Lightning protection shunting strip spacing optimization calculation method based on lightning breakdown and flashover effects

Abstract

The invention discloses a lightning protection shunting strip spacing optimization calculation method based on lightning breakdown and flashover effects. The method specifically comprises the following steps: step 1, determining a spacing H from a lightning starting point to a radome shell; 2, determining the minimum distance d between the protected device and the radome shell; 3, determining the thickness t of the radome shell; 4, determining the breakdown field strength # imgabs0 # of the material of the radome shell and the field strength Esurface flashover along the surface of the radome shell according to the material attribute of the radome shell; step 5, calculating a shunting strip spacing # imgabs 1 # under the condition that the shunting strip is directly hit by thunder and lightning; step 6, calculating a shunting strip spacing # imgabs2 # under the condition that the shunting strip is hit after lightning surface flashover occurs; and step 7, establishing a shunt strip spacing dual-condition constraint model. According to the method, the lightning current can be ensured to be received to the shunting strip under two conditions, and the lightning stroke damage of the composite radome shell is avoided or reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of lightning protection, and in particular relates to a method for optimizing the spacing between lightning protection shunt strips based on lightning breakdown and flashover effects. Background Art

[0002] Traditional designs for shunt strip spacing often fail to fully consider the structural relationship between the protected object (usually a metal structure like an antenna) and the composite radome shell, as well as the coupling effect between surface flashover and direct breakdown. Differences in radome shell materials and the spacing between the radome shell and the protected object can affect lightning termination. In the lightning protection design system of aerospace aircraft radome, there are two types of shunt strip lightning termination methods, such as Figure 1 As shown, the first type involves lightning striking the diverter bar directly. When lightning strikes a complex electromagnetic environment, its powerful energy travels along the most vulnerable path, potentially striking the diverter bar directly. In this case, the linear distance between the lightning origin and the diverter bar becomes the preferred path for the lightning current. Due to the diverter bar's unique structural design and electrical properties, it effectively disperses the lightning's immense energy, preventing localized accumulation and potentially serious damage to equipment. The second type involves lightning initially emanating from the origin and attaching to the surface of the radome. Before penetrating the radome, it flashes along the surface and strikes the diverter bar. In this scenario, the lightning energy first acts on the surface of the equipment's radome. Although the radome provides insulation and protection, the strong electric field of lightning can cause charge accumulation and uneven distribution on the surface. When this charge distribution and accumulation reaches a certain level, surface flashover occurs. Surface flashover is a special discharge phenomenon that conducts along the surface of the radome, rather than directly penetrating it. The path of lightning flashover along the radome's surface can be affected by a variety of factors, including the radome's surface material, roughness, and humidity. Once a flashover occurs, the energy conducted is highly likely to strike the diverter strips. These strips again fulfill the crucial task of dispersing the energy, shielding equipment from direct impacts, and ensuring the safety and stability of the protected equipment under lightning.

[0003] Direct breakdown has its own unique characteristics, and surface flashover also has corresponding laws. The two types of lightning diverter strips have a mutual influence on each other. However, traditional designs ignore this combined effect, resulting in design deficiencies in dealing with complex situations, and ultimately making it difficult to achieve the expected protection range. In addition, in current research and application in related fields, a quantitative spacing calculation model based on the dielectric strength of the antenna cover shell material and the air breakdown field strength has not yet been established. This may lead to a lack of scientific and accurate basis for setting the air gap spacing of lightning diverter strips in actual operation, and it is impossible to effectively combine the specific values ​​of the material and air field strength to determine the appropriate spacing, which may affect the safety and stability of the entire system. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for optimizing the spacing calculation of lightning protection shunt strips based on lightning breakdown and flashover effects. A method for calculating the spacing of shunt strips under two coupling conditions, direct strike and surface flashover, is given to ensure that the lightning current can be connected to the shunt strips under both conditions, thereby avoiding or reducing lightning damage to the composite antenna cover shell.

