Control method and system for reducing load of wind turbine generator under blade jamming working condition

Abstract

The invention discloses a control method and system for reducing the load of a wind turbine generator under the blade jamming working condition, and the method comprises the steps: after triggering the blade jamming fault, not feathering a non-fault blade, limiting the blade opening action of the non-fault blade, enabling the generator to laterally face wind at a preset angle in an active yawing manner, and enabling the wind turbine generator to generate the wind at a preset angle. Meanwhile, the maximum torque capable of being supported by the unit is continuously output, and the set value of the rotating speed of the unit is slowly reduced, so that the rotating speed of the unit is reduced, fault blades and non-fault blades are kept in a close state as far as possible in a short time, and after the rotating speed of the unit is reduced to a preset threshold value, the non-fault blades are commanded to perform feathering; and the feathering rate is switched according to the derivative of the pitch angle by the wind energy utilization coefficient, so that the load reduction capability of the unit on the blade stuck working condition is improved. According to the invention, the large part load of the wind generating set under the working condition that the blades are stuck can be effectively reduced, and the safety of the wind generating set is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a control method, system, storage medium and computing device for reducing the load of a wind turbine generator set under a blade stuck condition. Background Art

[0002] The blade jam condition is an extreme condition defined by the IEC standard, which is intended to simulate and verify whether the strength of the unit's components can withstand the impact of the extreme load when one of the unit's blades cannot move. In this condition, since one of the blades cannot move, if the other two blades are quickly aligned, the unbalanced load of the unit will increase rapidly, resulting in a load peak. With the increasing capacity and blade length of wind turbines, the maximum extreme loads of the unit's hub and yaw moment are more likely to occur in the blade jam condition, becoming a bottleneck condition for controlling the unit's extreme loads and a major test of the unit's safety.

[0003] At present, the research on load reduction control methods under the condition of blade jam has gradually been taken seriously by the main engine manufacturers, and some results have been achieved. The main idea is to reduce the speed of the unit first and then feather the propeller. However, in order to reduce the speed of the unit, it is necessary to retract the non-faulty blades to a certain extent. Although the retracting action is slow, it will undoubtedly increase the unbalanced load between the faulty blades and the non-faulty blades, and will still inhibit the effect of load reduction to a certain extent. Summary of the invention

[0004] The first purpose of the present invention is to solve the problem of excessive load on large components of a wind turbine when encountering a blade stuck condition, such as the hub and yaw bending moment, and to provide a control method for reducing the load on a wind turbine under a blade stuck condition, which can effectively reduce the load on large components of the unit under the blade stuck condition and greatly improve the safety of the wind turbine.

[0005] A second object of the present invention is to provide a control system for reducing the load of a wind turbine generator set under a blade stuck condition.

[0006] A third object of the present invention is to provide a storage medium.

[0007] A fourth object of the present invention is to provide a computing device.

[0008] The first objective of the present invention is achieved through the following technical solutions: a control method for reducing the load of a wind turbine under a blade jam condition, wherein after triggering the blade jam fault, the non-faulty blades are not feathered first, and the non-faulty blades are restricted from opening the blades, and then the unit is made to face the wind at a preset angle by active yaw, and at the same time, the maximum torque that the unit can support is continuously output, and the unit speed setting value is slowly reduced, thereby reducing the unit speed, so that the faulty blade and the non-faulty blade are kept as close as possible in a short time, and the non-faulty blades are commanded to feather only after the unit speed drops to a preset threshold value, and the feathering rate is switched on the derivative of the pitch angle according to the wind energy utilization coefficient, thereby improving the unit's load reduction capacity for blade jam conditions.

