as follows: Key features reflecting the geometric morphology of the discharge region are extracted from the PRPD image of any channel. These features are then compared with the morphological features of various types of defects in the typical defect PRPD image feature library to obtain the sub-feature similarity S. j ; The weighted summation of the feature similarities between the current PRPD map and a certain defect type is used to obtain the comprehensive similarity S between the current PRPD map and the defect type. After calculating the comprehensive similarity S between the PRPD map to be detected and all defect types in the typical defect PRPD map feature library, the defect type corresponding to the maximum comprehensive similarity S value is taken as the matching result. If S≥0.8, the matched defect type is output.

[0008] Furthermore, the importance of each extracted key feature is distinguished according to the different defect types, and different weights are assigned. The formula for calculating the comprehensive similarity S between the PRPD map to be detected in any channel and a certain defect type is as follows:

[0009] in, S j Indicates the first j Individual feature similarity, W j Indicates the first j Weights of individual feature similarity.

[0010] Furthermore, in S3, the device's three-dimensional structural model contains the spatial coordinates of all components, used to locate the propagation path of the sensor and the discharge power source, and to identify the components along the path.

[0011] Furthermore, in S3, the methods for inferring the location of the power supply include: Each channel uses the 90th percentile amplitude as the amplitude characteristic, denoted as... , where i is the channel number; Select the two channels with the largest overall similarity S, and denote them as A and B respectively, where A is the channel with the largest overall similarity S and B is the channel with the second largest overall similarity S. Calculate the signal attenuation S from channel A to channel B. AB ; like If the power supply position P is between the position of channel A and the position of channel B, then it is determined that the power supply position P is between the position of channel A and the position of channel B. like If so, it is determined that the power supply position P is on the outer side near the position of channel A; like If the signal is abnormal, return directly to S1.

[0012] Furthermore, signal attenuation occurs from channel A to channel B. The calculation formula is:

[0013] in, The distance between channel A and channel B. This is the sum of the attenuations of all components between channel A and channel B. The basic attenuation coefficient.

[0014] Furthermore, in S4, the methods for judging the amplitude patterns of each channel include: The actual distance between the power supply location P and each channel is denoted as . d i , i Number the channels; determine the equivalent distances of each component along the propagation path. Calculate the equivalent distance between each channel and the power source location P. D i : ; Sort all valid channels in ascending order of equivalent distance, and calculate the equivalent distance for all channels. and quantile amplitude Perform pairwise comparisons and statistically analyze the results if... ,but The percentage of samples with the number "" If the proportion is less than 90%, it is determined that it does not meet the internal defect signal attenuation characteristics, and returns to S1; If the proportion is ≥90%, and the amplitude attenuation trend is consistent with the equivalent distance, which is consistent with the attenuation characteristics of internal defect signals, then it is determined that there is a defective partial discharge signal inside the equipment.

[0015] Secondly, the present invention provides a partial discharge determination system for GIS equipment, which employs the method described above, including: The multi-channel data acquisition module is used to read sensor data from multiple adjacent channels of the GIS device and draw PRPD maps for each. The spectral feature judgment module is used to judge the spectral features of each PRPD and determine whether the number of signal channels with similar typical spectral features is ≥2. The positioning module is used to infer the location of the discharge source in a pre-built three-dimensional structural model of the device when there are ≥2 signal channels with similar typical spectral characteristics, based on the attenuation characteristics of the two channels with the largest amplitude. The partial discharge detection module is used to determine the amplitude pattern of each channel based on the located discharge source position. If it conforms to the attenuation pattern and there is an amplitude gradient between channels, it is finally determined that there is a partial discharge signal inside the device.

