Method for constructing shadow frequency distribution diagram of wind generating set

Abstract

The invention relates to the field of electrical digital data processing, in particular to a method for constructing a shadow frequency distribution diagram of a wind generating set, which comprises the following steps of: acquiring wind measurement data of a wind measurement tower at a target location, and analyzing and generating a wind direction rose diagram; performing three-dimensional modeling of the wind turbine generator, and generating fan shadows corresponding to different wind coming directions through a sun shadow change model; and overlapping the fan shadows in different wind coming directions, and generating a fan shadow frequency distribution map in combination with the frequencies in different wind coming directions. According to the method, accurate model construction is carried out on the wind turbine generator set, the shadows of the wind turbine generator set in different wind coming directions are calculated, accurate simulation is carried out on the shadows of the wind turbine generator set, and arrangement of a photovoltaic electric field can be better carried out.

Description

Technical Field

[0001] The invention relates to the field of electrical digital data processing, and in particular to a method for constructing a shadow frequency distribution diagram of a wind turbine generator set. Background Art

[0002] Wind and solar co-construction means building a photovoltaic field under the wind farm to generate wind power and photovoltaic power. However, a wind turbine is not a simple cylinder. The head of the wind turbine will rotate according to the direction of the wind, and the wind wheel of the head will also rotate. Therefore, different wind directions will cause the shadow of the head on the ground to change. The photovoltaic device of the photovoltaic field relies on receiving sunlight to generate electricity. When the photovoltaic device is under the wind turbine, the shadow of the wind turbine will affect the photoelectric conversion efficiency of the photovoltaic device. The design of the photovoltaic field needs to be calculated and adjusted according to the shadow of the wind turbine, which puts higher requirements on the layout of the photovoltaic field.

[0003] However, since the nose of a wind turbine rotates as the wind direction changes, the shadow of the wind turbine changes frequently, making it difficult to simulate and calculate. Summary of the invention

[0004] In order to solve the problem that the shadow of a wind turbine is difficult to simulate when designing a wind-solar system on the same site, the present invention provides a method for constructing a frequency distribution diagram of the shadow of a wind turbine.

[0005] The present invention provides a method for constructing a shadow frequency distribution diagram of a wind turbine generator set, which adopts the following technical solution:

[0006] A method for constructing a shadow frequency distribution diagram of a wind turbine generator set comprises the following steps:

[0007] Obtain wind data from the wind tower at the target location, analyze it, and generate a wind rose diagram;

[0008] Carry out 3D modeling of wind turbines and generate wind turbine shadows corresponding to different wind directions through the sun shadow variation model;

[0009] The wind turbine shadows from different wind directions are overlapped and combined with the frequencies of different wind directions to generate a frequency distribution map of wind turbine shadows.

[0010] In a specific possible implementation manner, the wind measurement data includes hourly wind speed and wind direction data.

[0011] In a specific possible implementation scheme, the method for three-dimensional modeling of a wind turbine generator system includes the following steps:

[0012] The wind rotor is approximated as a disk with the length of the wind rotor as its radius.

[0013] In a specific possible implementation scheme, the method for generating wind turbine shadows corresponding to different wind directions is:

[0014] The direction of the wind rotor in a windless state is 0°, and the model of the wind turbine is rotated and copied according to the preset rotation angle until the model is rotated 360°, thereby obtaining models of wind turbines with multiple different wind rotor directions;

[0015] Generate shadows of different models through the sun shadow variation model.

[0016] In a specific possible implementation scheme, the method for overlapping the shadows of wind turbines with different wind directions is:

[0017] Taking the projection of the tower axis as the base point, the shadows of wind turbines with different wind directions are overlapped.

[0018] In a specific feasible implementation plan, when the wind turbine shadows corresponding to different wind directions are generated by using the solar shadow variation model, the solar declination angle δ satisfies:

[0019] δ=0.3723+23.2567sin3θ+0.1149sin3θ-0.758cosθ+0.3656cosθ+0.0201 cos 3θ

[0020] θ=2π(N-N0) / 365.2422

[0021] N0=79.6764+0.2422×(year-1985)-int[(year-1985) / 4]

[0022] In the above formula, θ is used to describe the position of the sun relative to the reference point of the model;

[0023] N represents the cumulative day of the year, which is used to determine the sequence number of a date in the year;

[0024] N0 represents the base day number, which is used to determine the relative position of a day in a certain year.

