Terrain adaptive backtracking method based on photovoltaic tracker

Abstract

The invention relates to the technical field of photovoltaic trackers, in particular to a terrain-based adaptive backtracking method based on a photovoltaic tracker, which comprises the following steps that a three-dimensional coordinate system is established by taking a photovoltaic tracker mounting plane as a reference, and the initial state of a photovoltaic panel in the photovoltaic tracker is perpendicular to an xz plane; acquiring topographic slope data of the position where the photovoltaic tracker is located, and acquiring and calculating sun position parameters in real time; the tracking angle of the photovoltaic panel around the y axis is dynamically adjusted according to the position parameters of the sun and the initial state of the photovoltaic panel in combination with the installation mode of the adjacent photovoltaic panels, and it is ensured that the photovoltaic panel is always perpendicular to solar rays, so that more sunlight is obtained; and establishing a working state database of the photovoltaic tracker, recording rotation angle adjustment data of the photovoltaic panel under the conditions of different terrains and sun positions, and realizing rapid backtracking and adjustment. According to the invention, the photovoltaic panel on the photovoltaic tracker can be adaptively adjusted along with the terrain, so that the power generation efficiency of the photovoltaic panel is maximized, and efficient backtracking is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic trackers, and in particular to a terrain-adaptive backtracking method based on photovoltaic trackers. Background Art

[0002] With the growing global demand for renewable energy, photovoltaic power generation technology has been widely used. As a key device for improving the efficiency of photovoltaic power generation, photovoltaic trackers can adjust the angle of photovoltaic panels in real time so that they are always perpendicular to the sunlight, thereby maximizing the power generation efficiency of photovoltaic panels. However, under complex terrain conditions, especially uneven terrain with ups and downs, traditional photovoltaic trackers often face problems such as difficult layout, complex adjustment, and high costs. Although existing technologies have achieved slope adaptation to a certain extent by optimizing mechanical structures, they still have problems with inaccurate adjustment and low efficiency when faced with more extensive terrain changes and complex lighting conditions. Therefore, developing a photovoltaic tracker method that can adaptively adjust to the terrain and achieve efficient backtracking has become a technical problem that needs to be solved urgently in the current photovoltaic power generation field. Summary of the Invention

[0003] The purpose of the present invention is to propose a terrain-adaptive backtracking method based on a photovoltaic tracker, which can adaptively adjust the photovoltaic panels on the photovoltaic tracker according to the terrain to maximize the power generation efficiency of the photovoltaic panels and achieve efficient backtracking.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] A terrain-adaptive backtracking method based on a photovoltaic tracker includes the following steps:

[0006] S1. Using the PV tracker installation plane as a reference, define the x-axis pointing due east, the y-axis pointing due north, and the z-axis pointing perpendicular to the ground and upward, to establish a three-dimensional coordinate system, where the initial state of the PV panel in the PV tracker is perpendicular to the xz plane;

[0007] S2. Obtain terrain slope data at the location of the photovoltaic tracker, and collect and calculate solar position parameters in real time;

[0008] S3. Based on the solar position parameters and the initial state of the photovoltaic panel, and in combination with the installation method of adjacent photovoltaic panels, dynamically adjust the tracking angle θ of the photovoltaic panel around the y-axis to ensure that the photovoltaic panel is always perpendicular to the sunlight, thereby obtaining more sunlight. The installation method of adjacent photovoltaic panels includes the following situations:

[0009] S31. When two photovoltaic panels are arranged in the same row along the y-axis, that is, the x-axis coordinates of the two photovoltaic panels are the same but the y-axis coordinates and the z-axis coordinates are different, the rotation angles of the two photovoltaic panels are dynamically adjusted by introducing a correction value δ;

[0010] S32. When two photovoltaic panels are arranged parallel to the y-axis, that is, the y-axis coordinates of the two photovoltaic panels are the same, but the x-axis coordinates and z-axis coordinates are different, the shadow effect between adjacent photovoltaic panels is considered, and the total shadow offset Δ is introduced. t otal, dynamically adjusts the rotation angle of photovoltaic panels located at high positions;

[0011] S4. Establish a photovoltaic tracker working status database to record the photovoltaic panel rotation angle adjustment data under different terrain and sun position conditions to achieve rapid backtracking and adjustment.

[0012] Preferably, in S2, the calculation of the solar position parameter includes:

[0013] Based on date, time, GPS and time zone, get:

[0014]

[0015] Solar time = local time + (4*longitude of time zone center - longitude of observation point) + mean time difference;

[0016] The result unit of the solar hour angle ω is degrees, the hour angle is 0° at 12 noon, negative in the morning and positive in the afternoon;

[0017]

[0018] Solar altitude angle α = arcsin(sinτ·sinδ+cosτ·cosδ·cosω);

[0019]

[0020] Among them, τ represents the geographical latitude, and N represents the day of the year;

[0021] The solar altitude angle α represents the angle formed by the line connecting the sun and the origin in the three-dimensional coordinate system and projected onto the xy plane, and the line connecting the sun and the origin in the three-dimensional coordinate system;

[0022] The solar azimuth angle γ represents the angle between the projection line of the line connecting the sun and the origin in the three-dimensional coordinate system and the y-axis.

