Lightning trip risk assessment method and system for current collection line of wind power plant station

Abstract

The invention relates to a lightning trip risk assessment method and system for a current collection line of a wind power plant station, and belongs to the technical field of lightning protection of a power system, and the method comprises the following steps: collecting a multi-dimensional data set of a target wind power plant station, the multi-dimensional data set comprising lightning activity parameters, landform data, equipment structure parameters and historical lightning fault data; constructing a three-dimensional electromagnetic transient model of the current collection line, wherein the three-dimensional electromagnetic transient model of the current collection line integrates an electromagnetic transient program EMTP counterattack simulation model, a time domain finite difference method FDTD induction lightning shielding model and a terrain correction electrical geometric model EGM; calculating lightning trip-out rates based on the multi-dimensional data set and the three-dimensional electromagnetic transient model of the current collection line, wherein the lightning trip-out rates comprise an impact trip-out rate, a shielding failure trip-out rate and an induction lightning trip-out rate under fan shielding; and carrying out risk grading on the tower according to the lightning trip-out rate, establishing a terrain-tower type coupling risk assessment system, and outputting a risk assessment result.

Description

TECHNICAL FIELD

[0001] The application relates to the lightning protection technology field of a power system, and more particularly to a lightning trip-out risk assessment method and system for a power collection line of a wind power station. BACKGROUND

[0002] With the expansion of wind power stations to complex terrain areas, the lightning trip-out problem of the power collection line is increasingly prominent. The traditional lightning risk assessment method for the power transmission line has the following limitations:

[0003] Inadequate handling of terrain factors: the conventional electrical geometric model does not establish a correlation mechanism between complex terrains such as valleys and steep slopes and lightning strike paths, resulting in systematic deviation in the calculation of the striking distance.

[0004] Neglect of the electromagnetic characteristics of the wind turbine: the existing technology does not quantify the dynamic shielding effect of the metal structure of the wind turbine on the lightning electromagnetic field, so that the induced lightning trip-out rate calculation is deviated from the actual engineering scenario.

[0005] Lack of targeted protection strategy: the existing standard adopts a unified lightning protection configuration, which cannot adapt to special working conditions such as high soil resistivity in mountainous areas and strong wind areas on mountain tops, and insulation flashover still frequently occurs after the transformation. SUMMARY

[0006] To solve the above technical problems, the application provides a lightning trip-out risk assessment method and system for a power collection line of a wind power station.

[0007] The technical scheme of the application is as follows:

[0008] The application provides a lightning trip-out risk assessment method for a power collection line of a wind power station, which comprises the following steps:

[0009] Collecting a multi-dimensional data set of the target wind power station, the multi-dimensional data set comprising lightning activity parameters, terrain and topography data, equipment structure parameters and historical lightning fault data;

[0010] Constructing a three-dimensional electromagnetic transient model of the power collection line, the three-dimensional electromagnetic transient model of the power collection line integrating an electromagnetic transient program EMTP back strike simulation model, a finite difference time domain method FDTD induced lightning shielding model and a terrain corrected electrical geometric model EGM;

[0011] Calculating a lightning trip-out rate based on the multi-dimensional data set and the three-dimensional electromagnetic transient model of the power collection line, the lightning trip-out rate comprising a back strike trip-out rate, a shielding failure trip-out rate and an induced lightning trip-out rate under the shielding of the wind turbine;

[0012] Risk grading the tower according to the lightning trip-out rate, establishing a terrain-tower type coupled risk assessment system, and outputting the risk assessment results.

[0013] Preferably, the lightning activity parameters include ground-to-ground lightning density and lightning current amplitude probability distribution function; the topographic data include tower elevation, slope and soil resistivity; and the equipment structure parameters include lightning conductor protection angle, insulator model and measured ground resistance value.

