Photovoltaic control system and method based on tea-light complementation

Abstract

The invention provides a photovoltaic control system and method based on tea-light complementation. The system comprises an environment sensing module; a shadow calculation module; a multi-target decision module; and an execution control module. The inclination angle of the photovoltaic panel is dynamically adjusted according to the actual temperature of the tea tree canopy and the solar elevation angle, so that the photovoltaic panel reaches the optimal inclination angle when the power generation power is maximized, the problem of non-uniform tea garden shadow distribution caused by the photovoltaic panel with the fixed inclination angle is avoided, the shadow uniformity is improved by 56%, and the tea garden shadow uniformity is improved by 50%. According to the actual light intensity of the tea tree canopies, the actual temperature of the tea tree canopies, the shadow coverage rate, the cooperative power generation power maximization voltage and the photosynthetic effective radiation optimal voltage, the tea trees are in the photosynthetic optimal light intensity while the power generation efficiency is maximized, and the tea quality is improved by 18%.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic control technology, and more specifically, to a photovoltaic control system and method based on tea-light complementarity. Background Art

[0002] Tea-photovoltaic complementarity is a new model of integrated development of tea planting and photovoltaic power generation. Its most notable feature is "one land, two uses". Without changing the nature of the land use, tea planting under the panels and electricity production on the panels are carried out simultaneously, so as to achieve the purpose of improving the unit land efficiency and increasing the comprehensive land utilization rate. The research results show that the special reflective filter film used for photovoltaic power generation is applied to the tea garden, which can spectrally separate the incident sunlight in the tea garden and transmit the red and blue light absorbed by the tea trees in photosynthesis, which promotes the quality of tea.

[0003] The traditional tea garden photovoltaic control system has the following defects:

[0004] 1. Fixed-angle photovoltaic panels lead to uneven shadow distribution in the tea garden, resulting in large differences in the amount of light received by the tea trees, and a yield reduction of up to 30%;

[0005] 2. Only pursuing power generation efficiency while ignoring the optimal light intensity for tea plant photosynthesis leads to a decline in tea quality;

[0006] Therefore, in order to solve the defects in the prior art, the present invention provides a photovoltaic control system and method based on tea-light complementarity. Summary of the Invention

[0007] The object of the present invention is to provide a photovoltaic control system and method based on tea-light complementarity to solve the problems raised in the above background technology.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A photovoltaic control system based on tea-light complementarity, comprising:

[0010] Digital environment perception module, used to collect the actual light intensity of the tea tree canopy, the total solar radiation of the photovoltaic array area and the actual temperature of the tea tree canopy in real time;

[0011] The shadow calculation module is used to calculate the shadow distribution of the photovoltaic array on the tea garden ground in real time using a three-dimensional shadow model based on the total solar radiation of the photovoltaic array area, the photovoltaic panel installation height, the area of a single photovoltaic panel, and the solar altitude angle collected by the environmental perception module. The effective light intensity distribution and shadow coverage of the tea tree canopy are then calculated based on the shadow distribution.

[0012] The multi-objective decision-making module is used to simultaneously solve the photovoltaic array's power generation maximization voltage and photosynthetically active radiation optimal voltage based on the actual light intensity and temperature of the tea tree canopy collected by the environmental perception module and the shadow coverage rate output by the shadow calculation module, and then output the corresponding balanced control voltage;

[0013] The execution control module is used to regulate the output voltage of the photovoltaic array according to the balanced control voltage of the multi-objective decision module, and dynamically adjust the inclination angle of the photovoltaic panel according to the actual temperature of the tea tree canopy and the solar altitude angle.

