A lightning stroke type identification method, device and online monitoring system

Abstract

This application discloses a method, device, and online monitoring system for lightning strike type identification, relating to the field of power grid lightning protection safety technology. The solution provided in this application directly acquires the impulse discharge current on a 10kV surge arrester and performs waveform time-domain feature analysis. This analysis is then matched with a preset waveform time-domain feature threshold range to determine the lightning strike type. This avoids the complex reflection and cumbersome preprocessing procedures of traditional traveling wave data processing, simplifying the lightning strike type identification process, improving identification efficiency, and facilitating timely and targeted lightning protection measures to ensure the safe and stable operation of the power grid system.

Description

Technical Field

[0001] This application relates to the field of power grid lightning protection safety technology, and in particular to a lightning strike type identification method, device and online monitoring system. Background Technology

[0002] With the large-scale integration of adjustable loads such as distributed photovoltaic power generation, residential energy storage, and charging piles, low-voltage distribution transformer areas are exhibiting new characteristics of bidirectional power flow between source and load, and the coexistence of fluctuations at multiple time scales. The intermittent and random nature of photovoltaic output, the concentration of charging load, and the bidirectional power characteristics of energy storage lead to frequent multi-dimensional coupling problems in transformer operation, such as light and heavy overloads, three-phase imbalance, voltage fluctuations, and harmonic distortion.

[0003] 10kV surge arresters are commonly used lightning protection devices in power distribution networks. In 10kV overhead lines with ground wires, surge arresters are generally installed on the terminal tower where the overhead line and cable intersect, or on poles with transformers or switches, to provide lightning protection for critical equipment. In 10kV overhead lines with ground wires, three main types of lightning strikes are considered: backflashover, backflashover, and induced lightning. When a lightning strike occurs, it is necessary to quickly identify these types of strikes in order to take more targeted lightning protection measures.

[0004] However, current online monitoring of 10kV surge arresters mainly focuses on monitoring the leakage current of the arresters. The identification of the type of lightning strike after a lightning strike is mainly achieved by measuring the impulse traveling wave current on the line. Since the traveling wave data after a lightning strike monitored by the traveling wave device has complex reflections, the traveling wave front needs to be calibrated first to extract the corresponding multi-dimensional data features before it can be used for lightning strike type identification. In practical application scenarios, the cumbersome preprocessing process will limit the efficiency of lightning strike type identification, thereby delaying the response time of lightning protection measures and seriously affecting the safety and stability of the power grid system. Summary of the Invention

[0005] This application provides a method, device, and online monitoring system for identifying lightning strike types, aiming to achieve rapid and accurate identification of lightning strike types and improve the response speed of lightning protection measures.

[0006] To achieve the aforementioned objectives, the first aspect of this application provides a method for identifying lightning strike types, comprising:

[0007] The impulse discharge current is acquired, wherein the impulse discharge current is acquired by an impulse discharge current acquisition device mounted on a 10kV surge arrester;

[0008] Based on the impulse discharge current, waveform time-domain feature analysis is performed, and the actual waveform time-domain features of the impulse discharge current are extracted;

[0009] Based on the actual waveform time-domain characteristics and combined with a preset waveform time-domain characteristic threshold range, the lightning strike type identification result of the impulse discharge current is determined according to the matching result between the actual waveform time-domain characteristics and the waveform time-domain characteristic threshold range. The waveform time-domain characteristic threshold range is obtained by statistically analyzing the waveform time-domain characteristics extracted from discharge current samples of different lightning strike types.

[0010] Preferably, the actual waveform time-domain characteristics include: wavefront time and half-peak time.

[0011] Preferably, determining the lightning strike type identification result of the impulse discharge current based on the matching result between the actual waveform time-domain characteristics and the waveform time-domain characteristic threshold range includes:

[0012] Based on the waveform time-domain feature threshold intervals obtained by statistically analyzing the waveform time-domain features extracted from discharge current samples of different lightning strike types, the actual waveform time-domain features are matched with the waveform time-domain feature threshold intervals corresponding to different lightning strike types, so as to determine the lightning strike type identification result of the impulse discharge current according to the matching results.

[0013] Preferably, the method for determining the waveform time-domain feature threshold interval includes:

[0014] Based on the topology and parameter standards of a typical 10kV overhead line with a ground wire, a 10kV overhead line model is constructed using electromagnetic transient simulation tools.

[0015] Based on the 10kV overhead line model, a double exponential function was used as the lightning current simulation function to perform electromagnetic transient simulation of lightning currents of different lightning strike types, and the waveform parameters of impulse discharge currents of different lightning strike types were recorded.

[0016] Based on the waveform parameters of the impulse discharge current, waveform time-domain feature analysis is performed to obtain the waveform time-domain features corresponding to different lightning strike types. Then, the waveform time-domain features are classified and statistically analyzed according to the lightning strike type to obtain the waveform time-domain feature threshold ranges corresponding to different lightning strike types.

[0017] Preferably, the method for determining the waveform time-domain feature threshold interval includes:

[0018] Based on the historical impulse discharge current data recorded in the historical lightning strike event database, waveform time-domain feature analysis is performed on the historical impulse discharge current data to obtain the waveform time-domain features corresponding to different historical impulse discharge current data.

[0019] Based on the lightning strike type identifiers corresponding to each historical impulse discharge current data, the waveform time-domain features are classified and statistically analyzed to obtain the waveform time-domain feature threshold ranges corresponding to different lightning strike types.

[0020] A second aspect of this application provides a lightning strike type identification device, comprising:

[0021] The impulse current acquisition unit is used to acquire the collected impulse discharge current, wherein the impulse discharge current is acquired by an impulse discharge current acquisition device installed on a 10kV surge arrester.

[0022] The feature extraction unit is used to perform waveform time-domain feature analysis based on the impulse discharge current and extract the actual waveform time-domain features of the impulse discharge current.

