Fan blade low air loss encapsulation self-powered device and method based on force control grinding

Abstract

This invention relates to the field of wind power technology, specifically disclosing a low-air-loss self-powered device and method for wind turbine blade encapsulation based on force-controlled grinding. The device includes a piezoelectric element patch adhered to a predetermined high-strain region on the surface of the wind turbine blade, an aerodynamic encapsulation layer covering the patch and its surrounding area, and an energy harvesting unit electrically connected to the patch. The outer surface of the aerodynamic encapsulation layer smoothly transitions to the original curved surface of the wind turbine blade, and the surface height difference at the point of contact with the blade is limited to a preset range. This structure enables the device to efficiently capture blade vibration and strain energy and convert it into electrical energy. Simultaneously, the ultra-low profile streamlined encapsulation maximizes the preservation of the original aerodynamic shape of the blade, significantly reducing the negative impact on aerodynamic efficiency. This provides a long-term, stable, and externally power-free self-powered solution for loads such as monitoring sensors integrated on the blade.

Description

Technical Field

[0001] This invention relates to the field of wind power technology, and in particular to a low-air-loss self-powered device and method for wind turbine blade encapsulation based on force-controlled grinding. Background Technology

[0002] In wind power generation technology, wind turbine blades are core components, and real-time monitoring of their operating status (such as strain, vibration, and temperature) is crucial for ensuring the safe and stable operation of the equipment. This monitoring typically relies on various miniature sensors mounted on the blades. Currently, these sensors are primarily powered by either batteries or wired connections.

[0003] While battery-powered solutions avoid wiring, battery life is limited, requiring regular high-altitude replacements and resulting in high maintenance costs. Data shows that battery replacement costs for a single wind turbine blade can account for over 30% of its total operation and maintenance expenses. Furthermore, a mismatch between battery life and sensor lifespan can easily lead to monitoring interruptions. Wired power solutions require conductive slip rings between the rotating blades and the stationary structure. This method is susceptible to slip ring wear and aging, and the wiring is complex, posing reliability challenges.

[0004] Piezoelectric power generation technology, based on the piezoelectric effect, can convert mechanical vibration energy into electrical energy. It offers potential advantages such as compact structure, no moving parts, and long lifespan, making self-powered power supply possible for blade monitoring sensors. Currently, this technology has been explored in some areas on horizontal axis wind turbine blades. However, for vertical axis wind turbine blades, no mature self-powered integrated solution has been publicly disclosed.

[0005] Whether horizontal or vertical axis, the aerodynamic shape of the blades is crucial to wind energy capture efficiency. Horizontal axis blades operate with a high tip speed ratio, and even small geometric discontinuities on the blade surface can significantly induce turbulence, increase aerodynamic noise, and reduce power generation efficiency. Vertical axis blades experience drastic changes in angle of attack during operation, making them more sensitive to the integrity of the airfoil profile, and external attachments can easily disrupt the stability of their flow field.

[0006] In existing technologies, the installation of piezoelectric elements or other sensors on the blade surface is often achieved through direct bolt fixing or simple adhesive bonding. This method creates noticeable mounting steps or protrusions on the blade surface. Research indicates that for standard wind turbine airfoils such as the S809, a surface step height ≥0.5mm can trigger severe boundary layer separation, potentially leading to a drag coefficient increase exceeding 130% and a lift coefficient loss exceeding 35%, severely damaging the overall aerodynamic performance and annual power generation of the wind turbine. Existing solutions often focus on horizontal axis blades and generally lack the technology for finely restoring the aerodynamic shape of the blade after installation; the encapsulation structure itself often becomes a new source of aerodynamic interference. Furthermore, traditional physical connection methods pose a risk of loosening of connectors and detachment of piezoelectric elements under long-term centrifugal force and alternating loads, affecting the long-term reliability of power supply and monitoring functions.

[0007] Therefore, there is an urgent need for a technical solution that can be applied to different types of wind turbine blades, achieve long-term reliable self-power supply, and maintain or restore the original aerodynamic shape of the blades to the maximum extent while reducing aerodynamic performance loss. Summary of the Invention

[0008] The purpose of this invention is to provide a low-air-loss self-powered device and method for wind turbine blade packaging based on force-controlled grinding, so as to solve the long-standing power supply technology bottleneck in the condition monitoring system of horizontal and vertical axis wind turbine blades.

