An I-shaped cross-section column type composite insulator device and its optimal cross-section size calculation method

Abstract

The present invention discloses an I-shaped cross-section column type composite insulator device and an optimal cross-section size calculation method thereof. The device includes: an insulating core rod, a connecting fitting, and an insulating outer sheath. The cross-section of the insulating core rod is set to be I-shaped. The shape of the I-shaped cross-section includes a standard I-shaped cross-section and an I-shaped cross-section in which one or more straight lines of the outer contour are set as arcs with a preset curvature. The insulating core rod is used to ensure the mechanical performance of the insulator. The connecting fitting is used to connect the column type composite insulator with the components of the power transmission and transformation equipment, so that the column type composite insulator is reliably connected with the components of the power transmission and transformation equipment. The insulating outer sheath includes a plurality of umbrella skirts and a sheath. The insulating outer sheath is used to protect the insulating core rod. The umbrella skirts are used to increase the creepage distance of the insulator. The insulator device can be applied to AC and DC overhead transmission lines and substations with voltage levels above 1000V in the fields of electric power, railway, and power plant.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and more specifically, to an I-shaped cross-section column-type composite insulator device and an optimal cross-section size calculation method therefor. Background Art

[0002] At present, with the development of composite material manufacturing processes, the electrical and mechanical properties of composite materials have been greatly improved. In transmission projects at various voltage levels in China, column-type composite insulators have begun to be widely used, including line column-type composite insulators (also known as "composite insulation cross arms") and substation post composite insulators. The application of line column-type composite insulators has the main advantage of significantly improving the lightning withstand level of the line in the distribution network (10 kV) system, and can effectively reduce the width of the transmission corridor and improve the economic benefits of the line in the main network (35 kV and above). Column-type composite insulators are subjected to the combined action of electrical and various mechanical loads during operation. At present, the cross-sections of commonly used column-type composite insulators are mainly solid circles, hollow circles, solid circular shapes, and hollow rectangles. However, in actual application, it is generally reported that the solid column-type composite insulators are relatively heavy, which has a certain impact on the installation convenience, while the hollow column-type composite insulators have problems such as internal insulation, which has a certain impact on the safe and stable operation of the power transmission and transformation system. Summary of the Invention

[0003] In order to solve the problems in the background art that the existing solid column-type composite insulators are relatively heavy, resulting in a large load on the components of the power transmission and transformation equipment and poor installation convenience, while the hollow column-type composite insulators have hidden dangers such as internal insulation, which affect the safe and stable operation of the line, the present invention provides an I-shaped cross-section column-type composite insulator device and an optimal cross-section size calculation method therefor. The device is provided with a composite insulator having an I-shaped cross-section, and the optimal cross-section size is obtained according to the optimal cross-section size calculation method, so that the I-shaped composite insulator obtains the smallest cross-section size while ensuring that it meets various strengths in the environment to be used, thereby reducing the weight of the composite insulator itself. The optimal cross-section size calculation method for an I-shaped cross-section column-type composite insulator includes:

[0004] Presetting material strength design requirements according to the external load of the I-shaped insulator in the environment to be used and the central symmetry characteristics of the I-shaped cross-section; the material strength includes bending strength, compressive strength, and tensile strength; the central symmetry characteristics of the I-shaped cross-section include the design requirements for each region of the I-shaped cross-section determined by the center position and the axis of symmetry of the insulator;

[0005] Calculating the material strength of the I-shaped insulator according to the preset initial size of the I-shaped insulator cross-section and the insulator test parameters;

[0006] Determine whether the calculated material strength all meets the material strength design requirements;

[0007] If it meets, adjust the cross-sectional size of the I-shaped insulator according to a preset rule to reduce the cross-sectional area of the I-shaped insulator, calculate the material strength at this cross-sectional area, and compare it with the material strength design requirements; if it still meets, continue to adjust the cross-sectional size and judge again whether it meets the material strength design requirements until it does not meet the material strength design requirements;

[0008] When it does not meet, take the cross-sectional size that last met the material strength design requirements as the optimal cross-sectional size of the I-shaped column composite insulator;

