A design method and system for a two-section variable diameter wind-proof composite insulator

Abstract

The invention relates to a design method for a two-section variable diameter wind-proof composite insulator, comprising the following steps: inputting design data, including the size data of a first-order core rod and a second-order core rod and the maximum wind speed at the design height of a jumper string of a tension tower; calculating the wind receiving area of ​​an insulator body and the wind force received by the input design data; calculating the equivalent resultant force applied by the jumper to the end of the insulator according to the wind force received by the insulator body and the jumper data of the jumper string of the tension tower; calculating the equivalent section inertia moment of the insulator according to the size data of the first-order core rod and the second-order core rod; calculating the deflection of the end of the insulator according to the equivalent resultant force applied by the jumper to the end of the insulator and the equivalent section inertia moment of the insulator; querying requirements and judging whether the requirements are met according to the calculated deflection of the end of the insulator, if the requirements are met, outputting the size data of the current first-order core rod and the second-order core rod, if not, adjusting the size data of the first-order core rod and the second-order core rod and repeating the above steps.

Description

Technical Field

[0001] The invention relates to a design method and system for a two-section variable-diameter wind-proof composite insulator, belonging to the technical field of electrical equipment design. Background Art

[0002] Due to the influence of typhoons, the jumper strings of the tension towers in coastal overhead lines often experience power frequency flashover tripping accidents under the action of strong winds, thus affecting the safe and reliable power transmission of the power grid. Therefore, for coastal lines of 220kV and below, it is common to use vertical fixed wind-proof composite insulators as jumper strings. However, this type of insulator is an integrated structure (the insulator core rod is a cylinder with uniform diameter, and the formula for the moment of inertia of the section is I = πD 4 / 64), and 500kV hard-supported wind-proof composite insulators have also been used in small quantities. Due to the large wind load of 500kV jumper series, the vertical fixed wind-proof composite insulator core rods that have been in operation usually adopt a two-section variable diameter cylindrical structure. However, there are no clear technical regulations for the design method of this type of insulator for reference. In the design, it can only be simulated and designed through material finite element simulation software, and the design efficiency is low. Summary of the invention

[0003] In order to solve the problems existing in the above-mentioned prior art, the present invention proposes a design method and system for a two-section variable diameter wind-proof composite insulator, and proposes a method for calculating the moment of inertia of the cross-section of a two-section variable diameter cylinder that meets various extreme conditions. The method can be used for the design optimization of the two-section variable diameter wind-proof composite insulator and the design and verification of the engineering tower head dimensions, thereby reducing the design difficulty.

[0004] The technical solution of the present invention is as follows:

[0005] On the one hand, the present invention provides a design method for a two-section variable diameter windproof composite insulator, wherein the two-section variable diameter windproof composite insulator comprises a first-order core rod and a second-order core rod which are arranged in an upper and lower distribution and have a larger diameter at the top and a smaller diameter at the bottom, and the first-order core rod and the second-order core rod are made of the same material, and the design method comprises the following steps:

[0006] Input design data, including the size data of the first-order core rod and the second-order core rod and the maximum wind speed at the design height of the tension tower jumper string;

[0007] Calculating the wind-receiving area and wind force of the insulator body by using the input design data;

[0008] According to the wind force on the insulator body and the jumper data of the jumper string of the tension tower, the equivalent resultant force exerted by the jumper on the end of the insulator is calculated;

[0009] According to the dimension data of the first-order core rod and the second-order core rod, the equivalent section moment of inertia of the insulator is calculated;

[0010] Calculate the deflection of the insulator end based on the equivalent resultant force applied by the jumper to the insulator end and the equivalent section inertia moment of the insulator;

[0011] According to the calculated deflection of the insulator end, query the electrical engineering requirements and determine whether they meet the electrical requirements. If they meet the requirements, output the size data of the current first-order core rod and second-order core rod. If they do not meet the requirements, adjust the size data of the first-order core rod and second-order core rod and repeat the above steps.

[0012] As a preferred implementation, the method for calculating the wind receiving area and wind force of the insulator body by using the input design data is specifically as follows:

[0013] The following formula is used to calculate the wind-receiving area and wind force of the insulator body:

[0014]

[0015] Where A is the wind-exposed area of ​​the insulator body, a and c are the lengths of the first-order core rod and the second-order core rod, respectively; D and d are the diameters of the first-order core rod and the second-order core rod, respectively; P is the wind force on the insulator body; and v is the maximum wind speed at the design height of the jumper string of the tension tower.

