220kV high wind speed area single circuit composite material cross arm cathead type straight tower

Abstract

The present invention discloses a 220kV high wind speed zone single-circuit composite material cross-arm cathead type straight tower, which relates to a straight tower. At present, the cross-arm needs to hang the side phase conductor, needs to have sufficient strength, has many material requirements, occupies a large area, has high cost, and is difficult to assemble. The cross-arm of the present invention is provided with a special-shaped component fixed to the angle steel, and the outer contour of the cross section of the special-shaped component is formed by connecting two right-angle sides and a circular arc side, wherein the two right-angle sides match the right-angle inner side surface of the angle steel; the special-shaped component is a multi-layer structure, including an outer coating, a reinforcement layer, and a filling layer, and the outer coating, reinforcement layer, and filling layer are arranged in sequence from the outside to the inside. The use of special-shaped components can save a large amount of steel, and by utilizing their insulation properties, it is not only easy to solve the wind deviation and pollution flashover accidents of the line, and improve the safe operation level of the line, but also can reduce the size of the tower head, reduce the corridor width, save land resources, reduce demolition costs, and reduce engineering investment costs.

Description

Technical Field

[0001] The invention relates to a straight tower, in particular to a 220kV high wind speed zone single-circuit composite material cross-arm cathead type straight tower. Background Art

[0002] With the rapid development of urban construction, along with the rapid development of overhead transmission lines, land has become an increasingly scarce resource. The selection of line corridors and transmission line damage has become the primary problem in the construction of transmission lines. The great improvement of people's awareness of the environment and self-protection has made it very difficult to deal with the policy, resettlement and corridor conservation of transmission lines. The transmission line conductor is a special material. In the natural working environment, it is mainly affected by wind loads. The wind pressure on the conductor during operation accounts for 50% to 70% of the wind pressure on the line conductor. This makes the tower supporting the conductor bear the wind load on the basis of its own wind load. It must also bear the wind load transmitted by the conductor. The wind load has a high frequency of damage to the transmission line, a wide range of degrees, and serious economic losses. Studies have shown that the selection of conductor shape and the design of tower materials play an important role in the field of power transmission. For a long time, line workers have been striving for a simple way to minimize wind pressure. Meet the current power grid needs and meet the requirements of my country's power development. To this end, the design of 220kV transmission towers can adopt a compact and compact design scheme.

[0003] At present, the crossarm needs to hang the side phase conductors, so it needs to have sufficient strength to ensure the wind resistance of the transmission tower. In order to meet the strength requirements, the corridor width is required to be large, so there are problems such as many material requirements, large floor space, high cost, and difficult assembly. Summary of the invention

[0004] The technical problem to be solved and the technical task proposed by the present invention are to improve and perfect the existing technical solutions and provide a 220kV high wind speed single-circuit composite material cross-arm cathead type straight tower to achieve the purpose of reducing the tower head size. To this end, the present invention adopts the following technical solutions.

[0005] 220kV high wind speed zone single circuit composite material cross arm cat head type straight tower, including tower legs, tower body, cat head type tower head and ground wire bracket, the tower head includes a cross beam located at the top, an upper curved arm and a lower curved arm located below the two sides of the cross beam, the lower end of the lower curved arm is connected to the tower body, the lower curved arm is provided with a cross arm, the cross arm is provided with a special-shaped component fixed to the angle steel, the outer contour of the cross section of the special-shaped component is formed by connecting two right angles and arc edges, wherein the two right angles match the right angle inner side of the angle steel; the special-shaped component is a multi-layer structure, including an outer coating, a reinforcement layer, and a filling layer, and the outer coating, reinforcement layer, and filling layer are arranged in sequence from the outside to the inside. The special-shaped component can be fixed to the angle steel by bolts, screws, etc.; compared with the traditional flange connection method at the end, the weight is greatly reduced, the installation is basically the same as that of a conventional tower, the connection transition section is avoided, and the construction is convenient and fast. Due to the good insulation performance of composite materials, the length of the insulator string and the air spacing between the conductor and the tower body can be reduced under the condition of ensuring the same insulation level. Under the premise of meeting the electrical safety clearance, the spacing between the three-phase conductors can be reduced, the corridor can be compressed, and the lightning resistance can be improved. This technical solution uses composite crossarms to compress the corridor width. Ensure the wind resistance of the transmission tower. Composite materials have the advantages of light weight, high strength, corrosion resistance, convenient processing and molding, and good electrical insulation. After using composite materials, a large amount of steel can be saved, and by using their insulation properties, it is not only easy to solve the wind deviation and pollution flashover accidents of the line, and improve the safe operation level of the line, but also can reduce the size of the tower head, reduce the corridor width, save land resources, reduce demolition costs, and reduce engineering investment costs. In addition, due to the characteristics of light weight and easy processing and molding of composite materials, the transportation and assembly costs of poles and towers can be greatly reduced. This device makes full use of the above advantages of composite materials. The special-shaped components effectively increase the strength of the crossarms, overcome the shortcomings of weak wind resistance and large deadweight of traditional transmission towers, and are suitable for the design of transmission towers in high wind speed areas. Effectively solve the problem of excessive and wide corridors occupied by transmission lines.