[0009] Further, the determination of whether the calculated material strength meets the material strength design requirements includes:

[0010] If the material strength calculated according to the initial cross-sectional size does not meet the material strength design requirements, adjust the cross-sectional size of the I-shaped insulator according to a preset rule to increase the cross-sectional area of the I-shaped insulator, calculate the material strength at this cross-sectional area, and compare it with the material strength design requirements; if it still does not meet, continue to adjust the cross-sectional size and judge again whether it meets the material strength design requirements until it meets the material strength design requirements;

[0011] Take the cross-sectional size that meets the material strength design requirements as the optimal cross-sectional size of the I-shaped column composite insulator;

[0012] Further, the adjustment of the cross-sectional size of the I-shaped insulator according to a preset rule includes:

[0013] While ensuring that the maximum horizontal length and the maximum vertical length of the cross-section of the I-shaped insulator remain unchanged, enlarge or reduce the cross-sectional area of the cross-section according to a preset adjustment coefficient;

[0014] The shape of the I-shaped cross-section includes a standard I-shaped cross-section and an I-shaped cross-section with an arc with a preset curvature at the upper edge;

[0015] Further, the determination of whether the calculated material strength all meets the material strength design requirements includes judging whether the flexural strength meets the flexural strength design requirements:

[0016] The flexural strength judgment formula is:

[0017]

[0018] where M x and M y are respectively the design values of the bending moments about the X-axis and the Y-axis preset, fc is the design requirement for the bending strength of the insulator; the W x and W y are the sectional modulus of resistance to bending about the X-axis and the Y-axis respectively, and the sectional modulus of resistance to bending is obtained by calculating according to the sectional dimensions;

[0019] Further, judging whether the material strength obtained by calculation meets the material strength design requirements includes judging whether the compressive strength meets the compressive strength design requirements:

[0020] The compressive strength judgment formula is:

[0021]

[0022] Wherein, N is the design value of the axial tension or pressure of the insulator, A is the area of the gross cross-section of the insulator, φ is the stability coefficient of the insulator under axial compression, M is the preset bending moment design value, W is the sectional modulus of resistance to bending, and f p is the design requirement for the compressive strength of the insulator;

[0023] The stability coefficient is obtained by calculating the slenderness ratio, compressive strength and compressive elastic modulus of the insulator; the sectional modulus of resistance to bending is obtained by calculating according to the sectional dimensions;

[0024] Further, judging whether the material strength obtained by calculation meets the material strength design requirements includes judging whether the tensile strength meets the tensile strength design requirements:

[0025] The judgment of the tensile strength needs to simultaneously meet the following formulas:

[0026] and

[0027] Wherein, N is the design value of the axial tension or pressure of the insulator; A n is the area of the net cross-section of the insulator; m is the eccentric reduction coefficient of the I-shaped cross-section insulator; M is the preset bending moment design value; W is the sectional modulus of resistance to bending, and the sectional modulus of resistance to bending is obtained by calculating according to the sectional dimensions; f c is the design requirement for the bending strength of the insulator; f t is the design requirement for the tensile strength of the insulator;

[0028] The I-shaped cross-section column insulator device includes:

[0029] An insulating core rod, the cross-section of the insulating core rod is set to be I-shaped, and the cross-sectional dimensions of the insulating core rod are obtained by calculating through a preset method according to the external load of its intended use environment and the central symmetry characteristics of the I-shaped cross-section; the insulating core rod is used to ensure the mechanical properties of the insulator;

[0030] A connecting fitting, which is used to connect the post composite insulator and the power transmission and transformation equipment component, so that the post composite insulator and the power transmission and transformation equipment component are reliably connected;

[0031] An insulating jacket, which includes a plurality of umbrella skirts and a sheath. The insulating jacket is used to protect the insulating core rod; the umbrella skirts are vertically arranged on the sheath to increase the creepage distance of the I-shaped cross-section post insulator; the sheath is closely attached to the insulating core rod;

[0032] Furthermore, the insulating core rod is integrally formed by a thermosetting epoxy resin reinforced by glass fiber; the reinforcement methods include winding, pultrusion and vacuum impregnation;

