Wind power plant light and shadow effect evaluation method and device and medium

Abstract

The invention discloses a wind power plant light and shadow effect evaluation method and device and a medium. The problem that deviation exists in calculation of the shadow effect influence range of a traditional wind turbine generator is solved. The method comprises the following steps of: determining a shadow influence range of a wind wheel surface of each wind turbine generator at each moment in a year by taking true sun time at a machine location point of each wind turbine generator as a time standard; counting the total influence duration of each grid point according to the shadow influence ranges of all the wind turbine generators; and determining whether the design scheme meets a preset specification requirement or not according to the total influence duration of each grid point. According to the method, the wind power plant influence area is divided, the solar elevation angle and the solar azimuth angle are calculated point by point and moment by moment, so that the wind wheel surface shadow ellipse range of each wind turbine generator is calculated, the maximum influence duration of each point in the annual theory is obtained, the wind power plant shadow effect influence range calculation precision is improved, and the wind power plant shadow effect calculation efficiency is improved. And detailed data support is provided for environmental impact assessment of the wind power plant.

Description

Technical Field

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

[0002] With the depletion of traditional energy and the sustainable development of social economy, renewable resources have become particularly important, among which 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 which 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 flickering light and shadow produced by the rotating impellers of a wind turbine under the direction of sunlight. This flickering light and shadow will cause discomfort to people, so wind farms should be developed and constructed as far away from residential areas as possible. When the conditions for the installation site of a wind farm are limited and the impact of the light and shadow effect of the wind farm cannot be avoided, the theoretical maximum impact hours of the light and shadow effect of the wind farm should be calculated to evaluate whether it meets the requirements of the specification.

[0003] There are certain limitations in the traditional wind farm light and shadow effect assessment method. For example, it is believed that in the mid-latitude regions of the northern hemisphere, the solar azimuth angle follows the operating rules of due east (sunrise) → due south (noon) → due west (sunset) every day of the year. However, in fact, the daily sunrise time and daily operating rules of the solar azimuth angle in each region are changing, and customized calculations are required. In addition, when the wind wheel surface is not facing or facing away from the sun, it is not in the positive projection state. Although the shadow of the wind wheel surface is still elliptical, the four points on the upper, lower, left and right of the wind wheel surface are no longer the four endpoints of the wind wheel surface shadow ellipse. In this partial projection state, it is certainly possible to use the geodetic coordinates of the projection points of the four specific points on the upper, lower, left and right of the wind wheel surface on the ground to obtain the ellipse equation by numerical calculation methods, and then perform subsequent work, but on the one hand, it undoubtedly increases the amount of calculation and slows down the overall calculation efficiency; on the other hand, it also causes the shadow range of the wind wheel surface to be reduced compared to the positive projection state, and it is impossible to obtain the theoretical maximum impact hours of the wind farm light and shadow effect in the year.

[0004] It can be seen that how to solve the deviation in the calculation of the influence range of light and shadow effects of traditional wind turbines is a technical problem that needs to be solved urgently by people in this field. Summary of the invention

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

[0006] In order to solve the above technical problems, the present application provides a method for evaluating light and shadow effects of a wind farm, comprising:

[0007] Determine a rectangular area covering the wind farm and extending outward by a preset distance according to the model data and spatial layout of the wind farm;

[0008] Dividing the rectangular area into a plurality of grid points;

[0009] Taking the true solar time at the site of each wind turbine as the time standard, determine the shadow influence range of the wind rotor surface of each wind turbine at each time of the year;

[0010] Counting the total impact duration of each grid point according to the shadow impact range of all the wind turbines;

[0011] Determine whether the design solution meets the preset specification requirements based on the total impact duration of each grid point.

[0012] As an optional solution, in the above-mentioned wind farm light and shadow effect assessment method, the true solar time at the machine site of each wind turbine is used as the time standard to determine the shadow influence range of the wind rotor surface of each wind turbine at each time of the year, including:

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

[0014] Determine the true solar time at the site of each wind turbine generator set according to the site coordinate data of each wind turbine generator set;

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

[0016] The shadow influence range of the orthographic projection of the wind rotor surface of each wind turbine generator set in each time period is determined according to the solar altitude angle and the solar azimuth angle.

[0017] As an optional solution, in the above-mentioned wind farm light and shadow effect assessment method, the total impact duration of each grid point is counted according to the shadow impact range of all the wind turbines, including:

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

[0019] If yes, then increasing the total impact time of the current grid point according to the preset time step;

[0020] If not, proceed to the next grid point until all grid points in the current time period are counted;

[0021] After all the time periods are judged, the total impact duration of each grid point statistics is output.

