Wind turbine generator load reduction methods and systems and computer-readable storage media

Abstract

This invention provides a method and system for reducing load on a wind turbine generator set, as well as a computer-readable storage medium. The method includes: during the operation of the wind turbine generator set, acquiring the values ​​of variables characterizing wind speed and the rate of change of those variables; obtaining the pitch angle value of the wind turbine generator set based on the values ​​of the variables and the rate of change of those variables, and the correspondence between the variables, the rate of change of those variables, and the pitch angle; and determining the final pitch angle setpoint of the wind turbine generator set based on a pre-set pitch angle value and the obtained pitch angle value to achieve load reduction. This invention can achieve load reduction with almost no loss of power generation.

Description

Technical Field

[0001] The present invention relates to the field of wind power generation technology, and in particular to a method and system for unloading a wind turbine generator set and a computer-readable storage medium thereof. Background Technology

[0002] With the gradual depletion of energy sources such as coal and oil, humanity is increasingly emphasizing the utilization of renewable energy. Wind energy, as a clean and renewable energy source, is receiving growing attention worldwide. Along with the continuous development of wind power technology, the application of wind turbine generators in power systems is increasing. Wind turbine generators are large-scale devices that convert wind energy into electrical energy, typically installed in areas rich in wind resources.

[0003] Currently, the control scheme for conventional wind turbine generators is as follows: at low wind speeds, the pitch angle is set to the optimal pitch angle, and the torque is adjusted to make the rotor speed proportional to the wind speed to maintain the optimal tip speed ratio, thereby capturing maximum wind energy; after the rotor speed reaches the rated speed, the torque is adjusted to stabilize the rotor speed near the rated speed; as the wind speed continues to increase and the power reaches the rated power, the torque no longer changes, and the pitch angle is adjusted to maintain the rotor speed and power near the rated. Due to the inherent characteristics of wind turbine generators, when gusts occur, especially when the wind speed rapidly increases from below the rated speed to above the rated speed, the wind turbine generator will bear a large structural load.

[0004] To reduce the load on components such as blade roots, hubs, and towers under gust conditions, thereby reducing costs, the conventional approach is to use a scheme that triggers rapid feathering based on the rate of change of rotational speed, rotational speed error, and pitch angle signals. That is, when the product of the rate of change of rotational speed and the rotational speed error exceeds a certain threshold, an additional constant increment is added to the pitch speed. The trigger threshold is obtained by looking up a table based on the pitch angle.

[0005] However, the above-mentioned load reduction schemes have a problem: when the wind speed rises rapidly below the rated speed, the existing strategy triggers late or even fails to trigger, thus failing to achieve the load reduction objective. This problem arises because the pitch angle can only activate when the rotational speed exceeds the rated speed by a sufficiently large margin and the rate of increase is high enough, and the power output approaches the rated speed. However, below the rated power, due to the torque's inhibitory effect on rotational speed, even if the wind speed increases rapidly, the rotor speed will not rise rapidly enough to reach the threshold for triggering additional pitch control. Lowering the trigger threshold would lead to frequent triggering under normal power generation conditions, causing unstable operation of the wind turbine and significant power loss. Summary of the Invention

[0006] The purpose of this invention is to provide a method and system for reducing the load on a wind turbine generator set, as well as a computer-readable storage medium, which can reduce the load while almost without losing power generation.

[0007] One aspect of this invention provides a method for reducing load on a wind turbine generator set. The method includes: during the operation of the wind turbine generator set, acquiring the values ​​of a variable characterizing wind speed and the rate of change of the variable; obtaining the pitch angle value of the wind turbine generator set based on the values ​​of the variable and the rate of change of the variable, and based on the correspondence between the variable and the rate of change of the variable and the pitch angle; and determining a final pitch angle setpoint value for the wind turbine generator set based on a pre-set pitch angle value and the obtained pitch angle value to achieve load reduction.

[0008] Another aspect of the present invention provides a wind turbine unloading system. The wind turbine unloading system includes one or more processors for implementing the wind turbine unloading method described above.

[0009] Another aspect of the present invention provides a computer-readable storage medium. The computer-readable storage medium stores a program that, when executed by a processor, implements the load reduction method for a wind turbine generator as described above.

