A baffle pendulum and a multi-directional baffle comprising a baffle pendulum

Abstract

The application provides a kind of anti-dancer pendulum and a kind of multi-directional anti-dancer including the anti-dancer pendulum, the pendulum includes hollow protective shell (6), mass (5) in the protective shell (6), first spring (7) and second spring (8), multi-directional anti-dancer includes spacer rod (1), connecting rod (2) and pendulum (3), the pendulum (3) is hung below spacer rod (1) by connecting rod (2), the application has detuning, heavy and energy dissipation effect, and the anti-dancer effect is good, and the anti-dancer effect is small, and the anti-dancer effect is good.The application determines the linear stiffness and cubic stiffness of the pendulum based on the nonlinear energy sink theory, has the functions of detuning, heavy and wide frequency domain energy dissipation, prevents the energy flow between each degree of freedom, thereby effectively avoiding the easy occurrence of conductor dancing and dancing at low wind speed and thin ice, and the application can prevent the damage caused by excessive vibration energy of the main vibration body, and can effectively protect the conductor and the attached fittings.

Description

Technical Field

[0001] The present invention relates to the technical field of disaster prevention and reduction of power grids, and in particular to a pendulum for preventing dance and a multi-directional anti-dance device comprising the pendulum. Background Art

[0002] Conductor galloping is the low-frequency, high-amplitude self-excited vibration of overhead conductors subjected to lateral wind forces and uneven circumferential ice coverage. This phenomenon forms standing or traveling waves with one, two, or three antinodes within a conductor. The conductor primarily moves vertically, sometimes also in an elliptical pattern, with the major axis of the ellipse in the vertical or offset direction, sometimes accompanied by conductor torsion. The frequency of vertical vibration is approximately 0.1 to 1 Hz, with an amplitude ranging from tens of centimeters to several meters. Severe conductor galloping occurs when a single antinode vibrates within a large-span conductor. Combined with the swaying of the suspension insulator string along the line, the amplitude can reach or even slightly exceed the maximum sag value (approximately 10 to 12 meters).

[0003] The main cause of conductor galloping is uneven ice coverage, which is fundamentally different from the breeze vibration of unglazed or evenly iced conductors. In winter in high-latitude regions, such as the northern United States, Canada, Japan, the Soviet Union, Nordic countries, China, and New Zealand, when the temperature is between 0 and -10°C or lower, the wind speed is between 2 and 25 m / s or higher, and the angle between the wind direction and the line direction is between 45° and 90°, conductors with uneven ice coverage may gallop. Ice galloping is a common natural disaster that seriously threatens the safe and stable operation of overhead conductors. It generally exhibits multi-degree-of-freedom coupled vibration characteristics, such as vertical, horizontal, and torsional. The functions of existing anti-galloping devices are relatively simple. While achieving gallop suppression, most of them simply have detuning or weighting functions, such as double-pendulum anti-galloping devices or weighted anti-galloping devices. Due to the strong nonlinear characteristics of galloping, the anti-galloping devices in existing technologies have significant limitations. Summary of the Invention

[0004] In order to overcome the disadvantages of the above-mentioned prior art that the anti-dance function is greatly limited, the present invention provides an anti-dance pendulum and a multi-directional anti-dance device including the anti-dance pendulum, comprising: a hollow protective shell (6), a mass block (5) located in the protective shell (6), a first spring (7) and a second spring (8); the mass block (5) is horizontally connected to the inner wall of the protective shell (6) through the first spring (7) and the second spring (8); and the height of the mass block (5) is smaller than the height of the hollow part of the protective shell (6), and has the functions of detuning, weighting and energy consumption, and has a small limitation on the anti-dance effect and a good anti-dance effect.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0006] The present invention provides a pendulum for preventing dancing, comprising a hollow protective shell (6), a mass block (5) located in the protective shell (6), a first spring (7) and a second spring (8);

[0007] The mass block (5) is horizontally connected to the inner wall of the protective shell (6) via a first spring (7) and a second spring (8); and the height of the mass block (5) is smaller than the height of the hollow portion of the protective shell (6).