[0023] The lightning strike type identification unit is used to determine the lightning strike type identification result of the impulse discharge current based on the actual waveform time-domain characteristics and a preset waveform time-domain characteristic threshold range, according to the matching result of the actual waveform time-domain characteristics and the waveform time-domain characteristic threshold range. The waveform time-domain characteristic threshold range is obtained by statistically analyzing the waveform time-domain characteristics extracted from discharge current samples of different lightning strike types.

[0024] A third aspect of this application provides an online monitoring system for lightning strike types, comprising: an impulse discharge current acquisition device and a remote host;

[0025] The impulse discharge current acquisition device includes a sensor and a current processing circuit. The current processing circuit is fixed on the arrester support, and the sensor is in contact with the arrester body to acquire the impulse discharge current on the arrester body and transmit the impulse discharge current to the current processing circuit for preprocessing via a signal cable.

[0026] The current processing circuit includes a communication circuit for transmitting the pre-processed impulse discharge current data to the remote host.

[0027] The remote host includes: a memory and a processor;

[0028] The memory is used to store program code, which corresponds to the lightning strike type identification method provided in the first aspect of this application.

[0029] The processor is used to read and execute the program code to implement the lightning strike type identification method.

[0030] Preferably, the current processing circuit includes: a protection circuit, an attenuation amplification circuit, a data buffer module, a processor module, and a communication circuit;

[0031] The input terminal of the protection circuit is connected to the output terminal of the sensor, and the output terminal of the protection circuit is connected to the data buffer module through the attenuation amplification circuit. The attenuation amplification circuit is configured to trigger signal conditioning when the impulse discharge current is less than a preset overcurrent limit threshold.

[0032] The processor module is communicatively connected to the data cache module and the communication circuit, respectively, and is used to control the operation of the data cache module and the communication circuit.

[0033] Preferably, the data caching module includes: an analog-to-digital conversion circuit, a cache clock circuit, a cache trigger circuit, and a cache body circuit;

[0034] The buffer circuit is connected to the output of the attenuation amplifier circuit via the analog-to-digital converter circuit.

[0035] The cache trigger circuit is configured to control the cache body circuit to perform a write operation when the amplitude of the impulse discharge current is detected to be greater than the preset cache trigger threshold.

[0036] Preferably, the sensor is a Rogowski coil.

[0037] As can be seen from the above technical solutions, this application has the following advantages:

[0038] The solution provided in this application directly obtains the impulse discharge current on a 10kV surge arrester and performs waveform time-domain feature analysis on it. By matching it with a preset waveform time-domain feature threshold range, the type of lightning strike can be determined. This avoids the complex reflection and cumbersome preprocessing procedures in traditional traveling wave data processing, simplifies the lightning strike type identification process, improves identification efficiency, and helps to take timely and targeted lightning protection measures to ensure the safe and stable operation of the power grid system. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a flowchart illustrating an embodiment of a lightning strike type identification method provided in this application.

[0041] Figure 2 This is a flowchart illustrating an embodiment of a lightning strike type identification device provided in this application.

[0042] Figure 3 A schematic diagram of the impulse discharge current acquisition device in an online monitoring system for lightning strike types provided in this application.

[0043] Figure 4 The circuit module logic block diagram of an online monitoring system for lightning strike types provided in this application. Detailed Implementation

[0044] This application provides a lightning strike type identification method, device, and online monitoring system to achieve the invention objective of quickly and accurately identifying lightning strike types and improving the response speed of lightning protection measures.

[0045] To make the inventive objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0046] First, a detailed description of an embodiment of a lightning strike type identification method provided in this application is as follows:

[0047] Please see Figure 1 This application provides an embodiment of a lightning strike type identification method, the steps of which include:

[0048] Step 101: Obtain the collected impulse discharge current;

[0049] The impulse discharge current was acquired by an impulse discharge current acquisition device installed on a 10kV surge arrester.

[0050] Step 102: Perform waveform time-domain feature analysis based on the impulse discharge current, and extract the actual waveform time-domain features of the impulse discharge current;

[0051] Step 103: Based on the actual waveform time-domain characteristics and combined with the preset waveform time-domain characteristic threshold range, determine the lightning strike type identification result of the impulse discharge current according to the matching result of the actual waveform time-domain characteristics and the waveform time-domain characteristic threshold range.

[0052] It should be noted that, for ease of understanding, some key terms in this embodiment are explained below:

[0053] Impulse discharge current refers to the transient large current discharged through a 10kV surge arrester during a lightning strike. The waveform of this current contains characteristic information about the lightning strike event.

[0054] Waveform time-domain feature analysis refers to the processing and analysis of the waveform of the impulse discharge current in the time domain in order to extract its key parameters and morphological features.

[0055] Actual waveform time-domain characteristics refer to the specific time-domain parameters extracted from the actual collected impulse discharge current through waveform time-domain characteristic analysis, which are used to characterize the current waveform characteristics of the lightning strike event.

[0056] The waveform time-domain characteristic threshold range refers to a pre-established numerical range of waveform time-domain characteristics used to distinguish different types of lightning strikes. This range is obtained based on statistical analysis of a large number of discharge current samples of different lightning strike types.

[0057] The lightning strike type identification result refers to the specific lightning strike type determined based on the matching of the actual waveform time domain characteristics with the preset threshold range, such as lightning strike, backflash, or induced lightning.

[0058] This application provides a method for identifying lightning strike types. The method first acquires the collected impulse discharge current. Specifically, the impulse discharge current can be acquired using an impulse discharge current acquisition device mounted on a 10kV surge arrester. For example, a general-purpose current sensor, such as a shunt, can be directly connected to the surge arrester's discharge circuit to measure the transient current flowing through the arrester, and the analog signal is converted into a digital signal and recorded via a data acquisition card. Alternatively, a simple current transformer or oscilloscope probe can be used to perform inductive or direct measurements near the surge arrester, and the waveform data can be manually recorded or stored.