[0022] As an optional solution, in the above-mentioned wind farm light and shadow effect assessment method, the step of determining the shadow influence range of the orthographic projection of the wind rotor surface of each wind turbine in each time period according to the solar altitude angle and the solar azimuth angle includes:

[0023] Obtaining the rotor diameter and hub height of each wind turbine generator set;

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

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

[0026] The shadow influence range of the current wind turbine generator system is determined according to the ellipse equation parameters.

[0027] As an optional solution, in the above-mentioned wind farm light and shadow effect evaluation method, the step of determining, grid point by grid point, whether each of the grid points is within the shadow influence range of any wind turbine in the current time period includes:

[0028] Obtaining the grid coordinates of each of the grid points;

[0029] Obtaining the total distance between the grid point and the two ellipse foci according to the current grid coordinates and the coordinates of the two ellipse foci of the ellipse projection of the current wind turbine generator set;

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

[0031] If yes, it is determined that the current grid point is within the shadow influence range of any wind turbine generator system in the current time period, and the judgment process for the next grid point is entered;

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

[0033] If the current grid point is not in the shadow influence range of the last wind turbine in the current time period, it is determined that the current grid point is not in the shadow influence range of any wind turbine in the current time period, and the judgment process of the next time period is entered.

[0034] As an optional solution, in the above-mentioned wind farm light and shadow effect evaluation method, dividing a year into multiple time periods based on a preset time step includes:

[0035] The preset sunshine effective time of each day is divided into multiple time periods based on the preset time step.

[0036] As an optional solution, in the above wind farm light and shadow effect evaluation method, obtaining the grid coordinates of each grid point includes:

[0037] Taking the mid-latitude region of the northern hemisphere as an example, the shadow influence range of each wind turbine generator set on the winter solstice is obtained;

[0038] The maximum envelope range is obtained according to the shadow influence ranges on multiple winter solstices;

[0039] The grid coordinates of the grid points within the maximum envelope are obtained.

[0040] In order to solve the above technical problems, the present application also provides a wind farm light and shadow effect evaluation device, comprising:

[0041] Establishing a module for determining a rectangular area covering the wind farm and extending outward by a preset distance according to the model data and spatial layout of the wind farm;

[0042] A division module, used for dividing the rectangular area into a plurality of grid points;

[0043] The light and shadow impact analysis module is used to determine the shadow impact range of the wind rotor surface of each wind turbine at each time of the year, using the true solar time at the site of each wind turbine as the time standard;

[0044] A statistical module, used to count the total impact duration of each grid point according to the shadow impact range of all the wind turbines;

[0045] A judgment module is used to determine whether the design scheme meets the preset specification requirements according to the total impact duration of each grid point.

[0046] In order to solve the above technical problems, the present application also provides a wind farm light and shadow effect evaluation device, comprising:

[0047] Memory for storing computer programs;

[0048] The processor is used to implement the steps of the above-mentioned wind farm light and shadow effect evaluation method when executing the computer program.

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

[0050] The wind farm light and shadow effect evaluation method provided in this application determines the rectangular area covering the wind farm and extending a preset distance based on 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 site of each wind turbine as the time standard to determine the shadow impact range of the wind rotor surface of each wind turbine at each moment of the year; calculates the total impact duration of each grid point based on the shadow impact range of all wind turbines; and determines whether the design scheme meets the preset specification requirements based on the total impact duration of each grid point. This application divides the wind farm's impactable area, calculates the solar altitude angle and solar azimuth angle point by point and moment by moment, and thus calculates the shadow ellipse range of the wind rotor surface of each wind turbine, and then obtains the maximum impact duration of each point in theory in a year, thereby improving the calculation accuracy of the wind farm light and shadow effect impact range and providing detailed data support for the environmental impact assessment of the wind farm.

