A substation plant boundary sound environment quality improvement system and method

Abstract

The application provides a substation boundary sound environment quality improving system and method, the system comprises: a noise reduction wall, including a base buried below the ground and a wall body; at least one tunable sound absorption unit, installed at a predetermined height range of the wall body, each tunable sound absorption unit comprising: a unit shell having a sound absorption cavity opening towards the inside of the boundary; the sound absorption cavity has a rear wall parallel to the wall body and a side wall perpendicular to the wall body; a sound absorption plate movably arranged in the sound absorption cavity, the back of the sound absorption plate forms a movable front wall of the sound absorption cavity; one or more through holes are formed on the sound absorption plate for guiding the substation noise into the sound absorption cavity; an adjusting mechanism connected with the sound absorption plate is used to drive the sound absorption plate to move in the thickness direction of the wall body in the sound absorption cavity to adjust the distance between the movable front wall and the rear wall; and a control module is used to drive the adjusting mechanism to act. The application can significantly improve the sound absorption effect of the amplitude prominent frequency band.

Description

Technical Field

[0001] This invention relates to the field of sound insulation and noise reduction technology for power facilities, specifically to a system and method for improving the acoustic environment quality at the boundary of a substation. Background Technology

[0002] With the accelerating pace of urbanization in my country and the continuous expansion of urban areas, electricity demand has surged. To ensure reliable power supply and structural robustness of the power grid, the construction and expansion of transmission and transformation facilities have become inevitable. On the one hand, in densely populated urban centers, new or expanded substations are needed to increase reserve capacity and improve the power grid architecture. On the other hand, the outward expansion of urban boundaries means that substations originally located in the suburbs are gradually being surrounded by newly built residential areas, schools, hospitals, and other environmentally sensitive areas. These two factors combined have led to a shrinking distance between substations and surrounding sensitive points, compressing the natural noise attenuation space they should have, and exacerbating noise problems.

[0003] To effectively control substation noise, common methods currently include increasing the height and thickness of the substation boundary walls, adding sound barriers to the boundary walls, or installing sound-absorbing materials. These methods primarily focus on improving sound insulation from the perspectives of structural strength and geometric dimensions, or increasing noise reflection and absorption through the installation of sound-absorbing materials. However, none of these methods take into account the significant differences in noise energy at different frequencies and locations of the transformer, resulting in a low degree of matching between the noise reduction effect and the actual noise characteristics on site, making it difficult to achieve optimal noise reduction results.

[0004] In particular, transformer noise, which is mainly composed of low-frequency line spectrum components, has significantly different propagation characteristics from mid- and high-frequency noise. It has the characteristics of long propagation distance, strong penetration and slow attenuation. In the absence of effective noise reduction methods, it will have a continuous impact on the surrounding environment.

[0005] It is evident that there is an urgent need to improve the existing systems and methods for improving the acoustic environment quality at the substation boundaries. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a substation boundary acoustic environment quality improvement system and method, which enables precise setting and differentiated configuration of noise reduction parameters based on the spectral characteristics and spatial distribution patterns of transformer noise, thereby improving noise reduction performance while ensuring structural safety.

[0007] The present invention adopts the following technical solution.

[0008] According to a first aspect of the present invention, a substation boundary acoustic environment quality improvement system is provided. The system includes: Noise reduction wall, including base and wall body buried underground; At least one tunable sound-absorbing unit is installed at a predetermined height range of the wall body, and each tunable sound-absorbing unit includes: The unit housing has a sound-absorbing cavity that opens toward the inner side of the plant boundary; the sound-absorbing cavity has a rear wall parallel to the wall body and a side wall perpendicular to the wall body; A sound-absorbing panel is movably disposed within the sound-absorbing cavity, and the back of the sound-absorbing panel forms the movable front wall of the sound-absorbing cavity; one or more through holes are provided on the sound-absorbing panel for introducing substation noise into the sound-absorbing cavity; wherein the distance between the movable front wall and the rear wall is determined by the noise spectrum at the location.

[0009] Preferably, the base has a convex cross-section along the thickness direction; the wall body has a lower body with the same thickness as the top of the base and an upper body disposed above the lower body; the thickness of the upper body is less than the thickness of the lower body; outside the factory boundary, the surfaces of the upper body and the lower body are flush; inside the factory boundary, the upper body and the lower body form an L-shaped step for installing the at least one tunable sound-absorbing unit.

[0010] Preferably, the top of the wall body is provided with an arc-shaped cover; the arc-shaped cover is integrally pressed from aluminum alloy and filled with sound-absorbing material to prevent rainwater from seeping in, provide installation space for pipelines, and improve the attenuation effect of diffraction sound.

[0011] Preferably, a sound-absorbing mortar layer is provided between each tunable sound-absorbing unit and between each tunable sound-absorbing unit and the wall body; the sound-absorbing mortar has the following mix ratio: cement: lime paste: sand: organic fiber = 1:1:2.5:4~6; polypropylene short fibers are added to the sound-absorbing mortar layer.

