Limit load control method and system for wind turbine single blade stuck

Abstract

The application discloses a kind of wind generating set single blade dead limit load reduction control method and system, when the blade angle setting value of single blade and the actual blade angle measurement value deviation is greater than a certain threshold and the variable pitch rate of the blade is less than a certain threshold, trigger single blade dead fault, enter dead pitch shutdown mode, during shutdown process, first reduce generator speed setting value, make generator speed drop according to preset rate, at this time, blade is controlled by variable pitch PI, simultaneously control generator torque, when generator speed drops to a certain threshold, then according to preset rate, pitch-in shutdown is carried out.The application reduces generator speed setting value, controls the variable pitch of non-dead blade and generator torque, reduces the limit load of each component of unit, to improve the safety of unit, reduce the design cost of unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind power generation, and particularly to a wind turbine unit single-blade jamming limit load reduction control method, system, storage medium and computing device. BACKGROUND

[0002] At present, the overall wind turbine unit is developing towards high power, high tower and long blade design and manufacturing. Under the background of wind power bidding and parity, reducing the cost of electricity has become an urgent demand and key factor for current and future wind power development. According to the IEC standard, blade jamming is a fault condition that needs to be considered in the design load calculation stage of the wind turbine unit. When a blade appears jamming and cannot perform normal variable pitch action, the unit will control the non-jamming blade to achieve its pitch stop. If the unit still runs with a fault, the unit will face the risk of overspeed in the case of sudden increase in wind speed, and the aerodynamic unbalanced load of the three blades will also have a great impact on the service life of the unit. However, with the continuous increase of blade length and power, if the unit still adopts the traditional pitch stop strategy after the occurrence of jamming fault, only relying on reducing the pitch rate to reduce the limit load during the stop process cannot meet the load requirements of the overall design. At high speed, direct and continuous pitch action will exacerbate the aerodynamic unbalanced load of the three blades, resulting in a large limit load on the hub and yaw components, which will greatly increase the cost of unit components. Therefore, it is necessary to develop a limit load reduction method suitable for the jamming condition of the wind turbine unit to reduce the limit load of each component of the unit, thereby reducing the design cost of the unit.

[0003] In the existing load control technology under the jamming condition, the variable rate pitch stop control is performed according to the blade azimuth angle and the left-right direction acceleration measurement value during the stop process. However, under the condition of jamming, the unbalanced load of the blade is already large, and frequent switching of the pitch rate may exacerbate the aerodynamic unbalanced load of the blade. In addition, no matter what pitch rate is used, as long as there is a direct and continuous pitch action, it will cause changes in the aerodynamic unbalanced load between the blades, and the goal of load reduction cannot be completely achieved. In addition, the blade angle, blade azimuth angle and left-right direction acceleration of the nacelle jointly determine the final output pitch rate value, so the real-time and accuracy of multiple input variables are also problems to be considered.

[0004] In the existing load control technology under the jamming condition, after the occurrence of jamming fault, the generator torque of the unit is increased to 1.6 times the rated torque during the stop process. This control method requires a high-performance converter, which needs to have the ability to withstand a large torque even greater than the rated torque at low speed or even grid-connected speed. This will increase the cost of the converter to some extent, and will also have some impact on the service life of the converter. SUMMARY

[0005] The first object of the present application is to overcome the shortcomings and deficiencies of the prior art, and provide a safe and reliable extreme load reduction control method for a single-blade stuck wind turbine generator set, which does not immediately execute the pitch-in and shutdown after the fault is triggered, but first reduces the speed setting value, and then executes the pitch-in and shutdown when the speed is low, thereby reducing the unbalanced load aggravated by directly executing the pitch-in action at high speed, further reducing the extreme load of each component of the set, and the torque setting value during the shutdown process is given within the range that the converter can withstand, without increasing the cost of the converter, and ensuring the safe operation of the converter, thereby improving the safety of the set and reducing the design cost of the set.

[0006] The second object of the present application is to provide an extreme load reduction control system for a single-blade stuck wind turbine generator set.

[0007] The third object of the present application is to provide a storage medium.

[0008] The fourth object of the present application is to provide a computing device.