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

[0052] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0053] Figure 1 A flow chart of a method for evaluating light and shadow effects in a wind farm provided in an embodiment of the present application;

[0054] Figure 2 A schematic diagram of light and shadow effects of a wind turbine provided in an embodiment of the present application;

[0055] Figure 3 A schematic diagram of a solar altitude angle and a solar azimuth angle provided in an embodiment of the present application;

[0056] Figure 4 A schematic diagram of a wind rotor circumferential coordinate system provided in an embodiment of the present application;

[0057] Figure 5 A schematic diagram of a wind rotor orientation coordinate system and yaw rotation provided in an embodiment of the present application;

[0058] Figure 6 A schematic diagram of the wind wheel shadow length provided in an embodiment of the present application;

[0059] Figure 7 A schematic diagram of the distance from a grid point on the ground to two foci of a shadow ellipse provided in an embodiment of the present application;

[0060] FIG8 (a) is a schematic diagram of an hourly light and shadow effect evaluation effect on the vernal equinox provided by an embodiment of the present application;

[0061] FIG8( b ) is a schematic diagram of an hourly light and shadow effect evaluation effect on the summer solstice provided by an embodiment of the present application;

[0062] FIG8 (c) is a schematic diagram of an hourly light and shadow effect evaluation effect on the autumnal equinox provided by an embodiment of the present application;

[0063] FIG8 (d) is a schematic diagram of an hourly light and shadow effect evaluation effect on the winter solstice provided by an embodiment of the present application;

[0064] Fig. 9 A schematic diagram of the theoretical maximum number of hours of impact of light and shadow effects on a wind farm provided in an embodiment of the present application;

[0065] Fig.10 A structural diagram of a wind farm light and shadow effect evaluation device provided in an embodiment of the present application;

[0066] Fig.11 A structural diagram of another wind farm light and shadow effect evaluation device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0067] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0068] The core of this application is to provide a method, device and medium for evaluating light and shadow effects in a wind farm.

[0069] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0070] The rotating blades of wind turbines project onto the glass windows of residential buildings in the direction of incident sunlight, which can produce flickering light and shadow, interfering with the normal life of residents. This is usually called light and shadow impact. Usually, the light and shadow impact range of wind turbines 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 the site selection and layout planning of wind turbines are difficult to change once determined, staff are required to adjust the angle of the wind turbines to reduce the impact. Therefore, it is best to consider the influence of light and shadow when planning the site selection of wind turbines to avoid problems in advance.

[0072] In order to solve the above problems, the present application provides a method for evaluating light and shadow effects in a wind farm. Figure 1 A flow chart of a method for evaluating light and shadow effects in a wind farm provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, including:

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

[0074] S12: Divide the rectangular area into a plurality of grid points;

[0075] S13: using the true solar time at the site of each wind turbine as the time standard, determining the shadow influence range of the wind rotor surface of each wind turbine at each time of the year;

[0076] S14: Count the total impact duration of each grid point according to the shadow impact range of all wind turbines;

[0077] S15: Determine whether the design solution meets the preset specification requirements based on the total impact duration of each grid point.

[0078] In step S11, the model data of the wind farm refers to the model and model-related information, height, and rotor diameter of the wind turbines planned in the wind farm, and the spatial layout refers to the spatial arrangement and location of each wind turbine designed in the wind farm. A wind farm site arrangement model can be established to simulate the design of the wind farm.

[0079] A rectangular area is determined based on 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 scope of shadow impact, so it needs to be extended outward by a preset distance. This extension distance can be determined based on empirical data or relevant standards, such as an extension of 3km. In this way, the assessment method can fully consider all possible shadow impacts.

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

[0081] The density of grid division 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 A schematic diagram of the light and shadow effect of a wind turbine provided in an embodiment of the present application is shown in FIG. Figure 2 As shown in the figure, the rotation of the wind turbine forms a shadow on the ground. The true solar time at the site of each wind turbine is used as the time standard to determine the shadow influence range of the wind rotor surface of each wind turbine at each time of the year. 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 influence of the earth's revolution and rotation and is more accurate than the standard time.

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

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

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

[0086] For example, determine whether a grid point is within the shadow influence range of any wind turbine within a time period. If so, the total influence duration of this grid needs to be added with a time period. If the shadows of multiple wind turbines fall within 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 based on the total impact time of each grid point. The preset specification requirements usually mean that the impact of the wind turbine layout on the shadow flicker sensitive area should not exceed 30 hours per year. By comparing the actual statistical total impact time with the specification requirements, it is possible to evaluate 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 embodiment of the present application, according to the model data and spatial layout of the wind farm, a rectangular area covering the wind farm and extending a preset distance is determined; the rectangular area is divided into multiple grid points; the true solar time at the machine site of each wind turbine is used as the time standard to determine the shadow influence range of the wind rotor surface of each wind turbine at each moment of the year; the total influence time of each grid point is calculated according to the shadow influence range of all wind turbines; according to the total influence time of each grid point, it is determined whether the design scheme meets the preset specification requirements. This application divides the wind farm's influenceable area, calculates the solar altitude angle and solar azimuth angle point by point and moment by moment, and thus calculates the shadow ellipse range of the wind rotor surface of each wind turbine, and then obtains the maximum influence time of each point in theory in a year, thereby improving the calculation accuracy of the wind farm light and shadow effect influence range and providing detailed data support for the environmental impact assessment of the wind farm.

