Hilly orchard intelligent photovoltaic gravity drip irrigation collaborative system

Abstract

The application discloses a kind of hilly orchard intelligent photovoltaic gravity drip irrigation coordination systems, belong to agricultural irrigation technical field, including photovoltaic power generation subsystem, gravity drip irrigation subsystem, intelligent management subsystem and integrated control platform;Photovoltaic power generation subsystem includes photovoltaic array and energy storage unit, realizes solar energy capture and storage;Gravity drip irrigation subsystem includes high water reservoir, irrigation pipe network and drip irrigation terminal, high water reservoir is located at the highest point of orchard topography, utilizes natural difference to generate gravity head and realizes pump-free self-pressure drip irrigation;Intelligent management subsystem includes perception layer, transmission layer, decision layer and execution layer, perception layer gathers soil moisture regime, meteorology and crop physiological data, decision layer runs crop water demand model to generate irrigation strategy;Integrated control platform includes energy management module and water power scheduling module, according to irrigation strategy and photovoltaic power generation state coordination energy output and water power operation, when energy is insufficient, optimize irrigation timing and water quantity distribution.

Description

Technical Field

[0001] This invention relates to the field of agricultural irrigation technology, and in particular to a smart photovoltaic gravity drip irrigation system for orchards in hilly areas. Background Technology

[0002] As an important agricultural production base in Southwest China, the hilly area of ​​Chengdu is characterized by its undulating terrain, uneven spatial distribution of water resources, poor adaptability of traditional irrigation systems, frequent seasonal droughts, and prominent problems such as water shortages, low irrigation efficiency, and excessive energy consumption. In recent years, although photovoltaic power generation and water-saving irrigation technologies have been applied in agriculture, integrated systems that combine intelligent management with the complex terrain and crop needs of the hilly area are still in their infancy.

[0003] Currently, patents related to photovoltaic irrigation or gravity drip irrigation mainly fall into the following categories: The first category is photovoltaic (PV) water pumping irrigation systems. For example, Chinese patent CN206547313U discloses a PV-integrated water and fertilizer irrigation system that uses a photovoltaic array to power a PV water pump. The PV water pump, fertilizer applicator, and field irrigation equipment are connected sequentially via pipelines to achieve solar-driven irrigation and fertilization. Another example is Chinese patent CN204119914U, which discloses an automatic control water-saving gravity drip irrigation system, including solar panels, a central processing unit, a water tank, a level sensor, a humidity sensor, and irrigation pipelines. While these systems achieve a preliminary integration of PV power supply and gravity drip irrigation, the PV system only serves as a power source for the water pump, failing to achieve deep coupling between PV power generation and gravity water supply at the energy and water flow levels. Furthermore, irrigation decisions rely on simple sensor threshold judgments, lacking dynamic optimization capabilities based on crop water requirement models.

[0004] The second category is hilly and mountainous water storage irrigation systems. For example, Chinese Patent CN219248763U discloses an intelligent drip irrigation system based on solar photovoltaic power generation. The water source pool is located at the bottom of a hillside, and several water storage pools are evenly distributed upwards along the slope. Each water storage pool is connected to a drip irrigation system, and water is pumped in stages to achieve irrigation. Another example is a hilly and mountainous water storage irrigation system disclosed in Chinese Patent Application CN202310118569, which uses multiple water storage pools at different altitudes and a photovoltaic power station to power the water pumps, achieving drip irrigation under gravity. However, this type of system uses multiple water storage pools and pumps for staged water pumping, resulting in a complex system structure and high construction and maintenance costs. Furthermore, the synergy between photovoltaic power generation and gravity irrigation is only reflected in the water pump power supply stage, failing to form a self-balancing closed-loop system.

[0005] The third category is gravity-fed drip irrigation systems for hilly areas. For example, Chinese patent application CN202420062096 discloses an irrigation system for hilly areas, in which the agricultural fertilizer fermentation tank, water distribution tank, gravity filter components, and drip irrigation network are arranged sequentially from high to low, utilizing gravitational potential energy to deliver the fermentation liquid for drip irrigation. However, this system is only suitable for fermentation liquid irrigation scenarios, does not involve photovoltaic power supply and intelligent control, has a fixed irrigation strategy, and cannot be dynamically adjusted according to real-time environmental changes and crop needs.

[0006] The aforementioned existing technologies generally suffer from the following drawbacks: (1) There is a lack of efficient coordination mechanism between the photovoltaic power generation system and the gravity drip irrigation system. In the existing scheme, the photovoltaic power generation is only used to drive the water pump to lift water. The dynamic matching relationship between the fluctuation of photovoltaic power generation and the timing of irrigation water demand has not been established, which results in the inability to effectively store and utilize the surplus of photovoltaic power generation and the inability of the irrigation system to operate normally when the power generation is insufficient.

[0007] (2) The level of intelligence in irrigation decision-making is insufficient. Existing systems mostly rely on simple thresholds triggered by soil moisture sensors to trigger irrigation. A multi-source information fusion decision-making model integrating meteorological data, soil moisture, and crop physiological indicators has not been established, making it impossible to achieve precision irrigation.

[0008] (3) There is a lack of systematic integrated solutions for the complex terrain of hilly areas. Most existing systems are simply superimposed single functional modules, and do not fully consider the coupling relationship between the terrain elevation difference, water source distribution, crop water demand pattern and energy supply in hilly areas.

[0009] (4) The system has limited energy self-sufficiency and carbon emission reduction benefits. In the existing photovoltaic irrigation system, the photovoltaic power generation and irrigation water demand lack coordination in time sequence, the utilization rate of clean energy is not high, and the system still needs to rely on the external power grid to supplement power. Summary of the Invention

[0010] The purpose of this invention is to propose an intelligent photovoltaic gravity drip irrigation collaborative system for orchards in hilly areas. Through an integrated control platform, it realizes the energy-hydraulic coordinated scheduling of photovoltaic power generation and gravity drip irrigation, and combined with intelligent irrigation decision-making based on crop water requirement models, it improves the energy self-sufficiency rate, water resource utilization efficiency and operational reliability of orchard irrigation systems in hilly areas.

