Surge arrester bank monitoring system, monitoring method and processor-readable storage medium

Abstract

The present disclosure relates to the technical field of power transmission line monitoring, and particularly relates to a monitoring system of a lightning arrester group, a monitoring method and a processor readable storage medium, the lightning arrester group comprising a plurality of lightning arresters; the monitoring system comprises: a sensing module configured to output a voltage sensing signal based on a space electric field of the lightning arrester, and output a temperature sensing signal based on a temperature of a selected region of the lightning arrester; a feature extraction unit coupled with the sensing module and configured to output an electric field distribution vector based on the voltage sensing signal, and output a temperature feature based on the temperature sensing signal; a logic control unit coupled with the feature extraction unit and configured to output an alarm signal in a case that a ratio of at least one element of the electric field distribution vector of one lightning arrester to a corresponding element of the electric field distribution vector of the remaining lightning arresters is greater than or equal to a first voltage threshold; or, the logic control unit is configured to output an alarm signal in a case that a comprehensive deviation index is greater than or equal to a first deviation threshold.

Description

Technical Field

[0001] This disclosure relates to the field of power transmission line monitoring technology, and in particular to a monitoring system, monitoring method and processor-readable storage medium for a surge arrester assembly. Background Technology

[0002] Surge arresters, as one of the key overvoltage protection devices in power systems, are widely used in power generation, transmission, transformation, and distribution systems. Among them, metal oxide surge arresters (MOAs) are widely used due to their advantages such as fast response speed and flat volt-ampere characteristics, and their operating status is directly related to the reliability and safety of the power grid.

[0003] However, metal oxide surge arresters are susceptible to problems such as moisture and aging. Seal failure leading to internal moisture can cause partial discharge or even explosion. Under long-term power frequency voltage or overvoltage impact, the performance of their resistors deteriorates or leakage current increases, which seriously affects the reliability and stability of the power grid.

[0004] Therefore, there is a need for a transmission line monitoring system that can monitor the status of metal oxide surge arresters. Summary of the Invention

[0005] To address the aforementioned technical problems, this disclosure provides a monitoring system, monitoring method, and processor-readable storage medium for surge arrester assemblies.

[0006] On one hand, a monitoring system for a surge arrester group is provided, the surge arrester group including multiple surge arresters; the monitoring system includes: a sensing module configured to output a voltage sensing signal based on the spatial electric field of the surge arrester, and to output a temperature sensing signal based on the temperature of a selected area of ​​the surge arrester; a feature extraction unit coupled to the sensing module, configured to output an electric field distribution vector based on the voltage sensing signal, and to output a temperature feature based on the temperature sensing signal; a logic control unit coupled to the feature extraction unit, configured to output an alarm signal when the ratio of at least one element of the electric field distribution vector of one surge arrester to the corresponding element of the electric field distribution vector of the remaining surge arresters is greater than or equal to a first voltage threshold; or, the logic control unit is configured to determine a comprehensive deviation index based on the electric field distribution vector, the temperature feature, a reference electric field vector, and a reference temperature feature, and to output an alarm signal when the comprehensive deviation index is greater than or equal to the first deviation threshold.

[0007] In one feasible embodiment, the sensing module includes: a non-contact electric field sensing unit configured to output a voltage sensing signal characterizing the local electric field intensity based on the spatial electric field distribution of the surge arrester; and a temperature sensing unit configured to output a temperature sensing signal based on the temperature of a selected area of ​​the surge arrester; wherein the selected area includes any one of the surface of the surge arrester, the connection between the upper, middle, and lower sections of the surge arrester, or the housing corresponding to the valve plate area of ​​the surge arrester.

[0008] In one feasible embodiment, the non-contact electric field sensing unit includes: a first sub-electric field sensing unit located near the high-voltage end equalizing ring of the surge arrester; a second sub-electric field sensing unit located near the umbrella skirt structure of the surge arrester; and a third sub-electric field sensing unit located near the grounding busbar of the surge arrester.