[0009] As a first aspect of the present invention, the present invention provides a low-air-loss encapsulation self-powered device for wind turbine blades based on force-controlled grinding, comprising a piezoelectric element patch adhered to a predetermined high-strain region on the surface of the wind turbine blade; an aerodynamic encapsulation layer covering the piezoelectric element patch and its surrounding area, wherein the outer surface of the aerodynamic encapsulation layer smoothly transitions to the original curved surface of the wind turbine blade, and the surface height difference of the aerodynamic encapsulation layer in close contact with the wind turbine blade does not exceed a preset value; and an energy harvesting unit electrically connected to the piezoelectric element patch for collecting and processing the electrical energy generated by the piezoelectric element patch and supplying power to the load.

[0010] Optionally, the surface height difference of the pneumatic encapsulation layer in close contact with the fan blade is ≤0.2mm, the overall maximum protrusion height difference is ≤0.5mm, and the roughness Ra of the outer surface of the pneumatic encapsulation layer is ≤0.8μm.

[0011] Optionally, the predetermined high-strain region is the trailing edge of the blade root and / or the concave area in the middle of the blade, determined based on the airfoil pressure cloud map and modal analysis of the wind turbine blade.

[0012] Optionally, the piezoelectric element patch includes at least two root patches arranged in the pressure fluctuation region at the trailing edge of the blade root, and at least two middle patches arranged in the high strain region of the concave surface in the middle of the blade.

[0013] Optionally, the piezoelectric element patch is made of PZT-5H type piezoelectric ceramic, PVDF piezoelectric film or MFC piezoelectric fiber composite material.

[0014] Optionally, the pneumatic encapsulation layer is made of at least one of thin fiberglass, polyurethane coating, and modified epoxy resin coating.

[0015] Optionally, the energy harvesting unit includes a rectifier bridge, an energy storage capacitor, an MPPT module, and a DC-DC converter connected in sequence.

[0016] As a second aspect of the present invention, the present invention provides a method for low-air-loss packaging of wind turbine blades based on force-controlled grinding, and according to the self-powered device for low-air-loss packaging of wind turbine blades based on force-controlled grinding described in the first aspect above, the method includes the following steps: S1. Blade surface reverse scanning and deviation analysis: Perform three-dimensional scanning on the area to be mounted on the wind turbine blade to obtain actual shape data, and compare it with the ideal blade surface model to generate a deviation mapping map. S2. Base surface correction and mounting: The mounting surface of the wind turbine blade is pre-processed according to the deviation mapping diagram, and then the piezoelectric element patch is mounted in the predetermined position and covered with the initial material layer forming the aerodynamic encapsulation layer. S3. Grinding path planning for the encapsulation layer: Based on the curvature data of the original airfoil of the blade, generate a grinding path along the spanwise and / or chordwise direction of the blade. S4. Multi-process flexible force-controlled grinding: According to the grinding path, the initial material layer is subjected to coarse grinding, fine grinding, edge rounding transition and polishing treatment in sequence using a grinding equipment with a force control module; S5. Finished Product Inspection and Verification: Inspect the geometric dimensions, internal quality, and aerodynamic performance of the pneumatic encapsulation layer after polishing.

[0017] Furthermore, in step S4, the rough grinding process controls the grinding pressure to be constant at 1.5N, and provides real-time feedback to control the height difference between the contact surface of the pneumatic encapsulation layer and the contact surface of the fan blade and the piezoelectric element patch to be maintained between 0.1mm and 0.2mm.

[0018] Furthermore, the wind turbine blade is a vertical axis wind turbine blade or a horizontal axis wind turbine blade; for horizontal axis blades, the mounting area of ​​the piezoelectric element patch is the trailing edge or beam cap area from the blade root to the maximum chord length.

[0019] Furthermore, in step S4, the surface roughness Ra of the outer surface of the pneumatic encapsulation layer after the polishing process is ≤0.8μm.

