Wind turbine generator load test method, system and equipment and storage medium

Abstract

The invention discloses a wind turbine generator load test method, system and device and a storage medium, the operation state of a wind turbine generator is divided into a steady state operation and a transient event, the steady state operation comprises a power generation state and a shutdown state, and corresponding capture matrixes are set for the power generation state, the shutdown state and the transient event; meteorological data of the wind turbine generator and load data of different parts of the wind turbine generator are obtained according to the time sequence, and the load data meet the requirement of the capture matrix; and calculating to obtain load characteristics of different parts of the wind turbine generator under the conditions of steady-state operation and transient events in different meteorological environments. The mechanical load characteristics of the wind turbine generator in steady-state operation and transient event conditions are determined, and the load condition of the offshore wind turbine generator in the external environment is accurately calculated. The mechanical load characteristics of the wind turbine generator in steady-state operation and transient event conditions are determined, and the load condition of the offshore wind turbine generator in the external environment is accurately calculated.

Description

Technical Field

[0001] This invention belongs to the field of wind turbine generators and relates to a method, system, equipment and storage medium for testing the load of wind turbine generators. Background Technology

[0002] The components and foundations of wind turbines have a significant impact on the operational safety of the units. In recent years, offshore wind power has developed rapidly, with both installed capacity and unit capacity continuously increasing. Offshore wind turbines are affected by various factors such as wind, waves, and currents, leading to a greater fatigue load compared to onshore wind turbines. The increasing unit capacity of offshore wind turbines places increasingly higher demands on the lifespan of components and foundations, making the safe operation of offshore wind turbines within their design life a crucial concern. A comprehensive understanding and accurate quantification of loads are extremely important in the structural design of wind turbines. During the design phase, aeroelastic models and standards can be used to predict loads. However, due to limitations and uncertainties in these models, verification through load measurements is usually necessary.

[0003] However, current laboratory and simulation tests may not be able to fully simulate the various load conditions under actual operating conditions, leading to discrepancies between test results and actual performance. Furthermore, actual field measurements, due to the complex and variable operating environment of wind turbines, are affected by various environmental factors, resulting in inaccurate and unreliable results. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method, system, equipment and storage medium for testing wind turbine loads, to determine the mechanical load characteristics of wind turbines under steady-state operation and transient events, and to accurately calculate the load conditions of offshore wind turbines under the external environment.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A method for testing the load of a wind turbine generator includes the following steps:

[0007] The operating states of wind turbine units are divided into steady-state operation and transient events, and corresponding capture matrices are set for steady-state operation and transient events;

[0008] Meteorological data of wind turbines and load data of different parts of wind turbines are acquired in time sequence, and the load data is filtered based on the capture matrix.

[0009] Based on the selected load data, the load characteristics of different parts of the wind turbine under steady-state operation and transient events under different meteorological conditions were calculated.

[0010] Preferably, before acquiring load data, strain gauges measuring loads at different parts of the wind turbine are calibrated.

[0011] Preferably, the load data at different parts of the wind turbine are obtained as follows: the bending moment at the blade root is measured using a T-type strain gauge full-bridge connection, and the torque is measured using a V-type strain gauge full-bridge connection; the bending moment at the tower is measured using a T-type strain gauge full-bridge connection, and the torque at the tower top is measured using a V-type strain gauge full-bridge connection.

[0012] Preferably, steady-state operation includes power generation and shutdown states. For the power generation state, the capture matrix rule is as follows:

[0013] For greater than v in And less than or equal to v r For each wind speed range of -2 m / s, collect 20 10-minute time series data points; or at least one turbulence range with a value greater than 5%, in which there are 6 10-minute time series data points.

[0014] For greater than v r -2m / s and less than or equal to v r For each wind speed range of +2m / s, at least 20 time series data points should be collected;

[0015] For greater than v r +2m / s and less than or equal to v r For each wind speed range of +4 m / s, at least 10 time series data points should be collected;

[0016] For the halted state, the rules for the capture matrix are as follows:

[0017] The wind turbine is normally in operation when the wind speed exceeds the cut-out wind speed v out Under the operating conditions, one time series data point was collected at yaw errors of 30°, 0°, and -30° respectively.

