A double-circuit tower split transposition device and installation method thereof

Abstract

The present invention relates to a split transposition device for a double-circuit pole tower and an installation method thereof, comprising a main tower, wherein the main tower is provided with an upper cross arm, a middle cross arm and a lower cross arm, a middle phase-to-upper phase jumper is provided between the upper cross arm and the middle cross arm located at the same side end, a lower phase-to-middle phase jumper is provided between the middle cross arm and the lower cross arm located at the same side end, auxiliary towers are provided on both sides of the main tower, the auxiliary tower is provided with an upper cross arm and a lower cross arm near the main tower side, and an upper phase-to-lower phase jumper is provided between the upper cross arm and the lower cross arm. The device has simple wiring and controllable jumper gap; it reduces the height of the iron tower or the length of the cross arm, thereby reducing the torque and bending moment of the ground wire on the iron tower, improving the stress condition of the iron tower, and improving the reliability of the iron tower.

Description

Technical Field

[0001] The invention relates to a double-circuit pole tower split transposition device and an installation method thereof. Background Art

[0002] In long-distance high-voltage transmission lines, in order to control the imbalance of system voltage and current, the transmission lines need to be transposed to ensure the safe and stable operation of the power system.

[0003] Transmission line transposition is usually carried out on a transposition tower. For single-circuit lines, conductor transposition can be achieved by installing jumper racks on tension towers. For double-circuit transmission lines, since the three-phase conductors of the same circuit are arranged vertically on one side, the available space is small. The higher the voltage level, the greater the gap requirement, the longer the tension string and jumper string, the longer the jumper between strings, the larger the sag, the complex jumper arrangement during transposition, the difficult construction, and the difficult operation and maintenance. In order to achieve simultaneous transposition of the inner and outer circuits at the corner, the transposition tower is usually arranged at a smaller corner (generally not more than 20°).

[0004] In the early days, double-circuit lines adopted the "double-single-double" transposition method, which essentially divided a double circuit into two single circuits and then combined them into a double circuit after transposition. This transposition method is outdated and basically no longer used. Currently, most double-circuit lines adopt double-circuit tension tower transposition, and there are three common methods: single bus bypass jumper external winding method, double bus bypass jumper external winding method, and bypass jumper internal winding method.

[0005] The single bus bypass jumper external winding transposition method is suitable for lines with low voltage levels and small tower head clearance requirements; the double bus bypass jumper external winding transposition method and the bypass jumper internal winding transposition method are more suitable for lines with high voltage levels and large clearance requirements. At present, my country's 500 and 750kV lines all use the double bus bypass jumper external winding transposition method. The double bus bypass jumper external winding transposition method and the bypass jumper internal winding transposition method are relatively complex. Due to the long tension string and jumper string, various clearance requirements are large, and the jumper clearance is not easy to control, which is easy to cause phase spacing or relative distance tension problems; and the transposition tower cross arm is long, affected by the tower torque, and the transposition tower mass is large. Affected by the angle, the double bus bypass jumper external winding transposition method and the bypass jumper internal winding transposition method are only suitable for small angles (generally not more than 20°).

[0006] Double busbar bypass jumper internal winding transposition method: the bypass jumper is between the two circuits, the jumper gap is not easy to control, the tower height is higher than the ordinary tension tower by two jumper string heights, which is about 10m for 500kV line. At the same time, the bypass jumper on the front of the tower is inconvenient to operate and maintain.

[0007] Double busbar bypass jumper external winding transposition method: The bypass jumper is on the outside of the two circuits, and the jumper gap is not easy to control, which easily leads to the problem of phase spacing distance tension; and the transposition tower cross arm is longer (the length is about 10m longer than that of ordinary tension tower). Affected by the tower torque, the transposition tower has a large mass. After the cross arm length is doubled, the stress problem is serious. Summary of the invention

[0008] The object of the present invention is to provide a double-circuit pole tower split transposition device and an installation method thereof, wherein the device has simple wiring and controllable jumper gap; the height of the iron tower or the length of the cross arm is reduced, thereby reducing the torque and bending moment of the ground wire on the iron tower, improving the stress condition of the iron tower, and improving the reliability of the iron tower.

[0009] The technical solution of the present invention is: a double-circuit pole tower split transposition device, including a main tower, the main tower is provided with an upper crossarm, a middle crossarm and a lower crossarm, a middle-phase-changing upper-phase jumper is provided between the upper crossarm and the middle crossarm located at the same side end, a lower-phase-changing middle-phase jumper is provided between the middle crossarm and the lower crossarm located at the same side end, auxiliary towers are respectively provided on both sides of the main tower, the auxiliary towers are provided with an upper crossarm and a lower crossarm close to the main tower side, and an upper-phase-changing lower-phase jumper is provided between the upper crossarm and the lower crossarm.

