A risk prediction method for power transmission lines in complex terrain

Abstract

The present invention discloses a risk prediction method for power transmission lines in complex terrain, including: initializing data; calculating the response of power transmission towers under wind load, calculating the resistance index of power transmission towers, comparing the response and resistance index of power transmission towers, and establishing a wind disaster vulnerability model for power transmission towers that is universal for terrain; obtaining the layout parameters of the power transmission tower line system and the wind speed and wind direction of the microscale typhoon forecast wind field on the system based on the forecast results of the microscale typhoon forecast wind field, the longitude and latitude of the power transmission towers, and the digital elevation model data; obtaining the risk prediction of power transmission lines in complex terrain based on the wind disaster vulnerability model for power transmission towers that is universal for terrain, and based on the obtained layout parameters of the power transmission tower line system and the wind speed and wind direction of the microscale typhoon forecast wind field on the power transmission tower line system. The present invention realizes the risk prediction of power transmission lines in complex terrain by establishing a wind disaster vulnerability model for power transmission towers that is universal for terrain.

Description

Technical Field

[0001] The present invention relates to the technical field of risk prediction of power transmission lines, and in particular to a risk prediction method for power transmission lines in complex terrains. Background Art

[0002] The power transmission system in coastal areas is often attacked by typhoons. The transmission lines are affected by the strong winds caused by typhoons, which may cause the collapse of transmission towers, resulting in short circuits in the transmission lines and loss of power transmission function. Therefore, it is necessary to conduct real-time early warning of transmission lines during typhoon disasters, and then prepare maintenance resources in advance, or implement some preventive operation and management measures for the power grid, so as to reduce the time and space scope of power outages.

[0003] However, the existing research on real-time early warning of transmission lines is all for transmission lines on flat ground. It usually adopts a wind disaster vulnerability model of transmission towers dedicated to flat ground to predict the failure probability of transmission lines, while the transmission towers in the transmission system may be located in various complex terrains. Even if a wind disaster vulnerability model is established for transmission towers with a specific layout in a specific complex terrain, this specific vulnerability model is not suitable for thousands of transmission tower lines in different complex terrains with different layout parameters in the regional transmission system. How to develop from the previous flat ground-specific vulnerability model used for structural monomer risk analysis to a terrain-general vulnerability model suitable for engineering system risk assessment, so as to predict the risk of transmission lines in complex terrain, is the technical difficulty. Summary of the invention

[0004] In order to overcome the deficiencies of the above technologies, the present invention provides a risk prediction method for transmission lines in complex terrains. The present invention establishes a terrain-universal transmission tower wind disaster vulnerability model to predict the risks of transmission lines in complex terrains.

[0005] Terminology explanation:

[0006] Push-over: nonlinear static push-over.

[0007] The technical solution adopted by the present invention to overcome the technical problems is:

[0008] A risk prediction method for power transmission lines in complex terrains comprises the following steps:

[0009] S1, initialization data, the data at least including the forecast results of the micro-scale typhoon forecast wind field, the transmission system topology, the design data of the transmission tower and the ground wire, the longitude and latitude of the transmission tower, and the digital elevation model data, wherein the forecast accuracy of the micro-scale typhoon forecast wind field is 10 to 100m, and the transmission system topology is a geometric figure composed of the transmission tower and the ground wire connecting the adjacent transmission towers;

[0010] S2. Based on the design data of the transmission tower and the ground wire in step S1, a finite element model of the transmission tower line system is established, and sampling is performed based on the probability distribution of the gust response coefficient to consider the uncertainty of the wind load, and the response of the transmission tower under the wind load is calculated, wherein the transmission tower line system consists of a transmission tower and the ground wires on both sides thereof; the resistance index of the transmission tower is obtained by a push-over analysis method; the response and resistance index of the transmission tower are compared to determine whether the transmission tower collapses, thereby establishing a transmission tower wind disaster vulnerability model that is universal for terrain;

[0011] S3, based on the forecast result of the micro-scale typhoon forecast wind field in step S1, the longitude and latitude of the transmission tower, and the digital elevation model data, obtain the layout parameters of the transmission tower line system and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system;

[0012] S4. Based on the terrain-general transmission tower wind disaster vulnerability model obtained in step S2, and based on the layout parameters of the transmission tower line system obtained in step S3 and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system, a risk forecast for the transmission line in complex terrain is obtained.

