Wind turbine control method and device based on air density

Abstract

This invention discloses a wind turbine control method and apparatus based on air density, comprising: establishing a database containing minimum operating air density, minimum stall air density, maximum operating air density, and multiple different air densities and their corresponding optimal control parameters; in response to the operation of the wind turbine, acquiring the environmental parameters of the wind turbine, the current control parameters of the wind turbine, and the reference air density used to determine the current control parameters; calculating the air density of the current environment, comparing the calculated air density with the reference air density and the air density in the database, and controlling the operation of the wind turbine according to the comparison results; if the difference between the calculated air density and the reference air density does not exceed a first preset deviation threshold, then controlling the wind turbine to continue operating with the current control parameters. This invention can ensure that the wind turbine can operate in the optimal state under different environments and improve the operational stability of the wind turbine.

Description

Technical Field

[0001] This invention relates to the field of wind turbine technology, and in particular to a wind turbine control method and device based on air density. Background Technology

[0002] A wind turbine is a large-scale device that converts wind energy into electrical energy. It uses a rotating rotor to convert wind energy into mechanical energy, which is then converted back into electrical energy by a power generation system. With the continuous development of wind power technology, the application of wind turbines in power systems is increasing.

[0003] Air density is a crucial parameter affecting wind turbine performance, and it fluctuates in real time with changes in temperature, air pressure, and other parameters. During wind turbine operation, varying air densities influence control parameters, thus impacting the actual power curve and load. Therefore, to optimize wind turbine performance, control parameters must be adjusted based on changes in air density during operation.

[0004] Considering the influence of air density, the commonly used control methods for wind turbines mainly include two types. The first is to set a basic air density based on the annual average temperature and air pressure, and then control the wind turbine based on this set basic air density. Alternatively, multiple basic air densities can be set based on the temperature and air pressure conditions of different seasons, and the wind turbine can be controlled based on the basic air density corresponding to the season at different times. The second method is to acquire the air density of the environment in which the wind turbine is located in real time, and then calculate and adjust the control parameters of the wind turbine based on the real-time acquired air density.

[0005] However, the first control method described above uses a pre-set basic air density instead of the actual air density, failing to consider changes in the wind turbine's environment. Consequently, the wind turbine's control parameters and actual performance cannot reach their optimal state. The second control method calculates the corresponding control parameters for the wind turbine in real-time based on the acquired air density and adjusts the turbine accordingly. In actual operation, this leads to a significant increase in the number of times the wind turbine is started and adjusted. Frequent starts and adjustments are detrimental to the stable operation of the wind turbine and can easily damage it. Summary of the Invention

[0006] To address some or all of the technical problems existing in the prior art, the present invention provides a wind turbine control method and device based on air density.

[0007] The technical solution of the present invention is as follows:

[0008] Firstly, a wind turbine control method based on air density is provided, including:

[0009] Establish a database containing the minimum operating air density, the minimum stall air density, the maximum operating air density, and multiple different air densities and the optimal control parameters of the wind turbine corresponding to the air density;

[0010] In response to the operation of the wind turbine, the environmental parameters of the wind turbine, the current control parameters of the wind turbine, and the reference air density used to determine the current control parameters are obtained.

[0011] The air density of the current environment is calculated based on the acquired environmental parameters. The calculated air density is compared with the reference air density and the air density in the database. The operation of the wind turbine is controlled according to the comparison results. If the difference between the calculated air density and the reference air density does not exceed the first preset deviation threshold, the wind turbine is controlled to continue to operate with the current control parameters.

[0012] In some possible implementations, the environmental parameters include at least: temperature and air pressure.

[0013] In some possible implementations, the step of comparing the calculated air density with a reference air density and an air density in a database, and controlling the operation of the wind turbine based on the comparison results, includes:

[0014] The calculated air density is compared with the minimum operating air density, the minimum stall air density, the reference air density, and the maximum operating air density, respectively.