[0009] In one feasible embodiment, an environmental parameter sensing unit is further included, which is configured to collect ambient temperature, ambient humidity, and operating voltage. The logic control unit is further configured to, when the surge arrester is in normal operating condition, use the electric field distribution vector as a reference electric field vector and the temperature feature as a reference temperature feature to determine a reference database based on the ambient temperature, ambient humidity, operating voltage, reference electric field vector, and reference temperature feature under the current operating condition of the surge arrester.

[0010] In one feasible embodiment, the logic control unit is further configured to determine the reference electric field vector and the reference temperature characteristics based on the ambient temperature, the ambient humidity, the operating voltage, and the reference database.

[0011] In one feasible embodiment, the feature extraction unit is specifically configured to output an electric field distribution vector including the power frequency component amplitude, the third harmonic component amplitude, and the relative phase based on the voltage sensing signal, and to output temperature features including the maximum temperature rise, axial temperature gradient, and interphase temperature difference based on the temperature sensing signal.

[0012] In one feasible embodiment, the logic control unit is specifically configured to output a first sub-alarm signal when the ratio of at least one element of the electric field distribution vector of one surge arrester to the corresponding element of the electric field distribution vector of the other surge arresters is greater than or equal to a first voltage threshold; or, when the comprehensive deviation index is greater than or equal to the first deviation threshold, output a first sub-alarm signal.

[0013] In one feasible embodiment, the logic control unit is further configured to output a second sub-alarm signal if the overall deviation index is greater than or equal to a first deviation threshold and the ratio of at least one element of the electric field distribution vector of one of the surge arresters to the corresponding element of the electric field distribution vector of the remaining surge arresters is greater than or equal to a second voltage threshold.

[0014] In one feasible embodiment, the logic control unit is further configured to output a third sub-alarm signal if the difference between the temperature characteristic of one of the surge arresters and the temperature characteristics of the other surge arresters is greater than or equal to a first temperature threshold.

[0015] In one feasible embodiment, the system further includes: a signal processing and transmission module coupled to the sensing module and the feature extraction unit, configured to preprocess the voltage sensing signal and / or the temperature sensing signal, and output the preprocessed voltage sensing signal and / or the temperature sensing signal to the feature extraction unit; wherein the preprocessing includes at least one of filtering, amplification, and analog-to-digital conversion.

[0016] On the other hand, a monitoring method for a surge arrester group is provided, the surge arrester group including multiple surge arresters, the monitoring method including: acquiring voltage sensing signals and temperature sensing signals; the voltage sensing signals are used to characterize the spatial electric field of the surge arrester, and the temperature sensing signals are used to characterize the temperature of a selected area of ​​the surge arrester; determining an electric field distribution vector based on the voltage sensing signals, and determining a temperature characteristic based on the temperature sensing signals; outputting an alarm signal when at least one element of the electric field distribution vector of one surge arrester is greater than or equal to the corresponding element of the electric field distribution vector of the remaining surge arresters; or, outputting an alarm signal when a comprehensive deviation index is greater than or equal to the first deviation threshold; the comprehensive deviation index is determined based on the electric field distribution vector, the temperature characteristic, a reference electric field vector, and a reference temperature characteristic.

[0017] On the other hand, a processor-readable storage medium is provided, the processor-readable storage medium storing a program for causing the processor to perform the above-described method.

[0018] The technical solution provided in this disclosure has the following advantages compared with the prior art: The monitoring system disclosed herein utilizes the principle of spatial electric field coupling to convert the grounding wire leakage current, which is difficult to measure directly, into a measurable spatial electric field signal. Employing non-contact electric field sensing technology, it achieves effective perception of the surge arrester's operating status. The sensing module uses a non-contact installation method, requiring no modification to existing primary equipment wiring, offering advantages such as safe and convenient construction, making it particularly suitable for the renovation of old substations.