[0033] Furthermore, the connecting fitting is made of cast steel material with surface hot-dip galvanized treatment, and the connecting fitting and the made component are fixed by welding;

[0034] Furthermore, the insulating jacket is formed by thermostatic curing of silicone rubber in a preset mold; the forming methods of the plurality of umbrella skirts and the sheath of the insulating jacket include integral forming and forming by extrusion and through-umbrella process; the shapes of the umbrella skirts include circular and I-shaped;

[0035] Furthermore, the insulator device includes one or more series-connected insulating core rods, and the plurality of insulating core rods are connected by connecting fittings;

[0036] Furthermore, the connection method between the insulating core rod and the connecting fitting is fixed connection through bolts and limit grooves; one end of the insulating core rod has bolt holes and limit grooves matching the connecting fitting, so that after the insulating core rod and the connecting fitting are inserted together, they are fixed by bolts;

[0037] Furthermore, the connection method between the insulating core rod and the connecting fitting is fixed connection through a mortise and tenon structure; one end of the insulating core rod is inserted with the connecting fitting through a mortise and tenon, and is fixed by an insulating wedge nail arranged on the insertion surface;

[0038] Furthermore, the device includes one or more series-connected insulating core rods, and the plurality of insulating core rods are directly connected through a preset connection method; the connection methods include fixed connection through bolts and limit grooves and fixed connection through a mortise and tenon structure;

[0039] Furthermore, one or more straight lines of the outer contour of the I-shaped cross-section of the insulating core rod and the corresponding insulating jacket are set as curved lines with a preset curvature, and each right angle of the outer contour is set as an arc chamfer, so as to reduce the accumulation of foreign objects on the surface of the insulator.

[0040] The beneficial effects of the present invention are as follows: The technical solution of the present invention provides an I-shaped cross-section column composite insulator device and an optimal cross-section size calculation method thereof. The device is provided with a composite insulator having an I-shaped cross-section, and the optimal cross-section size is obtained according to the optimal cross-section size calculation method, so that the I-shaped composite insulator obtains the smallest cross-section size while ensuring that it meets various strengths in the environment to be used, thereby reducing the weight of the composite insulator itself, reducing the production cost of the product, and also reducing the load on the components of the power transmission and transformation equipment and improving the installation convenience. The insulator device can be applied to AC and DC overhead transmission lines and substations with voltage levels above 1000V in power, railways, and power plants. By setting various connection methods between the insulating core rods, the connection can be completed according to actual needs in different situations, improving the installation flexibility and laying a foundation for the popularization of subsequent column composite insulators; the device and method reduce the accumulation of foreign objects on the surface of the insulator by setting a convex arc on the upper surface of the insulator, reducing the operation risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The exemplary embodiments of the present invention can be more fully understood by referring to the following drawings:

[0042] Figure 1 It is a flowchart of a method for calculating the optimal cross-section size of an I-shaped cross-section column composite insulator according to a specific embodiment of the present invention;

[0043] Figure 2 It is a schematic diagram of an I-shaped cross-section column insulator device according to a specific embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] Now, the exemplary embodiments of the present invention will be introduced with reference to the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms in the exemplary embodiments shown in the drawings are not limitations on the present invention. In the drawings, the same units / components are denoted by the same reference numerals.

[0045] Unless otherwise specified, the terms (including scientific and technical terms) used herein have the ordinary meaning understood by those skilled in the art. In addition, it can be understood that the terms defined in the commonly used dictionary should be understood to have a meaning consistent with the context of their related fields and should not be understood as idealized or overly formal meanings.

