A method for calculating the wind speed in front of the nacelle of a wind turbine

Abstract

The present invention relates to the field of wind power generation, and particularly to a method for calculating the wind speed in front of the nacelle of a wind turbine generator set, which comprises the following steps: obtaining the wind measurement data of the project location and the nacelle wind speed of each machine position; selecting representative machine positions according to the selection principle; calculating the annual wind speed measured by the wind measurement tower and calculating the representative annual wind speed; making a representative year judgment on the current year of the representative machine position; correcting the representative annual wind speed of the wind measurement tower to the wind speed of the current year; importing the time series of the wind measurement tower data into a numerical simulation software for calculation to obtain the average wind speed in front of the nacelle of each representative machine position; establishing a quantitative relationship between the nacelle wind speed and the average wind speed in front of the nacelle of each representative machine position to obtain a transfer function; and calculating the wind speed in front of the nacelle through the transfer function. The present invention analyzes by using the existing early-stage wind measurement tower data, improves the efficiency of the post-evaluation work, and saves the investment in new wind measurement equipment.

Description

Technical Field

[0001] The present invention relates to the field of wind power generation, and particularly to a method for calculating the wind speed in front of the nacelle of a wind turbine generator set. Background Art

[0002] After a wind power project is completed, a post-evaluation of the wind power project will be carried out. By processing and analyzing the operation data of the wind turbine generator set, the operation effect of the wind turbine generator set in the wind farm is restored and verified, providing experience guidance for subsequent designs.

[0003] Generally, the nacelle wind speed V used in the post-evaluation n is generally affected by the impeller, resulting in the wind speed being lower than the actual value, causing a certain deviation between the operation conditions of the wind turbine generator set analyzed using this wind speed and the actual conditions. To obtain the wind speed V in front of the nacelle that is not affected by the impeller, the common practice is to install a new anemometer tower or lidar in front of a certain wind turbine generator set for synchronous observation, or install lidar wind measurement equipment in front of the nacelle. The above methods all require the installation of new wind measurement equipment, which has the problems of complex installation procedures, increased investment, and long time consumption. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a method for calculating the wind speed in front of the nacelle of a wind turbine generator set.

[0005] The present invention provides a method for calculating the wind speed in front of the nacelle of a wind turbine generator set, adopting the following technical solution:

[0006] A method for calculating the wind speed in front of the nacelle of a wind turbine generator set, characterized in that it includes the following steps:

[0007] Obtain the wind measurement data at the project location and the nacelle wind speed of each machine position;

[0008] Select representative machine positions according to the selection principle;

[0009] Calculate the annual wind speed measured by the anemometer tower and calculate the representative annual wind speed;

[0010] Judge the representative year for the current year of the representative machine position;

[0011] Revise the representative annual wind speed of the anemometer tower to the wind speed of the current year;

[0012] Import the time series of the anemometer tower data into numerical simulation software for calculation to obtain the average wind speed in front of the nacelle of each representative machine position;

[0013] Establish a quantitative relationship between the nacelle wind speed and the average wind speed in front of the nacelle of each representative machine position to obtain a transfer function;

[0014] Calculate the wind speed in front of the nacelle through the transfer function.

[0015] In a specific feasible implementation, the selection principle is specifically as follows: the horizontal distance between the wind turbine position and the anemometry tower does not exceed 2 km, and the vertical height difference is not greater than 50 m; for a mountain wind farm, the wind turbine position and the anemometry tower should be located on the same mountain ridge, and there is no obvious obstruction around.

[0016] In a specific feasible implementation, the anemometry data includes hourly wind speed and wind direction data for at least a complete year;

[0017] The anemometry data is obtained through the anemometry tower;

[0018] The nacelle wind speed is obtained by recording through the SCADA system installed on the nacelle of the wind turbine generator set.

[0019] In a specific feasible implementation, the method for calculating the annual anemometry wind speed of the anemometry tower is as follows:

[0020] Fit the wind shear power law index through the anemometry tower, and extrapolate the hourly wind speed in the anemometry data to the wind speed when it is consistent with the hub height of the wind turbine;

[0021] Calculate the average value to obtain the annual anemometry wind speed V1 of the anemometry tower for a complete year.