[0015] If the calculated air density is less than or equal to the minimum operating air density, the current ambient temperature is compared with the preset maximum operating temperature. If the current ambient temperature is greater than or equal to the preset maximum operating temperature, the wind turbine is shut down. If the current ambient temperature is less than the preset maximum operating temperature, the recorded error count is incremented by one, and it is determined whether the current error count is less than the set threshold. If so, the wind turbine is controlled to operate with the control parameters corresponding to the minimum operating air density. If not, the wind turbine is shut down, the wind turbine's sensors are checked for malfunctions, the parameter calculations are incorrect, and the error count is reset.

[0016] If the calculated air density is greater than the minimum operating air density and less than or equal to the minimum stall air density, the wind turbine will be controlled to operate with preset anti-stall control parameters.

[0017] If the calculated air density is greater than the minimum stall air density, and the difference between the calculated air density and the reference air density is less than or equal to the first preset deviation threshold, then the wind turbine will continue to operate with the current control parameters.

[0018] If the calculated air density is greater than the minimum stall air density, and the difference between the calculated air density and the reference air density is greater than the first preset deviation threshold and less than the second preset deviation threshold, then the current operating status parameters of the wind turbine are obtained, the current optimal tip speed ratio and optimal gain of the wind turbine are calculated, the optimal control parameters corresponding to the currently calculated air density are determined based on the data in the database, and the wind turbine is controlled to operate with the optimal control parameters.

[0019] If the calculated air density is greater than the minimum stall air density, and the difference between the calculated air density and the reference air density is greater than or equal to the second preset deviation threshold, then the wind turbine will be controlled to operate with preset low temperature control parameters.

[0020] If the calculated air density is greater than or equal to the maximum operating air density, the current ambient temperature is compared with the preset minimum operating temperature. If the current ambient temperature is less than or equal to the preset minimum operating temperature, the wind turbine is shut down. If the current ambient temperature is greater than the preset minimum operating temperature, the recorded error count is incremented by one, and it is determined whether the current error count is less than the set threshold. If so, the wind turbine is controlled to operate with the control parameters corresponding to the maximum operating air density. If not, the wind turbine is shut down, the wind turbine's sensors are checked for malfunctions, the parameter calculations are correct, and the error count is reset.

[0021] In some possible implementations, the first preset deviation threshold is 5%, and the second preset deviation threshold is 20%.

[0022] In some possible implementations, the operating state parameters include at least: power and speed.

[0023] In some possible implementations, the optimal control parameters corresponding to the currently calculated air density are determined by looking up data in the database or by interpolation.

[0024] In some possible implementations, the environmental parameters of the wind turbine, the current control parameters of the wind turbine, and the reference air density used to determine the current control parameters are acquired every preset time interval.

[0025] In some possible implementations, the control parameters of the wind turbine include:

[0026] Secondly, a wind turbine control device based on air density is also provided, including: turbine power, speed, gain, PID coefficient, pitch and headroom parameters.

[0027] The database module contains a database that includes the minimum operating air density, the minimum stall air density, the maximum operating air density, and multiple different air densities and the optimal control parameters of the wind turbine corresponding to each air density.

[0028] The parameter acquisition module is used to acquire the environmental parameters of the wind turbine, the current control parameters of the wind turbine, and the reference air density used to determine the current control parameters during the operation of the wind turbine.

[0029] The control module is connected to the database module and the parameter acquisition module respectively. It is used to calculate the air density of the current environment based on environmental parameters, compare the calculated air density with the reference air density and the air density in the database respectively, and control the operation of the wind turbine according to the comparison results. If the difference between the calculated air density and the reference air density does not exceed the first preset deviation threshold, the wind turbine is controlled to continue to operate with the current control parameters.

[0030] In some possible implementations, the control device is mounted on the wind turbine.

