Photovoltaic salt-light complementary power generation system and power generation control method

Abstract

The invention relates to the technical field of photovoltaic power generation and salt pan resource comprehensive utilization, in particular to a photovoltaic salt light complementary power generation system and a power generation control method, the system comprises a photovoltaic power generation subsystem, the photovoltaic power generation subsystem uses a double-sided double-glass assembly array to convert light energy into electric energy, and power output and grid-connected power supply are realized; the salt pan operation subsystem is used for refining salt and collecting refined crystal salt; the monitoring subsystem is used for collecting operation environment data and electric data of the photovoltaic salt-light complementary power generation system; and the intelligent control subsystem dynamically optimizes the photovoltaic dip angle, the photovoltaic height and the salt pan ventilation according to the operation environment data, and performs energy storage scheduling according to the power data. The problems that power generation and salt manufacturing are difficult to dynamically balance due to light-salt production space-time conflicts, energy storage collaboration is insufficient, and complex power utilization requirements are difficult to adapt are solved, and the comprehensive benefits and stability of the salt-light complementary system are improved.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power generation and comprehensive utilization of salt field resources, and in particular to a photovoltaic-salt-photovoltaic complementary power generation system and power generation control method. Background Technology

[0002] The photovoltaic industry urgently needs to explore "photovoltaic+" composite application models to improve the efficiency of comprehensive land use. The salt-photovoltaic complementary system, by integrating salt field production with photovoltaic power generation, has become an important path for the intensive development of coastal tidal flat resources. This model makes full use of the vast area of ​​salt fields, laying photovoltaic modules above the salt fields for power generation while continuing salt production below, achieving three-dimensional utilization of land resources and providing a new approach to the coordinated development of energy and the salt industry.

[0003] However, existing photovoltaic-salt-photovoltaic complementary technologies still face many unresolved issues. Regarding energy efficiency, traditional photovoltaic-salt-photovoltaic complementary systems mostly use single-sided photovoltaic modules, which can only generate electricity from direct sunlight, resulting in low photovoltaic power generation efficiency. Simultaneously, during salt field operations, brine evaporation and crystallization largely depend on natural conditions, lacking effective environmental control measures, which hinders salt production. In terms of intelligent control, existing systems lack comprehensive monitoring and intelligent regulation mechanisms, making it difficult to achieve optimal synergy between photovoltaic power generation and salt field operations, thus limiting the improvement of overall system efficiency. Therefore, developing a high-efficiency, intelligent, and highly synergistic photovoltaic-salt-photovoltaic complementary power generation system is of significant practical importance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a photovoltaic-salt-photovoltaic complementary power generation system and a power generation control method.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a photovoltaic-salt-photovoltaic complementary power generation system. The system includes: a photovoltaic power generation system that utilizes a double-sided double-glass module array to convert direct sunlight and reflected light from salt field brine into electrical energy, thereby achieving power output and grid connection; a salt field operation subsystem that extracts salt through a controlled evaporation crystallization process and collects the extracted crystallized salt; a monitoring subsystem that collects real-time operating environment data and electrical data of the photovoltaic-salt-photovoltaic complementary power generation system; and an intelligent control subsystem that dynamically optimizes the photovoltaic tilt angle, photovoltaic height, and salt field ventilation based on the operating environment data, and performs energy storage scheduling based on the electrical data. This invention solves the problems of difficulty in dynamically balancing power generation and salt production caused by the spatiotemporal conflict in photovoltaic-salt production, and the inability of sufficient energy storage coordination to adapt to complex electricity demands, thereby improving the overall efficiency and stability of the salt-photovoltaic complementary system.

[0006] Optionally, the photovoltaic power generation system includes: A double-sided double-glass module array, which is used to convert direct light and reflected light from salt field brine into electrical energy, and the double-sided double-glass module array includes multiple monocrystalline silicon double-sided double-glass modules; A support structure is provided for supporting a monocrystalline silicon bifacial double-glass module and for adjusting the photovoltaic tilt angle and the photovoltaic height. The support structure is a photovoltaic bracket. Power conversion and transmission equipment, which is used to realize power output and grid-connected power supply, includes string inverters, switch cabinets, transformer substations, step-up substations, cables and connectors; An energy storage device for storing electrical energy from a photovoltaic-salt-photovoltaic complementary power generation system, the energy storage device comprising a lithium battery and a supercapacitor.

[0007] This system uses a double-sided, double-glass module array to generate electricity not only from direct sunlight but also from reflected light from salt field brine, thus improving power generation efficiency. Furthermore, this invention utilizes an adjustable photovoltaic tilt and height support structure, which, by adjusting the photovoltaic tilt and height, facilitates optimal synergy between photovoltaic power generation and salt field operations.

[0008] Optionally, the salt field operation subsystem includes: Salt field infrastructure, which includes evaporation ponds and crystallization ponds; An environmental control device, which is used to accelerate the surface evaporation of brine, is an EC fan array. Salt production equipment, which is used to collect crystallized salt and maintain the circulation of brine, includes a salt collector and a brine circulation pump.

[0009] This system uses an EC fan array to enhance ventilation efficiency in salt fields, accelerate moisture evaporation, and shorten the crystallization cycle.

[0010] Optionally, the operating environment data includes air temperature, brine temperature, air vapor pressure, brine saturated vapor pressure, relative humidity, wind speed, light intensity, and salt field reflected light intensity. The monitoring subsystem includes: An environmental monitoring module is used to collect operating environment data, and the environmental monitoring module includes various sensors for collecting the operating environment data. The electrical data monitoring module is used to monitor the power generation and power consumption of the photovoltaic-salt-photovoltaic complementary power generation system, as well as the state charge value of the power storage device.