[0010] Furthermore, jumper racks are respectively provided on both sides of the upper crossarm, the middle crossarm and the lower crossarm, and wire hanging plates are respectively provided on the front and rear sides of the jumper racks, and insulating strings for connecting phase lines are installed on the wire hanging plates.

[0011] Furthermore, one end of the phase jumper on the middle phase transformer is connected to the phase line connected to the rear side of the middle crossarm, and is connected to the phase line connected to the front side of the upper crossarm via a squirrel cage jumper arranged between the upper crossarm and the middle crossarm.

[0012] Furthermore, one end of the phase jumper in the lower phase transformer is connected to the phase line connected to the rear side of the lower crossarm, and is connected to the phase line connected to the front side of the middle crossarm via a squirrel cage jumper arranged between the middle crossarm and the lower crossarm.

[0013] Furthermore, jumper strings for hanging and fixing squirrel cage jumpers are respectively provided on the lower side of the upper cross arm, the upper and lower sides of the middle cross arm, and the upper side of the lower cross arm.

[0014] Furthermore, one end of the upper phase-to-lower phase jumper is connected to the phase line connected to the rear side of the upper crossarm via an upper lap jumper, and the other end of the upper phase-to-lower phase jumper is connected to the phase line connected to the rear side of the lower crossarm via a lower lap jumper.

[0015] Furthermore, jumper racks are respectively provided on the front and rear sides of the upper cross arm and the lower cross arm, and jumper strings for hanging and fixing upper phase-to-lower phase jumpers are provided on the jumper racks.

[0016] Furthermore, the main tower is an umbrella-shaped or drum-shaped structure; the auxiliary tower is an F-shaped structure, and the supporting legs of the auxiliary tower are unequal-length leg-connecting structures, and the center of the auxiliary tower is 30-40m away from the center of the main tower.

[0017] A method for installing a double-circuit tower split transposition device comprises the following steps:

[0018] (1) Install auxiliary towers on both sides of the existing main tower and control the center distance between the auxiliary tower and the main tower;

[0019] (2) Connect the phase line connected to the rear side of the lower cross arm of the main tower with the phase line connected to the front side of the middle cross arm through the lower phase transformer middle phase jumper; and connect the phase line connected to the rear side of the middle cross arm of the main tower with the phase line connected to the front side of the upper cross arm through the middle phase transformer upper phase jumper;

[0020] (3) Connect the phase line connected to the rear side of the upper cross arm of the main tower to the upper rear part of the upper phase transformer lower phase jumper installed on the auxiliary tower through a jumper, and connect the lower front part of the upper phase transformer lower phase jumper to the phase line connected to the front side of the lower cross arm of the main tower through a jumper.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] The device is composed of a main tower and an auxiliary tower. The main tower is used for hanging the main line to reduce the occupation of corridor resources. The auxiliary tower is used for jumper winding. The jumper layout is simple and the jumper gap is controllable. The height of the tower is reduced or the size of the main tower cross arm is shortened by nearly 50%, which greatly reduces the cross arm torque, thereby reducing the torque and bending moment of the ground wire on the tower and improving the stress condition of the tower. Combined with the lower cross arm structure design, the load superposition of the upward wind caused by complex forms such as strong vertical shear at low altitude, strong convection zone, strong amplitude, and strong vertical movement is considered to improve the reliability of the transposition tower and facilitate operation and maintenance. In summary, although the auxiliary tower will increase a small amount of construction cost, it can improve the overall reliability of the line and reduce the occupation of corridor resources at the same time, and has good application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention;

[0024] Figure 2 For the present invention Figure 1 II sectional view;

[0025] Figure 3 For the present invention Figure 1 II-II sectional view;

[0026] Figure 4 It is a structural diagram of a 500kV double-circuit transposition jumper transposition device of the present invention;

[0027] In the figure: 10-ground wire 100-main tower 110-upper cross arm 120-middle cross arm 130-lower cross arm 140-middle phase transformer upper phase jumper 150-lower phase transformer middle phase jumper 160-jumper rack 170-insulating string 180-squirrel cage jumper 190-jumper string 200-auxiliary tower 210-upper cross arm 220-lower cross arm 230-upper phase transformer lower phase jumper 231-upper lap jumper 232-lower lap jumper 233-vertical conductor 234-horizontal conductor 240-jumper rack 250-jumper string. DETAILED DESCRIPTION

[0028] In order to make the above features and advantages of the present invention more easily understood, embodiments are given below with reference to the accompanying drawings for detailed description, but the present invention is not limited thereto.