[0008] The protective shell (6) is cylindrical, and the mass block (5) is horizontally connected to the centers of the two end surfaces of the protective shell (6) through a first spring (7) and a second spring (8).

[0009] The mass block (5) and the first spring (7), the first spring (7) and the protective shell (6), the mass block (5) and the second spring (8), and the second spring (8) and the protective shell (6) are all connected in the form of welding or hanging rings.

[0010] The length and stiffness of the first spring (7) and the second spring (8) are equal.

[0011] The linear stiffness of the pendulum (3) is determined based on the preload and length of the first spring (7) / second spring (8), and the cubic stiffness thereof is determined based on the preload, length and stiffness of the first spring (7) / second spring (8).

[0012] The linear stiffness of the pendulum (3) is determined as follows:

[0013]

[0014] Where k1 is the linear stiffness of the pendulum (3), f is the preload of the first spring (7) / the second spring (8), and l is the length of the first spring (7) / the second spring (8).

[0015] The cubic stiffness of the pendulum (3) is determined as follows:

[0016]

[0017] Where k3 is the cubic stiffness of the pendulum (3), and k is the stiffness of the first spring (7) / the second spring (8).

[0018] The first spring (7) and the second spring (8) are both cylindrical springs or conical springs.

[0019] The height of the hollow portion of the protective shell (6) is 5 to 20 cm, its length is greater than the height of the hollow portion, and its thickness is 5 to 10 mm.

[0020] The mass block (5) is spherical, and its diameter is 20% to 80% of the height of the hollow portion of the protective shell (6).

[0021] The mass block (5) is made of carbon steel;

[0022] The protective shell (6) and the connecting rod (2) are both made of aluminum alloy or carbon steel.

[0023] In another aspect, the present invention further provides a multi-directional anti-dancing device, which is fixed to a power transmission line via a wire clamp (4), and comprises: a spacer (1), a connecting rod (2), and a pendulum (3) as claimed in any one of claims 1 to 11;

[0024] The pendulum (3) is suspended horizontally just below the spacer bar (1) via a connecting rod (2).

[0025] The length of the connecting rod (2) is determined according to the splitting radius of the spacer rod (1).

[0026] The connecting rod (2) and the pendulum (3) are fixed by welding, and the connecting rod (2) and the spacer rod (1) are fixed by bolts.

[0027] The spacer bar (1) is a binary spacer bar, a triple spacer bar, a quadruple spacer bar, a sextuple spacer bar or an octuple spacer bar.

[0028] Compared with the closest existing technology, the technical solution provided by the present invention has the following beneficial effects:

[0029] The anti-dance pendulum provided by the present invention comprises: a hollow protective shell (6), a mass block (5) located in the protective shell (6), a first spring (7) and a second spring (8); the mass block (5) is horizontally connected to the inner wall of the protective shell (6) through the first spring (7) and the second spring (8); and the height of the mass block (5) is smaller than the height of the hollow part of the protective shell (6), and has both weight-bearing and energy-dissipating functions;

[0030] The multi-directional anti-dance device provided by the present invention is fixed to a power transmission line through a wire clamp (4), and comprises a spacer bar (1), a connecting rod (2) and a pendulum (3); the pendulum (3) is suspended directly below the spacer bar (1) through the connecting rod (2), and has the functions of detuning, weighting and energy consumption, and has small anti-dance limitations and good anti-dance effect.

[0031] The present invention determines the linear stiffness and cubic stiffness of the pendulum based on the nonlinear energy tank theory, so that the anti-dance device has the functions of detuning, weighting and wide-band energy dissipation.