[0023] Preferably, in S3, dynamically adjusting the tracking angle θ of the photovoltaic panel around the y-axis according to the solar position parameters and the initial state of the photovoltaic panel to ensure that the photovoltaic panel is always perpendicular to the sunlight, specifically, the sunlight direction vector s and the photovoltaic panel normal vector n are collinear, includes the following steps:

[0024] Obtain the sun ray direction vector s = (sinγ·cosα, cosγ·cosα, sinα) from the sun position parameters;

[0025] The initial state of the photovoltaic panel is that the plane of the photovoltaic panel is perpendicular to the xz plane, and its normal vector n = (0, 0, 1);

[0026] If the photovoltaic panel rotates by an angle θ around the y-axis, then its rotated normal vector n' = (sinθ, 0, cosθ);

[0027] To keep the photovoltaic panel always perpendicular to the sunlight, let the direction vector s of the sunlight be collinear with the normal vector n' of the photovoltaic panel, that is, the dot product of the two vectors is the largest, and the rotation angle θ obtained is:

[0028] θ = arctan(sinγ·cotα)

[0029] where γ represents the solar azimuth angle; α represents the solar altitude angle.

[0030] Preferably, in S31, when two photovoltaic panels are arranged in the same row along the y-axis, that is, the x-axis coordinates of the two photovoltaic panels are the same, and the y-axis coordinates and z-axis coordinates are different, by introducing a correction amount δ, the rotation angle of the photovoltaic panel is dynamically adjusted; specifically, it includes the following steps:

[0031] S311. Let the coordinate position of the photovoltaic panel at the higher position be (x 同 , y1, z 高 ), and let the coordinate position of the photovoltaic panel at the lower position be (x 同 , y2, z 低 ), obtain the y-axis difference d = |y1 - y2| between the two photovoltaic panels, and the z-axis difference h = z 高 - z 低 ;

[0032] S312. According to the solar azimuth angle γ, obtain the projection length Δ y of the z-axis difference h between the two photovoltaic panels in the y-axis direction:

[0033] Δ y = h·cotα·cosγ

[0034] S313. Compare the projection length Δ y with the y-axis difference d between the two photovoltaic panels to determine whether it is necessary to introduce a correction amount δ to adjust the rotation angle θ of the two photovoltaic panels:

[0035] If Δ y ≥ d or Δ y = 0, the shadows are staggered, there is no need to introduce a correction amount δ and there is no need to adjust the rotation angle θ of the two photovoltaic panels;

[0036] If Δ y < d, the shadows overlap, it is necessary to introduce a correction amount δ to adjust the rotation angle θ of the two photovoltaic panels, and the new rotation angle is:

[0037] θ'=θ±δ

[0038] The “+” in ± indicates rotation toward the east, and the “-” in ± indicates rotation toward the west.

[0039] Preferably, the calculation process of the correction amount δ is as follows:

[0040] At the solar azimuth angle γ, the ratio of the x-axis offset to the y-axis offset of the two photovoltaic panels is:

[0041]

[0042] When the photovoltaic panel rotates around the y-axis by an angle θ, the displacement of the edge of the photovoltaic panel in the x-axis direction is:

[0043] Δ x =Wsinθ·cotα

[0044] Where W represents the width of the photovoltaic panel along the x-axis, and α represents the solar altitude angle;

[0045] When the photovoltaic panel rotates around the y-axis by an angle θ, the displacement of the edge of the photovoltaic panel in the y-axis direction should be greater than or equal to the projection length of the edges of the two photovoltaic panels in the y-axis direction, that is,

[0046] Wsinθ·cotα·cotγ≥d-hcotα·cosγ

[0047] After simplification, the correction amount δ is:

[0048]

[0049] Where d represents the y-axis difference between the two photovoltaic panels.

[0050] Preferably, in S32, when the two photovoltaic panels are arranged parallel to the y-axis, that is, the y-axis coordinates of the two photovoltaic panels are the same, but the x-axis coordinates and the z-axis coordinates are different, the shadow effect between the adjacent photovoltaic panels is considered, and the total shadow offset Δ is introduced. t otal, dynamically adjusts the rotation angle of the photovoltaic panels located at high positions; specifically includes the following steps:

[0051] S321, let the coordinate position of the photovoltaic panel at the high position be (x1, y 同 , z 高 ), let the coordinate position of the photovoltaic panel at the lower position be (x2, y 同 , z 低 ), the width W of the two photovoltaic panels along the x-axis direction is the same, then the x-axis difference d of the two photovoltaic panels is obtained as |x1-x2|, and the z-axis difference h of the two photovoltaic panels is obtained as h=z 高 -z 低 ;

[0052] S322. Obtain the natural shadow offset of the z-axis difference h of the two photovoltaic panels in the x-axis direction according to the solar azimuth angle γ.

[0053]

[0054] S323, confirm the sun's position according to the sun's azimuth angle γ, and offset the natural shadows of the two photovoltaic panels by Δ t The x-axis difference d between otal and the two photovoltaic panels and the half width of the photovoltaic panel along the x-axis Compare the sum to determine whether it is necessary to introduce a total shadow offset Δ t otal adjusts the rotation angle θ of the photovoltaic panel located at a high position:

[0055] When the sun is in the east, that is, the shadow is cast to the west, it is necessary to ensure that the westernmost end of the shadow of the photovoltaic panel at the higher position does not exceed the easternmost end of the photovoltaic panel at the lower position:

[0056]

[0057] Similarly, the easternmost end of the photovoltaic panel at a lower position exceeds the westernmost end of the shadow of the photovoltaic panel at a higher position:

[0058]

[0059] When the sun is in the west, that is, the shadow is projected eastward, it should be satisfied that the westernmost end of the shadow of the photovoltaic panel located at a high position exceeds the easternmost end of the photovoltaic panel located at a low position:

[0060]

[0061] Similarly, the easternmost end of the photovoltaic panel at a lower position exceeds the westernmost end of the shadow of the photovoltaic panel at a higher position:

[0062]

[0063] When the above conditions are met, it means that the shadows are staggered and there is no need to introduce the total shadow offset Δ t otal and there is no need to adjust the rotation angle θ of the photovoltaic panel;

[0064] When the above conditions are not met, it means that the shadows overlap and the total shadow offset Δ needs to be introduced. t otal adjusts the rotation angle θ of the photovoltaic panel:

[0065] Total shadow offset Δ t otal offset by natural shadow After the photovoltaic panel at the upper position rotates around the y-axis by an angle θ, the displacement of the edge of the photovoltaic panel at the upper position in the x-axis direction is composition:

[0066]

[0067] in:

[0068]

[0069] so:

[0070] Δ total =hcotα·sinγ+Wsinθ·cotα·sinγ

[0071] At the same time, to ensure the natural shadow offset The total shadow offset Δ does not invade the area of ​​the photovoltaic panels located at the lower position t otal must be greater than or equal to the sum of the x-axis difference d of the two photovoltaic panels and the width W of the photovoltaic panels along the x-axis, that is:

[0072] hcotα·sinγ+Wsinθ·cotα·sinγ≥d+W

[0073] After sorting, the photovoltaic panel at a high position rotates around the y-axis by an angle θ:

[0074]

[0075] Among them, γ represents the solar azimuth angle; α represents the solar altitude angle.

[0076] Preferably, in S4, the method for establishing the photovoltaic tracker working status database includes:

[0077] S41, recording the rotation angle of the photovoltaic panel under different date, time, and sun position parameters;

[0078] S42, associating terrain slope data, adjacent photovoltaic panel installation locations, and corresponding correction values ​​δ or total shadow offsets;

[0079] S43. Establish a quick query index, and quickly trace back historical adjustment data and predict the optimal rotation angle based on the current terrain and sun position parameters.

[0080] One of the above technical solutions has the following beneficial effects:

[0081] 1. Improve power generation efficiency: By dynamically adjusting the angle of the photovoltaic panels, ensure that the photovoltaic panels are always perpendicular to the sunlight, and maximize the power generation efficiency of the photovoltaic panels.

[0082] 2. Adapt to complex terrain: This method can adaptively adjust the angle of the photovoltaic panels according to the terrain, without the need for a lot of manual adjustment and earthwork, reducing construction and production costs and improving site utilization.

[0083] 3. Reduce the impact of shadows: By introducing correction values ​​and total shadow offsets, the shadow impact between adjacent photovoltaic panels is taken into account, and the rotation angle of the photovoltaic panels is dynamically adjusted to avoid the decrease in power generation efficiency caused by shadow overlap.

[0084] 4. Achieve rapid backtracking and adjustment: By establishing a working status database to record the photovoltaic panel rotation angle adjustment data under different terrain and sun position conditions, rapid backtracking and adjustment can be achieved, thereby improving the response speed and adjustment accuracy of the photovoltaic tracker.

[0085] 5. Improve system stability: Comprehensively consider multiple factors such as terrain slope, sun position, and shadows of adjacent photovoltaic panels to improve the stability and reliability of the photovoltaic tracker system.

[0086] 6. Reduce maintenance costs: By reducing manual intervention and automating adjustments, the maintenance cost of photovoltaic trackers is reduced and the service life of the equipment is extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Figure 1 This is a flow chart of the terrain-adaptive backtracking method based on photovoltaic trackers;

[0088] Figure 2 This is a schematic diagram of the sun's position in the three-dimensional coordinate system of the photovoltaic panel in this terrain-adaptive backtracking method based on the photovoltaic tracker;

[0089] Figure 3 This is an analysis diagram of the normal vector of the photovoltaic panel when the photovoltaic panel rotates along the y-axis by an angle θ in the terrain-adaptive backtracking method based on the photovoltaic tracker;

[0090] Figure 4 This is a shadow projection analysis diagram when photovoltaic panels are arranged in the same row along the y-axis in this terrain-adaptive backtracking method based on photovoltaic trackers;

[0091] Figure 5 This is an analysis diagram of the total shadow offset when the photovoltaic panels are arranged parallel to the y-axis in this terrain-adaptive backtracking method based on photovoltaic trackers. DETAILED DESCRIPTION

[0092] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0093] A terrain-adaptive backtracking method based on a photovoltaic tracker includes the following steps:

[0094] S1. Using the PV tracker installation plane as a reference, define the x-axis pointing due east, the y-axis pointing due north, and the z-axis pointing perpendicular to the ground and upward, to establish a three-dimensional coordinate system, where the initial state of the PV panel in the PV tracker is perpendicular to the xz plane;

[0095] S2. Obtain terrain slope data at the location of the photovoltaic tracker, and collect and calculate solar position parameters in real time;

[0096] S3. Based on the solar position parameters and the initial state of the photovoltaic panel, and in combination with the installation method of adjacent photovoltaic panels, dynamically adjust the tracking angle θ of the photovoltaic panel around the y-axis to ensure that the photovoltaic panel is always perpendicular to the sunlight, thereby obtaining more sunlight. The installation method of adjacent photovoltaic panels includes the following situations:

[0097] S31. When two photovoltaic panels are arranged in the same row along the y-axis, that is, the x-axis coordinates of the two photovoltaic panels are the same but the y-axis coordinates and the z-axis coordinates are different, the rotation angles of the two photovoltaic panels are dynamically adjusted by introducing a correction value δ;

[0098] S32. When two photovoltaic panels are arranged parallel to the y-axis, that is, the y-axis coordinates of the two photovoltaic panels are the same, but the x-axis coordinates and z-axis coordinates are different, the shadow effect between adjacent photovoltaic panels is considered, and the total shadow offset Δ is introduced. t otal, dynamically adjusts the rotation angle of photovoltaic panels located at high positions;

[0099] S4. Establish a photovoltaic tracker working status database to record the photovoltaic panel rotation angle adjustment data under different terrain and sun position conditions to achieve rapid backtracking and adjustment.

