Calculation method for direct lightning tripping rate of power collection lines affected by wind turbines

Abstract

This invention discloses a method for calculating the direct lightning trip rate of a power collection line affected by a wind turbine, belonging to the field of lightning protection for wind farm power collection lines. The calculation method first obtains relevant parameters of the wind farm power collection line and the geographical location of the wind turbine. Then, it divides the line segment and lightning current amplitude range, comparing the line backflashover withstand level and the backflashover current range with the lightning current amplitude to calculate the line backflashover trip rate and backflashover trip rate. The direct lightning trip rate is corrected based on the overlap area between the wind turbine lightning interception area and the line direct lightning strike area. Finally, the method iteratively calculates different lightning current amplitudes and line segments and accumulates the results to obtain the line direct lightning trip rate. This invention considers the influence of the wind turbine on the line lightning strike probability when calculating the direct lightning trip rate of the power collection line, making the calculation results of the direct lightning trip rate of the wind farm power collection line more accurate.

Description

Technical Field

[0001] This invention belongs to the field of lightning protection for wind farm collector lines, and specifically relates to a method for calculating the tripping rate of collector lines affected by wind turbines due to direct lightning strikes. Background Technology

[0002] The 35kV collector line of a wind farm is an important power transmission channel. When the collector line trips due to a fault, it will cause the wind turbines on the entire line to shut down, which will have a significant impact on the normal production, operation and maintenance of the wind farm.

[0003] Outages caused by lightning strikes on overhead transmission lines are one of the major accidents affecting transmission lines in my country. From 2005 to 2010, the number of lightning-induced outages on State Grid Corporation of China's lines increased year by year, with lightning-induced outages accounting for approximately 40% of the total outages each year. Therefore, calculating the direct lightning strike outage rate of collector lines and reducing the risk of lightning damage to collector lines is of great practical significance.

[0004] Currently, the calculation of the direct lightning trip rate of wind farm collector lines typically employs the standard method and the electrical geometric model. The standard method assumes that the probability of a line tripping due to lightning strikes is related to the line parameters; the electrical geometric model is a geometric analysis method that links the discharge characteristics of lightning with the dimensions and structure of the line. However, wind farm collector lines are mostly installed near wind turbines. During a lightning strike, the wind turbines affect the probability of nearby collector lines being directly struck by lightning. Neither of the above methods considers the impact of wind turbines on the direct lightning trip rate of wind farm collector lines. Summary of the Invention

[0005] The technical problem this invention aims to solve is that, given the relatively high direct lightning strike trip rate of wind farms in my country, traditional methods using standard procedures and electrical geometric models fail to consider the impact of wind turbines on the direct lightning strike trip rate of collector lines, leading to discrepancies between the calculated results and the actual number of lightning strike trips. This invention corrects the direct lightning strike trip rate of wind farm collector lines by considering the influence of wind turbines on the probability of lightning strikes to collector lines, making the calculated results closer to the accurate value.

[0006] To address the above problems, this invention provides a method for calculating the tripping rate of a power line affected by a wind turbine, comprising the following steps:

[0007] Step 1: Obtain the parameters of the power collection line and the wind turbine generator.

[0008] Step 2: Division of line segments and amplitude ranges

[0009] The collector line is divided into m line segments according to the number of towers. The lightning current amplitude range is divided into n amplitude intervals according to the set amplitude difference ΔI. Any one of these line segments is denoted as line segment A. j The amplitude of lightning current within any given amplitude range is denoted as the lightning current amplitude I. k ,j=1,2,...,m,k=1,2,...,n;

[0010] Step 3, solve for line segment A j At lightning current amplitude I k The backflashover trip rate n jk，rt

[0011] The line backflashover resistance level I is calculated using the following formula. f :

[0012]

[0013] In the formula, U 50％ k is 50% of the lightning impulse discharge voltage of the surge arrester. h β is the inductive coupling coefficient between the lightning protection wire and the conductor, β is the shunt coefficient, and h is the inductive coupling coefficient between the lightning protection wire and the conductor. a h is the height of the conductor above the ground. t L represents the tower height. t K is the inductance of the tower body, and k0 is the geometric coupling coefficient between the lightning protection wire and the conductor.