[0005] The technical solution adopted by the present invention is a method for optimizing the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects, which is specifically as follows: Step 1: Determine the distance H between the lightning starting point and the radome shell; Step 2: Determine the minimum distance d between the protected device and the radome shell; Step 3: Determine the thickness t of the radome shell; Step 4: Determine the breakdown field strength of the radome shell material based on the material properties of the radome shell and the field strength of the flashover along the surface of the radome shell E surface ; Step 5: Calculate the distance between the diverter bars under the condition that the lightning directly hits the diverter bar ; Step 6: Calculate the shunt bar spacing under the condition that lightning strikes the shunt bar after surface flashover occurs ; Step 7: Establish a dual-condition constraint model for the spacing between diverter strips.

[0006] The present invention is also characterized in that: In step 1, the spacing H is specifically solved by the empirical formula, which is as follows: (1) Where E is the lightning discharge amplitude obtained from actual meteorological monitoring; k is the needle plate breakdown coefficient, which is positively correlated with the size of the radome shell. , ; is the air breakdown field strength, ; M is the maximum side length of the radome shell, in cm; m is the boundary margin of the radome shell, which reduces the influence of boundary effects. , unit is cm.

[0007] Step 2 is as follows: The key protection position is determined based on the three-dimensional structural model of the lightning protection object composed of the radome shell and the protected device; in the three-dimensional structural model of the lightning protection object, the position of the radome shell closest to the protected device is taken as the key protection position, and the vertical distance between the key protection position and the protected device is the minimum distance d between the protected device and the radome shell.

[0008] Step 3 is as follows: The three-dimensional structural model of the lightning protection object is measured using three-dimensional software to obtain the thickness t of the antenna cover shell.

[0009] In step 5: The condition for lightning to directly hit the diverter strip is: the total pressure drop of the air between the starting point of lightning and the diverter strip is Less than or equal to the voltage drop from the lightning starting point to the protected device, which is equal to the air breakdown voltage drop from the lightning starting point to the radome shell , Radome shell material breakdown voltage drop And the air breakdown pressure drop from the radome shell to the protected device sum; The total air breakdown pressure drop between the lightning starting point and the diverter strip is constructed based on the condition of directly hitting the diverter strip. The relationship between the voltage drop from the lightning starting point to the protected device is as follows: (2) in: is the air breakdown field strength; is the straight-line distance from the lightning starting point to the nearest diverter; H The distance from the lightning starting point to the radome shell; is the breakdown field strength of the radome shell material; is the thickness of the radome shell; is the minimum distance between the protected device and the radome shell; In formula (2), the straight-line distance from the lightning starting point to the nearest diverter is The expression is: (3) Substituting formula (3) into formula (2) to calculate the shunt strip spacing under the condition that lightning directly hits the shunt strip Satisfies the following expression: (4).

[0010] In step 6: The condition for lightning to hit the shunt strip after surface flashover occurs is: when lightning strikes but does not penetrate the radome shell, the insulation breakdown voltage drop required for the air to break down along the distance from the lightning point on the radome shell to the shunt strip is Need to be less than the breakdown voltage drop of the radome shell material ; The insulation breakdown voltage drop of the radome shell material is constructed based on the condition that lightning flashover occurs and hits the shunt bar. The insulation breakdown voltage drop required for air breakdown along the distance from the surface of the radome shell to the shunt strip and the lightning point on the radome shell The relationship between them ensures that the two insulation breakdown voltage drops satisfy formula (5), as follows: (5) in: E surface is the field strength of surface flashover; d surface = / 2 is the path length from the surface of the radome shell to the diverter strip; is the breakdown field strength of the radome shell material; is the thickness of the radome shell; Will d surface = / 2 is substituted into formula (5), and the shunt strip spacing under the condition that lightning flashover occurs and hits the shunt strip is obtained. , as follows: (6).

[0011] In step 7, the dual-condition constraint model of the diverter strip spacing is established, as shown in formula (7): (7) Where: S is the safety factor value.

[0012] In step 7: Determine the safety factor value S based on the lightning zone. When in zone 1A, S is 0.3, and in other lightning zones, S is 0.5.

