Sound barrier with adjustable sound absorption and insulation performance

Abstract

This application discloses a tunable sound-absorbing composite photovoltaic sound barrier, comprising a photovoltaic module, a tunable composite sound-absorbing structure, and an adaptive control unit. The tunable composite sound-absorbing structure includes a first adjustable frame and a second adjustable frame. The first adjustable frame is movable relative to the back of the photovoltaic power generation unit to adjust the depth of a first cavity between the piezoelectric film on the first adjustable frame and the back of the photovoltaic power generation unit. The second adjustable frame is movable relative to the piezoelectric film to adjust the depth of a second cavity between a micro-perforated plate and the piezoelectric film. The adaptive control unit is configured to adjust the depth of the first cavity and / or the depth of the second cavity based on the dominant noise frequency, and / or adjust the voltage applied to the piezoelectric film, so that the resonant frequency of the tunable composite sound-absorbing structure tracks the dominant noise frequency. This photovoltaic sound barrier, by organically combining photovoltaic power generation with acoustic control, can achieve adaptive noise reduction according to the characteristics of the external noise spectrum.

Description

Technical Field

[0001] This application relates to the fields of photovoltaic and noise reduction technology, and in particular to a superstructured photovoltaic sound barrier with adjustable sound absorption and insulation performance. Background Technology

[0002] In the strategic context of promoting green transformation and sustainable development, the development of green renewable energy technologies is crucial. Photovoltaic sound barriers, as an integrated solution, can generate clean energy while controlling noise, and have broad application prospects. Patent CN 120211210 A discloses a novel double-sided photovoltaic sound barrier, including two mounting components, with a transparent micro-perforated plate assembly and a photovoltaic panel assembly inserted between them; each mounting component is equipped with a locking unit for synchronously locking the transparent micro-perforated plate assembly and the photovoltaic panel assembly. This patent utilizes micro-perforated plates to improve the sound absorption performance of the sound barrier; however, due to the limited thickness of photovoltaic sound barriers, the micro-perforated plate sound absorption structure can typically only absorb mid-to-high frequency noise, and its low-frequency noise absorption performance is insufficient. However, substations, converter stations, and other major noise sources are mainly low-frequency noise (concentrated in 100–200Hz), making traditional photovoltaic sound barriers unsuitable for these scenarios. On the other hand, photovoltaic sound barriers are mostly passive designs, and their acoustic performance is fixed after installation, unable to adaptively adjust according to changes in the noise spectrum (such as noise frequency fluctuations caused by changes in substation load), thus limiting their application scenarios.

[0003] Therefore, there is an urgent need in this field to develop a superstructured photovoltaic sound barrier with adjustable sound absorption and insulation performance. By organically combining photovoltaic power generation with acoustic control, the sound absorption and insulation performance of the sound barrier can be automatically adjusted according to the characteristics of the external noise spectrum, while also possessing excellent low-frequency sound absorption performance. Summary of the Invention

[0004] The purpose of this application is to provide a superstructured photovoltaic sound barrier with adjustable sound absorption and insulation performance. By organically combining photovoltaic power generation with acoustic control, the sound absorption and insulation performance of the sound barrier can be automatically adjusted according to the characteristics of the external noise spectrum, while also possessing excellent low-frequency sound absorption performance.

