Multi-band torsional oscillation suppression method and system for offshore direct-current wind turbine generator shaft system

Abstract

The invention relates to the technical field of offshore direct-current wind power, in particular to a multi-band torsional oscillation suppression method and system for an offshore direct-current wind turbine generator shaft system, and the method comprises the steps: building a control model of an oscillation suppression device comprising a plurality of parallel channels which comprise a band-pass filter, a wave trap, a proportional amplification link and an amplitude limiting link; a shafting rotating speed signal is obtained and input into the control model, and a control output signal value is calculated; and superposing the control output signal value and the original electromagnetic torque instruction value of the offshore direct-current wind turbine generator to participate in the torque control of the whole offshore direct-current wind turbine generator. Compared with a single band-pass filter or a PI controller adopted in a traditional method, the torsional vibration of different frequency bands can be more effectively restrained, and the mutual influence between torsional vibration signals of similar frequency bands is reduced. In addition, the method overcomes the problem that the existing method only aims at the single oscillation frequency of the shaft system of the wind turbine generator, does not need to add extra hardware equipment, and has good technical economy.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of offshore direct current wind power technology, and particularly relates to a method and system for suppressing multi-frequency band torsional oscillation of an offshore direct current wind turbine shaft. BACKGROUND

[0002] With the advantages of higher and more stable wind speed, wide development area, no occupation of land resources, little impact on residents, easy to be absorbed near the load center, and many other advantages, offshore wind power has been developed rapidly on a large scale worldwide. With the gradual saturation of offshore resource development, offshore wind power is developing towards the middle and far sea direction. However, with the increasing distance from the shore, the conventional alternating current transmission mode is restricted by problems such as overvoltage, and therefore, the direct current transmission mode suitable for long-distance power transmission has begun to be valued. At present, the mode of alternating current generation-alternating current collection-flexible direct current transmission has been applied at home and abroad. At the same time, the all-direct-current mode of direct current generation-direct current collection-direct current transmission is also being tried at home and abroad. This mode can save the submarine cable, avoid the use of heavy power frequency alternating current transformer, and has no reactive overvoltage problem of alternating current collection and transmission system, and has good economy.

[0003] The capacity of offshore direct current wind turbine in the development or planning design stage generally exceeds the 10MW level, and there is a trend of increasing capacity. The shaft of the wind turbine is not an independent and complete rigid body, but a plurality of mass blocks connected flexibly. In actual operation, there is a problem of mutual torsional oscillation between the mass blocks. The existence of torsional oscillation (referred to as torsional vibration) has an adverse effect on the service life of the wind turbine shaft. In severe cases, it can cause the fracture of the wind turbine shaft. Therefore, the suppression of wind turbine torsional vibration is one of the hotspots of research at home and abroad.

[0004] The suppression method of offshore direct current wind turbine shaft torsional vibration mainly includes four types: wind turbine structure design improvement, mechanical side passive damping control, operation condition management, and electromagnetic side active damping control. Among them, the first method mainly adjusts the low-speed shaft stiffness or increases the generator moment of inertia to avoid the torsional vibration natural frequency from the relevant excitation frequency band; the second method mainly installs a tuned mass block on the gear box shell or the main shaft to transfer the shaft torsional vibration energy to the damper for dissipation; or uses a rubber-metal composite coupling or a magnetorheological damper to provide additional damping in the low frequency band below 10 Hz; the third method mainly reduces the speed setting value above the rated wind speed + advances the pitch to reduce the impact of aerodynamic torque fluctuation on the shaft; or actively reduces the load by 5% to 10% during the period when the grid strength is insufficient to reduce the electromagnetic torque mutation amplitude. The fourth method superimposes a compensation quantity opposite to the torsional angular velocity (or generator speed differential) on the original electromagnetic torque command, which is equivalent to increasing the shaft damping.