[0032] The mass block of the present invention can not only generate up and down motion, but also generate motion in three directions, horizontally and perpendicular to the paper surface, as well as motion in other directions generated by the sum of orthogonal vectors of each axis, so that the anti-dance device has a multi-directional anti-dance function;

[0033] The multi-directional anti-dancing device provided by the present invention can change the distribution quality of the conductor, promote the distribution characteristics of the conductor along the length of the line, so that the wind speed of each part of the conductor is different, effectively changing the dancing characteristics of the conductor length, and avoiding the easy occurrence of dancing in low wind speed and thin ice cover;

[0034] The multi-directional anti-dancing device provided by the present invention can change key parameters in a multi-split conductor system, causing the vertical natural frequency and the torsional natural frequency of the conductor to move away from each other, thereby preventing the flow of energy between the various degrees of freedom, and thus effectively preventing the occurrence of conductor galloping or other multi-degree-of-freedom coupled forms of galloping;

[0035] The multi-directional anti-dancing device provided by the present invention can produce a relatively large amplitude response condition in the range of 0 to 100 Hz for dancing of different frequencies on different lines, different conductors and under different ice coverage. Through the damping effect of the spring in the pendulum, it continuously absorbs and consumes vibration energy in multiple directions and a wide frequency range, has an energy consumption suppression effect, and can prevent the main oscillator from being damaged by excessive vibration energy, thereby effectively protecting the conductors and auxiliary hardware. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a diagram of the pendulum structure in an embodiment of the present invention;

[0037] Figure 2 This is a structural diagram of a multi-directional anti-dancing device according to an embodiment of the present invention;

[0038] Figure 3 This is a diagram showing the principle of geometric nonlinearity in an embodiment of the present invention;

[0039] Figure 4 1 is an amplitude-frequency response curve diagram of a multi-directional anti-dance device according to an embodiment of the present invention;

[0040] In the figure, 1. spacer rod, 2. connecting rod, 3. pendulum, 4. wire clamp, 5. mass block, 6. protective shell, 7. first spring, 8. second spring. DETAILED DESCRIPTION

[0041] The present invention will be described in further detail below with reference to the accompanying drawings.

[0042] Example 1

[0043] Embodiment 1 of the present invention provides a pendulum for preventing dancing, such as Figure 1 As shown, it includes a hollow protective shell 6, a mass block 5 located in the protective shell 6, a first spring 7 and a second spring 8;

[0044] The mass block 5 is horizontally connected to the inner wall of the protective shell 6 through the first spring 7 and the second spring 8 ; and the height of the mass block 5 is smaller than the height of the hollow portion of the protective shell 6 .

[0045] The protective shell 6 is cylindrical, and the mass block 5 is horizontally connected to the centers of the two end surfaces of the protective shell 6 through the first spring 7 and the second spring 8 .

[0046] The mass block 5 and the first spring 7 , the first spring 7 and the protective shell 6 , the mass block 5 and the second spring 8 , and the second spring 8 and the protective shell 6 are all connected by welding or hanging rings.

[0047] The length and stiffness of the first spring 7 and the second spring 8 are equal. The first spring 7 and the second spring 8 are both cylindrical springs or conical springs.

[0048] The height of the hollow portion of the protective shell 6 is 5 to 20 cm, its length is greater than the height of the hollow portion, and its thickness is 5 to 10 mm.

[0049] The mass block 5 is spherical, and its diameter is 20% to 80% of the height of the hollow portion of the protective shell 6 .

[0050] The material of the mass block 5 is carbon steel;

[0051] The protective shell 6 is made of aluminum alloy or carbon steel.

[0052] The Nonlinear Energy Sink (NES) theory is a novel vibration absorber technology developed based on dynamic vibration absorbers. By modifying the linear stiffness and damping of traditional vibration absorption systems (e.g., introducing a nonlinear spring into a traditional damped spring oscillator system), it aims to broaden the vibration absorption frequency range and improve the vibration reduction effect. The optimized nonlinear vibration absorber can absorb the vibration energy of the main structure over a wide frequency range, while also featuring low added mass, strong adaptability, and excellent economic efficiency.

