Tracking angle optimization method of flat single-axis tracking system and tracking bracket thereof

Abstract

The present invention provides a tracking angle optimization method for a flat single-axis tracking system and a tracking bracket thereof. By setting test installation planes with different installation angles in a transmission tracking bracket and installing small monitoring components and / or irradiance meters on these test installation planes, the current information or irradiance information of photovoltaic components at different installation angles at the same time is obtained, and then through a set tracking angle optimization strategy, the final tracking angle to be executed at the next moment after the tracking bracket is optimized is obtained, thereby finally improving the system power generation of the photovoltaic tracking system and increasing the system revenue.

Description

Technical Field

[0001] The invention relates to an intelligent tracking system for a solar cell mounting bracket, in particular to a tracking angle optimization method for a flat single-axis tracking system and a tracking bracket thereof, belonging to the technical field of solar cell mounting. Background Art

[0002] There are two forms of photovoltaic power station installation: fixed bracket installation and tracking bracket installation. Among them, the flat single-axis tracking bracket system has high power generation, relatively low cost, and relatively small footprint. The comprehensive cost and power generation economic analysis has more investment value. At the same time, due to the rapid development of bifacial photovoltaic module technology, bifacial photovoltaic module products have been rapidly applied and the market has gradually expanded. The combination of bifacial photovoltaic power generation modules and single-axis tracking brackets has a superposition effect of 1+1>2, and the market acceptance and application have shown rapid growth. The calculation of the tracking bracket system is the algorithm for controlling the tracking angle. Therefore, the development of related products and the optimization of the tracking angle algorithm have practical research significance and broad application prospects.

[0003] At present, the main tracking algorithm of the photovoltaic tracking system is still to track the apparent sun at the angle calculated by the traditional astronomical algorithm. Apparent sun tracking is to calculate the solar altitude angle and solar azimuth angle according to geographic information and time, and then obtain the projection of the sun's rays on the plane perpendicular to the axis, so as to obtain the tracking angle. Through experiments and research, it is found that different weather conditions such as cloudy, overcast, direct light, heat dissipation light, and surface reflectivity under clear weather have a significant impact on the power generation of the photovoltaic tracking system, especially for the bifacial components that can generate electricity on the back. In actual applications, due to the significant differences in meteorological weather in different regions, the traditional single astronomical algorithm cannot better meet the needs of the application. There is still room for optimization and improvement in the power generation of photovoltaic tracking systems under complex meteorological conditions. Summary of the invention

[0004] The purpose of the present invention is to solve the above problems and provide a tracking angle optimization method and a tracking bracket of a flat single-axis tracking system, optimize the tracking strategy of the existing tracking bracket, make the tracking angle of the bracket optimal, and ultimately improve the system power generation of the photovoltaic tracking system and increase the system revenue.

[0005] To this end, the present invention adopts the following technical solutions:

[0006] A tracking angle optimization method for a flat single-axis tracking system, the flat single-axis tracking system comprising a plurality of rows of tracking brackets, a first mounting plane for mounting photovoltaic modules formed on the tracking brackets, photovoltaic modules mounted on the first mounting plane, an initial tracking angle A0 of the tracking brackets obtained by calculation using an astronomical algorithm, and a final tracking angle A0n executed at the next moment after the tracking brackets are optimized obtained by calculation using the following steps:

[0007] S1: K test installation planes with different angles are set at the end or middle part of the tracking bracket, and a small battery cell assembly and / or an irradiation meter are installed on the test installation plane;

[0008] S2: Real-time collection of small cell components and / or irradiation values ​​by the irradiation meter to obtain K current values ​​and / or irradiation values ​​at the same time, and take the installation angle A1' of the test installation plane where the small cell component and / or irradiation meter with the maximum current value Imax and / or irradiation value Emax is located;

[0009] S3: setting a judgment reference value X, X>0; setting an angle deviation reference value θ, θ>0; the tracking angle obtained by the tracking bracket through the astronomical algorithm in the next step is A1; according to the set tracking angle optimization strategy, the tracking bracket is calculated to finally execute the tracking angle A01 at the next moment after optimization;

[0010] S4: Repeat steps S1-S3, and calculate in sequence to obtain the tracking angles A02, A03, A03...A0n to be finally executed at the next moment after the tracking bracket is optimized.

