Intelligent lightning interceptor and lightning protection method suitable for railway overhead line system framework region

Abstract

The application relates to the technical field of electric signal processing, in particular to an intelligent lightning interceptor suitable for a railway overhead line system framework area and a lightning protection method, which comprises the following steps: collecting lightning currents at each moment on each discharge rod of the intelligent lightning interceptor; determining a discharge rod corresponding to a lightning main channel based on the change rate of the lightning currents on each discharge rod; determining a main path linear deviation at the current moment; acquiring electromagnetic interference coefficients of each side branch path at the current moment, screening real lightning side branch paths in all side branch paths; determining a side branch interference degree of the real lightning side branch path at the current moment; correcting the lightning currents of the lightning main channel at the current moment based on the main path linear deviation, combining the lightning currents of the real lightning side branch path at the current moment and the side branch interference degree, acquiring total lightning currents at the current moment, and distributing and dredging the total lightning currents. Therefore, the effectiveness and precision of the lightning interceptor are improved.

Description

Intelligent lightning interceptors and lightning protection methods applicable to railway catenary systems Technical Field

[0001] This application relates to the field of electrical signal processing technology, specifically to an intelligent lightning interceptor and lightning protection method applicable to railway catenary architecture areas. Background Technology

[0002] With the continuous development of society and the economy, railway transportation has become an indispensable part of people's production and life. Railway operation has now fully transitioned to electrified railway transportation, with power supplied to electric locomotives via contact wires connected to pantographs on the overhead contact system. However, compared to the entire contact system, the elevated towers are the highest points in the area, making them more vulnerable to lightning strikes. A lightning strike can cause the contact system to overload instantaneously, leading to line tripping and train stoppages, thus affecting railway transportation safety. Therefore, it is necessary to implement lightning protection measures for the railway contact system structure area.

[0003] Lightning interceptors aim to actively intervene in lightning discharge to prevent direct lightning strikes, side lightning strikes, and lightning electromagnetic pulses from harming the protected area. They are primarily composed of lightning arresters, down conductors, and grounding devices. By connecting to the ground, the lightning interceptor induces a charge opposite to that of the thundercloud at the lightning induction end, causing the thundercloud to discharge prematurely and creating a circuit. This reduces damage to the surrounding railway contact network caused by the early discharge of the thundercloud charge. However, traditional lightning interceptors neglect the analysis of lightning discharge characteristics in actual operation and the interference analysis of external radiation under extreme lightning conditions. This results in poor current shunting effectiveness, leading to branching lightning strikes outside the main lightning path. Furthermore, they are prone to causing high vertical and horizontal potential gradients, affecting the operational safety of the contact network. Summary of the Invention

[0004] To address the aforementioned technical problems, the purpose of this application is to provide an intelligent lightning interceptor and lightning protection method suitable for railway catenary structures. The specific technical solution adopted is as follows:

[0005] In a first aspect, embodiments of this application provide a lightning protection method for intelligent lightning interceptors applicable to railway catenary architecture areas, the method comprising the following steps:

[0006] Collect the lightning current on each discharge rod of the intelligent lightning interceptor at each moment; determine the discharge rod corresponding to the main lightning channel based on the rate of change of the lightning current on each discharge rod;

[0007] Based on the linear fitting error of the lightning strike current on the main lightning channel discharge rod at the current moment, and the numerical distribution of the linear fitting error, the linear deviation of the main path at the current moment is determined.

[0008] Analyze the rate of change of lightning current on the discharge rod of each side path other than the main lightning channel, as well as the distance between each side path and the main lightning channel, determine the electromagnetic interference coefficient of each side path at the current moment, and screen out the real lightning-struck side paths among all side paths.

[0009] By comparing the similarity between the lightning current of the actual lightning side path and the main lightning path, combined with the electromagnetic interference coefficient of the actual lightning side path and the linear fitting error of its lightning current, the degree of side interference of the actual lightning side path at the current moment is determined.

[0010] Based on the linear deviation of the main path, the lightning current of the main lightning channel at the current moment is corrected. Combined with the lightning current of the actual lightning side path at the current moment and the degree of interference of the side path, the total lightning current at the current moment is obtained, and the total lightning current is distributed and cleared.

[0011] In one embodiment, determining the discharge rod corresponding to the main lightning channel includes:

[0012] Discharge rods whose rate of change of lightning current per unit time exceeds a preset threshold are designated as discharge rods corresponding to the main lightning channel.

[0013] In one embodiment, determining the main path linearity deviation at the current moment includes:

[0014] The dispersion of the linear fitting error of the lightning strike current on the main lightning channel discharge rod during the current moment and the previous local time period is calculated. The linear deviation of the main path is positively correlated with the dispersion and the linear fitting error of the lightning strike current on the main lightning channel discharge rod at the current moment.