[0009] Furthermore, the control method for reducing the load of a wind turbine generator set under a blade stuck condition comprises the following steps:

[0010] 1) The unit identifies that the propeller blade is stuck and reports a fault;

[0011] 2) The minimum blade angle limit of the non-faulty blade is (maximum blade angle + 1) degrees at the time when the stuck blade fault is reported, which limits the propeller opening action;

[0012] 3) The unit starts to actively yaw at a preset yaw rate, and the speed setting value of the unit slowly decreases at a preset rate. During the yaw process, the generator speed of the unit is obtained so that the unit can output the corresponding maximum torque to reduce the speed faster;

[0013] 4) Determine whether the generator speed has dropped to a preset threshold value, if it has dropped to the preset threshold value, execute step 5), otherwise jump to step 2);

[0014] 5) The non-faulty blades are feathered at a set rate. During the feathering process, the wind speed and impeller speed of the unit are obtained, the real-time tip speed ratio of the computer unit is calculated, the pitch angle of the unit is obtained, and the derivative of the wind energy utilization coefficient to the pitch angle under the tip speed ratio and the pitch angle is further calculated. When the derivative value is greater than a preset threshold, the non-faulty blades are retracted at a preset slow rate. When the derivative value is less than the preset threshold, the non-faulty blades are retracted at a preset fast rate.

[0015] 6) Obtain the yaw error and blade angle of the unit, determine whether the yaw error has reached the preset angle and whether the non-faulty blades are in place. If the yaw error has reached the preset angle and the non-faulty blades are in place, stop yaw, otherwise jump to step 5).

[0016] Further, in step 1), whether the unit has a stuck propeller is identified through the difference in the state of the propeller blades. If it is identified that the propeller blades are stuck, a fault is reported.

[0017] Further, in step 2), the pitch angle sensor information of the unit is read, and the (maximum blade angle + 1) degree at the time when the stuck blade fault is reported is used as the minimum blade angle limit of the non-faulty blade.

[0018] Further, in step 3), the maximum torque is obtained by looking up a table, which is pre-created in the unit based on a corresponding relationship curve of the maximum torque that the unit can output at different speeds.

[0019] Further, in step 5), the wind speed and impeller speed of the unit are obtained, and the real-time tip speed ratio of the computer unit is calculated as follows:

[0020]

[0021] According to the calculated tip speed ratio, the relationship curve of wind energy utilization coefficient-pitch angle under the tip speed ratio can be determined from the corresponding relationship curve of tip speed ratio-wind energy utilization coefficient-pitch angle pre-established for the unit, and the pitch angle of the unit can be obtained. The derivative of the wind energy utilization coefficient to the pitch angle under the tip speed ratio and pitch angle can be further calculated. The formula is as follows:

[0022]

[0023] Further, in step 6), the yaw error information is read through the wind vane.

[0024] The second object of the present invention is achieved by the following technical solution: a control system for reducing the load of a wind turbine generator set under a blade stuck condition, which is used to implement the control method for reducing the load of a wind turbine generator set under the blade stuck condition, comprising:

[0025] The propeller stuck identification module identifies whether the unit has a propeller stuck based on the difference in the propeller status. If a propeller stuck is detected, a fault is reported.

[0026] The first control module, after triggering the propeller stuck fault, does not feather the non-faulty propellers first, and limits the propeller opening action of the non-faulty propellers. The non-faulty propellers use the (maximum propeller angle + 1) degree at the time when the propeller stuck fault is reported as the minimum propeller angle limit.

[0027] The speed reduction module uses active yaw to make the unit face the wind at a preset angle, while continuously outputting the maximum torque that the unit can support, slowly reducing the set speed value of the unit, thereby reducing the unit speed and keeping the faulty blade and the non-faulty blade as close as possible in a short period of time;

[0028] The second control module commands the non-faulty blades to feather only after the rotation speed of the waiting unit drops to a preset threshold value, and the feathering rate is switched according to the derivative of the pitch angle based on the wind energy utilization coefficient.

[0029] 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, it implements the control method for reducing the load of the wind turbine under the above-mentioned blade stuck condition.

[0030] The fourth purpose of the present invention is achieved through the following technical solution: a computing device, comprising a processor and a memory for storing programs executable by the processor, when the processor executes the program stored in the memory, it implements the control method for reducing the load of the wind turbine under the above-mentioned blade stuck condition.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] 1. The present invention can greatly reduce the load on large components of a wind turbine generator set under a blade stuck condition, improve the safety of the set, and reduce the design cost of the set.

