Voltage uprating and capacity expansion method and transmission tower

Abstract

The present application relates to a voltage uprating and capacity expansion method, comprising: acquiring original design information of an original transmission tower to be retrofitted, and acquiring a voltage level and a transmission capacity of the retrofitted transmission tower having undergone voltage uprating and capacity expansion; performing analysis and calculation on the basis of the original design information, the voltage level and the transmission capacity, and generating design input conditions of the retrofitted transmission tower; performing electrical design and structural design of the retrofitted transmission tower on the basis of the design input conditions, determining the design of a composite cross arm assembly, performing matching connection design of the composite cross arm assembly and the original transmission tower, and adjusting the design of the composite cross arm assembly to obtain final design parameters of the retrofitted transmission tower; designing a construction scheme on the basis of the final design parameters, and manufacturing the composite cross arm assembly; and performing construction on the basis of the construction scheme, and hanging wires onto the composite cross arm assembly to obtain the retrofitted transmission tower. The present application further provides a transmission tower, which is retrofitted for voltage uprating and capacity expansion using the voltage uprating and capacity expansion method.

Description

A method for increasing capacity and voltage and a power transmission tower TECHNICAL FIELD

[0001] The present application relates to the technical field of power transmission, in particular to a method for increasing capacity and voltage and a power transmission tower. BACKGROUND

[0002] A power transmission tower is a pole-shaped or tower-shaped structure that supports overhead power transmission lines and overhead ground wires and maintains a certain distance between the power transmission lines and the ground wires and between the power transmission lines and the ground wires and the ground.

[0003] Currently, the commonly used capacity increasing method is to remove the original power transmission lines and newly build power transmission lines of a higher voltage level, which has the problems of long construction period and high cost.

[0004] In the above-mentioned capacity increasing method, the original power transmission lines of the entire line need to be removed, and new high-capacity lines need to be installed on the original power transmission tower.

[0005] Therefore, a new capacity and voltage increasing method is needed to retain the original power transmission lines and increase the voltage of the original power transmission tower, cancel the suspension insulator string by using a composite cross arm, and raise the height of the line hanging point. SUMMARY

[0006] The application provides a voltage boosting and capacity increasing method, comprising the following steps: S11: obtaining original design information of a to-be-reformed original power transmission tower, and obtaining voltage grade and transmission capacity of the reformed power transmission tower after voltage boosting and capacity increasing; S12: performing analysis and calculation based on the original design information, the voltage grade and the transmission capacity to generate design input conditions of the reformed power transmission tower; S13: performing electrical design and structural design of the reformed power transmission tower based on the design input conditions, determining design of a composite cross arm assembly, and performing matching connection design of the composite cross arm assembly and the original power transmission tower, adjusting the design of the composite cross arm assembly, and obtaining final design parameters of the reformed power transmission tower; S14: designing a construction scheme based on the final design parameters, and preparing the composite cross arm assembly; and S15: constructing according to the construction scheme, hanging a conductor on the composite cross arm assembly, and obtaining the reformed power transmission tower.

[0007] In an embodiment, the construction scheme comprises the following steps: S141: powering off the original power transmission tower; S142: temporarily suspending or removing the conductor and the ground wire hung on the original power transmission tower; S143: removing the original cross arm of the original power transmission tower; S144: reforming a tower head of the original power transmission tower; S145: suspending and installing the composite cross arm assembly to the tower head; and S146: hanging the conductor hung on the original power transmission tower on the composite cross arm assembly, hanging the ground wire hung on the original power transmission tower on the tower head, or installing a new conductor on the composite cross arm assembly and installing a new ground wire on the tower head.

[0008] In an embodiment, after step S142 and before step S145, a temporary reinforcing device is installed on the tower head; and after step S145, the temporary reinforcing device is removed.

[0009] In an embodiment, the tower head comprises a first curved arm and a second curved arm, and the temporary reinforcing device is fixed and supported between the first curved arm and the second curved arm.

[0010] In an embodiment, the construction scheme comprises the following steps: S241: powering off the original power transmission tower; S242: temporarily suspending or removing the conductor and the ground wire hung on the original power transmission tower; S243: separating the tower head from the tower body of the original power transmission tower, transporting the tower head to the ground, and removing the original cross arm of the original power transmission tower; S244: installing the composite cross arm assembly on the tower head; S245: suspending and installing the tower head and the composite cross arm assembly to the tower body; and S246: hanging the conductor hung on the original power transmission tower on the composite cross arm assembly, hanging the ground wire hung on the original power transmission tower on the tower head, or installing a new conductor on the composite cross arm assembly and installing a new ground wire on the tower head.

[0011] In an embodiment, before step S246, the construction scheme further comprises: removing an original ground wire support of the original power transmission tower, and installing a new ground wire support on the tower head.

[0012] In an embodiment, the tower head comprises a first curved arm and a second curved arm, the new ground wire support comprises a first ground wire support and a second ground wire support, the first ground wire support is installed on the top of the first curved arm, and the second ground wire support is installed on the top of the second curved arm.

[0013] In an embodiment, the composite cross arm assembly comprises a middle-phase composite cross arm, a first side-phase composite cross arm, and a second side-phase composite cross arm, in step S145 or step S244, the middle-phase composite cross arm is installed between the first curved arm and the second curved arm, the first side-phase composite cross arm is installed on the outside of the first curved arm, and the second side-phase composite cross arm is installed on the outside of the second curved arm.

[0014] In an embodiment, the hanging height of the conductor on the composite cross arm assembly is higher than the hanging height of the conductor on the original power transmission tower.

[0015] In an embodiment, step S144 comprises at least one of the following: installing a mounting hole, a mounting plate, and a truss on the tower head.

[0016] In an embodiment, the suspension uses a suspension mechanism, and the suspension mechanism comprises at least one of the following: a drone, a crane, a helicopter, and a pulley block.

[0017] In an embodiment, the installation height of the composite cross arm assembly is higher than the height of the original cross arm, and the height of the new ground wire support is higher than the height of the original ground wire support.

[0018] In an embodiment, the original design information comprises a tower drawing of the original power transmission tower, a conductor type, a ground wire type, a line section drawing, and a design meteorological condition.

[0019] In an embodiment, the design input condition comprises a tower head arrangement, a power transmission tower load, a conductor-to-ground net distance, a vertical line distance, a conductor-to-ground member electrical distance, a conductor sag, a conductor load, and an electromagnetic parameter, and the final design parameter comprises a corridor width, a transmission capacity, and a component structure size.

[0020] The application also provides a power transmission tower, which is obtained by using the voltage boosting and capacity increasing method of any one of the above to perform voltage boosting and capacity increasing reconstruction, and comprises a main tower structure, wherein the main tower structure defines a reference horizontal plane, the reference horizontal plane is used to be arranged in parallel with the ground horizontal plane; the main tower structure comprises a tower body and a tower head, the tower head comprises a first curved arm and a second curved arm, the first curved arm and the second curved arm are arranged at the top of the tower body, and the space between the first curved arm and the second curved arm is used to form a middle-phase assembly space, the middle-phase assembly space has a top space opening; a composite cross arm assembly is arranged in the tower head, and the composite cross arm assembly comprises a middle-phase composite cross arm and two side-phase composite cross arms; wherein the middle-phase composite cross arm is arranged in the middle-phase assembly space, and the two side-phase composite cross arms are arranged in the first curved arm and the second curved arm of the tower head respectively, and the two side-phase composite cross arms are both located outside the middle-phase assembly space; a wire hanging assembly is used to hang wires, and the number of the wire hanging assemblies is configured to be at least three, at least one wire hanging assembly is arranged on the middle-phase composite cross arm, and at least one wire hanging assembly is arranged on each side-phase composite cross arm.

[0021] In an embodiment, the middle-phase composite cross arm comprises a plurality of first cable-stayed insulating rod members and a plurality of first strut insulating rod members, the first ends of all the first cable-stayed insulating rod members are respectively connected to different positions of the first curved arm and the second curved arm, and all the first cable-stayed insulating rod members have an included angle with the reference horizontal plane, the first ends of all the first strut insulating rod members are respectively connected to different positions of the first curved arm and the second curved arm, and all the first strut insulating rod members have an included angle with the reference horizontal plane, the second ends of all the first cable-stayed insulating rod members and the second ends of all the first strut insulating rod members are connected into a middle-phase node in the middle-phase assembly space, and the middle-phase node is provided with at least one wire hanging assembly.