[0011] Optionally, the intelligent control subsystem includes: The central controller is used to run the salt-photovoltaic synergy algorithm, and then dynamically optimize the photovoltaic tilt angle, photovoltaic height and salt field ventilation according to the operating environment data, obtain the energy storage scheduling scheme according to the electrical data, and finally generate control commands. A control execution module is used to execute the control instructions, so that the salt field operation subsystem extracts salt through a controlled evaporation crystallization process and collects the extracted crystallized salt. The human-machine interaction module is used to display the monitoring data of the monitoring subsystem and adjust the control commands.

[0012] Optionally, the operation flow of the salt-light collaborative algorithm is as follows: The critical ratio for fan start-up and shutdown is calculated using the air temperature, brine temperature, air vapor pressure, and brine saturated vapor pressure. The initial value of the fan speed is obtained by initializing the fan control strategy based on the fan start / stop critical ratio, the relative humidity of the air, and the wind speed. The initial values ​​of the photovoltaic tilt angle, photovoltaic height, and wind turbine speed of the bifacial double-glass module array are updated to maximize the overall photovoltaic-salt efficiency and obtain the optimal photovoltaic tilt angle, photovoltaic height, and wind turbine speed.

[0013] Optionally, the step of initializing the fan control strategy based on the fan start-stop critical ratio, the relative humidity of the air, and the wind speed to obtain the initial value of the fan speed includes the following steps: Set the fan start / stop critical ratio threshold, air relative humidity threshold, and wind speed threshold, and then determine the fan start / stop status based on the fan start / stop critical ratio, air relative humidity, and wind speed; When the fan is in the on state, the initial value of the fan speed is set using the wind speed and the wind speed threshold.

[0014] This system sets thresholds for the fan start / stop critical ratio, relative humidity, and wind speed. Based on these thresholds, along with the fan start / stop critical ratio, relative humidity, and wind speed, it determines the fan's start / stop status. This prevents the fan from operating under unsuitable conditions, thus avoiding energy waste or adverse effects on the salt field environment. When the fan is in the on state, the system uses wind speed and wind speed thresholds to set the initial value of the fan wind speed. This setting method makes the fan wind speed more consistent with the actual evaporation needs of the salt field, which helps improve the evaporation efficiency of the brine and also lays the foundation for further optimization of the control strategy.

[0015] Optionally, updating the initial values ​​of the photovoltaic tilt angle, photovoltaic height, and wind turbine speed of the bifacial double-glass module array to maximize the overall photovoltaic-salt efficiency and obtain the optimal photovoltaic tilt angle, photovoltaic height, and wind turbine speed includes the following steps: Use the current photovoltaic tilt angle and photovoltaic height of the bifacial double-glass module array as their initial values; When the wind turbine is turned on, the gradient descent method is used to update the photovoltaic tilt angle, the photovoltaic height, and the wind turbine speed; otherwise, only the gradient descent method is used to update the photovoltaic tilt angle and the photovoltaic height. Machine learning algorithms are used to predict the unit power generation, unit electricity consumption, and unit salt production under different operating environment data, photovoltaic tilt angle, photovoltaic height, and wind turbine wind speed. The comprehensive benefits of photo-salt generation are calculated based on the predicted results of the unit power generation, the unit power consumption, and the unit salt production. When the overall benefits of photovoltaic and salt are maximized, the corresponding photovoltaic tilt angle, photovoltaic height, and wind turbine speed are taken as the optimal photovoltaic tilt angle, optimal photovoltaic height, and optimal wind turbine speed.

[0016] This system uses gradient descent to update the photovoltaic tilt angle, photovoltaic height, and wind turbine speed, gradually approaching the optimal parameters and improving search efficiency and accuracy. It predicts the unit power generation and unit salt production under different parameters using machine learning algorithms, then calculates the comprehensive photovoltaic-salt benefits based on the prediction results. Finally, it determines the optimal photovoltaic tilt angle, photovoltaic height, and wind turbine speed when the comprehensive photovoltaic-salt benefits are maximized, achieving optimal synergy between photovoltaic power generation and salt field operations. This ensures salt production while improving photovoltaic power generation efficiency, thereby enhancing the economic benefits and energy utilization efficiency of the entire photovoltaic-salt-photovoltaic complementary power generation system.

[0017] Optionally, the unit power generation when the comprehensive benefits of light and salt are maximized is recorded as the balanced power generation, and the power generation corresponding to the balanced power generation is recorded as the balanced power generation. The energy storage dispatch scheme includes: When the balanced power generation is greater than the load demand and the state charge value is not greater than 90%, the supercapacitor is charged first, and the remaining power is allocated to the lithium battery. When the balanced power generation capacity is greater than the load demand and the state charge value is greater than 90%, the remaining electricity will be connected to the grid for sale. When the balanced power generation is equal to the load demand, if the grid electricity price is less than the electricity price threshold, the lithium battery equalization charging is started; otherwise, the power storage device maintains the current state. When the balanced power generation is less than the load demand and the grid electricity price is not less than the electricity price threshold, the supercapacitor will be given priority in power supply. The insufficient part will be supplemented by lithium battery first, and then by grid. When the balanced power generation is less than the load demand and the grid electricity price is less than the electricity price threshold, the shortfall is supplemented by the grid.

