A method, device and medium for evaluating the light and shadow effect of a wind farm

Abstract

The present application discloses a method, device, and medium for evaluating the light and shadow effect of a wind farm; relating to the field of wind power generation, and solving the problem of deviation in the calculation of the influence range of the light and shadow effect of traditional wind turbines. The present application uses the true solar time at the machine position points of each wind turbine as the time standard to determine the shadow influence range of the wind wheel surface of each wind turbine at each moment throughout the year; counts the total influence duration of each grid point based on the shadow influence ranges of all wind turbines; and determines whether the design scheme meets the preset specification requirements based on the total influence duration of each grid point. By dividing the area that can be affected by the wind farm, calculating the solar altitude angle and solar azimuth angle point by point and moment by moment, the present application calculates the shadow ellipse range of the wind wheel surface of each wind turbine, and further obtains the maximum influence duration of each point theoretically in a year, improving the calculation accuracy of the influence range of the light and shadow effect of the wind farm and providing detailed data support for the environmental impact assessment of the wind farm.

Description

Technical Field

[0001] The present application relates to the field of wind power generation, and particularly to a method, device and medium for evaluating the light and shadow effect of a wind farm. Background Art

[0002] With the exhaustion of traditional energy sources and the continuous development of social economy, renewable resources have become particularly important. Among them, wind energy is an important component, and wind power generation is the main means of its utilization. With the large-scale development of wind power, the distance between wind farms and residential areas is getting closer and closer, which has an impact on the lives of residents. Among them, the light and shadow effect will have an adverse impact on people's lives. The light and shadow effect of a wind farm refers to a kind of flickering light and shadow generated by the rotating impeller of a wind turbine under the direction of sunlight. This flickering light and shadow will cause discomfort to people. Therefore, in the development and construction of wind farms, the residential areas should be avoided as much as possible. When the installable point conditions of the wind farm are limited and it is impossible to avoid the influence of the light and shadow effect of the wind farm, the annual theoretical maximum influence hours of the light and shadow effect of the wind farm should be calculated, and then it should be evaluated whether it meets the specification requirements.

[0003] There are certain limitations in the traditional method for evaluating the light and shadow effect of a wind farm. For example, it is considered that in the mid-latitude regions of the Northern Hemisphere, the solar azimuth angle follows the operation law of due east (sunrise) → due south (noon) → due west (sunset) every day throughout the year. However, in fact, the sunrise time and the daily operation law of the solar azimuth angle vary in each region and need to be calculated customized. In addition, when the wind turbine blade plane is not facing or facing away from the sun, it does not present a orthographic projection state. Although the shadow of the wind turbine blade plane is still elliptical, the four points of the upper, lower, left and right of the wind turbine blade plane are no longer the four endpoints of the ellipse of the shadow of the wind turbine blade plane. In this partial projection state, although the elliptical equation can be obtained by numerical calculation method through the geodetic coordinates of the projection points of the four specific points of the upper, lower, left and right of the wind turbine blade plane on the ground, and then the subsequent work can be carried out, on the one hand, it undoubtedly increases the calculation amount and slows down the overall calculation efficiency; on the other hand, it also causes the shadow range of the wind turbine blade plane to be smaller than that in the orthographic projection state, and the annual theoretical maximum influence hours of the light and shadow effect of the wind farm cannot be obtained.

[0004] Therefore, it can be seen that how to solve the deviation in the calculation of the influence range of the light and shadow effect of traditional wind turbines is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] The purpose of the present application is to provide a method, device and medium for evaluating the light and shadow effect of a wind farm, so as to solve the problem of deviation in the calculation of the influence range of the light and shadow effect of traditional wind turbines.

[0006] To solve the above technical problem, the present application provides a method for evaluating the light and shadow effect of a wind farm, including:

[0007] Determine a rectangular area that covers the wind farm and expands a preset distance according to the model data and spatial layout of the wind farm;

[0008] Divide the rectangular area into multiple grid points;

[0009] Taking the true solar time at the machine location of each wind turbine as the time standard, determine the shadow influence range of the wind turbine blade surface at each moment of each wind turbine in a year;

[0010] Statistically calculate the total influence duration of each grid point according to the shadow influence ranges of all the wind turbines;

[0011] Determine whether the design scheme meets the requirements of the preset specifications according to the total influence duration of each grid point.

[0012] As an optional solution, in the above wind farm light and shadow effect evaluation method, taking the true solar time at the machine location of each wind turbine as the time standard, determining the shadow influence range of the wind turbine blade surface at each moment of each wind turbine in a year includes:

[0013] Divide a year into multiple time periods based on a preset time step;

[0014] Determine the true solar time at the machine location of each wind turbine according to the machine location coordinate data of each wind turbine;

[0015] Determine the solar altitude angle and solar azimuth angle corresponding to each time period according to the true solar time;

[0016] Determine the shadow influence range of the orthographic projection of the wind turbine blade surface of each wind turbine within each time period according to the solar altitude angle and the solar azimuth angle.

[0017] As an optional solution, in the above wind farm light and shadow effect evaluation method, statistically calculating the total influence duration of each grid point according to the shadow influence ranges of all the wind turbines includes:

[0018] Judging grid point by grid point whether each grid point is within the shadow influence range of any one of the wind turbines in the current time period;

[0019] If so, increase the total influence duration of the current grid point according to the preset time step;

[0020] If not, move to the next grid point until the statistics of all grid points in the current time period are completed;

[0021] After the judgment of all the time periods is completed, output the total influence duration statistically calculated for each grid point.

[0022] As an alternative, in the above method for evaluating the light and shadow effect of a wind farm, determining the shadow influence range of the orthographic projection of the wind turbine blade surface of each wind turbine in each time period according to the solar altitude angle and the solar azimuth angle includes:

[0023] Obtain the rotor diameter and hub height of each wind turbine;

[0024] Assume that the wind turbine rotor faces the sun to present an orthographic projection state. According to the solar altitude angle, the solar azimuth angle, the rotor diameter and the hub height of the wind turbine, determine the four endpoint coordinates of the ellipse of the orthographic projection of the current wind turbine;

[0025] Obtain the ellipse equation parameters of the ellipse projection of the current wind turbine according to the four endpoint coordinates;

[0026] Determine the shadow influence range of the current wind turbine according to the ellipse equation parameters.