[0015] In one embodiment, the main path linear deviation is the normalized result of the product of the degree of dispersion and the linear fitting error of the lightning current on the lightning main channel discharge rod at the current moment.

[0016] In one embodiment, determining the electromagnetic interference coefficient of each side path at the current time includes:

[0017] For each side path, calculate the difference between the lightning current at each moment and the lightning current at the adjacent previous moment, and determine the absolute value of the difference between the current moment and the previous moment.

[0018] The spherical distance between each side path and the discharge hole on the main channel is obtained. The electromagnetic interference coefficient is positively correlated with the absolute value of the difference and the spherical distance.

[0019] In one embodiment, the step of screening all side paths for actual lightning strike side paths includes:

[0020] The electromagnetic interference coefficients of all side paths are thresholded, and the side paths with electromagnetic interference coefficients less than the threshold are taken as the real side paths.

[0021] In one embodiment, determining the degree of side-branch interference in the actual lightning strike side-branch path at the current moment includes:

[0022] The same calculation method used to calculate the linear deviation of the main path of the lightning main channel is adopted to determine the linear deviation of the actual lightning side path at the current moment.

[0023] Calculate the sum of the linear deviation of the actual lightning strike side path at the current moment and its electromagnetic interference coefficient, where the side interference degree is the normalized value of the ratio of the sum to the similarity degree.

[0024] In one embodiment, the correction of the lightning strike current of the main lightning channel at the current moment based on the linear deviation of the main path includes:

[0025] Determine the linear fitting value and the true value of the lightning strike current on the discharge rod of the main lightning channel at the current moment. Then, perform a weighted summation of the linear fitting value and the true value to obtain the corrected value of the lightning strike current of the main lightning channel at the current moment. The weight of the linear fitting value is the linear deviation of the main path at the current moment, and the sum of the weights of the linear fitting value and the true value is 1.

[0026] In one embodiment, obtaining the total lightning strike current at the current moment includes:

[0027] The difference between the natural number 1 and the degree of interference of the side branch of the actual lightning strike side branch path at the current moment is used as the weight to perform a weighted summation of the lightning current of all actual lightning strike side branch paths. The summation result is then combined with the corrected value of the lightning current of the main lightning channel at the current moment to obtain the total lightning current at the current moment.

[0028] Secondly, embodiments of this application also provide a smart lightning interceptor suitable for railway catenary architecture areas, the smart lightning interceptor comprising:

[0029] The lightning current acquisition module is used to acquire the lightning current on each discharge rod of the intelligent lightning interceptor at any time; and to determine the discharge rod corresponding to the main lightning channel based on the rate of change of the lightning current on each discharge rod.

[0030] The lightning current correction module is used to determine the linear deviation of the main path at the current moment based on the linear fitting error of the lightning current on the main lightning channel discharge rod at the current moment, and the numerical distribution of the linear fitting error.

[0031] Analyze the rate of change of lightning current on the discharge rod of each side path other than the main lightning channel, as well as the distance between each side path and the main lightning channel, determine the electromagnetic interference coefficient of each side path at the current moment, and screen out the real lightning-struck side paths among all side paths.

[0032] By comparing the similarity between the lightning current of the actual lightning side path and the main lightning path, combined with the electromagnetic interference coefficient of the actual lightning side path and the linear fitting error of its lightning current, the degree of side interference of the actual lightning side path at the current moment is determined.

[0033] The lightning strike current of the main lightning channel at the current moment is corrected based on the linear deviation of the main path. The total lightning strike current at the current moment is obtained by combining the lightning strike current of the actual lightning strike side path and the degree of interference of the side path.

[0034] Surge protection devices are used to evenly distribute the total lightning current to each current collection device;

[0035] A current collection device is used to collect lightning current distributed by surge protection devices.

[0036] This application has at least the following beneficial effects:

[0037] This application addresses the issue that traditional lightning interceptors typically analyze the main lightning current directly, neglecting potential side paths that may exist in the actual process. This leads to uneven distribution of the lightning current. Furthermore, traditional methods do not adequately consider the impact of electromagnetic interference on current observation. Under lightning conditions, strong electromagnetic radiation and current fluctuations can cause signal interference in current observation, resulting in errors in the current data. The presence of such interference often affects the accuracy of current measurement, which in turn affects subsequent current shunting processing, reducing the effectiveness and accuracy of the lightning interceptor.