[0013] Furthermore, in step S1, the microscale typhoon forecast wind field is obtained at least through the WRF meteorological model, and the output forecast result is an array of points, each point corresponds to a geographical location, and has the wind speed value and wind direction value at that location, and the distance between two adjacent points is the accuracy of the forecast wind field. In the microscale typhoon forecast wind field, the distance between two adjacent points is 10 to 100 meters, and the microscale typhoon forecast wind field includes the regional range where the entire power transmission system is located.

[0014] Furthermore, in step S1, the accuracy of the digital elevation model is 5 to 30 m.

[0015] Furthermore, in step S2, the terrain-general transmission tower wind disaster vulnerability model is expressed as follows:

[0016] (1)

[0017] In formula (1), P It represents the probability of transmission tower collapse; and They represent the wind speed and wind direction of the micro-scale typhoon forecast wind field at various locations on the transmission tower line system; represents the layout parameters of the transmission tower line system, and has ,in, L 1 and L 2 respectively represent the spans of the ground wires on both sides of the transmission tower in the transmission tower line system, H1 and H 2 respectively represent the height difference of the ground wires on both sides of the transmission tower in the transmission tower line system, θ Indicates the turning angle of the ground wire on both sides of the transmission tower in the transmission tower line system; f yes function.

[0018] Further, in step S2, the wind speed of the micro-scale typhoon forecast wind field at various locations on the transmission tower line system is ,wind direction And the layout parameters of the transmission tower line system The wind load on the transmission towers in the transmission tower line system is calculated.

[0019] Furthermore, in step S2, a wind load is applied to the finite element model of the transmission tower line system, and the response of the transmission tower is calculated, where the response of the transmission tower includes the displacement of the top of the transmission tower.

[0020] Furthermore, in step S2, the resistance index of the transmission tower is obtained by a push-over analysis method, which specifically includes:

[0021] Push-over analysis is performed in the finite element model of the transmission tower line system to obtain the Push-over curve. The turning point of the Push-over curve is taken as the critical state of the transmission tower, and the top displacement of the transmission tower corresponding to the critical state is set as the resistance index.

[0022] Furthermore, in step S4, the risk prediction of the transmission line refers to treating the transmission line as a series system of all transmission towers on the transmission line. The collapse of any transmission tower on the transmission line will cause the failure of the transmission line. The wind disaster vulnerability model of the transmission tower universal to the terrain, the layout parameters of the transmission tower line system, and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system are used to obtain the wind disaster vulnerability model of any transmission tower. k At the forecast time t The probability of collapse The prediction results of the transmission line The failure probability The forecast is:

[0023] (2)

[0024] In formula (2), k 1. k 2. k 3. … , k n For transmission lines All transmission towers on the tis a certain forecast time in the micro-scale typhoon forecast wind field; , , , … , The transmission towers are obtained by using the terrain-general transmission tower wind disaster vulnerability model, the layout parameters of the transmission tower line system, and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system. k 1. k 2. k 3. … , k n At the forecast time t The probability of collapse is:

[0025] (3)

[0026] In formula (3), and The transmission towers are obtained by using the terrain-general transmission tower wind disaster vulnerability model, the layout parameters of the transmission tower line system, and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system. k At the forecast time t and t -1 collapse probability; and At the forecast time t Any transmission tower k The wind speed and direction of the micro-scale typhoon forecast wind field at various locations on the transmission tower line system; For any transmission tower k The layout parameters of the transmission tower and line system; The wind speed in the micro-scale typhoon forecast wind field and wind direction And any transmission tower k Layout parameters of the transmission tower line system The transmission tower under k The probability of collapse, and t =0 .

