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

Abstract

The present invention discloses an L-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 L-shaped. The shape of the L-shaped cross-section includes a standard L-shaped cross-section and an L-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 to the power transmission and transformation equipment component, so that the column type composite insulator is reliably connected to the power transmission and transformation equipment component. 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 skirt is 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, railways, and power plants.

Description

Technical Field

[0001] The present invention relates to the field of electric power technology, and more specifically, to an L-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 efficiency 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. Currently, 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 applications, it is generally reported that solid column-type composite insulators are relatively heavy, which has a certain impact on the convenience of installation, while 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 potential hazards such as internal insulation, which affect the safe and stable operation of the line, the present invention provides an L-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 L-shaped cross-section, and the optimal cross-section size is obtained according to the optimal cross-section size calculation method, so that the L-shaped composite insulator obtains the smallest cross-section size while ensuring that it meets various strengths in the intended use environment, thereby reducing the weight of the composite insulator itself. The optimal cross-section size calculation method for an L-shaped cross-section column-type composite insulator includes:

[0004] Presetting material strength design requirements according to the external load of the L-shaped insulator in the intended use environment and the non-symmetrical characteristics of the L-shaped cross-section; the material strength includes flexural strength, compressive strength, and tensile strength; the non-symmetrical characteristics of the L-shaped cross-section include the stress characteristics of the horizontal and vertical parts of the L-shaped cross-section;

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

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

[0007] If it is satisfied, adjust the cross-sectional size of the L-shaped insulator according to the preset rules to reduce the cross-sectional area of the L-shaped insulator, calculate the material strength at this cross-sectional area, and compare it with the material strength design requirements; if it is still satisfied, 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 is not satisfied, take the cross-sectional size that finally meets the material strength design requirements as the optimal cross-sectional size of the L-shaped column composite insulator;

[0009] Furthermore, judging 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 L-shaped insulator according to the preset rules to increase the cross-sectional area of the L-shaped insulator, calculate the material strength at this cross-sectional area, and compare it with the material strength design requirements; if it is still not satisfied, 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 L-shaped column composite insulator;

[0012] Furthermore, adjusting the cross-sectional size of the L-shaped insulator according to the preset rules includes:

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

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

[0015] Furthermore, judging whether the calculated material strength all meets the material strength design requirements includes judging whether the bending strength meets the bending strength design requirements:

[0016] The bending strength judgment formula is:

[0017]

[0018] Wherein, M x and M y are respectively the preset bending moment design values about the X-axis and the Y-axis, f c is the bending strength design requirement of the insulator; the W x and Wy They are the sectional flexural rigidity about the X-axis and the Y-axis respectively, and the sectional flexural rigidity is obtained by calculation according to the sectional dimension;

[0019] Furthermore, judging whether the calculated material strength all 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 flexural rigidity, and f p is the compressive strength design requirement of the insulator;

[0023] The stability coefficient is obtained by calculation based on the slenderness ratio, compressive strength and compressive elastic modulus of the insulator; the sectional flexural rigidity is obtained by calculation according to the sectional dimension;

[0024] Furthermore, judging whether the calculated material strength all meets the material strength design requirements includes judging whether the tensile strength meets the tensile strength design requirements:

[0025] The tensile strength judgment needs to simultaneously satisfy 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 L-shaped cross-section insulator; M is the preset bending moment design value; W is the sectional flexural rigidity, and the sectional flexural rigidity is obtained by calculation according to the sectional dimension; f c is the bending strength design requirement of the insulator; f t is the tensile strength design requirement of the insulator;

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

[0029] An insulating core rod, the cross-section of the insulating core rod is set to be L-shaped, and the cross-sectional dimension of the insulating core rod is obtained by calculation through a preset method according to the external load of its intended use environment and the asymmetric characteristics of the L-shaped cross-section; the insulating core rod is used to ensure the mechanical performance of the insulator;

[0030] Connecting fittings, which are used to connect the post composite insulator and the power transmission and transformation equipment components, so that the post composite insulator and the power transmission and transformation equipment components are reliably connected;

[0031] 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 L-shaped cross-section post insulator; The sheath is closely attached to the insulating core rod;