[0016] As a preferred embodiment, the method for calculating the equivalent resultant force exerted by the jumper on the end of the insulator according to the wind force on the insulator body and the jumper data of the tension tower jumper string is specifically as follows:

[0017] The equivalent force exerted by the jumper on the end of the insulator is calculated using the following formula:

[0018]

[0019] Where n is the number of jumper splits, A cdr , L cdr , D cdr are the wind pressure area of ​​the jumper, the length of a single jumper and the outer diameter of the jumper, respectively; x is the equivalent centroid position corresponding to the wind load on the composite insulator itself; T is the soft jumper tension; T0 is the installation tension of a phase jumper; g1 and g6 are the unit deadweight load of the conductor and the comprehensive load at maximum wind speed, respectively; F is the equivalent resultant force exerted by the jumper on the end of the insulator; L=a+c; θ is the angle formed by the soft jumpers on both sides of the jumper string.

[0020] As a preferred implementation, the method for calculating the equivalent section inertia moment of the insulator according to the dimension data of the first-order core rod and the second-order core rod is specifically as follows:

[0021] The equivalent section moment of inertia of the insulator is calculated using the following formula:

[0022]

[0023] Where, and m are proportional coefficients, s is the calculated value, is pi, and I is the equivalent section moment of inertia of the insulator.

[0024] As a preferred implementation, the method for calculating the deflection of the insulator end is specifically as follows:

[0025] The deflection of the insulator end is calculated using the following formula:

[0026]

[0027] Where B is the stiffness under equivalent load, E is the bending elastic coefficient of the composite insulator, and y is the deflection of the insulator end.

[0028] On the other hand, the present invention provides a design system for a two-section variable diameter windproof composite insulator, wherein the two-section variable diameter windproof composite insulator comprises a first-order core rod and a second-order core rod which are arranged in an upper and lower distribution and have a larger diameter at the top and a smaller diameter at the bottom, and the first-order core rod and the second-order core rod are made of the same material, and the design system comprises:

[0029] A data input module, used to input design data, including the size data of the first-order core rod and the second-order core rod and the maximum wind speed at the design height of the jumper string of the tension tower;

[0030] A wind receiving area and wind force calculation module, used to calculate the wind receiving area and wind force received by the insulator body using the input design data;

[0031] The equivalent resultant force calculation module is used to calculate the equivalent resultant force exerted by the jumper on the end of the insulator according to the wind force on the insulator body and the jumper data of the jumper string of the tension tower;

[0032] Section inertia moment calculation module, used to calculate the equivalent section inertia moment of the insulator according to the size data of the first-order core rod and the second-order core rod;

[0033] A deflection calculation module is used to calculate the deflection of the insulator end according to the equivalent resultant force applied by the jumper to the insulator end and the equivalent section inertia moment of the insulator;

[0034] The verification module is used to query the electrical engineering requirements and determine whether they meet the electrical requirements based on the calculated deflection of the insulator end. If they meet the requirements, the size data of the current first-order core rod and the second-order core rod are output. If they do not meet the requirements, the size data of the first-order core rod and the second-order core rod are adjusted and the above steps are repeated.

[0035] As a preferred implementation, the method for the wind receiving area and wind force calculation module to calculate the wind receiving area and wind force received by the insulator body is specifically as follows:

[0036] The following formula is used to calculate the wind-receiving area and wind force of the insulator body:

[0037]

[0038] Where A is the wind-exposed area of ​​the insulator body, a and c are the lengths of the first-order core rod and the second-order core rod, respectively; D and d are the diameters of the first-order core rod and the second-order core rod, respectively; P is the wind force on the insulator body; and v is the maximum wind speed at the design height of the jumper string of the tension tower.

[0039] As a preferred implementation, the method for the equivalent force calculation module to calculate the equivalent force applied by the jumper to the end of the insulator is specifically as follows:

[0040] The equivalent force exerted by the jumper on the end of the insulator is calculated using the following formula:

[0041]

[0042] Where n is the number of jumper splits, A cdr , L cdr , D cdr are the wind pressure area of ​​the jumper, the length of a single jumper and the outer diameter of the jumper, respectively; x is the equivalent centroid position corresponding to the wind load on the composite insulator itself; T is the soft jumper tension; T0 is the installation tension of a phase jumper; g1 and g6 are the unit deadweight load of the conductor and the comprehensive load at maximum wind speed, respectively; F is the equivalent resultant force exerted by the jumper on the end of the insulator; L=a+c; θ is the angle formed by the soft jumpers on both sides of the jumper string.