[0014] Line segment A j At lightning current amplitude I k The backflashover trip rate at that time is denoted as backflashover trip rate n. jk，rt Its value is:

[0015] If I f ≥I k n jk，rt =0

[0016] If I f <I k n jk，rt =Nηg[P(I k +ΔI)-P(I k )]

[0017] Where η is the arc-building rate, g is the strike rate, and N is the number of lightning strikes per 100km of line per year. N g Let P(I) be the lightning density, and b be the horizontal distance between the two lightning conductors. When there is only one lightning conductor, take b = 0. k () indicates that the lightning current amplitude is greater than I k The probability, P(I) k +ΔI) represents the lightning current amplitude greater than I. kThe probability of +ΔI is taken as Pick

[0018] Step 4, solve for line segment A j At lightning current amplitude I k The tripping rate n at that time jk，sf

[0019] Step 4.1, denote the circuit winding current range as [I 2，min I 2，max ], where I 2，min For the minimum value of the winding current range, I 2，max The formulas for calculating the maximum value of the winding current range are as follows:

[0020]

[0021]

[0022] In the formula, r max The maximum striking distance of the line, F is the maximum shot distance parameter 1, G is the maximum shot distance parameter 2, and F = 100 - sin 2 θ, G = F[(h t -h a ) / cosθ] 2 θ is the line protection angle;

[0023] Step 4.2, calculate line segment A j At lightning current amplitude I k Hit distance coefficient k g Earth strike distance r g , conductor distance r a and lightning strike distance r t The calculation formulas are as follows:

[0024]

[0025] r g =k g I k 0.65

[0026] r a =r t =10I k 0.65

[0027] Using the midpoint of the lightning protection wire as the center and the lightning strike distance r of the lightning protection wire as the radius of the circle... t Draw an arc for the lightning protection wire with radius r, centered at the midpoint of the conductor and with the conductor's striking distance r as the radius. a Draw a circular arc of conductor with radius r, and use the ground strike distance r as the radius. gDraw a horizontal line to indicate the height. Point B is obtained by the intersection of the conductor arc and the horizontal line. Point D is obtained by the intersection of the conductor arc and the lightning protection wire arc.

[0028] The straight-line distance between the projections of points B and D onto the ground is defined as the exposure distance BD. j (I k The formula for its calculation is:

[0029]

[0030] In the formula, L1 is the horizontal distance between the projection of the conductor and the lightning protection wire onto the ground;

[0031] Step 4.3, transfer line segment A j At lightning current amplitude I k The tripping rate due to backlash is denoted as the backlash tripping rate n. jk，sf Its value is:

[0032] If the lightning current amplitude I k Not within the winding current range [I] 2，min I 2，max ], then the tripping rate n jk，sf =0;

[0033] If the lightning current amplitude I k Belongs to the winding current range [I] 2，min I 2，max The line tripping rate n is calculated according to the following formula. jk，sf :

[0034] n jk，sf =0.2N g BD j (I k )[P(I k +ΔI)-P(I k )]

[0035] Step 5, adjust the backflashover trip rate n jk，rt and the tripping rate n jk，sf Correction

[0036] Step 5.1, calculate the lightning strike width W ls and wind turbine distance r w The calculation formulas are as follows:

[0037] W ls =b+4h g

[0038] r w =6.72I k 0.8

[0039] Wind turbine strike distance rw A sphere is constructed with the radius as the radius and the top of the wind turbine as the center. The projected area of ​​this sphere on the ground is denoted as the lightning interception area Λ of the wind turbine.

[0040] Step 5.2, record line segment A. j At lightning current amplitude I k The area affected by the lightning strike is called the lightning strike area S. jk，sf Line Section A j At lightning current amplitude I k The counter-strike zone at that time is the counter-strike zone S. jk，rt The calculation formulas are as follows:

[0041] S jk，sf =2l Aj BD j (I k )

[0042] S jk，rt =l Aj W ls

[0043] Among them, l Aj For line segment A j Length;

[0044] Step 5.3, calculate the counterattack shielding factor k jk，rt and the shielding factor k jk，sf The calculation formulas are as follows:

[0045]

[0046]

[0047] Among them, S w，rt For countering lightning strike zone S jk，rt The overlapping area of ​​the lightning interception zone Λ of the wind turbine generator, s w，sf For the lightning strike area S jk，sf The area of ​​the overlapping region with the lightning interception area Λ of the wind turbine generator;