[0027] As an alternative, in the above method for evaluating the light and shadow effect of a wind farm, judging whether each grid point is within the shadow influence range of any one of the wind turbines in the current time period grid by grid point includes:

[0028] Obtain the grid coordinates of each grid point;

[0029] According to the current grid coordinates and the two ellipse focus coordinates of the ellipse projection of the current wind turbine, obtain the total distance of the grid point from the two ellipse foci;

[0030] Judge whether the total distance is less than the major axis of the ellipse of the current ellipse projection;

[0031] If so, determine that the current grid point is within the shadow influence range of any one of the wind turbines in the current time period, and enter the judgment process of the next grid point;

[0032] If not, determine that the current grid point is not within the shadow influence range of the current wind turbine in the current time period, and enter the step of obtaining the total distance of the grid point from the two ellipse foci according to the ellipse equation parameters of the ellipse projection of the next wind turbine;

[0033] If the current grid point is not within the shadow influence range of the last wind turbine in the current time period, determine that the current grid point is not within the shadow influence range of any one of the wind turbines in the current time period, and enter the judgment process of the next time period.

[0034] As an alternative, in the above method for evaluating the light and shadow effect of a wind farm, dividing a year into multiple time periods based on a preset time step includes:

[0035] Dividing the preset effective sunshine time of each day into multiple time periods based on a preset time step.

[0036] As an alternative, in the above method for evaluating the light and shadow effect of a wind farm, obtaining the grid coordinates of each grid point includes:

[0037] Taking the mid-latitude region of the Northern Hemisphere as an example, obtaining the shadow influence range of each wind turbine on the winter solstice;

[0038] Obtaining the maximum envelope range based on the shadow influence ranges of multiple winter solstices;

[0039] Obtaining the grid coordinates of the grid points located within the maximum envelope range.

[0040] To solve the above technical problems, the present application also provides a device for evaluating the light and shadow effect of a wind farm, including:

[0041] A building module, configured to determine a rectangular area that covers the wind farm and expands a preset distance outward according to the model data and spatial layout of the wind farm;

[0042] A dividing module, configured to divide the rectangular area into multiple grid points;

[0043] A light and shadow influence analysis module, configured to use the true solar time at the machine position of each wind turbine as the time standard to determine the shadow influence range of the wind wheel surface of each wind turbine at each moment of a year;

[0044] A statistics module, configured to count the total influence duration of each grid point according to the shadow influence ranges of all the wind turbines;

[0045] A judgment module, configured to determine whether the design scheme meets the requirements of a preset specification according to the total influence duration of each grid point.

[0046] To solve the above technical problems, the present application also provides a device for evaluating the light and shadow effect of a wind farm, including:

[0047] A memory, configured to store a computer program;

[0048] A processor, configured to implement the steps of the above method for evaluating the light and shadow effect of a wind farm when executing the computer program.

[0049] To solve the above technical problems, the present application also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method for evaluating the light and shadow effect of a wind farm are implemented.

[0050] The method for evaluating the light and shadow effect of a wind farm provided in this application determines a rectangular area that covers the wind farm and expands a preset distance according to the model data and spatial layout of the wind farm; divides the rectangular area into multiple grid points; uses the true solar time at the machine location of each wind turbine as the time standard to determine the shadow influence range of the wind turbine blade surface at each moment throughout the year; counts the total influence duration of each grid point according to the shadow influence ranges of all wind turbines; and determines whether the design scheme meets the requirements of the preset specifications based on the total influence duration of each grid point. By dividing the area that can be affected by the wind farm, calculating the solar altitude angle and solar azimuth angle point by point and moment by moment, this application calculates the shadow ellipse range of the wind turbine blade surface of each wind turbine, and then obtains the maximum influence duration of each point theoretically throughout the year, improving the calculation accuracy of the influence range of the light and shadow effect of the wind farm and providing detailed data support for the environmental impact assessment of the wind farm.

[0051] In addition, this application also provides a device and a medium, which correspond to the above-mentioned method for evaluating the light and shadow effect of a wind farm, and have the same effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] To more clearly illustrate the embodiments of this application, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0053] Figure 1 It is a flowchart of a method for evaluating the light and shadow effect of a wind farm provided by an embodiment of this application;

[0054] Figure 2 It is a schematic diagram of the light and shadow effect of a wind turbine provided by an embodiment of this application;

[0055] Figure 3 It is a schematic diagram of the solar altitude angle and solar azimuth angle provided by an embodiment of this application;

[0056] Figure 4 It is a schematic diagram of the circumferential coordinate system of the wind turbine blade provided by an embodiment of this application;

[0057] Figure 5 It is a schematic diagram of the wind turbine blade orientation coordinate system and yaw rotation provided by an embodiment of this application;

[0058] Figure 6 It is a schematic diagram of the shadow length of the wind turbine blade provided by an embodiment of this application;

[0059] Figure 7 It is a schematic diagram of the distances from the grid points on the ground to the two foci of the shadow ellipse provided by an embodiment of this application;

[0060] Figure 8(a) is a schematic diagram of the hourly light and shadow effect evaluation provided by the embodiment of the present application on the spring equinox day;

[0061] Figure 8(b) is a schematic diagram of the hourly light and shadow effect evaluation provided by the embodiment of the present application on the summer solstice day;

[0062] Figure 8(c) is a schematic diagram of the hourly light and shadow effect evaluation provided by the embodiment of the present application on the autumn equinox day;

[0063] Figure 8(d) is a schematic diagram of the hourly light and shadow effect evaluation provided by the embodiment of the present application on the winter solstice day;

[0064] Figure 9 is a schematic diagram of the annual theoretical maximum impact hours of the light and shadow effect of the wind farm provided by the embodiment of the present application;

[0065] Figure 10 is a structural diagram of an evaluation device for the light and shadow effect of a wind farm provided by the embodiment of the present application;

[0066] Figure 11 is a structural diagram of another evaluation device for the light and shadow effect of a wind farm provided by the embodiment of the present application. Detailed implementation manners

[0067] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0068] The core of the present application is to provide an evaluation method, device and medium for the light and shadow effect of a wind farm.

