A method and system for controlling wave pitching motion of an offshore floating wind turbine

Abstract

The present invention discloses a wave pitch motion control method and system for an offshore floating wind turbine generator set, comprising the following steps: obtaining an effective pitch angle of a floating base platform and an effective fore-aft acceleration of a nacelle; performing differential and integral operations on the effective pitch angle of the floating base platform and the effective fore-aft acceleration of the nacelle to output a first additional pitch instruction and a second additional pitch instruction; performing differential and integral operations on the effective pitch angle of the floating base platform and the effective fore-aft acceleration of the nacelle to output an additional speed bias; in a normal power generation state of the unit, superimposing the additional speed bias with a generator speed setting value input by a pitch controller, superimposing the first and second additional pitch instructions with the pitch instruction output by the pitch controller, and transmitting the final pitch instruction obtained after superposition to a pitch system for execution, thereby generating a thrust on the wind wheel to suppress the unit's wave motion and reduce the amplitude of the unit's wave motion.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine control, and in particular to a wave pitch motion control method, system, storage medium and computing device for an offshore floating wind turbine. Background Art

[0002] Offshore floating wind turbines use a floating foundation platform to float the wind turbine on the water surface and are connected to the seabed through a mooring system. Compared with fixed foundations such as monopiles or jackets, floating wind turbines have a greater motion response under the action of wind and waves. During their entire life cycle, floating wind turbines are affected by wind loads, wave loads, and flow loads, resulting in greater motion amplitudes, accelerations, and load amplitudes. Among them, floating wind turbines are impacted by waves, and the entire unit undergoes periodic pitching motion with the waves; thus, the fatigue load on the tower of the floating wind turbine will increase significantly. In order to reduce the fatigue load on the tower of the floating wind turbine, it is necessary to propose a wave pitching motion control method and system for offshore floating wind turbines based on the characteristics of the floating wind turbine's pitching motion with the waves. Summary of the Invention

[0003] The first purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and provide a method for controlling the wave pitch motion of an offshore floating wind turbine. The method calculates the measured pitch angle of the floating foundation platform and the fore-aft acceleration of the nacelle to obtain additional pitch control instructions and additional speed bias, and adjusts the thrust on the wind rotor side to suppress the floating wind turbine from moving with the waves.

[0004] A second object of the present invention is to provide a wave pitch motion control system for an offshore floating wind turbine.

[0005] A third object of the present invention is to provide a storage medium.

[0006] A fourth object of the present invention is to provide a computing device.

[0007] The first object of the present invention is achieved by the following technical solution: A method for controlling wave pitch motion of an offshore floating wind turbine, comprising the following operations:

[0008] Collect the pitch angle of the floating foundation platform and the fore-aft acceleration of the nacelle of the floating wind turbine and process the data to obtain the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle;

[0009] The obtained effective pitch angle of the floating base platform and the effective fore-aft acceleration of the nacelle are subjected to differential and integral operations to output two types of additional pitch commands, namely, a first additional pitch command and a second additional pitch command; wherein the first additional pitch command is an additional pitch command consistent with the pitch angle velocity of the floating base platform, and the second additional pitch command is an additional pitch command consistent with the fore-aft velocity of the nacelle;

[0010] The obtained effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle are used to output an additional speed bias through differential and integral operations;

[0011] Under the normal power generation state of the floating wind turbine, the output additional speed bias is superimposed on the generator speed set value input by the pitch controller of the floating wind turbine, and the two types of output additional pitch commands are superimposed on the pitch commands output by the pitch controller. The final pitch command obtained after superposition is transmitted to the pitch system of the floating wind turbine for execution, so as to generate thrust on the wind rotor of the floating wind turbine to suppress the movement of the floating wind turbine with waves, thereby reducing the amplitude of the movement of the floating wind turbine with waves.

[0012] Furthermore, the pitch angle of the floating foundation platform is measured by a tilt sensor. The tilt sensor is installed on the floating foundation platform of the floating wind turbine. The tilt sensor can measure the tilt angles of the floating foundation platform in two directions in real time, namely the pitch angle of the floating foundation platform and the lateral tilt angle of the floating foundation platform. The pitch angle of the floating foundation platform directly reflects the movement of the floating wind turbine under the action of waves. However, the pitch angle measured by the tilt sensor cannot be directly used for control.

