An agricultural photovoltaic complementary system

Abstract

The present application relates to photovoltaic power generation technical field, specifically relates to a kind of agricultural light complementary system, including multiple photovoltaic panels and grid-connected power generation system with battery, multiple photovoltaic panels absorb solar energy to generate electric energy, and grid-connected power generation system exports electric energy in the form of direct current to battery or by inverter into national power grid, photovoltaic panel is equipped with battery management system between battery, the area that the photovoltaic panel is installed is marked as installation area, still includes efficiency evaluation module, output control module, covering analysis module.Output control module includes output prediction unit and output control unit, output prediction unit is according to the power generation efficiency of photovoltaic panel and the weather condition in future certain time range to predict the power generation efficiency of photovoltaic panel, and output control unit regulates the output target of photovoltaic panel power generation according to predicted power generation, controls whether electric quantity is output to battery or is incorporated into power grid, improves resource utilization efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic power generation, in particular to a kind of agricultural light complementary system. BACKGROUND

[0002] Agricultural light complementary system, referred to as "agricultural light complementary", is a system that applies solar photovoltaic power generation technology to agricultural production. It realizes not occupying ground space while providing necessary power for agricultural production by installing photovoltaic panels above farmland. At the same time, the construction of photovoltaic panels can also provide suitable growing environment for crops, edible fungi and livestock breeding, realize land three-dimensional value-added utilization, and has the advantages of improving land utilization, promoting the development of green agriculture and increasing farmers' income. At present, agricultural light complementary projects have achieved remarkable results in practical application, and provide strong support for promoting the development of green energy and agriculture.

[0003] In the application process of large single agricultural light complementary power station, the generated electric energy can be stored in the battery to provide necessary power for agricultural production, and can also be converted into alternating current by inverter and connected to the power grid, so as to realize diversified utilization, fully utilize the generated clean electric energy and meet the necessary power demand of agricultural production. However, the existing agricultural light complementary system is difficult to predict the power generation situation, and it is difficult to intelligently control the storage capacity of the battery according to the prediction result, which is not conducive to maintaining the service life of the battery, and is easy to cause energy waste and affect the efficiency of the agricultural light complementary system. SUMMARY

[0004] In view of the above-mentioned shortcomings of the prior art, the present application provides an agricultural light complementary system, which can effectively solve the problems of the prior art that the agricultural light complementary system is difficult to monitor and analyze the abnormality of power generation efficiency, intelligently control the electric quantity of the battery, and lead to poor efficiency of photovoltaic power generation system.

[0005] To achieve the above purpose, the present application realizes the following technical scheme:

[0006] The present application provides an agricultural light complementary system, at least comprising: a plurality of photovoltaic panels and a grid-connected power generation system with a battery, a battery management system is provided between the photovoltaic panels and the battery, the area where the photovoltaic panels are installed is recorded as the installation area, and the system further comprises an efficiency evaluation module, an output control module and a coverage analysis module:

[0007] The efficiency evaluation module periodically monitors and analyzes the power generation efficiency of all photovoltaic panels, selects one of them as a target photovoltaic panel for comparison, monitors the change of solar radiation intensity value received by the target photovoltaic panel, calculates the power generation efficiency of the target photovoltaic panel at the moment when the solar radiation intensity value is the highest, and analyzes and compares the power generation efficiency of all photovoltaic panels to determine whether there is an abnormality in the working state of all photovoltaic panels.

[0008] The output regulation module comprises an output prediction unit and an output control unit. The output prediction unit selects appropriate working conditions according to historical working conditions of the photovoltaic panel, analyzes and calculates the ideal output power of the photovoltaic panel in combination with the power generation efficiency of the photovoltaic panel, and the output control unit adjusts the output relationship between the photovoltaic panel and the battery according to the weather in a certain time range in the future and the ideal output power, and controls the power storage capacity of the battery.

[0009] The coverage analysis module dynamically monitors and analyzes the power generation efficiency of the photovoltaic panel, calculates the power abnormal value of the photovoltaic panel in combination with the use time of the photovoltaic panel, generates a surface coverage abnormal signal when the power abnormal value exceeds the preset range, and cleans the dust on the surface of the corresponding photovoltaic panel.

