A method for visualizing calculation of a shielding failure trip-out rate of a power transmission line under complex terrain

Abstract

The present application relates to the technical field of transmission line risk assessment, and more particularly to a method for visualizing calculation of the shielding failure trip-out rate of a transmission line in complex terrain. The technical solution comprises the following steps: determining the transmission line in complex terrain as the main object of study, dividing the transmission line corridor, and obtaining three-dimensional data of the complex terrain using the spatial analysis function of GIS and the three-dimensional GIM model; based on the obtained terrain profile data, calculating the lightning withstand level of the insulator and taking it as the minimum shielding failure lightning current of the EGM, and then calculating the radius of the shielding failure circle of the ground wire, the radius of the shielding failure circle of the conductor, and the radius of the shielding failure circle of the ground through the shielding distance formula of the electrical geometry model to establish the electrical geometry model under the profile. The present application comprehensively considers the influence of complex terrain on the shielding failure of the transmission line, and provides scientific and effective support for lightning protection of the transmission line through accurate calculation and visualized analysis, which is of great significance to the safe and stable operation of the power grid.

Description

Technical Field

[0001] This invention relates to the field of transmission line risk assessment technology, and in particular to a method for visually calculating the tripping rate of transmission lines in complex terrain. Background Technology

[0002] Lightning disasters, listed as one of the ten most serious hazards by relevant UN organizations, pose a significant threat to the safe and stable operation of power systems. With the continuous expansion of my country's power grid construction, the coverage of overhead transmission lines is constantly extending, and line corridors are becoming increasingly dense, significantly increasing the probability of transmission lines being struck by lightning. Extensive operational experience shows that for high-tower and high-voltage transmission lines, lightning tripping accidents mainly occur in the form of bypass strikes. This is especially true when transmission lines traverse complex terrain, where the complexity of the topography greatly increases the difficulty of assessing bypass strike performance.

[0003] Transmission line corridors often face diverse and complex terrain environments, including winding, undulating mountains, valleys, and slopes. The diversity of topographic and geological parameters significantly increases the complexity of lightning protection work for transmission lines. For example, long-span lines crossing valleys and rivers face a significantly increased risk of lightning striking the conductor from the side, causing outages due to side strikes.

[0004] In existing technologies, conventional electrical geometric models (EGMs) use only a simple ground tilt angle to approximate complex terrain when calculating the tripping rate of transmission line corridors. This simplified approach cannot accurately reflect the actual impact of complex terrain on the risk of transmission line backflashover, resulting in a large deviation between the calculation results and the actual situation. This makes it difficult to formulate effective lightning protection measures and increases the risk to the safe operation of transmission lines.

[0005] Although the patent documents "A method and system for lightning protection of power grids in complex terrain areas" (CN119674887A) and "A system and method for assessing the lightning strike risk of transmission lines and storage medium" (CN119990740A) have studied the risk of lightning strikes on transmission lines in complex terrain and proposed corresponding calculation models based on lightning activity data, topographic features and other characteristics, they still use the ground tilt angle to approximate the complex terrain. They cannot accurately consider the impact of irregular mountain undulations on transmission lines in actual complex terrain areas, and it is difficult to specifically calculate and analyze the lightning strike trip rate of transmission line corridors in complex terrain.

[0006] Therefore, in order to achieve a refined and accurate assessment of the risk of power transmission line tripping due to indirect impacts in complex terrain, there is an urgent need for a calculation method that can fully incorporate the actual characteristics of complex terrain. Summary of the Invention

[0007] The purpose of this invention is to address the problem in the background technology that there are no corresponding lightning protection measures for the irregular undulation of mountains under complex terrain and the different shielding effects of different mountain terrains on transmission lines. The invention proposes a visualization calculation method for the tripping rate of transmission lines under complex terrain.

[0008] The technical solution of this invention: A method for visually calculating the tripping rate of transmission lines under complex terrain, comprising the following steps:

[0009] S1: Identify the transmission lines under complex terrain as the main research object, divide the transmission line corridor, and use the spatial analysis function of GIS and the three-dimensional GIM model to obtain the three-dimensional data of the complex terrain.

[0010] S2: Based on the obtained terrain profile data, calculate the lightning withstand level of the insulator and use it as the minimum lightning strike current around the EGM. Then, calculate the strike distance radius of the lightning conductor, the strike distance radius of the conductor, and the strike distance radius of the ground through the strike distance formula of the electrical geometry model, and establish the electrical geometry model under this profile.