[0018] This system has developed a detailed energy storage dispatch scheme for the balanced power generation and balanced power output at the optimal level for maximizing the combined benefits of photovoltaic and salt production. When the balanced power generation exceeds the load demand and the state charge is no more than 90%, the system prioritizes charging the supercapacitors, with the remaining power allocated to the lithium batteries. This fully utilizes the fast charging and discharging speed of the supercapacitors and the large energy storage capacity of the lithium batteries, achieving efficient energy storage. When the balanced power generation exceeds the load demand and the state charge is greater than 90%, the remaining power is sold to the grid, increasing the system's economic benefits. When the balanced power generation equals the load demand, the system determines whether to initiate balanced charging of the lithium batteries based on the grid electricity price, charging when the price is low to reduce charging costs. When the balanced power generation is less than the load demand, the system prioritizes power supply from the supercapacitors based on the grid electricity price, with the shortfall rationally allocated between the lithium batteries and the grid. This ensures stable power supply while minimizing electricity costs, improving the system's energy management level and economic efficiency.

[0019] Secondly, the present invention provides a photovoltaic-salt-photovoltaic complementary power generation control method, applicable to a photovoltaic-salt-photovoltaic complementary power generation system provided by the present invention. The method includes the following steps: using a photovoltaic power generation system to convert direct sunlight and reflected light from salt field brine into electrical energy, thereby outputting power and connecting to the grid; using a salt field operation subsystem to extract salt and collect the extracted crystalline salt; using a monitoring subsystem to collect real-time operating environment data and electrical data of the photovoltaic-salt-photovoltaic complementary power generation system; and using an intelligent control subsystem to dynamically optimize the photovoltaic tilt angle, photovoltaic height, and salt field ventilation, as well as to perform energy storage scheduling based on the operating environment data and the electrical data. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the framework of a photovoltaic-salt-solar complementary power generation system according to an embodiment of the present invention; Figure 2 This refers to the site of a photovoltaic-salt-solar hybrid power generation project according to an embodiment of the present invention; Figure 3 This is a simplified flowchart of the operation of the salt-light collaborative algorithm according to an embodiment of the present invention; Figure 4 This is a graph showing the relationship between wind speed and brine evaporation rate in an embodiment of the present invention. Figure 5This is a schematic flowchart of a photovoltaic-salt-photovoltaic complementary power generation control method according to an embodiment of the present invention. Detailed Implementation

[0022] Specific embodiments of the present invention will now be described in detail. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other instances, well-known circuits, software, or methods have not been specifically described to avoid obscuring the invention.

[0023] Throughout this specification, references to "an embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "in an embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale.

[0024] It should be noted in advance that, in one alternative embodiment, except for independent descriptions, the same symbols or letters appearing in all formulas have the same meaning and value.

[0025] In one optional embodiment, please refer to Figure 1 This invention provides a photovoltaic-salt-photovoltaic complementary power generation system, the system comprising: The system comprises: a photovoltaic power generation subsystem 1, which uses a double-sided double-glass module array to convert direct sunlight and reflected light from the brine in the salt field into electrical energy, thereby achieving power output and grid-connected power supply; a salt field operation subsystem 2, which extracts salt through a controlled evaporation crystallization process and collects the extracted crystallized salt; a monitoring subsystem 3, which collects real-time operating environment data and electrical data of the photovoltaic-salt-photovoltaic complementary power generation system; and an intelligent control subsystem 4, which dynamically optimizes the photovoltaic tilt angle, photovoltaic height, and salt field ventilation based on the operating environment data, and performs energy storage scheduling based on the electrical data.

[0026] Specifically, in this embodiment, the photovoltaic power generation system 1 includes a bifacial double-glass module array, a support structure, a power conversion and transmission device, and a power storage device. The various components of the photovoltaic power generation system 1 work collaboratively to achieve efficient photovoltaic power generation and power management. Specifically, the bifacial double-glass module array converts direct sunlight and reflected light from the salt field brine into electrical energy; the support structure supports the monocrystalline silicon bifacial double-glass modules; the power conversion and transmission device enables power output and grid connection; and the power storage device stores the electrical energy of the photovoltaic-salt-photovoltaic complementary power generation system.

[0027] The bifacial double-glass module array comprises multiple monocrystalline silicon bifacial double-glass modules used to convert direct sunlight and reflected light from salt field brine into electrical energy, improving power generation efficiency. It is the core energy harvesting component of the entire photovoltaic power generation system. The module dimensions conform to industry-standard specifications, facilitating compatibility and installation with subsequent equipment.

[0028] For more details, please see Figure 2 In this embodiment, the bifacial double-glass module array covers an area of ​​approximately 8437.62 acres, with an installed capacity of 520MW. It is divided into 158 photovoltaic power generation units, and all modules are 575Wp monocrystalline silicon N-type bifacial double-glass modules. 26 monocrystalline silicon bifacial double-glass modules are connected in series to form one string, and 7 or 8 photovoltaic power generation units are connected in parallel.

[0029] The supporting structure is a photovoltaic (PV) bracket, specifically an adjustable PV bracket. This adjustable PV bracket is equipped with an electric actuator and can be remotely adjusted via the intelligent control subsystem 4. This flexible adjustment method can adapt to changes in solar altitude angle in different seasons, optimizing the light-receiving angle of the PV modules, and can also be periodically adjusted to prevent crystallization and deposition during the evaporation of brine in the salt field, ensuring the normal operation of the system. The foundation of the adjustable PV bracket adopts a helical pile design to ensure structural stability in a saline-alkali corrosive environment.