[0027] The beneficial effects of the present invention are:

[0028] The present invention proposes a risk prediction method for power transmission lines in complex terrain, which is used to realize real-time risk prediction of power transmission systems in complex terrain. For power transmission towers located on complex terrain, the wind speed and wind direction at each point on the power transmission tower line system are different due to the influence of micro-topography, and the power transmission tower line system has specific layout parameters. In order to obtain more reliable early warning results for transmission lines, it is necessary to establish a terrain-universal power transmission tower wind disaster vulnerability model, so as to more accurately predict the risks of transmission lines in complex terrain. At the same time, the terrain-universal power transmission tower wind disaster vulnerability model requires lower computing resources and less time, which can ensure the real-time nature of risk prediction. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a flow chart showing the principle of a risk prediction method for power transmission lines in complex terrain according to an embodiment of the present invention.

[0030] Figure 2 It is a forecast result of a micro-scale typhoon forecast wind field of a certain typhoon described in an embodiment of the present invention and a transmission tower line system diagram affected by the micro-scale typhoon forecast wind field.

[0031] Figure 3 It is a schematic diagram of a transmission tower line system with a certain span and angle according to an embodiment of the present invention.

[0032] Figure 4 It is a schematic diagram of a transmission tower line system with a certain height difference described in an embodiment of the present invention.

[0033] Figure 5 It is a schematic diagram of a finite element model of a transmission tower line system according to an embodiment of the present invention.

[0034] Figure 6 It is a push-over curve of a certain transmission tower described in an embodiment of the present invention.

[0035] Figure 7 This is a wind field schematic diagram of a micro-scale typhoon forecast wind field under a certain typhoon described in an embodiment of the present invention.

[0036] Figure 8 It is a schematic diagram of the risk forecast result of a power transmission line in a complex terrain under a typhoon according to an embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to facilitate those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The following is only exemplary and does not limit the protection scope of the present invention.

[0038] The present invention discloses a risk prediction method for power transmission lines in complex terrain, comprising the following steps:

[0039] S1, initialization data, the data at least including the forecast results of the micro-scale typhoon forecast wind field, the transmission system topology, the design data of the transmission tower and the ground wire, the longitude and latitude of the transmission tower, and the digital elevation model data, wherein the forecast accuracy of the micro-scale typhoon forecast wind field is 10 to 100m, and the transmission system topology is a geometric figure composed of the transmission tower and the ground wire connecting the adjacent transmission towers;

[0040] S2. Based on the design data of the transmission tower and the ground wire in step S1, a finite element model of the transmission tower line system is established, and sampling is performed based on the probability distribution of the gust response coefficient to consider the uncertainty of the wind load, and the response of the transmission tower under the wind load is calculated, wherein the transmission tower line system consists of a transmission tower and the ground wires on both sides thereof; the resistance index of the transmission tower is obtained by a push-over analysis method; the response and resistance index of the transmission tower are compared to determine whether the transmission tower collapses, thereby establishing a transmission tower wind disaster vulnerability model that is universal for terrain;

[0041] S3, based on the forecast result of the micro-scale typhoon forecast wind field in step S1, the longitude and latitude of the transmission tower, and the digital elevation model data, obtain the layout parameters of the transmission tower line system and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system;

[0042] S4. Based on the terrain-general transmission tower wind disaster vulnerability model obtained in step S2, and based on the layout parameters of the transmission tower line system obtained in step S3 and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system, a risk forecast for the transmission line in complex terrain is obtained.

[0043] In the present invention, when establishing a terrain-universal transmission tower wind disaster vulnerability model, it is necessary to determine whether the transmission tower collapses during the modeling process. After establishing a terrain-universal transmission tower wind disaster vulnerability model, the terrain-universal transmission tower wind disaster vulnerability model can be used to assess the probability of transmission tower collapse during a typhoon process, thereby achieving risk prediction of transmission lines.

[0044] In order to better understand the above technical solution, the exemplary embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. These are only exemplary embodiments of the present invention. However, it should be understood that the present invention can also be implemented in various forms and is not limited to the embodiments described herein. These embodiments are intended to enable those skilled in the art to understand the present invention more clearly and thoroughly.

