Real-time dynamic evaluation method and system for lightning flashover risk of power transmission line

Abstract

The invention relates to a real-time dynamic evaluation method for lightning flashover risk of a power transmission line. The method comprises the following steps: acquiring current lightning condition information from a lightning monitoring system; calculating a ground wire lightning stroke probability and a lead lightning stroke probability by using a lightning stroke shielding analysis model based on the current lightning actual condition information; according to the ground wire lightning stroke probability and the wire lightning stroke probability, calculating the line lightning stroke flashover probability, and according to the line lightning stroke flashover probability, dividing the lightning stroke flashover risk level. Compared with the prior art, the method has the advantages that the lightning flashover risk of the line is dynamically evaluated in real time, targeted load control strategies are developed for dispatching departments, harm caused by lightning stroke is actively reduced, and the method has important guiding significance.

Description

Technical Field

[0001] This invention relates to the field of power grid lightning protection technology, specifically to a method and system for real-time dynamic assessment of lightning flashover risk of transmission lines. Background Technology

[0002] Lightning strikes have long been the primary cause of transmission line tripping. Lightning events are brief yet possess enormous energy, easily endangering transmission lines. Currently widely used lightning monitoring systems achieve real-time monitoring of parameters such as the time, location, amplitude, and polarity of lightning strikes. However, their principle is based on two-dimensional wide-area positioning, unable to distinguish whether the lightning strike point is on the line itself or nearby. Typical lightning damage risk assessments are based on long-term observations and statistics of lightning activity along the line, deriving distribution characteristics such as the frequency and current amplitude to determine the potential lightning damage risk to line towers, reflecting the risk under long-term transmission line operation. With the development of power systems and the increasing frequency of extreme weather events, relying on average risk distribution to guide post-event reinforcement measures is insufficient to meet increasingly stringent safety and stability requirements. This invention provides significant guidance for real-time dynamic assessment of line lightning flashover risk, enabling dispatching departments to develop targeted load control strategies and proactively reduce the harm caused by lightning strikes. Summary of the Invention

[0003] The purpose of this invention is to provide a method and system for real-time dynamic assessment of lightning flashover risk in power transmission lines.

[0004] The objective of this invention can be achieved through the following technical solutions: A method for real-time dynamic assessment of lightning flashover risk in power transmission lines, comprising the following steps: Obtain real-time lightning information from the lightning monitoring system; Based on the current lightning situation information, the probability of ground wire lightning strike and the probability of conductor lightning strike are calculated using a lightning strike shielding analysis model. Based on the ground wire lightning strike probability and conductor lightning strike probability, combined with the current lightning situation information and the backflashover and lightning withstand levels of tower T, the probability of line lightning flashover is calculated. The risk level of lightning flashover is classified according to the probability of lightning flashover on the power line.

[0005] A real-time dynamic assessment system for lightning flashover risk of transmission lines includes an information extraction module, a lightning strike probability calculation module, a flashover probability calculation module, and a risk assessment module. The information extraction module is used to obtain current lightning status information from the lightning monitoring system; The lightning strike probability calculation module is used to calculate the ground wire lightning strike probability and the conductor lightning strike probability based on the current lightning situation information and using the lightning strike shielding analysis model. The flashover probability calculation module is used to calculate the probability of line lightning flashover based on the ground wire lightning strike probability and conductor lightning strike probability, combined with the monitored current lightning current amplitude and the backflashover lightning withstand level and the backflashover lightning withstand level of tower T. The risk assessment module is used to classify the lightning flashover risk level based on the probability of line lightning flashover.

[0006] Compared with the prior art, the present invention has the following beneficial effects: 1. Real-time assessment of line lightning flashover risk facilitates dispatch decisions to reduce the damage caused by lightning strikes, taking into account the probability of lightning hitting targets (such as conductors, ground wires, and the earth) and the possibility of flashover after the strike. 2. It is not limited to conducting lightning flashover risk assessments on a single line. As long as the line ledger is entered into the system, it can be applied to any number of lines, making it highly scalable. 3. When calculating the probability of lightning hitting a target (such as a wire, ground wire, or earth), the influence of terrain and the probability distribution of the lightning incident angle are taken into account. At the same time, an analysis model that supports scenarios where multiple lines shield each other can be used to improve accuracy. 4. The probability of lightning strikes and flashovers is ultimately graded according to the numerical value and distinguished by color for easy visualization; 5. The data relied upon by this invention can all be obtained from existing information systems, such as line tower ledgers and lightning activity data. The entire process can be automated through a program, and the occurrence of lightning drives the dynamic update of the lightning flashover probability. Attached Figure Description