[0100] The working principle of this terrain-adaptive backtracking method based on photovoltaic trackers is as follows:

[0101] S1. Coordinate System Establishment: First, establish a three-dimensional coordinate system based on the PV tracker mounting plane, defining the x-axis as pointing due east, the y-axis as pointing due north, and the z-axis as perpendicular to the ground and pointing upward. The initial position of the PV panel in the PV tracker is perpendicular to the xz plane, which serves as the reference for adjustment.

[0102] S2. Data Collection and Calculation: Obtain terrain slope data at the PV tracker location and collect and calculate solar position parameters in real time, including the solar altitude and azimuth. This data is the basis for subsequent adjustments to the PV panel angle.

[0103] S3. Dynamically adjust the angle of the photovoltaic panel:

[0104] Co-row arrangement: When two photovoltaic panels are arranged in the same row along the y-axis, that is, the x-axis coordinates of the two photovoltaic panels are the same, but the y-axis coordinates and z-axis coordinates are different, the rotation angle of the photovoltaic panels is dynamically adjusted by introducing the correction value δ to ensure that the photovoltaic panels are always perpendicular to the sunlight.

[0105] Parallel arrangement: When two photovoltaic panels are arranged parallel to the y-axis, that is, the y-axis coordinates of the two photovoltaic panels are the same, but the x-axis coordinates and z-axis coordinates are different, the shadow effect between adjacent photovoltaic panels is considered by introducing the total shadow offset Δt otal, dynamically adjusts the rotation angle of photovoltaic panels to avoid the decrease in power generation efficiency caused by overlapping shadows.

[0106] S4. Establish an operating status database: This database records the PV tracker's operating status, recording the PV panel's rotation angle adjustment data under different terrain and sun position conditions. This allows for rapid determination of the optimal tracking angle for the PV panel by querying the database or performing real-time calculations as environmental conditions change, enabling rapid retrospective adjustments.

[0107] In summary, the beneficial effects of this terrain-adaptive backtracking method based on photovoltaic trackers include:

[0108] 1. Improve power generation efficiency: By dynamically adjusting the angle of the photovoltaic panels, ensure that the photovoltaic panels are always perpendicular to the sunlight, and maximize the power generation efficiency of the photovoltaic panels.

[0109] 2. Adapt to complex terrain: This method can adaptively adjust the angle of the photovoltaic panels according to the terrain, without the need for a lot of manual adjustment and earthwork, reducing construction and production costs and improving site utilization.

[0110] 3. Reduce the impact of shadows: By introducing correction values ​​and total shadow offsets, the shadow impact between adjacent photovoltaic panels is taken into account, and the rotation angle of the photovoltaic panels is dynamically adjusted to avoid the decrease in power generation efficiency caused by shadow overlap.

[0111] 4. Achieve rapid backtracking and adjustment: By establishing a working status database to record the photovoltaic panel rotation angle adjustment data under different terrain and sun position conditions, rapid backtracking and adjustment can be achieved, thereby improving the response speed and adjustment accuracy of the photovoltaic tracker.

[0112] 5. Improve system stability: Comprehensively consider multiple factors such as terrain slope, sun position, and shadows of adjacent photovoltaic panels to improve the stability and reliability of the photovoltaic tracker system.

[0113] 6. Reduce maintenance costs: By reducing manual intervention and automating adjustments, the maintenance cost of photovoltaic trackers is reduced and the service life of the equipment is extended.

[0114] To further illustrate, in S2, the calculation of the sun position parameter includes:

[0115] Based on date, time, GPS and time zone, get:

[0116]

[0117] Solar time = local time + (4*longitude of time zone center - longitude of observation point) + mean time difference;

[0118] The result unit of the solar hour angle ω is degrees, the hour angle is 0° at 12 noon, negative in the morning and positive in the afternoon;

[0119]

[0120] Solar altitude angle α = arcsin(sinτ·sinδ+cosτ·cosδ·cosω);

[0121]

[0122] Among them, τ represents the geographical latitude, and N represents the day of the year;

[0123] The solar altitude angle α represents the angle formed by the line connecting the sun and the origin in the three-dimensional coordinate system and projected onto the xy plane, and the line connecting the sun and the origin in the three-dimensional coordinate system;

[0124] The solar azimuth angle γ represents the angle between the projection line of the line connecting the sun and the origin in the three-dimensional coordinate system and the y-axis.