[0022] In a specific feasible implementation, the method for calculating the representative annual wind speed is as follows:

[0023] Judge the anemometry year of the anemometry tower in combination with the long-term reference data;

[0024] Revise the annual anemometry wind speed V1 to the representative annual wind speed V2 according to the anemometry year of the anemometry tower. The calculation formula is:

[0025]

[0026] In the above formula, V2 represents the representative annual wind speed;

[0027] VP represents the multi-year average wind speed;

[0028] VP1 represents the average wind speed of the anemometry year.

[0029] In a specific feasible implementation, the basis for judging the anemometry year of the anemometry tower in combination with the long-term reference data is:

[0030] If the deviation between the average wind speed VP1 of the long-term reference data in the anemometry year and the multi-year average wind speed VP is less than or equal to 2%, it indicates that the anemometry year of the anemometry tower is a normal wind year;

[0031] If the average wind speed VP1 of the long-term reference data in the anemometry year is more than 2% larger than the multi-year average wind speed VP, it indicates that the anemometry year of the anemometry tower is a high wind year;

[0032] If the average wind speed VP1 of the long-term reference data in the wind measurement year is more than 2% smaller than the multi-year average wind speed VP, it indicates that the wind measurement year of the wind measurement tower is a light wind year.

[0033] In a specific feasible implementation, the calculation formula for the average wind speed in front of the nacelle is:

[0034]

[0035] In the above formula, M is the total number of representative positions;

[0036] i represents the i-th representative position, i = 1, 2,..., M;

[0037] is the average wind speed in front of the nacelle;

[0038] V m is the wind speed in front of the nacelle.

[0039] In a specific feasible implementation, the method for establishing a quantitative relationship between the nacelle wind speed of each representative position and the average wind speed in front of the nacelle to obtain the transfer function is as follows:

[0040] Calculate the average wind speed of the nacelle;

[0041] Calculate the magnification coefficient according to the average wind speed of the nacelle and the average wind speed in front of the nacelle;

[0042] Construct the transfer function according to the magnification coefficient.

[0043] In a specific feasible implementation, the calculation formula for the magnification coefficient is:

[0044]

[0045] In the above formula, σ is the magnification coefficient;

[0046] is the average wind speed of the nacelle;

[0047] is the average wind speed in front of the nacelle.

[0048] In a specific feasible implementation, the transfer function is: V j = σV j ′

[0049] In the above formula, V j represents the wind speed in front of the nacelle of the j-th position, V j ′ represents the nacelle wind speed of the j-th position.

[0050] In summary, the present invention includes the following beneficial effects:

[0051] By using the measured wind data of the anemometers around the existing wind turbines, through methods such as data processing and numerical simulation calculation, the wind speed in front of the nacelle of the existing wind turbines is obtained, and a transfer function is established with the wind speed in the nacelle of the wind turbines, which can accurately calculate the transfer function of the nacelle wind speed, providing a better data basis for work such as power curve verification and unit operation condition judgment in the post-evaluation of wind power projects. At the same time, by analyzing the existing pre-construction anemometer data, the efficiency of the post-evaluation work is improved, and the investment in new anemometer equipment is saved. Description of the Drawings

[0052] Figure 1 It is a flow chart of the method for calculating the wind speed in front of the nacelle of a wind turbine generator.

[0053] Figure 2 It is a schematic diagram showing the layout of the machine positions. Detailed Implementation Manner

[0054] The following Figure 1 - Figure 2 further describes the present invention in detail.

[0055] Referring to Figure 1 , the method for calculating the wind speed in front of the nacelle of a wind turbine generator includes the following steps:

[0056] S100, obtaining the wind measurement data of the project location and the nacelle wind speed of each machine position.

[0057] The wind measurement data includes the hourly wind speed and wind direction data of at least a complete year at the project location, and the wind measurement data is obtained through the anemometers at the project location. The nacelle wind speed is obtained through the SCADA system installed on the nacelle of the wind turbine generator.

[0058] S200, selecting representative machine positions according to the selection principle.

[0059] The selection principle is specifically: the horizontal distance between the machine position and the anemometer does not exceed 2 km, and the vertical height difference is not greater than 50 m; for a mountain wind farm, the machine position and the anemometer should be on the same mountain ridge, and there is no obvious obstruction around.

[0060] For the sake of easy understanding, further explanation is made in combination with Figure 2 . There is a machine position 1 set at the anemometer, and machine positions 2 - 8 are also distributed around machine position 1. The machine positions that are on the same mountain ridge as the anemometer and are relatively close are machine position 8, machine position 2, and machine position 5. After further analysis, the distance between machine position 5 and the anemometer is relatively far; although the distance between machine position 2 and the anemometer is relatively close, there is an obvious decrease in altitude; the distance between machine position 8 and the anemometer is close, and the altitude tends to be the same. Therefore, machine position 1 and machine position 8 have better representativeness and are selected as representative machine positions.