[0013] If multiple inclination sensors are installed on a floating foundation platform, each inclination sensor measures the pitch angle of the floating foundation platform. The average pitch angle of the floating foundation platform can be obtained by weighted averaging data processing. The definition of the average pitch angle of the floating foundation platform is as follows:

[0014]

[0015] In the above formula, represents the average pitch angle of the floating foundation platform; k1 represents the weighting coefficient of the first tilt sensor; θ fa,1 represents the pitch angle of the floating foundation platform measured by the first tilt sensor; k2 represents the weighting coefficient of the second tilt sensor; θ fa,2 k represents the pitch angle of the floating foundation platform measured by the second tilt sensor; n Represents the weighting coefficient of the nth tilt sensor; θ fa,n represents the pitch angle of the floating foundation platform measured by the nth tilt sensor;

[0016] The pitch angle of the floating foundation platform measured by the inclination sensor contains signals of various frequencies. Only the pitch angle of the floating foundation platform in the wave frequency range can be used as the control input signal. Therefore, it is necessary to filter the measured data to extract the pitch angle of the floating foundation platform in the wave frequency range and filter out other high-frequency harmonic noise to define the effective pitch angle of the floating foundation platform. The details are as follows:

[0017]

[0018] In the above formula, Indicates the effective pitch angle of the floating foundation platform; F fa (s) represents the effective pitch filter, which contains a band-pass filter and a band-stop filter; Represents the average pitch angle of the floating foundation platform.

[0019] Furthermore, the fore-aft acceleration of the nacelle is measured by an acceleration sensor installed on the nacelle of the floating wind turbine. The acceleration sensor can measure the acceleration of the nacelle in two directions in real time, namely the fore-aft acceleration of the nacelle and the left-right acceleration of the nacelle. The fore-aft acceleration of the nacelle directly reflects the movement of the floating wind turbine under the action of waves. However, the nacelle acceleration measured by the acceleration sensor cannot be directly used for control.

[0020] If multiple acceleration sensors are installed on the cabin, each one measures the cabin fore-aft acceleration. The average cabin fore-aft acceleration can be obtained by weighted averaging the data. The definition of the average cabin fore-aft acceleration is as follows:

[0021]

[0022] In the above formula, represents the average front and rear acceleration of the cabin; m1 represents the weighting coefficient of the first acceleration sensor; a fa,1 represents the front and rear acceleration of the cabin measured by the first acceleration sensor; m2 represents the weighting coefficient of the second acceleration sensor; a fa,2 represents the front and rear acceleration of the cabin measured by the second acceleration sensor; m n Represents the weighting coefficient of the nth acceleration sensor; a fa,n represents the front and rear acceleration of the cabin measured by the nth acceleration sensor;

[0023] The nacelle fore-and-aft acceleration measured by the acceleration sensor contains signals of various frequencies. Only the nacelle fore-and-aft acceleration within the wave frequency range can be used as a control input signal. Therefore, it is necessary to filter the measured data to extract the nacelle fore-and-aft acceleration within the wave frequency range and filter out other high-frequency harmonic noise. This defines the effective nacelle fore-and-aft acceleration as follows:

[0024]

[0025] In the above formula, Indicates the effective front and rear acceleration of the cabin; H fa (s) represents the effective front and rear acceleration filter, which contains a band-pass filter and a band-stop filter; Indicates the average fore-aft acceleration of the cabin.

[0026] Furthermore, when the floating wind turbine performs pitching motion with waves, if an additional pitch command consistent with the pitching inclination speed of the floating foundation platform is superimposed on the pitch command, a thrust in the opposite direction to the pitching speed of the turbine is generated on the rotor side, thereby suppressing its pitching motion with waves. Therefore, this additional pitch command is defined as a first additional pitch command. The method for obtaining the first additional pitch command is as follows:

[0027] After performing a differential operation on the effective pitch angle of the floating foundation platform, the effective pitch angle velocity of the floating foundation platform is obtained, and then the first additional pitch command is obtained by applying a proportional gain. The calculation formula of the first additional pitch command is as follows:

[0028]

[0029] In the above formula, β fa,First Indicates the first additional pitch command; A fa represents the first additional pitch command proportional gain; Indicates the effective pitch angle of the floating foundation platform; It represents the differential of the effective pitch angle of the floating foundation platform with respect to time.

