Device and method for measuring dynamic aerodynamic performance of a scaled model of a floating wind turbine

Abstract

The application discloses a device and method for measuring dynamic aerodynamic performance of a floating wind turbine scale model, which adopts a wind turbine scale blade with a pressure measuring hole, a wind turbine scale model and a data acquisition controller. The application calculates the overall thrust and torque calculation model of the scale blade based on the pressure measuring data collected by the pressure measuring hole of the scale blade, so that accurate performance curves such as the thrust coefficient and the power coefficient can be obtained without force sensors and torque sensors. The application solves the difficulty of obtaining accurate dynamic thrust by stripping the inertial force of the force sensor and the difficulty of directly measuring the aerodynamic torque of the wind wheel by the torque sensor when measuring the thrust and torque of the scale wind turbine during the dynamic process in the wind tunnel environment. Meanwhile, the application solves the problem of the influence on the flow field caused by the excessive windward area of the components other than the wind wheel due to the installation of too many sensors of the wind turbine scale model.

Description

Technical Field

[0001] This invention belongs to the field of wind turbine testing technology, and relates to the dynamic aerodynamic performance measurement of floating wind turbine models. Specifically, it relates to a device and method for measuring the power curve and thrust curve of a floating wind turbine model under platform motion conditions. It solves the difficulties in obtaining accurate dynamic thrust by force sensors by separating inertial forces when measuring thrust and torque of scaled-up wind turbines in a wind tunnel environment, and the difficulties in directly measuring the aerodynamic torque of the wind turbine rotor by torque sensors. At the same time, it solves the problem that the excessive number of sensors installed in scaled-up wind turbines causes excessive windward area of ​​components other than the wind turbine rotor, which affects the flow field. Background Technology

[0002] The development of onshore and near-shore wind turbines has reached saturation. However, with abundant deep-sea wind resources, offshore floating wind turbines possess enormous development potential. Yet, due to the coupling effect of wind, waves, and currents, they also face numerous technical challenges. Wind tunnel testing is a powerful tool for studying the aerodynamic and operational characteristics of floating wind turbines, and researching the dynamic performance of floating wind turbine models in a wind tunnel environment is crucial for a deep understanding of the characteristics of floating turbines.

[0003] To ensure the safe and efficient operation of floating wind turbines, it is necessary to understand their dynamic response and performance characteristics under platform motion. Power and thrust curves are key performance indicators. The power curve reflects the power output of the floating wind turbine under the coupling effect of wind, waves, and current, and is an important basis for evaluating its power generation capacity. The thrust curve focuses on the thrust experienced by the floating wind turbine under complex operating conditions, which is also a crucial parameter when designing and deploying wind turbines in actual wind farms.

[0004] However, measuring the power and thrust curves of floating wind turbines in a wind tunnel environment still faces many challenges, mainly due to the following three reasons:

[0005] (i) The current method for measuring the power curve of a scaled-down model of a floating wind turbine is to install a speed and torque sensor on the main shaft to obtain the speed and torque of the main shaft. However, since the friction torque accounts for a large proportion of the small wind turbine model, it is difficult to accurately measure the aerodynamic torque of the wind turbine when there are other components between the torque sensor and the output shaft of the wind turbine, thus making it difficult to obtain the accurate power curve of the model.

[0006] (II) The traditional method for measuring the static thrust curve of a wind turbine in a wind tunnel environment is to use force sensors to measure the total thrust on the sensor and the parts above it, and then calculate the thrust coefficient accordingly. However, when the scaled-down model platform of a floating wind turbine moves, the force sensors contain a variety of complex forces, including but not limited to the aerodynamic forces, inertial forces, vibration forces caused by aerodynamic imbalances, thrust on the hub and tower, and the gravity of the model for sway, roll, and heave. For pitch and yaw, there are also gyroscopic torques. It is very difficult to extract the thrust of the wind turbine from the force sensor measurement data. At present, there is no good method to obtain the dynamic thrust of the scaled-down model of a floating wind turbine during the platform movement, and therefore it is difficult to obtain an accurate thrust curve.

[0007] (III) The current overall design of scaled-down models of floating wind turbines is still redundant. The traditional method to obtain thrust and torque is to install speed and torque sensors and force sensors, which requires corresponding compromises in the size of the nacelle and tower: ① It must be large enough to accommodate the sensor components, and the size of the two cannot be designed too small. This also makes the windward area of ​​the nacelle and tower too large, which has a certain impact on the wind field and thus leads to inaccurate measurement of the wind turbine's aerodynamic performance; ② At the same time, the complexity of the structure makes it difficult to align the main shaft and ensure aerodynamic balance. When the center of mass of the rotating parts does not coincide with the center of the shaft and the mass is large, the unit will experience strong vibrations with large amplitude near the critical speed, threatening its safety.

[0008] In summary, measuring the dynamic aerodynamic performance curves of floating wind turbine models in a wind tunnel environment presents significant challenges. These challenges include the difficulty in directly measuring the rotor aerodynamic torque, the difficulty in extracting the rotor aerodynamic thrust from force sensors, and the difficulty in achieving overall integration and lightweight design of the turbine. These issues directly impact the accurate evaluation and optimized design of floating wind turbine performance and represent urgent technical problems to be solved. Summary of the Invention

[0009] (I) Purpose of the Invention

[0010] To address at least one of the above-mentioned and other technical problems in the prior art, this invention first proposes a device for measuring the thrust and torque of a floating wind turbine model under platform motion conditions. Specifically, this device employs a scaled-down blade with a pressure measurement section. Based on this device, a method for measuring the dynamic thrust and torque of a floating wind turbine model under platform motion conditions is further proposed. By collecting pressure measurement data from the pressure measurement section and using the pressure measurement data-torque-thrust calculation model proposed in this invention, the dynamic thrust and torque of the floating wind turbine model during motion can be obtained in real time. This solves the difficulties encountered when using force sensors and torque sensors to measure the thrust and torque of scaled-down wind turbines in a wind tunnel environment. Specifically, it addresses the difficulty of obtaining accurate dynamic thrust by separating inertial forces from force sensors, and the difficulty of directly measuring the aerodynamic torque of the wind turbine rotor using torque sensors. Furthermore, it solves the problem of excessively large windward areas of components other than the wind turbine rotor due to the installation of too many sensors in scaled-down wind turbines, which negatively impacts the flow field.

