CN101882775B - Composite material pole tower outside vertical grounding led-down method and pole tower thereof - Google Patents

Abstract

The invention relates to a method for vertically directing the outer side of a composite material pole tower and the pole tower thereof. In this invention, a section of grounding down-conductor metal cross-arm is erected on the extension line of a certain side of the grounding cross-arm, and the end of the metal cross-arm vertically leads down the grounding down-conductor, and the grounding down-conductor is under the lower phase conductor A certain distance is connected to the pole tower through the metal cross arm of the corresponding grounding down conductor, and finally the grounding down conductor is grounded along the tower body. The cross arm is connected to the steel pipe for grounding. This invention is beneficial to compressing the width of the transmission corridor to the maximum, and at the same time, it is beneficial to the lightning protection design, avoiding the short-circuiting of the grounding down-conductor to the composite material tower body, and exerting the insulating effect of the composite material tower body. The single-sided grounding down-conductor is more Material saving, economical, simple structure, easy to realize.

Description

A method for vertically direct grounding the outer side of a composite material tower and its tower

technical field

The invention relates to a method for vertically directing the outer side of a composite material pole tower and the pole tower thereof, and belongs to the application field of power transmission technology in electric power systems.

Background technique

The tower is an important equipment of the transmission line, and the characteristics of the materials used directly affect the safety, economy and reliability of the line operation. Because steel has the advantages of high strength-to-weight ratio, easy processing and installation, most of the high-voltage grades at home and abroad currently use all-steel towers. However, the all-steel tower also has defects such as high quality (higher steel density) and easy corrosion, so it needs to invest a lot of manpower and material resources in the construction, transportation and maintenance of the tower. With the development of composite material production technology and its manufacturing process, composite materials have the characteristics of light weight, high strength, corrosion resistance, high and low temperature resistance, good durability and strong insulation, which makes composite material towers have low transportation costs (especially It is in sparsely populated mountainous areas), anti-fouling, anti-corrosion and other advantages, and has a good application prospect. At present, composite towers have been widely used in parts of Canada and the United States.

However, when Canada and the United States use composite towers, the problem of lightning protection is not considered. The main reason is that the area where the line using composite material towers passes is a less minefield (because Canada and some parts of the United States are in winter all year round, the thunderstorm days in these areas are very small). In addition, most of the lines using composite material towers in Canada and the United States have a voltage level below 110kV. These voltage level systems are center point ungrounded systems, and the voltage level is low, so lightning faults have little impact on the system.

At present, my country's line towers mainly use reinforced concrete, wood, steel and other materials (110kV and above voltage level lines usually use all-steel towers). At 110kV and above voltage level). Due to the problems in these areas: large investment in line corridors, intensive lightning activities, and serious pollution, the main purpose of using composite material towers in my country is to compress the width of transmission corridors (referring to reducing the maximum distance between transmission line conductors). Horizontal distance), lightning protection (refers to reducing the failure rate of lightning strikes) and anti-pollution (referring to reducing the failure rate of power frequency pollution flashover by increasing the creepage distance of pollution flashover), etc.

It is the composite material tower that is facing the problem of lightning protection, so it is necessary to erect a lightning protection line (because Canada and the United States did not consider the problem of lightning protection when using composite material towers, so the lightning protection line was not erected), and in order to release the lightning strike lightning line ( Also known as "ground wire") or the lightning energy at the top of the tower, in order to improve the lightning resistance level of the line and reduce the lightning failure rate of the line, it is necessary to ground the towers of composite materials tower by tower.

Therefore, in areas with intensive lightning activities, the application of transmission line composite material towers has the problem of grounding (the all-steel tower is a metal conductor, and the ground wire is directly connected to the earth through the tower body, so there is no longer To consider the problem of grounding down), there are many different methods for grounding down, the method of grounding down will directly affect the lightning protection effect of the composite material tower, and also affect the transmission corridor width compression and antifouling of the line. , so the grounding method of composite material tower is the key technology and difficulty that needs to be solved first in its application.

Contents of the invention

In order to solve the above problems, the present invention provides a method for vertically directing the outer side of a composite material tower and its tower. This invention can give full play to the insulation effect of the composite material tower body, so that the composite material tower can be compressed in the width of the transmission corridor, prevent Lightning and anti-pollution and other electrical performance reflect its value and advantages.