[0011] To achieve the above objectives, the present invention provides an intelligent photovoltaic gravity drip irrigation collaborative system for orchards in hilly areas, comprising a photovoltaic power generation system, a gravity drip irrigation subsystem, an intelligent management subsystem, and an integrated control platform; A photovoltaic power generation system includes a photovoltaic array and an energy storage unit. The photovoltaic array is used to convert solar energy into electrical energy, and the energy storage unit is used to store electrical energy and release it when power generation is insufficient. The gravity drip irrigation subsystem includes an elevated water storage tank, an irrigation pipeline network, and drip irrigation terminals. The elevated water storage tank is located at the highest point of the orchard and utilizes the natural elevation difference to generate gravity head. The irrigation pipeline network is laid along the terrain from the outlet of the elevated water storage tank, and the drip irrigation terminals are connected to the end of the irrigation pipeline network. The intelligent management subsystem includes a perception layer, a transmission layer, a decision-making layer, and an execution layer. The perception layer collects soil moisture data, meteorological data, or crop physiological data. The transmission layer is used for data transmission between the perception layer, the decision-making layer, and the execution layer. The decision-making layer generates irrigation strategies based on the data collected by the perception layer. The execution layer is used to control the operation of the gravity drip irrigation subsystem. The integrated control platform is communicatively connected to the photovoltaic power generation system, the gravity drip irrigation subsystem, and the intelligent management subsystem. The integrated control platform includes an energy management module and a hydraulic scheduling module. The energy management module monitors the power generation of the photovoltaic power generation system and the remaining power of the energy storage unit in real time, and generates an energy availability index based on photovoltaic power generation forecast data. The hydraulic scheduling module obtains the irrigation strategy generated by the intelligent management subsystem and determines whether the available energy meets the energy requirements for irrigation based on the energy availability index. If it does, it generates a valve action sequence according to the irrigation strategy. If not, the hydraulic scheduling module adjusts the irrigation timing of the irrigation strategy or the water allocation of each irrigation zone under the constraint of meeting the minimum water requirements of the fruit trees, to match the current energy supply capacity, and generates an optimized valve action sequence. The hydraulic scheduling module prioritizes the irrigation needs of the fruit trees during their water-sensitive periods.

[0012] Preferably, the photovoltaic power generation system further includes a maximum power point tracking controller and a photovoltaic tracking device; the maximum power point tracking controller adjusts the operating point of the photovoltaic array to obtain the maximum power generation; the photovoltaic tracking device includes an azimuth angle drive mechanism and an altitude angle adjustment mechanism to drive the photovoltaic array to track changes in the solar azimuth angle and altitude angle.

[0013] Preferably, the energy storage unit includes a battery pack and a charge / discharge management module; the charge / discharge management module monitors the state of charge of the battery pack, stores surplus energy in the battery pack when the power generation of the photovoltaic array is greater than the real-time power consumption of the system, and controls the battery pack to discharge to supplement the power gap when the power generation of the photovoltaic array is less than the real-time power consumption.

[0014] Preferably, there is a preset height difference between the bottom of the elevated water storage tank and the highest irrigation point in the orchard, and the gravity head generated by the preset height difference is sufficient to drive the drip irrigation terminal to operate within the rated working pressure range; the volume of the elevated water storage tank is set according to the irrigation area and irrigation cycle of the orchard, the inlet of the elevated water storage tank is connected to a rainwater collection surface or an external water source, and a filtration device is installed at the outlet of the elevated water storage tank.

[0015] Preferably, the irrigation network includes a main pipeline laid along the main slope of the orchard and branch pipelines distributed perpendicular to the main pipeline. Several outlet branch pipes are installed at intervals on the branch pipelines, and the end of each outlet branch pipe is connected to a drip irrigation terminal. The irrigation network also includes a pressure regulating valve installed at the connection node between the main pipeline and the branch pipeline. The pressure regulating valve adjusts the water pressure in the branch pipeline according to the elevation difference of each irrigation area and the preset irrigation pressure.

[0016] Preferably, the drip irrigation terminal includes an anti-clogging dripper and a flow stabilizer; the flow channel of the anti-clogging dripper has a labyrinth structure; the flow stabilizer is located on the upstream side of the anti-clogging dripper and has an internal elastic diaphragm and a throttling orifice plate. The flow area of ​​the throttling orifice plate is adjusted by the deformation of the elastic diaphragm to maintain a constant inlet water pressure of the anti-clogging dripper.

[0017] Preferably, the sensing layer includes a soil moisture sensor, a field weather station, and a fruit tree stem flow meter; the soil moisture sensor is buried in soil layers at different depths in the root zone of the fruit tree to measure the volumetric water content of the soil; the field weather station collects data on air temperature, air humidity, wind speed, solar radiation intensity, and rainfall; and the fruit tree stem flow meter is set on the outside of the fruit tree trunk to collect data on the sap flow rate of the trunk.

[0018] Preferably, the decision layer includes a data preprocessing module, a crop water requirement model, and an irrigation decision algorithm. The crop water requirement model calculates the reference crop evapotranspiration based on meteorological data, and calculates the actual crop evapotranspiration by combining the crop coefficient and the water stress coefficient determined based on soil moisture content. The irrigation decision algorithm determines the irrigation water requirement based on the actual evapotranspiration and the real-time monitored root zone soil moisture content, and adjusts the irrigation strategy based on the power generation prediction data of the photovoltaic power generation system.

[0019] Preferably, the execution layer includes electric valves and valve controllers installed at each node of the irrigation network; the valve controller receives irrigation strategy instructions from the decision layer and controls the opening, closing and opening degree of the electric valves; the electric valves are normally closed solenoid valves and remain closed when power is lost.

[0020] Preferably, the energy constraint optimization logic of the hydraulic scheduling module includes: assuming that in the original irrigation strategy, the first... The planned irrigation water volume for each irrigation district is: The corresponding water demand sensitivity coefficient is Among them, the critical period of water demand Non-sensitive period dormancy period When energy availability index When the energy required for the entire irrigation task is greater than or equal to the energy required for the entire irrigation task, maintain the original irrigation strategy; when When the energy required for all irrigation tasks is between 60% and 100%, priority should be given to ensuring the water demand sensitivity coefficient. The irrigation water volume of the irrigation districts remains unchanged, while the irrigation water volume of the non-sensitive period districts is reduced to 60%~80% of the original volume, and the irrigation period of the non-sensitive period districts is shifted to the predicted peak power generation period; when When the energy required for all irrigation tasks is less than 60%, only the minimum guaranteed irrigation for water-sensitive areas will be carried out, and irrigation tasks for non-sensitive areas will be suspended. The hydraulic scheduling module adopts a rolling time-domain optimization strategy, updating the energy availability index every 15 minutes based on the latest photovoltaic power generation forecast data and the remaining energy storage capacity, and dynamically correcting the valve action sequence.