[0069] In order to enable those skilled in the art to better understand the solution of the present application, the present application will be further described in detail below in conjunction with the drawings and specific implementation manners.

[0070] The continuously rotating blades of the wind turbine can project a flickering light and shadow onto the glass windows of residential houses in the direction of sunlight incidence, interfering with the normal life of residents, which is usually called the light and shadow impact. Generally, the light and shadow impact range of the wind turbine depends on the solar altitude angle. The larger the solar altitude angle, the shorter the shadow of the wind turbine, and the smaller the solar altitude angle, the longer the shadow of the wind turbine.

[0071] Since it is not easy to change the location and layout planning of wind turbines once they are determined, it is necessary for the staff to adjust the angles of the wind turbines to reduce the impact. Therefore, it is best to consider the influence of light and shadow during the planning and location selection of wind turbines to avoid problems in advance.

[0072] To solve the above problems, an embodiment of the present application provides a method for evaluating the light and shadow effect of a wind farm. Figure 1 The flowchart of a method for evaluating the light and shadow effect of a wind farm provided by an embodiment of the present application is as Figure 1 shown, including:

[0073] S11: Determine a rectangular area that covers the wind farm and expands a preset distance outward according to the model data and spatial layout of the wind farm;

[0074] S12: Divide the rectangular area into multiple grid points;

[0075] S13: Taking the true solar time at the machine location of each wind turbine as the time standard, determine the shadow influence range of the wind turbine blade surface at each moment of the year;

[0076] S14: Statistically calculate the total influence duration of each grid point according to the shadow influence ranges of all wind turbines;

[0077] S15: Determine whether the design scheme meets the preset specification requirements according to the total influence duration of each grid point.

[0078] In step S11, the model data of the wind farm refers to the models and model-related information of the wind turbines planned in the wind farm, such as height and rotor diameter, etc. The spatial layout refers to the spatial arrangement and occupied land positions of each wind turbine designed in the wind farm. A model of the arrangement of the machine locations in the wind farm can be established to simulate the design scheme of the wind farm.

[0079] Determine a rectangular area according to the model data and spatial layout of the wind farm. This rectangular area needs to cover the entire wind farm and take into account the possible range of shadow influence. Therefore, it is necessary to expand outward a preset distance. This expansion distance can be determined based on empirical data or relevant standards, such as expanding 3 km outward. In this way, the evaluation method can comprehensively consider all possible shadow influences.

[0080] Furthermore, dividing the rectangular area into multiple grid points means dividing the entire evaluation area into small units for more refined influence analysis. The grid points can specifically be the coordinates of the center point of each unit, and these points will be used for subsequent light and shadow effect calculations. Specifically, divide the rectangular area into several grid points according to the preset spatial resolution (for example, take the spatial resolution as 10 m).

[0081] The density of mesh generation can be determined according to actual needs and computing power to ensure the accuracy and operability of the assessment, and improve the efficiency and accuracy of the assessment.

[0082] Step S13 calculates the shadow influence range. Figure 2 This is a schematic diagram of the light and shadow effect of a wind turbine provided by an embodiment of the present application. As Figure 2 shown, the rotation of the wind turbine forms a projection on the ground. Using the true solar time at the location of each wind turbine as the time standard, the shadow influence range of the wind turbine blade surface at each moment of the year is determined for each wind turbine. In this step, the true solar time refers to the time corresponding to the actual position of the sun in the sky, which may deviate from the standard time. The true solar time takes into account the effects of the earth's revolution and rotation and is more accurate than the standard time.

[0083] The definition of the solar azimuth angle is the angle of the sun in the azimuth at a certain location and time, usually defined as the angle measured clockwise along the horizon from the north. The solar altitude angle is the angle between the incident direction of sunlight and the ground plane.

[0084] By calculating the solar altitude angle and azimuth angle and combining the geometric parameters of the wind turbine blade, the shadow range of the wind turbine blade on the ground can be accurately simulated.

[0085] Step S14 calculates the total influence duration statistics, and the total influence duration of each grid point is statistically calculated according to the shadow influence ranges of all wind turbines. In this step, by judging whether each grid point is within the shadow influence range of the wind turbine at each moment and recording the time length in the shadow, the total influence duration is obtained. It should be noted that the "each moment" mentioned in this embodiment can be replaced by a relatively short time period to reduce the calculation amount within the allowable error range.

[0086] For example, within a certain time period, it is judged whether a grid point is within the shadow influence range of any wind turbine. If so, the total influence duration of this grid needs to be increased by a time period. When the shadows of multiple wind turbines fall on the same grid point, the duration does not need to be accumulated.

[0087] Step S15 determines whether the design scheme meets the preset specification requirements according to the total influence duration of each grid point. The preset specification requirements usually mean that the influence of the wind turbine layout on the shadow flicker sensitive area should not exceed 30 hours per year. By comparing the actually statistically total influence duration with the specification requirements, it can be evaluated whether the current design scheme is qualified. If not, the layout and model of the wind turbine need to be adjusted.

[0088] Through the wind farm light and shadow effect evaluation method provided by the embodiments of the present application, according to the model data and spatial layout of the wind farm, a rectangular area covering the wind farm and expanding a preset distance is determined; the rectangular area is divided into multiple grid points; taking the true solar time at the machine position of each wind turbine as the time standard, the shadow influence range of the wind wheel surface of each wind turbine at each moment of the year is determined; according to the shadow influence ranges of all wind turbines, the total influence duration of each grid point is counted; according to the total influence duration of each grid point, it is determined whether the design scheme meets the requirements of the preset specification. By dividing the area that can be affected by the wind farm, calculating the solar altitude angle and solar azimuth angle point by point and moment by moment, the shadow ellipse range of the wind wheel surface of each wind turbine is calculated, and then the maximum influence duration of each point in a year is obtained, which improves the calculation accuracy of the influence range of the wind farm light and shadow effect and provides detailed data support for the environmental impact assessment of the wind farm.