[0012] Preferably, the rear wall, side wall and / or movable front wall of the sound-absorbing cavity are machined with spiral grooves.

[0013] Preferably, each tunable sound-absorbing unit further includes: A sealing gasket is disposed between the circumferential sidewall of the sound-absorbing panel and the sidewall of the unit housing, and is used to maintain a sliding seal between the sound-absorbing panel and the sidewall of the unit housing during the movement of the sound-absorbing panel along the thickness direction of the wall body.

[0014] Preferably, each tunable sound-absorbing unit further includes: An adjustment mechanism, connected to the sound-absorbing panel, is used to drive the sound-absorbing panel to move along the thickness direction of the wall body within the sound-absorbing cavity, so as to adjust the distance between the movable front wall and the rear wall; The control module is used to drive the adjustment mechanism to operate according to the received control commands.

[0015] Preferably, the adjustment mechanism includes: An electric telescopic rod, the rear end of which is fixed to the rear wall of the unit housing, and the front end of which is fixedly connected to the sound-absorbing panel; A miniature motor is fixedly installed on the rear wall of the unit housing and is used to drive the electric telescopic rod to perform telescopic movement under the control of the control module; A position sensor is fixedly mounted on the rear wall of the unit housing to detect the distance between the movable front wall and the rear wall in real time and feed it back to the control module. The control module is further configured to drive the micro motor until the electric telescopic rod moves the sound-absorbing panel to the target position based on the deviation between the actual position signal fed back by the position sensor and the target position. Preferably, the system further includes: A noise monitoring module is installed on the noise reduction wall and includes multiple microphones arranged at different positions along the wall to collect noise data at each position in real time. The main controller is communicatively connected to the control modules of the noise monitoring module and each tunable sound-absorbing unit, and the main controller is configured as follows: Real-time noise data is acquired at multiple microphone locations inside the factory boundary, wherein the multiple microphones inside the factory boundary are arranged at different locations along the wall body. Based on real-time noise data from multiple microphone locations inside the factory boundary, the actual noise spectrum at the location of each tunable sound-absorbing unit is evaluated. Based on the actual noise spectrum, determine the target noise frequency components at the location of each tunable sound-absorbing unit; Based on the target noise frequency component, an adjustment command or adjustment suggestion is generated to adjust the distance between the movable front wall and the rear wall of the corresponding tunable sound-absorbing unit. Preferably, the main controller is further configured to: Acquire real-time noise data at multiple microphone locations both inside and outside the plant boundary; The insertion loss of the wall is calculated based on real-time noise data from multiple sensor locations inside and outside the plant boundary. When the insertion loss is lower than a preset threshold, an early warning message is generated.

[0016] According to a second aspect of the present invention, a method for improving the acoustic environment quality at the boundary of a substation using the system described in the first aspect of the present invention is provided. The method includes: Real-time noise data is acquired at multiple microphone locations inside the factory boundary, wherein the multiple microphones inside the factory boundary are arranged at different locations along the wall body. Based on real-time noise data from multiple microphone locations inside the factory boundary, the actual noise spectrum at the location of each tunable sound-absorbing unit is evaluated. Based on the actual noise spectrum, determine the target noise frequency components at the location of each tunable sound-absorbing unit; Based on the target noise frequency component, an adjustment command or adjustment suggestion is generated to adjust the distance between the movable front wall and the rear wall of the corresponding tunable sound-absorbing unit.

[0017] Preferably, the method further includes: Acquire real-time noise data at multiple microphone locations both inside and outside the plant boundary; The insertion loss of the wall is calculated based on real-time noise data from multiple sensor locations inside and outside the plant boundary. When the insertion loss is lower than a preset threshold, an early warning message is generated.

[0018] The beneficial effects of this invention are that, compared with the prior art, 1. By setting a unit housing with a sound-absorbing cavity that opens toward the inner side of the plant boundary, and setting a sound-absorbing plate that is movably set in the sound-absorbing cavity, the distance between the sound-absorbing plate and the rear wall of the sound-absorbing cavity can be adjusted according to the spectral characteristics of the sound source in the substation, thereby significantly improving the noise absorption effect for the frequency band with prominent amplitude.

[0019] 2. By deploying microphones along the wall to collect noise data in real time, and combining this with the main controller to evaluate the actual noise spectrum at the location of each tunable sound-absorbing unit and determine the target noise frequency component, adjustment instructions or suggestions are generated to adjust the distance between the movable front and rear walls of the corresponding tunable sound-absorbing unit. This allows for differentiated adjustment of each sound-absorbing unit, thereby achieving intelligent adaptive control of the noise reduction system.