[0030] More specifically, the main structure of the adjustable photovoltaic support is made of Q355B hot-dip galvanized steel. The minimum east-west spacing between the supports is 0.4m, and the north-south spacing is 7m. The tilt angle and height adjustment range of the photovoltaic array are 15°-40° and 1.5m-3m, respectively.

[0031] Power conversion and transmission equipment includes string inverters, switchgear, transformer substations, step-up substations, cables, and connectors. First, the string inverter converts the direct current (DC) output from the bifacial double-glass module array into alternating current (AC). The converted power is then connected to the AC switchgear via cables and connectors. The AC output from the switchgear is connected to the transformer substation via cables and connectors. The medium- and high-voltage power output from the transformer substation is then connected to the step-up substation via cables or overhead lines, thereby raising the voltage to grid connection level.

[0032] More specifically, one 300kW string inverter is connected to every 26 strings, and one transformer substation is connected to every 11 string inverters, making the substation a 600MW substation. Power storage devices include lithium batteries and supercapacitors. The lithium batteries are specifically lithium iron phosphate batteries, with a specification of 48V 500Ah; the supercapacitors have a rated voltage of 750V and a capacity of 150F. The lithium batteries are connected to the DC bus via a bidirectional DC / DC converter, primarily responsible for surplus power storage and base load supply; the supercapacitors are connected to the system via a DC / AC converter to smooth out photovoltaic output fluctuations and compensate for instantaneous power shortages.

[0033] Specifically, in this embodiment, the salt field operation subsystem 2 includes salt field infrastructure, environmental control equipment, and salt production equipment. The environmental control equipment is used to accelerate the evaporation of brine on the surface, and the salt production equipment is used to collect crystallized salt and maintain the circulation of brine.

[0034] Saltworks infrastructure serves as the physical foundation for salt production, comprising evaporation ponds and crystallization ponds forming a gradient production unit. A 2mm thick HDPE membrane is laid at the bottom of the evaporation ponds to effectively prevent brine loss. A 3mm thick HDPE membrane is laid at the bottom of the crystallization ponds, with a 0.5% longitudinal slope to facilitate the collection and discharge of crystallized salt. The evaporation and crystallization ponds are connected by channels with a 0.3% slope to ensure natural brine flow and reduce power consumption.

[0035] The environmental control equipment is an EC fan array, which accelerates brine evaporation by actively intervening in the microclimate. The array uses the EC300 series EC external rotor axial flow fan from Zhejiang Dayang Fan Co., Ltd. (hereinafter referred to as the fan), and its operation is regulated by the intelligent control subsystem 5.

[0036] Salt production equipment includes a salt collecting machine and a brine circulation pump. The salt collecting machine is a HY495 model. The brine circulation pump is regulated by an intelligent control subsystem and is a CDLF4-20 vertical stainless steel centrifugal pump.

[0037] Specifically, in this embodiment, the monitoring subsystem 3 includes an environmental monitoring module and an electrical data monitoring module. The environmental monitoring module is used to collect operating environment data, and the electrical data monitoring module is used to monitor the power generation and power consumption of the photovoltaic-salt-solar hybrid power generation system, as well as the state charge value of the power storage equipment.

[0038] The operating environment data includes air temperature, brine temperature, air vapor pressure, brine saturated vapor pressure, relative humidity, wind speed, light intensity, and reflected light intensity from the salt field.

[0039] The monitoring subsystem 3 includes various sensors for collecting operating environment data, such as temperature sensors, pressure transmitters, humidity sensors, wind direction and speed sensors, and light sensors.

[0040] Specifically, in this embodiment, the intelligent control subsystem 4 includes a central controller, a control execution module, and a human-machine interaction module. The central controller is used to run the salt-photovoltaic synergy algorithm, and then dynamically optimize the photovoltaic tilt angle, photovoltaic height, and salt field ventilation based on the operating environment data. It also obtains an energy storage scheduling scheme based on the electrical data and finally generates control commands. The control execution module is used to execute the control commands, enabling the salt field operation subsystem to refine salt through a controlled evaporation crystallization process and collect the refined crystallized salt. The human-machine interaction module is used to display the monitoring data of the monitoring subsystem and adjust the control commands.

[0041] The control commands generated by the central controller include the following three parts: adjusting the photovoltaic tilt angle and photovoltaic height of the photovoltaic support according to the optimized photovoltaic tilt angle and photovoltaic height; starting or stopping the wind turbine according to the wind start-up and shutdown requirements, and controlling the wind turbine blade speed to achieve the optimal wind speed when the wind turbine is turned on; and controlling the charging and discharging behavior of the power storage equipment according to the energy storage scheduling scheme.

[0042] The intelligent control subsystem 4 communicates with the photovoltaic power generation system 1 and the monitoring subsystem 3 via the Internet of Things (IoT) or fiber optic communication. The intelligent control subsystem 4 can directly control the photovoltaic power generation system 1 and the monitoring subsystem 3, and indirectly control the salt field operation subsystem 2 through the control of the photovoltaic power generation system 1 and the monitoring subsystem 3. In other optional embodiments, the brine circulation pump can be equipped with a flow meter and a pressure sensor to monitor the brine flow and pressure in real time, and the central controller can also control the brine circulation pump based on the real-time collected brine flow and pressure data.

[0043] In this embodiment, the salt-light co-processing algorithm runs once per hour. Please refer to [link to relevant documentation]. Figure 3 The operation flow of the salt-light collaborative algorithm is as follows: 1. Calculate the critical ratio for fan start-up and shutdown using the aforementioned air temperature, brine temperature, air vapor pressure, and brine saturated vapor pressure.