[0010] Further, the efficiency evaluation module specifically comprises the following steps in the comparative analysis process:

[0011] Step one: obtaining the effective area of each photovoltaic panel, obtaining the rated power of the photovoltaic panel, obtaining the sunrise time and sunset time of the installation area every day, and recording the time interval from sunrise to sunset as the monitoring time interval;

[0012] Step two: in the monitoring time interval, one of the photovoltaic panels is recorded as a target photovoltaic panel, the solar radiation intensity value on the surface of the target photovoltaic panel is obtained in real time, the current environmental temperature value is obtained in real time, the output current and output voltage of each photovoltaic panel are obtained in real time, and the product of the output current and output voltage is calculated as the output power;

[0013] Step three: extracting the maximum value of the solar radiation intensity value and the corresponding environmental temperature value T MAX in the latest complete monitoring time interval, recording the maximum value of the solar radiation intensity value as the radiation maximum value I MAX , extracting the maximum value of the output power of each photovoltaic panel in the latest complete monitoring time interval as the output maximum value P i OUT , and extracting the output power of the target photovoltaic panel at the time corresponding to the radiation maximum value as the target power P real , wherein i represents the serial number of each photovoltaic panel;

[0014] Step four: substituting the environmental temperature value T MAX , the radiation maximum value I MAX , and the rated power P STC of the photovoltaic panel into the formula to calculate the maximum theoretical power P MAX of the target photovoltaic panel, wherein: α is a preset temperature coefficient, representing the percentage of the relative change of the output power of the photovoltaic panel per degree Celsius; ISTC is the light intensity under standard test conditions; T STC is the panel temperature under standard test conditions, and the target power P of the target photovoltaic panel is real With the theoretical maximum power P MAX Substitute into formula XL BZ =P real / P MAX Calculate the standard maximum efficiency XL BZ ;

[0015] Step 5: Extract the maximum output value of the target photovoltaic panel and the corresponding recording time and compare it with the target power P real and the corresponding recording time. If the power values ​​are the same and the corresponding recording time is also consistent, then go to step 6. Otherwise, generate a recording abnormality signal and send it to the staff's handheld terminal;

[0016] Step 6: Use the formula Calculate the measured maximum efficiency XL of each photovoltaic panel i The measured maximum efficiency of the target photovoltaic panel is its standard maximum efficiency. The measured maximum efficiency XL of each photovoltaic panel is calculated. i With standard maximum efficiency XL BZ The difference is recorded as efficiency deviation, and an efficiency difference threshold is preset. The efficiency deviation of each photovoltaic panel is compared with the efficiency difference threshold. When its efficiency deviation and the efficiency difference threshold are less than or equal to the efficiency difference threshold, a stable output signal is generated. When its efficiency deviation and the efficiency difference threshold are greater than the efficiency difference threshold, a stable abnormal signal is generated and the photovoltaic panel status is marked as abnormal. At the same time, the serial numbers of all abnormal photovoltaic panels are sent to the staff's handheld terminal.

[0017] Furthermore, the absolute value of the efficiency deviation of each photovoltaic panel is obtained, and the photovoltaic panel whose absolute value of efficiency deviation is greater than the efficiency difference threshold is recorded as a problem photovoltaic panel, and the measured maximum efficiency XL of the problem photovoltaic panel is recorded as i minus standard Max Efficiency XL BZ If the result is greater than 0, the photovoltaic panel with the problem is recorded as an abnormal photovoltaic panel, and the number of abnormal photovoltaic panels is counted. When the number of abnormal photovoltaic panels is greater than or equal to the preset number threshold, an abnormal signal of the target photovoltaic panel is generated, and the average of the measured maximum efficiency of all abnormal photovoltaic panels is calculated as the standard maximum efficiency, and step six is ​​repeated.