[0059] Subsequently, waveform time-domain feature analysis is performed based on the impulse discharge current, and the actual waveform time-domain features of the impulse discharge current are extracted. For example, the collected impulse discharge current data can be preliminarily processed, such as filtering and noise reduction, and then the waveform can be visually analyzed to estimate the waveform's rise time, fall time, peak value, and other time-domain features. As another approach, general signal processing software, such as the signal processing library in MATLAB or Python, can be used to programmatically process the digitized current data. By setting fixed current amplitude thresholds or time points, the starting point, peak point, and half-peak point of the waveform can be identified, and the time-domain parameters corresponding to the impulse discharge current can be calculated.

[0060] Furthermore, based on the actual waveform time-domain characteristics and a preset waveform time-domain characteristic threshold range, the lightning strike type identification result of the impulse discharge current is determined according to the matching result between the actual waveform time-domain characteristics and the waveform time-domain characteristic threshold range. The waveform time-domain characteristic threshold range is statistically obtained based on waveform time-domain characteristics extracted from discharge current samples of different lightning strike types. Specifically, the extracted actual waveform time-domain characteristics can be compared with a preset single fixed threshold. For example, if the value of the actual waveform time-domain characteristic falls within a certain specific range, it is determined to be the first type of lightning strike; if it falls within another specific range, it is determined to be the second type of lightning strike. Alternatively, a pre-established threshold table can be manually consulted, and the actual characteristic value can be compared with the waveform time-domain characteristic range corresponding to different lightning strike types in the table to determine the lightning strike type of this impulse discharge current. The determination of the waveform time-domain characteristic threshold range can be based on expert experience or a small amount of historical experimental data, directly setting the numerical range of waveform time-domain characteristics corresponding to different lightning strike types.

[0061] This application determines the lightning strike type by directly acquiring the impulse discharge current on a 10kV surge arrester, performing waveform time-domain feature analysis, and matching it with a preset waveform time-domain feature threshold range. This method avoids the complex reflection and cumbersome preprocessing procedures in traditional traveling wave data processing, simplifies the lightning strike type identification process, improves identification efficiency, and helps to take timely and targeted lightning protection measures to ensure the safe and stable operation of the power grid system.

[0062] Based on the above embodiments, this application further proposes that the actual waveform time-domain characteristics include wavefront time and half-peak time.

[0063] Wavefront time refers to the time required for the impulse current waveform to rise from its initial point to its peak value. It is a key parameter for measuring the steepness of the impulse current's rise and is of significant physical importance in distinguishing different types of lightning strikes, especially direct and induced lightning. In practical calculations, wavefront time can be defined as the time interval between the moment the waveform rises to 10% of its peak value and the moment it rises to 90% of its peak value, multiplied by a correction factor, or directly as the time from the waveform's initial point to its peak value. Half-peak time refers to the time required for the impulse current waveform to rise from its initial point to its peak value and then fall back to half its peak value. It reflects the duration of the impulse current and is another important indicator for distinguishing lightning strike types (especially long-wave and short-wave lightning strikes), as different types of lightning strikes have different energy release durations. In practical calculations, half-peak time can be defined as the time interval between the waveform's initial point and the moment the waveform falls back to half its peak value.

[0064] The above technical solution explicitly uses wavefront time and half-peak time as the actual waveform time-domain features, giving the feature extraction process clear quantitative standards and physical meaning. Wavefront time effectively characterizes the rise steepness of the lightning current, while half-peak time reflects the duration of the lightning current. These two features are the most representative and discriminative parameters in the lightning impulse current waveform, effectively capturing the core differences between different lightning strike types. By focusing on these key features, the efficiency and accuracy of feature extraction can be improved, thus providing more reliable and discriminative input for subsequent lightning strike type identification. This explicit feature selection helps simplify the design of the identification algorithm, reduce computational complexity, and significantly improve the robustness and practicality of the entire lightning strike type identification method.

[0065] Based on this, this application further proposes that, in the above-mentioned lightning strike type identification method, the lightning strike type identification result of the impulse discharge current is determined according to the matching result of the actual waveform time-domain features and the waveform time-domain feature threshold interval. This includes: matching the actual waveform time-domain features with the waveform time-domain feature threshold intervals corresponding to different lightning strike types according to the waveform time-domain features extracted from discharge current samples of different lightning strike types, so as to determine the lightning strike type identification result of the impulse discharge current based on the matching result.

[0066] Specifically, the waveform time-domain feature threshold intervals are not singular or generalized, but rather established separately for each preset lightning strike type (e.g., direct lightning strike, induced lightning strike, long-distance lightning strike, etc.). These intervals are obtained by performing waveform time-domain feature analysis on a large number of discharge current samples of known lightning strike types and then statistically processing these features. Each interval represents the typical distribution range of a specific lightning strike type in terms of time-domain features such as wavefront time and half-peak time, providing a typified reference benchmark for subsequent accurate matching. After obtaining the actual waveform time-domain features (e.g., wavefront time and half-peak time) of the impulse discharge current to be identified, the system compares them one by one with the pre-established waveform time-domain feature threshold intervals for each lightning strike type (e.g., direct lightning strike, induced lightning strike, etc.). This comparison can determine whether the actual feature falls within a threshold interval of a specific type, or it can calculate the distance or similarity between the actual feature and the center value of each threshold interval. Through this "one-to-many" comparison method, the degree of conformity between the actual feature and various known lightning strike types can be comprehensively evaluated. After matching the actual waveform's time-domain characteristics with threshold intervals for all lightning strike types, the system makes a final lightning strike type identification based on the specific matching conditions. For example, if the actual feature falls within only one specific lightning strike type's threshold interval, it is directly identified as that type; if the actual feature falls within multiple lightning strike type threshold intervals simultaneously, a decision can be made using preset priority rules, the nearest distance principle, or weighted voting strategies; if the actual feature does not fall within any preset threshold interval, it may be identified as an unknown type or an abnormal event. This decision-making mechanism based on multi-type matching ensures the accuracy and robustness of the identification results.