[0045] like Figure 1 As shown, a transmission system under a typhoon is taken as an example to explain in detail, including the following steps:

[0046] S1. Initialization data, the data at least including the forecast results of the micro-scale typhoon forecast wind field, the transmission system topology, the design data of the transmission tower and the ground wire, the longitude and latitude of the transmission tower, and the digital elevation model data, wherein the forecast accuracy of the micro-scale typhoon forecast wind field is 10 to 100 meters, and the transmission system topology is a geometric figure composed of transmission towers and ground wires connecting adjacent transmission towers.

[0047] Specifically, in step S1, the microscale typhoon forecast wind field includes two parts: a microscale typhoon forecast wind speed field and a microscale typhoon forecast wind direction field, that is, the microscale typhoon forecast wind field can forecast wind speed and wind direction.

[0048] Specifically, in step S1, the Digital Elevation Model, or DEM for short, is a digital simulation of the ground terrain using limited terrain elevation data, and is a physical ground model that uses an ordered numerical array to represent the ground elevation.

[0049] Specifically, in step S1, the micro-scale typhoon forecast wind field is obtained at least through the WRF meteorological model, wherein the WRF meteorological model is an existing model, which will not be described in detail in this embodiment. The forecast result output by the WRF meteorological model is an array of points, for example, 100 rows multiplied by 100 columns (a total of 10,000 points), each point corresponds to a geographical location, and has a wind speed value and a wind direction value at the location, and the distance between two adjacent points is the accuracy of the forecast wind field. In the micro-scale typhoon forecast wind field, the distance between two adjacent points is 10 to 100m, and the micro-scale typhoon forecast wind field includes the area where the entire power transmission system is located. The forecast duration can be 12h, 24h, 48h, etc. In the forecast service, multiples of 12h are usually used as the forecast duration, but it is not limited to this. Other times can also be selected as the forecast duration. This embodiment preferably outputs a wind field forecast result every 10 minutes to make the forecast result more accurate.

[0050] Specifically, in step S1, the digital elevation model represents an ordered array of values, in which each point corresponds to a geographical location and has the ground elevation at that location. The distance between two adjacent points is the accuracy of the digital elevation model. In order to reflect the characteristics of micro-topography, the accuracy of the digital elevation model needs to reach 5 to 30 meters. The accuracy of the digital elevation model selected in this embodiment is 30 meters.

[0051] Figure 2The forecast results of the micro-scale typhoon forecast wind field of a certain typhoon and a diagram of a transmission tower line system affected by the micro-scale typhoon forecast wind field. The forecast results of the micro-scale typhoon forecast wind field are obtained by the WRF meteorological model. It can be seen that the wind speed and wind direction at different positions on the transmission tower line system are different. This is because the wind field becomes uneven due to the influence of the micro-topography.

[0052] S2. Based on the design data of the transmission tower and the ground wire in step S1, a finite element model of the transmission tower line system is established, and sampling is performed based on the probability distribution of the gust response coefficient to consider the uncertainty of the wind load, and the response of the transmission tower under the wind load is calculated, wherein the transmission tower line system consists of a transmission tower and the ground wires on both sides thereof; the resistance index of the transmission tower is obtained by a push-over analysis method; the response and resistance index of the transmission tower are compared to determine whether the transmission tower collapses, thereby establishing a transmission tower wind disaster vulnerability model that is universal for all terrains.

[0053] Specifically, in step S2, the terrain-general transmission tower wind disaster vulnerability model is expressed as follows:

[0054] (1)

[0055] In formula (1), P It represents the probability of transmission tower collapse; and They represent the wind speed and wind direction of the micro-scale typhoon forecast wind field at various locations on the transmission tower line system; represents the layout parameters of the transmission tower line system, and has ,in, L 1 and L 2 respectively represent the spans of the ground wires on both sides of the transmission tower in the transmission tower line system, H 1 and H 2 respectively represent the height difference of the ground wires on both sides of the transmission tower in the transmission tower line system, θ Indicates the turning angle of the ground wire on both sides of the transmission tower in the transmission tower line system; f yes function.