[0043] As a preferred implementation, the method for calculating the equivalent moment of inertia of an insulator by the moment of inertia calculation module of the section is specifically as follows:

[0044] The equivalent section moment of inertia of the insulator is calculated using the following formula:

[0045]

[0046] Where, and m are proportional coefficients, s is the calculated value, is pi, and I is the equivalent section moment of inertia of the insulator.

[0047] As a preferred implementation, the method for the deflection calculation module to calculate the deflection of the insulator end is specifically as follows:

[0048] The deflection of the insulator end is calculated using the following formula:

[0049]

[0050] Where B is the stiffness under equivalent load, E is the bending elastic coefficient of the composite insulator, and y is the deflection of the insulator end.

[0051] The present invention has the following beneficial effects:

[0052] The invention discloses a design method system for a two-section variable diameter windproof composite insulator. According to the characteristics of the two-section variable diameter windproof composite insulator, the relevant theories of material mechanics and the understanding of elastic potential energy provide a corresponding section inertia formula to calculate the equivalent section inertia moment and overall deflection of the two-section variable diameter windproof composite insulator. It does not rely on the finite element method, so it does not need to spend a lot of modeling time, greatly simplifies the design process, and thus improves the design efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a flow chart of a method according to Embodiment 1 of the present invention;

[0054] Figure 2 The figure is a schematic structural diagram of a two-section variable diameter wind-proof composite insulator according to an embodiment of the present invention. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] It should be understood that the step numbers used in this document are only for convenience of description and are not intended to limit the order in which the steps are executed.

[0057] It should be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0058] The terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0059] The term "and / or" means and includes any and all possible combinations of one or more of the associated listed items.

[0060] Embodiment 1:

[0061] See also Figure 1 This embodiment provides a design method for a two-section variable diameter wind-proof composite insulator. Figure 2The top of the two-section variable-diameter wind-proof composite insulator is a flange plate for connecting to the pole tower. The bottom of the flange plate includes a first-order core rod and a second-order core rod distributed up and down and with a larger diameter at the top and a smaller diameter at the bottom. The first-order core rod and the second-order core rod are made of the same material.

[0062] The design method comprises the following steps:

[0063] Step S100, input design data, including the length a and diameter D of the first-order core rod, the length c and diameter d of the second-order core rod, and the maximum wind speed at the design height of the tension tower jumper string. In this embodiment, the maximum wind speed at the design height of the corresponding tension tower jumper string is queried according to the engineering meteorological conditions table.

[0064] Step S201, using the input size data of the first-order core rod and the second-order core rod and the wind speed data, calculate the wind receiving area of ​​the insulator body and the wind force received;

[0065] Step S202, calculating the equivalent resultant force exerted by the jumper on the end of the insulator according to the calculated wind force on the insulator body and the jumper data (known data) of the jumper string of the tension tower;

[0066] Step S203, calculating the equivalent section inertia moment of the insulator corresponding to the current size data according to the input size data of the first-order core rod and the second-order core rod;

[0067] Step S204, calculating the deflection of the insulator end according to the calculated equivalent resultant force applied by the jumper to the insulator end and the equivalent section inertia moment of the insulator under the current size data;

[0068] Step S300, according to the calculated deflection of the insulator end, query the electrical safety distance specified in the specification and the specific engineering clearance margin requirements (known conditions), and then draw the insulator gap circle verification diagram according to the deflection of the insulator end. If the size data of the selected first-order core rod and second-order core rod meet the electrical requirements, the size data of the current first-order core rod and second-order core rod are output after verification. If not, the diameter D of the first-order core rod is gradually increased in steps of 5 mm, and the above steps S100 to S204 are repeated until the gap circle drawn according to the calculated deflection is averaged. Until the electrical requirements are met, remember D at this time, and then fine-tune the proportional factors of a and c according to the principle of c≥a, so that the design parameters of the insulator are more in line with the usual engineering data (for example, when the calculated a=1.754m, a=1.75m can be adjusted, and when the calculated diameter d=6.48cm, d=6.5cm is taken). After adjustment, recalculate according to the adjusted dimensional data to verify that the gap circle drawn by the calculated deflection still meets the electrical requirements. Finally, output the dimensional data of the current first-order core rod and second-order core rod and submit them to the composite insulator manufacturer for processing.