[0020] 3. By calculating the insertion loss of the wall based on real-time noise data, and generating an early warning message when the insertion loss is lower than a preset threshold, the cost of manual inspection can be greatly reduced, supporting intelligent operation and maintenance throughout the entire life cycle and improving the long-term operational stability of the noise reduction system. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the wall used to improve the acoustic environment quality at the boundary of the substation in this invention; Figure 2 This is a schematic diagram of the tunable sound-absorbing unit of the present invention; Figures 3(a) to 3(e) are noise spectrum diagrams at frequencies of 100~600 Hz. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, other embodiments obtained by those skilled in the art without creative effort are all within the protection scope of this invention.

[0023] The first aspect of the present invention provides a substation boundary acoustic environment quality improvement system.

[0024] like Figure 1 In one embodiment, the substation boundary acoustic environment quality improvement system includes a noise reduction wall and multiple tunable sound-absorbing units 3 installed on the noise reduction wall. Figure 1 The left side shows a cross-sectional schematic diagram of the substation boundary acoustic environment quality improvement system. Figure 1 The right side is a front view of the substation's acoustic environment quality improvement system, viewed from the inside of the plant boundary.

[0025] The noise reduction wall consists of a base 2 embedded underground and a wall body 1. The base 2 is made of reinforced concrete to ensure the overall stability of the wall. The wall body 1 serves as the main structure of the noise reduction wall, providing the installation foundation for the sound-absorbing units 3.

[0026] The adjustable sound-absorbing unit 3 is installed at a predetermined height within the wall body 1. For example... Figure 2 Each tunable sound-absorbing unit 3 includes a unit housing 31 and a sound-absorbing plate 32. Figure 2 In the diagram, the upper left portion is a front view of the tunable sound-absorbing unit, the upper right portion is a schematic diagram of a vertical cross-section of the tunable sound-absorbing unit along the wall thickness direction, and the lower left portion is a schematic diagram of a horizontal cross-section of the tunable sound-absorbing unit. A sound-absorbing cavity with an opening facing the inner side of the plant boundary is formed inside the unit housing. This sound-absorbing cavity has a rear wall parallel to the wall body 1 and a side wall perpendicular to the wall body 1. A sound-absorbing panel 32 is movably disposed within the sound-absorbing cavity, and its back surface forms a movable front wall of the sound-absorbing cavity. One or more through holes are provided on the sound-absorbing panel 32 for introducing substation noise into the sound-absorbing cavity. The distance between the movable front wall and the rear wall is determined by the noise spectrum at that location.

[0027] In this embodiment, by setting a movable sound-absorbing panel 32, the depth of the sound-absorbing cavity can be adjusted according to the actual noise spectrum of the installation location, thereby achieving targeted absorption of noise in different frequency bands. Substation noise is mainly low-to-mid frequency, and traditional fixed-structure sound-absorbing units are difficult to cover the entire frequency band. However, this solution, by adjusting the depth of the resonant cavity, can match the resonant frequency of the sound-absorbing unit 3 with the target noise frequency, significantly improving the noise reduction effect. At the same time, the sound-absorbing unit 3 adopts a modular design, and only the sound-absorbing unit needs to be replaced or adjusted during later maintenance or upgrades, without modifying the wall body 1.

[0028] In a further preferred embodiment, the base 2 has a convex cross-section along its thickness direction. This structure effectively enhances the bending stiffness of the base 2 and improves the overall stability of the wall. The wall body 1 includes a lower body and an upper body. The lower body has the same thickness as the top of the base 2, and the upper body is located above the lower body, with a thickness less than that of the lower body. Outside the factory boundary, the surfaces of the upper and lower bodies are flush; inside the factory boundary, the upper and lower bodies form an L-shaped step for installing the at least one tunable sound-absorbing unit.

[0029] Specifically, the base 2 is buried at a depth of 1.5 meters, with a first-level step cast at the bottom to further enhance wind load resistance and prevent tipping. The lower body is 2.4 meters high and 40 centimeters thick; the upper body is 1.6 meters high and less thick than the lower body. The L-shaped step structure allows the sound-absorbing units to be stably stacked on the steps.

[0030] In this way, by pre-setting L-shaped steps on the wall body 1, the original wall does not need to be demolished during later noise reduction renovations. The noise reduction facilities can be installed simply by stacking sound-absorbing units 3 at the steps, which greatly reduces the amount of civil engineering work and the construction period. At the same time, the convex-shaped base 2 combined with the stepped bottom structure effectively enhances the wall's anti-overturning ability, ensuring that the wall can still meet the safety specifications such as wind load resistance after the sound-absorbing units 3 are installed.

[0031] In a further preferred embodiment, the top of the wall body 1 is provided with a multifunctional arc-shaped cover 5. The arc-shaped cover 5 is integrally molded from aluminum alloy and filled with sound-absorbing material. Specifically, the arc-shaped cover 5 is integrally molded from 3mm thick aluminum alloy, with an anodized surface, an arc radius of 20cm, and radiating 5cm thick sound-absorbing cotton inside.