[0038] To address the aforementioned issues, this application first obtains the dynamic characteristics of the current waveform through real-time monitoring and data analysis of the main channel lightning current. This helps to accurately identify the interference level of the lightning current and provides a reliable basis for lightning current correction. Furthermore, by analyzing the electromagnetic interference of the side paths, this application improves the accuracy of identifying actual lightning side paths and reduces the impact of electromagnetic interference on lightning current monitoring. Further, by analyzing the current waveform and interference, the application performs real-time correction of the lightning current in the main channel and side paths, ensuring that the lightning current is reasonably distributed in each path. This improves the monitoring accuracy and reliability of the lightning current, helps to accurately control the distribution and attenuation of the lightning current, ensures reasonable distribution of the lightning current, avoids current overload and current surge, thereby improving the protective effect of the lightning interceptor, enhancing its effectiveness and accuracy, significantly improving the stability of railway catenary operation, ensuring efficient and stable operation during thunderstorms, reducing lightning damage to railway equipment, and ensuring the long-term stability and safety of railway facilities. Attached Figure Description

[0039] To more clearly illustrate the technical solutions and advantages 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 is a flowchart of the lightning protection method of a smart lightning interceptor applicable to the railway catenary architecture area provided in an embodiment of this application;

[0041] Figure 2 is a flowchart for determining the total lightning strike current of a lightning interceptor. Detailed Implementation

[0042] To further illustrate the technical means and effects adopted by this application to achieve the intended purpose of the invention, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of the intelligent lightning interceptor and lightning protection method applicable to railway catenary structures proposed in this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0044] The following, in conjunction with the accompanying drawings, details the specific scheme of the intelligent lightning interceptor and lightning protection method applicable to railway catenary structures provided in this application.

[0045] Please refer to Figure 1, which shows a flowchart of the lightning protection method for a smart lightning interceptor suitable for railway catenary architecture areas according to an embodiment of this application. The method includes the following steps:

[0046] S1, collect the lightning current on each discharge rod of the lightning interceptor at each moment; determine the discharge rod corresponding to the main lightning channel based on the rate of change of the lightning current on each discharge rod.

[0047] To protect the stable operation of the railway catenary, multiple lightning interceptors are installed along the railway track in the catenary structure area. The distance between two adjacent lightning interceptors can be selected as 2 to 5 km. In this embodiment, the distance is 4 km. Implementers can set the distance according to the actual situation, which aims to improve the lightning protection effect of the railway catenary and improve the overall operational stability.

[0048] The core principle of lightning interceptors is to release corona ions in advance, thereby weakening the energy of thunderclouds. When extreme thunderstorms occur at high altitudes, the clouds in the sky carry a large amount of charge. The tip of the lightning interceptor, connected to the ground, can sense the opposite charge to that of the thundercloud. When the charges of both accumulate to a certain level, the air will be ionized, thus forming a lightning current channel. This causes the lightning energy of the thundercloud to be released in advance, thereby gradually weakening the charge density and electric field strength of the thundercloud and preventing interference with the operation of the railway overhead contact system.

[0049] In order to obtain the charge information of thunderclouds in real time and with relatively high accuracy, this embodiment deploys a corresponding smart current sensor on each discharge rod of the lightning interceptor to sense the lightning current. The smart current sensor is required to have a nanosecond-level response speed and a large range. Therefore, a photocurrent sensor is selected in this embodiment.

[0050] The lightning current on each discharge rod of the lightning interceptor is collected in this way. The time interval for collecting the lightning current is 1ns. The implementer can set it according to the actual situation. This embodiment does not limit it.

[0051] In traditional lightning interceptors, the resistance of the surge protector is distributed based on the observed current of the main channel, thereby achieving current distribution on the grounding wire. This allows the lightning current to be evenly distributed across the multi-point grounding device, achieving "multi-point current shunting," reducing local overheating caused by the skin effect of current, and improving the current carrying capacity of the lightning interceptor.

[0052] However, during the discharge process of thunderclouds, not only is there discharge in the main channel, but there may also be branch lightning strikes that guide to the side discharge rods. In addition, during the lightning current detection process, it is in the extreme electromagnetic environment of lightning, which leads to inaccurate detection of the overall lightning current and current distortion, which further affects the current distribution of the surge protection device and the protection effect of the lightning interceptor.

[0053] The discharge process of lightning mainly involves three stages of return current. In thunderclouds, the polarity of the charge is typically positive at the top and negative at the bottom. When enough charge accumulates in the thundercloud, a discharge phenomenon occurs within the cloud, known as the descending leader. Simultaneously, the discharge needle of the lightning interceptor generates a charge opposite to that of the lower thundercloud. When the electric field strength of the discharge needle reaches 30-50 V / cm, a corona discharge occurs, producing an upward stream of light, known as the ascending leader. When the upper and lower leaders connect, the charge rushes from the ground along the discharge channel to the cloud, neutralizing the thundercloud charge within the channel, thus forming the main discharge channel, which constitutes the first return stroke.