[0006] As a preferred technical means: the crossbeam, upper curved arm and lower curved arm form a tower window, in which an insulator string for connecting the middle phase conductor is arranged, and the insulator string is hoisted on the crossbeam.

[0007] As the preferred technical means: the two cross arms are in a dovetail shape, and the lower end of the cross arm is provided with an insulator string for connecting the two side phase conductors; the insulator string connecting the middle phase conductor and the insulator string connecting the two side phase conductors are arranged in a triangle. The dovetail shape is pulled down to further control the size of the tower head. Both side phase conductors are connected to the composite conductor cross arm with an "I" type insulator string. The reduction in the string length further shortens the cross arm length, thereby compressing the line corridor width. Compared with the conventional cathead type straight tower, the maximum line distance is compressed by 5.0m, the floor height is compressed by 1.5m, and the overall tower head compression is optimized.

[0008] As a preferred technical means: the hanging point of the ground wire support is located outside the side phase conductor. The hanging point of the ground wire top frame 1 is located outside the single-circuit side phase conductor to achieve the purpose of negative protection of the side phase conductor.

[0009] As a preferred technical means: the cross beam is provided with a special-shaped component fixedly connected to the angle steel. The cross beam also adopts a special-shaped component, which helps to further reduce the size of the cathead and reduce the cost.

[0010] As a preferred technical means: the outer coating is a fiber protective coating, the reinforcement layer is a glass fiber layer, and the filling layer is a foam filling layer. The reduction of the gap circle allows the vertical spacing of the tower head to be reduced, thereby improving the lightning resistance capability.

[0011] As a preferred technical means: the thickness of the reinforcement layer is less than the filling layer. The large size of the filling layer helps to improve the strength, while reducing the weight, it has sufficient strength and makes the two ends of the angle steel lower than the outermost point of the special-shaped component.

[0012] As a preferred technical means: the special-shaped component is connected to the angle steel by bolts, and adjacent angle steels are connected by flanges. One end of the flange is connected to an angle steel by bolts, and the other end of the flange is connected to another angle steel by bolts; the special-shaped component is directly or diagonally opposite to the insulator string suspended thereon.

[0013] As a preferred technical means: the middle phase conductor and the side phase conductor are both low wind pressure conductors; the low wind pressure conductor includes a core, an inner conductor, and an outer conductor; all inner conductors are covered by an outer conductor, and the side of each outer conductor in contact with the external environment is a conductor structure with an outward convex curvature, forming an undulating outer surface of the low wind pressure conductor, and forming grooves between adjacent outer conductors on the outer surface of the low wind pressure conductor. Compared with ordinary conventional transmission conductors, the cross section of the low wind pressure conductor has a circular arc of a certain angle, which can reduce the use of materials and reduce weight, thereby reducing the difficulty and cost of construction. By changing the curvature of the groove on the outside of the conductor, the roughness of the conductor surface is increased to a certain extent, making the wind resistance coefficient of the surface smaller. As a result, the pressure difference resistance of the entire transmission line conductor is also reduced, and the overall resistance coefficient of the low wind pressure line is also reduced accordingly, and the total resistance of the line is further reduced. In this way, the wind resistance of the conductor itself can be effectively improved under high wind speed conditions and the wind resistance coefficient can be reduced. Combining composite materials and a low wind pressure conductor on a transmission tower, the combination of the two can further improve the wind resistance of the transmission tower. This device uses a low-wind pressure conductor based on the composite material of the transmission tower. When the speed changes due to the influence of the incoming wind, the composite material on the transmission tower and the roughness of the surface of the low-wind pressure conductor used in the transmission tower can jointly reduce the influence of wind load to a certain extent, thereby improving the overall wind pressure resistance.

