Inerter vibration control method for power transmission tower

Abstract

The invention provides a power transmission tower inertial vibration control method, and belongs to the technical field of structural vibration control and damping. According to the technical scheme, an inerter high-performance vibration reduction technology is introduced, the high-performance vibration control problem of the power transmission tower is solved, and meanwhile, a transmission and dissipation mechanism of vibration energy of the power transmission tower in different-configuration vibration reducer connection modes is researched. On the basis, a high-performance inertial vibration reduction energy consumption element is designed based on the inertial vibration reduction principle, the passive vibration control device which can be tuned on site and is light in weight and high in performance is formed, and the actual vibration control requirement of the power transmission tower is met. The most unfavorable response control rate of vibration of the power transmission tower can exceed 20%, and under the same control effect, compared with a traditional tuned mass damper, the weight is reduced by more than 20%. The dynamic catastrophe effect of the power transmission tower structure is effectively controlled, the international first-class safety and toughness disaster prevention level is achieved, and the electric power construction technology level of the state grid is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of structural vibration control and shock absorption, and specifically relates to an inertial vibration control method for a transmission tower. Background Art

[0002] Transmission towers are typical high-flexible structures. The dynamic disaster effects under strong winds, earthquakes, etc. are extremely significant, and there are great safety hazards. Especially in Qinghai, which is located on the Qinghai-Tibet Plateau, with a high altitude, harsh climate, complex geological conditions and wind environment, strong winds and earthquakes occur from time to time. In addition, it is also common for ice-covered transmission lines to stimulate vibrations of transmission towers. The large vibration of the transmission line tower-line system can easily cause damage to the transmission line structure or hardware, thereby affecting the safe operation of the transmission line. Especially in recent years, with the application of shared poles and towers, the vibration control of transmission towers is particularly important for the safe operation of base station equipment. At present, the wind-resistant reinforcement of existing transmission lines is mainly based on the concept of "resistance" to improve the structural stiffness. On the one hand, the cost is high, and on the other hand, the control effect of vibration acceleration is poor.

[0003] In recent years, structural vibration control and shock absorption technology has achieved rapid development and wide application in the field of building structures, but its application in the field of power transmission engineering is almost blank, and there is no high-performance vibration control technology. Traditional building bridge-based vibration control equipment cannot meet the installation requirements of structural systems such as transmission towers and cannot be used directly. In view of the above problems, how to construct a high-performance inertial vibration control method suitable for transmission tower structures is a technical problem to be solved in this field. Summary of the invention

[0004] The technical problem to be solved by the present invention is: how to construct a high-performance inertial vibration control method suitable for transmission tower structures.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0006] A method for controlling inertial vibration of a transmission tower, in which an inertial capacity element is combined with a spring damping mechanical element, and the inertial capacity element and the spring damping mechanical element are installed and tuned on the transmission tower using components including connecting rods and cables.

[0007] Preferably, the inertial element is a gear rack type inertial element.

[0008] Preferably, the gear rack type inertial capacity element includes a gear, a rack, and a first flywheel, wherein two gears are provided, the two gears are meshed with each other, one of the gears is meshed with the rack for transmission, the other gear is fixed to the first flywheel, one connecting end is connected to the rack, and the other connecting end is located on the movement stroke of the rack.

[0009] Preferably, the inertia element is a ball screw type inertia element.

[0010] Preferably, the ball screw type inertial element includes a screw, a ball nut, a bearing, and a second flywheel, wherein the ball nut is rotatably connected to the bearing, the second flywheel is fixed to the ball nut, the ball nut is threadedly connected to the screw, one connecting end is connected to the screw, and the other connecting end is located on the movement stroke of the screw.

[0011] Preferably, the wind load and earthquake dynamics equations of the transmission tower are as follows:

[0012]

[0013] Where M, C, K represent the mass stiffness and damping matrices, f(t) is the wind load vector, represents the earthquake time history, and x is the vibration response vector.

[0014] Preferably, when the transmission tower is coupled to any i, j node inertia absorber, its motion equation is as follows:

[0015]

[0016] Among them, f1(t) and f2(t) are the control forces output by the two connecting ends of the vibration reduction device, J1 and J2 are the positioning vectors considering the installation position of the vibration reducer; the parameters of the inertia capacity shock absorber are vibration absorbing mass m, elastic coefficient k, damping coefficient c, and inertia capacity coefficient b; the vibration displacement of the vibration absorbing mass node is y.