[0067] For example, based on the pre-calculated waveform ranges of the surge arrester discharge current wavefront time and half-peak time under different lightning strike types, a lightning strike type identification method is proposed. In this example, the statistically determined waveform ranges are shown in Table 1 below:

[0068] Table 1. Waveform range of surge arrester impulse discharge current under different lightning strike types

[0069]

[0070] Comparative analysis shows that the half-peak times differ significantly among the three types of lightning strikes. Therefore, half-peak time can be used as a primary parameter with higher weight. The half-peak time of backlash lightning is the smallest, and that of induced lightning is the largest. Thus, a method for identifying lightning strike types can be proposed: half-peak time less than 2μs indicates backlash lightning, greater than 25μs indicates induced lightning, and other cases indicate circumferential lightning.

[0071] Lightning strike type identification is achieved by matching the actual waveform time-domain features obtained with the waveform time-domain feature threshold ranges corresponding to different lightning strike types. If the measured half-peak time uploaded to the host is less than 2μs, it is a backflash; if it is greater than 25μs, it is an induced lightning strike; otherwise, it is a circumferential strike.

[0072] Through the above technical solution, this application can effectively solve the problems of ambiguity and inaccuracy that may exist in the identification of multiple lightning strike types using single or generalized threshold matching. By systematically matching the actual waveform time-domain characteristics with the corresponding waveform time-domain characteristic threshold intervals for different lightning strike types one by one, the degree of conformity between the characteristics of the impulse discharge current and various lightning strike events can be evaluated more precisely. This multi-dimensional and typified matching mechanism enables the system to more accurately distinguish between different lightning strike types such as direct lightning strikes and induced lightning strikes, thereby significantly improving the accuracy and reliability of lightning strike type identification and providing more accurate data support for subsequent fault analysis and equipment maintenance.

[0073] In some of the above embodiments, the lightning strike type identification method relies on preset waveform time-domain feature threshold intervals to determine the lightning strike type based on the matching results between the actual waveform time-domain features and the threshold intervals. However, how to accurately and systematically acquire and establish these representative waveform time-domain feature threshold intervals to ensure the reliability and universality of the identification results is a key problem that needs to be solved. Especially in the absence of a large amount of real lightning strike sample data, traditional methods based on historical data statistics may have limitations.

[0074] To address this, this application further proposes a method for determining the waveform time-domain feature threshold interval, which specifically includes: constructing a 10kV overhead line model using an electromagnetic transient simulation tool based on the topology and parameter standards of a typical 10kV overhead line with a ground wire; performing electromagnetic transient simulations on lightning currents of different lightning strike types using a double exponential function as the lightning current simulation function, and recording the impulse discharge current waveform parameters of different lightning strike types; performing waveform time-domain feature analysis based on the impulse discharge current waveform parameters to obtain the waveform time-domain features corresponding to different lightning strike types, and then classifying and statistically analyzing the waveform time-domain features according to the lightning strike type to obtain the waveform time-domain feature threshold intervals corresponding to different lightning strike types.

[0075] Specifically, when constructing a 10kV overhead line model, national or industry standards, such as DL / T 5092-2000 "Design Code for 10kV and Below Distribution Lines," can be referenced to obtain typical structural and electrical parameters of the 10kV overhead line, including single-circuit, double-circuit, tower type, conductor type, ground wire configuration, conductor resistance, inductance, capacitance, tower grounding resistance, and insulator flashover characteristics. Subsequently, a professional electromagnetic transient simulation tool, such as EMTP-RV, ATP-EMTP, or PSCAD / EMTDC, is selected, and the aforementioned geometric and electrical parameters are input to establish a 10kV overhead line model that can accurately simulate the real power system environment. This model should include key protective equipment such as surge arresters to simulate their discharge behavior.

[0076] Building upon this, a double exponential function can be used as the lightning current simulation function to simulate different lightning strike events. The double exponential function can simulate lightning currents of varying intensities, steepness, and durations by adjusting parameters such as peak value, wavefront time, and wave tail time, thus representing different lightning strike types, such as direct lightning strikes, induced lightning strikes, strong lightning strikes, weak lightning strikes, or long-wave lightning strikes. In the simulation tool, these lightning currents generated by the double exponential function are injected into specific locations on the 10kV overhead line model, such as the top of the tower or the conductor, to simulate the lightning strike process. During the simulation, the impulse discharge current waveform data at the surge arrester is monitored and recorded in real time, including key parameters such as the instantaneous value, peak value, wavefront time, and half-peak time of the current.

[0077] Subsequently, time-domain feature analysis was performed on the recorded impulse discharge current waveform parameters. According to the method described above, these features specifically include wavefront time and half-peak time. Wavefront time refers to the time it takes for the current to rise from zero to its peak value, and half-peak time refers to the time it takes for the current to fall from its peak value to half its peak value. For each simulated lightning strike type, a series of corresponding impulse discharge current waveforms were obtained, and the corresponding wavefront time and half-peak time were extracted. Next, the extracted time-domain features, such as wavefront time and half-peak time, were grouped according to their corresponding lightning strike type. Within each group, statistical analysis was performed on these features, such as calculating the mean, standard deviation, maximum value, minimum value, and percentiles. Finally, based on the statistical results, threshold intervals for one or more waveform time-domain features were determined for each lightning strike type. For example, these intervals could be defined as the range of the mean plus or minus a certain standard deviation, or the minimum and maximum values ​​obtained statistically could be used directly as interval boundaries. These intervals will serve as the basis for subsequent identification of actual lightning strike types.