[0019] This disclosure utilizes intelligent algorithms to mine fault information and constructs an online fault monitoring system based on the principle of spatial electric field coupling and the fusion analysis of multiple sensing signals. By continuously monitoring and analyzing weak signals such as harmonic electric field components, the monitoring system can identify performance degradation trends in surge arresters before substantial thermal collapse or counter activation occurs, providing early warning time for planned maintenance. Ultimately, it achieves real-time monitoring of the surge arrester's operating status and early fault warning, thereby ensuring the safe and stable operation of the surge arrester. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0021] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of a power transmission line according to some embodiments; Figure 2 This is a schematic diagram of the structure of a monitoring system for a surge arrester assembly according to some embodiments; Figure 3 This is a flowchart of a monitoring method for a surge arrester assembly according to some embodiments. Detailed Implementation

[0023] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0024] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0025] The use of “applies to” in this document implies open and inclusive language, which does not exclude applicability to devices performing additional tasks or steps. The use of “configured to” implies open and inclusive language, which does not exclude devices configured to perform additional tasks or steps. In describing some embodiments, the term “coupled” and its derivative expressions may be used. For example, the term “coupled” may be used in describing some embodiments to indicate that two or more components have direct physical or electrical contact. However, the term “coupled” may also refer to two or more components that do not have direct contact with each other but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the content of this document.

[0026] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular "comprises" and the present participle "comprising," are interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, a particular feature, structure, material, or characteristic may be included in any suitable manner in any one or more embodiments or examples. In describing some embodiments, the term "connected" and its derivative expressions may be used. For example, the term "connected" may be used in describing some embodiments to indicate that two or more components are in direct physical or electrical contact with each other.

[0027] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "multiple" means two or more. "At least one of A, B, and C" has the same meaning as "at least one of A, B, or C," both including the following combinations of A, B, and C: only A, only B, only C, a combination of A and B, a combination of A and C, a combination of B and C, and a combination of A, B, and C. "A and / or B" describes the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural.

[0028] The use of "based on" implies openness and inclusivity, because a process, step, calculation, or other action "based on" one or more conditions or values ​​may in practice be based on additional conditions or values ​​beyond those conditions. In the description of this disclosure, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this disclosure and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0029] Figure 1 This is a schematic diagram of a power transmission line according to some embodiments. Taking a three-phase power transmission line as an example, the power transmission line 200 includes power transmission line 201, power transmission line 202 and power transmission line 203.

[0030] A surge arrester group 300 is coupled to the transmission line 200 to provide overvoltage protection for the transmission line 200. The surge arrester group 300 includes a number of surge arresters equal to the number of phases of the transmission line 200, specifically surge arrester 301, surge arrester 302, and surge arrester 303. Surge arrester 301 is coupled to the transmission line 201 to provide overvoltage protection for the transmission line 201; surge arrester 302 is coupled to the transmission line 202 to provide overvoltage protection for the transmission line 202; and surge arrester 303 is coupled to the transmission line 203 to provide overvoltage protection for the transmission line 203. The surge arresters are, for example, selected from metal oxide surge arresters.

[0031] The monitoring system 100 in the related technology adopts a technical solution of deploying clamp-on ammeters or dedicated sensors at the grounding down conductor for direct measurement to monitor the metal oxide surge arrester. By measuring the total current (Ix) and its resistive component (Ir), and analyzing the growth or harmonic characteristics of Ir, it is possible to determine whether the metal oxide surge arrester is damp or aging.

[0032] However, in some 220kV and above substations (especially some older stations or those with special designs), metal oxide surge arresters usually adopt a "no independent grounding down conductor" structure. That is, the grounding terminals of multiple phases or multiple metal oxide surge arresters are connected to a common grounding busbar and then grounded in a unified manner. This makes it impossible to extract the grounding down conductor current from a single device, rendering the relevant monitoring schemes completely ineffective. Only an annual power outage preventive test or observation of whether the discharge counter operates can be used for post-event judgment.