[0069] As a preferred implementation of this embodiment, in step S201, the method of calculating the wind receiving area and wind force of the insulator body by using the input design data is specifically as follows:

[0070] The following formula is used to calculate the wind-receiving area and wind force of the insulator body:

[0071]

[0072] Where A is the wind-exposed area of ​​the insulator body, a and c are the lengths of the first-order core rod and the second-order core rod, respectively; D and d are the diameters of the first-order core rod and the second-order core rod, respectively; P is the wind force on the insulator body, in N; and v is the maximum wind speed at the design height of the jumper string of the tension tower, in (m / s).

[0073] As a preferred implementation of this embodiment, in step S202, the method for calculating the equivalent resultant force exerted by the jumper on the end of the insulator according to the wind force on the insulator body and the jumper data of the jumper string of the tension tower is specifically as follows:

[0074] The equivalent force exerted by the jumper on the end of the insulator is calculated using the following formula:

[0075]

[0076] Where n is the number of jumper splits, A cdr , L cdr , D cdr are the wind pressure area of ​​the jumper, the length of a single jumper and the outer diameter of the jumper, respectively; x is the equivalent centroid position corresponding to the wind load on the composite insulator itself; T is the soft jumper tension; T0 is the installation tension of a phase jumper; g1 and g6 are the unit deadweight load of the conductor and the comprehensive load at maximum wind speed, respectively (which can be directly read from the stress characteristic table of the conductor (jumper) in the preliminary design stage of the line, which is equivalent to a known parameter, and the physical units of the two are the same); F is the equivalent resultant force exerted by the jumper on the end of the insulator, L=a+c, θ is the angle formed by the soft jumpers on both sides of the jumper string (this angle is determined by the planned rotation angle of the tension tower, and is generally taken as equal to the planned rotation angle); in this formula, the units of length and area are all in the International System of Units, and the unit of force is N.

[0077] As a preferred implementation of this embodiment, in step S203, the method for calculating the equivalent section inertia moment of the insulator according to the dimension data of the first-order core rod and the second-order core rod is specifically as follows:

[0078] The equivalent section moment of inertia of the insulator is calculated using the following formula:

[0079]

[0080] k and m are proportional coefficients, both dimensionless intermediate parameters, π is the ratio of the circumference of a circle, which can be 3.1416, and I is the moment of inertia of the section. In (Equation 3), the length and diameter units are cm, so that the moment of inertia calculated in this way is more in line with engineering practices.

[0081] As a preferred implementation of this embodiment, in step S204, the method for calculating the deflection of the insulator end is specifically:

[0082] The deflection of the insulator end is calculated using the following formula:

[0083]

[0084] Where B is the stiffness under equivalent load, in N*cm 2 ; E is the bending elastic coefficient of the composite insulator, in N / cm 2 ; y is the deflection of the insulator end, in cm.

[0085] The method proposed in this embodiment is obtained based on the characteristics of the two-section variable-diameter wind-proof composite insulator and combined with the basic properties of material mechanics. When the segment length coefficient k takes the extreme case of 0 or 1, the corresponding two integral composite insulator core rods with different diameters respectively have the numerical values ​​of their cross-sectional inertia moments that conform to the calculation results of material mechanics. It is worth noting that the materials of the upper and lower sections must be the same in order to use this method for calculation.

[0086] In this embodiment (Formula 3), s corresponds to the formula for the moment of inertia of a single-section cylinder (I = πD 4 The denominator 64 in / 64) changes according to the ratio of the two diameters and lengths.

[0087] Because the insulator corresponding to this embodiment is a vertically fixed composite insulator, it will not swing and only produce deflection displacement. Therefore, when calculating the wind pressure of the jumper, it is not necessary to multiply it by the wind pressure unevenness coefficient (this value is taken as 1.2 when calculating conventional jumpers, and is defined for the suspended swingable jumper string type).

[0088] The method proposed in this embodiment converts the uniform force of wind on the composite insulator into a concentrated load on the centroid of the composite insulator to simplify the calculation according to the characteristics of the line jumper string, and then the wind force on the insulator string itself, the wind force on the soft jumper, and the tension caused by the angle of the soft jumper are equivalent to the resultant force F applied to the end of the composite insulator;

[0089] According to the relevant theories of material mechanics and combined with the understanding of elastic potential energy, the fitting formula of the corresponding section inertia moment is given to calculate the equivalent section inertia moment of the two-section variable diameter cylinder and the overall deflection of the composite insulator.