[0011] S3: Calculate the exposed arc length of the lightning conductor and the conductor under the minimum lightning strike current using the program, consider the mutual shielding effect between the exposed arcs, obtain the projected length of the exposed arc of the conductor when the lightning strike angle is vertically downward and store it.

[0012] S4: Calculate different elevation angles The exposed arc oblique projection length of the conductor below The probability distribution of the initial lightning strike angle is determined, and the maximum lightning current is determined by judging whether the horizontal oblique projection length of the exposed arc of the conductor is 0.

[0013] S5: Convert the horizontal oblique projection length of the exposed arc of the conductor into the effective projection length of the exposed arc, calculate the number of times the line shield fails and causes flashover, and then obtain the backlash trip rate of the profile and the backlash trip rate of the micro-element.

[0014] S6: Perform segmented calculations for each span of the transmission line, and transfer half of the backlash trip rate on each side of the tower to the tower. Assess the backlash trip risk of the transmission line corridor through the backlash trip rate of the tower.

[0015] Optionally, in step S1, the entire complex terrain transmission line corridor is divided into segments at a fixed interval ΔL, and the extracted data includes the conductor-to-ground height, relative centerline distance, and complex terrain elevation of the entire complex terrain transmission line corridor.

[0016] Optionally, in step S2, the lightning withstand level of the insulator is calculated using a formula. And as the minimum lightning strike current of EGM. Lightning resistance level The calculation formula is:

[0017]

[0018] In the formula: This is the impulse flashover voltage at 50% of the negative polarity of the insulator, expressed in kV. This is the system's highest operating voltage, expressed in kV. The impedance of the lightning channel is expressed in Ω. This represents the wave impedance of the conductor, measured in Ω.

[0019] Optionally, in step S2, the radius of the lightning conductor's strike distance circle is calculated using the strike distance formula of the electrical geometric model. Wire striking distance radius and the radius of the ground strike distance The specific calculation formula is as follows:

[0020]

[0021]

[0022]

[0023] In the formula: The radius of the strike distance circle for the lightning protection wire is in meters. The radius of the conductor strike distance circle is in meters. The radius of the ground impact distance is in meters. This represents the amplitude of the lightning current, in kA. This represents the instantaneous value of the working voltage on the conductor, in kV. The height of the conductor above the ground is expressed in meters (m).

[0024] Optionally, in step S3, the profile is calculated using a Matlab program. Minimum lightning strike current The lengths of the exposed arcs AB and AF of the lower lightning protection conductor, and the lengths of the exposed arcs BC, CD, DE, FG, GD, and HI of the conductor, are calculated and stored in matrix form. These results are used to determine the maximum lightning current when the lightning protection conductor is fully shielded from the conductor. .

[0025] Optionally, in step S4, The range of values ​​is from arrive Each calculation interval The probability distribution of different lightning incident angles is calculated using the following formula:

[0026]

[0027] In the formula: The angle of incidence of lightning is expressed in rad. Let be the probability distribution of the lightning incident angle, and let the lightning current increment be... =0.1kA.

[0028] Optionally, in step S5, the horizontal oblique projection length of all exposed arcs of the conductor is calculated using a formula. Converted to effective exposed arc projection length The conversion formula is:

[0029] ,

[0030] In the formula, The effective exposed arc projection length, in meters; The horizontal oblique projection length of the exposed arc, in meters; The angle of incidence of lightning is expressed in rad. This represents the amplitude of the lightning current, in kA.

[0031] The number of line shielding failures and flashovers caused by different lightning incidence angles. Represented as:

[0032]

[0033] In the formula: The number of flashovers, measured in times per 100km. 2 ∙a; This refers to the lightning density, measured in lightning strikes per km. 2 ∙a; This represents the maximum lightning strike current, expressed in kA. This is the minimum lightning strike current, expressed in kA. The effective exposed arc projection length, in meters; The angle of incidence of lightning is expressed in rad. This represents the amplitude of the lightning current, in kA. This represents the probability distribution of the lightning incident angle. Let be the probability density function of lightning current. .