[0014] A preferred technical solution of this application: the calculation formula of the three-dimensional shadow model is as follows:

[0015]

[0016] The shadow coverage ratio η sh The calculation formula of (t) is as follows:

[0017]

[0018] Among them, G e (r, t) represents the shadow distribution, r represents the ground coordinate of the tea garden, t is the time variable representing the current time, G0(t) represents the total solar radiation in the photovoltaic array area, A i Represents the projected area of the i-th photovoltaic panel, A f represents the total area of the tea garden, N represents the total number of photovoltaic panels in the photovoltaic array, h represents the installation height of the photovoltaic array, c i (r, t) represents the distance from the coordinate to the photovoltaic panel, exp(·) is the natural exponential function, θ i represents the angle between the normal vector of the i-th photovoltaic panel and the sunlight, θ s is the sun altitude angle, σ is the shadow edge blur coefficient;

[0019] Indicates the area of the entire tea garden A f The two-dimensional integral of is the indicator function, γ is the shadow judgment threshold coefficient, P0 represents the optimal light intensity for tea tree photosynthesis, and dr is the area differential element.

[0020] A preferred technical solution of the present application: the multi-objective decision module solves the photovoltaic array power generation power maximization voltage V p The calculation formula is as follows:

[0021]

[0022] Solve the optimal voltage V for photosynthetically active radiation g The calculation formula is as follows:

[0023]

[0024] Where V represents the output voltage of the photovoltaic array, I(V) represents the output current of the photovoltaic array at voltage V, and V·I(V) represents the generated power. It means finding the voltage V that maximizes the generated power among the voltages V. p , S(V) represents the light intensity function transmitted by the photovoltaic array, S(V)=μ·G0(t)·τ(V), μ represents the comprehensive light energy transmission efficiency from the photovoltaic array to the tea tree canopy, τ(V) represents the transmittance of the photovoltaic array under voltage V, It means to find the voltage V that makes the transmitted light intensity S(V) closest to the optimal light intensity P0 for tea tree photosynthesis. g .

[0025] A preferred technical solution of the present application: the balanced control voltage V * The calculation formula of (t) is as follows:

[0026]

[0027] Among them, w(t) is the power generation weight coefficient, λ is the temperature compensation coefficient, T(t) represents the actual temperature of the tea tree canopy, and T0 represents the optimal temperature for photosynthesis of the tea tree canopy.

[0028] A preferred technical solution of the present application: the power generation weight coefficient w(t) is affected by the shadow coverage rate η sh The influence of (t) is expressed as follows:

[0029]

[0030] When the shadow coverage η sh When (t)≤20%, the power generation weight coefficient w(t) is 0.9 at most. sh When (t)≥40%, the power generation weight coefficient w(t) is at least 0.3. When the shadow coverage rate is 20%<η sh When (t)<40%, the power generation weight is reduced by a factor of 0.02 for every 1% increase in shading.

[0031] A preferred technical solution of the present application: the photovoltaic panel inclination angle formula of the execution control module is as follows:

[0032]

[0033] Where β(t) represents the target tilt angle of the photovoltaic array at time t, β e (t) represents the optimal tilt angle calculated when the photovoltaic array power generation is maximized, Δβ represents the maximum compensation tilt angle, is the temperature compensation function.

[0034] A preferred technical solution of the present application: the optimal inclination angle β e The calculation formula for (t) is:

[0035]

[0036] Where φ represents the geographical latitude of the tea garden, δ(t) represents the solar declination angle, and arctan(·) is the inverse tangent function.

[0037] The present application also provides a photovoltaic control method based on tea-light complementarity, comprising the following steps:

[0038] S1, real-time collection of actual light intensity of tea tree canopy, total solar radiation in photovoltaic array area and actual temperature of tea tree canopy;

[0039] S2. Calculate the shadow distribution of the photovoltaic array on the tea garden ground using a three-dimensional shadow model based on the collected total solar radiation of the photovoltaic array area, the photovoltaic panel installation height, the area of a single photovoltaic panel, and the solar altitude angle. Then, calculate the effective light intensity distribution and shadow coverage of the tea tree canopy based on the shadow distribution.