[0030] Furthermore, when a floating wind turbine performs pitching motion with waves, if an additional pitch command consistent with the fore-aft speed of the nacelle is superimposed on the pitch command, a thrust in the opposite direction to the pitching speed of the turbine is generated on the rotor side, thereby suppressing its pitching motion with waves. Therefore, this additional pitch command is defined as a second additional pitch command. The method for obtaining the second additional pitch command is as follows:

[0031] After integrating the effective front and rear acceleration of the nacelle, the effective front and rear speed of the nacelle is obtained, and then the second additional pitch command is obtained by applying a proportional gain. The calculation formula of the second additional pitch command is as follows:

[0032]

[0033] In the above formula, β fa,Second Indicates the second additional pitch command; B fa represents the second additional pitch command proportional gain; Indicates the effective fore-aft acceleration of the cabin; It represents the integral of the effective fore and aft acceleration of the cabin over time.

[0034] Furthermore, when a floating wind turbine pitches with the waves, if the rotor speed is fine-tuned to match the pitching rate, the rotor side thrust will be changed, generating thrust in the opposite direction of the turbine pitching speed, thereby suppressing its pitching with the waves. By superimposing an additional speed offset on the generator speed input by the pitch controller, the rotor speed can be adjusted.

[0035] Define additional speed offset, the specific formula is as follows:

[0036]

[0037] In the above formula, ω bias Indicates additional speed bias; C fa Indicates the additional speed bias gain of the inclination angle; It represents the differential of the effective pitch angle of the floating foundation platform with respect to time; D fa Indicates acceleration additional speed bias; It represents the integral of the effective fore and aft acceleration of the cabin over time.

[0038] Furthermore, the final speed setting value input to the pitch controller is defined as follows:

[0039]

[0040] In the above formula, Indicates the final speed setting value input to the pitch controller; ω set Indicates the rated speed setting value of the generator; ω bias Indicates additional speed bias; the comma indicates the condition.

[0041] Furthermore, the final pitch change command is defined as follows:

[0042]

[0043] In the above formula, Indicates the final pitch change instruction; β c represents the unified pitch control command output by the pitch control controller; β fa,First Indicates the first additional pitch command; β fa,Second Indicates the second additional pitch change instruction; the comma indicates the condition.

[0044] Furthermore, when the floating wind turbine is in a normal power generation state, the first additional pitch command, the second additional pitch command and the additional speed bias are superimposed to reduce the movement of the floating wind turbine with the waves, thereby reducing the fatigue load of the tower of the floating wind turbine; when the floating wind turbine is in an abnormal power generation state, in order to ensure the reliability and safety of the unit, no instructions are superimposed, wherein the abnormal power generation state includes the startup process, the shutdown process and the fault state.

[0045] The second object of the present invention is achieved by the following technical solution: a wave pitch motion control system for an offshore floating wind turbine, used to implement the above-mentioned wave pitch motion control method for an offshore floating wind turbine, comprising:

[0046] A measurement data processing module is used to collect the pitch angle of the floating foundation platform and the fore-aft acceleration of the nacelle of the floating wind turbine and perform data processing to obtain the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle;

[0047] a pitch command calculation module configured to perform differential and integral operations on the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle obtained by the measurement data processing module, and output two types of additional pitch commands, namely, a first additional pitch command and a second additional pitch command; wherein the first additional pitch command is an additional pitch command consistent with the pitch angle velocity of the floating foundation platform, and the second additional pitch command is an additional pitch command consistent with the fore-aft velocity of the nacelle;

[0048] The speed bias setting module is used to output an additional speed bias through differential and integral operations on the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle obtained by the measurement data processing module;

[0049] The instruction superposition execution module is used to superimpose the output additional speed bias with the generator speed set value input by the pitch controller of the floating wind turbine under the normal power generation state of the floating wind turbine, and superimpose the two types of output additional pitch instructions with the pitch instruction output by the pitch controller. The final pitch instruction obtained after superposition is transmitted to the pitch system of the floating wind turbine for execution.