[0005] Among the above four methods, the first and second methods involve hardware investment, especially the first method, which not only has a large economic cost but is also limited by the performance of the wind turbine; the third method limits the operating range and wind energy capture capacity of the wind turbine, and the fourth method, also known as the torque compensation method, does not require additional hardware investment and does not limit the operating range of the wind turbine, and is more commonly used. However, the current domestic and foreign literature generally only conducts torsional vibration suppression research on a 2-mass or 3-mass model, and the torsional vibration suppression strategy generally only uses a simple band-pass filter or proportional-integral (PI) control element, which is convenient for theoretical analysis but limits the accuracy of the research conclusions and has insufficient applicability.

[0006] The information disclosed in this BACKGROUND section is only for the purpose of enhancing the understanding of the general background of the application and should not be taken as admitting that the information forms the prior art that is already known to those skilled in the art. SUMMARY

[0007] The application provides a kind of offshore direct-current wind turbine shaft system multi-frequency band torsional oscillation suppression method and system, to effectively solve the problem of torsional vibration suppression method or need to increase hardware investment in prior art, or accuracy is limited, applicability is insufficient.

[0008] In order to achieve the above purpose, the technical scheme adopted by the application is: a kind of offshore direct-current wind turbine shaft system multi-frequency band torsional oscillation suppression method, comprising the following steps:

[0009] A control model of an oscillation suppression device including a plurality of parallel channels is established, the channels include: a band-pass filter, a notch filter, a proportional amplification element and a limiting element;

[0010] An input shaft speed signal is obtained and input into the control model to calculate a control output signal value;

[0011] The control output signal value is superimposed with the original electromagnetic torque command value of the offshore direct-current wind turbine to participate in the overall torque control of the offshore direct-current wind turbine.

[0012] Further, the input shaft speed signal is obtained and input into the control model to calculate a control output signal value, comprising the following steps:

[0013] The control model calculates a unit value according to the obtained shaft speed signal and the set shaft speed reference value;

[0014] The unit value is input into the band-pass filter of different channels to obtain a corresponding frequency band oscillation signal;

[0015] The corresponding frequency band oscillation signal is input into the corresponding notch filter to obtain a notch output signal;

[0016] The trap output signals are input into corresponding proportional amplification links to obtain proportional amplification signals;

[0017] The proportional amplification signals are input into corresponding limiting links to obtain control output signals of oscillation in the frequency band;

[0018] The control output signals of oscillation in each frequency band are superimposed and then limited to obtain the control output signal value.

[0019] Further, the acquisition of the shafting rotating speed signal comprises: collecting shafting head rotating speed and shafting tail rotating speed signals, and calculating an average value as the shafting rotating speed signal; the calculation formula is as follows:

[0020] W p＝ (W s +W m ) / 2;

[0021] In the formula, W p is an average value of measured values of the head and tail rotating speeds of the offshore direct-current wind turbine generator set, W s is the measured value of the head rotating speed of the offshore direct-current wind turbine generator set, and W m is the measured value of the tail rotating speed of the offshore direct-current wind turbine generator set.

[0022] Further, the unit value is calculated according to the following formula:

[0023] ΔW u =ΔW / W ref ;

[0024] In the formula, W ref is a shafting rotating speed reference value of the offshore direct-current wind turbine generator set, ΔW is a shafting rotating speed deviation, ΔW = W ref -W p , and W p is an average value of measured values of the head and tail rotating speeds.

[0025] Further, the superposition of the control output signal value and the original electromagnetic torque instruction value of the offshore direct-current wind turbine generator set to participate in the whole-machine torque control of the offshore direct-current wind turbine generator set further comprises:

[0026] establishing a shafting multi-mass block torsional vibration simulation analysis model of the offshore direct-current wind turbine generator set;

[0027] performing frequency domain analysis on the multi-mass block torsional vibration simulation analysis model by using a control method for suppressing oscillation and a control method without suppressing oscillation, respectively, to verify the effectiveness of the control method;

[0028] The multi-mass torsional vibration simulation analysis model is subjected to time domain simulation analysis by using the oscillation suppression control method and the oscillation suppression control method, respectively, to verify the effectiveness of the control method.