[0018] Furthermore, the output prediction unit obtains the measured maximum efficiency and efficiency deviation of each photovoltaic panel obtained from the most recent monitoring. When the efficiency deviations of all photovoltaic panels are less than or equal to the efficiency difference threshold, the minimum value of all measured maximum efficiencies is extracted and recorded as the efficiency prediction value XL. min, the minimum value of the annual direct solar radiation intensity of the installation area is obtained and recorded as a radiation standard value, a curve of the solar radiation intensity value over time in each monitoring time interval is drawn and recorded as a radiation intensity change graph, the radiation intensity change graph in the last month is extracted and processed;

[0019] In the radiation intensity change graph, a straight line represented by the radiation standard value is drawn, when the straight line intersects with the radiation intensity change curve in the radiation intensity change graph, the projection length of the part of the radiation intensity change curve above the straight line on the time axis is calculated and recorded as an effective duration, the effective duration is divided by the total duration of the corresponding monitoring time interval to obtain an effective proportion, an effective proportion threshold is set, when the effective proportion value is greater than or equal to the effective proportion threshold, the corresponding radiation intensity change graph is recorded as an ideal intensity change graph;

[0020] The mean value of the solar radiation intensity value in the ideal intensity change graph is calculated and recorded as an ideal intensity value I HP , the average temperature T HP of the day is obtained, and the formula is substituted to obtain the ideal output power OP MAX .

[0021] Further, the output control unit obtains the ideal output power OP MAX , sets a future time interval, and the duration T of the future time interval is calculated according to the formula , wherein represents the maximum integer not greater than , W all and W e represent the total power of the battery and the daily average power consumption of the electrical equipment, respectively, the weather of each day in the future time interval of the installation area is obtained, the weather is classified into two types, sunny and non-sunny, according to the weather, and a suitable storage ratio is preset.

[0022] When all days in the future time interval are sunny, the storage capacity of the battery is adjusted to the total storage capacity multiplied by the suitable storage ratio.

[0023] When there are some sunny days in the future time interval, the time difference between the last sunny day and the current day is calculated and recorded as T', the battery is charged and the charging duration is controlled, and the charging duration is calculated according to the formula , wherein W NOW and W' represent the current storage capacity and the storage capacity under the suitable storage ratio, respectively, and the charging continues until the battery is fully charged or the charging duration ends.

[0024] When there are no sunny days in the future time interval, the battery is controlled to be fully charged.

[0025] Further, the coverage analysis module analyzes the process as follows:

[0026] The measured maximum efficiency recorded for the first time after the installation of each photovoltaic panel is denoted as initial efficiency XL i Z The measured maximum efficiency of each photovoltaic panel monitored most recently is denoted as current efficiency XL i N The time interval from the installation completion time to the current time is calculated and denoted as working time t, and the formula UX = XL i Z *(1-t*k)-XL i N is calculated, where k is a preset time length influence coefficient, to obtain the power abnormal value UX, and there is a preset power abnormal threshold value; when the power abnormal value is greater than or equal to the power abnormal threshold value, a surface coverage abnormal signal is generated, the surface of the photovoltaic panel is cleaned and dusted, and the power abnormal value is recalculated and denoted as UX'; if the power abnormal value is still greater than or equal to the power abnormal threshold value, a corresponding photovoltaic panel abnormal signal is generated.

[0027] Compared with the known prior art, the technical scheme provided by the present application has the following beneficial effects:

[0028] 1. The efficiency evaluation module of the present application takes the target photovoltaic panel as the power generation efficiency standard, and determines the error degree between the power generation efficiency of all photovoltaic panels and the standard reference through the comparison process. The maximum power generation efficiency of the photovoltaic panels installed at the same time in the same working environment should be consistent, and even if there is an error, it should be within the set error range, otherwise it can be judged that the photovoltaic panel has a functional failure, so as to quickly distinguish the photovoltaic panel with abnormal power generation efficiency, facilitate targeted maintenance by the staff, and help to ensure the power generation efficiency.

[0029] 2. The present application dynamically analyzes the daily solar radiation intensity change value in the last month, selects the daily sunshine duration under good lighting conditions, and then analyzes the ideal output power that can be achieved at the current time, so as to predict the power generation efficiency of the photovoltaic panel in the future. In addition, according to different weather conditions in the future, the power flow direction of the photovoltaic panel is controlled to charge the battery, and the charging time and charging capacity are intelligently adjusted, so that the battery capacity is in an appropriate capacity range during daily use, thereby prolonging the service life of the battery as much as possible, and at the same time, the battery can supply power to the facility when the photovoltaic panel cannot generate electricity, fully utilize the generated electricity, and reasonably plan the battery capacity storage. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings in the following description only show some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0031] Figure 1 The overall module block diagram of the present application. DETAILED DESCRIPTION

[0032] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0033] The present application will be further described below in conjunction with the embodiments.