[0032] In this way, the arc-shaped cover 5 has three functions: first, it prevents rainwater from seeping in, improves the weather resistance of the wall and the sound-absorbing unit 3, and extends its service life; second, it provides installation space for the electronic fence, noise monitoring system, and lighting system pipelines, making it easy to disassemble and inspect, and facilitating later operation and maintenance; third, the arc-shaped structure can effectively improve the attenuation effect of diffraction sound at the top of the wall, increasing the noise reduction by an additional 2-3dB, further improving the overall noise reduction performance.

[0033] In a further preferred embodiment, a sound-absorbing mortar layer is provided between each tunable sound-absorbing unit 3 and between each tunable sound-absorbing unit 3 and the wall body 1. The sound-absorbing mortar has the following mix ratio: cement: lime paste: sand: organic fiber = 1:1:2.5:4~6. Polypropylene short fibers are added to the sound-absorbing mortar layer, specifically 10mm long polypropylene short fibers accounting for no more than 5% of the total volume.

[0034] In this way, the sound-absorbing mortar fills the gaps between the sound-absorbing units and between the units and the wall, preventing sound energy from leaking through these gaps. Furthermore, the organic fibers and short polypropylene fibers in the mortar improve the crack resistance of the mortar layer and enhance the acoustic damping characteristics of the hollow gray bricks, thus improving the overall sound insulation performance. This mortar layer works synergistically with the sound-absorbing unit 3 to form a continuous, multi-layered sound-absorbing and sound-insulating structure.

[0035] In a further preferred embodiment, spiral grooves are machined on the rear wall, side walls, and / or movable front wall of the sound-absorbing cavity. Specifically, spiral grooves with a depth of 5 mm and a pitch of 10 mm are machined on the inner wall of the sound-absorbing cavity.

[0036] In this way, the spiral grooves further scatter the reflection path of sound waves within the cavity, increasing the number of collisions between the sound waves and the wall surface, thereby improving the sound energy dissipation efficiency. Compared to a smooth inner wall, this structure effectively enhances the absorption performance of mid-to-low frequency noise without increasing the volume of the sound-absorbing unit 3.

[0037] In a further preferred embodiment, each tunable sound-absorbing unit 3 further includes a sealing gasket disposed between the circumferential sidewall of the sound-absorbing panel and the sidewall of the unit housing. This sealing gasket maintains a sliding seal between the sound-absorbing panel and the sidewall of the unit housing as the sound-absorbing panel moves along the thickness direction of the wall body 1. Specifically, the sealing gasket is 2mm thick, made of silicone rubber, and can be recycled from waste composite insulator silicone rubber.

[0038] In this way, the sealing gasket ensures the airtightness between the sound-absorbing panel and the unit housing during movement and adjustment, preventing sound energy leakage through gaps and ensuring the stable acoustic performance of the sound-absorbing cavity. At the same time, the use of recycled silicone rubber from waste composite insulators achieves the circular use of waste resources, aligning with green environmental protection principles.

[0039] In a further preferred embodiment, each tunable sound-absorbing unit 3 further includes an adjustment mechanism and a control module. The adjustment mechanism is connected to the sound-absorbing panel and is used to drive the sound-absorbing panel to move along the thickness direction of the wall body 1 within the sound-absorbing cavity to adjust the distance between the movable front wall and the rear wall. The control module is used to drive the adjustment mechanism to operate according to received control commands.

[0040] Specifically, the adjustment mechanism includes an electric telescopic rod, a micro motor, and a position sensor. The rear end of the electric telescopic rod is fixed to the rear wall of the unit housing, and the front end is fixedly connected to the sound-absorbing panel. The micro motor is fixedly installed on the rear wall of the unit housing and is used to drive the electric telescopic rod to extend and retract under the control of the control module. The position sensor is fixedly installed on the rear wall of the unit housing and is used to detect the distance between the movable front wall and the rear wall in real time and feed it back to the control module. The control module is also used to drive the micro motor until the electric telescopic rod moves the sound-absorbing panel to the target position based on the deviation between the actual position signal fed back by the position sensor and the target position.

[0041] In this way, the position of the sound-absorbing panel is automatically adjusted via an electric telescopic rod and a micro motor. Combined with closed-loop feedback control from a position sensor, the sound-absorbing panel can be precisely adjusted to the target position, ensuring that the resonant frequency of the sound-absorbing unit 3 accurately matches the target noise frequency. The automatic adjustment mechanism enables the system to dynamically respond to changes in the noise spectrum without manual intervention, improving the intelligence level and response speed of the noise reduction system.

[0042] In a further preferred embodiment, the system also includes a noise monitoring module and a main controller. The noise monitoring module is mounted on the noise reduction wall and includes multiple microphones deployed at different locations along the wall for real-time noise data collection at each location. The microphones are mounted on the wall using fixed brackets, and the measurement data is fed back to the noise monitoring system in real-time via a LoRa wireless network. The microphones can be located inside and outside the factory boundary of the noise reduction wall, and can also be uniformly or non-uniformly distributed along the length and height of the wall.