[0005] This application provides a metamorphic photovoltaic sound barrier with adjustable sound absorption and insulation performance, comprising: A photovoltaic module, comprising a photovoltaic power generation unit, wherein the photovoltaic power generation unit includes a back side; A tunable composite sound-absorbing structure, comprising a first adjustable frame and a second adjustable frame arranged sequentially from the inside out; wherein... A piezoelectric thin film is mounted on the first adjustable frame, which is configured to be mounted on the back of the photovoltaic power generation unit. The piezoelectric thin film faces the back of the photovoltaic power generation unit. A keel structure is provided inside the first adjustable frame, which divides the piezoelectric thin film into multiple piezoelectric thin film units. Each piezoelectric thin film unit is provided with a mass block, so that the piezoelectric thin film unit and the mass block together form a piezoelectric thin film-mass block resonant structure. The first adjustable frame is configured to be movable relative to the back of the photovoltaic power generation unit to adjust the depth of the first cavity between the piezoelectric film and the back of the photovoltaic power generation unit; The second adjustable frame is configured to be mounted on the piezoelectric film. A microperforated plate is disposed on the second adjustable frame, the microperforated plate facing the piezoelectric film. The second adjustable frame is also configured to be movable relative to the piezoelectric film, thereby adjusting the depth of the second cavity between the microperforated plate and the piezoelectric film. The second adjustable frame, the microperforated plate, and the second cavity together form a microperforated plate resonant structure. An acoustic sensor is also disposed on the microperforated plate. An adaptive control unit is configured to receive noise signals collected by the acoustic sensor, identify the dominant noise frequency, and adjust the first cavity depth and / or the second cavity depth based on the dominant noise frequency, and / or adjust the voltage applied to the piezoelectric film to change the equivalent stiffness of the piezoelectric film, so that the resonant frequency of the tunable composite sound-absorbing structure tracks the dominant noise frequency, thereby achieving adaptive noise reduction.

[0006] In another preferred embodiment, the acoustic sensor is disposed at the center of the microperforated plate.

[0007] In another preferred embodiment, the piezoelectric thin film is disposed opposite to the photovoltaic power generation unit.

[0008] In another preferred embodiment, the adaptive control unit adjusts the resonant frequency of the tunable composite sound-absorbing structure by at least one of the following methods: Adjusting the depth of the first cavity adjusts the resonant frequency of the piezoelectric film-mass resonant structure, thereby achieving mechanical coarse adjustment to absorb low-frequency noise. Adjusting the voltage applied to the piezoelectric film changes its equivalent stiffness, thereby adjusting the resonant frequency of the piezoelectric film-mass resonant structure and achieving electrical fine-tuning for absorbing low-frequency noise; and Adjusting the depth of the second cavity adjusts the resonant frequency of the micro-perforated plate resonant structure, thereby achieving frequency adjustment for absorbing mid-to-high frequency noise.

[0009] In another preferred embodiment, the low-frequency noise refers to noise in the range of 100 Hz to 200 Hz.

[0010] In another preferred embodiment, the mid-to-high frequency noise refers to noise in the frequency band above 300 Hz.

[0011] In another preferred embodiment, the resonant frequency of the piezoelectric thin film-mass resonant structure f 1 Represented by the following relation: in, c and ρ are the density of air and the speed of sound, respectively. This represents the mass per unit area of ​​the piezoelectric film. The mass of the mass block on the piezoelectric thin film. S is the height of the first adjustable frame, i.e., the depth of the first cavity; S is the area of ​​the piezoelectric film; and K is the equivalent stiffness of the piezoelectric film.

[0012] In another preferred embodiment, the keel structure is a rectangular mesh structure or a hexagonal mesh structure, such that the piezoelectric film has corresponding rectangular or hexagonal piezoelectric film units.

[0013] In another preferred embodiment, the photovoltaic power generation unit is a bifacial photovoltaic unit, the piezoelectric film is a transparent piezoelectric film, and / or the material of the transparent piezoelectric film includes polyvinylidene fluoride, with a thickness of 30-1000 μm and a polarization direction along the thickness direction of the film.

[0014] In another preferred embodiment, the micro-perforated plate has a pore size of 0.3 mm to 1 mm, a plate thickness of 0.3 mm to 1 mm, and a perforation rate of 0.5% to 3%.

[0015] In another preferred embodiment, the mass blocks disposed on the piezoelectric thin film unit have the same mass or different masses.

[0016] Preferably, the mass blocks on the piezoelectric thin film unit have different masses.

[0017] In another preferred embodiment, the mass block is made of a high-density metal or non-metal.

[0018] In another preferred embodiment, the photovoltaic sound barrier further includes a first drive mechanism for moving the first adjustable frame and a second drive mechanism for moving the second adjustable frame; The first drive mechanism and / or the second drive mechanism include a micro motor, a sleeve, and a slide rail connector; the micro motor drives the corresponding adjustable frame to move toward or away from the back of the photovoltaic power generation unit through the sleeve and slide rail connector.