[0033] 2. The present invention does not require new hardware structures or changes to the structure of the original wind turbine generator set, and is simple and efficient to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The control principle diagram of the method of the present invention.

[0035] Figure 2 It is a schematic diagram of the corresponding relationship curve of blade tip speed ratio-wind energy utilization coefficient-pitch angle.

[0036] Figure 3 It is a schematic diagram of the relationship curve between wind energy utilization coefficient and pitch angle under a fixed tip speed ratio.

[0037] Figure 4 Figure 2 is a schematic diagram of the pitch curve when the strategy proposed in this paper is enabled and not enabled under the same blade stuck condition.

[0038] Figure 5 The figure is a schematic diagram of the speed curve when the strategy proposed in this paper is enabled and not enabled under the same blade stuck condition.

[0039] Figure 6 Schematic diagram of the north-facing curve of the cabin with and without the strategy proposed in this paper enabled under the same blade jam condition.

[0040] Figure 7 Schematic diagram of the combined bending moment curve of the hub with and without the strategy of the present invention activated under the same blade stuck condition.

[0041] Figure 8 Schematic diagram of the yaw bending moment curve with and without the strategy proposed in this paper enabled under the same blade stuck condition.

[0042] Fig. 9Schematic diagram of the system of the present invention. DETAILED DESCRIPTION

[0043] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0044] Example 1

[0045] The present embodiment discloses a control method for reducing the load of a wind turbine under a blade jam condition. The method is that after a blade jam fault is triggered, the non-faulty blades are not feathered first, and the opening action of the non-faulty blades is restricted. Then, the unit is made to face the wind at a preset angle by active yaw, and at the same time, the maximum torque that the unit can support is continuously output, and the set speed value of the unit is slowly reduced, thereby reducing the unit speed, so that the faulty blade and the non-faulty blade are kept as close as possible in a short time. After the unit speed drops to a preset threshold, the non-faulty blade is commanded to feather, and the feathering rate is switched according to the derivative of the pitch angle according to the wind energy utilization coefficient, thereby improving the load reduction capacity of the unit under the blade jam condition; Figure 1 As shown, the following steps are included:

[0046] 1) Identify whether the unit has a stuck propeller based on the difference in propeller blade status. If a stuck propeller is detected, a fault is reported;

[0047] 2) Read the pitch angle sensor information of the unit. The minimum blade angle limit of the non-faulty blade is (maximum blade angle + 1) degrees at the time when the stuck blade fault is reported, limiting its propeller opening action;

[0048] 3) The unit starts active yaw at a preset yaw rate; the speed setting value of the unit slowly decreases at a preset rate; the corresponding relationship curve of the maximum torque that the unit can output at different speeds is obtained in advance in the laboratory, and a lookup table is created in the unit based on the relationship curve. During the yaw process, the generator speed of the wind turbine generator set is obtained, so that the unit outputs the maximum torque obtained by the lookup table, so as to reduce the speed faster;

[0049] 4) Determine whether the generator speed has dropped to a preset threshold value, if it has dropped to the preset threshold value, execute step 5), otherwise jump to step 2);

[0050] 5) The non-faulty blades are feathered at the set rate, as follows:

[0051] The corresponding relationship curve of blade tip speed ratio-wind energy utilization coefficient-pitch angle of the unit is established in advance, such as Figure 2 As shown;

[0052] Obtain the wind speed and impeller speed of the wind turbine generator set, and the real-time tip speed ratio of the computer group. The formula is as follows:

[0053]

[0054] According to the calculated tip speed ratio, the relationship curve between wind energy utilization coefficient and pitch angle under the tip speed ratio can be determined from the corresponding relationship curve between tip speed ratio, wind energy utilization coefficient and pitch angle, such as Figure 3 As shown;

[0055] Obtain the pitch angle of the wind turbine generator set, and further calculate the derivative of the wind energy utilization coefficient with respect to the pitch angle under the tip speed ratio and pitch angle. The formula is as follows:

[0056]

[0057] When the derivative value is greater than a preset threshold, the non-faulty blades are retracted at a preset slower rate, and when the derivative value is less than the preset threshold, the non-faulty blades are retracted at a preset faster rate;

[0058] 6) Obtain the yaw error of the unit (read the yaw error information from the wind vane) and the blade angle, and determine whether the yaw error has reached the preset angle and whether the non-faulty blades are in place. If the yaw error has reached the preset angle and the non-faulty blades are in place, stop yaw, otherwise jump to step 5).