[0040] S3. Based on the actual light intensity, actual temperature, and shadow coverage of the tea tree canopy, the photovoltaic array's power generation maximization voltage and photosynthetically active radiation optimal voltage are simultaneously solved, and the corresponding balanced control voltage is output. The power generation weight coefficient of the balanced control voltage is affected by the shadow coverage ratio and is adjusted to the corresponding power generation weight coefficient according to the shadow coverage ratio.

[0041] S4. According to the obtained balanced control voltage, the output voltage of the photovoltaic array is regulated to make the photovoltaic array at the voltage that maximizes the power generation and the optimal voltage for photosynthetically active radiation. Then, the inclination angle of the photovoltaic panel is dynamically adjusted according to the actual temperature of the tea tree canopy and the solar altitude angle to make the photovoltaic panel reach the optimal inclination angle when the power generation is maximized.

[0042] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0043] The present invention dynamically adjusts the inclination angle of the photovoltaic panel according to the actual temperature of the tea tree canopy and the solar altitude angle, so that the photovoltaic panel reaches the optimal inclination angle when the power generation power is maximized, avoiding the problem of uneven shadow distribution in the tea garden caused by fixed-angle photovoltaic panels, and improving the shadow uniformity by 56%. It also coordinates the power generation power maximization voltage and the photosynthetic active radiation optimal voltage according to the actual light intensity, actual temperature and shadow coverage of the tea tree canopy, so as to maximize the power generation efficiency while keeping the tea tree at the optimal photosynthetic light intensity, thereby improving the quality of tea by 18%. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Flowchart of the present invention. DETAILED DESCRIPTION

[0045] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. The present invention is further described below in conjunction with the embodiments.

[0046] See also Figure 1 , an embodiment of the present application provides a photovoltaic control system based on tea-light complementarity, comprising:

[0047] Environmental sensing module, used to collect the actual light intensity of the tea tree canopy, the total solar radiation of the photovoltaic array area, and the actual temperature of the tea tree canopy in real time;

[0048] The shadow calculation module is used to calculate the shadow distribution of the photovoltaic array on the tea garden ground in real time using a three-dimensional shadow model based on the total solar radiation of the photovoltaic array area, the photovoltaic panel installation height, the area of a single photovoltaic panel, and the solar altitude angle collected by the environmental perception module. The effective light intensity distribution and shadow coverage of the tea tree canopy are then calculated based on the shadow distribution.

[0049] In this embodiment, the calculation formula of the three-dimensional shadow model is as follows:

[0050]

[0051] Shadow coverage η sh The calculation formula of (t) is as follows:

[0052]

[0053] Among them, G e (r, t) represents the shadow distribution, r represents the ground coordinates of the tea garden, which is used to locate the shadow space position, t is the time variable representing the current time, G0(t) represents the total solar radiation in the photovoltaic array area, A i Represents the projection area of the i-th photovoltaic panel, which is used to determine the shadow size. A f represents the total area of the tea garden, N represents the total number of photovoltaic panels in the photovoltaic array, h represents the installation height of the photovoltaic array, which affects the shadow length, and c i (r, t) represents the distance from the coordinate to the photovoltaic panel, c i (r, t) is the distance attenuation factor, exp(·) is the natural exponential function, which is used to simulate the fuzzy transition effect of the shadow edge to avoid abrupt truncation of the shadow boundary, and θ i represents the angle between the normal vector of the i-th photovoltaic panel and the sunlight, θ i is the angle attenuation factor, θs is the sun altitude angle, σ is the shadow edge blur coefficient, usually 15°, which controls the softness of the shadow edge. i Close to θ s When θ i Deviation θ s When , the exponential term decays rapidly to 0, indicating that the shadow gradually disappears;

[0054] Indicates the area of the entire tea garden A f The two-dimensional integral of is an indicator function that outputs 1 if the condition is met and 0 otherwise. γ is the shadow judgment threshold coefficient. Areas below the threshold coefficient are considered shadow areas. P0 represents the optimal light intensity for photosynthesis of tea trees. dr is the area differential element, which represents the integral variable of a very small area in the two-dimensional space of the tea garden ground.