[0034] Optionally, in step S5, to simplify the calculation, The integral calculation is transformed into the sum of differentials, and the specific calculation formula is as follows:

[0035]

[0036] In the formula, The number of flashovers, measured in times per 100km. 2 ∙a; This refers to the lightning density, measured in lightning strikes per km. 2 ∙a; This represents the maximum lightning strike current, expressed in kA. This is the minimum lightning strike current, expressed in kA. The effective exposed arc projection length, in meters; The angle of incidence of lightning is expressed in rad. This represents the amplitude of the lightning current, in kA. This represents the probability distribution of the lightning incident angle. Let be the probability of lightning current, expressed as The calculation results Substituting the matrix into the above formula yields the cross-section. Number of flashovers Through formula The profile can then be calculated. The tripping rate of the circuit breaker is calculated, and the tripping rate of the circuit breaker in this profile is multiplied by the segmentation spacing. Approximately this infinitesimal element The tripping rate of the circuit breaker .

[0037] In the formula: The tripping rate is measured in trips per 100km. 2 ∙a; The number of flashovers, measured in times per 100km. 2 ∙a; The probability of tripping after flashover is given for lines without automatic reclosing. Lines equipped with automatic reclosing .

[0038] Optionally, in step S6, after obtaining all infinitesimal elements... The tripping rate of the circuit breaker Then, each span of the transmission line is calculated in segments, and the tripping rate of half of the spans on both sides of a certain tower is attributed to the tower.

[0039] Compared with the prior art, this application includes at least one of the following beneficial technical effects:

[0040] Breaking away from the limitations of traditional methods that only simplify complex terrain based on ground inclination angle, this paper establishes an electrical geometric model (EGM) based on elevation data of actual terrain features. This model can more accurately calculate the out-of-line tripping rate of transmission lines under complex terrain, and fully consider the impact of irregular terrain such as mountain undulations on out-of-line risk, making the assessment results more consistent with the actual situation.

[0041] By analyzing and saving the EGM of complex terrain under different lightning currents and lightning leader incidence angles, the changes in the electrical geometry model are presented intuitively. This makes it easy to clearly observe the changes in the development path of the lightning leader (such as mountain tops, slopes, valleys, etc.) and its impact on the probability of backflashover, and to gain a deeper understanding of the shielding effect of complex terrain on transmission lines.

[0042] This provides a basis for scientific lightning risk assessment of transmission line corridors in complex terrain, which helps to develop targeted lightning protection measures. By accurately assessing the tripping rate of each tower, differentiated protection can be implemented according to the risk level of different sections, thereby improving the effectiveness of lightning protection work.

[0043] By accurately calculating the lightning strike trip rate and conducting risk assessments, we can identify the weak points of transmission lines in complex terrain in advance, take reasonable lightning protection measures, reduce the occurrence of lightning trip accidents, and thus ensure the high reliability of transmission lines and maintain the stability of the entire power grid.

[0044] In summary, this invention comprehensively considers the impact of complex terrain on lightning strikes on transmission lines. Through precise calculations and visualization analysis, it provides scientific and effective support for lightning protection of transmission lines, which is of great significance for ensuring the safe and stable operation of the power grid. Attached Figure Description

[0045] Figure 1 A flowchart illustrating a method for visually calculating the tripping rate of transmission lines in complex terrain;

[0046] Figure 2 A 3D GIM model and a schematic diagram of the subdivision of a power transmission line in complex terrain;

[0047] Figure 3 A schematic diagram of the line and terrain parameters extracted from the profile of the power transmission line corridor;

[0048] Figure 4 The EGM model diagram is shown when the lightning current incident angle is 90°.

[0049] Figure 5 The EGM model diagram is shown when the lightning current incident angle is 50°.

[0050] Figure 6 The diagram shows the EGM model with a lightning current incident angle of 130°. Detailed Implementation

[0051] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0052] Example

[0053] like Figure 1As shown, the present invention provides a visualization calculation of the tripping rate of transmission line corridors in complex terrain, comprising the following steps:

[0054] Step S1: Identify the transmission lines in complex terrain as the main research subject, and divide the entire transmission line corridor in complex terrain into sections with fixed intervals. Perform subdivision, such as Figure 2 As shown, 3D data of complex terrain was obtained using the spatial analysis functions of GIS and a 3D GIM model. The main focus was on extracting relevant data such as the conductor-to-ground height, distance from the centerline, and elevation of the complex terrain along the entire transmission line corridor. The extracted profile... Data such as Figure 3 As shown in the figure, the conductor and ground wire heights of the transmission line and the complex terrain can be seen.