[0029] Further, in the frequency domain analysis of the multi-mass torsional vibration simulation analysis model by using the oscillation suppression control method and the oscillation suppression control method, respectively:

[0030] If the oscillation amplitude of the oscillation frequency point in the Fourier analysis result of the shaft system speed signal in the multi-mass torsional vibration simulation analysis model is weakened after using the oscillation suppression control method, the control method is effective; otherwise, it is not effective.

[0031] Further, in the time domain simulation analysis of the multi-mass torsional vibration simulation analysis model by using the oscillation suppression control method and the oscillation suppression control method, respectively:

[0032] If the oscillation phenomenon is suppressed in the time domain simulation result of the multi-mass torsional vibration simulation analysis model after using the oscillation suppression control method, the control method is effective; otherwise, it is not effective.

[0033] The application also includes a multi-frequency band torsional oscillation suppression system for a marine direct-current wind turbine shaft system, which uses the method described above, and the system comprises:

[0034] A modeling unit is configured to establish a control model of an oscillation suppression device comprising a plurality of parallel channels, the channels comprising: a band-pass filter, a notch filter, a proportional amplification link and a limiting link;

[0035] A calculation unit is configured to input a shaft system speed signal into the control model and calculate a control output signal value.

[0036] A control unit is configured to superimpose the control output signal value and an original electromagnetic torque instruction value of the marine direct-current wind turbine to participate in the torque control of the marine direct-current wind turbine.

[0037] The application also includes a computer device comprising 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 method described above.

[0038] The application also includes a storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the method described above.

[0039] The beneficial effects of the present application are: the oscillation suppression scheme mainly adopts a band-pass filter and a notch filter, and is matched with a proportional amplification link and a limiting link, compared with the single band-pass filter or PI controller used in the traditional method, the oscillation of different frequency bands can be more effectively suppressed, and the mutual influence between the torsional vibration signals of similar frequency bands is reduced. The problem that the existing invention is generally only for a single oscillation frequency of the wind turbine shaft system is overcome, and no additional hardware devices need to be added, and good technical and economic efficiency is achieved. By superimposing the oscillation suppressor on the electromagnetic torque control ring of the offshore direct-current wind turbine, the physical concept is clear, the implementation is convenient, and it is beneficial for power industry engineers and scientific researchers to master and use. The multi-parallel channel suppression scheme can well adapt to wind turbine shaft system models of different details, different numbers of channels can be used according to different research problem requirements, the adaptability is strong, and the application prospect is broad. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0041] Figure 1 It is a flowchart of the method in embodiment 1.

[0042] Figure 2 It is a structural schematic diagram of the system in embodiment 1.

[0043] Figure 3 It is a flowchart of the control method in embodiment 2.

[0044] Figure 4 It is a structural schematic diagram of the offshore direct-current wind turbine grid-connected analysis system in embodiment 2.

[0045] Figure 5 It is a control model diagram of the multi-frequency torsional oscillation suppression device in embodiment 2.

[0046] Figure 6 It is a calculation diagram expression structural schematic diagram of the limiting link in embodiment 2.

[0047] Figure 7 It is a multi-mass block model diagram of the offshore direct-current wind turbine in embodiment 2.

[0048] Figure 8 It is a structural schematic diagram of the computer equipment of the present application. DETAILED DESCRIPTION

[0049] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below, obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments.

[0050] Embodiment 1:

[0051] As shown in the figure: a kind of offshore direct-current wind turbine shaft system multi-band torsional oscillation suppression method, comprising the following steps: Figure 1

[0052] The control model of the oscillation suppression device including multiple parallel channels is established, and the channel includes a band-pass filter, a notch filter, a proportional amplification link and a limiting link;

[0053] The shaft speed signal is input into the control model to calculate the control output signal value;

[0054] The control output signal value is superimposed with the original electromagnetic torque command value of the offshore direct-current wind turbine to participate in the torque control of the offshore direct-current wind turbine.