[0089] According to the above embodiments, further, in a specific embodiment, the above wind farm light and shadow effect evaluation method, taking the true solar time at the machine position of each wind turbine as the time standard, determining the shadow influence range of the wind wheel surface of each wind turbine at each moment of the year, includes:

[0090] Dividing a year into multiple time periods based on a preset time step;

[0091] Determining the true solar time at the machine position of each wind turbine according to the machine position data of each wind turbine;

[0092] Determining the solar altitude angle and solar azimuth angle corresponding to each time period according to the true solar time;

[0093] Determining the shadow influence range of the orthographic projection of the wind wheel surface of each wind turbine within each time period according to the solar altitude angle and solar azimuth angle.

[0094] Dividing a year into multiple time periods according to a preset time step (for example, every 10 minutes or every hour). Such a division allows the evaluation method to consider the change of the sun's position at fixed time intervals, so as to more accurately simulate the movement of the shadow of the wind wheel surface.

[0095] Using the geographical location (latitude and longitude) of each wind turbine and the date and moment, calculating the true solar time (not the standard time of the local time zone) of each machine position in each time period. True solar time is the solar time considering the influence of the earth's revolution and rotation, and it can more accurately reflect the actual position of the sun than the standard time.

[0096] Specifically, the true solar time at the machine position of each wind turbine is obtained through formula (1):

[0097] (1)

[0098] In formula (1), represents the true solar time at each machine position (unit: hour, h); represents the standard time of the local time zone (taking the longitude range of 112.5°E to 127.5°E as an example, that is, UTC+8); represents the longitude corresponding to the standard time of the local time zone (taking the longitude range of 112.5°E to 127.5°E as an example, that is, 120°E); represents the longitude at each machine position; since one time zone spans 15 longitudes, therefore, every difference of 1 longitude means a difference of 1 / 15 hour.

[0099] Using the true solar time, combined with the geographical location, date, and time, calculate the solar altitude angle and azimuth angle for each time period. These two parameters are the key to determining the shadow position and range. Figure 3 This is a schematic diagram of the solar altitude angle and solar azimuth angle provided by the embodiment of the present application. As Figure 3 shown, a spatial rectangular coordinate system is established on the horizontal plane, with the due east direction as the positive x-axis and the due north direction as the positive y-axis. The definition of the solar altitude angle is the angle between the incident direction of sunlight at a certain place and time and the horizontal plane, denoted as h. The definition of the solar azimuth angle is the angle of the sun at a certain place and time in terms of azimuth, usually defined as the angle measured clockwise from the north along the horizon, denoted as γ.

[0100] The solar altitude angle h at a certain machine position and time: The calculation method is:

[0101] (2)

[0102] In formula (2), represents the geographical latitude of this machine position, rad, . represents the solar declination angle at this time, rad, . The solar declination angle is the angle between the equatorial plane of the earth and the line connecting the sun and the center of the earth. Therefore, it can also be considered as the latitude of the sun's direct point on this day. represents the solar hour angle, rad.

[0103] In formula (2), , where represents the latitude at this machine position.

[0104] In formula (2), , rad.

[0105] where n represents the day sequence (day order) of this day in a year. Taking December 17, 2022 as an example, n = 31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 + 31 + 30 + 17 = 351.

[0106] In Equation (2), , rad, where e represents the time in hours (local true solar time). Taking December 17, 2022, 07:28:33 as an example, e = 7 + 28 / 60 + 33 / 3600.

[0107] The cosine value of the solar azimuth angle γ (rad) at a certain moment of a certain machine point The calculation method is as follows:

[0108] (3)

[0109] Since the value range of the inverse cosine function is , which does not conform to the value range of the solar azimuth angle, therefore, for the calculation of the solar azimuth angle, Equation (3) needs to be converted according to the specific location and specific time, specifically:

[0110] (4)

[0111] In Equation (4), indicates that the machine point is north of the latitude of the solar direct point on this day, so at local noon, the sun is in the due south, and the solar azimuth angle is equal to π (180°); indicates that the machine point is south of the latitude of the solar direct point on this day, so at local noon, the sun is in the due north, and the solar azimuth angle is equal to 0 (0°); indicates that the machine point is exactly equal to the latitude of the solar direct point on this day, so at local noon, the sun is directly overhead, and at this time, the solar azimuth angle is meaningless, and NaN in the above formula indicates being empty.

[0112] Determine the shadow influence range of the orthographic projection of the wind turbine blade surface for each time period and each wind turbine according to the solar altitude angle and the solar azimuth angle. By assuming that the wind turbine blade surface always faces the sun when there is sunlight, making it in an orthographic projection state, so that the shadow of the blade surface has the largest influence range on the ground, calculate the maximum influence duration, ensuring that it always remains in the orthographic projection state. Through the four points of the blade surface in the up, down, left, and right directions, a standard ellipse equation can be established.

[0113] According to the above embodiment, further, in a specific embodiment, for the above-mentioned wind farm light and shadow effect evaluation method, the total influence duration of each grid point is statistically calculated according to the shadow influence ranges of all wind turbines, including:

[0114] Judging for each grid point whether it is within the shadow influence range of any wind turbine during the current time period;

[0115] If so, increase the total influence duration of the current grid point according to the preset time step;

[0116] If not, move to the next grid point until the statistics for all grid points in the current time period are completed;

[0117] After the judgments for all time periods are completed, output the total influence duration counted for each grid point.

[0118] Judging grid point by grid point whether each grid point is within the shadow influence range of any wind turbine in the current time period means that for each grid point, during the current time period, it is checked whether the shadow of the wind turbine blade surface covers this grid point. Here, the grid point refers to each small cell within a pre-divided rectangular area, and the shadow influence range refers to the area covered by the shadow generated by the rotation of the wind turbine blades at the current moment.