[0011] Furthermore, the tracking angle optimization strategy is:

[0012] ①When A1>A0, A1'≥A0:

[0013] If A1'-A1>X, the final tracking angle at the next moment is A01=Max(A0+θ,A1);

[0014] If 0<A1'-A1<X, then the final tracking angle at the next moment is A01=A1;

[0015] If -X<A1'-A1<0, the final tracking angle at the next moment is A01=A1;

[0016] If A1'-A1<-X, then the final tracking angle at the next moment is A01=Max(A0+θ,A1');

[0017] ②When A1>A0, A1'<A0:

[0018] If -X<A1'-A0<0, the final tracking angle at the next moment will be A01=A0, without adjustment;

[0019] If A1'-A0<-X, then the final tracking angle at the next moment is A01=A0-θ;

[0020] ③When A1<A0, A1'≥A0:

[0021] If 0<A1'-A0<X, the final tracking angle at the next moment will be A01=A0, without adjustment;

[0022] If A1'-A0>X, the final tracking angle at the next moment is A01=A0+θ;

[0023] ④When A1<A0, A1'<A0:

[0024] If A1'-A1<-X, then the final tracking angle at the next moment is A01=Min(A0-θ,A1);

[0025] If -X<A1'-A1<0, the final tracking angle at the next moment is A01=A1;

[0026] If 0<A1'-A1<X, then the final tracking angle at the next moment is A01=A1;

[0027] If A1'-A1>X, the final tracking angle at the next moment is A01=Min(A0-θ,A1').

[0028] Furthermore, the angle difference △ between the installation angles of the K test installation planes with different angles set on the tracking bracket and the first installation plane is fixed and can rotate with the tracking bracket; the installation angle difference △ between two adjacent test installation planes is also fixed.

[0029] Furthermore, the value of △ is 2-5°.

[0030] Furthermore, the judgment reference value X is set at 2-8°.

[0031] Furthermore, the angle deviation reference value θ is set at 2-8°.

[0032] Another aspect of the present invention provides a tracking bracket of a flat single-axis tracking system, wherein a first mounting plane for mounting photovoltaic components is formed on the tracking bracket, K test mounting planes with different angles are arranged at the end or middle part of the tracking bracket, and a small battery cell component and / or an irradiance meter are installed on the test mounting plane.

[0033] Furthermore, the angle difference △ between the installation angles of the K test installation planes with different angles set on the tracking bracket and the first installation plane is fixed and can rotate with the tracking bracket; the installation angle difference △ between two adjacent test installation planes is also fixed.

[0034] Furthermore, the value of △ is 2-5°.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] On the basis of traditional astronomical algorithms, test installation planes with different installation angles are set in the transmission tracking bracket, and small monitoring components and / or irradiance meters are installed on these test installation planes to obtain the current information or irradiance information of the photovoltaic components at different installation angles at the same time. Then, through the set tracking angle optimization strategy, the final tracking angle to be executed at the next moment after the tracking bracket is optimized is obtained, thereby ultimately improving the system power generation of the photovoltaic tracking system and increasing the system revenue.

[0037] The tracking angle optimization method of the present invention only requires adding some small test components, irradiance meters or simple irradiance meters to the original tracking bracket system. It can be applied to various existing tracking bracket systems and obtain the optimal system power generation without much increase in cost. It has a wide range of applications and broad application prospects.

[0038] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic diagram of different installation surface angles of the tracking bracket system of the present invention and a schematic diagram of the change of the tracking process from east to west;

[0040] Figure 2a , 2b This is an example of the tracking angle of the tracking bracket in the present invention;

[0041] Figure 3 This is another example of the tracking angle of the tracking bracket in the present invention;

[0042] Figure 4 This is another example of the tracking angle of the tracking bracket in the present invention;

[0043] Figure 5a , 5b This is another example of the tracking angle of the tracking bracket in the present invention;

[0044] Figure 6 It is a flowchart of determining the optimal tracking angle by comparing the current values ​​of components at different angles in the present invention;

[0045] Figure 7 It is a flowchart of the present invention for determining the optimal tracking angle by comparing irradiation at different angles. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings.

