A wind turbine drive train torsional vibration protection method and system

Abstract

The application discloses a wind turbine transmission chain torsional vibration protection method and system, and the method comprises the following steps: 1) obtaining a generator rotating speed component under a transmission chain modal characteristic frequency; 2) performing logical operation on the generator rotating speed component to obtain a logical operation value; and 3) comparing the logical operation value with a preset threshold value; if the logical operation value is greater than the preset threshold value, a transmission chain torsional vibration protection mode is started. The application has the advantages of avoiding transmission chain torsional vibration, high reliability, strong universality and the like.

Description

Technical Field

[0001] This invention mainly relates to the field of wind power technology, specifically to a method and system for torsional vibration protection of the transmission chain of a wind turbine generator set. Background Technology

[0002] Traditional variable-speed, variable-pitch wind turbine generators control torque and pitch using torque and pitch actuators. Their drivetrain mainly consists of the rotor, main shaft, gearbox, and generator components. As turbine capacity increases, the damping of torsional vibrations in the drivetrain decreases. Therefore, during operation, the drivetrain modes are easily excited, causing severe torque fluctuations at the first-order modal frequency, resulting in serious damage to various components of the turbine.

[0003] Existing torque control technology mainly focuses on torque-speed control. To ensure the stability of the torque-speed control loop and to achieve good time-domain and frequency-domain characteristics, a resistance is often added to the transmission chain to increase its damping. For example... Figure 1 As shown, existing torque control technology involves controlling the measured generator speed ω. gen Perform low-pass and band-stop filtering, then compare with the speed reference point ω. ref (The reference point for rotational speed in the low wind speed range is set to the minimum steady-state speed, and the reference point for rotational speed in the high wind speed range is set to the rated speed.) A subtraction calculation is performed to obtain the rotational speed error. This error is then used as the input to the torque-speed PID controller, which calculates the intermediate torque value T. pid Additionally, the measured generator speed ω gen After bandpass and bandstop filtering, the torque value T of the transmission chain is obtained by multiplying by the resistance gain coefficient and phase compensation. damp Torque median T pid With the resistance torque value T of the transmission chain damp The torque command value T is obtained by superposition. ref The torque is fed to the torque actuator, which then executes the torque according to the input torque command value T. ref Perform excitation control.

[0004] In addition, patent application CN201610761512.9 uses the method of increasing transmission chain damping to suppress transmission chain vibration. Patent application CN201610872961.0 uses the angular acceleration data of the fan to extract the torsional vibration frequency of the fan transmission chain. Patent application CN201510013213.2 suppresses transmission chain oscillation by dynamically adjusting the damping torque parameters.

[0005] The existing control algorithms have all studied the transmission chain resistance technology, which can achieve a certain degree of resistance. However, when replacing major gearbox components or when the transmission chain modal frequency shifts due to load factors, the previously set resistance method is still used. The resistance device does not function, and no protective measures are taken for transmission chain torsional vibration caused by unsatisfactory resistance or abnormal transmission chain modal frequency identification. In some cases, abnormal frequencies are extracted, calculated by the transmission chain resistance module, and superimposed on the output command of the torque and speed PID module, which may cause severe torsional vibration of the transmission chain, thus causing great damage to the unit. Summary of the Invention

[0006] The technical problem to be solved by the present invention is: in view of the technical problems existing in the prior art, the present invention provides a method and system for protecting the torsional vibration of the transmission chain of a wind turbine generator set.

[0007] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0008] A method for torsional vibration protection of a wind turbine generator drive chain includes the following steps:

[0009] 1) Obtain the generator speed components at the modal characteristic frequencies of the transmission chain;

[0010] 2) Perform logical operations on the generator speed component to obtain the logical operation value;

[0011] 3) Compare the logical operation value with the preset threshold; if the logical operation value is greater than the preset threshold, the transmission chain torsional vibration protection mode is activated.

[0012] As a further improvement to the above technical solution:

[0013] In step 2), the logical operation is to take the absolute value or the square, and the corresponding logical operation value is the absolute value of the generator speed component or the square value of the generator speed component.

[0014] In step 3), when the logical operation value is the absolute value of the generator speed component, the preset threshold includes a first threshold and a second threshold. If the absolute value of the generator speed component at the characteristic frequency of the transmission chain mode is within the first threshold range, the transmission chain torsional vibration protection is not triggered, and the unit enters normal operation mode. If the absolute value of the generator speed component at the characteristic frequency of the transmission chain mode is greater than the first threshold and less than the second threshold, the transmission chain torsional vibration protection is triggered, and the unit enters mild transmission chain torsional vibration protection mode. If the absolute value of the generator speed component at the characteristic frequency of the transmission chain mode is greater than the second threshold, the unit enters severe transmission chain torsional vibration protection mode.