[0054] After the initial return stroke, a current channel is formed with the main channel as the discharge path. Due to the large amount of charge in the thundercloud, this return stroke process will repeat continuously after the initial return stroke, but the overall amplitude will be slightly reduced, forming multiple subsequent return stroke current pulses. Typically, there are no fewer than three subsequent return stroke currents in the overall return stroke current. In addition, during the discharge process of the subsequent current pulses, there is a charge within the channel that maintains the channel until the discharge ends. As a result, there is a continuous current with a constant direction of motion at the bottom of the subsequent return stroke current pulse, which is the DC component of the lightning strike channel process.

[0055] When the lightning discharge in a thundercloud is nearing its end, a final return stroke current will be generated. Typically, the final return stroke current will have a certain time interval from the last subsequent return stroke current, and its amplitude is no weaker than the first return stroke current. Thus, from the first return stroke current to the final return stroke current, the multi-pulse current discharge of lightning strikes ends, forming the complete three stages of lightning discharge.

[0056] The above analysis primarily focuses on the lightning discharge distribution in the main channel. Due to the large overall area of ​​thunderclouds, during the electric field induction phase, a significant electric field intensity is often induced at the tips of multiple discharge rods on the lightning interceptor. Therefore, the main lightning channel will form a discharge path at a single tip among these multiple discharge rods. While a main current forms in the main channel, the spacing between the lightning interceptor tips is relatively small compared to the length of the arc in the air, potentially leading to side arcs forming discharge paths with other tips. Furthermore, the intense electromagnetic fluctuations during the discharge process can cause significant interference with the lightning current monitored by some sensors, resulting in discrepancies in the final overall grounding channel current distribution and affecting the operational stability of the lightning interceptor.

[0057] During lightning discharge, the rate of change of current on each discharge rod of the lightning interceptor is calculated based on the monitored current value. Discharge rods with a rate of change greater than a preset threshold are designated as the discharge rods corresponding to the main lightning channel. If multiple discharge rods have a rate of change greater than the preset threshold, the discharge rod with the largest rate of change of current per unit time is designated as the discharge rod corresponding to the main lightning channel. In this embodiment, the preset threshold is 80 kA / µs, but implementers can set it according to their actual needs.

[0058] S2. Based on the linear fitting error of the lightning strike current on the main lightning channel discharge rod at the current moment, and the numerical distribution of the linear fitting error, determine the linear deviation of the main path at the current moment.

[0059] During the release of lightning current, the neutralization of thundercloud charge is mainly achieved within the main channel. Under normal weather conditions, the current in the discharge rod within the main channel is relatively small. When an induced electric field forms a discharge path, the current will increase almost instantaneously and linearly, and the linearity of the current is relatively high as the main channel is connected.

[0060] Therefore, this embodiment performs linear fitting on the lightning strike current on the main lightning channel discharge rod during the current moment and previous local time periods to obtain the linear fitting value of the lightning strike current on the main lightning channel discharge rod at the current moment. This embodiment uses the least squares method for linear fitting, which is a known existing technique. Implementers can choose other feasible linear fitting algorithms. In this embodiment, the duration of the local time period is 20 data collection moments. Implementers can set the length of the local time period according to actual conditions.

[0061] The linear deviation of the main path at the current moment is determined by the difference between the linearly fitted value of the lightning strike current on the discharge rod of the main lightning channel at the current moment and its true value. The specific expression is as follows:

[0062] In the formula, The linear deviation of the main path at time t. Let be the linearly fitted value of the lightning strike current on the discharge rod of the main lightning channel at time t. Let be the lightning strike current value on the main discharge rod of the lightning strike channel at time t. The first difference is denoted as the linear fitting error of the lightning strike current at the current moment on the main lightning channel discharge rod. The first difference is the degree of dispersion of the current time and all times within the previous local time period, and norm() is the normalization function.

[0063] It should be noted that the degree of dispersion can be calculated using methods such as variance, standard deviation, and coefficient of variation. In this embodiment, variance is used as the calculation method for the coefficient of variation.

[0064] It should be understood that linear deviation is used to measure the linearity of the lightning current at the current sampling moment within the main lightning strike channel. Ideally, the lightning current in the main lightning strike channel is linearly distributed, resulting in a smaller overall current linear deviation. Furthermore, the accuracy of the linear deviation is measured by the degree of dispersion; a larger degree of dispersion indicates a greater influence of external electromagnetic interference on the lightning current.

[0065] S3. Analyze the rate of change of lightning current on the discharge rod of each side path other than the main lightning channel, as well as the distance between each side path and the main lightning channel, determine the electromagnetic interference coefficient of each side path at the current moment, and screen out the real lightning-struck side path among all side paths.