[0056] Furthermore, the response of the transmission tower under wind load is calculated, including:

[0057] First, the wind speed of the micro-scale typhoon forecast wind field at various locations on the transmission tower line system ,wind direction And the layout parameters of the transmission tower line system The wind load on the transmission towers in the transmission tower line system can be obtained by standard calculation. The standard calculation described in this embodiment refers to the calculation according to the corresponding specifications in the "Technical Regulations for Structural Design of Overhead Transmission Line Towers" (DLT5154-2012), which will not be repeated here.

[0058] Then, the wind load is applied to the finite element model of the transmission tower line system, and the response of the transmission tower is calculated. The response of the transmission tower includes the displacement of the top of the transmission tower.

[0059] Specifically, in step S2, the resistance index of the transmission tower is obtained by the Push-over analysis method, which specifically includes:

[0060] Push-over analysis is performed in the finite element model of the transmission tower line system to obtain the Push-over curve. The turning point of the Push-over curve is taken as the critical state of the transmission tower, and the top displacement of the transmission tower corresponding to the critical state is set as the resistance index.

[0061] Figure 3 It is a schematic diagram of a transmission tower line system with a certain span and angle according to an embodiment of the present invention. Figure 3 In the figure, dots represent transmission towers, and horizontal lines represent ground wires. A red dot and two red ground wires together form a transmission tower line system with one tower and two ground wires. L 1. L 2 and corner θ These are some layout parameters of the transmission tower line system.

[0062] Figure 4 It is a schematic diagram of a transmission tower line system with a certain height difference described in an embodiment of the present invention. Figure 4 In the complex terrain, the transmission towers may have different elevations from the adjacent transmission towers on both sides, so there is a height difference. H 1 and H 2.

[0063] In this embodiment, based on the design data of the transmission tower and the ground wire in step S1, a finite element model of the transmission tower line system is established. Figure 5 This is a schematic diagram of a finite element model of a transmission tower line system established in this embodiment. The transmission tower line system consists of a transmission tower and ground wires on both sides thereof. Since the transmission tower line system is located in a complex terrain, its layout is determined by layout parameters. Figure 5 The one shown is a special case.

[0064] Figure 6 It is a push-over curve of a certain transmission tower described in an embodiment of the present invention. Figure 6In the figure, the horizontal axis represents the displacement of the tower top in meters, and the vertical axis represents the total wind load in kN. The turning point of the curve is regarded as the critical state of the transmission tower. The top displacement of the transmission tower corresponding to the critical state is 0.867m, which is regarded as the resistance index. If the top displacement response of the transmission tower under the action of wind load exceeds the resistance index of 0.867m, the transmission tower is considered to have collapsed.

[0065] S3. Based on the forecast results of the micro-scale typhoon forecast wind field in step S1, the longitude and latitude of the transmission towers and the digital elevation model data, the layout parameters of the transmission tower line system and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system are obtained.

[0066] Step S3 obtains the layout parameters of a specific transmission tower line system in practice and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system.

[0067] S4. Based on the terrain-general transmission tower wind disaster vulnerability model obtained in step S2, and based on the layout parameters of the transmission tower line system obtained in step S3 and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system, a risk forecast for the transmission line in complex terrain is obtained.

