A photovoltaic control system and method based on tea light complementation

Abstract

The application provides a photovoltaic control system and method based on tea light complementation, and the system comprises an environment sensing module, a shadow calculation module, a multi-target decision module and an execution control module. According to the actual temperature of the tea tree canopy and the solar elevation angle, the inclination angle of the photovoltaic panel is dynamically adjusted, so that the photovoltaic panel reaches the optimal inclination angle when the power generation power is maximized, the problem of uneven shadow distribution caused by the fixed inclination angle photovoltaic panel is avoided, the uniformity of the shadow is improved by 56%, and according to the actual light intensity of the tea tree canopy, the actual temperature of the tea tree canopy and the shadow coverage, the maximum power generation efficiency voltage and the optimal photosynthetic active radiation voltage are coordinated, so that the tea tree is in the optimal photosynthetic light intensity at the maximum power generation efficiency, and the quality of the tea is improved by 18%.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic control, more particularly to a photovoltaic control system and method based on tea-light complementation. BACKGROUND

[0002] Tea-light complementation is a new mode of development combining tea planting and photovoltaic power generation, and its most prominent feature is "one land for two purposes". Under the premise of not changing the nature of the land, tea planting under the board and power production on the board are carried out at the same time, so as to improve the efficiency of unit land and increase the comprehensive utilization rate of land. The research results show that the special reflective filter film used for photovoltaic power generation applied in the tea garden can separate the incident sunlight spectrum of the tea garden, and the red and blue light absorbed by the photosynthesis of tea trees can be transmitted, which can promote the quality of tea leaves.

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

[0004] 1. Fixed inclination angle photovoltaic board leads to uneven distribution of tea garden shadow, large difference in tea tree light receiving, and up to 30% reduction in yield;

[0005] 2. Only the power generation efficiency is pursued, and the optimal light intensity for photosynthesis of tea trees is ignored, resulting in a decrease in tea quality;

[0006] Therefore, in order to solve the defects in the prior art, the present application provides a photovoltaic control system and method based on tea-light complementation. SUMMARY

[0007] The purpose of the present application is to provide a photovoltaic control system and method based on tea-light complementation to solve the problems raised in the background art.

[0008] To achieve the above purpose, the present application provides the following technical scheme:

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

[0010] An environmental perception module for real-time acquisition of actual light intensity of tea tree canopy, total solar radiation of photovoltaic array area and actual temperature of tea tree canopy;

[0011] A shadow calculation module for real-time calculation of shadow distribution projected on the ground of the tea garden by a three-dimensional shadow model according to the total solar radiation of the photovoltaic array area collected by the environmental perception module, and the installation height of the photovoltaic board, the area of a single photovoltaic board and the solar altitude angle, and then calculating the effective light intensity distribution and shadow coverage of the tea tree canopy according to the shadow distribution;

[0012] The multi-objective decision module is configured to simultaneously solve a maximum power generation voltage of the photovoltaic array and an optimal photosynthetically active radiation voltage according to the actual light intensity of the tea tree canopy, the actual temperature of the tea tree canopy, and the shadow coverage rate output by the shadow calculation module, and output a corresponding balanced control voltage.

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

[0014] In an embodiment, the three-dimensional shadow model is calculated according to the following formula:

[0015]

[0016] The shadow coverage rate η sh is calculated according to the following formula:

[0017]

[0018] wherein G e (r, t) represents the shadow distribution, r represents a coordinate of the tea garden ground, t is a time variable representing the current time, G0(t) represents the total solar radiation of the photovoltaic array area, A i represents the projection 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 a 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 solar elevation angle, and σ is a shadow edge blur coefficient.

[0019] represents a two-dimensional integral over the entire tea garden area A f , is an indicator function, γ is a shadow judgment threshold coefficient, P0represents the optimal light intensity for photosynthesis of the tea tree, and dr is an area differential element.

[0020] In an embodiment, the multi-objective decision module is configured to solve the maximum power generation voltage V p of the photovoltaic array according to the actual light intensity of the tea tree canopy, the actual temperature of the tea tree canopy, and the shadow coverage rate output by the shadow calculation module, and output a corresponding balanced control voltage.