[0013] The beneficial effects of the present invention are: The method of the present invention fully considers the relationship between the metal antenna structure and the composite antenna cover shell, and provides a method for calculating the spacing of the shunt strips under two coupling conditions: direct strike and surface flashover. This ensures that the lightning current can be connected to the shunt strips under both conditions, avoiding or reducing lightning damage to the composite antenna cover shell. This method can accurately analyze the electric field characteristics and determine the optimal lightning shunt strip layout strategy based on the electric field breakdown principle. Its application scenarios are very wide, and it is particularly suitable for composite antenna cover shell structures such as aerospace vehicles and buildings that require lightning protection. In the field of aerospace, it can ensure flight safety; in the field of construction, it can effectively protect the personnel and facilities inside. The effectiveness of lightning protection is significantly improved through innovative methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 Schematic diagram of two lightning connection methods for lightning diverter strips; Figure 2 This is a schematic diagram of lightning directly hitting the diverter bar; Figure 3 Schematic diagram of lightning flashover along the surface to the shunt strip; Figure 4 Schematic diagram of lightning connection.

[0015] In the figure, 1. Starting point of lightning, 2. Direct breakdown path of lightning, 3. Surface flashover path of lightning, 4. Diverter strip, 5. Radome shell, 6. Protected device, 7. Lightning current. DETAILED DESCRIPTION

[0016] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] The present invention provides a method for optimizing the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects, which is as follows: Step 1: Determine the distance H between the lightning starting point 1 and the radome shell 5. The specific solution formula is as follows: (1) Where, E is the lightning discharge amplitude obtained from actual meteorological monitoring, E=1000kV; k is the needle plate breakdown coefficient, which is positively correlated with the size of the antenna cover shell 5. , ; is the air breakdown field strength, ; M is the maximum side length of the radome shell 5, in cm; m is the boundary margin of the radome shell 5, which reduces the influence of the boundary effect, , unit is cm.

[0018] Step 2: Determine the minimum distance d between the protected device 6 and the radome housing 5, specifically: Determine the key protection position based on the three-dimensional structural model of the lightning protection object consisting of the radome shell 5 and the protected device 6. In the three-dimensional structural model of the lightning protection object, the position of the radome shell 5 closest to the protected device 6 is used as the key protection position. The vertical distance between this key protection position and the protected device 6 is the minimum distance d between the protected device 6 and the radome shell 5. Step 3: Determine the thickness t of the radome shell 5, specifically: Using 3D software (such as CATIA, etc.) to measure the 3D structural model of the lightning protection object, and obtain the thickness t of the radome shell 5; Step 4: Determine the breakdown field strength of the radome shell material based on the material properties of the radome shell 5 and the field strength of the flashover along the surface of the radome shell E surface ; Step 5: Calculate the distance between the diverter bars when the lightning strikes the diverter bar 4 directly ; In step 5: The condition for lightning to directly hit the diverter bar 4 is: the total air breakdown pressure drop between the lightning starting point 1 and the diverter bar 4 Less than or equal to the voltage drop from the lightning starting point 1 to the protected device 6 (e.g. the distance between the radome shell 5 and the protected device 6 is 65mm), which is equal to the air breakdown voltage drop from the lightning starting point 1 to the radome shell 5 , Radome shell material breakdown voltage drop And the air breakdown pressure drop from the radome shell 5 to the protected device 6 The running trajectory of lightning current 7 is as follows: Figure 1-Figure 2 Direct lightning breakdown path 2 is shown.

[0019] The total air breakdown pressure drop between the lightning starting point 1 and the diverter strip 4 is constructed based on the condition of directly hitting the diverter strip 4. The relationship between the voltage drop from the lightning starting point 1 to the protected device 6 is as follows: (2) in: is the air breakdown field strength; is the straight-line distance from the lightning starting point 1 to the nearest diverter bar 4; H The distance between the lightning starting point 1 and the radome shell 5 (1m to 3m); is the breakdown field strength of the radome shell material; is the thickness of the radome shell 5; is the minimum distance between the protected device 6 and the radome shell 5; In formula (2), the straight-line distance from the lightning starting point 1 to the nearest diverter 4 is The expression is: (3) Substituting formula (3) into formula (1) yields the following calculation of the shunt strip spacing when lightning directly strikes shunt strip 4: Satisfies the following expression: (4).