[0031] The main advantages of the technical solution of this invention are as follows:

[0032] The wind turbine control method and apparatus based on air density of the present invention establishes a database containing theoretical data in advance, and then calculates the actual air density during the actual operation of the wind turbine. The calculated air density is compared with the reference air density under the current control parameters and the air density pre-stored in the database. Different wind turbine control modes are adopted based on different comparison results. This ensures that the wind turbine can operate in the optimal state under different environments, significantly improves the power generation of the wind turbine, and reduces the load on the unit. Furthermore, when the difference between the calculated air density and the reference air density does not exceed a first preset deviation threshold, the wind turbine continues to operate with the current control parameters, which can avoid frequent start-up and adjustment of the wind turbine and effectively improve the operational stability and service life of the wind turbine. Attached Figure Description

[0033] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and constitute a part of this invention, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0034] Figure 1 This is a flowchart of a wind turbine control method based on air density according to an embodiment of the present invention;

[0035] Figure 2 This is a flowchart of another wind turbine control method based on air density according to an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of a wind turbine control device based on air density according to an embodiment of the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0038] The technical solutions provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0039] refer to Figure 1 In a first aspect, an embodiment of the present invention provides a wind turbine control method based on air density, the method comprising the following steps:

[0040] Step S1: Establish a database containing the minimum operating air density, the minimum stall air density, the maximum operating air density, and multiple different air densities and the optimal control parameters of the wind turbine corresponding to each air density.

[0041] In one embodiment of the present invention, the minimum operating air density represents the lowest critical air density that the wind turbine can be designed to operate at; below this air density, the wind turbine will shut down. The minimum stall air density represents the air density at which the wind turbine will stall, obtained through theoretical calculations and actual testing. A certain stall margin can be considered when determining the minimum stall air density; below this air density, the wind turbine is prone to stalling. The maximum operating air density represents the highest critical air density that the wind turbine can be designed to operate at; above this air density, the wind turbine will shut down. The optimal control parameters of the wind turbine corresponding to the air density represent the control parameters that allow the wind turbine to achieve optimal power generation and load under the current air density.

[0042] In one embodiment of the present invention, by conducting modeling and simulation analysis experiments on wind turbine units, the power generation and load size of wind turbine units under different air densities are calculated and iteratively optimized to obtain the optimal control parameters of wind turbine units corresponding to different air densities, as well as the minimum operating air density, minimum stall air density, and maximum operating air density corresponding to the wind turbine units.

[0043] Step S2: In response to the operation of the wind turbine, acquire the environmental parameters of the wind turbine, the current control parameters of the wind turbine, and the reference air density used to determine the current control parameters.

[0044] Specifically, during the operation of the wind turbine, the environmental parameters of the wind turbine, the current control parameters of the wind turbine, and the reference air density used to determine the current control parameters are acquired in real time.

[0045] Environmental parameters are detected and acquired through sensors installed on the wind turbine, while control parameters and reference air density are obtained from the wind turbine's control system.

[0046] Step S3: Calculate the air density of the current environment based on the acquired environmental parameters, compare the calculated air density with the reference air density and the air density in the database, and control the operation of the wind turbine based on the comparison results. If the difference between the calculated air density and the reference air density does not exceed the first preset deviation threshold, the wind turbine will continue to operate with the current control parameters.

[0047] In one embodiment of the present invention, the air density of the current environment is calculated based on the environmental parameters obtained in step S2. The calculated air density is compared with the baseline air density obtained in step S2 and the minimum operating air density, minimum stall air density, and maximum operating air density in the database established in step S1. Different control methods are used to control the operation of the wind turbine based on the different comparison results.

[0048] An embodiment of the present invention provides a wind turbine control method based on air density. By pre-establishing a database containing theoretical data, the method calculates the actual air density during the actual operation of the wind turbine, compares the calculated air density with the reference air density under the current control parameters and the air density pre-stored in the database, and adopts different wind turbine control methods based on different comparison results. This ensures that the wind turbine can operate in the optimal state under different environments, significantly improving the power generation of the wind turbine and reducing the load on the unit. Furthermore, when the difference between the calculated air density and the reference air density does not exceed a first preset deviation threshold, the method controls the wind turbine to continue operating with the current control parameters, avoiding frequent start-up adjustments of the wind turbine and effectively improving the operational stability and service life of the wind turbine.

