CN102296864A - Novel tower for extra-high voltage dual-circuit compact transmission - Google Patents

Abstract

The present invention provides a new type of tower for ultra-high voltage double-circuit compact transmission lines on the same tower, which consists of: upper side cross arm, V-type insulator string, I-type straight string, lower phase flexible insulator, lower side cross arm Composed with the tower body, it is characterized in that: two rounds of 6-phase UHV grade conductors are hung between the upper cross arm and the lower cross arm; the upper two phase conductors are suspended on the same cross arm, and the cross arm has no side crank arm The lower phase wire is fixed by pulling force applied from the opposite direction by the upper and lower insulators; the lower insulator for fixing the lower phase wire adopts a flexible insulator, which not only makes the wire have a certain elastic space, but also controls the lateral displacement of the wire. The novel tower structure of the present invention removes the lower bending arm, which avoids the possibility of the lower bending arm being bent, deformed or even broken under heavy load conditions; The active space controls the lateral displacement of the conductor.

Description

A new type of tower for UHV same-tower double-circuit compact power transmission

technical field

The invention relates to a new type of tower used for ultra-high voltage double-circuit compact power transmission on the same tower, which belongs to the field of power system transmission line pole tower design, and especially relates to 1000kV and above ultra-high voltage level double-circuit compact power transmission lines on the same tower supporting three-phase conductors The design scheme of the tower structure that forms the insulation gap.

Background technique

In order to reduce the cost of electric energy transmission and reduce the land occupation of transmission corridors, the use of UHV-grade lines and compact power transmission methods are two very effective ways. Therefore, UHV power transmission and compact power transmission are regarded as long-distance The optimal solution for large-capacity power transmission. According to the needs of long-distance transmission of electric energy in my country, my country has vigorously promoted the construction of UHV power grids in recent years. At present, a 1000kV UHV test demonstration project has been built and put into operation, and research on UHV transmission technology is also deepening; compact transmission lines Through the optimized arrangement of the wires, the three-phase wires are placed in the same tower window, and there is no grounding component between the three-phase wires, so as to increase the natural transmission power, reduce the width of the line corridor, and increase the transmission capacity of the unit corridor. In recent years, with the increasing shortage of land resources in our country, compact lines have also been vigorously developed in our country. 500kV single-circuit and double-circuit compact lines have been widely used and standardized. In 2008, Northwest Power Grid Corporation completed the key technology research work of 750kV single-circuit and double-circuit compact lines. In order to build a resource-saving and environment-friendly power grid in our country, the State Grid Corporation of China continues to promote the research and engineering construction of UHV power grids, and proposes a plan for the construction of UHV compact transmission lines.

Since the three-phase conductors of the compact line are arranged in the same tower window, there is no supporting frame between the phases, and the gravity load of the conductors is all concentrated on the outer tower window, so that the overall structure size of the tower window is significantly larger than the size of the tower frame of the conventional line, and the tower window steel The mechanical strength requirements of the frame are higher. For ultra-high voltage compact lines, the number of wire splits increases, the volume and weight of the metal body further increase, and the insulation distance between the wires and the frame and between wires increases. The distance between conductors can reach 14m to 15m, and the ultra-high voltage compact tower window covering three-phase conductors has a huge structure, a large mechanical load on the structure, and a large investment in the tower. Therefore, when designing UHV compact tower windows, it is necessary to optimize the structural size of the tower while ensuring the bearing strength and electrical insulation strength of the tower to reduce the construction cost of the UHV compact line.

As shown in Figure 1, at present, the double-circuit compact poles and towers of the same tower in my country adopt T-shaped structures. The included angle of phase V strings is usually in the range of 130° to 140°, resulting in the tension along the insulator strings being twice that of the insulators of the upper phase V strings (with an included angle of 85° to 95°). In order to ensure that the lower bending arm is not deformed by tension, the design size is usually larger, which increases the cost of the tower. If the ultra-high voltage double-circuit compact tower with the same tower still uses this type of tower, the design size of the lower bending arm of the T-shaped tower will be significantly increased to ensure sufficient bearing capacity, and the ability to resist heavy loads such as strong winds and repeated ice poor. For this reason, in view of the load and conductor arrangement characteristics of UHV double-circuit compact towers on the same tower, further innovations are needed on the basis of existing tower structures to meet the needs of subsequent UHV project construction in my country.

Contents of the invention

The purpose of the present invention is: in view of the large design size and high cost of the existing double-circuit compact tower with the same tower, and the poor ability to resist heavy loads such as strong winds and repeated ice, the present invention proposes a UHV A new tower type for double-circuit compact power transmission on the same tower. While ensuring the load-bearing strength and electrical insulation strength of the tower, this tower type optimizes the structural size of the tower, which can reduce the construction cost of UHV compact lines.

