A floating photovoltaic power response test device under extreme wind wave flow coupling action

Abstract

An extreme wind wave current coupling under floating photovoltaic power response test device, including environment simulation system, semi-submersible photovoltaic platform system, mooring system and data measurement and acquisition system. The environment simulation system simulates the coupling effect of wind, wave and flow composite load. The semi-submersible photovoltaic platform system contains photovoltaic component model constructed according to the predetermined scale ratio and the float component providing support and buoyancy for the photovoltaic component model, which can truly reflect the wind load effect of photovoltaic structure and the platform hydrodynamic response. In the data measurement and acquisition system, the cooperation of dynamic visual sensor and pressure sensor realizes the synchronous and accurate observation and measurement of the six degrees of freedom motion of the platform, the mooring tension, especially the deck wave process and the slamming load. The invention solves the problem of fine observation of traditional test in complex load simulation and extreme sea state, and provides a reliable test means for the safety design and performance evaluation of deep sea floating photovoltaic platform.

Description

TECHNICAL FIELD

[0001] The application relates to a floating photovoltaic dynamic response test device under the coupling action of extreme wind, wave and current. BACKGROUND

[0002] The offshore floating photovoltaic is a new type of marine energy development equipment floating on the sea surface, used for carrying photovoltaic components and realizing solar photoelectric conversion. The offshore floating photovoltaic does not need to rely on land resources or seabed pile foundation fixing, can be widely adapted to multiple marine scenes such as near-shore sheltered sea areas and deep sea areas, and can be cooperatively developed with offshore wind power and other energy forms, thereby providing a key technical path for expanding the application boundary of photovoltaic and improving the comprehensive utilization efficiency of marine energy. The offshore floating photovoltaic is gradually developing into an important part of the clean energy industry, and its position is increasingly prominent in global energy transformation.

[0003] The response analysis method of the floating photovoltaic platform mainly includes an analytical method, numerical simulation and physical model test. The floating body-mooring system will produce significant dynamic response under the action of complex marine environmental loads, directly affecting the safety, stability and power generation efficiency of the system. The floating photovoltaic platform has a complex structure, and its dynamic response under various loads involves multi-body coupling and fluid-structure interaction effects, so the theoretical calculation of the response of the floating photovoltaic is relatively limited. At the current stage, the commonly used analysis methods are physical model test and numerical simulation. As an offshore floating structure, the floating photovoltaic platform is significantly affected by environmental loads such as wind, wave and current. The numerical simulation method inevitably simplifies the environmental effects, so the physical model test becomes the most intuitive and effective method to study the dynamic response of the floating photovoltaic under combined loads.

[0004] As an offshore floating structure, the floating photovoltaic platform is significantly affected by environmental loads such as wind, wave and current. Typhoons frequently occur in deep sea areas, and extreme conditions caused by typhoons and other factors will challenge the safety of the floating photovoltaic system. Great wind, wave and current may cause platform overturning, mooring breakage, photovoltaic panel damage and other failure modes. In order to ensure the safety of the floating photovoltaic power station under different sea conditions, it is necessary to deeply understand the motion characteristics of the platform under extreme working conditions. Due to the small size, low overall rigidity and large laying area of the common floating photovoltaic platform, the stability of the platform under the action of wind, wave and current cannot be guaranteed, which further increases the difficulty of the floating photovoltaic model test, and it is necessary to find a photovoltaic platform more suitable for deep sea.

[0005] Under the condition of frequent extreme working conditions in deep sea, the deck wave has a great threat to the stability of the platform, how to effectively observe the dynamic evolution process of the photovoltaic deck wave under extreme sea conditions, and analyze the influence of the slamming load is related to the safety of the platform. The traditional method uses high-speed camera technology to record the shape change of the wave, but it is easy to be restricted by strong reflection, splashing and laboratory lighting conditions, at the same time, it produces a large amount of frame-by-frame image data, and the post-processing workload is large. At present, there is a lack of deep-sea floating photovoltaic test device that can effectively simulate the influence of deck wave under the coupling action of extreme wind, wave and current.

[0006] It should be noted that the information disclosed in the above background section is only for understanding the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0007] The main purpose of the present application is to overcome the defects in the above background, and to provide a floating photovoltaic dynamic response test device under the coupling action of extreme wind, wave and current.

[0008] To achieve the above purpose, the present application adopts the following technical scheme:

[0009] A floating photovoltaic dynamic response test device under the coupling action of extreme wind, wave and current, comprising:

[0010] An environment simulation system for generating controllable wind field, wave field and flow field in a test pool, simulating the coupling action of wind, wave and flow load;

[0011] A semi-submersible photovoltaic platform system arranged in the test pool for simulating the hydrodynamic response of the floating photovoltaic platform under the load generated by the environment simulation system; the semi-submersible photovoltaic platform system comprises a photovoltaic assembly and a floating body assembly, the photovoltaic assembly is constructed as a scale model according to a predetermined scale ratio based on the prototype of the floating photovoltaic platform, and is arranged above the floating body assembly for bearing wind load and reflecting the influence of the photovoltaic structure on the platform movement; the floating body assembly is used to bear wave load, flow load and wind load, and provides support and buoyancy for the photovoltaic assembly;