[0034] Reference Figure 1 A solar-light complementary system, at least comprising: a plurality of photovoltaic panels and a grid-connected power generation system with a battery, the plurality of photovoltaic panels absorb solar energy to generate electric energy, and the grid-connected power generation system outputs the electric energy in the form of direct current to the battery or is connected to the national power grid through an inverter, a battery management system (BMS) is arranged between the photovoltaic panels and the battery to adjust the charging current and voltage stability, an installation area of the photovoltaic panels is recorded, and the system further comprises an efficiency evaluation module, an output control module and a coverage analysis module.

[0035] The efficiency evaluation module monitors the power generation efficiency of all photovoltaic panels, selects one of them as a target photovoltaic panel for comparison, and analyzes whether the working state of all photovoltaic panels is abnormal according to the power generation efficiency of the target photovoltaic panel.

[0036] The comparative analysis process is specifically as follows: step one: obtaining the effective area of each photovoltaic panel (the effective area refers to the solar panel surface area on the photovoltaic panel that can convert solar energy into electric energy, excluding the fixed frame outside the solar panel), obtaining the rated power of the photovoltaic panel (the rated power refers to the unit area photovoltaic panel under standard test conditions, that is, STC: 1000W / m 2The solar radiation intensity, ambient temperature of 25°C and power generation under the spectral distribution of AM1.5 are calculated. The sunrise and sunset times of each day in the installation area are obtained (they can be obtained through the meteorological data of the local meteorological station). The time interval from sunrise to sunset is recorded as the monitoring time interval. By using the current monitoring time interval, invalid data can be monitored and the monitoring efficiency can be improved.

[0037] Step 2: During the monitoring time interval, obtain the solar radiation intensity value of one of the photovoltaic panels in real time at the angle opposite to the target photovoltaic panel and record the photovoltaic panel as the target photovoltaic panel (the solar radiation intensity value can be directly measured by a solar radiation measuring instrument in the prior art. The measuring instrument can be installed on the target photovoltaic panel to measure the solar radiation intensity value at the angle opposite to the target photovoltaic panel). Obtain the current ambient temperature value in real time, obtain the output current and output voltage of each photovoltaic panel in real time, and calculate the product of the output current and output voltage as the output power;

[0038] Step 3: Extract the maximum solar radiation intensity value within the most recent complete monitoring time interval and the ambient temperature value T at the corresponding moment MAX , the maximum solar radiation intensity value is recorded as the maximum radiation value I MAX , extract the maximum output power of each photovoltaic panel within the most recent complete monitoring time interval and record it as the output maximum value P i OUT , extract the output power of the target photovoltaic panel at the moment of the maximum radiation value and record it as the target power P real , where i represents the serial number of each photovoltaic panel;

[0039] It should be noted that the photovoltaic panels in a single agricultural-photovoltaic complementary power station are generally installed in a centralized manner. That is to say, the hardware data parameters of the photovoltaic panels are kept consistent, and the installation locations of multiple photovoltaic panels are all in the same solar exposure area. Therefore, if not affected by external factors, the maximum value of the solar radiation intensity value corresponding to a single photovoltaic panel can be used as the maximum value of the solar radiation intensity value absorbed by each photovoltaic panel. In addition, if not affected by other factors in the same area, the ambient temperature of each photovoltaic panel can also be considered to be the same.

[0040] Step 4: Set the ambient temperature value T MAX , Radiation Maximum I MAX , Rated power P of photovoltaic panels STC Substitute into the formula Calculate the maximum theoretical power P of the target photovoltaic panel MAX , where: α is the preset temperature coefficient, which represents the percentage of relative change in photovoltaic panel output power per degree Celsius change (% / ℃), generally provided by the manufacturer; I STCis the light intensity under standard test conditions (W / m 2 );T STC is the panel temperature under standard test conditions, usually 25°C, and the target power P of the target photovoltaic panel real With the theoretical maximum power P MAX Substitute into formula XL BZ =P real / P MAX Calculate the standard maximum efficiency XL BZ ;

[0041] Step 5: Extract the maximum output value of the target photovoltaic panel and the corresponding recording time and compare it with the target power P real and the corresponding recording time. If the power values ​​are the same and the corresponding recording times are also consistent, then go to step 6. Otherwise, generate a recording abnormality signal and send it to the staff's handheld terminal, and the staff will check the target photovoltaic panel and its corresponding time.