[0020] Furthermore, in step S4, the edge rounding transition process uses a rounding grinding head with R=1mm, controls the grinding pressure to 1N, and scans and detects the processed rounded corner. If the deviation from the ideal rounded corner is >0.05mm, automatic grinding correction is performed.

[0021] Furthermore, in step S5, the geometric dimensions of the aerodynamic encapsulation layer are measured by a laser scanner, the presence of air bubbles inside and cracks in the piezoelectric element patch are checked by an ultrasonic phased array detector, and its aerodynamic performance is verified by a wind tunnel test.

[0022] Further, in step S1, a blue light 3D scanner is used to perform scanning, and the point cloud data is imported into 3D software for deviation analysis.

[0023] Furthermore, in step S2, a six-axis industrial robot equipped with a flexible grinding head is used to pre-treat the surface of the blade. If the surface is raised, subtractive grinding is performed, and if the surface is concave, it is retained.

[0024] Furthermore, the process for achieving a smooth transition between the aerodynamic encapsulation layer and the original curved surface of the blade is digital adaptive force-controlled grinding, high-precision additive manufacturing, or mold hot pressing.

[0025] Compared with the prior art, the present invention discloses at least the following beneficial effects: This invention directly adheres piezoelectric element patches to predetermined high-strain areas on the surface of wind turbine blades, enabling efficient capture of vibration and strain energy generated by the blades under wind loads, and converting this energy into electrical energy through the piezoelectric effect. The aerodynamic encapsulation layer covering the patch and its surrounding area forms a smooth transition with the original curved surface of the blade, and the height difference at the contact points is strictly controlled. This minimizes surface protrusions and geometric discontinuities introduced by the added device, effectively suppressing airflow separation and additional turbulence, significantly reducing aerodynamic drag, preserving the overall aerodynamic shape of the blade, and resulting in extremely low aerodynamic efficiency loss. Simultaneously, the energy harvesting unit electrically connected to the piezoelectric element patch constitutes a complete energy harvesting, conditioning, and storage loop, achieving reliable collection and stable output of micro-variable electrical energy. This provides long-term, stable, and self-powered capability for loads such as condition monitoring sensors integrated on the blade, eliminating reliance on external lines or frequent battery replacements. This fundamentally improves the power supply autonomy and operational reliability of the wind turbine monitoring system and reduces the overall lifecycle maintenance cost. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the mounting position of the device of the present invention on the wind turbine blade; Figure 2 for Figure 1 Sectional view at point AA; Figure 3 for Figure 2 A magnified view of a section at point B in the middle; Figure 4 This is a schematic diagram of the structure of the piezoelectric element patch in the device of the present invention; Figure 5 This is a schematic diagram of the pneumatic encapsulation layer in the device of the present invention; Figure 6 This is a circuit block diagram of the energy harvesting unit in the device of the present invention; Figure 7 This is a pressure cloud map of the original blade; Figure 8 This is the velocity contour map of the original blade; Figure 9 Pressure cloud diagram of the encapsulated blade of this invention; Figure 10 The velocity cloud diagram is for the encapsulated blade of this invention.

[0028] In the diagram: 100, fan blade; 200, self-powered device; 201, piezoelectric element patch; 202, pneumatic encapsulation layer. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1 Reference Figures 1 to 6As shown, Embodiment 1 of the present invention provides a low-air-loss encapsulation self-powered device for wind turbine blades based on force-controlled grinding. The device integrates a piezoelectric power generation element and a streamlined aerodynamic encapsulation layer. It achieves aerodynamic shape reconstruction through digital grinding process to ensure long-term stable power supply and minimize aerodynamic performance loss.

[0032] like Figure 1 As shown, the self-powered device 200 of this embodiment is integrated on the surface of the wind turbine blade 100 of the wind turbine generator. It is used to provide power to the blade condition monitoring sensor and can solve the problems of negative impact on the aerodynamic performance of the blade and high long-term power supply maintenance costs of existing external power supply solutions.

[0033] In one specific embodiment, the self-powered device 200 includes a piezoelectric element patch 201, a pneumatic encapsulation layer 202, and an energy harvesting unit (not shown).