[0018] For transient events, the capture matrix rule is: data acquisition must be repeated at least 3 times.

[0019] Preferably, the FFT algorithm is used to perform spectral analysis on the load time series of the wind turbine under steady-state operation and transient event conditions.

[0020] Preferably, the rainflow counting method is used to statistically analyze the 1Hz equivalent fatigue load and obtain the level of the 1Hz equivalent fatigue load under different wind speeds.

[0021] Preferably, load sample data of normal power generation during the load cumulative spectrum statistical test period are used.

[0022] A wind turbine load testing system, comprising:

[0023] State classification module: used to classify the operating state of wind turbine into steady-state operation and transient events. Steady-state operation includes power generation state and shutdown state. The module sets corresponding capture matrices for power generation state, shutdown state and transient events.

[0024] Load acquisition module: used to acquire meteorological data of wind turbine and load data at different parts of wind turbine in a time sequence, and the load data meets the requirements of the capture matrix;

[0025] Load analysis module: used to calculate the load characteristics of different parts of the wind turbine under steady-state operation and transient events under different meteorological conditions.

[0026] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the wind turbine load testing method.

[0027] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the wind turbine load testing method.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] This invention divides the operating states of wind turbines and sets targeted capture matrices, which can be used to specify the minimum requirements for data measurement under each load condition, ensuring the reliability of the collected data. It collects meteorological data, synchronizes the load conditions of different parts of the wind turbine, and analyzes and processes the data to determine the mechanical load characteristics of the wind turbine under steady-state operation and transient events, accurately calculating the load conditions of offshore wind turbines under the external environment. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the components of the basic load of the wind turbine generator according to an embodiment of the present invention;

[0031] Figure 2 This is a side view of the mounting position of the blade root strain gauge according to the present invention;

[0032] Figure 3 This is a cross-sectional view of the installation position of the blade root strain gauge of the present invention;

[0033] Figure 4 This is a schematic diagram of the load testing system of the present invention. Detailed Implementation

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terms “installation,” “connection,” and “linkage” should be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; a mechanical connection, an electrical connection, or a connection that allows communication; a direct connection or an indirect connection via an intermediate medium; or a connection within two elements or an interaction between two elements. The term “and / or” as used herein includes any and all combinations of one or more of the associated listed items. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0037] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0038] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0039] To more accurately calculate the load conditions of offshore wind turbines under external environmental conditions, this invention's load testing scheme is formulated based on relevant load testing standards. By collecting meteorological parameters such as nacelle wind speed and direction, and simultaneously recording parameters such as blade load, tower load, SCADA power value, and turbine output status signals, the mechanical load characteristics of the wind turbine under steady-state operation and transient events are determined through analysis and processing.

[0040] The testing system mainly consists of the following components: one load acquisition system located in the hub, one load acquisition system located at the top of the tower, one load acquisition system located on the platform in the middle of the tower, and one load acquisition system located on the platform at the bottom of the tower. Each part of the testing system is synchronized with an industrial server on-site. If the time of any part of the testing system deviates from the time of the industrial server, the data acquisition unit will immediately correct the time of the deviated part to maintain consistency with the industrial server's time. The entire system communicates via CAN and fiber optics, and the acquired data is stored on the on-site server. Bending moment and torque are measured using T-type full-bridge strain gauges and V-type full-bridge strain gauges, respectively. The unit's control signals are output to the acquisition unit on the platform at the bottom of the tower via the unit's PLC.

[0041] After the data acquisition system was set up, strain gauges at key locations such as the turbine blades and tower were calibrated to determine the stress-load relationship at each location. The calibration results, statistical values, and time series were checked, and valid data for normal turbine power generation were obtained after data screening. Based on the data from normal power generation, statistical results of environmental parameters, wind turbine control parameters, load statistics at key locations of the wind turbine, and extrapolated cumulative load spectra were calculated for all operating conditions and specific turbulent conditions.