[0042] It should be noted that under normal circumstances, the moment when the photovoltaic panel generates the highest power should correspond to the moment when the intensity of solar radiation it receives is the highest, because when the intensity of solar radiation is the highest, the more solar energy it absorbs, and accordingly, the higher the output power.

[0043] Step 6: Use the formula Calculate the measured maximum efficiency XL of each photovoltaic panel i The measured maximum efficiency of the target photovoltaic panel is its standard maximum efficiency. The measured maximum efficiency XL of each photovoltaic panel is calculated. i With standard maximum efficiency XL BZ The difference is recorded as efficiency deviation, and an efficiency difference threshold is preset. The efficiency deviation of each photovoltaic panel is compared with the efficiency difference threshold. When its efficiency deviation and the efficiency difference threshold are less than or equal to the efficiency difference threshold, a stable output signal is generated. When its efficiency deviation and the efficiency difference threshold are greater than the efficiency difference threshold, a stable abnormal signal is generated and the photovoltaic panel status is marked as abnormal. At the same time, the serial numbers of all abnormal photovoltaic panels are sent to the staff's handheld terminal.

[0044] The target photovoltaic panel is used as the power generation efficiency standard, and the degree of error between the power generation efficiency of all photovoltaic panels and the standard reference is determined through a comparison process. This is because the maximum power generation efficiency of photovoltaic panels installed at the same time should be consistent under the same working environment. Even if there is an error, it should be within the set error range. Otherwise, it can be determined that the photovoltaic panel has a functional failure, thereby quickly distinguishing photovoltaic panels with abnormal power generation efficiency, making it convenient for staff to carry out targeted inspection and maintenance, which is conducive to ensuring power generation efficiency.

[0045] Further, the absolute value of the efficiency deviation of each photovoltaic panel is obtained, and the photovoltaic panel with an efficiency deviation absolute value greater than the efficiency difference threshold is recorded as a problem photovoltaic panel. The measured maximum efficiency XL i of the problem photovoltaic panel is subtracted from the standard maximum efficiency XL BZ . If the result is greater than 0, the problem photovoltaic panel is recorded as an abnormal photovoltaic panel. The number of abnormal photovoltaic panels is counted. When the number of abnormal photovoltaic panels is greater than or equal to a preset number threshold (in a specific embodiment, the number threshold is equal to 5% of the total number of photovoltaic panels), a target photovoltaic panel abnormality signal is generated, and the target photovoltaic panel is maintained by a worker. The average of the measured maximum efficiencies of all abnormal photovoltaic panels is calculated as the standard maximum efficiency, and step 6 is performed again.

[0046] The output control module includes an output prediction unit and an output control unit. The output prediction unit selects appropriate working conditions according to historical working conditions of the photovoltaic panel to analyze and calculate the ideal output power of the photovoltaic panel. The output control unit adjusts the output relationship between the photovoltaic panel and the battery according to the weather in a certain future time range and the ideal output power to control the storage capacity of the battery.

[0047] The output prediction unit obtains the measured maximum efficiency and the efficiency deviation of each photovoltaic panel obtained in the last monitoring. When the efficiency deviation of all photovoltaic panels is less than or equal to the efficiency difference threshold, the minimum value of all measured maximum efficiencies is extracted as the efficiency prediction value XL min . The minimum value of the annual direct solar radiation intensity of the installation area (that is, the minimum value of the radiation intensity under the direct sunlight in the target area within the annual range, which means the minimum intensity of the radiation in the sunlight) is obtained as the radiation standard value. The curve of the solar radiation intensity value changing with time in each monitoring time interval is drawn as the radiation intensity change graph. The radiation intensity change graph in the last month is extracted and processed. The processing process is as follows:

[0048] A straight line represented by the radiation standard value is drawn in the radiation intensity change graph. When the straight line intersects with the radiation intensity change curve in the radiation intensity change graph, the projection length of the part of the radiation intensity change curve above the straight line on the time axis is calculated as the effective time length. The effective time length is divided by the total time length of the corresponding monitoring time interval to obtain the effective proportion. An effective proportion threshold is set. When the effective proportion value is greater than or equal to the effective proportion threshold, the corresponding radiation intensity change graph is recorded as an ideal intensity change graph. The ideal intensity change graph closest to the current date is selected for further analysis.