The technical solution of the present invention is: a new type of tower for UHV same-tower double-circuit compact transmission line, which consists of: upper side cross arm, V-shaped insulator string, I-type straight string, lower phase flexible insulator, Composed of the lower cross arm and the tower body, it is characterized in that:

1) Two circuits of 6-phase UHV grade conductors are hung between the upper cross-arm and the lower cross-arm;

2) The two-phase wires on the upper side are suspended on the same cross arm, and the cross arm has no side crank arm;

3) The lower phase wire is fixed by pulling force applied from opposite directions by the upper and lower insulators;

4) The lower insulator for fixing the lower phase wire adopts a flexible insulator, which not only makes the wire have a certain elastic space, but also controls the lateral displacement of the wire.

The beneficial effects of the present invention are: compared with the conventional T-shaped tower structure, the novel tower structure of the present invention removes the lower bending arm, which avoids the possibility of the lower bending arm being bent, deformed or even broken under heavy load conditions; the lower side increases In order to fix the cross arm of the lower phase conductor, although the amount of tower material is increased to a certain extent, because the cross arm mainly limits the range of movement of the conductor in the horizontal direction and upward, and the load is small, the design structure size is also small; in addition , The lower side insulator that fixes the lower phase wire adopts a flexible insulator, which not only makes the wire have a certain elastic space, but also controls the lateral displacement of the wire. Therefore, according to the characteristics of the ultra-high voltage double-circuit compact line, the tower type comprehensively considers the arrangement of the UHV compact three-phase conductors, the volume of the tower, and the safety of the tower under heavy loads. Compared with the existing double-circuit compact The tower type has innovations in the upper side beam structure and the lower phase wire string type.

Description of drawings

Fig. 1 is a structural schematic diagram of a double-circuit compact T-shaped tower in the prior art.

Fig. 2 is a schematic structural diagram of a new type of tower for UHV same-tower double-circuit compact power transmission according to an embodiment of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Notes in Figure 1: 1-beam, 2-lower curved back, 3-tower body, 4-upper-phase v-string, 5-lower-phase v-string.

Marking description in Figure 2: 6-upper side cross arm, 7-V-type insulator string, 8-I type medium straight string, 9-lower phase flexible insulator, 10-lower side cross arm, 11-tower body.

The novel tower structure design scheme of the embodiment of the present invention is shown in FIG. 2 . The material of this tower type is angle steel. A round of (A, B, C three-phase) conductors are suspended between the upper and lower layers of cross arms on both sides of the tower, in an inverted triangle distribution. The pole tower is divided into upper and lower layers of cross arms. The upper cross arm 6 hangs V-shaped insulator strings 7 of two-phase conductors and I-type straight strings 8 of the lower phase conductors. The lower cross arm 10 fixes the lower phase conductors through inverted V-shaped strings to reduce the In Type I, the straight-series conductor has a large lateral swing, and the problem of jumping off the ice in the vertical direction. Compared with the conventional double-circuit compact T-shaped tower, the cross arm for suspending the upper phase conductor cancels the side lower bending arm, which avoids the problem that the side bending arm is easy to be bent and deformed by overload, and the stability of the cross arm is significantly enhanced. The lower phase flexible insulator 9 that fixes the lower phase wire adopts a flexible insulator, so that the wire has a certain elastic space, and the lateral swing range of the wire is controlled.

Compared with the conventional T-shaped tower structure, the new tower structure removes the lower bending arm, which avoids the possibility of the lower bending arm being bent, deformed or even broken under heavy load conditions. A cross arm for fixing the lower phase conductor is added on the lower side. Although the amount of tower material is increased to a certain extent, because the cross arm mainly limits the range of movement of the conductor in the horizontal direction and upward, and the load is small, the design structure size is also relatively small. Small.

Therefore, according to the characteristics of the UHV double-circuit compact line, this tower type comprehensively considers the arrangement of the UHV compact three-phase conductors, the volume of the tower, and the safety of the tower under heavy loads. Compared with the existing double-circuit compact tower The model has innovations in the structure of the upper beam and the string type of the lower phase wire.

Claims (1)

1. novel tower that is used for the extra-high voltage same tower double circuit compact transmission line, its by in upside cross-arm, V-type insulator string, the I type directly string,, phase flexible insulation, downside cross-arm and body of the tower are formed down, it is characterized in that:

1) mounts twice 6 phase extra-high voltage grade leads between upper strata cross-arm and the lower floor's cross-arm;

2) upside two phase conductors hang on the same cross-arm, and this cross-arm does not have side and cranks arm;

3) descending phase conductor to apply pulling force the other way around by upper and lower insulator fixes;

4) the fixing downside insulator of phase conductor has down adopted flexible insulation, has both made lead that certain elasticity activity space is arranged, and has controlled the lateral displacement of lead again.

Images