A method and system for determining the torsional frequency of a wind turbine drive train

Abstract

This application discloses a method and system for determining the torsional frequency of a wind turbine generator drivetrain. The method includes: determining the range of the torsional frequency of the wind turbine generator drivetrain based on a theoretical model of the wind turbine generator drivetrain; adding a wind turbine generator drivetrain torsional frequency identification module to the existing wind turbine generator control system; during wind turbine generator operation, turning the wind turbine generator drivetrain torsional frequency identification module on and off, adding or removing excitation torque in the normal operating torque command, and recording the operating speed data when the wind turbine generator drivetrain torsional frequency identification module is on and off; comparing the differences in the spectrum of the operating speed data when the wind turbine generator drivetrain torsional frequency identification module is on and off at different frequency points to obtain the torsional frequency of the wind turbine generator drivetrain. This application can identify the torsional frequency of a wind turbine generator drivetrain with high accuracy.

Description

Technical Field

[0001] This application relates to the field of wind turbine generator technology, and in particular to a method and system for determining the torsional frequency of a wind turbine generator drive chain. Background Technology

[0002] With the development of wind power generation technology and market demand, wind turbine generators are becoming larger and their blades are becoming longer. As a key transmission device in wind turbine generators that transmits force and motion, the performance of the transmission chain directly determines the reliability and safety of the entire unit.

[0003] Actual field operation of wind turbine generator sets shows that, due to mass production and subsequent operation modes, the torsional frequency of the wind turbine generator set transmission chain may deviate from the design value. The torsional frequency of the wind turbine generator set transmission chain is a key parameter for condition monitoring, and the accuracy of the parameter must be ensured. Summary of the Invention

[0004] In view of this, this application provides a method and system for determining the torsional frequency of a wind turbine generator drive chain, which automatically and accurately identifies the torsional frequency of the wind turbine generator drive chain, and identifies the torsional frequency of the wind turbine generator drive chain with high precision.

[0005] This application discloses a method for determining the torsional frequency of a wind turbine generator drive train, which includes:

[0006] Step 1: Based on the theoretical model of the wind turbine generator drive chain, determine the range of torsional frequencies of the wind turbine generator drive chain;

[0007] Step 2: Add a wind turbine drive chain torsion frequency identification module to the existing wind turbine control system;

[0008] Step 3: During the operation of the wind turbine generator set, turn the wind turbine generator set transmission chain torsional frequency identification module on and off respectively, add or remove the excitation torque in the normal operating torque command, and record the operating speed data when the wind turbine generator set transmission chain torsional frequency identification module is on and off; the operating speed data is the speed data sequence of the excitation torque when the wind turbine generator set transmission chain torsional frequency identification module is off and the speed data sequence of the excitation torque when the wind turbine generator set transmission chain torsional frequency identification module is on.

[0009] Step 4: Compare the differences in the spectrum of the operating speed data of the wind turbine generator drive chain torsion frequency identification module at different frequency points when the module is turned on and off, and obtain the torsion frequency of the wind turbine generator drive chain.

[0010] Further, step 1 includes:

[0011] Based on the theoretical model of the wind turbine drive train, the range of torsional frequencies of the wind turbine drive train is obtained. .

[0012] Further, step 2 includes:

[0013] The electromagnetic torque output by the original wind turbine generator control system and the excitation torque output by the wind turbine generator transmission chain torsion frequency identification module are added together. The result of the sum is input into the wind turbine generator, and the wind turbine generator responds to the sum to obtain the wind turbine generator speed.

[0014] Furthermore, the method for obtaining the excitation torque includes:

[0015] Based on the range of torsional frequencies of the wind turbine generator's drive train, multiple frequency points are obtained;

[0016] Based on the number of multiple frequency points, the corresponding initial phase is randomly generated;

[0017] Based on multiple frequency points and initial phase, the excitation torque output by the torsional frequency identification module of the wind turbine generator drive chain is constructed.

[0018] Furthermore, based on the range of torsional frequencies of the wind turbine generator drive chain, multiple frequency points are obtained, including:

[0019] Range of torsional frequencies of wind turbine drivetrain Divided into N frequency points, i.e.

[0020] (1)

[0021] in, , , .

[0022] Furthermore, the step of randomly generating the corresponding initial phase based on the number of multiple frequency points includes:

[0023] Randomly generated The N numbers between them are used as the initial phase:

[0024] (2)

[0025] in, Let i be the i-th initial phase.

[0026] Furthermore, the step of constructing the excitation torque output by the wind turbine drivetrain torsional frequency identification module based on multiple frequency points and initial phase includes:

[0027] The formula for calculating the excitation torque output by the torsional frequency identification module of the wind turbine drive train is as follows:

[0028] (3)

[0029] in, To excite torque, It is the amplitude at each excitation frequency, and satisfies... , It is the maximum energy that can be used for excitation.

