A tower wind load model test device and test method

Abstract

The present invention provides a tower wind load model test device and test method, the device includes a tower simulation and a damping adjustment unit, an eddy current conductor assembly and an electromagnetic assembly of the damping adjustment unit, the eddy current conductor assembly includes an eddy current conductor and a magnetic conductive back plate, and an air gap is left between the electromagnetic assembly and the eddy current conductor. The method includes constructing a tower simulation according to a scale ratio, determining the thickness of the longitudinal main tower rod of the tower simulation according to the thickness and elastic modulus of the longitudinal main tower rod of the tower and the elastic modulus of the tower simulation; screening out the critical vortex vibration starting wind speed of the tower that is less than the preset safe wind speed from the vortex vibration starting wind speed of the tower during each order of vibration; determining the optimal test simulation wind speed of the tower simulation according to the critical vortex vibration starting wind speed and the wind speed ratio; and the electromagnetic assembly adjusts the initial damping force of the damping adjustment unit to the target damping force. The present invention has the advantages of improving the accuracy and reliability of the test results and reducing the safety hazards of the tower.

Description

Technical Field

[0001] The invention relates to the field of tower wind load testing, and in particular to a tower wind load model testing device and a testing method. Background Art

[0002] High-voltage transmission line towers are an important and widely used lifeline engineering structure. With the continuous expansion of facility scale and the continuous improvement of voltage level, the tower height and transmission line span are also increasing. High-rise, ultra-high voltage and large-span transmission line towers have become a trend. Different from general civil engineering structures, lattice towers, as a common tower for high-voltage transmission line towers, are highly flexible and wind-sensitive. Wind load is the control load of lattice tower design. The greater the height and span of the lattice tower, the wind load will increase exponentially, which is easy to cause tower damage. In severe cases, it will lead to the paralysis of the entire power system. However, due to the randomness of wind loads, as well as the complex airflow separation and vortex shedding generated by wind flow passing through the lattice tower, the wind effect problem of lattice towers becomes more complicated. It can be seen that wind loads are not only crucial to the overall structural design of transmission line towers, but also play a decisive role in the safety and economy of tower design.

[0003] To solve the above problems, the design wind load of the existing lattice tower structure usually needs to be determined through wind tunnel tests, especially the wind-induced vibration and wind load distribution of the tower under different wind speeds, wind directions and geographical conditions. It is necessary to use wind tunnel experiments to obtain accurate simulation data to study the wind load and wind-induced vibration characteristics of the lattice tower structure. The wind load on the structure includes static wind load and dynamic wind load. The static wind is related to the structural shape, and the dynamic wind is related to the structural response. Therefore, in order to obtain accurate structural wind loads, the model in the wind tunnel test must not only meet the requirements of maintaining the same appearance as the prototype, but also ensure that the stiffness satisfies the similarity relationship (related to static wind). At the same time, the damping ratio of the structure itself affects its wind-induced vibration response, and the simulation of the wind tunnel model damping (related to dynamic wind) cannot be ignored. In the existing lattice tower wind tunnel tests, the precise processing of the aeroelastic model has the following problems:

[0004] 1. During the experimental simulation, once the model is processed, the structural damping is determined and difficult to adjust. To solve the above problems, the usual method is to use a core beam and outer shell combination. Due to the large number of rods and complex connections, the damping ratio is usually high and the integrity of the model is insufficient. In this case, the wind-induced vibration response obtained by the wind tunnel test is smaller than that of the prototype, which directly affects the wind load design of the actual structure and poses potential safety hazards. It directly leads to the wind load design of the actual structure being dangerous, which may lead to the durability and safety of the structure being unable to be effectively guaranteed under extreme weather conditions, posing a huge safety risk.

[0005] Second, the existing lattice tower is usually composed of multiple complex angle steel components, and the existing processing methods are difficult to meet the requirements of appearance and stiffness at the same time. Although the 3D printing technology gradually introduced in recent years can be used to make tower models, its material properties are very different from those of steel and cannot meet the requirements of shape accuracy and structural stiffness at the same time; at the same time, due to the excessive damping ratio of the 3D printed model, the vibration characteristics of the model cannot match the actual steel tower, thus affecting the accuracy of the experimental results. It can be seen that the traditional tower wind load model cannot meet the requirements of appearance, stiffness, quality and damping at the same time, and the operation is complicated, the process is numerous, and it is difficult to control the overall weight.

[0006] 3. The lattice tower has a huge number of rods and nodes, and each node has multiple rods intersecting. The positioning and connection of the rods are extremely difficult and inefficient. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a tower wind load model test device and test method which can improve the accuracy and reliability of wind tunnel test results and reduce the potential safety hazards of the tower.

[0008] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0009] A tower wind load model test device includes a tower simulation component and a damping adjustment unit for ensuring the accuracy of dynamic wind load determination, wherein the damping adjustment unit includes an eddy current conductor assembly and an electromagnetic assembly, wherein the eddy current conductor assembly is installed on the top of the tower simulation component, the eddy current conductor assembly includes an eddy current conductor and a magnetic back plate arranged in a superimposed manner, and the magnetic back plate is located between the tower simulation component and the eddy current conductor; the electromagnetic assembly is installed on the top surface of the test wind tunnel, and the electromagnetic assembly and the eddy current conductor are arranged relative to each other with an air gap.

[0010] Furthermore, the tower simulation is a lattice tower simulation, and the lattice tower simulation is formed by connecting a plurality of groups of modular tower units along the length direction of the lattice tower simulation, and each group of the modular tower units is enclosed by two half-side processed segments.

[0011] Furthermore, the half-side processing segment includes a plurality of longitudinal main tower rods arranged along the circumference of the lattice tower, cross-connecting rods connected between adjacent longitudinal main tower rods, frame-type connecting rods connected in the cross-connecting rods, angle connecting rods connected in the frame-type connecting rods, and triangular connecting rods connected in the angle connecting rods, wherein the cross-connecting rods are arranged in multiple groups along the length direction of the longitudinal main tower rods and are connected to each other end to end; the frame-type connecting rods are located in adjacent cross-connecting rods on both sides of the longitudinal main tower rods.

[0012] Furthermore, the electromagnetic assembly includes an electromagnet, a controller, a voltage-stabilized power supply and a vibration displacement detector, wherein the electromagnet is installed on the top surface of the test wind tunnel through a connecting rod, and the arrangement length of the electromagnet covers the vibration range of the tower simulation during the test; the vibration displacement detector is installed on the tower simulation, and is used to detect the real-time vibration displacement value of the tower simulation under different wind loads; the vibration displacement detector, the controller and the voltage-stabilized power supply are electrically connected in sequence; the controller is used to control and adjust the excitation current of the electromagnet through the voltage-stabilized power supply according to the real-time vibration displacement value of the vibration displacement detector, so as to adjust the damping force of the damping adjustment unit.

[0013] Furthermore, the controller comprises:

[0014] A judging unit, used to judge the magnitude relationship between the real-time vibration displacement value and the upper displacement threshold and the lower displacement threshold;

[0015] a target excitation current calculation unit, configured to, when the judgment unit judges that the real-time vibration displacement value is greater than or equal to the upper displacement threshold, add a first preset excitation current to the initial excitation current to obtain a target excitation current; when the real-time vibration displacement value is less than or equal to the lower displacement threshold, subtract a second preset excitation current from the initial excitation current to obtain a target excitation current; when the real-time vibration displacement value is less than the upper displacement threshold and greater than the lower displacement threshold, use the initial excitation current as the target excitation current;

[0016] The instruction generating unit is used to generate a corresponding control instruction according to the target excitation current calculated by the target excitation current calculating unit and send it to the voltage-stabilized power supply to control the electromagnet to output the target excitation current.

[0017] Furthermore, the controller comprises:

[0018] An error distance calculation unit, used to obtain the error distance according to the distance between the real-time vibration displacement position point and the target position point;

[0019] The target excitation current calculation unit is used to calculate the target excitation current according to the error distance based on the PID algorithm using the following expression:

[0020] ,

[0021] in, I is the target excitation current, e is the error distance, K p is the proportionality coefficient, K i is the integration coefficient, K dis the differential coefficient, t For time;

[0022] The instruction generating unit is used to generate a corresponding control instruction according to the target excitation current calculated by the target excitation current calculating unit and send it to the voltage-stabilized power supply to control the electromagnet to output the target excitation current.

