CN202503249U - A three-wire damping wire used in the field of high-voltage power transmission - Google Patents

Abstract

The utility model relates to a three-line damping wire used in the field of high-voltage power transmission. The three-line tree-shaped damping wire is composed of three damping line segments; the clamps at both ends of the first damping line segment are all connected to overhead wires One end of the second damping line segment is connected to the lace stranded wire of the first damping line segment, the other end is connected to the overhead wire, and one end of the third damping line segment is connected to the second damping line segment The other end is connected to the overhead wire. The tree-shaped damping wire of the utility model has the characteristics of stable holding force, no wear on the wire, continuous strands, no loosening, light weight and long service life. Power lines, ground wires, OPGW optical cables) low frequency and high frequency anti-vibration requirements.

Description

A three-wire damping wire used in the field of high-voltage power transmission

【Technical field】

The utility model relates to the technical field of high-voltage power transmission, in particular to a three-wire damping wire used in the field of high-voltage power transmission.

【Background technique】

Wind vibration of transmission line conductors is one of the important factors that threaten the safe operation of transmission lines, and it is a problem that line design, construction and operation management departments must attach great importance to. Because various stresses can lead to wire failure.

For example, stress, the main stresses at the support of overhead conductors are: tension, radial extrusion and bending stress. The torsional stress and the transverse shear stress are very small and are not considered here. The main factors that cause the above stress are as follows: for example, the tension directly from the line; the static bending stress caused by the bending of the wire at the suspension point; the radial extrusion force is generated by: tension, bending of the clamp, internal clamping force. On the surface, various static stresses are independent of each other. However, they are interconnected in a complex manner, and they concentrate into very high radial compressive forces on the wire.

Tension, the tension in the wire creates a static tensile stress in the wire. In ACSR, the tension of the aluminum wire varies unevenly with temperature. When extremely severe vibration occurs in extremely cold weather conditions, the tension of the aluminum wire may be 70Mpa higher at -40°C, and the high tension on the aluminum wire increases the self-vibration on the wire structure, which in turn leads to very severe vibration.

Static bending stress, the static bending stress at the hanging clamp is related to the hanging arc of the wire and the tension of the wire, as well as the flexibility of the wire and the shape of the clamp.

Extrusion stress, extrusion stress is an important part of stress, and plays a large role in the abrasion process. It goes up with the tension, the dangling line clamp pads and the clamping force inside.

For a typical multilayer wire, the layer-to-layer contact begins as a point-to-point contact. When extremely high contact stress is generated, the point-to-point contact produces plastic deformation. This indentation develops as the stress rises due to the dynamic action.

Dynamic stress, which can vary widely in magnitude, depending on the type of vibration and the degree of vibration. They are produced by breeze vibrations, galloping, vibrations of split wires, vibrations produced by wind pendulums. Icing falls and other transients can also generate dynamic loads. Severe galloping leads to a large bending stress acting on the support point, and the fluctuation of tension causes the hardware and accessories to be damaged with the fatigue of the wire. In addition, repeated bending stresses from vibrations of the split wires occur in more or lesser planes, which have no effect on the static bending stresses at the hanging clamps. Signs of fatigue failure of the bolt-type spacer can be seen in the severe vibration area of the split conductor.

It can be seen from the above that breeze vibration is the most common form of conductor vibration, and it is also the main cause of overhead line damage. When the wire gallops, there will be a large dynamic deformation and tension change, which will cause serious damage to the wire in a very short time. In addition, stress reduction is the key to solving fatigue problems. By reducing static and dynamic stress, the fatigue life of wire support fittings will be greatly extended.

Dealing with wind vibration requires specially designed fittings, such as anti-vibration hammers, guard lines, damping lines, anti-vibration whips, etc., which can effectively reduce the stress combination at the suspension point of the transmission line.

Excessive breeze vibration of wires often causes wire fatigue, broken strands, hardware damage, etc., which poses a threat to the safe and stable operation of the line.

Usually, ordinary lines are equipped with anti-vibration hammers to prevent vibration. Generally, installing 1 to 3 anti-vibration hammers can effectively control the breeze vibration of wires and ground wires. However, due to the characteristics of high hanging points, large spans, and open terrain in large-span projects, laminar wind is likely to form above the water surface and cause a wide range of wire excitation wind speeds. The distance from the line is much larger, and the wind vibration level of the wire is much larger than that of the ordinary line, so a special anti-vibration device must be designed, otherwise the wire breakage accident is likely to occur.