[0016] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: This invention, by comprehensively analyzing the spectral characteristics, signal source location, and amplitude changes of multi-channel sensor signals, can more accurately determine whether internal partial discharge has occurred in GIS equipment. It effectively overcomes the limitations of single-channel signal judgment, thereby significantly reducing the probability of false alarms, improving the online monitoring efficiency of partial discharge in GIS equipment, and promoting the development of intelligent operation and maintenance technology for gas-insulated metal-enclosed high-voltage switchgear. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0018] Figure 1 A flowchart of the partial discharge determination method for GIS equipment provided by the present invention; Figure 2 The structural block diagram of the partial discharge determination system for GIS equipment provided by the present invention is shown. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] like Figure 1 As shown in the figure, an embodiment of the present invention discloses a method for determining partial discharge in GIS equipment, including the following steps: S1. Read sensor data from adjacent multiple channels of the GIS device and draw PRPD maps respectively; S2. Judge the characteristics of each PRPD spectrum. If the number of signal channels with similar typical spectrum characteristics is ≥2, then execute S3; otherwise, return to S1. S3. Combining the attenuation characteristics of the two channels with the largest amplitude, infer the location of the power supply in the pre-built three-dimensional structural model of the device. If the location is successful, execute S4; otherwise, return to S1. S4. Based on the located discharge source position, judge the amplitude pattern of each channel. If it conforms to the attenuation pattern and there is an amplitude gradient between channels, then it is finally determined that there is a partial discharge signal inside the device; otherwise, return to S1.

[0021] The steps described above in this invention will be further explained below.

[0022] S1, Multi-channel data reading: Read the data from adjacent multi-channel sensors collected by the UHF partial discharge online monitoring system, and plot the PRPD spectrum for each channel's partial discharge data according to the "phase-amplitude-frequency" dimension.

[0023] S2 and PRPD map feature judgment: 1) Extract key features (shape, distribution pattern, and density, etc.) that reflect the geometric morphology of the discharge region from the PRPD image of any channel, and calculate the similarity between these features and the morphological features of various types of defects in the typical defect PRPD image feature library to obtain the sub-feature similarity S. j .

[0024] 2) The weighted sum of the feature similarities between the current PRPD map and a certain defect type is used to obtain the comprehensive similarity S between the current PRPD map and that defect type. During calculation, the importance of each extracted key feature is distinguished according to the different defect types, and different weights are assigned. The formula for calculating the comprehensive similarity S between the PRPD map to be detected in any channel and a certain defect type is as follows:

[0025] in, S j Indicates the first j Individual feature similarity, W j Indicates the first j Weights of individual feature similarity.

[0026] 3) Calculate the comprehensive similarity S between the PRPD map to be detected and all defect types in the typical defect PRPD map feature library one by one, and take the defect type corresponding to the maximum comprehensive similarity S value as the matching result. If S≥0.8, output the matched defect type; otherwise, return S1.

[0027] S3. Power supply positioning judgment: A three-dimensional structural model of the GIS equipment is pre-established, containing the spatial coordinates of all components (such as basins, circuit breakers, disconnect switches, T-shaped structures, L-shaped structures, etc.) to locate the propagation path of the sensor and the discharge power source and identify the components on the path.

[0028] The fundamental attenuation coefficient of the known signal ( Signal attenuation per meter), for internal components (or special structures) of the equipment. Its attenuation coefficient is known to be ( (Attenuation value of signal through components or special structures).

[0029] Each channel uses the 90th percentile amplitude (the upper limit of amplitude after removing 10% extreme outliers) as the amplitude characteristic. The amplitude characteristic can be directly obtained from the PRPD spectrum, denoted as . Let i be the channel number. Select the two channels with the highest overall similarity S, denoted as A and B, where A is the channel with the highest overall similarity S and B is the channel with the second highest overall similarity S. Calculate the signal attenuation S from channel A to channel B. AB The calculation formula is:

[0030] in, The distance between channel A and channel B. It is the sum of the attenuations of all components or special structures between channel A and channel B. The basic attenuation coefficient.