[0032] The horizontal part of the L-shaped cross-section post insulator device faces upward and is parallel to the ground. The application environment of the device includes a power scenario with unilateral force; In the power scenario with unilateral force, the vertical part of the device and the stressed side are on the same side;

[0033] Furthermore, the insulating core rod is integrally formed by thermosetting epoxy resin reinforced with glass fiber; The reinforcement methods include winding, drawing, and vacuum impregnation;

[0034] Furthermore, the connecting fittings are made of cast steel material with surface hot-dip galvanized treatment, and the connecting fittings and the made components are fixed by welding;

[0035] 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 L-shaped;

[0036] 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;

[0037] Furthermore, the connection method between the insulating core rod and the connecting fitting is fixed connection through bolts and limit slots; One section of the insulating core rod has bolt holes and limit slots matching the connecting fitting, so that after the insulating core rod and the connecting fitting are inserted together, they are fixed by bolts;

[0038] 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 into the connecting fitting through a mortise and tenon, and is fixed by an insulating wedge nail arranged on the insertion surface;

[0039] 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 slots and fixed connection through a mortise and tenon structure;

[0040] Further, one or more straight lines of the outer contour of the L-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.

[0041] The beneficial effects of the present invention are as follows: The technical solution of the present invention provides an L-shaped cross-section post composite insulator device and an optimal cross-section size calculation method thereof. The device is provided with a composite insulator with an L-shaped cross-section, and the optimal cross-section size is obtained according to the optimal cross-section size calculation method, so that the L-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, 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 method can be selected according to actual needs in different situations to complete the connection, improving the installation flexibility and laying a foundation for the popularization of subsequent post composite insulators; The device and method reduce the accumulation of foreign objects on the insulator surface by setting a convex arc on the upper surface of the insulator, thereby reducing the operation risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The exemplary embodiments of the present invention can be more fully understood by referring to the following drawings:

[0043] Figure 1 It is a flowchart of a method for calculating the optimal cross-section size of an L-shaped cross-section post composite insulator according to a specific embodiment of the present invention;

[0044] Figure 2 It is a schematic diagram of an L-shaped cross-section post insulator device according to a specific embodiment of the present invention. SPECIFIC EMBODIMENTS

[0045] 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 intended to limit the present invention. In the drawings, the same unit / element is denoted by the same reference numeral.

[0046] Unless otherwise specified, the terms used herein (including technical terms) have the ordinary meaning understood by those skilled in the relevant technical field. Additionally, it can be understood that terms defined in commonly used dictionaries should be construed as having a meaning consistent with the context of their relevant fields, and should not be construed as idealized or overly formal meanings.

[0047] Figure 1 This is a flowchart of a method for calculating the optimal cross-sectional dimensions of an L-shaped column composite insulator in a specific embodiment of the present invention. The method calculates the material strengths of the L-shaped composite insulator in the environment where it is to be used, and obtains the optimal cross-sectional dimensions, so as to reduce the weight of the composite insulator itself while ensuring that the strength requirements are met. The method for calculating the optimal cross-sectional dimensions of an L-shaped column composite insulator includes:

[0048] Step 110, preset the material strength design requirements according to the external load of the L-shaped insulator in the environment where it is to be used and the asymmetric characteristics of the L-shaped cross-section; the material strengths include flexural strength, compressive strength, and tensile strength; the asymmetric characteristics of the L-shaped cross-section include the force-bearing characteristics of the horizontal part and the vertical part of the L-shaped cross-section.

[0049] Taking this embodiment as an example, the preset material strength design requirements can be confirmed by the regulations in DL / L1580-2016 "Technical Specification for Rod Suspension Composite Insulators for AC and DC Systems", and adjusted and modified according to the specific environment where it is to be used; for example, in extremely cold, extremely hot, high-altitude, high-humidity and other environments, a certain 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, since the L-shaped cross-section is non-vertically symmetric, in the application process, the force-bearing conditions of its horizontal part and vertical part are different, and the design requirements for the strengths corresponding to each part need to be set separately according to the use environment.

[0050] Step 120, calculate the material strength of the L-shaped insulator according to the preset initial dimensions of the L-shaped insulator cross-section and the insulator test parameters.

[0051] For the cross-section of the L-shaped insulator, an initial dimension needs to be preset first as the starting point for the optimal calculation. The initial dimension can be the empirical value of historical data, so as to reach the optimal dimension corresponding to the external load of the environment where it is to be used, and reduce the number of calculations.