[0012] A mooring system connected at both ends to the semi-submersible photovoltaic platform system and the bottom of the test pool respectively, providing restoring stiffness for the platform and constraining its movement;

[0013] The data measurement and collection system collects the six-degree-of-freedom motion response, mooring tension, wave load on the deck and wave slamming evolution process data of the platform under the coupling action of wind, wave and current through a plurality of sensors arranged in the semi-submersible photovoltaic platform system and the test environment; wherein the data measurement and collection system includes a wave on deck observation system for observing the wave on the deck, the wave on deck observation system includes a dynamic visual sensor and a pressure sensor, the dynamic visual sensor is used to collect dynamic visual event data of the wave on deck process, and the wave slamming evolution process is reconstructed through image processing; the pressure sensor is arranged on the deck surface of the platform for real-time measurement of the wave slamming load.

[0014] Further, the environmental simulation system includes a wind generating module, a wave and current generating module, and a wave absorbing module, wherein the wind generating module is configured to generate a steady wind field and a random turbulent wind field in the test tank; the wave and current generating module is configured to generate a wave field including regular waves, irregular waves and focused waves, and a uniform current field in the test tank; the wave absorbing module is arranged at the end of the test tank to absorb wave energy to reduce the influence of reflected waves on the test.

[0015] Further, the wind generating module includes an elevator and a water surface jet wind tunnel body, the elevator is used to adjust the height of the wind tunnel body relative to the water surface to adapt to the wind field simulation requirements of different test conditions.

[0016] Further, the wave and current generating module includes a wave generating mechanism and a current generating mechanism, the wave generating mechanism is configured with a plurality of parallel arranged rocking plate type wave makers, the rocking plate type wave makers are driven by servo motors, and are used to generate regular waves, irregular waves and focused waves; the current generating mechanism includes a current generating pump for regulating the flow to generate a uniform current field.

[0017] Further, the photovoltaic assembly includes photovoltaic panels and their support structure, the photovoltaic panels are made of high-strength organic materials to simulate the wind load effect in the scale model.

[0018] Further, the floating body assembly includes a platform deck, pontoons and frame crossbeams, the pontoons include a plurality of pontoons arranged on the periphery and one pontoon located in the center, each pontoon is connected by the frame crossbeams, the platform deck is fixed on the upper part of the pontoons for installing photovoltaic assemblies and sensors; the pontoons are hollow structures including hollow heeling plates and hollow columns for providing buoyancy; the frame crossbeams are made of stainless steel pipes including upper crossbeams and lower crossbeams for enhancing the overall structural strength of the platform.

[0019] Further, the platform deck is processed into a hexagonal structure by alloy plates; the number of the pontoons is seven, which are made of stainless steel plates, six of which are arranged in the periphery and in a hexagonal arrangement, and one in the center; the platform deck, the pontoons and the frame cross beam are fixedly connected by welding.

[0020] Further, the mooring system includes springs, steel wires and anchor blocks, constituting a four-point tension mooring arrangement, wherein one end of the spring is connected to the photovoltaic platform, the other end is connected to the steel wire through a tension sensor, and the other end of the steel wire is anchored to the anchor block at the bottom of the pool.

[0021] Further, the data measurement and acquisition system further includes an anemometer arranged upstream of the wind field, a flow speed meter and a wave height meter arranged on the platform, a tension sensor arranged in the mooring system, and a displacement measurement system for measuring the six-degree-of-freedom motion of the platform.

[0022] Further, the displacement measurement system includes a six-component target mounted on the platform and a high-speed camera arranged outside the pool, and the six-degree-of-freedom displacement of the platform is calculated by capturing the motion of the target.

[0023] Further, the deck wave observation system is configured to perform the following processing for reconstructing the wave slamming evolution process according to the event stream data recorded by the dynamic vision sensor:

[0024] The dynamic vision sensor works in an event-driven manner, and outputs an event stream composed of pixel spatial coordinates, time stamps and event polarity representing the direction of brightness change;

[0025] The continuous event stream is divided into a series of continuous and non-overlapping time windows according to a fixed number of events;

[0026] For each time window, a spatio-temporal voxel grid is constructed, and each event in the window is assigned to adjacent voxels in the time dimension by interpolation according to its time stamp and polarity, so as to encode the event set into a fixed-size tensor;

[0027] The tensor and the internal state of the recurrent convolutional neural network at the previous time are jointly input into the recurrent convolutional neural network, and the internal state at the current time is obtained by updating the recurrent convolutional unit of the recurrent convolutional neural network, and the corresponding reconstructed image sequence is output by the image decoding head of the recurrent convolutional neural network;

[0028] Based on the reconstructed image sequence, an L-K optical flow method is adopted, by calculating the partial derivative of the image sequence in the spatial direction and the gradient in the time direction, and taking the constant optical flow in the neighborhood of the target pixel as a constraint, an optical flow equation set is established, and the least square method is used to solve the equation set to obtain the optical flow component, so that the target motion information between adjacent image sequences is calculated, and the morphological change and nonlinear evolution process of the wave slamming are reconstructed.