[0046] Figure 1The present invention is a flowchart of a method for calculating the optimal cross-sectional dimensions of an I-shaped column composite insulator according to a specific embodiment of the present invention. The method obtains the optimal cross-sectional dimensions by calculating the strength of each material of the I-shaped composite insulator in the environment to be used, so as to reduce the weight of the composite insulator itself while ensuring that the strength is met. The method for calculating the optimal cross-sectional dimensions of an I-shaped column composite insulator includes:

[0047] Step 110, preset material strength design requirements according to the external load of the environment in which the I-shaped insulator is to be used and the central symmetry characteristics of the I-shaped cross section; the material strength includes bending strength, compressive strength and tensile strength; the central symmetry characteristics of the I-shaped cross section include design requirements for each area of ​​the I-shaped cross section determined by the center position of the insulator and the symmetry axis;

[0048] Taking this embodiment as an example, the preset material strength design requirements can be confirmed by the provisions of DL / I-shaped 1580-2016 "Technical Specifications for Core Rods for AC and DC Rod-shaped Suspension Composite Insulators", and adjusted and modified according to the specific environment to be used; for example, in extremely cold, extremely hot, high altitude, high humidity and other environments, a corresponding specific design requirement needs to be more stringent; in order to ensure the safety of the design, the design requirements can be tightened as a whole; further, the I-shaped cross section is centrally symmetrical, and the four parts symmetrically divided about the center point are also symmetrical with the stress conditions, and the strength design requirements corresponding to each part need to be set symmetrically according to the use environment;

[0049] Step 120, calculating the material strength of the I-shaped insulator according to the preset initial cross-sectional dimensions of the I-shaped insulator and the insulator test parameters;

[0050] For the cross section of the I-shaped insulator, an initial size must be preset as the starting point for the optimal calculation. The initial size can be an empirical value of historical data, so as to achieve the optimal size that is closest to the external load of the environment to be used, thereby reducing the number of calculations.

[0051] The insulator test parameters include parameters obtained through test calculations and used to calculate material strength. The test calculations may be calculations performed on historical data based on existing requirements. In this embodiment, the insulator test parameters include section bending modulus W, stability coefficient φ of insulator axial compression, insulator elastic modulus E, section moment of inertia I, etc.

[0052] For the stability coefficient φ of the insulator axial compression, this embodiment adopts an algorithm combining a fitting empirical formula with the Perry formula, which is fitted in the form of the Perry formula based on a large number of finite element analyses and experimental studies, and has high accuracy and is easy to calculate;

[0053] For the section modulus in bending W, it can be calculated by the following formula:

[0054] W = I / Ymax

[0055] where I is the moment of inertia with respect to the neutral layer; Ymax is the maximum distance with respect to the neutral layer;

[0056] Among them, when calculating the moment of inertia I, the product of the differential area element dA of the calculation process and the square of its distance to the z-axis or y-axis, y 2 dA or z 2 dA is respectively called the moment of inertia or the second moment of area of the area element with respect to the z-axis or y-axis. The moment of inertia about the Z-axis: IZ = ∫y^2dA, and the moment of inertia about the Y-axis;

[0057] Step 130, determine whether the calculated material strengths all meet the material strength design requirements;

[0058] The calculated material strengths include bending strength, compressive strength, tensile strength, and deflection deformation;

[0059] Furthermore, determining whether the calculated material strengths all meet the material strength design requirements includes determining whether the bending strength meets the bending strength design requirements:

[0060] The judgment formula for the bending strength is:

[0061]

[0062] where M x and M y are respectively the design values of the bending moments about the X-axis and the Y-axis, f c is the design requirement for the bending strength of the insulator; the W x and W y are respectively the section moduli in bending about the X-axis and the Y-axis, and the section modulus in bending is calculated according to the section dimensions;

[0063] Furthermore, determining whether the calculated material strengths all meet the material strength design requirements includes determining whether the compressive strength meets the compressive strength design requirements:

[0064] The judgment formula for the compressive strength is:

[0065]

[0066] where N is the design value of the axial tension or pressure of the insulator, A is the area of the gross section of the insulator, φ is the stability coefficient of the insulator under axial compression, M is the preset design value of the bending moment, W is the section modulus in bending, fp For the design requirements of the compressive strength of the insulator;

[0067] The stability coefficient is obtained by calculating the slenderness ratio, compressive strength, and compressive elastic modulus of the insulator; the section modulus of flexure is obtained according to the section dimensions;