[0055] Step S2: After obtaining the topographic profile data of the transmission line corridor in complex terrain, the profile is... The tripping rate is calculated using the formula. Calculate the lightning withstand level of the insulator And as the minimum lightning strike current around the EGM The minimum lightning strike current calculated in this example ;

[0056]

[0057] In the formula: The impulse flashover voltage of the insulator's negative polarity is 50% in kV; The system's highest operating voltage is in kV. The impedance of the lightning channel is given in Ω. The conductor wave impedance is expressed in Ω.

[0058] The striking distance formula based on the electrical geometry model ~ The radius of the lightning strike distance circle was calculated separately. Wire striking distance radius and the radius of the ground strike distance And establish the electrical geometry model under this section.

[0059]

[0060]

[0061]

[0062] In the formula: The radius of the strike distance circle of the lightning protection wire is in meters. The radius of the conductor striking distance circle is in meters. The radius of the ground impact distance is in meters. The magnitude of the lightning current is kA; The instantaneous value of the working voltage on the conductor, in kV; The height of the conductor above the ground, in meters (m).

[0063] Step S3: Use Matlab programming to calculate the profile. Minimum lightning strike current The lengths of the exposed arcs AB and AF of the lower lightning protection conductor, and the exposed arcs BC, CD, DE, FG, GD, and HI of the conductor are determined. By judging the relative positions of the conductor and ground wire and considering the mutual shielding effect between the exposed arcs, the final profile is obtained. Minimum lightning strike current And the projected length of the exposed arc of the conductor when the lightning strikes at a perpendicular downward angle. The calculated results are stored in matrix form for calculating the bypass tripping rate and determining the maximum bypass lightning current when the lightning protection conductor is fully shielded. ;

[0064] Step S4: Based on step S3, calculate different elevation angles The exposed arc oblique projection length of the conductor below To realize different lightning strike incident angles, the EGM model under different lightning current incident angles is as follows: Figures 4-6 As shown in the figure, the location information of the lightning protection wire and the conductor, their exposure arcs, the ground strike distance curve, and the calculated values ​​are displayed. ; Figure 4 for The visualization results at an incident angle of 90° under kA show that the exposed arc projection length of the lightning protection wire is 45.6m and the exposed arc projection length of the conductor is 4.4m. Figures 5-6 for The visualization results at kA with incident angles of 50° and 130° show that, due to the influence of the mountain on the left, the exposed arc projection length of the conductor is 16.2m and 12.6m at incident angles of 50° and 130°, respectively. The visualization results can help to better analyze the impact of complex terrain on EGM and thus more accurately calculate the out-of-line tripping rate of the transmission line. The range of values ​​is from arrive Each calculation interval In reality, the initial incidence angle of lightning follows a certain probability distribution, as expressed by the equation... To calculate the probability distribution of different lightning incident angles.

[0065]

[0066] In the formula: The angle of incidence of lightning is expressed in rad. Let be the probability distribution of the lightning incident angle, and let the lightning current increment be... =0.1kA.

[0067] Horizontal oblique projection length of the exposed arc of the conductor at each angle Stored in a matrix, then judged. If the value is 0, it means the conductor is completely shielded by the lightning protection wire and the ground; otherwise, the lightning current is changed to... Continue repeating steps S2, S3, and S4 to calculate the exposed arc of the conductor and then make a judgment, until... When all values ​​are 0, the current lightning current is the maximum lightning strike current. The lightning current increment is The calculated matrices for different lightning current incident angles and different lightning current amplitudes. As shown in Table 1;

[0068] Table 1. Lightning current incident angles at different lightning current amplitudes Calculation results

[0069] Incident angle / ° Lightning current amplitude / kA 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 110.0 120.0 130.0 140.0 150.0 160.0 2.2. 99.0 60.6 40.1 26.8 16.8 8.9 4.3 1.5 4.3 8.9 16.9 26.9 40.4 61.0 99.8 2.3 79.6 49.2 33.1 22.6 14.7 8.4 4.0 1.0 4.0 8.8 15.9 24.6 36.3 54.2 87.8 2.4 67.9 42.5 29.0 20.2 13.6 8.3 3.8 0.5 3.8 8.5 14.3 21.5 31.1 45.8 73.6 2.5 53.6 33.8 23.3 16.4 11.3 7.2 3.5 0.0 3.5 7.5 12.0 17.6 25.1 36.6 58.1 2.6 37.6 23.9 16.5 11.8 8.2 5.3 2.8 0.0 2.8 5.3 8.1 11.7 16.4 23.7 37.3 2.7 21.9 13.9 9.7 6.9 4.9 3.2 1.7 0.0 1.5 2.8 4.2 6.0 8.4 12.0 18.8 2.8 3.1 2.0 1.4 1.0 0.7 0.5 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