[0021] Therefore, the present invention employs the above-mentioned intelligent photovoltaic gravity drip irrigation coordinated system for orchards in hilly areas, which has the following advantages: (1) The energy-hydraulic coordinated scheduling of photovoltaic power generation and gravity drip irrigation is realized through the integrated control platform. When photovoltaic power generation is in surplus, it stores electrical energy and releases electrical energy to supplement when power generation is insufficient. When energy is insufficient, the system is ensured to operate stably by optimizing irrigation timing and water allocation, which significantly improves the utilization rate of clean energy and the robustness of the system. (2) Through the closed-loop architecture of perception-transmission-decision-execution of the intelligent management subsystem, multi-source information such as soil moisture, meteorological environment and crop physiology is integrated to realize precise irrigation decision based on crop water requirement model, which greatly improves irrigation accuracy and water resource utilization efficiency. (3) Make full use of the natural terrain elevation difference in the hilly area to achieve gravity self-pressurized drip irrigation. The irrigation water is transported entirely by gravity without the need for water pump pressurization, which greatly reduces the irrigation system's dependence on the power grid and its operating energy consumption. (4) A systematic integrated solution suitable for the complex terrain of hilly areas is formed. Each subsystem adopts modular design and standardized interface, and can be installed, debugged and maintained independently. It is easy to replicate and promote in different orchards, and provides a replicable technical path for the green and low-carbon transformation of agriculture in the hilly areas of Southwest China.

[0022] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of an intelligent photovoltaic gravity drip irrigation system for orchards in hilly areas, as described in an embodiment of the present invention. Figure 2 This is a block diagram of the composition structure of the photovoltaic power generation system in an embodiment of the present invention; Figure 3 This is a schematic diagram of the pipeline layout of the gravity drip irrigation subsystem in an embodiment of the present invention; Figure 4 This is an information flow diagram of the intelligent management subsystem in an embodiment of the present invention; Figure 5This is a flowchart illustrating the collaborative control process of the integrated control platform in this embodiment of the invention.

[0024] Figure label: 100. Photovoltaic power generation system; 110. Photovoltaic array; 120. Maximum power point tracking controller; 130. Energy storage unit; 131. Battery pack; 132. Charge and discharge management module; 140. Photovoltaic tracking device; 150. Inverter unit; 160. Photovoltaic water pump; 200. Gravity drip irrigation subsystem; 210. Elevated reservoir; 220. Irrigation network; 221. Main irrigation network; 222. Branch network; 223. Outlet branch pipe; 224. Pressure regulating valve; 230. Drip irrigation terminal; 231 1. Anti-clogging dripper; 2. Flow stabilizer; 3. Intelligent management subsystem; 3. Sensing layer; 3. 1. Soil moisture sensor; 3. 1. Field weather station; 3. 1. Fruit tree stem flow meter; 3. 2. Transmission layer; 3. 3. Decision layer; 3. 1. Data preprocessing module; 3. 2. Crop water requirement model; 3. 3. 3. 4. Irrigation decision algorithm; 3. 5. Execution layer; 3. 1. Electric valve; 3. 1. Valve controller; 4. 2. Integrated control platform; 4. 10. Energy management module; 4. 11. Hydraulic scheduling module. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0026] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] Example 1: Overall System Structure: like Figures 1-5 As shown in the figure, this embodiment proposes a smart photovoltaic gravity drip irrigation collaborative system for orchards in hilly areas, such as... Figure 1 As shown, the system includes a photovoltaic power generation system 100, a gravity drip irrigation subsystem 200, an intelligent management subsystem 300, and an integrated control platform 400.

[0028] A photovoltaic power generation system 100 is installed in the area of ​​the orchard with the best sunlight conditions, and includes a photovoltaic array 110 and an energy storage unit 130. The photovoltaic array 110 consists of multiple photovoltaic modules connected in series and parallel, converting solar energy into direct current (DC) electricity. The energy storage unit 130 stores surplus energy when the power generation of the photovoltaic array 110 is greater than the real-time load power consumption of the system, and releases energy to make up for the power gap when the power generation of the photovoltaic array 110 is less than the real-time load power consumption of the system.

[0029] The gravity drip irrigation subsystem 200 includes an elevated reservoir 210, an irrigation network 220, and drip irrigation terminals 230. The elevated reservoir 210 is constructed in the highest area of ​​the orchard, utilizing the natural elevation difference to generate gravity head. The irrigation network 220 is laid from the outlet of the elevated reservoir 210 along the slope to each irrigation zone. The drip irrigation terminals 230 are connected to the end of the irrigation network 220, delivering irrigation water to the root zone of the fruit trees in a drip manner.

[0030] The intelligent management subsystem 300 comprises a sensing layer 310, a transmission layer 320, a decision-making layer 330, and an execution layer 340. The sensing layer 310 is deployed at various monitoring points in the orchard, collecting multi-dimensional data such as soil moisture, meteorological conditions, and crop physiology. The transmission layer 320 uses wireless communication methods (such as LoRa, NB-IoT, or 4G / 5G) to achieve data transmission between the sensing layer 310, the decision-making layer 330, and the execution layer 340, ensuring real-time uploading of monitoring data and reliable distribution of control commands. The decision-making layer 330 runs on a host computer or cloud platform server, executing crop water requirement models and irrigation decision algorithms to generate the optimal irrigation strategy based on real-time sensing data. The execution layer 340 receives commands from the decision-making layer 330 and controls the operation of each valve in the gravity drip irrigation subsystem 200.

[0031] The integrated control platform 400 is communicatively connected to the photovoltaic power generation system 100, the gravity drip irrigation subsystem 200, and the intelligent management subsystem 300. The integrated control platform 400 acquires in real-time the power generation of the photovoltaic power generation system 100, the remaining power of the energy storage unit 130, and the irrigation strategy generated by the intelligent management subsystem 300. Through energy management algorithms and hydraulic scheduling algorithms, it coordinates the energy output of the photovoltaic power generation system 100 with the hydraulic operation of the gravity drip irrigation subsystem 200, achieving adaptive matching between energy supply and irrigation demand.

[0032] In this embodiment, the system operates as follows: The perception layer 310 continuously collects orchard environmental data and crop physiological data, which are then uploaded to the decision layer 330 via the transmission layer 320. The decision layer 330 runs a crop water requirement model to calculate the actual evapotranspiration and irrigation water requirement of the current crop, generating an irrigation strategy. After obtaining the irrigation strategy, the integrated control platform 400 queries the real-time power generation of the photovoltaic power generation system 100 and the remaining power of the energy storage unit 130 to determine whether the available energy in the current and future period meets the irrigation demand. If it does, an irrigation command is issued to the execution layer 340. If it does not, the irrigation strategy is adjusted (e.g., delaying the irrigation start time, reducing the amount of water used in a single irrigation), to ensure that the irrigation task is completed within the available energy range. This closed-loop control process achieves adaptive matching between energy supply and irrigation demand, significantly improving the system's energy self-sufficiency and operational reliability.

[0033] Example 2: Specific structure of a photovoltaic power generation system: like Figure 2 As shown, the photovoltaic power generation system 100 includes a photovoltaic array 110, a maximum power point tracking controller 120, an energy storage unit 130, a photovoltaic tracking device 140, and an inverter unit 150.

[0034] The photovoltaic array 110 is composed of several photovoltaic modules connected in series and parallel. The photovoltaic modules can be monocrystalline silicon or polycrystalline silicon photovoltaic modules, and their rated power is determined according to the total power load of the orchard irrigation system and the local solar energy resources.