[0068] Furthermore, judging whether the calculated material strengths all meet the material strength design requirements includes judging whether the tensile strength meets the tensile strength design requirements:

[0069] The judgment of the tensile strength needs to simultaneously satisfy the following formula:

[0070] and

[0071] where N is the design value of the axial tension or pressure of the insulator; A n is the area of the net section of the insulator; m is the eccentric reduction coefficient of the I-shaped section insulator; M is the preset bending moment design value; W is the section modulus of flexure, and the section modulus of flexure is obtained according to the section dimensions; f c is the bending strength design requirement of the insulator; f t is the tensile strength design requirement of the insulator;

[0072] According to the dimensions of the I-shaped section and the resulting eccentric situation, an eccentric reduction coefficient is set; in this embodiment, the eccentric reduction coefficient m is taken as 0.7;

[0073] Furthermore, for the strength reduction caused by the need to open holes due to the connection with other components (such as connecting fittings), an opening reduction coefficient k is set; the opening reduction coefficient has the same effect as the eccentric reduction coefficient and is used for non-normal strength reduction; in this embodiment, the opening reduction coefficient m is taken as 0.7;

[0074] The formula for adding the opening reduction coefficient is:

[0075]

[0076]

[0077] Furthermore, judging whether the calculated material strengths all meet the material strength design requirements includes judging whether the deflection deformation amount meets the deflection deformation amount design requirements:

[0078] The judgment formula for the deflection deformation amount is:

[0079] fl 3 / (3EI) ≤ Δl

[0080] Wherein, f is the end load of the insulator, l is the maximum horizontal distance of the I-shaped cross-section of the insulator, E is the elastic modulus of the insulator, I is the moment of inertia of the cross-section, and Δl is the maximum deflection deformation, i.e., the design requirement for the deflection deformation;

[0081] In step 130, if the judgment is satisfied, then jump to step 131, and adjust the cross-sectional dimensions of the I-shaped insulator according to a preset rule to reduce the cross-sectional area of the I-shaped insulator, and calculate the material strength under this cross-sectional area;

[0082] Furthermore, the adjusting the cross-sectional dimensions of the I-shaped insulator according to a preset rule includes:

[0083] While ensuring that the maximum horizontal length and the maximum vertical length of the cross-section of the I-shaped insulator remain unchanged, enlarge or reduce the cross-sectional area of the cross-section according to a preset adjustment coefficient;

[0084] The shape of the I-shaped cross-section includes a standard I-shaped cross-section and an I-shaped cross-section with an arc having a preset curvature at the upper edge;

[0085] Furthermore, after calculating the material strength under the current cross-sectional area, execute step 130 again for judgment. If it is still satisfied, continue to adjust the cross-sectional dimensions and judge again whether the material strength design requirement is met until the material strength design requirement is not met;

[0086] If not satisfied, then execute step 132:

[0087] Step 132, take the cross-sectional dimensions that finally meet the material strength design requirement as the optimal cross-sectional dimensions of the I-shaped cross-section column composite insulator;

[0088] Furthermore, if the material strength calculated according to the initial cross-sectional dimensions does not meet the material strength design requirement, then adjust the cross-sectional dimensions of the I-shaped insulator according to a preset rule to increase the cross-sectional area of the I-shaped insulator, calculate the material strength under this cross-sectional area, and compare it with the material strength design requirement; if it is still not satisfied, continue to adjust the cross-sectional dimensions and judge again whether the material strength design requirement is met until the material strength design requirement is met;

[0089] Take the cross-sectional dimensions that meet the material strength design requirement as the optimal cross-sectional dimensions of the I-shaped cross-section column composite insulator.