[0049] The average value of the solar radiation intensity value in the ideal intensity change graph is calculated as the ideal intensity value I HP . The average temperature T HP, substitute into the formula Calculate the ideal output power OP MAX .

[0050] By dynamically analyzing the daily solar radiation intensity change value in the last month, the daily sunshine duration under good light conditions is screened out, and the daily sunshine duration under sufficient sunshine is screened out according to the length of the sunshine duration, and then the ideal output power that can be achieved at present is analyzed, in order to predict the power generation efficiency of the photovoltaic power generation panel.

[0051] The output control unit obtains the ideal output power OP MAX , sets a future time interval, and the length T of the future time interval is calculated as Where represents the maximum integer not greater than , W all , W e respectively represent the total power of the battery and the daily power consumption of the electrical equipment (including all DC electrical equipment in the installation area), obtain the weather condition of each day in the future time interval of the installation area (obtained through the weather forecast of the local weather station), according to the weather condition, the weather is divided into two types of sunny and non-sunny, and a suitable storage ratio is preset;

[0052] When all the future time interval is sunny, the storage capacity of the battery is adjusted to the total storage capacity multiplied by the suitable storage ratio, and the power of the battery is adjusted by controlling the charging and discharging to be in a suitable ratio, so as to prolong the service life of the battery as much as possible and ensure the storage effect of the battery;

[0053] When there is part of the sunny day in the future time interval, calculate the time difference between the last sunny day and the current day as T' (in days), charge the battery and control the charging time, and the charging time is calculated as Where W NOW , W' respectively represent the current storage capacity and the storage capacity under the suitable storage ratio state, and the charging continues until the battery is full or the charging time is over.

[0054] When there is no sunny day in the future time interval, control the battery power to be full.

[0055] According to the different weather conditions in the future, control the power flow direction of the photovoltaic power generation panel to charge the battery, and intelligently adjust the charging time and charging capacity, so that the power of the battery is in a suitable power range during daily use, and the service life of the battery is prolonged as much as possible, and at the same time, the battery can supply power to the facilities when the photovoltaic power generation panel cannot generate power, fully utilize the generated power, and reasonably plan the power storage of the battery.

[0056] The coverage analysis module analyzes the abnormal situation of the photovoltaic panel, generates a corresponding abnormal data signal, and reminds the worker to clean the dust on the surface of the photovoltaic panel in time, thereby helping to improve the power generation efficiency of the photovoltaic panel.

[0057] The coverage analysis module analysis process is as follows:

[0058] Record the measured maximum efficiency of each photovoltaic panel for the first time after installation as initial efficiency XL i Z Record the measured maximum efficiency of each photovoltaic panel for the first time after installation as initial efficiency XL i N Calculate the time interval from the installation completion time to the current time as the working time t, and substitute it into the formula UX=XL i Z *(1-t*k)-XL i N Calculate the power abnormal value UX, wherein k is a preset time length influence coefficient, and the power abnormal threshold is preset. In a specific embodiment, the power abnormal threshold is 10%, a surface coverage abnormal signal is generated when the power abnormal value is greater than or equal to the power abnormal threshold, the surface of the photovoltaic panel is cleaned (cleaning can be done by a worker holding a cleaning device, or by a mechanical device), and the power abnormal value is recalculated as UX'. If the power abnormal value is still greater than or equal to the power abnormal threshold, a corresponding photovoltaic panel abnormal signal is generated, and the corresponding photovoltaic panel is maintained by the worker.

[0059] It should be noted that when the power of the photovoltaic panel abnormally decreases, that is, it decreases due to reasons other than aging, it is generally caused by dust coverage, and the coverage of dust usually causes the power of the photovoltaic panel to decrease by more than 10%. Therefore, by analyzing the power decrease of the photovoltaic panel, the worker can timely discover that the photovoltaic panel is covered with dust, clean it in time, and the efficiency is higher than that of regular cleaning. After excluding the dust coverage reason, an abnormal signal of the corresponding photovoltaic panel can be generated, the worker can timely troubleshoot the photovoltaic panel with functional abnormalities, and the efficiency of the photovoltaic panel is further optimized and improved.