[0025] In a specific feasible implementation plan, when the wind turbine shadows corresponding to different wind directions are generated by using the solar shadow variation model, the solar hour angle ω satisfies:

[0026] ω=(ST-12)×15

[0027] ST=t+Δt

[0028] Δt=0.0175+0.4281cosβ-7.3515sinβ-3.3495cos2β-9.3619sin2β

[0029] β=2πN / 365

[0030] In the above formula, ST is the standard time;

[0031] t is the Beijing time of the measured area.

[0032] In a specific possible implementation scheme, when the wind turbine shadows corresponding to different wind directions are generated by using the solar shadow variation model, the solar altitude angle α satisfies:

[0033] In a specific feasible implementation plan, when the wind turbine shadows corresponding to different wind directions are generated by using the solar shadow variation model, the solar azimuth angle γ satisfies:

[0034] In a specific feasible implementation plan, when the wind turbine shadows corresponding to different wind directions are generated by using the solar shadow variation model, the incident angle ε and the azimuth angle γ satisfy the relationship:

[0035] If the measurement time is in the morning:

[0036] If the measurement time is in the afternoon:

[0037] The calculation formula for the endpoint coordinates of the model projection is:

[0038]

[0039] x=-h×cotα×cosε

[0040] y=h×cotα×cosγ=h×cotα×sin{ε

[0041]

[0042] In the above formula, α>0.

[0043] In summary, the present invention has the following beneficial effects:

[0044] Through accurate simulation of wind turbine shadows, taking into account the shadow changes caused by wind turbine yaw, the full range of wind turbine shadow influence is obtained, the boundaries in the layout of photovoltaic modules are better defined, and the shadow shielding effect of wind turbines on photovoltaic modules is reduced. In the context of tight land resources, the project's power generation and economic benefits are increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a flow chart of a method for constructing a wind turbine shadow frequency distribution map.

[0046] Figure 2 It's a wind rose diagram.

[0047] Figure 3It is a schematic diagram of the wind turbine shadow under different wind directions.

[0048] Figure 4 It is the frequency distribution spectrum of wind turbine shadow. DETAILED DESCRIPTION

[0049] The following is combined with Figure 1-4 The present invention is described in further detail.

[0050] Reference Figure 1 ,The method for constructing the shadow frequency distribution diagram of a wind turbine generator set includes the following steps:

[0051] S100, obtaining wind measurement data from a wind tower at a target location, analyzing the data, and generating a wind rose diagram.

[0052] The wind measurement data includes at least one year's hourly wind speed and wind direction data, and the hourly wind speed is the wind speed of the target location every hour. Combined with the hourly wind speed and wind direction data, the frequency of wind in different directions around the center of the target location can be calculated and analyzed. According to the frequency and wind direction, a wind rose diagram is obtained, and the center of the rose diagram is the center of the target location. Different angles are marked on the rose diagram, indicating the wind blowing to the center of the target location (different incoming wind directions) from different directions. The radius in the rose diagram indicates the frequency of wind in the corresponding direction. The higher the frequency of wind at this angle, the farther away from the center of the circle.

[0053] S200, three-dimensional modeling of the wind turbine is performed, and wind turbine shadows corresponding to different wind directions are generated through a solar shadow variation model.

[0054] When modeling a wind turbine, the tower of the wind turbine is converted into a cylinder or a frustum. Since the wind rotor of the wind turbine rotates all the time, the wind rotor is converted into a disk with the length of the wind rotor as the radius.

[0055] After completing the 3D modeling of the wind turbine, in order to simulate the different states of the wind rotor under different wind directions, the direction of the wind rotor in the windless state is 0°. According to the preset rotation angle, the model of the wind turbine is rotated and copied until the model is rotated 360°, and multiple models of wind turbines with different wind rotor directions are obtained. The rotation angle of the wind rotor is the angle of change of the incoming wind direction.