[0017] As a preferred embodiment, the reduced-order two-degree-of-freedom model of the power system of the transmission tower is as follows:

[0018]

[0019] Among them, M, C, K are generalized mass, damping, and stiffness coefficients, ξ(t) is the generalized excitation time history, and the parameters It is the characteristic coefficient considering the installation position of the vibration absorber on the transmission tower.

[0020] The present invention provides a method for controlling inertial vibration of a transmission tower. The technical solution introduces high-performance vibration reduction technology of inertia capacity to solve the problem of high-performance vibration control of transmission towers, and at the same time studies the transmission and dissipation mechanism of vibration energy of transmission towers under different configurations of vibration absorber connection modes. On this basis, the present invention designs high-performance inertial vibration reduction and energy dissipation elements based on the inertial capacity vibration reduction principle to form a field-tunable, lightweight, high-performance passive vibration control device to meet the actual transmission tower vibration control needs.

[0021] In addition, the present invention proposes a design method for a high-performance inertial vibration control device for a transmission tower that meets actual installation requirements. Combining the vibration characteristics of the transmission tower and the excitation characteristics of natural disasters, considering the installation restrictions of the transmission tower on the vibration control device, the "transmission tower-vibration control device" coupling motion equation is constructed. Based on the dynamic optimization control theory, the robust optimal parameter empirical formula of the high-performance vibration control device of the transmission tower is proposed, which provides a basis for the parameter optimization design of the transmission tower vibration damper.

[0022] The present invention can make the most adverse response control rate of transmission tower vibration exceed 20%. Under the same control effect, it can reduce weight by more than 20% compared with the traditional tuned mass damper. It can effectively control the dynamic disaster effect of the transmission tower structure, achieve the world-class safety resilience disaster prevention level, and significantly improve the power construction technology level of the State Grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of a gear-rack type inertial capacity element in the present invention;

[0024] Figure 2 It is a structural schematic diagram of a ball-screw type inertia element in the present invention;

[0025] Figure 3 It is a schematic diagram of the principle of the inertia element in the present invention;

[0026] Figure 4 It is a structural schematic diagram of a transmission tower in the present invention;

[0027] Figure 5 It is a full-order dynamic model diagram of a transmission tower-shock absorber in the present invention;

[0028] Figure 6 It is a diagram of a transmission tower-shock absorber reduced-order dynamics model in the present invention;

[0029] In the figure:

[0030] 1. Gear 2. Rack 3. First flywheel 4. Screw

[0031] 5. Ball nut 6. Bearing 7. Second flywheel. DETAILED DESCRIPTION

[0032] The specific embodiments of the present invention will be described in detail below. In order to avoid too much unnecessary details, the well-known structures or functions will not be described in detail in the following examples. The approximate language used in the following examples can be used for quantitative expression, indicating that the quantity can be allowed to have a certain change without changing the basic function. Unless otherwise defined, the technical and scientific terms used in the following examples have the same meaning as those generally understood by those skilled in the art to which the present invention belongs.

[0033] According to previous research results, through the gear rack ( Figure 1 ), or ball screw ( Figure 2 ) Mechanical transmission components, in conjunction with the flywheel, can realize the conversion of the relative motion between the two ends of the element into the rotation of the flywheel. The schematic diagram of the inertia element is shown as follows Figure 3 , so that the control force f output at both ends of the mechanical element in , which is proportional to the relative acceleration of the two ends As shown in formula (1),

[0034]

[0035] In the formula, the proportionality coefficient b has the same dimension as mass, which is called the inertia coefficient, or apparent mass. Through reasonable mechanical construction, the inertia coefficient b can reach hundreds or thousands of times its physical mass. In other words, the inertia can provide an inertial control force hundreds or thousands of times its own weight. Therefore, applying it in the design of vibration control devices can greatly improve the energy consumption capacity of vibration control devices.

[0036] By integrating inertial capacitance mechanical elements into the design of transmission tower vibration devices, combining inertial capacitance elements with traditional spring damping mechanical elements, and coordinating with connecting rods, cables and other components to achieve installation and tuning on the transmission tower, high-performance energy dissipation and vibration reduction of the transmission tower can be achieved.

[0037] According to the structural dynamics analysis theory, the tall structure of transmission towers (such as Figure 4 ) is simplified into a multi-degree-of-freedom cantilever structure, such as Figure 5 , which can be expressed in wind load and earthquake dynamics equation as:

[0038]

[0039] Where M, C, K represent the mass stiffness and damping matrices, f(t) is the wind load vector, represents the earthquake time history, and x is the vibration response vector. When the system is coupled to the inertial absorber at any i and j nodes, the motion equation changes to:

[0040]

[0041] Among them, f1(t) and f2(t) are the control forces output by the two connecting ends of the vibration reduction device, and J1 and J2 are the positioning vectors considering the installation position of the vibration reducer. The parameters of the inertia capacity shock absorber are vibration absorbing mass m, elastic coefficient k, damping coefficient c, and inertia capacity coefficient b. The vibration displacement of the vibration absorbing mass node is y. The vibration energy of the transmission tower can be absorbed by the vibration of the vibration absorbing mass and then consumed by the damper and inertia capacity element. Different output control forces can be adjusted through different damper structures and installation positions, thereby controlling the vibration response of the transmission tower.