[0029] refer to Figures 1 to 4

[0030] A double-circuit pole tower split transposition device comprises a main tower 100, wherein the main tower is provided with an upper cross arm 110, a middle cross arm 120 and a lower cross arm 130, a middle phase-to-upper phase jumper 140 (B phase) is provided between the upper cross arm and the middle cross arm located at the same side end, and a lower phase-to-middle phase jumper 150 (C phase) is provided between the middle cross arm and the lower cross arm located at the same side end, auxiliary towers 200 are provided on both sides of the main tower, and an upper cross arm 210 and a lower cross arm 220 are provided on the auxiliary tower near the main tower side, and an upper phase-to-lower phase jumper 230 (A phase) is provided between the upper cross arm and the lower cross arm.

[0031] In this embodiment, jumper racks 160 are respectively provided on both sides of the upper cross arm, the middle cross arm and the lower cross arm, and wire hanging plates are respectively provided on the front and rear sides of the jumper racks. Insulating strings 170 for connecting phase lines are installed on the wire hanging plates.

[0032] In this embodiment, one end of the upper phase jumper of the middle phase transformer is connected to the phase line connected to the rear side of the middle crossarm through an insulating string, and is connected to the phase line connected to the front side of the upper crossarm through an insulating string via a squirrel cage jumper 180 arranged between the upper crossarm and the middle crossarm.

[0033] In this embodiment, one end of the phase jumper in the lower phase transformer is connected to the phase line connected to the rear side of the lower crossarm through an insulating string, and is connected to the phase line connected to the front side of the middle crossarm through an insulating string via a squirrel cage jumper arranged between the middle crossarm and the lower crossarm.

[0034] In this embodiment, jumper strings 190 for hanging or fixing the squirrel cage jumper are respectively provided on the lower side of the upper crossarm, the upper and lower sides of the middle crossarm, and the upper side of the lower crossarm, thereby achieving fixed positioning of the squirrel cage jumper.

[0035] In this embodiment, one end of the upper phase-to-lower phase jumper is connected to the phase line connected to the rear side of the upper crossarm through an upper jumper 231, and the other end of the upper phase-to-lower phase jumper is connected to the phase line connected to the rear side of the lower crossarm through a lower jumper 232.

[0036] In this embodiment, jumper racks 240 are respectively provided on the front and rear sides of the upper crossarm and the lower crossarm, and the upper phase-to-lower phase jumper includes a jumper string suspended on the lower side of the jumper rack of the upper crossarm and a jumper string 250 fixed on the upper side of the jumper rack of the lower crossarm. The upper and lower jumper strings on the front side and the upper and lower jumper strings on the rear side are respectively connected via vertical wires 233, and the two vertical wires are connected via horizontal wires 234.

[0037] In this embodiment, the height of the lower jumper hanging point of the auxiliary tower makes the upper end of the jumper string located on the lower side the same height as the hanging point of the main tower, and the height of the upper jumper hanging point of the auxiliary tower makes the lower end of the jumper string located on the upper side and suspended the same height as the conductor of the upper crossarm. The length of the auxiliary tower jumper crossarm is controlled according to the distance requirement of the jumper windage to the tower body.

[0038] In this embodiment, both sides of the upper end of the main tower are also connected to the ground wire 10 respectively.

[0039] In this embodiment, the main tower adopts a conventional tension tower or corner tower style, and the main tower is an umbrella-shaped or drum-shaped structure; according to the layout requirements of the jumper, the auxiliary tower is an F-shaped structure; and the supporting legs of the auxiliary tower adopt an all-round unequal length leg structure, and the long and short leg configuration can meet the requirement of basically no base surface opening under the terrain conditions of this project.

[0040] In this embodiment, the center of the auxiliary tower is 30-40m away from the center of the main tower, and the height of the tower is determined according to the terrain elevation at the location of the auxiliary tower.

[0041] In this embodiment, the front side is the wire output direction, and the rear side is the wire input direction.

[0042] In this embodiment, the electrical clearance between the live part of the jumper and the grounding structure such as the tower body meets the requirements of the corresponding design specifications. The minimum clearance (m) is as follows:

[0043]

[0044] Note: For the 500kV air gap column, the data on the left is applicable to altitudes not exceeding 500m, and the data on the right is applicable to altitudes between 500-1000m.

[0045] For details, please refer to the 500kV double circuit tower split transposition device. Figure 4 , where the jumper sag and line length are as follows:

[0046] .