[0007] Figure 1 To implement the flowchart and system composition; Figure 2 A schematic diagram illustrating the probability of lightning strikes on the ground wire and conductor of a power transmission line. Figure 3 This is a structural diagram of the present invention. Detailed Implementation

[0008] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0009] Example 1 This embodiment discloses a method for real-time dynamic assessment of lightning flashover risk in power transmission lines, such as... Figure 1 As shown, the method includes: Obtain real-time lightning information from the lightning monitoring system; Based on current lightning situation information, the probability of ground wire lightning strike and the probability of conductor lightning strike are calculated using existing lightning strike shielding analysis models. Based on the ground wire lightning strike probability and conductor lightning strike probability, combined with the current lightning situation information and the backflashover and lightning withstand levels of tower T, the probability of line lightning flashover is calculated. The risk level of lightning flashover is classified according to the probability of lightning flashover on the power line.

[0010] The core technical advantage of this invention lies in achieving real-time, accurate, comprehensive, and practical assessment of lightning flashover risk in transmission lines, providing a scientific basis for targeted prevention and control measures by dispatching departments. Firstly, by acquiring current lightning status information from the lightning monitoring system, it breaks through the limitations of traditional reliance on long-term lightning statistics. Using real-time dynamic parameters such as lightning time, location, current amplitude, and polarity as input, it ensures that risk assessment closely follows the immediate state of each lightning event, avoiding the lag in reflecting sudden lightning risks that historical average data cannot reflect. Secondly, it calculates the lightning strike probability of ground wires and conductors based on a lightning shielding analysis model, combining an electrical geometric model with the ground wire / The conductor strike distance clearly indicates whether lightning has struck the line itself, and it also considers the probability distribution of lightning incident at different tilt angles. It covers both backflashover and side-striking lightning scenarios, making it more realistic than a single vertical incident assumption and single-scenario assessment, significantly improving the accuracy of lightning strike probability calculations. Furthermore, it calculates flashover probability by combining lightning current amplitude with tower lightning withstand levels. By retrieving specific backflashover and side-striking lightning withstand levels from tower records, it correlates lightning strike probability with line withstand capability. Flashover risk is only identified when the lightning current exceeds the withstand limit, avoiding the misjudgment of directly equating lightning strike with flashover, further refining the risk quantification results. Finally, risk levels are classified based on flashover probability. A clear probability threshold transforms abstract probabilities into intuitive risk levels, facilitating visualization and rapid decision-making. This helps staff take timely targeted measures such as load control and inspection, effectively reducing the harm of lightning-induced tripping. The entire process is interconnected, forming a closed loop from real-time data input to risk level output. It conforms to the physical characteristics of lightning and the electrical principles of power lines, and meets the actual needs of power systems for dynamic prevention and control of lightning risks.

[0011] A method for real-time dynamic assessment of lightning flashover risk in transmission lines, the specific method for obtaining current lightning status information from a lightning monitoring system is as follows: The system obtains current lightning information, including current lightning time t, current lightning location L, current lightning current amplitude I, and current lightning polarity.

[0012] The lightning time information t is used to look up lightning information based on the current time and is also retained in the output query results. The current lightning location L is used to calculate the horizontal distance to the line. The current lightning current amplitude I is used to calculate the lightning flashover probability. The current lightning polarity information is used to calculate the lightning withstand level.

