A variable frequency power equipment vibration and noise reduction method

Abstract

The present application relates to a kind of variable frequency electric power equipment vibration reduction noise reduction method, obtains the vibration characteristic information of electric power equipment, installs built-in barrier particle damper on the transmission path of electric power equipment;Based on the parameter information of built-in barrier particle damper and particle damper numerical simulation model, with each vibration frequency of electric power equipment as variable, with the area of barrier in vibration direction as dependent variable, the mapping relationship of the magnetic field intensity around electric power equipment and the area of barrier in vibration direction is constructed;The area of barrier in built-in barrier particle damper in vibration direction is adjusted according to the magnetic field intensity around electric power equipment;When the power frequency of transformer is monitored by magnetic sensor to change, motor adjusts the size of barrier by stud, so that the vibration reduction effect of built-in barrier particle damper follows change is beneficial to reach the best vibration reduction effect under corresponding power frequency.

Description

Technical Field

[0001] The present invention relates to the technical field of vibration reduction and noise reduction, and in particular to a method for vibration reduction and noise reduction of variable frequency power equipment. Background Art

[0002] To meet the needs of deep peak regulation and energy conservation in power grids, power plant equipment has switched from traditional power frequency operation to variable frequency operation. At certain frequencies, transformers resonate, generating environmental vibration and electromagnetic noise that significantly impacts the safe operation of equipment and adversely affects the environment. The vibration and noise generated by transformers can also impact residents' lives and reduce their quality of life.

[0003] Transformer noise is primarily caused by vibration within the transformer itself, originating in the core and windings. This noise is caused by the magnetostrictive effect, which causes the core's silicon steel laminations to undergo minute dimensional changes in the alternating magnetic field. This magnetostriction causes the core to vibrate periodically with changes in the excitation frequency. In transformers, the vibrations generated by the core and windings are transmitted to the oil tank via the transformer oil and components such as the body's supports and positioning. There, combined with the vibration noise generated by the cooling system, these vibrations radiate noise to the outside world.

[0004] Particle damping technology is a nonlinear passive vibration reduction technique that achieves vibration reduction by filling an additional cavity or reserved space within the damping structure with damping particles. As the damping structure vibrates, particles within the cavity collide and rub against each other and the inner walls, dissipating vibration energy and achieving the desired vibration reduction effect. Particle dampers are also characterized by their simple structure, easy installation, no changes to the original structure, adaptability to harsh environments, and high cost-effectiveness.

[0005] For example, Chinese patent publication number CN11316789B discloses a "vibration reduction method and vibration-damping sleeper based on particle damping." The method installs a particle damper inside the sleeper, which is located on the transmission path. The method uses a discretized model to determine the target particle size, target particle filling ratio, and target particle material corresponding to the maximum total energy dissipated by the particles. This allows for a rapid establishment of a damping and vibration reduction solution for the vibration-damping sleeper.

[0006] For example, the Chinese patent with publication number CN114607720B discloses a “particle damper with a built-in obstacle network”, which enhances the energy dissipation of the particle damper through a built-in obstacle network structure;

[0007] The energy dissipation of particles within a particle damper changes with changes in excitation. Under low excitation, the particles primarily dissipate energy through friction. Under high excitation, the particles' motion changes, agglomerating, and inter-particle interactions decrease, reducing the vibration damping effect. Due to the constantly changing operating conditions of transformers, the excitation amplitude caused by magnetostriction in the transformer core constantly fluctuates. High excitation amplitudes reduce the particle damping effectiveness of the particle damper, hindering transformer vibration and noise reduction. New transformer damping methods are needed to suppress vibration and noise within the enclosure. Therefore, there is a lack of effective vibration damping methods for power equipment that do not alter the original structure of the primary system. Summary of the Invention

[0008] In view of the deficiencies in the prior art, the present invention provides a method and construction method for reducing vibration and noise of variable frequency power equipment to solve the above problems.