[0050] The third object of the present invention is achieved through the following technical solution: a storage medium stores a program, and when the program is executed by a processor, the wave pitch motion control method of the above-mentioned offshore floating wind turbine is implemented.

[0051] The fourth object of the present invention is achieved through the following technical solution: a computing device, comprising a processor and a memory for storing a program executable by the processor, wherein when the processor executes the program stored in the memory, the above-mentioned wave pitch motion control method of the offshore floating wind turbine is implemented.

[0052] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0053] 1. The present invention extracts the signal of the wave frequency range from the pitch angle of the floating foundation platform, establishes a connection between the effective pitch angle of the floating foundation platform and the first additional pitch control instruction through differential and proportional operations, and generates thrust on the wind rotor to suppress the movement of the floating wind turbine with waves, thereby reducing the amplitude of the unit's movement with waves.

[0054] 2. The present invention extracts the signal of the wave frequency range from the fore-aft acceleration of the nacelle and establishes a connection between the effective fore-aft acceleration of the nacelle and the second additional pitch control instruction through integral and proportional operations, thereby generating thrust on the wind rotor to suppress the movement of the floating wind turbine with waves and reduce the amplitude of the unit's movement with waves.

[0055] 3. The present invention establishes a connection between the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle and the additional speed bias, and by adjusting the speed of the wind rotor, generates a thrust on the wind rotor that suppresses the movement of the floating wind turbine with waves, thereby reducing the amplitude of the movement of the turbine with waves.

[0056] 4. The present invention uses existing sensor measurement data and does not increase the cost of additional sensor equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 This is an architecture diagram of the system of the present invention. DETAILED DESCRIPTION

[0058] The present invention will be described in further detail below with reference to the embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0059] Example 1

[0060] This embodiment discloses a method for controlling wave pitching motion of an offshore floating wind turbine, which is characterized by performing the following operations:

[0061] a. Collect the pitch angle of the floating foundation platform and the fore-aft acceleration of the nacelle of the floating wind turbine and process the data to obtain the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle, with the following conditions:

[0062] The pitch angle of the floating foundation platform is measured by a tilt sensor. The tilt sensor is installed on the floating foundation platform of the floating wind turbine. The tilt sensor can measure the tilt angles of the floating foundation platform in two directions in real time, namely the pitch angle of the floating foundation platform and the lateral tilt angle of the floating foundation platform. The pitch angle of the floating foundation platform directly reflects the movement of the floating wind turbine under the action of waves. However, the pitch angle measured by the tilt sensor cannot be directly used for control.

[0063] If multiple inclination sensors are installed on a floating foundation platform, each inclination sensor measures the pitch angle of the floating foundation platform. The average pitch angle of the floating foundation platform can be obtained by weighted averaging data processing. The definition of the average pitch angle of the floating foundation platform is as follows:

[0064]

[0065] In the above formula, represents the average pitch angle of the floating foundation platform; k1 represents the weighting coefficient of the first tilt sensor; θ fa,1 represents the pitch angle of the floating foundation platform measured by the first tilt sensor; k2 represents the weighting coefficient of the second tilt sensor; θ fa,2 k represents the pitch angle of the floating foundation platform measured by the second tilt sensor; n Represents the weighting coefficient of the nth tilt sensor; θ fa,n represents the pitch angle of the floating foundation platform measured by the nth tilt sensor;

[0066] The pitch angle of the floating foundation platform measured by the inclination sensor contains signals of various frequencies. Only the pitch angle of the floating foundation platform in the wave frequency range can be used as the control input signal. Therefore, it is necessary to filter the measured data to extract the pitch angle of the floating foundation platform in the wave frequency range and filter out other high-frequency harmonic noise to define the effective pitch angle of the floating foundation platform. The details are as follows:

[0067]

[0068] In the above formula, Indicates the effective pitch angle of the floating foundation platform; F fa (s) represents the effective pitch filter, which contains a band-pass filter and a band-stop filter; Represents the average pitch angle of the floating foundation platform.

[0069] The nacelle's fore-aft acceleration is measured using an acceleration sensor installed on the nacelle of a floating wind turbine. The acceleration sensor can measure the nacelle's acceleration in two directions in real time: the fore-aft acceleration and the left-right acceleration. The fore-aft acceleration directly reflects the movement of the floating wind turbine under wave action. However, the nacelle acceleration measured by the acceleration sensor cannot be directly used for control.