[0042] The measured load time history is classified in two ways: one is to treat it as a steady-state operating load, and the other is to treat it as a transient event load. The steady-state operating time series is assumed to be 10 minutes.

[0043] Steady-state load measurement conditions include both power generation and shutdown. During power generation, the cut-in wind speed and cut-out wind speed or v should be measured. r Measurements should be taken between +4 m / s (depending on wind turbine configuration). When measuring the load on the wind turbine during shutdown, measurements should be taken under the highest possible wind speed conditions.

[0044] The load measurement conditions during transient processes include four types: startup, normal shutdown, emergency shutdown, and power grid failure.

[0045] The capture matrix is ​​used to organize and manage the time series of measurements. This matrix serves two purposes: first, it can be used to specify the minimum requirements for data under each load measurement condition; second, it can be used to apply for a test database to demonstrate whether the minimum data requirements have been met. For each specific test, the number of capture matrix partitions must be matched to the technical parameters of the wind turbine (e.g., cut-in wind speed v). in and rated wind speed v r ).

[0046] (1) Power generation status

[0047] For the power generation operation of pitch-controlled wind turbines, as shown in Table 1, the capture matrix should be controlled as follows:

[0048] 1) For values ​​greater than v in And less than or equal to v r For each wind speed range of -2 m / s, 20 10-minute time series data points should be collected, or at least one turbulent range with a value greater than 5% should have 6 10-minute time series data points.

[0049] 2) For values ​​greater than v r -2m / s and less than or equal to v r For each wind speed range of +2 m / s, at least 20 time series data should be collected.

[0050] 3) For values ​​greater than vr +2m / s and less than or equal to v r For each wind speed range of +4 m / s, at least 10 time series data should be collected.

[0051] Table 1. Capture Matrix for Normal Power Generation of Pitch-Controlled Wind Turbines

[0052]

[0053] (2) Shutdown status

[0054] The shutdown load measurement condition refers to the normal operation of the wind turbine when the wind speed exceeds v. out The operating conditions (stationary or idling). One time series data should be collected at yaw errors of 30°, 0° and -30°, as shown in Table 2.

[0055] If the number of datasets collected exceeds the minimum number listed in the capture matrix, only the minimum number of datasets is required.

[0056] Table 2. Capture Matrix in Shutdown State

[0057]

[0058] (3) Transient events

[0059] The capture matrices for transient events are given in Tables 3 and 4. Table 3 shows the minimum number of repetitions and the minimum wind speed range. The wind speed is the wind speed at the start of the transient event. Emergency shutdown and grid fault tests should be performed at rated power.

[0060] Table 3. Capture matrix for normal transient events

[0061]

[0062] Table 4. Capture Matrix for Abnormal Transient Events

[0063]

[0064] Measured physical quantity

[0065] The primary purpose of mechanical load measurement is to verify the design load model of the wind turbine being tested. This is achieved through repeated aeroelastic analyses and adjustments to model parameters to match actual field conditions. Therefore, a thorough description of meteorological and operational parameters is crucial to enable the comparison of measured and simulated loads.

[0066] To describe the characteristics of wind turbine loads, the relevant physical quantities that have been determined can be divided into:

[0067] (1) Loads (e.g., blade loads, rotor loads, and tower loads);

[0068] (2) Meteorological parameters (e.g., wind speed and direction, air density);

[0069] (3) Operating parameters (e.g., power, speed, pitch angle, yaw angle, wind turbine azimuth).

[0070] The required and recommended measurements listed in Tables 5-8 are essential for model validation. Recommended measurement channels help explain discrepancies between simulated and measured data. Tables 5, 7, and 8 describe the minimum measurement requirements. These requirements are valid for variable-pitch wind turbines with tubular steel towers and conventional blades. For special designs, such as hybrid towers, hybrid blades, two-part connected blades, blades with active aerodynamic controllers, seesaw hubs, etc., additional measurements (e.g., flapping state, yaw angle) may be required for model validation.