[0029] The present application has the following beneficial effects:

[0030] The present application provides a kind of extreme wind wave flow coupling effect under floating photovoltaic power response test device, including environment simulation system, semi-submersible photovoltaic platform system, mooring system and data measurement and acquisition system, construct a kind of can in test pool high fidelity coupling effect of wind, wave, flow and other environmental loads, this test device can high fidelity simulate the coupling effect of wind, wave, flow and other environmental loads in pool, real restoration floating photovoltaic platform in sea, especially in deep sea extreme working condition actual operating condition, thereby significantly improve the reliability and engineering guidance value of test response result.

[0031] Specifically, one of the cores of the test device of the present application is to construct a semi-submersible photovoltaic platform system suitable for deep sea conditions. The present application deeply considers the influence of photovoltaic module itself on platform dynamic response, the semi-submersible photovoltaic platform system not only contains a floating body structure for providing buoyancy, but also its photovoltaic module is constructed as a scale model according to a predetermined scale ratio based on the prototype of floating photovoltaic platform. This design ensures that in the scale model test, the photovoltaic module can truly simulate and withstand wind load, and its aerodynamic effect is accurately reflected in the overall motion response of the platform, thereby making up for the risk of insufficient evaluation of platform motion response in traditional tests due to the neglect of photovoltaic module aerodynamic load, making the test analysis more comprehensive and accurate. The present application also innovatively introduces a dynamic visual sensor into the deck wave observation system of ocean engineering model test. The dynamic visual sensor works cooperatively with the pressure sensor arranged on the deck surface, overcoming the limitations of traditional high-speed cameras in strong reflection, high dynamic range and instantaneous shielding scenes, and can clearly capture and reconstruct the transient evolution process of nonlinear wave slamming with microsecond-level response and ultra-high dynamic range, realizing complete and accurate physical observation and load measurement of the dynamic whole process of deck wave in extreme sea conditions, and providing a new technical approach for in-depth research on slamming load and its influence on platform safety.

[0032] Further, the test device of the present application realizes accurate simulation of various wave forms such as steady to random turbulent wind field, regular wave to focused wave and uniform flow field through the wind making, wave making, flow making and wave absorbing modules which can be independently controlled and cooperatively operated, thereby truly restoring the comprehensive stress environment of the floating photovoltaic platform under extreme working conditions in the sea, especially in deep sea.

[0033] Further, the floating body assembly of the semi-submersible photovoltaic platform system is composed of floating cylinders, frame cross beams and platform decks, especially adopts a structure form of seven floating cylinders with peripheral hexagonal plus central layout and stainless steel pipe frame welded connection, which endows the platform with the characteristics of high strength, large draft and high freeboard, and the overall structure is stable, laying a foundation for maintaining stability in bad sea conditions. The mooring system adopts a four-point tensioning arrangement containing springs, steel wires and anchor blocks, which provides the platform with controllable restoring stiffness and motion constraint, further enhancing the survivability and safety of the platform under the coupling action of wind, wave and flow.

[0034] In summary, the present application can truly and efficiently simulate and observe the comprehensive dynamic response of the photovoltaic platform in complex marine environment under different sea conditions, especially under the coupling action of extreme wind, wave and flow, fully observe the wave dynamic evolution process on the photovoltaic deck under extreme sea conditions, thereby facilitating efficient research on the hydrodynamic characteristics of the floating photovoltaic platform under the coupling action of extreme wind, wave and flow.

[0035] Other beneficial effects in the embodiments of the present application will be further described below. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is the elevation layout of the floating photovoltaic dynamic response test device of the embodiments of the present application;

[0037] Figure 2 is the plan layout of the floating photovoltaic dynamic response test device of the embodiments of the present application;

[0038] Figure 3 is the three-dimensional structure schematic diagram of the semi-submersible photovoltaic platform system in the embodiments of the present application;

[0039] The reference signs are as follows:

[0040] 1-elevator, 2-water surface jet wind making tunnel body, 3-wave making and flow making module, 4-anemograph, 5-flow rate meter, 6-wave height meter, 7-anchor block, 8-steel wire, 9-tension sensor, 10-spring, 11-six-component target, 12-floating cylinder, 13-frame cross beam, 14-photovoltaic assembly, 15-pressure sensor, 16-high-speed camera, 17-wave absorbing module, 18-dynamic visual sensor, 19-platform deck. DETAILED DESCRIPTION

[0041] The embodiments of the present application will be described in detail below. It should be emphasized that the following description is merely exemplary and is not intended to limit the scope of the present application and its applications.

[0042] It is to be understood that when an element is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or indirectly on or connected to the other element by way of one or more other elements. In addition, the connection can be fixed or it can be a removable connection.

[0043] It is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, specify relative positions and orientations as shown in the drawings, and are used only for ease of description and illustration of the embodiments of the present application, and do not connote or imply that the apparatus or element referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be construed as limiting the application.

[0044] In addition, the terms "first", "second", and the like, are used only for ease of description and are not intended to connote or imply relative importance or a quantity of the indicated elements. Thus, a feature described as "first" or "second" can implicitly or explicitly include one or more of the features. In the description of embodiments of the present application, the meaning of "a plurality" is two or more, unless otherwise explicitly specifically defined.