[0078] Through the above technical solution, this application provides a systematic and reliable method for determining the threshold interval of waveform time-domain features. Given the randomness of actual lightning strikes and the difficulty in obtaining a large number of real samples, this method utilizes electromagnetic transient simulation tools to simulate the impact of different lightning strike types on 10kV overhead lines under controlled conditions, thereby generating abundant impulse discharge current waveform data. This ensures that the obtained waveform time-domain feature threshold interval can fully cover various typical and extreme lightning strike situations, significantly improving the representativeness and accuracy of the threshold interval, and thus enhancing the reliability and universality of subsequent lightning strike type identification results. Furthermore, this method avoids dependence on a large amount of historical lightning strike event data, reducing the difficulty and cost of data acquisition, and providing a solid data foundation for lightning strike type identification.

[0079] In addition to obtaining impulse discharge current samples through the above-mentioned simulation method, this application also proposes a method for determining the waveform time-domain feature threshold range, including: based on historical impulse discharge current data recorded in the historical lightning event database, performing waveform time-domain feature analysis on the historical impulse discharge current data to obtain the waveform time-domain features corresponding to different historical impulse discharge current data; classifying and statistically analyzing the waveform time-domain features according to the lightning strike type identifier corresponding to each historical impulse discharge current data to obtain the waveform time-domain feature threshold range corresponding to different lightning strike types.

[0080] Specifically, "historical impulse discharge current data based on historical lightning strike event databases" refers to using a database that stores information related to past lightning strikes. This database typically includes the time and location of the lightning strikes, the impulse discharge current waveform data actually collected by an impulse discharge current acquisition device, and the pre-identified or labeled lightning strike type (e.g., positive polarity lightning, negative polarity lightning, multiple lightning strikes, etc.). This historical data is an objective reflection of real-world lightning strike events, providing valuable experimental evidence for subsequent characteristic analysis.

[0081] After obtaining historical impulse discharge current data, it is necessary to "perform waveform time-domain feature analysis on the historical impulse discharge current data to obtain the waveform time-domain features corresponding to different historical impulse discharge current data." This step involves extracting the waveform time-domain features for each historical impulse discharge current data obtained from the historical lightning strike event database. This analysis process is similar to the feature extraction process for actual impulse discharge currents; for example, time-domain features such as wavefront time and half-peak time can be extracted. Through the analysis of a large amount of historical data, the specific time-domain feature values ​​corresponding to each historical impulse discharge current waveform can be obtained.

[0082] Subsequently, the process of "classifying and statistically analyzing the waveform time-domain characteristics according to the lightning strike type identifiers corresponding to each historical impulse discharge current data" is performed. After obtaining the waveform time-domain characteristics of each historical impulse discharge current data, these waveform time-domain characteristics are grouped according to the existing lightning strike type identifiers in the historical lightning event database. For example, the waveform time-domain characteristics of all impulse discharge currents identified as "positive polarity lightning" are grouped into one category, and those of "negative polarity lightning" are grouped into another category. For each lightning strike type group, statistical analysis is performed, such as calculating the average, standard deviation, maximum, and minimum values ​​of all waveform time-domain characteristics under that type.

[0083] Based on the above classification and statistical results, a waveform time-domain characteristic threshold interval is defined for each lightning strike type, ultimately yielding the waveform time-domain characteristic threshold intervals corresponding to different lightning strike types. For example, an interval can be determined based on the minimum and maximum values ​​obtained statistically, or a confidence interval can be defined based on the mean and standard deviation (e.g., the mean plus or minus three times the standard deviation). These threshold intervals will serve as reference standards for subsequent identification of actual impulse discharge current lightning strike types.

[0084] By utilizing the aforementioned technical solution and the accumulated real impulse discharge current data and corresponding lightning strike type identifiers from a historical lightning strike event database, threshold ranges for waveform time-domain characteristics of different lightning strike types can be objectively and accurately established in a data-driven manner. This threshold determination method, based on actual operational experience and historical data, avoids the biases that may arise from relying solely on theoretical calculations or simulation models, making the obtained threshold ranges more representative and reliable. When the waveform time-domain characteristics of actual impulse discharge currents are matched with these threshold ranges verified by historical data, the accuracy and robustness of lightning strike type identification can be significantly improved, thus providing more solid data support for the operation and maintenance of 10kV surge arresters and the optimization of lightning protection strategies.

[0085] The above is a detailed description of an embodiment of a lightning strike type identification method provided by this application. The following is a detailed description of an embodiment of a lightning strike type identification device provided by this application.

[0086] Please see Figure 2 This application provides an embodiment of a lightning strike type identification device, comprising:

[0087] The impulse current acquisition unit 201 is used to acquire the collected impulse discharge current, wherein the impulse discharge current is acquired by the impulse discharge current acquisition device installed on the 10kV surge arrester.

[0088] The feature extraction unit 202 is used to perform waveform time-domain feature analysis based on the impulse discharge current and extract the actual waveform time-domain features of the impulse discharge current.

[0089] The lightning strike type identification unit 203 is used to determine the lightning strike type identification result of the impulse discharge current based on the actual waveform time domain characteristics and the preset waveform time domain characteristic threshold range, according to the matching result of the actual waveform time domain characteristics and the waveform time domain characteristic threshold range. The waveform time domain characteristic threshold range is obtained by statistically analyzing the waveform time domain characteristics extracted from discharge current samples of different lightning strike types.

[0090] This solution directly mounts the impulse discharge current acquisition device onto a 10kV surge arrester and performs waveform time-domain feature analysis on the acquired impulse discharge current. Matching this analysis with a preset waveform time-domain feature threshold range avoids the complex reflection and wavefront calibration processes inherent in traditional traveling wave data processing, thus simplifying the lightning strike type identification process and improving identification efficiency. Specifically, the impulse current acquisition unit consists of a data acquisition card and a signal conditioning circuit, used to receive analog signals from the impulse discharge current acquisition device and convert them into digital signals. The feature extraction unit executes signal processing algorithms through a processor to filter and denoise the digitized current data and calculate key time-domain parameters such as wavefront time and half-peak time. The lightning strike type identification unit compares the actually extracted time-domain features with the pre-stored waveform time-domain feature threshold range, outputting the identification result for lightning strikes, backflashovers, or induced lightning.