[0022] In an embodiment, each side-phase composite cross arm comprises a plurality of second cable-stayed insulating rod members and a plurality of second strut insulating rod members, the first ends of all the second cable-stayed insulating rod members in each side-phase composite cross arm are respectively connected to different positions of the tower head, and all the second cable-stayed insulating rod members in each side-phase composite cross arm have an included angle with the reference horizontal plane, the first ends of all the second strut insulating rod members in each side-phase composite cross arm are respectively connected to different positions of the tower head, and all the second strut insulating rod members in each side-phase composite cross arm have an included angle with the reference horizontal plane, the second ends of all the second cable-stayed insulating rod members in each side-phase composite cross arm and the second ends of all the second strut insulating rod members are connected into a side-phase node outside the side-phase assembly space, and the side-phase node is provided with at least one wire hanging assembly.

[0023] In an embodiment, the wire hanging assembly comprises a connecting fitting, one end of the connecting fitting is connected to the middle-phase node, and a wire support is connected to the other end of the connecting fitting, wherein the wire support has a support inner cavity in the inside, and the support inner cavity is used to pass through the wire.

[0024] In an embodiment, the main tower structure further comprises: a ground wire support, the ground wire support comprising a first ground wire support and a second ground wire support, the first ground wire support being arranged at the top of the first curved arm, and the second ground wire support being arranged at the top of the second curved arm, the top of the first ground wire support and the top of the second ground wire support being used for hanging a ground wire.

[0025] In the above-mentioned voltage increasing and capacity increasing method, the transmission capacity of the transmission line is increased by modifying the traditional transmission tower, the original cross arm structure of the original transmission tower to be modified, such as an iron cross arm, a steel cross arm, etc., is removed, and a new composite cross arm assembly is installed, and the electrical clearance is increased to meet the voltage increasing and capacity increasing requirement. The voltage increasing and capacity increasing method provided in the present application has the following technical effects: (1) the composite cross arm assembly is used for voltage increasing and capacity increasing, the suspension insulator string is omitted, the conductor hanging height is raised, the wind deflection swing is reduced, and the voltage is increased without replacing the tower; (2) the transmission voltage is increased, the line loss is reduced, and the effective transmission efficiency is improved; (3) in the working condition that the corridor is limited and the voltage is to be increased, the composite cross arm assembly has low economic cost, high modification efficiency, and strong competitiveness; (4) the transmission tower after voltage increasing and capacity increasing has significantly improved the anti-pollution, wind resistance, lightning resistance, and other capabilities; (5) the suspension insulator string is removed, and the later operation and maintenance workload and cost are greatly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0026] FIG. 1 is a plan structure schematic diagram of a transmission tower provided in an embodiment of the present application.

[0027] FIG. 2 is a three-dimensional structure schematic diagram of a transmission tower provided in an embodiment of the present application.

[0028] FIG. 3 is a structure schematic diagram of a tower head and a ground wire support provided in an embodiment of the present application.

[0029] FIG. 4 is a partial assembly structure schematic diagram of a first cable-stayed insulating rod, a first support insulating rod, and a middle-phase connecting assembly provided in an embodiment of the present application.

[0030] FIG. 5 is a partial assembly structure schematic diagram of a second cable-stayed insulating rod, a second support insulating rod, and a side-phase connecting assembly provided on one side in an embodiment of the present application.

[0031] FIG. 6 is a partial assembly structure schematic diagram of a second cable-stayed insulating rod, a second support insulating rod, and a side-phase connecting assembly provided on the other side in an embodiment of the present application.

[0032] FIG. 7 is a structure schematic diagram of a transmission tower with a shielding ring provided in an embodiment of the present application.

[0033] FIG. 8 is a plan structure schematic diagram of a wine glass tower in the prior art.

[0034] FIG. 9 is a use state schematic diagram of a temporary reinforcing device provided in an embodiment of the present application.

[0035] Figure 10 is a schematic diagram of the first orientation structure of a temporary reinforcement device provided in one embodiment of this application.

[0036] Figure 11 is a schematic diagram of the second-direction structure of a temporary reinforcement device provided in one embodiment of this application.

[0037] Figure 12 is a left view of the temporary reinforcement device shown in Figure 11.

[0038] Figure 13 is a right view of the temporary reinforcement device shown in Figure 11. Detailed Implementation

[0039] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below. Where the terms "first" and "second" appear, these terms are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0040] The voltage boosting and capacity increasing method of the present application is used for transforming the conventional power transmission tower to increase the transmission capacity of the power transmission line, removing the original cross arm structure of the original power transmission tower to be transformed, such as iron cross arm, steel cross arm, etc., and installing a new composite cross arm assembly to increase the electrical gap between the conductor and the ground to meet the voltage boosting and capacity increasing demand. The composite cross arm assembly is assembled by insulating composite material and metal joint, and the structure composition and component specification can be flexibly adjusted according to the actual design load. It is not only insulated, but also has good mechanical properties. After the voltage boosting and capacity increasing of the conventional power transmission tower, the traditional suspension insulator string can be omitted. The conductor is hung on the composite cross arm assembly through a shorter wire hanger string, which can raise the height of the conductor hanging, reduce the wind deflection amplitude, release the safety gap, and ensure that the length of the composite cross arm assembly is the same as or close to the length of the original cross arm before and after the transformation, to meet the voltage boosting and capacity increasing within a certain range. And without removing the original power transmission line to build a higher voltage grade power transmission line, the original tower can be boosted, the required material quantity is less, the construction period is short, the cost is low, the construction cost is low; without large-scale land acquisition, the corridor problem is solved and the land acquisition cost is reduced; after boosting, the power transmission capacity is increased to meet the rapidly growing load requirements. For ease of description, the conventional power transmission tower before voltage boosting and capacity increasing is referred to as the original power transmission tower to be transformed, and the power transmission tower after voltage boosting and capacity increasing is referred to as the transformed power transmission tower. Taking the conventional wine glass tower as the above-mentioned original power transmission tower to be transformed, the voltage boosting and capacity increasing method of the present application can transform the original power transmission tower shown in FIG. 8 into the transformed power transmission tower shown in FIGS. 1 to 6.

[0041] Referring to FIGS. 1 to 6, the transformed power transmission tower includes a main tower structure 1000, a composite cross arm assembly 2000 and a wire hanging assembly 3000. Among them, the main tower structure 1000 can be defined with a reference horizontal plane 1000a, which belongs to a virtual plane constructed and does not actually exist, but only uses the reference horizontal plane 1000a as an auxiliary reference for describing the relationship between the main tower structure 1000 and the ground. For example, when the transformed power transmission tower is installed on the ground, the reference horizontal plane 1000a of the main tower structure 1000 is parallel to the ground level, which realizes the vertical installation of the transformed power transmission tower relative to the ground. In addition, the reference horizontal plane 1000a is also used to determine the angle and direction of the composite cross arm assembly 2000 arranged on the main tower structure 1000, which can be seen below.

[0042] As shown in FIG. 1, the main tower structure 1000 includes a tower body 1100 and a tower head 1200, the tower body 1100 is a basic structure of a modified transmission tower, and is used to be installed in direct contact with the ground. The tower head 1200 is arranged on the tower body 1100, and is mainly used to arrange a composite cross arm assembly 2000, a ground wire support 4000, a conductor 100 and a ground wire, etc. As shown in FIGS. 1 to 3, the tower head 1200 includes a first curved arm 1210 and a second curved arm 1220, the first curved arm 1210 and the second curved arm 1220 are arranged at the top of the tower body 1100 in a spaced manner, and the first curved arm 1210 and the second curved arm 1220 are arranged in a left-right symmetrical manner, at this time, a space enclosed between the first curved arm 1210 and the second curved arm 1220 can be used to form a middle-phase assembly space 1000b.

[0043] Since the bottom of the first curved arm 1210 and the second curved arm 1220 is connected with the tower body 1100, the top of the first curved arm 1210 and the second curved arm 1220 is not connected with each other, and the first curved arm 1210 and the second curved arm 1220 are arranged in a direction away from each other in the horizontal direction, therefore, the middle-phase assembly space 1000b formed between the first curved arm 1210 and the second curved arm 1220 has a top space opening 1000c facing upward, so that the first curved arm 1210 and the second curved arm 1220 form a structure similar to a "U" shape with the tower body 1100. Moreover, the first curved arm 1210 and the second curved arm 1220 can each include an upper curved arm and a lower curved arm connected in sequence, and the included angle between the upper curved arm and the lower curved arm is an obtuse angle. Taking the first curved arm 1210 as an example, the lower curved arm is used to be arranged at the top of the tower body 1100 and connected with the tower body 1100, and the upper curved arm is located at the top of the lower curved arm and used to be connected with the ground wire support 4000. The second curved arm 1220 is the same and will not be repeated here.