[0014] Preferably, the electromagnetic transient program EMTP counter-strike simulation model simulates the transient overvoltage propagation process of the top of the tower struck by lightning by establishing a distributed parameter circuit model of the tower-grounding system-line, and calculates the counter-strike lightning withstand level threshold and the corresponding lightning current probability distribution;

[0015] The finite-difference time-domain (FDTD) induced lightning shielding model constructs a three-dimensional spatial grid containing the dynamic electromagnetic characteristics of the wind turbine tower to quantify the spatial shielding effect of the wind turbine metal structure on the lightning electromagnetic field, calculate the induced overvoltage waveforms at different lightning strike locations, and determine the critical distance parameter for insulator flashover caused by induced lightning.

[0016] The terrain-corrected electrical geometry model (EGM) introduces terrain slope parameters to perform nonlinear correction on the strike distance formula, establishes a strike distance amplification coefficient calculation model under cross-valley terrain, and dynamically calculates the capture width of the exposed arc segment of the conductor in complex mountainous terrain.

[0017] Preferably, the calculation formula of the back-attack trip rate is:

[0018] P f =NgP I η;

[0019] Where: P f is the strike-back tripping rate; N is the total number of lightning strikes per year; g is the pole striking rate; P I is the probability of occurrence of lightning current greater than the strike-back lightning withstand level; η is the arcing rate.

[0020] Preferably, the shielding failure trip rate is based on the strike distance calculated by the terrain corrected electrical geometry model EGM, combined with the exposure distance method to determine the shielding failure lightning current amplitude probability distribution.

[0021] Preferably, the calculation formula for the induced lightning trip rate under the wind turbine shield is:

[0022]

[0023] Where: P g is the induced lightning trip rate under wind turbine shielding; N g Ground lightning density; K is the upper limit of lightning current amplitude; ΔI is the step size of lightning current amplitude interval; k is the lightning current amplitude interval index; I k is the current value of the kth interval; P(I) is the lightning current distribution function; S(I k ) is the lightning current I kThe critical distance of lightning flashover when the induced lightning current is I k The striking distance of the electrical geometric model when the lightning current is I k .

[0024] Preferably, the method further comprises formulating a differentiated protection scheme, specifically:

[0025] The average value of the lightning trip-out rate of the whole line tower is calculated, and the specific formula is:

[0026]

[0027] In the formula, S is the average value of the lightning trip-out rate of the whole line tower, T is the total number of towers, m n is the trip-out rate of the nth tower, and n is the tower index;

[0028] According to the risk classification of the tower lightning trip-out rate and the average trip-out rate, a differentiated protection scheme is formulated in combination with the terrain-tower type coupling relationship:

[0029] The tower with a trip-out rate less than the first threshold value is classified as a first-level risk, and only real-time monitoring is implemented without modification;

[0030] The tower with a trip-out rate greater than or equal to the first threshold value and less than the second threshold value is classified as a second-level risk, and the protection scheme of the tower grounding resistance is optimized;

[0031] The tower with a trip-out rate greater than or equal to the second threshold value and less than the third threshold value is classified as a third-level risk, and the protection scheme of the lightning arrester + silicon rubber climbing skirt is adopted for a conventional area; the protection scheme of the lightning arrester + graphene grounding module is adopted for a high soil resistivity area;

[0032] The tower with a trip-out rate greater than or equal to the third threshold value is classified as a fourth-level risk, and the protection scheme of the lightning arrester + grounding modification + lateral lightning rod is adopted for a cross-valley terrain, and the inclination angle of the lateral lightning rod is dynamically adjusted according to the slope; the protection scheme of the lightning arrester + insulation strengthening is adopted for a mountain top terrain, and the creepage distance of the insulator is increased.

[0033] On the other hand, the present application also provides a wind power station power collection line lightning trip-out risk assessment system, comprising:

[0034] A data acquisition module acquires a multi-dimensional data set of the target wind power station, and the multi-dimensional data set includes lightning activity parameters, terrain data, equipment structure parameters and historical lightning fault data;

[0035] A model simulation module constructs a three-dimensional electromagnetic transient model of the power collection line, and the three-dimensional electromagnetic transient model of the power collection line integrates an electromagnetic transient program EMTP back strike simulation model, a finite difference time domain method FDTD induced lightning shielding model and a terrain corrected electrical geometric model EGM;

[0036] A trip-out rate calculation module calculates a lightning trip-out rate based on the multidimensional dataset and the three-dimensional electromagnetic transient model of the power collection line, the lightning trip-out rate including back flash trip-out rate, shielding failure trip-out rate and induced lightning trip-out rate under the shielding of the wind turbine;

[0037] A risk assessment module classifies the tower according to the lightning trip-out rate, establishes a terrain-tower coupling risk assessment system and outputs the risk assessment result.