[0052] The insulator test parameters include the parameters obtained through test calculations and used for calculating the material strength. The test calculations can be calculations based on historical data and existing requirements; in this embodiment, the insulator test parameters include the section modulus of resistance to bending W, the stability coefficient φ of the insulator under axial compression, the elastic modulus E of the insulator, the moment of inertia I of the section, etc.

[0053] For the stability coefficient φ of the insulator under axial compression, in this embodiment, an algorithm combining a fitting empirical formula and the Perry formula is adopted. It is fitted in the form of the Perry formula based on a large number of finite element analyses and experimental studies, with high accuracy and convenient calculation;

[0054] For the section modulus of resistance to bending W, it can be calculated by the following formula:

[0055] W = I / Ymax

[0056] Where I is the moment of inertia with respect to the neutral layer; Ymax is the maximum distance with respect to the neutral layer;

[0057] Among them, when calculating the moment of inertia I, the product of the area element dA in 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 this area element with respect to the z-axis or y-axis. The moment of inertia about the Z-axis: IZ = ∫y^2dA. The moment of inertia about the Y-axis;

[0058] Step 130, determine whether the calculated material strengths all meet the material strength design requirements;

[0059] The calculated material strengths include flexural strength, compressive strength, tensile strength, and deflection deformation;

[0060] Furthermore, determining whether the calculated material strengths all meet the material strength design requirements includes determining whether the flexural strength meets the flexural strength design requirements:

[0061] The flexural strength judgment formula is:

[0062]

[0063] Where M x and M y are respectively the design values of the bending moments about the X-axis and the Y-axis preset, f c is the flexural strength design requirement of the insulator; the W x and W y are respectively the section moduli of resistance to bending about the X-axis and the Y-axis, and the section modulus of resistance to bending is calculated according to the section size;

[0064] 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:

[0065] The compressive strength judgment formula is:

[0066]

[0067] Among them, 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 section modulus of resistance to bending, and f p is the design requirement for the compressive strength of the insulator;

[0068] The stability coefficient is obtained by calculating the slenderness ratio, compressive strength, and compressive elastic modulus of the insulator; the section modulus of resistance to bending is obtained according to the section dimensions;

[0069] Furthermore, judging whether the material strengths obtained by calculation all meet the material strength design requirements includes judging whether the tensile strength meets the tensile strength design requirements:

[0070] The judgment of the tensile strength needs to simultaneously satisfy the following formulas:

[0071] and

[0072] Among them, 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 L-shaped cross-section insulator; M is the preset bending moment design value; W is the section modulus of resistance to bending, and the section modulus of resistance to bending is obtained according to the section 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;

[0073] According to the size of the L-shaped cross-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;

[0074] 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;

[0075] The formula with the opening reduction coefficient added is:

[0076]

[0077]

[0078] Further, determining whether the calculated material strength all meets the material strength design requirements includes determining whether the deflection deformation amount meets the deflection deformation amount design requirements:

[0079] The formula for judging the deflection deformation amount is:

[0080] fl 3 / (3EI) ≤ Δl

[0081] Wherein, f is the end load of the insulator, l is the maximum horizontal distance of the L-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 amount, that is, the deflection deformation amount design requirement;

[0082] In step 130, if it is judged to be satisfied, then jump to step 131, and adjust the cross-sectional size of the L-shaped insulator according to a preset rule to reduce the cross-sectional area of the L-shaped insulator, and calculate the material strength under this cross-sectional area;

[0083] Further, adjusting the cross-sectional size of the L-shaped insulator according to the preset rule includes:

[0084] While ensuring that the maximum horizontal length and the maximum vertical length of the cross-section of the L-shaped insulator remain unchanged, enlarge or reduce the area of the cross-section according to a preset adjustment coefficient;

[0085] The shape of the L-shaped cross-section includes a standard L-shaped cross-section and an L-shaped cross-section with an arc having a preset curvature provided at the upper edge;

[0086] Further, 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 size and judge again whether it meets the material strength design requirements until it does not meet the material strength design requirements;

[0087] If it is not satisfied, then execute step 132:

[0088] Step 132, take the cross-sectional size that finally meets the material strength design requirements as the optimal cross-sectional size of the L-shaped cross-section column composite insulator;

[0089] Further, if the material strength calculated according to the initial cross-sectional size does not meet the material strength design requirements, then adjust the cross-sectional size of the L-shaped insulator according to a preset rule to increase the cross-sectional area of the L-shaped insulator, calculate the material strength under this cross-sectional area, and compare it with the material strength design requirements; if it is still not satisfied, 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;

[0090] Take the cross-sectional dimension that meets the material strength design requirements as the optimal cross-sectional dimension of the L-shaped cross-section column-type composite insulator.