[0013] A real-time dynamic assessment method for lightning flashover risk of transmission lines, such as Figure 2 As shown, the specific method for calculating the ground wire lightning strike probability and conductor lightning strike probability using existing lightning strike shielding analysis models based on current lightning situation information is as follows: Based on the line tower register in the lightning information system, calculate the horizontal distance D from the current lightning location L to the line. Taking the nearest tower T as the target, determine the line ground wire strike distance r according to the recommended formula in the regulations. s Line conductor strike distance r c ; (1) In the formula, U ph This is the operating potential of the conductor; Calculate the line grounding distance r s Line conductor strike distance r c Its core function is to provide key threshold criteria for lightning strike target determination. By clearly defining the spatial boundaries of the area where lightning may strike the ground wire or conductor, it accurately distinguishes whether lightning will strike the line itself, thereby providing a basis for determining the probability P of a lightning strike on the ground wire. 01 The probability of a conductor being struck by lightning, P 02 This lays the foundation for calculations. Its effects are reflected in significantly improving the accuracy and practicality of lightning strike probability calculations, avoiding misjudging lightning strikes near the line that haven't actually struck the line as potentially hitting it, and providing reliable prerequisite parameters for subsequent calculations of flashover probability based on lightning withstand levels. The reason for these effects lies in: the grounding distance r... s , conductor distance r c Based on actual parameters such as the line ground wire height and conductor operating potential, and derived through a formula recommended in the regulations, it objectively reflects the line's own structural ability to intercept lightning; (r) s and r c To determine the criteria, we can first screen out the lightning scenarios that are truly likely to hit the line, eliminate unrelated lightning interference, and then further refine the probability of lightning strike targets by combining the probability distribution of the lightning incident angle. This ensures that the entire assessment process conforms to the physical principles of the electrical geometric model and fits the actual operating environment of the transmission line, ultimately guaranteeing the accuracy and dynamism of the lightning flashover risk assessment.

[0014] Define the probability of a ground wire being struck by lightning as P. 01 The probability of a conductor being struck by lightning is P. 02 When D>r s And D>r c At that time, it was assumed that lightning would not strike the line itself, P 01 =P 02=0; otherwise, consider lightning incident at different tilt angles θ above the current lightning location L, where θ satisfies the probability distribution of equation (2). Let θ take values ​​θ1, θ2, ..., θ1 in the range (-π / 2, π / 2) with a certain step size. m To ensure accuracy, this invention takes m=100, that is, the step size is π / 100. Based on the electrical geometry model, the possible targets (ground wire, conductor) that lightning may strike are calculated. If the ground wire is struck, P is accumulated according to formula (3). 01_j Add q(θ) to P01. If the conductor is hit, add P according to formula (4). 02_j Where j represents the traversal index of θ, taking values ​​of 1, 2, 3...m, and the initial value is P. 01_0 =P 02_0= 0. At the end of the iteration, P 01 =P 01_m P 02 =P0 2_m .

[0015] q(θ) = 0.75 cos 3 θ (2) (3) (4) Where q(θ) represents the incident probability distribution, P 01_j P represents the probability of a ground wire lightning strike accumulated over the j-th time. 02_j Let q(θ) represent the cumulative probability of a wire being struck by lightning for the j-th time. j ) indicates that θ takes the value θ in the j-th time. j The incident probability distribution P at time 01_j-1 P represents the cumulative grounding lightning strike probability for the (j-1)th iteration. 02_j-1 This represents the cumulative probability of a lightning strike on the conductor in the (j-1)th iteration.

[0016] This invention calculates the probability of lightning strikes on the ground wire and the probability of lightning strikes on the conductor based on current lightning situation information using a lightning strike shielding analysis model. It can assess the lightning risk based on real-time lightning information. When assessing the lightning risk, it considers the risks caused by lightning striking the conductor (backflash) and lightning striking the ground wire (backflash), as well as the possibility of lightning entering at different angles. This is more in line with reality than simply considering vertical downward entry.