[0009] The first object of the present application is achieved by the following technical solution: an extreme load reduction control method for a single-blade stuck wind turbine generator set, when the deviation between the pitch angle setting value of a single blade and the actual pitch angle measurement value is greater than a certain threshold value and the pitch rate of the blade is less than a certain threshold value, a single-blade stuck fault is triggered, and a stuck pitch shutdown mode is entered, during the shutdown process, the generator speed setting value is first reduced, the generator speed is lowered at a preset rate, at this time the blade is controlled by pitch PI control, and the generator torque is controlled, and when the generator speed is lowered to a certain threshold value, the pitch-in and shutdown is performed at a preset rate.

[0010] Further, the extreme load reduction control method for a single-blade stuck wind turbine generator set performs the following steps:

[0011] Based on the actual pitch angle measurement value of each blade, the deviation between the actual pitch angle measurement value of each blade and the pitch angle setting value is calculated, when the deviation is greater than a certain threshold value and the pitch rate of the blade is less than a certain threshold value, it is judged that the blade is in a stuck state, and then the stuck pitch shutdown mode is entered;

[0012] When the wind turbine generator set enters the stuck pitch shutdown mode, considering that the direct pitch-in and shutdown of the wind turbine generator set at high speed will aggravate the unbalanced load of the three blades, the wind turbine generator set does not immediately execute the pitch-in and shutdown after the fault occurs, but first reduces the generator speed setting value, and lets the generator speed decrease at a preset rate, at this time the non-stuck blade is controlled by pitch PI control by measuring the deviation between the generator speed and the generator speed setting value, and when the measured generator speed is lowered to a certain threshold value, the non-stuck blade performs the pitch-in and shutdown at a preset rate.

[0013] When the wind turbine enters the pitch stall shutdown mode, the generator torque is controlled according to the current measured generator speed, that is, the generator torque is adjusted in real time according to the measured generator speed, the corresponding generator torque set value is obtained through the generator measured speed-torque set value lookup table in the pitch stall shutdown mode, and then the generator torque set value is responded by the converter of the wind turbine; wherein the generator torque set value in the generator measured speed-torque set value lookup table in the pitch stall shutdown mode can be adjusted according to the load shedding demand, but it must be within the bearing range of the converter, and when the measured power of the wind turbine is less than a certain threshold, the generator torque set value is 0.

[0014] Further, each blade of the wind turbine is provided with a pitch angle sensor, through which the actual pitch angle measurement value of each blade can be obtained, and θ i represents the pitch angle measurement value of the blade, i = 1, 2, 3, i = 1 represents blade 1, i = 2 represents blade 2, and i = 3 represents blade 3, represents the pitch rate of the blade, D i represents the pitch angle set value of the blade, then the deviation Δθ i of the pitch angle measurement value of each blade from the pitch angle set value is i - i , the maximum value of the allowed pitch angle deviation is set as Δθ max , δ represents the allowed pitch rate measurement deviation value, which is a number close to 0, when Δθ i > Δθ max and , it is judged that the blade is in the pitch stall state, and then the pitch stall shutdown mode is entered.

[0015] Further, when the wind turbine enters the pitch stall shutdown mode, the generator speed set value is modified to the grid-connected speed S1, and the generator speed is lowered at a preset rate V, at this time the pitch angle θ dem of the non-pitch stall blade is controlled by measuring the deviation of the generator speed S from the grid-connected speed S1, when the generator speed S is lowered to α * S rated , the non-pitch stall blade is further pitched in according to the preset rate V1 to stop the shutdown, until the pitch angle reaches the maximum shutdown pitch angle; wherein the S rated is the rated generator speed, and α is a decimal number between 0 and 1, which is a percentage of the rated generator speed, and can be determined according to actual load simulation calculation.

[0016] Further, in the generator measured speed-torque set value lookup table in the pitch stall shutdown mode, the column of generator speed, from small to large, from left to right, is S minS1, S2, S rated S over The column of generator torque set value corresponds to the above-mentioned S min S1, S2, S rated S over From small to large, from left to right, they are 0, T1, T2, T3, T4, wherein, S min is the off-grid rotating speed of the converter, S2 is the synchronous rotating speed of the generator, S over is the software overspeed threshold value, which is set as a multiple of the rated rotating speed of the generator.