[0034] The piezoelectric element patch 201 is tightly bonded to a predetermined high-strain area on the surface of the wind turbine blade 100 (taking a circular arc hollow blade as an example) through an adhesive layer (e.g., 3M DP460 epoxy adhesive), forming a gapless adhesive constraint structure to ensure efficient transmission of strain energy.

[0035] The pneumatic encapsulation layer 202 covers the piezoelectric element patch 201 and its surrounding area. It is made of thin fiberglass, with an initial coverage thickness of about 0.2 mm, and covers the piezoelectric ceramic patch and its surrounding area of ​​about 5 mm.

[0036] The energy harvesting unit is electrically connected to the piezoelectric element patch 201 and is used to process and store the alternating microcurrent generated by the piezoelectric element, and output a stable DC power to supply the load (such as a sensor or wireless module).

[0037] Based on the above embodiments, the wind turbine blade 100 is further described as an H-type vertical axis wind turbine blade, which can be made of aluminum alloy or composite materials and adopts a symmetrical airfoil hollow structure. For example, the blade has a spanwise length of 320 mm, a chord length of 80 mm, and a wall thickness of 3 mm. To enhance structural rigidity, two reinforcing ribs extending along the spanwise direction can be provided inside the blade at approximately 30% and 70% of the chord length. The trailing edge of the blade adopts a circular arc transition with a radius of R=2 mm, and the maximum thickness is approximately 18 mm.

[0038] Based on the above embodiments, the piezoelectric element patch 201 is further selected from PZT-5H type piezoelectric ceramics, with a piezoelectric constant d31 of -274 pC / N. The patch group can be divided into root patches and middle patches according to the mounting position. The root patches are 20mm × 40mm × 0.3mm in size, with a total of 4 patches. Two of these patches are mounted chordally in the spanwise region of the outer wall approximately 10mm above the blade root flange, specifically in the pressure fluctuation area on the upper and lower surfaces near the trailing edge of the blade. The middle patches are 40mm × 40mm × 0.3mm in size, with a total of 4 patches. Two of these patches are mounted in a spanwise array in the high-strain region of the concave surface in the middle of the blade, with their long sides distributed along the spanwise direction, and a distance of approximately 10mm from the flange. The mounting position is determined based on the airfoil pressure contour map and modal analysis, thereby precisely arranging the piezoelectric ceramics in the areas of concentrated mechanical strain energy, such as the trailing edge of the blade root and the concave surface in the middle.

[0039] Building upon the above embodiments, the core feature of the aerodynamic encapsulation layer 202 lies in its streamlined geometric shape after final molding. Through subsequent digital adaptive force-controlled grinding, the aerodynamic encapsulation layer 202 achieves a smooth transition with the original curved surface of the fan blade 100, ultimately reaching a surface roughness Ra ≤ 0.8 μm. Furthermore, the height difference between the aerodynamic encapsulation layer 202 and the portion of the fan blade 100 that is in close contact with the blade is ≤ 0.2 mm, and the overall maximum protrusion height difference is ≤ 0.5 mm. After this treatment, the increase in the drag coefficient of the encapsulated blade compared to the original blade can be controlled to ≤ 0.5%, achieving "zero compromise" or extremely low loss in aerodynamic performance.

[0040] Based on the above embodiments, further, such as Figure 6 As shown, the specific circuit configuration of the energy harvesting unit includes: a rectifier bridge (for full-bridge rectification), an energy storage capacitor (such as a supercapacitor), an MPPT module (such as a TI BQ25504 chip), and a DC-DC converter (for regulated output, such as 3.3V or 5V). These circuit components are electrically connected in sequence, and their function is to convert the irregular alternating micro-current output from the piezoelectric element patch 201 into a stable DC current suitable for the downstream load (sensor or wireless module) after rectification, energy storage, voltage regulation, and maximum power point tracking, thereby achieving long-term, stable self-powered operation.