[0045] The present application aims to provide a floating photovoltaic platform dynamic response test device capable of high-fidelity simulation of the coupling effect of extreme environmental loads in deep sea, by designing a test system including environmental simulation, semi-submersible platform, mooring and data acquisition, and innovatively constructing a prototype-based scaled photovoltaic model, introducing dynamic visual sensing technology, overcoming the technical bottlenecks of traditional tests in wind load true simulation and deck wave observation, and being able to truly restore the comprehensive stress and motion state of the platform under the complex coupling of wind, wave and current, especially achieving high-precision simulation of the aerodynamic effect of photovoltaic components and clear capture of the nonlinear wave slamming evolution process, thereby significantly improving the reliability, comprehensiveness and engineering guidance value of test analysis.

[0046] Referring to Figures 1 to 3The embodiment of the present application provides a kind of extreme wind wave flow coupling effect under floating photovoltaic power response test device, including environmental simulation system, semi-submersible photovoltaic platform system, mooring system and data measurement and acquisition system.The environmental simulation system, it is used to generate controllable wind field, wave field and flow field in test pool, simulate the coupling effect of wind, wave, flow load.The semi-submersible photovoltaic platform system, it is arranged in the test pool, for simulating the hydrodynamic response of floating photovoltaic platform under the load generated by the environmental simulation system;The semi-submersible photovoltaic platform system includes photovoltaic assembly 14 and float assembly, the photovoltaic assembly 14 is based on floating photovoltaic platform prototype, and is constructed as scale model according to predetermined scale ratio, and is arranged above float assembly, for bearing wind load and reflecting the influence of photovoltaic structure on platform movement;The float assembly is used to bear wave load, flow load and wind load, and provides support and buoyancy for the photovoltaic assembly 14.The mooring system, its two ends are connected to the semi-submersible photovoltaic platform system and test pool bottom respectively, provide recovery stiffness for platform and constrain its movement.The data measurement and acquisition system, it is through being arranged in the semi-submersible photovoltaic platform system and test environment, six degrees of freedom motion response, mooring tension, deck wave load and wave slamming evolution process data of platform under the coupling effect of wind, wave, flow are collected;Wherein, the data measurement and acquisition system has deck wave observation system for observing deck wave, and the deck wave observation system includes dynamic vision sensor 18 and pressure sensor 15, the dynamic vision sensor 18 is used to collect dynamic vision event data of deck wave process, and reconstructs wave slamming evolution process by image processing;The pressure sensor 15 is arranged on the surface of platform deck 19, for measuring wave slamming load size in real time.

[0047] The test device can simulate the coupling effect of wind, wave, flow and other environmental loads in the pool with high fidelity, truly restore the actual operating conditions of floating photovoltaic platform in the sea, especially in extreme conditions of deep sea, thereby significantly improving the reliability of test response results. The semi-submersible photovoltaic platform system not only includes a float structure for providing buoyancy, but also a photovoltaic assembly based on a floating photovoltaic platform prototype and constructed as a scale model according to a predetermined scale ratio. This design ensures that the photovoltaic assembly can truly simulate and bear wind load in the scale model test, and its aerodynamic effect is accurately reflected in the overall motion response of the platform, which makes up for the risk of insufficient evaluation of platform motion response in traditional tests due to the neglect of photovoltaic assembly aerodynamic load, and makes the test analysis more comprehensive and accurate. By introducing a dynamic vision sensor into the deck wave observation system and working with the pressure sensor arranged on the deck surface, the transient evolution process of nonlinear wave slamming can be clearly captured and reconstructed with microsecond-level response and ultra-high dynamic range, achieving complete and accurate physical observation and load measurement of the dynamic whole process of deck wave in extreme sea conditions.

[0048] Referring to Figure 1 and Figure 2 In some embodiments, the environmental simulation system comprises a wind generation module, a wave and current generation module 3 and a wave absorption module 17, wherein the wind generation module is configured to generate a steady wind field and a random turbulent wind field in the test tank; the wave and current generation module 3 is configured to generate a wave field including regular waves, irregular waves and focused waves and a uniform current field in the test tank; the wave absorption module 17 is arranged at the end of the test tank to absorb wave energy to reduce the influence of reflected waves on the test.

[0049] Referring to Figure 1 and Figure 2 In some embodiments, the wind generation module comprises an elevator 1 and a water surface jet wind tunnel body 2, the elevator 1 is used to adjust the height of the water surface jet wind tunnel body 2 relative to the calm water surface to adapt to the wind field simulation requirements of different test working conditions. In some embodiments, the wave and current generation module 3 comprises a wave generating mechanism and a current generating mechanism, the wave generating mechanism is configured with a plurality of parallel arranged rocking plate type wave makers driven by servo motors for generating regular waves, irregular waves and focused waves; the current generating mechanism comprises a current generating pump for regulating the flow to generate a uniform current field. The above embodiments realize the accurate simulation of steady to random turbulent wind field, regular wave to focused wave and other wave forms and uniform current field through the independently controllable and cooperatively operating wind, wave, current and wave absorption modules, thereby truly restoring the comprehensive stress environment of the floating photovoltaic platform in the sea, especially in the extreme working conditions of the deep sea.

