Branch tower for four-loop overhead transmission line
Technical Field
The invention relates to a high-voltage overhead transmission line iron tower, in particular to a bifurcation tower for a four-loop overhead transmission line.
Background
In recent years, the power grid of China has been developed at a high speed, and the scale of the power grid is the first in the world. With the increasingly prominent contradiction between power grid construction and local economy, the land resources of the power corridor are increasingly tense, so that the adoption of the same-tower four-loop power transmission technology has high economic and social benefits for reducing the occupied area of the overhead power transmission corridor and removing houses.
Chinese utility model patent publication CN203729648U discloses a 66 kilovolt is with tower four return circuit double T connects bifurcation tower, this bifurcation tower includes that the top hangs the tower head of ground wire, body of the tower and tower seat, from last down be provided with three-phase upper strata double loop phase line cross arm and three-phase lower floor double loop phase line cross arm in proper order syntropy, still be provided with on this body of the tower with upper strata double loop phase line cross arm or lower floor double loop phase line cross arm orientation looks vertically three-phase double loop double T connects lower floor double loop wire cross arm, according to from down ascending order, double loop double T connects lower floor double loop wire cross arm and lower floor double loop phase line cross arm according to ABABAB's sequence distribution, wherein a stands for double loop double T and connects lower floor double loop wire cross arm, B stands for lower floor double loop phase line cross arm. The same-tower four-loop double-T-connection branching tower adopts a T-shaped wiring mode to lead out double-loop branching lines from two ends of a three-phase upper-layer double-loop phase line or a three-phase lower-layer double-loop phase line cross arm and respectively connect the double-loop branching lines to the end parts of the corresponding lower-layer double-loop wire cross arm to complete double-loop branching construction.
Disclosure of Invention
The purpose of the invention is: the utility model provides a simple structure, construction convenience's four return circuits branch tower for overhead transmission line to solve the problem that current four return circuits of same tower double T connect the branch tower to exist.
The technical scheme of the invention is as follows: a branching tower for a four-loop overhead transmission line comprises a tower body, wherein a ground wire cross arm, an upper-layer double-loop wire cross arm and a lower-layer double-loop wire cross arm are sequentially arranged on the tower body from top to bottom, and the lower-layer wire cross arm rotates clockwise or anticlockwise around a vertical central line of the tower body, so that an included angle of 30-60 degrees is formed between the upper-layer double-loop wire cross arm and the lower-layer double-loop wire cross arm.
The included angle between the upper layer lead cross arm and the lower layer lead cross arm is 45 DEG
The upper-layer double-loop wire cross arm is provided with three pairs of upper wire cross arms which are vertically spaced and symmetrically arranged relative to the tower body, the lower-layer double-loop wire cross arm group is provided with three pairs of lower wire cross arms which are vertically spaced and symmetrically arranged relative to the tower body, and the projections of the upper wire cross arms and the lower wire cross arms on the corresponding vertical planes are triangular structures.
The tower body on vertical interval be equipped with the cross partition face, the lower plane of lower wire cross arm include the material to one pair of main materials of being connected with the tower body and connect the oblique material between this pair of main materials, be located the intermediate part of the material to one side of the root of tower body between a pair of main materials and the gusset plate fixed connection of the cross partition face of corresponding position on the tower body.
The ground wire cross arms comprise a pair of main ground wire cross arms and a pair of divergent ground wire cross arms which are symmetrically arranged relative to the tower body, and the projections of the main ground wire cross arms and the divergent ground wire cross arms on the horizontal plane are in a vertical midline cross distribution structure surrounding the tower body.
The projections of the main ground wire cross arm and the branch ground wire cross arm on the horizontal plane are in a mutually vertical cross structure.
The projection of the main ground wire cross arm on the vertical plane is of an inverted triangle structure, and the projection of the divergent ground wire cross arm on the vertical plane is of a forward triangle structure.
The invention has the beneficial effects that: the bifurcation tower of the invention is based on the existing four-loop strain tower, and rotates the lower layer double-loop wire cross arm by 30-60 degrees on the horizontal plane, so that the bifurcation tower plays the role of a bifurcation cross arm, and compared with the existing four-loop double-T bifurcation tower, the bifurcation tower reduces the installation structure of a three-phase double-loop T bifurcation cross arm, thereby solving the problem of independent bifurcation of the upper two loops and the lower two loops of the four-loop overhead transmission line bifurcation tower, greatly simplifying the structure of the same-tower four-loop bifurcation tower, effectively reducing the tower height and the tower weight of the four-loop bifurcation tower, and simultaneously reducing the cost of laying the overhead four-loop line of the same tower.
Drawings
Fig. 1 is a schematic perspective view of a branching tower for a four-circuit overhead transmission line according to the present invention;
fig. 2 is a schematic top view of the upper dual-loop wire cross arm and the lower dual-loop wire cross arm in fig. 1;
fig. 3 is a schematic perspective view of the ground wire cross arm in fig. 1;
in the figure: 1. a tower body; 2. a ground wire cross arm; 20. a main ground wire cross arm; 21. a divergent ground wire cross arm; 3. an upper double-loop wire cross arm; 30. an upper wire cross arm; 4. a lower double-loop wire cross arm; 40. a lower wire cross arm; 41. a lower wire cross arm main material; 42. a lower wire cross arm diagonal material; 5. the tower body is transversely divided.