[0091] In practical applications, the signal conditioning circuit of the impulse current acquisition unit can use a high-precision operational amplifier to achieve signal attenuation and amplification, ensuring that the impulse discharge current is accurately captured within the measurement range. The signal processing algorithm of the feature extraction unit can be integrated into an embedded processor, automatically identifying the waveform start point and peak point by setting dynamic thresholds, avoiding manual intervention. The threshold range database of the lightning strike type identification unit can be updated periodically to adapt to changes in lightning strike characteristics under different line topologies. Through the above technical solutions, this application directly utilizes the impulse discharge current on the surge arrester body for lightning strike type identification, without relying on the complex preprocessing of line traveling wave data, significantly shortening the identification time, improving the response speed of lightning protection measures, and effectively ensuring the safe and stable operation of the power grid system.

[0092] The above is a detailed description of an embodiment of a lightning strike type identification device provided in this application. The following is a detailed description of an embodiment of an online lightning strike type monitoring system provided in this application.

[0093] like Figure 3 and Figure 4As shown in the figure, this application provides an online monitoring system for lightning strike types. The system includes: an impulse discharge current acquisition device A and a remote host B. The impulse discharge current acquisition device includes a sensor A1 and a current processing circuit A2. The current processing circuit is fixed to the surge arrester support, and the sensor is in contact with the surge arrester body to acquire the impulse discharge current on the surge arrester body. The impulse discharge current is then transmitted to the current processing circuit for preprocessing via a signal cable. A specific installation example can be found in [reference needed]. Figure 3 The current processing circuit includes a communication circuit for transmitting the pre-processed impulse discharge current data to the remote host. The remote host includes a memory and a processor. The memory stores program code corresponding to the aforementioned lightning strike type identification method, and the processor reads and executes the program code to implement the lightning strike type identification method.

[0094] By directly integrating the impulse discharge current acquisition device into the surge arrester body, the impulse discharge current waveform is acquired in real time. Combined with remote host execution of identification logic based on waveform time-domain characteristics, this avoids the wavefront calibration problem caused by reflection and refraction in traditional traveling wave data processing. Specifically, since the impulse discharge current directly characterizes the transient lightning strike characteristics of the surge arrester, its waveform time-domain characteristics (such as wavefront time and half-peak time) can directly map the lightning strike type without needing to handle the complex interference of traveling waves in multi-path propagation. Based on this, after preprocessing the raw signal through a current processing circuit, the system uses a preset waveform time-domain characteristic threshold range for matching analysis by the remote host, achieving rapid determination of the lightning strike type. This design not only eliminates the multi-dimensional feature extraction step of traveling wave data but also ensures the real-time performance and accuracy of the identification process.

[0095] Through the above technical solution, the system can efficiently identify the type of lightning strike and promptly trigger targeted lightning protection measures. Compared with traditional solutions that rely on traveling wave data, this embodiment significantly shortens the data processing link, improves response speed, and effectively solves the timeliness problem caused by cumbersome preprocessing procedures, thereby providing a reliable guarantee for the safe and stable operation of the power grid system.

[0096] In online lightning strike type monitoring systems, the current processing circuit in the impulse discharge current acquisition device needs to preprocess the acquired impulse discharge current. However, the impulse discharge current generated by lightning strikes has extremely high amplitude and transient characteristics, which may damage sensitive electronic components in the current processing circuit and make subsequent data acquisition and processing difficult to perform accurately. Meanwhile, effectively conditioning the impulse current signal with a wide dynamic range and ensuring the stable operation of data buffering and communication are key challenges for achieving reliable lightning strike type identification.

[0097] This application further proposes a specific configuration for the aforementioned current processing circuit, which includes: a protection circuit, an attenuation amplification circuit, a data buffer module, a processor module, and a communication circuit. The input terminal of the protection circuit is connected to the output terminal of the sensor, and the output terminal of the protection circuit is connected to the data buffer module via the attenuation amplification circuit. The attenuation amplification circuit is configured to trigger signal conditioning when the impulse discharge current is less than a preset overcurrent limit threshold. The processor module is communicatively connected to both the data buffer module and the communication circuit, and is used to control the operation of these two circuits. For details, please refer to [reference needed]. Figure 4 .

[0098] Specifically, the protection circuit is mainly used to prevent excessively high transient voltages or currents from damaging subsequent precision electronic components when an impulse discharge current occurs. It can be implemented using various technical solutions. For example, it can be composed of overvoltage protection devices such as transient suppression diodes, varistors, or gas discharge tubes. These devices can quickly conduct or clamp the voltage when the impulse current reaches a dangerous level, dissipating excess energy and thus ensuring the safe operation of core components such as attenuation amplifier circuits and data buffer modules.

[0099] The attenuation amplifier circuit is responsible for precisely conditioning the signal after it has been processed by the protection circuit. Because the amplitude range of the impulse discharge current can be very wide, this circuit is designed to adaptively adjust according to the actual amplitude of the signal. When the amplitude of the impulse discharge current is small, i.e., less than a preset overcurrent limit threshold, the attenuation amplifier circuit is triggered to perform signal conditioning. This may include amplifying the signal to improve the signal-to-noise ratio, or performing appropriate attenuation to prevent signal saturation, ensuring that the signal is in its optimal dynamic range before analog-to-digital conversion. This configuration can be implemented using a programmable gain amplifier (PGA) or an amplifier with automatic range switching, thereby ensuring a high-quality signal regardless of the magnitude of the impulse current.