[0014] As a preferred technical means: the diameter of the low wind pressure conductor is related to the groove, and the diameter of the low wind pressure conductor increases as the curvature of the groove decreases; when the curvature of the groove is 10° to 15°, the diameter range corresponding to the low wind pressure conductor is 30mm to 40mm; when the curvature of the groove is 15° to 20°, the diameter range corresponding to the low wind pressure conductor is 20mm to 30mm; when the curvature of the groove is 20° to 25°, the diameter of the low wind pressure conductor is not more than 20mm.

[0015] As an optimal technical means: the radius r from the outermost point of the low conductor outer surface to the center of the low wind pressure conductor is calculated related to the wind speed, conductor diameter and center angle θ; the radius r decreases with increasing wind speed and increases with increasing center angle θ.

[0016] The calculation formula of radius r is:

[0017]

[0018] In the formula: In the formula: is the design wind speed value of the line, its unit is m / s; θ is the central angle formed by the outer arcs of two adjacent outer conductors, its unit is °; radius r, its unit is mm.

[0019] Beneficial effects:

[0020] 1) Light weight, high strength-to-weight ratio, saving a lot of steel.

[0021] 2) Good insulation performance, effectively reducing the insulation design level, reducing the distance between phase conductors, reducing the width of the corridor, and also significantly reducing lightning flashover, ice flash, dancing and other accidents.

[0022] 3) Chemical corrosion resistance, wear resistance, waterproof, fire retardant.

[0023] 4) Easy to process and shape, and convenient to install, transport and assemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0025] Figure 2 It is a schematic cross-sectional view of the heterosexual component of the present invention.

[0026] FIG3( a ) is a schematic diagram of wind load on existing conductors.

[0027] Figure 3(b) is a schematic diagram of the wind load reduction mechanism of low wind pressure conductors.

[0028] Figure 4 It is a schematic diagram of the cross-sectional structure of a low-voltage wind conductor.

[0029] Figure 5 It is a schematic diagram of the horizontal swing angle of the conductor.

[0030] Figure 6 This is a schematic diagram of the wire being subjected to tension.

[0031] Figure 7 It is a schematic diagram of the bending moment of the conductor.

[0032] Figure 8 It is a connection diagram of the heterosexual components of the present invention.

[0033] Fig. 9 It is the angle steel connection diagram of the present invention.

[0034] The numbers shown in the figure are: 1. ground wire bracket; 2. upper curved arm; 3. lower curved arm; 4. crossbeam; 5. crossarm; 6. tower head; 7. insulator string; 8. tower window; 9. tower body; 10. tower leg; 11. special-shaped component; 12. exterior coating; 13. filling layer; 14. angle steel; 15. reinforcement layer; 16. low wind pressure conductor; 17. core; 18. inner conductor; 19. outer conductor; 20. groove; 21. flange; 22. bolt. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings.