[0017] Further, the wind turbine generator set is provided with a sensor for measuring the generator rotating speed.

[0018] The second object of the application is achieved by the following technical scheme: a wind turbine generator set single-blade jamming limit load reduction control system for implementing the wind turbine generator set single-blade jamming limit load reduction control method, which comprises:

[0019] A blade jamming judgment module calculates the deviation of the actual blade angle measurement value of each blade from the blade angle set value based on the actual blade angle measurement value of each blade, and when the deviation is greater than a certain threshold value and the variable pitch rate of the blade is less than a certain threshold value, it is judged that the blade is in the blade jamming state, and then enters the blade jamming shutdown mode;

[0020] A variable pitch control module is used to reduce the generator rotating speed set value after the wind turbine generator set enters the blade jamming shutdown mode, so that the generator rotating speed decreases at a preset rate, and at this time, the non-blade jamming blades perform variable pitch PI control by measuring the deviation of the generator rotating speed from the generator rotating speed set value, and when the measured generator rotating speed decreases to a certain threshold value, the non-blade jamming blades perform pitch shutdown at a preset rate;

[0021] A generator torque control module is used to control the generator torque according to the current measured generator rotating speed after the wind turbine generator set enters the blade jamming shutdown mode, that is, to adjust the generator torque in real time according to the measured generator rotating speed, to obtain the corresponding generator torque set value through the generator measured rotating speed-torque set value lookup table in the blade jamming shutdown mode, and then the converter of the wind turbine generator set responds to the generator torque set value; wherein the generator torque set value in the generator measured rotating speed-torque set value lookup table in the blade jamming shutdown mode can be adjusted according to the load reduction demand, but it must be within the bearing range of the converter, and when the measured power of the wind turbine generator set is less than a certain threshold value, the generator torque set value is 0.

[0022] The third object of the present application is achieved by the following technical solution: a storage medium, which stores a program, the program being executed by a processor to implement the wind turbine unit single blade stuck limit load reduction control method.

[0023] The fourth object of the present application is achieved by the following technical solution: a computing device, comprising a processor and a memory for storing a program executable by the processor, the processor executing the program stored in the memory to implement the wind turbine unit single blade stuck limit load reduction control method.

[0024] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0025] 1. The present application improves the shutdown control logic on the basis of the existing single blade stuck control method, does not increase the requirements for the original system hardware configuration of the unit, and avoids increasing the hardware development cost.

[0026] 2. The present application improves the pitch control logic of the non-stuck blade during shutdown according to the original single blade stuck fault alarm logic, does not change the safety chain fault alarm logic of the unit, and does not affect the overall safety of the unit.

[0027] 3. The present application does not immediately execute the pitch-in shutdown after triggering the stuck fault, but first reduces the generator speed set value, and then pitches in the shutdown at a certain rate when the generator speed drops to a certain threshold, so that the unbalanced load of the three blades is effectively reduced.

[0028] 4. The generator torque set value during shutdown in the present application is given within the range that the converter can withstand, which does not increase the cost of the converter and can also ensure the safe operation of the converter.

[0029] 5. The present application details the shutdown logic after the single blade stuck fault occurs, which can effectively solve the problem of large hub load of the large wind turbine unit under single blade stuck working condition, and the hub system load meets the design requirements according to the logic. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 Figure 1 is a stuck fault shutdown control logic diagram.

[0031] Figure 2 Figure 5 is a hub bending moment load timing comparison diagram.

[0032] Figure 3 Figure 6 is a yaw bending moment load timing comparison diagram.

[0033] Figure 4 Figure 7 is a blade 2 angle timing comparison diagram.

[0034] Figure 5 Figure 8 is an architecture diagram of the system of the present application. DETAILED DESCRIPTION

[0035] 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.