[0090] To demonstrate the superiority of the method proposed in this embodiment, the specific application scenarios and application effects of this embodiment are provided below:

[0091] For a 500kV jumper, the jumper length is L cdr =28m, number of splits is 4, outer diameter of jumper is 26.82mm, maximum wind speed is 43.5m / s, ratio of wind load to deadweight load of jumper is 2.237, angle of jumper is 40°, installation tension is 200N per phase. The structural parameters of vertical fixed composite insulator are as follows: a=3m, c=1.9m, D=9cm, d=4.5cm, bending elastic coefficient E=4.5N / cm 2 , calculate the equivalent section moment of inertia I and the deflection y at the end of the insulator.

[0092] According to (Formula 1) and (Formula 2), the intermediate results are as follows:

[0093]

[0094] According to the above calculation results, F is taken as 4000N during design.

[0095] According to (Equation 3), we can obtain s = 45.388 and the equivalent section moment of inertia I = 228.4 cm 4 According to (Formula 4), the insulator end deflection y = 152.6 cm is obtained.

[0096] The above calculated value is only +2.8% different from the test value of the project, 149.2cm, and is on the safe side, so it can theoretically be well consistent with the actual test value.

[0097] Assuming that the design F remains unchanged, when the length of a changes, that is, k changes while other parameters remain unchanged, a series of results are calculated as shown in the following table:

[0098] Table 1 Calculated values ​​of s, I, and y when F = 4000N and k changes

[0099] k=a / L a(m) c(m) D(cm) m=d / D s <![CDATA[I(cm 4 )]]> y(cm) 0 0 4.9 9 0.5 16 80.5 432.9 0.1 0.49 4.41 9 0.5 20.8 104.7 333.0 0.2 0.98 3.92 9 0.5 25.6 128.8 270.6 0.3 1.47 3.43 9 0.5 30.4 153.0 227.9 0.4 1.96 2.94 9 0.5 35.2 177.1 196.8 0.5 2.45 2.45 9 0.5 40 201.3 173.2 0.6 2.94 1.96 9 0.5 44.8 225.4 154.6 0.7 3.43 1.47 9 0.5 49.6 249.6 139.7 0.8 3.92 0.98 9 0.5 54.4 273.8 127.3 0.9 4.41 0.49 9 0.5 59.2 297.9 117.0 1 4.9 0 9 0.5 64 322.1 108.2

[0100] It can be seen from Table 1 above that the larger the proportion of thick rods, the smaller the deflection. When k = 0, it is equivalent to a single thin rod. According to I = πd 4 / 64 is the same as the calculated value of I in the above table. When k = 1, it is equivalent to a single thick rod. According to I = πD 4 / 64 is the same as the calculated value of I in the above table. The formula of y is the basic formula of material mechanics, which remains unchanged. The key lies in how to calculate the equivalent value of s.

[0101] By adjusting the k and m values, the equivalent section inertia moment under different combination conditions can be calculated. The corresponding deflection value can also be determined by the designed tower body size to meet the electrical safety distance requirements. It cannot be designed arbitrarily.

[0102] When the length of a changes and m is adjusted to 0.707, a series of results are calculated and shown in Table 2.

[0103] Table 2 Calculated values ​​of s, I, and y when F = 4000N, m = 0.707, and k changes

[0104] k a(m) c(m) D(cm) m=d / D s <![CDATA[I(cm 4 )]]> y(cm) 0 0 4.9 9 0.707 32 161 216.5 0.1 0.49 4.41 9 0.707 35.2 177.1 196.8 0.2 0.98 3.92 9 0.707 38.4 193.2 180.4 0.3 1.47 3.43 9 0.707 41.6 209.3 166.5 0.4 1.96 2.94 9 0.707 44.8 225.4 154.6 0.5 2.45 2.45 9 0.707 48 241.5 144.3 0.6 2.94 1.96 9 0.707 51.2 257.6 135.3 0.7 3.43 1.47 9 0.707 54.4 273.8 127.3 0.8 3.92 0.98 9 0.707 57.6 289.9 120.3 0.9 4.41 0.49 9 0.707 60.8 306 113.9 1 4.9 0 9 0.707 64 322.1 108.2

[0105] It can be seen from Table 2 that when the diameter of the thin rod is thickened to the original 1.414 or 6.363 cm, under the same deflection requirement, the proportion of the thick rod can be reduced to about 2 / 3 of the original. In this way, the root is thick and short, and the tip is thin and long, which is closer to natural objects such as bamboo and tree trunks, and more in line with mechanical properties and aesthetic characteristics, thereby optimizing the original design parameters.