[0019] In another preferred embodiment, the first adjustable frame and / or the second adjustable frame are connected to the micro motor via a sleeve and slide rail connector.

[0020] In another preferred embodiment, the adaptive control unit is configured to be electrically connected to the acoustic sensor, the voltage regulation circuit of the piezoelectric film, and the first and second drive mechanisms, and to adjust the voltage applied to the piezoelectric film by controlling the voltage regulation circuit, and to adjust the first cavity depth and / or the second cavity depth by controlling the first and second drive mechanisms.

[0021] In another preferred embodiment, the photovoltaic power generation unit is a bifacial photovoltaic unit, and the photovoltaic module further includes a power management system, which includes an energy storage device and a power control module. The power control module is configured to preferentially allocate the electrical energy generated by the bifacial photovoltaic unit to the adaptive control unit, the first drive mechanism, and the second drive mechanism.

[0022] This application has at least one of the following advantages: (a) The adjustable sound absorption and insulation performance of the superstructure photovoltaic sound barrier of this application achieves broadband high-efficiency noise reduction. Specifically, it combines a piezoelectric thin film-mass block resonant system for low frequencies and a micro-perforated plate resonant structure for mid-to-high frequencies to form a broadband composite sound absorber, which effectively broadens the effective noise reduction frequency range of the sound barrier. (b) The adjustable sound absorption and insulation performance of the superstructure photovoltaic sound barrier of this application achieves adaptive and precise noise reduction. Through the dual tuning mechanism of "mechanical coarse adjustment" (changing the cavity depth) and "electrical fine adjustment" (changing the film stiffness), the resonant frequency of the sound barrier can track and lock the changing noise source frequency in real time and dynamically. It is particularly effective in targeted absorption of low-frequency noise of 100-200Hz in substations, and the noise reduction effect is significantly improved. (c) The adjustable sound absorption and insulation performance of the super-structured photovoltaic sound barrier of this application achieves deep integration of functions and energy self-sufficiency. The photovoltaic power generation is directly used to drive the noise reduction and regulation mechanism, forming an energy closed loop of "self-generation and self-use, intelligent regulation", which improves the system's energy efficiency and intelligence, and realizes the organic integration of photovoltaic power generation and noise control functions. (d) The adjustable sound absorption and insulation performance of the super-structured photovoltaic sound barrier of this application has a compact structure and high space utilization. It integrates power generation, energy storage, sensing and noise reduction units within the limited thickness of the sound barrier, making it particularly suitable for space-constrained scenarios.

[0023] It should be understood that, within the scope of this invention, the above-described technical features of this invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be described in detail here. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. It should be understood that the accompanying drawings described below are merely some implementation examples of the present invention, and those skilled in the art can obtain other implementation examples based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the overall structure of a superconducting photovoltaic sound barrier with adjustable sound absorption and insulation performance according to an embodiment of the present invention; Figure 2 This is a schematic cross-sectional view of a superconducting photovoltaic sound barrier with adjustable sound absorption and insulation performance according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the periodic unit piezoelectric layer of a superstructured photovoltaic sound barrier with adjustable sound absorption and insulation performance according to an embodiment of the present invention; Figure 4 This is a simulation calculation result of the sound absorption coefficient of a superstructured photovoltaic sound barrier with adjustable sound absorption and insulation performance according to an embodiment of the present invention under specific structural parameters; Figure 5 This is a simulation curve of the sound absorption coefficient of an adjustable sound absorption and insulation metamorphic photovoltaic sound barrier according to an embodiment of the present invention after adjusting the depths of the first and second adjustable frames; Figure 6 This is a simulation curve of the sound absorption coefficient of an adjustable sound-absorbing and sound-insulating superstructure photovoltaic sound barrier according to an embodiment of the present invention after adjusting the equivalent stiffness of the piezoelectric film.