[0043] The main controller is communicatively connected to the noise monitoring module and the control modules of each tunable sound-absorbing unit 3. The main controller is configured to: acquire real-time noise data at multiple microphone locations inside the plant boundary; evaluate the actual noise spectrum at the location of each tunable sound-absorbing unit based on the real-time noise data at the multiple microphone locations inside the plant boundary; determine the target noise frequency component at the location of each tunable sound-absorbing unit based on the actual noise spectrum; and generate adjustment commands or adjustment suggestions for adjusting the distance between the movable front and rear walls of the corresponding tunable sound-absorbing unit based on the target noise frequency component.

[0044] Furthermore, the main controller is also configured to: acquire real-time noise data at multiple microphone locations inside and outside the plant boundary; calculate the insertion loss of the wall based on the real-time noise data at multiple sensor locations inside and outside the plant boundary; and generate an early warning message when the insertion loss is lower than a preset threshold. Specifically, an early warning is automatically issued when the insertion loss is lower than 10% of the design value, prompting maintenance personnel to check the status of the sound-absorbing unit 3.

[0045] Furthermore, the specific details and principles of how the main controller implements the above configuration will be described in detail in Part II of this invention.

[0046] In this way, by deploying microphones at different locations on the wall, spatial distribution monitoring of noise at the plant boundary is achieved. The main controller generates targeted adjustment commands based on the actual noise spectrum at each location, enabling differentiated and refined control of the sound-absorbing units. Simultaneously, it calculates insertion loss in real time and generates early warnings, promptly detecting noise reduction performance degradation and prompting maintenance personnel to conduct inspections and maintenance. Monitoring data is synchronously uploaded to the power grid environmental management cloud platform, supporting multi-station-level noise data aggregation and analysis, providing data support for optimizing noise reduction schemes in regional substations. The system incorporates an AI adaptive optimization algorithm that automatically assesses the performance degradation of sound-absorbing units 3 at different frequency bands based on real-time noise spectrum characteristics. When the noise reduction in a specific frequency band is insufficient, it automatically pushes a replacement plan for the sound-absorbing unit 3, achieving intelligent operation and maintenance throughout the entire lifecycle of the noise reduction system.

[0047] In a further preferred embodiment, a display screen 4 is installed on the outer side of the plant boundary wall. This display screen can visualize and transmit the results of the microphone's 24 / 7 online monitoring and analysis to the outside of the plant boundary. The display screen 4 is linked in real-time with the noise monitoring system, dynamically displaying information such as the current noise level at the plant boundary, the daytime and nighttime equivalent sound level, and the operating status of noise reduction facilities. The data update frequency is ≤1 minute, allowing nearby residents to monitor the substation's noise emissions in real time. During off-peak hours, the display screen 4 can continuously play public service announcements such as electricity science popularization and environmental protection propaganda.

[0048] This approach, by displaying noise monitoring data in real time on the external display screen 4, improves the transparency of substation operation information, effectively alleviating noise concerns among nearby residents and reducing noise complaints. Simultaneously, the broadcast of public service announcements helps enhance interaction between the substation and the surrounding community, improving public awareness and acceptance of power facilities.

[0049] In a further preferred embodiment, the underground portion of the wall has pre-installed openings 6 to provide channels for cables and water supply / drainage pipes. Specifically, the underground foundation of the wall has multiple sets of high-strength PVC sleeves with a diameter of 150-300mm, a spacing of not less than 100mm between the sleeves, fireproof material filling the spaces between the sleeves, and flexible waterproof sealing rings at both ends, with a waterproof rating of IP67, which can meet the installation requirements of substation cables, water supply / drainage pipes, and communication lines. Traction steel wires are pre-installed inside the sleeves, so subsequent pipe laying does not require damage to the wall structure.

[0050] This method, by pre-installing conduits in the underground portion of the wall, avoids damage to the wall structure during subsequent pipeline installation, improving construction efficiency by over 60%. Filling the conduit space with fire-resistant material effectively prevents the spread of fire along the pipeline, while flexible waterproof sealing rings ensure waterproofing performance and extend the pipeline's lifespan. Simultaneously, the pre-installed traction steel wire makes pipeline installation more convenient, further reducing construction difficulty and cost.

[0051] A second aspect of the present invention provides a method for improving the acoustic environment quality at the boundary of a substation using the above-described system.

[0052] In one embodiment, the method for improving the acoustic environment quality at the substation boundary of the present invention can be executed at the main controller of the above-described system of the present invention, including the following steps: S1. Acquire real-time noise data at multiple microphone locations inside the factory boundary.

[0053] Preferably, noise data collected by multiple microphones can be transmitted to the main controller in real time via a LoRa wireless network.