[0020] Step 6: Calculate the shunt bar spacing under the condition that lightning strikes shunt bar 4 after surface flashover occurs ; In step 6: The condition for lightning to hit the shunt bar 4 after the surface flashover occurs is: when the lightning strikes but does not penetrate the radome shell 5, the insulation breakdown voltage drop required for the air to break down along the distance from the lightning point on the radome shell 5 to the shunt bar 4 is Need to be less than the breakdown voltage drop of the radome shell material , the trajectory of the lightning current 7 is as follows Figure 1 and Figure 3 The lightning surface flashover path 3 is shown.

[0021] According to the condition that lightning flashover occurs and hits the shunt bar 4, the insulation breakdown voltage drop of the radome shell material is constructed. The insulation breakdown voltage drop required for air breakdown along the distance from the lightning point on the radome shell 5 to the shunt strip 4 The relationship between them ensures that the two insulation breakdown voltage drops satisfy formula (5), as follows: (5) in: E surface is the field strength of surface flashover; d surface = / 2 is the path length from the surface of the radome shell 5 to the diverter strip 4; is the breakdown field strength of the radome shell material; is the thickness of the radome shell 5; Will d surface = / 2 is substituted into formula (5), and the shunt strip spacing under the condition that lightning strikes the shunt strip 4 after the surface flashover occurs is obtained. , as follows: (6); Step 7: Establish a dual-condition constraint model for the spacing of the diverter strips to determine the final spacing of the diverter strips 4 , avoid the risk of edge electric field distortion and ensure that the lightning current 7 is connected to the shunt bar, such as Figure 4 As shown in formula (7): (7) Where: S is the safety factor value; the safety factor value S is determined according to the lightning zone. In zone 1A, S is 0.3, and in other lightning zones, S is 0.5; Example 1 The optimization calculation method for the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects is as follows: Step 1: Determine the distance H between the lightning starting point 1 and the test piece; According to the lightning protection test method specified in SAE ARP 5416A or GJB 3567A-2023, the electrode simulating the lightning source is suspended above the test piece, and the distance between the electrode and the test piece should be no less than 1 meter. The distance between the electrode and the test piece is determined based on the size of the test piece and is between 1 meter and 3 meters. The lightning starting point 1 is equated with the position of the electrode simulating the lightning source in SAE ARP 5416A or GJB 3567A-2023. The test piece is equated with the radome shell 5. A voltage generator is used to simulate lightning. The specific method is as follows: The test piece (equivalent to the radome shell 5) is a 1000mm×1000mm flat plate structure. According to the lightning protection test method specified in SAE ARP5416A or GJB 3567A-2023, the following empirical formula is used for calculation: (1) Where, E is the discharge amplitude of the voltage generator, which simulates the lightning discharge amplitude obtained by actual meteorological monitoring, E=1000kV; k is the needle plate breakdown coefficient, ; is the air breakdown field strength, ; M is the maximum side length of the test piece, M=100cm, in cm; m is the boundary margin of the test piece, m=10cm.

[0022] After calculation, H = 0.92m. According to the standard SAE ARP 5416A, the minimum value of H is 1m. Therefore, H = 1m in this example.

[0023] Step 2: Determine the minimum distance d between the protected device 6 and the test piece. The specific method is as follows: Based on the three-dimensional structural model of the lightning protection object consisting of the test piece and the protected device 6, the position of the test piece closest to the protected device 6 is taken as the key protection position. The vertical distance between this key protection position and the protected device 6 is the minimum distance d between the protected device 6 and the test piece. In this case, the minimum distance d between the test piece and the protected device 6 is 65 mm. Step 3: Determine the thickness t of the test piece as follows: The 3D structural model of the lightning protection object was measured using the 3D software CATIA, and the thickness t of the test piece was found to be 4.8 mm. Step 4: The material of this test piece is glass fiber composite material, and its breakdown field strength and the field strength of the flashover along the surface of the radome shell E surface They are 12.8kV / mm and 140kV / m respectively.

