Photovoltaic tracking assembly cloudy day mode trigger control method and system

Abstract

The invention discloses a cloudy day mode trigger control method and a cloudy day mode trigger control system for a photovoltaic tracking assembly. The cloudy day mode trigger control method comprises the following steps: acquiring global horizontal irradiation dose GHI, a solar zenith angle Zenth and a solar constant; according to the GHI and the Zenth sum, calculating to obtain a clearness index, and according to the clearness index, calculating to obtain a scattering irradiation amount ratio; according to the GHI, calculating to obtain a scattering irradiation dose DHI; according to the DHI, the GHI and the Zenth, the direct irradiation dose DNI is obtained through calculation; according to the GHI, the DHI and the DNI, calculating to obtain a total irradiation amount POA received by a photovoltaic tracking assembly plane; and comparing the POA with the GHI, and carrying out cloudy day mode triggering judgment on the photovoltaic tracking module according to a comparison result. The problem that in an existing cloudy day mode triggering judgment method based on the GHI threshold value, under the sunrise or sunset or other low-irradiation conditions, the GHI is smaller than the threshold value, and misjudgment is caused is solved.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic tracking module technology, specifically a method and system for triggering control of a photovoltaic tracking module in a cloudy weather mode. Background Technology

[0002] Photovoltaic tracking modules typically use single-axis or dual-axis tracking technology to track the sun's position in real time, maximizing the amount of direct sunlight they receive. However, on cloudy or overcast days, direct sunlight is significantly reduced or even disappears, and the modules primarily receive diffused sunlight. Under these conditions, continuing normal daily tracking not only fails to increase power generation but also results in power loss due to improper module orientation, causing the back of the module to receive sunlight. It also increases motor energy consumption and mechanical wear on the support structure. To address these issues, photovoltaic tracking modules usually automatically trigger a cloudy mode, which involves laying the module flat. Current technology uses a threshold based on the Global Horizontal Irradiance (GHI) to trigger the cloudy mode; for example, laying the module flat when GHI < 200 W / m². However, this GHI-based method can lead to misjudgments and unnecessary module actions during sunrise, sunset, or other low-irradiance conditions, where GHI may also be below the threshold. Summary of the Invention

[0003] To address the aforementioned shortcomings, this invention proposes a cloudy mode triggering control method and system for photovoltaic tracking modules. The aim is to solve the problem that in existing cloudy mode triggering determination methods based on the Global Horizontal Irradiance (GHI) threshold, GHI may be less than the threshold under sunrise, sunset, or other low irradiance conditions, leading to misjudgments.

[0004] To achieve this objective, the present invention adopts the following technical solution: A method for triggering control of a photovoltaic tracking module in a cloudy weather mode includes the following steps: Step S1: Obtain global horizontal irradiance (GHI), solar zenith angle (Zenith), and solar constant. ; Step S2: Based on GHI, Zenith and The clear sky index was calculated. ,in, The specific calculation formula is as follows: ; Step S3: According to The proportion of scattered irradiance was calculated. ; Step S4: According to The diffuse irradiance DHI is calculated from GHI and Zenith; and the direct irradiance DNI is calculated from DHI, GHI, and Zenith; the specific formula for calculating DHI is as follows: ; The specific formula for calculating DNI is as follows: ; Step S5: Calculate the total irradiance (POA) received by the photovoltaic tracking module in the plane based on GHI, DHI, and DNI; Step S6: Compare POA with GHI, and determine the trigger for the cloudy mode of the photovoltaic tracking module based on the comparison results; if When this happens, the cloudy mode will be triggered. If the weather is cloudy, the overcast mode will not be triggered or will be exited. The overcast mode refers to laying the photovoltaic tracking module flat when it is cloudy or partly cloudy.

[0005] Preferably, in step S3, when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: ; when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: ; when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: .

[0006] Preferably, step S5 specifically includes the following sub-steps: Step S51: Obtain the tilt angle of the photovoltaic tracking module and according to The projection factor of the scattered light was calculated. ,in, The specific calculation formula is as follows: ; Step S52: Obtain the angle between sunlight and the normal of the photovoltaic tracking module. and ground albedo ; Step S53: According to , , The total irradiance (POA) received by the photovoltaic tracking module in the plane is calculated using GHI, DHI, and DNI. The specific formula for calculating POA is as follows: .