[0119] If so, increase the total influence duration of the current grid point according to the preset time step, which means that if a certain grid point is within the shadow influence range of a certain wind turbine during the check, then the total influence duration of this grid point will be accumulated according to the preset time step.

[0120] If not, move to the next grid point until the statistics for all grid points in the current time period are completed. This step ensures that each grid point is checked to determine whether it is affected by the shadow of the wind turbine.

[0121] After the judgments for all time periods are completed, output the total influence duration counted for each grid point. This means that for each grid point, the total duration of being affected by the shadow of the wind turbine during the entire evaluation period has been counted.

[0122] Through the solution provided by this embodiment, it is possible to accurately count the total duration of each grid point being affected by the shadow of the wind turbine throughout the year.

[0123] According to the above embodiment, further, in a specific embodiment, the above method for evaluating the light and shadow effect of a wind farm determines the shadow influence range of the orthographic projection of the wind turbine blade surface for each time period and each wind turbine according to the solar altitude angle and the solar azimuth angle, including:

[0124] Obtain the blade diameter and hub height of each wind turbine;

[0125] Assume that the wind turbine blade faces the sun to present an orthographic projection state. According to the solar altitude angle, the solar azimuth angle, the blade diameter and the hub height of the wind turbine, determine the four endpoint coordinates of the ellipse of the orthographic projection of the current wind turbine;

[0126] Obtain the ellipse equation parameters of the elliptical projection of the current wind turbine according to the four endpoint coordinates;

[0127] Determine the shadow influence range of the current wind turbine according to the ellipse equation parameters.

[0128] The rotor diameter and hub height of a wind turbine are necessary for calculating the shadow range. The rotor diameter determines the size of the shadow, while the hub height affects the landing point of the shadow.

[0129] Figure 4 The following is a schematic diagram of the wind turbine rotor circumferential coordinate system provided by an embodiment of the present application. As Figure 4 shown, it is assumed that the rotor faces due south. Taking the rotor plane as the coordinate plane, with the center point of the rotor (three-dimensional geodetic coordinate ) as the origin, the due east direction as the polar axis, and the front view perspective to establish the first polar coordinate system, denoted as polar coordinate system 1. A certain point on the rotor circumference (polar angle is θ, ), when converted into three-dimensional geodetic coordinate , is:

[0130] (5)

[0131] In formula (5), x is the east-west geodetic coordinate of the center point of the rotor, y is the north-south geodetic coordinate of the center point of the rotor, H is the hub height of the wind turbine, and D is the rotor diameter of the wind turbine.

[0132] Figure 5 The following is a schematic diagram of the wind turbine rotor orientation coordinate system and yaw rotation provided by an embodiment of the present application. As Figure 5 shown, considering the rotor orientation deflection, with the center point of the rotor (three-dimensional geodetic coordinate ) as the origin, the due east direction as the polar axis, and the bird's-eye view perspective to establish the second polar coordinate system, denoted as polar coordinate system 2.

[0133] The conversion relationship formula between the polar coordinate system and the conventional wind direction coordinate system is:

[0134] (6)

[0135] In formula (6), is the polar angle in the second polar coordinate system, . mod(·) represents the modulo operator; is the angle value in the conventional wind direction coordinate system, in rad. For example, due north is 0 (0°), due east is (90°), due south is π (180°), and due west is (270°). After conversion, the directions in the polar coordinate system are: due north, (90°); due east, 0 (0°); due south: (270°); due west: π (180°).

[0136] Let the polar angle of the rotor orientation be . When the rotor faces due south, its orientation polar angle (the polar angle in polar coordinate system 2) The three-dimensional geodetic coordinates of a certain point on the circumference of the wind wheel (the polar angle in the polar coordinate system 1 is θ) when the wind wheel is facing due south After that, through the coordinate rotation model, the three-dimensional geodetic coordinates when the polar angle of the wind wheel facing is can be obtained , specifically as follows:

[0137] (7)

[0138] According to the assumption that the wind wheel surface always faces the sun, in formula (7) That is, the polar angle value of the sun azimuth in the polar coordinate system 2, which can be denoted as , and its calculation formula is:

[0139] (8)

[0140] Substitute into formula (7), and the three-dimensional geodetic coordinates of a certain point on the circumference of the wind wheel (the polar angle in the polar coordinate system 1 is θ) at this moment can be obtained , specifically as follows:

[0141] (9)

[0142] Figure 6 is a schematic diagram of the shadow length of the wind wheel provided by an embodiment of the present application. Referring to Figure 6 as shown, at this moment, the point on the circumference of the wind wheel, after being projected onto the ground by sunlight (requiring the solar altitude angle: ), forms a shadow length which is:

[0143] (10)

[0144] Figure 6 In it, point 1: the vertical projection point of this point on the wind wheel circle to the ground; point 2: the point after this point is projected onto the ground by sunlight. The distance between point 1 and point 2 is the shadow length .

[0145] Since the shadow is directly opposite to the solar azimuth angle, the azimuth angle (rad) and polar angle (rad) of the shadow are respectively:

[0146] (11)

[0147] (12)

[0148] Therefore, the calculation method of the geodetic coordinates of this shadow point on the ground is:

[0149] (13)

[0150] In the polar coordinate system 1, take the four vertices of the wind turbine circumference at the top, bottom, left, and right. The polar angle of the upper vertex of the wind turbine circumference is , the polar angle of the lower vertex is , the polar angle of the left vertex is , and the polar angle of the right vertex is .

[0151] Substitute the current solar azimuth angle γ and the polar angles of the four vertices of the wind turbine circumference at the top, bottom, left, and right in the polar coordinate system 1 into equations (8) to (13), and finally obtain the geodetic coordinates of the four vertices of the shadow of the wind turbine surface. Among them, the upper and lower points on the wind turbine surface, when presented on the shadow ellipse, are the two endpoints of the major axis of the ellipse, and their geodetic coordinates are: , ; the left and right points on the wind turbine surface, when presented on the shadow ellipse, are the two endpoints of the minor axis of the ellipse, and their geodetic coordinates are: , . That is, according to the solar altitude angle, solar azimuth angle, wind turbine diameter, and hub height, the coordinates of the four endpoints of the ellipse of the orthographic projection of the current wind turbine are determined.