[0036] like Figure 1-2As shown, a 220 kV high wind speed zone single-circuit composite material cross arm 5 cathead-shaped straight tower comprises a tower leg 10, a tower body 9, a cathead-shaped tower head 6 and a ground wire bracket 1, wherein the cathead comprises a cross beam 4 located at the upper part, an upper curved arm 2 and a lower curved arm 3 located below both sides of the cross beam 4, wherein the lower end of the lower curved arm 3 is connected to the tower body 9, a cross arm 5 is arranged on the lower curved arm 3, and a special-shaped component 11 fixedly connected to an angle steel 14 is arranged on the cross arm 5, wherein the outer contour of the cross section of the special-shaped component 11 is formed by connecting two right-angled sides and an arc side, wherein the two right-angled sides match the right-angled inner side surface of the angle steel 14; the special-shaped component 11 is a multi-layer structure, comprising an outer coating 12, a reinforcing layer 15 and a filling layer 13, wherein the outer coating 12, the reinforcing layer 15 and the filling layer 13 are arranged in sequence from the outside to the inside. The special-shaped component 11 can be fixed to the angle steel 14 by bolts, screws, etc.; compared with the traditional composite material components with flanges at the ends, the weight is greatly reduced, the installation is basically the same as that of conventional towers, the connection transition section is avoided, and the construction is convenient and fast. Due to the good insulation performance of the composite material, the length of the insulator string 7 and the air spacing between the conductor and the tower body can be reduced under the condition of ensuring the same insulation level. Under the premise of meeting the electrical safety clearance, the spacing between the three-phase conductors is reduced, the corridor is compressed, and the lightning resistance is improved. This technical solution uses a composite cross arm 5 to compress the corridor width. Ensure the wind resistance of the transmission tower. Composite materials have the advantages of light weight, high strength, corrosion resistance, convenient processing and molding, and good electrical insulation. After using composite materials, a large amount of steel can be saved, and by utilizing its insulation properties, it is not only easy to solve the wind deviation and pollution flash accidents of the line, and improve the safe operation level of the line, but also can reduce the size of the tower head 6, reduce the corridor width, save land resources, reduce demolition costs, and reduce project investment costs. In addition, due to the characteristics of light weight and easy processing and molding of composite materials, the transportation and assembly costs of the tower can be greatly reduced. This device makes full use of the above advantages of composite materials, overcomes the shortcomings of traditional transmission towers, such as weak wind resistance and heavy weight, and is suitable for the design of transmission towers in high wind speed areas. It effectively solves the problem of transmission lines occupying too many corridors and being too wide.

[0037] In this embodiment, the crossbeam 4, the upper curved arm 2, and the lower curved arm 3 form a tower window 8, in which an "I" type insulator string 7 for connecting the middle phase conductor is provided, and the insulator string 7 is hoisted on the crossbeam 4. The two cross arms 5 are in a dovetail shape pulled down, and the lower end of the cross arm 5 is provided with an insulator string 7 for connecting the two side phase conductors; the insulator string 7 connecting the middle phase conductor and the insulator string 7 connecting the two side phase conductors are arranged in a triangle. The dovetail shape pulled down further controls the size of the tower head 6. Both side phase conductors are connected to the composite conductor cross arm 5 by an "I" type insulator string 7. The reduction in the string length further shortens the length of the cross arm 5, thereby compressing the width of the line corridor. Compared with the conventional cathead type straight tower, the maximum line distance is compressed by 5.0m, the layer height is compressed by 1.5m, and the overall tower head 6 is compressed and optimized.

[0038] In order to improve the protection purpose, the hanging point of the ground wire support 1 is located outside the side phase conductor. The hanging point of the ground wire top frame 1 is located outside the single-circuit side phase conductor to achieve the purpose of negative protection of the side phase conductor.

[0039] In order to further reduce the size of the cathead, the cross beam 4 is provided with a special-shaped component 11 fixedly connected to the angle steel 14. The cross beam 4 also adopts the special-shaped component 11, which helps to further reduce the size of the cathead and reduce costs.

[0040] In order to ensure light weight and easy assembly while ensuring strength: the outer coating 12 is a fiber protective coating, the reinforcement layer 15 is a glass fiber layer, and the filling layer 13 is a foam filling layer. The reduction of the gap circle allows the vertical spacing of the tower head 6 to be reduced, thereby improving the lightning resistance. To further improve safety, the length of the inner right-angle side of the angle steel 14 matched with the special-shaped component 11 is basically the same as the length of the two right-angle sides of the special-shaped component 11; the arc surface of the special-shaped component 11 is higher than the matching angle steel 14. The thickness of the reinforcement layer 15 is less than the filling layer 13. The large size of the filling layer 13 helps to improve the strength. While reducing the weight, it has sufficient strength and makes the two ends of the angle steel 14 lower than the outermost point of the special-shaped component 11. The composite material has good insulation performance. Under the condition of ensuring the same insulation level, the length of the insulator string 7 and the air spacing between the conductor and the tower body can be reduced, thereby reducing the spacing between the three-phase conductors and compressing the corridor; on the premise of meeting the electrical safety gap, the height of the tower head 6 can be effectively reduced, thereby improving the lightning resistance. The side-phase conductors on both sides are connected with the composite conductor crossarm 5 by "I" type insulator string 7. The reduction of string length further shortens the length of crossarm 5, thereby compressing the width of the line corridor. Compared with the conventional cathead type straight tower, the maximum line distance is compressed by 5.0m, the layer height is compressed by 1.5m, and the overall tower head 6 is compressed and optimized. The reduction of the gap circle allows the vertical spacing of the tower head 6 to be reduced, thereby improving the lightning resistance capability.