[0024] Step 5: Calculate the distance between the diverter bars when the lightning strikes the diverter bar 4 directly ; The total air breakdown pressure drop between the lightning starting point 1 and the diverter strip 4 is constructed based on the condition of directly hitting the diverter strip 4. The relationship between the voltage drop from the lightning starting point 1 to the protected device 6 is as follows: (2) in: The breakdown field strength for air is 3kV / mm; is the straight-line distance from the lightning starting point 1 to the nearest diverter bar 4; H is the distance between the lightning starting point 1 and the test piece; is the breakdown field strength of the radome shell material; is the thickness of the test piece; is the minimum distance between the protected device 6 and the test piece; In formula (2), the straight-line distance from the lightning starting point 1 to the nearest diverter 4 is The expression is: (3) Substituting formula (3) into formula (2) yields the following calculation of the shunt strip spacing when lightning directly strikes shunt strip 4: Satisfies the following expression: (4).

[0025] Substitute the parameter values ​​obtained from steps 1 to 4 into the above formula: =844.4mm Step 6: Calculate the shunt bar spacing under the condition that lightning strikes shunt bar 4 after surface flashover occurs ; Make sure the following formula is met: (5) in: E surface is the field strength of surface flashover; d surface = / 2 is the path length from the surface of the test piece to the diverter strip 4; is the breakdown field strength of the radome shell material; is the thickness of the test piece; Will d surface = / 2 is substituted into formula (5), and the shunt strip spacing under the condition that lightning strikes the shunt strip 4 after the surface flashover occurs is obtained. , as follows: (6); Substitute the parameter values ​​obtained in steps 3 and 4 into formula (6): =877.7mm Step 7: Establish a dual-condition constraint model for the spacing of the diverter strips, as shown in formula (7): Determine the final spacing of the diverter strips 4 , avoid the risk of edge electric field distortion and ensure that the lightning current is connected to the shunt bar; (7) Since the lightning zone of the test piece is zone 1A, its safety factor is 0.3. Substituting the calculation results obtained in steps 5 and 6 into formula (7), we get : =253mm; Arrange the lightning protection diverter strips on the test piece according to the calculation results of step 7, and carry out the verification test according to the method TL101 (initial pilot adhesion test) in the standard GJB3576A-2023. First, carry out the verification test of the radome flat-plate test piece. Arrange four diverter strips on the surface of the test piece in parallel with each other and with equal spacing (the spacing between two adjacent diverter strips is 1 / 4 of the original strip). ), these four shunt strips are named: the first shunt strip, the second shunt strip, the third shunt strip and the fourth shunt strip. The test results are shown in Table 1. A total of 6 tests were conducted, 3 times each with positive and negative polarity (simulating actual lightning strikes). The lightning currents generated by the 6 test voltage generators were directly connected to the lightning shunt strips, and no damage was caused to the composite flat test piece. Then, an initial pilot adhesion test was carried out on a certain type of antenna cover. Nine parallel shunt strips with equal spacing were arranged on a certain type of antenna cover (the spacing between two adjacent shunt strips was ). ), these nine shunt strips are named, in sequence: the fifth shunt strip, the sixth shunt strip, the seventh shunt strip, the eighth shunt strip, the ninth shunt strip, the tenth shunt strip, the eleventh shunt strip, the twelfth shunt strip, and the thirteenth shunt strip. The test results are shown in Table 2. A total of 12 tests were conducted, with six positive and six negative lightning polarities (simulating actual lightning strikes). The lightning currents generated by the voltage generator in all 12 tests were connected to the lightning protection shunt strips, and no damage such as breakdown or ablation occurred on the radome itself. Therefore, the spacing of the lightning protection shunt strips calculated by this invention meets the requirements for lightning protection of the radome.

[0026] Table 1 Test results of flat plate test pieces

[0027] Table 2 Test results of a certain type of radome

[0028] Example 2 The optimization calculation method for the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects is as follows: Step 1: Determine the distance H between the lightning starting point 1 and the radome shell 5; Step 2: Determine the minimum distance d between the protected device 6 and the radome shell 5; Step 3: Determine the thickness t of the radome shell 5; Step 4: Determine the breakdown field strength of the radome shell material based on the material properties of the radome shell 5 and the field strength of the flashover along the surface of the radome shell E surface ; Step 5: Calculate the distance between the diverter bars when the lightning strikes the diverter bar 4 directly ; Step 6: Calculate the shunt bar spacing under the condition that lightning strikes shunt bar 4 after surface flashover occurs ; Step 7: Establish a dual-condition constraint model for the spacing between diverter strips.