[0007] Another aspect of this application provides a cloudy day mode triggering control system for a photovoltaic tracking module, the system comprising: The acquisition module is used to acquire global horizontal irradiance (GHI), solar zenith angle (Zenith), and the solar constant. ; The first calculation module is used to calculate based on GHI, Zenith, and The clear sky index was calculated. ,in, The specific calculation formula is as follows: ; The second calculation module is used to calculate based on... The proportion of scattered irradiance was calculated. ; The third calculation module is used to calculate based on... From GHI, the diffuse irradiance DHI is calculated, where the specific formula for calculating DHI is as follows: ; The fourth calculation module is used to calculate the direct radiation dose (DNI) based on DHI, GHI, and Zenith. The specific calculation formula for DNI is as follows: ; The fifth calculation module is used to calculate the total irradiance (POA) received by the photovoltaic tracking module in the plane based on GHI, DHI, and DNI. The comparison and judgment module is used to compare the POA with the GHI and determine the cloudy mode trigger for the photovoltaic tracking module based on the comparison result; if When this happens, the cloudy mode will be triggered. If the weather is cloudy, the overcast mode will not be triggered or will be exited. The overcast mode refers to laying the photovoltaic tracking module flat when it is cloudy or partly cloudy.

[0008] Preferably, in the second calculation module, when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: ; when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: ; when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: .

[0009] Preferably, the fifth calculation module includes: The first acquisition submodule is used to acquire the tilt angle of the photovoltaic tracking module. ; The first calculation submodule is used to calculate based on... The projection factor of the scattered light was calculated. ,in, The specific calculation formula is as follows: ; The second acquisition submodule is used to obtain the angle between sunlight and the normal of the photovoltaic tracking module. ; The third acquisition submodule is used to acquire ground albedo. ; The second calculation submodule is used to calculate based on... , , The total irradiance (POA) received by the photovoltaic tracking module in the plane is calculated using GHI, DHI, and DNI. The specific formula for calculating POA is as follows: .

[0010] The technical solution provided by this invention may include the following beneficial effects: Compared to the cloud cover triggering method based on the Global Horizontal Irradiance (GHI) threshold, this solution calculates the Total Radiance (POA) received by the photovoltaic tracking module plane and compares the GHI with the POA to determine the cloud cover triggering method. Since the POA comprehensively considers the actual reception of both direct and diffuse irradiance on the photovoltaic tracking module plane, this solution effectively distinguishes between cloudy days and non-cloudy conditions such as sunrise, sunset, or other low-irradiance days by comparing GHI with POA. This avoids misjudgments caused by GHI threshold-based determinations and reduces unnecessary module actions. Attached Figure Description

[0011] Figure 1 This is a flowchart illustrating the steps of a cloudy day mode triggering control method for a photovoltaic tracking module. Detailed Implementation

[0012] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0013] A method for triggering control of a photovoltaic tracking module in a cloudy weather mode includes the following steps: Step S1: Obtain global horizontal irradiance (GHI), solar zenith angle (Zenith), and solar constant. ; Step S2: Based on GHI, Zenith and The clear sky index was calculated. ,in, The specific calculation formula is as follows: ; Step S3: According to The proportion of scattered irradiance was calculated. ; Step S4: According to The diffuse irradiance DHI is calculated from GHI and Zenith; and the direct irradiance DNI is calculated from DHI, GHI, and Zenith; the specific formula for calculating DHI is as follows: ; The specific formula for calculating DNI is as follows: ; Step S5: Calculate the total irradiance (POA) received by the photovoltaic tracking module in the plane based on GHI, DHI, and DNI; Step S6: Compare POA with GHI, and determine the trigger for the cloudy mode of the photovoltaic tracking module based on the comparison results; if When this happens, the cloudy mode will be triggered. If the weather is cloudy, the overcast mode will not be triggered or will be exited. The overcast mode refers to laying the photovoltaic tracking module flat when it is cloudy or partly cloudy.