[0044] Continuing to refer to FIG. 3, the composite cross arm assembly 2000 is arranged on the tower head 1200, and is used to hang the conductor 100 including the middle-phase conductor 100 and the side-phase conductor 100 on the tower head 1200. Therefore, the composite cross arm assembly 2000 can include a middle-phase composite cross arm 2100 and two side-phase composite cross arms 2200, wherein the middle-phase composite cross arm 2100 is arranged in the middle-phase assembly space 1000b of the main tower structure 1000, so that the middle-phase composite cross arm 2100 can be used to hang the middle-phase conductor 100 in the middle-phase assembly space 1000b, and the two side-phase composite cross arms 2200 can be arranged on the left and right sides of the tower head 1200, and are used to hang the side-phase conductor 100 on the left and right sides (i.e. outside the middle-phase assembly space 1000b) of the tower head 1200, and the two side-phase composite cross arms 2200 are arranged in a symmetrical structure.

[0045] As shown in FIG. 3, the middle-phase composite cross arm 2100 includes a plurality of first diagonal insulating rods 2110 and a plurality of first strut insulating rods 2120. The first ends of all the first diagonal insulating rods 2110 are respectively connected to different positions of the first curved arm 1210 and the second curved arm 1220, and all the first diagonal insulating rods 2110 have an angle with the reference horizontal plane 1000a. Similarly, the first ends of all the first strut insulating rods 2120 are respectively connected to different positions of the first curved arm 1210 and the second curved arm 1220, and all the first strut insulating rods 2120 have an angle with the reference horizontal plane 1000a.

[0046] The second ends of all the first diagonal insulating rods 2110 and the second ends of all the first strut insulating rods 2120 are connected to a middle-phase node in the middle-phase assembly space 1000b. In an embodiment, the heights of the plurality of first diagonal insulating rods 2110 gradually increase, and the heights of the plurality of first strut insulating rods 2120 gradually decrease in the direction from the middle-phase node to the first curved arm 1210 or the second curved arm 1220, thereby forming the middle-phase composite cross arm 2100 as shown in FIG. 3. In addition, the first diagonal insulating rods 2110 connected to the first curved arm 1210 and the first diagonal insulating rods 2110 connected to the second curved arm 1220 are symmetrically arranged about the middle-phase node, and the first strut insulating rods 2120 connected to the first curved arm 1210 and the first strut insulating rods 2120 connected to the second curved arm 1220 are also symmetrically arranged about the middle-phase node.

[0047] As shown in FIG. 3, in an embodiment, the middle-phase composite cross arm 2100 includes a middle-phase connecting assembly 2130 for forming the middle-phase node. As shown in FIG. 4, the middle-phase connecting assembly 2130 includes a middle-phase node fitting 2131, a plurality of first diagonal fittings 2111, and a plurality of first strut fittings 2121. The first ends of the first diagonal fittings 2111 are detachably connected to the middle-phase node fitting 2131, the second ends of each of the first diagonal fittings 2111 are connected to the end of one of the first diagonal insulating rods 2110, the first ends of the first strut fittings 2121 are detachably connected to the middle-phase node fitting 2131, and the second ends of each of the first strut fittings 2121 are connected to the end of one of the first strut insulating rods 2120. In addition, those skilled in the art can realize the connection between the middle-phase connecting assembly 2130 and the first diagonal insulating rods 2110 and the first strut insulating rods 2120 by other detachable ways according to actual needs, which are not limited herein.

[0048] The number of the wire hanging assembly 3000 is configured to be at least three, and the wire hanging assembly 3000 is used for hanging the conductor 100. At this time, the middle-phase node of the middle-phase composite cross arm 2100 is provided with at least one wire hanging assembly 3000, and after the wire hanging assembly 3000 is used for hanging the conductor 100 on the middle-phase composite cross arm 2100, the wire hanging assembly 3000 has a lower sag height relative to the middle-phase node, and the conductor 100 is also lower than the middle-phase node.

[0049] Therefore, compared with the original power transmission tower shown in FIG. 8, in the modified power transmission tower after the capacity increase, the suspension insulator string for hanging the middle-phase conductor 100 is omitted, and the shorter wire hanging assembly 300 is matched, so that the conductor 100 of the middle phase is relatively close to the middle-phase node, the distance of the conductor 100 of the middle phase to the ground is lifted, and the requirement of the increased distance of the conductor 100 to the ground after the capacity increase is met. Moreover, after the suspension insulator string for hanging the middle-phase conductor 100 is cancelled, the wind deviation of the conductor 100 of the middle phase is small, so that the gap between the conductor 100 after the capacity increase and the main tower structure 1000 still meets the requirement.

[0050] In the structure design of the above-mentioned middle-phase composite cross arm 2100 of the modified power transmission tower, the middle-phase composite cross arm 2100 can adjust and control the height of the middle-phase node formed in the middle-phase composite cross arm 2100 relative to the ground by adjusting the connection positions of all the first diagonal tension insulating rods 2110 and all the first strut insulating rods 2120 on the first curved arm 1210 and the second curved arm 1220, and simultaneously adaptively adjusting the included angle of all the first diagonal tension insulating rods 2110 and all the first strut insulating rods 2120 relative to the reference horizontal plane 1000a, and adaptively adjusting the sag length of the wire hanging assembly 3000, and adjusting the height of the conductor 100 of the middle phase relative to the ground.

[0051] Based on the structure design of the above-mentioned middle-phase composite cross arm 2100, the original cross arm structure of the original power transmission tower can be replaced, and the height of the conductor 100 of the middle phase is adjusted by using the modified middle-phase composite cross arm 2100 shown in FIGS. 1 to 3, so that the conductor 100 of the middle phase can be lifted without removing the original main tower structure 1000, and the modification of the capacity increase is realized. In combination with FIGS. 1 and 8, in an embodiment, the main tower structure of the original power transmission tower and the main tower structure 1000 of the modified power transmission tower after the capacity increase are the same structure, and the slight differences in the height, size, etc. of the tower body 1100, the tower head 1200 and the ground wire support 4000 are all regarded as the same structure of the main tower structure 1000, so the same reference signs are used to facilitate description.

[0052] Continuing to refer to FIG. 3, two edge-phase composite crossarms 2200 are arranged at the first curved arm 1210 and the second curved arm 1220 of the tower head 1200, and both of the two edge-phase composite crossarms 2200 are located outside the middle-phase assembly space 1000b. Each edge-phase composite crossarm 2200 includes a plurality of second diagonal insulating rod members 2210 and a plurality of second strut insulating rod members 2220. The first ends of all the second diagonal insulating rod members 2210 in each edge-phase composite crossarm 2200 are connected to different positions of the tower head 1200, and all the second diagonal insulating rod members 2210 in each edge-phase composite crossarm 2200 have an angle with the reference horizontal plane 1000a. Meanwhile, the first ends of all the second strut insulating rod members 2220 in each edge-phase composite crossarm 2200 are connected to different positions of the tower head 1200, and all the second strut insulating rod members 2220 in each edge-phase composite crossarm 2200 have an angle with the reference horizontal plane 1000a.

[0053] The second ends of all the second diagonal insulating rod members 2210 and the second ends of all the second strut insulating rod members 2220 in each edge-phase composite crossarm 2200 are connected to an edge-phase node outside the middle-phase assembly space. For example, as shown in FIG. 3, the two edge-phase composite crossarms 2200 located at the left side and the right side of the tower head 1200 construct an edge-phase node at the left side and the right side of the tower head 1200 respectively, and a wire hanging assembly 3000 is arranged at the edge-phase node of each edge-phase composite crossarm 2200. The wire hanging assembly 3000 is consistent with the wire hanging assembly 3000 arranged at the middle-phase composite crossarm 2100. After the edge-phase conductor 100 is hung on the wire hanging assembly 3000 of the edge-phase composite crossarm 2200, the conductor 100 can be lowered below the edge-phase node due to the lower sag height of the wire hanging assembly 3000 relative to the edge-phase node.

[0054] In an embodiment, in the direction from the edge-phase node to the first curved arm 1210 or the second curved arm 1220, the heights of the second diagonal insulating rod members 2210 gradually increase, and the heights of the second strut insulating rod members 2220 gradually decrease, thereby forming the two edge-phase composite crossarms 2200 as shown in FIG. 3.