[0017] First, the lightning strike shielding analysis model uses current lightning situation information as input, rather than relying on historical statistical data. It can capture the specific parameters of each lightning event in real time, avoiding the limitation that historical average data cannot reflect immediate risks, thus realizing dynamic assessment of lightning strike risk. Second, the model clearly distinguishes between two core flashover scenarios: "lightning strikes the conductor (backflash)" and "lightning strikes the ground wire (backflash)". These are the main causes of lightning tripping of transmission lines, and their corresponding lightning resistance levels are also very different. By incorporating the risk calculation of both scenarios, it can comprehensively cover the potential fault paths of the line after being struck by lightning, avoiding risk omissions or errors caused by single-scenario assessment. Finally, the model abandons the simplified assumption that "lightning only occurs vertically downwards", and is based on the probability distribution of the lightning incident angle θ in equation (2) (q(θ)=0.75cos 3 The method uses θ to iterate through the range (-π / 2, π / 2) with small steps, fully considering the possibility that natural lightning may be incident at arbitrary angles due to the influence of terrain, towers, and electric fields near the ground when it approaches the ground. The electrical geometry model (EGM) combines the threshold determination of ground wire strike distance rs and conductor strike distance rc, which can accurately match the actual target (ground wire, conductor, or earth) hit by lightning under different incident angles, making the probability calculation more consistent with the actual lightning trajectory. Therefore, it has more practical reference value than the simple vertical incident assumption.

[0018] A real-time dynamic assessment method for lightning flashover risk of transmission lines, which can also calculate the line ground strike distance r based on current lightning situation information and a lightning strike shielding analysis model. g The electrical geometric model (EGM) is based on the line ground strike distance r. g Identify the target of the lightning strike.

[0019] Line ground strike distance r g The calculation method is as follows: (5) In the formula, h represents the height of the ground line from the earth. A real-time dynamic assessment method for lightning flashover risk of transmission lines, which calculates the probability of lightning flashover based on the ground wire lightning strike probability and conductor lightning strike probability, combined with current lightning situation information and the backflashover withstand level and the backflashover withstand level of tower T, is as follows: Define the backflashover probability as P1 and the line flashover probability as P2. Let T be the tower closest to the current lightning strike location L. Based on the tower register in the system, retrieve the backflashover withstand level I1 and the line flashover withstand level I2 of tower T. If the current lightning current amplitude I ≥ I1, then P1 = P2. 01 Otherwise, P1=0; if the current lightning current amplitude I≥I2, then P2=P 02 Otherwise, P2=0; the probability of lightning flashover of the line is P = P1+P2.

[0020] Since the line itself has a certain lightning withstand level, this invention also considers the current amplitude and compares it with the lightning withstand level when considering lightning strikes on the conductor or ground wire.

[0021] This invention precisely quantifies the flashover risk of transmission lines under actual lightning strike scenarios. It avoids ignoring the risk differences arising from the line's own lightning withstand level after a lightning strike, and comprehensively integrates the two key factors of "lightning strike probability" and "flashover likelihood" to form a scientific and comprehensive risk assessment logic. Its technical effects are reflected in: enabling refined calculation of lightning flashover risk, avoiding assessment bias caused by directly equating "lightning strike probability" with "flashover probability," and clearly distinguishing the risk contribution of backflashover and side-strike flashover paths, providing accurate data support for subsequent risk level classification and operation and maintenance decisions. The reasons for these effects are as follows: On the one hand, the design fully considers the different lightning withstand capabilities of different towers due to differences in structure and insulation configuration by retrieving the backflashover lightning withstand level I1 and the backflashover lightning withstand level I2 of a specific tower T in the tower ledger, making the assessment more in line with the actual conditions of the line; on the other hand, the present invention uses the "comparison between the current lightning current amplitude I and the lightning withstand level" as the basis for determining the flashover probability - only when the lightning current amplitude exceeds the corresponding lightning withstand level of the tower (I≥I1 or I≥I2) will the previously calculated ground wire / conductor lightning strike probability be used to obtain the line flashover probability (P1, P2), otherwise the flashover probability is 0. This is in line with the objective law in electrical principles that "flashover will only occur when the lightning current energy exceeds the line withstand level". At the same time, through the superposition calculation of P=P1+P2, the comprehensive risk of the two flashover scenarios is fully covered, ultimately ensuring the accuracy and practicality of the lightning flashover probability calculation.