[0044] The critical ratio for wind turbine start-up and shutdown satisfies the following relationship: Where R is the critical ratio for wind turbine start-up and shutdown. This is the saturated vapor pressure of the brine. It is the vapor pressure of air. The temperature of the brine. The temperature is the air temperature between the brine and the monocrystalline silicon double-sided double-glass module.

[0045] 2. Initialize the fan control strategy based on the fan start / stop critical ratio, the relative humidity of the air, and the wind speed to obtain the initial value of the fan wind speed.

[0046] Step 2 specifically includes the following steps: (1) Set the fan start-stop critical ratio threshold, air relative humidity threshold and wind speed threshold, and then determine the fan start-stop status based on the fan start-stop critical ratio, air relative humidity and wind speed.

[0047] Monocrystalline silicon bifacial double-glass modules generate waste heat during power generation, which heats the brine, raising its temperature. According to the Clausius-Clapeyron equation, the increased brine temperature leads to an increase in saturated vapor pressure. With the surrounding air vapor pressure remaining constant, this increases the vapor pressure difference, accelerating brine evaporation. Simultaneously, turning on the fan to accelerate airflow further speeds up evaporation. However, as wind speed increases, the rate of heat loss accelerates. If excessive heat loss occurs, the brine surface temperature decreases, leading to a reduction in saturated vapor pressure and vapor pressure difference, thus slowing down evaporation. Based on these considerations, if nonlinear effects such as turbulence, humidity gradients, and brine concentration changes in the actual environment are ignored, the balance equation between evaporation and heat dissipation can be simply expressed as: in, This is an evaporation-promoting term. This is a heat dissipation suppression item. For evaporation gain, and These are the fitting coefficients. This refers to wind speed. and The method requires brine evaporation experiments in salt fields, followed by fitting data using MATLAB. In this embodiment, , .when hour, ,Right now Therefore, the critical ratio threshold R for wind turbine start-up and shutdown is set to 0.63.

[0048] According to Dalton's law of evaporation, at a constant temperature, an increase in relative humidity leads to a decrease in the driving force of evaporation, and consequently, a decrease in the evaporation rate. Once the relative humidity reaches a certain value, the amount of extra water vapor the air can hold is very small. At this point, while turning on a fan can accelerate airflow, its effect on accelerating brine evaporation, regardless of wind speed, will be greatly reduced, and it will also consume a significant amount of energy. In various agricultural and ecological fields, the threshold for relative humidity is typically concentrated in the range of 70%-90%. Referring to this range, this embodiment initially sets the relative humidity threshold to 70%.

[0049] In the aforementioned balance equation between evaporation and heat dissipation, wind speed can affect temperature and vapor pressure, thereby altering the evaporation gain. Excessive fan speed may reduce the net evaporation gain and lead to significant unnecessary energy loss; therefore, it is necessary to determine the wind speed threshold. This embodiment uses a controlled variable method in the laboratory to determine the wind speed threshold for different times of day. During the experiment, the brine concentration was kept constant, with wind speed as the independent variable. Other controllable environmental parameters were set based on the actual environment of the salt field at different times of day. Taking the period from 1 PM to 3 PM on a sunny summer day as an example, the experimental results are as follows: Figure 4 As shown. According to Figure 4 It is known that the evaporation rate of brine begins to decrease when the wind speed exceeds 8 m / s. Therefore, for sunny summer weather from 1 pm to 3 pm, this embodiment sets the wind speed threshold to 8 m / s.

[0050] When both conditions are met RH < 70% and If the EC wind turbine array should be turned on, it should be turned off; otherwise, it should be turned off.

[0051] This system sets thresholds for the fan start-stop critical ratio, relative humidity, and wind speed. Based on these thresholds, the system determines the fan start-stop status, thus preventing energy waste or adverse effects on the salt field environment caused by the fan operating under unsuitable conditions.

[0052] (2) When the fan start-stop state is the on state, the initial value of the fan speed is set using the wind speed and the wind speed threshold.

[0053] The initial value of the fan speed satisfies the following relationship: in, This is the initial value of the fan speed; The wind speed is the wind speed measured by the wind direction and speed sensor, i.e., the ambient wind speed. and They are in the same direction.

[0054] When the fan is in the on state, the system uses wind speed and wind speed threshold to set the initial value of the fan wind speed. This setting method makes the fan wind speed more in line with the actual evaporation needs of the salt field, which helps to improve the evaporation efficiency of the salt field, and also lays the foundation for further optimization of the control strategy.

[0055] 3. Update the initial values ​​of the photovoltaic tilt angle, photovoltaic height, and wind speed of the bifacial double-glass module array to maximize the overall photovoltaic-salt efficiency and obtain the optimal photovoltaic tilt angle, photovoltaic height, and wind speed.

[0056] Step 3 specifically includes the following steps: (1) The current photovoltaic tilt angle and photovoltaic height of the bifacial double-glass module array are used as their initial values.

[0057] (2) When the wind turbine is turned on, the photovoltaic tilt angle, the photovoltaic height and the wind turbine speed are updated using the gradient descent method; otherwise, only the photovoltaic tilt angle and the photovoltaic height are updated using the gradient descent method.

[0058] Gradient descent is a current technical method and will not be described in detail here.

[0059] (3) Predict the unit power generation, unit electricity consumption and unit salt production under different operating environment data, photovoltaic tilt angle, photovoltaic height and wind speed by using machine learning algorithms.