[0106] In the theory of material mechanics, only the formula for the moment of inertia of a single cylindrical body with equal diameter is given: I = πD 4 / 64, and there is no ready-made formula for the equivalent section inertia moment of the two-section variable diameter cylinder. Due to the nonlinear characteristics of material mechanics, there is no ability to derive a simple and perfect analytical calculation formula based on theory. This method is based on relevant experimental data, combined with its own understanding of material mechanics, and inspired by the concept of yin and yang interaction in traditional culture. The formula for the section inertia moment of the two-section variable diameter cylinder that meets the limit and basically matches the test data is fitted. It can be used for the design optimization of vertical fixed composite insulators and the engineering design and verification of this type of jumper string gap, thus reducing the design difficulty. In the past, the design of two-section variable diameter cylinders could only be assisted by the material finite element simulation model. This method can solve such problems without relying on the finite element method, so it is a significant improvement in the design process and can effectively improve the design efficiency.

[0107] Embodiment 2:

[0108] This embodiment provides a design system for a two-section variable diameter windproof composite insulator, wherein the two-section variable diameter windproof composite insulator comprises a first-order core rod and a second-order core rod which are arranged in an upper and lower distribution and have a larger diameter at the top and a smaller diameter at the bottom, and the first-order core rod and the second-order core rod are made of the same material. The design system comprises:

[0109] A data input module is used to input design data, including the size data of the first-order core rod and the second-order core rod and the maximum wind speed at the design height of the jumper string of the tension tower; this module is used to implement the solution of step S100 as described in the first embodiment, which will not be repeated here;

[0110] A wind receiving area and wind force calculation module, used to calculate the wind receiving area and wind force received by the insulator body using the input design data; this module is used to implement the solution of step S201 as described in the first embodiment, which will not be described in detail here;

[0111] An equivalent resultant force calculation module is used to calculate the equivalent resultant force applied by the jumper to the end of the insulator according to the wind force on the insulator body and the jumper data of the jumper string of the tension tower; this module is used to implement the solution of step S202 as described in the first embodiment, and will not be repeated here;

[0112] A section inertia moment calculation module, used to calculate the equivalent section inertia moment of the insulator according to the size data of the first-order core rod and the second-order core rod; this module is used to implement the solution of step S203 as described in the first embodiment, which will not be described in detail here;

[0113] A deflection calculation module, used to calculate the deflection of the insulator end according to the equivalent resultant force applied by the jumper to the insulator end and the equivalent section inertia moment of the insulator; this module is used to implement the solution of step S204 as described in the first embodiment, which will not be described in detail here;

[0114] The verification module is used to query the electrical engineering requirements and determine whether the electrical requirements are met based on the calculated deflection of the insulator end. If the requirements are met, the size data of the current first-order core rod and the second-order core rod are output. If not, the size data of the first-order core and the second-order core rod are adjusted and the above steps are repeated. This module is used to implement the solution of step S300 as described in Example 1 and will not be repeated here.

[0115] As a preferred implementation of this embodiment, the method for the wind receiving area and wind force calculation module to calculate the wind receiving area and wind force received by the insulator body is specifically as follows:

[0116] The following formula is used to calculate the wind-receiving area and wind force of the insulator body:

[0117]

[0118] Where A is the wind-exposed area of ​​the insulator body, a and c are the lengths of the first-order core rod and the second-order core rod, respectively; D and d are the diameters of the first-order core rod and the second-order core rod, respectively; P is the wind force on the insulator body, in N; and v is the maximum wind speed at the design height of the jumper string of the tension tower, in (m / s).