[0047] The tracking angle optimization method of the present invention is applicable to a flat single-axis tracking system. The flat single-axis tracking system is a prior art and generally includes several rows of flat single-axis tracking brackets. A first mounting plane for mounting photovoltaic components is formed on the tracking brackets. Photovoltaic components are mounted on the first mounting plane. The tracking angle of the tracking bracket determines the mounting angle of the photovoltaic components on the first mounting plane. In this application, the tracking angle of the tracking bracket, the angle of the first mounting plane, and the mounting angle of the photovoltaic components on the first mounting plane will be used under the same concept.

[0048] First, the tracking bracket system in the photovoltaic power station is optimized and designed. K test installation planes with different angles are designed at the end or middle of a single-row tracking bracket that can be used to install a long string of photovoltaic modules. K is an integer greater than 2. These test installation planes will rotate with the main rotation axis of the tracking bracket, and maintain a fixed difference angle with the main axis installation surface, that is, the first installation plane angle, such as Figure 1 As shown in . Small cell modules or irradiation meters are installed on the test installation planes at different angles, and the current or irradiation of small modules on the test installation planes at different angles are monitored in real time, so as to compare and obtain the best angle. Specifically:

[0049] The tracking angle of the tracking bracket system is set to rotate from the east to the west gradually following the sun. The tracking angle of the tracking bracket is defined as rotating from the east extreme position -60° to the west extreme position +60°, and 0° when it is flat. According to the following tracking angle optimization strategy, the tracking angle of the tracking bracket at the next moment is obtained, that is, the final tracking angle A0n executed at the next moment after the tracking bracket is optimized.

[0050] First, some letter codes are set as follows:

[0051] A0 is the tracking angle at the current moment, A01 is the final tracking angle at the next moment, and the final tracking angles at the next moment are A02, A03…A0n.

[0052] A1' is the optimal angle at the current moment selected by real-time monitoring of irradiation at the current angle A0 and other different positive offset and negative offset angles (A0+△, A0+2△..., A0-△, A0-2△,...), which can be used as one of the options for tracking angles at the next moment;

[0053] A1 is the tracking angle calculated by the astronomical algorithm at the next moment, followed by A2, A3…An, where the value of An is in the tracking angle range of -60°~60°;

[0054] X is the reference value, which is a positive angle value. It can be 3°, 5°, 8°, etc. according to the needs.

[0055] θ is the angle deviation reference value, which is a positive angle value and can be set to 3°, 5°, 8°, etc. according to needs;

[0056] During the tracking process, the tracking angle is optimized according to the following agreed strategy. When the tracking is started for the first time, the A0 angle is the angle obtained according to the astronomical algorithm:

[0057] (I) When A1>A0, A1'≥A0, that is Figure 2a , Figure 2b The two states shown, at this time:

[0058] If A1'-A1>X, the final tracking angle at the next moment is A01=Max(A0+θ,A1);

[0059] If 0<A1'-A1<X, then the final tracking angle at the next moment is A01=A1;

[0060] If -X<A1'-A1<0, the final tracking angle at the next moment is A01=A1;

[0061] If A1'-A1<-X, the final tracking angle at the next moment is A01=Max(A0+θ,A1')

[0062] (ii) When A1>A0, A1'<A0, that is Figure 3 When the status shown is:

[0063] If -X<A1'-A0<0, the final tracking angle at the next moment will be A01=A0, without adjustment;

[0064] If A1'-A0<-X, then the final tracking angle at the next moment is A01=A0-θ;

[0065] (III) When A1<A0, A1'≥A0, that is Figure 4 The status shown, at this time:

[0066] If 0<A1'-A0<X, the final tracking angle at the next moment will be A01=A0, without adjustment;

[0067] If A1'-A0>X, the final tracking angle at the next moment is A01=A0+θ;

[0068] (IV) When A1<A0, A1'<A0, that is Figure 5a , the state shown in 5b, at this time:

[0069] If A1'-A1<-X, then the final tracking angle at the next moment is A01=Min(A0-θ,A1);

[0070] If -X<A1'-A1<0, the final tracking angle at the next moment is A01=A1;

[0071] If 0<A1'-A1<X, then the final tracking angle at the next moment is A01=A1;

[0072] If A1'-A1>X, the final tracking angle at the next moment is A01=Min(A0-θ,A1').