[0026] In each of the attached figures, the markings are as follows: 1- Photovoltaic Modules 11-Photovoltaic power generation unit 12-Power Control System 2-Acoustic Components 21-First Adjustable Frame 211-Sleeve and slide rail connector 212-Motor 213-Film Keel 22-Piezoelectric Thin Film 221-Mass Block 23-Second Adjustable Frame 24-Micro-perforated plate 241-Microphone 3-Adaptive control unit. Detailed Implementation

[0027] Through extensive and in-depth research, the inventors have developed for the first time a superstructured photovoltaic sound barrier with adjustable sound absorption and insulation performance. By setting a low-frequency sound-absorbing structure including a first adjustable frame and a transparent piezoelectric film and a mid-to-high-frequency sound-absorbing structure including a second adjustable frame and a micro-perforated plate on the back side of the photovoltaic module, the sound absorption and insulation performance of the photovoltaic sound barrier of this application can be adaptively adjusted over a wide frequency range. In particular, it effectively solves the problem of low-frequency noise control in substations and converter stations, which is mainly in the range of 100-200Hz, while achieving energy self-sufficiency.

[0028] In the following description, many technical details are presented to help the reader better understand this application. However, those skilled in the art will understand that the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0029] the term As used herein, the terms “acoustic component”, “tunable composite sound-absorbing structure”, and “composite sound-absorbing structure” are used interchangeably. As used herein, the terms "periodic unit" and "piezoelectric thin film unit" are used interchangeably; As used herein, the terms "height of the adjustable frame" and "corresponding cavity depth" refer to the same thing, because the adjustable frame of this application forms a sleeve structure together with the sleeve, and the depth of the cavity is adjusted by adjusting the height of the adjustable frame.

[0030] It should be noted that in this patent application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this patent application, if it refers to performing an action according to an element, it means performing the action at least according to that element, including two cases: performing the action only according to that element, and performing the action according to that element and other elements. Expressions such as "multiple," "repeatedly," and "various" include two, two times, two kinds, and more than two, more than two times, and more than two kinds.

[0031] In this invention, all directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0032] A superstructure photovoltaic sound barrier with adjustable sound absorption and insulation performance A superstructured photovoltaic sound barrier with adjustable sound absorption and insulation performance is composed of photovoltaic modules, acoustic components and an adaptive control unit.

[0033] The photovoltaic module includes a photovoltaic power generation unit and a power management system electrically connected thereto. The photovoltaic power generation unit includes a back side and is used to convert solar energy into electrical energy. The power management system includes an energy storage device and a power control system for storing electrical energy and powering other units of the sound barrier. Preferably, the photovoltaic power generation unit is a bifacial photovoltaic unit.

[0034] The power control module prioritizes the allocation of electrical energy generated by the photovoltaic modules to the adaptive control unit and the micro motor; The acoustic component (i.e., the tunable composite sound-absorbing structure) is located on the back side of the photovoltaic power generation unit, and its core is the composite sound-absorbing structure. The tunable composite sound-absorbing structure, from the inside out, consists of a first adjustable frame, a transparent piezoelectric film, a second adjustable frame, and a micro-perforated plate. The transparent piezoelectric film is positioned on the first adjustable frame, and the micro-perforated plate is positioned on the second adjustable frame. The transparent piezoelectric film faces the back of the photovoltaic power generation unit, and the micro-perforated plate faces the transparent piezoelectric film.

[0035] The first adjustable frame is fixedly installed on the back of the photovoltaic power generation unit. Its interior has a periodic grid of cells divided by a grid. Each cell carries a transparent piezoelectric film and a mass block, forming a resonant system (i.e., a piezoelectric film-mass block resonant structure). Specifically, the grid divides the transparent piezoelectric film it carries into several independent cells. Each cell, divided by the grid, has a mass block.

[0036] The first adjustable frame is connected to a micro motor, which drives the first adjustable frame to move to change the depth of the first cavity between the piezoelectric film and the photovoltaic backsheet. The first adjustable frame is provided with a sleeve and a slide rail connector, which are connected to the micro motor. The first adjustable frame can be driven to move by external commands, thereby changing the depth of the first cavity between the piezoelectric film and the photovoltaic backsheet.

[0037] The second adjustable frame is fixedly mounted on the piezoelectric film, and an acoustic sensor is provided at the center of the microperforated plate. The second adjustable frame is provided with a sleeve and a slide rail connector, which are connected to a micro motor to drive the second adjustable frame to move and change the depth of the second cavity between the microperforated plate and the piezoelectric film.