[0023] A test method for the tower wind load model test device described above comprises the following steps:

[0024] Constructing a tower simulation part simulating a tower according to a preset scale ratio, and determining the thickness of the longitudinal main tower pole of the tower simulation part according to the thickness and elastic modulus of the longitudinal main tower pole of the actual tower, the elastic modulus of the tower simulation part, the scale ratio of the preset value, and the preset wind speed ratio;

[0025] Obtaining natural frequencies of different orders of actual towers, determining the vortex-vibration starting wind speed of the tower under each order vibration mode according to the natural frequencies of different orders of the tower, and screening out a critical vortex-vibration starting wind speed that is less than a preset safety wind speed from the vortex-vibration starting wind speed of the tower under each order vibration; determining the optimal test simulation wind speed of the tower simulation component according to the critical vortex-vibration starting wind speed of the tower and a preset wind speed ratio;

[0026] The constructed tower simulation is tested and simulated at the optimal test simulation wind speed, and the electromagnetic component is used to adjust the initial damping force of the damping adjustment unit at different test simulation wind speeds to the target damping force, thereby achieving a true simulation of the vibration characteristics of the tower simulation under different wind loads.

[0027] Furthermore, the thickness of the longitudinal main tower rod of the tower simulation is determined according to the following formula:

[0028] ,

[0029] in, tm is the thickness of the longitudinal main tower rod of the tower simulation, tp is the thickness of the longitudinal main tower pole of the actual tower, E p is the elastic modulus of the actual tower material, E d is the elastic modulus of the tower simulation material, n is the preset scale ratio, m The preset wind speed ratio.

[0030] Further, using the electromagnetic component to adjust the initial damping force of the damping adjustment unit at different test simulated wind speeds to a target damping force includes:

[0031] Determine the target damping ratio of the actual tower under different test simulated wind speeds;

[0032] Calculating the target damping force of the tower simulation under different test simulated wind speeds according to the target damping ratio, the mass and the natural frequency of the tower simulation;

[0033] By adjusting the excitation current of the electromagnet in the electromagnetic assembly and / or the air gap between the electromagnetic assembly and the eddy current conductor, the initial damping force of the damping adjustment unit at different test simulated wind speeds is adjusted to the target damping force.

[0034] Further, the excitation current of the electromagnet and the air gap are calculated according to the following formula to adjust the initial damping force of the damping adjustment unit to the target damping force:

[0035] ,

[0036] in, F is the target damping force of the damping adjustment unit, k It is a coefficient determined by the material of the electromagnet. I is the excitation current, A is the air gap, n The preset value is in the range [1, 2].

[0037] Furthermore, the tower simulation part is an angle steel simulation part. After the tower simulation part simulating the tower is constructed according to a preset scale ratio, the tower simulation part is further processed and installed, which includes the following steps:

[0038] Splitting the constructed tower simulation into a plurality of processing segments, and tiling the processing segments to obtain a plurality of tiling sizes of the processing segments, wherein the processing segments are half-side processing segments obtained by segmenting the tower simulation into a plurality of groups of modular tower units along the length direction, and splitting each group of the modular tower units equally;

[0039] Determine the size of the processing plate according to the tiling size of each half-side processing segment, cut the processing plate according to the tiling size of each half-side processing segment, and obtain a plane component corresponding to the tiling shape of the corresponding half-side processing segment;

[0040] The obtained plane components of each section are bent according to the actual axis of the half-side processing segment, and the angle steel component is bent along the center line of the angle steel component to obtain an angle steel component corresponding to the shape of the half-side processing segment;

[0041] The two ends of the two angle steel members corresponding to the equally split half-side processing segments are fixedly connected or detachably connected to each other to obtain an assembly unit corresponding to the shape of each section of the modular tower unit;

[0042] Weighing each section of the assembly unit obtained, comparing the weighed mass of each section of the assembly unit with the mass of the corresponding modular tower unit, and when the weighed mass of the assembly unit is less than the mass of the modular tower unit, providing an additional counterweight block on the assembly unit to make the mass of the assembly unit equal to the mass of the modular tower unit;

[0043] The assembly units of each section are assembled and connected in sequence to obtain the tower simulation component.

[0044] Compared with the prior art, the advantages of the present invention are:

[0045] The tower simulation of the present invention is provided with a damping adjustment unit, the damping adjustment unit includes an eddy current conductor assembly and an electromagnetic assembly, the eddy current conductor assembly includes an eddy current conductor and a magnetic back plate arranged in a superimposed manner, the magnetic back plate is located between the tower simulation and the eddy current conductor; the electromagnetic assembly is installed on the top surface of the test wind tunnel, the electromagnetic assembly and the eddy current conductor are arranged oppositely, and an air gap is left. The layout is compact and the space occupied is small.

[0046] When the tower simulation component of the present invention vibrates, the eddy current conductor assembly moves with the tower simulation component. At this time, the eddy current conductor and the electromagnetic assembly produce relative movement, and the eddy current conductor cuts the magnetic flux lines to induce eddy currents. At the same time, the eddy currents also excite the induced magnetic field. It can be seen from Lenz's law that under the action of the induced magnetic field, the structure produces a force that hinders the relative movement of the eddy current conductor and the electromagnetic assembly, that is, an eddy current damping force is applied. The wind-induced vibration response vibration characteristics of the tower simulation component are adjusted to be close to the wind-induced vibration response characteristics of the actual tower under the action of the eddy current damping force, thereby avoiding the problem of difficulty in adjustment after the damping is determined, improving the accuracy of wind tunnel test results and dynamic wind load determination, thereby ensuring the reliability of the actual tower wind load design and reducing the safety hazards of the tower.

[0047] At the same time, the magnetic backplate can effectively guide and concentrate the magnetic flux, reduce the magnetic resistance and leakage of the magnetic circuit, and the magnetic backplate, electromagnetic components and eddy current conductors together form a closed magnetic circuit, thereby optimizing the magnetic field distribution and enhancing the magnetic flux density in the eddy current conductor area. That is, the magnetic backplate enhances the magnetic flux density by increasing the concentration of the magnetic flux and reducing the magnetic resistance of the magnetic circuit. The increase in magnetic flux density makes the generation of eddy currents more significant, thereby greatly enhancing the damping capacity of the eddy current conductor, so as to more conveniently adjust the wind-induced vibration response vibration characteristics of the tower simulation component.

[0048] The present invention provides a damping adjustment unit at the top position of the tower simulation part, and increases the damping of the tower simulation part by using the eddy current damping principle of the damping adjustment unit. Adjustable damping can be achieved by introducing an electromagnetic component, which avoids the problem that the wind-induced vibration response obtained in the existing wind tunnel test is smaller than that of the prototype. It greatly improves the accuracy and reliability of the wind tunnel test results, and provides more accurate wind load data for the structural design of the tower, thereby improving the wind resistance of the tower and the rationality of the tower design, and saving costs while ensuring the safe and reliable operation of the tower.

[0049] The relative arrangement of the electromagnetic assembly and the eddy current conductor of the present invention makes the damping adjustment unit a frictionless, non-contact damping component with small starting friction. The damping adjustment unit enables the tower simulation component to substantially improve the damping even under a small amplitude under the action of a breeze, thereby realizing the adjustment of the wind-induced vibration response characteristics of the tower simulation component in the wind tunnel test at a small amplitude. The non-contact damping provided effectively reduces the possibility of fatigue damage of local components compared to viscous damping, and the non-contact damping component is easy to disassemble, repair and maintain, and has low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings, wherein:

[0051] Figure 1 It is a three-dimensional structural diagram of the tower wind load model test device of the present invention;

[0052] Figure 2 yes Figure 1 An enlarged schematic diagram of point A;

[0053] Figure 3 yes Figure 2 The main view;

[0054] Figure 4 is a schematic diagram of a tower wind load model test device of the present invention;

[0055] Figure 5 It is a structural schematic diagram of a lattice tower simulation component of the present invention;

[0056] Figure 6 It is a structural principle diagram of the controller of the present invention;

[0057] Figure 7 is another structural principle diagram of the controller of the present invention;

[0058] Figure 8 It is a flow chart of the test method of the tower wind load model test device of the present invention;

[0059] Fig. 9 It is a control flow chart of the controller of the present invention.

[0060] The symbols in the figure represent:

[0061] 1. Tower simulation part; 11. Modular tower unit; 111. Half-side processing segment; 1111. Longitudinal main tower pole; 1112. Cross connecting rod; 1113. Frame connecting rod; 1114. Angle connecting rod; 1115. Triangle connecting rod; 2. Damping adjustment unit; 21. Eddy current conductor assembly; 211. Eddy current conductor; 212. Magnetic back plate; 22. Electromagnetic assembly; 221. Electromagnet; 222. Voltage stabilized power supply; 223. Vibration displacement detection part; 224. Controller; 225. Connecting support rod; 23. Air gap; 3. Test wind tunnel. DETAILED DESCRIPTION

[0062] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereby.

[0063] like Figures 1 to 4 As shown, the tower wind load model test device of this embodiment includes a tower simulation 1 and a damping adjustment unit 2. The damping adjustment unit 2 includes an eddy current conductor assembly 21 and an electromagnetic assembly 22. The eddy current conductor assembly 21 is installed at the top of the tower simulation 1. The eddy current conductor assembly 21 includes an eddy current conductor 211 and a magnetic back plate 212 arranged in a superimposed manner. The magnetic back plate 212 is located between the tower simulation 1 and the eddy current conductor 211; the electromagnetic assembly 22 is installed on the top surface of the test wind tunnel 3. The electromagnetic assembly 22 and the eddy current conductor 211 are arranged opposite to each other, and an air gap 23 is left. It has a compact layout and occupies a small space.

