CN201430402Y

CN201430402Y - Connection system for tower and ground wires

Info

Publication number: CN201430402Y
Application number: CN2009200909555U
Authority: CN
Inventors: 庞可; 李本良; 张天光; 刘玉孝; 邹军; 唐明贵
Original assignee: Hennan Electric Power Survey and Design Institute
Current assignee: Hennan Electric Power Survey and Design Institute
Priority date: 2009-06-19
Filing date: 2009-06-19
Publication date: 2010-03-24
Anticipated expiration: 2019-06-19

Abstract

The utility model discloses a connection system for a transmission tower and ground wires. The system comprises the transmission tower, as well as an ordinary ground wire and a composite fiber-optic overhead ground wire which are arranged on two sides at the top end of the tower, the composite fiber-optic overhead ground wire is fixed on one side of the tower through a ground wire insulator string, the connection part of the composite fiber-optic overhead ground wire is connected with a strain wire clamp, and the strain wire clamp is fixed on the tower. The construction of the utility model involves fixing the composite fiber-optic overhead ground wire onto the tower through the ground wire insulator string, and in doing so the composite fiber-optic overhead ground wire is insulated segment by segment through the ground wire insulator string and is only grounded at the connection part of two neighboring composite fiber-optic overhead ground wire coils, together with the tower through the strain wire clamp. The utility model can also apply to a fiber-optic composite insulator which can be insulated segment by segment and grounded at one point, rather than being subject to the traditional method, e.g. being grounded tower by tower. The utility model has the advantages of reducing the occurrence of circumfluence arising in the ground wires, greatly reducing loss, and curtailing the cost of electrical production.

Description

A kind of shaft tower ground wire connected system

Technical field

The utility model relates to the earth system in a kind of ultra-high-tension power transmission line, relates in particular to a kind of shaft tower of transmission losses and connected system of ground wire of reducing.

Background technology

When transmission line normally moves, can flow through certain induced current in the ground wire, thereby cause electric energy loss.The proportion in the electrical network total losses of the loss of ground wire in the past is little, the concern that is subjected to is less, but along with the continuous development of electrical network and the continuous expansion of transmission capacity, the loss that ground wire causes in the electric power system is also increasing, by domestic present domestic electric power total capacity estimation, the annual ground wire electric energy loss in the whole nation will reach 10,000,000,000 kilowatt hours, so ground wire power-saving technology particular importance in transmission line.

Ground wire is high pressure and the most basic lightning protection measures of extra high voltage network, and it can prevent thunder direct attack transmission line; Can reduce the lightning current that flows into shaft tower by shunting action, thereby the cat head current potential is descended, with the safe operation of protection high-tension line lightning current.In addition can be by the coupling on the lead being reduced the voltage on the line insulation; Can be used for reducing the induced voltage on the lead by Pingdong to lead; Power-frequency overvoltage when reducing unsymmetrical short-circuit, reduce secondary arc current; As shielding conductor to reduce the interference of power line to order wire.The ground wire of at present domestic 500KV transmission line is that optical cable is formed by a common ground wire and an Optical Fiber composite overhead Ground Wire mostly, and for the consideration of circuit leakage current under short circuit or thunderbolt situation, optical cable adopts the operational mode by tower ground connection usually.

The operational mode of earthed circuit has two kinds at present:

One, as shown in Figure 2, common ground wire graded insulation one point earth, optical cable is by tower ground connection;

Two, as shown in Figure 1, common ground wire and optical cable are all by tower ground connection.

Two: two ground wires of mode are all by tower ground connection, as shown in Figure 1, two ground are fixed on by wire clamp 3 on the both sides of shaft tower 4, and the adjacent two ground wire junctions of every side are fixed on the shaft tower by wire clamp, such structure be exactly common ground wire and optical cable all by tower ground connection, cause huge electric energy loss.Mode one: as shown in Figure 2, common ground wire graded insulation, one point earth, another optical cable is by tower ground connection, and after common like this ground wire was insulated, electric current can't form the loop, can significantly reduce the additional electrical energy loss of transmission line, but still have bigger electric energy loss on the optical cable.Result of study shows that this dual mode can cause ground wire circulation owing to have a ground wire at least by tower ground connection, causes very lossy.