[0070] If multiple acceleration sensors are installed on the cabin, each one measures the cabin fore-aft acceleration. The average cabin fore-aft acceleration can be obtained by weighted averaging the data. The definition of the average cabin fore-aft acceleration is as follows:

[0071]

[0072] In the above formula, represents the average front and rear acceleration of the cabin; m1 represents the weighting coefficient of the first acceleration sensor; a fa,1 represents the front and rear acceleration of the cabin measured by the first acceleration sensor; m2 represents the weighting coefficient of the second acceleration sensor; a fa,2 represents the front and rear acceleration of the cabin measured by the second acceleration sensor; m n Represents the weighting coefficient of the nth acceleration sensor; a fa,n represents the front and rear acceleration of the cabin measured by the nth acceleration sensor;

[0073] The nacelle fore-and-aft acceleration measured by the acceleration sensor contains signals of various frequencies. Only the nacelle fore-and-aft acceleration within the wave frequency range can be used as a control input signal. Therefore, it is necessary to filter the measured data to extract the nacelle fore-and-aft acceleration within the wave frequency range and filter out other high-frequency harmonic noise. This defines the effective nacelle fore-and-aft acceleration as follows:

[0074]

[0075] In the above formula, Indicates the effective front and rear acceleration of the cabin; H fa (s) represents the effective front and rear acceleration filter, which contains a band-pass filter and a band-stop filter; Indicates the average fore-aft acceleration of the cabin.

[0076] b. The obtained effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle are subjected to differential and integral operations to output two types of additional pitch control instructions, namely the first additional pitch control instruction and the second additional pitch control instruction. The specific situation is as follows:

[0077] When a floating wind turbine performs pitching motion with waves, if an additional pitch command consistent with the pitching inclination speed of the floating foundation platform is superimposed on the pitch command, a thrust in the opposite direction to the pitching speed of the turbine is generated on the rotor side, thereby suppressing its pitching motion with waves. Therefore, this additional pitch command is defined as a first additional pitch command. The method for obtaining the first additional pitch command is as follows:

[0078] After performing a differential operation on the effective pitch angle of the floating foundation platform, the effective pitch angle velocity of the floating foundation platform is obtained, and then the first additional pitch command is obtained by applying a proportional gain. The calculation formula of the first additional pitch command is as follows:

[0079]

[0080] In the above formula, β fa,First Indicates the first additional pitch command; A fa represents the first additional pitch command proportional gain; Indicates the effective pitch angle of the floating foundation platform; It represents the differential of the effective pitch angle of the floating foundation platform with respect to time.

[0081] When a floating wind turbine pitches with waves, if an additional pitch command consistent with the fore-aft speed of the nacelle is superimposed on the pitch command, a thrust in the opposite direction of the pitch speed of the turbine is generated on the rotor side, thereby suppressing its pitching with waves. Therefore, this additional pitch command is defined as a second additional pitch command. The method for obtaining the second additional pitch command is as follows:

[0082] After integrating the effective front and rear acceleration of the nacelle, the effective front and rear speed of the nacelle is obtained, and then the second additional pitch command is obtained by applying a proportional gain. The calculation formula of the second additional pitch command is as follows:

[0083]

[0084] In the above formula, β fa,Second Indicates the second additional pitch command; B fa represents the second additional pitch command proportional gain; Indicates the effective fore-aft acceleration of the cabin; It represents the integral of the effective fore and aft acceleration of the cabin over time.

[0085] c. The obtained effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle are used to output the additional speed bias through differential and integral operations. The specific situation is as follows:

[0086] When a floating wind turbine pitches with the waves, if the rotor speed is adjusted slightly to match the pitching rate, the rotor thrust will be altered, generating thrust in the opposite direction of the turbine's pitching speed, thus suppressing its pitching with the waves. By superimposing an additional speed bias on the generator speed input by the pitch controller, the rotor speed can be adjusted.

[0087] Define additional speed offset, the specific formula is as follows:

[0088]

[0089] In the above formula, ω bias Indicates additional speed bias; C fa Indicates the additional speed bias gain of the inclination angle; It represents the differential of the effective pitch angle of the floating foundation platform with respect to time; D fa Indicates acceleration additional speed bias; It represents the integral of the effective fore and aft acceleration of the cabin over time.