[0041] Example 2 Reference Figures 7 to 10 As shown, to achieve precise molding of the above-mentioned aerodynamic encapsulation layer 202, Embodiment 2 of the present invention also provides a low-air-loss encapsulation method for wind turbine blades based on force-controlled grinding. According to the self-powered device for low-air-loss encapsulation of wind turbine blades based on force-controlled grinding described in the above embodiments, the method includes the following steps: S1. Perform reverse scanning and deviation analysis of the blade surface. Use a blue light 3D scanner to scan the area to be mounted on the wind turbine blade 100 to obtain high-precision actual shape point cloud data. Import this point cloud data into software such as Geomagic DesignX and SolidWorks, and compare it with the ideal 3D model of the blade surface to generate a mapping map containing height deviation and curvature deviation.

[0042] S2. Perform substrate correction and mounting. Based on the deviation data generated in the previous step, a six-axis industrial robot (such as a KUKA KR6 R900) equipped with a flexible grinding head is used to pre-treat the mounting surface of the fan blade 100. If there are protrusions on the surface, subtractive grinding is performed according to the deviation data; if the surface is concave, it is retained for subsequent adhesive filling. After the surface pre-treatment is completed, epoxy adhesive (such as 3M DP460) is used to mount the piezoelectric element patch 201 to the predetermined position planned in step S1, and then a fiberglass material of initial thickness (such as 0.2 mm) is covered to form the prototype of the pneumatic encapsulation layer 202.

[0043] S3. Plan the polishing path for the encapsulation layer. Using robot offline programming software (such as RobotStudio), with the blade spanwise and chordal directions as the main streamline directions, generate a curved path for subsequent polishing based on the curvature data of the original airfoil.

[0044] S4. Perform multi-stage flexible force-controlled grinding. Step S4 includes four sub-steps S401 to S404, specifically: S401, Rough Grinding: The robot is equipped with a flexible grinding head with a force control module, which controls the grinding pressure to be constant at about 1.5N, grinding the aerodynamic encapsulation layer 202 along the spanwise and chordwise directions of the blade. The force control module provides real-time feedback on the height difference between the grinding head and the blade surface and dynamically corrects the grinding head posture to ensure that the height difference between the contact surface of the aerodynamic encapsulation layer 202 and the contact surface of the fan blade 100 and the piezoelectric element patch 201 is maintained between 0.1mm and 0.2mm, effectively avoiding excessive grinding that could damage the brittle piezoelectric ceramic.

[0045] S402, Fine Grinding: Switch to the flexible grinding head equipped with 1200-grit sandpaper and grind strictly along the pre-planned streamline direction until the surface roughness Ra of the encapsulation layer is detected by a portable roughness meter to be ≤3.2μm.

[0046] S403, Rounded Corner Transition: Switch to a rounded corner grinding head with R=1mm, control the grinding pressure to approximately 1N, and perform rounded corner smoothing on the edge of the pneumatic encapsulation layer 202. Then, use a laser profilometer to scan the rounded corner area. If a deviation from the ideal rounded corner is detected to be >0.05mm, the system will automatically generate a grinding path for correction.

[0047] S404 Polishing: Finally, switch to the wool polishing wheel and use polishing fluid to perform unidirectional polishing on the surface of the pneumatic encapsulation layer 202 until the surface roughness is confirmed to reach IT8 level accuracy, i.e., Ra≤0.8μm, by white light interferometer.

[0048] S5. Finished Product Inspection and Verification. The final product is measured using a laser scanner. The height difference between the aerodynamic encapsulation layer 202 and the fan blade 100 is required to be ≤0.2mm, and the overall maximum protrusion height difference is required to be ≤0.5mm. An ultrasonic phased array detector is used to inspect the internal quality of the aerodynamic encapsulation layer 202, ensuring there are no air bubbles and no cracks in the internal piezoelectric element patch 201. Finally, its aerodynamic performance is verified through low-speed wind tunnel testing and a PIV particle image velocimetry system, ensuring continuous airflow and turbulence intensity ≤1% in the region.

[0049] like Figures 7 to 10 As shown, a rationality verification was performed on the original blade and the packaged blade processed by the method of this invention, resulting in a comparison of the pressure and velocity cloud maps of the original blade and the packaged blade. Specifically, this includes: Figure 7 Pressure cloud map of the original blade; Figure 8 Velocity contour map of the original blade; Figure 9 Pressure cloud map of the packaged blades; Figure 10 Velocity contour plot of the packaged blades. The streamlined package design minimizes aerodynamic performance loss, controls the increase in drag coefficient to within 0.5%, has almost no impact on the aerodynamic efficiency of the fan, and the aerodynamic performance loss is essentially zero.