[0038] In another aspect, the application further provides an electronic device having a computer program stored thereon, the computer program being executed by a processor to implement the method for assessing lightning trip-out risk of a power collection line of a wind power station according to any one of the embodiments of the application.

[0039] In another aspect, the application further provides a computer readable medium for storing one or more programs, the one or more programs being executed by one or more processors to implement the method for assessing lightning trip-out risk of a power collection line of a wind power station according to any one of the embodiments of the application.

[0040] The application has the following beneficial effects: a multi-model collaborative calculation system: the terrain correction EGM model introduces a slope parameter to dynamically correct the striking distance formula, significantly improving the lightning path prediction accuracy of complex terrain in mountainous areas; the FDTD three-dimensional model fuses the electromagnetic shielding effect of the wind turbine tower, and for the first time realizes the field-circuit coupling accurate simulation of induced lightning overvoltage; the EMTP distributed parameter circuit completely restores the back flash overvoltage propagation path. The back flash trip-out rate, the shielding failure trip-out rate (based on terrain EGM) and the wind turbine shielding induced lightning trip-out rate calculation are synchronously integrated to establish an analysis framework covering all lightning fault modes of the power collection line. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments of the application. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0042] Figure 1 It is a method flowchart of the application;

[0043] Figure 2 It is a back flash calculation model diagram of the power collection line;

[0044] Figure 3 It is a three-dimensional shielding failure trip-out rate calculation diagram;

[0045] Figure 4 It is an induced lightning interval and interval division diagram. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0047] It should be understood that the step numbers used herein are only for the convenience of description, and are not limited to the execution sequence of the steps.

[0048] It should be understood that the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and the appended claims of the present application, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0049] The terms "comprise" and "include" indicate the presence of described features, integers, steps, operations, elements, and / or components, but do not exclude one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0050] The term "and / or" means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0051] Embodiment one:

[0052] In order to make the purposes, technical solutions and advantages of the present application clearer, the following will combine specific embodiments of the present application, and refer to the accompanying drawings Figure 1 The technical solutions of the present application are clearly and completely described.

[0053] To solve the problems in the prior art, the present application provides a wind power station power collection line lightning trip-out risk assessment method, comprising the following steps:

[0054] Collecting a multi-dimensional data set of the target wind power station, the multi-dimensional data set including lightning activity parameters, topographic and geomorphic data, equipment structure parameters and historical lightning fault data;

[0055] As a preferred embodiment of the present embodiment, the lightning activity parameters include ground flash density and lightning current amplitude probability distribution function; the topographic and geomorphic data include tower elevation, slope and soil resistivity; the equipment structure parameters include lightning protection angle, insulator type and measured value of grounding resistance.

[0056] Construct a three-dimensional electromagnetic transient model of the collector line, which integrates the electromagnetic transient program EMTP counterattack simulation model, the finite difference time domain method FDTD induction lightning shielding model and the terrain correction electrical geometry model EGM;

[0057] As a preferred implementation of this embodiment, the electromagnetic transient program EMTP counter-strike simulation model simulates the transient overvoltage propagation process of the top of the lightning-struck tower by establishing a distributed parameter circuit model of the tower-grounding system-line, and calculates the counter-strike lightning withstand level threshold and the corresponding lightning current probability distribution;

[0058] As a preferred implementation of this embodiment, the finite-difference time-domain method (FDTD) induced lightning shielding model constructs a three-dimensional spatial grid containing the dynamic electromagnetic characteristics of the wind turbine tower, quantifies the spatial shielding effect of the wind turbine metal structure on the lightning electromagnetic field, calculates the induced overvoltage waveforms at different lightning strike locations, and determines the critical distance parameter for insulator flashover caused by induced lightning;

[0059] As a preferred implementation of this embodiment, the terrain-corrected electrical geometry model EGM performs nonlinear correction on the strike distance formula by introducing terrain slope parameters, establishes a strike distance amplification coefficient calculation model under cross-valley terrain, and dynamically calculates the capture width of the exposed arc segment of the wire in complex mountainous terrain.