[0089] According to the above embodiment, further, in a specific embodiment, the above wind farm light and shadow effect evaluation method uses the true solar time at the machine site of each wind turbine as the time standard to determine the shadow influence range of the wind rotor surface of each wind turbine at each time of the year, including:

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

[0091] Determine the true solar time at the site of each wind turbine generator set according to the site data of each wind turbine generator set;

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

[0093] The shadow influence range of the positive projection of the wind rotor surface of each wind turbine generator set in each time period is determined according to the solar altitude angle and the solar azimuth angle.

[0094] The year is divided into multiple time periods with a preset time step (e.g., every 10 minutes or every hour). This division allows the evaluation method to take into account the changes in the sun's position at fixed time intervals, thereby more accurately simulating the movement of the shadow on the wind rotor surface.

[0095] The true solar time (not the standard time of the local time zone) of each wind turbine site in each period is calculated using the geographical location (latitude and longitude) of each wind turbine, as well as the date and time. True solar time is the solar time after taking into account the influence of the earth's revolution and rotation, and it can more accurately reflect the actual position of the sun than standard time.

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

[0097] (1)

[0098] In formula (1), Indicates the true solar time at each aircraft location (unit: hour, h); Indicates the standard time of the local time zone (taking the longitude range of 112.5°E~127.5°E as an example, that is, UTC+8); Indicates the longitude corresponding to the standard time of the local time zone (taking the longitude range of 112.5°E~127.5°E as an example, that is, 120°E); Indicates the longitude of each airport location. Since one time zone spans 15 degrees of longitude, each difference of one degree of longitude means a difference of 1 / 15 hour.

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

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

[0101] (2)

[0102] In formula (2), Indicates the geographical latitude of the aircraft location, rad, . Indicates the solar declination angle at that moment, rad, The solar declination is the angle between the Earth's equatorial plane and the line connecting the Sun and the Earth's center, so it can also be considered the latitude of the point where the Sun is directly overhead on that day. Represents the solar hour angle, rad.

[0103] In formula (2), ,in Indicates the latitude of the station.

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

[0105] Where n is the sequence of days in a year. Taking 2022-12-17 as an example, n=31+28+31+30+31+30+31+31+30+31+30+17=351.

[0106] In formula (2), , rad, where e represents the time in hours (local true solar time). Taking 2022-12-17, 07:28:33 as an example, e=7+28 / 60+33 / 3600.

[0107] The cosine value of the solar azimuth γ (rad) at a certain aircraft position at a certain time The calculation method is:

[0108] (3)

[0109] Since the range of the arccosine function is , does not conform to the value range of the solar azimuth angle. Therefore, the calculation of the solar azimuth angle needs to be converted to formula (3) according to the specific position and time. Specifically,

[0110] (4)

[0111] In formula (4), It means that the station is located north of the latitude of the sun's direct point on this day, so the sun is located due south at noon, and the solar azimuth is equal to π (180°); It means that the station is located south of the latitude of the sun's direct point on this day, so the sun is located due north at noon and the solar azimuth is 0 (0°); It means that the position of the aircraft is exactly equal to the latitude of the sun's direct point on that day. Therefore, the sun is directly overhead at noon. At this time, the solar azimuth loses its meaning. NaN in the above formula represents empty.

[0112] The shadow influence range of the orthographic projection of the wind rotor surface of each wind turbine in each time period is determined according to the solar altitude angle and solar azimuth angle. By assuming that the wind rotor surface of the wind turbine is always facing the sun when there is sun, it is in an orthographic projection state, so that the shadow of the wind rotor surface has the largest influence range on the ground. The maximum influence duration is calculated to ensure that the orthographic projection state is always maintained. The standard ellipse equation can be established through the four points on the upper, lower, left and right sides of the wind rotor surface.

[0113] According to the above embodiment, further, in a specific embodiment, the above wind farm light and shadow effect evaluation method, according to the shadow influence range of all wind turbines, counts the total influence time of each grid point, including:

[0114] Determine grid point by grid point whether each grid point is within the shadow influence range of any wind turbine in the current time period;

[0115] If yes, increase the total impact time of the current grid point according to the preset time step;

[0116] If not, proceed to the next grid point until all grid points in the current time period are counted;

[0117] After all time periods are judged, the total impact duration of each grid point statistics is output.