[0011] (II) Technical Solution

[0012] The specific technical solution adopted by this invention to achieve its inventive purpose and solve its technical problem is as follows:

[0013] The first objective of this invention is to provide a device for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine, used to simulate and measure the dynamic aerodynamic performance of a floating wind turbine, comprising a wind tunnel, a multi-degree-of-freedom motion platform, a scaled-down model of the wind turbine, and a data acquisition controller, wherein:

[0014] --The multi-degree-of-freedom motion platform is set on the bottom surface of the wind tunnel test section, and an incoming wind speed measuring device is set at the entrance of the wind tunnel test section;

[0015] --The scaled-down model of the wind turbine includes a tower, a nacelle at the top of the tower, and a wind turbine at the front of the nacelle. The tower is fixedly connected to a motion platform at its bottom via a force sensor. The wind turbine includes a main shaft, several pitch-adjustable wind turbine blades, and a fairing. Each blade has a pitch adjustment device at its root for adjusting the pitch angle. Each blade has several spaced pressure measurement sections along its span, each with multiple pressure measurement holes. Multiple pressure measurement tubes, corresponding to and connected to each pressure measurement hole, are located inside the blade cavity. The fairing contains a pressure scanning valve for collecting pressure measurement data from the blades, with each channel of the pressure scanning valve corresponding to each pressure measurement tube. The nacelle contains a load motor driven to the rear end of the main shaft, and the main shaft is equipped with a speed and torque sensor.

[0016] --The data acquisition controller is communicatively connected to the motion platform, each pitch adjustment device, the load motor, the incoming wind speed measurement device, the pressure scanning valve, the speed and torque sensor, and the force sensor. It is used to collect the incoming wind speed at the wind tunnel test section inlet, the pressure data from the pressure measuring holes of each wind turbine blade, the speed and torque data of the wind turbine main shaft, and the thrust data of the tower. It is also used to control and adjust the attitude of the motion platform, the pitch angle of each wind turbine blade, and the speed of the load motor.

[0017] Under static test conditions, the pressure data from the pressure measuring holes are processed to calculate the tangential and normal forces per unit length along the chord direction of each pressure measuring section, and then the tangential and normal forces per unit length of each pressure measuring section on the wind turbine plane are calculated. The relationship model between the force on the pressure measuring section and the wind turbine thrust torque is established by fitting the least squares method.

[0018] Under dynamic experimental conditions, based on the fitted relationship model between the force on the pressure measurement section and the thrust torque of the wind turbine, the dynamic thrust F of the wind turbine under platform motion is calculated based on the pressure data from the pressure measurement orifice. x-dyno and torque T dyno The power coefficient C under different operating conditions was calculated. p and thrust coefficient C t Furthermore, the C-axis of the scaled-down model of the wind turbine during the platform's dynamic motion was plotted. p -λ、C t -λ curves are used to evaluate the dynamic aerodynamic performance of wind turbines.

[0019] Another objective of this invention is to provide a test method for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine. This test method, based on the aforementioned apparatus, conducts dynamic aerodynamic performance testing of the scaled-down floating wind turbine model in a wind tunnel, and includes at least seven steps: test condition design, initial parameter setting, synchronous acquisition of turbine control and data, construction of a pressure data-thrust-torque calculation model, and obtaining dynamic thrust-torque using blade surface pressure data.

[0020] SS1. Static and Dynamic Test Condition Design

[0021] Based on the actual operating conditions of wind turbines at sea, multiple static test conditions are designed by changing the incoming wind speed, rotor speed, and / or blade pitch angle while keeping the multi-degree-of-freedom motion platform stationary. This allows for the measurement of the aerodynamic performance of the scaled-down model of the wind turbine under different static test conditions. Simultaneously, by applying motion excitation to the multi-degree-of-freedom motion platform, multiple dynamic test conditions are designed by changing the motion frequency and amplitude of the motion platform, the incoming wind speed, rotor speed, and / or blade pitch angle. This allows for the measurement of the aerodynamic performance of the scaled-down model of the wind turbine under different dynamic test conditions.

[0022] SS2. Initial parameter settings for static test conditions

[0023] According to the static test conditions designed in step SS1, the initial operating parameters of the test device are preset, and the wind tunnel and the scaled-down model of the wind turbine are started in sequence according to the preset initial operating parameters until the operating state of the test device stabilizes and the design static test conditions are met to enter the formal testing stage.

[0024] SS3. Synchronous Acquisition of Unit Control and Data

[0025] Under static test conditions, based on the data acquisition controller, the load motor is adjusted to run within the set speed range, and various data from the force sensor, speed and torque sensor, incoming wind speed measuring device, and pressure scanning valve are collected simultaneously, including at least thrust, torque, speed, incoming wind speed, and pressure data from the pressure measuring holes of each wind turbine blade.