[0050] Referring to Figure 3 In some embodiments, the photovoltaic assembly 14 comprises a photovoltaic panel and its support structure, the photovoltaic panel is made of high-strength organic material to truly simulate the wind load effect in the scale model.

[0051] Referring to Figures 1 to 3 In some embodiments, the floating body assembly comprises a platform deck 19, a float 12 and a frame crossbeam 13, the float 12 comprises a plurality of floats 12 arranged at the periphery and one float 12 located at the center, each float 12 is connected through the frame crossbeam 13, the platform deck 19 is fixed to the upper part of the float 12 for installing the photovoltaic assembly 14 and sensors; the float 12 is a hollow structure comprising a hollow heaving plate and a hollow column for providing buoyancy; the frame crossbeam 13 is made of stainless steel pipe comprising an upper crossbeam and a lower crossbeam for enhancing the overall structural strength of the platform.

[0052] As Figure 3As shown, in some embodiments, the platform deck 19 is processed into a hexagonal structure by alloy plate; the number of the pontoons 12 is seven, which are made of stainless steel plate, six of which are arranged in the periphery and in a hexagonal arrangement, and one in the center; the platform deck 19, the pontoons 12 and the frame cross beam 13 are fixedly connected by welding.

[0053] The above-mentioned floating body assembly adopts the design of cooperation of pontoons, frame cross beams and platform decks, especially the structure form of seven pontoons arranged in a peripheral hexagonal plus center and welded connection with stainless steel pipe frame, which endows the platform with the characteristics of high strength, large draft and high freeboard, and the overall structure is stable, laying a foundation for maintaining stability in severe sea conditions.

[0054] Referring to Figure 1 and Figure 2 , in some embodiments, the mooring system includes a spring 10, a steel wire rope 8 and an anchor block 7, constituting a four-point tension type mooring arrangement, wherein one end of the spring 10 is connected to the photovoltaic platform, and the other end is connected to the steel wire rope 8 through a tension sensor 9, and the other end of the steel wire rope 8 is anchored to the anchor block 7 at the bottom of the pool. The four-point tension type arrangement is realized by the spring, the steel wire rope and the anchor block, which provides controllable restoring stiffness and motion constraint for the platform, further enhancing its survivability and safety under the coupling action of wind, wave and current.

[0055] Referring to Figure 1 and Figure 2 , in some embodiments, the data measurement and acquisition system further includes an anemometer 4 arranged upstream of the wind field, a current meter 5 and a wave height meter 6 arranged on the platform side facing the flow and the wave, a tension sensor 9 arranged in the mooring system, and a displacement measurement system for measuring the six-degree-of-freedom motion of the platform.

[0056] Referring to Figure 1 and Figure 2 , in some embodiments, the displacement measurement system includes a six-component target 11 installed on the platform and a high-speed camera 16 arranged outside the pool, and the six-degree-of-freedom displacement of the platform is calculated by capturing the motion of the six-component target 11.

[0057] In some embodiments, the on-deck wave observation system is configured to perform the following processing for reconstructing the wave slamming evolution process according to the event stream data recorded by a dynamic vision sensor: the dynamic vision sensor works in an event-driven manner, and outputs an event stream composed of pixel spatial coordinates, time stamps, and event polarity representing the direction of brightness change; the continuous event stream is divided into a series of continuous and non-overlapping time windows according to a fixed number of events; for each time window, a spatiotemporal voxel grid is constructed, and each event within the window is assigned to adjacent voxels in the time dimension by interpolation according to its time stamp and polarity, so as to encode the event set into a fixed-size tensor; the tensor and the internal state of the recurrent convolutional neural network at the previous time are jointly input into the recurrent convolutional neural network, the internal state at the current time is obtained through the update of the recurrent convolutional unit of the recurrent convolutional neural network, and the corresponding reconstructed image sequence is output from the image decoding head; based on the reconstructed image sequence, the L-K optical flow method is used to calculate the target motion information between adjacent image sequences, and the morphological change and nonlinear evolution process of the wave slamming are reconstructed by calculating the partial derivative in the spatial direction and the gradient in the time direction of the image sequence, and taking the constancy of the optical flow in the neighborhood of the target pixel as a constraint to establish an optical flow equation set, and solving the equation set by the least square method to obtain the optical flow component.

[0058] The test device can truly and efficiently simulate and observe the comprehensive dynamic response of the photovoltaic platform under different sea conditions, especially under the coupling action of extreme wind, wave and current, and fully observe the dynamic evolution process of the on-deck wave of the photovoltaic platform under extreme sea conditions, so as to conveniently and efficiently study the hydrodynamic characteristics of the floating photovoltaic platform under the coupling action of extreme wind, wave and current.

[0059] The features and advantages of specific embodiments of the present application are further described below.

[0060] A test device for the dynamic response of a floating photovoltaic platform under the coupling action of extreme wind, wave and current, as shown in Figure 1 and Figure 2 . Specifically, the test device includes an environment simulation system, a semi-submersible photovoltaic platform system, a mooring system, and a data measurement and acquisition system. The environment simulation system is used to generate wind fields, wave fields and flow fields, and can simulate the coupling action of wind, wave and flow loads. The semi-submersible photovoltaic platform system is used to simulate the hydrodynamic response of the photovoltaic platform under the combined action of environmental loads and the mooring system. The mooring system is connected to the photovoltaic platform and the bottom of the pool at both ends, providing restoring stiffness for the platform. The data measurement and acquisition system collects platform six-degree-of-freedom motion displacement, mooring tension, on-deck wave load, and nonlinear wave slamming evolution process data under the coupling action of wind, wave and flow through a variety of sensors.