[0125] To further illustrate, in S3, the tracking angle θ of the photovoltaic panel around the y-axis is dynamically adjusted according to the solar position parameters and the initial state of the photovoltaic panel to ensure that the photovoltaic panel is always perpendicular to the sunlight. Specifically, the sunlight direction vector s is collinear with the photovoltaic panel normal vector n. The steps include:

[0126] Obtain the sun ray direction vector s = (sinγ·cosα, cosγ·cosα, sinα) from the sun position parameters;

[0127] The initial state of the photovoltaic panel is that the photovoltaic panel plane is perpendicular to the xz plane, and its normal vector n = (0, 0, 1);

[0128] If the photovoltaic panel rotates around the y-axis by an angle θ, then its normal vector n' = (sinθ, 0, cosθ);

[0129] To make the photovoltaic panel always perpendicular to the sunlight, let the sunlight direction vector s and the photovoltaic panel normal vector n' be collinear, that is, the dot product of the two vectors is maximized, and the resulting rotation angle θ is:

[0130] θ=arctan(sinγ·cotα)

[0131] Among them, γ represents the solar azimuth angle; α represents the solar altitude angle.

[0132] To further illustrate, in S31, when the two photovoltaic panels are arranged in the same row along the y-axis, that is, the x-axis coordinates of the two photovoltaic panels are the same but the y-axis coordinates and the z-axis coordinates are different, the rotation angle of the photovoltaic panels is dynamically adjusted by introducing a correction value δ; specifically, the following steps are included:

[0133] S311. Let the coordinate position of the photovoltaic panel at the higher position be (x 同 , y1, z 高 ), and let the coordinate position of the photovoltaic panel at the lower position be (x 同 , y2, z 低 ). Obtain the difference d in the y-axis between the two photovoltaic panels as d = |y1 - y2|, and the difference h in the z-axis between the two photovoltaic panels as h = z 高 - z 低 ;

[0134] S312. According to the solar azimuth angle γ, obtain the projection length Δ y in the y-axis direction of the difference h in the z-axis between the two photovoltaic panels:

[0135] Δ y = h · cotα · cosγ

[0136] S313. Compare the projection length Δ y with the difference d in the y-axis between the two photovoltaic panels to determine whether a correction amount δ needs to be introduced to adjust the rotation angle θ of the two photovoltaic panels:

[0137] If Δ y ≥ d or Δ y = 0, the shadows are staggered, no correction amount δ needs to be introduced and the rotation angles θ of the two photovoltaic panels do not need to be adjusted;

[0138] If Δ y < d, the shadows overlap, a correction amount δ needs to be introduced to adjust the rotation angles θ of the two photovoltaic panels, and the new rotation angle is:

[0139] θ’ = θ ± δ <s

[0140] Among them, the “+” in ± means rotating eastward, and the “-” in ± means rotating westward.

[0141] For further explanation, the calculation process of the correction amount δ is as follows:

[0142] At the solar azimuth angle γ, the ratio of the x-axis offset to the y-axis offset between the two photovoltaic panels is:

[0143]

[0144] When the photovoltaic panel rotates by an angle θ around the y-axis, the displacement amount of the edge of the photovoltaic panel in the x-axis direction is:

[0145] Δ x = Wsinθ · cotα

[0146] Among them, W represents the width of the photovoltaic panel in the x-axis direction, and α represents the solar altitude angle;

[0147] When the photovoltaic panel rotates around the y-axis by an angle θ, the displacement of the edge of the photovoltaic panel in the y-axis direction should be greater than or equal to the projection length of the edges of the two photovoltaic panels in the y-axis direction, that is,

[0148] Wsinθ·cotα·cotγ≥d-hcotα·cosγ

[0149] After simplification, the correction amount δ is:

[0150]

[0151] Where d represents the y-axis difference between the two photovoltaic panels.

[0152] To further illustrate, in S32, when the two photovoltaic panels are arranged parallel to the y-axis, that is, the y-axis coordinates of the two photovoltaic panels are the same, but the x-axis coordinates and the z-axis coordinates are different, the shadow effect between the adjacent photovoltaic panels is considered, and the total shadow offset Δ is introduced. t otal, dynamically adjusts the rotation angle of the photovoltaic panels located at high positions; specifically includes the following steps:

[0153] S321, let the coordinate position of the photovoltaic panel at the high position be (x1, y 同 , z 高 ), let the coordinate position of the photovoltaic panel at the lower position be (x2, y 同 , z 低 ), the width W of the two photovoltaic panels along the x-axis direction is the same, then the x-axis difference d of the two photovoltaic panels is obtained as |x1-x2|, and the z-axis difference h of the two photovoltaic panels is obtained as h=z 高 -z 低 ;

[0154] S322. Obtain the natural shadow offset of the z-axis difference h of the two photovoltaic panels in the x-axis direction according to the solar azimuth angle γ.

[0155]

[0156] S323, confirm the sun's position according to the sun's azimuth angle γ, and offset the natural shadows of the two photovoltaic panels by Δ t The x-axis difference d between otal and the two photovoltaic panels and the half width of the photovoltaic panel along the x-axis Compare the sum to determine whether it is necessary to introduce a total shadow offset Δ t otal adjusts the rotation angle θ of the photovoltaic panel located at a high position:

[0157] When the sun is in the east, that is, the shadow is cast to the west, it is necessary to ensure that the westernmost end of the shadow of the photovoltaic panel at the higher position does not exceed the easternmost end of the photovoltaic panel at the lower position:

[0158]

[0159] Similarly, the easternmost end of the photovoltaic panel at a lower position exceeds the westernmost end of the shadow of the photovoltaic panel at a higher position:

[0160]

[0161] When the sun is in the west, that is, the shadow is projected eastward, it should be satisfied that the westernmost end of the shadow of the photovoltaic panel located at a high position exceeds the easternmost end of the photovoltaic panel located at a low position:

[0162]

[0163] Similarly, the easternmost end of the photovoltaic panel at a lower position exceeds the westernmost end of the shadow of the photovoltaic panel at a higher position:

[0164]

[0165] When the above conditions are met, it means that the shadows are staggered and there is no need to introduce the total shadow offset Δ t otal and there is no need to adjust the rotation angle θ of the photovoltaic panel;

[0166] When the above conditions are not met, it means that the shadows overlap and the total shadow offset Δ needs to be introduced. t otal adjusts the rotation angle θ of the photovoltaic panel:

[0167] Total shadow offset Δ t otal offset by natural shadow After the photovoltaic panel at the upper position rotates around the y-axis by an angle θ, the displacement of the edge of the photovoltaic panel at the upper position in the x-axis direction is composition:

[0168]

[0169] in:

[0170]

[0171] so:

[0172] Δ total =hcotα·sinγ+Wsinθ·cotα·sinγ

[0173] At the same time, to ensure the natural shadow offset The total shadow offset Δ does not invade the area of ​​the photovoltaic panels located at the lower position t otal must be greater than or equal to the sum of the x-axis difference d of the two photovoltaic panels and the width W of the photovoltaic panels along the x-axis, that is:

[0174] hcotα·sinγ+Wsinθ·cotα·sinγ≥d+W

[0175] After sorting, the photovoltaic panel at a high position rotates around the y-axis at an angle θ:

[0176]

[0177] Among them, γ represents the solar azimuth angle; α represents the solar altitude angle.

[0178] To further illustrate, in S4, the method for establishing the photovoltaic tracker working status database includes:

[0179] S41, recording the rotation angle of the photovoltaic panel under different date, time, and sun position parameters;

[0180] S42, associating terrain slope data, adjacent photovoltaic panel installation locations, and corresponding correction values ​​δ or total shadow offsets;

[0181] S43. Establish a quick query index, and quickly trace back historical adjustment data and predict the optimal rotation angle based on the current terrain and sun position parameters.

[0182] The present invention is further described in detail below with reference to specific embodiments.

[0183] Example 1: Applicable to the case where adjacent photovoltaic panels are arranged in the same row;

[0184] A power station is located at 110° longitude and 30° latitude, in the GMT+8 time zone. The local time is 8:00 AM on May 21, 2025 (N = 141). The mean time difference (MTD) is -3 minutes. Adjacent photovoltaic panels are arranged in a row. The panel length (i.e., the y-axis difference between the two panels, d) is 2 meters. The z-axis difference caused by the terrain is h = 0.2 meters, meaning the second panel is 0.2 meters higher than the first. The panels have an initial angle of 0.

[0185] Based on date, time, GPS and time zone, get:

[0186] Time difference correction: Δ t =4×(120°-110°)+(-3)=37 minutes;

[0187] Solar time: 8:37;

[0188] Solar hour angle:

[0189] Solar declination:

[0190] Sun Altitude Angle:

[0191] α=arcsin(sin30°·sin20.14°+cos30°cos20.14°cos(-50.75°))=43.4°;

[0192] Solar azimuth:

[0193]

[0194] According to the solar azimuth angle γ, the projection length Δ of the z-axis difference h of the two photovoltaic panels in the y-axis direction is obtained y :

[0195] Shadow interference check:

[0196] Δ y =h·cot43.4°·cos90°=0;

[0197] Shadow staggering is achieved, so there is no need to introduce a correction value δ and adjust the photovoltaic panel angle.

[0198] Example 2: Applicable to the case where two adjacent photovoltaic panels are arranged in parallel;

[0199] It is known that a power station is located at longitude 110°, latitude 30°, and the time zone is East 8. The local time is 10:00 am on May 21, 2025 (N=141). At this time, the sun is in the east, and the mean time difference is -3 minutes. The photovoltaic panels are arranged in parallel, and the coordinate position of the photovoltaic panel at the highest position (x1, y 同 , z 高 ) is (2, 0, 0.5), the coordinate position of the photovoltaic panel at the lower position is (x2, y 同 , z 低 ) is (0, 0, 0), the width W of the two photovoltaic panels along the x-axis is the same, both are 1.5m, the x-axis difference d of the two photovoltaic panels is d = |x1-x2| = |2-0| = 2m, and the z-axis difference h of the two photovoltaic panels is h = z 高 -z 低 =0.5-0=0.5;

[0200] Based on date, time, GPS and time zone, get:

[0201] Time difference correction: Δ t =4×(120°-110°)+(-3)=37 minutes;

[0202] Solar time: 10:37;

[0203] Solar hour angle:

[0204] Solar declination:

[0205] Sun Altitude Angle:

[0206] α=arcsin(sin30°·sin20.14°+cos30°cos20.14°cos(-20.75°))=68.7°;

[0207] Solar azimuth:

[0208]

[0209] Minimum shadow rotation angle:

[0210] θ=arctan(sin112.1°·cot68.7°)=19.95°;

[0211] Shadow interference check, using the photovoltaic panel located at a low position as the inspection reference:

[0212]

[0213] Among them, 0.182m<2.75m, that is, the easternmost end of the photovoltaic panel at the lower position exceeds the westernmost end of the shadow of the photovoltaic panel at the higher position; therefore, the shadow is not blocked, and there is no need to adjust the rotation angle of the photovoltaic panel. It is only necessary to rotate the rotation angle of the photovoltaic panel at the higher position by 19.95°.

[0214] Example 3: If the time is 5:00 in the morning at the same place as in Example 2, the mean time difference is the same as in the above example. Using the date, time, GPS, and time zone, the solar hour angle is -95.75°, the declination angle is 20.14°, the altitude angle is 5.2°, and the azimuth angle is 69.72°.