[0050] It should be understood that the above embodiments are merely preferred embodiments of the present invention and not limitations thereof. Those skilled in the art can make various substitutions, modifications, and variations without departing from the spirit and essence of the present invention, and all such modifications and variations fall within the protection scope of the present invention. For example: In some optional embodiments, the mounting position, quantity, and size of the piezoelectric element patch 201 can be adaptively adjusted based on the fluid-structure interaction analysis results of the specific blade airfoil (such as strain contour maps and pressure pulsation distribution maps obtained from finite element analysis). The key is to arrange the piezoelectric element patch 201 in high-strain regions on the surface of the wind turbine blade 100 (such as the trailing edge from the blade root to the maximum chord length of a horizontal axis blade, the beam cap region, or the trailing edge and concave surface at the root of a vertical axis blade) to ensure effective capture of mechanical strain energy. The specific arrangement of the patches can be a spiral array along the blade root torsion direction for horizontal axis blades, and a arrangement based on specific modal analysis of the symmetrical airfoil for vertical axis blades. The patch size can be proportionally enlarged or reduced according to the required power generation and strain area.

[0051] In some optional embodiments, the material of the piezoelectric element patch 201 is not limited to PZT-5H piezoelectric ceramic, but can also be replaced with other functional materials with positive piezoelectric effect, such as PVDF (polyvinylidene fluoride) piezoelectric film, or MFC (piezoelectric fiber composite material). These materials have different flexibility, piezoelectric constant and frequency response characteristics, and can be selected according to the blade vibration spectrum and the curvature requirements of the mounting surface.

[0052] In some alternative embodiments, the material of the pneumatic encapsulation layer 202 is not limited to thin fiberglass. To adapt to different environmental conditions (such as the high humidity and high salt spray environment of offshore wind power) or process requirements, other materials with good weather resistance, adhesion and abrasion resistance may also be used, such as polyurethane coatings, modified epoxy resin coatings or composite prepregs.

[0053] In some alternative embodiments, the process for achieving a smooth transition between the aerodynamic encapsulation layer 202 and the original curved surface of the wind turbine blade 100 is not limited to digital adaptive force-controlled grinding. Other high-precision surface forming technologies can also be used, such as: using high-precision additive manufacturing (3D printing) technology to directly print the aerodynamic encapsulation layer 202 with a streamlined profile on the surface of the wind turbine blade 100 on which the piezoelectric element patch 201 is attached; or using a pre-prepared mold that precisely matches the curved surface of the blade to integrally form the aerodynamic encapsulation layer 202 through a thermoforming process.

[0054] In some alternative embodiments, the specific electronic components in the energy harvesting unit can be replaced according to actual needs. For example, the maximum power point tracking (MPPT) module can use other high-efficiency energy harvesting chips besides the TI BQ25504, such as the LTC3588; the energy storage element can use different types of supercapacitors or rechargeable batteries; and the DC-DC converter can be selected with different output voltage levels according to load requirements.

[0055] It should also be understood that the above description uses a vertical axis blade as an example, but the technical solution of the present invention is also applicable to horizontal axis wind turbine blades. For horizontal axis blades, the mounting area of ​​the piezoelectric element patch 201 can be selected in high strain areas such as the trailing edge from the blade root to the maximum chord length or the beam cap; its layout can be based on the maximum pressure pulsation and bending strain point on the blade surface determined by finite element analysis, and distributed in a spiral array along the blade root torsion direction to fully utilize the coupled modes of flapping and oscillation to capture more strain energy.

[0056] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0057] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A low-air-loss self-powered device for wind turbine blade encapsulation based on force-controlled grinding, characterized in that, include: A piezoelectric element patch (201) is adhered to a predetermined high-strain region on the surface of a fan blade (100); A pneumatic encapsulation layer (202) covers the piezoelectric element patch (201) and its surrounding area. The outer surface of the pneumatic encapsulation layer (202) smoothly transitions to the original curved surface of the fan blade (100), and the surface height difference of the pneumatic encapsulation layer (202) in close contact with the fan blade (100) does not exceed a preset value. An energy harvesting unit, electrically connected to the piezoelectric element patch (201), is used to collect and process the electrical energy generated by the piezoelectric element patch (201) and to supply power to the load.