[0014] This solution presents a method for triggering control of a photovoltaic tracking module in a cloudy weather mode, such as... Figure 1 As shown, the first step is to obtain the global horizontal irradiance (GHI), the solar zenith angle (Zenith), and the solar constant. In this embodiment, the global horizontal irradiance (GHI) is collected in real time by a horizontal irradiance meter on the photovoltaic tracking module. The solar zenith angle (Zenith) is calculated using existing astronomical algorithms based on the geographical location and time information of the photovoltaic tracking module, and will not be elaborated here. The solar constant... This was obtained through a table lookup, and its generally accepted standard value is 1367 W / m². This was obtained by consulting GHI, Zenith, and... This provides a solid data foundation for subsequent calculations of clear sky index, diffuse irradiance, direct irradiance, and total irradiance received by the photovoltaic tracking module. The second step is based on GHI, Zenith, and The clear sky index was calculated. ,in, The specific calculation formula is as follows: ， In this embodiment, the clear sky index The Clear Sky Index indicates the degree to which solar radiation is transmitted through the atmosphere. It is calculated by... This effectively reflects the current level of sky clearness, providing crucial information for distinguishing between direct and diffuse radiation. The third step is based on... The proportion of scattered irradiance was calculated. In this embodiment, the proportion of scattered irradiance is calculated. This clarifies the proportion of diffused radiation in the total irradiance, which helps in the targeted analysis of the light-receiving characteristics of photovoltaic tracking modules on cloudy days. The fourth step is based on... The diffuse irradiance DHI is calculated from GHI and Zenith; and the direct irradiance DNI is calculated from DHI, GHI, and Zenith; the specific formula for calculating DHI is as follows: The specific calculation formula for DNI is as follows: In this embodiment, by calculating the diffuse irradiance (DHI) and direct irradiance (DNI), the direct and diffuse irradiance received by the photovoltaic tracking module can be clearly distinguished, accurately reflecting the irradiance composition under different weather conditions. The fifth step is to calculate the total irradiance (POA) received by the photovoltaic tracking module plane based on GHI, DHI, and DNI. In this embodiment, by calculating the total irradiance (POA) received by the photovoltaic tracking module plane, the actual reception of direct and diffuse irradiance on the photovoltaic tracking module plane is comprehensively considered, which can truly reflect the effective light reception level of the photovoltaic tracking module and provide a key quantitative indicator for the accurate determination of the subsequent cloudy weather mode. The sixth step is to compare the POA with GHI and determine the cloudy weather mode trigger for the photovoltaic tracking module based on the comparison results; if... When this happens, the cloudy mode will be triggered. When the weather is cloudy, the overcast mode will not be triggered or will be exited. The overcast mode refers to laying the photovoltaic tracking module flat during overcast or cloudy weather. In this embodiment, when... When this occurs, it indicates that scattered radiation is dominant. In this case, placing the photovoltaic tracking module flat to enter the cloudy mode can maximize the absorption of scattered light. When the weather is cloudy, it indicates that direct radiation is dominant. In this case, the cloudy mode can be left off or exited in order to maintain or restore the normal tracking mode of the photovoltaic tracking module.

[0015] Compared to the cloud cover triggering method based on the Global Horizontal Irradiance (GHI) threshold, this solution calculates the Total Radiance (POA) received by the photovoltaic tracking module plane and compares the GHI with the POA to determine the cloud cover triggering method. Since the POA comprehensively considers the actual reception of both direct and diffuse irradiance on the photovoltaic tracking module plane, this solution effectively distinguishes between cloudy days and non-cloudy conditions such as sunrise, sunset, or other low-irradiance days by comparing GHI with POA. This avoids misjudgments caused by GHI threshold-based determinations and reduces unnecessary module actions.

[0016] Preferably, in step S3, when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: ; when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: ; when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: .

[0017] In this embodiment, based on the clear sky index Different numerical ranges were used to calculate the proportion of diffuse irradiance using a piecewise formula. This allows for a more accurate representation of the distribution patterns of diffused radiation under actual weather conditions. Further explanation is needed when... A larger value indicates a clear sky and a lower proportion of diffused radiation; when... A lower value indicates that the sky is cloudy or the atmosphere is turbid, and the proportion of scattered radiation is relatively high.

[0018] Preferably, step S5 specifically includes the following sub-steps: Step S51: Obtain the tilt angle of the photovoltaic tracking module and according to The projection factor of the scattered light was calculated. ,in, The specific calculation formula is as follows: ; Step S52: Obtain the angle between sunlight and the normal of the photovoltaic tracking module. and ground albedo ; Step S53: According to , , The total irradiance (POA) received by the photovoltaic tracking module in the plane is calculated using GHI, DHI, and DNI. The specific formula for calculating POA is as follows: .