[0070] Step S5: Step 4 can be used to obtain the conductor under lightning current. and the angle of lightning incidence Matrix, through formula Horizontal oblique projection length of all exposed arcs of the conductor Converted to effective exposed arc projection length .

[0071]

[0072] The number of line shielding failures and flashovers caused by different lightning incidence angles. It can be represented as:

[0073]

[0074] In the formula: The density of ground flashes is given in terms of flashes per km. 2 ∙a; Let be the probability density function of lightning current. .

[0075] To simplify the calculation, the integral calculation is converted into a differential summation calculation. Transform into formula .

[0076]

[0077] In the formula: Let be the probability of lightning current, expressed as ;

[0078] The calculation results Matrix substitution Calculated profile Number of flashovers Through the formula The profile can then be calculated. The tripping rate of the circuit breaker is calculated, and the tripping rate of the circuit breaker in this profile is multiplied by the segmentation spacing. Approximately this infinitesimal element The tripping rate of the circuit breaker The calculations in this example yielded... The tripping rate due to the impact is 0.0062 times / (100 km·year).

[0079]

[0080] In the formula: The probability of tripping after flashover is given for lines without automatic reclosing. Lines equipped with automatic reclosing ;

[0081] Step S6: After obtaining all infinitesimal elements The tripping rate of the circuit breaker Subsequently, segmented calculations were performed for each span of the transmission line. The tripping rate from the backlashes on both sides of a certain tower was allocated to the tower itself, and the backlash tripping rate of the tower was used to assess the risk of backlash tripping in transmission line corridors under complex terrain. The calculated backlash tripping rate for the 200km transmission line in this example was 0.0124 times / year. Furthermore, the impact of terrain on the EGM model can be studied through visualization.

[0082] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A method for visually calculating the tripping rate of transmission lines in complex terrain, characterized in that, Includes the following steps: S1: Identify the transmission lines under complex terrain as the main research object, divide the transmission line corridor, and use the spatial analysis function of GIS and the three-dimensional GIM model to obtain the three-dimensional data of the complex terrain. S2: Based on the obtained terrain profile data, calculate the lightning withstand level of the insulator and use it as the minimum lightning strike current around the EGM. Then, calculate the strike distance radius of the lightning conductor, the strike distance radius of the conductor, and the ground strike distance radius using the strike distance formula of the electrical geometry model, and establish the electrical geometry model under this profile; use the formula to calculate the lightning withstand level of the insulator. And as the minimum lightning strike current of EGM Lightning resistance level The calculation formula is: ， In the formula: This is the impulse flashover voltage of 50% of the negative polarity of the insulator, expressed in kV. This is the system's highest operating voltage, expressed in kV. The impedance of the lightning channel is expressed in Ω. The wave impedance of the conductor is expressed in Ω. S3: Calculate the exposed arc length of the lightning conductor and the conductor under the minimum lightning strike current using the program, consider the mutual shielding effect between the exposed arcs, obtain the projected length of the exposed arc of the conductor when the lightning strike angle is vertically downward and store it. S4: Calculate different elevation angles The exposed arc oblique projection length of the conductor below The probability distribution of the initial lightning strike angle is determined, and the maximum lightning current is determined by judging whether the horizontal oblique projection length of the exposed arc of the conductor is 0. S5: Convert the horizontal oblique projection length of the exposed arc of the conductor into the effective projection length of the exposed arc, calculate the number of times the line shield fails and causes flashover, and then obtain the backlash trip rate of the profile and the backlash trip rate of the micro-element. S6: Perform segmented calculations for each span of the transmission line, and transfer half of the backlash trip rate on each side of the tower to the tower. Assess the backlash trip risk of the transmission line corridor through the backlash trip rate of the tower.