[0035] The photovoltaic tracking device 140 includes an azimuth drive mechanism and an elevation adjustment mechanism. The azimuth drive mechanism uses a horizontal rotation axis to drive the photovoltaic array 110 to track changes in the solar azimuth angle in the horizontal direction, while the elevation adjustment mechanism uses a pitch rotation axis to drive the photovoltaic array 110 to track changes in the solar elevation angle in the vertical direction. The photovoltaic tracking device 140 calculates the sun's position based on a real-time clock and local latitude and longitude, or based on the light intensity signal fed back by a light sensor, and drives the photovoltaic array 110 to always face the direction of maximum solar radiation intensity, thereby maximizing the amount of solar energy received.

[0036] The maximum power point tracking controller 120 has a built-in maximum power point tracking algorithm. It calculates the maximum power point voltage and current of the photovoltaic array 110 in real time under the current light and temperature conditions through the perturbation observation method or the incremental conductance method, and adjusts the operating point of the photovoltaic array 110 to the maximum power point to ensure that the photovoltaic array 110 always operates in the optimal working state and improves the power generation efficiency.

[0037] The energy storage unit 130 includes a battery pack 131 and a charge / discharge management module 132. The battery pack 131 can use lithium iron phosphate batteries or lead-acid batteries, and its total capacity is determined based on the average daily power consumption of the orchard irrigation system and the number of consecutive rainy days. The charge / discharge management module 132 monitors the state of charge (SOC) of the battery pack 131. When the power generation of the photovoltaic array 110 is greater than the system load power consumption, the charge / discharge management module 132 controls the battery pack 131 to enter a charging state, storing the surplus energy in the battery pack 131; when the power generation of the photovoltaic array 110 is less than the system load power consumption, the charge / discharge management module 132 controls the battery pack 131 to enter a discharging state, releasing the stored energy to make up for the power shortfall. The charge / discharge management module 132 also has overcharge protection, over-discharge protection, overcurrent protection, and temperature protection functions to ensure the safe operation and service life of the battery pack 131.

[0038] Inverter unit 150 converts the DC power output from energy storage unit 130 into AC power to supply power to various electrical devices in the system (such as valve controllers, communication equipment, sensors, etc.). Inverter unit 150 can be a pure sine wave inverter with an output voltage of 220V / 50Hz to ensure the stable operation of electrical devices.

[0039] The photovoltaic power generation system 100 can also be equipped with a photovoltaic water pump 160 for replenishing water from a low-level water source (such as a mountain pond, reservoir, or municipal water supply network) to a high-level reservoir 210. The photovoltaic water pump 160 is directly powered by the photovoltaic array 110 or via the energy storage unit 130, and uses frequency conversion control to automatically adjust the pump speed and flow rate according to the photovoltaic power generation and the reservoir water level. The head of the photovoltaic water pump 160 is determined based on the elevation difference between the low-level water source and the high-level reservoir 210, and the flow rate is determined based on the orchard irrigation water demand and the replenishment time window. The pump efficiency is typically 0.6~0.8.

[0040] Example 3: Pipeline layout of gravity drip irrigation subsystem: like Figure 3 As shown, the gravity drip irrigation subsystem 200 includes an elevated water storage tank 210, a main irrigation network 221, a branch network 222, an outlet branch pipe 223, a pressure regulating valve 224, and a drip irrigation terminal 230.

[0041] The elevated reservoir 210 is constructed at the highest point of the orchard, with a predetermined elevation difference between its bottom and the highest irrigation point in the orchard. This elevation difference generates sufficient gravity head to drive the drip irrigation terminal 230 within its rated operating pressure range, ensuring uniform drip irrigation water distribution. In this embodiment, the predetermined elevation difference is 15-25 meters, corresponding to a static pressure of 0.15-0.25 MPa. The actual operating pressure is the static pressure minus head loss along the flow path, local head loss, and changes in the water level of the elevated reservoir 210. Calculations show that this pressure meets the rated operating pressure requirements of commonly used drip irrigation terminals 230. The volume of the elevated reservoir 210 is designed based on the orchard's irrigation area, irrigation quota, and irrigation cycle. For example, for a 20-hectare citrus orchard, the irrigation quota is 30 m³ / h. 3 If the irrigation frequency is 1 / hectare / time and the irrigation cycle is 3 days, then the effective volume of the elevated reservoir 210 shall not be less than 150m³. 3 The inlet of the elevated water storage tank 210 is connected to a rainwater collection surface and / or an external water source to maintain the water level of the tank through natural rainfall collection and / or external water replenishment. A filtration device is installed at the outlet of the elevated water storage tank 210. The filtration device can be a mesh filter or a disc filter to remove suspended solids and particulate impurities from the irrigation water and prevent clogging of the drip irrigation terminal 230.

[0042] The main irrigation network 221 extends from the outlet of the elevated reservoir 210 along the main slope of the orchard terrain, using PE or PVC pipes. The pipe diameter is determined based on the design flow rate and head loss along the route. Branch networks 222 are distributed perpendicular to the main irrigation network 221, extending along the secondary slope of the orchard terrain to each irrigation zone. The pipe diameter is determined based on the design flow rate of each irrigation zone. Outlet branch pipes 223 are spaced out on the branch networks 222, with each outlet branch pipe 223 connected to a drip irrigation terminal 230. The spacing of the outlet branch pipes 223 is determined based on the tree spacing. For example, in a citrus orchard with a tree spacing of 3 meters, the spacing of the outlet branch pipes 223 is 3 meters, with each outlet branch pipe 223 corresponding to one fruit tree.

[0043] Pressure regulating valve 224 is installed at the connection nodes between the main irrigation network 221 and each branch network 222. Based on the elevation difference between each irrigation zone and the water surface of the elevated reservoir 210, and the preset target working pressure for that irrigation zone, pressure regulating valve 224 automatically adjusts the pressure at the inlet of the branch network 222 to the target value, ensuring that the drip irrigation terminals 230 in each irrigation zone operate within the designed working pressure range. For irrigation zones with lower elevations, due to the larger natural elevation difference and higher gravitational head, pressure regulating valve 224 increases the throttling degree to reduce the inlet pressure; for irrigation zones with higher elevations, due to the smaller natural elevation difference and lower gravitational head, pressure regulating valve 224 decreases the throttling degree to maintain the inlet pressure. Through the adjustment of pressure regulating valve 224, the problem of uneven irrigation pressure caused by the elevation difference in hilly areas can be effectively eliminated, improving the irrigation uniformity of the entire orchard.