[0033] In view of this, the present disclosure provides a monitoring system for surge arrester assemblies, such as Figure 2 As shown, Figure 2 This is a schematic diagram of a monitoring system for a surge arrester assembly according to some embodiments. The following is in conjunction with... Figure 1 and Figure 2 The monitoring system provided in the embodiments of this disclosure will be described.

[0034] The monitoring system 100 includes a sensing module 110 and an intelligent analysis and diagnosis module 130.

[0035] The sensing module 110 is configured to output a voltage sensing signal based on the spatial electric field of the surge arrester, and to output a temperature sensing signal based on the temperature of a selected area of ​​the surge arrester. The surge arrester is, for example, any one of surge arrester 301, surge arrester 302, or surge arrester 303.

[0036] In some embodiments, the sensing module 110 includes a non-contact electric field sensing array 111 and a temperature sensing unit 112.

[0037] The non-contact electric field sensing array 111 is configured for changes in the spatial electric field distribution of a non-contact inductive surge arrester, and outputs a voltage sensing signal to characterize the local electric field strength.

[0038] In this embodiment, the non-contact electric field sensing array 111 includes, for example, a first sub-electric field sensing unit, a second sub-electric field sensing unit, and a third sub-electric field sensing unit. The first sub-electric field sensing unit is located near the high-voltage end equalizing ring of the surge arrester, for example, below the equalizing ring, at a distance greater than or equal to 0.5m and less than or equal to 1m from the equalizing ring. The second sub-electric field sensing unit is located near the awning structure of the surge arrester or the middle part of the surge arrester body. The third sub-electric field sensing unit is located near the grounding busbar of the surge arrester but is not electrically connected to the grounding busbar, for example, located 0.3m away from the grounding busbar above the base. The first, second, and third sub-electric field sensing units are selected from broadband (0-1000Hz) electric field sensors.

[0039] The temperature sensing unit 112 is configured to output a temperature sensing signal based on the temperature of a selected area of ​​the surge arrester. The selected area includes any one of the following: the surface of the surge arrester, the connection point between the upper, middle, and lower sections of the surge arrester, or the housing corresponding to the valve plate area of ​​the surge arrester. The temperature sensing unit 112 is selected, for example, from an infrared thermal imager and / or a multi-point temperature measurement unit. The temperature sensing unit 112 is aligned with the surge arrester body, so that its field of view covers at least one surge arrester and its adjacent surge arresters, to obtain a surface temperature distribution map of the surge arrester or the temperature of key points, such as those selected from the connection point between the upper, middle, and lower sections of the surge arrester, or the housing corresponding to the valve plate area of ​​the surge arrester.

[0040] In some feasible embodiments, the sensing module 110 further includes an environmental parameter sensing unit 113, which is configured to collect ambient temperature, ambient humidity, and operating voltage. For example, the environmental parameter sensing unit 113 outputs an environmental parameter sensing signal based on the ambient temperature, ambient humidity, and operating voltage. The operating voltage is provided, for example, by a potential transformer (PT) within the station. The environmental parameter sensing unit 113 can be located in a shaded area near the surge arrester.

[0041] The intelligent analysis and diagnosis module 130 includes a feature extraction unit 131 and a logic control unit 132.

[0042] The feature extraction unit 131 is coupled to the sensing module 110. The feature extraction unit 131 is configured to output an electric field distribution vector based on a voltage sensing signal and output a temperature feature based on a temperature sensing signal.

[0043] In this embodiment, the feature extraction unit 131 is specifically configured to output an electric field distribution vector including the power frequency component amplitude, the third harmonic component amplitude and the relative phase based on the voltage sensing signal, and to output temperature features including the maximum temperature rise, axial temperature gradient and interphase temperature difference based on the temperature sensing signal.