[0029] Example 3 The optimization calculation method for the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects is as follows: Step 1: Determine the distance H between the lightning starting point 1 and the radome shell 5; In step 1, the spacing H is specifically solved by the empirical formula, which is as follows: (1) Where, E is the lightning discharge amplitude obtained from actual meteorological monitoring, E=1000kV; k is the needle plate breakdown coefficient, which is positively correlated with the size of the antenna cover shell 5. , ; is the air breakdown field strength, ; M is the maximum side length of the radome shell 5, in cm; m is the boundary margin of the radome shell 5, which reduces the influence of the boundary effect, , unit is cm.

[0030] Step 2: Determine the minimum distance d between the protected device 6 and the radome shell 5; Step 3: Determine the thickness t of the radome shell 5; Step 4: Determine the breakdown field strength of the radome shell material based on the material properties of the radome shell 5 and the field strength of the flashover along the surface of the radome shell E surface ; Step 5: Calculate the distance between the diverter bars when the lightning strikes the diverter bar 4 directly ; Step 6: Calculate the shunt bar spacing under the condition that lightning strikes shunt bar 4 after surface flashover occurs ; Step 7: Establish a dual-condition constraint model for the spacing between diverter strips.

[0031] Example 4 The optimization calculation method for the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects is as follows: Step 1: Determine the distance H between the lightning starting point 1 and the radome shell 5; In step 1, the spacing H is specifically solved by the empirical formula, which is as follows: (1) Where, E is the lightning discharge amplitude obtained from actual meteorological monitoring, E=1000kV; k is the needle plate breakdown coefficient, which is positively correlated with the size of the antenna cover shell 5. , ; is the air breakdown field strength, ; M is the maximum side length of the radome shell 5, in cm; m is the boundary margin of the radome shell 5, which reduces the influence of the boundary effect, , unit is cm.

[0032] Step 2: Determine the minimum distance d between the protected device 6 and the radome shell 5; Step 2 is as follows: The key protection position is determined based on the three-dimensional structural model of the lightning protection object composed of the antenna cover shell 5 and the protected device 6; in the three-dimensional structural model of the lightning protection object, the position of the antenna cover shell 5 closest to the protected device 6 is taken as the key protection position, and the vertical distance between the key protection position and the protected device 6 is the minimum distance d between the protected device 6 and the antenna cover shell 5.

[0033] Step 3: Determine the thickness t of the radome shell 5; Step 4: Determine the breakdown field strength of the radome shell material based on the material properties of the radome shell 5 and the field strength of the flashover along the surface of the radome shell E surface ; Step 5: Calculate the distance between the diverter bars when the lightning strikes the diverter bar 4 directly ; Step 6: Calculate the shunt bar spacing under the condition that lightning strikes shunt bar 4 after surface flashover occurs ; Step 7: Establish a dual-condition constraint model for the spacing between diverter strips.

[0034] Example 5 The optimization calculation method for the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects is as follows: Step 1: Determine the distance H between the lightning starting point 1 and the radome shell 5; In step 1, the spacing H is specifically solved by the empirical formula, which is as follows: (1) Where, E is the lightning discharge amplitude obtained from actual meteorological monitoring, E=1000kV; k is the needle plate breakdown coefficient, which is positively correlated with the size of the antenna cover shell 5. , ; is the air breakdown field strength, ; M is the maximum side length of the radome shell 5, in cm; m is the boundary margin of the radome shell 5, which reduces the influence of the boundary effect, , unit is cm.

[0035] Step 2: Determine the minimum distance d between the protected device 6 and the radome shell 5; Step 2 is as follows: The key protection position is determined based on the three-dimensional structural model of the lightning protection object composed of the antenna cover shell 5 and the protected device 6; in the three-dimensional structural model of the lightning protection object, the position of the antenna cover shell 5 closest to the protected device 6 is taken as the key protection position, and the vertical distance between the key protection position and the protected device 6 is the minimum distance d between the protected device 6 and the antenna cover shell 5.