[0022] A real-time dynamic assessment method for lightning flashover risk of transmission lines, wherein the specific method for classifying the lightning flashover risk level according to the probability of lightning flashover of the line as shown in Table 1 is as follows: When the P-value is greater than or equal to 0.5, the risk is classified as red. When the P-value is greater than 0 and less than 0.5, the risk level is classified as orange. When the P-value is 0, the risk level is classified as no risk. Table 1 Lightning Flashover Risk Level Standards Example 2 This embodiment discloses a real-time dynamic assessment system for lightning flashover risk of transmission lines, such as... Figure 3 As shown, it includes an information extraction module, a lightning strike probability calculation module, a flashover probability calculation module, and a risk assessment module: The information extraction module is used to obtain current lightning status information from the lightning monitoring system; The lightning strike probability calculation module is used to calculate the ground wire lightning strike probability and the conductor lightning strike probability based on the current lightning situation information and using the lightning strike shielding analysis model. The flashover probability calculation module is used to calculate the probability of line lightning flashover based on the ground wire lightning strike probability and conductor lightning strike probability, combined with the monitored current lightning current amplitude and the backflashover lightning withstand level and the backflashover lightning withstand level of tower T. The risk assessment module is used to classify the lightning flashover risk level based on the probability of line lightning flashover.

[0023] A real-time dynamic assessment system for lightning flashover risk of transmission lines, wherein the information extraction module obtains current lightning status information from a lightning monitoring system using the following specific method: Obtain current lightning information from the lightning monitoring system, including the current lightning location L and the current lightning current amplitude I.

[0024] A real-time dynamic assessment system for lightning flashover risk of transmission lines, wherein the lightning probability calculation module calculates the ground wire lightning probability and conductor lightning probability based on current lightning situation information using a lightning shielding analysis model. Based on the line tower register in the system, calculate the horizontal distance D from the current lightning location L to the line. Taking the nearest tower T as the target, determine the line ground wire strike distance r according to the recommended formula in the regulations. s Line conductor strike distance r c ; (6) In the formula, h is the height of the ground line from the earth, and U ph This is the operating potential of the conductor; Define the probability of a ground wire being struck by lightning as P. 01 The probability of a conductor being struck by lightning is P. 02 When D>r s And D>r c At that time, it was assumed that lightning would not strike the line itself, P 01 =P 02 =0; otherwise, consider lightning incident at different tilt angles θ above L, where θ satisfies the probability distribution of equation (7), and let θ take values ​​θ1, θ2, ..., θ in the range (-π / 2, π / 2) with a certain step size. m Based on the electrical geometry model, the possible targets (ground wire, conductor) that lightning may strike are calculated. If the ground wire is struck, P is accumulated according to formula (8). 01_j If the conductor is hit, P is accumulated according to formula (9). 02_j Where j represents the traversal index of θ, taking values ​​of 1, 2, 3...m, and the initial value is P. 01_0 =P 02_0=0. At the end of the iteration, P 01 =P 01_m P 02 =P 02_m .

[0025] q(θ) = 0.75 cos 3 θ (7) (8) (9) A real-time dynamic assessment system for lightning flashover risk of transmission lines, wherein the flashover probability calculation module is used to calculate the probability of lightning flashover of the line based on the ground wire lightning strike probability and conductor lightning strike probability, combined with the monitored current lightning current amplitude and the backflashover withstand level and the backflashover withstand level of tower T. The specific method for calculating the probability of lightning flashover of the line is as follows: Let P1 be the probability of a line backflashover and P2 be the probability of a line side-strike flashover. Let T be the tower closest to the current lightning strike location L. Based on the tower register in the system, retrieve the backflashover withstand level I1 and the side-strike withstand level I2 of tower T. If I ≥ I1, then P1 = P2. 01 Otherwise, P1=0; if I≥I2, then P2=P 02 Otherwise, P2=0; the probability of lightning flashover of the line is P = P1+P2.

[0026] A real-time dynamic assessment system for lightning flashover risk of transmission lines, wherein the risk assessment module uses the following specific method to classify the lightning flashover risk level based on the probability of lightning flashover of the line: When the P-value is greater than or equal to 0.5, the risk of lightning flashover is classified as red. When the P value is greater than 0 and less than 0.5, the lightning flashover risk level is classified as orange. When the P-value is equal to 0, the lightning flashover risk level is classified as no risk level.

[0027] For details regarding the above modules, please refer to the relevant descriptions and effects in Example 1 for further understanding.