[0060] Calculate the lightning trip rate based on the multidimensional data set and the three-dimensional electromagnetic transient model of the collector line. The lightning trip rate includes the strike-back trip rate, the shielding trip rate, and the induced lightning trip rate under the wind turbine shield;

[0061] In this embodiment, for the counter-attack tripping rate of the collector line, firstly, the electromagnetic transient simulation software is used to build a lightning transient simulation model of the collector line, such as Figure 2 As shown in Figure 1, the strike-back lightning withstand level is calculated based on the EMTP. Once the strike-back lightning withstand level is obtained, the probability of a lightning current greater than the strike-back lightning withstand level can be calculated, and the strike-back trip rate can be calculated using the formula.

[0062] As a preferred implementation of this embodiment, the calculation formula of the back-strike trip rate is:

[0063] P f =NgP I η;

[0064] Where: P f is the strike-back tripping rate; N is the total number of lightning strikes per year; g is the pole striking rate; P I is the probability of occurrence of lightning current greater than the strike-back lightning withstand level; η is the arcing rate.

[0065] As a preferred embodiment of the present embodiment, the shielding failure trip-out rate is determined based on the shielding distance calculated by the terrain-corrected electrical geometry model (EGM) and the exposure distance method.

[0066] For the calculation of the shielding failure trip-out rate, the present application proposes a method of calculating the maximum shielding failure lightning current of the line based on the electrical geometry model method and then calculating the shielding failure trip-out rate of the line according to the exposure distance method, considering the terrain factor. The principle of EGM is that before the head of the lightning development leader reaches the critical breakdown distance (i.e. the shielding distance) of the struck object, the striking point is uncertain. The object that reaches the shielding distance first is discharged to the object, the size of the shielding distance is related to the leader head potential, and the latter is related to the main discharge current. Therefore, it is considered that the shielding distance is a function of the lightning current amplitude. Based on the electrical geometry model EGM and the lightning current probability distribution, the shielding distance formula is as follows:

[0067] Conductor shielding distance:

[0068] r c = 10I 0.62 ;

[0069] Ground shielding distance:

[0070]

[0071] Fan shielding distance:

[0072] r s = 6.72I 0.8 ;

[0073] In the formula, I is the amplitude of the expected lightning current, which is the core variable in the electrical geometry model (EGM) and represents the size of the lightning current that may cause flashover. It needs to be calculated in combination with the lightning current probability distribution.

[0074] Considering the complex structure of high-altitude mountainous areas, the present application selects a three-dimensional electrical geometry model. First, the catenary equation is used to obtain the corresponding height of the ground for any point of the conductor and the height of the ground for any point of the ground wire. Second, a three-dimensional electrical geometry model considering the influence of the terrain near the tower is established, as shown in Figure 3 The maximum lightning current amplitude of the shielding flashover is obtained by the formula using the ground wire striking moment, conductor striking moment, and ground striking moment. Finally, considering the influence of the terrain on both sides of Tn on the shielding failure trip-out rate, the arithmetic mean of the lightning trip-out rates of each half span on both sides of Tn is taken.