[0036] Example 1

[0037] like Figure 1 As shown, this embodiment discloses a method for controlling the extreme load reduction when a single blade of a wind turbine generator set is stuck, and specifically performs the following steps:

[0038] Each blade of the wind turbine is equipped with a blade angle sensor, which can obtain the actual blade angle measurement value of each blade. Based on the actual blade angle measurement value of each blade, the deviation between the actual blade angle measurement value of each blade and the blade angle set value can be calculated; let θ i Indicates the blade angle measurement value of the blade, i=1,2,3, when i=1 it represents blade 1, when i=2 it represents blade 2, when i=3 it represents blade 3, represents the blade pitch rate, D i represents the blade angle setting value of the blade, then the deviation Δθ between the blade angle measurement value and the blade angle setting value of each blade i =|θ i -D i |, the maximum allowable blade angle deviation is set to Δθ max , δ represents the allowable pitch rate measurement deviation value, which is close to 0. i >Δθ max and When the blade is judged to be in a stuck state, the engine enters the stuck propeller shutdown mode.

[0039] When the wind turbine generator set enters the stuck blade shutdown mode, considering that the wind turbine generator set will aggravate the unbalanced load of the three blades if it is shut down by retracting the blades directly at high speed, the wind turbine generator set does not immediately execute the retracting blade shutdown after the fault occurs. Instead, the generator speed setting value is modified to the grid-connected speed S1, and the generator speed is reduced according to the preset rate V. Generally, the wind turbine generator set is basically equipped with a sensor to measure the generator speed. At this time, the blade angle θ of the non-stuck blade dem By measuring the deviation between the generator speed S and the grid-connected speed S1, the pitch PI control is performed. When the generator speed S drops to α*S rated When the blades that are not stuck are retracted and stopped at the preset rate V1, the blade angle reaches the maximum feathering angle for shutdown. The pitch angle of the blades that are not stuck changes as follows: Figure 4 As shown by the dotted line; wherein, the S ratedis the rated speed of the generator, α is a decimal between 0 and 1, which is the percentage of the rated speed of the generator and can be determined based on the actual load simulation calculation.

[0040] When the wind turbine generator set enters the pitch-stuck shutdown mode, the generator torque is controlled according to the currently measured generator speed, that is, the generator torque is adjusted in real time according to the measured generator speed. The corresponding generator torque setting value is obtained by looking up the generator measured speed-torque setting value table in the pitch-stuck shutdown mode shown in Table 1, and then the converter of the wind turbine generator set responds to the generator torque setting value; among which, the generator torque setting value in the generator measured speed-torque setting value lookup table in the pitch-stuck shutdown mode can be adjusted according to the load reduction demand, but it must be within the tolerance range of the converter. When the measured power of the wind turbine generator set is less than a certain threshold, the generator torque setting value is 0.

[0041] Table 1 Generator measured speed-torque setting value lookup table in propeller-stuck shutdown mode

[0042]

[0043]

[0044] In Table 1, the generator speed column is S from small to large and from left to right. min , S1, S2, S rated 、S over , the generator torque setting value column corresponds to the above S min , S1, S2, S rated 、S over From small to large, from left to right, they are 0, T1, T2, T3, T4, among which S min is the off-grid speed of the converter, S2 is the synchronous speed of the generator, S over It is the software overspeed threshold, which is generally set to 1.12 times the rated speed of the generator.

[0045] Compared with the original control mode (i.e., after the stuck blade fault is triggered, the non-stuck blades will immediately perform the blade retraction and shutdown action), the new shutdown logic can significantly reduce the hub bending moment and yaw bending moment limit loads of the turbine. Figure 2 、 Figure 3 shown.

[0046] Example 2

[0047] This embodiment discloses a wind turbine generator set single blade stuck extreme load reduction control system, which is used to implement the wind turbine generator set single blade stuck extreme load reduction control method described in Example 1, such as Figure 5 As shown, the system includes the following functional modules:

[0048] The pitch judging module calculates the deviation between the actual pitch angle measurement value of each blade and the pitch angle setting value based on the actual pitch angle measurement value of each blade, judges that the blade is in the pitch jam state when the deviation is greater than a certain threshold value and the pitch rate of the blade is less than a certain threshold value, and then enters the pitch jam shutdown mode.