[0041] like Figure 8 , 9 As shown, in order to facilitate the connection of adjacent angle steels and special-shaped components, the special-shaped component 11 is connected to the angle steel 14 by bolts, and the adjacent angle steels 14 are connected by flanges 21. One end of the flange 21 is connected to an angle steel by bolts 22, and the other end of the flange 21 is connected to another angle steel by bolts 22; the special-shaped component 11 is directly or obliquely opposite to the insulator string 7 suspended thereon. The connection is reliable and the connection of adjacent angle steels 14 is also convenient. In order to reduce the impact on the special-shaped component 11 and ensure the strength at the same time, the bolts 22 can be arranged in an array to fix the special-shaped component 11 on the angle steel 14. The special-shaped component 11 is set in the angle of the angle steel, and bolt arrays are set on both folded edges of the angle steel 14, so that the special-shaped component 11 is reliably fixed to the angle steel 14.

[0042] As shown in FIG3(a), it is a general conductor, the separation point between air and the conductor is early, and the wind resistance is large. To reduce the wind resistance, the middle phase conductor and the side phase conductor are both low wind pressure conductors 16; as shown in FIG3(b), the low wind pressure conductor 16 with an undulating outer surface effectively reduces the wind resistance; Figure 4 As shown, the low wind pressure conductor 16 includes a core 17, an inner conductor 18, and an outer conductor 19; all inner conductors 18 are covered by the outer conductor 19, and the side of each outer conductor in contact with the external environment is a conductor structure with an outward convex curvature, forming an undulating outer surface of the low wind pressure conductor 16, and a groove 20 is formed between adjacent outer conductors on the outer surface of the low wind pressure conductor 16. Compared with ordinary conventional transmission conductors, the cross section of the low wind pressure conductor 16 has a circular arc of a certain angle, which can reduce the use of materials and weight, thereby reducing the difficulty and cost of construction. By changing the curvature of the groove 20 on the outside of the conductor, the roughness of the conductor surface is increased to a certain extent, so that the wind resistance coefficient of the surface becomes smaller. As a result, the pressure difference resistance of the entire transmission line conductor is also reduced, and the overall resistance coefficient of the low wind pressure line is also reduced accordingly, and the total resistance of the line is further reduced. This can effectively improve the wind resistance of the conductor itself under high wind speed conditions and reduce the wind resistance coefficient. Combining composite materials and a low-wind pressure conductor 16 on a transmission tower, the combination of the two can further improve the wind resistance of the transmission tower. This device uses a low-wind pressure conductor 16 on the basis of the composite material of the transmission tower. When the speed changes due to the influence of the incoming wind, the composite material on the transmission tower and the roughness of the surface of the low-wind pressure conductor 16 used in the transmission tower can jointly reduce the influence of the wind load to a certain extent, thereby improving the overall wind pressure resistance. Compared with ordinary conventional transmission wires, the cross section of the low-wind pressure conductor 16 has a circular arc with a certain angle, which can reduce the use of materials and reduce the weight, thereby reducing the construction difficulty and cost. The low-wind pressure conductor 16 can effectively reduce the wind resistance coefficient, thereby reducing the wind load, further increasing the service life of the conductor, and reducing the material production cost. The center of the low-wind pressure conductor 16 is located on the same reference circle, and the center of the arc structure of each conductor in contact with the external environment is located on the same arc. The radii of the inner arc, inner circle and outer arc within a suitable range, combined with the improvement of construction technology and manufacturing process, can obtain a low-wind pressure conductor 16 structure with a small wind resistance coefficient. The curved conductor surface with a certain angle on the conductor structure surface will give the conductor structure appropriate roughness. Under the influence of the incoming wind, the return flow area is relatively small, resulting in a decrease in the pressure difference resistance of the entire transmission line conductor. The overall line resistance of the low wind pressure line becomes smaller, and the resistance coefficient also becomes smaller accordingly. This can effectively improve the wind resistance of the conductor itself under high wind speed conditions and reduce the wind resistance coefficient.