[0026] SS4. Pressure Measurement Data - Thrust Torque Calculation Model Construction

[0027] Based on the pressure data from the pressure measurement holes of wind turbine blades under static test conditions, and after calculating the tangential and normal forces per unit length of each pressure measurement section, the actual position and orientation of each pressure measurement section in the wind turbine plane are combined to calculate the tangential and normal forces per unit length of each pressure measurement section in the wind turbine plane. Finally, the tangential and normal force data of all pressure measurement sections are fitted as a whole based on the least squares method to establish a relationship model between the forces on the pressure measurement sections and the thrust and torque of the wind turbine under static test conditions, thereby converting the pressure data measured on the blade surface into the thrust and torque of the wind turbine.

[0028] SS5. Dynamic Test Condition Operating Parameter Settings

[0029] Based on the dynamic test conditions designed in step SS1, the scaled-down model of the wind turbine and the multi-degree-of-freedom motion platform are synchronously controlled, and various operating parameters are adjusted, including setting the wind tunnel inflow wind speed, wind turbine speed, blade pitch angle, motion frequency and motion amplitude of the motion platform, test duration, control time step and initial values ​​of each sensor, until the operating state of the test device stabilizes to the dynamic test conditions.

[0030] SS6. Obtaining dynamic thrust torque using blade surface pressure data

[0031] The data acquisition controller synchronously and in real time collects the following data at different times: downflow wind speed v, multi-degree-of-freedom displacement of the platform, wind turbine speed Ω, and pressure data P measured by the pressure measuring holes on each wind turbine blade. 11 ...P ikTo ensure the consistency of various data over time, a time-strictly corresponding dataset was obtained. Based on the pressure measurement data-thrust-torque calculation model constructed in step SS4, the thrust F of the wind turbine at different times under dynamic test conditions was calculated. x-dyno and torque T dyno Then, the aerodynamic thrust and torque at each moment are calculated;

[0032] SS7. Dynamic Performance Curve C p -λ、C t -λ plotting

[0033] The tip speed ratio λ is calculated based on the rotor speed Ω and incoming wind speed v collected at different times in step SS6, and the calculated thrust F is then used to determine the tip speed ratio λ. x-dyno and torque T dyno The power coefficient C under different operating conditions was calculated. p and thrust coefficient C t Furthermore, the C-axis of the scaled-down model of the wind turbine during the platform's dynamic motion was plotted. p -λ、C t -λ curves are used to evaluate the dynamic aerodynamic performance of wind turbines:

[0034]

[0035]

[0036]

[0037] Where λ is the tip speed ratio, Ω is the rotor speed, R is the rotor radius, A is the swept area of ​​the rotor, v is the incoming air velocity, and ρ is the air density.

[0038] (III) Technical Effects

[0039] Compared with existing technologies, the device and method for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine proposed in this invention have significant technical advantages:

[0040] (1) The present invention provides a device and method for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine. This experimental device and method solves the problem that the speed and torque sensor cannot directly measure the wind turbine torque due to the presence of components such as slip rings. It can effectively measure the dynamic aerodynamic torque in real time during the test.

[0041] (2) The present invention provides a device and method for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine. This experimental device and method avoid the difficulty of separating inertial force, vibration force caused by aerodynamic imbalance, gyro torque, and aerodynamic thrust of components other than the wind turbine from the force sensor. Instead, it uses pressure measurement data-torque thrust model to directly obtain aerodynamic thrust, which is faster and more accurate in calculation.

[0042] (3) The present invention provides a device and method for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine. This test device and method are applicable to wind turbine models without speed, torque and force sensors. It can make the wind turbine model more integrated and lightweight, effectively reduce the vibration problem of the unit and reduce the impact of other components on the wind turbine wind field. Attached Figure Description

[0043] Figure 1 A scaled-down model of a floating wind turbine and a scaled-down blade with a pressure measuring hole.

[0044] Figure 2 A schematic diagram of the test setup for measuring the dynamic performance curve of a floating wind turbine.

[0045] Figure 3 This is a schematic diagram of the pressure measuring hole and the force applied to the pressure measuring section;

[0046] Figure 4 A flowchart illustrating the method for measuring the dynamic performance curves of floating wind turbines;

[0047] Figure 5 Schematic diagram of pressure data (a) at the blade root and (b) at the blade midsection measured at different rotational speeds;

[0048] Figure 6 A schematic diagram comparing the calculated and measured values ​​of the tangential and normal forces per unit length of the wind turbine plane at different span positions;

[0049] Figure 7 This is a schematic diagram of dynamic thrust timing values;

[0050] Figure 8 This is a schematic diagram of the dynamic torque timing values;

[0051] Explanation of reference numerals in the attached figures:

[0052] 1-Scaled-down wind turbine blade, 2-Tower, 3-Multi-degree-of-freedom motion platform, 4-Pressure measurement section, 5-Pressure scanning valve, 6-Fairing, 7-Slip ring, 8-Speed ​​and torque sensor, 9-Load motor, 10-Data acquisition controller, 11-Wind tunnel and incoming wind speed measurement device. Detailed Implementation

[0053] The present invention will now be described in further detail with reference to the accompanying drawings. This description is intended to explain, not limit, the invention and to make its objectives and technical solutions clearer. Throughout the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The described embodiments are some, but not all, embodiments of the present invention and are intended to explain the invention, not to limit it. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0054] To address the shortcomings and deficiencies of existing technologies, this invention first proposes a device for measuring the thrust and torque of a floating wind turbine model under platform motion conditions. Specifically, this device employs scaled-down blades with a pressure measurement section. Based on this device, a method for measuring the dynamic thrust and torque of a floating wind turbine model under platform motion conditions is further proposed. By collecting pressure measurement data from the pressure measurement section and using the pressure measurement data-torque-thrust calculation model proposed in this invention, the dynamic thrust and torque of the floating wind turbine model during motion can be obtained in real time. This solves the difficulties encountered when using force sensors and torque sensors to measure the thrust and torque of scaled-down wind turbines in a wind tunnel environment. Specifically, it addresses the difficulty of obtaining accurate dynamic thrust by isolating inertial forces with force sensors, and the difficulty of directly measuring the aerodynamic torque of the wind turbine rotor with torque sensors. Furthermore, it solves the problem of excessively large windward areas of components other than the rotor in scaled-down wind turbines, which negatively impacts the flow field.