[0100] The data buffer module is used to temporarily store conditioned impulse discharge current data. Given the transient nature of lightning impulse currents, the data buffer module needs high-speed acquisition and storage capabilities to fully record the waveform details of the impulse current. This module typically includes a high-speed analog-to-digital converter (ADC) to convert analog signals into digital signals, and a high-speed random access memory (RAM) or first-in-first-out (FIFO) memory to quickly store this digital data, ensuring that the data is not lost or distorted before being processed by the processor module or transmitted by the communication circuitry.

[0101] The processor module is the control core of the entire current processing circuit, communicating with the data cache module and the communication circuit. The processor module coordinates and manages the operation of each component; for example, it controls the start, stop, and data read operations of the data cache module, and manages the data encapsulation, protocol processing, and data transmission timing of the communication circuit. Through the intelligent control of the processor module, the efficiency and accuracy of data acquisition, storage, and transmission processes can be ensured.

[0102] The communication circuit is responsible for reliably transmitting the pre-processed and buffered impulse discharge current data to the remote host. This module can use wired or wireless communication technologies, such as RS485, Ethernet, LoRa, NB-IoT, or 4G / 5G, selecting the appropriate communication method according to the needs of the actual application scenario to ensure that the data can be delivered to the remote host in a timely and accurate manner for subsequent lightning strike type identification.

[0103] Through the above technical solutions, this application can effectively cope with the extreme transient characteristics and high amplitude of lightning impulse discharge current, ensuring the stability and reliability of the current processing circuit. The protection circuit can effectively prevent excessive impulse current from damaging subsequent precision circuits and extend equipment life. The attenuation amplifier circuit intelligently conditions the signal according to the impulse current amplitude, ensuring the accuracy and readability of the signal over a wide dynamic range and avoiding signal saturation or loss. The data buffer module can store transient impulse current data at high speed and reliably, providing a complete and high-quality data source for subsequent lightning strike type identification. The introduction of the processor module enables effective control and coordination of the entire data acquisition, processing, and transmission process, improving the automation and intelligence level of the system. Ultimately, these collaborative efforts ensure that impulse discharge current data can be accurately and safely acquired, preprocessed, and transmitted to the remote host, providing a solid data foundation for the remote host to perform accurate lightning strike type identification, thereby significantly improving the overall performance and reliability of the online lightning strike type monitoring system.

[0104] Building upon this, this application further proposes the specific structure of the data buffer module, which includes an analog-to-digital converter (ADC), a buffer clock circuit, a buffer trigger circuit, and a buffer body circuit. The ADC converts the analog impulse discharge current signal, after being conditioned by the attenuation amplification circuit, into a digital signal. This is because subsequent data processing and storage are typically performed in the digital domain, and the performance of the ADC (such as sampling rate and resolution) directly affects the accuracy of capturing the details of the impulse discharge current waveform. For example, a successive approximation (SAR) ADC or a pipelined ADC can be used to meet the requirements of high sampling rate and high accuracy, ensuring the integrity of transient waveform information. The buffer clock circuit is responsible for providing precise timing control signals to the various components within the data buffer module. During high-speed data acquisition and storage, the stability and accuracy of the clock signal are crucial. It ensures that the ADC samples at the correct time and coordinates the write operation of the buffer body circuit, thereby guaranteeing the timing consistency and integrity of the stored data. The buffer trigger circuit is a key component for achieving on-demand storage. Its main function is to monitor the amplitude of the impulse discharge current in real time and immediately issue a trigger signal when the amplitude exceeds a preset buffer trigger threshold. The trigger signal initiates the write operation of the buffer circuit, ensuring that data recording only begins upon the occurrence of an actual impact event. This mechanism effectively avoids the continuous storage of invalid data in non-impact states, significantly improving storage efficiency. The buffer circuit is the actual storage unit for digitized impact discharge current data. It needs to possess sufficiently fast write speeds and storage capacity to handle the transient characteristics and large volume of data associated with impact discharge currents. For example, high-speed static random access memory (SRAM) or first-in-first-out (FIFO) memory can be used to ensure that the complete waveform data of the impact discharge current can be recorded quickly and reliably after the trigger signal arrives.

[0105] Specifically, the buffer circuit is connected to the output of the attenuation amplifier circuit via an analog-to-digital converter circuit. This connection method clarifies the data flow path: the analog signal output from the attenuation amplifier circuit first enters the analog-to-digital converter circuit for digitization, and then the digitized data is transmitted to the buffer circuit for storage. This ensures that the signal has undergone appropriate conditioning and digitization before data storage, laying the foundation for subsequent accurate analysis. The buffer trigger circuit is configured to control the buffer circuit to perform a write operation when the amplitude of the impulse discharge current is detected to be greater than a preset buffer trigger threshold. This configuration enables the data buffer module to intelligently respond to impulse events. When the amplitude of the impulse discharge current reaches or exceeds the preset buffer trigger threshold, the buffer trigger circuit immediately activates the buffer circuit and begins recording impulse waveform data. This amplitude-triggered mechanism can accurately capture the starting point and key waveform features of the impulse event, avoiding the waste of resources caused by continuous recording and ensuring effective capture of transient events.

[0106] Through the above technical solution, the data buffer module in the current processing circuit no longer continuously and indiscriminately stores data. Instead, it efficiently converts analog signals into digital signals through an analog-to-digital converter circuit, and the buffer clock circuit provides precise timing synchronization. More importantly, the buffer trigger circuit can monitor the amplitude of the impulse discharge current in real time. Once it detects that the amplitude exceeds the preset buffer trigger threshold, it immediately controls the buffer circuit to initiate a write operation, thereby achieving accurate and on-demand capture of the impulse discharge current waveform. This intelligent triggering mechanism greatly improves the efficiency of data storage, avoids the waste of storage resources, and ensures that critical transient waveform data is recorded only when an actual impulse event occurs. Therefore, this solution can effectively acquire complete and high-quality impulse discharge current waveforms, providing a reliable data foundation for subsequent waveform time-domain feature analysis and lightning strike type identification, significantly improving the accuracy of lightning strike type identification and the overall operating efficiency of the system.