[0068] Specifically, in step S4, the risk forecast of the transmission line refers to treating the transmission line as a series system of all transmission towers on the transmission line. The collapse of any transmission tower on the transmission line will cause the failure of the transmission line. The wind disaster vulnerability model of the transmission tower universal to the terrain, the layout parameters of the transmission tower line system, and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system are used to obtain the wind disaster vulnerability model of any transmission tower. k At the forecast time t The probability of collapse The prediction results of the transmission line The failure probability The forecast is:

[0069] (2)

[0070] In formula (2), k 1. k 2. k 3. … , k n For transmission lines All transmission towers on the t is a certain forecast time in the micro-scale typhoon forecast wind field; , , , … , The transmission towers are obtained by using the terrain-general transmission tower wind disaster vulnerability model, the layout parameters of the transmission tower line system, and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system. k 1. k 2. k 3. … , k n At the forecast time t The probability of collapse is:

[0071] (3)

[0072] In formula (3), and The transmission towers are obtained by using the terrain-general transmission tower wind disaster vulnerability model, the layout parameters of the transmission tower line system, and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system. k At the forecast time t and t -1 collapse probability; and At the forecast time t Any transmission tower k The wind speed and direction of the micro-scale typhoon forecast wind field at various locations on the transmission tower line system; For any transmission tower k The layout parameters of the transmission tower and line system; The wind speed in the micro-scale typhoon forecast wind field and wind direction And any transmission tower k Layout parameters of the transmission tower line system The transmission tower under k The probability of collapse, and t =0 .

[0073] Figure 7 This is a wind field schematic diagram of a micro-scale typhoon forecast wind field under a certain typhoon described in an embodiment of the present invention, which is the load borne by different transmission lines in the transmission system. It can be seen that the wind speeds borne by transmission lines at different positions are different.

[0074] Figure 8 This is a schematic diagram of the risk forecast result of a power transmission line in a complex terrain under a typhoon according to an embodiment of the present invention. It should be noted that: Figure 7 and Figure 8 The maps and transmission lines involved are virtual and do not exist in reality. Figure 8In the forecast, the forecast start time is 00:00, and the forecast results at 00:30, 04:30 and 11:30 are given respectively. At the forecast time 00:30, only 3 transmission lines have a high failure probability, and their failure probability is greater than 0.9; at the forecast time 04:30, 30 transmission lines have a failure probability greater than 0.9; and by the forecast time 11:30, 55 transmission lines have a failure probability greater than 0.9. This shows that the ultra-short-term forecast shows that the typhoon will continue to cause damage to the transmission lines. In the test of this embodiment, the terrain-general transmission tower wind disaster vulnerability model used requires low computing resources and takes less time, so the collapse probability of the transmission tower in complex terrain can be output within 0.1s on an ordinary home notebook. This shows that the method of this embodiment requires extremely low computing resources and can predict the risks of transmission lines in complex terrain in real time.

[0075] The above only describes the basic principles and preferred embodiments of the present invention. Those skilled in the art may make many changes and improvements based on the above description, and these changes and improvements should fall within the protection scope of the present invention.

Claims

1. A risk prediction method for power transmission lines in complex terrain, characterized in that: The steps include: S1, initialization data, the data at least including the forecast results of the micro-scale typhoon forecast wind field, the transmission system topology, the design data of the transmission tower and the ground wire, the longitude and latitude of the transmission tower, and the digital elevation model data, wherein the forecast accuracy of the micro-scale typhoon forecast wind field is 10 to 100m, and the transmission system topology is a geometric figure composed of the transmission tower and the ground wire connecting the adjacent transmission towers; S2. Based on the design data of the transmission tower and the ground wire in step S1, a finite element model of the transmission tower line system is established, and sampling is performed based on the probability distribution of the gust response coefficient to consider the uncertainty of the wind load, and the response of the transmission tower under the wind load is calculated, wherein the transmission tower line system consists of a transmission tower and the ground wires on both sides thereof; the resistance index of the transmission tower is obtained by a push-over analysis method; the response and resistance index of the transmission tower are compared to determine whether the transmission tower collapses, thereby establishing a terrain-universal transmission tower wind disaster vulnerability model; the terrain-universal transmission tower wind disaster vulnerability model is expressed as follows: （1） In formula (1), P It represents the probability of transmission tower collapse; and They represent the wind speed and wind direction of the micro-scale typhoon forecast wind field at various locations on the transmission tower line system; represents the layout parameters of the transmission tower line system, and has ,in, L 1 and L 2 respectively represent the spans of the ground wires on both sides of the transmission tower in the transmission tower line system, H 1 and H 2 respectively represent the height difference of the ground wires on both sides of the transmission tower in the transmission tower line system, θ Indicates the turning angle of the ground wire on both sides of the transmission tower in the transmission tower line system; f yes Function of S3, based on the forecast result of the micro-scale typhoon forecast wind field in step S1, the longitude and latitude of the transmission tower, and the digital elevation model data, obtain the layout parameters of the transmission tower line system and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system; S4. Based on the terrain-general transmission tower wind disaster vulnerability model obtained in step S2, and based on the layout parameters of the transmission tower line system obtained in step S3 and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system, a risk forecast for the transmission line in complex terrain is obtained.

