CN210838892U - Inertia amplification type transmission line vibration damping cable - Google Patents

Abstract

The utility model discloses an inertia amplifying type transmission line vibration damping and damping cable. The utility model is an inertia-amplifying transmission line vibration-absorbing and damping cable, the transmission line is suspended between the transmission towers; the damping cable is connected to the transmission line and the transmission tower obliquely; After bypassing the fixed pulley, it is connected to the upper end of the vibration damping device, and the fixed pulley and the vibration damping device are installed on the transmission tower in turn; At the same time, both ends of the transverse link are cross-connected with the damping devices on the left and right sides of the transmission tower with damping cables. The utility model can reduce the vibration of the transmission line and eliminate the dynamic load of the transmission line.

Description

A kind of inertia amplification type transmission line vibration damping and damping cable

technical field

The utility model belongs to the technical field of vibration reduction of transmission tower lines, in particular to an inertia amplification type transmission line vibration reduction damping cable.

Background technique

The transmission tower line system is a widely used high-flexible and large-span structure, and it is an important lifeline project. Under external factors such as wind, the power transmission line will vibrate. The harm caused by these vibrations is multi-faceted. In the light, flashover and tripping occur. In the severe case, the insulator is damaged, the wire is disconnected, the tower bolts are loosened, fall off, or even collapse.

According to the different frequencies and amplitudes, the vibration of power lines can be roughly divided into three types: high-frequency and slight-amplitude breeze vibration, medium-frequency and medium-amplitude sub-gap vibration, and low-frequency and large-scale galloping.

(1) Breeze vibration: Differential vibration is the formation of a stable eddy current on the leeward side of the wire when a uniform wind with a wind speed of 0.5-10m/s blows vertically to the wire. Due to the effect of the periodic eddy current lift component, the wire vibrates.

(2) Galloping: when the wind speed is about 5-15m/s on the wire with asymmetric shape, the most common case is when it acts on the wire with asymmetric thickness of ice coating, which is caused by the change of the wind angle. The pulsating wind destroys the static balance of the wire and forms a large gallop; it is characterized by large vibration, low frequency and long duration (the amplitude is below 10m and the frequency is 0.1-1Hz); the duration of the vibration can reach dozens of times For a long time, it often caused large-scale disconnection and tower collapse in many places.

(3) Secondary pitch vibration: Secondary pitch oscillation refers to an oscillation that occurs in the pitch between two adjacent spacers of the split wire; because the frequency of the vibration is very low, it is generally called "oscillation"; Secondary pitch oscillation rarely occurs in the line, usually under the action of wind speed of 5-15m/s, due to the turbulent flow generated by the windward conductor, the leeward conductor is affected and the airflow disturbance is generated, which destroys the balance of the conductor. Oscillation; its manifestation is often the swing of each sub-conductor in different periods, periodic separation and gathering, and the motion trajectory of the wire in space is elliptical; the amplitude of the secondary pitch oscillation is related to the secondary pitch length, wind speed and split The structure of the wire is related. Generally, the amplitude of the sub-range oscillation ranges from the diameter of the wire to 0.5m, and the frequency is 1 to 3Hz.

The main measures for vibration reduction of existing transmission lines include: anti-vibration hammers, damping lines, or a combination of the two.

(1) Anti-vibration hammer: The small hammer suspended on the wire is called anti-vibration hammer. As shown in Figure 1, it is a tuned mass damper (TMD); in order to prevent and reduce the vibration of the wire, it is generally used in the suspension of the wire. A certain number of anti-vibration hammers are installed near the clamp; when the wire vibrates, the anti-vibration hammer also moves up and down, generating a force that is out of sync or even opposite to the vibration of the wire, which can reduce the amplitude of the wire and even eliminate the vibration of the wire; In Fig. 1, 1 denotes a power transmission line, 2 denotes an elastic beam, and 3 denotes a mass.

The principle of TMD vibration reduction is shown in Figure 2. In Figure 2, m is the mass of the mass block, k is the spring stiffness, c is the damper damping, M is the mass of the structure, k1 is the main structure stiffness, and c1 is the main structure damping , F is the dynamic part of the wind, fluid and other excitation loads on the structure, F ₀ is the amplitude of the external excitation, ω is the frequency of the external excitation, and t is the time.

When the structure vibrates, the resonance principle is used, that is, the natural frequency of the TMD is consistent with the natural frequency of the structure, so that the TMD vibrates, and the inertial force of the TMD is used to balance the external excitation, thereby suppressing the vibration of the structure.

The anti-vibration hammer can effectively prevent the breeze vibration, but due to the characteristics of the tuned mass damper (TMD) itself, the tuned vibration damping has always had the problem of narrow vibration suppression frequency and difficulty in suppressing multiple frequencies of the structure at the same time, and the fundamental frequency of the structure continues to decrease. , the effect of tuning vibration reduction is also reduced, so for low-frequency high-amplitude dancing, the tuned mass damper cannot play a good role.