[0055] As shown in FIG. 3, in one embodiment, the edge-phase composite cross arm 2200 includes an edge-phase connecting assembly 2230 for forming an edge-phase node. As shown in FIG. 5, the edge-phase connecting assembly 2230 includes an edge-phase node fitting 2231, a plurality of second catenary fittings 2211, and a plurality of second strut fittings 2221. The first end of each second catenary fitting 2211 is detachably connected to the edge-phase node fitting 2231, and the second end of each second catenary fitting 2211 is connected to the end of a second catenary insulator rod 2210. The first end of each second strut fitting 2221 is detachably connected to the edge-phase node fitting 2231, and the second end of each second strut fitting 2221 is connected to the end of a second strut insulator rod 2220. In addition, those skilled in the art can realize the connection between the edge-phase connecting assembly 2230 and the second catenary insulator rod 2210 and the second strut insulator rod 2220 in other detachable manners according to actual needs, which are not limited herein.

[0056] For the same reason, since the edge-phase hanging catenary insulator string is omitted, the matching shorter size of the wire hanging assembly 300 makes the relative distance between the edge-phase conductor 100 and the edge-phase node closer, which raises the ground distance of the edge-phase conductor 100 and meets the requirement of increasing the ground clearance of the conductor 100 after voltage boosting. Moreover, after the edge-phase hanging catenary insulator string is cancelled, the wind deviation of the edge-phase conductor 100 is smaller, so that the clearance between the conductor 100 after voltage boosting and the main tower structure 1000 still meets the requirement.

[0057] Therefore, in the above structure design of the edge-phase composite cross arm 2200 of the modified power transmission tower, the height of the edge-phase node formed in the edge-phase composite cross arm 2200 relative to the ground can be adjusted and controlled by adjusting the connection positions of all the second catenary insulator rods 2210 and all the second strut insulator rods 2220 on the first curved arm 1210 and the second curved arm 1220, and simultaneously adaptively adjusting the included angle of all the second catenary insulator rods 2210 and all the second strut insulator rods 2220 relative to the reference horizontal plane 1000a, and the height of the edge-phase conductor 100 relative to the ground can be adjusted by adaptively adjusting the suspension length of the wire hanging assembly 3000.

[0058] Based on the above structure design of the edge-phase composite cross arm 2200, the original cross arm structure of the original power transmission tower can be replaced by the modified edge-phase composite cross arm 2200 shown in FIGS. 1 to 3 to adjust the height of the edge-phase conductor 100, so that the conductor 100 can be raised without removing the original main tower structure 1000, and the modification of voltage boosting and capacity increasing can be realized.

[0059] Continuing to refer to FIG. 4, in one embodiment, the wire hanging assembly 3000 includes a connecting fitting 3100 and a wire support 3200, the first end of the connecting fitting 3100 is connected to the neutral node fitting 2131, and the wire support 3200 is connected to the second end of the connecting fitting 3100, wherein the connecting fitting 3100 can be a fixed-length connecting plate, or can also be composed of a plurality of connecting plates connected in sequence. The connecting plate can be a PT adjusting plate, a parallel hanging plate, etc., and different connecting plates can be selected to be hingedly connected to form the connecting fitting 3100 according to the actual working conditions, so that the connecting fitting 3100 has different lengths to meet different wire-to-ground height requirements. The wire support 3200 has a support inner cavity 3200a inside, which is used to pass through the wire 100. For example, the wire support 3200 can adopt a wire clamp capable of supporting the wire 100 and other structures capable of supporting the wire 100, which are not limited here. Therefore, in order to stabilize the wire 100, the wire support 3200 can be designed to be linear and have a certain length, so that the support inner cavity 3200a of the wire support 3200 also adaptively presents a linear inner cavity, which has a linear trajectory, and the wire 100 is movably arranged in the support inner cavity 3200a along the linear trajectory of the support inner cavity 3200a, so that the wire 100 can be arranged in the support inner cavity 3200a of the wire support 3200 along the length direction of the wire support 3200, and a stable wrapping is formed based on the length design of the wire support 3200.

[0060] Moreover, as shown in FIG. 4, at least one end of the wire support 3200 along the linear trajectory is provided with a curved portion 3210, for example, both ends of the wire support 3200 are designed with the curved portion 3210, wherein from the central position of the wire support 3200 to at least one end thereof, the curved portion 3210 gradually expands in a direction perpendicular to the linear trajectory, and in the upward and downward directions shown in FIG. 4, the curved portion 3210 presents a gradually downward shape. Therefore, with the gradually downward shape of the curved portion 3210, the wire 100 can form a natural downward shape between the two reconstructed transmission towers along with the gradually downward shape of the curved portion 3210, so as to ensure that the wire 100 is not tight.

[0061] It can be understood that, if there is no structural design of the bending part 3210, the bearing inner cavity 3200a inside the conductor support 3200 is straight in the transverse direction, and the conductor 100 will form a transverse and horizontal tight (straight) state between the two modified transmission towers, and the conductor 100 will be damaged if it bends downward due to gravity. Based on the structural design of the bending part 3210, the conductor 100 will form an intermediate sagging arc state between the two modified transmission towers, avoiding damage to the conductor 100. Moreover, as the conductor 100 extends to both ends of the conductor support 3200, the bending part 3210 at both ends of the conductor support 3200 can also avoid the conductor 100, preventing the sharp end from damaging the surface of the conductor 100.

[0062] Referring to FIG. 4, in one embodiment, the wire hanging assembly 3000 further comprises a first wire hanging part 3300 and a second wire hanging part 3400, the first wire hanging part 3300 is connected to the second end of the connecting fitting 3100, and the number of the second wire hanging part 3400 is configured to be at least two, and the plurality of second wire hanging parts 3400 are respectively hinged to different positions of the first wire hanging part 3300. As shown in FIG. 4, the first wire hanging part 3300 can adopt a triangular connecting plate or other structure that can centrally connect the plurality of second wire hanging parts 3400, which is not limited herein. The number of the conductor support 3200 is configured to be at least two, so that each conductor support 3200 can be connected to one second wire hanging part 3400, and then connected to the second end of the connecting fitting 3100 through the second wire hanging part 3400 and the first wire hanging part 3300. At this time, a plurality of second wire hanging parts 3400 can be provided through the first wire hanging part 3300, and a plurality of conductor supports 3200 are connected through the plurality of second wire hanging parts 3400, so as to realize the hanging of a plurality of conductors 100 on the same wire hanging assembly 3000.

[0063] The wire hanging assembly 3000 directly hung on the middle phase node and the edge phase node of the composite cross arm assembly 2000 bears the line nominal voltage, and the protruding part is prone to electric field distortion and corona discharge, which affects the service life of the wire hanging assembly 3000 and the quality of people's living environment. Therefore, as shown in FIG. 7, a racetrack-shaped, semicircular or other shielding ring can be arranged outside the wire hanging assembly 3000, the shielding ring has a large curvature radius and a smooth metal surface, so it will not produce extreme electric field distortion. Therefore, placing the shielding ring on the middle phase node and the edge phase node can well cover the protruding metal surface below, improve the electric field distribution around the middle phase node and the edge phase node, reduce the local concentration of the electric field, and make the electric field distribution more uniform. The shielding ring can be parallel to the direction of the composite cross arm assembly 2000 or perpendicular to the direction of the composite cross arm assembly 2000.

[0064] With reference to Fig. 3, in one embodiment, the main tower structure 1000 further comprises a ground wire support 4000, which comprises a first ground wire support 4100 arranged at the top of the first curved arm 1210 and a second ground wire support 4200 arranged at the top of the second curved arm 1220, the top of the first ground wire support 4100 and the top of the second ground wire support 4200 being used for hanging the ground wire. For the case of higher voltage level, the ground wire support 4000 can be raised, and the middle-phase composite cross arm 2100 is appropriately moved upward on the tower head 1200 by a certain height, and since the space of the middle-phase assembly space 1000b is larger, the requirement of larger gap after voltage boosting can be met. At the same time, the side-phase composite cross arm 2200 is also moved upward, and the conductors 100 of the three phases are located on the same horizontal plane, so that the distance of the conductors 100 to the ground is increased to meet the requirement of the distance of the conductors 100 to the ground, and higher voltage level voltage boosting is realized.