The technical solution of the present invention is: a method for vertically direct down-conducting the outer side of a composite material pole tower, characterized in that a section of metal cross-arm on the grounding down-conductor is erected on the extension line of a certain side of the grounding cross-arm, and the metal cross-arm The end of the pole leads vertically to the grounding down-conductor. The grounding down-conductor is connected to the tower through the metal cross-arm of the corresponding grounding down-conductor at a certain distance below the lower phase conductor. Finally, the grounding down-conductor is grounded along the tower body. If the lower part of the tower body is a steel pipe, the grounding down conductor can be directly connected to the steel pipe through the metal cross arm under the grounding down conductor to ground.

The above-mentioned method for vertically direct grounding on the outside of a composite material tower is characterized in that two sections of metal cross-arms on the grounding down-conductor are erected on the extension lines of both sides of the grounding cross-arm, and the two sections are grounded at the same time. The end of the metal cross-arm on the down-conductor vertically leads two grounding down-conductors.

The above-mentioned method for vertically direct grounding on the outside of a composite material tower is characterized in that: the grounding down conductor and the composite material pole tower can be supported by insulating rods or composite insulators to ensure that the grounding down conductor withstands the load during operation. No large bending deformation will occur under the action of strong wind and other stresses.

A composite material pole tower directly grounded on the outside, which is characterized in that: a section of metal cross-arm on the grounding down-conductor is erected on the extension line of a certain side of the grounding cross-arm, and the end of the metal cross-arm is vertically connected to the grounding conductor. The grounding down conductor is connected to the tower through the metal cross arm of the corresponding grounding down conductor at a certain distance below the lower phase conductor, and finally the grounding down conductor is grounded along the tower body. If the lower part of the tower body is a steel pipe, the grounding The down-conductor can be directly connected to the steel pipe through the metal cross-arm of the grounding down-conductor to ground.

The outer vertically grounded composite material pole tower as described above is characterized in that: two sections of metal cross-arms on grounding down-conductors are erected on the extension lines of both sides of the grounding cross-arm, and at the same time, the two sections of grounding down-conducting lines Two grounding down-conductors are vertically led down from the end of the metal cross-arm.

The outer vertically grounded composite material pole tower as described above is characterized in that: the grounding downconductor and the supporting part of the composite material pole tower are insulating rods or composite insulators.

The beneficial effects of the present invention are:

(1) It is beneficial to compress the width of the transmission corridor. The width of the transmission corridor of the line affects the tripping rate of lightning flashover between phases or the double-circuit simultaneous lightning tripping rate of the line.

(2) Conducive to lightning protection design. By adjusting the minimum gap distance between the grounding down conductor and the near-side conductor to control the lightning impact insulation strength of the line's primary conductor to the ground, so as to control the single-circuit tripping rate, and because of this unilateral grounding down conductor The two circuits of the line are unbalanced insulation, and the double circuit simultaneous lightning tripping rate of the line has been greatly reduced.

(3) It avoids the short-circuiting of the grounding down-conductor to the composite material tower body, and exerts the insulation effect of the composite material tower body, which increases the creepage distance of the wire to the ground and enhances its ability to withstand industrial pollution flashover;

(4) Avoiding the inconvenient impact on life when the grounding down-conductor is pulled to the ground;

(5) Since the line adopts a unilateral grounding down conductor, it is more material-saving and economical;

(6) The structure is simple and easy to realize.

Description of drawings

Fig. 1 is a front view of a single-sided grounding downconductor in an embodiment of the present invention.

Fig. 2 is a front view of a single-sided grounding downconductor in an embodiment of the present invention.

Fig. 3 is a front view of a double-sided grounding downconductor in an embodiment of the present invention.

Fig. 4 is a front view of a double-sided grounding downconductor in an embodiment of the present invention.

Detailed ways

Figures 1 and 3 mark instructions: 1-ground cross arm, 2-metal cross arm on ground down conductor, 3-ground down conductor, 4-metal cross arm under ground conductor, 5-composite insulator, 6 -Cross-arm fittings, 7-tower body part of the tower head, 8-ground wire, 9-near side wire, 10-far side wire, 11-lower phase wire, 12-lower part of the tower body, 13-lower part of the tower body .