[0043] Embodiment: A 220kV high wind speed zone single-circuit composite cross arm 5 cathead type straight tower, which includes a ground wire support 1, a tower leg 10, a tower body 9, a tower head 6 and a conductor insulator string 7, and the tower head 6 is composed of a tower window 8 and two side composite conductor cross arms 5.

[0044] After the conductor cross arm 5 of the cathead-type straight tower in the high wind speed zone is made of composite materials, the conductor cross arm 5 is considered semi-insulated, the length of the insulator string 7 is shortened, the gap circle is correspondingly reduced, and the corridor width is reduced, thereby improving the transmission capacity of the unit corridor.

[0045] The arc size between the two small arcs varies according to the low wind pressure diameter. As the conductor diameter increases, the arc size decreases accordingly. When the conductor diameter is less than or equal to 20mm, the required arc should be 20°~25°. When the conductor diameter ranges from 20° to 30°, the required arc is 15°~20°. When the conductor diameter ranges from 30° to 40°, the required arc is 10°~15°.

[0046] Table 1 Relationship between the arc of the groove on the outer surface of the low wind pressure conductor and the conductor diameter

[0047] Wire diameter D≥20 20＜D≤30 30＜D≤40 Groove curvature 20°～25° 15°～20° 10°～15°

[0048] The present invention provides a low wind pressure conductor to address the shortcomings of the existing conductors, such as high wind resistance and large wind drag. As a new type of conductor, it reduces its wind drag coefficient, especially the wind drag coefficient under high wind speed. The conductor is designed with an external groove curvature to reduce the resistance and reduce the damage to the transmission line, thus having an excellent energy-saving effect. The outer conductor generally adopts a fan-shaped cross-section to make the surface closer to a smooth circle to reduce the wind resistance coefficient. There is a certain relationship between the outer surface roughness and the fillet radius of the V-groove, the diameter of the conductor, and the center angle θ, which is specifically expressed as follows:

[0049]

[0050] In the formula, is the design wind speed value of the line (m / s), r is the surface roughness of the structure and the circular corner radius of two adjacent V-shaped grooves (mm), and θ is the central angle formed by two adjacent outer arcs (°).

[0051] like Figure 5 is a schematic diagram of the horizontal swing angle θ of the conductor. The static horizontal swing angle can be expressed by the conductor weight and the wind load acting on the conductor as parameters:

[0052]

[0053] W m =(ρ·V 2 ·C D·D·L) / 2

[0054] Where: W m W is the wind load on the conductor (kg / m); c is the weight per unit length of the conductor; ρ is the air density (kg·s 2 / m 4 ) ; V is wind speed (m / s); C D is the resistance coefficient; D is the outer diameter of the wire (m);

[0055] As a part of the low wind pressure conductor, the analysis of the stress of the strand is helpful to analyze the wind load. Figure 6 , 7 The conductor is subjected to a tensile force F along the axial direction, and the total bending moment M is the superposition of the bending moment caused by the axial force translated to the center of each strand cross section and the spiral strand and the bending moment caused by the friction between the center strands on the spiral strand.

[0056] The tension of the strand along its own axis tangent direction is:

[0057] Z d =F d / cosβ

[0058] The tensile force on the wire is:

[0059] F=∑F d =∑Z d cosβ

[0060] The stress on the center strand section is:

[0061] σ1=Z d / A

[0062] The stress on the cross section of the spiral strand is:

[0063]

[0064] Among them: F d is the component force of the strand along the axial direction; β is the helix angle of the strand; A is the cross-sectional area of ​​the strand;

[0065] I z is the moment of inertia; y is the height from the neutral axis.

[0066] The middle strand coincides with the axis of the conductor cross section, and the external force F is parallel and collinear with the axis of the cross section. Therefore, the low wind pressure conductor only bears axial tension and only tensile stress on the cross section. Since the spiral strands are subjected to non-collinearity and bending moment, there are tensile stress and bending stress on the cross section.

[0067] The 220kV high wind speed zone single-circuit composite material cross-arm cathead-shaped straight tower shown in the above figure is a specific embodiment of the present invention, which has embodied the substantial characteristics and progress of the present invention. According to actual use needs and under the guidance of the present invention, equivalent modifications in shape, structure, etc. can be made to it, which are all within the protection scope of this scheme.