[0071] (1) Load

[0072] Table 5 lists the basic loads to be measured. From these basic loads at key locations on the wind turbine structure, the relevant loads in all wind turbines can be derived. Figure 1 The components of the basic load are also given.

[0073] Table 5 Basic Loads of Wind Turbine Units

[0074] load Importance <![CDATA[Blade root flapping moment (M bf )]]> One leaf must be measured; measurements of the other leaves are recommended. <![CDATA[Flapping moment at blade root (M be )]]> One leaf must be measured; measurements of the other leaves are recommended. <![CDATA[Pitch moment of wind turbine rotor (M tilt )]]> Required <![CDATA[Yaw moment of wind turbine rotor (M yaw )]]> Required <![CDATA[Wind turbine torque (M x ))]]> Required <![CDATA[Normal moment at the tower bottom (M tn )]]> Required <![CDATA[Tower bottom transverse moment (M tl )]]> Required

[0075] For wind turbines with a rated power output greater than 1500kW and a rotor diameter greater than 75m, additional physical quantities are required to be measured, as shown in Table 6. Signals for measuring the physical quantities in Table 6 should be installed, and if a signal failure occurs, it should be repaired when feasible.

[0076] Measurements are required to be performed on the second blade to verify similar performance and correct calibration. Measurements performed on the second blade may not need to cover the entire capture matrix.

[0077] Table 6 Additional Loads for Wind Turbine Units with Rated Power Output Greater Than 1500kW and Rotor Diameter Greater Than 75m

[0078] load Importance Blade flapping moment distribution Two blades must be measured; measurements of the other blades are recommended. Blade oscillation bending moment distribution Two blades must be measured; measurements of the other blades are recommended. Leaf root waving bending moment Two blades must be measured; measurements of the other blades are recommended. Blade root oscillation bending moment Two blades must be measured; measurements of the other blades are recommended. Blade torsional frequency and damping recommend Pitch Drive Load One blade must be measured Tower top normal acceleration Required when used for controller feedback Lateral acceleration at the top of the tower Required when used for controller feedback Normal moment in tower recommend Lateral moment in the tower recommend Tower top normal moment Required Lateral moment at the top of the tower Required Tower torque Required

[0079] (2) Meteorological parameters

[0080] Table 7 lists the meteorological parameters that will need to be measured in the load measurement scheme.

[0081] Table 71 Meteorological Parameters

[0082]

[0083]

[0084] (3) Wind turbine operating parameters

[0085] Table 8 lists the operating parameters to be tested.

[0086] Table 2 Wind Turbine Unit Operating Parameters

[0087]

[0088] In order to properly categorize the recorded data, wind turbine status information (e.g., grid connection, emergency shutdown, protection system activation, etc.) is necessary.

[0089] The wind turbine status signal should indicate online / offline status and fault / non-fault status. For situations where multiple operating modes exist during load measurement activities (e.g., noise reduction mode, load control mode), it is also recommended to obtain a signal to allow for automatic detection of those different modes.

[0090] Testing system and testing equipment.

[0091] (1) Blade strain gauge installation location and strain gauge bridging instructions

[0092] enter Figure 2 and Figure 3 As shown, the blade strain gauges are installed on the circumferential surface near the blade root, with four sets of strain gauges evenly distributed in a ring, forming an angle with the pitch zero mark. The bending moment at the blade root is tested using a full-bridge connection of T-type strain gauges, and the torque is tested using a full-bridge connection of V-type strain gauges.

[0093] (2) Installation location of strain gauges on the tower and description of strain gauge bridging

[0094] The bending moment of the tower was tested using a full-bridge connection of T-type strain gauges. TBB_56_236 and TBB_146_326 strain gauges measured the bending moment in two orthogonal directions at the bottom of the tower, respectively; TMUP_51_231 and TMUP_141_321 strain gauges measured the bending moment in two orthogonal directions in the upper middle part of the tower, respectively; TMDOWN_51_231 and TMDOWN_51_231 strain gauges measured the bending moment in two orthogonal directions in the lower middle part of the tower, respectively; TTB_41_221 and TTB_131_311 strain gauges measured the bending moment in two orthogonal directions in the middle of the tower, respectively. TTT_41_221 was used for measuring the torque at the top of the tower, and a V-type full-bridge connection was used.