[0118] Judging whether each grid point is in the shadow influence range of any wind turbine in the current time period by grid point means checking whether the wind turbine rotor surface shadow of any wind turbine covers the grid point in the current time period. The grid point here refers to each small cell in the pre-divided rectangular area, and the shadow influence range refers to the area covered by the shadow caused by the rotation of the wind turbine rotor at the current moment.

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

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

[0121] When all time periods are judged, the total impact duration of each grid point is output, which means that the total duration of each grid point affected by the shadow of the wind turbine during the entire evaluation period has been calculated.

[0122] Through the solution provided in this embodiment, the total duration of each grid point being affected by the shadow of the wind turbine in the whole year can be accurately counted.

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

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

[0125] Assume that the wind turbine rotor faces the sun, so that it is in an orthographic projection state. According to the solar altitude angle and solar azimuth angle, the wind turbine rotor diameter and hub height, determine the coordinates of the four endpoints of the orthographic projection ellipse of the current wind turbine;

[0126] Obtain the ellipse equation parameters of the ellipse projection of the current wind turbine generator set according to the coordinates of the four endpoints;

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

[0128] The rotor diameter and hub height of a wind turbine are necessary to calculate the shadow range. The rotor diameter determines the size of the shadow, while the hub height affects where the shadow falls.

[0129] Figure 4 A schematic diagram of a wind wheel circumferential coordinate system provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, it is assumed that the wind rotor faces due south. Take the wind rotor surface as the coordinate plane and the wind rotor center point (three-dimensional geodetic coordinate ) as the origin, with the east direction as the polar axis, and the first polar coordinate system is established from the perspective of the front view, which is recorded as polar coordinate system 1. A point on the circumference of the wind wheel (polar angle is θ, ), converted into three-dimensional geodetic coordinates ,for:

[0130] (5)

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

[0132] Figure 5 A wind rotor orientation coordinate system and yaw rotation schematic diagram provided in an embodiment of the present application, such as Figure 5 As shown, considering the deflection of the wind rotor, the center point of the wind rotor (three-dimensional geodetic coordinates ) as the origin, due east as the polar axis, and a second polar coordinate system is established from a bird's-eye view, recorded as polar coordinate system 2.

[0133] The conversion relationship 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 modulus operator; is the angle value in the conventional wind direction coordinate system, rad. For example, due north is 0 (0°), due east is (90°), due south is π (180°), due west is (270°). After conversion, the directions in the polar coordinate system are: true north, (90°); Due East, 0 (0°); Due South: (270°); Due west: π(180°).

[0136] Assume the polar angle of the wind rotor is When the wind rotor faces due south, it faces the polar angle (polar angle in polar coordinate system 2) The three-dimensional geodetic coordinates of a point on the circumference of the wind rotor (the polar angle in the polar coordinate system 1 is θ) when the wind rotor is facing due south After that, the coordinate rotation model can be used to obtain the wind rotor polar angle as The three-dimensional geodetic coordinates at , specifically:

[0137] (7)

[0138] According to the assumption that the wind wheel always faces the sun, That is, the polar angle value of the sun's position in the polar coordinate system 2 can be expressed as , and its calculation formula is:

[0139] (8)

[0140] Will Substituting into equation (7), we can obtain the three-dimensional geodetic coordinates of a point on the circumference of the wind rotor at that moment (the polar angle in the polar coordinate system 1 is θ): , specifically:

[0141] (9)

[0142] Figure 6 A schematic diagram of the wind wheel shadow length provided in an embodiment of the present application, referring to Figure 6 As shown, at this moment, after the sunlight is projected onto the ground at this point on the circumference of the wind wheel (the required solar altitude angle is: ), the length of the shadow formed for:

[0143] (10)

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

[0145] Since the shadow is directly opposite the sun's azimuth, the shadow's azimuth (rad), polar angle (rad), respectively:

[0146] (11)

[0147] (12)

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

[0149] (13)

[0150] In polar coordinate system 1, take the four vertices of the upper, lower, left and right sides of the wind rotor circumference. , the lower vertex polar angle , left vertex polar angle , right vertex polar angle .