[0059] See also Figures 4 to 8 As shown, it shows the operating status of whether the above method of this embodiment (i.e., the strategy of this invention) is used under the condition of blade jam. It can be seen from the figure that under the same blade jam condition, after the strategy of the method of the present invention is enabled, the ultimate loads of the hub bending moment and the yaw bending moment of the unit are significantly reduced, thereby greatly reducing the loads of large components of the wind turbine generator set under the condition of blade jam, improving the safety of the unit, and reducing the design cost of the unit.

[0060] Example 2

[0061] This embodiment discloses a control system for reducing the load of a wind turbine generator set under a blade stuck condition, which is used to implement the control method for reducing the load of a wind turbine generator set under a blade stuck condition described in Example 1, such as Fig. 9 As shown, including:

[0062] The propeller stuck identification module identifies whether the unit has a propeller stuck based on the difference in the propeller status. If a propeller stuck is detected, a fault is reported.

[0063] The first control module, after triggering the propeller stuck fault, does not feather the non-faulty propellers first, and limits the propeller opening action of the non-faulty propellers. The non-faulty propellers use the (maximum propeller angle + 1) degree at the time when the propeller stuck fault is reported as the minimum propeller angle limit.

[0064] The speed reduction module uses active yaw to make the unit face the wind at a preset angle, while continuously outputting the maximum torque that the unit can support, slowly reducing the set speed value of the unit, thereby reducing the unit speed and keeping the faulty blade and the non-faulty blade as close as possible in a short period of time;

[0065] The second control module commands the non-faulty blades to feather only after the rotation speed of the waiting unit drops to a preset threshold value, and the feathering rate is switched according to the derivative of the pitch angle based on the wind energy utilization coefficient.

[0066] Example 3

[0067] This embodiment discloses a storage medium storing a program. When the program is executed by a processor, the control method for reducing the load of a wind turbine generator set under a blade stuck condition described in Embodiment 1 is implemented.

[0068] The storage medium in this embodiment can be a 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 other media.

[0069] Example 4

[0070] 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 control method for reducing the load of a wind turbine under a blade stuck condition described in Example 1 is implemented.

[0071] 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.

[0072] 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 equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A control method for reducing the load of a wind turbine when blades are stuck. It is characterized in that The method is that after triggering the blade jam fault, the non-faulty blades are not feathered first, and the non-faulty blades are restricted from opening. Then, the unit is made to face the wind at a preset angle by active yaw, and at the same time, the maximum torque that the unit can support is continuously output, and the unit speed setting value is slowly reduced, thereby reducing the unit speed, so that the faulty blade and the non-faulty blade are kept as close as possible in a short time. After the unit speed drops to the preset threshold, the non-faulty blade is commanded to feather. The feathering rate is switched according to the derivative of the pitch angle according to the wind energy utilization coefficient, thereby improving the unit's load reduction capability for blade jam conditions.