[0048] Step 5.4: Record the corrected backflashover trip rate as the final backflashover trip rate n′. jk，rt The corrected tripping rate after the backlash is denoted as the final tripping rate n′. jk，sf The calculation formulas are as follows:

[0049] n′ jk，rt =k jk，rt n jk，rt

[0050] n′ jk，sf =k jk，sf n jk，sf

[0051] Final counterattack trip rate n′ jk，rt and the final trip rate n′ jk，sf The units are all times per 100 kilometers per year;

[0052] Step 6: Following the methods in Steps 3-5, calculate the final backflashover trip rate n′ for m line segments across n amplitude ranges. jk，rt and the final tripping rate n′ jk，sf Calculations are performed to obtain the final back-off trip rates n′ for m×n circuit breakers. jk，rt and the final tripping rate n jk，sf The calculation results are then summed to obtain the direct lightning trip rate n of the entire collector line, considering the influence of wind turbines. l The calculation formula is as follows:

[0053]

[0054] The direct lightning tripping rate n of the collector line considering the influence of wind turbine generators l The unit is times per 100 kilometers per year.

[0055] Preferably, the parameters of the collecting line in step 1 include lightning density, tower geographical location, number of towers, tower height, arc rate, horizontal distance between lightning protection wires, span length of each section, 50% impulse discharge voltage of tower insulators, tower grounding resistance, conductor height above ground, tower inductance, crossarm length, line protection angle, inductive coupling coefficient between lightning protection wire and conductor, and geometric coupling coefficient between lightning protection wire and conductor; the parameters of the wind turbine include the geographical location and height of the wind turbine.

[0056] Preferably, step 2 is implemented as follows:

[0057] Step 2.1: First, number the towers in the collector line, and designate any one of them as tower Γ. j Where m is the number of towers; then, the collector line is divided into m line segments according to the number of towers, and any one of these line segments is denoted as line segment A. j Section A of the line j The starting point and the ending point are:

[0058] When j = 2 to m-1, line segment A j The starting point is the tower Γ j-1 and towers j The midpoint of the conductor wire is between the pole and the end point is the tower. j and towers j+1 The midpoint of the conductor wires;

[0059] When j=1, line segment A jThe starting point is tower Γ1, and the ending point is the midpoint of the collector wire between tower Γ1 and tower Γ2;

[0060] When j = m, line segment A m The starting point is the tower Γ m-1 and towers m The midpoint of the conductor wire is between the pole and the end point is the tower. m ;

[0061] Step 2.2: First, according to the State Grid enterprise standard Q / GDW 11452-2015 Lightning Protection Guidelines for Overhead Transmission Lines, determine the lightning current amplitude range as [0, 35°]. Then, divide this lightning current amplitude range into n equal amplitude intervals according to the set amplitude difference ΔI. Let the lightning current amplitude at the beginning of each amplitude interval be taken as the lightning current amplitude of that interval, and obtain the lightning current amplitude of n amplitude intervals. Record the lightning current amplitude of any one of the amplitude intervals as the lightning current amplitude I. k Where, I1=0, I n =350kA.

[0062] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0063] 1. The impact of wind turbines on the calculation of direct lightning strike trip rate of collector lines is considered, making the calculation of direct lightning strike trip rate of collector lines more accurate and enabling effective risk assessment of direct lightning strikes on wind farm collector lines.

[0064] 2. The application of this invention can help wind farm operation and maintenance personnel formulate accurate lightning protection plans for collector lines and reduce the risk of direct lightning strikes tripping the collector lines. Attached Figure Description

[0065] Figure 1 This is a schematic diagram of the counter-lightning strike area in an embodiment of the present invention.

[0066] Figure 2 This is a schematic diagram of the lightning strike area and exposure distance in an embodiment of the present invention.

[0067] Figure 3 This is a flowchart of the calculation method of the present invention.

[0068] Figure 4 This is a block diagram of the calculation method of the present invention. Detailed Implementation

[0069] The technical solutions in the embodiments of the present invention will be described in detail below with reference to the embodiments of the present invention.

[0070] Figure 3 This is a flowchart of the calculation method of the present invention. Figure 4 This is a block diagram of the calculation method of the present invention. Figure 3 and Figure 4 As can be seen, the method for calculating the direct lightning tripping rate of a power collection line affected by a wind turbine, as described in this invention, includes the following steps:

[0071] Step 1: Obtain the parameters of the power collection line and the wind turbine generator.