[0021]

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

[0023]

[0024] wherein V represents the output voltage of the photovoltaic array, I(V) represents the output current of the photovoltaic array at voltage V, V*I(V) represents the power generation, represents finding the voltage V in voltage V that maximizes the power generation V*I(V) p , S(V) represents the transmitted light intensity function of the photovoltaic array, S(V) = μ*G0(t)*τ(V), μ represents the comprehensive light energy transmission efficiency of the photovoltaic array to the tea tree canopy, and τ(V) represents the light transmittance of the photovoltaic array at voltage V, represents finding the voltage V in voltage V that makes the transmitted light intensity S(V) closest to the photosynthetic optimum light intensity P0 of the tea tree g .

[0025] A preferred technical solution of the present application is that the equalization control voltage V * (t) is calculated according to the following formula:

[0026]

[0027] wherein w(t) is a power generation weight coefficient, λ is a temperature compensation coefficient, T(t) represents the actual temperature of the tea tree canopy, and T0 represents the photosynthetic optimum temperature of the tea tree canopy.

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

[0029]

[0030] When the shadow coverage rate η sh (t) ≤ 20%, the maximum value of the power generation weight coefficient w(t) is 0.9, when the shadow coverage rate η sh (t) ≥ 40%, the minimum value of the power generation weight coefficient w(t) is 0.3, and when 20% < η sh (t) < 40%, the power generation weight decreases by 0.02 for every 1% increase in shadow.

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

[0032]

[0033] wherein β(t) represents the target inclination of the photovoltaic array at time t, β e (t) represents the optimal inclination calculated when the power generation of the photovoltaic array is maximized, and Δβ represents the maximum compensation inclination, which is a temperature compensation function.

[0034] The optimal inclination angle β of the present application is preferably e The calculation formula of (t) is:

[0035]

[0036] Wherein, 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 complementation, comprising the following steps:

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

[0039] S2, according to the collected total solar radiation of photovoltaic array area, photovoltaic panel installation height, single photovoltaic panel area and solar altitude angle, the shadow distribution projected on the ground of the tea garden is calculated through a three-dimensional shadow model, and then the effective light intensity distribution and shadow coverage of the tea tree canopy are calculated according to the shadow distribution;

[0040] S3, according to the actual light intensity of the tea tree canopy, the actual temperature of the tea tree canopy and the shadow coverage, the maximum power generation voltage of the photovoltaic array and the optimal photosynthetically active radiation voltage are solved synchronously, and the corresponding balanced control voltage is outputted, and the power generation weight coefficient of the balanced control voltage is affected by the shadow coverage, and the corresponding power generation weight coefficient is adjusted according to the shadow coverage;

[0041] S4, according to the obtained balanced control voltage, the output voltage of the photovoltaic array is regulated, so that the photovoltaic array is in the maximum power generation voltage and the optimal photosynthetically active radiation voltage, and 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, so that the photovoltaic panel reaches the optimal inclination angle when the power generation is maximized.

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

[0043] According to the present application, 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, so that the photovoltaic panel reaches the optimal inclination angle when the power generation is maximized, thereby avoiding the problem of uneven shadow distribution in the tea garden caused by fixed inclination angle photovoltaic panels, and the uniformity of the shadow is improved by 56%, and according to the actual light intensity of the tea tree canopy, the actual temperature of the tea tree canopy and the shadow coverage, the maximum power generation voltage and the optimal photosynthetically active radiation voltage are coordinated, so that the tea tree is in the optimal photosynthetically active radiation voltage, the tea quality is improved by 18%, and the maximum power generation efficiency is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 The flowchart of the present application. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application. The present application will be further described below with reference to the embodiments.

[0046] Please refer to Figure 1 The embodiment of the present application provides a photovoltaic control system based on tea light complementation, comprising:

[0047] An environment perception module is configured to collect actual light intensity of a tea tree canopy, total solar radiation of a photovoltaic array region, and actual temperature of the tea tree canopy in real time.