[0215] Shadow interference check, using the photovoltaic panel located at a low position as the inspection reference:

[0216]

[0217] Among them, 5.15m>2.75m, that is, the easternmost end of the photovoltaic panel at the lower position does not exceed the westernmost end of the shadow of the photovoltaic panel at the higher position; therefore, the shadows overlap, and the rotation angle of the photovoltaic panel needs to be additionally adjusted. At this time, the rotation angle is:

[0218] θ=arctan(sin69.72°·cot5.2°)=84°;

[0219] Corrected rotation angle:

[0220]

[0221] That is, the corrected rotation angle should be -6.1°.

[0222] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and are not to be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will be able to devise other specific embodiments of the present invention without inventive effort, and such equivalent variations or substitutions are intended to be encompassed within the scope of the claims of this application.

Claims

1. A terrain-adaptive backtracking method based on photovoltaic trackers, characterized in that: The following steps are involved: S1. Using the PV tracker installation plane as a reference, define the x-axis pointing due east, the y-axis pointing due north, and the z-axis pointing perpendicular to the ground and upward, to establish a three-dimensional coordinate system, where the initial state of the PV panel in the PV tracker is perpendicular to the xz plane; S2. Obtain terrain slope data at the location of the photovoltaic tracker, and collect and calculate solar position parameters in real time; S3. Based on the solar position parameters and the initial state of the photovoltaic panel, and in combination with the installation method of adjacent photovoltaic panels, dynamically adjust the tracking angle θ of the photovoltaic panel around the y-axis to ensure that the photovoltaic panel is always perpendicular to the sunlight, thereby obtaining more sunlight. The installation method of adjacent photovoltaic panels includes the following situations: S31. When two photovoltaic panels are arranged in the same row along the y-axis, that is, the x-axis coordinates of the two photovoltaic panels are the same but the y-axis coordinates and the z-axis coordinates are different, the rotation angles of the two photovoltaic panels are dynamically adjusted by introducing a correction value δ; S32. When two photovoltaic panels are arranged parallel to the y-axis, that is, the y-axis coordinates of the two photovoltaic panels are the same, but the x-axis coordinates and z-axis coordinates are different, the shadow effect between adjacent photovoltaic panels is considered, and the total shadow offset Δ is introduced. t otal, dynamically adjusts the rotation angle of photovoltaic panels located at high positions; S4. Establish a photovoltaic tracker working status database to record the photovoltaic panel rotation angle adjustment data under different terrain and sun position conditions to achieve rapid backtracking and adjustment.

2. The terrain-adaptive backtracking method based on photovoltaic tracker according to claim 1, characterized in that: In S2, the calculation of the sun position parameters includes: Based on date, time, GPS and time zone, get: solar hour angle Solar time = local time + (4*longitude of time zone center - longitude of observation point) + mean time difference; The result unit of the solar hour angle ω is degrees, the hour angle is 0° at 12 noon, negative in the morning and positive in the afternoon; Solar declination Solar altitude angle α = arcsin(sinτ·sinδ+cosτ·cosδ·cosω); Solar azimuth Among them, τ represents the geographical latitude, and N represents the day of the year; The solar altitude angle α represents the angle formed by the line connecting the sun and the origin in the three-dimensional coordinate system and projected onto the xy plane, and the line connecting the sun and the origin in the three-dimensional coordinate system; The solar azimuth angle γ represents the angle between the projection line of the line connecting the sun and the origin in the three-dimensional coordinate system and the y-axis.

3. The terrain-adaptive backtracking method based on photovoltaic tracker according to claim 2, characterized in that: In S3, the tracking angle θ of the photovoltaic panel around the y-axis is dynamically adjusted according to the solar position parameters and the initial state of the photovoltaic panel to ensure that the photovoltaic panel is always perpendicular to the sunlight. Specifically, the sunlight direction vector s is collinear with the photovoltaic panel normal vector n. The steps include: Obtain the sun ray direction vector s = (sinγ·cosα, cosγ·cosα, sinα) from the sun position parameters; The initial state of the photovoltaic panel is that the photovoltaic panel plane is perpendicular to the xz plane, and its normal vector n = (0, 0, 1); If the photovoltaic panel rotates around the y-axis by an angle θ, then its normal vector n' = (sinθ, 0, cosθ); To make the photovoltaic panel always perpendicular to the sunlight, let the sunlight direction vector s and the photovoltaic panel normal vector n' be collinear, that is, the dot product of the two vectors is maximized, and the resulting rotation angle θ is: θ=arctan(sinγ·cotα) Among them, γ represents the solar azimuth angle; α represents the solar altitude angle.

4. The terrain-adaptive backtracking method based on photovoltaic tracker according to claim 1, characterized in that: In S31, when the two photovoltaic panels are arranged in the same row along the y-axis, that is, the x-axis coordinates of the two photovoltaic panels are the same but the y-axis coordinates and the z-axis coordinates are different, the rotation angle of the photovoltaic panels is dynamically adjusted by introducing a correction value δ; specifically, the following steps are included: S311, let the coordinate position of the photovoltaic panel at the high position be (x 同 ,y1,z 高 ), let the coordinate position of the photovoltaic panel at the lower position be (x 同 ,y2,z 低 ), obtain the y-axis difference d = d = |y1-y2| of the two photovoltaic panels, and the z-axis difference h = z 高 -z 低 ; S312, according to the solar azimuth angle γ, obtain the projection length Δ of the z-axis difference h of the two photovoltaic panels in the y-axis direction y : D y =h·cotα·cosγ S313, the projection length Δ y Compare this with the y-axis difference d of the two photovoltaic panels to determine whether a correction δ is needed to adjust the rotation angle θ of the two photovoltaic panels: If Δ y ≥d or Δ y = 0, the shadows are staggered, and there is no need to introduce the correction value δ and adjust the rotation angle θ of the two photovoltaic panels; If Δ y <d, the shadows overlap. It is necessary to introduce a correction amount δ to adjust the rotation angle θ of the two photovoltaic panels. Then the new rotation angle is: θ'=θ±δ Among them, "+" in ± indicates rotation towards the east, and "-" in ± indicates rotation towards the west.