[0061] S300, calculate the annual wind speed V1 of the anemometer tower and calculate the representative annual wind speed V2.

[0062] Use the anemometer tower to fit the wind shear power law index, and extrapolate the hourly wind speed in the anemometer data to the wind speed at the same height as the hub height of the wind turbine. By calculating the average value, the annual wind speed V1 of the anemometer tower for a complete year can be further obtained. Combine long-term reference data such as meteorological station data or mesoscale data to judge the anemometer tower's annual wind measurement year. The anemometer tower's annual wind measurement year is specifically a high-wind year, a normal-wind year, and a low-wind year. Specifically:

[0063] The deviation between the average wind speed VP1 of the long-term reference data in the anemometer tower's annual wind measurement year and the multi-year average wind speed VP is less than or equal to 2%, that is It indicates that the anemometer tower's annual wind measurement year is a normal-wind year;

[0064] The average wind speed VP1 of the long-term reference data in the anemometer tower's annual wind measurement year is more than 2% larger than the multi-year average wind speed VP, that is VP1 > VP, and It indicates that the anemometer tower's annual wind measurement year is a high-wind year;

[0065] The average wind speed VP1 of the long-term reference data in the anemometer tower's annual wind measurement year is more than 2% smaller than the multi-year average wind speed VP, that is VP1 < VP, and It indicates that the anemometer tower's annual wind measurement year is a low-wind year.

[0066] Revise the annual wind speed V1 of the anemometer tower according to the anemometer tower's annual wind measurement year to obtain the representative annual wind speed V2. The revision method can adopt the proportional revision method or the sector revision method. For the convenience of understanding, the proportional revision method is used for expansion and explanation.

[0067] Revise the annual wind speed V1 of the anemometer tower according to the ratio of the difference between the average wind speed VP1 of the long-term reference data in the anemometer tower's annual wind measurement year and the multi-year average wind speed VP to the multi-year average wind speed VP. The calculation formula is as follows:

[0068]

[0069] Thus, the representative annual wind speed V2 is obtained.

[0070] S400, judge the representative year of the anemometer tower for the current year of the representative location.

[0071] Combine long-term reference data such as meteorological station data or mesoscale data to judge the representative year of the current year.

[0072] S500, revise the representative annual wind speed V2 of the anemometer tower to the wind speed V3 of the current year.

[0073] Use the proportional revision method or the sector revision method to revise the representative annual wind speed V2 to the wind speed V3 of the current year. The calculation method is the same as that in step S300 and will not be repeated.

[0074] In step S600, import the time series of the wind measurement tower data V3 into the numerical simulation software for calculation to obtain the average wind speed V in front of the nacelle of each representative wind turbine position.

[0075] Perform a simulation and modeling of the terrain at the project location. The simulation and modeling can adopt CFD flow field simulation, etc. Substitute the time series of the wind speed V3 in the current year into the model for calculation to obtain the wind speed V in front of the nacelle of the representative wind turbine positions. m Based on the wind speed V in front of the nacelle of the representative wind turbine positions m calculate the average wind speed in front of the nacelle The calculation formula is as follows:

[0076]

[0077] In the above formula, M is the total number of representative wind turbine positions, i represents the i-th representative wind turbine position, and i = 1, 2,..., M.

[0078] Continue to use the example in step S200 for further illustration:

[0079] Substitute the time series of the wind speed V3 in the current year into the model for calculation, and the wind speed in front of the nacelle of wind turbine position 1 can be obtained as V m1 and the wind speed in front of the nacelle of wind turbine position 8 is V m8 . The average wind speed in front of the nacelle

[0080] In step S700, establish a quantitative relationship between the nacelle wind speed and the average wind speed V in front of the nacelle of each representative wind turbine position to obtain the transfer function NTF.

[0081] Calculate the average nacelle wind speed based on the nacelle wind speed of the representative wind turbine positions Based on the average nacelle wind speed and the average wind speed in front of the nacelle calculate the magnification factor σ.