[0090] Figure 2 Schematic diagram of an I-shaped cross-section column insulator device according to a specific embodiment of the present invention, as Figure 2 shown, the I-shaped cross-section column insulator device includes:

[0091] Insulating core rod 210, the cross-section of the insulating core rod 210 is set to an I-shaped, and the cross-sectional dimensions of the insulating core rod are obtained by a preset method according to the external load of its intended use environment and the central symmetry characteristics of the I-shaped cross-section; the insulating core rod 210 is used to ensure the mechanical properties of the insulator;

[0092] Further, the insulating core rod 210 is integrally formed by a thermosetting epoxy resin reinforced with glass fiber; the reinforcement methods include winding, pultrusion, and vacuum impregnation;

[0093] Connecting fitting 220, the connecting fitting 220 is used to connect the post composite insulator and the power transmission and transformation equipment component, so that the post composite insulator and the power transmission and transformation equipment component are reliably connected;

[0094] Further, the connecting fitting 220 is made of cast steel material with a surface hot-dip galvanized treatment, and the connecting fitting 220 and the made component are fixed by welding;

[0095] Insulating jacket 230, the insulating jacket 230 includes a plurality of umbrella skirts and a sheath, and the insulating jacket 230 is used to protect the insulating core rod 210; the umbrella skirts are vertically arranged on the sheath to increase the creepage distance of the I-shaped cross-section post insulator; the sheath is closely attached to the insulating core rod 210;

[0096] Further, the insulating jacket 230 is formed by thermally controlling and curing silicone rubber in a preset mold; the forming methods of the plurality of umbrella skirts and the sheath of the insulating jacket 230 include integral forming and forming by an extrusion and threading-through umbrella process; the shapes of the umbrella skirts include circular and I-shaped;

[0097] Further, the insulator device includes one or more series-connected insulating core rods 210, and the plurality of insulating core rods 210 are connected by connecting fittings 220;

[0098] Further, the connection method between the insulating core rod 210 and the connecting fitting 220 is fixed connection through bolts and a limiting groove; one section of the insulating core rod 210 has bolt holes and a limiting groove that match the connecting fitting 220, so that after the insulating core rod 210 and the connecting fitting 220 are inserted together, they are fixed by bolts;

[0099] Further, the connection method between the insulating core rod 210 and the connecting fitting 220 is fixed connection through a mortise and tenon structure; one end of the insulating core rod 210 is inserted with the connecting fitting through a mortise and tenon, and is fixedly connected by an insulating wedge nail arranged on the insertion surface;

[0100] Further, one end of the connecting fitting 220 is provided with a jack, and the inner contour of the jack matches the outer contour of the insulating core rod 210; the insulating core rod 210 does not need to be drilled or have a special shape, and the insulating core rod 210 is connected to the connecting fitting 220 by means of plugging;

[0101] Further, the device includes one or more serially connected insulating core rods 210, and the plurality of insulating core rods 210 are directly connected by a preset connection method; the connection method includes fixed connection by bolts and a limit groove and fixed connection by a mortise and tenon structure;

[0102] Further, one or more straight lines of the outer contour of the I-shaped cross-section of the insulating core rod 210 and the corresponding insulating jacket 230 are set as curved lines with a preset curvature, and each right angle of the outer contour is set as an arc chamfer, so as to reduce the accumulation of foreign objects on the surface of the insulator;

[0103] Further, the application environment of the device includes power scenarios with axial symmetry force, central symmetry force, and unilateral force.

[0104] In the specification provided here, a large number of specific details are described. However, it can be understood that the embodiments of the present disclosure can be practiced without these specific details. In some instances, well-known methods, structures, and technologies are not shown in detail so as not to obscure the understanding of this specification.

[0105] Those skilled in the art can understand that the modules in the devices in the embodiments can be adaptively changed and arranged in one or more devices different from this embodiment. The modules or units or components in the embodiments can be combined into one module or unit or component, and in addition, they can be divided into multiple sub-modules or sub-units or sub-components. Except that at least some of such features and / or processes or units are mutually exclusive, any combination can be used to combine all the features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all the processes or units of any method or device so disclosed. Unless otherwise clearly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) can be replaced by an alternative feature that provides the same, equivalent, or similar purpose. The step numbers involved in this specification are only used to distinguish each step and do not limit the time or logical relationship between each step. Unless there is a clear limitation in the text, the relationship between each step includes various possible situations.

[0106] In addition, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments rather than other features, the combination of features of different embodiments is meant to be within the scope of the present disclosure and forms different embodiments. For example, any one of the embodiments claimed in the claims can be used in any combination.