[0019] In this embodiment, in step S51, the tilt angle of the photovoltaic tracking module is used as a reference. Calculate the projection factor of scattered light This effectively reflects the proportion of scattered light on the plane of the photovoltaic tracking module. In step S52, the angle between sunlight and the normal of the photovoltaic tracking module is obtained. This is beneficial for subsequent calculations of the effective amount of direct sunlight received on the photovoltaic tracking module plane. By obtaining the ground albedo... This is beneficial for quantifying the contribution of ground-reflected light to photovoltaic tracking modules. In step S53, by according to , , The calculation of POA using GHI, DHI, and DNI comprehensively considers the effective reception of the photovoltaic tracking module plane under direct irradiation, the effective reception of the photovoltaic tracking module plane under diffuse irradiation, and the contribution of ground reflected light, and can accurately reflect the total irradiance level of the photovoltaic tracking module plane under the current attitude.

[0020] Another aspect of this application provides a cloudy day mode triggering control system for a photovoltaic tracking module, the system comprising: The acquisition module is used to acquire global horizontal irradiance (GHI), solar zenith angle (Zenith), and the solar constant. ; The first calculation module is used to calculate based on GHI, Zenith, and The clear sky index was calculated. ,in, The specific calculation formula is as follows: ; The second calculation module is used to calculate based on... The proportion of scattered irradiance was calculated. ; The third calculation module is used to calculate based on... From GHI, the diffuse irradiance DHI is calculated, where the specific formula for calculating DHI is as follows: ; The fourth calculation module is used to calculate the direct radiation dose (DNI) based on DHI, GHI, and Zenith. The specific calculation formula for DNI is as follows: ; The fifth calculation module is used to calculate the total irradiance (POA) received by the photovoltaic tracking module in the plane based on GHI, DHI, and DNI. The comparison and judgment module is used to compare the POA with the GHI and determine the cloudy mode trigger for the photovoltaic tracking module based on the comparison result; if When this happens, the cloudy mode will be triggered. If the weather is cloudy, the overcast mode will not be triggered or will be exited. The overcast mode refers to laying the photovoltaic tracking module flat when it is cloudy or partly cloudy.

[0021] This solution provides a cloudy day mode triggering control system for photovoltaic (PV) tracking modules. Through the coordinated operation of an acquisition module, a first calculation module, a second calculation module, a third calculation module, a fourth calculation module, a fifth calculation module, and a comparison and judgment module, the system enables the PV tracking module to determine the triggering of cloudy day modes. Compared to cloudy day mode triggering determination methods based on the GHI threshold, this solution effectively distinguishes between cloudy days and non-cloudy conditions such as sunrise, sunset, or other low-irradiance situations by comparing GHI with POA (Power Oxygen Absorption). This avoids misjudgments caused by GHI threshold-based determinations, thereby reducing unnecessary module actions.

[0022] Preferably, in the second calculation module, when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: ; when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: ; when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: .

[0023] In this embodiment, in the second calculation module, based on the clear sky index Different numerical ranges were used to calculate the proportion of diffuse irradiance using a piecewise formula. This allows for a more accurate representation of the distribution patterns of diffused radiation under actual weather conditions.

[0024] Preferably, the fifth calculation module includes: The first acquisition submodule is used to acquire the tilt angle of the photovoltaic tracking module. ; The first calculation submodule is used to calculate based on... The projection factor of the scattered light was calculated. ,in, The specific calculation formula is as follows: ; The second acquisition submodule is used to obtain the angle between sunlight and the normal of the photovoltaic tracking module. ; The third acquisition submodule is used to acquire ground albedo. ; The second calculation submodule is used to calculate based on... , , The total irradiance (POA) received by the photovoltaic tracking module in the plane is calculated using GHI, DHI, and DNI. The specific formula for calculating POA is as follows: .

[0025] In this embodiment, by setting a first acquisition submodule and a first calculation submodule, the effective proportion of scattered light on the photovoltaic tracking module plane can be effectively reflected. Setting a second acquisition submodule facilitates subsequent calculation of the effective amount of direct irradiation received on the photovoltaic tracking module plane. Setting a third acquisition submodule helps quantify the contribution of ground-reflected light to the photovoltaic tracking module. By setting a second calculation submodule, the effective reception of direct irradiation, effective reception of scattered irradiation, and the contribution of ground-reflected light on the photovoltaic tracking module plane are comprehensively considered, accurately reflecting the total irradiance level of the photovoltaic tracking module plane in its current orientation.