[0053] The embodiment of the present invention determines the linear stiffness and cubic stiffness of the pendulum 3 based on NES. The advantage of geometric nonlinearity is that the nonlinear characteristics can be realized by using linear springs. The specific geometric nonlinear principle diagram is as follows: Figure 3 As shown, Figure 3 Where f is the preload of the first spring 7 / second spring 8, l is the length of the first spring 7 / second spring 8, F is the resultant external force of the pendulum 3, Δs is the displacement of the mass block 5, and Δl is the axial extension of the first spring 7 / second spring 8. Figure 3 The relationship expressed is as follows:

[0054]

[0055] In the above formula, the left side of the equal sign is the force vector triangle, and the right side is the deformation triangle.

[0056] The corresponding geometric relationship is:

[0057] l 2 +Δs 2 =(l+Δl) 2

[0058] Joint and l 2 +Δs 2 =(l+Δl) 2 , eliminating Δl, we get:

[0059]

[0060] Will Do Taylor expansion near the origin Δs = 0, retaining the first cubic terms, and we have:

[0061]

[0062] Therefore, it can be seen that the linear stiffness of the pendulum 3 is determined based on the preload and length of the first spring 7 / second spring 8, and the cubic stiffness of the pendulum 3 is determined based on the preload, length and stiffness of the first spring 7 / second spring 8, specifically:

[0063] The linear stiffness of pendulum 3 is determined as follows:

[0064]

[0065] Wherein, k1 is the linear stiffness of the pendulum 3, f is the preload force of the first spring 7 / the second spring 8, and l is the length of the first spring 7 / the second spring 8.

[0066] The cubic stiffness of pendulum 3 is determined as follows:

[0067]

[0068] Wherein, k3 is the cubic stiffness of the pendulum 3, and k is the stiffness of the first spring 7 / the second spring 8.

[0069] Example 2

[0070] Embodiment 2 of the present invention provides a multi-directional anti-dance device, such as Figure 2 As shown, the multi-directional anti-dancing device is fixed to the transmission line through a wire clamp 4, which includes a spacer 1, a connecting rod 2 and the pendulum 3 of embodiment 1;

[0071] The pendulum 3 is arranged horizontally and is suspended directly below the spacer bar 1 through the connecting rod 2 .

[0072] The length of the connecting rod 2 is determined according to the splitting radius of the spacer rod 1.

[0073] The connecting rod 2 and the pendulum 3 are fixed by welding, and the connecting rod 2 and the spacer bar 1 are fixed by bolts.

[0074] The spacer bar 1 is a binary spacer bar, a triple spacer bar, a quadruple spacer bar, a sextuple spacer bar or an octuple spacer bar.

[0075] The multi-directional anti-dance device provided in Example 2 of the present invention not only has the most basic anti-dance function, but also has detuning, weight-reducing and energy-consuming functions, as follows:

[0076] (1) Weight function

[0077] Changing the distribution quality of the conductors promotes the distribution characteristics of the conductors along the length of the line, so that the wind speeds at different parts of the conductors are different, effectively changing the dancing characteristics of the conductor length and avoiding the easy occurrence of dancing at low wind speeds and thin ice cover.

[0078] (2) Detuning function

[0079] Changing the key parameters in the multi-split conductor system (such as increasing the ice wind threshold of dancing by changing the torsional stiffness and rotational inertia of the conductor) will cause the vertical natural frequency and the torsional natural frequency of the conductor to move away from each other, thereby preventing the energy flow between the various degrees of freedom, thereby effectively avoiding conductor dancing or the occurrence of other multi-degree-of-freedom coupling forms of dancing.