[0066] The linear deviation of the main path is primarily based on the linear distribution within the main channel, and the linear deviation result measures the characteristics of electromagnetic interference affecting the current within the main lightning channel. In practice, the main channel, being the primary pathway for lightning current release, is less susceptible to electromagnetic interference; the focus is on the accuracy of current measurement on the side paths. Specifically, the current paths on the lightning interceptor other than the main lightning channel are referred to as side paths.

[0067] Because of the randomness in the side path, that is, the side path may be at one discharge rod tip in the current return current range, but at another discharge rod tip in the next return current, and the current flowing in the side path is relatively small compared to the current in the main channel, the circuit on the side path is more susceptible to external electromagnetic interference, which interferes with the accuracy of the monitoring current.

[0068] In practice, the current value in a single side circuit may be caused by a lightning strike on the side circuit or by electromagnetic interference. For the current generated by a genuine lightning strike on the side circuit, the current value is often continuous, and the difference between adjacent intervals is relatively small. However, the current value generated by electromagnetic interference will be discontinuous, and its specific magnitude is often related to the intensity of the external electromagnetic field, exhibiting a certain degree of randomness.

[0069] Based on the current change before the current sampling time, the electromagnetic interference coefficient of each side path at the current time is determined. Specifically, for each side path, the difference between the lightning current at each time and the lightning current at the adjacent previous time is calculated, and the absolute value of the difference between the current time and the previous time is determined.

[0070] The spherical distance between each side path and the discharge hole on the main lightning channel is obtained. The electromagnetic interference coefficient is positively correlated with the absolute value of the difference and the spherical distance.

[0071] In this embodiment, the specific expression for the electromagnetic interference coefficient of each side path at the current moment is:

[0072] In the formula, Let be the electromagnetic interference coefficient of each side path at time t. This represents the difference between the lightning current of each branch path at time t and the lightning current at the adjacent previous time. Let be the difference between the lightning current of each branch path at time t-1 and the lightning current at the adjacent previous time. Let be the spherical distance between each branch path and the discharge hole on the main lightning channel. The maximum spherical distance between all side paths and the discharge holes on the main lightning channel is given by norm(), which is the normalization function.

[0073] The electromagnetic interference (EMI) coefficient of a side path is mainly derived from the differences in current variation and spatial distribution. Discharge rods closer to the main channel are often aligned with the direction of the thundercloud, resulting in a greater amount of induced charge and thus a higher probability of being a true lightning strike side path, making them less susceptible to EMI. Conversely, the greater the current difference and the farther away from the main discharge channel, the more likely the current is to generate EMI.

[0074] For the electromagnetic interference coefficients of all side paths at the current moment, the Otsu threshold segmentation algorithm is used for threshold segmentation. Side paths with electromagnetic interference coefficients less than the segmentation threshold are identified as actual lightning strike side paths, while other side paths are judged as current paths generated by electromagnetic interference. The Otsu threshold is a well-known existing technology, and the specific process will not be elaborated here.

[0075] S4. By comparing the similarity between the lightning current of the actual lightning side path and the lightning main path, combined with the electromagnetic interference coefficient of the actual lightning side path and the linear fitting error of its lightning current, the degree of side interference of the actual lightning side path at the current moment is determined.

[0076] For a real lightning strike side path, there is also a certain amount of electromagnetic interference. The changes in the side current inside it are similar to those in the main path, and it also exhibits a phased discharge phenomenon. Moreover, the change pattern is basically consistent with that of the main channel, and it has the characteristic of being at the same frequency.

[0077] Therefore, by combining the electromagnetic interference coefficients on the actual lightning strike side paths, the degree of side interference in each actual lightning strike side path at the current moment can be determined:

[0078] First, using the same calculation method as for the linear deviation of the main lightning path, the linear deviation of each actual lightning strike side path at the current moment is determined. The specific expression is as follows:

[0079] In the formula, The linear deviation of each actual lightning strike side path at time t. The linear fitting value of the lightning current on the discharge rod of each actual lightning strike side path at time t is given. Let be the actual lightning current value on the discharge rod of each lightning strike side path at time t. This is denoted as the second difference. Let be the variance of the second difference over all times in the current local time period and before it, and norm() be the normalization function.

[0080] The expression for the degree of side branch interference is:

[0081] In the formula, This indicates the degree of side interference in each actual lightning strike side path at time t. Let be the electromagnetic interference coefficient of each side path at time t. This represents the degree of similarity between the lightning currents of each actual lightning side path and the main lightning path within a local time period up to and including the current time t. In this embodiment, the similarity is calculated using the Pearson correlation coefficient. Implementers can choose other feasible similarity calculation methods, such as cosine similarity.