[0090] d. When the floating wind turbine is in a normal power generation state, the output additional speed bias is superimposed on the generator speed set value input by the pitch controller of the floating wind turbine, and the two types of output additional pitch commands are superimposed on the pitch commands output by the pitch controller. The final pitch command obtained after superposition is transmitted to the pitch system of the floating wind turbine for execution, so as to generate thrust on the wind rotor of the floating wind turbine to suppress the movement of the floating wind turbine with waves, reduce the amplitude of the movement of the floating wind turbine with waves, and thus reduce the fatigue load of the tower of the floating wind turbine; when the floating wind turbine is in an abnormal power generation state such as the startup process, shutdown process and fault state, in order to ensure the reliability and safety of the unit, no command is superimposed.

[0091] The final speed setpoint input to the pitch controller is defined as follows:

[0092]

[0093] In the above formula, Indicates the final speed setting value input to the pitch controller; ω set Indicates the rated speed setting value of the generator; ω bias Indicates additional speed bias; the comma indicates the condition.

[0094] The final pitch change command is defined as follows:

[0095]

[0096] In the above formula, Indicates the final pitch change instruction; β crepresents the unified pitch control command output by the pitch control controller; β fa,First Indicates the first additional pitch command; β fa,Second Indicates the second additional pitch change instruction; the comma indicates the condition.

[0097] Example 2

[0098] This embodiment discloses a wave pitch motion control system for an offshore floating wind turbine, which is used to implement the wave pitch motion control method for an offshore floating wind turbine described in Example 1. Figure 1 As shown, the system includes the following functional modules:

[0099] A measurement data processing module is used to collect the pitch angle of the floating foundation platform and the fore-aft acceleration of the nacelle of the floating wind turbine and perform data processing to obtain the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle;

[0100] a pitch command calculation module configured to perform differential and integral operations on the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle obtained by the measurement data processing module, and output two types of additional pitch commands, namely, a first additional pitch command and a second additional pitch command; wherein the first additional pitch command is an additional pitch command consistent with the pitch angle velocity of the floating foundation platform, and the second additional pitch command is an additional pitch command consistent with the fore-aft velocity of the nacelle;

[0101] The speed bias setting module is used to output an additional speed bias through differential and integral operations on the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle obtained by the measurement data processing module;

[0102] The instruction superposition execution module is used to superimpose the output additional speed bias with the generator speed set value input by the pitch controller of the floating wind turbine under the normal power generation state of the floating wind turbine, and superimpose the two types of output additional pitch instructions with the pitch instruction output by the pitch controller. The final pitch instruction obtained after superposition is transmitted to the pitch system of the floating wind turbine for execution.

[0103] Example 3

[0104] This embodiment discloses a storage medium storing a program. When the program is executed by a processor, the wave pitch motion control method of the offshore floating wind turbine described in Example 1 is implemented.

[0105] The storage medium in this embodiment can be a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), a USB flash drive, a mobile hard disk, or the like.

[0106] Example 4

[0107] This embodiment discloses a computing device, including a processor and a memory for storing a program executable by the processor. When the processor executes the program stored in the memory, the wave pitch motion control method of the offshore floating wind turbine described in Example 1 is implemented.

[0108] The computing device described in this embodiment may be a desktop computer, a laptop computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC), or other terminal devices with a processor function.