[0080] (3) Energy consumption function

[0081] According to mechanical vibration theory, the forced vibration equation of the vibration structure of the shock absorber is:

[0082] x(t) is the displacement of mass block 5, i.e. Δs; is the acceleration of mass block 5, Ω is the external excitation frequency, when the mass of mass block 5 is m = 200 kg, the cubic stiffness of pendulum 3 is k3 = 20 000 N / m 3 When the net external force F of pendulum 3 is 3N, according to the results of nonlinear dynamic analysis, we can get Figure 4 The amplitude-frequency response curve is shown in the figure. Figure 4 It can be seen that the vibration absorber's response is non-zero at all frequencies. In the dynamic system composed of the wire and the multi-directional vibration absorber, this characteristic clearly facilitates the multi-directional vibration absorber's ability to continuously absorb and dissipate the system's vibration energy through the damping action of the spring, thus suppressing the energy consumption of ice dancing at all frequencies.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Ordinary technicians in the relevant field can still modify or replace the specific implementation methods of the present invention with equivalents by referring to the above embodiments. Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention are within the scope of protection of the claims of the present invention to be approved.

Claims

1. A multi-directional anti-dance device, characterized in that: include: Spacer rod (1), connecting rod (2) and pendulum (3); The pendulum (3) is suspended horizontally directly below the spacer bar (1) via the connecting rod (2); The pendulum (3) comprises: a hollow protective shell (6), a mass block (5) located inside the protective shell (6), a first spring (7) and a second spring (8); The mass block (5) is horizontally connected to the inner wall of the protective shell (6) via a first spring (7) and a second spring (8); and the height of the mass block (5) is smaller than the height of the hollow portion of the protective shell (6); The linear stiffness of the pendulum is determined based on the preload force and length of the first spring (7) / second spring (8), and its cubic stiffness is determined based on the preload force f, length l and stiffness k of the first spring (7) / second spring (8); The linear stiffness of the pendulum (3) is determined as follows: Where k1 is the linear stiffness of the pendulum (3); The cubic stiffness of the pendulum (3) is determined as follows: Where k3 is the cubic stiffness of the pendulum (3).

2. The multi-directional anti-dance device according to claim 1, characterized in that: The protective shell (6) is cylindrical, and the mass block (5) is horizontally connected to the centers of the two end surfaces of the protective shell (6) via a first spring (7) and a second spring (8).

3. The multi-directional anti-dancing device according to claim 1, characterized in that: The mass block (5) and the first spring (7), the first spring (7) and the protective shell (6), the mass block (5) and the second spring (8), and the second spring (8) and the protective shell (6) are all connected in the form of welding or hanging rings.

4. The multi-directional anti-dancing device according to claim 1, characterized in that: The length and stiffness of the first spring (7) and the second spring (8) are equal.

5. The multi-directional anti-dancing device according to claim 1, characterized in that: The first spring (7) and the second spring (8) are both cylindrical springs or conical springs.

6. The multi-directional anti-dancing device according to claim 2, characterized in that: The height of the hollow portion of the protective shell (6) is 5 to 20 cm, its length is greater than the height of the hollow portion, and its thickness is 5 to 10 mm.

7. The multi-directional anti-dancing device according to claim 6, characterized in that: The mass block (5) is spherical, and its diameter is 20% to 80% of the height of the hollow portion of the protective shell (6).

8. The multi-directional anti-dancing device according to claim 1, characterized in that: The mass block (5) is made of carbon steel; The material of the protective shell (6) is aluminum alloy or carbon steel.

9. The multi-directional anti-dancing device according to claim 1, characterized in that: The length of the connecting rod (2) is determined according to the splitting radius of the spacer rod (1).

10. The multi-directional anti-dancing device according to claim 1, characterized in that: The connecting rod (2) and the pendulum (3) are fixed by welding, and the connecting rod (2) and the spacer rod (1) are fixed by bolts.

11. The multi-directional anti-dancing device according to claim 1, characterized in that: The spacer bar (1) is a binary spacer bar, a triple spacer bar, a quadruple spacer bar, a sextuple spacer bar or an octuple spacer bar.

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