[0042] By reducing the dynamic degrees of freedom of the full-order model and expressing the dynamic equation (3) in modal coordinates, we can obtain a reduced-order two-degree-of-freedom model of the dynamic system:

[0043]

[0044] Among them, M, C, K are generalized mass, damping, and stiffness coefficients, ξ(t) is the generalized excitation time history, and the parameters This is the characteristic coefficient of the installation position of the vibration absorber on the transmission tower. Using this equation, combined with the H-norm optimization criterion of dynamic optimization, the optimal parameter value of the vibration absorber can be obtained.

[0045] The present invention aims at several major technical defects in the prior art, such as the lack of consideration of the actual installation location, the lack of multi-vibration scenario parameter design methods and on-site misalignment parameter re-tuning. The present invention studies the use of inertia vessels, elasticity, damping, mass components and cables, levers, chain rods and other structures and mechanical components to design a field-tunable, lightweight and high-performance passive vibration control device for the transmission tower structure, solving the problems of the difficulty in installing and using vibration control devices on transmission towers. The light-weight and high-performance vibration control of the transmission tower is achieved, and the most unfavorable response control rate is effectively improved. Under the same control effect, compared with the traditional tuned mass damper, the weight can be significantly reduced, reducing its burden on the transmission tower.

[0046] The embodiments of the present invention are described in detail above, but the contents are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the scope of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for controlling inertial vibration of a transmission tower, characterized in that: In the method, an inertia capacity element is combined with a spring damping mechanical element, and the inertia capacity element and the spring damping mechanical element are installed and tuned on a transmission tower using components including connecting rods and cables.

2. The method for controlling inertial vibration of a transmission tower according to claim 1, characterized in that: The inertia element is a gear rack type inertia element.

3. The method for controlling inertial vibration of a transmission tower according to claim 2, characterized in that: The gear rack type inertial element comprises a gear (1), a rack (2), and a first flywheel (3), wherein the gear (1) is provided with two gears (1), the two gears (1) are meshed with each other, one of the gears (1) is meshed with the rack (2) for transmission, and the other gear (1) is fixed to the first flywheel (3), one connecting end is connected to the rack (2), and the other connecting end is located on the movement stroke of the rack (2).

4. The method for controlling inertial vibration of a transmission tower according to claim 1, characterized in that: The inertia component is a ball screw type inertia component.

5. The method for controlling inertial vibration of a transmission tower according to claim 4, characterized in that: The ball screw type inertial element comprises a screw (4), a ball nut (5), a bearing (6), and a second flywheel (7), wherein the ball nut (5) is rotatably connected to the bearing (6), the second flywheel (7) is fixed to the ball nut (5), the ball nut (5) is threadedly connected to the screw (4), one connecting end is connected to the screw (4), and the other connecting end is located on the movement stroke of the screw (4).

6. The method for controlling inertial vibration of a transmission tower according to claim 1, characterized in that: The wind load and earthquake dynamic equations of the transmission tower are as follows: Where M, C, K represent the mass stiffness and damping matrices, f(t) is the wind load vector, represents the earthquake time history, and x is the vibration response vector.

7. The method for controlling inertial vibration of a transmission tower according to claim 6, characterized in that: When the transmission tower is coupled to an inertial absorber at any i and j nodes, its motion equation is as follows: Among them, f1(t) and f2(t) are the control forces output by the two connecting ends of the vibration reduction device, J1 and J2 are the positioning vectors considering the installation position of the vibration reducer; the parameters of the inertia capacity shock absorber are vibration absorbing mass m, elastic coefficient k, damping coefficient c, and inertia capacity coefficient b; the vibration displacement of the vibration absorbing mass node is y.

8. The method for controlling inertial vibration of a transmission tower according to claim 7, characterized in that: The reduced-order two-degree-of-freedom model of the power system of the transmission tower is shown as follows: Among them, M, C, K are generalized mass, damping, and stiffness coefficients, ξ(t) is the generalized excitation time history, and the parameters It is the characteristic coefficient considering the installation position of the vibration absorber on the transmission tower.

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