[0060] First, the hourly power generation, power consumption, and salt production of the entire salt field were collected under different air temperatures, brine temperatures, air vapor pressure, brine saturated vapor pressure, relative humidity, wind speed, light intensity, salt field reflected light intensity, photovoltaic tilt angle, photovoltaic height, and wind turbine wind speed. That is, the unit power generation, unit power consumption, and unit salt production. The collected data were then preprocessed to construct a database.

[0061] Then, a BP neural network is used to construct a prediction model for unit power generation and unit salt production, respectively, while a long short-term memory neural network is used to construct a prediction model for unit electricity consumption. For unit power generation, the inputs to the prediction model are air temperature, light intensity, salt field reflected light intensity, photovoltaic tilt angle, and photovoltaic height; for unit electricity consumption, the inputs are time-series data of salt production and electricity consumption; for unit salt production, the inputs are air temperature, brine temperature, air vapor pressure, brine saturated vapor pressure, relative humidity, wind speed, light intensity, salt field reflected light intensity, photovoltaic tilt angle, photovoltaic height, and wind turbine speed. This embodiment does not incorporate brine concentration because the brine concentration varies in different areas of the salt field, and this embodiment aims to predict the salt production of the entire salt field, rather than predicting specific areas. Of course, in other alternative embodiments, if only a specific area is targeted, brine concentration can be considered.

[0062] Next, for each prediction model's input and output data type, corresponding data is extracted from the database to construct a dataset for training the model. The dataset is then divided into a training set and a validation set in a 7:3 ratio, and the training and validation of the corresponding prediction models are completed.

[0063] Finally, before the first update and after each update of the photovoltaic tilt angle, photovoltaic height, and wind turbine speed, the prediction model was used to predict the unit power generation, unit power consumption, and unit salt production, providing a data foundation for further calculation of the comprehensive benefits of photovoltaic and salt production.

[0064] (4) Calculate the comprehensive benefits of light and salt based on the prediction results of the unit power generation, the unit power consumption and the unit salt production.

[0065] The overall benefits of light and salt content satisfy the following relationship: in, For the comprehensive benefits of light and salt; The predicted unit power generation is expressed in kWh. The predicted electricity consumption per unit is expressed in kWh. The electricity price for the next hour; M is the predicted salt production per unit, in kg / h; For the price of salt, and For weights. Generally, and All values ​​are set to 0.5, and relevant personnel can adjust the weights according to their emphasis on power generation or salt production.

[0066] (5) When the comprehensive benefits of photovoltaic salt are maximized, the corresponding photovoltaic tilt angle, photovoltaic height and wind speed are taken as the optimal photovoltaic tilt angle, optimal photovoltaic height and optimal wind speed.

[0067] When the fan is shut down, the maximum number of iterations t is reached. When the photovoltaic tilt angle and photovoltaic height corresponding to the maximum combined photovoltaic and salt benefits are selected, they are output as the optimal photovoltaic tilt angle and optimal photovoltaic height. When the wind turbine is started, the maximum iteration number is reached when the iteration number t is reached. When the photovoltaic tilt angle, photovoltaic height, and wind turbine speed corresponding to the maximum value of the comprehensive photovoltaic-salt benefits are selected, they are taken as the optimal photovoltaic tilt angle, optimal photovoltaic height, and optimal wind turbine speed and output.

[0068] This system uses gradient descent to update the photovoltaic tilt angle, photovoltaic height, and wind turbine speed, gradually approaching the optimal parameters and improving search efficiency and accuracy. It predicts unit power generation and unit salt production under different parameters using machine learning algorithms, then calculates the comprehensive photovoltaic-salt benefits based on the prediction results. Finally, it determines the optimal photovoltaic tilt angle, photovoltaic height, and wind turbine speed when the comprehensive photovoltaic-salt benefits are maximized, achieving optimal synergy between photovoltaic power generation and salt field operations. This ensures salt production while improving photovoltaic power generation efficiency, thereby enhancing the economic benefits and energy utilization efficiency of the entire photovoltaic-salt-photovoltaic complementary power generation system.

[0069] In this embodiment, the unit power generation at which the comprehensive benefits of light and salt are maximized is denoted as the balanced power generation, and the power generation corresponding to the balanced power generation is denoted as the balanced power generation. The energy storage dispatch scheme includes: 1. When the balanced power generation is greater than the load demand and the state charge value is not greater than 90%, the supercapacitor is charged first, and the remaining power is allocated to the lithium battery.

[0070] 2. When the balanced power generation capacity is greater than the load demand and the state charge value is greater than 90%, the remaining power will be connected to the grid for sale.

[0071] 3. When the balanced power generation is equal to the load demand, if the grid electricity price is less than the electricity price threshold, the lithium battery equalization charging will be started; otherwise, the power storage device will maintain its current state.

[0072] In this embodiment, the electricity price threshold is set as the average of the peak electricity price and the off-peak electricity price. In other alternative embodiments, relevant personnel can adjust the electricity price threshold according to local electricity pricing policies, system operating costs, and revenues.

[0073] 4. When the balanced power generation is less than the load demand and the grid electricity price is not less than the electricity price threshold, the supercapacitor shall be given priority in power supply. The insufficient part shall be supplemented by the lithium battery first, and then by the grid.

[0074] 5. When the balanced power generation is less than the load demand and the grid electricity price is less than the electricity price threshold, the shortfall shall be supplemented by the grid.