[0082] The calculation formula for the magnification factor σ is:

[0083] Furthermore, a transfer function NTF can be constructed: V j = σV j ′

[0084] In the above formula, V j represents the wind speed in front of the nacelle of the j-th wind turbine position, and V j ′ represents the nacelle wind speed of the j-th wind turbine position. Through the transfer function NTF, without additionally setting up a wind measurement tower, the wind speed in front of the nacelle can be calculated based on the nacelle wind speed recorded by the SCADA system installed on the nacelle of the wind turbine generator.

[0085] The above are all preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A method for calculating the wind speed in front of the nacelle of a wind turbine, characterized in that: The steps include: Obtain wind measurement data at the project site and cabin wind speed at each position; Select representative seats according to the selection principles; Calculate the annual wind speed measured by the wind tower and the representative annual wind speed; Determine the representative year for the current year of the representative aircraft positions; Correct the annual wind speed represented by the wind tower to the wind speed of the current year; The time series of wind measurement data was imported into numerical simulation software for calculation to obtain the average wind speed in front of the cabin of each representative aircraft position; Establish a quantitative relationship between the cabin wind speed of each representative aircraft position and the average wind speed in front of the cabin to obtain the transfer function; Calculate the wind speed in front of the cabin through the transfer function; The selection principles are as follows: the horizontal distance between the machine site and the wind tower should not exceed 2km, and the vertical height difference should not exceed 50m; for mountainous wind farms, the machine site and the wind tower should be located on the same ridge, and there should be no obvious obstruction around them; Among them, the method of establishing a quantitative relationship between the cabin wind speed of each representative position and the average wind speed in front of the cabin to obtain the transfer function is: Calculate the average wind speed in the computer cabin; Calculate the multiplication factor based on the average wind speed in the cabin and the average wind speed in front of the cabin; Construct the transfer function based on the multiplication coefficients.

2. The method for calculating the wind speed in front of the nacelle of a wind turbine according to claim 1, characterized in that: Wind data include hourly wind speed and direction data for at least one full year; Wind data is obtained through wind towers; The nacelle wind speed is recorded by the SCADA system installed on the nacelle of the wind turbine.

3. The method for calculating the wind speed in front of the nacelle of a wind turbine generator according to claim 1, characterized in that: The method for calculating the annual wind speed of the wind tower is: By fitting the wind shear power law index through the wind tower, the hourly wind speed in the wind measurement data is extrapolated to the wind speed when the height is consistent with the hub height of the wind turbine; Calculate the average value to obtain the annual wind speed V1 measured by the wind tower for a full year.

4. The method for calculating the wind speed in front of the nacelle of a wind turbine according to claim 3, characterized in that: The method for calculating the representative annual wind speed is: Combined with long-sequence reference data, the wind measurement year of the wind tower is judged; According to the wind tower wind measurement year, the wind speed V1 of the wind measurement year is corrected to the representative year wind speed V2. The calculation formula is: In the above formula, V2 represents the annual wind speed; VP represents the multi-year average wind speed; VP1 represents the average wind speed in the wind measurement year.

5. The method for calculating the wind speed in front of the nacelle of a wind turbine according to claim 4, characterized in that: The basis for judging the wind measurement year of the wind tower in combination with the long sequence reference data is: If the deviation between the average wind speed VP1 of the long-sequence reference data in the wind measurement year and the multi-year average wind speed VP is less than or equal to 2%, it indicates that the wind measurement year of the wind tower is a year of average wind; If the average wind speed VP1 of the long-series reference data in the wind measurement year is more than 2% higher than the average wind speed VP of many years, it indicates that the wind measurement year of the wind tower is a strong wind year; If the average wind speed VP1 of the long-series reference data in the wind measurement year is more than 2% smaller than the average wind speed VP of many years, it indicates that the wind measurement year of the wind tower is a year with low winds.

6. The method for calculating the wind speed in front of the nacelle of a wind turbine according to claim 1, characterized in that: The calculation formula for the average wind speed in front of the nacelle is: In the above formula, M is the total number of representative seats; Indicates the th representative camera position, ; is the average wind speed in front of the engine nacelle; V m is the wind speed in front of the engine nacelle.

7. The method for calculating the wind speed in front of the nacelle of a wind turbine according to claim 1, characterized in that: The calculation formula of the multiplication factor is: In the above formula, is the magnification coefficient; is the average wind speed in the engine room; is the average wind speed in front of the engine nacelle.

8. The method for calculating the wind speed in front of the nacelle of a wind turbine according to claim 7, characterized in that: The transfer function is: In the above formula, V j represents the wind speed in front of the nacelle at the j-th position, and represents the wind speed in the nacelle at the j-th position.

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