[0054] S2. Based on the real-time noise data at multiple microphone locations inside the factory boundary, evaluate the actual noise spectrum at the location of each tunable sound-absorbing unit.

[0055] This step specifically includes the following sub-steps: S21. Based on the transformer structural parameters and electromagnetic excitation, an integrated sound radiation model is established, and the theoretical spectrum of sound pressure level at each location in space is obtained by solving the model.

[0056] First, a three-dimensional geometric model is established based on the actual structural parameters of the transformer (tank dimensions, core and winding layout, and radiator geometry).

[0057] According to the fundamental equation of acoustics, we have:

[0058] in, For sound pressure, For wave number, Angular frequency, The speed of sound.

[0059] A rectangular air region enclosing the transformer housing and radiator is defined around the transformer, and the outer surface of this rectangular air region is set as the fusion boundary.

[0060] Within the fusion boundary, the near-field sound pressure is solved using the FEM (finite element method). The magnetostriction of the iron core and the electromagnetic force of the windings are used as excitation sources, and the vibration velocity distribution on the tank wall is solved using structural dynamics equations.

[0061] in, , , These are the structural mass matrix, damping matrix, and stiffness matrix, respectively. It is a displacement vector. The electromagnetic force vector, ω is the angular frequency.

[0062] Vibration velocity of fuel tank wall As acoustic boundary conditions, they are substituted into the acoustic wave equation to solve for the near-field sound pressure distribution.

[0063] Outside the fusion boundary, the far-field acoustic radiation is solved using the Boundary Element Method (BEM). Based on the Helmholtz integral equation, the sound pressure at any field point r is calculated. for:

[0064] in, Indicates the fusion boundary, This represents a point located on the fusion boundary. For free space Green's function, .

[0065] By integrating the continuous sound pressure and normal particle velocity conditions at the boundary, and coupling the FEM and BEM equations, a unified sound radiation model is obtained, expressed as:

[0066] Solving the above coupled equations yields the results for any position. Theoretical noise spectrum of sound pressure level .

[0067] In this step, by setting a flat cuboid fusion boundary, the complex geometry is wrapped within the FEM computational domain. The BEM only needs to perform surface meshing on the flat boundary. Compared with the method of directly using the complex transformer box surface as the boundary between FEM and BEM, this avoids the difficulty of meshing, significantly reduces the computational degrees of freedom, and solves the problem of difficult convergence of complex geometric boundaries.

[0068] S22. Based on the theoretical spectrum of sound pressure level at various locations in space, and combined with real-time noise data from multiple microphone locations inside the factory boundary, the actual noise spectrum at each sound-absorbing unit location on the wall is reconstructed using the Kriging interpolation method.

[0069] Assume the location of the microphone inside the factory boundary is as follows: ( i =1,2,…,m, where m is the number of microphones), the measured sound pressure level noise spectrum is The theoretical noise spectrum of the sound pressure level calculated by solving the coupled equations. Establish the spatial mutability function:

[0070] in, h It is a spatial distance vector. N (h) represents the number of sample point pairs at a distance of h.

[0071] Using real-time noise data from each microphone location inside the factory boundary as control points, the location of each tunable sound-absorbing unit on the noise-reducing wall was monitored. Solve the following Kriging equations to obtain the weighting coefficients for each microphone. ,

[0072]

[0073]

[0074] in, μ It is a Lagrange multiplier.

[0075] Then, the actual noise spectrum of the sound pressure level at that location is calculated for subsequent determination of the target noise frequency components. The actual noise spectrum... Represented as: .

[0076] As a specific example, Figures 3(a) to 3(e) show the noise spectrum diagrams at frequencies of 100-600 Hz obtained using the above method, i.e., the spatial sound pressure level distribution diagrams.

[0077] In this step, the theoretical spectrum of sound pressure level at each location in space is obtained by solving the integrated sound radiation model, and the variogram parameters of the Kriging interpolation are calibrated so that the interpolation result conforms to the physical attenuation law of the actual sound field, rather than a simple mathematical interpolation. This allows for high-precision spatial spectrum reconstruction under limited measurement point conditions.

[0078] Preferably, in this step, the positions of the multiple microphones can be optimized based on the theoretical spectrum of the sound pressure level at each location in space.

[0079] Specifically, the main controller can perform spectral analysis on the time-domain noise signal at each location, extract the sound pressure level distribution of each frequency band, and then calculate the total sound pressure level at each location. Then, it analyzes the gradient of the total sound pressure level along the length and height of the wall, identifies areas where the total sound pressure level changes drastically (i.e., areas where the rate of change exceeds a preset threshold, such as the transformer projection area and the area directly opposite the radiator) and the peak area of ​​the total sound pressure level. These areas are used as key measurement points to prioritize the placement of microphones, while reference measurement points are evenly placed at both ends and the middle of the wall to form a non-uniformly optimized microphone array.