[0015] In step 3), when the logical operation value is the square of the generator speed component, the preset threshold is the third threshold and the fourth threshold. If the square of the generator speed component at the characteristic frequency of the transmission chain mode is within the range of the third threshold, the transmission chain torsional vibration protection is not triggered. If the square of the generator speed component at the characteristic frequency of the transmission chain mode is greater than the third threshold and less than the fourth threshold, the transmission chain torsional vibration protection is triggered, and the transmission chain torsional vibration protection mode is entered. If the square of the generator speed component at the characteristic frequency of the transmission chain mode is greater than the fourth threshold, the transmission chain torsional vibration protection mode is entered.

[0016] The mild transmission chain torsional vibration protection mode limits the unit's power output, causing it to operate within a variable speed range; the severe transmission chain torsional vibration protection mode shuts down the unit.

[0017] In step 1), a second-order bandpass filter, a third-order bandpass filter, or a higher-order bandpass filter is used to extract the generator speed component at the characteristic frequency of the transmission chain mode.

[0018] This invention also discloses a torsional vibration protection system for the transmission chain of a wind turbine generator set, comprising:

[0019] The first module is used to obtain the generator speed component at the modal characteristic frequency of the transmission chain;

[0020] The second module is used to perform logical operations on the generator speed component to obtain logical operation values;

[0021] The third module is used to compare the logical operation value with a preset threshold; if the logical operation value is greater than the preset threshold, the transmission chain torsional vibration protection mode is activated.

[0022] The present invention further discloses a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when run by a processor, executes the steps of the wind turbine generator drive chain torsional vibration protection method as described above.

[0023] The present invention also discloses a computer device, including a memory and a processor, wherein the memory stores a computer program, and the computer program, when run by the processor, executes the steps of the wind turbine generator drive chain torsional vibration protection method as described above.

[0024] Compared with the prior art, the advantages of the present invention are as follows:

[0025] This invention effectively identifies torsional vibration of the transmission chain by extracting the generator speed component under the modal characteristic frequency of the transmission chain. This avoids torsional vibration of the transmission chain caused by the failure to accurately identify the modal characteristic frequency of the transmission chain, thereby enhancing the protection performance of the unit for large components such as the transmission chain gearbox and extending the service life of each component.

[0026] This invention employs a multi-mode approach to extract the generator speed component under the characteristic frequency of the transmission chain modal, which can effectively identify the transmission chain mode. It uses multiple methods to calculate and process the extracted results and combines multiple threshold judgment methods to design a transmission chain torsional vibration protection system, which can effectively identify the transmission chain torsional vibration phenomenon and provide real-time protection for the unit, thereby improving reliability. In addition, it also designs protection logic for the transmission chain torsional vibration phenomenon using different mechanisms. Attached Figure Description

[0027] Figure 1 This is a block diagram of torque control in the prior art.

[0028] Figure 2 This is a block diagram of the torque control system in this invention.

[0029] Figure 3 This is the logic diagram for the torsional vibration protection of the transmission chain in this invention.

[0030] Figure 4 This is a schematic diagram of generator speed component extraction under the modal characteristic frequency of the transmission chain according to the present invention.

[0031] Figure 5 This is a schematic diagram of the transmission chain torsional vibration protection of the present invention. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 3 As shown, the wind turbine generator drive chain torsional vibration protection method of this embodiment includes the following steps:

[0034] 1) Obtain the generator speed components at the modal characteristic frequencies of the transmission chain;

[0035] 2) Perform logical operations on the generator speed components to obtain the logical operation values;

[0036] 3) Compare the logical operation value with the preset threshold; if the logical operation value is greater than the preset threshold, the transmission chain torsional vibration protection mode is activated.

[0037] This invention effectively identifies torsional vibration of the transmission chain by extracting the generator speed component under the modal characteristic frequency of the transmission chain, thus avoiding torsional vibration of the transmission chain caused by the failure to accurately identify the modal characteristic frequency of the transmission chain, thereby enhancing the protection performance of the unit for large components such as the transmission chain gearbox; the overall method is simple to apply and highly versatile.

[0038] In one specific embodiment, in step 2), the logical operation is to take the absolute value or the square, and the corresponding logical operation value is the absolute value of the generator speed component or the square value of the generator speed component.

[0039] In one specific embodiment, in step 3), when the logical operation value is the absolute value of the generator speed component, the preset threshold includes a first threshold and a second threshold. If the absolute value of the generator speed component at the characteristic frequency of the transmission chain mode is within the first threshold range, the transmission chain torsional vibration protection is not triggered, and the unit enters normal operation mode. If the absolute value of the generator speed component at the characteristic frequency of the transmission chain mode is greater than the first threshold and less than the second threshold, the transmission chain torsional vibration protection is triggered, and the unit enters mild transmission chain torsional vibration protection mode. If the absolute value of the generator speed component at the characteristic frequency of the transmission chain mode is greater than the second threshold, the unit enters severe transmission chain torsional vibration protection mode.