[0044] In this embodiment, the gravity drip irrigation subsystem 200 utilizes the natural elevation difference between the elevated reservoir 210 and the irrigation area to generate a gravity head. Under the action of gravity, the irrigation water flows out from the elevated reservoir 210 and flows sequentially through the main irrigation network 221, the pressure regulating valve 224, the branch network 222, the outlet branch pipe 223, and the drip irrigation terminal 230. The entire process does not require a water pump for pressurization and is entirely driven by gravity.

[0045] Example 4: Specific structure of the drip irrigation terminal: The drip irrigation terminal 230 includes an anti-clogging dripper 231 and a flow stabilizer 232.

[0046] The anti-clogging dripper 231 features a labyrinthine flow channel inside its casing. This channel, composed of multiple continuous bends, generates eddies and turbulence as irrigation water flows through it. Fine particles in the water are thrown against the channel walls by the eddies and flushed out with the flow, preventing them from accumulating and clogging the channel. Simultaneously, the long flow path of the labyrinthine channel helps dissipate energy and stabilize pressure, ensuring a stable water flow rate. The rated flow rate of the anti-clogging dripper 231 can be selected based on the water requirements of the fruit trees. For example, for mature citrus trees, a dripper with a flow rate of 2-4 L / h can be used.

[0047] The flow stabilizer 232 is located upstream of the anti-clogging dripper 231 and incorporates an elastic diaphragm and a throttling orifice plate. When the upstream water pressure increases, the elastic diaphragm deforms under the pressure, reducing the flow area of ​​the throttling orifice plate and increasing the flow resistance, thereby reducing the flow rate through the flow stabilizer 232. When the upstream water pressure decreases, the elastic diaphragm returns to its original shape, increasing the flow area of ​​the throttling orifice plate and reducing the flow resistance, thus maintaining a stable flow rate through the flow stabilizer 232. Through this mechanism, the flow stabilizer 232 can maintain a constant inlet pressure of the anti-clogging dripper 231 under fluctuating inlet pressure, ensuring a stable dripper outlet flow rate. The pressure stabilization range of the flow stabilizer 232 can be selected according to the system pressure fluctuations; for example, a flow stabilizer with a pressure stabilization range of 0.1~0.3MPa can be used.

[0048] The combined use of the anti-clogging dripper 231 and the flow stabilizer 232 ensures the uniformity of irrigation and operational reliability of the gravity drip irrigation subsystem 200 under complex terrain conditions in hilly areas.

[0049] Example 5: Perception Layer of Intelligent Management Subsystem: like Figure 4 As shown, the sensing layer 310 of the intelligent management subsystem 300 includes a soil moisture sensor 311, a field weather station 312, and a fruit tree stem flow meter 313.

[0050] Soil moisture sensors 311 are buried at different depths in the root zone of fruit trees at various monitoring points (e.g., but not limited to 20cm, 40cm, and 60cm depths). They measure the volumetric water content of the soil using frequency domain reflectance (FDR) or time domain reflectance (TDR) principles, with a measurement accuracy of ±2%. By monitoring the water content at different soil depths, the vertical distribution of soil moisture is obtained, providing a basis for judging changes in soil water storage in the root zone and the effectiveness of irrigation. The deployment density of the soil moisture sensors 311 is determined based on the orchard area and the degree of spatial variability in the soil, for example, one monitoring point per 1-2 hectares.

[0051] Field weather station 312 is installed in an open area of ​​the orchard. It includes temperature, humidity, wind speed, solar radiation, and rainfall sensors. These sensors collect data on air temperature, relative humidity, wind speed, solar radiation intensity, and rainfall to calculate reference crop evapotranspiration. The temperature sensor has a measurement range of -40 to 60℃ with an accuracy of ±0.2℃; the humidity sensor has a measurement range of 0 to 100%RH with an accuracy of ±3%RH; the wind speed sensor has a measurement range of 0 to 60 m / s with an accuracy of ±0.3 m / s; and the solar radiation sensor has a measurement range of 0 to 2000 W / m². 2 The accuracy is ±5%; the resolution of the rain gauge is 0.2 mm. The data acquisition frequency of field weather station 312 can be set to once every 10 minutes.

[0052] The fruit tree stem flow meter 313 is installed on the outside of the fruit tree trunk (e.g., about 1.3 meters above the ground). It measures the sap flow rate using either the thermal pulse method or the thermal balance method, directly reflecting the actual transpiration water consumption rate of the fruit tree. This is an important physiological indicator for assessing the water stress state of the fruit tree. The measurement range of the fruit tree stem flow meter 313 is 0–200 cm. 3 / h, with an accuracy of ±2%. At each monitoring point, select 3 to 5 representative fruit trees and install fruit tree stem flow meters 313. Take the average value as the transpiration water consumption rate of the fruit trees at that monitoring point.

[0053] The perception layer 310 forms a three-dimensional monitoring network of "soil-meteorology-crops" in space through the above three types of sensors, providing a comprehensive and real-time data foundation for the decision-making layer 330 to make precise irrigation decisions.

[0054] Example 6: Decision-making layer of the intelligent management subsystem: The decision layer 330 runs on a cloud platform server and includes a data preprocessing module 331, a crop water requirement model 332, and an irrigation decision algorithm 333.

[0055] The data preprocessing module 331 receives the raw data uploaded by the sensing layer 310, performs data cleaning, data interpolation, and data standardization to generate a structured standardized dataset. Data cleaning includes removing outliers (such as data outside the sensor's measurement range) and duplicate data; data interpolation uses linear interpolation or the mean of adjacent time periods to fill in missing data; data standardization converts sensor data of different dimensions into a unified standard format to facilitate subsequent model calculations.

[0056] Crop water requirement model 332 adopts the Penman-Monteith formula, a reference crop evapotranspiration calculation model recommended by the Food and Agriculture Organization of the United Nations (FAO), and calculates the reference crop evapotranspiration based on meteorological data. : ; in, For reference crop evapotranspiration (mm / d); Net radiation (MJ / m 2 ·d), calculated from solar radiation intensity and ground longwave radiation; Soil heat flux (MJ / m 2 ·d), which can be approximated in day-scale calculations. ; The average air temperature (°C) was collected by the temperature sensor at field weather station 312. The wind speed (m / s) at a height of 2 meters was collected by the wind speed sensor at field weather station 312. The saturated vapor pressure (kPa) is based on the average temperature. Calculated; The actual water vapor pressure (kPa) is calculated from the relative humidity of the air and the saturated water vapor pressure. The slope of the saturated vapor pressure-temperature curve (kPa / ℃) is based on the average air temperature. Calculated; This is the hygrometer constant (kPa / ℃), calculated based on the local altitude and temperature.

