CN-119651464-B - Vibration damper based on autonomous excitation internal resonance principle and vibration damping method

CN119651464BCN 119651464 BCN119651464 BCN 119651464BCN-119651464-B

Abstract

The invention discloses a damper and a damping method based on an autonomous excitation internal resonance principle, wherein the damper comprises a power transmission wire, a plurality of cantilever type damper bodies fixed on the power transmission wire through fastening screws and nuts, wherein the power transmission wire and the cantilever type damper bodies are orthogonal in space position, the natural frequency ratio is a preset value, the cantilever type damper bodies and the power transmission wire form an autonomous excitation internal resonance system, and the autonomous excitation internal resonance system is simulated to obtain the mode damping of the cantilever type damper bodies under the condition that the damping effect of the cantilever type damper bodies is the best under the condition that the natural frequency ratio is the preset value, so that the mode frequency of the cantilever type damper bodies is adjusted. The invention utilizes the principle of autonomous parametric excitation internal resonance to realize the great absorption of the vibration energy of the transmission line so as to achieve the purpose of passive vibration absorption.

Inventors

Mei Zhenchao
XIONG HUI
LIU BO
WANG SHENG
CAI QINGHUA
QI YEPENG
Peng jingang
ZHENG WENJUAN
WANG HUI

Assignees

国网江西省电力有限公司上饶供电分公司

Dates

Publication Date: 20260508
Application Date: 20241209

Claims (4)