[0026] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0027] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for triggering control of a cloudy mode for a photovoltaic tracking module, characterized in that: Includes the following steps: Step S1: Obtain global horizontal irradiance (GHI), solar zenith angle (Zenith), and solar constant. ; Step S2: Based on GHI, Zenith and The clear sky index was calculated. ,in, The specific calculation formula is as follows: ； Step S3: According to The proportion of scattered irradiance was calculated. ; Step S4: According to The diffuse irradiance DHI is calculated from GHI and Zenith; and the direct irradiance DNI is calculated from DHI, GHI, and Zenith; the specific formula for calculating DHI is as follows: ； The specific formula for calculating DNI is as follows: ； Step S5: Calculate the total irradiance (POA) received by the photovoltaic tracking module in the plane based on GHI, DHI, and DNI; Step S6: Compare POA with GHI, and determine the trigger for the cloudy mode of the photovoltaic tracking module based on the comparison results; if When this happens, the cloudy mode will be triggered. If the weather is cloudy, the overcast mode will not be triggered or will be exited. The overcast mode refers to laying the photovoltaic tracking module flat when it is cloudy or partly cloudy.

2. The method for triggering control of a cloudy mode for a photovoltaic tracking module according to claim 1, characterized in that: In step S3, when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: ； when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: ； when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: 。 3. The method for triggering control of a photovoltaic tracking module in cloudy mode according to claim 1, characterized in that: Step S5 specifically includes the following sub-steps: Step S51: Obtain the tilt angle of the photovoltaic tracking module and according to The projection factor of the scattered light was calculated. ,in, The specific calculation formula is as follows: ； Step S52: Obtain the angle between sunlight and the normal of the photovoltaic tracking module. and ground albedo ; Step S53: According to , , The total irradiance (POA) received by the photovoltaic tracking module in the plane is calculated using GHI, DHI, and DNI. The specific formula for calculating POA is as follows: 。 4. A cloudy mode triggering control system for a photovoltaic tracking module, using the cloudy mode triggering control method for a photovoltaic tracking module as described in any one of claims 1-3, characterized in that: The system includes: The acquisition module is used to acquire global horizontal irradiance (GHI), solar zenith angle (Zenith), and the solar constant. ; The first calculation module is used to calculate based on GHI, Zenith, and The clear sky index was calculated. ,in, The specific calculation formula is as follows: ； The second calculation module is used to calculate based on... The proportion of scattered irradiance was calculated. ; The third calculation module is used to calculate based on... From GHI, the diffuse irradiance DHI is calculated, where the specific formula for calculating DHI is as follows: ； The fourth calculation module is used to calculate the direct radiation dose (DNI) based on DHI, GHI, and Zenith. The specific calculation formula for DNI is as follows: ； The fifth calculation module is used to calculate the total irradiance (POA) received by the photovoltaic tracking module in the plane based on GHI, DHI, and DNI. The comparison and judgment module is used to compare the POA with the GHI and determine the cloudy mode trigger for the photovoltaic tracking module based on the comparison result; if When this happens, the cloudy mode will be triggered. If the weather is cloudy, the overcast mode will not be triggered or will be exited. The overcast mode refers to laying the photovoltaic tracking module flat when it is cloudy or partly cloudy.

5. The cloud cover mode triggering control system for a photovoltaic tracking module according to claim 4, characterized in that: In the second calculation module, when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: ； when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: ； when At that time, the proportion of scattered irradiance The specific calculation formula is as follows: 。 6. The cloud cover mode triggering control system for a photovoltaic tracking module according to claim 4, characterized in that: The fifth calculation module includes: The first acquisition submodule is used to acquire the tilt angle of the photovoltaic tracking module. ; The first calculation submodule is used to calculate based on... The projection factor of the scattered light was calculated. ,in, The specific calculation formula is as follows: ； The second acquisition submodule is used to obtain the angle between sunlight and the normal of the photovoltaic tracking component. ; The third acquisition submodule is used to acquire ground albedo. ; The second calculation submodule is used to calculate based on... , , The total irradiance (POA) received by the photovoltaic tracking module in the plane is calculated using GHI, DHI, and DNI. The specific formula for calculating POA is as follows: 。

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