[0057] In calculation Based on this, crop coefficients are further introduced. and water stress coefficient Calculate the actual evapotranspiration of the crop. : ; in, Actual crop evapotranspiration (mm / d); This is a crop coefficient, determined based on the growth stage of the fruit tree, for example, during the budding stage of citrus trees. During the new shoot growth period During the fruit enlargement period During the fruit ripening period During dormancy ; The water stress coefficient is determined based on the root zone soil moisture content monitored by soil moisture sensor 311. It is defined as the soil moisture content in the root zone exceeding 70% of field capacity. =1, when the soil moisture content in the root zone is between 50% and 70% of field capacity. It exhibits a linear variation between 0.5 and 1, and when the soil moisture content in the root zone is less than 50% of the field capacity... .

[0058] Irrigation decision algorithm 333 calculates based on crop water requirement model 332. The system uses real-time monitoring of soil moisture content and fruit tree stem flow rate by the sensing layer 310, along with power generation prediction data from the photovoltaic power generation system 100, to generate an optimal irrigation strategy. The irrigation strategy includes: irrigation start time (selected based on the photovoltaic power generation prediction, taking advantage of the optimal light conditions and highest power generation), irrigation duration (calculated based on irrigation water demand and the rated flow rate of the drip irrigation terminal 230), and target irrigation water volume for each irrigation plot (set differently based on the soil moisture content and crop water requirements of each plot).

[0059] Example 7: Execution layer of the intelligent management subsystem: The execution layer 340 includes electric valves 341 and valve controllers 342 installed at each node of the irrigation network 220.

[0060] Electric valves 341 are installed at the connection points between the main irrigation network 221 and each branch network 222, and at the connection points between each branch network 222 and each outlet branch pipe 223. Electric valves 341 are normally closed solenoid valves, meaning they remain closed in the absence of power and open when energized, ensuring that the system will not experience accidental irrigation in the event of a power outage or malfunction. The nominal diameter of electric valves 341 is determined based on the design flow rate of the pipeline. For example, the nominal diameter of electric valves 341 on the main pipeline is DN50~DN100, on branch pipelines it is DN25~DN50, and on outlet branch pipes it is DN15~DN20. The working pressure of electric valves 341 is not less than 0.6MPa, meeting the pressure requirements of gravity drip irrigation systems.

[0061] Each valve controller 342 corresponds to one electric valve 341, with each controller controlling the opening, closing, and opening adjustment of one electric valve 341. The valve controller 342 integrates a microcontroller unit (MCU) and a communication module, communicating with the integrated control platform 400 via the communication module. It receives valve action commands from the integrated control platform 400 and outputs corresponding drive signals (such as PWM signals to adjust the opening) to the electric valve 341. The valve controller 342 also has a manual control function, allowing manual control of the electric valve 341 via local buttons during communication failures or debugging phases. The valve controller 342 employs a low-power design, powered by the photovoltaic power generation system 100 via the inverter unit 150, or by a separate small photovoltaic panel and battery.

[0062] Example 8: Collaborative Control of an Integrated Control Platform like Figure 5 As shown, the integrated control platform 400 includes an energy management module 410 and a hydraulic scheduling module 420.

[0063] The energy management module 410 monitors the power generation of the photovoltaic power generation system 100 in real time. and the remaining power of energy storage unit 130 The energy management module 410 has a built-in photovoltaic power generation prediction submodule. This submodule predicts the power generation in the future period based on solar radiation intensity prediction data from weather forecasts and historical power generation data of the photovoltaic array 110. The energy management module 410 also monitors the system's real-time load power consumption. Calculate the energy availability index : ; in, The energy availability index (kWh) reflects the total amount of available energy that the system can use for irrigation in the current and predicted future period. The state of charge of the energy storage unit 130 ranges from 0 to 1 (in decimal form) and is monitored in real time by the charge and discharge management module 132. The minimum safe state of charge for energy storage is typically set at 0.2 to 0.3, to prevent over-discharge of the battery pack 131. The total capacity (kWh) of the energy storage unit 130 is determined by the rated voltage and rated capacity of the battery pack 131; For discharge efficiency, a value of 0.9 to 0.95 is typically used; This is the starting time of integration, i.e., the current moment; This is the time when the integration ends, i.e., the time when the irrigation task is scheduled to be completed. for The predicted photovoltaic power generation (kW) at any given time is obtained by the photovoltaic power generation prediction submodule based on weather forecasts and historical power generation data; This is the rated maximum power (kW) of the photovoltaic array 110. Used to limit photovoltaic power generation to no more than the rated value; For charging efficiency, a value of 0.9 to 0.95 is typically used. for Real-time system load power consumption (kW), including: valve drive power consumption Sensor power consumption Power consumption of communication equipment and power consumption of photovoltaic water pumps (If any).

[0064] The hydraulic scheduling module 420 receives irrigation strategies generated by the decision layer 330 of the intelligent management subsystem 300, including the target irrigation water volume for each irrigation zone. and recommended irrigation period The hydraulic dispatching module 420 uses the energy availability index provided by the energy management module 410. Determine the recommended irrigation period The energy required to perform all irrigation tasks Is it less than or equal to? If so, the valve action sequence is generated directly according to the irrigation strategy of decision layer 330 and sent to execution layer 340 for execution. If not, energy constraint optimization is initiated.

[0065] In this embodiment, the specific logic of energy constraint optimization is as follows: Let the original irrigation strategy have the following... The planned irrigation water volume for each irrigation district is: The corresponding water demand sensitivity coefficient is (Critical period of water demand) Non-sensitive period dormancy period Irrigation energy required by the system. It includes two parts: one is the energy consumption of the photovoltaic water pump that replenishes water to the high-level water storage tank 210. Secondly, the energy consumption of valves, sensors, and communication equipment during irrigation. Energy consumption of photovoltaic water pumps for water lifting Calculated based on water lifting head, water lifting capacity, and pump efficiency: ,in The density of water (1000 kg / m³) 3 ), The acceleration due to gravity (9.8 m / s²) 2 ), The lifting head (m) is the water lifting head. Total water lifting volume (m³)3 ), For pump efficiency, a value of 0.6 to 0.8 is typically used. Operating energy consumption. ,in This refers to the number of valves that need to be activated during the irrigation process. Energy consumption per single valve switching cycle (kWh / cycle). This represents the system standby power consumption (kW). The duration of irrigation (h).

[0066] The hydraulic scheduling module 420 calculates the optimal water allocation under energy constraints. Its decision-making logic is as follows: (1) When Maintain the original strategy, that is ; (2) When At that time, priority should be given to ensuring the water supply of communities sensitive to water demand. The irrigation water volume remains unchanged, while the irrigation water volume of non-sensitive areas is reduced proportionally to 60% to 80% of the original volume, and the irrigation period of non-sensitive areas is shifted to the predicted peak power generation period. (3) When At that time, only the minimum guaranteed irrigation for water-sensitive areas will be implemented (i.e., Irrigation of all non-sensitive residential areas will be suspended until the energy storage units are charged by photovoltaic power. Restored to above the threshold.