[0028] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for real-time dynamic assessment of lightning flashover risk in transmission lines, characterized in that, It includes the following steps: Obtain real-time lightning information from the lightning monitoring system; Based on the current lightning situation information, the probability of ground wire lightning strike and the probability of conductor lightning strike are calculated using a lightning strike shielding analysis model. Based on the ground wire lightning strike probability and conductor lightning strike probability, combined with the current lightning situation information and the tower's backflashover and backflashover withstand levels, the probability of line lightning flashover is calculated. The risk level of lightning flashover is classified according to the probability of lightning flashover on the power line.

2. The method for real-time dynamic assessment of lightning flashover risk in transmission lines according to claim 1, characterized in that, Current lightning information includes the current lightning location L and the current lightning current amplitude I.

3. The method for real-time dynamic assessment of lightning flashover risk in transmission lines according to claim 2, characterized in that, The specific method for calculating the probability of lightning strikes on ground wires and conductors using a lightning strike shielding analysis model based on current lightning situation information is as follows: Based on the line tower register in the system, calculate the horizontal distance D from the current lightning location L to the line. Taking the nearest tower T as the target, determine the line ground wire strike distance r according to the recommended formula in the regulations. s Line conductor strike distance r c ; （1） In the formula, U ph This is the operating potential of the conductor; Define the probability of a ground wire being struck by lightning as P. 01 The probability of a conductor being struck by lightning is P. 02 When D>r s And D>r c At that time, it was assumed that lightning would not strike the line itself, P 01 =P 02 =0; otherwise, consider lightning incident at different tilt angles θ above the previous lightning position L, where θ satisfies the probability distribution of equation (2). Let θ take values ​​θ1, θ2, ... θj... in the range (-π / 2, π / 2) with a certain step size. m Based on the electrical geometry model, the possible targets that lightning may strike are calculated. If the lightning strikes the ground wire, P is accumulated according to formula (3). 01_j , will P 01 Accumulate q(θ), and if the wire is hit, accumulate P according to equation (4). 02_j Where j represents the traversal index of θ, taking values ​​of 1, 2, 3...j...m, where m is given empirically, and the initial value is P. 01_0 =P 02_0 =0; at the end of the iteration, P 01 =P 01_m P 02 =P 02_m ; q(θ) = 0.75 cos 3 θ (2) （3） （4） Where q(θ) represents the incident probability distribution, P 01_j P represents the probability of a ground wire lightning strike accumulated over the j-th time. 02_j Let q(θ) represent the cumulative probability of a wire being struck by lightning for the j-th time. j ) indicates that θ takes the value θ in the j-th time. j The incident probability distribution P at time 01_j-1 P represents the cumulative grounding lightning strike probability for the (j-1)th iteration. 02_j-1 This represents the cumulative probability of a wire being struck by lightning in the (j-1)th iteration.

4. The method for real-time dynamic assessment of lightning flashover risk in transmission lines according to claim 3, characterized in that, The specific method for calculating the probability of line lightning flashover, based on the ground wire lightning strike probability and conductor lightning strike probability, combined with current lightning situation information and the tower's backflashover withstand level and the tower's over-the-horizon lightning withstand level, is as follows: Define the probability of line backflashover as P1 and the probability of line flashover by swivel as P2. Based on the line tower ledger in the system, retrieve the tower's backflashover withstand level I1 and the tower's swivel withstand level I2. If the current lightning current amplitude I ≥ I1, then P1 = P2. 01 Otherwise, P1=0; if the current lightning current amplitude I≥I2, then P2=P 02 Otherwise, P2=0; the probability of lightning flashover of the line is P = P1+P2.

5. The method for real-time dynamic assessment of lightning flashover risk in transmission lines according to claim 4, characterized in that, The specific method for classifying the risk level of lightning flashover based on the probability of lightning flashover on power lines is as follows: When the P-value is greater than or equal to 0.5, the risk is classified as red. When the P-value is greater than 0 and less than 0.5, the risk level is classified as orange. When the P-value is 0, the risk level is classified as no risk.