[0064] In the present invention, when the tower simulation component 1 vibrates, the eddy current conductor assembly 21 moves with the tower simulation component 1. At this time, the eddy current conductor 211 and the electromagnetic assembly 22 produce relative movement, and the eddy current conductor 211 cuts the magnetic flux lines to induce eddy currents. At the same time, the eddy currents will also excite the induced magnetic field. It can be seen from Lenz's law that under the action of the induced magnetic field, the structure produces a force that hinders the relative movement of the eddy current conductor 211 and the electromagnetic assembly 22, that is, an eddy current damping force is applied to the tower simulation component 1. The wind-induced vibration response vibration characteristics of the tower simulation component 1 are adjusted to be close to the wind-induced vibration response characteristics of the actual tower under the action of the eddy current damping force, thereby avoiding the problem of difficulty in adjustment after the damping is determined, improving the accuracy of the wind tunnel test results and the accuracy of dynamic wind load determination, thereby ensuring the reliability of the actual tower wind load design and reducing the safety hazards of the tower.

[0065] At the same time, the magnetic backplate 212 can effectively guide and concentrate the magnetic flux, reduce the magnetic resistance and leakage of the magnetic circuit, and the magnetic backplate 212, the electromagnetic component 22 and the eddy current conductor 211 together form a closed magnetic circuit, thereby optimizing the magnetic field distribution and enhancing the magnetic flux density in the eddy current conductor 211 area, that is, the magnetic backplate 212 enhances the magnetic flux density by increasing the concentration of the magnetic flux and reducing the magnetic resistance of the magnetic circuit. The increase in magnetic flux density makes the generation of eddy currents more significant, thereby greatly enhancing the damping capacity of the eddy current conductor 211, so as to more conveniently adjust the wind-induced vibration response vibration characteristics of the tower simulation component 1.

[0066] It can be seen that the present invention has a damping adjustment unit 2 at the top position of the tower simulation 1, and increases the damping of the tower simulation 1 by the eddy current damping principle of the damping adjustment unit 2. The damping can be adjusted by introducing the electromagnetic component 22, which avoids the problem that the wind-induced vibration response obtained in the existing wind tunnel test is smaller than that of the prototype, and makes the wind-induced vibration response vibration characteristics of the tower simulation 1 in the wind tunnel test closer to the wind-induced vibration response characteristics of the actual tower. It greatly improves the accuracy and reliability of the wind tunnel test results, and provides more accurate wind load data for the structural design of the tower, thereby improving the wind resistance of the lattice tower and the rationality of the tower design, while ensuring the safe and reliable operation of the tower, saving costs.

[0067] The electromagnetic component 22 and the eddy current conductor 211 of the present invention are arranged relative to each other so that the damping adjustment unit 2 is a frictionless, non-contact damping component with small starting friction. The damping adjustment unit 2 enables the tower simulation component 1 to substantially improve the damping even under a small amplitude under the action of a breeze, thereby achieving the adjustment of the wind-induced vibration response characteristics of the tower simulation component 1 in the wind tunnel test at a small amplitude. The non-contact damping provided effectively reduces the possibility of fatigue damage of local components compared to viscous damping, and the non-contact damping component is easy to disassemble, repair and maintain, and has low cost.

[0068] Furthermore, the length of the eddy current conductor 211 is equal to the length of the magnetic conductive back plate 212 , which further optimizes the electromagnetic performance, reduces energy loss, and has a simple arrangement structure.

[0069] In this embodiment, the eddy current conductor 211 is usually made of a non-ferromagnetic material with high electrical conductivity, such as copper, aluminum, copper alloy or aluminum alloy, etc. The magnetic conductive back plate 212 is made of a material with high magnetic permeability, such as steel, etc.

[0070] Since the distribution of static wind load is closely related to the tower shape, the high-precision geometric dimensions of the modular tower unit 11 can ensure that the distribution of wind load on the surface of the tower simulation part 1 is consistent with the actual tower situation. In order to solve the above problems, the present invention further sets the tower simulation part 1 as a lattice tower simulation part, and the lattice tower simulation part is formed by connecting multiple groups of modular tower units 11 along the length direction of the lattice tower simulation part, and each group of modular tower units 11 is surrounded by two half-side processing segments 111, that is, the lattice tower simulation part is split into modular tower units 11 along the length direction, and the modular tower unit 11 is split into two half-side processing segments 111, so that each section of the lattice tower simulation part can be adjusted and set independently, which can better ensure the consistency of the geometric dimensions and shape accuracy of the tower simulation part 1 with the actual tower, thereby ensuring the accuracy of the static wind load distribution.

[0071] At the same time, the plurality of modular tower units 11 can better control and adjust the surface roughness of the lattice tower simulation, ensuring that the surface roughness of the modular tower unit 11 meets the design requirements. The surface roughness will affect the wind resistance coefficient and thus the size of the static wind load, so that the present invention can further improve the accuracy of the static wind load determination. At the same time, the modular design of the tower simulation 1 has high construction efficiency and manufacturability.

[0072] In this embodiment, the modular tower units 11 are connected by high-strength bolts or welding to provide sufficient strength and rigidity to ensure connection reliability and prevent deformation or displacement under wind load, which affects the distribution and size of static wind load. The modular tower units 11 and the actual tower are made of the same material to ensure the consistency of the material properties of the tower simulation 1 and the actual tower. The elastic modulus, density and other parameters of the material have a direct impact on the structural rigidity and force characteristics. Material consistency helps to reduce the static wind load measurement error caused by material differences.

[0073] like Figure 5 As shown, the half-side processing segment 111 includes a plurality of longitudinal main tower rods 1111, cross-connecting rods 1112, frame-type connecting rods 1113, angle connecting rods 1114 and triangular connecting rods 1115. The longitudinal main tower rods 1111 are arranged along the circumference of the lattice tower; the cross-connecting rods 1112 are connected between adjacent longitudinal main tower rods 1111, and the cross-connecting rods 1112 are arranged in multiple groups along the length direction of the longitudinal main tower rods 1111, and the heads and tails of adjacent groups of cross-connecting rods 1112 are connected to each other; the frame-type connecting rods 1113 are connected inside the cross-connecting rods 1112, and the frame-type connecting rods 1113 are located inside the adjacent cross-connecting rods 1112 on both sides of the longitudinal main tower rods 1111; the angle connecting rods 1114 are connected inside the frame-type connecting rods 1113, and the triangular connecting rods 1115 are connected inside the angle connecting rods 1114.

[0074] Among them, the longitudinal main tower rod 1111 is the main load-bearing member of the tower simulation 1, bearing wind load, deadweight and various loads transmitted from the superstructure (including axial pressure and bending moment), and the longitudinal main tower rod 1111 transmits these loads downward to the tower base. In this embodiment, the number of longitudinal main tower rods 1111 is four, so as to ensure the overall stiffness and stability of the tower simulation 1. In other embodiments, the number of longitudinal main tower rods 1111 can be adjusted according to actual conditions, such as the number of longitudinal main tower rods 1111 can also be set to three, five, etc., with effective resistance to bending and torsional deformation as the standard.

[0075] The cross-connecting rods 1112 connect the adjacent longitudinal main tower rods 1111 to form a stable lattice tower structure, which can prevent the tower simulation 1 from lateral bending or torsional deformation and enhance the overall stability and shear resistance of the tower simulation 1; the cross-connecting rods 1112 can effectively transmit the shear force caused by wind load, so that the lattice tower structure can work together as a whole and resist external forces together. At the same time, multiple groups of cross-connecting rods 1112 are arranged along the length direction of the longitudinal main tower rods 1111. The space truss structure formed by connecting the heads and tails of adjacent groups of cross-connecting rods 1112 can better disperse and transfer the load, thereby further improving the overall stiffness of the tower simulation 1 and ensuring the stability and bearing capacity of the tower simulation 1.

[0076] The frame-type connecting rod 1113 can strengthen the local part of the tower simulation component 1, effectively resist local bending and torsional deformation, and improve the local stability of the tower; the frame-type connecting rod 1113 can be used as a load transfer path to transfer the local load to the longitudinal main tower rod 1111, so that the load distribution is more uniform; the frame-type connecting rod 1113 transforms the original plane truss structure into a spatial truss structure, and enhances the ability of the tower simulation component 1 to resist three-dimensional loads; at the same time, the frame-type connecting rod 1113 can stabilize the cross-connecting rod 1112, prevent the cross-connecting rod 1112 from buckling and instability, and ensure the effective operation of the cross-connecting rod 1112.