[0152] Furthermore, by calculating the projection distances of the two endpoints of the major axis and the two endpoints of the minor axis on the ground, the parameters of the standard ellipse equation can be obtained: the semi-major axis a and the semi-minor axis b, which are respectively:

[0153] (14)

[0154] (15)

[0155] And the semi-focal length c and the geodetic coordinates of the center point of the ellipse can be further obtained: , the geodetic coordinates of the two foci of the ellipse: , , which are respectively:

[0156] (16)

[0157] (17)

[0158] (18)

[0159] (19)

[0160] The parameters of the ellipse equation such as the semi-major axis, semi-minor axis, and focal coordinates obtained are used to determine the shadow influence range of the current wind turbine.

[0161] According to the above embodiments, further, in a specific embodiment, for the above method for evaluating the light and shadow effect of a wind farm, it is determined grid point by grid point whether each grid point is within the shadow influence range of any wind turbine during the current time period, including:

[0162] Obtain the grid coordinates of each grid point;

[0163] Based on the current grid coordinates and the coordinates of the two foci of the elliptical projection of the current wind turbine, obtain the total distance from the grid point to the two foci;

[0164] Judge whether the total distance is less than the major axis of the current elliptical projection;

[0165] If so, determine that the current grid point is within the shadow influence range of any wind turbine during the current time period, and enter the judgment process for the next grid point;

[0166] If not, determine that the current grid point is not within the shadow influence range of the current wind turbine during the current time period, and enter the step of obtaining the total distance from the grid point to the two foci based on the elliptical equation parameters of the elliptical projection of the next wind turbine;

[0167] If the current grid point is not within the shadow influence range of the last wind turbine during the current time period, determine that the current grid point is not within the shadow influence range of any wind turbine during the current time period, and enter the judgment process for the next time period.

[0168] Obtaining the grid coordinates of each grid point means determining the specific position of each grid point in the rectangular area. Denote the geodetic coordinates of the grid point as .

[0169] It is judged whether the grid point is within the shadow range by calculating the distance from the grid point to the foci of the shadow ellipse of the wind turbine. Figure 7 FIG. is a schematic diagram of the distance from a grid point on the ground to the two foci of the shadow ellipse provided by the embodiment of the present application. As Figure 7 shown, by calculating the sum of the distances L from the grid point (with geodetic coordinates of ) to the two foci of the shadow ellipse, compare whether L is greater than the major axis 2a of the ellipse for judgment. If the sum of the distances L is greater than 2a, it indicates that the grid point is not affected by the light and shadow effect of the wind turbine at this moment; if the sum of the distances L is less than or equal to 2a, it indicates that the grid point is affected by the light and shadow effect of the wind turbine at this moment. The calculation method of the sum of the distances L is:

[0170] (20)

[0171] If a grid point is within the shadow influence range of a wind turbine during the current time period, there is no need to determine whether it is within the shadow influence range of the next wind turbine, and the judgment process for the next grid point is entered; if a grid point is not within the shadow influence range of the current wind turbine during the current time period, it is necessary to determine whether it is within the shadow influence range of the next wind turbine until the judgment of the shadow influence range of the last wind turbine is completed. If it is not within the shadow influence range of the last wind turbine, it is determined that the current grid point is not within the shadow influence range of any wind turbine during the current time period; enter the judgment for the next time period, and successively judge whether all grid points are within the shadow influence range of any wind turbine during the current time period according to the total distance of the grid points from the ellipse foci.

[0172] Through this embodiment, it is possible to accurately and simply determine whether each grid point is affected by the shadow of the wind turbine during the current time period.

[0173] According to the above embodiment, further, in a specific embodiment, in the above wind farm light and shadow effect evaluation method, dividing a year into multiple time periods based on a preset time step includes:

[0174] Dividing the preset effective sunshine time of each day into multiple time periods based on a preset time step.

[0175] The effective sunshine time refers to the time period during a day when the sun shines directly on the ground. This time period usually ranges from sunrise to sunset, but the specific time period will vary due to factors such as geographical location, season, and weather. Taking the mid-latitude region in the Northern Hemisphere as an example, the sunshine time in summer is usually longer than that in winter because the tilt angle of the earth causes the sun to shine directly on the ground for a longer time in summer.

[0176] Determine the time period from sunrise to sunset every day. During this time period, the solar altitude angle is greater than 0, which is the time when the light and shadow effect of the wind farm may occur. The preset effective sunshine time can be adjusted according to geographical location and seasonal changes to adapt to the differences in the sun's trajectory in different regions. The preset effective sunshine time can be adjusted monthly or quarterly, and can be set according to actual needs. For example, setting the preset effective sunshine time as 8:00 - 16:00 every day, only the time period corresponding to the preset effective sunshine time needs to be analyzed, reducing the amount of data to be processed.

[0177] According to the above embodiment, further, in a specific embodiment, in the above wind farm light and shadow effect evaluation method, obtaining the grid coordinates of each grid point includes:

[0178] Taking the mid-latitude region in the Northern Hemisphere as an example, obtaining the shadow influence range of each wind turbine on the winter solstice;

[0179] Obtain the maximum envelope range based on the shadow influence ranges on multiple winter solstice days;

[0180] Obtain the grid coordinates of the grid points located within the maximum envelope range.

[0181] Obtaining the shadow influence range of each wind turbine on the winter solstice day means that on the winter solstice day, by using the changes in the solar altitude angle and azimuth angle, calculate the shadow influence range of each wind turbine at specific moments during the day. Since the winter solstice is the day with the lowest solar altitude angle in the Northern Hemisphere throughout the year, the shadow range at this time can represent the maximum shadow range throughout the year.