[0151] Substitute the solar azimuth γ at this moment and the polar angles of the four vertices of the wind rotor circumference in the polar coordinate system 1 into equations (8) to (13), and finally obtain the geodetic coordinates of the four vertices of the wind rotor shadow. The upper and lower points on the wind rotor surface appear on the shadow ellipse as the two endpoints of the major axis of the ellipse, and their geodetic coordinates are: , The two points on the left and right of the wind wheel surface are shown on the shadow ellipse as the two endpoints of the minor axis of the ellipse, and their geodetic coordinates are: , That is, according to the solar altitude angle and solar azimuth angle, the rotor diameter and hub height of the wind turbine, the four end point coordinates of the ellipse of the positive 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, we can obtain the parameters of the standard ellipse equation: the semi-major axis a and the semi-minor axis b, which are:

[0153] (14)

[0154] (15)

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

[0156] (16)

[0157] (17)

[0158] (18)

[0159] (19)

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

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

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

[0163] The total distance between the grid point and the two ellipse foci is obtained according to the current grid coordinates and the coordinates of the two ellipse foci of the ellipse projection of the current wind turbine generator set;

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

[0165] If yes, it is determined that the current grid point is within the shadow influence range of any wind turbine in the current time period, and the judgment process of the next grid point is entered;

[0166] If not, it is determined that the current grid point is not within the shadow influence range of the current wind turbine in the current time period, and according to the ellipse equation parameters of the ellipse projection of the next wind turbine, a step of obtaining the total distance between the grid point and the two ellipse foci according to the grid coordinates and the coordinates of the two ellipse foci of the current ellipse projection is entered;

[0167] If the current grid point is not in the shadow influence range of the last wind turbine in the current time period, it is determined that the current grid point is not in the shadow influence range of any wind turbine in the current time period, and the judgment process of the next time period is entered.

[0168] Obtaining the grid coordinates of each grid point refers to determining the specific position of each grid point in the rectangular area. The geodetic coordinates of the grid point are recorded as .

[0169] Whether the grid point is within the shadow range is determined by calculating the distance from the grid point to the focus of the wind turbine shadow ellipse. Figure 7 A schematic diagram of the distance from a grid point on the ground to two foci of a shadow ellipse is provided in an embodiment of the present application, such as Figure 7 As shown, by calculating the grid point (geodetic coordinates are ) The sum of the distances L from the two foci of the shadow ellipse is compared to see whether L is greater than the major axis 2a of the ellipse. 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 located in the shadow influence range of a wind turbine in the current time period, there is no need to determine whether it is located in the shadow influence range of the next wind turbine and enter the judgment process for the next grid point; if a grid point is not located in the shadow influence range of the current wind turbine in the current time period, it is necessary to determine whether it is located in the shadow influence range of the next wind turbine until the shadow influence range of the last wind turbine is determined. If it is not in the shadow influence range of the last wind turbine, it is determined that the current grid point is not in the shadow influence range of any wind turbine in the current time period; enter the judgment of the next time period and determine whether all grid points are located in the shadow influence range of any wind turbine in the current time period according to the total distance of the grid point from the focus of the ellipse.

[0172] This embodiment can accurately and simply determine whether each grid point is affected by the shadow of the wind turbine in 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, a year is divided into multiple time periods based on a preset time step, including:

[0174] The preset sunshine effective time of each day is divided into multiple time periods based on the preset time step.

[0175] The effective sunshine time refers to the time period of the day when the sun shines directly on the ground. This time period is usually from sunrise to sunset, but the specific time period varies depending on factors such as geographical location, season and weather. Taking the mid-latitude areas of the Northern Hemisphere as an example, the sunshine time in summer is usually longer than that in winter because the tilt 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, 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 sunshine effective time can be adjusted according to the geographical location and seasonal changes to adapt to the differences in the sun's trajectory in different regions. The preset sunshine effective time can be adjusted monthly or quarterly, and can be set according to actual needs. For example, if the preset sunshine effective time is set to 8:00~16:00 every day, only the time period corresponding to the preset sunshine effective time needs to be analyzed, which reduces 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 of the northern hemisphere as an example, the shadow influence range of each wind turbine on the winter solstice is obtained;

[0179] The maximum envelope range is obtained based on the shadow impact ranges of multiple winter solstices;

[0180] Get the grid coordinates of a grid point that lies within the maximum envelope.

[0181] Obtaining the shadow influence range of each wind turbine on the winter solstice means calculating the shadow influence range of each wind turbine at a specific time of the day using the changes in the solar altitude angle and azimuth angle on the winter solstice. Since the winter solstice is the day with the lowest solar altitude angle in the northern hemisphere in a year, the shadow range at this time can represent the maximum shadow range in a year.