[0055] The oscillation suppression scheme mainly uses a band-pass filter and a notch filter, with a proportional amplification link and a limiting link. Compared with the single band-pass filter or PI controller used in the traditional method, it can more effectively suppress torsional vibration of different frequency bands and reduce the mutual influence between similar frequency band torsional vibration signals. It overcomes the problem that existing inventions generally only target a single oscillation frequency of the wind turbine shaft system, and does not require additional hardware devices, with good technical and economic efficiency. By superimposing the oscillation suppressor in the electromagnetic torque control loop of the offshore direct-current wind turbine, the physical concept is clear, the implementation is convenient, and it is beneficial for power industry engineers and researchers to master and use. The multi-parallel channel suppression scheme can well adapt to wind turbine shaft system models of different levels of detail, and different numbers of channels can be used according to different research problem requirements, with strong adaptability and broad application prospects.

[0056] In this embodiment, the shaft speed signal is input into the control model to calculate the control output signal value, comprising the following steps:

[0057] The control model calculates the unit value according to the obtained shaft speed signal and the set shaft speed reference value;

[0058] The unit value is input into the band-pass filter of different channels to obtain the corresponding frequency band oscillation signal;

[0059] The corresponding frequency band oscillation signal is input into the corresponding notch filter to obtain the notch output signal;

[0060] The notch output signal is input into the corresponding proportional amplification link to obtain the proportional amplification signal; ​

[0061] The proportional amplification signals are input into corresponding limiting links to obtain control output signals of the frequency bands;

[0062] The control output signals of the frequency bands are superimposed and then limited to obtain a control output signal value.

[0063] The shaft system speed signal is obtained by collecting the shaft system head-end speed and shaft system tail-end speed signals and calculating an average value, and the average value is taken as the shaft system speed signal; the calculation formula is as follows:

[0064] W p＝ (W s +W m ) / 2;

[0065] In the formula, W p is the average value of the measured values of the head-end and tail-end speeds of the offshore direct-current wind turbine generator system, W s is the measured value of the head-end speed of the offshore direct-current wind turbine generator system, and W m is the measured value of the tail-end speed of the offshore direct-current wind turbine generator system.

[0066] In the formula, the unit value is calculated according to the following formula:

[0067] ΔW u =ΔW / W ref ;

[0068] In the formula, W ref is the reference value of the shaft system speed of the offshore direct-current wind turbine generator system, ΔW is the shaft system speed deviation, ΔW = W ref -W p , and W p is the average value of the measured values of the head-end and tail-end speeds.

[0069] The control output signal value is superimposed with the original electromagnetic torque instruction value of the offshore direct-current wind turbine generator system to participate in the overall torque control of the offshore direct-current wind turbine generator system, and the method further comprises:

[0070] A multi-mass torsional vibration simulation analysis model of the shaft system of the offshore direct-current wind turbine generator system is established;

[0071] The multi-mass torsional vibration simulation analysis model is subjected to frequency domain analysis using the control method for suppressing oscillation and the control method without suppressing oscillation, respectively, to verify the effectiveness of the control method;

[0072] The multi-mass torsional vibration simulation analysis model is subjected to time domain simulation analysis using the control method for suppressing oscillation and the control method without suppressing oscillation, respectively, to verify the effectiveness of the control method.

[0073] In the embodiment, the multi-mass torsional vibration simulation analysis model is subjected to frequency domain analysis using the oscillation suppression control method and the oscillation suppression control method is not used:

[0074] If the oscillation suppression control method is used, the oscillation amplitude of the oscillation frequency point in the Fourier analysis result of the shafting speed signal in the multi-mass torsional vibration simulation analysis model is weakened, and the control method is effective; otherwise, it is not effective.