5. The terrain-adaptive backtracking method based on photovoltaic tracker according to claim 4 is characterized in that: The calculation process of the correction amount δ is as follows: At the solar azimuth angle γ, the ratio of the x-axis offset to the y-axis offset of the two photovoltaic panels is: When the photovoltaic panel rotates around the y-axis by an angle θ, the displacement of the edge of the photovoltaic panel in the x-axis direction is: D x =Wsinθ·cotα Where W represents the width of the photovoltaic panel along the x-axis, and α represents the solar altitude angle; When the photovoltaic panel rotates around the y-axis by an angle θ, the displacement of the edge of the photovoltaic panel in the y-axis direction should be greater than or equal to the projection length of the edges of the two photovoltaic panels in the y-axis direction, that is, Wsinθ·cotα·cotγ≥d-hcotα·cosγ After simplification, the correction amount δ is: Where d represents the y-axis difference between the two photovoltaic panels.

6. The terrain-adaptive backtracking method based on photovoltaic tracker according to claim 1, characterized in that: In S32, when the two photovoltaic panels are arranged parallel to the y-axis, that is, the y-axis coordinates of the two photovoltaic panels are the same, but the x-axis coordinates and the z-axis coordinates are different, the shadow effect between the adjacent photovoltaic panels is considered, and the total shadow offset Δ is introduced. t otal, dynamically adjusts the rotation angle of the photovoltaic panels located at high positions; specifically includes the following steps: S321, let the coordinate position of the photovoltaic panel at the high position be (x1, y 同 , z 高 ), let the coordinate position of the photovoltaic panel at the lower position be (x2, y 同 , z 低 ), the width W of the two photovoltaic panels along the x-axis direction is the same, then the x-axis difference d = |x1-x2| of the two photovoltaic panels and the z-axis difference h = zhigh-zlow of the two photovoltaic panels are obtained; S322. Obtain the natural shadow offset of the z-axis difference h of the two photovoltaic panels in the x-axis direction according to the solar azimuth angle γ. S323, confirm the sun's position according to the sun's azimuth angle γ, and offset the natural shadows of the two photovoltaic panels by Δ t The x-axis difference d between otal and the two photovoltaic panels and the half width of the photovoltaic panel along the x-axis Compare the sum to determine whether it is necessary to introduce a total shadow offset Δ t otal adjusts the rotation angle θ of the photovoltaic panel located at a high position: When the sun is in the east, that is, the shadow is cast to the west, it is necessary to ensure that the westernmost end of the shadow of the photovoltaic panel at the higher position does not exceed the easternmost end of the photovoltaic panel at the lower position: Similarly, the easternmost end of the photovoltaic panel at a lower position exceeds the westernmost end of the shadow of the photovoltaic panel at a higher position: When the sun is in the west, that is, the shadow is projected eastward, it should be satisfied that the westernmost end of the shadow of the photovoltaic panel located at a high position exceeds the easternmost end of the photovoltaic panel located at a low position: Similarly, the easternmost end of the photovoltaic panel at a lower position exceeds the westernmost end of the shadow of the photovoltaic panel at a higher position: When the above conditions are met, it means that the shadows are staggered and there is no need to introduce the total shadow offset Δ t otal and there is no need to adjust the rotation angle θ of the photovoltaic panel; When the above conditions are not met, it means that the shadows overlap and the total shadow offset Δ needs to be introduced. t otal adjusts the rotation angle θ of the photovoltaic panel: Total shadow offset Δ t otal offset by natural shadow After the photovoltaic panel at the upper position rotates around the y-axis by an angle θ, the displacement of the edge of the photovoltaic panel at the upper position in the x-axis direction is composition: in: so: D total =hcota·sinγ+Wsinθ·cota·sinγ At the same time, to ensure the natural shadow offset The total shadow offset Δ does not invade the area of ​​the photovoltaic panels located at the lower position t otal must be greater than or equal to the sum of the x-axis difference d of the two photovoltaic panels and the width W of the photovoltaic panels along the x-axis, that is: hcotα·sinγ+Wsinθ·cotα·sinγ≥d+W After sorting, the photovoltaic panel at a high position rotates around the y-axis at an angle θ: Among them, γ represents the solar azimuth angle; α represents the solar altitude angle.

7. The terrain-adaptive backtracking method based on photovoltaic tracker according to claim 1, characterized in that: In S4, the method for establishing the photovoltaic tracker working status database includes: S41, recording the rotation angle of the photovoltaic panel under different date, time, and sun position parameters; S42, associating terrain slope data, adjacent photovoltaic panel installation locations, and corresponding correction values ​​δ or total shadow offsets; S43. Establish a quick query index, and quickly trace back historical adjustment data and predict the optimal rotation angle based on the current terrain and sun position parameters.

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