[0061] Specifically, as shown in Figure 1 and Figure 2As shown, the environment simulation system includes a wind generating module, a wave and current generating module 3 and a wave absorbing module 17. The wind generating module is used to generate a wind field, which includes a steady wind field and a random turbulent wind field. The wave and current generating module 3 is used to generate a wave field and a current field, the wave field includes regular wave, irregular wave and focused wave, and the current field includes uniform current field. The wave absorbing module 17 is used to absorb wave energy to reduce the influence of reflected wave. The wind generating module includes an elevator 1 and a water surface jet wind tunnel body 2. The height of the water surface jet wind tunnel body 2 from the static water surface is adjusted by the elevator 1 to meet different working condition requirements. The wave and current generating module 3 includes a wave generating mechanism and a current generating mechanism. The wave generating mechanism is provided with 10 parallel arranged rocking plate type wave generators, which are in transmission connection with servo motors, and are used to generate regular wave, irregular wave and focused wave. The current generating mechanism is provided with a current generating pump, which is used to regulate the flow of water to generate a current field. The wave generating mechanism and the current generating mechanism are connected with an external computer and corresponding software for wave and current generating parameter input.

[0062] As shown in Figure 1 and Figure 3 , the semi-submersible photovoltaic platform system includes a photovoltaic assembly 14 and a floating body assembly. The photovoltaic assembly 14 is used to bear the action of wind load, simulate the influence of the response of the photovoltaic structure to the platform motion, and the floating body assembly is used to bear the action of wind load, current load and wave load, and provide support for the photovoltaic assembly 14. The material of the photovoltaic assembly 14 is high-strength organic material, including photovoltaic panels and support structures, which can effectively capture the action of wind load on the photovoltaic assembly, and prevent the response evaluation from being too small due to the neglect of the influence of the photovoltaic assembly. More specifically as shown in Figure 3 , the floating body assembly includes a platform deck 19, a float 12 and a frame cross beam 13. The platform deck 19 is used to provide support for the photovoltaic assembly 14 and sensors, and is processed into a hexagonal deck by using an alloy plate; the float 12 includes a hollow heaving plate and a hollow column, and is used to provide buoyancy for the platform; the frame cross beam 13 includes an upper cross beam and a lower cross beam, and is used to connect the float 12 and provide strength for the platform structure, and is made of stainless steel pipe. The float 12 is made of stainless steel plate, including 6 peripheral floats and 1 central float, the peripheral floats 12 are arranged in a hexagonal shape, and then are welded with the frame cross beam 13 and the platform deck 19.

[0063] As shown in Figure 1 and Figure 2 , the mooring system includes a spring 10, a steel wire rope 8 and an anchoring block 7. One end of the spring 10 is connected to the photovoltaic platform, and the other end is connected to a tension sensor 9, and the stiffness of the spring 10 depends on the mooring restoring stiffness requirement. One end of the steel wire rope 8 is connected to the tension sensor 9, and the other end is connected to the anchoring block 7. A total of four moorings are provided to form a four-point tension type mooring system.

[0064] like Figure 1 and Figure 2 As shown, the data measurement and acquisition system includes an anemometer 4, a current meter 5, a wave height meter 6, a tension sensor 9, a six-degree-of-freedom displacement measurement system, and a deck wave observation system. The anemometer 4 is positioned upstream of the wind field to measure wind speed. The current meter 5 and wave height meter 6 are positioned on the upstream and downstream sides of the floating platform to measure current velocity and wave height. The tension sensor 9 is positioned between the spring 10 and the wire rope 8 to measure mooring tension. The deck wave observation system includes a dynamic visual sensor 18 and a pressure sensor 15. The dynamic visual sensor 18 records event flow data of wave morphology changes on the deck. It can reconstruct wave image data using a convolutional neural network and use the LK optical flow method to track the target area to obtain wave morphology changes. The specific implementation is as follows.

[0065] The dynamic vision sensor operates in an event-driven manner, triggering events only when it detects a change in the scene, and outputting the address and information of the corresponding pixel whose light intensity has changed. Each event... e It can be represented as:

[0066]

[0067] In the formula, ( x , y () represents the spatial coordinates of the event on the sensor plane. t Indicates the timestamp of the event. g This indicates the direction of grayscale change. Among them, g The range {+1, -1} indicates the direction of brightness change, where +1 represents increased brightness and -1 represents decreased brightness. When the cumulative brightness change of a pixel reaches a threshold ±... C The event is triggered at a certain time.