[0009] The present invention provides the following technical solutions:

[0010] A method for reducing vibration and noise of variable frequency power equipment comprises the following steps:

[0011] Obtain vibration characteristic information of power equipment and install particle dampers with built-in obstacles on the transmission path of power equipment;

[0012] Establish a numerical simulation model of particle damper;

[0013] Conducting simulation tests based on the particle damper numerical simulation model to obtain particle size, particle filling rate, and obstacle size parameter information of the built-in obstacle particle damper;

[0014] Based on the above-mentioned particle damper numerical simulation model and the parameter information of the built-in obstacle particle damper, the vibration frequencies of the power equipment are used as variables and the area of ​​the obstacle in the vibration direction is used as the dependent variable to obtain the mapping relationship between the vibration frequency of the power equipment and the area of ​​the obstacle in the vibration direction;

[0015] Obtaining a mapping relationship between the vibration frequency of the power equipment and the magnetic field strength around the power equipment, thereby constructing a mapping relationship between the magnetic field strength around the power equipment and the area of ​​the obstacle in the vibration direction;

[0016] The area of ​​the obstacle in the built-in obstacle particle damper in the vibration direction is correspondingly adjusted according to the magnetic field strength around the power equipment.

[0017] Preferably, the power equipment is a dry-type transformer.

[0018] Preferably, the built-in obstacle particle damper includes a container, obstacles and damping particles in a three-dimensional network structure arranged in the container, a magnetic sensor, and a power component electrically connected to the magnetic sensor, and the power component is used to adjust the size of the obstacles in the three-dimensional network structure.

[0019] Preferably, the obstacle comprises a plurality of grid frames arranged in parallel at equal intervals, and any two adjacent grid frame nodes are connected by telescopic rods.

[0020] Preferably, the power assembly includes a motor and a stud arranged at an output end of the motor, and the stud is threadedly connected to each of the grid frames.

[0021] Preferably, the interior of the telescopic rod is hollow for the stud to pass through.

[0022] Preferably, a grid groove is provided on an inner side wall of the container, and the contour of the grid groove is adapted to the contour of the grid frame.

[0023] Preferably, a flexible blocking member is provided at the opening of the grid groove near the inner cavity of the container, and the flexible blocking member includes two groups of symmetrically arranged elastic substrates, and the elastic substrates extend in an arc shape from the avoidance groove to the bottom wall of the grid groove. The side wall of the elastic substrate is provided with a row of elastic clips arranged at equal intervals, and the distance between two adjacent elastic clips is smaller than the outer diameter of the damping particles. The two rows of elastic clips on the side walls of the two groups of elastic substrates are staggered.

[0024] Preferably, the side wall of the elastic clip forms a slot.

[0025] Preferably, the inner side wall of the container is provided with sound insulation cotton.

[0026] The present invention has the following beneficial technical effects:

[0027] This invention enhances the energy dissipation of particle dampers by creating a built-in network of obstacles. The damping particles dissipate vibration energy through inelastic collision and friction, thereby suppressing structural vibration. This technology is particularly suitable for multi-excitation, wide-band vibration environments. This technology optimizes traditional vibration isolation techniques by targeting the overall dynamic structural characteristics of transformers, achieving the desired effect of isolating high frequencies while blocking low frequencies.

[0028] It can be widely used in various types of power equipment. The vibration reduction effect can be achieved by simply placing the designed particle damping device at the predetermined position of the target power equipment.

[0029] The present invention reduces vibration and noise of power equipment without changing the power equipment. Compared with the traditional method, it does not require much change to the transformer body, reduces the amount of engineering work, and reduces the cost of noise and vibration reduction.

[0030] When the magnetic sensor detects that the transformer power frequency changes, the motor adjusts the size of the obstacle through the stud, so that the damping effect of the built-in obstacle particle damper changes, which is beneficial to achieve the best damping effect at the corresponding power frequency. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a flow chart of the method of the present application;

[0032] Figure 2 is a schematic diagram of the built-in obstacle particle damper installed in a dry-type transformer of the present application;

[0033] Figure 3 is a schematic diagram of the structure of the built-in obstacle particle damper of the present application;

[0034] Figure 4 is a schematic diagram of the obstacle structure of the present application;

[0035] Figure 5 is a schematic diagram of the grid slot structure of one side wall of the container of the present application;

[0036] Figure 6 is a schematic diagram of the cooperation of the telescopic rod and the stud of the present application;

[0037] Figure 7 is a side view of the grid slot and the flexible sealing member at its opening of the present application;

[0038] Figure 8 is a partial A enlarged schematic diagram of Figure 7 ;

[0039] Figure 9 is a schematic diagram of the structure of the flexible sealing member of the present application;

[0040] Figure 10 is a schematic diagram of the state that the damping particles are clamped by two groups of elastic clamping pieces of the present application.