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

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

[0184] In addition, the total impact duration of each grid point is used to determine whether the design solution meets the preset specification requirements, including:

[0185] According to the total impact duration of each grid point, a heat map representing the impact duration of light and shadow effects of each grid point in the rectangular area is generated.

[0186] Fig. 9 A schematic diagram of the maximum number of hours of theoretical annual impact of light and shadow effects on a wind farm provided in an embodiment of the present application is shown in FIG. Fig. 9 As shown, whether the current design scheme meets the requirements can be judged based on whether the area where the annual theoretical maximum impact hours exceed the preset impact time is located in a residential area, so as to adjust the design plan.

[0187] In the above embodiments, the wind farm light and shadow effect evaluation method is described in detail, and the present application also provides an embodiment corresponding to the wind farm light and shadow effect evaluation device. It should be noted that the present application describes the embodiments of the device part from two perspectives, one is based on the functional module perspective, and the other is based on the hardware perspective.

[0188] From the perspective of functional modules, Fig.10 A structural diagram of a wind farm light and shadow effect evaluation device provided in an embodiment of the present application, such as Fig.10 As shown, a wind farm light and shadow effect evaluation device comprises:

[0189] Establishing module 21, for determining a rectangular area covering the wind farm and extending outward by a preset distance according to the model data and spatial layout of the wind farm;

[0190] A division module 22, used for dividing the rectangular area into a plurality of grid points;

[0191] The light and shadow impact analysis module 23 is used to determine the shadow impact range of the wind rotor surface of each wind turbine at each time of the year by taking the true solar time at the machine site of each wind turbine as the time standard;

[0192] A statistics module 24 is used to count the total impact duration of each grid point according to the shadow impact range of all wind turbines;

[0193] The judgment module 25 is used to determine whether the design solution meets the preset specification requirements according to the total impact duration of each grid point.

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

[0195] Fig.11 A structural diagram of another wind farm light and shadow effect evaluation device provided in an embodiment of the present application, such as Fig.11 As shown, the wind farm light and shadow effect evaluation device includes: a memory 30, for storing a computer program;

[0196] The processor 31 is used to implement the steps of the method for obtaining user operation habit information in the above embodiment (wind farm light and shadow effect evaluation method) when executing the computer program.

[0197] The wind farm light and shadow effect evaluation device provided in this embodiment may include but is not limited to a smart phone, a tablet computer, a laptop computer or a desktop computer.

[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), and a programmable logic array (PLA). The processor 31 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing 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 computing operations related to machine learning.

[0199] The memory 30 may include one or more computer-readable storage media, which may be non-transitory. The memory 30 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In this embodiment, the memory 30 is at least used to store the following computer program 301, wherein, 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 aforementioned 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. Data 303 may include but is not limited to data involved in implementing the wind farm light and shadow effect evaluation method, etc.

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

[0201] Those skilled in the art will understand that Fig.11 The structure shown in the figure does not constitute a limitation on the wind farm light and shadow effect evaluation device, and may include more or fewer components than those shown in the figure.

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

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

[0204] It is understandable 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 this understanding, the technical solution of the present application is essentially 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, and the computer software product is stored in a storage medium to execute all or part of the steps of the methods of each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

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

[0206] The above is a detailed introduction to the wind farm light and shadow effect evaluation method, device and medium provided by the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can refer 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, and the relevant parts can refer to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present 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 that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" 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 includes not only those elements, but also other elements that are not explicitly listed, or also includes elements inherent to such a process, method, article or device. Without more constraints, an element defined by the phrase "comprising a..." does not exclude the existence of other identical elements in the process, method, article or apparatus comprising the element.

Claims

1. A method for evaluating light and shadow effects of a wind farm, characterized in that: include: Determine a rectangular area covering the wind farm and extending outward by a preset distance according to the model data and spatial layout of the wind farm; Dividing the rectangular area into a plurality of grid points; Taking the true solar time at the site of each wind turbine as the time standard, determine the shadow influence range of the wind rotor surface of each wind turbine at each time of the year; Counting the total impact duration of each grid point according to the shadow impact range of all the wind turbines; Determine whether the design solution meets the preset specification requirements based on the total impact duration of each grid point.