(2) Damping line: Damping lines of different lengths and sags are used, which are connected to the conductors through clips, and the vibration of the transmission line is reduced by the swing of the conductors. Its structure is shown in Figure 3, and its vibration reduction principle is the same as that of TMD. In Fig. 3, 1 denotes a power transmission line, 4 denotes a wire clamp, and 11 denotes a damping wire.

Whether it is an anti-vibration hammer or a damping cable, it is based on the vibration reduction principle of TMD, which is easily affected by the vibration frequency of the structure; and the use of its own material to damp energy dissipation, the energy dissipation effect is poor. Therefore, after the installation of these vibration reduction devices, various accidents caused by vibration still frequently occur in the existing transmission lines, resulting in heavy losses of national property.

SUMMARY OF THE INVENTION

The purpose of the utility model is to provide an inertia amplification type transmission line vibration damping and damping cable in order to reduce the vibration of the transmission line and eliminate the dynamic load of the transmission line.

The above purpose of the present utility model is achieved through the following technical solutions: the inertia-amplified transmission line vibration damping and damping cable, the transmission line is suspended between the transmission towers; the damping cable obliquely connects the transmission line and the transmission tower, and the upper end of the damping cable A mass block is installed at the connection with the transmission line, and the lower end of the damping cable is connected to the upper end of the vibration damping device after bypassing the fixed pulley. The fixed pulley and the vibration damping device are installed on the transmission tower in sequence; The transmission lines are connected at the upper ends of the damping cables at the same height by transverse links, and both ends of the transverse links are cross-connected with the damping devices on the left and right sides of the transmission tower with damping cables.

Specifically, the vibration damping device includes an upper beam and a lower beam, a return spring and a damper are connected between the upper beam and the lower beam, wherein the lower beam is fixed on the transmission tower.

Specifically, the damping cables are treated with insulators or other insulating materials and meet electrical requirements; the connecting rods meet electrical insulation requirements.

The vibration reduction principle of the inertia amplification type transmission line vibration reduction damping cable of the utility model is: when the transmission line vibrates laterally, for the convenience of discussion, the vibration reduction principle of the damping cable is described by the up and down vibration of the transmission line. The vibration makes the shape of the transmission line take the form of a sine wave. With the change of wind speed, the number of sine waves and the vibration frequency change; when the transmission line vibrates, the mode shape of the sine wave makes its amplitude small near the transmission towers at both ends. , while the position farther from the transmission tower has a larger amplitude; the upper end of the damping cable is connected to the transmission line, and the lower end is connected to the damping device. Extend into a straight line; when the upper end of the damping cable moves up with the transmission line, the damper is stretched to provide a downward damping force for the transmission line; when the upper end of the damping cable moves down with the transmission line, the spring is reset in the energy dissipation device Under the action, the damper is compressed to provide upward damping force for the transmission line; the direction of the damping force is always opposite to the moving direction of the transmission line, which consumes the vibration mechanical energy of the transmission line, thereby suppressing the vibration of the transmission line. The mass blocks, connecting rods, etc. installed on the transmission line at the upper end of the damping cable can change the mode shape of the transmission line. Under the condition of the same maximum amplitude, the additional mass significantly increases the amplitude of the connection between the transmission line and the damping cable, and increases the damper. stroke, significantly improving the damping effect of the damping cable on the transmission line.

For the case of multiple transmission lines on both sides of the transmission tower, after using insulators to connect the transmission lines along the axial and vertical directions of the damping cable, the vibration reduction principle is the same as the above.

The advantages of the utility model relative to the existing vibration reduction system are embodied as follows:

(1) Compared with the anti-vibration hammer and the damping wire, the damping cable of the present invention can utilize various dampers to dissipate energy, and the energy consumption effect is good.

(2) Compared with the anti-vibration hammer and the damping wire, the damping effect of the damping cable of the present invention is not affected by the change of the frequency of the transmission line, and can suppress the vibration of all frequencies of the transmission line at the same time.

(3) The increase of inertial mass can change the mode shape of the transmission line and significantly increase the vibration reduction effect of the damping cable.

(4) Compared with the existing damper for vibration reduction, the span of the damping cable is large, and the large amplitude of the transmission line away from the transmission tower can be used to drive the damper to reduce vibration.

Description of drawings

FIG. 1 is a schematic structural diagram of a shock-proof hammer in the prior art.

Figure 2 is a schematic diagram of TMD vibration reduction.

FIG. 3 is a schematic structural diagram of a damping wire in the prior art.

FIG. 4 is a schematic diagram of an application structure of an embodiment of the present invention.

FIG. 5 is an enlarged view of part I in FIG. 4 .

FIG. 6 is a view A-A in FIG. 4 .

FIG. 7 is a time-displacement curve diagram of comparative vibration attenuation with or without additional mass in the embodiment of the present invention.

8 is a schematic structural diagram of changing the linear damping cable structure into a broken-line displacement amplifying structure and then using the vibration damping device of the present invention.

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings and embodiments. The same reference numerals in the drawings represent the same or similar parts or elements unless otherwise specified.