[0036] Step 3: Determine the thickness t of the radome shell 5; Step 3 is as follows: The three-dimensional structural model of the lightning protection object is measured using three-dimensional software to obtain the thickness t of the radome shell 5 .

[0037] Step 4: Determine the breakdown field strength of the radome shell material based on the material properties of the radome shell 5 and the field strength of the flashover along the surface of the radome shell E surface ; Step 5: Calculate the distance between the diverter bars when the lightning strikes the diverter bar 4 directly ; Step 6: Calculate the shunt bar spacing under the condition that lightning strikes shunt bar 4 after surface flashover occurs ; Step 7: Establish a dual-condition constraint model for the spacing between diverter strips.

[0038] Example 6 The optimization calculation method for the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects is as follows: Step 1: Determine the distance H between the lightning starting point 1 and the radome shell 5; In step 1, the spacing H is specifically solved by the empirical formula, which is as follows: (1) Where, E is the lightning discharge amplitude obtained from actual meteorological monitoring, E=1000kV; k is the needle plate breakdown coefficient, which is positively correlated with the size of the antenna cover shell 5. , ; is the air breakdown field strength, ; M is the maximum side length of the radome shell 5, in cm; m is the boundary margin of the radome shell 5, which reduces the influence of the boundary effect, , unit is cm.

[0039] Step 2: Determine the minimum distance d between the protected device 6 and the radome shell 5; Step 2 is as follows: The key protection position is determined based on the three-dimensional structural model of the lightning protection object composed of the antenna cover shell 5 and the protected device 6; in the three-dimensional structural model of the lightning protection object, the position of the antenna cover shell 5 closest to the protected device 6 is taken as the key protection position, and the vertical distance between the key protection position and the protected device 6 is the minimum distance d between the protected device 6 and the antenna cover shell 5.

[0040] Step 3: Determine the thickness t of the radome shell 5; Step 3 is as follows: The three-dimensional structural model of the lightning protection object is measured using three-dimensional software to obtain the thickness t of the radome shell 5 .

[0041] Step 4: Determine the breakdown field strength of the radome shell material based on the material properties of the radome shell 5 and the field strength of the flashover along the surface of the radome shell E surface ; Step 5: Calculate the distance between the diverter bars when the lightning strikes the diverter bar 4 directly ; In step 5: The condition for lightning to directly hit the diverter bar 4 is: the total air breakdown pressure drop between the lightning starting point 1 and the diverter bar 4 Less than or equal to the voltage drop from the lightning starting point 1 to the protected device 6, which is equal to the air breakdown voltage drop from the lightning starting point 1 to the radome shell 5 , Radome shell material breakdown voltage drop And the air breakdown pressure drop from the radome shell 5 to the protected device 6 sum; The total air breakdown pressure drop between the lightning starting point 1 and the diverter strip 4 is constructed based on the condition of directly hitting the diverter strip 4. The relationship between the voltage drop from the lightning starting point 1 to the protected device 6 is as follows: (2) in: is the air breakdown field strength; is the straight-line distance from the lightning starting point 1 to the nearest diverter bar 4; H is the distance from the lightning starting point 1 to the radome shell 5; is the breakdown field strength of the radome shell material; is the thickness of the radome shell 5; is the minimum distance between the protected device 6 and the radome shell 5; In formula (2), the straight-line distance from the lightning starting point 1 to the nearest diverter 4 is The expression is: (3) Substituting formula (3) into formula (2) yields the following calculation of the shunt strip spacing when lightning directly strikes shunt strip 4: Satisfies the following expression: (4).

[0042] Step 6: Calculate the shunt bar spacing under the condition that lightning strikes shunt bar 4 after surface flashover occurs ; Step 7: Establish a dual-condition constraint model for the spacing between diverter strips.