[0049] Furthermore, in one embodiment of the present invention, in order to ensure that the air density of the current environment can be calculated based on the acquired environmental parameters, the acquired environmental parameters of the wind turbine include at least: air temperature and air pressure.

[0050] Air density can be calculated using the following formula:

[0051] Air density = 1.293 × (actual air pressure / standard physical atmospheric pressure) × (273.15 / actual absolute temperature), absolute temperature = Celsius temperature + 273.15.

[0052] refer to Figure 2Furthermore, in one embodiment of the present invention, the calculated air density is compared with a reference air density and an air density in a database, and the operation of the wind turbine is controlled based on the comparison results, further including the following steps:

[0053] Step S31: Compare the calculated air density with the minimum operating air density, the minimum stall air density, the reference air density, and the maximum operating air density, respectively.

[0054] Step S32: If the calculated air density is less than or equal to the minimum operating air density, compare the current ambient temperature with the preset maximum operating temperature. If the current ambient temperature is greater than or equal to the preset maximum operating temperature, control the wind turbine to shut down. If the current ambient temperature is less than the preset maximum operating temperature, increment the recorded error count by one and determine whether the current error count is less than the set threshold. If yes, control the wind turbine to operate with the control parameters corresponding to the minimum operating air density. If no, control the wind turbine to shut down, check whether the wind turbine's sensors are faulty and whether the parameter calculation is incorrect, and reset the error count.

[0055] Step S33: If the calculated air density is greater than the minimum operating air density and less than or equal to the minimum stall air density, then control the wind turbine to operate with the preset anti-stall control parameters.

[0056] Step S34: If the calculated air density is greater than the minimum stall air density, and the difference between the calculated air density and the reference air density is less than or equal to the first preset deviation threshold, then control the wind turbine to continue operating with the current control parameters.

[0057] Step S35: If the calculated air density is greater than the minimum stall air density, and the difference between the calculated air density and the reference air density is greater than the first preset deviation threshold and less than the second preset deviation threshold, then obtain the current operating status parameters of the wind turbine, calculate the current optimal tip speed ratio and optimal gain of the wind turbine, determine the optimal control parameters corresponding to the currently calculated air density based on the data in the database, and control the wind turbine to operate with the optimal control parameters.

[0058] Step S36: If the calculated air density is greater than the minimum stall air density, and the difference between the calculated air density and the reference air density is greater than or equal to the second preset deviation threshold, then control the wind turbine to operate with preset low temperature control parameters.

[0059] Step S37: If the calculated air density is greater than or equal to the maximum operating air density, compare the current ambient temperature with the preset minimum operating temperature. If the current ambient temperature is less than or equal to the preset minimum operating temperature, control the wind turbine to shut down. If the current ambient temperature is greater than the preset minimum operating temperature, increment the recorded error count by one and determine whether the current error count is less than the set threshold. If yes, control the wind turbine to operate with the control parameters corresponding to the maximum operating air density. If no, control the wind turbine to shut down, check whether the wind turbine's sensors are faulty and whether the parameter calculation is incorrect, and reset the error count.

[0060] Based on different comparison results, the above-mentioned control method can ensure that the wind turbine can operate in the best condition under different environments, significantly improve the power generation of the wind turbine, reduce the load on the unit, and improve the operational stability and service life of the wind turbine.

[0061] The maximum and minimum operating temperatures are set according to actual conditions. Specifically, both the maximum and minimum operating temperatures are determined based on the unit's design level, taking into account the allowable stress and fatigue safety factor of each material in the unit, the suitable temperature of the lubricating oil or grease, and the load on the unit.

[0062] The anti-stall control parameters are set according to the specific circumstances. Specifically, when determining the anti-stall control parameters, the minimum stall air density is first determined. By adjusting the control parameters at the minimum stall air density, the unit can transition from a stall condition to a stall-free state. The control parameters of the unit at this point are the anti-stall control parameters. A certain margin can also be considered when determining the anti-stall control parameters.