[0072] In this embodiment, the parameters of the power collection line include ground flash density, tower geographical location, number of towers, tower height, arc rate, horizontal distance between lightning protection wires, span length of each section, 50% impulse discharge voltage of tower insulators, tower grounding resistance, conductor height above ground, tower inductance, crossarm length, line protection angle, inductive coupling coefficient between lightning protection wire and conductor, and geometric coupling coefficient between lightning protection wire and conductor; the parameters of the wind turbine include the geographical location and height of the wind turbine.

[0073] Step 2: Division of line segments and amplitude ranges

[0074] The collector line is divided into m line segments according to the number of towers. The lightning current amplitude range is divided into n amplitude intervals according to the set amplitude difference ΔI. Any one of these line segments is denoted as line segment A. j The amplitude of lightning current within any given amplitude range is denoted as the lightning current amplitude I. k , j=1,2,...,m,k=1,2,...,n.

[0075] In this embodiment, step 2 is implemented as follows:

[0076] Step 2.1: First, number the towers in the collector line, and designate any one of them as tower Γ. j Where m is the number of towers; then, the collector line is divided into m line segments according to the number of towers, and any one of these line segments is denoted as line segment A. j Section A of the line j The starting point and the ending point are:

[0077] When j = 2 to m-1, line segment A j The starting point is the tower Γ j-1 and towers j The midpoint of the conductor wire is between the pole and the end point is the tower. j and towers j+1 The midpoint of the conductor wires;

[0078] When j=1, line segment A j The starting point is tower Γ1, and the ending point is the midpoint of the collector wire between tower Γ1 and tower Γ2;

[0079] When j = m, line segment A m The starting point is the tower Γ m-1 and towersm The midpoint of the conductor wire is between the pole and the end point is the tower. m .

[0080] Step 2.2: First, according to the State Grid enterprise standard Q / GDW 11452-2015 Lightning Protection Guidelines for Overhead Transmission Lines, determine the lightning current amplitude range as [0, 35°]. Then, divide this lightning current amplitude range into n equal amplitude intervals according to the set amplitude difference ΔI. Let the lightning current amplitude at the beginning of each amplitude interval be taken as the lightning current amplitude of that interval, and obtain the lightning current amplitude of n amplitude intervals. Record the lightning current amplitude of any one of the amplitude intervals as the lightning current amplitude I. k Where, I1=0, I n =350kA.

[0081] In this embodiment, m = 50, n = 1000~2000.

[0082] Step 3, solve for line segment A j At lightning current amplitude I k The backflashover trip rate n jk，rt

[0083] The line backflashover resistance level I is calculated using the following formula. f :

[0084]

[0085] In the formula, U 50％ k is 50% of the lightning impulse discharge voltage of the surge arrester. h β is the inductive coupling coefficient between the lightning protection wire and the conductor, β is the shunt coefficient, and h is the inductive coupling coefficient between the lightning protection wire and the conductor. a h is the height of the conductor above the ground. t L represents the tower height. t K is the inductance of the tower body, and k0 is the geometric coupling coefficient between the lightning protection wire and the conductor.

[0086] Line segment A j At lightning current amplitude I k The backflashover trip rate at that time is denoted as backflashover trip rate n. jk，rt Its value is:

[0087] If I f ≥I k n jk，rt =0

[0088] If I f <I k n jk，rt =Nηg[P(I k +ΔI)-P(I k )]

[0089] Where η is the arc-building rate, g is the strike rate, and N is the number of lightning strikes per 100km of line per year. N g Let P(I) be the lightning density, and b be the horizontal distance between the two lightning conductors. When there is only one lightning conductor, take b = 0. k () indicates that the lightning current amplitude is greater than I k The probability, P(I) k +ΔI) represents the lightning current amplitude greater than I. k The probability of +ΔI is taken as Pick

[0090] In this embodiment, β = 0.86 and g = 0.25.