[0067] Meanwhile, the hydraulic dispatch module 420 adopts a rolling time-domain optimization strategy, adjusting the data every 15 minutes based on the latest photovoltaic power generation forecast data and energy storage. Update once It also dynamically corrects the subsequent valve action sequence to cope with sudden changes in light such as localized cloudy weather in hilly areas.

[0068] After generating the optimized valve action sequence, the hydraulic scheduling module 420 sends it to each valve controller 342 via the communication network to execute the irrigation task.

[0069] Example 9: System Operation Flow: The complete operation flow of the intelligent photovoltaic gravity drip irrigation collaborative system for orchards in hilly areas according to the present invention is as follows, which demonstrates the collaborative working method between the various subsystems of the system: Step S1: Data Acquisition. The sensing layer 310 continuously collects data on the volumetric water content of soil at various depths, air temperature, humidity, wind speed, solar radiation, rainfall, and sap flow rate of tree trunks. All collected data is uploaded to the host computer or cloud platform via the transmission layer 320. Simultaneously, the energy management module 410 monitors the photovoltaic power generation in real time. and remaining energy storage capacity .

[0070] Step S2: Data Processing and Irrigation Strategy Generation. The data preprocessing module 331 of the decision layer 330 cleans and standardizes the received raw data. The crop water requirement model 332 calculates the reference crop evapotranspiration using the Penman-Monteith formula based on meteorological data. Combined with crop coefficient and water stress coefficient Calculate the actual evapotranspiration of the crop. Irrigation decision algorithm 333 is based on the actual evapotranspiration of the crop. Calculate the irrigation water requirement based on the current root zone soil moisture content, effective rainfall, and irrigation water use coefficient: ; ; in, Net irrigation water requirement (mm); Gross irrigation water requirement (mm); Target soil volumetric water content (cm³) 3 / cm 3 The water holding capacity is usually taken as 70% to 90% of the field water holding capacity, depending on the fruit tree growth stage and soil texture. The current average volumetric water content of the root zone (cm³) 3 / cm 3 The result was obtained by weighted averaging of soil moisture content at different depths monitored by soil moisture sensor 311. The root zone depth (m) is determined based on the root distribution depth of the fruit tree. For example, the root zone depth of a mature citrus tree is 0.6~0.8m; 1000 is the conversion factor from meters to millimeters (1m=1000mm). Effective rainfall (mm), rainfall monitored by field weather station 312. Multiply by the effective utilization coefficient of rainfall To obtain, that is , The value is determined based on rainfall intensity, soil infiltration capacity, and topographic slope, and is usually taken as 0.7 to 0.9. The irrigation water use coefficient is typically set at 0.85 to 0.95 for drip irrigation systems, determined based on network water loss and field irrigation uniformity. When the current soil moisture content plus effective rainfall is sufficient to meet the crop's water requirements, irrigation is not necessary; when... At this time, irrigation supplementation is required, and the gross irrigation water requirement is... Divide by the irrigation water utilization coefficient.

[0071] like The decision-making layer generates irrigation strategies, including target irrigation water volume and recommended irrigation periods for each irrigation district (prioritizing the period with the highest predicted photovoltaic power generation).

[0072] Step S3: Energy Assessment and Strategy Optimization. The energy management module 410 of the integrated control platform 400 acquires the real-time power generation of the photovoltaic power generation system 100. The remaining power of energy storage unit 130 The hydraulic scheduling module 420 calculates the total energy required to execute the irrigation strategy based on the above-mentioned water lifting energy consumption and operating energy consumption. ,judge Does it not exceed If yes, proceed to step S4; otherwise, adjust the irrigation timing and / or the water allocation of each irrigation zone according to the energy constraint optimization logic in Example 8, and then proceed to step S4.

[0073] Step S4: Irrigation Execution and Feedback. The integrated control platform 400 converts the optimized irrigation strategy into a valve action sequence and sends it to the valve controllers 342 of the execution layer 340. Each valve controller 342 controls the electric valves 341 to open and adjust sequentially according to the action sequence. Irrigation water flows out from the high-level storage tank 210 under gravity and is transported through the irrigation network 220 to the drip irrigation terminals 230 of each irrigation zone, irrigating the root zone of the fruit trees in a drip manner. During irrigation, the sensing layer 310 continuously monitors the changes in soil moisture content in each irrigation zone and provides real-time feedback. If the soil moisture content of a certain irrigation zone reaches the target value within the preset irrigation time, the decision layer 330 sends an instruction to the integrated control platform 400 to terminate irrigation in that zone in advance. The integrated control platform 400 then controls the corresponding electric valve 341 to close in advance. After irrigation is completed, the system returns to step S1 to continue the next round of data acquisition and decision-making loop.

[0074] Example 10: Application Scenarios and Effects of the System This system is particularly suitable for irrigation management in orchards (such as citrus orchards, kiwi orchards, and vineyards) in the hilly areas of Chengdu and similar hilly terrain in Southwest China.

[0075] Taking the Pujiang citrus orchard in the hilly area of ​​Chengdu as an example, the orchard covers an area of ​​20 hectares with significant topographic relief, a height difference of approximately 15-25 meters. After installing this system, the total installed capacity of the photovoltaic power generation system 100 will be 25kW, with an annual power generation of approximately 30,000kWh, which can meet most of the annual electricity demand of the irrigation system and improve the system's energy self-sufficiency rate. The elevated reservoir 210 has a total water storage capacity of 150m³. 3Utilizing the elevation differences in the orchard terrain to generate gravity-driven water head, irrigation water is transported entirely by gravity, eliminating the need for pumps. The intelligent management subsystem 300 achieves on-demand water supply and precise irrigation through real-time monitoring and accurate decision-making. Compared to traditional irrigation methods, it has better water-saving effects, improved irrigation uniformity, and significantly improved fruit yield and fruit quality.

[0076] This system adopts a modular design and standardized interfaces. Each subsystem can be installed, debugged and maintained independently, making it easy to replicate and promote in different orchards. It has good economic, ecological and social benefits.