[0077] The angle connecting rod 1114 can further enhance the stability of the frame-type connecting rod 1113 and prevent it from deformation; the angle connecting rod 1114 can refine the force transmitted from the frame-type connecting rod 1113 and distribute it more evenly to the triangular connecting rod 1115 and the longitudinal main tower rod 1111 to avoid stress concentration; at the same time, the angle connecting rod 1114 can allow fine-tuning of the angle of the frame-type connecting rod 1113 to adapt to different design requirements and stress conditions.

[0078] The triangular connecting rod 1115 adopts a triangular structure. The triangle is the most stable shape in structural mechanics. The triangular connecting rod 1115 takes advantage of this feature to provide extremely high stability and rigidity, effectively resist deformation in various directions, and ensure the overall stability of the tower simulation 1. At the same time, the triangular connecting rod 1115 more effectively transmits the force transmitted by the angle connecting rod 1114 to the longitudinal main tower rod 1111, forming a stable mechanical transmission path. The triangular structure can use less material, thereby achieving lightweight tower simulation 1.

[0079] It can be seen that the tower simulation 1 of the present invention forms a multi-level reinforced and multi-stabilized lattice tower structure. Specifically:

[0080] 1. High load-bearing capacity. The multi-level and multi-connection design enables the tower to have a higher load-bearing capacity and withstand greater wind loads and other external loads.

[0081] Second, high stability. The present invention effectively transmits and disperses the load through the combination of the cross connecting rod 1112, the frame connecting rod 1113, the angle connecting rod 1114 and the triangular connecting rod 1115, avoiding stress concentration, so that the tower simulation 1 can resist deformation and instability in various directions, and improve the overall stability and bearing capacity of the tower simulation 1.

[0082] 3. High reliability. The multi-level and multi-connection design actually introduces the concept of structural redundancy. Even if a component fails locally, other components can still continue to bear the load, thereby improving the overall reliability and anti-collapse ability of the structure. For example, even if a cross-connecting rod 1112 fails, the structure composed of other connecting rods can still maintain local stability and continue to transfer loads.

[0083] 4. High torsion resistance: The combination of the frame-type connecting rod 1113, the angle connecting rod 1114 and the triangular connecting rod 1115 can significantly improve the torsion resistance of the tower simulation 1, and can effectively resist torsional deformation, so that the tower simulation 1 can resist torsional deformation caused by asymmetric wind loads and is not prone to torsional instability.

[0084] It can be seen that the half-side processed segment 111 of the present invention forms a lattice tower structure with high load-bearing capacity, high stability, high reliability and high torsion resistance through a clever combination of the longitudinal main tower rod 1111, the cross connecting rod 1112, the frame connecting rod 1113, the angle connecting rod 1114 and the triangular connecting rod 1115. While improving the mechanical properties of the tower, it optimizes the aerodynamic performance and damping characteristics, ensures the accuracy and reliability of the tower wind load model test device, and provides a reliable design reference for the actual tower structure.

[0085] Furthermore, by reasonably designing the size, shape and arrangement of the connecting rods, the modal parameters of the tower can be optimized so that its natural frequency avoids the excitation frequency of the wind load, thereby avoiding the occurrence of resonance. At the same time, the design of each connecting rod can optimize the aerodynamic shape of the tower simulation 1 to a certain extent, reduce the wind resistance coefficient, and thus reduce the impact of wind load on the tower simulation 1. For example, the connecting rod can be designed to be streamlined to reduce airflow separation and the generation of vortices.

[0086] Furthermore, if Figures 2 to 4 As shown, the electromagnetic assembly 22 includes an electromagnet 221, a controller 224, a voltage-stabilized power supply 222 and a vibration displacement detector 223. Among them, the electromagnet 221 is installed on the top surface of the test wind tunnel 3 by connecting the support rod 225. The electromagnet 221 generates a magnetic field and interacts with the eddy current conductor assembly 21 to generate an electromagnetic damping force. The arrangement length of the electromagnet 221 covers the vibration range of the tower simulation 1 during the test to ensure that the tower simulation 1 can effectively apply the damping force during the entire vibration process. The vibration displacement detector 223 is installed on the tower simulation 1 to detect the real-time vibration displacement value of the tower simulation 1 under different wind loads. The electromagnetic assembly 22 has a simple structure, occupies a small space and has a low cost.

[0087] At the same time, the vibration displacement detection member 223, the controller 224, the voltage-stabilized power supply 222 and the electromagnet 221 are electrically connected in sequence, and the controller 224 is used to control and adjust the excitation current of the electromagnet 221 through the voltage-stabilized power supply 222 according to the real-time vibration displacement value of the vibration displacement detection member 223, so as to adjust the damping force of the damping adjustment unit 2. An effective feedback control loop is established between the vibration displacement detection member 223, the controller 224 and the electromagnet 221, so as to further ensure the accurate adjustment of the damping force of the damping adjustment unit 2.

[0088] Furthermore, if Figure 6 As shown, the controller 224 includes a judgment unit, a target excitation current calculation unit and an instruction generation unit. Among them:

[0089] The judging unit is used to judge the magnitude relationship between the real-time vibration displacement value and the upper displacement threshold and the lower displacement threshold.

[0090] The target excitation current calculation unit is used to add the first preset excitation current to the initial excitation current to obtain the target excitation current when the judgment unit judges that the real-time vibration displacement value is greater than or equal to the upper displacement threshold; when the real-time vibration displacement value is less than or equal to the lower displacement threshold, subtract the second preset excitation current from the initial excitation current to obtain the target excitation current; when the real-time vibration displacement value is less than the upper displacement threshold and greater than the lower displacement threshold, use the initial excitation current as the target excitation current.

[0091] The instruction generating unit is used to generate a corresponding control instruction according to the target excitation current calculated by the target excitation current calculating unit and send it to the voltage-stabilized power supply to control the electromagnet to output the target excitation current.

[0092] The controller 224 of this embodiment adjusts the initial excitation current of the electromagnet 221 according to the real-time vibration displacement value detected by the vibration displacement detection component 223, and the preset upper displacement threshold and lower displacement threshold, to obtain the target excitation current of the electromagnet 221; then, the controller 224 controls the voltage-stabilized power supply 222 to output a corresponding current to the electromagnet 221 according to the target excitation current, thereby changing the magnetic force of the electromagnet 221, adjusting the damping force of the damping adjustment unit 2, and realizing closed-loop control of the vibration of the tower simulation component 1. The damping adjustment method is convenient and simple, and the adjustment efficiency is high.

[0093] The present invention increases structural damping through the eddy current damping principle and realizes precise and adjustable damping by introducing the electromagnetic component 22, thereby ensuring that the damping characteristics of the tower simulation component 1 can be adjusted in the wind tunnel test to more accurately simulate the wind-induced vibration response of the actual tower under wind loads, thereby being able to accurately simulate the vibration characteristics of the tower under different wind loads, overcoming the problem of excessively large damping ratio of existing 3D printed models and greatly improving the reliability of wind tunnel test results.

[0094] In this embodiment, the first preset excitation current and the second preset excitation current can be set according to actual conditions, and the first preset excitation current and the second preset excitation current can be equal or unequal, which is not limited here. In other embodiments, when the real-time vibration displacement value is less than the upper displacement threshold and greater than the lower displacement threshold, the third preset excitation current can be subtracted or added to the initial excitation current to obtain the target excitation current, and the third preset excitation current is less than the first preset excitation current and the second preset excitation current. The initial excitation current can be fine-tuned according to the third preset excitation current.

[0095] In other embodiments, Figure 7 As shown, the controller 224 may also use other control structures to adjust the excitation current of the electromagnet 221, and the controller 224 includes an error distance calculation unit, a target excitation current calculation unit, and an instruction generation unit.

[0096] The error distance calculation unit is used to obtain the error distance according to the distance between the real-time vibration displacement position point and the target position point. The target position point is the position point of the vibration state that the tower simulation part 1 is expected to maintain.

[0097] The target excitation current calculation unit is used to calculate the target excitation current according to the error distance based on the PID algorithm using the following expression: ,

[0098] in, I is the target excitation current, e is the error distance, K p is the proportionality coefficient, K i is the integration coefficient, K d is the differential coefficient, t For time.

[0099] K p e is a proportional term, which is proportional to the error distance. The larger the error distance, the larger the value of the proportional term, and the stronger the control effect. K p Reflects the current error to the target excitation current I The impact of K p It is an adjustable parameter used to adjust the control strength of the proportional term.

[0100] Ki∫e dt The integral term is the integral of the error distance over time, which takes into account the cumulative effect of the error distance. Even if the current error is small, if there is a continuous error before, the integral term will have a greater control effect and help eliminate static errors. Integral coefficient K i Reflects the cumulative error to the target excitation current I The influence of K i It is an adjustable parameter used to adjust the control strength of the integral term. ∫e dt It represents the time integration of the error distance. ∫e dt The calculation range is from the time when the controller is started to the current time, or the time when the integral is cleared to the current time, which means the accumulated value of the error distance over time from the beginning to the present.