2. The risk prediction method for power transmission lines in complex terrain according to claim 1, characterized in that: In step S1, the micro-scale typhoon forecast wind field is obtained at least through the WRF meteorological model, and the output forecast result is an array of points, each point corresponds to a geographical location, and has the wind speed value and wind direction value at that location. The distance between two adjacent points is the accuracy of the forecast wind field. In the micro-scale typhoon forecast wind field, the distance between two adjacent points is 10 to 100 meters, and the micro-scale typhoon forecast wind field includes the area where the entire power transmission system is located.

3. The risk prediction method for power transmission lines in complex terrain according to claim 1 is characterized in that: In step S1, the accuracy of the digital elevation model is 5 to 30 m.

4. The risk prediction method for power transmission lines in complex terrain according to claim 1, characterized in that: In step S2, the wind speed of the micro-scale typhoon forecast wind field at various locations on the transmission tower line system is ,wind direction And the layout parameters of the transmission tower line system The wind load on the transmission towers in the transmission tower line system is calculated.

5. The risk prediction method for power transmission lines in complex terrain according to claim 4 is characterized in that: In step S2, a wind load is applied to the finite element model of the transmission tower line system, and the response of the transmission tower is calculated, where the response of the transmission tower includes the displacement of the top of the transmission tower.

6. The risk prediction method for power transmission lines in complex terrain according to claim 1, characterized in that: In step S2, the resistance index of the transmission tower is obtained by the Push-over analysis method, which specifically includes: Push-over analysis is performed in the finite element model of the transmission tower line system to obtain the Push-over curve. The turning point of the Push-over curve is taken as the critical state of the transmission tower, and the top displacement of the transmission tower corresponding to the critical state is set as the resistance index.

7. The risk prediction method for power transmission lines in complex terrain according to any one of claims 1 to 6, characterized in that: In step S4, the risk forecast of the transmission line refers to treating the transmission line as a series system of all transmission towers on the transmission line. The collapse of any transmission tower on the transmission line will cause the failure of the transmission line. The wind disaster vulnerability model of the transmission tower universal to the terrain, the layout parameters of the transmission tower line system, and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system are used to obtain the wind disaster vulnerability model of any transmission tower. k At the forecast time t The probability of collapse The prediction results of the transmission line The failure probability The forecast is: （2） In formula (2), k 1. k 2. k 3. … , k n For transmission lines All transmission towers on the t is a certain forecast time in the micro-scale typhoon forecast wind field; , , , … , The transmission towers are obtained by using the terrain-general transmission tower wind disaster vulnerability model, the layout parameters of the transmission tower line system, and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system. k 1. k 2. k 3. … , k n At the forecast time t The probability of collapse is: （3） In formula (3), and The transmission towers are obtained by using the terrain-general transmission tower wind disaster vulnerability model, the layout parameters of the transmission tower line system, and the wind speed and wind direction of the micro-scale typhoon forecast wind field on the transmission tower line system. k At the forecast time t and t -1 collapse probability; and At the forecast time t Any transmission tower k The wind speed and direction of the micro-scale typhoon forecast wind field at various locations on the transmission tower line system; For any transmission tower k The layout parameters of the transmission tower line system; The wind speed in the micro-scale typhoon forecast wind field and wind direction And any transmission tower k Layout parameters of the transmission tower line system The transmission tower under k The probability of collapse, and t =0 .

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