[0077] 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 preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A smart photovoltaic gravity drip irrigation system for orchards in hilly areas, characterized in that, It includes a photovoltaic power generation system, a gravity drip irrigation subsystem, an intelligent management subsystem, and an integrated control platform; A photovoltaic power generation system includes a photovoltaic array and an energy storage unit. The photovoltaic array is used to convert solar energy into electrical energy, and the energy storage unit is used to store electrical energy and release it when power generation is insufficient. The gravity drip irrigation subsystem includes an elevated water storage tank, an irrigation pipeline network, and drip irrigation terminals. The elevated water storage tank is located at the highest point of the orchard and utilizes the natural elevation difference to generate gravity head. The irrigation pipeline network is laid along the terrain from the outlet of the elevated water storage tank, and the drip irrigation terminals are connected to the end of the irrigation pipeline network. The intelligent management subsystem includes a perception layer, a transmission layer, a decision-making layer, and an execution layer. The perception layer collects soil moisture data, meteorological data, or crop physiological data. The transmission layer is used for data transmission between the perception layer, the decision-making layer, and the execution layer. The decision-making layer generates irrigation strategies based on the data collected by the perception layer. The execution layer is used to control the operation of the gravity drip irrigation subsystem. The integrated control platform is communicatively connected to the photovoltaic power generation system, the gravity drip irrigation subsystem, and the intelligent management subsystem. The integrated control platform includes an energy management module and a hydraulic scheduling module. The energy management module monitors the power generation of the photovoltaic power generation system and the remaining power of the energy storage unit in real time, and generates an energy availability index based on photovoltaic power generation forecast data. The hydraulic scheduling module obtains the irrigation strategy generated by the intelligent management subsystem and determines whether the available energy meets the energy requirements for irrigation based on the energy availability index. If it does, it generates a valve action sequence according to the irrigation strategy. If not, the hydraulic scheduling module adjusts the irrigation timing of the irrigation strategy or the water allocation of each irrigation zone under the constraint of meeting the minimum water requirements of the fruit trees, to match the current energy supply capacity, and generates an optimized valve action sequence. The hydraulic scheduling module prioritizes the irrigation needs of the fruit trees during their water-sensitive periods.

2. The intelligent photovoltaic gravity drip irrigation system for orchards in hilly areas according to claim 1, characterized in that: The photovoltaic power generation system also includes a maximum power point tracking controller and a photovoltaic tracking device; the maximum power point tracking controller adjusts the operating point of the photovoltaic array to obtain the maximum power generation; the photovoltaic tracking device includes an azimuth drive mechanism and an elevation adjustment mechanism, which drive the photovoltaic array to track changes in the solar azimuth and elevation angles.

3. The intelligent photovoltaic gravity drip irrigation system for orchards in hilly areas according to claim 1, characterized in that: The energy storage unit includes a battery pack and a charge / discharge management module. The charge / discharge management module monitors the state of charge of the battery pack. When the power generation of the photovoltaic array is greater than the real-time power consumption of the system, the excess power is stored in the battery pack. When the power generation of the photovoltaic array is less than the real-time power consumption, the module controls the battery pack to discharge to make up for the power shortage.

4. The intelligent photovoltaic gravity drip irrigation system for orchards in hilly areas according to claim 1, characterized in that: There is a preset height difference between the bottom of the elevated water storage tank and the highest irrigation point in the orchard. The gravity head generated by the preset height difference is sufficient to drive the drip irrigation terminal to operate within the rated working pressure range. The volume of the elevated water storage tank is set according to the irrigation area and irrigation cycle of the orchard. The inlet of the elevated water storage tank is connected to a rainwater collection surface or an external water source, and a filter device is installed at the outlet of the elevated water storage tank.

5. The intelligent photovoltaic gravity drip irrigation system for orchards in hilly areas according to claim 1, characterized in that: The irrigation network includes a main pipeline laid along the main slope of the orchard and branch pipelines distributed perpendicular to the main pipeline. Several outlet branches are installed at intervals on the branch pipelines, and the end of each outlet branch is connected to a drip irrigation terminal. The irrigation network also includes pressure regulating valves installed at the connection nodes of the main pipeline and the branch pipelines. The pressure regulating valves adjust the water pressure in the branch pipelines according to the elevation difference of each irrigation area and the preset irrigation pressure.

6. The intelligent photovoltaic gravity drip irrigation system for orchards in hilly areas according to claim 1, characterized in that: The drip irrigation terminal includes an anti-clogging dripper and a flow stabilizer; the flow channel of the anti-clogging dripper has a labyrinth structure; the flow stabilizer is located on the upstream side of the anti-clogging dripper and has a built-in elastic diaphragm and a throttling orifice plate. The flow area of ​​the throttling orifice plate is adjusted by the deformation of the elastic diaphragm to maintain a constant inlet water pressure of the anti-clogging dripper.

7. The intelligent photovoltaic gravity drip irrigation system for orchards in hilly areas according to claim 1, characterized in that: The sensing layer includes a soil moisture sensor, a field weather station, and a fruit tree stem flow meter. The soil moisture sensor is buried in different depths of soil in the root zone of the fruit tree to measure the volumetric water content of the soil. The field weather station collects data on air temperature, air humidity, wind speed, solar radiation intensity, and rainfall. The fruit tree stem flow meter is set on the outside of the fruit tree trunk to collect data on the sap flow rate of the trunk.

8. The intelligent photovoltaic gravity drip irrigation system for orchards in hilly areas according to claim 1, characterized in that: The decision-making layer includes a data preprocessing module, a crop water requirement model, and an irrigation decision algorithm; The crop water requirement model calculates the reference crop evapotranspiration based on meteorological data, and calculates the actual crop evapotranspiration by combining the crop coefficient and the water stress coefficient determined based on soil moisture content. The irrigation decision algorithm determines the irrigation water requirement based on the actual evapotranspiration and the real-time monitored root zone soil moisture content, and adjusts the irrigation strategy based on the power generation forecast data of the photovoltaic power generation system.

9. The intelligent photovoltaic gravity drip irrigation system for orchards in hilly areas according to claim 1, characterized in that: The execution layer includes electric valves and valve controllers installed at each node of the irrigation network; the valve controllers receive irrigation strategy instructions from the decision layer and control the opening, closing and opening degree of the electric valves; the electric valves are normally closed solenoid valves and remain closed when power is lost.

10. The intelligent photovoltaic gravity drip irrigation system for orchards in hilly areas according to claim 1, characterized in that: The energy constraint optimization logic of the hydraulic scheduling module includes: assuming the original irrigation strategy has the following parameters... The planned irrigation water volume for each irrigation district is: The corresponding water demand sensitivity coefficient is Among them, the critical period of water demand Non-sensitive period dormancy period When energy availability index When the energy required for the entire irrigation task is greater than or equal to the energy required for the entire irrigation task, maintain the original irrigation strategy; when When the energy required for all irrigation tasks is between 60% and 100%, priority should be given to ensuring the water demand sensitivity coefficient. The irrigation water volume of the irrigation districts remains unchanged, while the irrigation water volume of the non-sensitive period districts is reduced to 60%~80% of the original volume, and the irrigation period of the non-sensitive period districts is shifted to the predicted peak power generation period; when When the energy required for all irrigation tasks is less than 60%, only the minimum guaranteed irrigation for water-sensitive areas will be carried out, and irrigation tasks for non-sensitive areas will be suspended. The hydraulic scheduling module adopts a rolling time-domain optimization strategy, updating the energy availability index every 15 minutes based on the latest photovoltaic power generation forecast data and the remaining energy storage capacity, and dynamically correcting the valve action sequence.

Images