[0041] The reference signs in the drawings are:

[0042] 1, obstacle; 2, container; 21, grid slot; 22, avoidance slot; 3, flexible sealing member; 31, elastic base sheet; 32, elastic clamping piece; 33, clamping groove; 5, upper clamping piece of iron core; 6, winding; 7, iron core; 8, lower clamping piece; 9, support; 10, motor; 11, grid frame; 12, telescopic rod; 13, stud. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0044] Example

[0045] A method for reducing vibration and noise of variable frequency power equipment, such as Figure 1 As shown:

[0046] Obtain the normal vibration characteristic information (100 Hz) of the power equipment (dry-type transformer) and install the particle damper with built-in obstacles on the transmission path of the dry-type transformer;

[0047] Establish a numerical simulation model of particle damper;

[0048] Based on the numerical simulation model of the particle damper, simulation tests are conducted to obtain the particle size, particle filling rate, obstacle size parameter information, size parameter information of the container 2, and installation direction of the built-in obstacle particle damper;

[0049] like Figure 2 As shown, the dry-type transformer includes an upper clamp 5, a lower clamp 8, a winding 6, an iron core 7, and a support 9. Multiple particle dampers with built-in obstacles are mounted on the lower clamp 8. When the dry-type transformer is operating, the iron core 7 and winding 6 vibrate under the action of alternating current and DC bias magnetization. The vibration energy is transmitted to the upper clamp 5 and then to the support 9 through the lower clamp 8. The vibration energy is transmitted to the damping particles through the container 2, causing friction and collision between the damping particles and between the damping particles and the inner wall of the container 2, thereby consuming the vibration energy and achieving the purpose of reducing vibration. To determine the optimal filling ratio of the particle damper, discrete element simulation software was used to simulate the damper state at different particle filling ratios to obtain the number of particle collisions and average kinetic energy.

[0050] The above steps belong to the prior art and the specific details will not be repeated here.

[0051] A three-dimensional network-shaped obstacle 1 is placed inside the container 2. Due to the variable operating conditions of the transformer (20Hz-2000Hz), the damping particles inside the particle damper attached to the transformer's additional position are constantly rubbing and colliding, which will cause the internal temperature to rise. The obstacle 1 is made of a material with good heat resistance and strong oxidation resistance, and is 3D printed using stainless steel.

[0052] Under different excitation amplitudes, the size of built-in obstacle 1 also affects particle energy consumption. When the excitation amplitude is low, a too small obstacle 1 will inhibit interparticle motion, reducing particle energy consumption. When the excitation amplitude is high, a larger obstacle 1 will reduce its effectiveness in suppressing particle agglomeration and reduce vibration reduction. Therefore, the present invention utilizes the differences in the magnetic field surrounding the dry-type transformer under different operating conditions to adjust the size of obstacle 1.

[0053] The magnetic field changes are detected by a magnetic sensor, and the signal data is obtained through analysis. The motor 10 on the top of the built-in obstacle 1 is driven to rotate, and the screw 13 connected to it rotates, causing the grid frame 11 to move accordingly, thereby adjusting the size of the obstacle 1.

[0054] The container 2 is made of stainless steel and has a shell inner wall gap of 5 mm. The interior is filled with sound insulation cotton to isolate the noise generated by particle collision.

[0055] The damping particles are spherical particles with a diameter of 2 mm. The damping particles are metal particles or tungsten alloy particles that are not affected by the magnetic field of the dry-type transformer. The filling rate of the damping particles is 90%.

[0056] Based on the above-mentioned particle damper numerical simulation model and the parameter information of the built-in obstacle particle damper, the vibration frequencies of the dry-type transformer are used as variables, and the area of ​​obstacle 1 in the vibration direction (the area formed by two adjacent grid frames 11 and two adjacent telescopic rods 12) is used as the dependent variable. The mapping relationship between the vibration frequency of the dry-type transformer and the area of ​​the obstacle in the vibration direction is obtained.

[0057] Obtaining a mapping relationship between the vibration frequency of the dry-type transformer and the magnetic field strength around the dry-type transformer, thereby constructing a mapping relationship between the magnetic field strength around the dry-type transformer and the area of ​​obstacle 1 in the vibration direction;

[0058] The area of ​​the obstacle 1 in the built-in obstacle particle damper in the vibration direction is adjusted accordingly according to the magnetic field strength around the dry-type transformer.