[0073] According to the above agreement, the final tracking angle A01 is determined at the next moment. After the tracking system tracks the angle, the current angle A0 is A01. In this way, the optimization of the tracking angle at the next moment is performed according to the program and the above agreement.

[0074] In order to further illustrate the present invention in detail, the following will be described in detail: Embodiment 1:

[0075] This embodiment utilizes the monitoring component current to compare and select the optimal angle, which is achieved through a current detection device or an IV test device.

[0076] In this embodiment, the △ value is 3°, and the X value and the θ value are both 5. Figure 6 As shown, the steps of tracking angle optimization measurement of the tracking bracket are as follows:

[0077] At the first startup, A0 is the initial tracking angle of the tracking bracket determined by the astronomical algorithm. Five test installation planes with different angles are set at the end or middle part of the tracking bracket. The angles of the test installation planes are A0 and A0+3°, A0+6°, A0-3°, and A0-6° respectively. Small battery cell assemblies are installed on the above five test installation planes with different angles; the current information of the small battery cell assemblies on the above five test installation planes is monitored in real time.

[0078] The final tracking angle A01 at the next moment after the tracking bracket is optimized is calculated by the following steps:

[0079] Compare the currents of small solar cell modules on the test installation planes at different angles, and select the test installation plane where the small solar cell module with the largest current value is located. The angle of this test installation plane is one of the optimal angles A1'. Combined with the calculation angle A1 of the next moment of the astronomical algorithm, further judgment is made:

[0080] In the first case, when A1>A0, A1'≥A0:

[0081] If A1'-A1>5, the final tracking angle at the next moment is A01=Max(A0+5,A1);

[0082] If 0<A1'-A1<5, the final tracking angle at the next moment is A01=A1;

[0083] If -5<A1'-A1<0, the final tracking angle at the next moment is A01=A1;

[0084] If A1'-A1<-5, the final tracking angle at the next moment is A01=Max(A0+5,A1')

[0085] The second case, when A1>A0, A1'<A0:

[0086] If -5<A1'-A0<0, the final tracking angle at the next moment will be A01=A0, without adjustment;

[0087] If A1'-A0<-5, the final tracking angle at the next moment is A01=A0-5;

[0088] The third case, when A1<A0, A1'≥A0:

[0089] If 0<A1'-A0<5, the final tracking angle at the next moment will be A01=A0, without adjustment;

[0090] If A1'-A0>5, the final tracking angle at the next moment is A01=A0+5;

[0091] The fourth case, when A1<A0, A1'<A0:

[0092] If A1'-A1<-5, then the final tracking angle at the next moment is A01=Min(A0-5,A1);

[0093] If -5<A1'-A1<0, the final tracking angle at the next moment is A01=A1;

[0094] If 0<A1'-A1<5, the final tracking angle at the next moment is A01=A1;

[0095] If A1'-A1>5, the final tracking angle at the next moment will be A01=Min(A0-5,A1').

[0096] According to the above agreement, the tracking angle A01 is finally determined at the next moment. After the tracking system tracks this angle, the current angle A0 is A01, so that the other angle surfaces become new angle values ​​A0+3°, A0+6°, A0-3°, A0-6°. In this way, the optimization of the tracking angle at the next moment is looped according to the program and the above agreement. Embodiment 2:

[0097] like Figure 7As shown, the difference between this embodiment and embodiment 1 is that this embodiment uses the irradiance of the monitoring component to compare and select the optimal angle, which can be achieved through a irradiance meter or a simple irradiance meter. By real-time monitoring of the irradiance value information on K test installation planes, and comparing the irradiance values ​​of the test installation planes at different angles, the test installation plane with the largest irradiance value is selected, and the angle of the test installation plane is one of the optimal angles A1'. Finally, according to the set tracking angle optimization strategy, the tracking angle A01, A02, A03... A0n is finally executed at the next moment after the tracking bracket is optimized.

[0098] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways without departing from the spirit of the present invention.