[0075] The multi-mass torsional vibration simulation analysis model is subjected to time domain simulation analysis using the oscillation suppression control method and the oscillation suppression control method is not used:

[0076] If the oscillation suppression control method is used, the oscillation phenomenon is suppressed in the time domain simulation result of the multi-mass torsional vibration simulation analysis model, and the control method is effective; otherwise, it is not effective.

[0077] As shown in Figure 2 , the embodiment also includes a sea direct-current wind turbine shaft system multi-frequency band torsional oscillation suppression system, which uses the method as described above, and the system includes:

[0078] A modeling unit is configured to establish a control model of an oscillation suppression device including a plurality of parallel channels, and each channel includes a band-pass filter, a notch filter, a proportional amplification link, and a limiting link.

[0079] A calculation unit is configured to input a shafting speed signal into the control model and calculate a control output signal value.

[0080] A control unit is configured to superimpose the control output signal value and an original electromagnetic torque instruction value of the sea direct-current wind turbine to participate in the whole machine torque control of the sea direct-current wind turbine.

[0081] Embodiment 2:

[0082] The embodiment provides a sea direct-current wind turbine shaft system multi-frequency band torsional oscillation suppression method, and a flow chart is shown in Figure 3 , which includes:

[0083] S11, input the obtained shafting speed signal into the pre-established control model of the oscillation suppression device, and calculate a control output signal value.

[0084] S12, superimpose the control output signal value and an original electromagnetic torque instruction value of the sea direct-current wind turbine to participate in the whole machine torque control of the sea direct-current wind turbine.

[0085] The pre-established control model of the oscillation suppression device includes a plurality of parallel channels, and each channel includes a band-pass filter, a notch filter, a proportional amplification link, and a limiting link.

[0086] The set shaft speed signal includes:

[0087] like Figure 4 The schematic diagram of the offshore DC wind turbine grid connection analysis system shown above first measures the shaft speed amplitude of the offshore DC wind turbine and sets the reference value of the shaft speed of the offshore DC wind turbine.

[0088] In step S11, the acquired shaft speed signal is input into the pre-established control model of the oscillation suppression device. The control model is as follows: Figure 5 As shown, the calculation of the control output signal value includes:

[0089] The shaft speed is taken as the average of the speed signals at the beginning and end of the shaft system;

[0090] The per-unit value is calculated based on the measured shaft speed and the preset shaft speed reference value;

[0091] The per-unit values ​​are input into different bandpass filters to obtain the corresponding frequency band oscillation signals;

[0092] The corresponding frequency band oscillation signal is input into the corresponding notch filter to obtain the notch output signal;

[0093] The notch output signal is input into the corresponding proportional element to obtain the proportionally amplified signal;

[0094] The proportionally amplified signals are input to the corresponding limiting circuits to obtain the control output signal value for the oscillation in that frequency band.

[0095] The signal obtained by superimposing the control output signal values ​​of each frequency band oscillation is input to the total limiting circuit to obtain the final control output signal value. This signal is then superimposed with the original electromagnetic torque command of the offshore DC wind turbine to obtain a new electromagnetic torque command value.

[0096] Wherein: Step S11 after assignment includes:

[0097] Step 1: Measure the rotational speed W of the forward shaft system of the offshore DC wind turbine. s and the end shaft speed W m ;

[0098] Step 2: Calculate the average value W of the measured values ​​at the beginning and end of the shaft rotation speed. p ;

[0099] Step 3: Set the initial reference value (W) of the shaft rotation speed of the offshore DC wind turbine. ref Subtract the measured shaft speed value W p The deviation ΔW is obtained, and the deviation ΔW is divided by the shaft speed reference value W. ref The per-unit value ΔW is obtained. u ;