[0060] The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some technical features; and these modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present application.

Claims

1. An agricultural-photovoltaic complementary system, comprising a plurality of photovoltaic panels and a grid-connected power generation system with a battery. The photovoltaic panels are centrally installed in a single agricultural-photovoltaic complementary power station. A battery management system is provided between the photovoltaic panels and the battery. The system is characterized in that: The area where photovoltaic panels are installed is recorded as the installation area, and also includes efficiency evaluation module, output control module, and coverage analysis module: The efficiency evaluation module periodically monitors and analyzes the power generation efficiency of all photovoltaic panels, selects one as a target photovoltaic panel for comparison, monitors the changes in the solar radiation intensity received by the target photovoltaic panel, calculates the power generation efficiency of the target photovoltaic panel at the moment of the highest solar radiation intensity, and analyzes and compares the power generation efficiency of all photovoltaic panels to determine whether there is any abnormality in the working status of all photovoltaic panels; The output control module includes an output prediction unit and an output control unit. The output prediction unit selects the appropriate operating conditions based on the historical operating conditions of the photovoltaic panels, analyzes and calculates the ideal output power based on the power generation efficiency of the photovoltaic panels, and adjusts the output relationship between the photovoltaic panels and the battery according to the weather conditions within a certain time range in the future and the ideal output power, thereby controlling the battery's storage capacity. The output prediction unit obtains the measured maximum efficiency and efficiency deviation of each photovoltaic power generation panel obtained from the most recent monitoring. When the efficiency deviations of all photovoltaic power generation panels are less than or equal to the efficiency difference threshold, the minimum value of all measured maximum efficiencies is extracted and recorded as the efficiency prediction value. , obtain the lowest value of direct solar radiation intensity in the installation area throughout the year and record it as the radiation standard value, draw a curve of solar radiation intensity value changing with time in each monitoring time interval and record it as radiation intensity change graph, extract the radiation intensity change graph in the most recent month and perform screening processing; Draw a straight line representing the radiation standard value in the radiation intensity change graph. When the straight line intersects the radiation intensity change curve in the radiation intensity change graph, calculate the projection length of the portion of the radiation intensity change curve above the straight line on the time axis and record it as the effective duration. Calculate the effective duration and divide it by the total duration of the corresponding monitoring duration interval to obtain the effective ratio. Set an effective ratio threshold. When the effective ratio value is greater than or equal to the effective ratio threshold, record the corresponding radiation intensity change graph as the ideal intensity change graph. Calculate the mean of the solar radiation intensity values ​​in the ideal intensity variation diagram and record it as the ideal intensity value. , get the average temperature of the day , substitute into the formula Calculate in and get the ideal output power ,in: It is the preset temperature coefficient, which indicates the percentage of relative change in the photovoltaic panel output power per degree Celsius change; is the light intensity under standard test conditions; is the panel temperature under standard test conditions, is the rated power of the photovoltaic panel; The output control unit obtains the ideal output power , set a future duration interval, the calculation formula for the duration T of the future duration interval is ,in Indicates that it is not greater than The largest integer, Represent the total battery capacity and the average daily power consumption of the power facilities respectively. Obtain the weather conditions of each day in the future time interval of the installation area. According to the weather conditions, the weather is divided into two types: sunny and cloudy. An appropriate storage ratio is preset. When the future time interval is entirely sunny, the battery capacity is adjusted to the total capacity multiplied by the appropriate storage ratio; When there are some sunny days in the future time interval, calculate the time difference between the last sunny day and the current day and record it as , charge the battery and control the charging time. The charging time calculation formula is: ,in Respectively indicate the current storage capacity and the storage capacity at the appropriate storage ratio. Charging continues until the battery is fully charged or the charging time ends. When there is no sunny day in the future time interval, the control will fully charge the battery; The coverage analysis module dynamically monitors and analyzes the power generation efficiency of photovoltaic panels, calculates the power abnormality value based on the usage time of the photovoltaic panels, generates a surface coverage abnormality signal when the power abnormality value exceeds the preset range, and cleans the dust on the surface of the corresponding photovoltaic panels.