[0040] In one specific embodiment, in step 3), when the logical operation value is the square of the generator speed component, the preset thresholds are the third threshold and the fourth threshold. If the square of the generator speed component at the characteristic frequency of the transmission chain mode is within the range of the third threshold, the transmission chain torsional vibration protection is not triggered. If the square of the generator speed component at the characteristic frequency of the transmission chain mode is greater than the third threshold and less than the fourth threshold, the transmission chain torsional vibration protection is triggered, and the transmission chain torsional vibration protection mode is entered. If the square of the generator speed component at the characteristic frequency of the transmission chain mode is greater than the fourth threshold, the transmission chain torsional vibration protection mode is entered.

[0041] In one specific embodiment, the mild transmission chain torsional vibration protection mode limits the power output of the unit, causing it to operate in a variable speed range; the severe transmission chain torsional vibration protection mode shuts down the unit.

[0042] In one specific embodiment, in step 1), a second-order bandpass filter, a third-order bandpass filter, or a higher-order bandpass filter is used to extract the generator speed component at the characteristic frequency of the transmission chain mode.

[0043] This invention employs a multi-mode approach to extract the generator speed component under the characteristic frequency of the transmission chain modal, which can effectively identify the transmission chain mode. It uses multiple methods to calculate and process the extracted results and combines multiple threshold judgment methods to design a transmission chain torsional vibration protection system, which can effectively identify the transmission chain torsional vibration phenomenon and provide real-time protection for the unit, thereby improving reliability. In addition, it also designs protection logic for the transmission chain torsional vibration phenomenon using different mechanisms.

[0044] This invention also discloses a torsional vibration protection system for the transmission chain of a wind turbine generator set, comprising:

[0045] The first module is used to obtain the generator speed component at the modal characteristic frequency of the transmission chain;

[0046] The second module is used to perform logical operations on the generator speed components to obtain logical operation values.

[0047] The third module is used to compare the logical operation value with a preset threshold; if the logical operation value is greater than the preset threshold, the transmission chain torsional vibration protection mode is activated.

[0048] The protection system of the present invention, used to perform the method described above, also has the advantages described above.

[0049] like Figure 2 As shown, the torque control system consists of a speed error calculation module, a torque-speed PID module, a transmission chain resistance module, a generator speed component extraction module under the transmission chain modal characteristic frequency, a calculation and processing module, a transmission chain torsional vibration judgment module, and a transmission chain torsional vibration protection module; the principles of the speed error calculation module, the torque-speed PID module, and the transmission chain resistance module are as follows: Figure 1 As shown, the generator speed component extraction module under the modal characteristic frequency of the transmission chain is used to extract the generator speed component under the modal characteristic frequency of the transmission chain; the calculation and processing module is used to perform logical operations on the generator speed component to obtain the logical operation value; the transmission chain torsional vibration judgment module is used to compare the logical operation value with the preset threshold; and the transmission chain torsional vibration protection module adopts a mild transmission chain torsional vibration protection mode or a severe transmission chain torsional vibration protection mode according to the comparison result.

[0050] The present invention will now be described in further detail with reference to the schematic diagrams and specific implementation methods.

[0051] like Figure 3 and Figure 4 As shown, firstly, a second-order bandpass filter, a third-order bandpass filter, or a higher-order bandpass filter can be used to extract the generator speed component at the characteristic frequency of the drive train mode. The absolute value of the extracted result is then compared with a first threshold. If the absolute value of the generator speed component at the characteristic frequency of the drive train mode is within the first threshold range, the drive train torsional vibration protection is not triggered, and the unit enters normal operation mode. If the absolute value of the generator speed component at the characteristic frequency of the drive train mode is greater than the first threshold but less than the second threshold, the drive train torsional vibration protection is triggered, and the unit enters a mild drive train torsional vibration protection mode. If the absolute value of the generator speed component at the characteristic frequency of the drive train mode is greater than the second threshold, the unit enters a severe drive train torsional vibration protection mode.

[0052] Of course, in other embodiments, the generator speed component at the extracted drivetrain modal characteristic frequency can also be squared to set a threshold. The square of the generator speed component at the drivetrain modal characteristic frequency is compared with a third threshold. If the square of the generator speed component at the drivetrain modal characteristic frequency is within the range of the third threshold, drivetrain torsional vibration protection is not triggered. If the square of the generator speed component at the drivetrain modal characteristic frequency is greater than the third threshold but less than the fourth threshold, drivetrain torsional vibration protection is triggered, and a mild drivetrain torsional vibration protection mode is entered. If the square of the generator speed component at the drivetrain modal characteristic frequency is greater than the fourth threshold, a severe drivetrain torsional vibration protection mode is entered.