[0075] This system has developed a detailed energy storage dispatch scheme for the balanced power generation and balanced power output at the optimal level for maximizing the combined benefits of photovoltaic and salt production. When the balanced power generation exceeds the load demand and the state charge is no more than 90%, the system prioritizes charging the supercapacitors, with the remaining power allocated to the lithium batteries. This fully utilizes the fast charging and discharging speed of the supercapacitors and the large energy storage capacity of the lithium batteries, achieving efficient energy storage. When the balanced power generation exceeds the load demand and the state charge is greater than 90%, the remaining power is sold to the grid, increasing the system's economic benefits. When the balanced power generation equals the load demand, the system determines whether to initiate balanced charging of the lithium batteries based on the grid electricity price, charging when the price is low to reduce charging costs. When the balanced power generation is less than the load demand, the system prioritizes power supply from the supercapacitors based on the grid electricity price, with the shortfall rationally allocated between the lithium batteries and the grid. This ensures stable power supply while minimizing electricity costs, improving the system's energy management level and economic efficiency.

[0076] It should be noted that in some cases, the actions described in the specification can be performed in different orders and still achieve the desired results. In this embodiment, the order of steps is given only to make the embodiment clearer and easier to explain, and not to limit it.

[0077] In one optional embodiment, please refer to Figure 5The present invention also provides a photovoltaic-salt-photovoltaic complementary power generation control method, wherein the photovoltaic-salt-photovoltaic complementary power generation control method uses the photovoltaic-salt-photovoltaic complementary power generation system provided by the present invention, and the method includes the following steps: S1. A photovoltaic power generation system is used to convert direct sunlight and reflected light from salt field brine into electrical energy, which is then used for power output and grid connection.

[0078] S2. Use the salt field operation subsystem to extract salt and collect the extracted crystallized salt.

[0079] S3. Use the monitoring subsystem to collect real-time operating environment data and electrical data of the photovoltaic-salt-photovoltaic complementary power generation system.

[0080] S4. Based on the operating environment data and the electrical data, use the intelligent control subsystem to dynamically optimize the photovoltaic tilt angle, photovoltaic height, and salt field ventilation, as well as to perform energy storage scheduling.

[0081] Since the photovoltaic-salt-photovoltaic complementary power generation control method in this embodiment uses a photovoltaic-salt-photovoltaic complementary power generation system, and the photovoltaic-salt-photovoltaic complementary power generation system has already been described, for the sake of simplicity, the contents of steps S1 to S4 will not be described in detail here.

[0082] The present invention has at least the following beneficial effects: 1. This invention uses a double-sided double-glass module array, which generates electricity by utilizing both direct sunlight and reflected light from salt field brine. Combined with an adjustable photovoltaic support to dynamically optimize the tilt angle and height, the module can maximize the light intensity received, thereby effectively increasing the power generation.

[0083] 2. By actively regulating the microclimate of the salt field through the EC fan array and maintaining the flow of brine with the brine circulation pump, the evaporation rate of the brine is improved.

[0084] 3. The photovoltaic tilt angle, height, and wind turbine speed are dynamically optimized every hour using the salt-photovoltaic synergy algorithm. Combined with machine learning prediction models, the comprehensive benefits of photovoltaic and salt-photovoltaic complementary power generation are maximized, and the intelligence level of photovoltaic-salt-photovoltaic complementary power generation is improved.

[0085] 4. In this invention, the supercapacitor and lithium battery work together, and through a graded charging and discharging strategy, the system's stable power supply is ensured, while the electricity cost is reduced as much as possible, thereby improving the system's energy management level and economic benefits.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A photovoltaic-salt-photovoltaic complementary power generation system, characterized in that, The system includes: A photovoltaic power generation system, which uses a double-sided double-glass module array to convert direct sunlight and reflected light from salt field brine into electrical energy, thereby realizing power output and grid-connected power supply; A salt field operation subsystem, wherein the salt field operation subsystem extracts salt through a controlled evaporation crystallization process and collects the extracted crystallized salt; The monitoring subsystem is used to collect real-time operating environment data and electrical data of the photovoltaic-salt-solar hybrid power generation system; The intelligent control subsystem dynamically optimizes the photovoltaic tilt angle, photovoltaic height, and salt field ventilation based on the operating environment data, and performs energy storage scheduling based on the electrical data.

2. The photovoltaic-salt-photovoltaic complementary power generation system according to claim 1, characterized in that, The photovoltaic power generation system includes: A double-sided double-glass module array, which is used to convert direct light and reflected light from salt field brine into electrical energy, and the double-sided double-glass module array includes multiple monocrystalline silicon double-sided double-glass modules; A support structure is provided for supporting a monocrystalline silicon bifacial double-glass module and for adjusting the photovoltaic tilt angle and the photovoltaic height. The support structure is a photovoltaic bracket. Power conversion and transmission equipment, which is used to realize power output and grid-connected power supply, includes string inverters, switch cabinets, transformer substations, step-up substations, cables and connectors; An energy storage device for storing electrical energy from a photovoltaic-salt-photovoltaic complementary power generation system, the energy storage device comprising a lithium battery and a supercapacitor.

3. A photovoltaic-salt-photovoltaic complementary power generation system according to claim 1, characterized in that, The salt field operation subsystem includes: Salt field infrastructure, which includes evaporation ponds and crystallization ponds; An environmental control device, which is used to accelerate the surface evaporation of brine, is an EC fan array. Salt production equipment, which is used to collect crystallized salt and maintain the circulation of brine, includes a salt collector and a brine circulation pump.