[0044] For example, due to the nonlinearity of the surge arrester varistor, the resistive component of its leakage current, especially harmonics, or its reaction in the spatial electric field, is addressed by a non-contact electric field sensing array 111 comprising an array of multiple sensors, which can be used to construct an electric field distribution vector. ,

[0045] Among them, E 50 E represents the amplitude of the power frequency component. 150 The value represents the amplitude of the third harmonic component, φ represents the phase, and the superscript (n) indicates that the surge arrester group includes n surge arresters. This indicates that the element represents the power frequency component amplitude of the first surge arrester. This indicates that the element is the amplitude of the third harmonic component of the nth surge arrester. Feature extraction unit 131 extracts the maximum temperature rise from the temperature sensing signal. T_max), axial temperature gradient (Grad_T) and interphase temperature difference (T_max), The temperature characteristic T is obtained by using T_phase.

[0046] In some embodiments, the logic control unit 132 is coupled to the feature extraction unit 131. The logic control unit 132 is configured to, when the surge arrester is in normal operating condition, use the electric field distribution vector as the reference electric field vector and the temperature feature as the reference temperature feature to determine the database based on the ambient temperature, ambient humidity, operating voltage, reference electric field vector and reference temperature feature under the current operating condition of the surge arrester.

[0047] For example, the monitoring system 100 establishes an independent file for each surge arrester. During a preset period after the monitoring system 100 is put into operation, or when the surge arrester is under normal operating conditions, the monitoring system 100 monitors the electric field distribution vector and temperature characteristics of the surge arrester under various operating conditions through the sensing module 110. The electric field distribution vector is used as a reference electric field vector, and the temperature characteristics are used as reference temperature characteristics to establish a reference database. The reference database includes the reference electric field vector and reference temperature characteristics of the surge arrester under different ambient temperatures, different ambient humidity levels, and different operating voltages. The preset period is, for example, one month.

[0048] The logic control unit 132 is further configured to output an alarm signal if the ratio of at least one element of the electric field distribution vector of one surge arrester in the surge arrester group 300 to the corresponding element of the electric field distribution vector of the remaining surge arresters in the surge arrester group 300 is greater than or equal to a first voltage threshold; or, the logic control unit 132 is configured to determine a comprehensive deviation index based on the electric field distribution vector, temperature characteristics, a reference electric field vector, and a reference temperature characteristic, and output an alarm signal if the comprehensive temperature deviation index is greater than or equal to a first deviation threshold. The first voltage threshold is, for example, 1.5.

[0049] In some feasible embodiments, the logic control unit 132 is also configured to determine a reference electric field vector and a reference temperature characteristic based on ambient temperature, ambient humidity, operating voltage and a reference database.

[0050] The logic control unit 132 includes a monitoring strategy consisting of lateral comparison and longitudinal comparison. The lateral comparison is a phase-to-phase comparison, which calculates the electric field characteristic vectors at corresponding locations of the three surge arresters coupled one-to-one with the three-phase transmission line, particularly E... 150 The difference lies in the E of a certain surge arrester. 150 Significantly higher than the other two surge arresters' E 150 In cases such as when this surge arrester is used in conjunction with two other surge arresters (E...),... 150 If the ratio is greater than 1.5, the surge arrester is considered to be potentially deteriorated, and an alarm signal is output. Alternatively, the temperature characteristics of three surge arresters coupled one-to-one with the three-phase transmission line are calculated. If the maximum temperature rise of a certain surge arrester is significantly higher, for example, greater than or equal to 20°C, the surge arrester is considered to be potentially deteriorated, and an alarm signal is output.

[0051] Longitudinal comparison refers to a time-series comparison, using the real-time monitored electric field distribution vector. The comprehensive deviation index DI is calculated by comparing the electric field vector with the reference electric field vector under the same historical operating conditions. The comprehensive deviation index DI is, for example, the electric field distribution vector. The Euclidean distance or similarity to the reference electric field vector under the same historical operating conditions, for example.