[0109] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for controlling wave pitch motion of an offshore floating wind turbine, characterized in that: Do the following: Collect the pitch angle of the floating foundation platform and the fore-aft acceleration of the nacelle of the floating wind turbine and process the data to obtain the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle; The obtained effective pitch angle of the floating base platform and the effective fore-aft acceleration of the nacelle are subjected to differential and integral operations to output two types of additional pitch commands, namely, a first additional pitch command and a second additional pitch command; wherein the first additional pitch command is an additional pitch command consistent with the pitch angle velocity of the floating base platform, and the second additional pitch command is an additional pitch command consistent with the fore-aft velocity of the nacelle; The obtained effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle are used to output an additional speed bias through differential and integral operations; In the normal power generation state of the floating wind turbine, the output additional speed bias is superimposed on the generator speed set value input by the pitch controller of the floating wind turbine, and the two types of output additional pitch commands are superimposed on the pitch commands output by the pitch controller. The final pitch command obtained after superposition is transmitted to the pitch system of the floating wind turbine for execution, so as to generate thrust on the wind rotor of the floating wind turbine to suppress the movement of the floating wind turbine with waves, thereby reducing the amplitude of the movement of the floating wind turbine with waves; When a floating wind turbine performs pitching motion with waves, if an additional pitch command consistent with the pitching inclination speed of the floating foundation platform is superimposed on the pitch command, a thrust in the opposite direction to the pitching speed of the turbine is generated on the rotor side, thereby suppressing its pitching motion with waves. Therefore, this additional pitch command is defined as a first additional pitch command. The method for obtaining the first additional pitch command is as follows: After performing a differential operation on the effective pitch angle of the floating foundation platform, the effective pitch angle velocity of the floating foundation platform is obtained, and then the first additional pitch command is obtained by applying a proportional gain. The calculation formula of the first additional pitch command is as follows: In the above formula, β fa,First Indicates the first additional pitch command; A fa represents the first additional pitch command proportional gain; Indicates the effective pitch angle of the floating foundation platform; It represents the differential of the effective pitch angle of the floating foundation platform with respect to time; When a floating wind turbine pitches with waves, if an additional pitch command consistent with the fore-aft speed of the nacelle is superimposed on the pitch command, a thrust in the opposite direction of the pitch speed of the turbine is generated on the rotor side, thereby suppressing its pitching with waves. Therefore, this additional pitch command is defined as a second additional pitch command. The method for obtaining the second additional pitch command is as follows: After integrating the effective front and rear acceleration of the nacelle, the effective front and rear speed of the nacelle is obtained, and then the second additional pitch command is obtained by applying a proportional gain. The calculation formula of the second additional pitch command is as follows: In the above formula, β fa,Second Indicates the second additional pitch command; B fa represents the second additional pitch command proportional gain; Indicates the effective fore-aft acceleration of the cabin; It represents the integral of the effective fore and aft acceleration of the cabin over time; The final pitch change command is defined as follows: In the above formula, Indicates the final pitch change instruction; β c represents the unified pitch control command output by the pitch control controller; β fa,First Indicates the first additional pitch command; β fa,Second Indicates the second additional pitch change instruction; the comma indicates the condition.

2. The method for controlling wave pitching motion of an offshore floating wind turbine according to claim 1, characterized in that: The pitch angle of the floating foundation platform is measured by a tilt sensor, which is installed on the floating foundation platform of the floating wind turbine. The tilt sensor can measure the tilt angles of the floating foundation platform in two directions in real time, namely the pitch angle of the floating foundation platform and the lateral tilt angle of the floating foundation platform; When multiple inclination sensors are installed on a floating foundation platform, each inclination sensor measures the pitch angle of the floating foundation platform. The average pitch angle of the floating foundation platform is obtained by weighted averaging the data. The definition of the average pitch angle of the floating foundation platform is as follows: In the above formula, represents the average pitch angle of the floating foundation platform; k1 represents the weighting coefficient of the first tilt sensor; θ fa,1 represents the pitch angle of the floating foundation platform measured by the first tilt sensor; k2 represents the weighting coefficient of the second tilt sensor; θ fa,2 k represents the pitch angle of the floating foundation platform measured by the second tilt sensor; n Represents the weighting coefficient of the nth tilt sensor; θ fa,n represents the pitch angle of the floating foundation platform measured by the nth tilt sensor; The pitch angle of the floating foundation platform in the wave frequency range is taken out, and other high-frequency harmonic noises are filtered out to define the effective pitch angle of the floating foundation platform, as follows: In the above formula, Indicates the effective pitch angle of the floating foundation platform; F fa (s) represents the effective pitch filter, which contains a band-pass filter and a band-stop filter; Represents the average pitch angle of the floating foundation platform.