[0030] Further, step 4 includes:

[0031] Acquire the spectrum of operating speed data from the wind turbine generator drive chain torsion frequency identification module when it is turned on and off;

[0032] By comparing the differences in the spectrum of the operating speed data of the wind turbine generator drive chain torsion frequency identification module when it is turned on and off at different frequency points, the frequency point with the largest peak deviation is identified as the torsion frequency of the wind turbine generator drive chain.

[0033] This application also discloses a system for determining the torsional frequency of a wind turbine generator drive train, used to implement the above-described method, comprising:

[0034] The range determination module is used to determine the range of torsional frequencies of the wind turbine's drivetrain based on the theoretical model of the wind turbine's drivetrain.

[0035] The optimization module is used to add a wind turbine drive chain torsion frequency identification module to the original wind turbine generator control system.

[0036] The operating speed data acquisition module is used to turn the wind turbine generator set transmission chain torsional frequency identification module on and off during wind turbine generator set operation, add or remove excitation torque in the normal operating torque command, and record the operating speed data when the wind turbine generator set transmission chain torsional frequency identification module is turned on and off; the operating speed data is the speed data sequence when the wind turbine generator set transmission chain torsional frequency identification module is turned off and the speed data sequence when the wind turbine generator set transmission chain torsional frequency identification module is turned on.

[0037] The transmission chain torsion frequency acquisition module is used to compare the differences in the spectrum of the operating speed data of the wind turbine generator transmission chain torsion frequency identification module at different frequency points when the module is turned on and off, so as to obtain the torsion frequency of the wind turbine generator transmission chain.

[0038] Due to the adoption of the above technical solution, this application has the following advantages: This application can accurately identify the torsional frequency of the wind turbine generator transmission chain in the actual device. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0040] Figure 1 A schematic diagram illustrating the addition or removal of excitation torque in the torque command for normal operation of embodiments of this application;

[0041] Figure 2 This is a schematic diagram comparing the spectrum of the operating speed data of the wind turbine generator drive chain torsion frequency identification module when it is turned on and off, according to an embodiment of this application. Detailed Implementation

[0042] The present application will be further described in conjunction with the accompanying drawings and embodiments. The described embodiments are only some, not all, of the embodiments of the present application. All other embodiments obtained by those skilled in the art should fall within the protection scope of the embodiments of the present application.

[0043] See Figure 1 This application provides an embodiment of a method for determining the torsional frequency of a wind turbine generator drive train, which includes the following steps:

[0044] The first step is to determine the range of torsional frequencies of the wind turbine's drivetrain based on a theoretical model of the drivetrain. ;

[0045] The second step is to add a wind turbine drivetrain torsion frequency identification module to the existing wind turbine control system. The specific steps are as follows:

[0046] S1: Range of torsional frequencies of the wind turbine generator drive chain Divided into N frequency points, i.e.

[0047] (1)

[0048] in , , ;

[0049] S2: Randomly generate N items The number between them is used as the initial phase:

[0050] (2)

[0051] S3: Construct the excitation torque of the wind turbine generator drivetrain torsional frequency identification module.

[0052] (3)

[0053] in, It is the amplitude at each excitation frequency, and satisfies... , It is the maximum energy that can be used for excitation.

[0054] The third step involves turning the wind turbine's drivetrain torsional frequency identification module on and off during operation, and adding or removing the excitation torque from the normal operating torque commands, such as... Figure 1 As shown, the operating speed data of the wind turbine generator drive chain torsion frequency identification module is recorded when it is turned on and off. ,in It is a sequence of rotational speed data for the excitation torque of the wind turbine generator's drivetrain torsional frequency identification module when it is turned off. It is the speed data sequence of the excitation torque of the wind turbine generator's transmission chain torsion frequency identification module.

[0055] The fourth step involves comparing the spectrum of the operating speed data from the wind turbine generator drivetrain torsion frequency identification module with and without the module turned on and off at different frequency points. The frequency point with the largest peak deviation is identified as the torsion frequency of the wind turbine generator drivetrain. The spectrum of the operating speed data from the wind turbine generator drivetrain torsion frequency identification module with and without the module turned on and off is shown below. Figure 2 As shown. (Through) Figure 2 It can be seen that the frequency of the transmission chain can be identified as 1.318Hz by the excitation torque.

[0056] This application also provides an embodiment of a system for determining the torsional frequency of a wind turbine generator drive train, used to implement the method described in the above embodiment, comprising:

[0057] The range determination module is used to determine the range of torsional frequencies of the wind turbine's drivetrain based on the theoretical model of the wind turbine's drivetrain.

[0058] The optimization module is used to add a wind turbine drive chain torsion frequency identification module to the original wind turbine generator control system.

[0059] The operating speed data acquisition module is used to turn the wind turbine generator set transmission chain torsional frequency identification module on and off during wind turbine generator set operation, add or remove excitation torque in the normal operating torque command, and record the operating speed data when the wind turbine generator set transmission chain torsional frequency identification module is turned on and off; the operating speed data is the speed data sequence when the wind turbine generator set transmission chain torsional frequency identification module is turned off and the speed data sequence when the wind turbine generator set transmission chain torsional frequency identification module is turned on.