[0055] Example 1

[0056] As a specific example, such as Figure 1 , 2 As shown, the device for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine according to the present invention is used to simulate and measure the dynamic aerodynamic performance of a floating wind turbine in a wind tunnel test. It includes a wind tunnel 11, a motion platform 3, a floating wind turbine model matching the size of the wind tunnel, and the wind turbine model includes a tower 2, several scaled-down wind turbine blades 1 with pressure measuring sections, a hub, a fairing 6, an electronic pressure scanning valve 5 installed in the hub, a slip ring 7, a speed and torque sensor 8, a brushless motor 9, and a unit control and data acquisition device 10.

[0057] Specifically, the scaled-down model of the wind turbine in this invention includes a multi-degree-of-freedom motion platform 3, a tower 2 mounted on the motion platform 3, a nacelle mounted at the top of the tower 2, and a wind turbine mounted at the front of the nacelle. The motion platform 3 is installed on the bottom surface of the wind tunnel test section, and the bottom of the tower 2 is fixedly connected to the motion platform 3 via force sensors. The wind turbine includes a main shaft, several pitch-adjustable wind turbine blades 1, and a fairing 6. Each wind turbine blade 1 has a corresponding pitch adjustment device at its root for adjusting the pitch angle, and each wind turbine blade 1 has several spaced pressure measuring sections 4 along its span. Each pressure measuring section 4 has multiple pressure measuring holes arranged on both the pressure and suction surfaces (see diagram of pressure measuring section perforation and force). Figure 3 As shown), the blade cavity is provided with multiple pressure measuring tubes that are connected to each pressure measuring hole in a one-to-one manner. The fairing is provided with a pressure scanning valve 5 for collecting pressure measuring data of the blade, and each channel of the valve is connected to each pressure measuring tube in a one-to-one manner. The nacelle is provided with a load motor 9 that is driven to the rear end of the wind turbine main shaft, and the wind turbine main shaft is provided with a speed and torque sensor 8.

[0058] The data acquisition controller 10 in this invention is communicatively connected to the motion platform 3, each pitch adjustment device, the load motor 9, the incoming wind speed measurement device, the pressure scanning valve 5, the speed and torque sensor 8, and the force sensor. It is used to acquire the incoming wind speed at the entrance of the wind tunnel test section, the pressure data from the pressure measuring holes of each wind turbine blade 1, the speed and torque data of the wind turbine main shaft, and the thrust data of the tower 2. It is also used to control and adjust the attitude of the motion platform 3, the pitch angle of each wind turbine blade 1, and the speed of the load motor 9.

[0059] Under static test conditions, the pressure data from the pressure measuring holes, after data processing, are used to calculate the tangential and normal forces per unit length along the chord direction at each pressure measuring section. This leads to the calculation of the tangential and normal forces per unit length at each pressure measuring section on the rotor plane. A relationship model between the forces acting on the pressure measuring sections and the rotor thrust torque is then established using the least squares method. Under dynamic test conditions, based on the established relationship model between the forces acting on the pressure measuring sections and the rotor thrust torque, the dynamic thrust F of the rotor under platform motion is calculated using the pressure data from the pressure measuring holes. x-dyno and torque T dyno The power coefficient C under different operating conditions was calculated. p and thrust coefficient C t Furthermore, the C-axis of the scaled-down model of the wind turbine during the platform's dynamic motion was plotted. p -λ、C t -λ curves are used to evaluate the dynamic aerodynamic performance of wind turbines.

[0060] In a preferred embodiment of the present invention, the inner cavity of the fairing 6 is provided with a plurality of pressure scanning valves 5, each of which is connected to the copper tube of the pressure measuring hole in the blade extending out of the blade root through a pressure measuring tube. In addition, the nacelle is provided with at least one slip ring 7, one load motor 9, and a plurality of data communication control cards. The slip ring 7 can be installed at any position on the main shaft, and the data lines of the pressure scanning valves 5 in the fairing 6 are connected to the corresponding data acquisition system (DAQ) through the slip ring 7. The load motor 9 is installed at the rear end of the main shaft, and the load motor 9 is connected to the data acquisition controller 10 through its corresponding plurality of data communication control cards.

[0061] In a preferred embodiment of the present invention, a six-degree-of-freedom motion platform or other motion platforms are selected as the multi-degree-of-freedom motion platform. Its function is to provide the required motion response for the wind turbine model, which is used to simulate the six-degree-of-freedom response of a floating wind turbine in the ocean.

[0062] In a preferred embodiment of the invention, during dynamic testing, dynamic thrust and torque are obtained solely from the pressure data measured at the pressure measurement section by removing the force sensor and speed / torque sensor. Therefore, the hub and nacelle casing can be designed to be smaller, reducing their impact on the blade wind field.

[0063] In summary, this embodiment 1 provides a device for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine. By simulating the actual marine operating environment in a wind tunnel, and utilizing a multi-degree-of-freedom motion platform and a precise data acquisition system, the device successfully measures the dynamic thrust and torque of the wind turbine under different operating conditions, providing important support for the optimized design and performance evaluation of wind turbines.