[0101] K d de / dt The differential term is the differential (or rate of change) of the error distance over time, which reflects the changing trend of the error. If the error is increasing rapidly, the differential term will produce a reverse control effect to suppress the rapid change of the error and prevent the system from overshooting and oscillation. K d Reflects the error change rate to the target excitation current I The influence of K d It is an adjustable parameter used to adjust the control strength of the derivative term. de / dtIt represents the differential of the error distance with respect to time, that is, the rate of change of the error distance, that is, the speed at which the error changes with time. dt Represents a small change in time. In calculus, dt Represents an infinitesimal time interval. In actual control systems, dt Usually refers to the sampling period, that is, how often the controller performs calculations and control.

[0102] The instruction generating unit is used to generate a corresponding control instruction according to the target excitation current calculated by the target excitation current calculating unit and send it to the voltage-stabilized power supply to control the electromagnet to output the target excitation current.

[0103] At this time, the controller 224 realizes closed-loop control. The controller 224 will continuously adjust the target excitation current according to the real-time feedback of the real-time vibration displacement, so that the vibration displacement of the tower simulation 1 is always kept near the target value. In order to achieve precise control of the electromagnetic damping force, the vibration displacement of the tower simulation 1 can quickly and smoothly reach the target value; it can adapt to different wind load conditions and tower simulation 1 characteristics, and has strong robustness,

[0104] At the same time, the proportionality coefficient K p , integral coefficient K i , differential coefficient K d The tuning is performed by using empirical methods, theoretical calculation methods or automatic tuning methods to determine the appropriate parameter values ​​so that the system has good dynamic response performance and steady-state performance. Among them, the empirical method is to gradually adjust the parameters according to the response characteristics of the device to achieve a satisfactory control effect. Commonly used empirical methods include the Ziegler-Nichols method, etc. The theoretical calculation method is to calculate the appropriate parameter values ​​based on the mathematical model of the device and the control theory knowledge; the automatic tuning method is to use intelligent algorithms or optimization algorithms to automatically adjust the parameter values ​​to achieve the optimal control effect. Through the reasonable tuning of the coefficients, the device can have good dynamic response performance and quickly suppress vibration.

[0105] visible, Figure 7 The controller shown enables the target excitation current to be adjusted continuously, achieving more precise and smoother damping adjustment, and having strong adaptability and fast dynamic response.

[0106] Preferably, the electromagnet 221 is installed on the top surface of the test wind tunnel 3 in a liftable manner through the connecting rod 225 to adjust the air gap 23 between the electromagnetic assembly 22 and the eddy current conductor 211. The size of the air gap 23 will directly affect the magnetic field strength and the size of the electromagnetic damping force. Generally, the smaller the air gap 23, the higher the magnetic field strength and the greater the electromagnetic damping force. However, when the air gap 23 is too small, magnetic saturation may occur, resulting in an insignificant increase in the electromagnetic damping force. At this time, the air gap 23 needs to be adjusted within a certain range to obtain the best damping effect. It is easy to adjust and has high adjustment reliability.

[0107] In this embodiment, the lifting and lowering adjustment method of the connecting rod 225 only needs to ensure the strength and rigidity of the connecting rod 225 to ensure the stability of the electromagnetic assembly 22 during the adjustment operation, such as a lead screw, a gear rack, a hydraulic cylinder, or a pneumatic cylinder. Furthermore, the fine adjustment of the air gap 23 can be achieved by setting a scale on the connecting rod 225 or setting a displacement sensor on the connecting rod 225 to detect the air gap 23 in real time.

[0108] Furthermore, when the swing amplitude of the tower simulation part 1 is large, there are multiple groups of damping adjustment units 2, and the multiple groups of damping adjustment units 2 are arranged along the height direction and / or the periphery of the tower simulation part 1. The setting direction of the multiple groups of damping adjustment units 2 can be set according to the actual damping requirements. Specifically, arranging multiple groups of damping adjustment units 2 along the height direction of the tower simulation part 1 can better control the vibration of the tower simulation part 1 at different heights to prevent excessive local vibration; arranging multiple groups of damping adjustment units 2 along the periphery direction of the tower simulation part 1 can better control the torsional vibration of the tower and improve the torsional resistance; arranging multiple groups of damping adjustment units 2 along the height direction and periphery of the tower simulation part 1 can achieve comprehensive control of the three-dimensional vibration of the tower.

[0109] Multiple groups of damping adjustment units 2 can provide greater damping force and more effectively suppress the large swing of the tower simulation 1. Especially when the tower simulation 1 is high or the wind load is unevenly distributed, multiple groups of damping adjustment units 2 can provide more precise control, avoid the situation where the control capacity of a single damping point is insufficient, and improve the damping capacity. By controlling the damping force of the damping adjustment units 2 at different positions, the vibration mode of the tower simulation 1 can be more finely controlled, such as suppressing a specific vibration mode or guiding the tower simulation 1 to vibrate according to the expected vibration mode, providing an experimental basis for studying the force characteristics of the tower simulation 1 under a specific vibration mode. It can be seen that the provision of multiple groups of damping adjustment units 2 of the present invention can effectively improve the damping effect and control accuracy.

[0110] At the same time, in actual engineering, the wind field is often complex and changeable, and multiple groups of damping adjustment units 2 can simulate the influence of more complex and non-uniformly distributed wind fields on the tower simulation 1, making the test closer to the actual situation. For example, the tower simulation 1 can be simulated to be affected by different wind speeds and directions at different heights or different directions.

[0111] In this embodiment, each group of damping adjustment units 2 can perform independent feedback control according to the vibration displacement of each position, and the control method is simple. In other embodiments, all damping adjustment units 2 can also be coordinated and centrally controlled by the same central controller 224, and the damping force of each group of damping components can be adjusted according to the overall vibration state of the tower and the preset control target, so that the control effect is better. Or each group of damping adjustment units 2 has an independent controller 224, and the controllers 224 communicate with each other and work together to achieve distributed control, so as to reduce the control complexity while ensuring the control effect.

[0112] Figure 8 The test method of the tower wind load model test device of the present embodiment is shown. When the tower simulation 1 is constructed, the method of the present invention determines the thickness of the longitudinal main tower rod 1111 of the tower simulation 1 by taking into account the thickness of the longitudinal main tower rod and the preset scale ratio, and combining the elastic modulus of the tower, the elastic modulus of the tower simulation 1, the wind speed ratio and the scale ratio. This avoids the problem that the mechanical similarity between the tower simulation 1 and the prototype tower cannot be guaranteed by simply considering the scale ratio, so as to improve the authenticity of the tower simulation.

[0113] When determining the test simulation wind speed, the vortex-vibration starting wind speeds of the tower when vibrating at different orders are obtained according to the natural frequencies of the tower at different orders, and the critical vortex-vibration starting wind speed of the tower that is less than the preset safety wind speed is screened out from the vortex-vibration starting wind speeds of the tower when vibrating at each order. The optimal test simulation wind speed of the tower simulation component 1 is obtained according to the critical vortex-vibration starting wind speed of the tower and the preset wind speed ratio to determine the wind speed range of the simulation scene, so that the test simulation wind speed of the tower simulation component 1 can be finally determined based on a comprehensive consideration of the vortex-vibration starting wind speeds of towers of different orders and the actual pressure conditions of the tower (preset safety wind speed), so that the test simulation can be selected according to the actual needs of the tower, which improves the simulation efficiency and accuracy.

[0114] During the test simulation, the electromagnetic component 22 is used to adjust the initial damping force of the damping adjustment unit 2 at different test simulation wind speeds to the target damping force, which can accurately control the damping characteristics of the tower simulation component 1 at different wind speeds, thereby realizing a true simulation of the vibration characteristics of the tower simulation component 1 under different wind loads.

[0115] See also Figure 8 The specific steps of the test method of the tower wind load model test device of the present invention are:

[0116] Step 1), construct a tower simulation 1 of a simulated tower according to a preset scale ratio, and determine the thickness of the longitudinal main tower pole 1111 of the tower simulation 1 according to the thickness and elastic modulus of the longitudinal main tower pole of the actual tower, the elastic modulus of the tower simulation 1, the scale ratio of the preset value and the preset wind speed ratio.

[0117] The preset scale ratio can be determined according to the size of the actual tower and the wind tunnel test section, and can also take into account factors such as the manufacturing measurement accuracy of the tower simulation 1 and the wind tunnel blocking effect. When constructing the tower simulation 1 that simulates the tower, the same material as the tower can be selected, and the geometric dimensions of the actual tower can be scaled according to the preset scale ratio.