[0107] Each component embodiment of the present disclosure can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. The present disclosure can also be implemented as a device or system program (e.g., a computer program and a computer program product) for performing part or all of the methods described herein. Such a program implementing the present disclosure can be stored on a computer-readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier signal, or in any other form.

[0108] It should be noted that the above embodiments illustrate rather than limit the present disclosure, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present disclosure can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. In the unit claims listing several systems, several of these systems can be embodied by the same item of hardware.

[0109] The above are only specific embodiments of the present disclosure. It should be noted that for those of ordinary skill in the art, without departing from the spirit of the present disclosure, several improvements, modifications, and variations can be made, and these improvements, modifications, and variations should all be regarded as falling within the protection scope of this application.

Claims

1. A calculation method for the optimal cross-sectional size of an I-shaped column composite insulator, the method comprises: The cross-section of the insulating core rod of the I-shaped insulator is I-shaped; Preset the material strength design requirements according to the external load of the environment where the I-shaped insulator is to be used and the central symmetry characteristics of the I-shaped cross-section; the material strength includes bending strength, compressive strength and tensile strength; the central symmetry characteristics of the I-shaped cross-section include the design requirements for each region of the I-shaped cross-section determined by the center position and the symmetry axis of the insulator; Calculate the material strength of the I-shaped insulator according to the preset initial cross-sectional size of the I-shaped insulator and the insulator test parameters; Judge whether the calculated material strength all meets the material strength design requirements; If it meets, adjust the cross-sectional size of the I-shaped insulator according to the preset rules to reduce the cross-sectional area of the I-shaped insulator, calculate the material strength under this cross-sectional area, and compare it with the material strength design requirements; if it still meets, continue to adjust the cross-sectional size and judge again whether it meets the material strength design requirements until it does not meet the material strength design requirements; When it does not meet, take the cross-sectional size that meets the material strength design requirements last time as the optimal cross-sectional size of the I-shaped column composite insulator.

2. The method according to claim 1, characterized in that, The judgment of whether the calculated material strength meets the material strength design requirements includes: If the material strength calculated according to the initial cross-sectional size does not meet the material strength design requirements, adjust the cross-sectional size of the I-shaped insulator according to the preset rules to increase the cross-sectional area of the I-shaped insulator, calculate the material strength under this cross-sectional area, and compare it with the material strength design requirements; if it still does not meet, continue to adjust the cross-sectional size and judge again whether it meets the material strength design requirements until it meets the material strength design requirements; Take the cross-sectional size that meets the material strength design requirements as the optimal cross-sectional size of the I-shaped column composite insulator.

3. The method according to claim 2, characterized in that: The adjustment of the cross-sectional size of the I-shaped insulator according to the preset rules includes: Under the condition of ensuring that the maximum horizontal length and the maximum vertical length of the cross-section of the I-shaped insulator remain unchanged, enlarge or reduce the cross-sectional area of the cross-section according to the preset adjustment coefficient; The shape of the I-shaped cross-section includes a standard I-shaped cross-section and an I-shaped cross-section in which one or more straight lines of the outer contour are set as arcs with a preset curvature.

4. The method according to claim 1, characterized in that: The judgment of whether the calculated material strength all meets the material strength design requirements includes judging whether the bending strength meets the bending strength design requirements: The bending strength judgment formula is: Among them, M x and M y are respectively the design values of the bending moments about the X-axis and the Y-axis as preset, and f c is the design requirement for the bending strength of the insulator; the W x and W y are respectively the section modulus of resistance to bending about the X-axis and the Y-axis, and the section modulus of resistance to bending is obtained by calculating according to the section size.

5. The method according to claim 1, characterized in that: The judgment of whether the calculated material strength all meets the material strength design requirements includes judging whether the compressive strength meets the compressive strength design requirements: The compressive strength judgment formula is: Wherein, N is the design value of the axial tension or pressure of the insulator, A is the area of the gross cross-section of the insulating rod, φ is the stability coefficient of the insulator under axial compression, M is the preset design value of the bending moment, W is the section modulus of resistance to bending, and f p is the design requirement for the compressive strength of the insulator; The stability coefficient is obtained by calculating the slenderness ratio, compressive strength, and compressive elastic modulus of the insulator; the section modulus of bending is obtained based on the section size.