[0119] As a preferred implementation of this embodiment, the method for the equivalent force calculation module to calculate the equivalent force applied by the jumper to the end of the insulator is specifically:

[0120] The equivalent force exerted by the jumper on the end of the insulator is calculated using the following formula:

[0121]

[0122] Where n is the number of jumper splits, A cdr , L cdr , D cdr are the wind pressure area of ​​the jumper, the length of a single jumper and the outer diameter of the jumper, respectively; x is the equivalent centroid position corresponding to the wind load on the composite insulator itself; T is the soft jumper tension; T0 is the installation tension of a phase jumper; g1 and g6 are the unit deadweight load of the conductor and the comprehensive load at maximum wind speed, respectively (which can be directly read from the stress characteristic table of the conductor (jumper) in the preliminary design stage of the line, which is equivalent to a known parameter, and the physical units of the two are the same); F is the equivalent resultant force exerted by the jumper on the end of the insulator, L=a+c, θ is the angle formed by the soft jumpers on both sides of the jumper string (this angle is determined by the planned rotation angle of the tension tower, and is generally taken as equal to the planned rotation angle); in this formula, the units of length and area are all in the International System of Units, and the unit of force is N.

[0123] As a preferred implementation of this embodiment, the method for the section inertia moment calculation module to calculate the equivalent section inertia moment of the insulator is specifically:

[0124] The equivalent section moment of inertia of the insulator is calculated using the following formula:

[0125]

[0126] k and m are proportional coefficients, both dimensionless intermediate parameters, π is the ratio of the circumference of a circle, which can be 3.1416, and I is the moment of inertia of the section. In (Equation 3), the length and diameter units are cm, so that the moment of inertia calculated in this way is more in line with engineering practices.

[0127] As a preferred implementation of this embodiment, the method for the deflection calculation module to calculate the deflection of the insulator end is specifically:

[0128] The deflection of the insulator end is calculated using the following formula:

[0129]

[0130] Where B is the stiffness under equivalent load, in N*cm 2 ; E is the bending elastic coefficient of the composite insulator, in N / cm 2 ; y is the deflection of the insulator end, in cm.

[0131] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A design method for a two-section variable diameter windproof composite insulator, wherein the two-section variable diameter windproof composite insulator comprises a first-order core rod and a second-order core rod which are arranged in an upper and lower distribution and have a larger diameter at the top and a smaller diameter at the bottom, and the first-order core rod and the second-order core rod are made of the same material, It is characterized in that The design method comprises the following steps: Input design data, including the size data of the first-order core rod and the second-order core rod and the maximum wind speed at the design height of the tension tower jumper string; Calculating the wind-receiving area and wind force of the insulator body by using the input design data; According to the wind force on the insulator body and the jumper data of the jumper string of the tension tower, the equivalent resultant force exerted by the jumper on the end of the insulator is calculated; According to the dimension data of the first-order core rod and the second-order core rod, the equivalent section moment of inertia of the insulator is calculated; Calculate the deflection of the insulator end based on the equivalent resultant force applied by the jumper to the insulator end and the equivalent section inertia moment of the insulator; According to the calculated deflection of the insulator end, query the electrical engineering requirements and determine whether they meet the electrical requirements. If they meet the requirements, output the size data of the current first-order core rod and the second-order core rod. If they do not meet the requirements, adjust the size data of the first-order core rod and the second-order core rod and repeat the above steps. The method for calculating the equivalent resultant force exerted by the jumper on the end of the insulator according to the wind force on the insulator body and the jumper data of the jumper string of the tension tower is specifically as follows: The equivalent force exerted by the jumper on the end of the insulator is calculated using the following formula: Where n is the number of jumper splits, A cdr , L cdr , D cdr are the wind pressure area of ​​the jumper, the length of a single jumper and the outer diameter of the jumper respectively; x is the equivalent centroid position corresponding to the wind load on the composite insulator itself; T is the tensile force of the soft jumper; T 0 The installation tension of one-phase jumper, g 1 , g 6 are the unit deadweight load of the conductor and the comprehensive load at the maximum wind speed, respectively; F is the equivalent force exerted by the jumper on the end of the insulator; L = a + c; θ is the angle formed by the soft jumpers on both sides of the jumper string; a and c are the lengths of the first-order core rod and the second-order core rod, respectively; D and d are the diameters of the first-order core rod and the second-order core rod, respectively; P is the wind force on the insulator body; v is the maximum wind speed at the design height of the jumper string of the tension tower; The method for calculating the equivalent section inertia moment of the insulator according to the dimension data of the first-order core rod and the second-order core rod is specifically as follows: The equivalent section moment of inertia of the insulator is calculated using the following formula: Where k and m are proportional coefficients, s is the calculated value, π is the circumference of a circle, and I is the equivalent section moment of inertia of the insulator.