[0118] The existing method of directly scaling the thickness of the longitudinal main tower rod 1111 of the actual tower according to a preset scale ratio to obtain the thickness of the longitudinal main tower rod 1111 of the tower simulation 1 cannot ensure the mechanical similarity between the tower simulation 1 and the prototype tower. EA The calculation expression of the thickness of the longitudinal main tower rod 1111 of the tower simulation 1 is derived under similar conditions, so as to ensure that the deformation and stress of the tower simulation 1 under wind load are consistent with the actual tower. Specifically:

[0119] During wind tunnel testing, tensile stiffness EA The formula for similar conditions is:

[0120] ,

[0121] in, (EA) d is the tensile stiffness of the tower simulation 1, (EA) p is the tensile stiffness of the actual tower, n is the preset scale ratio, m is a preset wind speed ratio. The preset scale ratio can be determined according to the size of the actual tower and the size of the wind tunnel test section, and the preset wind speed ratio can be preset according to the actual wind field and wind tunnel conditions.

[0122] The thickness of the longitudinal main tower rod 1111 of the tower simulation 1 is derived according to the EA similarity condition:

[0123] ，

[0124] in, tm is the thickness of the longitudinal main tower rod 1111 of the tower simulation 1, tp is the thickness of the longitudinal main tower rod 1111 of the actual tower, E p is the elastic modulus of the actual tower material, Ed is the elastic modulus of the tower simulation component 1 material.

[0125] The thickness of the longitudinal main tower rod 1111 of the tower simulation 1 obtained by the above formula can ensure the mechanical similarity between the tower simulation 1 and the actual tower, thereby realizing a true simulation of the vibration characteristics of the tower under different wind loads.

[0126] Preferably, the tower simulation part 1 is an angle steel simulation part. After the tower simulation part 1 simulating the tower is constructed according to a preset scale ratio, the tower simulation part 1 is processed and installed, which includes the following steps:

[0127] In step 11, the constructed tower simulation component 1 is split into a plurality of processing segments, and the processing segments are flattened to obtain the flattened sizes of the plurality of processing segments. The processing segments are obtained by segmenting the tower simulation component 1 into a plurality of groups of modular tower units 11 along the length direction, and each group of modular tower units 11 is equally split to obtain a half-side processing segment 111, so as to decompose the complex three-dimensional tower simulation component 1 structure into a plane structure that is easy to process.

[0128] Step 12), according to the tiling size of each half-side processing segment 111, the size of the processing plate is determined, and the processing plate is cut according to the tiling size of each half-side processing segment 111 to obtain a plane component corresponding to the tiling shape of the corresponding half-side processing segment 111, so as to prepare for subsequent bending into an angle steel component. The plate can be processed by automatic machine tool wire cutting to ensure cutting accuracy.

[0129] In step 13, each section of the obtained planar component is bent according to the actual axis of the half-edge processing segment 111, and the angle steel component is bent along the center line of the angle steel component to obtain an angle steel component corresponding to the shape of the half-edge processing segment 111, so as to convert the planar component into an angle steel component with a three-dimensional shape.

[0130] In step 14, the two ends of the two angle steel members corresponding to the equally split half-side processing segments 111 are fixedly connected or detachably connected to each other to obtain assembly units corresponding to the shapes of each section of the modular tower unit 11, so as to assemble the half-side processing segments 111 into complete modular units.

[0131] Step 15), weigh each section of the obtained assembly unit, and compare the weighed mass of each section of the assembly unit with the mass of the corresponding modular tower unit 11. When the weighed mass of the assembly unit is less than the mass of the modular tower unit 11, an additional counterweight is set on the assembly unit to make the mass of the assembly unit equal to the mass of the modular tower unit 11, so as to ensure the similarity in mass distribution between the tower simulation 1 and the actual tower. In other embodiments, the material density of some components can also be adjusted to achieve the purpose of counterweight.

[0132] In this embodiment, the additional counterweight blocks can be arranged in the assembly unit in a centralized counterweight manner, that is, the counterweight blocks are concentrated at specific positions of the tower simulation part 1, such as the tower top, the tower body, etc., which is easy to operate. In other embodiments, the counterweight blocks can also be evenly arranged on the tower body to better simulate the mass distribution of the actual tower.

[0133] Step 16), assemble and connect the assembly units in sequence to obtain the tower simulation part 1.

[0134] The tower simulation part 1 obtained in this embodiment can ensure the shape accuracy of the tower simulation part 1 while maintaining the stiffness of the tower simulation part 1 to meet the similarity relationship with the actual tower structure through segmented processing and combined installation. Compared with traditional casting or 3D printing technology, this method avoids the problem of insufficient or excessive model stiffness caused by processing errors, and effectively solves the difficult problem that traditional 3D printing technology cannot take into account both model shape and stiffness. It improves the accuracy of the test and enhances the realization of model similarity, making it closer to the vibration response under real conditions, thereby providing a more reliable basis for the wind load design of the actual tower.

[0135] The modular segmented processing and installation of this embodiment enables each segment of the component to be accurately manufactured and assembled, ensuring that the tower simulation part 1 will not produce additional stress concentration or deformation due to processing errors during the actual assembly process, and ensuring the rigidity and stability of the overall structure. Especially in wind tunnel tests, modular processing and installation help simulate the rigidity changes of real towers at different heights. Improve the integrity and structural stability of the tower simulation part 1, and effectively ensure the reliability of the experimental results.

[0136] At the same time, the present invention simplifies the processing and installation process of the tower simulation part 1, greatly reduces the difficulty of positioning and connecting between components, and greatly reduces the processing and installation time and cost of the tower simulation part 1.

[0137] The above-mentioned processing and installation method of the tower simulation component 1 of the present invention, and the combination of the electromagnetic component 22 for adjusting the damping force, make the vibration characteristics of the tower simulation component 1 in the wind tunnel experiment closer to the vibration characteristics of the actual tower, thereby greatly improving the reliability and practicality of the experimental results, thereby providing more accurate wind load data for the structural design of the actual tower, improving the wind resistance of the lattice tower and the rationality of the tower design, further optimizing the safety and economy of the tower, and providing important support for the safe and reliable operation of the power infrastructure.

[0138] Step 2), obtain the natural frequencies of different orders of the actual tower, determine the vortex vibration starting wind speed of the tower when it vibrates at different orders according to the natural frequencies of different orders of the tower, and select the critical vortex vibration starting wind speed of the tower that is less than the preset safety wind speed from the vortex vibration starting wind speed of the tower when vibrating at each order; determine the optimal test simulation wind speed of the tower simulation component 1 according to the critical vortex vibration starting wind speed of the tower and the preset wind speed ratio. The preset safety wind speed is the basic wind speed of the tower setting area, which can be determined according to the design standards and safety requirements of the tower, such as by referring to the basic wind speed tables of various places and combining with field observations.

[0139] The optimal test simulation wind speed of the tower simulation part 1 determined in this embodiment allows the test simulation wind speed of the rod simulation part 1 to be finally determined based on the vortex vibration starting wind speed of towers of different orders and the actual pressure-bearing conditions of the tower (preset safety wind speed). At the same time, the optimal test simulation wind speed of the tower simulation part 1 can be used as a criterion for judging whether to perform simulation. When the wind speed exceeds the optimal test simulation wind speed of the tower simulation part 1, it is assumed that the situation will not actually occur in the tower, and no simulation is required. This allows the test simulation to be selected according to the actual needs of the tower, avoiding the problem of low simulation efficiency and poor simulation effect that is out of touch with the actual situation of the tower, and improving the simulation efficiency and accuracy, and greatly reducing the number of simulations.

[0140] The natural frequencies of different orders of the actual tower of this embodiment can be obtained through finite element analysis or field measurement. Among them, finite element analysis is a commonly used method, such as using finite element software such as ANSYS and ABAQUS to establish a refined model of the actual tower, including the size, connection method, material properties, etc. of the tower. Then, the natural frequencies of different orders of the tower are obtained through modal analysis, which has high accuracy and can consider complex boundary conditions and load conditions. If conditions permit, the natural frequency can also be obtained by field measurement, that is, using a knock test or environmental excitation test. The knock test is to knock the tower with a hammer or other tool to measure its vibration response, and then obtain the natural frequency through spectrum analysis; the environmental excitation test is to use environmental excitations such as wind and earthquake to measure the vibration response of the tower, and then perform modal identification to obtain the natural frequency. Field measurement can more directly reflect the actual situation of the tower.

[0141] Optionally, the vortex vibration starting wind speed of the tower when it vibrates at different orders can be calculated according to the natural frequencies of the tower at different orders according to the following formula:

[0142] ,

[0143] in, is the tower vortex vibration starting wind speed, is the natural frequency of the tower at different orders, is the characteristic size of the tower, is the Strohal number.

[0144] In this embodiment, The characteristic dimension of the tower is the diameter of the longitudinal main tower pole 1111 of the tower. The Stohal number is a dimensionless constant used to describe the relationship between the vortex frequency of the fluid shedding on the surface of the object and the incoming flow velocity and characteristic length. The Stohal number can be taken using the European standard, and the Stohal number is 0.18. In other embodiments, the Stohal number can also be taken using the national standard, and the Stohal number is 0.2.