[0048] A shadow calculation module is configured to calculate shadow distribution projected on the ground of a tea garden by a three-dimensional shadow model according to total solar radiation of the photovoltaic array region collected by the environment perception module, installation height of the photovoltaic panel, area of a single photovoltaic panel, and solar altitude angle, and calculate effective light intensity distribution and shadow coverage of the tea tree canopy according to the shadow distribution.

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

[0050]

[0051] The calculation formula of the shadow coverage η is as follows: sh

[0052]

[0053] Wherein, G e (r, t) represents shadow distribution, r represents coordinates of the ground of the tea garden, which is used to locate the position of the shadow space, t is a time variable representing the current time, G0(t) represents total solar radiation of the photovoltaic array region, A i represents projection area of the i-th photovoltaic panel, which is used to determine the size of the shadow, A f represents total area of the tea garden, N represents total number of photovoltaic panels in the photovoltaic array, h represents installation height of the photovoltaic array, which affects the length of the shadow, c i (r, t) represents distance from the coordinates to the photovoltaic panel, c i (r, t) is a distance attenuation factor, exp(·) is a natural exponential function, which is used to simulate the fuzzy transition effect of the shadow edge, so as to avoid the hard truncation of the shadow boundary, θ i represents the angle between the normal vector of the i-th photovoltaic panel and the sunlight, θ i is an angle attenuation factor, and θ​s θ is the solar altitude angle, and σ is the shadow edge blurring coefficient, usually taken as 15°, which controls the softness of the shadow edge. i Approaching θ s When the exponential term is close to exp(0) = 1, the shading is the darkest. i Deviation from θ s When the exponent term rapidly decays to 0, it indicates that the shadow is gradually disappearing;

[0054] This indicates that the total area A of the tea garden is... f Two-dimensional integral, The function is an indicator function; it outputs 1 if the condition is met, and 0 otherwise. γ is the shadow determination threshold coefficient; areas below the threshold coefficient are considered shadowed areas. P0 represents the optimal light intensity for tea tree photosynthesis. dr is the area differential element, representing 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 power generation voltage and the optimal voltage for photosynthetically effective radiation of the photovoltaic array 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 equalization control voltage.

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

[0057]

[0058] Solve for 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) is the output current of the photovoltaic array under voltage V, and V·I(V) represents the power generation. This means finding the voltage V that maximizes the power generation within a given voltage V. p S(V) represents the transmitted light intensity function of the photovoltaic array, describing the effect of voltage V on the transmitted light intensity. It represents the actual photosynthetically effective radiation intensity transmitted to the tea tree canopy when the photovoltaic array's operating voltage is V. It is directly related to the electrical control of the photovoltaic system and the photosynthetic requirements of the tea tree. S(V) = μ·G0(t)·τ(V), where μ represents the overall light energy transmission efficiency from the photovoltaic array to the tea tree canopy, and τ(V) represents the transmittance of the photovoltaic array under voltage V, describing the effect of voltage on the light transmission characteristics of the module. It is used to convert electrical control quantities into optical control quantities to achieve precise light intensity control. represents the voltage V found in the voltage V that makes the transmitted light intensity S(V) closest to the tea tree photosynthetic optimum light intensity P0 g ;

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

[0062]

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

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

[0065]

[0066] When the shadow coverage rate η sh (t) ≤20%, the maximum power generation weight coefficient w(t) is 0.9, when the shadow coverage rate η sh (t) ≥40%, the minimum power generation weight coefficient w(t) is 0.3, when the shadow coverage rate 20% < η sh (t) <40%, every 1% of shadow increase, the power generation weight reduction coefficient is 0.02.