[0095] (3) Data Acquisition System

[0096] This test included load and unit control parameter measurements. The test system (DAS) mainly consists of the following parts:

[0097] 1) One Campbell CR5000 digital acquisition unit located in the wheel hub

[0098] 2) One Campbell CR3000 digital acquisition unit located on the tower top platform.

[0099] 3) One Campbell CR3000 digital data acquisition unit located on the upper platform of the tower.

[0100] 4) One Campbell CR3000 digital data acquisition unit located on the lower platform of the tower.

[0101] 5) One Campbell CR3000 digital acquisition unit located on the platform at the bottom of the tower.

[0102] The various parts of the testing system are synchronized with a field industrial server. A schematic diagram of the testing system is shown below. Figure 4 As shown.

[0103] Meteorological parameters are measured by sensors installed on the wind measurement tower. The data is collected by a Campbell CR3000 digital data logger and transmitted to a server at the bottom of the tower via serial communication.

[0104] Load and unit control parameters are acquired by Campbell digital acquisition units located on the unit. The entire system communicates via serial port and fiber optic cable. Data is acquired by the CR3000 digital acquisition unit on the tower base platform and transmitted to the field server for storage via TCP / IP protocol. Acquisition modules located in the nacelle, tower top, and tower base transmit signals via fiber optic cable through serial-to-FIBER conversion modules to mitigate the impact of electromagnetic interference (EMI) on the signals.

[0105] Bending moment and torque were measured using T-type full-bridge strain gauges and V-type full-bridge strain gauges, respectively.

[0106] The loads at the blade root and blade cross-section, as well as the rotor azimuth, are collected by a CR5000 digital data acquisition unit installed in the hub. The signal line is connected wirelessly via Wi-Fi.

[0107] The bending moment and torque at the top of the tower were measured using a CR3000 digital data acquisition unit installed on the platform at the top of the tower.

[0108] The bending moment at the upper part of the tower was measured using a CR3000 digital data acquisition unit installed on the platform in the tower.

[0109] The bending moment at the lower part of the tower was measured using a CR3000 digital data acquisition unit installed on the platform in the tower.

[0110] The bending moment at the base of the tower was measured using a CR3000 digital data acquisition unit installed on the platform at the base of the tower.

[0111] The unit's control signals are output to the CR3000 digital acquisition unit on the tower base platform via the unit's PLC.

[0112] Data processing.

[0113] (1) Leaf root bending moment calibration

[0114] The blade root bending moment is calibrated as follows: For the blade under test, the rotor is slowly rotated at low wind speeds with the blade angles at 0° and 90° respectively. The bending moment is derived by using the peak and valley values ​​of the signals from the oscillation and flapping directions when the blade is horizontal on both sides, as well as the bending moment generated by the blade's own weight at the corresponding positions. The following relationship is assumed between the signals and the load:

[0115]

[0116] Where M be and M bf These represent the bending moments in the oscillation and swing directions, respectively, while S... e S f S represents the signals output by the strain gauges in the oscillation and flapping directions, respectively. e0 S f0 Let be the average values ​​of the signals, and the conversion relationship be obtained according to the following formula:

[0117]

[0118] (2) Tower top bending moment calibration

[0119] The tower top bending moment was calibrated as follows: The theoretical load was calculated using the material and geometric properties of the patch section, combined with the bridge connection method. By connecting large resistors of different resistance values ​​in parallel to the bridge arms, the slope in the conversion relationship was derived using linear regression. The zero point was determined by the average value of the strain gauge signals during one yaw cycle. The conversion formula is as follows:

[0120] M=K s ×S+Z s

[0121] Where M is the bending moment and S is the signal output value; then, based on the yaw angle, the loads of the two sets of strain gauges are converted into forward and backward bending moments in the nacelle coordinate system, as follows:

[0122]

[0123] M d1 and M d2 θ represents the load values ​​measured by two sets of orthogonal strain gauges.yaw Represents the yaw angle, θ d1 and θ d2 These are the yaw angles corresponding to the peak values ​​of the yaw calibration signal.