[0107] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the terminals, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0108] In the several embodiments provided in this application, it should be understood that the disclosed terminals, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between devices or units, and may be electrical, mechanical, or other forms.

[0109] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0110] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0111] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0112] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0113] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0114] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for identifying lightning strike types, characterized in that, include: The impulse discharge current is acquired, wherein the impulse discharge current is acquired by an impulse discharge current acquisition device mounted on a 10kV surge arrester; Based on the impulse discharge current, waveform time-domain feature analysis is performed, and the actual waveform time-domain features of the impulse discharge current are extracted; Based on the actual waveform time-domain characteristics and combined with a preset waveform time-domain characteristic threshold range, the lightning strike type identification result of the impulse discharge current is determined according to the matching result between the actual waveform time-domain characteristics and the waveform time-domain characteristic threshold range. The waveform time-domain characteristic threshold range is obtained by statistically analyzing the waveform time-domain characteristics extracted from discharge current samples of different lightning strike types.

2. The lightning strike type identification method according to claim 1, characterized in that, The actual waveform time-domain characteristics include: wavefront time and half-peak time.

3. The lightning strike type identification method according to claim 2, characterized in that, The step of determining the lightning strike type identification result of the impulse discharge current based on the matching result between the actual waveform time-domain characteristics and the threshold range of the waveform time-domain characteristics includes: Based on the waveform time-domain feature threshold intervals obtained by statistically analyzing the waveform time-domain features extracted from discharge current samples of different lightning strike types, the actual waveform time-domain features are matched with the waveform time-domain feature threshold intervals corresponding to different lightning strike types, so as to determine the lightning strike type identification result of the impulse discharge current according to the matching results.

4. The lightning strike type identification method according to claim 3, characterized in that, The methods for determining the waveform time-domain feature threshold range include: Based on the topology and parameter standards of a typical 10kV overhead line with a ground wire, a 10kV overhead line model is constructed using electromagnetic transient simulation tools. Based on the 10kV overhead line model, a double exponential function was used as the lightning current simulation function to perform electromagnetic transient simulation of lightning currents of different lightning strike types, and the waveform parameters of impulse discharge currents of different lightning strike types were recorded. Based on the waveform parameters of the impulse discharge current, waveform time-domain feature analysis is performed to obtain the waveform time-domain features corresponding to different lightning strike types. Then, the waveform time-domain features are classified and statistically analyzed according to the lightning strike type to obtain the waveform time-domain feature threshold ranges corresponding to different lightning strike types.

5. The lightning strike type identification method according to claim 3, characterized in that, The methods for determining the waveform time-domain feature threshold range include: Based on the historical impulse discharge current data recorded in the historical lightning strike event database, waveform time-domain feature analysis is performed on the historical impulse discharge current data to obtain the waveform time-domain features corresponding to different historical impulse discharge current data. Based on the lightning strike type identifiers corresponding to each historical impulse discharge current data, the waveform time-domain features are classified and statistically analyzed to obtain the waveform time-domain feature threshold ranges corresponding to different lightning strike types.

6. A lightning strike type identification device, characterized in that, include: The impulse current acquisition unit is used to acquire the collected impulse discharge current, wherein the impulse discharge current is acquired by an impulse discharge current acquisition device installed on a 10kV surge arrester. The feature extraction unit is used to perform waveform time-domain feature analysis based on the impulse discharge current and extract the actual waveform time-domain features of the impulse discharge current. The lightning strike type identification unit is used to determine the lightning strike type identification result of the impulse discharge current based on the actual waveform time-domain characteristics and a preset waveform time-domain characteristic threshold range, according to the matching result of the actual waveform time-domain characteristics and the waveform time-domain characteristic threshold range. The waveform time-domain characteristic threshold range is obtained by statistically analyzing the waveform time-domain characteristics extracted from discharge current samples of different lightning strike types.

7. An online monitoring system for lightning strike types, characterized in that, include: Impact discharge current acquisition device and remote host; The impulse discharge current acquisition device includes a sensor and a current processing circuit. The current processing circuit is fixed on the arrester support, and the sensor is in contact with the arrester body to acquire the impulse discharge current on the arrester body and transmit the impulse discharge current to the current processing circuit for preprocessing via a signal cable. The current processing circuit includes a communication circuit for transmitting the pre-processed impulse discharge current data to the remote host. The remote host includes: a memory and a processor; The memory is used to store program code, which corresponds to the lightning strike type identification method as described in any one of claims 1 to 5; The processor is used to read and execute the program code to implement the lightning strike type identification method.

8. The online monitoring system for lightning strike types according to claim 7, characterized in that, The current processing circuit includes: a protection circuit, an attenuation amplification circuit, a data buffer module, a processor module, and a communication circuit; The input terminal of the protection circuit is connected to the output terminal of the sensor, and the output terminal of the protection circuit is connected to the data buffer module through the attenuation amplification circuit. The attenuation amplification circuit is configured to trigger signal conditioning when the impulse discharge current is less than a preset overcurrent limit threshold. The processor module is communicatively connected to the data cache module and the communication circuit, respectively, and is used to control the operation of the data cache module and the communication circuit.

9. The online monitoring system for lightning strike types according to claim 8, characterized in that, The data caching module includes: an analog-to-digital conversion circuit, a cache clock circuit, a cache trigger circuit, and a cache body circuit; The buffer circuit is connected to the output of the attenuation amplifier circuit via the analog-to-digital converter circuit. The cache trigger circuit is configured to control the cache body circuit to perform a write operation when the amplitude of the impulse discharge current is detected to be greater than the preset cache trigger threshold.

10. The online monitoring system for lightning strike types according to claim 7, characterized in that, The sensor is specifically a Rogowski coil.

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