[0052] In the formula, As the reference electric field vector, For the temperature rise in the real-time monitored temperature characteristics, The temperature rise represents the temperature characteristic under historical operating conditions, with α and β being weighting coefficients that can be adjusted according to the actual application scenario. Reference electric field vector. and reference temperature rise Based on ambient temperature, ambient humidity, and operating voltage, the data is obtained from a benchmark database.

[0053] For example, the alarm signal includes a first sub-alarm signal. Specifically, the logic control unit 132 is configured to output the first sub-alarm signal when the ratio of at least one element of the electric field distribution vector of one surge arrester to the corresponding element of the electric field distribution vector of the other surge arresters is greater than or equal to a first voltage threshold; or, when the comprehensive deviation index is greater than or equal to a first deviation threshold. The first sub-alarm signal is, for example, a "caution" level reminder message.

[0054] The alarm signal also includes a second sub-alarm signal. The logic control unit 132 is further configured to output the second sub-alarm signal when the comprehensive deviation index is greater than or equal to a first deviation threshold, and the ratio of at least one element of the electric field distribution vector of one surge arrester to the corresponding element of the electric field distribution vector of the other surge arresters is greater than or equal to a second voltage threshold. The second sub-alarm signal is, for example, an "abnormal" level alert message.

[0055] The alarm signal also includes a third sub-alarm signal. The logic control unit 132 is further configured to output a third sub-alarm signal when the comprehensive deviation index is greater than or equal to a first deviation threshold, and the ratio of at least one element of the electric field distribution vector of one surge arrester to the corresponding element of the electric field distribution vector of the other surge arresters is greater than or equal to a second voltage threshold, and the difference between the temperature characteristics of one surge arrester and the temperature characteristics of the other surge arresters is greater than or equal to a first temperature threshold. The third sub-alarm signal is, for example, a "serious" level alert. The second voltage threshold is, for example, 1.8. For example, the first temperature threshold is selected from 2K-3K, and can be determined according to the actual application scenario, such as 2K, 2.5K, or 3K.

[0056] The alarm signal also includes a fourth sub-alarm signal. The logic control unit 132 is further configured to output the fourth sub-alarm signal when the amplitude of the third harmonic component of a surge arrester steadily increases over time. The fourth sub-alarm signal is used, for example, to indicate slow degradation of the surge arrester's performance for maintenance personnel to refer to.

[0057] In some embodiments, in addition to the preset threshold judgment, machine learning models such as support vector machine (SVM) and neural network can also be used for judgment.

[0058] The monitoring system 100 is also configured to issue audible and visual warnings and remote alarms based on alarm signals, and to output status reports.

[0059] The monitoring system 100 provided in this disclosure converts the grounding wire leakage current, which is difficult to measure directly, into a measurable spatial electric field signal through the principle of spatial electric field coupling. It also employs non-contact electric field sensing technology to effectively perceive the operating status of surge arresters. The sensing module 110 adopts a non-contact installation method, which does not require modification of the existing primary equipment wiring. It has the advantages of safe and convenient construction, and is particularly suitable for the renovation of old substations.

[0060] This disclosure utilizes intelligent algorithms to mine fault information and constructs an online fault monitoring system 100 based on the principle of spatial electric field coupling and the fusion analysis of multiple sensing signals. By continuously monitoring and analyzing weak signals such as harmonic electric field components, the monitoring system 100 can identify the performance degradation trend of the surge arrester before substantial thermal collapse or counter operation occurs, providing early warning time for planned maintenance. Ultimately, it achieves real-time monitoring of the surge arrester's operating status and early fault warning, thereby ensuring the safe and stable operation of the surge arrester.

[0061] The monitoring system 100 combines the electric field characteristics of the surge arrester, the temperature anomaly spectrum of the surge arrester, and multi-dimensional information such as ambient temperature and humidity. Through the dual mechanisms of "horizontal comparison" and "vertical comparison", it effectively overcomes the shortcomings of single signals being susceptible to interference, greatly improves the accuracy and reliability of diagnosis, and reduces the false alarm rate.