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

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

[0069]

[0070] Wherein, β(t) represents the target inclination angle of the photovoltaic array at time t, by adjusting the inclination angle, the receiving efficiency of the photovoltaic panel to sunlight and the light distribution of the tea tree canopy are optimized, β e (t) represents the optimal inclination angle calculated when the photovoltaic array power is maximized, so that the photovoltaic panel is perpendicular to the sun, and the maximum light energy capture is achieved, Δβ represents the maximum compensation inclination angle, when the canopy temperature is too high, by increasing the inclination angle, the photovoltaic panel is reduced. Light shielding, enhance the ventilation and cooling of tea tree, It is a temperature compensation function, which adjusts the inclination compensation amount smoothly through S-shaped function, avoiding mutation;

[0071] Specifically, the calculation formula of the optimal inclination angle β e (t) is as follows:

[0072]

[0073] wherein, φ represents the geographical latitude of the tea garden, δ(t) represents the solar declination angle, arctan(·) is an inverse tangent function for converting the ratio in the parentheses into an angle value, and is used to correct the inclination angle of the photovoltaic panel so as to face the sun.

[0074] The embodiment provides a photovoltaic control method based on tea-light complementation, comprising the following steps:

[0075] S1, collecting the actual light intensity of the tea tree canopy, the total solar radiation of the photovoltaic array region and the actual temperature of the tea tree canopy in real time;

[0076] S2, calculating the shadow distribution projected by the photovoltaic array on the ground of the tea garden according to the total solar radiation of the photovoltaic array region and the installation height of the photovoltaic panel, the area of a single photovoltaic panel and the solar altitude angle through a three-dimensional shadow model, and then calculating the effective light intensity distribution and the shadow coverage rate of the tea tree canopy according to the shadow distribution;

[0077] S3, synchronously solving the maximum power generation voltage and the optimal photosynthetically active radiation voltage of the photovoltaic array according to the actual light intensity of the tea tree canopy, the actual temperature of the tea tree canopy and the shadow coverage rate, and then outputting the corresponding balanced control voltage, wherein the power generation weight coefficient of the balanced control voltage is influenced by the shadow coverage rate and is adjusted to the corresponding power generation weight coefficient according to the shadow coverage rate;

[0078] S4, regulating the output voltage of the photovoltaic array according to the balanced control voltage, so that the photovoltaic array is in the maximum power generation voltage and the optimal photosynthetically active radiation voltage, and then dynamically adjusting 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 is maximized.

[0079] The above description is illustrative of the present application and its implementation, and is not restrictive, and the embodiment shown in the drawings is only one of the embodiments of the present application, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired thereby, without departing from the purpose of the present application, similar structural modes and embodiments can be designed without creativity, which should all belong to the protection scope of the present application.

[0080] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains an independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A photovoltaic control system based on tea-photovoltaic complementarity, characterized in that, include: The environmental sensing module is 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 through a three-dimensional shadow model based on the total solar radiation of the photovoltaic array area, the installation height of the photovoltaic panels, the area of ​​a single photovoltaic panel, and the solar altitude angle collected by the environmental perception module. Then, based on the shadow distribution, the effective light intensity distribution and shadow coverage of the tea tree canopy are calculated. The multi-objective decision-making module is used to simultaneously solve the power generation voltage and the optimal voltage for photosynthetically effective radiation of the photovoltaic array 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 equalization control voltage. The execution control module is used to regulate the output voltage of the photovoltaic array based on the balanced control voltage of the multi-objective decision module, and to dynamically adjust the tilt angle of the photovoltaic panel according to the actual temperature of the tea tree canopy and the solar altitude angle. The calculation formula for the three-dimensional shadow model is as follows: The shadow coverage η sh The formula for calculating (t) is as follows: Among them, G e (r,t) represents the shadow distribution, r represents the ground coordinates of the tea garden, t is a time variable representing the current time, G0(t) represents the total solar radiation of the photovoltaic array area, and A i Let A represent the projected area of ​​the i-th photovoltaic panel. f N represents the total area of ​​the tea garden, h represents the total number of photovoltaic panels in the photovoltaic array, and c represents the installation height of the photovoltaic array. i (r,t) represents the distance from the photovoltaic panel, exp(·) is the natural exponential function, and θ i Let θ represent the angle between the normal vector of the i-th photovoltaic panel and the sunlight. s Where σ is the solar altitude angle, and σ is the shadow edge blur coefficient; This indicates that the total area A of the tea garden is... f Two-dimensional integral, is the indicator function, γ is the shadow determination threshold coefficient, P0 represents the optimal light intensity for tea tree photosynthesis, and dr is the area differential element.