2. The agricultural-photovoltaic complementary system according to claim 1, characterized in that: The comparative analysis process of the efficiency evaluation module is as follows: Step 1: Obtain the effective area of ​​each photovoltaic panel, obtain the rated power of the photovoltaic panel, obtain the daily sunrise and sunset times in the installation area, and record the time interval from sunrise to sunset as the monitoring duration interval; Step 2: During the monitoring time interval, one of the photovoltaic panels is designated as the target photovoltaic panel. The solar radiation intensity value on the surface of the target photovoltaic panel is obtained in real time, the current ambient temperature value is obtained in real time, and the output current and output voltage of each photovoltaic panel are obtained in real time. The product of the output current and the output voltage is calculated and recorded as the output power. Step 3: Extract the maximum solar radiation intensity value within the most recent complete monitoring time interval and the ambient temperature value at the corresponding moment , the maximum solar radiation intensity value is recorded as the maximum radiation value , extract the maximum output power of each photovoltaic panel within the most recent complete monitoring time interval and record it as the output maximum value , extract the output power of the target photovoltaic panel at the moment of the maximum radiation value and record it as the target power , where i represents the serial number of each photovoltaic panel; Step 4: Set the ambient temperature value , radiation maximum , Rated power of photovoltaic panels Substitute into the formula Calculate the maximum theoretical power of the target photovoltaic panel , the target power of the target photovoltaic panel Theoretical maximum power Substitute into the formula Calculate the standard maximum efficiency ; Step 5: Extract the maximum output value of the target photovoltaic panel and the corresponding recording time and compare it with the target power and the corresponding recording time. If the power values ​​are the same and the corresponding recording time is also consistent, then go to step 6. Otherwise, generate a recording abnormality signal and send it to the staff's handheld terminal; Step 6: Use the formula Calculate the measured maximum efficiency of each photovoltaic panel The measured maximum efficiency of the target photovoltaic panel is its standard maximum efficiency. The measured maximum efficiency of each photovoltaic panel is calculated. Maximum efficiency with standard The difference is recorded as efficiency deviation, and an efficiency difference threshold is preset. The efficiency deviation of each photovoltaic panel is compared with the efficiency difference threshold. When its efficiency deviation and the efficiency difference threshold are less than or equal to the efficiency difference threshold, a stable output signal is generated. When its efficiency deviation and the efficiency difference threshold are greater than the efficiency difference threshold, a stable abnormal signal is generated and the photovoltaic panel status is marked as abnormal. At the same time, the serial numbers of all abnormal photovoltaic panels are sent to the staff's handheld terminal.

3. The agricultural-photovoltaic complementary system according to claim 2, characterized in that: Obtain the absolute value of the efficiency deviation of each photovoltaic panel, record the photovoltaic panel whose efficiency deviation absolute value is greater than the efficiency difference threshold as a problem photovoltaic panel, and set the measured maximum efficiency of the problem photovoltaic panel as Subtract standard maximum efficiency If the result is greater than 0, the problematic photovoltaic panel is recorded as an abnormal photovoltaic panel, and the number of abnormal photovoltaic panels is counted. When the number of abnormal photovoltaic panels is greater than or equal to the preset number threshold, an abnormal signal of the target photovoltaic panel is generated. At the same time, the average of the measured maximum efficiency of all abnormal photovoltaic panels is calculated as the standard maximum efficiency, and step 6 is repeated.

4. The agricultural-photovoltaic complementary system according to claim 2, characterized in that: The analysis process of the coverage analysis module is as follows: The maximum efficiency of each photovoltaic panel after installation is obtained and recorded as the initial efficiency , obtain the most recently monitored maximum efficiency of each photovoltaic panel and record it as the current efficiency Calculate the time interval between the current time and the installation completion time as the working time t, and substitute it into the formula Calculate in , where k is the preset duration influence coefficient, and get the power abnormal value , preset power abnormality threshold, when the power abnormality value is greater than or equal to the power abnormality threshold, generate surface coverage abnormality signal, clean the surface of the photovoltaic panel and remove dust, and recalculate the power abnormality value and record it as ,If the power abnormal value is still greater than or equal to the power abnormal threshold, the corresponding photovoltaic panel abnormal signal is generated.

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