6. According to the method described in claim 1, it is characterized in that: judging whether the calculated material strengths all meet the material strength design requirements includes judging whether the tensile strength meets the tensile strength design requirements: The judgment of the tensile strength needs to simultaneously satisfy the following formula: and Wherein, N is the design value of the axial tension or pressure of the insulator; A n is the area of the net cross-section of the insulating core rod; m is the eccentric reduction coefficient of the I-shaped cross-section insulator; M is the preset bending moment design value; Wn is the section modulus of the insulating core rod in bending, and the section modulus is obtained by calculating according to the section size; f c is the design requirement for the bending strength of the insulator; f t is the design requirement for the tensile strength of the insulator.

7. An I-shaped cross-section column insulator device, the device comprises: An insulating core rod, the cross-section of the insulating core rod is set as an I-shape, the cross-section size of the insulating core rod presets material strength design requirements according to the external load of its intended use environment and the central symmetry characteristics of the I-shaped cross-section, and the material strength includes bending strength, compressive strength, and tensile strength; the central symmetry characteristics of the I-shaped cross-section include the design requirements for each region of the I-shaped cross-section determined by the center position and symmetry axis of the insulator; the insulating core rod is used to ensure the mechanical properties of the insulator; Connecting fittings, the connecting fittings are used to connect the column composite insulator and the power transmission and transformation equipment components, so that the column composite insulator is reliably connected to the power transmission and transformation equipment components; An insulating outer sheath, the insulating outer sheath includes a plurality of umbrella skirts and a sheath, and the insulating outer sheath is used to protect the insulating core rod; the umbrella skirts are vertically arranged on the sheath to increase the creepage distance of the I-shaped cross-section column insulator; the sheath is closely attached to the insulating core rod.

8. According to the device described in claim 7, it is characterized in that: The insulating core rod is integrally formed by a thermosetting epoxy resin reinforced with glass fiber; the reinforcement methods include winding, pultrusion, and vacuum impregnation.

9. According to the device described in claim 7, it is characterized in that: The connecting fittings are made of cast steel material with a surface hot-dip galvanized treatment.

10. According to the device described in claim 7, it is characterized in that: The insulating outer sheath is formed by thermostatic curing of silicone rubber in a preset mold; the forming methods of the plurality of umbrella skirts and the sheath of the insulating outer sheath include integral forming and forming by an extrusion-through umbrella process; the shapes of the umbrella skirts include circular and I-shaped.

11. According to the device described in claim 7, it is characterized in that: The insulator device includes one or more series-connected insulating core rods, and the plurality of insulating core rods are connected by connecting fittings.

12. According to the device described in claim 11, it is characterized in that: The connection method between the insulating core rod and the connecting fitting is fixed connection through bolts and a limit groove; one section of the insulating core rod has bolt holes and a limit groove matching the connecting fitting, so that after the insulating core rod and the connecting fitting are inserted together, they are fixed by bolts.

13. According to the device described in claim 11, it is characterized in that: The connection method between the insulating core rod and the connecting fitting is fixed connection through a mortise and tenon structure; one end of the insulating core rod is inserted into the connecting fitting through a mortise and tenon, and is fixedly connected by an insulating wedge nail arranged on the insertion surface.

14. According to the device described in claim 7, it is characterized in that: The device includes one or more insulating mandrels connected in series, and the plurality of insulating mandrels are directly connected by a preset connection method; the connection method includes fixed connection by bolts and a limit groove and fixed connection by a mortise and tenon structure.

15. The device according to claim 7, wherein: One or more straight lines of the outer contour of the I-shaped cross-section of the insulating mandrel and the corresponding insulating jacket are set as curved lines with a preset curvature, and each right angle of the outer contour is set as an arc chamfer, so as to reduce the accumulation of foreign matters on the surface of the insulator.

Images