[0038] An adaptive control unit, connected to an acoustic sensor, a voltage regulation circuit for a piezoelectric film, and a micromotor, is configured to: receive signals from the acoustic sensor, identify the dominant noise frequency, and synchronously adjust the voltage applied to the piezoelectric film (achieving electrical fine-tuning of the resonant frequency) to change its equivalent stiffness; and drive the motor to adjust the depth of the first and / or second cavities (achieving mechanical coarse-tuning of the resonant frequency). This enables the resonant frequency of the composite sound-absorbing structure to accurately track and lock onto the target noise frequency, achieving adaptive noise reduction. In other words, it enables the resonant frequency of the resonant system to track the target noise frequency, thus achieving adaptive noise reduction.

[0039] Furthermore, the internal keel of the first adjustable frame is rectangular or hexagonal, so that the independent periodic units into which the piezoelectric film is divided are rectangular or hexagonal in shape, and the periodic units are piezoelectric film units.

[0040] Furthermore, mass blocks with the same mass can be set on the independent periodic units. Preferably, mass blocks with different masses can be set on the independent periodic units to broaden the overall sound absorption frequency band of the sound barrier.

[0041] Preferably, the material of the mass block can be a high-density metal or non-metal, which needs to be easily and firmly bonded to the piezoelectric film.

[0042] Preferably, the transparent piezoelectric film is made of polyvinylidene fluoride, with a thickness of 30-1000µm and a polarization direction along the thickness direction of the film.

[0043] Furthermore, the power management system also includes a power control module for prioritizing the allocation of electrical energy generated by the photovoltaic modules to the adaptive control unit and micro motors.

[0044] Preferably, the micro-perforated plate has a pore size of 0.3mm-1mm, a plate thickness of 0.3-1mm, and a perforation rate of 0.5%-3%.

[0045] To make the objectives, technical solutions, and advantages of the present invention clearer, embodiments of the present invention will be described in further detail below with reference to the accompanying drawings. It should be understood that these are merely examples provided to the reader of possible implementations of the present invention and are not intended to limit the scope of the invention.

[0046] Example 1 like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a superstructured photovoltaic sound barrier with adjustable sound absorption and insulation performance, which consists of a photovoltaic module 1, an acoustic module 2, and an adaptive control unit 3.

[0047] The photovoltaic module includes a bifacial photovoltaic unit 11 and a power management system 12 electrically connected thereto. The bifacial photovoltaic unit 11 includes a back side, which forms the back side of the sound barrier for converting solar energy into electrical energy. The power management system 12 includes an energy storage device 121 and a power control system 122 for storing electrical energy and powering other units of the sound barrier.

[0048] Acoustic component 2 is disposed on one side of photovoltaic power generation unit 1, and its core is a composite sound-absorbing structure. The composite sound-absorbing structure, from the inside out, consists of a first adjustable frame 21, a transparent piezoelectric film 22, a second adjustable frame 23, and a micro-perforated plate 24. The first adjustable frame 21 is fixedly installed on the back of the bifacial photovoltaic unit 11. The piezoelectric film 22 is disposed on the first adjustable frame 21, facing the back of the bifacial photovoltaic unit. The first adjustable frame 21 contains a sleeve and a slide rail connector 211, which is connected to a micro motor 212. The first adjustable frame 21 can be moved by external commands, thereby changing the depth of the first cavity between the piezoelectric film 22 and the back of the bifacial photovoltaic unit 11. Figure 3 As shown, a keel 213 is provided inside the first adjustable frame, which divides the transparent piezoelectric film 22 it supports into several independent units. Each transparent piezoelectric film 22 has a mass block on each unit divided by the keel.

[0049] The second adjustable frame 23 is fixedly mounted on the transparent piezoelectric film, and the micro-perforated plate 24 is disposed on the second adjustable frame, with the micro-perforated plate 24 facing the piezoelectric film 22. The second adjustable frame is provided with a sleeve and slide rail connector 211, which is connected to a micro motor 212 for adjusting the depth of the second cavity between the micro-perforated plate 24 and the piezoelectric film 22; an acoustic sensor 241 is provided at the center of the micro-perforated plate 24.