[0062] In some feasible embodiments, the monitoring system 100 further includes a signal processing and transmission module 120, which is coupled to the sensing module 110 and the feature extraction unit 131. The signal processing and transmission module 120 is configured to preprocess the voltage sensing signal and / or temperature sensing signal and output the preprocessed voltage sensing signal and / or temperature sensing signal to the feature extraction unit 131.

[0063] For example, preprocessing includes at least one of filtering, amplification, and analog-to-digital conversion. The signal processing and transmission module 120 is capable of bandpass filtering the voltage sensing signal and / or temperature sensing signal to filter out high-frequency interference and DC interference. The signal processing and transmission module 120 is also capable of power frequency phase-locked amplification of the voltage sensing signal and / or temperature sensing signal.

[0064] This disclosure also provides a method for monitoring surge arrester assemblies, such as Figure 3 As shown, Figure 3 This is a flowchart illustrating a monitoring method for a surge arrester group according to some embodiments. The surge arrester group includes multiple surge arresters, and the monitoring method includes steps S10 to S30.

[0065] In step S10, voltage sensing signals and temperature sensing signals are acquired. The voltage sensing signal is used to characterize the spatial electric field of the surge arrester, and the temperature sensing signal is used to characterize the temperature of a selected area of ​​the surge arrester.

[0066] In step S20, the electric field distribution vector is determined based on the voltage sensing signal, and the temperature characteristics are determined based on the temperature sensing signal.

[0067] In step S30, an alarm signal is output if the ratio of at least one element of the electric field distribution vector of one surge arrester to the corresponding element of the electric field distribution vector of the other surge arresters is greater than or equal to a first voltage threshold; or, an alarm signal is output if the comprehensive deviation index is greater than or equal to the first deviation threshold. The comprehensive deviation index is determined based on the electric field distribution vector, temperature characteristics, a reference electric field vector, and reference temperature characteristics.

[0068] This disclosure also provides a processor-readable storage medium storing a program for causing the processor to perform the methods described above.

[0069] The above are merely specific embodiments of this disclosure, enabling those skilled in the art to understand or implement this disclosure. 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 this disclosure. Therefore, this disclosure is not to be limited to these embodiments, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A monitoring system for a surge arrester group, wherein the surge arrester group comprises multiple surge arresters; characterized in that, The monitoring system includes: The sensing module is configured to output a voltage sensing signal based on the spatial electric field of the surge arrester, and to output a temperature sensing signal based on the temperature of a selected area of ​​the surge arrester. The feature extraction unit, coupled to the sensing module, is configured to output an electric field distribution vector based on the voltage sensing signal and output a temperature feature based on the temperature sensing signal. A logic control unit, coupled to the feature extraction unit, is configured to output an alarm signal if the ratio of at least one element of the electric field distribution vector of one surge arrester to the corresponding element of the electric field distribution vector of the other surge arresters is greater than or equal to a first voltage threshold; or, The logic control unit is configured to determine a comprehensive deviation index based on the electric field distribution vector, the temperature characteristics, the reference electric field vector, and the reference temperature characteristics, and to output an alarm signal when the comprehensive deviation index is greater than or equal to a first deviation threshold.

2. The monitoring system according to claim 1, characterized in that, The sensing module includes: The non-contact electric field sensing unit is configured to output a voltage sensing signal to characterize the local electric field intensity based on the spatial electric field distribution of the surge arrester. The temperature sensing unit is configured to output a temperature sensing signal based on the temperature of a selected area of ​​the surge arrester; wherein... The selected area includes any one of the following: the surface of the surge arrester, the connection between the upper, middle, and lower sections of the surge arrester, or the outer casing corresponding to the valve plate area of ​​the surge arrester.