[0091] Figure 2 The figure is a schematic diagram of an L-shaped cross-section column-type insulator device according to a specific embodiment of the present invention. As Figure 2 shown, the L-shaped cross-section column-type insulator device includes:

[0092] An insulating core rod 210, the cross-section of the insulating core rod 210 is set to be L-shaped, and the cross-sectional dimension of the insulating core rod is obtained by a preset method according to the external load of its intended use environment and the asymmetric characteristics of the L-shaped cross-section; the insulating core rod 210 is used to ensure the mechanical performance of the insulator;

[0093] 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;

[0094] A connecting fitting 220, the connecting fitting 220 is used to connect the column-type composite insulator and the power transmission and transformation equipment component, so that the column-type composite insulator is reliably connected to the power transmission and transformation equipment component;

[0095] Further, the connecting fitting 220 is made of cast steel material with a surface hot-dip galvanized treatment, and the connecting fitting 220 is fixed to the made component by welding;

[0096] An insulating jacket 230, the insulating jacket 230 includes a plurality of umbrella skirts and a sheath, 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 L-shaped cross-section column-type insulator; the sheath is closely attached to the insulating core rod 210;

[0097] Further, the insulating jacket 230 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 230 include integral forming and forming by an extrusion and threading-through umbrella process; the shapes of the umbrella skirts include circular and L-shaped;

[0098] 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;

[0099] Further, the connection method between the insulating core rod 210 and the connecting fitting 220 is fixed connection by 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 is inserted into the connecting fitting 220, it is fixed by bolts;

[0100] Furthermore, the connection between the insulating mandrel 210 and the connecting fitting 220 is a fixed connection through a mortise and tenon structure; one end of the insulating mandrel 210 is inserted into the connecting fitting through a mortise and tenon, and is fixedly connected through an insulating wedge nail arranged on the insertion surface;

[0101] Furthermore, 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 mandrel 210; there is no need to drill holes or set special shapes on the insulating mandrel 210, and the insulating mandrel 210 and the connecting fitting 220 are connected by insertion;

[0102] Furthermore, the device includes one or more series-connected insulating mandrels 210, and the multiple insulating mandrels 210 are directly connected through a preset connection method; the connection method includes fixed connection through bolts and limit grooves and fixed connection through a mortise and tenon structure;

[0103] Furthermore, one or more straight lines of the outer contour of the L-shaped cross-section of the insulating mandrel 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;

[0104] Furthermore, the horizontal part of the L-shaped cross-section post insulator device is upward and parallel to the ground, and the application environment of the device includes a power scenario with unilateral force; in a power scenario with unilateral force, the vertical part of the device is on the same side as the stressed side; in a power scenario with unilateral force, compared with an axially symmetric or centrally symmetric insulator, the side corresponding to the vertical part of the L-shaped cross-section post insulator device can bear a greater force. On the premise of ensuring material strength, the L-shaped cross-section has a smaller cross-sectional area and a smaller weight, thus ensuring operation safety.

[0105] 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.

[0106] 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 those of the embodiments. 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 adopted 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 explicitly 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 explicitly defined in the text, the relationship between each step includes various possible situations.

[0107] In addition, those skilled in the art can understand that although some of the embodiments described herein include certain features included in other embodiments rather than other features, the combination of the features of different embodiments means that it is 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.

[0108] Each component embodiment of the present disclosure can be implemented in hardware, or implemented as a software module running on one or more processors, or implemented in combination thereof. The present disclosure can also be implemented as a device or system program (for example, a computer program and a computer program product) for executing 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 provided in any other form.