2. The design method of a two-section variable diameter wind-proof composite insulator according to claim 1, It is characterized in that The method for calculating the wind receiving area and wind force of the insulator body by using the input design data is specifically as follows: The following formula is used to calculate the wind-receiving area and wind force of the insulator body: Where A is the wind-exposed area of ​​the insulator body, a and c are the lengths of the first-order core rod and the second-order core rod, respectively; D and d are the diameters of the first-order core rod and the second-order core rod, respectively; P is the wind force on the insulator body; and v is the maximum wind speed at the design height of the jumper string of the tension tower.

3. The design method of a two-section variable diameter wind-proof composite insulator according to claim 2, It is characterized in that The method for calculating the deflection of the insulator end is specifically as follows: The deflection of the insulator end is calculated using the following formula: Where B is the stiffness under equivalent load, E is the bending elastic coefficient of the composite insulator, and y is the deflection of the insulator end.

4. A design system for a two-section variable diameter windproof composite insulator, wherein the two-section variable diameter windproof composite insulator comprises a first-order core rod and a second-order core rod which are arranged in an upper and lower distribution and have a larger diameter at the top and a smaller diameter at the bottom, and the first-order core rod and the second-order core rod are made of the same material, It is characterized in that The design system includes: A data input module, used to input design data, including the size data of the first-order core rod and the second-order core rod and the maximum wind speed at the design height of the jumper string of the tension tower; A wind receiving area and wind force calculation module, used to calculate the wind receiving area and wind force received by the insulator body using the input design data; The equivalent resultant force calculation module is used to calculate the equivalent resultant force exerted by the jumper on the end of the insulator according to the wind force on the insulator body and the jumper data of the jumper string of the tension tower; Section inertia moment calculation module, used to calculate the equivalent section inertia moment of the insulator according to the size data of the first-order core rod and the second-order core rod; A deflection calculation module is used to calculate the deflection of the insulator end according to the equivalent resultant force applied by the jumper to the insulator end and the equivalent section inertia moment of the insulator; A verification module is used to query the electrical engineering requirements and determine whether the electrical requirements are met based on the calculated deflection of the insulator end. If the requirements are met, the size data of the current first-order core rod and the second-order core rod are output. If the requirements are not met, the size data of the first-order core rod and the second-order core rod are adjusted and the above steps are repeated; The method for calculating the equivalent force applied by the jumper to the end of the insulator by the equivalent force calculation module is as follows: The equivalent force exerted by the jumper on the end of the insulator is calculated using the following formula: Where n is the number of jumper splits, A cdr , L cdr , D cdr are the wind pressure area of ​​the jumper, the length of a single jumper and the outer diameter of the jumper respectively; x is the equivalent centroid position corresponding to the wind load on the composite insulator itself; T is the tensile force of the soft jumper; T 0 The installation tension of one-phase jumper, g 1 , g 6 are the unit deadweight load of the conductor and the comprehensive load at the maximum wind speed, respectively; F is the equivalent force exerted by the jumper on the end of the insulator; L = a + c; θ is the angle formed by the soft jumpers on both sides of the jumper string; a and c are the lengths of the first-order core rod and the second-order core rod, respectively; D and d are the diameters of the first-order core rod and the second-order core rod, respectively; P is the wind force on the insulator body; v is the maximum wind speed at the design height of the jumper string of the tension tower; The method for calculating the equivalent moment of inertia of an insulator by the moment of inertia calculation module of the section is specifically as follows: The equivalent section moment of inertia of the insulator is calculated using the following formula: Where k and m are proportional coefficients, s is the calculated value, π is the circumference of a circle, and I is the equivalent section moment of inertia of the insulator.

5. A design system for a two-section variable diameter wind-proof composite insulator according to claim 4, It is characterized in that The method for calculating the wind receiving area and wind force of the insulator body by the wind receiving area and wind force calculation module is specifically as follows: The following formula is used to calculate the wind-receiving area and wind force of the insulator body: Where A is the wind-exposed area of ​​the insulator body, a and c are the lengths of the first-order core rod and the second-order core rod, respectively; D and d are the diameters of the first-order core rod and the second-order core rod, respectively; P is the wind force on the insulator body; and v is the maximum wind speed at the design height of the jumper string of the tension tower.

6. A design system for a two-section variable diameter wind-proof composite insulator according to claim 5, It is characterized in that The method for calculating the deflection of the insulator end by the deflection calculation module is specifically as follows: The deflection of the insulator end is calculated using the following formula: Where B is the stiffness under equivalent load, E is the bending elastic coefficient of the composite insulator, and y is the deflection of the insulator end.

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