[0031] Subsequently, the defect location was determined based on spectral characteristics (insulation, particles, suspension, and tips) and signal attenuation patterns. like If the location of the discharge source P is determined to be between channel A and channel B, the initial determination is that the location of the discharge source P is the high-incidence area of ​​defects closest to channel A in the middle of channel A and channel B (for example, for insulation defects, the discharge location is the insulation component closest to channel A in the middle of A and B). High-incidence areas of various defect types need to be marked in advance in the 3D structural model. Insulation defects exist in basin insulators, support insulators, and insulation rods; suspension defects exist in the fastening parts of metal components, caused by loosening due to long-term operational vibration; particle defects exist in easily worn parts of conductors / contacts; and sharp point defects exist in areas of poor outer casing welding, conductor splicing, or contact wear, forming burrs.

[0032] like If the discharge source P is located on the outer side of the channel A, it is determined that the nearest high-incidence area of ​​defects on the outer side of channel A is the location of the discharge source P (for example, for insulation defects, the nearest insulating component on the outer side of A is taken as the discharge location).

[0033] like If the signal is abnormal, return directly to S1.

[0034] S4. Determine the amplitude pattern of each channel: The actual distance between the power supply location P and each channel is denoted as . d i , i Number the channels; determine the equivalent distances of each component along the propagation path. Calculate the equivalent distance between each channel and the power source location P. D i : Because signal propagation is not unobstructed, there is wear and tear on components. Compare The difference is significant. If two points are close together but have many special structural components in between, the propagation loss may be greater than that between two points that are farther apart. Therefore, it is necessary to calculate the equivalent distance. D i .

[0035] Sort all valid channels in ascending order of equivalent distance, for example... Equivalent distance for all channels D and quantile amplitude Perform pairwise comparisons and statistically analyze the results if... ,but The percentage of samples with the number "" If the proportion is less than 90%, it is determined that it does not meet the internal defect signal attenuation characteristics, and returns to S1; If the proportion is ≥90%, and the amplitude attenuation trend is consistent with the equivalent distance, which is consistent with the attenuation characteristics of internal defect signals, then it is determined that there is a defective partial discharge signal inside the equipment.

[0036] In other embodiments, such as Figure 2 As shown, the present invention also provides a partial discharge determination system for GIS equipment, which employs the method described above, including: The multi-channel data acquisition module is used to read sensor data from multiple adjacent channels of the GIS device and draw PRPD maps for each. The spectral feature judgment module is used to judge the spectral features of each PRPD and determine whether the number of signal channels with similar typical spectral features is ≥2. The positioning module is used to infer the location of the discharge source in a pre-built three-dimensional structural model of the device when there are ≥2 signal channels with similar typical spectral characteristics, based on the attenuation characteristics of the two channels with the largest amplitude. The partial discharge detection module is used to determine the amplitude pattern of each channel based on the located discharge source position. If it conforms to the attenuation pattern and there is an amplitude gradient between channels, it is finally determined that there is a partial discharge signal inside the device.

[0037] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0038] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A GIS device partial discharge determination method characterized by, The method comprises the following steps: S1, reading sensor data of adjacent multiple channels of a GIS device, and drawing PRPD maps respectively; S2, judging features of each PRPD map, if the number of signal channels with similar typical map features is greater than or equal to 2, performing S3, otherwise returning to S1; S3, combining the attenuation characteristics of the two channels with the largest amplitudes, and inferring the discharge source position in a pre-constructed three-dimensional structure model of the device, if the positioning is successful, performing S4, otherwise returning to S1; S4, based on the positioned discharge source position, judging the amplitude regularity of each channel, if the amplitude gradient exists between the channels and the amplitude attenuation rule is met, finally determining that there is a partial discharge signal in the device, otherwise returning to S1.