For example, the 1000KV Jindongnan-Nanyang-Jingmen ultra-high voltage test and demonstration project has successively crossed the Yellow River and the Han River. The ordinary line conductor adopts the eight-split type, and the long-span section adopts the six-split type. Compared with the ultra-high voltage line, the hanging point of the conductor is higher. The span is larger and the wind vibration of the wire lasts longer, so great attention must be paid to the vibration prevention of the 1000KV ultra-high voltage line.

The vibration fatigue strand breaking of the wire is the result of the cumulative effect of vibration. The vibration of the wire is generally measured by the dynamic bending strain. When the strain does not exceed a certain value, it can be considered that the wire will not break within the entire service life of the wire. The value is the allowable value of dynamic bending strain. There is no uniform standard for the allowable value of the dynamic bending strain of conductors in the world, but different requirements are put forward for the same type of conductor when it is applied to long-span and ordinary lines. The former is more stringent because of the strong breeze vibration of long-span lines. , long duration and special importance of the project are considered.

Breeze vibration prevention and control of 1000KV ultra-high voltage ordinary lines. Usually, the ordinary line of the 1000KV ultra-high voltage test demonstration project adopts eight-split conductors and installs damping spacers, because the damping spacers have

It has a good energy dissipation and vibration reduction effect, and the allowable value of the horizontal dynamic bending strain of the breeze vibration of the sub-conductor can be properly controlled.

As another example, the EHV line conductors of the former Soviet Union and Japan all adopt the eight-split type and only spacers are installed, and no other types of anti-vibration devices are installed. If damping spacers are installed on domestic 500KV ordinary line 4-split conductors, anti-vibration hammers are generally not installed when the span is not > 500m, and 1 or 2 anti-vibration hammers are installed when the span is > 500m.

This is because, due to the higher average hanging point of the EHV line conductors, when the anti-vibration scheme is not installed, the dynamic bending strain at the outlet of the conductor suspension (tension) clamp exceeds the allowable value of dynamic bending strain at about 15-70 Hz, and the maximum dynamic The bending strain reaches 412×10 ^-6 , which is far beyond the requirements of technical conditions. Therefore, an anti-vibration scheme must be installed to suppress the vibration of the wires, so as to control the vibration level of the wires within a safe range.

To control vibration damage, the following methods are used:

1. Hanging fittings. In order to prevent the vibration damage of the wire, theoretically, the method of reducing the stress of the wire can be adopted to increase the self-damping effect of the wire, but this method is not realistic, and it will mainly increase the number of towers used, which is very uneconomical.

2. Guard lines. The protection line is made of elastic high-strength aluminum alloy wire according to the specified number, prefabricated into a spiral pre-twisted wire protection line, tightly wrapped around the outer layer of the wire, and put into the clamp at the suspension point. Its function is to increase the stiffness of the wire near the outlet of the clamp, reduce the static and dynamic bending stress on the wire, make the stress evenly distributed, and protect the wire. However, the guard line cannot control the vibration of the line, but only eliminates its influence. In addition, the guard line cannot completely guarantee that the line will not be fatigued and damaged under long-term severe vibration conditions.

3. Vibration dampers, such as breeze vibration dampers. In order to prevent damage to the wire, there are two types of shock absorbers used to reduce the influence of breeze vibration, namely the frequency modulation shock absorber and the impact type shock absorber.

4. Anti-vibration hammer. The anti-vibration hammer is a widely used vibration damper with frequency modulation. The principle of the anti-vibration hammer is that when the wire vibrates, the splint of the anti-vibration hammer also moves up and down with the wire. Since the two heavy hammers have a large inertia and cannot move synchronously with the splint, the two ends of the steel strand of the anti-vibration hammer are constantly Bending up and down causes the strands to constantly rub against each other, dissipating the energy imparted to it by the vibrations of the wire.

However, the anti-vibration hammer has a poor effect on reducing the dynamic bending strain value of the wire at the lace clamp and changing the response frequency of the lace.

【Content of utility model】

The purpose of the utility model is to overcome the deficiencies of the prior art and provide a three-wire damping wire used in the field of high-voltage power transmission.