[0010] The wind turbine generator set load reduction method, system, and computer-readable storage medium of one or more embodiments of the present invention can reduce the load on large components such as blade roots, hubs, and towers by adjusting the pitch when the wind speed rises rapidly from below the rated value. Under normal power generation conditions, the pitch adjustment action is rarely triggered, thereby achieving load reduction and cost reduction while almost without losing power generation. Attached Figure Description

[0011] Figure 1 This is a flowchart of a method for unloading a wind turbine generator set according to an embodiment of the present invention;

[0012] Figure 2 A simulation comparison chart showing the load reduction effects of a certain model of wind turbine generator set using and not using the load reduction methods of the present invention;

[0013] Figure 3 This is a schematic block diagram of a wind turbine generator unloading system according to an embodiment of the present invention. Detailed Implementation

[0014] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses consistent with some aspects of the invention as detailed in the appended claims.

[0015] The terminology used in this invention embodiment is for the purpose of describing particular embodiments only and is not intended to limit the invention. Unless otherwise defined, the technical or scientific terms used in this invention embodiment should be understood in their ordinary sense by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. "A plurality" or "several" indicates two or more. Unless otherwise stated, "front," "rear," "lower," and / or "upper," and similar terms are for ease of description only and are not limited to a location or spatial orientation. The terms "comprising" or "including," and similar terms mean that the element or object preceding "comprising" covers the element or object listed following "comprising" or "including" and its equivalents, and do not exclude other elements or objects. The terms "connected," "linked," and similar terms are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect. The singular forms “a,” “the,” and “the” used in this specification and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0016] This invention provides a method for reducing the load on a wind turbine generator set. Figure 1 A flowchart illustrating a method for unloading a wind turbine generator according to an embodiment of the present invention is provided. Figure 1 As shown, a method for unloading a wind turbine generator set according to an embodiment of the present invention may include steps S1 to S3.

[0017] In step S1, during the operation of the wind turbine generator set, the values ​​of the variables characterizing wind speed and the rate of change of the variables can be obtained.

[0018] In some embodiments, the variable characterizing wind speed may include the equivalent average wind speed V of the wind turbine rotor surface.

[0019] In this case, obtaining the values ​​of the variables representing wind speed and the rate of change of the variables in step S1 may include: obtaining the value of the equivalent average wind speed V of the wind turbine surface and the rate of change of the equivalent average wind speed of the wind turbine surface. The value of .

[0020] Since the wind speed measured by the anemometer installed in the nacelle of the wind turbine does not represent the average wind speed at the rotor surface, in one embodiment, the equivalent average wind speed V at the rotor surface can be estimated based on the current rotational speed, current torque, and current pitch angle of the wind turbine. For example, when the wind turbine is not operating at full capacity, the equivalent average wind speed V at the rotor surface can be estimated based on the current rotational speed and current torque of the wind turbine; while when the wind turbine is operating at full capacity, the equivalent average wind speed V at the rotor surface can be estimated based on the current rotational speed and current pitch angle of the wind turbine.

[0021] After estimating the value of the equivalent average wind speed V on the rotor surface in the current sampling period, the equivalent average wind speed V on the rotor surface calculated in the previous sampling period can be subtracted from the calculated value of the equivalent average wind speed V on the rotor surface in the current period to obtain the difference between the two. The rate of change of the variable within the sampling period can then be obtained by dividing the difference by the sampling period.

[0022] In other embodiments, the variable characterizing wind speed may include the output torque of the wind turbine generator.

[0023] In this case, obtaining the values ​​of the variables representing wind speed and the rate of change of the variables in step S1 may include obtaining the value of the output torque and the rate of change of the output torque.

[0024] In one embodiment, in order to obtain a smoother wind speed and wind speed change rate, obtaining the value of the variable and the value of the variable change rate in step S1 may include: calculating the average value of the variable and the variable change rate over a predetermined time period (e.g., 0.5 seconds).

[0025] In another embodiment, to give the wind speed increase and decrease processes different dynamic characteristics, different moving average time constants can be used for the two processes. Therefore, during the wind speed increase process, the average value of the variable and the rate of change of the variable can be calculated for a first predetermined time period; while during the wind speed decrease process, the average value of the variable and the rate of change of the variable can be calculated for a second predetermined time period, wherein the first predetermined time period and the second predetermined time period are different.