[0059] like Figure 3-9 As shown, container 2 is a rectangular container. Obstacle 1 comprises multiple equally spaced grid frames 11. Adjacent grid frames 11 are connected by telescopic rods 12, allowing for adjustable spacing between adjacent grid frames 11. The three-dimensional network-like structure of obstacle 1 has individual small spaces ranging in size from 10*14*14 to 14*14*14 mm.

[0060] The motor 10 and the magnetic sensor are mounted on the outer wall of the container 2. A stud 13 is mounted on the output end of the motor 10. The stud 13 is threadedly connected to the nodes of a plurality of grid frames 11 arranged in parallel at equal intervals. The modules of the threaded connection between the stud 13 and each grid frame 11 are arranged in equal steps. When the stud 13 is rotated to adjust the spacing between two adjacent grid frames 11, the spacing between each grid frame 11 is kept the same. Figure 6 As shown, the stud 13 is relatively located inside the coaxial multiple telescopic rods 12, thereby preventing the damping particles from colliding with the stud 13 and causing wear on the thread.

[0061] like Figure 5 As shown, one of the inner side walls of the container 2 is provided with a grid groove 13 adapted to the grid frame 11, and the width of the grid groove 13 is slightly larger than the outer diameter of the grid frame 11 and the telescopic rod 12; since the inner cavity space of the container 2 remains unchanged, the grid groove 13 is used to accommodate redundant grid frames 11 and telescopic rods 12 when the distance between two adjacent grid frames 11 is large.

[0062] Since the width of the grid groove 13 is larger than the outer diameter of the damping particles, if too many damping particles flow into the grid groove 13, there will be too few damping particles for consuming vibration energy, and the set vibration reduction effect cannot be achieved. Therefore, a flexible blocking member 3 is provided at each opening of the grid groove 13;

[0063] like Figure 8 As shown, a avoidance groove 22 is provided on the inner wall of each opening of the grid groove 13; the state of the flexible blocking member 3 under normal conditions is shown in FIG. Figure 7-9 As shown, the flexible sealing member 3 includes two groups of symmetrically arranged elastic base sheets 31 and elastic clips 32. The upper end of the elastic base sheet 31 is fixed to the inner top wall of the avoidance groove 22, and the lower end of the elastic base sheet 31 is freely suspended. The elastic base sheet 31 itself has a certain elastic deformation ability. A row of elastic clips 32 arranged at equal intervals are provided on the side wall of the elastic base sheet 31. The elastic clips 32 themselves have a certain elastic deformation ability. The distance between two adjacent elastic clips 32 is smaller than the outer diameter of the damping particles. A card groove 33 is formed on the upper part of the side wall of the elastic clip 32 near the inner cavity of the container 2. The distance between the two card grooves 33 between the two adjacent elastic clips 32 gradually increases towards the edge of one side close to the inner cavity of the container 2.

[0064] Working principle:

[0065] When the operating conditions of the transformer change, the magnetic field around it will also change. The magnetic field changes are detected by magnetic sensors and analyzed to obtain signal data.

[0066] According to the pre-established mapping relationship between the magnetic field strength around the transformer and the area of ​​the obstacle in the vibration direction, the motor 10 is driven to rotate a set number of circles. The rotation of the motor 10 drives the stud 13 to rotate. The rotation of the stud 13 drives all the grid frames 11 to follow and move to adjust the distance between two adjacent grid frames 11, thereby adjusting the area of ​​the obstacle 1 in the vibration direction (the length direction of the container 2).

[0067] Under normal conditions, the flexible blocking member 3 relatively blocks the opening of the grid groove 13 to prevent the damping particles from flowing into the grid groove 13 .

[0068] During the process of the grid frame 11 entering and exiting the grid slot 13, since the elastic base 31 and the elastic clip 32 can be elastically deformed, the grid frame 11 can be smoothly pushed open and passed through, and the elastic base 31 and the elastic clip 32 can be rotated into the avoidance slot 22 for the grid frame 11 to pass through.

[0069] In the process of the grid frame 11 entering the grid slot 13, a small amount of damping particles are located on the upper surface of the two rows of elastic clips 32. In the process of the grid frame 11 entering the grid slot 13, the damping particles are first pressed into two adjacent elastic clips 32. The distance between the two elastic clips 32 is slightly smaller than the outer diameter of the damping particles and can be elastically deformed to achieve the position of the slot 33 in which the damping particles are clamped. Figure 10 As shown, the subsequent grid frame 11 continues to enter the grid groove 13, and the damping particles are clamped and rotate together with the deformed elastic substrate 31 to avoid the avoidance groove 22. The above arrangement can prevent the damping particles from passing through together. After the grid frame 11 passes through the flexible blocking member 3, the elastic substrate 31 elastically deforms and resets.