[0080] In this way, by identifying the location of key measurement points based on the model calculation results, the data that best reflects the spatial variation characteristics of the sound field can be obtained with the fewest microphones, thus reducing the system hardware cost.

[0081] S3. Based on the actual noise spectrum, determine the target noise frequency components at the location of each tunable sound-absorbing unit.

[0082] The main controller can identify target frequency components with prominent amplitudes that need to be suppressed.

[0083] Specifically, the main controller detects the actual noise spectrum at the location of each sound-absorbing unit. Perform the analysis and identify the target frequency components that need to be suppressed by following these steps: S31. Emerging Frequency Screening: Calculate the sound pressure level rise of each frequency point relative to adjacent frequency bands, and mark frequencies with a rise of more than 3dB as candidate emerging frequencies.

[0084] S32. Energy percentage assessment: Calculate the percentage of energy of each candidate frequency to the total energy, and retain frequencies with a percentage exceeding 10%.

[0085] S33. Transformer Harmonic Matching: Transformer noise energy is mainly concentrated at 100Hz and its integer multiples of harmonics (200Hz, 300Hz, 400Hz, 500Hz, 600Hz). Match candidate frequencies with the above harmonics, and give higher priority to frequencies with a deviation within ±2Hz.

[0086] S34. Tunability Judgment: Based on the structural parameters of the sound-absorbing unit (opening area, cavity volume, adjustable depth range), determine whether the candidate frequency falls within the adjustable resonant frequency range of the unit. If it is within the range, the frequency can be targeted for absorption by adjusting the cavity depth; otherwise, it is not considered a primary target.

[0087] S35. Comprehensive decision: Considering the three factors of energy ratio, harmonic matching degree, and tunability, select the frequency with the highest score as the target frequency component of the sound-absorbing unit.

[0088] S36. Spatial coordination: Group adjacent sound-absorbing units. If most units in a group have chosen the same frequency, then all units in that group will use the same frequency to avoid sound wave interference.

[0089] Finally, the main controller outputs the target frequency component for each sound-absorbing unit, which is used to generate subsequent adjustment commands.

[0090] S4. Based on the target noise frequency component, generate adjustment instructions or adjustment suggestions for adjusting the distance between the movable front wall and rear wall of the corresponding tunable sound-absorbing unit.

[0091] This adjustment is based on the Helmholtz resonance principle, ensuring that the resonant frequency of the sound-absorbing unit matches the target noise frequency component. Adjustment commands can be directly sent to the control module of the corresponding sound-absorbing unit, which then drives the adjustment mechanism to automatically perform position adjustments. Adjustment suggestions can be presented to maintenance personnel through a human-machine interface for confirmation and execution.

[0092] In this step, a closed-loop control process involving real-time monitoring, spectrum analysis, and differentiated adjustment is used to achieve the adaptive response of the noise reduction system to the dynamic changes in substation noise, ensuring that each sound-absorbing unit always works in the optimal state and significantly improving the noise reduction effect.

[0093] The method also includes a step of real-time monitoring of the noise reduction effect, including: S5. Acquire real-time noise data at multiple microphone locations inside and outside the plant boundary.

[0094] S6. Calculate the insertion loss of the wall based on real-time noise data from multiple sensor locations inside and outside the factory boundary. When the insertion loss is lower than a preset threshold, generate an early warning message.

[0095] Insertion loss is defined as the difference in total sound pressure level at the same receiving point before and after the noise reduction wall is installed.

[0096] This warning message can prompt maintenance personnel to check the status of the sound-absorbing unit or perform maintenance.

[0097] In this step, by calculating the insertion loss in real time and comparing it with a preset threshold, the degradation of noise reduction performance can be detected in a timely manner, enabling early warning of faults and proactive maintenance, and preventing the continuous decline in noise reduction effect from affecting the sound environment quality at the plant boundary.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. A substation boundary acoustic environment quality improvement system, characterized in that, include: Noise reduction wall, including the wall body and the base buried underground; At least one tunable sound-absorbing unit is installed at a predetermined height range of the wall body, and each tunable sound-absorbing unit includes: The unit housing has a sound-absorbing cavity that opens toward the inner side of the plant boundary; the sound-absorbing cavity has a rear wall parallel to the wall body and a side wall perpendicular to the wall body; A sound-absorbing panel is movably disposed within the sound-absorbing cavity, and the back of the sound-absorbing panel forms the movable front wall of the sound-absorbing cavity; one or more through holes are provided on the sound-absorbing panel for introducing substation noise into the sound-absorbing cavity; wherein the distance between the movable front wall and the rear wall is determined by the noise spectrum at the location.

2. The substation boundary acoustic environment quality improvement system according to claim 1, characterized in that, The base has a convex cross-section along the thickness direction; the wall body has a lower body with the same thickness as the top of the base and an upper body disposed above the lower body; the thickness of the upper body is less than the thickness of the lower body; outside the factory boundary, the surfaces of the upper body and the lower body are flush; inside the factory boundary, the upper body and the lower body form an L-shaped step for installing the at least one tunable sound-absorbing unit.