[0026] In step S2, the pitch angle of the wind turbine generator can be obtained based on the values ​​of the variables and the rate of change of the variables obtained in step S1, and based on the correspondence between the variables and the rate of change of the variables and the pitch angle.

[0027] In some embodiments, step S2, which obtains the pitch angle value of the wind turbine generator based on the value of the variable and the value of the rate of change of the variable, and based on the correspondence between the variable and the rate of change of the variable and the pitch angle, may further include steps S21 and S22.

[0028] In step S21, the value of the variable and the product of the variable's rate of change can be calculated based on the value of the variable and the value of the rate of change of the variable.

[0029] In step S22, the corresponding pitch angle value can be obtained based on the product of the variable and the rate of change of the variable calculated in step S21, and based on the correspondence between the variable and the product of the rate of change of the variable and the pitch angle.

[0030] In some embodiments, the correspondence between a variable and the product of its rate of change and the pitch angle may include a lookup table of the variable and the product of its rate of change and the pitch angle. Therefore, the load reduction method for wind turbine generator sets in this embodiment may further include: pre-establishing a lookup table of the variable and the product of its rate of change and the pitch angle through simulation. For example, the horizontal columns of the lookup table can be set to the values ​​of the variable and the product of its rate of change, while the vertical columns can be set to the pitch angle values ​​corresponding to the wind turbine generator set. Therefore, after calculating the value of the variable and the product of its rate of change, the corresponding pitch angle value can be easily obtained by consulting the lookup table of the variable and the product of its rate of change and the pitch angle.

[0031] In step S3, the final pitch angle setpoint of the wind turbine generator set can be determined based on the preset pitch angle setpoint and the obtained pitch angle value to achieve load reduction.

[0032] In some embodiments, the larger of the pitch angle setpoint and the obtained pitch angle value can be selected as the final pitch angle setpoint for the constant wind turbine generator set. In this way, pitch control can be triggered when the product of the variable and the rate of change of the variable exceeds the normal range, thereby achieving load reduction.

[0033] Figure 2 The simulation results show a comparison of the load reduction methods of a certain wind turbine model using and not using embodiments of the present invention. Figure 2 The paper presents a comparison of pitch angle and output power (i.e., electrical power) for wind turbine generators using and not using the load reduction methods of this invention. From... Figure 2 As shown in the curves of pitch angle (strategy on) and pitch angle (strategy off) as well as the rated power curve, it can be clearly seen that when the wind speed rises rapidly from below the rated value, the pitch angle action can be significantly advanced after adopting the load reduction method of the wind turbine generator set of the present invention, thereby reducing the structural load of the wind turbine generator set.

[0034] The load reduction method of the wind turbine generator set in this embodiment of the invention can reduce the load on large components such as blade roots, hubs and towers by adjusting the pitch when the wind speed rises rapidly from below the rated value. Under normal power generation conditions, the pitch adjustment action is rarely triggered, so as to achieve load reduction and cost reduction while almost without losing power generation.

[0035] This invention also provides a load shedding system 200 for a wind turbine generator set. Figure 3 A schematic block diagram of a wind turbine unloading system 200 according to an embodiment of the present invention is shown. Figure 3 As shown, the wind turbine unloading system 200 may include one or more processors 201 for implementing the wind turbine unloading method described in any of the above embodiments. In some embodiments, the wind turbine unloading system 200 may include a computer-readable storage medium 202, which may store a program that can be called by the processor 201, and may include a non-volatile storage medium. In some embodiments, the wind turbine unloading system 200 may include memory 203 and an interface 204. In some embodiments, the wind turbine unloading system 200 of the present invention may also include other hardware depending on the actual application.

[0036] The load reduction system 200 of the wind turbine generator set in this embodiment of the invention has similar beneficial technical effects to the load reduction method of the wind turbine generator set described above, so it will not be described again here.

[0037] This invention also provides a computer-readable storage medium. The computer-readable storage medium stores a program that, when executed by a processor, implements the load reduction method for wind turbine generators described in any of the above embodiments.

[0038] This invention can take the form of a computer program product implemented on one or more storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing program code. Computer-readable storage media include permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer-readable storage media include, but are not limited to: novel memories such as phase-change memory / resistive random access memory / magnetic memory / ferroelectric memory (PRAM / RRAM / MRAM / FeRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, read-only optical disc read-only memory (CD-ROM), digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device.