2. A photovoltaic control system based on tea-photovoltaic complementarity according to claim 1, characterized in that, The multi-objective decision module solves for maximizing the power generation voltage V of the photovoltaic array. p The calculation formula is as follows: Solve for 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) is the output current of the photovoltaic array under voltage V, and V·I(V) represents the power generation. This means finding the voltage V that maximizes the power generation within a given voltage V. p S(V) represents the transmitted light intensity function of the photovoltaic array, S(V) = μ·G0(t)·τ(V), where μ represents the overall light energy transmission efficiency from the photovoltaic array to the tea tree canopy, and τ(V) represents the transmittance of the photovoltaic array under voltage V. This means finding the voltage V that makes the transmitted light intensity S(V) closest to the optimal light intensity P0 for photosynthesis in tea trees. g .

3. A photovoltaic control system based on tea-photovoltaic complementarity according to claim 2, characterized in that, The equalization control voltage V * The formula for calculating (t) is as follows: Where w(t) is the power generation weighting 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.

4. A photovoltaic control system based on tea-photovoltaic complementarity according to claim 3, characterized in that, The power generation weighting coefficient w(t) is affected by the shadow coverage η. sh The effect of (t) is expressed as follows: When the shadow coverage η sh When (t)≤20%, the power generation weighting coefficient w(t) is at its maximum of 0.9, and when the shadow coverage η sh When η(t) ≥ 40%, the power generation weighting coefficient w(t) is at its minimum of 0.

3. When the shadow coverage is 20% < η sh When (t) < 40%, for every 1% increase in shading, the power generation weight reduction factor is 0.

02.

5. A photovoltaic control system based on tea-photovoltaic complementarity according to claim 4, characterized in that, The formula for the photovoltaic panel tilt angle 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 to maximize the power generation of the photovoltaic array, and Δβ represents the maximum compensation tilt angle. This is the temperature compensation function.

6. A photovoltaic control system based on tea-photovoltaic complementarity according to claim 5, characterized in that, The optimal tilt angle β e The formula for calculating (t) is: Where φ represents the geographical latitude of the tea garden, δ(t) represents the solar declination angle, and arctan(·) is the arctangent function.

7. A control method for a photovoltaic control system based on tea-photovoltaic complementarity as described in claim 6, characterized in that, Includes the following steps: S1. Real-time acquisition of actual light intensity of tea tree canopy, total solar radiation in photovoltaic array area and actual temperature of tea tree canopy; S2. Based on the total solar radiation collected in the photovoltaic array area, as well as the installation height of the photovoltaic panels, the area of ​​a single photovoltaic panel, and the solar altitude angle, the shadow distribution of the photovoltaic array projected on the tea garden ground is calculated using a three-dimensional shadow model. Then, based on the shadow distribution, the effective light intensity distribution and shadow coverage of the tea tree canopy are calculated. S3. Based on the actual light intensity, actual temperature and shade coverage of the tea tree canopy, simultaneously solve the voltage for maximizing power generation of the photovoltaic array and the voltage for optimal photosynthetic radiation, and then output the corresponding equalization control voltage. Moreover, the power generation weight coefficient of the equalization control voltage is affected by the shade coverage and is adjusted to the corresponding power generation weight coefficient according to the shade coverage. S4. Based on the obtained equalization control voltage, adjust the output voltage of the photovoltaic array to make the photovoltaic array reach the voltage that maximizes power generation and the voltage that is optimal for photosynthetic effective radiation. Then, dynamically adjust the tilt angle of the photovoltaic panel according to the actual temperature of the tea tree canopy and the solar altitude angle to make the photovoltaic panel reach the optimal tilt angle when maximizing power generation.

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