2. The GIS apparatus partial discharge determination method according to claim 1, characterized by, In S2, the way of judging the PRPD map features is as follows: From any channel corresponding to the PRPD spectrum to be detected, the key features reflecting the geometric shape of the discharge region are extracted, and the similarity is calculated with the shape features of each type of defect in the typical defect PRPD spectrum feature library, to obtain a feature similarity S j ; The similarity of the current PRPD map and the specific features of a certain defect type is weighted and summed to obtain the comprehensive similarity S of the current PRPD map and the defect type; After calculating the comprehensive similarity S of the PRPD map to be detected and all defect types in the typical defect PRPD map feature library, the defect type corresponding to the maximum comprehensive similarity S value is taken as the matching result, and if S is greater than or equal to 0.8, the matched defect type is output.

3. The GIS apparatus partial discharge determination method according to claim 2, characterized by, In S2, the importance of each key feature is distinguished according to the different defect types, and different weights are given. The calculation formula of the comprehensive similarity S of any channel of the PRPD map to be detected and a certain defect type is as follows: wherein, S j denotes the j th sub-feature similarity, W j denotes the weight of the j th sub-feature similarity.

4. The GIS apparatus partial discharge determination method according to claim 1, characterized by, In S3, the three-dimensional structure model of the device contains the spatial coordinates of all components, which is used to locate the propagation path of the sensor and the discharge source and identify the components on the path.

5. The GIS apparatus partial discharge determination method according to claim 2, characterized by, In S3, the way of inferring the discharge source position includes: The 90% quantile amplitude of each channel is used as the amplitude feature, denoted as , where i is the channel number. Selecting the two channels with the largest comprehensive similarity S, denoted as A and B, wherein A is the channel with the largest comprehensive similarity S, and B is the channel with the second largest comprehensive similarity S; calculating the signal attenuation S from the A-channel position to the B-channel position AB ; If then the discharge source position P is determined to be between the A channel position and the B channel position. If then the discharge source position P is judged to be on the outside of the A passage position; If then the signal is judged to be abnormal and the routine returns directly to S1.

6. The GIS apparatus partial discharge determination method according to claim 5, characterized by, Signal attenuation from the A channel position to the B channel position The formula for calculating this is: wherein, is the distance between the A channel and the B channel, is the sum of the attenuation of all parts between the A channel and the B channel, is the base attenuation coefficient.

7. The GIS apparatus partial discharge determination method according to claim 1, characterized by, In S4, the method of judging the amplitude regularity of each channel includes: Let the actual distance between the discharge source position P and each channel be denoted as d i , i is the channel number; the equivalent distance of each component on the propagation path is combed The equivalent distance of each channel to the discharge source position P is calculated D i : ; Sort all valid channels by equivalent distance from small to large, and calculate the equivalent distance of all channels and quantile amplitude Compare each two channels, and calculate the proportion of sample pairs that satisfy "if , then " If the proportion is less than 90%, it is determined that the internal defect signal attenuation characteristics are not met, and the process returns to S1; If the proportion is greater than or equal to 90%, the amplitude attenuation trend is consistent with the equivalent distance, the internal defect signal attenuation characteristics are met, and it is determined that there is a defect partial discharge signal in the device.

8. A GIS device partial discharge determination system characterized by comprising: The method comprises the following steps: A multi-channel data acquisition module is configured to read sensor data of adjacent multiple channels of a GIS device, and draw PRPD maps respectively; A map feature judgment module is configured to judge features of each PRPD map, and judge whether the number of signal channels with similar typical map features is greater than or equal to 2; A positioning module is configured to, when the number of signal channels with similar typical map features is greater than or equal to 2, combine the attenuation characteristics of the two channels with the largest amplitudes, and infer the discharge source position in a pre-constructed three-dimensional structure model of the device; A partial discharge judgment module is configured to, based on the positioned discharge source position, judge the amplitude regularity of each channel, if the amplitude gradient exists between the channels and the amplitude attenuation rule is met, finally determine that there is a partial discharge signal in the device.

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