The anti-vibration principle of the product of the utility model is as follows. The lace twisted wire of the tree-shaped damping wire is like the balance pendulum of the shock-proof hammer. The tail radius swings back and forth along a certain angle, consuming the energy brought by the vibration spread from the conductor vibration to the vicinity of the clamp, so that the vibration is greatly weakened and the vibration elimination effect is achieved, which can meet the large span of overhead transmission lines with a voltage level above 35kV High-frequency and low-frequency anti-vibration technical requirements for wires. According to the anti-vibration scheme of various natural frequency wires, the arrangement is optimized, and the expected anti-vibration effect can be achieved by lengthening or shortening the length of the lace twisted wire.

The purpose of this utility model is achieved through the following technical solutions:

A three-wire damping line used in the field of high-voltage power transmission, characterized in that the three-line tree-shaped damping line is composed of three damping line segments; the clamps at both ends of the first damping line segment are all connected to overhead wires One end of the second damping line segment is connected to the lace stranded wire of the first damping line segment, the other end is connected to the overhead wire, and one end of the third damping line segment is connected to the second damping line segment The other end is connected to the overhead wire.

The damping wires are suspended on the overhead wires at intervals, and the damping wires are respectively crimped with a clamp at both ends of a lace twisted wire, and the lace twisted wire is a steel strand.

The wire clip is composed of the wire clip body, the wire clip wire groove for built-in wires on the wire clip, the wire clip gland for covering and clamping the wire, and the extension arm that is rotatably connected with the wire clip gland. The coil spring on the wire clamp is used to fasten the bolts and nuts of the coil spring. After the wire clamp cover is pressed and the wire is clamped, and the coil spring installed on the wire clamp is locked, the extension arm is embedded in the wire clamp body. Clamp the bolts and nuts that fasten the coil spring.

The clamp gland is on the same straight line as the center point of the boom hinge and the center line of the coil spring.

Compared with prior art, the positive effect of the utility model is:

The damping wire clamp of the product of the utility model is fixed by a spring preset load locking device, so it has the characteristics of stable grip, easy operation, and not easy to damage the wire.

The tree-shaped damping wire of the utility model has the characteristics of stable holding force, no wear on the wire, continuous strands, no loosening, light weight and long service life. Power lines, ground wires, OPGW optical cables) low frequency and high frequency anti-vibration requirements.

【Description of drawings】

Fig. 1A, B are respectively the front view and the top view of the tree-shaped damping wire of the present invention in use.

2A and B are the front view and top view of the tree-shaped damping line segment of the present invention, respectively.

3A and B are respectively the front view and the cross-sectional view of the wire clamp of the tree-shaped damping line segment of the present invention with the wire clamp gland closed.

Fig. 4 is an explanatory diagram of the wire clamp of the tree-shaped damping line segment of the present invention after opening the arm.

Fig. 5 is a schematic diagram of the clamp nut end of the tree-shaped damping line segment of the present invention when the extension arm is about to be closed.

In the figure, 1 is the lace stranded wire, A is the clamp, 2 is the clamp body, 3 is the clamp cover, 4 is the coil spring, 5 is the extension arm, 6 is the clamp nut, 7 is the bolt, and 8 is the pad 9 is a tree-shaped damping line segment, 10 is an overhead wire, and 11 is a wire clamp wire groove.

【Detailed ways】

A specific embodiment of a three-wire damping wire used in the field of high-voltage power transmission of the present invention is provided below.

Example 1

Please refer to accompanying drawings 1A, 1B, 2A, 2B, 3A, 3B, 4, 5; a tree-shaped damping wire used for anti-vibration of 35-1000kV large-span overhead conductors, the tree-shaped damping wire is a three-wire type The tree-shaped damping line is composed of three damping line segments 9 . The tree-shaped damping wire is tied to two ends of a lace twisted wire 1 and respectively crimped with a damping wire clip A, and the lace twisted wire is a steel strand.

That is, the three damping line segments are respectively suspended on the overhead wires at equal intervals.

The damping wire clamp A includes: a clamp body 2, a clamp wire groove for a built-in wire 10 on the clamp, a clamp cover 3 for covering and clamping the wire, and a clamp cover 3 for pressing and clamping the wire. 3 Rotate and connect the extension arm 5, the extension arm 5 is a double-arm type, on which is formed a buckle-type member for clamping the bolt 7 and nut 6 of the fastening coil spring, and the coil spring 4 installed on the clamp , the bolts 7 and nuts 6 used to fasten the coil spring, after the wire clamp gland is pressed, the wire is clamped, and the coil spring installed on the wire clamp is forbidden, the extension arm 5 can be embedded into the wire The clip body 2 clamps the bolt 7 and the nut 6 of the fastening coil spring.