[0091] Step 4, solve for line segment A j At lightning current amplitude I k The tripping rate n at that time jk，sf

[0092] Step 4.1, denote the circuit winding current range as [I 2，min I 2，max ], where I 2，min For the minimum value of the winding current range, I 2，max The formulas for calculating the maximum value of the winding current range are as follows:

[0093]

[0094]

[0095] In the formula, r max The maximum striking distance of the line, F is the maximum shot distance parameter 1, G is the maximum shot distance parameter 2, and F = 100 - sin 2 θ, G = F[(h t -h a ) / cosθ] 2 θ is the line protection angle;

[0096] Step 4.2, calculate line segment A j At lightning current amplitude I k Hit distance coefficient k g Earth strike distance r g , conductor distance r a and lightning strike distance r t The calculation formulas are as follows:

[0097]

[0098] r g =k g I k0.65

[0099] r a =r t =10I k 0.65

[0100] Using the midpoint of the lightning protection wire as the center and the lightning strike distance r of the lightning protection wire as the radius of the circle... t Draw an arc for the lightning protection wire with radius r, centered at the midpoint of the conductor and with the conductor's striking distance r as the radius. a Draw a circular arc of conductor with radius r, and use the ground strike distance r as the radius. g Draw a horizontal line to indicate the height. Point B is obtained by the intersection of the conductor arc and the horizontal line. Point D is obtained by the intersection of the conductor arc and the lightning protection wire arc.

[0101] The straight-line distance between the projections of points B and D onto the ground is defined as the exposure distance BD. j (I k The formula for its calculation is:

[0102]

[0103] In the formula, L1 is the horizontal distance between the projection of the conductor and the lightning protection wire onto the ground;

[0104] Step 4.3, transfer line segment A j At lightning current amplitude I k The tripping rate due to backlash is denoted as the backlash tripping rate n. jk，sf Its value is:

[0105] If the lightning current amplitude I k Not within the winding current range [I] 2，min I 2，max ], then the tripping rate n jk，sf =0;

[0106] If the lightning current amplitude I k Belongs to the winding current range [I] 2，min I 2，max The line tripping rate n is calculated according to the following formula. jk，sf :

[0107] n jk，sf =0.2N g BD j (I k )[P(I k +ΔI)-P(I k )]

[0108] Step 5, adjust the backflashover trip rate n jk，rt and the tripping rate n jk，sf Correction

[0109] Step 5.1, calculate the lightning strike width W ls and wind turbine distance r w The calculation formulas are as follows:

[0110] W ls =b+4h g

[0111] r w =6.72I k 0.8

[0112] Wind turbine strike distance r w A sphere is constructed with the radius as the radius and the top of the wind turbine as the center. The projected area of ​​this sphere on the ground is denoted as the lightning interception area Λ of the wind turbine.

[0113] Step 5.2, record line segment A. j At lightning current amplitude I k The area affected by the lightning strike is called the lightning strike area S. jk，sf Line Section A j At lightning current amplitude I k The counter-strike zone at that time is the counter-strike zone S. jk，rt The calculation formulas are as follows:

[0114] S jk，sf =2l Aj BD j (I k )

[0115] S jk，r t = l Aj W ls

[0116] Among them, l Aj For line segment A j Length;

[0117] Step 5.3, calculate the counterattack shielding factor k jk，rt and the shielding factor k jk，sf The calculation formulas are as follows:

[0118]

[0119]

[0120] Among them, S w，rt For countering lightning strike zone S jk，rt The overlapping area of ​​the lightning interception zone Λ of the wind turbine generator, s w，sf For the lightning strike area S jk，sf The area of ​​the overlapping region with the lightning interception area Λ of the wind turbine generator;

[0121] Step 5.4: Record the corrected backflashover trip rate as the final backflashover trip rate n′. jk，rt The corrected tripping rate after the backlash is denoted as the final tripping rate n′. jk，sf The calculation formulas are as follows:

[0122] n′ jk，rt =k jk，rt n jk，rt

[0123] n′ jk，sf =k jk，sf n jk，sf

[0124] Final counterattack trip rate n′ jk，rt and the final tripping rate n′ jk，sf The units are all times per 100 kilometers per year.

[0125] Figure 1 This is a schematic diagram of the counter-lightning strike area in an embodiment of the present invention. Figure 2 This is a schematic diagram of the lightning strike area and exposure distance in an embodiment of the present invention.

[0126] Step 6: Following the methods in Steps 3-5, calculate the final backflashover trip rate n′ for m line segments across n amplitude ranges. jk，rt and the final tripping rate n′ jk，sf Calculations are performed to obtain the final back-off trip rates n′ for m×n circuit breakers. jk，rt and the final tripping rate n′ jk，sf The calculation results are then summed to obtain the direct lightning trip rate n of the entire collector line, considering the influence of wind turbines. l The calculation formula is as follows:

[0127]

[0128] The direct lightning tripping rate n of the collector line considering the influence of wind turbine generators l The unit is times per 100 kilometers per year. In this embodiment, the direct lightning trip rate n of the collector line is... l = 2.348 times / 100 kilometers per year.