[0100] Step 4: input ΔW u to the corresponding band-pass filter (for example, a 2-order band-pass filter, whose transfer function is where s is a complex variable in Laplace transform, f0 is the center frequency, unit Hz, BW is the bandwidth, unit Hz, and k is the gain), to obtain the oscillation signal ΔW w of the corresponding frequency band;

[0101] Step 5: input ΔW w to the corresponding notch filter (for example, a double quadratic 2-order notch filter, whose transfer function is where ω0 is the center angular frequency of the notch, unit rad / s, and Q is the quality factor, which determines the notch width, i.e. the sharpness), to obtain the notch output signal ΔW N1 ;

[0102] Step 6: input ΔW N1 to the proportional link K1, to obtain the proportional amplification signal ΔW K1 ;

[0103] Step 7: input ΔW K1 to the limiting link, and the calculation graph expression structure diagram of the limiting link is as shown in Figure 6 to obtain the control output signal value ΔW out1 ;

[0104] Step 8: superimpose the control output signal values ΔW out1 of each frequency band oscillation to obtain the signal ΔW outL ;

[0105] Step 9: input the proportional amplification signal ΔW outL to the total limiting link (the upper limit is Limit_max, and the lower limit is Limit_min), to obtain the control output signal value ΔW out ; if the control output signal value ΔW out > Limit_max, then the control output signal value ΔW out = Limit_max; if the control output signal value ΔW out < Limit_min, then the control output signal value ΔW out = Limit_min.

[0106] Step 10: superimpose ΔW out on the reference value of the electromagnetic torque control loop of the offshore direct-current wind turbine generator set, to achieve the effect of suppressing the multi-frequency torsional oscillation of the shaft system.

[0107] Step 11: establish the multi-mass block torsional vibration simulation analysis model of the offshore direct-current wind turbine generator set shaft system as shown in Figure 7 .

[0108] Step 12: The frequency domain analysis before and after the input of the oscillation suppression controller is respectively performed on the model established in step 11, and the oscillation amplitude values of different oscillation frequency points are obtained. If the oscillation amplitude of the oscillation frequency point is weakened after the input of the controller, the effective effect of the controller is illustrated from the frequency domain analysis; otherwise, the controller is ineffective.

[0109] Step 13: The time domain simulation analysis before and after the input of the oscillation suppression controller is respectively performed on the model established in step 11, that is, the disturbance is set, and the effect of the controller is observed. If the oscillation phenomenon is suppressed (the oscillation times are less, and the oscillation is quickly calmed or attenuated) after the input of the controller, the effective effect of the controller is illustrated from the time domain analysis; otherwise, the controller is ineffective.

[0110] In the embodiment, the collected shafting rotating speed signal is input into the pre-established control model of the oscillation suppression device, and a control output signal value is calculated; the control output signal value is superimposed with an original electromagnetic torque instruction value of the offshore direct-current wind turbine generator set, and participates in the torque control of the offshore direct-current wind turbine generator set; the pre-established control model of the oscillation suppression device includes a plurality of parallel channels, and each channel includes a band-pass filter, a notch filter, a proportional amplification link and a limiting link. The technical scheme provided in the embodiment is an additional damping control method for the multi-frequency band torsional oscillation of the shafting of the offshore direct-current wind turbine generator set, overcomes the problem that the existing invention is generally only directed to a single oscillation frequency of the shafting of the wind turbine generator set, and does not need to increase additional hardware devices, and has good technical and economic efficiency.

[0111] The oscillation suppression scheme in the embodiment mainly adopts a band-pass filter and a notch filter, and is matched with a proportional amplification link and a limiting link, compared with a single band-pass filter or a PI controller used in a traditional method, can more effectively suppress torsional vibrations of different frequency bands, and reduce the mutual influence between torsional vibration signals of similar frequency bands.

[0112] By superimposing the oscillation suppressor on the electromagnetic torque control ring of the offshore direct-current wind turbine generator set, the physical concept is clear, the implementation is convenient, and it is beneficial for engineers and researchers in the power industry to master and use.