[0075] As shown in Figure 4As shown, the traditional induced lightning trip rate is mainly based on the formula method, which has a simple calculation process and few selectable influencing factors. It cannot reflect the insulator induced lightning flashover process under multiple influencing factors. In this embodiment, for the calculation of the induced lightning trip rate under the wind turbine shield, the present invention is based on the FDTD algorithm and proposes a statistical method that simulates the induced overvoltage of the collector line under the wind turbine shield and adopts the electrical geometry model and the induced lightning interval through the interval combination to calculate the induced lightning trip rate. First, within the lightning current amplitude of 0 to 300kA, the amplitude interval increment ΔI is divided into 300 / ΔI sub-intervals; secondly, according to the FDTD modeling simulation of the insulator flashover induced lightning withstand level curve at different lightning strike point locations (lightning strikes the wind turbine, lightning strikes the earth), the farthest interval S of the induced lightning flashover is determined for function fitting; finally, SD can be used to determine the area where the induced overvoltage causes the insulator flashover.

[0076] As a preferred implementation of this embodiment, the calculation formula for the induced lightning trip rate under the wind turbine shield is:

[0077]

[0078] Where: P g is the induced lightning trip rate under wind turbine shielding; N g Ground-to-ground lightning density; K is the upper limit of lightning current amplitude; ΔI is the step size of lightning current amplitude interval; k is the lightning current amplitude interval index; I k is the current value of the kth interval; P(I) is the lightning current distribution function, using the IEEE standard S(I k ) is the lightning current I k Critical distance of induced lightning flashover when D(I k ) is the lightning current I k Electrical geometric model at the time of strike distance.

[0079] The towers are graded according to the lightning tripping rate, a terrain-tower type coupling risk assessment system is established, and the risk assessment results are output.

[0080] As a preferred implementation of this embodiment, the risk classification and differentiated protection scheme are specifically as follows:

[0081] Calculate the average lightning trip rate of all towers along the entire line. The specific formula is:

[0082]

[0083] Where: S is the average lightning trip rate of all towers; T is the total number of towers; m n is the trip rate of the nth tower. The tower trip rate can be the sum or weighted sum of the lightning trip rate including the back-strike trip rate, the shielding trip rate and the induced lightning trip rate under the wind turbine shield; n is the tower index;

[0084] Risk classification is performed based on the tower lightning trip rate and the average trip rate, as shown in Table 1. Differentiated protection plans are formulated based on the terrain-tower type coupling relationship:

[0085] Table 1. Risk classification standard for tower-tower lightning tripping

[0086]

[0087]

[0088] If the trip rate of a tower is less than the first threshold, it is classified as a Level 1 risk and only real-time monitoring is performed without modification.

[0089] If the trip rate of the tower is greater than or equal to the first threshold and less than the second threshold, it is classified as a level 2 risk and the protection scheme of the tower's grounding resistance is optimized;

[0090] If the tripping rate of the tower is greater than or equal to the second threshold and less than the third threshold, it is classified as level three risk. For conventional areas, the protection solution of lightning arrester + silicone rubber climbing skirt is adopted; for areas with high soil resistivity, the protection solution of lightning arrester + graphene grounding module is adopted.

[0091] The tripping rate of the tower is greater than or equal to the third threshold and is classified as level four risk. For cross-valley terrain, the protection scheme of lightning arrester + grounding modification + lateral lightning rod is adopted, and the inclination angle of the lateral lightning rod is dynamically adjusted according to the slope; for mountaintop terrain, the protection scheme of lightning arrester + insulation reinforcement is adopted to increase the creepage distance of the insulator.

[0092] The lightning tripping risk value of the entire collector line is an indicator to measure the lightning risk of different lines in the entire wind farm. The average value of the lightning tripping risk of each tower in the tower section is calculated and the lightning risk weight of each section is calculated. The lightning tripping risk value of the entire collector line R L As shown in the formula:

[0093]

[0094] Where: R L is the lightning tripping risk of the entire line; T is the total number of line sections; n is the line section index; M n is the weight coefficient of the nth segment, reflecting differences in topography, thunderstorm activity, and equipment importance; is the average lightning tripping rate of towers in the nth section.

[0095] Example 2:

[0096] This embodiment provides a wind farm station collector line lightning tripping risk assessment system, including:

[0097] The data acquisition module acquires a multi-dimensional data set of the target wind power station, and the multi-dimensional data set includes lightning activity parameters, topographic data, equipment structure parameters and historical lightning stroke failure data.