Transmission line can generate an electromagnetic field around the lead when normal operation, can produce electromagnetism and Electrostatic Coupling between ground wire and the lead.Therefore induction produces longitudinal induction electromotive force and the electrostatic induction voltage that distributes along the line on ground wire, and its magnitude of voltage can reach more than thousands of volts.If ground wire by tower ground connection, then can produce circulation between line between two ground wires, every ground wire is respectively again the loop with the earth, forms the induced current loop.The generation of these two kinds of electric currents will increase the additional electrical energy loss of transmission line greatly, and this loss is in direct ratio with the quadratic sum line length of load current.The ground wire loss of 220kV single back line is about 100 km years of (5～10) * 104kwh/, and the 330kV transmission line is about 100 km years of 60 * 104kwh/, and the 500kV transmission line is about 100 km years of 500 * 104kwh/.U.S. 765kV transmission line, its ground wire loss is about 2.7kW/km, and only the annual ground wire wear and tear expense of 765kV circuit is up to 1,000,000 dollars, and number is considerable.

Summary of the invention

The purpose of this utility model just is to overcome above-mentioned deficiency a kind of shaft tower ground wire connected system is provided.

The technical solution of the utility model is as follows:

A kind of shaft tower ground wire connected system, comprise shaft tower, be arranged on the common ground wire and the Optical Fiber composite overhead Ground Wire of both sides, shaft tower top, described Optical Fiber composite overhead Ground Wire is fixed on a side of shaft tower by the ground wire insulator string, the junction of Optical Fiber composite overhead Ground Wire is connected with strain clamp, and strain clamp is fixed on the shaft tower.

Above-mentioned shaft tower ground wire connected system, described common ground wire is fixed on the opposite side of shaft tower by the ground wire insulator string, shaft tower between at least two shaft towers in shaft tower homonymy interval is provided with insulator and strain clamp, strain clamp is connected with the head end of back one section common ground wire, insulator links to each other with the tail end of common ground wire the last period, and strain clamp and insulator are fixed on the shaft tower.

Above-mentioned shaft tower ground wire connected system also is provided with protection in parallel gap on insulator.

Above-mentioned shaft tower ground wire connected system, shaft tower between three shaft towers in interval is provided with insulator and strain clamp, strain clamp is connected with the head end of back one section common ground wire, and insulator links to each other with the tail end of common ground wire the last period, and strain clamp and insulator are fixed on the shaft tower.

Above-mentioned shaft tower ground wire connected system, shaft tower between four shaft towers in interval is provided with insulator and strain clamp, strain clamp is connected with the head end of back one section common ground wire, and insulator links to each other with the tail end of common ground wire the last period, and strain clamp and insulator are fixed on the shaft tower.

The utility model adopts said structure, because Optical Fiber composite overhead Ground Wire is to be fixed on the shaft tower by the ground wire insulator string, Optical Fiber composite overhead Ground Wire is just by ground wire insulator string graded insulation like this, only at adjacent two coiled optical fiber composite overhead ground wire connecting places by strain clamp and tower grounding, thereby changed the mode of traditional optical fiber composite insulator by tower ground connection, optical fiber composite insulator also is a graded insulation like this, one point earth, reduce the generation of ground wire circulation, reduce loss significantly, reduced the cost of electrical production.On the ground wire insulator string, also be provided with protection in parallel gap in addition; when the induced potential on the insulator ground wire during greater than the flashover voltage of insulator parallel connection gaps; can cause the disruptive discharge in gap; cause the faradic formation of ground line loop thus; and to the strong demagnetizing effect of circuit zero-sequence current generation; and then the size of the equivalent zero sequence impedance of reduction transmission line unit length, and influence its phase place.Because two ground wires are graded insulation all, each segmentation all has a reliable earth point, and when thunderbolt, and the clearance for insulation of ground wire discharges breakdown and property-line is by basic ground state the thunder and lightning pioneer, improves its lightning protection effect.