[0068] Furthermore, in order to transform a continuous stream of events into a sequence of images, the event stream is divided into a fixed number of events. N Cut into continuous, non-overlapping windows:

[0069]

[0070] To adapt to the known processing requirements of convolutional neural networks, the window... Encoded as a fixed-size tensor E k A spatiotemporal voxel grid is used, with linear interpolation assignment performed in the time dimension. The window is... Duration of crossing Discretize the data into B time intervals. Assign polarity to each event as follows: p iis assigned to the two nearest spatio-temporal voxels:

[0071]

[0072] where, is the normalized event timestamp.

[0073] Further, the image reconstruction is implemented using a recurrent convolutional neural network, where the internal state s k is updated over time. For each window whose tensor is E k , the previous time state s k-1 outputs the current image sequence and updates the state to s k :

[0074]

[0075]

[0076] where, f θ (•) is a recurrent convolutional unit, g θ (•) is an image decoding head.

[0077] Further, the classical L-K optical flow method is employed to calculate the object motion information between adjacent image sequences, reconstructing the clear nonlinear wave slamming evolution process. The L-K method assumes that the optical flow is constant within the neighborhood of a pixel, and then solves the basic equation of all pixels within the neighborhood using the least squares method:

[0078]

[0079]

[0080]

[0081] where, q b is the pixel point within the window, b is the total number of pixel points within the window. For p ∈ [1, b], I x q p and I y q p are the image I at the pixel point​​q p along x direction and y derivative of the direction, I t ( q p ) is the gradient of the optical flow in time t V x and V y are the optical flow components to be solved.

[0082] The dynamic vision sensor 18 can have an ultra-high dynamic range of more than 140 dB, and can still clearly and accurately capture target events in a complex light environment with strong light contrast or sharp light changes. The response speed of the dynamic vision sensor 18 can reach the microsecond level. The pressure sensor 15 is used to measure the size of the deck slamming load, and to analyze the influence of the slamming on the structure. The six-degree-of-freedom displacement measurement system includes a six-component target 11 and a high-speed camera 16. The six-component target 11 is provided with a photosensitive element, the motion displacement of the target is captured by the high-speed camera 16, and the motion of the photovoltaic platform is obtained through conversion.

[0083] Before the test starts, the wave height instrument 6 and the flow velocity instrument 5 are installed in the test pool, the wind speed instrument 4 is arranged at the outlet of the water surface jet wind tunnel body 2, the environmental condition calibration is carried out, and the actual environmental parameters to be input into the wind making module and the wave and flow making module 3 are determined. Secondly, the test working condition is determined according to the test scale ratio and the prototype, and the model is processed. The semi-submersible photovoltaic platform is arranged in the center of the pool, and the mooring connection is carried out. The pressure sensor 15 and the six-component target 11 are installed on the deck 19 of the platform. After the equipment debugging is completed, the test starts, the environmental simulation system is opened after the data measurement and acquisition system is started, and the dynamic response parameters of the semi-submersible photovoltaic platform system are measured.

[0084] ​In conclusion, the extreme wind wave current coupling under the floating photovoltaic power response test device provided by the application has the following technical advantages: through the cooperation of high-fidelity environment simulation, semi-submersible photovoltaic platform with stable structure, reliable restraint mooring system and accurate data measurement and acquisition system, a complete physical model test device capable of truly reproducing the extreme wind, wave and current multi-load coupling in deep sea is constructed; based on the semi-submersible photovoltaic platform, the photovoltaic component model is innovatively constructed based on the prototype and the scale ratio, the wind load effect of the photovoltaic structure is accurately simulated, and the dynamic visual sensing means is introduced, which cooperates with the pressure sensor to overcome the limitations of traditional observation means in the strong reflection and high dynamic range scene, realizes the clear capture and load measurement of the deck wave slamming evolution process, and significantly improves the authenticity, observation accuracy and analysis reliability of the test, thereby providing strong test support for the safety design and performance evaluation of the deep sea floating photovoltaic platform.

[0085] The above is a further detailed description of the application in combination with specific / preferred embodiments, and cannot be regarded as limiting the specific implementation of the application to these descriptions. For those skilled in the art to which the application belongs, without departing from the concept of the application, they can make several substitutions or modifications to the described embodiments, and these substitutions or modifications shall be regarded as falling within the protection scope of the application. In the description of the specification, the description of the terms "an embodiment", "some embodiments", "preferred embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the application. In the description of the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. Those skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of different embodiments or examples without contradiction. Although the embodiments of the application and its advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made herein without departing from the scope of the patent application.