[0063] Low temperature control parameters refer to the control parameters corresponding to certain control measures taken in low temperature environments (such as turning on the nacelle heater, slightly increasing the speed, and speeding up the unit response). The low temperature control parameters are set according to actual needs.

[0064] Among them, the preset maximum operating temperature, preset anti-stall control parameters, preset low temperature control parameters, and preset minimum operating temperature can be stored in the database.

[0065] Furthermore, in one embodiment of the present invention, the set threshold, the first preset deviation threshold, and the second preset deviation threshold are specifically set according to actual conditions. Preferably, the first preset deviation threshold is 5%, the second preset deviation threshold is 20%, and the set threshold is 5. The set threshold, the first preset deviation threshold, and the second preset deviation threshold can be pre-stored in a database.

[0066] Furthermore, the initial value for the number of errors is set to 0.

[0067] In one embodiment of the present invention, the operating status parameters of the wind turbine obtained in step S35 include at least: power and speed.

[0068] In one embodiment of the present invention, the optimal tip speed ratio and the optimal gain are calculated using the following formulas:

[0069] λ= ΩR

[0070]

[0071] Where λ represents the tip speed ratio, Ω represents the impeller speed, R represents the impeller radius, V represents the wind speed, K represents the optimal gain, π represents pi, ρ represents the air density, and C p λ represents the power coefficient corresponding to the tip speed ratio, and G represents the gearbox speed ratio.

[0072] Furthermore, since the specific air density data in the database may or may not include the currently calculated air density, in one embodiment of the present invention, in step S35, the optimal control parameter corresponding to the currently calculated air density is determined based on the data in the database using a table lookup or interpolation method. Specifically, when the specific air density data in the database includes the currently calculated air density, the optimal control parameter corresponding to the currently calculated air density is determined by looking up a table; when the specific air density data in the database does not include the currently calculated air density, the optimal control parameter corresponding to the currently calculated air density is determined by interpolation.

[0073] Furthermore, considering that the air density changes relatively little in a short period of time, in one embodiment of the present invention, in step S2, the environmental parameters of the wind turbine, the current control parameters of the wind turbine, and the reference air density used to determine the current control parameters are acquired every preset time interval.

[0074] The preset time can be set according to the actual situation, for example, it can be set to 2 hours.

[0075] Furthermore, in one embodiment of the present invention, the control parameters of the wind turbine are specifically set according to the actual situation, including, for example, turbine power, speed, gain, PID coefficient, pitch and headroom parameters, etc.

[0076] refer to Figure 3 Secondly, an embodiment of the present invention also provides a wind turbine control device based on air density, the control device comprising:

[0077] Database module 100 is pre-stored with a database containing the minimum operating air density, the minimum stall air density, the maximum operating air density, and multiple different air densities and the optimal control parameters of the wind turbine corresponding to the air density;

[0078] The parameter acquisition module 200 is used to acquire the environmental parameters of the wind turbine, the current control parameters of the wind turbine, and the reference air density used to determine the current control parameters during the operation of the wind turbine.

[0079] The control module 300 is connected to the database module 100 and the parameter acquisition module 200 respectively. It is used to calculate the air density of the current environment based on environmental parameters, compare the calculated air density with the reference air density and the air density in the database respectively, and control the operation of the wind turbine according to the comparison results. If the difference between the calculated air density and the reference air density does not exceed the first preset deviation threshold, the wind turbine is controlled to continue to operate with the current control parameters.

[0080] In one embodiment of the present invention, a wind turbine control device based on air density is provided, and each module is a device corresponding to the steps of the above method. It can realize all the processes of the wind turbine control method based on air density described in any of the above embodiments. The specific working principle, function and technical effect of each module are the same as those of the wind turbine control method based on air density described in the above embodiments, and will not be repeated here.

[0081] Furthermore, for ease of control, the control device is installed on the wind turbine.