1. A damping method based on autonomous excitation internal resonance principle adopts a damper comprising: A power transmission wire; The cantilever type shock hammers are fixed on the electric transmission wires through fastening screws and nuts; the transmission wire is orthogonal to the space position of the cantilever type shock absorber hammer, and the ratio of the natural frequencies is a preset value; The cantilever type shock-absorbing hammer and the power transmission wire form an autonomous parametric excitation internal resonance system, and the first two-order modes of the system structure are respectively a first-order bending mode of a vertical cantilever beam and the power transmission wire in the cantilever type shock-absorbing hammer, and are respectively defined as a direct excitation mode and a parameter excitation mode; The optimal modal damping of the cantilever type damper under the condition that the ratio of the transmission lead to the natural frequency is a preset value is obtained by simulating the autonomous parametric excitation internal resonance system, so that the modal damping of the cantilever type damper is adjusted; the method is characterized by comprising the following steps of: step S1, measuring modal frequency of a power transmission wire ; S2, selecting a vertical cantilever beam and a spherical mass block with specific dimensions to enable the modal frequencies of the cantilever type shock damper and the power transmission wire to meet And based thereon, construct a model: the model is a lumped parameter model of an autonomous parametric internal resonance system, and the model is described by the following dimensionless global coupling motion equation and expressed as follows: ; ; Wherein, the Representing the displacement in the horizontal direction, i.e. the displacement of the parametric excitation mode, Representing the displacement in the vertical direction, i.e. the displacement of the direct excitation mode, Represents the modal damping coefficient in the horizontal direction, Represents the modal damping coefficient in the vertical direction, Represents the modal frequencies in the horizontal direction, Representing the modal frequencies in the vertical direction; representing the nonlinear coupling coefficient in the horizontal direction, Representing a nonlinear coupling coefficient in a vertical direction; representing the magnitude of the drive, The driving angular frequency is indicated as such, Representing small disturbance parameters; Wherein, the formulas (1) and (2) are second-order ordinary differential equations with weak secondary coupling terms, which are deduced by adopting a multi-scale method to quantify the response characteristics of the research system, and approximate solutions of the formulas (1) and (2) are obtained and expressed as fast variable time scales And slow variable time scale Specifically: ; ; Wherein, the Representing an approximate solution in the vertical direction, Representing an approximate solution in the horizontal direction, Representing the principal solution in the vertical direction when not affected by the small perturbation parameters, Representing the principal solution in the horizontal direction when not affected by the small perturbation parameters, Representing the first correction of the system response in the vertical direction due to the small disturbance parameters, Representing the first correction of the system response in the horizontal direction due to the small disturbance parameters, Representing a high order small amount; the chained rules are employed and higher order terms of second order and above are ignored, the first and second derivatives over time are expressed as: ; ; Wherein, the Representing the first derivative with respect to time t, Representing the second derivative with respect to time t, Representing a fast variable time scale Is used for the partial derivative of (a), Representing slow variable time scale Is a partial derivative of (2); Bringing formulae (5) and (6) into formulae (1) and (2) and separating the two-stage components And The method can obtain: Level of step : ; ; Wherein, the formula (7) represents a 0-order equation in the vertical direction, and the formula (8) represents a 0-order equation in the horizontal direction; Level of step : ; ; Wherein, the formula (9) represents a first order correction equation in the vertical direction, the formula (10) represents a first order correction equation in the horizontal direction, A first order correction solution in the horizontal direction is represented, A first order correction solution in the vertical direction; the analytical solutions of formulas (9) and (10) are further expressed as: ; ; Wherein, the Representing a first order approximation amplitude term to be determined in the horizontal direction, Representing a first order approximation amplitude term to be determined in the vertical direction, Is the conjugate complex term of each item in the formula; Introducing first frequency detuning parameters Mode frequencies for describing direct excitation modes And driving frequency Level of detuning between, introducing a second frequency detuning parameter Mode frequencies of direct excitation mode and parametric excitation mode And The level of detuning between, expressed as: ; ; bringing formulae (11) - (14) into formulae (9) and (10) to obtain: ; ; Wherein, the A kinetic equation representing a first order correction term in the vertical direction, Representing the impact of the slow variable time scale in the vertical direction and the damping effect, Representing the effect of a nonlinear coupling effect in the horizontal direction on the vertical direction, Indicating the influence of the external driving force on the vertical direction, The impact and damping effect of slow variable time scale in the horizontal direction; Middle and long term item (15) And the medium-long term of formula (16) The coefficients of (2) are zero respectively, and can be obtained: ; ; wherein equation (17) represents a steady state equation in the vertical direction, equation (18) represents a steady state equation in the horizontal direction, Representation of Complex conjugate of (a); Further, the polar coordinate form representation is imported And : ; Wherein, the And First order approximate magnitudes of the parametric excitation mode and the direct excitation mode, respectively A phase difference between the real part of the vibration response and the periodic driving signal; Taking equation (19) into equations (17) and (18) and separating the real and imaginary parts, the following averaging equation can be obtained: ; ; ; ; Wherein, the Indicating the phase difference between the external driving force and the vertical direction vibration phase, Representing the phase difference between the vibration phases in the horizontal direction and the vertical direction; When the autonomous parametric excitation internal resonance system reaches a steady-state vibration state under the excitation of a driving signal, the amplitude and the phase are kept stable and unchanged; Satisfies the condition , The steady state conditions that can be obtained are as follows: ; ; Bringing equations (24) and (25) into equations (20) - (23) can result from steady state equations of motion of the self-excited internal resonance system: ; ; ; ; Carrying out numerical simulation on formulas (26) - (29) by writing an iterative program by MATLAB, verifying the influence of the modal damping on a direct excitation modal amplitude-frequency response curve, and obtaining the optimal modal damping; S3, assembling a clamp, a vertical cantilever beam and a spherical mass block into a cantilever type shock-absorbing hammer according to the modal damping of the step S2, and fixing four identical cantilever type shock-absorbing hammers to proper positions on a power transmission line, namely a power transmission line through a plurality of fastening screws and nuts; S4, observing whether the cantilever type damper vibrates or not when the transmission wire vibrates at low frequency under the action of external force, and simultaneously inhibiting the vibration intensity of the transmission wire; If the cantilever type shock-absorbing hammer vibrates, the shock absorption is successfully realized, otherwise, the vertical cantilever beams with different lengths are replaced, and the shock absorption effect is continuously observed until the cantilever type shock-absorbing hammer can vibrate obviously, so that the shock absorption effect is achieved.
2. The method of damping according to claim 1, wherein the damper comprises: The cantilever type damper comprises: the clamp is provided with a plurality of threaded holes, and the fastening screw and the nut fix the clamp on the electric transmission wire through the threaded holes; one end of the vertical cantilever is fixed on the clamp, and the ratio of the transmission wire to the natural frequency of the cantilever type shock absorber hammer is a preset value by adjusting the length of the vertical cantilever; The spherical mass block is fixed at the other end of the vertical cantilever beam, the size of the spherical mass block is determined according to the required modal frequency of the cantilever type shock absorber hammer, and the modal frequency of the spherical mass block is changed by adjusting the radius of the spherical mass block so as to be matched with the modal frequency of the power transmission wire.
3. The method of claim 2, wherein the predetermined value is 1:2.
4. The method of claim 2, wherein the number of cantilever shock hammers is 4 and are disposed equidistant from each other.