[0109] It should be noted that the above embodiments illustrate the present disclosure 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 existence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the existence 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 claims listing several system units, several of these systems can be embodied by the same hardware item.

[0110] 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 deformations can be made, and these improvements, modifications, and deformations should all be regarded as falling within the protection scope of this application.

Claims

1. A method for calculating the optimal cross-sectional size of an L-shaped column composite insulator, the method comprises: The cross-section of the insulating core rod of the L-shaped insulator is L-shaped; Preset the material strength design requirements according to the external load of the environment where the L-shaped insulator is to be used and the asymmetric characteristics of the L-shaped cross-section; the material strength includes flexural strength, compressive strength, and tensile strength; the asymmetric characteristics of the L-shaped cross-section include the stress characteristics of the horizontal part and the vertical part of the L-shaped cross-section; Calculate the material strength of the L-shaped insulator according to the preset initial cross-sectional size of the L-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 L-shaped insulator according to the preset rules to reduce the cross-sectional area of the L-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 finally meets the material strength design requirements as the optimal cross-sectional size of the L-shaped column composite insulator.

2. The method according to claim 1, wherein, 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 L-shaped insulator according to the preset rules to increase the cross-sectional area of the L-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 L-shaped column composite insulator.

3. The method according to claim 2, wherein: The adjustment of the cross-sectional size of the L-shaped insulator according to the preset rules includes: While ensuring that the maximum horizontal length and the maximum vertical length of the cross-section of the L-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 L-shaped cross-section includes a standard L-shaped cross-section and an L-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, wherein: The judgment 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: The flexural 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, 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, wherein: 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 core 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 calculated through the slenderness ratio, compressive strength, and compressive elastic modulus of the insulator; the section modulus of resistance to bending is calculated according to the cross-sectional size.

6. The method according to claim 1, It is characterized in that: judging whether the material strength obtained by the judgment calculation meets the material strength design requirements, including judging whether the tensile strength meets the tensile strength design requirements: The judgment of the tensile strength needs to simultaneously meet the following formula: and Among them, 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 L-shaped cross-section insulator; M is the preset bending moment design value; W n is the flexural modulus of the insulating core rod, and the flexural modulus is obtained by calculating according to the cross-sectional dimension; 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 L-shaped cross-section post insulator device, the device comprises: an insulating core rod, the cross-section of the insulating core rod is set to be L-shaped, and the cross-sectional dimensions of the insulating core rod are preset with material strength design requirements according to the external load of its intended use environment and the asymmetric characteristics of the L-shaped cross-section; the material strength includes bending strength, compressive strength and tensile strength; the asymmetric characteristics of the L-shaped cross-section include the stress characteristics of the horizontal part and the vertical part of the L-shaped cross-section; The insulating core rod is used to ensure the mechanical performance of the insulator; a connecting fitting, the connecting fitting is used to connect the post composite insulator and the power transmission and transformation equipment component, so that the post composite insulator is reliably connected with the power transmission and transformation equipment component; an insulating jacket, the insulating jacket includes a plurality of umbrella skirts and a sheath, and 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 L-shaped cross-section post insulator; the sheath is closely attached to the insulating core rod; The horizontal part of the L-shaped cross-section post insulator device is upward and parallel to the ground, and the application environment of the device includes a power scenario with unilateral stress; in the power scenario with unilateral stress, the vertical part of the device is on the same side as the stress side.

8. The device according to 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, drawing and vacuum impregnation.

9. The device according to claim 7, It is characterized in that: The connecting fitting is made of cast steel material with surface hot-dip galvanized treatment.

10. The device according to claim 7, It is characterized in that: 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 threading through the umbrella process; the shapes of the umbrella skirts include circular and L-shaped.

11. The device according to 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. The device according to 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 limiting groove; one section of the insulating core rod has bolt holes and a limiting groove matching with the connecting fitting, so that after the insulating core rod and the connecting fitting are inserted together, they are fixed by bolts.

13. The device according to 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 with the connecting fitting through a mortise and tenon, and is fixedly connected by an insulating wedge nail arranged on the insertion surface.

14. The device according to 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 through a preset connection method; the connection method includes fixed connection through bolts and a limit groove and fixed connection through a mortise and tenon structure.

15. The device according to claim 7, wherein: One or more straight lines of the outer contour of the L-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.

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