[0145] The preferred formula (4) can be used to determine the vortex vibration starting wind speed of the tower when it vibrates at different orders through the natural frequencies of the tower at different orders, and the calculation is convenient and accurate. In other embodiments, the vortex vibration starting wind speed of the tower when it vibrates at different orders can also be determined according to other calculation formulas or methods as required.

[0146] Optionally, the critical vortex vibration starting wind speed of the actual tower and the preset wind speed ratio can be used to determine the optimal test simulation wind speed of the tower simulation member 1 according to the following formula:

[0147] ,

[0148] in, V crit is the critical vortex vibration starting wind speed of the actual tower, V m is the optimal test simulated wind speed of the tower simulation 1; m is the preset wind speed ratio, n The preset scaling ratio.

[0149] The preset scale ratio can be determined according to the size of the actual tower and the size of the wind tunnel test section, and the preset wind speed ratio can be preset according to the actual wind field and wind tunnel conditions.

[0150] Step 3) A test simulation is performed on the constructed tower simulation 1 under the test simulated wind speed, and the electromagnetic component 22 is used to adjust the initial damping force of the damping adjustment unit 2 under different test simulated wind speeds to the target damping force. The damping characteristics of the tower simulation 1 under different wind speeds can be accurately controlled, thereby achieving a true simulation of the vibration characteristics of the tower simulation 1 under different wind loads.

[0151] Furthermore, the electromagnetic component 22 is used to adjust the initial damping force of the damping adjustment unit 2 at different test simulated wind speeds to the target damping force, which specifically includes the following steps:

[0152] Step 31) determines the target damping ratio of the actual tower under different test simulated wind speeds. The target damping ratio can be obtained through structural free vibration attenuation curves, field measurements, numerical simulations, or empirical formulas, and is not limited here.

[0153] Step 32), calculating the target damping force of the tower simulation member 1 at different test simulated wind speeds according to the target damping ratio, the mass and the natural frequency of the tower simulation member 1;

[0154] Preferably, the target damping ratio, the mass and the natural frequency of the tower simulation member 1 can be used to calculate the target damping force of the tower simulation member 1 at different test simulated wind speeds according to the following formula (6):

[0155] ,

[0156] in, F is the target damping force of tower simulation 1 (in units of N ), ζ is the target damping ratio of the actual tower (dimensionless), m is the mass of the tower simulation 1 (in units of kg ), ωn is the natural frequency of the tower simulation 1 (in units rad / s ).

[0157] Step 33), by adjusting the excitation current of the electromagnet 221 in the electromagnetic assembly 22, or the air gap 23 between the electromagnetic assembly 22 and the eddy current conductor 211, the initial damping force of the damping adjustment unit 2 at different test simulated wind speeds is adjusted to the target damping force, so that the damping ratio of the tower simulation 1 matches the damping ratio of the actual tower. This can be achieved through closed-loop control, real-time monitoring of the vibration response of the tower simulation 1, and automatic adjustment of the damping force of the tower simulation 1 according to the target damping ratio.

[0158] Preferably, the excitation current of the electromagnet 221 and the air gap value can be calculated according to the following formula (7) to adjust the initial damping force of the damping adjustment unit 2 to the target damping force:

[0159] ,

[0160] in, F is the target damping force of the damping adjustment unit 2, k is a coefficient determined according to the material of the electromagnet 221, I is the exciting current of the electromagnet 221, A is the air gap value, n is a preset coefficient in the range of [1, 2].

[0161] when n = 1, formula (7) is F = k I² / A , indicating that the target damping force of the damping adjustment unit 2 is in a simple inverse proportional relationship with the air gap value. n= 2, formula (7) is F = k I² / A² , indicating that the target damping force of the damping adjustment unit 2 is inversely proportional to the square of the air gap value. n When the value is between 1 and 2, it means that the relationship between the target damping force of the damping adjustment unit 2 and the air gap value is between a simple inverse ratio and an inverse square ratio.

[0162] According to the above formula (7), the relationship between the excitation current of the electromagnet 221 and the air gap 23 and the target damping force of the damping adjustment unit 2 can be obtained. Therefore, by adjusting the excitation current of the electromagnet 221 and the air gap 23, the target damping force of the damping adjustment unit 2 can be accurately adjusted, so that the damping ratio of the tower simulation component 1 can be more accurately controlled in the wind tunnel test, so that the vibration characteristics of the tower under different wind loads can be more realistically simulated.

[0163] Optionally, the present embodiment can verify the accuracy of the simulation by measuring the vibration response of the tower simulation 1 at different wind speeds, such as the amplitude, frequency and damping ratio of the tower simulation 1. If the simulation result does not match the vibration characteristics of the actual tower, the damping adjustment scheme described above can be repeated to adjust the damping force of the damping adjustment unit 2 until a satisfactory simulation effect is achieved.

[0164] Alternatively, if Fig. 9 As shown, the excitation current can be controlled and adjusted as follows:

[0165] The controller adjusts the initial excitation current of the electromagnet according to the real-time vibration displacement value detected by the vibration displacement detection member, and the preset upper displacement threshold and lower displacement threshold, to obtain the target excitation current of the electromagnet, or obtains the target excitation current of the electromagnet according to the distance between the real-time vibration displacement position point of the vibration displacement detection member and the target position point. Afterwards, the controller controls the voltage-stabilized power supply to output the corresponding current to the electromagnet according to the target excitation current, thereby adjusting the damping force of the damping adjustment unit.

[0166] Furthermore, the controller 224 adjusts the initial excitation current of the electromagnet 221 according to the real-time vibration displacement value detected by the vibration displacement detection element 223 and the preset upper displacement threshold and lower displacement threshold to obtain the target excitation current of the electromagnet 221, including:

[0167] When the real-time vibration displacement value is greater than or equal to the upper displacement threshold, the controller 224 sends a first instruction to the voltage stabilizer 222, and the first instruction is used to instruct to add a first preset excitation current on the basis of the initial excitation current to obtain a target excitation current. That is, the controller 224 determines that the vibration of the tower simulation part 1 is too large, and sends a first instruction to increase the initial excitation current of the electromagnet 221, thereby enhancing the electromagnetic damping force and suppressing the vibration of the tower.

[0168] When the real-time vibration displacement value is less than or equal to the lower displacement threshold, the controller 224 sends a second instruction to the voltage stabilizer 222, and the second instruction is used to instruct to subtract the second preset excitation current from the initial excitation current to obtain the target excitation current. That is, the controller 224 determines that the vibration of the tower simulation part 1 is small, and sends a second instruction to reduce the initial excitation current of the electromagnet 221, thereby weakening the electromagnetic damping force to avoid excessive damping affecting the test results.

[0169] When the real-time vibration displacement value is less than the upper displacement threshold and greater than the lower displacement threshold, the controller 224 keeps the initial excitation current unchanged or adjusts the initial excitation current according to the third preset excitation current to obtain the target excitation current. That is, the controller 224 determines the vibration of the tower simulation component 1. The controller 224 keeps the initial excitation current unchanged or makes fine adjustments according to the third preset excitation current.

[0170] Further, according to the distance between the real-time vibration displacement position point of the vibration displacement detection member and the target position point, obtaining the target excitation current of the electromagnet includes: the controller 224 is used to obtain the error distance according to the distance between the real-time vibration displacement position point and the target position point, and calculate the target excitation current according to the error distance using the following expression algorithm: .

[0171] Preferably, before step 3), before the test simulation of the tower simulation 1 under the determined test simulation wind speed, an aeroelastic model similarity simulation is performed. The dimensionless parameter similarity simulation is to compare the dimensionless parameters of the tower with the dimensionless parameters of the tower simulation 1. When the dimensionless parameters of the tower and the dimensionless parameters of the tower simulation 1 meet the consistency condition (the error does not exceed 5%), it means that the tower simulation 1 reflects the performance of the tower, and the test data of the tower simulation 1 can reflect the actual rod, thereby ensuring that the results of the wind tunnel test truly reflect the aeroelastic effect of the actual tower in the atmospheric boundary layer. Specifically, the dimensionless parameters include elastic parameters and density ratio parameters.

[0172] Optionally, the elastic parameters of the tower and the elastic parameters of the tower simulation component 1 may be calculated according to the following formula:

[0173] ,

[0174] Optionally, the density ratio parameter of the tower and the density ratio parameter of the tower simulation 1 may be calculated according to the following formula: ,

[0175] in, are the elastic parameters of the tower or the elastic parameters of the tower simulation 1; E is the material elastic modulus of the tower or the material elastic modulus of the tower simulation 1; Iis the bending inertia moment of the material section of the tower or the bending inertia moment of the material section of the tower simulation part 1; is the air density of the actual application or the air density of the wind tunnel; L is the characteristic length of the tower or the characteristic length of the tower simulation 1; U Wind speed for actual application or wind tunnel simulation; is the density ratio parameter of the tower or the density ratio parameter of the tower simulation 1, is the mass per unit length of the tower or the mass per unit length of the tower simulation 1; It is the characteristic cross-sectional dimension of the tower or the characteristic cross-sectional dimension of the tower simulation 1.