[0113] The multi-parallel-channel suppression scheme can well adapt to wind turbine generator set shafting models of different detailed levels, different numbers of channels can be used according to different research problem requirements, has strong adaptability, and has wide application prospect.

[0114] See Figure 8The structural schematic diagram of the computer device provided by the embodiment of the application is shown. The computer device 400 provided by the embodiment of the application comprises a processor 410 and a memory 420, the memory 420 stores a computer program executable by the processor 410, and the computer program is executed by the processor 410 to perform the method as above.

[0115] The embodiment of the application further provides a storage medium 430, the storage medium 430 stores a computer program, and the computer program is executed by the processor 410 to perform the method as above.

[0116] The storage medium 430 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as a static random access memory (SRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a magnetic memory, a flash memory, a magnetic disk or an optical disk.

[0117] In the description of the application, the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. The meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0118] In the application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the communication or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0119] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples, without contradiction.

[0120] Any process or method descriptions or descriptions of the flow diagrams in the specification can be understood as representing code modules, segments, or portions of code which include one or more executable instructions for performing specific logic functions or steps in the process, and the various embodiments of the application include additional or different modules, segments, or portions of code when implemented in software or firmware in combination with the process described. The various embodiments of the application can be implemented in a computer program product tangibly embodied in a machine-readable storage medium (e.g., magnetic disk, optical disk, memory, etc.) including one or more code modules or portions of code.

[0121] The logic and / or steps represented in the flow diagrams or otherwise described herein, for example, can be embodied in computer-readable instructions, modules, or portions of code, which can be executed by one or more processing units, cores, or processors of one or more computing devices or systems. The various embodiments of the application include additional or different modules, segments, or portions of code when implemented in software or firmware in combination with the process described. The various embodiments of the application can be implemented in a computer program product tangibly embodied in a machine-readable storage medium (e.g., magnetic disk, optical disk, memory, etc.) including one or more code modules or portions of code.

[0122] It should be understood that portions of the present application can be implemented with hardware, software, firmware or a combination thereof. In the above embodiments, a plurality of steps or methods can be implemented with software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following technologies, known in the art, or their combinations can be used: discrete logic circuitry having logic gates for implementing logic functions on data signals, application specific integrated circuits having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), etc.

[0123] Those skilled in the art of the present technology can understand that all or part of the steps carried out by the above-mentioned embodiments can be completed by a program instructing the relevant hardware, and the program can be stored in a computer readable storage medium. When the program is executed, it includes one of the steps of the method embodiment or a combination thereof.

[0124] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above-mentioned embodiments within the scope of the present application.

Claims

1. A method for suppressing multi-frequency torsional oscillation of a shaft system of an offshore direct-drive wind turbine generator unit, characterized in that, The method comprises the following steps: A control model of an oscillation suppression device comprising a plurality of parallel channels is established, the channels comprising: a band-pass filter, a notch filter, a proportional amplification link and a limiting link; An input of a shaft system rotating speed signal is obtained and input into the control model to calculate a control output signal value; The control output signal value is superimposed with an original electromagnetic torque instruction value of an offshore direct current wind turbine generator set to participate in the whole machine torque control of the offshore direct current wind turbine generator set.

2. The offshore direct drive wind turbine shafting multi-frequency band torsional oscillation suppression method according to claim 1, characterized in that, The input of the shaft system rotating speed signal into the control model to calculate the control output signal value comprises the following steps: The control model calculates a unit value according to the obtained shaft system rotating speed signal and a set shaft system rotating speed reference value; The unit value is input into the band-pass filter of each channel to obtain corresponding frequency band oscillation signals; The corresponding frequency band oscillation signals are input into the corresponding notch filters to obtain notch output signals; The notch output signals are input into the corresponding proportional amplification links to obtain proportional amplification signals; The proportional amplification signals are input into the corresponding limiting links to obtain the control output signals of the frequency band oscillation; The control output signals of each frequency band oscillation are superimposed and then limited to obtain the control output signal value.