Claims

1. A method for calculating the tripping rate of a power collection line affected by a wind turbine, characterized in that, Includes the following steps: Step 1: Obtain the parameters of the power collection line and the wind turbine generator. Step 2: Division of line segments and amplitude ranges The collector line is divided into m line segments according to the number of towers. The lightning current amplitude range is divided into n amplitude intervals according to the set amplitude difference ΔI. Any one of these line segments is denoted as line segment A. j The amplitude of lightning current within any given amplitude range is denoted as the lightning current amplitude I. k ,j=1,2,...,m,k=1,2,...,n; Step 3, solve for line segment A j At lightning current amplitude I k The backflashover trip rate n jk，rt The line backflashover resistance level I is calculated using the following formula. f : In the formula, U 50％ k is 50% of the lightning impulse discharge voltage of the surge arrester. h β is the inductive coupling coefficient between the lightning protection wire and the conductor, β is the shunt coefficient, and h is the inductive coupling coefficient between the lightning protection wire and the conductor. a h is the height of the conductor above the ground. t L represents the tower height. t K is the inductance of the tower body, and k0 is the geometric coupling coefficient between the lightning protection wire and the conductor. Line segment A j At lightning current amplitude I k The backflashover trip rate at that time is denoted as backflashover trip rate n. jk，rt Its value is: Young I f ≥I k ,n jk，rt = 0 If I f <I k , n jk，rt = Nηg[P(I k +ΔI)-P(I k )] Where η is the arc-building rate, g is the strike rate, and N is the number of lightning strikes per 100km of line per year. N g Let P(I) be the lightning density, and b be the horizontal distance between the two lightning conductors. When there is only one lightning conductor, take b = 0. k () indicates that the lightning current amplitude is greater than I k The probability, P(I) k +ΔI) represents the lightning current amplitude greater than I. k The probability of +ΔI is taken as Pick Step 4, solve for line segment A j At lightning current amplitude I k The tripping rate n at that time jk，sf Step 4.1, denote the circuit winding current range as [I 2，min I 2，max ], where I 2，min For the minimum value of the winding current range, I 2，max The formulas for calculating the maximum value of the winding current range are as follows: In the formula, r max The maximum striking distance of the line. F is the maximum shot distance parameter 1, G is the maximum shot distance parameter 2, and F = 100 - sin 2 θ, G = F[(h t -h a ) / cosθ] 2 θ is the line protection angle; Step 4.2, calculate line segment A j At lightning current amplitude I k Hit distance coefficient k g Earth strike distance r g , conductor distance r a and lightning strike distance r t The calculation formulas are as follows: r g =k g I k 0.65 r a ＝r t ＝10I k 0.65 Using the midpoint of the lightning protection wire as the center and the lightning strike distance r of the lightning protection wire as the radius of the circle... t Draw an arc for the lightning protection wire with radius r, centered at the midpoint of the conductor and with the conductor's striking distance r as the radius. a Draw a circular arc of conductor with radius r, and use the ground strike distance r as the radius. g Draw a horizontal line to indicate the height, and make the arc of the conductor intersect the horizontal line to obtain point B. Make the arc of the conductor intersect the arc of the lightning protection wire to obtain point D. The straight-line distance between the projections of points B and D onto the ground is defined as the exposure distance BD. j (I k The formula for its calculation is: In the formula, L1 is the horizontal distance between the projection of the conductor and the lightning protection wire onto the ground; Step 4.3, transfer line segment A j At lightning current amplitude I k The tripping rate due to backlash is denoted as the backlash tripping rate n. jk，sf Its value is: If the lightning current amplitude I k Not within the winding current range [I] 2，min I 2，max ], then the tripping rate n jk，sf =0; If the lightning current amplitude I k Belongs to the winding current range [I] 2，min I 2，max The line tripping rate n is calculated according to the following formula. jk，sf : n jk，sf =0.2N g BD j (I k )[P(I k +ΔI)-P(I k )] Step 5, adjust the backflashover trip rate n jk，rt and the tripping rate n jk，sf Correction Step 5.1, calculate the lightning strike width W ls and wind turbine distance r w The calculation formulas are as follows: W ls =b+4h g r w ＝6.72I k 0.8 Wind turbine strike distance r w A sphere is constructed with the radius as the radius and the top of the wind turbine as the center. The projected area of ​​this sphere on the ground is denoted as the lightning interception area Λ of the wind turbine. Step 5.2, record line segment A. j At lightning current amplitude I k The area affected by the lightning strike is called the lightning strike area S. jk，sf Line Section A j At lightning current amplitude I k The counter-strike zone at that time is the counter-strike zone S. jk，rt The calculation formulas are as follows: S jk，sf =2l Aj BD j (I k ) S jk，rt =l Aj W ls Among them, l Aj For line segment A j Length; Step 5.3, calculate the counterattack shielding factor k jk，rt and the shielding factor k jk，sf The calculation formulas are as follows: Among them, S w，rt For countering lightning strike zone S jk，rt The overlapping area of ​​the lightning interception zone Λ of the wind turbine generator, S w，sf For the lightning strike area S jk，sf The area of ​​the overlapping region with the lightning interception area Λ of the wind turbine generator; Step 5.4: Record the corrected backflashover trip rate as the final backflashover trip rate n′. jk，rt The corrected tripping rate after the backlash is denoted as the final tripping rate n′. jk，sf The calculation formulas are as follows: n′ jk，rt =k jk，rt n jk，rt n′ jk，sf =k jk，sf n jk，sf Final counterattack trip rate n′ jk，rt and the final tripping rate n′ jk，sf The units are all times per 100 kilometers per year; Step 6: Following the methods in Steps 3-5, calculate the final backflashover trip rate n′ for m line segments across n amplitude ranges. jk，rt and the final tripping rate n′ jk，sf Calculations are performed to obtain the final back-off trip rates n′ for m×n circuit breakers. jk，rt and the final tripping rate n′ jk，sf The calculation results are then summed to obtain the direct lightning trip rate n of the entire collector line, considering the influence of wind turbines. l The calculation formula is as follows: The direct lightning tripping rate n of the collector line considering the influence of wind turbine generators l The unit is times per 100 kilometers per year.