4. A photovoltaic-salt-photovoltaic complementary power generation system according to claim 2, characterized in that: The operating environment data includes air temperature, air vapor pressure, brine saturated vapor pressure, air relative humidity, wind speed, brine concentration, light intensity, and salt field reflected light intensity. The monitoring subsystem includes: An environmental monitoring module is used to collect operating environment data, and the environmental monitoring module includes various sensors for collecting the operating environment data. The electrical data monitoring module is used to monitor the power generation and power consumption of the photovoltaic-salt-photovoltaic complementary power generation system, as well as the state charge value of the power storage device.

5. A photovoltaic-salt-photovoltaic complementary power generation system according to claim 1, characterized in that, The intelligent control subsystem includes: The central controller is used to run the salt-photovoltaic synergy algorithm, and then dynamically optimize the photovoltaic tilt angle, photovoltaic height and salt field ventilation according to the operating environment data, obtain the energy storage scheduling scheme according to the electrical data, and finally generate control commands. A control execution module is used to execute the control instructions, so that the salt field operation subsystem extracts salt through a controlled evaporation crystallization process and collects the extracted crystallized salt. The human-machine interaction module is used to display the monitoring data of the monitoring subsystem and adjust the control commands.

6. A photovoltaic-salt-photovoltaic complementary power generation system according to claim 5, characterized in that, The operation flow of the salt-light collaborative algorithm is as follows: The critical ratio for fan start-up and shutdown is calculated using the air temperature, brine temperature, air vapor pressure, and brine saturated vapor pressure. The initial value of the fan speed is obtained by initializing the fan control strategy based on the fan start / stop critical ratio, the relative humidity of the air, and the wind speed. The photovoltaic tilt angle, photovoltaic height, and wind speed of the bifacial double-glass module array are updated to maximize the overall photovoltaic-salt efficiency and obtain the optimal photovoltaic tilt angle, photovoltaic height, and wind speed.

7. A photovoltaic-salt-photovoltaic complementary power generation system according to claim 6, characterized in that, The step of initializing the fan control strategy based on the fan start / stop critical ratio, the relative humidity of the air, and the wind speed to obtain the initial value of the fan wind speed includes the following steps: Set the fan start / stop critical ratio threshold, air relative humidity threshold, and wind speed threshold, and then determine the fan start / stop status based on the fan start / stop critical ratio, air relative humidity, and wind speed; When the fan is in the on state, the initial value of the fan speed is set using the wind speed and the wind speed threshold.

8. A photovoltaic-salt-photovoltaic complementary power generation system according to claim 6, characterized in that, The process of updating the initial values ​​of the photovoltaic tilt angle, photovoltaic height, and wind turbine speed of the bifacial double-glass module array to maximize the overall photovoltaic-salt efficiency and obtain the optimal photovoltaic tilt angle, photovoltaic height, and wind turbine speed includes the following steps: Use the current photovoltaic tilt angle and photovoltaic height of the bifacial double-glass module array as their initial values; When the wind turbine is turned on, the gradient descent method is used to update the photovoltaic tilt angle, the photovoltaic height, and the wind turbine speed; otherwise, only the gradient descent method is used to update the photovoltaic tilt angle and the photovoltaic height. Machine learning algorithms are used to predict the unit power generation, unit electricity consumption, and unit salt production under different operating environment data, photovoltaic tilt angle, photovoltaic height, and wind turbine wind speed. The comprehensive benefits of photo-salt generation are calculated based on the predicted results of the unit power generation, the unit power consumption, and the unit salt production. When the overall benefits of photovoltaic and salt are maximized, the corresponding photovoltaic tilt angle, photovoltaic height, and wind turbine speed are taken as the optimal photovoltaic tilt angle, optimal photovoltaic height, and optimal wind turbine speed.

9. A photovoltaic-salt-photovoltaic complementary power generation system according to claim 6, characterized in that: The unit power generation at which the comprehensive benefits of light and salt are maximized is denoted as the balanced power generation, and the power generation corresponding to the balanced power generation is denoted as the balanced power generation. The energy storage dispatch scheme includes: When the balanced power generation is greater than the load demand and the state charge value is not greater than 90%, the supercapacitor is charged first, and the remaining power is allocated to the lithium battery. When the balanced power generation capacity is greater than the load demand and the state charge value is greater than 90%, the remaining electricity will be connected to the grid for sale. When the balanced power generation is equal to the load demand, if the grid electricity price is less than the electricity price threshold, the lithium battery equalization charging is started; otherwise, the power storage device maintains the current state. When the balanced power generation is less than the load demand and the grid electricity price is not less than the electricity price threshold, the supercapacitor will be given priority in power supply. The insufficient part will be supplemented by lithium battery first, and then by grid. When the balanced power generation is less than the load demand and the grid electricity price is less than the electricity price threshold, the shortfall is supplemented by the grid.

10. A photovoltaic-salt-photovoltaic complementary power generation control method, wherein the photovoltaic-salt-photovoltaic complementary power generation control method is applicable to the photovoltaic-salt-photovoltaic complementary power generation system according to any one of claims 1-9, the method comprising the following steps: The photovoltaic power generation system converts direct sunlight and reflected light from the salt field brine into electrical energy, which is then used for power output and grid connection. Salt is extracted using a salt field operation subsystem, and the extracted crystalline salt is collected. The monitoring subsystem is used to collect real-time operating environment data and electrical data of the photovoltaic-salt-photovoltaic hybrid power generation system. Based on the operating environment data and the electrical data, the intelligent control subsystem dynamically optimizes the photovoltaic tilt angle, photovoltaic height, and salt field ventilation, as well as performs energy storage scheduling.

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