Claims

1. A 220 kV high wind speed zone single-circuit composite material cross-arm cathead-shaped straight tower, comprising a tower leg (10), a tower body (9), a cathead-shaped tower head (6) and a ground wire support (1), characterized in that: The tower head (6) comprises a crossbeam (4) located at the top, an upper curved arm (2) and a lower curved arm (3) located below both sides of the crossbeam (4), the lower end of the lower curved arm (3) is connected to the tower body (9), the lower curved arm (3) is provided with a cross arm (5), the cross arm (5) is provided with a special-shaped component (11) fixedly connected to the angle steel (14), the outer contour of the cross section of the special-shaped component (11) is formed by connecting two right-angled sides and a circular arc side, wherein the two right-angled sides match the right-angled inner side surface of the angle steel (14); the special-shaped component (11) is a multi-layer structure, comprising an outer coating (12), a reinforcement layer (15), and a filling layer (13), and the outer coating (12), the reinforcement layer (15), and the filling layer (13) are arranged in sequence from the outside to the inside; The crossbeam (4), the upper curved arm (2), and the lower curved arm (3) form a tower window (8), and an insulator string (7) for connecting a middle phase conductor is provided in the tower window (8), and the insulator string (7) is hoisted on the crossbeam (4); The two cross arms (5) are in a downward dovetail shape, and the lower end of the cross arm (5) is provided with an insulator string (7) for connecting the two side phase conductors; the insulator string (7) connecting the middle phase conductor and the insulator string (7) connecting the two side phase conductors are arranged in a triangle; The crossbeam (4) is provided with a special-shaped component (11) fixedly connected to the angle steel (14); The outer coating (12) is a fiber protective coating, the reinforcing layer (15) is a glass fiber layer, the filling layer (13) is a foam filling layer, and the thickness of the reinforcing layer (15) is smaller than that of the filling layer (13); The special-shaped component (11) is connected to the angle steel (14) by bolts, and adjacent angle steels (14) are connected by flanges (21). One end of the flange (21) is connected to one angle steel by bolts, and the other end of the flange (21) is connected to another angle steel by bolts. The special-shaped component (11) is directly opposite or obliquely opposite to the insulator string (7) suspended thereon. The middle phase conductor and the side phase conductor are both low wind pressure conductors (16); the low wind pressure conductor (16) includes a wire core (17), an inner conductor (18), and an outer conductor (19); all inner conductors (18) are covered by the outer conductor (19), and the side of each outer conductor in contact with the external environment is a conductor structure with an outward convex arc, forming an undulating outer surface of the low wind pressure conductor (16), and grooves (20) are formed between adjacent outer conductors on the outer surface of the low wind pressure conductor (16).

2. The 220kV high wind speed zone single circuit composite material cross arm cathead type straight tower according to claim 1 is characterized in that: The hanging point of the ground wire support (1) is located outside the side phase conductor.

3. The 220kV high wind speed zone single circuit composite material cross arm cathead type straight tower according to claim 1 is characterized in that: The diameter of the low wind pressure conductor (16) is related to the groove (20), and the diameter of the low wind pressure conductor (16) increases as the curvature of the groove (20) decreases; when the curvature of the groove (20) is 10° to 15°, the diameter range corresponding to the low wind pressure conductor (16) is 30 mm to 40 mm; when the curvature of the groove (20) is 15° to 20°, the diameter range corresponding to the low wind pressure conductor (16) is 20 mm to 30 mm; when the curvature of the groove (20) is 20° to 25°, the diameter of the low wind pressure conductor (16) is not greater than 20 mm.

4. The 220kV high wind speed zone single circuit composite material cross arm cathead type straight tower according to claim 3 is characterized by: The radius r from the outermost point of the outer surface of the low conductor to the center of the low wind pressure conductor (16) is calculated in correlation with the wind speed, the conductor diameter, and the center angle θ; the radius r decreases as the wind speed increases, and increases as the center angle θ increases; The calculation formula of radius r is: Where: is the line design wind speed value, the unit is m / s; θ is the central angle formed by the outer arcs of two adjacent outer conductors, in degrees; the radius r is in mm.

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