2. The method for calculating the direct lightning tripping rate of a power collection line affected by a wind turbine, as described in claim 1, is characterized in that... The parameters of the collecting line mentioned in step 1 include ground flash density, tower geographical location, number of towers, tower height, arc rate, horizontal distance between lightning protection wires, span length of each section, 50% impulse discharge voltage of tower insulators, tower grounding resistance, conductor height above ground, tower inductance, crossarm length, line protection angle, inductive coupling coefficient between lightning protection wire and conductor, and geometric coupling coefficient between lightning protection wire and conductor; the parameters of the wind turbine include the geographical location and height of the wind turbine.

3. The method for calculating the direct lightning tripping rate of a power collection line affected by a wind turbine, as described in claim 1, is characterized in that... The process of step 2 is as follows: Step 2.1: First, number the towers in the collector line, and designate any one of them as tower Γ. j Where m is the number of towers; then, the collector line is divided into m line segments according to the number of towers, and any one of these line segments is denoted as line segment A. j Section A of the line j The starting point and the ending point are: When j = 2 to m-1, line segment A j The starting point is the tower Γ j-1 and towers j The midpoint of the conductor wire is between the pole and the end point is the tower. j and towers j+1 The midpoint of the connecting wires; When j=1, line segment A j The starting point is tower Γ1, and the ending point is the midpoint of the collector wire between tower Γ1 and tower Γ2; When j = m, line segment A m The starting point is the tower Γ m-1 and towers m The midpoint of the conductor wire is between the pole and the end point is the tower. m ; Step 2.2: First, according to the State Grid enterprise standard Q / GDW 11452-2015 Lightning Protection Guidelines for Overhead Transmission Lines, determine the lightning current amplitude range as [0, 35°]. Then, divide this lightning current amplitude range into n equal amplitude intervals according to the set amplitude difference ΔI. Let the lightning current amplitude at the beginning of each amplitude interval be taken as the lightning current amplitude of that interval, and obtain the lightning current amplitude of n amplitude intervals. Record the lightning current amplitude of any one of the amplitude intervals as the lightning current amplitude I. k Where, I1=0, I n =350kA.

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