[0082] In a real lightning strike side path that is not subject to electromagnetic interference, the overall current distribution of the side path is usually consistent with the change of the main path, and the two have a high degree of similarity and synchronous distribution changes. However, when subjected to electromagnetic interference, the linear deviation of the corresponding real lightning strike side path is large, and the value of the electromagnetic interference coefficient is large.

[0083] Therefore, by observing the degree of interference in the side path of a real lightning strike, the overall electromagnetic interference of the detected current can be reflected, and the current data can be corrected based on this electromagnetic interference.

[0084] S5. Based on the linear deviation of the main path, the lightning current of the main lightning channel at the current moment is corrected. Combined with the lightning current of the actual lightning side path at the current moment and the degree of interference of the side path, the total lightning current at the current moment is obtained, and the total lightning current is distributed and cleared.

[0085] Because the current value in the main lightning channel is relatively large, its shunting effect on the overall surge protection device is quite important. Therefore, this embodiment first corrects the lightning current in the main lightning channel based on the linear deviation of the main path at the current time t. The specific expression is as follows:

[0086] In the formula, This represents the corrected value of the lightning strike current in the main lightning channel at time t. The linear deviation of the main path at time t. Let be the linearly fitted value of the lightning strike current on the discharge rod of the main lightning channel at time t. This represents the lightning strike current value on the main lightning discharge rod at time t.

[0087] The more severe the electromagnetic interference on the lightning current in the main channel at time t, the less accurate the monitored current value is. Therefore, the linear fitting value of the lightning current at time t is given greater weight, reducing the impact of electromagnetic interference on the main channel current.

[0088] Furthermore, by considering the interference levels of each actual lightning strike bypass path, the overall lightning current value is obtained, specifically expressed as follows:

[0089] In the formula, This represents the total lightning current at time t. This represents the corrected value of the lightning strike current in the main lightning channel at time t. This represents the number of actual lightning strike side paths at time t. This indicates the degree of side interference in the k-th real lightning strike side path at time t. This represents the monitoring current value on the k-th actual lightning strike side path at time t. The flowchart for determining the total lightning strike current of the lightning interceptor is shown in Figure 2.

[0090] In the calculation of the total lightning current, the focus is on correcting the current after correction of the main lightning channel. For other branch currents, if the electromagnetic interference experienced by the actual lightning-struck branch path is more severe, it indicates that the monitored current value of the branch contains not only the actual current value but also a certain electromagnetic interference component. Therefore, it is necessary to reduce the weight of the current value of the branch to reduce the impact of electromagnetic interference on the calculation of the total lightning current and improve the accuracy of the total lightning current statistics.

[0091] Finally, the surge protection device of the lightning interceptor evenly distributes the total lightning current to each current collection device. The surge protection device can quickly distribute the resistance value according to the input current value, thereby evenly distributing the total lightning current value at the current moment to each current collection device, so as to quickly conduct the lightning current to the ground, reduce the interference of thunderclouds on the railway contact network, improve the current diversion capacity, and improve the lightning interception efficiency.

[0092] Based on the same inventive concept as the above method, this application also provides an intelligent lightning interceptor suitable for railway catenary architecture areas, the intelligent lightning interceptor comprising:

[0093] Outer protection and discharge auxiliary module: mainly composed of a metal outer casing and a discharge cylinder. The metal outer casing is an open-bottomed metal cover made of aluminum alloy, with several discharge holes evenly distributed on its outer wall, through which fixed connecting sleeves pass. The discharge cylinder is fixed to the bottom of the metal outer casing, made of the same material as the metal outer casing, with several circular holes evenly distributed on its wall corresponding to the discharge gaps.

[0094] Its important function is to provide physical protection for internal insulation supports, electrodes and other components, and prevent external environment from corroding the core structure. In addition, the circular hole of the discharge tube can guide the diffusion of corona ions generated between the discharge gaps, while limiting the position of the insulation supports and the discharge gaps, and determining the stability of the discharge.

[0095] The core module for tip discharge consists of a discharge rod and discharge needles. The discharge rod is a hollow structure made of highly conductive material. One end is fixed to a metal casing via a connecting sleeve, and the other end connects to a limiting end, which provides a certain angle adjustment range for the discharge rod. The discharge needles are arranged in a circumferential array at the end of the discharge rod and can be rotated for installation via a mounting ring.

[0096] Its main function is tip discharge. Due to the "tip effect," the tip of the discharge needle generates a high charge and a strong electric field, which, under the excitation of the thundercloud's electric field, ionizes the air first, initiating the first stage of discharge. The entire assembly is fixedly connected, with thread-locking adhesive applied to the connecting parts to ensure continuity of conductivity and prevent poor contact from affecting the discharge.