[0070] like Figure 9 As shown, the two rows of elastic clips 32 are staggered to prevent the damping particles from passing through the two rows of elastic clips 32. Furthermore, during the resetting of the elastic base plate 31, the damping particles clamped by two adjacent sets of elastic clips 32 can be lifted by the third set of elastic clips 32 inserted between them, helping the damping particles to escape from the retaining slots 33. Due to the vibration of the particle damper with built-in obstacles, the damping particles can slowly escape from between the two sets of elastic clips 32 and return to the inner cavity of the container 2.

[0071] By arranging the side with the grid grooves 13 at the top, the probability of the damping particles entering the grid grooves 13 can be greatly reduced.

[0072] The above-described embodiments merely represent specific implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A method for reducing vibration and noise of variable frequency power equipment, comprising the following steps: Obtain vibration characteristic information of power equipment and install particle dampers with built-in obstacles on the transmission path of power equipment; Establish a numerical simulation model of particle damper; Conducting simulation tests based on the particle damper numerical simulation model to obtain particle size, particle filling rate, and obstacle size parameter information of the built-in obstacle particle damper; Its characteristics are: Based on the above-mentioned particle damper numerical simulation model and the parameter information of the built-in obstacle particle damper, the vibration frequencies of the power equipment are used as variables and the area of ​​the obstacle in the vibration direction is used as the dependent variable to obtain the mapping relationship between the vibration frequency of the power equipment and the area of ​​the obstacle in the vibration direction; Obtaining a mapping relationship between the vibration frequency of the power equipment and the magnetic field strength around the power equipment, thereby constructing a mapping relationship between the magnetic field strength around the power equipment and the area of ​​the obstacle in the vibration direction; The area of ​​the obstacle in the built-in obstacle particle damper in the vibration direction is adjusted accordingly according to the magnetic field strength around the power equipment; The built-in obstacle particle damper comprises a container (2), an obstacle (1) and damping particles in a three-dimensional network structure arranged in the container (2), a magnetic sensor, and a power component electrically connected to the magnetic sensor, wherein the power component is used to adjust the size of the obstacle (1) in the three-dimensional network structure; The obstacle (1) comprises a plurality of grid frames (11) arranged in parallel at equal intervals, and the nodes of two adjacent grid frames (11) are connected by telescopic rods (12); The power assembly comprises a motor (10) and a stud (13) arranged at an output end of the motor (10), wherein the stud (13) is threadedly connected to each of the grid frames (11).

2. A method for reducing vibration and noise of variable frequency power equipment according to claim 1, characterized in that: The electric power equipment is a dry-type transformer.

3. The method for reducing vibration and noise of variable frequency power equipment according to claim 1, characterized in that: The telescopic rod (12) is hollow inside and is used for the stud (13) to pass through.

4. The method for reducing vibration and noise of variable frequency power equipment according to claim 1, characterized in that: An inner side wall of the container (2) is provided with a grid groove (21), and the outline of the grid groove (21) is adapted to the outline of the grid frame (11).

5. A method for reducing vibration and noise of variable frequency power equipment according to claim 4, characterized in that: A flexible blocking member (3) is provided at an opening on one side of the grid groove (21) close to the inner cavity of the container (2), and the flexible blocking member (3) includes two groups of symmetrically arranged elastic substrates (31). The elastic substrates (31) extend in an arc shape from the avoidance groove (22) to one side of the bottom wall of the grid groove (21). The side wall of the elastic substrate (31) is provided with a row of elastic clips (32) arranged at equal intervals, and the distance between two adjacent elastic clips (32) is smaller than the outer diameter of the damping particles. The two rows of elastic clips (32) on the side walls of the two groups of elastic substrates (31) are staggered.

6. A method for reducing vibration and noise of variable frequency power equipment according to claim 5, characterized in that: A clamping groove (33) is formed on the side wall of the elastic clip (32).

7. The method for reducing vibration and noise of variable frequency power equipment according to claim 1, characterized in that: The inner side wall of the container (2) is provided with sound insulation cotton.

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