[0065] The voltage boosting and capacity increasing method provided in the application comprises the following steps: S11: obtaining original design information of a to-be-transformed original power transmission tower, and obtaining voltage level and transmission capacity of the transformed power transmission tower after voltage boosting and capacity increasing; S12: performing analysis and calculation based on the original design information, the voltage level and the transmission capacity to generate design input conditions of the transformed power transmission tower; S13: performing electrical design and structural design of the transformed power transmission tower based on the design input conditions, determining design of a composite cross arm assembly and performing matching connection design of the composite cross arm assembly and the original power transmission tower, adjusting the design of the composite cross arm assembly, and obtaining final design parameters of the transformed power transmission tower; S14: designing a construction scheme based on the final design parameters, and preparing the composite cross arm assembly; and S15: constructing according to the construction scheme, hanging the conductors on the composite cross arm assembly, and obtaining the transformed power transmission tower.

[0066] Referring to Fig. 8, when the original power transmission tower is designed, the clearance requirement of the conductor to the tower body 1100 under the windage of the suspension insulator string needs to be considered, so that the length of the original cross arm is relatively long, and the distance between layers is relatively large, which results in a large size of the tower head 1200; at the same time, the projection of the suspension insulator string in the horizontal direction after windage is relatively long, which results in a very wide corridor width.

[0067] When voltage boosting and capacity increasing design is performed, the original design information of the original power transmission tower needs to be obtained first, including tower drawing, conductor type, ground wire type, line section drawing, design meteorological condition and other main information. At the same time, the voltage level and transmission capacity of the transformed power transmission tower need to be obtained.

[0068] Based on the original design information and the voltage level and transmission capacity of the modified transmission tower, the analysis and calculation are performed, mainly including electrical arrangement based on the tower map, transmission tower modeling for transmission tower load calculation, conductor-to-ground clearance check, transmission tower load check, corridor width calculation and transmission capacity comparison calculation according to the conductor type and ground wire type, conductor-to-ground clearance check, transmission tower load calculation and electrical clearance check according to the line section view, and conductor sag and load calculation according to the design meteorological conditions. Thus, the design input conditions can be obtained, including tower head arrangement, transmission tower load, conductor-to-ground clearance, vertical line distance, electrical distance between conductor and ground member, conductor sag, conductor load and electromagnetic parameters.

[0069] Based on the design input conditions, the electrical design and structural design are performed. According to the initially selected conductor, the load at the conductor hanging point is calculated, and combined with the requirements of voltage increase and capacity increase and the tower body planning, the tower body structural strength is checked, and the original transmission tower foundation is checked. The load after voltage increase is applied to the model of the original transmission tower to determine the transmission tower component structure that needs to be strengthened or replaced; the load calculation is performed using the conductor after voltage increase, and the load is applied to the original transmission tower for stress check of the transmission tower component structure. The load calculation will be performed according to the working conditions. Generally, the weight of the modified conductor is basically the same as that of the original conductor, so that the load of the tower body can meet the standard requirements, thereby eliminating the need for demolition and reconstruction. If the degree of voltage increase and capacity increase is high, and in order to meet the lightning protection requirements, the original ground wire support needs to be modified, which will be demolished and reconstructed, part of the auxiliary materials of the tower body will also be replaced, and the tower body foundation will be checked.

[0070] Combined with the preliminary tower body planning and checking, the preliminary composite cross arm assembly design is performed, including selection and structural design, and further checking of the tower body planning is performed to meet the overall tower body planning and design. After the structural design of the composite cross arm assembly is further reviewed and analyzed, and the electrical design of the components such as the grading ring, shielding ring and arc corner is further reviewed and analyzed, the matching connection design of the composite cross arm assembly and the original transmission tower is performed combined with the actual working conditions of voltage increase and capacity increase, the preliminary design of the composite cross arm assembly, the design of the tower body strengthening or replacement, the design of the transmission tower foundation strengthening, the design of the conductor replacement, etc. The design of the composite cross arm assembly is further adjusted to obtain the final design parameters of the modified transmission tower. The final design parameters include corridor width, transmission capacity and component structure size. Then, based on the final design parameters, the construction scheme is designed, the composite cross arm assembly is prepared, the construction is performed, the voltage increase and capacity increase modification is completed, and the modified transmission tower is obtained.

[0071] In an embodiment, the construction scheme comprises the following steps: S141: powering off the original power transmission tower; S142: temporarily suspending or removing the wires and ground wires connected to the original power transmission tower; S143: removing the original cross arm of the original power transmission tower; S144: modifying the tower head of the original power transmission tower; S145: suspending the composite cross arm assembly and installing it to the tower head; S146: connecting the wires connected to the original power transmission tower to the composite cross arm assembly, connecting the ground wires connected to the original power transmission tower to the tower head, or installing new wires on the composite cross arm assembly and installing new ground wires on the tower head.

[0072] In a specific application scenario, the original power transmission tower is powered off first, and then the wires and ground wires are removed, or the wires and ground wires are temporarily suspended by using pulleys or cranes, and then the original cross arm is disassembled and transported to the ground. The original cross arm can be suspended and transported by using a suspension mechanism. Removing all the wires and ground wires is suitable for complete reconstruction; temporarily suspending the wires and ground wires is suitable for reconstructing a specific original power transmission tower or original power transmission towers on a certain section of line.

[0073] The suspension mechanism comprises at least one of a drone, a crane, a helicopter or a pulley block. The suspension mechanism can be selected from one of a drone, a crane, a helicopter or a pulley block, or several of them can be used in cooperation to achieve stable suspension. Of course, the suspension mechanism can also be other tools other than the above tools, which are not limited herein. During the entire suspension process, a windproof rope can also be used to fix the entire structure to prevent it from swaying during suspension, thereby avoiding damage caused by collision with other structures on the tower head.

[0074] The tower head of the original power transmission tower is modified, i.e., step S144 comprises: setting necessary installation holes, installation plates and trusses on the tower head according to installation requirements to facilitate subsequent installation of the composite cross arm assembly. After the composite cross arm assembly is assembled on the ground, the composite cross arm assembly is suspended and installed to the tower head by using the suspension mechanism. Finally, the wires and ground wires are installed.

[0075] In another specific application scenario, referring to FIGS. 1-8, the original power transmission tower is the wine glass tower shown in FIG. 8, which has a middle tower window surrounded by a first curved arm 1210, a second curved arm 1220 and a middle phase bridge structure 10, and a first side phase angle steel structure 20 located at the first curved arm 1210 and a second side phase angle steel structure 30 located at the second curved arm 1220, the middle phase bridge structure 10, the first side phase angle steel structure 20, the second side phase angle steel structure 30 and the suspension insulator string hung thereon are all original cross arms to be removed. Among them, the middle phase bridge structure 10 is used to hang the middle phase conductor 100 in the original power transmission tower, and needs to be replaced by the middle phase composite cross arm 2100 of the modified power transmission tower in the present application. The first side phase angle steel structure 20 and the second side phase angle steel structure 30 are used to hang the side phase conductor 100 in the original power transmission tower, and need to be replaced by two side phase composite cross arms 2200 of the modified power transmission tower. The two side phase composite cross arms 2200 can be respectively referred to as a first side phase composite cross arm 2200 and a second side phase composite cross arm 2200. The first side phase composite cross arm 2200 is used to replace the first side phase angle steel structure 20, and the second side phase composite cross arm 2200 is used to replace the second side phase angle steel structure 30.

[0076] The above modification process may change the ground wire support, for example, the lightning protection angle of the modified power transmission tower changes, and if reinforcement is needed on the basis of the original ground wire support, the ground wire support needs to be changed accordingly. Those skilled in the art can modify according to actual needs, which is not limited here.

[0077] During construction, after step S142, before step S145, a temporary reinforcing device 200 is installed on the tower head; and after step S145, the temporary reinforcing device 200 is removed.

[0078] A temporary reinforcing device 200 is arranged on the tower head 1200 of the original power transmission tower, as shown in FIG. 9, which is used to fix and support between the first curved arm 1210 and the second curved arm 1220 of the tower head 1200. In this state, the original middle phase bridge structure 10 between the first curved arm 1210 and the second curved arm 1220 is removed. The temporary reinforcing device 200 forms a temporary support between the first curved arm 1210 and the second curved arm 1220 of the tower head 1200, replacing the original middle phase bridge structure 10, which can still ensure the stability of the tower head 1200 after the middle phase bridge structure 10 is removed.