[0050] The adaptive control unit 3 is connected to the acoustic sensor 241, the voltage regulation circuit of the transparent piezoelectric film 22, and the micro motor 212. It is used to receive the acoustic sensor signal, identify the dominant noise frequency, and adjust the voltage applied to the piezoelectric film (to achieve electrical fine-tuning of the resonant frequency) and drive the micro motor to adjust the depth of the first cavity and / or the second cavity (to achieve mechanical coarse-tuning of the resonant frequency). This enables the resonant frequency of the composite sound-absorbing structure to accurately track and lock the target noise frequency, thereby achieving adaptive noise reduction.

[0051] The core principle of this patent lies in the creative integration of photovoltaic power generation technology, tunable acoustic metasurfaces, and adaptive intelligent control to construct a photovoltaic sound barrier capable of energy self-sufficiency and adaptive, precise noise reduction. The system uses bifacial photovoltaic units as its energy source, with most of the generated electricity fed into the power grid, and a small portion used to charge an energy storage device to power the entire system. Its acoustic core can be considered a composite sound-absorbing structure consisting of a thin-film / plate resonant sound-absorbing structure and a micro-perforated plate resonant sound-absorbing structure connected in series. The operating frequency of the first part, the thin-film / plate resonant sound-absorbing structure, can be estimated using the following formula: in, c and ρ are the density of air and the speed of sound, respectively. This represents the mass per unit area of ​​the piezoelectric film. The mass of the mass block on the piezoelectric thin film. Let S be the height of the first adjustable frame, i.e., the depth of the first cavity, and let S be the area of ​​the piezoelectric film. K This represents the equivalent stiffness of the piezoelectric film. The method to achieve adjustable sound absorption and sound insulation performance of this structure is as follows: Firstly, the height of the first adjustable frame is adjusted using a micro-motor. (i.e., the depth of the first cavity) can effectively adjust the resonant frequency of the thin film / plate resonant sound-absorbing structure, thereby achieving a coarse adjustment of the sound absorption and insulation performance of the photovoltaic sound barrier. On the other hand, based on the piezoelectric effect, the equivalent stiffness of the film can be further changed by applying a different voltage to the piezoelectric film. k This allows for fine-tuning of the structure's sound absorption and insulation performance. Note that because the adjustable frame and the sleeve together form a sleeve structure, adjusting the height of the adjustable frame adjusts the depth of the cavity.

[0052] For the second part of the micro-perforated plate resonant sound-absorbing structure, its operating frequency can be estimated by the following formula: in, c It is the speed of sound in the air. The height of the second adjustable frame is equal to the depth of the second cavity. t , d and P These are the thickness of the micro-perforated plate, the diameter of the perforations, and the perforation rate, respectively. The micro-perforated plate resonant sound-absorbing structure has a relatively wide sound absorption bandwidth and is mainly designed for mid-to-high frequency noise. Therefore, by adjusting the height of the second adjustable frame through a motor, i.e., adjusting the depth of the second cavity, the sound absorption and sound insulation performance of this structure can be effectively controlled.

[0053] In actual operation, the adaptive control unit receives and analyzes the noise collected by the microphone, and analyzes its noise spectrum in real time through intelligent algorithms. On the one hand, it changes the depth of the first cavity and / or the second cavity of the composite structure by driving the bracket with a motor to perform "mechanical coarse adjustment" of the working frequency. On the other hand, it adjusts the voltage applied to the piezoelectric film and changes the equivalent stiffness of the film by utilizing the inverse piezoelectric effect to perform rapid "electrical fine adjustment" of the working frequency. This allows the peak noise reduction frequency of the sound barrier to dynamically track and lock onto the strong penetrating low-frequency noise, mainly in the 100-200Hz range, generated by facilities such as substations and converter stations, achieving targeted absorption of specific noise and ultimately achieving closed-loop operation from energy harvesting to intelligent noise reduction.