[0182] Determine the possible maximum shadow influence range of the entire wind farm throughout the year based on the shadow influence ranges of all wind turbines on the winter solstice day. This maximum envelope range will serve as the basis for evaluation because it represents the shadow influence under the most unfavorable conditions (i.e., when the solar altitude angle is the lowest). After determining the maximum envelope range, further identify all the grid points located within this range. There is no need to judge all the grid points in the whole field, thus improving the calculation efficiency. Specifically, if the farthest horizontal distance between the shadow ellipse and the wind turbine is 960.12m, the envelope distance can be taken as 1000m.

[0183] Figure 8(a) is a schematic diagram of the hourly light and shadow effect evaluation effect on the spring equinox day provided by an embodiment of the present application, Figure 8(b) is a schematic diagram of the hourly light and shadow effect evaluation effect on the summer solstice day provided by an embodiment of the present application, Figure 8(c) is a schematic diagram of the hourly light and shadow effect evaluation effect on the autumn equinox day provided by an embodiment of the present application, and Figure 8(d) is a schematic diagram of the hourly light and shadow effect evaluation effect on the winter solstice day provided by an embodiment of the present application. As shown, the shadow influence range is the largest on the winter solstice day, and the figure shows a simulated topographic map.

[0184] In addition, determine whether the design scheme meets the preset specification requirements according to the total influence duration of each grid point, including:

[0185] Generate a heat map of the light and shadow effect influence duration of each grid point within the rectangular area according to the total influence duration of each grid point.

[0186] Figure 9 It is a schematic diagram of the maximum theoretical annual influence hours of the light and shadow effect of a wind farm provided by an embodiment of the present application. As Figure 9 shown, it can be judged whether the current design scheme meets the requirements according to whether the area where the maximum theoretical annual influence hours exceed the preset influence duration is located in the residential area, so as to facilitate adjusting the design plan.

[0187] In the above embodiments, the method for evaluating the light and shadow effect of a wind farm is described in detail. The present application also provides embodiments corresponding to the device for evaluating the light and shadow effect of a wind farm. It should be noted that the embodiments of the device part of the present application are described from two perspectives, one is from the perspective of functional modules, and the other is from the perspective of hardware.

[0188] From the perspective of functional modules, Figure 10 is a structural diagram of a device for evaluating the light and shadow effect of a wind farm provided by an embodiment of the present application. As Figure 10 shown, a device for evaluating the light and shadow effect of a wind farm includes:

[0189] A establishing module 21, configured to determine a rectangular area that covers the wind farm and expands a preset distance according to the model data and spatial layout of the wind farm;

[0190] A dividing module 22, configured to divide the rectangular area into multiple grid points;

[0191] A light and shadow influence analysis module 23, configured to use the true solar time at the machine position of each wind turbine as the time standard to determine the shadow influence range of the wind turbine blade surface at each moment of the year for each wind turbine;

[0192] A statistical module 24, configured to statistically calculate the total influence duration of each grid point according to the shadow influence ranges of all wind turbines;

[0193] A judging module 25, configured to determine whether the design scheme meets the requirements of the preset specification according to the total influence duration of each grid point.

[0194] Since the embodiments of the device part correspond to the embodiments of the method part, for the embodiments of the device part, please refer to the description of the embodiments of the method part, which will not be elaborated here.

[0195] Figure 11 is another structural diagram of a device for evaluating the light and shadow effect of a wind farm provided by an embodiment of the present application. As Figure 11 shown, the device for evaluating the light and shadow effect of a wind farm includes: a memory 30, configured to store a computer program;

[0196] A processor 31, configured to implement the steps of the method for obtaining user operation habit information as described in the above embodiments (the method for evaluating the light and shadow effect of a wind farm) when executing the computer program.

[0197] The device for evaluating the light and shadow effect of a wind farm provided in this embodiment may include, but is not limited to, a smart phone, a tablet computer, a notebook computer, or a desktop computer, etc.

[0198] Among them, the processor 31 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 31 may be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), or a programmable logic array (PLA). The processor 31 may also include a main processor and a coprocessor. The main processor is a processor used to process data in the wake state, also known as the central processing unit (CPU); the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 31 may be integrated with a graphics processing unit (GPU), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 31 may also include an artificial intelligence (AI) processor, which is used to process computational operations related to machine learning.

[0199] The memory 30 may include one or more computer-readable storage media, and the computer-readable storage media may be non-transitory. The memory 30 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices and flash storage devices. In this embodiment, the memory 30 is at least used to store the following computer program 301. After the computer program is loaded and executed by the processor 31, it can implement the relevant steps of the wind farm light and shadow effect evaluation method disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 30 may also include an operating system 302 and data 303, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system 302 may include Windows, Unix, Linux, etc. The data 303 may include, but is not limited to, the data involved in implementing the wind farm light and shadow effect evaluation method.

[0200] In some embodiments, the wind farm light and shadow effect evaluation device may further include a display screen 32, an input / output interface 33, a communication interface 34, a power supply 35, and a communication bus 36.

[0201] Those skilled in the art can understand that Figure 11 the structure shown in

[0202] The wind farm light and shadow effect evaluation device provided by the embodiment of the present application includes a memory and a processor. When the processor executes the program stored in the memory, the following method can be implemented: the wind farm light and shadow effect evaluation method.

[0203] Finally, the present application also provides an embodiment corresponding to a computer-readable storage medium. A computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the steps recorded in the above-mentioned embodiment of the wind farm light and shadow effect evaluation method are implemented.

[0204] It can be understood that if the method in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and executes all or part of the steps of the methods in the various embodiments of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0205] The computer-readable storage medium provided in this embodiment stores a computer program, and when the processor executes the program, the following method can be implemented: the wind farm light and shadow effect evaluation method.