Claims

1. A floating photovoltaic dynamic response test device under extreme wind, wave and current coupling, characterized in that, include: An environmental simulation system is used to generate controllable wind, wave, and flow fields in a test pool to simulate the coupling effects of wind, wave, and flow loads. A semi-submersible photovoltaic platform system is arranged in the test pool to simulate the hydrodynamic response of a floating photovoltaic platform under the loads generated by the environmental simulation system. The semi-submersible photovoltaic platform system includes photovoltaic modules and a floating body assembly. The photovoltaic modules are constructed as a scaled-down model based on a floating photovoltaic platform prototype at a predetermined scale and are positioned above the floating body assembly to withstand wind loads and reflect the influence of the photovoltaic structure on the platform's movement. The floating body assembly is used to withstand wave loads, current loads, and wind loads, and provides support and buoyancy for the photovoltaic modules. The floating body assembly includes a platform deck, pontoons, and frame beams. The pontoons include multiple pontoons arranged on the periphery and a central pontoon, connected by the frame beams. The platform deck is fixed to the upper part of the pontoons and is used to install the photovoltaic modules and sensors. The pontoons are hollow structures, including hollow heave plates and hollow columns, used to provide buoyancy. The mooring system, with its two ends connected to the semi-submersible photovoltaic platform system and the bottom of the test pool respectively, provides restoring stiffness to the platform and constrains its movement; The data measurement and acquisition system uses various sensors deployed in the semi-submersible photovoltaic platform system and the test environment to collect data on the platform's six-degree-of-freedom motion response, mooring tension, deck wave load, and wave impact evolution under the coupled effects of wind, waves, and currents. The system includes a deck wave observation system for observing deck waves, comprising a dynamic visual sensor and a pressure sensor. The dynamic visual sensor collects dynamic visual event data of the deck wave process and reconstructs the wave impact evolution process through image processing. The pressure sensor is deployed on the platform deck surface to measure the magnitude of the wave impact load in real time.

2. The test apparatus as described in claim 1, characterized in that, The environmental simulation system includes a wind generation module, a wave generation and flow generation module, and a wave damping module. The wind generation module is configured to generate a steady wind field and a random turbulent wind field in the test water tank. The wave generation and flow generation module is configured to generate a wave field including regular waves, irregular waves, and focused waves, as well as a uniform flow field in the test water tank. The wave damping module is located at the end of the test water tank and is used to absorb wave energy to reduce the impact of reflected waves on the test.

3. The test apparatus as described in claim 2, characterized in that, The wind-generating module includes an elevator and a water jet wind tunnel. The elevator is used to adjust the height of the wind tunnel relative to the still water surface to adapt to the wind field simulation requirements of different test conditions.

4. The test apparatus as described in claim 2, characterized in that, The wave-generating and flow-generating module includes a wave-generating mechanism and a flow-generating mechanism. The wave-generating mechanism is equipped with multiple parallel-arranged rocker-type wave generators. The rocker-type wave generators are driven by servo motors and are used to generate regular waves, irregular waves, and focused waves. The flow-generating mechanism includes a flow-generating pump, which is used to regulate the water flow rate to generate a uniform flow field.

5. The test apparatus according to any one of claims 1 to 4, characterized in that, The photovoltaic module includes a photovoltaic panel and its supporting structure. The photovoltaic panel is made of high-strength organic material to realistically simulate wind load in a scaled-down model.

6. The test apparatus according to any one of claims 1 to 4, characterized in that, The frame beams are made of stainless steel tubing and include upper and lower beams to enhance the overall structural strength of the platform. The platform deck is made of alloy plate processed into a hexagonal structure. There are seven pontoons made of stainless steel plate, six of which are arranged on the periphery in a hexagonal pattern, and one is located in the center. The platform deck, the pontoons, and the frame beams are fixedly connected by welding.

7. The test apparatus according to any one of claims 1 to 4, characterized in that, The mooring system includes a spring, a steel wire rope, and an anchor block, forming a four-point tensioned mooring arrangement. One end of the spring is connected to the photovoltaic platform, and the other end is connected to the steel wire rope via a tension sensor. The other end of the steel wire rope is anchored to the anchor block at the bottom of the pool.

8. The test apparatus according to any one of claims 1 to 4, characterized in that, The data measurement and acquisition system also includes an anemometer located upstream of the wind field, a current meter and a wave height meter located on the upstream and downstream sides of the platform, a tension sensor installed in the mooring system, and a displacement measurement system for measuring the six degrees of freedom motion of the platform.

9. The test apparatus as described in claim 8, characterized in that, The displacement measurement system includes a six-component target mounted on the platform and a high-speed camera positioned outside the pool. It calculates the six-degree-of-freedom displacement of the platform by capturing the target's motion.

10. The test apparatus according to any one of claims 1 to 4, characterized in that, The deck wave observation system is configured to perform the following processing to reconstruct the wave slamming evolution process based on event stream data recorded by dynamic visual sensors: The dynamic vision sensor operates in an event-driven manner, outputting an event stream consisting of pixel spatial coordinates, timestamps, and event polarities representing the direction of brightness changes. Divide a continuous event stream into a series of consecutive and non-overlapping time windows based on a fixed number of events; For each time window, a spatiotemporal voxel grid is constructed, and each event within the window is interpolated along the time dimension according to its timestamp and polarity to be distributed to adjacent voxels, thereby encoding the event set into a tensor of fixed size. The tensor and the internal state of the recurrent convolutional neural network at the previous time step are input into the recurrent convolutional neural network. The internal state at the current time step is updated by its recurrent convolutional units, and the corresponding reconstructed image sequence is output by its image decoding head. Based on the reconstructed image sequence, the LK optical flow method is used. By calculating the partial derivatives of the image sequence in the spatial direction and the gradient in the temporal direction, and taking the constant optical flow in the neighborhood of the target pixel as a constraint, a set of optical flow equations is established. The least squares method is used to solve the set of equations to obtain the optical flow components, thereby calculating the target motion information between adjacent image sequences and reconstructing the morphological changes and nonlinear evolution process of wave impact.

Images