[0053] The transmission chain torsional vibration protection mode is divided into mild transmission chain torsional vibration protection mode and severe transmission chain torsional vibration protection mode based on threshold judgment. If the mild transmission chain torsional vibration protection mode is triggered, the unit's power is limited, causing the unit to operate in a variable speed range. If the severe transmission chain torsional vibration protection mode is triggered, the unit is shut down.

[0054] This invention also discloses a computer-readable storage medium storing a computer program thereon. When the computer program is run by a processor, it executes the steps of the wind turbine generator drivetrain torsional vibration protection method described above. This invention further discloses a computer device including a memory and a processor. The memory stores a computer program, which, when run by a processor, executes the steps of the wind turbine generator drivetrain torsional vibration protection method described above. This invention can implement all or part of the processes in the methods of the above embodiments, or it can be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. Memory can be used to store computer programs and / or modules. The processor performs various functions by running or executing the computer programs and / or modules stored in the memory, and by accessing data stored in the memory. Memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disks, RAM, plug-in hard disks, smart media cards (SMC), secure digital cards (SD cards), flash cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.

[0055] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A method for torsional vibration protection of a wind turbine generator drive chain, characterized in that, Including the following steps: 1) Obtain the generator speed components at the modal characteristic frequencies of the transmission chain; 2) Perform logical operations on the generator speed component to obtain the logical operation value; 3) Compare the logical operation value with the preset threshold; if the logical operation value is greater than the preset threshold, then activate the transmission chain torsional vibration protection mode; In step 2), the logical operation is to take the absolute value or the square, and the corresponding logical operation value is the absolute value of the generator speed component or the square value of the generator speed component. In step 1), a second-order bandpass filter, a third-order bandpass filter, or a higher-order bandpass filter is used to extract the generator speed component at the characteristic frequency of the transmission chain mode.

2. The method for torsional vibration protection of the transmission chain of a wind turbine generator set according to claim 1, characterized in that, In step 3), when the logical operation value is the absolute value of the generator speed component, the preset threshold includes a first threshold and a second threshold. If the absolute value of the generator speed component at the characteristic frequency of the transmission chain mode is within the first threshold range, the transmission chain torsional vibration protection is not triggered, and the unit enters normal operation mode. If the absolute value of the generator speed component at the characteristic frequency of the transmission chain mode is greater than the first threshold and less than the second threshold, the transmission chain torsional vibration protection is triggered, and the unit enters mild transmission chain torsional vibration protection mode. If the absolute value of the generator speed component at the characteristic frequency of the transmission chain mode is greater than the second threshold, the unit enters severe transmission chain torsional vibration protection mode.

3. The method for torsional vibration protection of the transmission chain of a wind turbine generator set according to claim 1, characterized in that, In step 3), when the logical operation value is the square of the generator speed component, the preset threshold is the third threshold and the fourth threshold. If the square of the generator speed component at the characteristic frequency of the transmission chain mode is within the range of the third threshold, the transmission chain torsional vibration protection is not triggered. If the square of the generator speed component at the characteristic frequency of the transmission chain mode is greater than the third threshold and less than the fourth threshold, the transmission chain torsional vibration protection is triggered, and the transmission chain torsional vibration protection mode is entered. If the square of the generator speed component at the characteristic frequency of the transmission chain mode is greater than the fourth threshold, the transmission chain torsional vibration protection mode is entered.

4. The method for torsional vibration protection of the transmission chain of a wind turbine generator set according to claim 2 or 3, characterized in that, The mild transmission chain torsional vibration protection mode limits the unit's power output, causing it to operate within a variable speed range; the severe transmission chain torsional vibration protection mode shuts down the unit.

5. A torsional vibration protection system for a wind turbine generator drive chain, used to perform the steps of the torsional vibration protection method for a wind turbine generator drive chain as described in any one of claims 1 to 4, characterized in that, include: The first module is used to obtain the generator speed component at the modal characteristic frequency of the transmission chain; The second module is used to perform logical operations on the generator speed component to obtain logical operation values; The third module is used to compare the logical operation value with a preset threshold; if the logical operation value is greater than the preset threshold, the transmission chain torsional vibration protection mode is activated.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is run by the processor, it executes the steps of the wind turbine generator drive chain torsional vibration protection method as described in any one of claims 1 to 4.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the computer program is run by the processor, it executes the steps of the wind turbine generator drive chain torsional vibration protection method as described in any one of claims 1 to 4.

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