[0056] The shadows of different models are generated through the sun shadow change model, that is, the shadows of wind turbines in different wind directions. Specifically:

[0057] Assume that the earth is a sphere, the ground is regarded as a horizontal plane, and the model of the wind turbine is perpendicular to the ground.

[0058] A plane rectangular coordinate system is established with the bottom of the model as the origin, the due east direction as the x-axis, and the due north direction as the y-axis. The sunlight is parallel light, and the measurement time is standard Beijing time.

[0059] The solar declination angle δ satisfies the following formula:

[0060] δ=0.3723+23.2567sin3θ+0.1149sin3θ-0.758cosθ+0.3656cosθ

[0061] +0.0201cos 3θ

[0062] θ=2π(N-N0) / 365.2422

[0063] N0=79.6764+0.2422×(year-1985)-int[(year-1985) / 4]

[0064] In the above formula, θ is used to describe the position of the sun relative to the reference point of the model;

[0065] N represents the cumulative day of the year, which is used to determine the sequence number of a date in the year;

[0066] N0 represents the base day number, which is used to determine the relative position of a day in a certain year.

[0067] From the above formula, we can know that the solar declination angle δ is related to the annual accumulated days and years.

[0068] The solar hour angle ω satisfies:

[0069] ω=(ST-12)×15

[0070] ST=t+Δt

[0071] Δt=0.0175+0.4281cosβ-7.3515sinβ-3.3495cos2β-9.3619sin2β

[0072] β=2πN / 365

[0073] In the above formula, ST is the standard time;

[0074] t is the Beijing time of the measured area.

[0075] By analyzing the above formula, we can understand that the solar hour angle ω is related to the true solar time. The true solar time is calculated based on the true solar day. The time interval between two consecutive times the sun passes through noon is called the true solar day. For the same time, the larger the longitude value, the larger the corresponding solar hour angle; for the same longitude, the larger the time value, the larger the corresponding solar hour angle.

[0076] The solar altitude angle α satisfies:

[0077]

[0078] In the above formula, Indicates the latitude of the measured area, with positive values ​​for north latitude and negative values ​​for south latitude. Through analysis, it can be seen that the solar altitude angle α is directly related to the latitude of the measured area, the solar hour angle and the solar declination angle. When the solar altitude angle is 90°, the solar radiation intensity is the highest; when the sun is obliquely shining on the ground, the solar radiation intensity is small. The angle is 0 at sunrise and sunset, and the solar altitude angle is the highest at noon.

[0079] The solar azimuth γ satisfies:

[0080]

[0081] The incident angle ε and the azimuth angle γ satisfy the relationship:

[0082] If the measurement time is in the morning:

[0083] If the measurement time is in the afternoon:

[0084] We can further obtain the changes of the shadow over time, and then obtain the calculation formula of the endpoint coordinates of the model projection:

[0085]

[0086] x=-h×cotα×cosε

[0087] y=h×cotα×cosγ=h×cotα×sin{ε

[0088]

[0089] The solar altitude angle α must satisfy α>0, that is, the calculation range of the shadow trajectory is the curve between the sunrise and sunset time points of the sun at a certain place on a certain day.

[0090] The coordinates of the model are (0,0), so the calculation formula for the shadow length l is:

[0091] S300, overlapping the wind turbine shadows from different wind directions, combining the frequencies of the different wind directions, and generating a wind turbine shadow frequency distribution map.

[0092] Specifically, the wind turbine shadows in different wind directions are overlapped with the projection of the tower axis as the base point, and the wind speed frequency in the corresponding direction is used as the proportion to generate the wind turbine shadow frequency distribution. The wind speed frequency is the proportion of the wind speed in the wind direction to the wind speed in all wind directions.

[0093] Example:

[0094] To facilitate understanding, further explanation is given below through examples.

[0095] Assume that the height of the wind turbine is 80m, the height of the tower is 70m, the diameter of the tower bottom is 4m, the diameter of the top is 3m, and the length of the wind rotor is 50m.

[0096] S100, obtain the wind measurement data of the wind tower at the target location within one year and analyze it. The wind direction is divided into 16 different wind directions at intervals of 22.5°, and the frequency is divided at intervals of 400 to form concentric circles in the rose diagram, generating the following: Figure 2 The wind rose diagram shown.