[0064] Example 2

[0065] When using the apparatus provided in Embodiment 1 of the present invention to conduct dynamic aerodynamic performance testing of a scaled-down model of a floating wind turbine in a wind tunnel, such as... Figure 4 As shown, the experimental method includes at least seven steps in its implementation: test condition design, initial parameter setting, synchronous acquisition of unit control and data, construction of a pressure measurement data-thrust torque calculation model, and obtaining dynamic thrust torque using blade surface pressure data. An example is a floating wind turbine model with two blades, each with two pressure-measuring airfoil sections, a speed and torque sensor installed in the middle of the main shaft, a force sensor installed at the bottom of the tower, and a six-degree-of-freedom platform as its foundation, used to measure the dynamic aerodynamic performance.

[0066] SS1. Static and Dynamic Test Condition Design

[0067] Based on the actual operating conditions of wind turbines at sea, multiple static test conditions are designed by changing the incoming wind speed, rotor speed, and / or blade pitch angle while keeping the multi-degree-of-freedom motion platform stationary. This allows for the measurement of the aerodynamic performance of the scaled-down model of the wind turbine under different static test conditions. Simultaneously, by applying motion excitation to the multi-degree-of-freedom motion platform, multiple dynamic test conditions are designed by changing the motion frequency and amplitude of the motion platform, the incoming wind speed, rotor speed, and / or blade pitch angle. This allows for the measurement of the aerodynamic performance of the scaled-down model of the wind turbine under different dynamic test conditions.

[0068] This step requires consideration of variables including but not limited to incoming wind speed, rotor speed, blade pitch angle, and platform motion attitude. Different tip speed ratios are obtained by changing the incoming wind speed and rotor speed. A static test condition is shown in Table 1 below, and a dynamic test condition is shown in Table 2 below.

[0069] Table 1. A static test condition

[0070]

[0071] Table 2. A specific dynamic test condition

[0072]

[0073] SS2. Initial parameter settings for static test conditions

[0074] According to the static test conditions designed in step SS1, the initial operating parameters are preset. The initial operating parameters include at least the wind tunnel wind speed of 5 m / s, the speed of the scaled-down wind turbine of 300-1200 rpm, the test duration of 20 s, the control time step of 0.02 s, the load parameters of the load motor (P = 761.070 mV / A, I = 451.681 Mv / (A*ms)), the initial values ​​of the sensors, etc. The wind tunnel and the scaled-down wind turbine are turned on according to the preset operating parameters until the operating state is stable.

[0075] SS3. Synchronous Acquisition of Unit Control and Data

[0076] Under static test conditions, based on the data acquisition controller, the load motor is adjusted to run within the set speed range, and various data from the force sensor, speed and torque sensor, incoming wind speed measuring device, and pressure scanning valve are collected simultaneously, including at least thrust, torque, speed, incoming wind speed, and pressure data from the pressure measuring holes of each wind turbine blade.

[0077] In a preferred embodiment of the present invention, a PID control algorithm is used to regulate the load motor to operate within a set speed range, and the load motor is adjusted and tuned according to the following sub-steps:

[0078] SS31. Identify and model the load motor winding. First, perform preliminary adjustment and identification of the load motor to obtain the basic parameters of the winding. Then, apply positive and negative currents to the winding to generate stable oscillations until a stable oscillation with a fixed amplitude is obtained. Repeat the experiment at different frequencies and measure the oscillation characteristics of the winding at each frequency to obtain accurate model parameters of the motor winding. Establish a dynamic response model of the motor winding and use the model parameters to determine the initial settings of the controller to ensure the stable operation and adjustment accuracy of the subsequent control system.

[0079] SS32. Map the model parameters of the winding to derive the controller parameters (PID parameters). Based on the identification and modeling results of sub-step SS31, use the obtained winding model parameters to calculate and determine the parameters of the PID control algorithm. By adjusting the proportional (P), integral (I) and derivative (D) parameters, optimize the response characteristics of the controller so that the controller can accurately regulate the motor speed.

[0080] SS33. Verify the final control loop structure. Based on the parameters of the PID control algorithm determined in sub-step SS32, conduct actual operation tests on the load motor. By monitoring the speed and response of the load motor, observe the stability and adjustment accuracy of the load motor within the set speed range to ensure that the control loop maintains efficient and reliable control performance under various test conditions.

[0081] In a preferred embodiment of the present invention, the data acquisition controller is communicatively connected to a force sensor, a speed and torque sensor, a load motor, and a pressure scanning valve. While controlling the speed of the load motor, it synchronously and in real-time acquires various types of data, including at least the thrust F. x Torque T sensor Rotational speed (Ω), incoming wind speed (v), and pressure data (P) measured by pressure gauges on each wind turbine blade. 11 ...P ik , where P ik This represents the pressure data from the k-th pressure measuring hole at the i-th pressure measuring section of the wind turbine blade.

[0082] More specifically, the blade root pressure distribution data measured at rotational speeds of 400 rpm, 700 rpm, and 1000 rpm in this example are as follows: Figure 5 As shown. By Figure 5 It can be seen that as the tip velocity ratio increases, the pressure distribution in the leaf and at the leaf root gradually increases, and the pattern is obvious.