3. The monitoring system according to claim 2, characterized in that, The non-contact electric field sensing unit includes: The first sub-electric field sensing unit is located near the high-voltage end equalizing ring of the surge arrester; The second sub-electric field sensing unit is located near the umbrella skirt structure of the surge arrester; The third sub-electric field sensing unit is located near the grounding busbar of the surge arrester.

4. The monitoring system according to claim 2, characterized in that, It also includes an environmental parameter sensing unit, which is configured to collect ambient temperature, ambient humidity and operating voltage; The logic control unit is further configured to, when the surge arrester is in normal operating condition, use the electric field distribution vector as a reference electric field vector and the temperature feature as a reference temperature feature, and determine a reference database based on the ambient temperature, ambient humidity, operating voltage, reference electric field vector and reference temperature feature under the current operating condition of the surge arrester.

5. The monitoring system according to claim 4, characterized in that, The logic control unit is further configured to determine the reference electric field vector and the reference temperature characteristics based on the ambient temperature, the ambient humidity, the operating voltage, and the reference database.

6. The monitoring system according to claim 1, characterized in that, The feature extraction unit is specifically configured to output an electric field distribution vector including the power frequency component amplitude, the third harmonic component amplitude, and the relative phase based on the voltage sensing signal, and to output temperature features including the maximum temperature rise, axial temperature gradient, and interphase temperature difference based on the temperature sensing signal.

7. The monitoring system according to any one of claims 1-6, characterized in that, The logic control unit is specifically configured as follows: If at least one element of the electric field distribution vector of one surge arrester is greater than or equal to the ratio of the corresponding element of the electric field distribution vector of the remaining surge arresters to a first voltage threshold, a first sub-alarm signal is output; or, If the comprehensive deviation index is greater than or equal to the first deviation threshold, a first sub-alarm signal is output.

8. The monitoring system according to any one of claims 1-6, characterized in that, The logic control unit is further configured to output a second sub-alarm signal when the comprehensive deviation index is greater than or equal to a first deviation threshold and the ratio of at least one element of the electric field distribution vector of one of the surge arresters to the corresponding element of the electric field distribution vector of the remaining surge arresters is greater than or equal to a second voltage threshold.

9. The monitoring system according to claim 8, characterized in that, The logic control unit is further configured to output a third sub-alarm signal if the difference between the temperature characteristic of one of the surge arresters and the temperature characteristics of the other surge arresters is greater than or equal to a first temperature threshold.

10. The monitoring system according to any one of claims 1-6, characterized in that, Also includes: A signal processing and transmission module, coupled to the sensing module and the feature extraction unit, is configured to preprocess the voltage sensing signal and / or the temperature sensing signal, and output the preprocessed voltage sensing signal and / or temperature sensing signal to the feature extraction unit; wherein... The preprocessing includes at least one of filtering, amplification, and analog-to-digital conversion.

11. A monitoring method for a surge arrester group, wherein the surge arrester group comprises multiple surge arresters, characterized in that, The monitoring method includes: Acquire voltage sensing signals and temperature sensing signals; the voltage sensing signals are used to characterize the spatial electric field of the surge arrester, and the temperature sensing signals are used to characterize the temperature of a selected area of ​​the surge arrester. The electric field distribution vector is determined based on the voltage sensing signal, and the temperature characteristics are determined based on the temperature sensing signal. An alarm signal is output if at least one element of the electric field distribution vector of one surge arrester is greater than or equal to the ratio of the corresponding element of the electric field distribution vector of the remaining surge arresters; or, An alarm signal is output when the comprehensive deviation index is greater than or equal to the first deviation threshold; the comprehensive deviation index is determined based on the electric field distribution vector, the temperature characteristics, the reference electric field vector, and the reference temperature characteristics.

12. A processor-readable storage medium, characterized in that, The processor-readable storage medium stores a program for causing the processor to perform the method as described in claim 11.

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