Claims

1. A method for optimizing the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects, characterized in that: The details are as follows: Step 1: Determine the distance H between the lightning starting point and the radome shell; Step 2: Determine the minimum distance d between the protected device and the radome shell; Step 3: Determine the thickness t of the radome shell; Step 4: Determine the breakdown field strength of the radome shell material based on the material properties of the radome shell and the field strength of the flashover along the surface of the radome shell E surface ; Step 5: Calculate the distance between the diverter bars under the condition that the lightning directly hits the diverter bar ; Step 6: Calculate the shunt bar spacing under the condition that lightning strikes the shunt bar after surface flashover occurs ; Step 7: Establish a dual-condition constraint model for the spacing between diverter strips.

2. The method for optimizing the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects according to claim 1 is characterized in that: In step 1, the spacing H is specifically solved by the empirical formula, which is as follows: （1） Where, E is the lightning discharge amplitude obtained from actual meteorological monitoring; k is the needle plate breakdown coefficient, , ; is the air breakdown field strength, ; M is the maximum side length of the radome shell, in cm; m is the margin of the radome shell, , unit is cm.

3. The method for optimizing the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects according to claim 1 is characterized in that: Step 2 is as follows: The key protection position is determined based on the three-dimensional structural model of the lightning protection object composed of the radome shell and the protected device; in the three-dimensional structural model of the lightning protection object, the position of the radome shell closest to the protected device is taken as the key protection position, and the vertical distance between the key protection position and the protected device is the minimum distance d between the protected device and the radome shell.

4. The method for optimizing the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects according to claim 1, characterized in that: Step 3 is as follows: The three-dimensional structural model of the lightning protection object is measured using three-dimensional software to obtain the thickness t of the antenna cover shell.

5. The method for optimizing the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects according to claim 1 is characterized in that: In step 5: The condition for lightning to directly hit the diverter strip is: the total pressure drop of the air between the starting point of lightning and the diverter strip is Less than or equal to the voltage drop from the lightning starting point to the protected device, which is equal to the air breakdown voltage drop from the lightning starting point to the radome shell , Radome shell material breakdown voltage drop And the air breakdown pressure drop from the radome shell to the protected device sum; The total air breakdown pressure drop between the lightning starting point and the diverter strip is constructed based on the condition of directly hitting the diverter strip. The relationship between the voltage drop from the lightning starting point to the protected device is as follows: （2） in: is the air breakdown field strength; is the straight-line distance from the lightning starting point to the nearest diverter; H The distance from the lightning starting point to the radome shell; is the breakdown field strength of the radome shell material; is the thickness of the radome shell; is the minimum distance between the protected device and the radome shell; In formula (2), the straight-line distance from the lightning starting point to the nearest diverter is The expression is: （3） Substituting formula (3) into formula (2) to calculate the shunt strip spacing under the condition that lightning directly hits the shunt strip Satisfies the following expression: （4）。 6. The method for optimizing the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects according to claim 1, characterized in that: In step 6: The condition for lightning to hit the shunt strip after surface flashover occurs is: when lightning strikes but does not penetrate the radome shell, the insulation breakdown voltage drop required for the air to break down along the distance from the lightning point on the radome shell to the shunt strip is Need to be less than the breakdown voltage drop of the radome shell material ; The insulation breakdown voltage drop of the radome shell material is constructed based on the condition that lightning flashover occurs and hits the shunt bar. The insulation breakdown voltage drop required for air breakdown along the distance from the surface of the radome shell to the shunt strip and the lightning point on the radome shell The relationship between them ensures that the two insulation breakdown voltage drops satisfy formula (5), as follows: （5） in: E surface is the field strength of surface flashover; d surface = / 2 is the path length from the surface of the radome shell to the diverter strip; is the breakdown field strength of the radome shell material; is the thickness of the radome shell; Will d surface = / 2 is substituted into formula (5), and the shunt strip spacing under the condition that lightning flashover occurs and hits the shunt strip is obtained. , as follows: （6）。 7. The method for optimizing the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects according to claim 1, characterized in that: In step 7, the dual-condition constraint model of the diverter strip spacing is established, as shown in formula (7): （7） Where: S is the safety factor value.

8. The method for optimizing the spacing of lightning protection shunt strips based on lightning breakdown and flashover effects according to claim 7, characterized in that: In step 7: Determine the safety factor value S based on the lightning zone. When in zone 1A, S is 0.3, and in other lightning zones, S is 0.5.

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