The three-line tree type damping line is composed of the damping line segments, the clamps at both ends of the first damping line segment 9 are all connected to the overhead conductor 10, and the clamps at one end of the second damping line segment 9 are connected to On the lace stranded wire 1 of the first damping line segment, the other end is connected to the overhead conductor 10, and one end clamp of the third damping line segment is connected to the lace stranded wire 1 of the second damping line segment, and the other end is connected to On the overhead conductor 10. For this reason, the shape of the utility model product installed on the wire is like a tree, so it is habitually called a tree-shaped damping wire by users.

The anti-vibration principle of the product of the utility model is as follows. The lace twisted wire of the tree-shaped damping wire is like the balance pendulum of the shock-proof hammer. The tail radius swings back and forth along a certain angle, consuming the energy brought by the vibration spread from the conductor vibration to the vicinity of the clamp, so that the vibration is greatly weakened and the vibration elimination effect is achieved, which can meet the large span of overhead transmission lines with a voltage level above 35kV High-frequency and low-frequency anti-vibration technical requirements for wires. According to the anti-vibration scheme of various natural frequency wires, the arrangement is optimized, and the expected anti-vibration effect can be achieved by lengthening or shortening the length of the lace twisted wire.

In this embodiment, the wire clip of the damping wire of the utility model can hold the wire by setting the load of the coil spring in the wire clip to ensure that it does not damage the wire and has enough wire holding force, and The grip force of the wire clip on the wire will not be affected by the change of the climate environment temperature.

According to the tree-type damping wire of this embodiment, its operation is simple and convenient. When installing, it is only necessary to place the wire in the wire groove of the wire clamp, close the wire clamp gland on the wire clamp body, and close the extension arm to the wire clamp body to install the coil spring. After the specified position in the casing, the nut is loosened and removed or tightened with a special tool, and the clamp immediately produces a constant holding force on the wire.

In addition, in this embodiment, the axis line of the casing of the damping wire clamp, that is, the axis line of the clamp, and the axis line of the wire slot between the clamp body and the clamp gland, that is, the overhead wire The axis oblique angle α = 10 °.

In this embodiment, the bushing and the clamp body are integrally cast, one end of the clamp body of the damping wire clamp is hinged to the pin of the clamp gland, and the other end of the sleeve is sequentially connected with a bolt, a coil spring, and a nut. The expansion arms are embedded in the inner walls of both sides of the casing in a double-arm shape, and clamp the coil springs, bolts and nuts.

According to the tree type damping wire clamp of the present invention, it is characterized in that the clamp gland is on the same plane as the axis line of the boom hinge, the axis line of the bolt, the center line of the coil spring and the washer.

The above is only a preferred embodiment of the present utility model, and it should be pointed out that for those of ordinary skill in the art, some improvements and modifications can also be made without departing from the concept of the present utility model. Should be regarded as within the protection scope of the present utility model.

Claims (4)

1. three line style damping wires that are used for the high voltage power transmission field is characterized in that, three line style tree type damping wires then are made up of three described damping line segments; Article one, two end terminals of damping line segment all are connected on the aerial condutor; One end terminal of its second damping line segment is connected on the lace twisted wire of article one damping line segment; The other end is connected on the aerial condutor; One end terminal of its 3rd damping line segment is connected on the lace twisted wire of second damping line segment, and the other end is connected on the aerial condutor.

2. a kind of three line style damping wires that are used for the high voltage power transmission field as claimed in claim 1; It is characterized in that; Described damping linear system hangs on the aerial condutor (10) at interval, and damping wire ties up to wire clamp of two ends difference crimping of a lace twisted wire (1), and said lace twisted wire is steel strand wire.

3. a kind of three line style damping wires that are used for the high voltage power transmission field as claimed in claim 1; It is characterized in that described wire clamp is used to cover the wire clamp gland (3) of pressure, clamping wire by the wire clamp metallic channel (11) that is used for inner conductors (10) on wire clip body (2), the wire clamp; The exhibition arm (5) that is rotationally connected with the wire clamp gland; Be installed on the helical spring (4) on the wire clamp, be used for fastening helical spring bolt (7), nut (6), online cramping lid lid presses, clamp said lead, be installed on helical spring on the wire clamp prohibited solid after; The exhibition arm embeds wire clip body, blocks fastening helical spring bolt, nut.

4. a kind of three line style damping wires that are used for the high voltage power transmission field as claimed in claim 3 is characterized in that, the central point of said wire clamp gland and exhibition arm hinge and helical spring center line are on same straight line.

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