[0083] SS4. Pressure Measurement Data - Thrust Torque Calculation Model Construction

[0084] Based on the pressure data from the pressure measurement holes of wind turbine blades under static test conditions, and after calculating the tangential and normal forces per unit length of each pressure measurement section, the actual position and orientation of each pressure measurement section in the wind turbine plane are combined to calculate the tangential and normal forces per unit length of each pressure measurement section in the wind turbine plane by projection. Finally, the tangential and normal force data of all pressure measurement sections are fitted as a whole based on the least squares method to establish a relationship model between the forces on the pressure measurement sections and the thrust and torque of the wind turbine under static test conditions, thereby converting the pressure data measured on the blade surface into the thrust and torque of the wind turbine.

[0085] In a preferred embodiment of the present invention, a model relating the tangential and normal forces acting on the pressure measurement section under static test conditions to the wind turbine thrust and torque is constructed according to the following sub-steps:

[0086] SS41. Based on the pressure data from the pressure measuring holes of the wind turbine blade under static test conditions, the chordal tangential force dF per unit length of each pressure measuring section of the wind turbine blade is obtained according to the following calculation formula. ai Normal force dF bi :

[0087]

[0088]

[0089] Among them, P ik and P i(k+1) Let x be the pressure data of the k-th and (k+1)-th pressure measuring holes on the i-th pressure measuring section, respectively. k and x k+1 y k and y k+1 P respectively ik The horizontal and vertical coordinates of the corresponding pressure measuring holes, where u is the number of pressure measuring holes at that pressure measuring section;

[0090] SS42. Based on the following calculation formula, the chordal tangential force and normal force per unit length of each pressure measurement section are converted into the tangential force dF per unit length of the wind turbine plane. ti Normal force dF ni :

[0091] dF ti =dF ai ·cosθ i -dF bi ·sinθ i

[0092] dF ni =dF ai ·sinθ i +dF bi ·cosθ i

[0093] Where, θ i Let dF be the torsion angle of the i-th pressure measurement section. ai and dF bi These represent the tangential and normal forces per unit length of the pressure measurement section, respectively. A comparison of the calculated and measured values ​​of the tangential and normal forces per unit length of the wind turbine plane at different elongation positions is shown below. Figure 6 As shown in the figure, it can be seen that the thrust calculated by the computational model corresponds well with the thrust measured by the force sensor.

[0094] SS43. Tangential force dF at each pressure measurement section calculated based on sub-step SS42. ti Normal force dF ni and the thrust F collected in step SS3 x Torque T sensor Data were used to establish a model relating the force on the pressure measurement section to the wind turbine thrust and torque under static test conditions using the least squares method.

[0095]

[0096]

[0097] Where B is the number of wind turbine blades, m is the number of pressure measurement sections, and λ is the tip speed ratio. K i (λ), A i B i C i Here, r is the fitting coefficient, R is the blade radius, and r is the blade radius. i Let be the radius of the i-th pressure measurement section.

[0098] In a further preferred embodiment of the present invention, in the above sub-step SS43, the fitting effect of the least squares method is evaluated by using the error between the discrete observation points and the fitted curve, and the fitting coefficients are obtained. K i (λ), A i B i C i The specific values ​​are then used to indirectly fit the optimal curve:

[0099]

[0100] in, Let Y be the observed values ​​at each discrete point, and R be the corresponding polynomial fitting function value. 2 The sum of squared residuals represents the observed values. The error evaluation index between the observed and fitted function values ​​Y is obtained by minimizing the sum of squared residuals between the observed and fitted values ​​to obtain the optimal polynomial coefficients. K i(λ), A i B i C i An analytical relationship model was established between pressure measurement data and the overall thrust and torque of the wind turbine.

[0101] In a specific example, the present invention establishes a model for the relationship between the force on the pressure measurement section and the wind turbine thrust and torque under static test conditions using the least squares method, as follows:

[0102]

[0103]

[0104] SS5. Dynamic Test Condition Operating Parameter Settings

[0105] Based on the dynamic test conditions designed in step SS1, the scaled-down model of the wind turbine and the multi-degree-of-freedom motion platform are controlled synchronously, and various operating parameters are adjusted, including setting the wind tunnel inflow wind speed, wind turbine speed, blade pitch angle, motion frequency and motion amplitude of the motion platform, test duration, control time step and initial values ​​of each sensor, until the operating state of the test device stabilizes to the dynamic test conditions.

[0106] In a preferred embodiment of the present invention, when setting dynamic test conditions, the wind tunnel inflow wind speed, wind turbine speed, and blade pitch angle are first set. After the scaled-down model of the wind turbine unit is running stably and the inflow is stable, the attitude of the platform motion is set, and its motion frequency and motion amplitude are adjusted.

[0107] SS6. Obtaining dynamic thrust torque using blade surface pressure data

[0108] The data acquisition controller synchronously and in real time collects the following data at different times: downflow wind speed v, multi-degree-of-freedom displacement of the platform, wind turbine speed Ω, and pressure data P measured by the pressure measuring holes on each wind turbine blade. 11 ...P ik To ensure the consistency of various data over time, a time-strictly corresponding dataset was obtained. Based on the pressure measurement data-thrust-torque calculation model constructed in step SS4, the thrust F of the wind turbine at different times under dynamic test conditions was calculated. x-dyno and torque T dyno Then, the aerodynamic thrust and torque at each moment are calculated.

[0109] This example uses a 1Hz oscillation condition as an example. The calculated tangential and normal forces at the pressure measurement sections at the blade root and mid-blade, and the calculated overall thrust torque are as follows: Figure 7 , 8 As shown.