[0060] The transmission chain torsion frequency acquisition module is used to compare the differences in the spectrum of the operating speed data of the wind turbine generator transmission chain torsion frequency identification module at different frequency points when the module is turned on and off, so as to obtain the torsion frequency of the wind turbine generator transmission chain.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and not to limit them. Although this application has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this application. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this application should be covered within the protection scope of the claims of this application.

Claims

1. A method for determining the torsional frequency of a wind turbine generator drive chain, characterized in that, include: Step 1: Based on the theoretical model of the wind turbine generator drive chain, determine the range of torsional frequencies of the wind turbine generator drive chain; Step 2: Add a wind turbine drive chain torsion frequency identification module to the existing wind turbine control system; Step 3: During the operation of the wind turbine generator set, turn the wind turbine generator set transmission chain torsional frequency identification module on and off respectively, add or remove the excitation torque in the normal operating torque command, and record the operating speed data when the wind turbine generator set transmission chain torsional frequency identification module is on and off; the operating speed data is the speed data sequence of the excitation torque when the wind turbine generator set transmission chain torsional frequency identification module is off and the speed data sequence of the excitation torque when the wind turbine generator set transmission chain torsional frequency identification module is on. Step 4: Compare the differences in the spectrum of the operating speed data of the wind turbine generator drive chain torsion frequency identification module at different frequency points when the module is turned on and off, and obtain the torsion frequency of the wind turbine generator drive chain. Step 2 includes: The electromagnetic torque output by the original wind turbine generator control system and the excitation torque output by the wind turbine generator transmission chain torsional frequency identification module are added together. The result of the sum is input into the wind turbine generator, and the wind turbine generator responds to the sum to obtain the wind turbine generator speed. The method for obtaining the excitation torque includes: Based on the range of torsional frequencies of the wind turbine generator's drive train, multiple frequency points are obtained; Based on the number of multiple frequency points, the corresponding initial phase is randomly generated; Based on multiple frequency points and initial phase, the excitation torque output by the torsional frequency identification module of the wind turbine generator drive chain is constructed.

2. The method according to claim 1, characterized in that, Step 1 includes: Based on the theoretical model of the wind turbine drive train, the range of torsional frequencies of the wind turbine drive train is obtained. .

3. The method according to claim 1, characterized in that, Based on the range of torsional frequencies of the wind turbine generator drive chain, multiple frequency points are obtained, including: Range of torsional frequencies of wind turbine drivetrain Divided into N frequency points, i.e. (1) in, , , .

4. The method according to claim 3, characterized in that, The step of randomly generating the corresponding initial phase based on the number of multiple frequency points includes: Randomly generated The N numbers between them are used as the initial phase: (2) in, Let i be the i-th initial phase.

5. The method according to claim 4, characterized in that, The process of constructing the excitation torque output by the wind turbine drivetrain torsional frequency identification module based on multiple frequency points and initial phase includes: The formula for calculating the excitation torque output by the torsional frequency identification module of the wind turbine drive train is as follows: (3) in, To excite torque, It is the amplitude at each excitation frequency, and satisfies... , It is the maximum energy that can be used for excitation.

6. The method according to claim 1, characterized in that, Step 4 includes: Acquire the spectrum of operating speed data from the wind turbine generator drive chain torsion frequency identification module when it is turned on and off; By comparing the differences in the spectrum of the operating speed data of the wind turbine generator drive chain torsion frequency identification module when it is turned on and off at different frequency points, the frequency point with the largest peak deviation is identified as the torsion frequency of the wind turbine generator drive chain.

7. A system for determining the torsional frequency of a wind turbine generator drive chain, used to implement the method described in any one of claims 1-6, characterized in that, include: The range determination module is used to determine the range of torsional frequencies of the wind turbine's drivetrain based on the theoretical model of the wind turbine's drivetrain. The optimization module is used to add a wind turbine drive chain torsion frequency identification module to the original wind turbine generator control system. The operating speed data acquisition module is used to turn the wind turbine generator set transmission chain torsional frequency identification module on and off during wind turbine generator set operation, add or remove excitation torque in the normal operating torque command, and record the operating speed data when the wind turbine generator set transmission chain torsional frequency identification module is turned on and off; the operating speed data is the speed data sequence when the wind turbine generator set transmission chain torsional frequency identification module is turned off and the speed data sequence when the wind turbine generator set transmission chain torsional frequency identification module is turned on. The transmission chain torsion frequency acquisition module is used to compare the differences in the spectrum of the operating speed data of the wind turbine generator transmission chain torsion frequency identification module at different frequency points when the module is turned on and off, so as to obtain the torsion frequency of the wind turbine generator transmission chain.

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