[0124] (3) Tower top torque calibration

[0125] The tower top torque is calibrated as follows: The theoretical load is calculated using the material and geometric properties of the patch cross-section, combined with the bridge connection method. By connecting large resistors of different resistance values ​​in parallel to the bridge arms, the slope in the conversion relationship is derived using linear regression. The zero point is determined by the average value of the strain gauge signal during yaw. The conversion formula is as follows:

[0126] M tt_tor =K s ×S+Z n

[0127] S represents the output value of the torque signal.

[0128] (4) Bending moment calibration in the upper part of the tower

[0129] The bending moment in the upper part of the tower was calibrated as follows: The theoretical load was calculated using the material and geometric properties of the patch section, combined with the bridge connection method. By connecting large resistors of different resistance values ​​in parallel to the bridge arms, the slope in the transformation relationship was derived using linear regression. The zero point was determined by the average value of the strain gauge signal during one yaw cycle. The transformation formula is as follows:

[0130] M=K s ×S+Z s

[0131] Where M is the bending moment and S is the signal output value; then, based on the yaw angle, the loads of the two sets of strain gauges are converted into forward and backward bending moments in the nacelle coordinate system, as follows:

[0132]

[0133] M d1 and M d2 θ represents the load values ​​measured by two sets of orthogonal strain gauges. yaw Represents the yaw angle, θ d1 and θ d2 These are the yaw angles corresponding to the peak values ​​of the yaw calibration signal.

[0134] (5) Bending moment calibration of the lower part of the tower

[0135] The bending moment in the lower part of the tower was calibrated as follows: The theoretical load was calculated using the material and geometric properties of the patch section, combined with the bridge connection method. By connecting large resistors of different resistance values ​​in parallel to the bridge arms, the slope in the transformation relationship was derived using linear regression. The zero point was determined by the average value of the strain gauge signal during one yaw cycle. The transformation formula is as follows:

[0136] M=K s ×S+Z s

[0137] Where M is the bending moment and S is the signal output value; then, based on the yaw angle, the loads of the two sets of strain gauges are converted into forward and backward bending moments in the nacelle coordinate system, as follows:

[0138]

[0139] M d1 and M d2 θ represents the load values ​​measured by two sets of orthogonal strain gauges. yaw Represents the yaw angle, θ d1 and θ d2 These are the yaw angles corresponding to the peak values ​​of the yaw calibration signal.

[0140] (6) Tower base bending moment calibration

[0141] The bending moment at the base of the tower was calibrated as follows: The theoretical load was calculated using the material and geometric properties of the patch section, combined with the bridge connection method. By connecting large resistors of different resistance values ​​in parallel to the bridge arms, the slope in the transformation relationship was derived using linear regression. The zero point was determined by the average value of the strain gauge signals during one yaw cycle. The transformation formula is as follows:

[0142] M=K s ×S+Z s

[0143] Where M is the bending moment and S is the signal output value; then, based on the yaw angle, the loads of the two sets of strain gauges are converted into forward and backward bending moments in the nacelle coordinate system, as follows:

[0144]

[0145] M d1 and M d2 θ represents the load values ​​measured by two sets of orthogonal strain gauges. yaw Represents the yaw angle, θ d1 and θ d2 θ d2 These are the yaw angles corresponding to the peak values ​​of the yaw calibration signal.

[0146] Post-processing methods

[0147] (1) Wind shear

[0148] Wind shear α at the height of the wind speed v at the center of the hub hub The wind speed at the lower blade tip anemometer was obtained by curve fitting according to the exponential wind profile formula.

[0149] The fitting formula is

[0150] v(z) / v hub =(z / z) hub )α

[0151] (2) Air density

[0152] The average air density over 10 minutes is calculated using the following formula:

[0153]

[0154] Where R0 is the dry gas constant, with a value of 287.05 J / (kgK); R w The gas constant for water vapor is 461.5 J / (kgK); T 10min The average temperature over 10 minutes is expressed in Kelvin (K); B 10min The pressure is the average value over 10 minutes, in Pa; Φ is the relative humidity (0%–100%); P w The vapor pressure is given by the formula P. w =0.0000205exp(0.0631846×T) 10min ).