[0110] SS7. Dynamic Performance Curve C p -λ、C t -λ plotting

[0111] The tip speed ratio λ is calculated based on the rotor speed Ω and incoming wind speed v collected at different times in step SS6, and the calculated thrust F is then used to determine the tip speed ratio λ. x-dyno and torque T dyno The power coefficient C under different operating conditions was calculated. p and thrust coefficient C t Furthermore, the C-axis of the scaled-down model of the wind turbine during the platform's dynamic motion was plotted. p -λ、C t -λ curves are used to evaluate the dynamic aerodynamic performance of wind turbines:

[0112]

[0113]

[0114]

[0115] Where λ is the tip speed ratio, Ω is the rotor speed, R is the rotor radius, A is the swept area of ​​the rotor, v is the incoming air velocity, and ρ is the air density.

[0116] As can be seen from the above scheme, the experimental device and method for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine proposed in this invention uses a scaled-down wind turbine blade with several pressure measuring sections. During the experiment, the pressure measuring data of the pressure measuring sections are measured, and a model is proposed to calculate the dynamic thrust and torque based on the pressure measuring data, thereby obtaining the dynamic C of the floating wind turbine model under platform motion. p -λ、C t -λ curve.

[0117] The objectives of this invention have been fully and effectively achieved through the above embodiments. All equivalent or simple variations made to the structures, features, and principles described in this patent concept are included within the protection scope of this patent. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of this invention or exceed the scope defined in these claims, all of which should fall within the protection scope of this invention.

Claims

1. A device for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine, used to simulate and measure the dynamic aerodynamic performance of a floating wind turbine, comprising a wind tunnel, a multi-degree-of-freedom motion platform, a scaled-down model of the wind turbine, and a data acquisition controller, characterized in that, The multi-degree-of-freedom motion platform is set on the bottom surface of the wind tunnel test section, and an incoming wind speed measuring device is set at the entrance of the wind tunnel test section. The scaled-down model of the wind turbine includes a tower, a nacelle at the top of the tower, and a rotor at the front of the nacelle. The tower is fixedly connected to a motion platform at its base via force sensors. The rotor includes a rotor shaft, several pitch-adjustable wind turbine blades, and a fairing. Each blade has a pitch adjustment device at its root for adjusting the pitch angle. Each blade has several spaced pressure measurement sections along its span, each with multiple pressure measurement holes. Multiple pressure measurement tubes, corresponding to and connected to each pressure measurement hole, are located inside the blade cavity. The fairing contains a pressure scanning valve for collecting blade pressure data, with each channel of the pressure scanning valve corresponding to each pressure measurement tube. The nacelle houses a load motor driven to the rear end of the rotor shaft, and the rotor shaft is equipped with a speed and torque sensor. The data acquisition controller is communicatively connected to the motion platform, each pitch adjustment device, the load motor, the incoming wind speed measurement device, the pressure scanning valve, the speed and torque sensor, and the force sensor. It is used to collect the incoming wind speed at the wind tunnel test section inlet, the pressure data from the pressure measuring holes of each wind turbine blade, the speed and torque data of the wind turbine main shaft, and the thrust data of the tower. It is also used to control and adjust the attitude of the motion platform, the pitch angle of each wind turbine blade, and the speed of the load motor. Under static test conditions, the pressure data from the pressure measuring holes are processed to calculate the tangential and normal forces per unit length along the chord direction of each pressure measuring section, and then the tangential and normal forces per unit length of each pressure measuring section on the wind turbine plane are calculated. The relationship model between the force on the pressure measuring section and the wind turbine thrust torque is established by fitting the least squares method. Under dynamic test conditions, based on the fitted relationship model between the force on the pressure measurement section and the thrust torque of the wind turbine, the dynamic thrust F of the wind turbine under platform motion is calculated based on the pressure data from the pressure measurement orifice. x-dyno and torque T dyno The power coefficient C under different operating conditions was calculated. p and thrust coefficient C t Furthermore, the C-axis of the scaled-down model of the wind turbine during the platform's dynamic motion was plotted. p -λ、C t -λ curves are used to evaluate the dynamic aerodynamic performance of wind turbines, where λ is the tip speed ratio. The wind turbine includes at least a hub, several wind turbine blades with several pressure measuring holes evenly distributed circumferentially on the hub, and a fairing fixedly disposed at the front end of the hub.

2. The device for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine as described in claim 1, characterized in that, The multi-degree-of-freedom motion platform is selected as a six-degree-of-freedom motion platform to simulate the six-degree-of-freedom response of a floating wind turbine in the ocean, providing the required motion response for the wind turbine model.

3. The device for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine as described in claim 1, characterized in that, In dynamic test conditions, the force sensor and speed and torque sensor are removed, and only the pressure measurement data obtained from the pressure measurement section is used to obtain the dynamic thrust and torque.