Description

Vibration damper based on autonomous excitation internal resonance principle and vibration damping method Technical Field The invention belongs to the technical field of power transmission lines, and particularly relates to a damper based on an autonomous excitation internal resonance principle and a damping method. Background In a power transmission line, a damper is an important protection device, and is mainly used for reducing vibration of the power transmission line caused by wind power, earthquake or other external forces so as to improve the stability and reliability of the line. The transmission overhead line has higher pole position and larger span. When the wire is subjected to wind force, vibration and galloping occur. At this time, the transmission line is periodically bent and fatigue is generated at the bending position. At this time, after the damper is hung to a proper position of the power transmission line, the damper can generate motion in the opposite direction to the wire in the vibration process of the power transmission line, so that the vibration of the power transmission line is eliminated or weakened, and the service life of the power transmission line is prolonged. The damper is a tuned vibration damper that produces an optimal vibration damping effect when its natural frequency matches the vibration frequency of the transmission line, thereby transferring more of the vibration energy of the transmission line into the damper system and dissipating that energy through the damper's own damping action. At present, the wind speed range for causing breeze vibration of the power transmission line is generally 0.5-10m/s, the vibration frequency is 2-140Hz, and the vibration direction is changeable. Most of the existing damper can only resonate with a power transmission line in a natural environment in a single direction, and vibration energy absorption efficiency is low, so that a good damping effect cannot be achieved. Therefore, it is needed to provide a damper which is suitable for the vibration environment of the power transmission line in multiple directions and is used for absorbing the vibration energy generated by the power transmission line to achieve the damping effect. Disclosure of Invention In order to overcome the above-mentioned drawbacks of the prior art, the damper according to the present invention, which is based on the principle of autonomous parametric excitation of internal resonance, comprises: A power transmission wire; The cantilever type shock hammers are fixed on the electric transmission wires through fastening screws and nuts; the transmission wire is orthogonal to the space position of the cantilever type shock absorber hammer, and the ratio of the natural frequencies is a preset value; The cantilever type shock-absorbing hammer and the power transmission wire form an autonomous parametric excitation internal resonance system, and the first two-order modes of the system structure are respectively a first-order bending mode of a vertical cantilever beam and the power transmission wire in the cantilever type shock-absorbing hammer, and are respectively defined as a direct excitation mode and a parameter excitation mode; and simulating the autonomous parametric excitation internal resonance system to obtain the optimal modal damping of the cantilever type damper under the condition that the ratio of the transmission lead to the cantilever type damper meets the natural frequency is a preset value, so that the modal damping of the cantilever type damper is adjusted. Further, the damper includes: The cantilever type damper comprises: the clamp is provided with a plurality of threaded holes, and the fastening screw and the nut fix the clamp on the electric transmission wire through the threaded holes; one end of the vertical cantilever is fixed on the clamp, and the ratio of the transmission wire to the natural frequency of the cantilever type shock absorber hammer is a preset value by adjusting the length of the vertical cantilever; The spherical mass block is fixed at the other end of the vertical cantilever beam, the size of the spherical mass block is determined according to the required modal frequency of the cantilever type shock absorber hammer, and the modal frequency of the spherical mass block is changed by adjusting the radius of the spherical mass block so as to be matched with the modal frequency of the power transmission wire. Further, the preset value is 1:2. Further, the number of the cantilever type shock-absorbing hammers is 4, and the cantilever type shock-absorbing hammers are arranged at equal intervals. A damping method based on an autonomous parametric excitation internal resonance principle comprises the following steps: Step S1, measuring modal frequency omega 2 of a power transmission wire; Step S2, selecting a vertical cantilever beam and a spherical mass block with specific dimensions, enabling the modal frequencies of the cantilever typ