[0155] (3) Turbulence

[0156] For a 10-minute wind speed sequence, the overall slow trend of change increases turbulence intensity. The turbulence intensity used in this application is not detrended, but the ratio of the detrended turbulence intensity to the original turbulence intensity is presented as a turbulence intensity trend indicator. For detrending, the method chosen in this application is as follows: the original 10-minute wind speed time series is divided into 10 1-minute time series; the average value of each 1-minute wind speed time series is subtracted, and the series is then concatenated to calculate the turbulence intensity.

[0157] (4) Spectrum Analysis

[0158] This application uses the FFT algorithm (rectangular window) to perform spectral analysis on the load time series.

[0159] (5) Equivalent fatigue load

[0160] The fatigue load cycle count was performed using the rainflow counting method defined in ASTM standard E1049-85 (Reapproved 2005). The equivalent fatigue load (EQL) at 1 Hz was calculated using the following formula:

[0161]

[0162] Among them, f i N represents the load corresponding to the i-th load interval; i N represents the number of load cycles in the i-th load interval; ref is the selected reference number; m is the material coefficient.

[0163] This application uses 10 minutes of sample data to provide data at different wind speeds, 1Hz (N) ref =600) equivalent fatigue load level, the load cycle is full amplitude loading.

[0164] (6) Fatigue load cumulative spectrum

[0165] The load cumulative spectrum is a statistical test of load sample data during normal power generation. The load interval is divided into 128 intervals, and half-cycles are statistically analyzed at 0.5. This load cumulative spectrum cannot be used as a basis for evaluating the fatigue life of the unit.

[0166] Finally, the mechanical load characteristics of different parts of the wind turbine under steady-state operation and transient events were obtained.

[0167] The following are embodiments of the apparatus of the present invention, which can be used to execute embodiments of the method of the present invention. For details not omitted in the apparatus embodiments, please refer to the embodiments of the method of the present invention.

[0168] In another embodiment of the present invention, a wind turbine load testing system is provided. This wind turbine load testing system can be used to implement the above-mentioned wind turbine load testing method. Specifically, the wind turbine load testing system includes a state classification module, a load acquisition module, and a load analysis module.

[0169] The state classification module is used to divide the operating state of wind turbines into steady-state operation and transient events. Steady-state operation includes power generation state and shutdown state. Corresponding capture matrices are set for power generation state, shutdown state and transient events.

[0170] The load acquisition module is used to acquire meteorological data of the wind turbine and load data at different parts of the wind turbine in a time sequence, and the load data meets the requirements of the capture matrix.

[0171] The load analysis module is used to calculate the load characteristics of different parts of the wind turbine under steady-state operation and transient events under different meteorological conditions.

[0172] In another embodiment of the present invention, a terminal device is provided, the terminal device including a processor and a memory, the memory being used to store a computer program, the computer program including program instructions, and the processor being used to execute the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, and is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to realize the corresponding method flow or corresponding function. The processor described in this embodiment of the invention can be used in the operation of a wind turbine load testing method, including: dividing the wind turbine operating state into steady-state operation and transient events, with steady-state operation including power generation state and shutdown state; setting corresponding capture matrices for power generation state, shutdown state, and transient events; acquiring meteorological data of the wind turbine and load data at different parts of the wind turbine according to the time sequence, with the load data meeting the requirements of the capture matrix; and calculating the load characteristics of different parts of the wind turbine under steady-state operation and transient event conditions under different meteorological environments.

[0173] In another embodiment, the present invention also provides a computer-readable storage medium (Memory), which is a memory device in a terminal device for storing programs and data. It is understood that the computer-readable storage medium here may include both the built-in storage medium in the terminal device and extended storage media supported by the terminal device. The computer-readable storage medium provides storage space that stores the terminal's operating system. Furthermore, the storage space also stores one or more instructions suitable for loading and execution by a processor, which may be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here may be high-speed RAM or non-volatile memory, such as at least one disk storage device.