4. A test method for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine, based on the apparatus for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine as described in any one of claims 1-2, characterized in that, The experimental method includes the following steps when implemented: SS1. Static and Dynamic Test Condition Design Based on the actual operating conditions of wind turbines at sea, multiple static test conditions are designed by changing the incoming wind speed, rotor speed, and / or blade pitch angle while keeping the multi-degree-of-freedom motion platform stationary. This allows for the measurement of the aerodynamic performance of the scaled-down model of the wind turbine under different static test conditions. Simultaneously, by applying motion excitation to the multi-degree-of-freedom motion platform, multiple dynamic test conditions are designed by changing the motion frequency and amplitude of the motion platform, the incoming wind speed, rotor speed, and / or blade pitch angle. This allows for the measurement of the aerodynamic performance of the scaled-down model of the wind turbine under different dynamic test conditions. SS2. Initial Parameter Settings for Static Test Conditions According to the static test conditions designed in step SS1, the initial operating parameters of the test device are preset, and the wind tunnel and the scaled-down model of the wind turbine are started in sequence according to the preset initial operating parameters until the operating state of the test device stabilizes and the design static test conditions are entered into the formal testing stage. SS3. Synchronous Acquisition of Unit Control and Data Under static test conditions, based on the data acquisition controller, the load motor is adjusted to run within the set speed range, and various data from the force sensor, speed and torque sensor, incoming wind speed measuring device, and pressure scanning valve are collected simultaneously, including at least thrust, torque, speed, incoming wind speed, and pressure data from the pressure measuring holes of each wind turbine blade. SS4. Construction of the Pressure Measurement Data-Thrust Torque Calculation Model Based on the pressure data from the pressure measurement holes of wind turbine blades under static test conditions, and after calculating the chordal tangential force and normal force per unit length of each pressure measurement section, the torsion angle of each pressure measurement section is combined to project and calculate the tangential force and normal force per unit length of each pressure measurement section in the wind turbine plane. Finally, the tangential force and normal force data of all pressure measurement sections are fitted as a whole based on the least squares method to establish a relationship model between the force on the pressure measurement section and the thrust and torque of the wind turbine under static test conditions, thereby converting the pressure data measured on the blade surface into the thrust and torque of the wind turbine. SS5. Setting Operating Parameters for Dynamic Test Conditions Based on the dynamic test conditions designed in step SS1, the scaled-down model of the wind turbine and the multi-degree-of-freedom motion platform are controlled synchronously, and various operating parameters are adjusted, including setting the wind tunnel incoming wind speed, wind turbine speed, blade pitch angle, motion frequency and motion amplitude of the motion platform, test duration, control time step and initial values ​​of each sensor, until the operating state of the test device stabilizes to the dynamic test conditions. SS6. Obtaining dynamic thrust torque using blade surface pressure data The data acquisition controller synchronously and in real time collects the following data at different times: downflow wind speed v, multi-degree-of-freedom displacement of the platform, wind turbine speed Ω, and pressure data P measured by the pressure measuring holes on each wind turbine blade. 11 ...P ik To ensure the consistency of various data over time, a time-strictly corresponding dataset was obtained. Based on the pressure measurement data-thrust-torque calculation model constructed in step SS4, the thrust F of the wind turbine at different times under dynamic test conditions was calculated. x-dyno and torque T dyno Then, the aerodynamic thrust and torque at each moment are calculated; SS7. Dynamic Performance Curve C p -λ、C t -λ plotting The tip speed ratio was calculated based on the rotor speed Ω and incoming wind speed v collected at different times in step SS6. And based on the calculated thrust F x-dyno and torque T dyno The power coefficient C under different operating conditions was calculated. p and thrust coefficient C t Furthermore, the C-axis of the scaled-down model of the wind turbine during the platform's dynamic motion was plotted. p -λ、C t -λ curves are used to evaluate the dynamic aerodynamic performance of wind turbines: Where λ is the tip speed ratio, Ω is the rotor speed, R is the rotor radius, A is the swept area of ​​the rotor, v is the incoming air velocity, and ρ is the air density.

5. The test method for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine according to claim 4, characterized in that, In step SS2 above, under static test conditions, the initial operating parameters include at least the incoming wind speed, load motor parameters, blade pitch angle, and initial values ​​of each sensor. By setting these initial operating parameters, it is ensured that the various operating conditions during the test meet the design test conditions, thus guaranteeing the accuracy and reliability of the test data.

6. The test method for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine according to claim 4, characterized in that, In step SS3 above, a PID control algorithm is used to regulate the load motor, and the load motor is adjusted and tuned according to the following sub-steps: SS31. Identify and model the load motor winding. First, perform preliminary adjustment and identification of the load motor to obtain the basic parameters of the winding. Then, apply positive and negative currents with varying amplitudes to the winding to induce stable oscillations until a stable oscillation with a fixed amplitude is obtained. Repeat this experiment at different frequencies and measure the oscillation characteristics of the winding at each frequency to obtain accurate model parameters of the motor winding. Establish a dynamic response model of the motor winding and use these model parameters to determine the initial settings of the controller to ensure the stable operation and adjustment accuracy of the subsequent control system. SS32. Map the model parameters of the winding to derive the controller parameters. Based on the identification and modeling results of sub-step SS31, use the obtained winding model parameters to calculate and determine the parameters of the PID control algorithm. By adjusting the proportional, integral and derivative parameters, optimize the response characteristics of the controller so that the controller can accurately regulate the motor speed. SS33. Verify the final control loop structure. Based on the parameters of the PID control algorithm determined in sub-step SS32, conduct actual operation tests on the load motor. By monitoring the speed and response of the load motor, observe the stability and adjustment accuracy of the load motor within the set speed range to ensure that the control loop maintains efficient and reliable control performance under various test conditions.

7. The test method for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine according to claim 4, characterized in that, In step SS3 above, the data acquisition controller is communicatively connected to the force sensor, speed and torque sensor, load motor, and pressure scanning valve. While controlling the speed of the load motor, it synchronously and in real time acquires various types of data, including at least thrust. Torque T sensor Rotational speed (Ω), incoming wind speed (v), and pressure data (P) measured by pressure gauges on each wind turbine blade. 11 ...P ik , where P ik This represents the pressure data from the k-th pressure measuring hole at the i-th pressure measuring section of the wind turbine blade.

8. The test method for measuring the dynamic aerodynamic performance of a scaled-down model of a floating wind turbine according to claim 4, characterized in that, In step SS5 above, when setting the dynamic test conditions, first set the wind tunnel inflow wind speed, wind turbine speed, and blade pitch angle. After the scaled-down model of the wind turbine unit is running stably and the inflow is stable, set the attitude of the platform movement and adjust its movement frequency and amplitude.

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