Description of drawings

Fig. 1 is that common ground wire and optical cable are all by the shaft tower ground wire connected system structural representation of tower ground connection;

Fig. 2 is common ground wire graded insulation one point earth, and optical cable draws the shaft tower ground wire connected system schematic diagram on ground by tower;

Fig. 3 is a structural representation of the present utility model;

Fig. 4 is the utility model insulator structure for amplifying schematic diagram.

Embodiment

A kind of shaft tower ground wire connected system as shown in Figure 3 and Figure 4; comprise shaft tower 4; be arranged on the common ground wire 2 and the Optical Fiber composite overhead Ground Wire 1 of both sides, shaft tower top; described Optical Fiber composite overhead Ground Wire 1 is fixed on a side of shaft tower by ground wire insulator string 6; the junction of Optical Fiber composite overhead Ground Wire is connected with strain clamp 5; strain clamp 5 is fixed on the shaft tower; on insulator, also be provided with protection in parallel gap 8; common ground wire 2 is fixed on the opposite side of shaft tower by insulator string 6; shaft tower between at least two shaft towers in interval is provided with insulator 7 and strain clamp 5; strain clamp is connected with the head end of back one section common ground wire; insulator links to each other with the tail end of common ground wire the last period; strain clamp 5 and insulator 7 are fixed on the shaft tower 4; this structure is that common ground wire and Optical Fiber composite overhead Ground Wire all adopt insulation; the mode of one point earth; reduce the generation of ground wire circulation, reduced loss significantly, reduced the cost of electrical production.

The utility model can also can both reach the effect that the utility model reduces electrical loss according to the different situations of transmission line between two shaft towers of common ground wire, between three shaft towers, between four shaft towers or on the shaft tower between five shaft towers insulator 7 and strain clamp 5 being set.

Operation principle of the present utility model is with the Optical Fiber composite overhead Ground Wire graded insulation, the several tower groundings in interval, thus reach the effect that reduces electrical loss to reduce ground wire circulation.

Claims

1, a kind of shaft tower ground wire connected system, comprise shaft tower (4), be arranged on the common ground wire (2) and the Optical Fiber composite overhead Ground Wire (1) of both sides, shaft tower top, it is characterized in that: described Optical Fiber composite overhead Ground Wire (1) is fixed on a side of shaft tower by ground wire insulator string (6), the junction of Optical Fiber composite overhead Ground Wire is connected with strain clamp (5), and strain clamp (5) is fixed on the shaft tower.

2, shaft tower ground wire connected system according to claim 1, it is characterized in that: described common ground wire (2) is fixed on the opposite side of shaft tower by ground wire insulator string (6), shaft tower between at least two shaft towers in interval is provided with insulator (7) and strain clamp (5), strain clamp is connected with the head end of back one section common ground wire, insulator links to each other with the tail end of common ground wire the last period, and strain clamp (5) and insulator (7) are fixed on the shaft tower (4).

3, shaft tower ground wire connected system according to claim 2 is characterized in that: also be provided with protection in parallel gap (8) on insulator.

4, shaft tower ground wire connected system according to claim 3, it is characterized in that: the shaft tower between three shaft towers is provided with insulator (7) and strain clamp (5) at interval, strain clamp is connected with the head end of back one section common ground wire, insulator links to each other with the tail end of common ground wire the last period, and strain clamp (5) and insulator (7) are fixed on the shaft tower (4).

5, shaft tower ground wire connected system according to claim 3, it is characterized in that: the shaft tower between four shaft towers in interval is provided with insulator (7) and strain clamp (5), strain clamp is connected with the head end of back one section common ground wire, insulator links to each other with the tail end of common ground wire the last period, and strain clamp (5) and insulator (7) are fixed on the shaft tower (4).