[0082] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Additionally, the terms "front," "back," "left," "right," "upper," and "lower" in this document refer to the placement shown in the accompanying drawings.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wind turbine control method based on air density, characterized in that, include: Establish a database containing the minimum operating air density, the minimum stall air density, the maximum operating air density, and multiple different air densities and the optimal control parameters of the wind turbine corresponding to the air density; In response to the operation of the wind turbine, the environmental parameters of the wind turbine, the current control parameters of the wind turbine, and the reference air density used to determine the current control parameters are obtained. The air density of the current environment is calculated based on the acquired environmental parameters. The calculated air density is compared with the reference air density and the air density in the database. The operation of the wind turbine is controlled according to the comparison results. If the difference between the calculated air density and the reference air density does not exceed a first preset deviation threshold, the wind turbine continues to operate with the current control parameters. The step of comparing the calculated air density with a reference air density and an air density in a database, and controlling the operation of the wind turbine based on the comparison results, includes: The calculated air density is compared with the minimum operating air density, the minimum stall air density, the reference air density, and the maximum operating air density, respectively. If the calculated air density is less than or equal to the minimum operating air density, the current ambient temperature is compared with the preset maximum operating temperature. If the current ambient temperature is greater than or equal to the preset maximum operating temperature, the wind turbine is shut down. If the current ambient temperature is less than the preset maximum operating temperature, the recorded error count is incremented by one, and it is determined whether the current error count is less than the set threshold. If so, the wind turbine is controlled to operate with the control parameters corresponding to the minimum operating air density. If not, the wind turbine is shut down, the wind turbine's sensors are checked for malfunctions, the parameter calculations are incorrect, and the error count is reset. If the calculated air density is greater than the minimum operating air density and less than or equal to the minimum stall air density, the wind turbine will be controlled to operate with preset anti-stall control parameters. If the calculated air density is greater than the minimum stall air density, and the difference between the calculated air density and the reference air density is less than or equal to the first preset deviation threshold, then the wind turbine will continue to operate with the current control parameters. If the calculated air density is greater than the minimum stall air density, and the difference between the calculated air density and the reference air density is greater than the first preset deviation threshold and less than the second preset deviation threshold, then the current operating status parameters of the wind turbine are obtained, the current optimal tip speed ratio and optimal gain of the wind turbine are calculated, the optimal control parameters corresponding to the currently calculated air density are determined based on the data in the database, and the wind turbine is controlled to operate with the optimal control parameters. If the calculated air density is greater than the minimum stall air density, and the difference between the calculated air density and the reference air density is greater than or equal to the second preset deviation threshold, then the wind turbine will be controlled to operate with preset low temperature control parameters. If the calculated air density is greater than or equal to the maximum operating air density, the current ambient temperature is compared with the preset minimum operating temperature. If the current ambient temperature is less than or equal to the preset minimum operating temperature, the wind turbine is shut down. If the current ambient temperature is greater than the preset minimum operating temperature, the recorded error count is incremented by one, and it is determined whether the current error count is less than the set threshold. If so, the wind turbine is controlled to operate with the control parameters corresponding to the maximum operating air density. If not, the wind turbine is shut down, the wind turbine's sensors are checked for malfunctions, the parameter calculations are correct, and the error count is reset.

2. The wind turbine control method based on air density according to claim 1, characterized in that, The environmental parameters include at least: temperature and air pressure.

3. The wind turbine control method based on air density according to claim 1, characterized in that, The first preset deviation threshold is 5%, and the second preset deviation threshold is 20%.

4. The wind turbine control method based on air density according to claim 1, characterized in that, Operating parameters should include at least: power and speed.

5. The wind turbine control method based on air density according to claim 1, characterized in that, The optimal control parameters corresponding to the calculated air density are determined by looking up tables or by interpolation based on data in the database.

6. The wind turbine control method based on air density according to any one of claims 1-5, characterized in that, The system acquires the environmental parameters of the wind turbine, the current control parameters of the wind turbine, and the reference air density used to determine the current control parameters every preset time interval.

7. The wind turbine control method based on air density according to any one of claims 1-5, characterized in that, The control parameters of a wind turbine include: turbine power, speed, gain, PID coefficient, pitch control, and headroom parameters.

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