[0049] The pitch control module is configured to, after the wind turbine enters the pitch jam shutdown mode, not immediately perform the pitch-in shutdown, but first reduce the generator speed setting value, so that the generator speed decreases at a preset rate, and at this time, the non-pitch-jam blade performs pitch-in PI control by measuring the deviation between the generator speed and the generator speed setting value, and when the measured generator speed decreases to a certain threshold value, the non-pitch-jam blade performs the pitch-in shutdown at a preset rate.

[0050] The generator torque control module is configured to, after the wind turbine enters the pitch jam shutdown mode, control the generator torque according to the current measured generator speed, that is, adjust the generator torque in real time according to the measured generator speed, obtain the corresponding generator torque setting value through the generator measured speed-torque setting value lookup table in the pitch jam shutdown mode, and then the converter of the wind turbine responds to the generator torque setting value. In the generator measured speed-torque setting value lookup table in the pitch jam shutdown mode, the generator torque setting value can be adjusted according to the load shedding demand, but must be within the bearing range of the converter. When the measured power of the wind turbine is less than a certain threshold value, the generator torque setting value is 0.

[0051] Embodiment 3

[0052] The embodiment discloses a storage medium, which stores a program. When the program is executed by a processor, the wind turbine single-pitch-jam extreme load shedding control method in embodiment 1 is realized.

[0053] The storage medium in the embodiment can be a disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), a U disk, a mobile hard disk, or the like.

[0054] Embodiment 4

[0055] The embodiment discloses a computing device, which comprises a processor and a memory for storing a program executable by the processor. When the processor executes the program stored in the memory, the wind turbine single-pitch-jam extreme load shedding control method in embodiment 1 is realized.

[0056] The computing device described in the embodiments can be a desktop computer, a notebook computer, a smart phone, a PDA handheld terminal, a tablet computer, a programmable logic controller (PLC), or other terminal device with processor function.

[0057] The above embodiments are preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application should be equivalent replacement methods and should be included in the protection scope of the present application.

Claims

1. A method for controlling the extreme load reduction when a single blade of a wind turbine generator set is stuck, characterized in that: When the deviation between the blade angle setting value of a single blade and the actual blade angle measurement value is greater than a certain threshold and the pitch rate of the blade is less than a certain threshold, a single blade stuck fault is triggered and the engine enters the stuck-blade shutdown mode. During the shutdown process, the generator speed setting value is first reduced so that the generator speed decreases at a preset rate. At this time, the blade is controlled by the pitch PI and the generator torque is controlled at the same time. When the generator speed drops to a certain threshold, the blade is retracted and shut down at a preset rate. The following steps are performed: Based on the actual blade angle measurement value of each blade, the deviation between the actual blade angle measurement value and the blade angle set value is calculated. When the deviation is greater than a certain threshold and the pitch rate of the blade is less than a certain threshold, the blade is judged to be in a stuck state and the engine enters the stuck blade shutdown mode. When the wind turbine generator set enters the stuck-pitch shutdown mode, considering that the direct blade retraction and shutdown of the wind turbine generator set at high speed will aggravate the unbalanced load of the three blades, the wind turbine generator set does not immediately perform the blade retraction and shutdown after the fault occurs. Instead, it first reduces the generator speed setting value, allowing the generator speed to drop at a preset rate. At this time, the non-stuck-pitch blades perform variable pitch PI control by measuring the deviation between the generator speed and the generator speed setting value. When the measured generator speed drops to a certain threshold, the non-stuck-pitch blades are retracted and shut down at a preset rate. When the wind turbine generator set enters the pitch-stuck shutdown mode, the generator torque is controlled according to the currently measured generator speed, that is, the generator torque is adjusted in real time according to the measured generator speed, and the corresponding generator torque setting value is obtained by looking up the generator measured speed-torque setting value table in the pitch-stuck shutdown mode, and then the converter of the wind turbine generator set responds to the generator torque setting value; among them, the generator torque setting value in the generator measured speed-torque setting value lookup table in the pitch-stuck shutdown mode can be adjusted according to the load reduction demand, but it must be within the tolerance range of the converter. When the measured power of the wind turbine generator set is less than a certain threshold, the generator torque setting value is 0.