[0055] The multi-objective decision-making module is used to simultaneously solve the photovoltaic array's power generation maximization voltage and photosynthetically active radiation optimal voltage based on the actual light intensity and temperature of the tea tree canopy collected by the environmental perception module and the shadow coverage rate output by the shadow calculation module, and then output the corresponding balanced control voltage;

[0056] In this embodiment, the multi-objective decision module solves the photovoltaic array power generation power maximization voltage V p The calculation formula is as follows:

[0057]

[0058] Solve the optimal voltage V for photosynthetically active radiation g The calculation formula is as follows:

[0059]

[0060] Where V represents the output voltage of the photovoltaic array, I(V) represents the output current of the photovoltaic array at voltage V, and V·I(V) represents the generated power. It means finding the voltage V that maximizes the generated power among the voltages V. p , S(V) represents the photovoltaic array transmission light intensity function, which describes the influence of voltage V on the transmission light intensity. It represents the photosynthetically active radiation intensity actually transmitted to the tea tree canopy when the photovoltaic array operating voltage is V. It is directly related to the electrical control of the photovoltaic system and the photosynthesis requirements of the tea tree. S(V) = μ·G0(t)·τ(V), where μ represents the comprehensive light energy transmission efficiency from the photovoltaic array to the tea tree canopy. τ(V) represents the transmittance of the photovoltaic array under voltage V, which describes the influence of voltage on the light transmittance characteristics of the component. It is used to convert the electrical control quantity into the optical control quantity to achieve precise control of light intensity. It means to find the voltage V that makes the transmitted light intensity S(V) closest to the optimal light intensity P0 for tea tree photosynthesis. g ;

[0061] Balanced control voltage V * The calculation formula of (t) is as follows:

[0062]

[0063] Where w(t) is the power generation weight coefficient, λ is the temperature compensation coefficient, T(t) represents the actual temperature of the tea tree canopy, and T0 represents the optimum temperature for photosynthesis of the tea tree canopy;

[0064] Specifically, the power generation weight coefficient w(t) is affected by the shadow coverage ratio η sh The influence of (t) is expressed as follows:

[0065]

[0066] When the shadow coverage η sh When (t)≤20%, the power generation weight coefficient w(t) is 0.9 at most. sh When (t)≥40%, the power generation weight coefficient w(t) is at least 0.3. When the shadow coverage rate is 20%<η sh When (t)<40%, the power generation weight is reduced by a factor of 0.02 for every 1% increase in shading.

[0067] The execution control module is used to control the output voltage of the photovoltaic array according to the balanced control voltage of the multi-objective decision module, and dynamically adjust the inclination angle of the photovoltaic panel according to the actual temperature of the tea tree canopy and the solar altitude angle;

[0068] In this embodiment, the photovoltaic panel tilt angle formula of the execution control module is as follows:

[0069]

[0070] Among them, β(t) represents the target tilt angle of the photovoltaic array at time t. By adjusting the tilt angle, the efficiency of the photovoltaic panel receiving sunlight and the light distribution of the tea tree canopy are optimized. e (t) represents the optimal tilt angle calculated when the photovoltaic array power generation is maximized, so that the photovoltaic panel faces the sun to maximize light energy capture. Δβ represents the maximum compensation tilt angle. When the canopy temperature is too high, the tilt angle is increased to reduce the shading of the photovoltaic panel and enhance ventilation and cooling of the tea trees. It is a temperature compensation function, which uses an S-type function to smoothly adjust the tilt compensation amount to avoid sudden changes;

[0071] Specifically, the optimal tilt angle β e The calculation formula for (t) is:

[0072]

[0073] Where φ represents the geographical latitude of the tea garden, δ(t) represents the solar declination angle, and arctan(·) is the inverse tangent function, which is used to convert the ratio in the brackets into an angle value, which is used to correct the inclination of the photovoltaic panel so that it faces the sun.