2. The wind farm light and shadow effect evaluation method according to claim 1, characterized in that: The method of using the true solar time at the site of each wind turbine as the time standard to determine the shadow influence range of the wind rotor surface of each wind turbine at each time of the year includes: Divide a year into multiple time periods based on a preset time step; Determine the true solar time at the site of each wind turbine generator set according to the site coordinate data of each wind turbine generator set; Determine the solar altitude angle and solar azimuth angle corresponding to each time period according to the true solar time; The shadow influence range of the orthographic projection of the wind rotor surface of each wind turbine generator set in each time period is determined according to the solar altitude angle and the solar azimuth angle.

3. The wind farm light and shadow effect evaluation method according to claim 2, characterized in that: The total impact duration of each grid point is calculated based on the shadow impact range of all wind turbines, including: Determine, grid point by grid point, whether each of the grid points is within the shadow influence range of any of the wind turbines in the current time period; If yes, then increasing the total impact time of the current grid point according to the preset time step; If not, proceed to the next grid point until all grid points in the current time period are counted; After all the time periods are judged, the total impact duration of each grid point statistics is output.

4. The wind farm light and shadow effect evaluation method according to claim 3, characterized in that: The determining, according to the solar altitude angle and the solar azimuth angle, the shadow influence range of the orthographic projection of the wind rotor surface of each wind turbine generator set in each time period comprises: Obtaining the rotor diameter and hub height of each wind turbine generator set; Assume that the wind turbine rotor faces the sun, so that it is in an orthographic projection state. According to the solar altitude angle and solar azimuth angle, the wind turbine rotor diameter and hub height, determine the coordinates of the four endpoints of the orthographic projection ellipse of the current wind turbine; Obtaining ellipse equation parameters of the ellipse projection of the current wind turbine generator set according to the four endpoint coordinates; The shadow influence range of the current wind turbine generator set is determined according to the ellipse equation parameters.

5. The wind farm light and shadow effect evaluation method according to claim 4, characterized in that: The step of determining, grid point by grid point, whether each of the grid points is within a shadow influence range of any of the wind turbine generator sets in a current time period includes: Obtaining the grid coordinates of each of the grid points; Obtaining the total distance between the grid point and the two ellipse foci according to the current grid coordinates and the coordinates of the two ellipse foci of the ellipse projection of the current wind turbine generator set; Determine whether the total distance is less than the major axis of the ellipse of the current ellipse projection; If yes, it is determined that the current grid point is within the shadow influence range of any wind turbine in the current time period, and the judgment process for the next grid point is entered; If not, it is determined that the current grid point is not within the shadow influence range of the current wind turbine in the current time period, and the step of obtaining the total distance between the grid point and the two ellipse foci according to the grid coordinates and the two ellipse foci coordinates of the current ellipse projection is entered according to the ellipse equation parameters of the next ellipse projection of the wind turbine; If the current grid point is not in the shadow influence range of the last wind turbine in the current time period, it is determined that the current grid point is not in the shadow influence range of any wind turbine in the current time period, and the judgment process of the next time period is entered.

6. The wind farm light and shadow effect evaluation method according to claim 4, characterized in that: The method of dividing a year into multiple time periods based on a preset time step includes: The preset sunshine effective time of each day is divided into multiple time periods based on the preset time step.

7. The wind farm light and shadow effect evaluation method according to claim 5, characterized in that: The obtaining of the grid coordinates of each grid point comprises: Taking the mid-latitude region of the northern hemisphere as an example, the shadow influence range of each wind turbine generator set on the winter solstice is obtained; The maximum envelope range is obtained according to the shadow influence ranges on multiple winter solstices; The grid coordinates of the grid points within the maximum envelope are obtained.

8. A wind farm light and shadow effect evaluation device, characterized in that: include: Establishing a module for determining a rectangular area covering the wind farm and extending outward by a preset distance according to the model data and spatial layout of the wind farm; A division module, used for dividing the rectangular area into a plurality of grid points; The light and shadow impact analysis module is used to determine the shadow impact range of the wind rotor surface of each wind turbine at each time of the year, using the true solar time at the site of each wind turbine as the time standard; A statistical module, used to count the total impact duration of each grid point according to the shadow impact range of all the wind turbines; A judgment module is used to determine whether the design scheme meets the preset specification requirements according to the total impact duration of each grid point.

9. A wind farm light and shadow effect evaluation device, characterized in that: include: Memory for storing computer programs; A processor is used to implement the steps of the wind farm light and shadow effect evaluation method as claimed in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for evaluating light and shadow effects of a wind farm according to any one of claims 1 to 7 are implemented.

Images