Detailed Description
The invention discloses a bifurcation tower for a four-loop overhead transmission line, which comprises a tower body 1, wherein a ground wire cross arm 2, an upper-layer double-loop wire cross arm 3 and a lower-layer double-loop wire cross arm 4 are sequentially arranged on the tower body 1 from the top to the bottom, wherein an upper-layer double-loop wire cross arm group 3 is provided with three pairs of upper wire cross arms 30 which are symmetrically arranged at intervals up and down; the lower double-loop wire cross arm group 4 is provided with three pairs of lower wire cross arms 40 which are symmetrically arranged at intervals up and down, and the projections of the upper wire cross arms 30 and the lower wire cross arms 40 on the corresponding vertical planes are all forward triangular structures. In the invention, the lower layer double-loop wire cross arm group 4 rotates clockwise or anticlockwise on a horizontal plane around the vertical central line of the tower body 1, so that an included angle a exists between the upper layer double-loop wire cross arm group 3 and the lower layer double-loop wire cross arm 4, and the included angle a is between 30 and 60 degrees. Since the main line conveying direction is substantially perpendicular to the branch line conveying direction, in order to improve the stability of the branch tower, in this embodiment, as shown in fig. 2, the included angle a between the lower double-loop wire cross arm 4 and the upper double-loop wire cross arm 3 after rotating clockwise or counterclockwise on the horizontal plane around the vertical central line of the tower body 1 is 45 °.
When the branching tower for the four-loop overhead transmission line is used specifically, each pair of upper wire cross arms 30 in the upper-layer double-loop wire cross arm group 3 is set as one layer, the vertical distance between the two adjacent layers of upper wire cross arms 30 is 3 meters, and in the three-layer upper wire cross arms 30, the horizontal length of the upper wire cross arms 30 positioned at the upper layer and the lower layer is smaller than that of the upper wire cross arm 30 positioned at the middle, so that the double-loop wires connected with the upper-layer double-loop wire cross arms 3 are arranged in a drum shape. Each pair of lower wire cross arms 40 in the lower layer double-loop wire cross arm 4 is set as one layer, the vertical distance between two adjacent layers of lower wire cross arms 40 is 4 meters, and in the three layers of lower wire cross arms 40, the transverse length of the lower wire cross arm 40 positioned in the middle is smaller than that of the lower wire cross arms 40 positioned in the upper and lower layers, so that the double-loop wires connected on the lower layer double-loop wire cross arm 4 are arranged in a foggy shape. The distance between the upper layer double-loop wire cross arm 3 and the lower layer double-loop wire cross arm 4 is 4.5 meters. The directions indicated by arrows in fig. 2 are the incoming direction and the outgoing direction on the upper layer double-loop wire cross arm 3 and the lower layer double-loop wire cross arm 4, respectively, wherein the incoming and outgoing direction of each upper wire cross arm 30 in the upper layer double-loop wire cross arm 3 and the incoming direction of each lower wire cross arm 40 in the lower layer double-loop wire cross arm 4 are set as the main line conveying direction, and the outgoing direction of each lower wire cross arm 40 in the lower layer double-loop wire cross arm 4 is set as the branch line direction.
The bifurcation tower provided by the invention is based on a conventional double-loop strain tower, the lower layer double-loop wire cross arm rotates 30-60 degrees on the horizontal plane around the vertical center line of the tower body, so that the lower layer double-loop wire cross arm can play a role of the bifurcation cross arm without changing the position of each hanging point on the lower layer double-loop wire cross arm, and compared with the existing four-loop double-T bifurcation tower, the bifurcation tower reduces the mounting structure of the three-phase double-loop T bifurcation cross arm, thereby greatly simplifying the structure of the same-tower four-loop bifurcation tower while solving the problem that the upper two loops and the lower two loops of the four-loop overhead transmission line bifurcation tower are independently bifurcated, effectively reducing the tower height and tower weight of the four-loop bifurcation tower and reducing the laying cost of the same-tower four-loop overhead line.
In practical application, in order to maintain the overall structural performance of the power transmission line tower and improve the wind resistance of the power transmission line tower, the tower body of the high-voltage realizing line tower is further provided with the cross partition surfaces 5 at intervals in the vertical direction, as shown in fig. 2, in the embodiment, in order to improve the load capacity of each lower lead cross arm 40, the lower plane of each lower lead cross arm 40 is provided with a pair of main materials 41 connected with the tower body 1 and an inclined material 42 connected between the pair of main materials 41, and the middle part of the inclined material 42 positioned near the root part of the tower body 1 between the pair of main materials 41 is fixedly connected with a node plate (not shown in the figure) of the cross partition surface 5 at the corresponding position on the tower body 1.
As shown in fig. 3, the ground wire cross arm 2 mainly comprises a pair of main ground wire cross arms 20 and a pair of divergent ground wire cross arms 21, wherein the main ground wire cross arms 20 are symmetrically arranged, the projections of the main ground wire cross arms 20 on a vertical plane are in an inverted triangle structure, the projections of the divergent ground wire cross arms 21 on the vertical plane are in a forward triangle structure, and the main ground wire cross arms 20 and the divergent ground wire cross arms 21 are arranged in a crossed manner around a vertical center line of the tower body.