2. The method for visually calculating the tripping rate of transmission lines in complex terrain according to claim 1, characterized in that, In step S1, the entire complex terrain transmission line corridor is divided into segments with a fixed spacing ΔL. The extracted data includes the conductor-to-ground height, relative centerline distance, and complex terrain elevation of the entire complex terrain transmission line corridor.

3. The method for visually calculating the tripping rate of transmission lines in complex terrain according to claim 1, characterized in that, In step S2, the radius of the lightning conductor's strike distance circle is calculated using the strike distance formula from the electrical geometric model. Wire striking distance radius and the radius of the ground strike distance The specific calculation formula is as follows: ； ， ， In the formula: The radius of the strike distance circle for the lightning protection wire is in meters. The radius of the conductor strike distance circle is in meters. The radius of the ground impact distance is in meters. This represents the amplitude of the lightning current, in kA. This represents the instantaneous value of the working voltage on the conductor, in kV. The height of the conductor above the ground is expressed in meters (m).

4. The method for visually calculating the tripping rate of transmission lines in complex terrain according to claim 1, characterized in that, In step S3, the profile is calculated using a Matlab program. Minimum lightning strike current The lengths of the exposed arcs AB and AF of the lower lightning protection conductor, and the lengths of the exposed arcs BC, CD, DE, FG, GD, and HI of the conductor, are calculated and stored in matrix form. These results are used to determine the maximum lightning current when the lightning protection conductor is fully shielded from the conductor. .

5. The method for visually calculating the tripping rate of transmission lines in complex terrain according to claim 1, characterized in that, In step S4, The range of values ​​is from arrive Each calculation interval The probability distribution of different lightning incident angles is calculated using the following formula: ， In the formula: The angle of incidence of lightning is expressed in rad. Let be the probability distribution of the lightning incident angle, and let the lightning current increment be... =0.1kA.

6. The method for visually calculating the tripping rate of transmission lines in complex terrain according to claim 1, characterized in that, In step S5, the horizontal oblique projection length of all exposed arcs of the conductor is calculated using a formula. Converted to effective exposed arc projection length The conversion formula is: ， In the formula, The effective exposed arc projection length, in meters; The horizontal oblique projection length of the exposed arc, in meters; The angle of incidence of lightning is expressed in rad. This represents the amplitude of the lightning current, in kA. The number of line shielding failures and flashovers caused by different lightning incidence angles. Represented as: ， In the formula: The number of flashovers, measured in times per 100km. 2 ∙a; This refers to the lightning density, measured in lightning strikes per km. 2 ∙a; This represents the maximum lightning strike current, expressed in kA. This is the minimum lightning strike current, expressed in kA. The effective exposed arc projection length, in meters; The angle of incidence of lightning is expressed in rad. This represents the amplitude of the lightning current, in kA. This represents the probability distribution of the lightning incident angle. Let be the probability density function of lightning current. .

7. The method for visually calculating the tripping rate of transmission lines in complex terrain according to claim 6, characterized in that, In step S5, to simplify the calculation, The integral calculation is transformed into the sum of differentials, and the specific calculation formula is as follows: ， In the formula, The number of flashovers, measured in times per 100km. 2 ∙a; This refers to the lightning density, measured in lightning strikes per km. 2 ∙a; This represents the maximum lightning strike current, expressed in kA. This is the minimum lightning strike current, expressed in kA. The effective exposed arc projection length, in meters; The angle of incidence of lightning is expressed in rad. This represents the amplitude of the lightning current, in kA. This represents the probability distribution of the lightning incident angle. Let be the probability of lightning current, expressed as The calculated result Substituting the matrix into the above formula yields the cross-section. Number of flashovers Through formula The profile can then be calculated. The tripping rate of the circuit breaker is calculated, and the tripping rate of the circuit breaker in this profile is multiplied by the segmentation spacing. Approximately this infinitesimal element The tripping rate of the circuit breaker ; In the formula: The tripping rate is measured in trips per 100km. 2 ∙a; The number of flashovers, measured in times per 100km. 2 ∙a; The probability of tripping after flashover is given for lines without automatic reclosing. Lines equipped with automatic reclosing .

8. The method for visually calculating the tripping rate of transmission lines in complex terrain according to claim 7, characterized in that, In step S6, after obtaining all infinitesimal elements... The tripping rate of the circuit breaker Then, each span of the transmission line is calculated in segments, and the tripping rate of half of the spans on both sides of a certain tower is attributed to the tower.

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