[0054] To verify the acoustic performance of a metamorphic photovoltaic sound barrier with adjustable sound absorption and insulation properties, COMSOL was used to verify its sound absorption performance. The piezoelectric film is a PVDF film with a density of 1780 kg / m³. 3 The photovoltaic sound barrier has a Young's modulus of 2.5 GPa, a Poisson's ratio of 0.35, and a thickness of 120 μm; the mass of the mass block is 0.45 g; the thickness of the micro-perforated plate 24 is 0.8 mm, the pore size is 0.2 mm, and the perforation rate is 1.5%; the heights of the first and second adjustable frames are 42 mm and 18 mm, respectively, meaning the depths of the first and second cavities are 42 mm and 18 mm, respectively. The sound absorption coefficient of this photovoltaic sound barrier is shown in [reference needed]. Figure 4 ,have Figure 4 It can be seen that the sound barrier has a sound absorption coefficient of 0.83 at a low frequency of 100Hz, and also exhibits good mid-to-high frequency sound absorption performance within the frequency range of 300-900Hz. The sound absorption performance of the sound barrier can be coarsely adjusted by changing the first and second adjustable frames. For example, adjusting the heights of the first and second adjustable frames to 50mm and 50mm respectively (i.e., adjusting the depths of the first and second cavities to 50mm and 50mm respectively) will result in the desired sound absorption performance. Figure 5 .Depend on Figure 5It can be seen that the low-frequency absorption peak of the sound barrier remains basically unchanged, while the broadband absorption peak also shifts to lower frequencies, exhibiting good sound absorption performance in the 200-700Hz frequency range. On the other hand, by applying voltage to the piezoelectric film, the equivalent stiffness and prestress of the piezoelectric film can be changed, thereby altering the low-frequency sound absorption performance of the sound barrier. Since the equivalent stiffness of the film caused by the inverse piezoelectric effect is relatively complex, it is difficult to directly obtain accurate changes in sound absorption performance through simulation. To approximate the influence of film stiffness on the overall sound absorption performance of the photovoltaic sound barrier, the influence of the film's Young's modulus (which is positively correlated with the film's equivalent stiffness) on the sound absorption performance of the sound barrier was further simulated and calculated. Figure 6 The sound absorption performance of the photovoltaic sound barrier at a Young's modulus of 25 GPa is given, compared to... Figure 4 The low-frequency absorption peak of the photovoltaic sound barrier shifts to around 200Hz, and the broadband absorption peak also shifts to higher frequencies. These results indicate that increasing the equivalent stiffness of the piezoelectric film raises the resonant frequency of the composite sound-absorbing structure, thereby achieving dynamic adjustment of the sound absorption frequency band. This demonstrates that the present invention's method of adjusting the voltage applied to the piezoelectric film to change its equivalent stiffness can effectively achieve electrical tuning of the sound barrier's sound absorption performance. Therefore, the sound absorption performance control method proposed in this invention is feasible and effective. Furthermore, due to the improved low-frequency sound absorption performance of the photovoltaic sound barrier, its corresponding low-frequency sound insulation also increases.

[0055] All documents mentioned in this application are considered to be incorporated in their entirety into the disclosure of this application so that they can serve as a basis for modifications if necessary. Furthermore, it should be understood that after reading the foregoing disclosure of this application, those skilled in the art can make various alterations or modifications to this application, and these equivalent forms also fall within the scope of protection claimed in this application.

Claims

1. A superstructured photovoltaic sound barrier with adjustable sound absorption and insulation performance, characterized in that, include: A photovoltaic module, comprising a photovoltaic power generation unit, wherein the photovoltaic power generation unit includes a back side; A tunable composite sound-absorbing structure, comprising a first adjustable frame and a second adjustable frame arranged sequentially from the inside out; wherein... A piezoelectric thin film is mounted on the first adjustable frame, which is configured to be mounted on the back of the photovoltaic power generation unit. The piezoelectric thin film faces the back of the photovoltaic power generation unit. A keel structure is provided inside the first adjustable frame, which divides the piezoelectric thin film into multiple piezoelectric thin film units. Each piezoelectric thin film unit is provided with a mass block, so that the piezoelectric thin film unit and the mass block together form a piezoelectric thin film-mass block resonant structure. The first adjustable frame is configured to be movable relative to the back of the photovoltaic power generation unit to adjust the depth of the first cavity between the piezoelectric film and the back of the photovoltaic power generation unit; The second adjustable frame is configured to be mounted on the piezoelectric film. A microperforated plate is disposed on the second adjustable frame, the microperforated plate facing the piezoelectric film. The second adjustable frame is also configured to be movable relative to the piezoelectric film, thereby adjusting the depth of the second cavity between the microperforated plate and the piezoelectric film. The second adjustable frame, the microperforated plate, and the second cavity together form a microperforated plate resonant structure. An acoustic sensor is also disposed on the microperforated plate. An adaptive control unit is configured to receive noise signals collected by the acoustic sensor, identify the dominant noise frequency, and adjust the first cavity depth and / or the second cavity depth based on the dominant noise frequency, and / or adjust the voltage applied to the piezoelectric film to change the equivalent stiffness of the piezoelectric film, so that the resonant frequency of the tunable composite sound-absorbing structure tracks the dominant noise frequency, thereby achieving adaptive noise reduction.