[0206] The above has introduced in detail the method, device and medium for evaluating the light and shadow effect of a wind farm provided in this application. The various embodiments in the specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same and similar parts among the various embodiments, reference can be made to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple. For the relevant parts, reference can be made to the description in the method part. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of this application, several improvements and modifications can be made to this application, and these improvements and modifications also fall within the protection scope of the claims of this application. It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

Claims

1. A method for evaluating the light and shadow effect of a wind farm, characterized in that, Including: Determine a rectangular area that covers the wind farm and expands a preset distance according to the model data and spatial layout of the wind farm; Divide the rectangular area into multiple grid points; Taking the true solar time at the location of each wind turbine as the time standard, determine the shadow influence range of the wind turbine blade surface at each moment of the year; Statistically calculate the total influence duration of each grid point according to the shadow influence ranges of all the wind turbines; Determine whether the design scheme meets the requirements of the preset specifications according to the total influence duration of each grid point; Among them, taking the true solar time at the location of each wind turbine as the time standard, determining the shadow influence range of the wind turbine blade surface at each moment of the year includes: Divide a year into multiple time periods based on a preset time step; Determine the true solar time at the location of each wind turbine according to the coordinate data of the location of each wind turbine; Determine the solar altitude angle and solar azimuth angle corresponding to each time period according to the true solar time; Determine the shadow influence range of the orthographic projection of the wind turbine blade surface of each wind turbine within each time period according to the solar altitude angle and the solar azimuth angle; Among them, statistically calculating the total influence duration of each grid point according to the shadow influence ranges of all the wind turbines includes: Judging grid point by grid point whether each grid point is within the shadow influence range of any one of the wind turbines during the current time period; If so, increase the total influence duration of the current grid point according to the preset time step; If not, move on to the next grid point until the statistics of all grid points in the current time period are completed; After the judgment of all the time periods is completed, output the total influence duration statistically calculated for each grid point.

2. The method for evaluating the light and shadow effect of a wind farm according to claim 1, wherein Determining the shadow influence range of the orthographic projection of the wind turbine blade surface of each wind turbine within each time period according to the solar altitude angle and the solar azimuth angle includes: Obtain the blade diameter and hub height of each wind turbine; Assume that the wind turbine blade faces the sun to present an orthographic projection state, and determine the four endpoint coordinates of the ellipse of the orthographic projection of the current wind turbine according to the solar altitude angle, the solar azimuth angle, the blade diameter and the hub height of the wind turbine; Obtain the ellipse equation parameters of the elliptical projection of the current wind turbine according to the four endpoint coordinates; Determine the shadow influence range of the current wind turbine according to the ellipse equation parameters.

3. The method for evaluating the light and shadow effect of a wind farm according to claim 2, wherein Judging grid point by grid point whether each grid point is within the shadow influence range of any one of the wind turbines during the current time period includes: Obtain the grid coordinates of each grid point; According to the current grid coordinates and the two ellipse focus coordinates of the elliptical projection of the current wind turbine, obtain the total distance of the grid point from the two ellipse foci; Judge whether the total distance is less than the major axis of the ellipse of the current elliptical projection; If so, determine that the current grid point is within the shadow influence range of any one of the wind turbines during the current time period, and enter the judgment process of the next grid point; Otherwise, it is determined that the current grid point is not within the shadow influence range of the current wind turbine during the current time period, and according to the elliptical equation parameters of the elliptical projection of the next wind turbine, the step of obtaining the total distance of the grid point from the two elliptical foci based on the grid coordinates and the two elliptical focus coordinates of the current elliptical projection is entered; If the current grid point is not within the shadow influence range of the last wind turbine during the current time period, it is determined that the current grid point is not within the shadow influence range of any of the wind turbines during the current time period, and the judgment process for the next time period is entered.

4. The method for evaluating the light and shadow effect of a wind farm according to claim 2, wherein The division of a year into multiple time periods based on a preset time step includes: Dividing the preset effective sunshine time of each day into multiple time periods based on a preset time step.

5. The method for evaluating the light and shadow effect of a wind farm according to claim 3, wherein The obtaining of the grid coordinates of each grid point includes: Taking the mid-latitude region of the Northern Hemisphere as an example, obtaining the shadow influence range of each wind turbine on the winter solstice; Obtaining the maximum envelope range based on the shadow influence ranges of multiple winter solstices; Obtaining the grid coordinates of the grid points located within the maximum envelope range.

6. An evaluation device for the light and shadow effect of a wind farm, characterized in that, Includes: A building module for determining a rectangular area that covers the wind farm and expands a preset distance according to the model data and spatial layout of the wind farm; A division module for dividing the rectangular area into multiple grid points; A light and shadow influence analysis module for using the true solar time at the machine position of each wind turbine as the time standard to determine the shadow influence range of the wind wheel surface of each wind turbine at each moment of the year; A statistics module for statistically calculating the total influence duration of each grid point according to the shadow influence ranges of all the wind turbines; A judgment module for determining whether the design scheme meets the preset specification requirements according to the total influence duration of each grid point; Among them, the use of the true solar time at the machine position of each wind turbine as the time standard to determine the shadow influence range of the wind wheel surface of each wind turbine at each moment of the year includes: Dividing a year into multiple time periods based on a preset time step; Determining the true solar time at the machine position of each wind turbine according to the machine position coordinate data of each wind turbine; Determining the solar altitude angle and solar azimuth angle corresponding to each time period according to the true solar time; Determining the shadow influence range of the orthographic projection of the wind wheel surface of each wind turbine within each time period according to the solar altitude angle and the solar azimuth angle; Among them, the statistical calculation of the total influence duration of each grid point according to the shadow influence ranges of all the wind turbines includes: Judging grid point by grid point whether each grid point is within the shadow influence range of any of the wind turbines during the current time period; If so, increasing the total influence duration of the current grid point according to the preset time step; If not, moving on to the next grid point until the statistics of all grid points in the current time period are completed; After the judgment of all the time periods is completed, outputting the total influence duration statistically calculated for each grid point.

7. An evaluation device for the light and shadow effect of a wind farm, characterized in that, Includes: A memory for storing computer programs; A processor for implementing the steps of the wind farm light and shadow effect evaluation method according to any one of claims 1 to 5 when executing the computer program.

8. A computer-readable storage medium, characterized in that, A computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the steps of the method for evaluating the light and shadow effect of a wind farm according to any one of claims 1 to 5 are implemented.

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