[0047] A method for installing a double-circuit tower split transposition device comprises the following steps:

[0048] (1) Install auxiliary towers on both sides of the existing main tower and control the center distance between the auxiliary tower and the main tower;

[0049] (2) Connect the phase line connected to the rear side of the lower cross arm of the main tower with the phase line connected to the front side of the middle cross arm through the lower phase transformer middle phase jumper; and connect the phase line connected to the rear side of the middle cross arm of the main tower with the phase line connected to the front side of the upper cross arm through the middle phase transformer upper phase jumper;

[0050] (3) Connect the phase line connected to the rear side of the upper cross arm of the main tower to the upper rear part of the upper phase transformer lower phase jumper installed on the auxiliary tower through a jumper, and connect the lower front part of the upper phase transformer lower phase jumper to the phase line connected to the front side of the lower cross arm of the main tower through a jumper.

[0051] In this embodiment, the overlapping jumpers between the auxiliary tower and the main tower, the upper transformer and lower jumper strings of the auxiliary tower, and the jumper strings in the upper and lower transformers of the middle transformer on the main tower all take into account the structural load effects under the superposition of lateral wind and upward wind, and consider the disturbance deformation of the tower structure under the load, the structural effects caused by the above-mentioned connection structure, and verify the electrical clearance.

[0052] The above description is only a preferred embodiment of the present invention. For ordinary technicians in this field, according to the teachings of the present invention, designing different forms of double-circuit pole tower split transposition devices does not require creative labor. Without departing from the principle and spirit of the present invention, all equal changes, modifications, substitutions and variations made within the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A double-circuit tower split transposition device, comprising a main tower, characterized in that: The main tower is provided with an upper cross arm, a middle cross arm and a lower cross arm, a middle phase-to-upper phase jumper is provided between the upper cross arm and the middle cross arm at the same side end, a lower phase-to-middle phase jumper is provided between the middle cross arm and the lower cross arm at the same side end, auxiliary towers are provided on both sides of the main tower, the auxiliary tower is provided with an upper cross arm and a lower cross arm close to the main tower, an upper phase-to-lower phase jumper is provided between the upper cross arm and the lower cross arm; the main tower is an umbrella-shaped or drum-shaped structure; the auxiliary tower is an F-shaped structure, and the supporting legs of the auxiliary tower are unequal-length leg-connecting structures, and the center of the auxiliary tower is 30-40m away from the center of the main tower; the upper cross arm, the middle cross arm and the lower cross arm are provided on both sides respectively A jumper rack is provided, and a conductor hanging plate is respectively arranged on the front and rear sides of the jumper rack, and an insulating string for connecting the phase line is installed on the conductor hanging plate; one end of the upper phase jumper of the middle phase transformer is connected to the phase line connected to the rear side of the middle crossarm, and is connected to the phase line connected to the front side of the upper crossarm via a squirrel cage jumper arranged between the upper crossarm and the middle crossarm; one end of the middle phase jumper of the lower phase transformer is connected to the phase line connected to the rear side of the lower crossarm, and is connected to the phase line connected to the front side of the middle crossarm via a squirrel cage jumper arranged between the middle crossarm and the lower crossarm; jumper strings for hanging and fixing squirrel cage jumpers are respectively arranged on the lower side of the upper crossarm, the upper and lower sides of the middle crossarm, and the upper side of the lower crossarm.

2. The double-circuit tower split transposition device according to claim 1, characterized in that: One end of the upper phase-to-lower phase jumper is connected to the phase line connected to the rear side of the upper crossarm via an upper lap jumper, and the other end of the upper phase-to-lower phase jumper is connected to the phase line connected to the rear side of the lower crossarm via a lower lap jumper.

3. The double-circuit tower split transposition device according to claim 1 or 2, characterized in that: Jumper racks are respectively arranged at the front and rear sides of the upper cross arm and the lower cross arm, and jumper strings for hanging and fixing upper phase-to-lower phase jumpers are arranged on the jumper racks.

4. An installation method for the split-type transposition device for double-circuit towers according to claim 1, characterized in that: The following steps are involved: (1) Install auxiliary towers on both sides of the existing main tower and control the center distance between the auxiliary tower and the main tower; (2) Connect the phase line connected to the rear side of the lower cross arm of the main tower with the phase line connected to the front side of the middle cross arm through the lower phase transformer middle phase jumper; and connect the phase line connected to the rear side of the middle cross arm of the main tower with the phase line connected to the front side of the upper cross arm through the middle phase transformer upper phase jumper; (3) Connect the phase line connected to the rear side of the upper cross arm of the main tower to the upper rear part of the upper phase transformer lower phase jumper installed on the auxiliary tower through a jumper, and connect the lower front part of the upper phase transformer lower phase jumper to the phase line connected to the front side of the lower cross arm of the main tower through a jumper.

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