[0039] The foregoing has provided a detailed description of the wind turbine generator load reduction method, system, and computer-readable storage medium provided in the embodiments of the present invention. Specific examples have been used to illustrate the wind turbine generator load reduction method, system, and computer-readable storage medium of the present invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the core ideas of the present invention and are not intended to limit the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the spirit and principles of the present invention, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method of de-rating a wind turbine generator system, the method comprising: It comprises: during the operation of the wind turbine, obtaining a value of a variable representing wind speed and a value of a rate of change of the variable; obtaining a value of a pitch angle of the wind turbine according to the value of the variable and the value of the rate of change of the variable and based on a corresponding relationship between the variable and the rate of change of the variable and the pitch angle; and determining a final pitch angle given value of the wind turbine to achieve load reduction based on a pitch angle setting value pre-set for the wind turbine and the obtained value of the pitch angle, the variable representing wind speed comprises an equivalent average wind speed of a rotor plane of the wind turbine, and the obtaining of the value of the variable representing wind speed and the value of the rate of change of the variable comprises: obtaining a value of the equivalent average wind speed of the rotor plane and a value of a rate of change of the equivalent average wind speed of the rotor plane, the obtaining of the value of the equivalent average wind speed of the rotor plane comprises: estimating the value of the equivalent average wind speed of the rotor plane based on a current rotational speed, a current torque and a current pitch angle of the wind turbine.

2. The method of claim 1, wherein: the estimating of the value of the equivalent average wind speed of the rotor plane based on the current rotational speed, the current torque and the current pitch angle of the wind turbine comprises: when the wind turbine is in an under-rated state, the value of the equivalent average wind speed of the rotor plane is estimated based on the current rotational speed and the current torque of the wind turbine; and when the wind turbine is in a full-rated state, the value of the equivalent average wind speed of the rotor plane is estimated based on the current rotational speed and the current pitch angle of the wind turbine.

3. The method of claim 1, wherein: the variable representing wind speed comprises a torque of the wind turbine, and the obtaining of the value of the variable representing wind speed and the value of the rate of change of the variable comprises: obtaining a value of the torque and a value of a rate of change of the torque.

4. The method of any one of claims 1 to 3, wherein: the obtaining of the value of the variable and the value of the rate of change of the variable comprises: calculating average values of the variable and the rate of change of the variable within a predetermined time length.

5. The method of claim 4, wherein: the calculating of the average values of the variable and the rate of change of the variable within the predetermined time length comprises: in a process of wind speed rising, the average values of the variable and the rate of change of the variable are calculated in a first predetermined time length; and in a process of wind speed falling, the average values of the variable and the rate of change of the variable are calculated in a second predetermined time length, wherein the first predetermined time length is different from the second predetermined time length.

6. The method of any one of claims 1 to 3, wherein: the obtaining of the value of the pitch angle of the wind turbine according to the value of the variable and the value of the rate of change of the variable and based on the corresponding relationship between the variable and the rate of change of the variable and the pitch angle comprises: calculating a value of a product of the variable and the rate of change of the variable according to the value of the variable and the value of the rate of change of the variable; and obtaining the value of the pitch angle according to the value of the product of the variable and the rate of change of the variable and based on a corresponding relationship between the product of the variable and the rate of change of the variable and the pitch angle.

7. The method of claim 6, wherein: the corresponding relationship between the product of the variable and the rate of change of the variable and the pitch angle comprises a lookup table of the product of the variable and the rate of change of the variable and the pitch angle, and the method further comprises: pre-establishing the lookup table of the product of the variable and the rate of change of the variable and the pitch angle through simulation.

8. The method of any one of claims 1 to 3, wherein: The determining the final pitch angle given value of the wind turbine generator set based on the pitch angle set value and the obtained pitch angle value of the wind turbine generator set includes: Selecting a larger one of the pitch angle set value and the obtained pitch angle value as the final pitch angle given value.

9. A de-rating system for a wind turbine generator system, characterized by: One or more processors are configured to implement the load reduction method of the wind turbine generator set according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, A computer program product is provided, and the computer program product has a program stored thereon, wherein the program, when executed by a processor, implements the load reduction method of the wind turbine generator set according to any one of claims 1 to 8.

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