[0079] The temporary reinforcing device 200 can adopt various structures, and various connection modes are adopted to form fixed support connection with the first curved arm 1210 and the second curved arm 1220 of the tower head 1200. For example, referring to FIG. 9, the temporary reinforcing device 200 can adopt a crossbar structure, and the two ends of the crossbar structure can be threadedly connected with the first curved arm 1210 and the second curved arm 1220 of the tower head 1200 respectively, or various connection modes such as plate connection, flange connection, cross plate connection, etc. can also be adopted. The crossbar structure adjusts the transverse length according to the transverse distance between the first curved arm 1210 and the second curved arm 1220 of the tower head 1200, so that the first curved arm 1210 and the second curved arm 1220 can be kept in the original structural state under the fixed support of the crossbar structure, and will not be changed unexpectedly before and after the removal of the middle phase bridge structure 10.

[0080] In one embodiment, as shown in FIGS. 10-13, the temporary reinforcing device 200 includes a reinforcing rod 210 and an adjusting assembly 220. The reinforcing rod 210 is a fixed-length rod, and the adjusting assembly 220 is arranged at one end of the reinforcing rod 210. The adjusting assembly 220 can be used to adjust the length, so that the overall length of the temporary reinforcing device 200 is adjusted based on the fixed length of the reinforcing rod 210 and the length adjustment of the adjusting assembly 220 itself. The adjusting assembly 220 can include an adjusting body 221, a first connecting portion 222 and a second connecting portion 223. The adjusting body 221 can adopt various telescopic structures such as hydraulic cylinders and telescopic rods. Those skilled in the art can select appropriate telescopic structures according to actual stress requirements, installation convenience and other factors, which are not limited here. The temporary reinforcing device 200 only needs to meet the stress requirements to stabilize the overall structure of the original power transmission tower, and does not affect the installation of the middle phase composite cross arm 2100.

[0081] The first connecting part 222 and the second connecting part 223 are respectively arranged at two ends of the adjusting body part 221. The adjusting body part 221 is connected with the end of the reinforcing rod part 210 through the first connecting part 222, so that the adjusting body part 221 can be connected with the reinforcing rod part 210, the overall length of the temporary reinforcing device 200 is increased on the basis of the fixed length of the reinforcing rod part 210, and the adjusting body part 221 is used to be connected with the tower head 1200 of the power transmission tower through the second connecting part 223. In addition, the third connecting part 211 and the fourth connecting part 212 can be arranged on the reinforcing rod part 210. The reinforcing rod part 210 can be connected with the first connecting part 222 through the third connecting part 211, and the reinforcing rod part 210 is used to be connected with the tower head 1200 of the power transmission tower through the fourth connecting part 212. For example, the adjusting body part 221 is connected with the first curved arm 1210 of the tower head 1200 through the second connecting part 223, and the reinforcing rod part 210 is connected with the second curved arm 1220 of the tower head 1200 through the fourth connecting part 212. The first connecting part 222 and the third connecting part 211 can adopt a connecting flange structure, and the second connecting part 223 and the fourth connecting part 212 can adopt a connecting ear structure, which are not limited herein.

[0082] The reinforcing rod part 210 and the adjusting assembly 220 are detachably connected. The cross-sectional shape of the reinforcing rod part 210 can be circular, triangular, quadrilateral or other shapes, which are not limited herein. According to different working conditions, the reinforcing rod part 210 with a certain size and the adjusting assembly 220 with a certain type are selected to be connected, so as to form the temporary reinforcing device 200 which can meet the load requirements, the tower head size requirements and other requirements, thereby expanding the application range of the temporary reinforcing device 200.

[0083] In addition, the temporary reinforcing device 200 can be constructed in various ways such as a force-bearing pull wire and an inclined supporting rod. When various forms are adopted, the force-bearing requirements are met, so that the overall structure of the power transmission tower is stable, and the installation of the middle-phase composite cross arm 2100 is not affected. The structure of the temporary reinforcing device 200 can be set according to actual needs by those skilled in the art, which is not limited herein.

[0084] The power transmission tower in which the middle-phase bridge structure 10 is removed is in a state shown in FIG. 9. In this state, the assembled middle-phase composite cross arm 2100 is hung up and installed between the first curved arm 1210 and the second curved arm 1220 of the tower head 1200. After the installation is completed, the temporary reinforcing device 200 fixed and supported between the first curved arm 1210 and the second curved arm 1220 is removed.

[0085] The assembly of the middle-phase composite cross arm 2100 can be completed on the ground. As for the installation of the temporary reinforcing device 200, the middle-phase bridge structure 10 can be disassembled after the temporary reinforcing device 200 is installed. In this case, the temporary reinforcing device 200 needs to be installed at a position that does not interfere with the disassembly of the middle-phase bridge structure 10. Alternatively, the middle-phase bridge structure 10 can be disassembled first, for example, two cranes are used to hoist the first curved arm 1210 and the second curved arm 1220 of the tower head 1200, and then the temporary reinforcing device 200 is installed. In this case, the temporary reinforcing device 200 is installed at the position of the original middle-phase bridge structure 10. Those skilled in the art can select the installation mode according to actual needs, as long as the power transmission tower is in the state shown in FIG. 9 before the middle-phase composite cross arm 2100 is hung, which can meet the condition of installing the middle-phase composite cross arm 2100 and realize the priority reconstruction of the middle-phase composite cross arm 2100.

[0086] During the process of installing the middle-phase composite cross arm 2100 between the first curved arm 1210 and the second curved arm 1220, the middle-phase installation hole or the middle-phase erecting plate can be provided on the first curved arm 1210 and the second curved arm 1220 before the middle-phase composite cross arm 2100 is hung. Then, the assembled middle-phase composite cross arm 2100 is hung, and the middle-phase composite cross arm 2100 is installed between the first curved arm 1210 and the second curved arm 1220 of the tower head 1200 by using the middle-phase installation hole or the middle-phase erecting plate. For example, the middle-phase composite cross arm 2100 can be quickly installed between the first curved arm 1210 and the second curved arm 1220 by means of the middle-phase installation hole through the threaded components, clamping components or other connecting components. For another example, the middle-phase erecting plate can be set to an appropriate shape, size or the like according to the installation requirements of the middle-phase composite cross arm 2100, and then the middle-phase erecting plate is installed on the first curved arm 1210 and the second curved arm 1220, so that the middle-phase composite cross arm 2100 can be quickly installed between the first curved arm 1210 and the second curved arm 1220 by means of the middle-phase erecting plate.

[0087] After the installation of the middle-phase composite cross arm 2100 is completed, the side-phase composite cross arm 2200 can be installed, i.e., the first side-phase composite cross arm 2200 and the second side-phase composite cross arm 2200 located on the left and right sides of the tower head 1200. For example, in one embodiment, the first side-phase angle steel structure 20 originally located on the first curved arm 1210 and the second side-phase angle steel structure 30 originally located on the second curved arm 1220 are first removed, and the assembled first side-phase composite cross arm 2200 and the second side-phase composite cross arm 2200 are suspended. The first side-phase composite cross arm 2200 is installed on the outer side of the first curved arm 1210, and the second side-phase composite cross arm 2200 is installed on the outer side of the second curved arm 1220. Among them, the assembly of the first side-phase composite cross arm 2200 and the second side-phase composite cross arm 2200 can be completed on the ground, and the assembly of the first side-phase composite cross arm 2200 and the second side-phase composite cross arm 2200, and the disassembly of the first side-phase angle steel structure 20 and the second side-phase angle steel structure 30 can be performed simultaneously, as long as the first side-phase angle steel structure 20 and the second side-phase angle steel structure 30 are in a state of being disassembled before the first side-phase composite cross arm 2200 and the second side-phase composite cross arm 2200 are suspended. At this time, the conditions for installing the side-phase composite cross arm 2200 can be met, and the installation of the side-phase composite cross arm 2200 can be realized.

[0088] During the installation of the first side-phase composite cross arm 2200 and the second side-phase composite cross arm 2200 on the first curved arm 1210 and the second curved arm 1220, a first side-phase installation hole or a second side-phase installation hole can be formed on the first curved arm 1210 or the second curved arm 1220 of the tower head 1200 before the first side-phase composite cross arm 2200 or the second side-phase composite cross arm 2200 is suspended. Then, the assembled first side-phase composite cross arm 2200 or second side-phase composite cross arm 2200 is suspended, and the first side-phase composite cross arm 2200 or the second side-phase composite cross arm 2200 is installed on the first curved arm 1210 or the second curved arm 1220 of the tower head 1200 by using the first side-phase installation hole or the second side-phase installation hole, for example, by using a threaded component, a clamping component or other connecting component that can be inserted into the first side-phase installation hole or the second side-phase installation hole, so that the first side-phase composite cross arm 2200 or the second side-phase composite cross arm 2200 can be quickly installed on the first curved arm 1210 or the second curved arm 1220 by means of the first side-phase installation hole or the second side-phase installation hole.