[0097] S200, conducts three-dimensional modeling of wind turbines, and generates wind turbine shadows corresponding to 16 different wind directions through the sun shadow change model. Figure 3 .

[0098] S300 overlaps the shadows of wind turbines with different wind directions and combines the frequencies of different wind directions to generate Figure 4 Frequency distribution of wind turbine shadows.

[0099] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for constructing a wind turbine shadow frequency distribution diagram, characterized in that: The steps include: Obtain wind data from the wind tower at the target location, analyze it, and generate a wind rose diagram; Carry out 3D modeling of wind turbines and generate wind turbine shadows corresponding to different wind directions through the sun shadow variation model; The wind turbine shadows from different wind directions are overlapped and combined with the frequencies of different wind directions to generate a wind turbine shadow frequency distribution map.

2. The method for constructing a shadow frequency distribution diagram of a wind turbine generator set according to claim 1, characterized in that: Wind measurement data includes hourly wind speed and direction data.

3. The method for constructing a wind turbine shadow frequency distribution diagram according to claim 1, characterized in that: The method for three-dimensional modeling of a wind turbine generator system comprises the following steps: Approximate the tower as a cylinder or a truncated cone; The wind rotor is approximated as a disk with the length of the wind rotor as its radius.

4. The method for constructing a wind turbine shadow frequency distribution diagram according to claim 1, characterized in that: The method for generating wind turbine shadows corresponding to different wind directions is: The direction of the wind rotor in a windless state is 0°, and the model of the wind turbine is rotated and copied according to the preset rotation angle until the model is rotated 360°, thereby obtaining models of wind turbines with multiple different wind rotor directions; Generate shadows of different models through the sun shadow variation model.

5. The method for constructing a shadow frequency distribution diagram of a wind turbine generator set according to claim 1, characterized in that: The method to overlap the shadows of wind turbines with different wind directions is: Taking the projection of the tower axis as the base point, the shadows of wind turbines with different wind directions are overlapped.

6. The method for constructing a wind turbine shadow frequency distribution diagram according to claim 1, characterized in that: When the wind turbine shadows corresponding to different wind directions are generated through the solar shadow variation model, the solar declination angle δ satisfies: δ=0.3723+23.2567sin3θ+0.1149sin3θ-0.758cosθ+0.3656cosθ+0.0201cos 3θ θ=2π(N-N0) / 365.2422 N0=79.6764+0.2422×(year-1985)-int[(year-1985) / 4] In the above formula, θ is used to describe the position of the sun relative to the reference point of the model; N represents the cumulative day of the year, which is used to determine the sequence number of a date in the year; N0 represents the base day number, which is used to determine the relative position of a day in a certain year.

7. The method for constructing a shadow frequency distribution diagram of a wind turbine generator set according to claim 6, characterized in that: When the wind turbine shadows corresponding to different wind directions are generated through the solar shadow variation model, the solar hour angle ω satisfies: ω=(ST-12)×15 ST=t+Δt Δt=0.0175+0.4281cosβ-7.3515sinβ-3.3495cos 2β-9.3619sin 2β β＝2πN / 365 In the above formula, ST is the standard time; t is the Beijing time of the measured area.

8. The method for constructing a wind turbine generator set shadow frequency distribution diagram according to claim 7, characterized in that: When the wind turbine shadows corresponding to different wind directions are generated through the solar shadow variation model, the solar altitude angle α satisfies:

9. The method for constructing a shadow frequency distribution diagram of a wind turbine generator set according to claim 8, characterized in that: When the wind turbine shadows corresponding to different wind directions are generated through the solar shadow variation model, the solar azimuth angle γ satisfies:

10. The method for constructing a shadow frequency distribution diagram of a wind turbine generator set according to claim 9, characterized in that: When the wind turbine shadows corresponding to different wind directions are generated through the solar shadow variation model, the incident angle ε and the azimuth angle γ satisfy the relationship: If the measurement time is in the morning: If the measurement time is in the afternoon: The calculation formula for the endpoint coordinates of the model projection is: x=-h×cotα×cosε y=h×cotα×cosγ=h×cotα×sin{ε In the above formula, α>0.

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