Claims

1. A tracking angle optimization method for a flat single-axis tracking system, characterized in that: The flat single-axis tracking system includes a plurality of rows of tracking brackets, a first mounting plane for mounting photovoltaic modules is formed on the tracking brackets, photovoltaic modules are mounted on the first mounting plane, an initial tracking angle A0 of the tracking brackets is obtained by astronomical algorithm calculation, and a final tracking angle A0n executed at the next moment after the tracking brackets are optimized is obtained by the following steps: S1: K test installation planes with different angles are set at the end or middle part of the tracking bracket, and a small battery cell assembly and / or an irradiation meter are installed on the test installation plane; S2: collect the current value and / or irradiance value of the small battery cell assembly and / or irradiance meter in real time, obtain K current values ​​and / or irradiance values ​​at the same time, and take the installation angle A1' of the test installation plane where the small battery cell assembly and / or irradiance meter with the maximum current value Imax and / or irradiance value Emax is located; S3: setting a judgment reference value X, X>0; setting an angle deviation reference value θ, θ>0; the tracking angle obtained by the tracking bracket through the astronomical algorithm in the next step is A1; according to the set tracking angle optimization strategy, the tracking bracket is calculated to finally execute the tracking angle A01 at the next moment after optimization; The tracking angle optimization strategy is: ①When A1>A0, A1'≥A0: If A1'-A1>X, the final tracking angle at the next moment is A01=Max(A0+θ,A1); If 0<A1'-A1<X, then the final tracking angle at the next moment is A01=A1; If -X<A1'-A1<0, the final tracking angle at the next moment is A01=A1; If A1'-A1<-X, then the final tracking angle at the next moment is A01=Max(A0+θ,A1'); ②When A1>A0, A1'<A0: If -X<A1'-A0<0, the final tracking angle at the next moment will be A01=A0, without adjustment; If A1'-A0<-X, then the final tracking angle at the next moment is A01=A0-θ; ③When A1<A0, A1'≥A0: If 0<A1'-A0<X, the final tracking angle at the next moment will be A01=A0, without adjustment; If A1'-A0>X, the final tracking angle at the next moment is A01=A0+θ; ④When A1<A0, A1'<A0: If A1'-A1< -X, then the final tracking angle at the next moment is A01=Min(A0-θ,A1); If -X<A1'-A1<0, the final tracking angle at the next moment is A01=A1; If 0<A1'-A1<X, then the final tracking angle at the next moment is A01=A1; If A1'-A1>X, the final tracking angle at the next moment is A01=Min(A0-θ,A1'); S4: Repeat steps S1-S3, and calculate in sequence to obtain the tracking angles A02, A03, A03...A0n to be finally executed at the next moment after the tracking bracket is optimized.

2. The tracking angle optimization method of the flat single-axis tracking system according to claim 1, characterized in that: The angle difference △ between the installation angles of the K test installation planes with different angles arranged on the tracking bracket and the first installation plane is fixed and can rotate with the tracking bracket; the installation angle difference △ between two adjacent test installation planes is also fixed.

3. The tracking angle optimization method of the flat single-axis tracking system according to claim 2, characterized in that: The value of △ is 2-5°.

4. The tracking angle optimization method of the flat single-axis tracking system according to claim 1, characterized in that: The judgment reference value X is set at 2-8°.

5. The tracking angle optimization method of the flat single-axis tracking system according to claim 1, characterized in that: The angle deviation reference value θ is set at 2-8°.

6. A tracking bracket of a flat single-axis tracking system, used in the tracking angle optimization method according to any one of claims 1 to 5, characterized in that: A first mounting plane for mounting photovoltaic components is formed on the tracking bracket, and K test mounting planes with different angles are arranged at the end or middle part of the tracking bracket, and small battery cell components and / or irradiance meters are mounted on the test mounting planes.

7. The tracking bracket of the flat single-axis tracking system according to claim 6, characterized in that: The angle difference △ between the installation angles of the K test installation planes with different angles arranged on the tracking bracket and the first installation plane is fixed and can rotate with the tracking bracket; the installation angle difference △ between two adjacent test installation planes is also fixed.

8. The tracking bracket of the flat single-axis tracking system according to claim 7, characterized in that: The value of △ is 2-5°.

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