In the present invention, a section of metal cross-arm 2 on the grounding down-conductor is erected on the extension line of a certain side of the grounding cross-arm 1, and the end of the metal cross-arm 2 vertically leads down the grounding down-conductor 3, and the grounding down-conductor 3 The minimum air gap distance from the proximal conductor is D ₁ (the value of D ₁ is determined by lightning protection calculation)), and the grounding downconductor 3 is connected by the corresponding grounding downconductor lower metal cross-arm 4 at a certain distance below the lower phase conductor to the tower

When erecting two sections of grounding down-conductors, connect the grounding cross-arm 1 on the extension lines on both sides to lead out the metal cross-arms 2 of two sections of grounding down-conductors (the length of the left grounding down-conductor is D 1 , and the length of the right grounding down-conducting line is D ₁ ). The length of D ₂ is D 2 , and the values of D ₁ and D ₂ are determined by lightning protection calculations), the ends of the metal cross-arm 2 on the two grounding down-conductors vertically lead down two grounding down-conductors 3, and the two grounding down-conductors The down conductor 3 is connected to the pole tower through the other two corresponding grounding down conductor lower metal cross arms 4 at a certain distance _D3 below the lower phase conductor 12 .

Since the tower body part of the tower head is made of insulating composite materials, the width of the line corridor is not controlled by the relative ground insulation requirements, but only by the phase-to-phase insulation requirements of two conductors at the same level. Therefore, the line corridor width can be greatly reduced. Since the grounding down-conductor does not pass through the tower body, the short-circuiting of the grounding down-conductor to the composite material tower body is avoided, and the insulation effect of the composite material tower body is played, so that the creepage distance of the wire to the ground is increased, and its work resistance is enhanced. The ability to strobe.

The present invention can also adjust the minimum air gap distance between the grounding downconductor and the near side conductor by adjusting the lengths of _D1 and _D2 according to the law of lightning activity in the area where the line is located, so as to control the single-circuit lightning tripping rate of the line, The double-circuit simultaneous tripping rate of the line is related to the corridor width of the line.

After the two grounding down conductors 3 under the vertical lead are connected to the metal cross arm 4 under the grounding down conductor, the grounding down conductor 3 is connected to the ground along the tower body. If the composite material tower is made of composite material for the tower head and the remaining part If steel pipes are used, as long as the metal cross arm 4 under the grounding downconductor is a steel pipe fixed on the remaining part, it can be directly connected to the earth through the steel pipe tower body, thereby avoiding that the grounding downconductor 3 is directly vertically pulled to the ground. , Inconvenient impact on life.

The metal cross-arm 2 on the grounding down-conductor and the metal cross-arm 4 under the grounding down-conductor also play the role of supporting the grounding down-conductor 3 under the vertical lead, so that the grounding down-conductor 3 will not be damaged under stresses such as strong winds. Larger bending deformation will occur, and the grounding down conductor 3 should adopt a conductor with high strength and is not easy to deform. It is separated from the composite material pole tower; it is also possible to add support composite insulators 5 on the conductor cross-arm to support the two grounding down-conductors 3 and the conductors.

In general, the structure of the grounding downconduction method of the composite material tower is intuitive, simple and clear, and easy to realize. Compared with the double-sided grounding down-conductor, the unilateral grounding down-conductor is used, which is more material-saving and economical. However, if the unilateral grounding down conductor is used, the line corridor width is limited by the simultaneous tripping rate of double circuits, so it is not suitable for extreme compression.

Claims (4)

1. A method for vertically direct down-conducting the outer side of a composite material tower, characterized in that: a section of grounding down-conductor metal cross-arm is erected on the extension line of a certain side or both sides of the grounding cross-arm, and each metal cross-arm The end leads down the grounding down-conductor vertically, and the grounding down-conductor is connected to the tower through the metal cross-arm of the corresponding grounding down-conductor at a certain distance below the lower phase conductor, and finally the grounding down-conductor is grounded along the tower body. The lower part is a steel pipe, and the grounding down conductor is directly connected to the steel pipe through the metal cross arm under the grounding down conductor to ground. 2. The method for vertically and directly grounding the outer side of a composite material pole tower according to claim 1, characterized in that: the grounding downconductor and the composite material pole tower are supported by insulating rods or composite insulators to ensure that the grounding downconductor is in the No large bending deformation will occur when subjected to strong wind stress during operation. 3. A composite material pole tower vertically grounded on the outside, characterized in that: a section of grounding down-conductor metal cross-arm is erected on the extension line of a certain side or both sides of the ground wire cross-arm, and the vertical pole at the end of each metal cross-arm The grounding down-conductor is directly led down, and the grounding down-conductor is connected to the tower through the metal crossarm of the corresponding grounding down-conductor at a certain distance below the lower phase conductor, and finally the grounding down-conductor is grounded along the tower body. If the lower part of the tower body It is a steel pipe, and the grounding down conductor is directly connected to the steel pipe through the metal cross arm under the grounding down conductor to ground. 4. The outer vertically grounded composite material pole tower according to claim 3, characterized in that: an insulating rod or a composite insulator is used to support the grounding downconductor and the composite material pole tower.

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