3. The method for controlling wave pitching motion of an offshore floating wind turbine according to claim 2, characterized in that: Measuring the front and rear acceleration of the nacelle by an acceleration sensor, which is installed on the nacelle of the floating wind turbine. The acceleration sensor can measure the acceleration of the nacelle in two directions in real time, namely the front and rear acceleration of the nacelle and the left and right acceleration of the nacelle; If multiple acceleration sensors are installed on the cabin, each one measures the cabin fore-aft acceleration. The average cabin fore-aft acceleration is obtained by weighted averaging the data. The definition of the average cabin fore-aft acceleration is as follows: In the above formula, represents the average front and rear acceleration of the cabin; m1 represents the weighting coefficient of the first acceleration sensor; a fa,1 represents the front and rear acceleration of the cabin measured by the first acceleration sensor; m2 represents the weighting coefficient of the second acceleration sensor; a fa,2 represents the front and rear acceleration of the cabin measured by the second acceleration sensor; m n Represents the weighting coefficient of the nth acceleration sensor; a fa,n represents the front and rear acceleration of the cabin measured by the nth acceleration sensor; The nacelle's fore-and-aft acceleration in the wave frequency range is extracted, and other high-frequency harmonic noise is filtered out to define the nacelle's effective fore-and-aft acceleration as follows: In the above formula, Indicates the effective front and rear acceleration of the cabin; H fa (s) represents the effective front and rear acceleration filter, which contains a band-pass filter and a band-stop filter; Indicates the average fore-aft acceleration of the cabin.

4. The method for controlling wave pitching motion of an offshore floating wind turbine according to claim 3, characterized in that: When a floating wind turbine pitches with the waves, if the rotor speed is adjusted slightly to match the pitching rate, the rotor thrust will be altered, generating thrust in the opposite direction of the turbine's pitching speed, thus suppressing its pitching with the waves. By superimposing an additional speed bias on the generator speed input by the pitch controller, the rotor speed can be adjusted. Define additional speed offset, the specific formula is as follows: In the above formula, ω bias Indicates additional speed bias; C fa Indicates the additional speed bias gain of the inclination angle; It represents the differential of the effective pitch angle of the floating foundation platform with respect to time; D fa Indicates acceleration additional speed bias; It represents the integral of the effective fore and aft acceleration of the cabin over time.

5. The method for controlling wave pitching motion of an offshore floating wind turbine according to claim 4, characterized in that: The final speed setpoint input to the pitch controller is defined as follows: In the above formula, Indicates the final speed setting value input to the pitch controller; ω set Indicates the rated speed setting value of the generator; ω bias Indicates additional speed bias; The comma indicates the condition.

6. The method for controlling wave pitching motion of an offshore floating wind turbine according to claim 5, characterized in that: When the floating wind turbine is in a normal power generation state, the first additional pitch command, the second additional pitch command and the additional speed bias are superimposed to reduce the movement of the floating wind turbine with the waves, thereby reducing the fatigue load of the tower of the floating wind turbine; when the floating wind turbine is in an abnormal power generation state, in order to ensure the reliability and safety of the unit, no instructions are superimposed, wherein the abnormal power generation state includes the startup process, the shutdown process and the fault state.

7. A wave pitch motion control system for an offshore floating wind turbine, characterized in that: A method for controlling wave pitching motion of an offshore floating wind turbine according to any one of claims 1 to 6, comprising: A measurement data processing module is used to collect the pitch angle of the floating foundation platform and the fore-aft acceleration of the nacelle of the floating wind turbine and perform data processing to obtain the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle; a pitch command calculation module configured to perform differential and integral operations on the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle obtained by the measurement data processing module, and output two types of additional pitch commands, namely, a first additional pitch command and a second additional pitch command; wherein the first additional pitch command is an additional pitch command consistent with the pitch angle velocity of the floating foundation platform, and the second additional pitch command is an additional pitch command consistent with the fore-aft velocity of the nacelle; The speed bias setting module is used to output an additional speed bias through differential and integral operations on the effective pitch angle of the floating foundation platform and the effective fore-aft acceleration of the nacelle obtained by the measurement data processing module; The instruction superposition execution module is used to superimpose the output additional speed bias with the generator speed set value input by the pitch controller of the floating wind turbine under the normal power generation state of the floating wind turbine, and superimpose the two types of output additional pitch instructions with the pitch instruction output by the pitch controller. The final pitch instruction obtained after superposition is transmitted to the pitch system of the floating wind turbine for execution.

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