[0176] Characteristic length of the tower or the characteristic length of the tower simulation 1 L Usually refers to the total height of the tower or the height of the main load-bearing part. For example, for a tall tower, L This can be the total height of the tower; for a tower with a platform, L This can be the height of the main support structure below the platform. Characteristic Length L The unit is usually m.

[0177] In this embodiment, the tower and the tower simulation 1 are made of the same material (usually steel). If the dimensionless parameters of the tower with the same material have an error of less than 5% with the dimensionless parameters of the tower simulation 1, it means that the test results in the simulation scenario can truly reflect the aeroelastic effect of the actual tower in the atmospheric boundary layer; if the error exceeds 5%, the relevant settings in the simulation scenario are readjusted to an error of less than 5%. This is the basis for ensuring that the wind tunnel test can achieve a true simulation of the tower.

[0178] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A tower wind load model test device, comprising a tower simulation part, characterized in that: It also includes a damping adjustment unit to ensure the accuracy of dynamic wind load determination, the damping adjustment unit includes an eddy current conductor assembly and an electromagnetic assembly, wherein the eddy current conductor assembly is installed on the top of the tower simulation, the eddy current conductor assembly includes a superimposed eddy current conductor and a magnetic back plate, and the magnetic back plate is located between the tower simulation and the eddy current conductor; the electromagnetic assembly is installed on the top surface of the test wind tunnel, the electromagnetic assembly and the eddy current conductor are arranged relative to each other and an air gap is left; the electromagnetic assembly includes an electromagnet, a controller, a voltage-stabilized power supply and a vibration displacement detection component, the electromagnet is installed on the top surface of the test wind tunnel, and the vibration displacement detection component is installed on the tower simulation, and is used to detect the real-time vibration displacement value of the tower simulation under different wind loads; the vibration displacement detection component, the controller and the voltage-stabilized power supply are electrically connected in sequence; the controller is used to control and adjust the excitation current of the electromagnet through the voltage-stabilized power supply according to the real-time vibration displacement value of the vibration displacement detection component, so as to adjust the damping force of the damping adjustment unit.

2. The tower wind load model test device according to claim 1, characterized in that: The tower simulation is a lattice tower simulation, which is formed by connecting a plurality of groups of modular tower units along the length direction of the lattice tower simulation, and each group of modular tower units is enclosed by two half-side processed segments.

3. The tower wind load model test device according to claim 2, characterized in that: The half-side processing segment includes a plurality of longitudinal main tower rods arranged along the circumference of the lattice tower, cross-connecting rods connected between adjacent longitudinal main tower rods, frame-type connecting rods connected in the cross-connecting rods, angle connecting rods connected in the frame-type connecting rods, and triangular connecting rods connected in the angle connecting rods. The cross-connecting rods are arranged in multiple groups along the length direction of the longitudinal main tower rods and are connected to each other end to end; the frame-type connecting rods are located in the adjacent cross-connecting rods on both sides of the longitudinal main tower rods.

4. The tower wind load model test device according to any one of claims 1 to 3, characterized in that: The electromagnet is installed on the top surface of the test wind tunnel through a connecting rod, and the arrangement length of the electromagnet covers the vibration range of the tower simulation component during the test.

5. The tower wind load model test device according to claim 4, characterized in that: The controller comprises: A judging unit, used to judge the magnitude relationship between the real-time vibration displacement value and the upper displacement threshold and the lower displacement threshold; a target excitation current calculation unit, configured to, when the judgment unit judges that the real-time vibration displacement value is greater than or equal to the upper displacement threshold, add a first preset excitation current to the initial excitation current to obtain a target excitation current; when the real-time vibration displacement value is less than or equal to the lower displacement threshold, subtract a second preset excitation current from the initial excitation current to obtain a target excitation current; when the real-time vibration displacement value is less than the upper displacement threshold and greater than the lower displacement threshold, use the initial excitation current as the target excitation current; The instruction generating unit is used to generate a corresponding control instruction according to the target excitation current calculated by the target excitation current calculating unit and send it to the voltage-stabilized power supply to control the electromagnet to output the target excitation current.

6. The tower wind load model test device according to claim 4, characterized in that: The controller comprises: An error distance calculation unit, used to obtain the error distance according to the distance between the real-time vibration displacement position point and the target position point; A target excitation current calculation unit is used to calculate the target excitation current according to the error distance. The algorithm calculates the target excitation current using the following expression: in, is the target excitation current, is the error distance, is the proportionality coefficient, is the integration coefficient, is the differential coefficient, For time; The instruction generating unit is used to generate a corresponding control instruction according to the target excitation current calculated by the target excitation current calculating unit and send it to the voltage-stabilized power supply to control the electromagnet to output the target excitation current.

7. A test method for the tower wind load model test device according to any one of claims 1 to 6, characterized in that: The steps include: Constructing a tower simulation part simulating a tower according to a preset scale ratio, and determining the thickness of the longitudinal main tower pole of the tower simulation part according to the thickness and elastic modulus of the longitudinal main tower pole of the actual tower, the elastic modulus of the tower simulation part, the scale ratio of the preset value, and the preset wind speed ratio; Obtaining natural frequencies of different orders of actual towers, determining the vortex-vibration starting wind speed of the tower under each order vibration mode according to the natural frequencies of different orders of the tower, and screening out a critical vortex-vibration starting wind speed that is less than a preset safety wind speed from the vortex-vibration starting wind speed of the tower under each order vibration; determining the optimal test simulation wind speed of the tower simulation component according to the critical vortex-vibration starting wind speed of the tower and a preset wind speed ratio; The constructed tower simulation is tested and simulated at the optimal test simulation wind speed, and the electromagnetic component is used to adjust the initial damping force of the damping adjustment unit at different test simulation wind speeds to the target damping force, thereby achieving a true simulation of the vibration characteristics of the tower simulation under different wind loads.

8. The test method according to claim 7, characterized in that: The thickness of the longitudinal main tower rod of the tower simulation is determined according to the following formula: in, is the thickness of the longitudinal main tower rod of the tower simulation, is the thickness of the longitudinal main tower pole of the actual tower, is the elastic modulus of the actual tower material, is the elastic modulus of the tower simulation material, is the preset scale ratio, The preset wind speed ratio.

9. The test method according to claim 7, characterized in that: Using the electromagnetic component to adjust the initial damping force of the damping adjustment unit at different test simulated wind speeds to the target damping force includes: Determine the target damping ratio of the actual tower under different test simulated wind speeds; Calculating the target damping force of the tower simulation under different test simulated wind speeds according to the target damping ratio, the mass and the natural frequency of the tower simulation; By adjusting the excitation current of the electromagnet in the electromagnetic assembly and / or the air gap between the electromagnetic assembly and the eddy current conductor, the initial damping force of the damping adjustment unit at different test simulated wind speeds is adjusted to the target damping force.

10. The test method according to claim 9, characterized in that: The target damping force of the damping adjustment unit is calculated according to the following formula: in, is the target damping force of the damping adjustment unit, It is a coefficient determined by the material of the electromagnet. is the excitation current, is the air gap, The preset value is in the range [1, 2].

11. The test method according to claim 7, characterized in that: The tower simulation part is an angle steel simulation part. After the tower simulation part simulating the tower is constructed according to a preset scale ratio, the tower simulation part is further processed and installed, which includes the following steps: Splitting the constructed tower simulation into a plurality of processing segments, and tiling the processing segments to obtain a plurality of tiling sizes of the processing segments, wherein the processing segments are half-side processing segments obtained by segmenting the tower simulation into a plurality of groups of modular tower units along the length direction, and splitting each group of the modular tower units equally; Determine the size of the processing plate according to the tiling size of each half-side processing segment, cut the processing plate according to the tiling size of each half-side processing segment, and obtain a plane component corresponding to the tiling shape of the corresponding half-side processing segment; The obtained plane components of each section are bent according to the actual axis of the half-side processing segment, and the angle steel component is bent along the center line of the angle steel component to obtain an angle steel component corresponding to the shape of the half-side processing segment; The two ends of the two angle steel members corresponding to the equally split half-side processing segments are fixedly connected or detachably connected to each other to obtain an assembly unit corresponding to the shape of each section of the modular tower unit; Weighing each section of the assembly unit obtained, comparing the weighed mass of each section of the assembly unit with the mass of the corresponding modular tower unit, and when the weighed mass of the assembly unit is less than the mass of the modular tower unit, providing an additional counterweight block on the assembly unit to make the mass of the assembly unit equal to the mass of the modular tower unit; The assembly units of each section are assembled and connected in sequence to obtain the tower simulation component.

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