Referring to FIG. 4 to FIG. 6 , in the inertia amplification type transmission line vibration damping and damping cable of this embodiment, the transmission line 1 is suspended between the transmission towers 6 . The damping cable 5 is connected to the transmission line 1 and the transmission tower 6 obliquely. A mass block 3 is installed at the connection between the upper end of the damping cable 5 and the transmission line 1. Connected, the fixed pulley 7 and the vibration damping device 8 are installed on the transmission tower 6 in turn; as can be seen from FIG. 9 is connected, both ends of the transverse link 9 are cross-connected with damping cables 5 with the vibration damping devices 8 on the left and right sides of the transmission tower 6 at the same time. Referring to FIG. 5 , the vibration damping device 8 includes an upper beam 801 and a lower beam 802 . A return spring 803 and a damper 804 are connected between the upper beam 801 and the lower beam 802 , wherein the lower beam 802 is fixed on the transmission tower 6 . Among them, the damping cables are treated with insulators or other insulating materials, and meet the electrical requirements; the connecting rods also need to meet the electrical insulation requirements.

The following is an application comparison experiment:

The two ends of the steel wire rope with a diameter of 10mm are used for tensioning to simulate a power transmission line with a span of 13m. The above-mentioned damping cable, fixed pulley and vibration damping device (using a damper) of the present utility model are applied. A mass block (with additional mass) is installed. In another experiment, the damping cable is not equipped with a mass block (without additional mass), and resonance excitation is used to make the transmission line vibrate greatly. When the external excitation is removed, the transmission line vibrates freely. According to The time-displacement curve of vibration attenuation is used to judge the pros and cons of the vibration damping effect. In Figure 7, when there is no additional mass, the attenuation of the transmission line is relatively slow; when other parameters remain unchanged, only the additional mass is added, and it can be seen that the attenuation speed of the vibration of the transmission line is significantly accelerated.

The innovative point of the present utility model is embodied as follows:

(1) The damping cable is connected between the transmission line and the transmission tower. The pretensioned return spring keeps the damping cable always in a tensioned state, and the vibration of the transmission line changes the length of the damping cable, thereby driving the damper to consume energy.

(2) The increase of the mass block can change the mode shape of the transmission line. Under the premise of the same maximum amplitude of the transmission line, the amplitude of the upper end of the damping cable can be significantly increased, and the vibration reduction effect of the damping cable can be improved.

(3) The damper is used to consume energy. As long as the transmission line vibrates, the damper consumes energy, which is essentially different from the existing vibration reduction measures based on tuning and vibration reduction, and the utility model is not affected by the vibration frequency.

(4) The utility model can not only reduce the vibration of a single transmission line, but also can simultaneously reduce the vibration of a plurality of transmission lines.

(5) Compared with the existing damper vibration reduction method, no support column is required, and the span is much larger than the existing support column structure, so the vibration reduction effect is better.

In addition to the implementation of the above-mentioned embodiments, the present utility model can also have other similar ways or equivalent transformations, such as:

(1) The vibration damping principle of the present invention can also be applied to the vibration damping of cable net structures and other large-span and towering structures.

(2) Change the linear damping cable structure to a broken-line displacement amplifying structure and then use the vibration damping device of the present utility model to consume energy, as shown in Figure 8, or increase the damping of devices such as lever principle amplification, chain transmission amplification, gear transmission amplification, etc. cable; in Fig. 8, 10 denotes a displacement amplifying device.

(3) Add auxiliary measures to reduce the sag of the damping cable and improve the vibration reduction effect.

(4) Change the return spring of the vibration damping device to gravity return.

(5) The lower end of the damping cable is changed from the transmission tower to the ground or other structures or objects that are stationary relative to the ground.

(6) The damper adopts other forms, or increases the inertial mass and so on.

Therefore, under the basic concept of the present invention, the transformation of other equivalent technical features shall all belong to the protection scope of the present invention.

Claims (3)

1. An inertia amplification type transmission line vibration damping cable, wherein a transmission line is suspended between transmission towers; the method is characterized in that: the damping cable is obliquely connected with the power transmission line and the power transmission tower, a mass block is additionally arranged at the joint of the upper end of the damping cable and the power transmission line, the lower end of the damping cable is connected with the upper end of the vibration damper after passing around the fixed pulley, and the fixed pulley and the vibration damper are sequentially arranged on the power transmission tower from top to bottom; the two power transmission lines on the left side and the right side of the power transmission tower are connected at the upper ends of the damping cables at the same height through the transverse connecting rod, and the two ends of the transverse connecting rod are simultaneously in cross connection with the damping devices on the left side and the right side of the power transmission tower through the damping cables.

2. The inertia amplified transmission line damping lanyard of claim 1 wherein: the vibration damping device comprises an upper cross beam and a lower cross beam, wherein a return spring and a damper are connected between the upper cross beam and the lower cross beam, and the lower cross beam is fixedly connected to the power transmission tower.

3. The inertia amplified transmission line damping lanyard of claim 1 wherein: the damping cable is treated by adopting an insulator and meets the electrical requirement; the connecting rod meets the electrical insulation requirement.

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