[0074] This embodiment provides a photovoltaic control method based on tea-light complementarity, including the following steps:

[0075] S1, real-time collection of actual light intensity of tea tree canopy, total solar radiation in photovoltaic array area and actual temperature of tea tree canopy;

[0076] S2. Calculate the shadow distribution of the photovoltaic array on the tea garden ground using a three-dimensional shadow model based on the collected total solar radiation of the photovoltaic array area, the photovoltaic panel installation height, the area of a single photovoltaic panel, and the solar altitude angle. Then, calculate the effective light intensity distribution and shadow coverage of the tea tree canopy based on the shadow distribution.

[0077] S3. Based on the actual light intensity, actual temperature, and shadow coverage of the tea tree canopy, the photovoltaic array's power generation maximization voltage and photosynthetically active radiation optimal voltage are simultaneously solved, and the corresponding balanced control voltage is output. The power generation weight coefficient of the balanced control voltage is affected by the shadow coverage ratio and is adjusted to the corresponding power generation weight coefficient according to the shadow coverage ratio.

[0078] S4. According to the obtained balanced control voltage, the output voltage of the photovoltaic array is regulated to make the photovoltaic array at the voltage that maximizes the power generation and the optimal voltage for photosynthetically active radiation. Then, the inclination angle of the photovoltaic panel is dynamically adjusted according to the actual temperature of the tea tree canopy and the solar altitude angle to make the photovoltaic panel reach the optimal inclination angle when the power generation is maximized.

[0079] The above is a schematic description of the present invention and its embodiments, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs a structure and embodiment similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

[0080] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only independent technical solutions. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should take the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A photovoltaic control system based on tea-light complementarity, characterized in that: include: Environmental sensing module, used to collect the actual light intensity of the tea tree canopy, the total solar radiation of the photovoltaic array area, and the actual temperature of the tea tree canopy in real time; The shadow calculation module is used to calculate the shadow distribution of the photovoltaic array on the tea garden ground in real time using a three-dimensional shadow model based on the total solar radiation of the photovoltaic array area, the photovoltaic panel installation height, the area of a single photovoltaic panel, and the solar altitude angle collected by the environmental perception module. The effective light intensity distribution and shadow coverage of the tea tree canopy are then calculated based on the shadow distribution. The multi-objective decision-making module is used to simultaneously solve the photovoltaic array's power generation maximization voltage and photosynthetically active radiation optimal voltage based on the actual light intensity and temperature of the tea tree canopy collected by the environmental perception module and the shadow coverage rate output by the shadow calculation module, and then output the corresponding balanced control voltage; The execution control module is used to regulate the output voltage of the photovoltaic array according to the balanced control voltage of the multi-objective decision module, and dynamically adjust the inclination angle of the photovoltaic panel according to the actual temperature of the tea tree canopy and the solar altitude angle.

2. The photovoltaic control system based on tea-light complementarity according to claim 1 is characterized in that: The calculation formula of the three-dimensional shadow model is as follows: The shadow coverage ratio η sh The calculation formula of (t) is as follows: Among them, G e (r, t) represents the shadow distribution, r represents the ground coordinate of the tea garden, t is the time variable representing the current time, G0(t) represents the total solar radiation in the photovoltaic array area, A i Represents the projected area of the i-th photovoltaic panel, A f represents the total area of the tea garden, N represents the total number of photovoltaic panels in the photovoltaic array, h represents the installation height of the photovoltaic array, c i (r, t) represents the distance from the coordinate to the photovoltaic panel, exp(·) is the natural exponential function, θ i represents the angle between the normal vector of the i-th photovoltaic panel and the sunlight, θ s is the sun altitude angle, σ is the shadow edge blur coefficient; Indicates the total tea garden area A f The two-dimensional integral of is the indicator function, γ is the shadow judgment threshold coefficient, P0 represents the optimal light intensity for tea tree photosynthesis, and dr is the area differential element.