2. The low-air-loss self-powered device for wind turbine blade encapsulation based on force-controlled grinding according to claim 1, characterized in that, The surface height difference of the pneumatic encapsulation layer (202) in close contact with the fan blade (100) is ≤0.2mm, the overall maximum protrusion height difference is ≤0.5mm, and the roughness Ra of the outer surface of the pneumatic encapsulation layer (202) is ≤0.8μm.

3. The low-air-loss self-powered device for wind turbine blade encapsulation based on force-controlled grinding according to claim 1, characterized in that, The predetermined high-strain region is the trailing edge of the blade root and / or the concave area in the middle of the blade, determined by the airfoil pressure cloud map and modal analysis of the wind turbine blade (100).

4. The low-air-loss self-powered encapsulation device for wind turbine blades based on force-controlled grinding according to claim 3, characterized in that, The piezoelectric element patch (201) includes at least two root patches arranged in the pressure fluctuation zone at the trailing edge of the blade root, and at least two middle patches arranged in the high strain zone of the concave surface in the middle of the blade.

5. The low-air-loss self-powered device for wind turbine blade encapsulation based on force-controlled grinding according to claim 1, characterized in that, The piezoelectric element patch (201) is made of PZT-5H type piezoelectric ceramic, PVDF piezoelectric film or MFC piezoelectric fiber composite material.

6. The low-air-loss self-powered device for wind turbine blade encapsulation based on force-controlled grinding according to claim 1, characterized in that, The pneumatic encapsulation layer (202) is made of at least one of thin fiberglass, polyurethane coating, and modified epoxy resin coating.

7. The low-air-loss self-powered device for wind turbine blade encapsulation based on force-controlled grinding according to claim 1, characterized in that, The energy harvesting unit includes a rectifier bridge, an energy storage capacitor, an MPPT module, and a DC-DC converter connected in sequence.

8. A method for low-air-loss encapsulation of wind turbine blades based on force-controlled grinding, comprising the self-powered device for low-air-loss encapsulation of wind turbine blades based on force-controlled grinding according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Blade surface reverse scanning and deviation analysis: Perform three-dimensional scanning on the area to be mounted on the wind turbine blade (100) to obtain actual shape data and compare it with the ideal blade surface model to generate a deviation mapping map. S2, Base surface correction and mounting: The mounting surface of the fan blade (100) is pre-processed according to the deviation mapping diagram, and then the piezoelectric element patch (201) is mounted in the predetermined position and covered with the initial material layer forming the aerodynamic encapsulation layer (202). S3. Grinding path planning for the encapsulation layer: Based on the curvature data of the original airfoil of the blade, generate a grinding path along the spanwise and / or chordwise direction of the blade. S4. Multi-process flexible force-controlled grinding: According to the grinding path, the initial material layer is subjected to coarse grinding, fine grinding, edge rounding transition and polishing treatment in sequence using a grinding equipment with a force control module; S5. Finished product inspection and verification: Inspect the geometric dimensions, internal quality and aerodynamic performance of the pneumatic encapsulation layer (202) after polishing.

9. The low-air-loss encapsulation method for wind turbine blades based on force-controlled grinding according to claim 8, characterized in that, In step S4, the rough grinding process controls the grinding pressure to be constant at 1.5N, and provides real-time feedback to control the height difference between the contact surface of the pneumatic encapsulation layer (202) and the fan blade (100) and the contact surface of the piezoelectric element patch (201) to be maintained between 0.1mm and 0.2mm.

10. The method for low-air-loss encapsulation of wind turbine blades based on force-controlled grinding according to claim 8, characterized in that, The wind turbine blade (100) is a vertical axis wind turbine blade or a horizontal axis wind turbine blade; for horizontal axis blades, the mounting area of ​​the piezoelectric element patch (201) is the trailing edge or beam cap area from the blade root to the maximum chord length.

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