[0098] The model simulation module constructs a three-dimensional electromagnetic transient model of the power collection line, and the three-dimensional electromagnetic transient model of the power collection line integrates an electromagnetic transient program (EMTP) back strike simulation model, a finite difference time domain (FDTD) induced lightning shielding model and a topographic correction electrical geometric model (EGM).

[0099] The trip-out rate calculation module calculates a lightning stroke trip-out rate based on the multi-dimensional data set and the three-dimensional electromagnetic transient model of the power collection line, and the lightning stroke trip-out rate includes a back strike trip-out rate, a shielding failure trip-out rate and an induced lightning trip-out rate under the shielding of the wind turbine.

[0100] The risk assessment module classifies the tower according to the lightning stroke trip-out rate, establishes a topographic-tower type coupling risk assessment system and outputs a risk assessment result.

[0101] Embodiment three

[0102] The embodiment provides an electronic device having a computer program stored thereon, and the computer program is executed by a processor to implement a lightning stroke trip-out risk assessment method for a power collection line of a wind power station according to any one of the embodiments.

[0103] Embodiment four

[0104] The embodiment provides a computer readable medium for storing one or more programs, and when the one or more programs are executed by one or more processors, the one or more processors implement a lightning stroke trip-out risk assessment method for a power collection line of a wind power station according to any one of the embodiments.

[0105] In the embodiments of the present application, "at least one" means one or more, and "multiple" means two or more. The "and / or" describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which means that A exists alone, A and B exist together, and B exists alone. Wherein A and B can be singular or plural. The character " / " generally represents an "or" relationship between the front and rear associated objects. "At least one of the following" and the like means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b and c can mean: a, b, c, a and b, a and c, b and c or a and b and c, wherein a, b and c can be single or multiple.

[0106] Those skilled in the art can clearly understand that the units and algorithm steps described in the embodiments disclosed herein can be realized by electronic hardware, computer software and a combination of the two. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0107] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be described here.

[0108] In several embodiments provided in the present application, any function realized in the form of a software function unit and sold or used as an independent product can be stored in a computer-readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the parts that make contributions to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes instructions used to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0109] The above is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A method for assessing the risk of lightning tripping of a wind farm collector line, characterized in that: include: Collect multidimensional data sets from the target wind farm, including lightning activity parameters, topographic data, equipment structure parameters, and historical lightning fault data; Construct a three-dimensional electromagnetic transient model of the collector line, which integrates the electromagnetic transient program EMTP counterattack simulation model, the finite difference time domain method FDTD induction lightning shielding model and the terrain correction electrical geometry model EGM; Calculate the lightning trip rate based on the multidimensional data set and the three-dimensional electromagnetic transient model of the collector line. The lightning trip rate includes the strike-back trip rate, the shielding trip rate, and the induced lightning trip rate under the wind turbine shield; The towers are graded according to the lightning tripping rate, a terrain-tower type coupling risk assessment system is established, and the risk assessment results are output.

2. A wind farm station collector line lightning trip risk assessment method according to claim 1, characterized in that: The lightning activity parameters include ground-to-ground lightning density and lightning current amplitude probability distribution function; topographic data include tower elevation, slope and soil resistivity; equipment structure parameters include lightning conductor protection angle, insulator model and measured ground resistance value.

3. A wind farm station collector line lightning trip risk assessment method according to claim 1, characterized in that: The electromagnetic transient program (EMTP) counter-strike simulation model simulates the transient overvoltage propagation process of lightning-struck tower tops by establishing a distributed parameter circuit model of tower-grounding system-line, and calculates the counter-strike lightning withstand level threshold and the corresponding lightning current probability distribution; The finite-difference time-domain (FDTD) induced lightning shielding model constructs a three-dimensional spatial grid containing the dynamic electromagnetic characteristics of the wind turbine tower to quantify the spatial shielding effect of the wind turbine metal structure on the lightning electromagnetic field, calculate the induced overvoltage waveforms at different lightning strike locations, and determine the critical distance parameter for insulator flashover caused by induced lightning. The terrain-corrected electrical geometry model (EGM) introduces terrain slope parameters to perform nonlinear correction on the strike distance formula, establishes a strike distance amplification coefficient calculation model under cross-valley terrain, and dynamically calculates the capture width of the exposed arc segment of the conductor in complex mountainous terrain.