[0089] Alternatively, in one of the embodiments, before suspending the first phase composite cross arm 2200 or the second phase composite cross arm 2200, the first phase erecting plate member or the second phase erecting plate member can be arranged on the first curved arm 1210 or the second curved arm 1220 of the tower head 1200, and then the assembled first phase composite cross arm 2200 or the second phase composite cross arm 2200 is suspended, and the first phase composite cross arm 2200 or the second phase composite cross arm 2200 is installed on the first curved arm 1210 or the second curved arm 1220 of the tower head 1200 by using the first phase erecting plate member or the second phase erecting plate member. For example, the first phase erecting plate member or the second phase erecting plate member can be arranged in a suitable shape, size, etc. according to the installation requirements of the first phase composite cross arm 2200 or the second phase composite cross arm 2200, so as to construct a suitable structure basis for installation, which is not limited herein.

[0090] The temporary reinforcing device can be removed after the installation of the middle phase composite cross arm 2100 is completed, or can be removed after the installation of the middle phase composite cross arm 2100 and the phase composite cross arm 2200 is completed.

[0091] In another embodiment, the construction scheme includes the following steps: S241: powering off the original power transmission tower; S242: temporarily suspending or removing the wires and ground wires connected to the original power transmission tower; S243: separating the tower head and the tower body of the original power transmission tower, transporting the tower head to the ground, and removing the original cross arm of the original power transmission tower; S244: installing the composite cross arm assembly on the tower head; S245: suspending the tower head and the composite cross arm assembly and installing them to the tower body; S246: connecting the wires of the original power transmission tower to the composite cross arm assembly, connecting the ground wires of the original power transmission tower to the tower head, or installing new wires on the composite cross arm assembly and installing new ground wires on the tower head.

[0092] Specifically, with reference to FIGS. 1-8, first, ensure that the original power transmission tower is powered off, then remove or temporarily suspend the original power transmission tower using a crane or other equipment to hang the conductor and ground wire, then separate the tower head 1200 and the tower body 1100 of the main tower structure 1000 of the original power transmission tower, the purpose of separation is to remove the tower head 1200 and the original middle-phase bridge structure 10, the first side-phase angle steel structure 20, and the second side-phase angle steel structure 30 arranged on the tower head 1200, thereby achieving one-time removal of the above structures. After removal, the above-mentioned removed structures are lifted from a high place to the ground, and the above-mentioned structures are replaced and modified on the ground. First, remove the original cross arm, that is, remove the middle-phase bridge structure 10, the first side-phase angle steel structure 20, and the second side-phase angle steel structure 30 from the tower head 1200, then install the assembled composite cross arm assembly 2000 on the first curved arm 1210 and the second curved arm 1220 of the tower head 1200, and replace the middle-phase bridge structure 10, the first side-phase angle steel structure 20, and the second side-phase angle steel structure 30 with the composite cross arm assembly 2000. After installation, the tower head 1200 and the composite cross arm assembly 2000 installed on the tower head 1200 are suspended and installed on the tower body 1100, and then the ground wire and the conductor are connected. Thus, the overall construction and modification of the tower head 1200 is realized, and for the voltage increase and capacity increase scheme with high voltage increase degree, the overall modification and installation of the composite cross arm assembly 2000 on the ground is more convenient, and the modification requirement can be realized at one time. For example, first, install the middle-phase composite cross arm 2100 between the first curved arm 1210 and the second curved arm 1220 of the tower head 1200, at this time, the structure composed of the middle-phase composite cross arm 2100 and the tower head 1200 is stable, and it is convenient to suspend, then suspend and install the tower head 1200 and the middle-phase composite cross arm 2100 on the tower body 1100, then suspend and install the two side-phase composite cross arms 2200 on the outside of the first curved arm 1210 and the outside of the second curved arm 1220 of the tower head 1200, respectively, thus installing the middle-phase composite cross arm 2100 and the side-phase composite cross arm 2200, respectively, to reduce the difficulty of suspension.

[0093] For the voltage increase and capacity increase scheme with high voltage increase degree, the tower head 1200 of the original power transmission tower cannot meet the size requirement of the installation of the composite cross arm assembly 2000, by increasing the installation height of the original ground wire support 4000 or lengthening the length of the original ground wire support 4000, the tower head 1200 has more space, and then the overall structure of the composite cross arm assembly 2000 can be moved upward during installation, the installation height of the composite cross arm assembly 2000 is higher than the height of the original cross arm, that is, higher than the installation position of the middle-phase bridge structure 10, the first side-phase angle steel structure 20, and the second side-phase angle steel structure 30 of the original power transmission tower, and a higher voltage grade of voltage increase can be realized.

[0094] After the voltage is boosted, the original ground wire support 4000 is modified to meet the lightning protection requirements, and a new ground wire support 4000 is installed, and the height of the new ground wire support 4000 is higher than that of the original ground wire support 4000. In an embodiment, similar to the previous construction scheme, the tower head 1200 and the tower body 1100 of the main tower structure 1000 of the original power transmission tower are first separated, and after disassembly, the disassembled structure is lifted from a high place to the ground, and the replacement modification is carried out on the ground. The original cross arm, i.e., the original middle-phase bridge structure 10, the first side-phase angle steel structure 20, the second side-phase angle steel structure 30, and the original ground wire support 4000 arranged on the tower head 1200 are removed from the tower head 1200, and then the composite cross arm assembly 2000 and the new ground wire support 4000 are installed. For example, the middle-phase composite cross arm 2100 is installed between the first curved arm 1210 and the second curved arm 1220, the first side-phase composite cross arm 2200 is installed on the outside of the first curved arm 1210, the second side-phase composite cross arm 2200 is installed on the outside of the second curved arm 1220, the first ground wire support 4100 is installed on the top of the first curved arm 1210, and the second ground wire support 4200 is installed on the top of the second curved arm 1220. The composite cross arm assembly 2000 replaces the middle-phase bridge structure 10, the first side-phase angle steel structure 20, and the second side-phase angle steel structure 30, and the new ground wire support 4000 replaces the original ground wire support 4000. After installation, the tower head 1200, the composite cross arm assembly 2000, and the new ground wire support 4000 are suspended and installed on the tower body 1100 together, thereby realizing the overall construction modification of the tower head 1200. For the voltage boosting and capacity increasing scheme with a higher degree of voltage increase, the modification and installation of the composite cross arm assembly 2000 and the ground wire support 4000 on the ground are more convenient, and the modification can be realized at one time without the need for multiple constructions.

[0095] For example, the middle-phase composite cross arm 2100 is installed between the first curved arm 1210 and the second curved arm 1220, and then the tower head 1200 and the middle-phase composite cross arm 2100 are suspended and installed on the tower body 1100. Then, the two side-phase composite cross arms 2200 are suspended and installed on the outside of the first curved arm 1210 and the outside of the second curved arm 1220, respectively, and the new ground wire support 4000 is suspended and installed on the top of the first curved arm 1210 and the top of the second curved arm 1220. The installation is convenient for suspension and reduces the construction difficulty. It can be understood that only the original ground wire support 4000 of the original power transmission tower needs to be removed and the new ground wire support 4000 needs to be installed on the tower head 1200 before the step S246 of connecting the conductor and the ground wire.

[0096] In the embodiment, the tower head 1200 is separated from the tower body 1100, and the tower head 1200 can be hoisted and transported as a whole for construction, so that the operation is convenient, the construction efficiency is high, and the construction period and cost of the voltage boosting project can be reduced; and the power transmission capacity is greatly increased after voltage boosting, so that the load requirement of rapid economic growth can be met.

[0097] The voltage boosting and capacity increasing method has the following technical effects: (1) the composite cross arm assembly is used for voltage boosting and capacity increasing, the suspension insulator string is omitted, the wire hanging height is raised, the wind deflection swing is reduced, and the tower is not replaced during voltage boosting; (2) the power transmission voltage is increased, so that the line loss is reduced and the effective power transmission efficiency is improved; (3) in the working condition of limited corridor and voltage boosting, the composite cross arm assembly has low economic cost, high transformation efficiency, and strong competitiveness; (4) the power transmission tower after voltage boosting and capacity increasing has obviously improved the abilities of anti-pollution, wind resistance, lightning resistance and the like; and (5) the suspension insulator string is removed, so that the later operation and maintenance workload and cost can be greatly reduced.