3. The substation boundary acoustic environment quality improvement system according to claim 2, characterized in that, The top of the wall body is provided with an arc-shaped cover; the arc-shaped cover is made of aluminum alloy and filled with sound-absorbing material to prevent rainwater from seeping in, provide installation space for pipelines, and improve the attenuation effect of diffraction sound.

4. The substation boundary acoustic environment quality improvement system according to claim 1, characterized in that, A sound-absorbing mortar layer is provided between each tunable sound-absorbing unit and between each tunable sound-absorbing unit and the wall body; the sound-absorbing mortar has the following mix ratio: cement: lime paste: sand: organic fiber = 1:1:2.5:4~6; polypropylene short fibers are added to the sound-absorbing mortar layer.

5. The substation boundary acoustic environment quality improvement system according to claim 1, characterized in that, The rear wall, side wall and / or movable front wall of the sound-absorbing cavity are machined with spiral grooves.

6. The substation boundary acoustic environment quality improvement system according to claim 1, characterized in that, Each tunable sound-absorbing unit also includes: A sealing gasket is disposed between the circumferential sidewall of the sound-absorbing panel and the sidewall of the unit housing, and is used to maintain a sliding seal between the sound-absorbing panel and the sidewall of the unit housing during the movement of the sound-absorbing panel along the thickness direction of the wall body.

7. The substation boundary acoustic environment quality improvement system according to claim 1, characterized in that, Each tunable sound-absorbing unit also includes: An adjustment mechanism, connected to the sound-absorbing panel, is used to drive the sound-absorbing panel to move along the thickness direction of the wall body within the sound-absorbing cavity, so as to adjust the distance between the movable front wall and the rear wall; The control module is used to drive the adjustment mechanism to operate according to the received control commands.

8. The substation boundary acoustic environment quality improvement system according to claim 7, characterized in that, The adjustment mechanism includes: An electric telescopic rod, the rear end of which is fixed to the rear wall of the unit housing, and the front end of which is fixedly connected to the sound-absorbing panel; A miniature motor is fixedly installed on the rear wall of the unit housing and is used to drive the electric telescopic rod to perform telescopic movement under the control of the control module; A position sensor is fixedly mounted on the rear wall of the unit housing to detect the distance between the movable front wall and the rear wall in real time and feed it back to the control module. The control module is further configured to drive the micro motor until the electric telescopic rod moves the sound-absorbing panel to the target position based on the deviation between the actual position signal fed back by the position sensor and the target position.

9. The substation boundary acoustic environment quality improvement system according to claim 1, characterized in that, Also includes: A noise monitoring module is installed on the noise reduction wall and includes multiple microphones arranged at different positions along the wall to collect noise data at each position in real time. The main controller is communicatively connected to the control modules of the noise monitoring module and each tunable sound-absorbing unit, and the main controller is configured as follows: Acquire real-time noise data at multiple microphone locations inside the factory boundary; Based on real-time noise data from multiple microphone locations inside the factory boundary, the actual noise spectrum at the location of each tunable sound-absorbing unit is evaluated. Based on the actual noise spectrum, determine the target noise frequency components at the location of each tunable sound-absorbing unit; Based on the target noise frequency component, an adjustment command or adjustment suggestion is generated to adjust the distance between the active front wall and the rear wall of the corresponding tunable sound-absorbing unit.

10. The substation boundary acoustic environment quality improvement system according to claim 9, characterized in that, The main controller is also configured to: Acquire real-time noise data at multiple microphone locations inside and outside the plant boundary; The insertion loss of the wall is calculated based on real-time noise data from multiple sensor locations inside and outside the plant boundary. When the insertion loss is lower than a preset threshold, an early warning message is generated.

11. A method for improving the acoustic environment quality at the boundary of a substation using the system described in any one of claims 1-10, characterized in that, include: Acquire real-time noise data at multiple microphone locations inside the factory boundary; Based on real-time noise data from multiple microphone locations inside the factory boundary, the actual noise spectrum at the location of each tunable sound-absorbing unit is evaluated. Based on the actual noise spectrum, determine the target noise frequency components at the location of each tunable sound-absorbing unit; Based on the target noise frequency component, an adjustment command or adjustment suggestion is generated to adjust the distance between the active front wall and the rear wall of the corresponding tunable sound-absorbing unit.

12. The method for improving the acoustic environment quality at the boundary of a substation according to claim 11, characterized in that, Also includes: Acquire real-time noise data at multiple microphone locations inside and outside the plant boundary; Based on real-time noise data from multiple sensor locations inside and outside the factory boundary, the insertion loss of the wall is calculated. When the insertion loss is lower than a preset threshold, an early warning message is generated.

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