3. The offshore direct drive wind turbine shaft train multi-frequency torsional oscillation suppression method according to claim 2, characterized in that, The input of the shaft system rotating speed signal comprises: collecting a shaft system head end rotating speed signal and a shaft system tail end rotating speed signal, calculating an average value, and taking the average value as the shaft system rotating speed signal; the calculation formula is as follows: W p＝ (W s +W m ) / 2; In the formula: W p W is the average value of the measured values of the shaft head and tail end rotating speed of the offshore direct-current wind turbine generator set, W s W is the measured value of the shaft head rotating speed of the offshore direct-current wind turbine generator set, W m W is the measured value of the shaft tail end rotating speed of the offshore direct-current wind turbine generator set.

4. The offshore direct drive wind turbine shaft train multi-frequency torsional oscillation suppression method of claim 2, wherein, The unit value is calculated according to the following formula: ΔW u = ΔW / W ref ; In the formula, W ref is the shafting rotating speed reference value of the offshore direct-current wind turbine generator set, ΔW is the shafting rotating speed deviation amount, ΔW=W ref -W p , W p is the average of the measured values of the shafting head and tail rotating speeds.

5. The offshore direct drive wind turbine shafting multi-band torsional oscillation suppression method according to claim 1, characterized in that, The superimposition of the control output signal value with the original electromagnetic torque instruction value of the offshore direct current wind turbine generator set to participate in the whole machine torque control of the offshore direct current wind turbine generator set further comprises: A shaft system multi-mass block torsional vibration simulation analysis model of the offshore direct current wind turbine generator set is established; Frequency domain analysis of the multi-mass block torsional vibration simulation analysis model using the oscillation suppression control method and not using the oscillation suppression control method is performed to verify the effectiveness of the control method; Time domain simulation analysis of the multi-mass block torsional vibration simulation analysis model using the oscillation suppression control method and not using the oscillation suppression control method is performed to verify the effectiveness of the control method.

6. The offshore direct drive wind turbine shaft train multi-frequency torsional oscillation suppression method of claim 5, wherein, In the frequency domain analysis of the multi-mass block torsional vibration simulation analysis model using the oscillation suppression control method and not using the oscillation suppression control method: If the oscillation amplitude of the oscillation frequency point in the Fourier analysis result of the shaft system rotating speed signal in the multi-mass block torsional vibration simulation analysis model is weakened after using the oscillation suppression control method, the control method is effective; otherwise, it is not effective.

7. The offshore direct drive wind turbine shaft train multi -frequency torsional oscillation suppression method of claim 5, wherein, In the time domain simulation analysis of the multi-mass block torsional vibration simulation analysis model using the oscillation suppression control method and not using the oscillation suppression control method: If the oscillation phenomenon in the time domain simulation result of the multi-mass block torsional vibration simulation analysis model is suppressed after using the oscillation suppression control method, the control method is effective; otherwise, it is not effective.

8. A multi-band torsional oscillation suppression system for the shaft system of an offshore DC wind turbine, characterized in that, The system comprises: A modeling unit for establishing a control model of an oscillation suppression device comprising a plurality of parallel channels, the channels comprising: a band-pass filter, a notch filter, a proportional amplification link and a limiting link; A computing unit is configured to acquire a shafting rotating speed signal input into the control model and calculate a control output signal value. A control unit is configured to superimpose the control output signal value and an original electromagnetic torque instruction value of the offshore direct-current wind generator set to participate in overall torque control of the offshore direct-current wind generator set.

9. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the computer program to implement the method of any one of claims 1-7.

10. A storage medium having stored thereon a computer program, characterized in that The computer program is executed by the processor to implement the method of any one of claims 1-7.

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