2. The photovoltaic sound barrier as described in claim 1, characterized in that, The adaptive control unit adjusts the resonant frequency of the tunable composite sound-absorbing structure in at least one of the following ways: Adjusting the depth of the first cavity adjusts the resonant frequency of the piezoelectric film-mass resonant structure, thereby achieving mechanical coarse adjustment to absorb low-frequency noise. Adjusting the voltage applied to the piezoelectric film changes the equivalent stiffness of the piezoelectric film, thereby adjusting the resonant frequency of the piezoelectric film-mass resonant structure and achieving electrical fine-tuning for absorbing low-frequency noise. as well as Adjusting the depth of the second cavity adjusts the resonant frequency of the micro-perforated plate resonant structure, thereby achieving frequency adjustment for absorbing mid-to-high frequency noise.

3. The photovoltaic sound barrier as described in claim 1, characterized in that, The resonant frequency of the piezoelectric thin film-mass resonant structure f 1 Represented by the following relation: in, c and ρ are the density of air and the speed of sound, respectively. This represents the mass per unit area of ​​the piezoelectric film. The mass of the mass block on the piezoelectric thin film. S is the height of the first adjustable frame, i.e., the depth of the first cavity; S is the area of ​​the piezoelectric film; and K is the equivalent stiffness of the piezoelectric film.

4. The photovoltaic sound barrier as described in claim 1, characterized in that, The keel structure is a rectangular grid structure or a hexagonal grid structure, so that the piezoelectric film has a corresponding rectangular or hexagonal piezoelectric film unit.

5. The photovoltaic sound barrier as described in claim 1, characterized in that, The photovoltaic power generation unit is a bifacial photovoltaic unit, the piezoelectric film is a transparent piezoelectric film, and / or the material of the transparent piezoelectric film includes polyvinylidene fluoride, with a thickness of 30-1000 μm and a polarization direction along the thickness direction of the film.

6. The photovoltaic sound barrier as described in claim 1, characterized in that, The micro-perforated plate has a pore size of 0.3 mm to 1 mm, a plate thickness of 0.3 mm to 1 mm, and a perforation rate of 0.5% to 3%.

7. The photovoltaic sound barrier as described in claim 1, characterized in that, The mass blocks disposed on the piezoelectric thin film unit may have the same mass or different masses.

8. The photovoltaic sound barrier as described in claim 7, characterized in that, The mass block is made of high-density metal or non-metal.

9. The photovoltaic sound barrier as described in claim 1, characterized in that, The photovoltaic sound barrier also includes a first drive mechanism for moving the first adjustable frame and a second drive mechanism for moving the second adjustable frame. The first drive mechanism and / or the second drive mechanism include a micro motor, a sleeve, and a slide rail connector; the micro motor drives the corresponding adjustable frame to move toward or away from the back of the photovoltaic power generation unit through the sleeve and slide rail connector.

10. The photovoltaic sound barrier as described in claim 9, characterized in that, The photovoltaic power generation unit is a bifacial photovoltaic unit, and the photovoltaic module also includes a power management system, which includes an energy storage device and a power control module. The power control module is configured to preferentially allocate the electrical energy generated by the bifacial photovoltaic unit to the adaptive control unit, the first drive mechanism, and the second drive mechanism.

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