[0098] The technical features of the above-described embodiments can be combined arbitrarily, and in order to make the description simple, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, it should be considered that the combinations are within the scope of the present application.

[0099] The above-described embodiments only express several implementation manners of the present application, the description is relatively specific and detailed, but it should not be understood as a limitation on the patent application scope. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A method of boosting capacity, characterized by, The method comprises the following steps: S11: obtaining original design information of a to-be-transformed original power transmission tower, and obtaining voltage level and transmission capacity of the transformed power transmission tower after voltage increase and capacity expansion; S12: performing analysis and calculation based on the original design information, the voltage level and the transmission capacity to generate design input conditions of the transformed power transmission tower; S13: performing electrical design and structural design of the transformed power transmission tower based on the design input conditions, determining design of a composite cross arm assembly, and performing matching connection design of the composite cross arm assembly and the original power transmission tower, adjusting the design of the composite cross arm assembly, and obtaining final design parameters of the transformed power transmission tower; S14: designing a construction scheme based on the final design parameters, and preparing the composite cross arm assembly; S15: constructing according to the construction scheme, hanging a conductor on the composite cross arm assembly, and obtaining the transformed power transmission tower.

2. The method of claim 1, wherein, The construction scheme comprises the following steps: S141: powering off the original power transmission tower; S142: temporarily suspending or removing conductors and ground wires hung on the original power transmission tower; S143: removing original cross arms of the original power transmission tower; S144: transforming a tower head of the original power transmission tower; S145: suspending and installing the composite cross arm assembly to the tower head; S146: hanging the conductors hung on the original power transmission tower on the composite cross arm assembly, hanging the ground wires hung on the original power transmission tower on the tower head, or installing new conductors on the composite cross arm assembly and installing new ground wires on the tower head.

3. The method of claim 2, wherein, After the step S142 and before the step S145, a temporary reinforcing device is installed on the tower head; and after the step S145, the temporary reinforcing device is removed.

4. The method of claim 3, wherein, The tower head comprises a first curved arm and a second curved arm, and the temporary reinforcing device is fixed and supported between the first curved arm and the second curved arm.

5. The method of claim 1, wherein, The construction scheme comprises the following steps: S241: powering off the original power transmission tower; S242: temporarily suspending or removing conductors and ground wires hung on the original power transmission tower; S243: separating a tower head and a tower body of the original power transmission tower, transporting the tower head to the ground, and removing original cross arms of the original power transmission tower; S244: installing the composite cross arm assembly on the tower head; S245: suspending and installing the tower head and the composite cross arm assembly to the tower body; S246: hanging the conductors hung on the original power transmission tower on the composite cross arm assembly, hanging the ground wires hung on the original power transmission tower on the tower head, or installing new conductors on the composite cross arm assembly and installing new ground wires on the tower head.

6. The method of claim 5, wherein, Before the step S246, the original ground wire support of the original power transmission tower is removed, and a new ground wire support is installed on the tower head.

7. The method of claim 6, wherein, The tower head comprises a first curved arm and a second curved arm, and the new ground wire support comprises a first ground wire support and a second ground wire support, the first ground wire support being installed on a top of the first curved arm, and the second ground wire support being installed on a top of the second curved arm.

8. The method of claim 2 or 5, wherein The composite cross arm assembly comprises a middle-phase composite cross arm, a first side-phase composite cross arm and a second side-phase composite cross arm, and in the step S145 or the step S244, the middle-phase composite cross arm is installed between the first curved arm and the second curved arm, the first side-phase composite cross arm is installed outside the first curved arm, and the second side-phase composite cross arm is installed outside the second curved arm.

9. The method of claim 1, wherein, The hanging height of the conductor on the composite cross arm assembly is higher than the hanging height of the conductor on the original power transmission tower.

10. The method of claim 2, wherein, The step S144 comprises at least one of the following: an installation hole, an installation plate and a truss arranged on the tower head.

11. The pressure boosting capacity increasing method according to claim 2 or 5, characterized by, The suspension adopts a suspension mechanism, and the suspension mechanism comprises at least one of a drone, a crane, a helicopter and a pulley block.

12. The method of claim 6, wherein, The installation height of the composite cross arm assembly is higher than the height of the original cross arm, and the height of the new ground wire support is higher than the height of the original ground wire support.

13. The method of claim 1, wherein, The original design information comprises a tower drawing, a conductor type, a ground wire type, a line section drawing and a design meteorological condition of the original power transmission tower.

14. The method of claim 1, wherein, The design input condition comprises a tower head arrangement, a power transmission tower load, a conductor-to-ground net distance, a vertical line distance, a conductor-to-ground member electrical distance, a conductor sag, a conductor load and an electromagnetic parameter, and the final design parameter comprises a corridor width, a transmission capacity and a component structure size.

15. A power transmission tower, characterized by, The power transmission tower is obtained by using the voltage boosting and capacity increasing method in any one of claims 1 to 14 for voltage boosting and capacity increasing reconstruction, the power transmission tower comprises a main tower structure, the main tower structure defines a reference horizontal plane, the reference horizontal plane is arranged in parallel with a ground horizontal plane, the main tower structure comprises a tower body and a tower head, the tower head comprises a first curved arm and a second curved arm, the first curved arm and the second curved arm are arranged at the top of the tower body, and a space between the first curved arm and the second curved arm is used to form a middle-phase assembly space, the middle-phase assembly space has a top space opening; A composite cross arm assembly is arranged on the tower head, and the composite cross arm assembly comprises a middle-phase composite cross arm and two side-phase composite cross arms; wherein the middle-phase composite cross arm is arranged in the middle-phase assembly space, the two side-phase composite cross arms are arranged on the first curved arm and the second curved arm of the tower head respectively, and the two side-phase composite cross arms are both located outside the middle-phase assembly space; A wire hanging assembly is used to hang a conductor, and the number of the wire hanging assemblies is configured to be at least three, at least one wire hanging assembly is arranged on the middle-phase composite cross arm, and at least one wire hanging assembly is arranged on each side-phase composite cross arm.

16. The power transmission tower of claim 15, wherein, The middle-phase composite cross arm comprises a plurality of first diagonal pull insulating rods and a plurality of first support insulating rods, the first ends of all the first diagonal pull insulating rods are respectively connected to different positions of the first curved arm and the second curved arm, and all the first diagonal pull insulating rods have an angle with the reference horizontal plane, the first ends of all the first support insulating rods are respectively connected to different positions of the first curved arm and the second curved arm, and all the first support insulating rods have an angle with the reference horizontal plane, the second ends of all the first diagonal pull insulating rods and the second ends of all the first support insulating rods are connected into a middle-phase node in the middle-phase assembly space, and the middle-phase node is provided with at least one wire hanging assembly.

17. The power transmission tower of claim 15, wherein, Each of the edge-phase composite cross arms comprises a plurality of second diagonal pull insulating rods and a plurality of second support insulating rods, the first ends of all the second diagonal pull insulating rods in each of the edge-phase composite cross arms are respectively connected to different positions of the tower head, and all the second diagonal pull insulating rods in each of the edge-phase composite cross arms have an angle with the reference horizontal plane, the first ends of all the second support insulating rods in each of the edge-phase composite cross arms are respectively connected to different positions of the tower head, and all the second support insulating rods in each of the edge-phase composite cross arms have an angle with the reference horizontal plane, the second ends of all the second diagonal pull insulating rods in each of the edge-phase composite cross arms and the second ends of all the second support insulating rods are connected into an edge-phase node outside the edge middle-phase assembly space, and the edge-phase node is provided with at least one wire hanging assembly.

18. The power transmission tower of claim 16, wherein, The wire hanging assembly comprises: a connecting fitting, one end of the connecting fitting being connected to the middle-phase node; a wire support, the other end of the connecting fitting being connected to the wire support, wherein the wire support has a support inner cavity inside, and the support inner cavity is used for penetrating the wire.

19. The power transmission tower of claim 15, wherein, The main tower structure further comprises: a ground wire support, the ground wire support comprising a first ground wire support and a second ground wire support, the first ground wire support being arranged at the top of the first curved arm, the second ground wire support being arranged at the top of the second curved arm, and the top of the first ground wire support and the top of the second ground wire support being used for hanging a ground wire.

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