[0097] Electric field and grounding conduction module: Insulating support and electrodes. Mounted on the inner wall of the opening end of the metal casing, made of insulating material, used to fix the electrodes and isolate the metal casing from the electrodes; the electrodes are located at the bottom of the insulating support, made of superconducting metal, with a fixed metal transition support at the bottom, and a certain gap exists between the electrodes and the inner wall of the metal casing to form a secondary discharge region.

[0098] Its main functions are electric field isolation and insulation support to prevent direct conductivity between the electrode and the metal casing. At the same time, it forms a stable discharge gap between the electrode and the inner wall of the metal casing. Under the electric field of thunderclouds, the electrode carries a positive charge and the inner wall of the metal casing carries a negative charge. A strong electric field is formed in the gap, triggering a secondary discharge. In addition, the electrode is connected to the grounding wire through the metal transition support, which guides the positive charge of the ground to the discharge area and conducts the negative charge generated by the discharge to the grounding system.

[0099] Lightning current acquisition module: used to acquire the lightning current on each discharge rod of the intelligent lightning interceptor at any time; and to determine the discharge rod corresponding to the main lightning channel based on the rate of change of the lightning current on each discharge rod.

[0100] Lightning current correction module: used to determine the linear deviation of the main path at the current moment based on the linear fitting error of the lightning current on the main lightning channel discharge rod at the current moment, and the numerical distribution of the linear fitting error;

[0101] Analyze the rate of change of lightning current on the discharge rod of each side path other than the main lightning channel, as well as the distance between each side path and the main lightning channel, determine the electromagnetic interference coefficient of each side path at the current moment, and screen out the real lightning-struck side paths among all side paths.

[0102] By comparing the similarity between the lightning current of the actual lightning side path and the main lightning path, combined with the electromagnetic interference coefficient of the actual lightning side path and the linear fitting error of its lightning current, the degree of side interference of the actual lightning side path at the current moment is determined.

[0103] The lightning strike current of the main lightning channel at the current moment is corrected based on the linear deviation of the main path. The total lightning strike current at the current moment is obtained by combining the lightning strike current of the actual lightning strike side path and the degree of interference of the side path.

[0104] Charge transport module: grounding wire and current collection device. The grounding wire connects the metal transition support to the current collection device. The current collection device is pre-buried underground to collect and dissipate excess charge. Multiple grounding wires are used to ensure effective conduction of lightning current. A surge protection device connects the grounding wire and the metal transition support. This surge protection device evenly distributes the total lightning current to each current collection device, preventing excessive lightning current from damaging the lightning interceptor.

[0105] Its main function is to conduct charge, introducing the positive charge accumulated on the electrodes into the discharge area, while simultaneously conducting the negative charge generated during the discharge process into the ground through the grounding wire, thus preventing the accumulation of charge from affecting the railway contact network. Furthermore, through surge protection devices, it effectively distributes the lightning current, reducing the vertical and horizontal potential difference and minimizing charge interference to the railway contact network.

[0106] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, specific embodiments of this specification have been described above. Additionally, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0107] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0108] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A lightning protection method for intelligent lightning interceptors applicable to railway catenary structures, characterized in that, The method includes the following steps: collecting the lightning current on each discharge rod of the intelligent lightning interceptor at each moment; determining the discharge rod corresponding to the main lightning channel based on the rate of change of the lightning current on each discharge rod; determining the linear deviation of the main path at the current moment based on the linear fitting error of the lightning current on the discharge rod of the main lightning channel at the current moment, and the numerical distribution of the linear fitting error; analyzing the rate of change of the lightning current on the discharge rods of each branch path other than the main lightning channel, and the distance between each branch path and the main lightning channel, to determine the electromagnetic interference coefficient of each branch path at the current moment. The actual lightning strike side path is screened from all side paths. The similarity between the actual lightning strike side path and the lightning strike current of the main lightning channel, combined with the electromagnetic interference coefficient of the actual lightning strike side path and the linear fitting error of its lightning strike current, determines the side interference degree of the actual lightning strike side path at the current moment. Based on the linear deviation of the main path, the lightning strike current of the main lightning channel at the current moment is corrected. Combining the lightning strike current of the actual lightning strike side path at the current moment and its side interference degree, the total lightning strike current at the current moment is obtained, and the total lightning strike current is distributed and cleared.

2. The lightning protection method for intelligent lightning interceptors applicable to railway catenary structures as described in claim 1, characterized in that, The step of determining the discharge rod corresponding to the main lightning channel includes: taking the discharge rod whose rate of change of lightning current per unit time is greater than a preset threshold as the discharge rod corresponding to the main lightning channel.