2. A control method for reducing the load of a wind turbine generator set under a blade stuck condition according to claim 1, It is characterized in that The following steps are involved: 1) The unit identifies that the propeller blade is stuck and reports a fault; 2) The minimum blade angle limit of the non-faulty blade is (maximum blade angle + 1) degrees at the time when the stuck blade fault is reported, which limits the propeller opening action; 3) The unit starts to actively yaw at a preset yaw rate, and the speed setting value of the unit slowly decreases at a preset rate. During the yaw process, the generator speed of the unit is obtained so that the unit can output the corresponding maximum torque to reduce the speed faster; 4) Determine whether the generator speed has dropped to a preset threshold value, if it has dropped to the preset threshold value, execute step 5), otherwise jump to step 2); 5) The non-faulty blades are feathered at a set rate. During the feathering process, the wind speed and impeller speed of the unit are obtained, the real-time tip speed ratio of the computer unit is calculated, the pitch angle of the unit is obtained, and the derivative of the wind energy utilization coefficient to the pitch angle under the tip speed ratio and the pitch angle is further calculated. When the derivative value is greater than a preset threshold, the non-faulty blades are retracted at a preset slow rate. When the derivative value is less than the preset threshold, the non-faulty blades are retracted at a preset fast rate. 6) Obtain the yaw error and blade angle of the unit, determine whether the yaw error has reached the preset angle and whether the non-faulty blades are in place. If the yaw error has reached the preset angle and the non-faulty blades are in place, stop yaw, otherwise jump to step 5).

3. A control method for reducing the load of a wind turbine generator set under a blade stuck condition according to claim 2, It is characterized in that In step 1), whether the unit has a stuck propeller is identified by the difference in the status of the propeller blades. If the propeller blades are identified to be stuck, a fault is reported.

4. A control method for reducing the load of a wind turbine generator set under a blade stuck condition according to claim 2, It is characterized in that In step 2), the pitch angle sensor information of the unit is read, and the (maximum blade angle + 1) degree at the time when the stuck blade fault is reported is used as the minimum blade angle limit of the non-faulty blade.

5. A control method for reducing the load of a wind turbine generator set under a blade stuck condition according to claim 2, It is characterized in that In step 3), the maximum torque is obtained by looking up a table, which is pre-created in the unit based on a corresponding relationship curve of the maximum torque that the unit can output at different speeds.

6. A control method for reducing the load of a wind turbine generator set under a blade stuck condition according to claim 2, It is characterized in that In step 5), the wind speed and impeller speed of the unit are obtained, and the real-time tip speed ratio of the computer unit is calculated as follows: According to the calculated tip speed ratio, the relationship curve of wind energy utilization coefficient-pitch angle under the tip speed ratio can be determined from the corresponding relationship curve of tip speed ratio-wind energy utilization coefficient-pitch angle pre-established for the unit, and the pitch angle of the unit can be obtained. The derivative of the wind energy utilization coefficient to the pitch angle under the tip speed ratio and pitch angle can be further calculated. The formula is as follows:

7. A control method for reducing the load of a wind turbine generator set under a blade stuck condition according to claim 2, It is characterized in that In step 6), the yaw error information is read through the wind vane.

8. A control system for reducing the load of a wind turbine when blades are stuck. It is characterized in that A control method for reducing the load of a wind turbine generator set under a blade stuck condition according to any one of claims 1 to 7, comprising: The propeller stuck identification module identifies whether the unit has a propeller stuck based on the difference in the propeller status. If a propeller stuck is detected, a fault is reported. The first control module, after triggering the propeller stuck fault, does not feather the non-faulty propellers first, and limits the propeller opening action of the non-faulty propellers. The non-faulty propellers use the (maximum propeller angle + 1) degree at the time when the propeller stuck fault is reported as the minimum propeller angle limit. The speed reduction module uses active yaw to make the unit face the wind at a preset angle, while continuously outputting the maximum torque that the unit can support, slowly reducing the set speed value of the unit, thereby reducing the unit speed and keeping the faulty blade and the non-faulty blade as close as possible in a short period of time; The second control module commands the non-faulty blades to feather only after the rotation speed of the waiting unit drops to a preset threshold value, and the feathering rate is switched according to the derivative of the pitch angle based on the wind energy utilization coefficient.

9. A storage medium storing a program, It is characterized in that When the program is executed by a processor, the control method for reducing the load of a wind turbine generator set under a blade stuck condition according to any one of claims 1 to 7 is implemented.

10. A computing device comprising a processor and a memory for storing a program executable by the processor, It is characterized in that When the processor executes the program stored in the memory, the control method for reducing the load of the wind turbine generator set under the blade stuck condition described in any one of claims 1 to 7 is implemented.

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