4. A wind farm station collector line lightning trip risk assessment method according to claim 1, characterized in that: The calculation formula of the back-strike trip rate is: P f =NgP I η; Where: P f is the strike-back tripping rate; N is the total number of lightning strikes per year; g is the pole striking rate; P l The probability of occurrence of lightning current greater than the strike-back lightning withstand level; η is the arc building rate.

5. The method for assessing lightning tripping risk of wind farm collector lines according to claim 3, characterized in that: The shielding failure trip rate is based on the strike distance calculated by the terrain corrected electrical geometry model (EGM), combined with the exposure distance method to determine the shielding failure lightning current amplitude probability distribution.

6. A wind farm station collector line lightning trip risk assessment method according to claim 3, characterized in that: The calculation formula for the induced lightning trip rate under the fan shield is: Where: P g is the induced lightning trip rate under wind turbine shielding; N g Ground-to-ground lightning density; K is the upper limit of lightning current amplitude; ΔI is the lightning current amplitude interval step; k is the lightning current amplitude interval index; I k is the current value of the kth interval; P(I) is the lightning current distribution function; S(I k ) is the lightning current I k Critical distance of induced lightning flashover when D(I k ) is the lightning current I k Electrical geometric model at the time of strike distance.

7. The method for assessing lightning tripping risk of wind farm collector lines according to claim 1, characterized in that: The method also includes formulating differentiated protection plans, specifically: Calculate the average lightning trip rate of all towers along the entire line. The specific formula is: Where: S is the average lightning trip rate of all towers; T is the total number of towers; m n is the trip rate of the nth tower; n is the tower index; Risk classification is performed based on the tower lightning trip rate and the average trip rate, and differentiated protection plans are developed based on the terrain-tower type coupling relationship: If the trip rate of a tower is less than the first threshold, it is classified as a Level 1 risk and only real-time monitoring is performed without modification. If the trip rate of the tower is greater than or equal to the first threshold and less than the second threshold, it is classified as a level 2 risk and the protection scheme of the tower's grounding resistance is optimized; If the tripping rate of the tower is greater than or equal to the second threshold and less than the third threshold, it is classified as level three risk. For conventional areas, the protection solution of lightning arrester + silicone rubber climbing skirt is adopted; for areas with high soil resistivity, the protection solution of lightning arrester + graphene grounding module is adopted. The tripping rate of the tower is greater than or equal to the third threshold and is classified as level four risk. For cross-valley terrain, the protection scheme of lightning arrester + grounding modification + lateral lightning rod is adopted, and the inclination angle of the lateral lightning rod is dynamically adjusted according to the slope; for mountaintop terrain, the protection scheme of lightning arrester + insulation reinforcement is adopted to increase the creepage distance of the insulator.

8. A wind farm station collector line lightning trip risk assessment system, characterized in that: include: The data acquisition module collects multi-dimensional data sets from the target wind farm, including lightning activity parameters, topographic data, equipment structure parameters, and historical lightning fault data; Model simulation module, builds a three-dimensional electromagnetic transient model of the collector line, which integrates the electromagnetic transient program EMTP counterattack simulation model, the finite difference time domain method FDTD induction lightning shielding model and the terrain correction electrical geometry model EGM; A trip rate calculation module calculates the lightning trip rate based on a multidimensional dataset and a three-dimensional electromagnetic transient model of the collector line. The lightning trip rate includes the strike trip rate, the shielding trip rate, and the induced lightning trip rate under the wind turbine shield; The risk assessment module classifies the risks of towers according to the lightning tripping rate, establishes a terrain-tower type coupling risk assessment system, and outputs the risk assessment results.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the method for assessing the risk of lightning tripping of a wind farm collector line according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, a method for assessing lightning tripping risks of collector lines in a wind farm station as claimed in any one of claims 1 to 7 is implemented.

Images