2. The extreme load reduction control method for a stuck single blade of a wind turbine generator set according to claim 1, characterized in that: Each blade of the wind turbine is equipped with a blade angle sensor, which can obtain the actual blade angle measurement value of each blade. represents the blade angle measurement of the blade, ,when Hour represents leaf 1, Hour represents leaf 2, Hour represents leaf 3, represents the blade pitch rate, Indicates the blade angle setting value of the blade, then the deviation between the blade angle measurement value of each blade and the blade angle setting value The maximum allowable blade angle deviation is set to , Indicates the allowable pitch rate measurement deviation value, which is close to 0. and When the blade is judged to be in a stuck state, the engine enters the stuck propeller shutdown mode.

3. The extreme load reduction control method for a stuck single blade of a wind turbine generator set according to claim 1, characterized in that: When the wind turbine enters the stuck-propeller shutdown mode, the generator speed setting value is changed to the grid-connected speed. , let the generator speed follow the preset rate Descending, the blade angle of the non-stuck blade By measuring the generator speed and grid-connected speed The deviation of the pitch PI control is performed, when the generator speed Descend to When the non-stuck blades are The propeller is retracted and the engine is stopped until the propeller blade angle reaches the maximum angle for stopping and feathering. is the rated speed of the generator, It is a decimal between 0 and 1, which is a percentage of the rated speed of the generator and can be determined based on actual load simulation calculations.

4. The extreme load reduction control method for a stuck single blade of a wind turbine generator set according to claim 3, characterized in that: In the generator speed measurement-torque setting value lookup table in the stuck propeller shutdown mode, the generator speed column is as follows from small to large and from left to right: 、 、 、 、 , the generator torque setting value column corresponds to the above 、 、 、 、 From small to large, from left to right, they are 0, T1, T2, T3, T4, among which, is the off-grid speed of the converter, is the synchronous speed of the generator, It is the software overspeed threshold, which is set as a multiple of the rated speed of the generator.

5. The extreme load reduction control method for a stuck single blade of a wind turbine generator set according to claim 1, characterized in that: The wind turbine generator set is equipped with a sensor to measure the generator rotation speed.

6. The extreme load reduction control system for a wind turbine blade stuck is characterized by: A method for implementing an extreme load reduction control method for a wind turbine generator set with a single blade stuck according to any one of claims 1 to 5, comprising: The stuck blade judgment module calculates the deviation between the actual blade angle measurement value of each blade and the blade angle setting value based on the actual blade angle measurement value of each blade. When the deviation is greater than a certain threshold and the pitch rate of the blade is less than a certain threshold, the blade is judged to be in the stuck blade state and the engine enters the stuck blade shutdown mode. The pitch control module is used to not immediately perform pitch retraction and shutdown after the wind turbine enters the stuck-pitch shutdown mode, but first reduce the generator speed set value to allow the generator speed to drop at a preset rate. At this time, the non-stuck-pitch blades perform pitch PI control by measuring the deviation between the generator speed and the generator speed set value. When the measured generator speed drops to a certain threshold, the non-stuck-pitch blades are retracted and shut down at a preset rate. The generator torque control module is used to control the generator torque according to the currently measured generator speed after the wind turbine generator set enters the pitch-stuck shutdown mode, that is, to adjust the generator torque in real time according to the measured generator speed, and obtain the corresponding generator torque setting value by looking up the generator measured speed-torque setting value table in the pitch-stuck shutdown mode, and then the converter of the wind turbine generator set responds to the generator torque setting value; among which, the generator torque setting value in the generator measured speed-torque setting value lookup table in the pitch-stuck shutdown mode can be adjusted according to the load reduction demand, but it must be within the tolerance range of the converter. When the measured power of the wind turbine generator set is less than a certain threshold, the generator torque setting value is 0.

7. A storage medium storing a program, characterized in that: When the program is executed by a processor, the extreme load reduction control method for a stuck single blade of a wind turbine generator set according to any one of claims 1 to 5 is implemented.

8. A computing device comprising a processor and a memory for storing a program executable by the processor, characterized in that: When the processor executes the program stored in the memory, the extreme load reduction control method for a stuck single blade of a wind turbine generator set according to any one of claims 1 to 5 is implemented.

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