[0174] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the wind turbine load testing method in the above embodiments. One or more instructions in the computer-readable storage medium are loaded and executed by the processor as follows: the wind turbine operating state is divided into steady-state operation and transient events, the steady-state operation includes power generation state and shutdown state, and corresponding capture matrices are set for power generation state, shutdown state and transient events; meteorological data of the wind turbine and load data at different parts of the wind turbine are acquired in time sequence, and the load data meets the requirements of the capture matrix; the load characteristics of different parts of the wind turbine under steady-state operation and transient event conditions under different meteorological environments are calculated.

[0175] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0176] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0177] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0178] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0179] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0180] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed inventive subject matter.

Claims

1. A method for testing the load of a wind turbine generator set, characterized in that, Includes the following processes: The operating states of wind turbine units are divided into steady-state operation and transient events, and corresponding capture matrices are set for steady-state operation and transient events; Meteorological data of wind turbines and load data of different parts of wind turbines are acquired in time sequence, and the load data is filtered based on the capture matrix. Based on the selected load data, the load characteristics of different parts of the wind turbine under steady-state operation and transient events under different meteorological conditions were calculated.

2. The wind turbine load testing method according to claim 1, characterized in that, Before acquiring load data, strain gauges measuring loads at different parts of the wind turbine are calibrated.

3. The wind turbine load testing method according to claim 1, characterized in that, The load data at different parts of the wind turbine were obtained as follows: the bending moment at the blade root was measured using a full-bridge connection of T-type strain gauges, and the torque was measured using a full-bridge connection of V-type strain gauges; the bending moment at the tower was measured using a full-bridge connection of T-type strain gauges, and the torque at the tower top was measured using a full-bridge connection of V-type strain gauges.

4. The wind turbine load testing method according to claim 1, characterized in that, Steady-state operation includes power generation and shutdown states. For the power generation state, the rules for the capture matrix are as follows: For greater than v in And less than or equal to v r For each wind speed range of -2 m / s, collect 20 10-minute time series data points; or at least one turbulence range with a value greater than 5%, in which there are 6 10-minute time series data points. For greater than v r -2m / s and less than or equal to v r For each wind speed range of +2m / s, at least 20 time series data points should be collected; For greater than v r +2m / s and less than or equal to v r For each wind speed range of +4 m / s, at least 10 time series data points should be collected; For the halted state, the rules for the capture matrix are as follows: The wind turbine is normally in operation when the wind speed exceeds the cut-out wind speed v out Under the operating conditions, one time series data point was collected at yaw errors of 30°, 0°, and -30° respectively. For transient events, the capture matrix rule is: data acquisition must be repeated at least 3 times.

5. The wind turbine load testing method according to claim 1, characterized in that, The FFT algorithm was used to perform spectral analysis on the load time series of wind turbines under steady-state operation and transient event conditions.

6. The wind turbine load testing method according to claim 1, characterized in that, The rainflow counting method was used to statistically analyze the equivalent fatigue load at 1 Hz, and the level of the equivalent fatigue load at 1 Hz under different wind speeds was obtained.

7. The wind turbine load testing method according to claim 1, characterized in that, Load sample data of normal power generation during the test period were used by load cumulative spectrum statistical analysis.

8. A wind turbine load testing system, characterized in that, include: State classification module: used to classify the operating state of wind turbine into steady-state operation and transient events. Steady-state operation includes power generation state and shutdown state. The module sets corresponding capture matrices for power generation state, shutdown state and transient events. Load acquisition module: used to acquire meteorological data of wind turbine and load data at different parts of wind turbine in a time sequence, and the load data meets the requirements of the capture matrix; Load analysis module: used to calculate the load characteristics of different parts of the wind turbine under steady-state operation and transient events under different meteorological conditions.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the wind turbine load testing method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the wind turbine load testing method as described in any one of claims 1 to 7.

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