3. The lightning protection method for intelligent lightning interceptors applicable to railway catenary structures as described in claim 1, characterized in that, The determination of the linear deviation of the main path at the current moment includes: calculating the dispersion of the linear fitting error of the lightning current on the lightning main channel discharge rod during the current moment and the previous local time period. The linear deviation of the main path is positively correlated with the dispersion and the linear fitting error of the lightning current on the lightning main channel discharge rod at the current moment.

4. The lightning protection method for intelligent lightning interceptors applicable to railway catenary structures as described in claim 3, characterized in that, The linear deviation of the main path is the normalized result of the product of the degree of dispersion and the linear fitting error of the lightning current on the lightning main channel discharge rod at the current moment.

5. The lightning protection method for intelligent lightning interceptors applicable to railway catenary structures as described in claim 1, characterized in that, Determining the electromagnetic interference coefficient of each side path at the current moment includes: for each side path, calculating the difference between the lightning current at each moment and the lightning current at the adjacent previous moment, and determining the absolute value of the difference between the current moment and the previous moment; obtaining the spherical distance between each side path and the discharge hole on the main channel, wherein the electromagnetic interference coefficient is positively correlated with the absolute value of the difference and the spherical distance.

6. The lightning protection method for intelligent lightning interceptors applicable to railway catenary structures as described in claim 1, characterized in that, The step of screening all side paths for real lightning strike side paths includes: performing threshold segmentation on the electromagnetic interference coefficients of all side paths, and taking the side paths with electromagnetic interference coefficients less than the segmentation threshold as real side paths.

7. The lightning protection method for intelligent lightning interceptors applicable to railway catenary structures as described in claim 1, characterized in that, The determination of the side interference degree of the actual lightning strike side path at the current moment includes: using the same calculation method as the calculation of the linear deviation of the main path of the lightning main channel to determine the linear deviation of the actual lightning strike side path at the current moment; calculating the sum of the linear deviation of the actual lightning strike side path at the current moment and its electromagnetic interference coefficient, wherein the side interference degree is the normalized value of the ratio of the sum to the similarity degree.

8. The lightning protection method for intelligent lightning interceptors applicable to railway catenary structures as described in claim 1, characterized in that, The step of correcting the lightning strike current of the main lightning channel at the current moment based on the linear deviation of the main path includes: determining the linear fitting value and the true value of the lightning strike current on the discharge rod of the main lightning channel at the current moment; performing a weighted summation of the linear fitting value and the true value to obtain the corrected value of the lightning strike current of the main lightning channel at the current moment; wherein the weight of the linear fitting value is the linear deviation of the main path at the current moment, and the sum of the weights of the linear fitting value and the true value is 1.

9. The lightning protection method for intelligent lightning interceptors applicable to railway catenary structures as described in claim 8, characterized in that, The process of obtaining the total lightning current at the current moment includes: using the difference between the natural number 1 and the side interference level of the actual lightning side path at the current moment as a weight, performing a weighted summation of the lightning currents of all actual lightning side paths, and using the summation result and the corrected value of the lightning current of the main lightning channel at the current moment as the total lightning current at the current moment.

10. A smart lightning interceptor suitable for railway catenary structure areas, implementing the lightning protection method of the smart lightning interceptor suitable for railway catenary structure areas as described in claim 1, characterized in that, The intelligent lightning interceptor includes: a lightning current acquisition module, used to acquire the lightning current on each discharge rod of the intelligent lightning interceptor at each moment; determining the discharge rod corresponding to the main lightning channel based on the rate of change of the lightning current on each discharge rod; a lightning current correction module, used to determine the linear deviation of the main path at the current moment based on the linear fitting error of the lightning current on the discharge rod of the main lightning channel at the current moment, and the numerical distribution of the linear fitting error; analyzing the rate of change of the lightning current on the discharge rods of each side path other than the main lightning channel, and the distance between each side path and the main lightning channel, determining the electromagnetic interference coefficient of each side path at the current moment, and screening all side paths... The system identifies the actual lightning strike side path; by assessing the similarity between the actual lightning strike side path and the main lightning path's lightning current, combined with the electromagnetic interference coefficient of the actual lightning strike side path and its linear fitting error, the system determines the side interference level of the actual lightning strike side path at the current moment; based on the linear deviation of the main path, the system corrects the lightning current of the main lightning path at the current moment, and by combining the lightning current of the actual lightning strike side path at the current moment and its side interference level, the system obtains the total lightning current at the current moment; a surge protection device is used to evenly distribute the total lightning current to each current collection device; and a current collection device is used to collect the lightning current distributed by the surge protection device.

Images