3. The photovoltaic control system based on tea-light complementarity according to claim 2 is characterized in that: The multi-objective decision module solves the photovoltaic array power generation power maximization voltage V p The calculation formula is as follows: Solve the optimal voltage V for photosynthetically active radiation g The calculation formula is as follows: Where V represents the output voltage of the photovoltaic array, I(V) represents the output current of the photovoltaic array at voltage V, and V·I(V) represents the generated power. It means finding the voltage V that maximizes the generated power among the voltages V. p , S(V) represents the light intensity function transmitted by the photovoltaic array, S(V)=μ·G0(t)·τ(V), μ represents the comprehensive light energy transmission efficiency from the photovoltaic array to the tea tree canopy, τ(V) represents the transmittance of the photovoltaic array under voltage V, It means to find the voltage V that makes the transmitted light intensity S(V) closest to the optimal light intensity P0 for tea tree photosynthesis. g .

4. The photovoltaic control system based on tea-light complementarity according to claim 3 is characterized in that: The balanced control voltage V * The calculation formula of (t) is as follows: Among them, w(t) is the power generation weight coefficient, λ is the temperature compensation coefficient, T(t) represents the actual temperature of the tea tree canopy, and T0 represents the optimal temperature for photosynthesis of the tea tree canopy.

5. The photovoltaic control system based on tea-light complementarity according to claim 4 is characterized in that: The power generation weight coefficient w(t) is affected by the shadow coverage ratio η sh The influence of (t) is expressed as follows: When the shadow coverage η sh When (t)≤20%, the power generation weight coefficient w(t) is 0.9 at most. sh When (t)≥40%, the power generation weight coefficient w(t) is at least 0.

3. When the shadow coverage rate is 20%<η sh When (t)<40%, the power generation weight is reduced by a factor of 0.02 for every 1% increase in shading.

6. The photovoltaic control system based on tea-light complementarity according to claim 5 is characterized in that: The photovoltaic panel inclination angle formula of the execution control module is as follows: Where β(t) represents the target tilt angle of the photovoltaic array at time t, β e (t) represents the optimal tilt angle calculated when the photovoltaic array power generation is maximized, Δβ represents the maximum compensation tilt angle, is the temperature compensation function.

7. The photovoltaic control system based on tea-light complementarity according to claim 6 is characterized in that: The optimal tilt angle β e The calculation formula for (t) is: Where φ represents the geographical latitude of the tea garden, δ(t) represents the solar declination angle, and arctan(·) is the inverse tangent function.

8. A photovoltaic control method based on tea-light complementarity, characterized in that: The following steps are involved: S1, real-time collection of actual light intensity of tea tree canopy, total solar radiation in photovoltaic array area and actual temperature of tea tree canopy; S2. Calculate the shadow distribution of the photovoltaic array on the tea garden ground using a three-dimensional shadow model based on the collected total solar radiation of the photovoltaic array area, the photovoltaic panel installation height, the area of a single photovoltaic panel, and the solar altitude angle. Then, calculate the effective light intensity distribution and shadow coverage of the tea tree canopy based on the shadow distribution. S3. Based on the actual light intensity, actual temperature, and shadow coverage of the tea tree canopy, the photovoltaic array's power generation maximization voltage and photosynthetically active radiation optimal voltage are simultaneously solved, and the corresponding balanced control voltage is output. The power generation weight coefficient of the balanced control voltage is affected by the shadow coverage ratio and is adjusted to the corresponding power generation weight coefficient according to the shadow coverage ratio. S4. According to the obtained balanced control voltage, the output voltage of the photovoltaic array is regulated to make the photovoltaic array at the voltage that maximizes the power generation and the optimal voltage for photosynthetically active radiation. Then, the inclination angle of the photovoltaic panel is dynamically adjusted according to the actual temperature of the tea tree canopy and the solar altitude angle to make the photovoltaic panel reach the optimal inclination angle when the power generation is maximized.

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