6. A real-time dynamic assessment system for lightning flashover risk of transmission lines, characterized in that, It includes an information extraction module, a lightning strike probability calculation module, a flashover probability calculation module, and a risk assessment module: The information extraction module is used to obtain current lightning status information from the lightning monitoring system; The lightning strike probability calculation module is used to calculate the ground wire lightning strike probability and the conductor lightning strike probability based on the current lightning situation information and using the lightning strike shielding analysis model. The flashover probability calculation module is used to calculate the probability of line lightning flashover based on the ground wire lightning strike probability and conductor lightning strike probability, combined with the monitored current lightning situation information and the tower's backflashover resistance level and tower's backflashover resistance level. The risk assessment module is used to classify the lightning flashover risk level based on the probability of line lightning flashover.

7. A real-time dynamic assessment system for lightning flashover risk of transmission lines according to claim 6, characterized in that, The specific method by which the information extraction module obtains current lightning situation information from the lightning monitoring system is as follows: Obtain current lightning information from the lightning monitoring system, including the current lightning location L and the current lightning current amplitude I.

8. The real-time dynamic assessment system for lightning flashover risk of transmission lines according to claim 6, characterized in that, The specific method used by the lightning strike probability calculation module to calculate the ground wire lightning strike probability and the conductor lightning strike probability based on the current lightning situation information and using the lightning strike shielding analysis model is as follows: Based on the line tower register in the system, calculate the horizontal distance D from the current lightning location L to the line. Taking the nearest tower T as the target, determine the line ground wire strike distance r according to the recommended formula in the regulations. s Line conductor strike distance r c ; （5） In the formula, U ph This is the operating potential of the conductor; Define the probability of a ground wire being struck by lightning as P. 01 The probability of a conductor being struck by lightning is P. 02 When D>r s And D>r c At that time, it was assumed that lightning would not strike the line itself, P 01 =P 02 =0; otherwise, consider lightning incident at different tilt angles θ above L, where θ satisfies the probability distribution of equation (6), and let θ take values ​​θ1, θ2, ..., θ in the range (-π / 2, π / 2) with a certain step size. m Based on the electrical geometry model, the possible targets (ground wire, conductor) that lightning may strike are calculated. If the ground wire is struck, P is accumulated according to formula (7). 01_j If the wire is hit, P is added according to formula (8). 02_j Where j represents the traversal index of θ, taking values ​​of 1, 2, 3...m, and the initial value is P. 01_0 =P 02_0 =0; at the end of the iteration, P 01 =P 01_m P 02 =P 02_m ; q(θ) = 0.75 cos 3 θ (6) （7） （8） Where q(θ) represents the incident probability distribution, P 01_j P represents the probability of a ground wire lightning strike accumulated over the j-th time. 02_j Let q(θ) represent the cumulative probability of a wire being struck by lightning for the j-th time. j ) indicates that θ takes the value θ in the j-th time. j The incident probability distribution P at time 01_j-1 P represents the cumulative grounding lightning strike probability for the (j-1)th iteration. 02_j-1 This represents the cumulative probability of a wire being struck by lightning in the (j-1)th iteration.

9. A real-time dynamic assessment system for lightning flashover risk of transmission lines according to claim 6, characterized in that, The flashover probability calculation module is used to calculate the probability of line lightning flashover based on the ground wire lightning strike probability and conductor lightning strike probability, combined with the monitored current lightning current amplitude and the backflashover withstand level and the backflashover withstand level of tower T. The specific method for calculating the probability of line lightning flashover is as follows: Define the backflashover probability as P1 and the line flashover probability as P2. Based on the line tower ledger in the system, retrieve the backflashover withstand level I1 and the line flashover withstand level I2 of tower T. If the current lightning current amplitude I ≥ I1, then P1 = P2. 01 Otherwise, P1=0; if the current lightning current amplitude I≥I2, then P2=P 02 Otherwise, P2=0; the probability of lightning flashover of the line is P = P1+P2.

10. A real-time dynamic assessment system for lightning flashover risk of transmission lines according to claim 6, characterized in that, The specific method used by the risk assessment module to classify the lightning flashover risk level based on the probability of line lightning flashover is as follows: When the P-value is greater than or equal to 0.5, the risk of lightning flashover is classified as red. When the P value is greater than 0 and less than 0.5, the lightning flashover risk level is classified as orange. When the P-value is equal to 0, the lightning flashover risk level is classified as no risk level.

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