Energy Self-sufficient Smart Anti-frost Fan System and Control Method Thereof

Abstract

An energy-independent smart frost-prevention fan system for preventing frost damage to crops in open-field environments where electricity supply is difficult, according to an embodiment of the present invention, comprises: a photovoltaic power generation module that generates electricity using external natural light; a battery management system that controls the charging of electricity supplied from the photovoltaic power generation module and generates battery status information including the voltage, current, and state of charge (SOC) of the battery; a sensor unit that measures weather environment data including temperature, humidity, and wind speed in real time in an area where the frost-prevention fan is installed; a main control unit that generates a control signal by analyzing the battery status information received from the battery management system and the weather environment data received from the sensor unit; and a drive unit including a direct current (DC) motor and a blower fan that operates according to the control signal of the main control unit to generate airflow. The main control unit operates the drive unit using only the power of the battery without the input of external power, and variably controls the operating time and rotation speed of the drive unit by mutually calculating the trend of change in the weather environment data and the battery state of charge (SOC).

Description

Technology Field

[0001] The present invention relates to an agricultural frost protection fan, and more specifically, to an energy-independent smart frost protection fan system and a control method thereof that can be operated by self-powered energy by utilizing solar power generation and a battery management system (BMS) in open-field environments where electricity supply is difficult, and maximizes energy efficiency and frost protection performance by applying a load prediction-based battery efficiency operation algorithm. Background Technology

[0003] In general, in crop cultivation environments, especially in open-field environments such as orchards or tea fields, frost or cold damage caused by a sudden drop in temperature during the spring flowering or autumn harvest seasons has a fatal impact on crop yield and quality. To prevent this, a method of raising the surface temperature by installing frost fans at a height of 6 to 10 meters above the ground and blowing warm air from the upper layer down to the lower layer is widely used.

[0005] However, most conventional frost protection fan systems are designed to drive motors using commercial AC power, requiring separate power connection work in open-field environments such as mountainous regions or vast plains where utility poles or distribution facilities are not available. The installation of such power facilities not only incurs substantial initial costs but has also been a factor that makes the proper placement of frost protection fans difficult due to topographical constraints at the installation site.

[0007] Furthermore, conventional control methods relied on on-off control, where managers manually operated switches on-site or uniformly activated fans when the temperature dropped below a set threshold. This manual control approach has the disadvantage of being unable to take preemptive action before frost forms, as it fails to account for complex meteorological variables that influence frost formation, such as humidity, wind speed, and atmospheric pressure. In particular, there were limitations to inefficient operation, such as fans being activated belatedly during a rapid drop in temperature or, conversely, fans being unnecessarily activated even when the likelihood of frost was low, leading to wasted power.

[0009] In addition, some types of anti-storage fans combining solar power generation and batteries have been proposed, but they remain at a one-dimensional structure that simply stores and uses electricity. In other words, there was a lack of technology to regulate energy consumption by comprehensively calculating the battery's state of charge (SOC), the variability of solar power generation, and the expected load of the anti-storage fan that must be maintained during the night. As a result, there were problems that made it difficult to guarantee stable, energy-independent operation, such as the battery discharging and stopping operation during late-night hours or at the lowest temperatures of dawn, or the battery life being shortened due to excessive discharge.

[0011] Therefore, there is a need for a new type of smart frost-prevention fan system and a control method thereof that enables independent operation through solar power generation and energy storage devices even in open-field environments where external power supply is cut off, and simultaneously secures energy efficiency and frost prevention performance by optimizing operating patterns through the analysis of weather data and battery status. Prior art literature

[0013] Korean Patent Publication No. 2024-0169225 (December 3, 2024) The problem to be solved

[0014] The present invention is devised based on the aforementioned problems, and the objective of the present invention is to provide an energy-independent smart frost-proof fan system that can be installed and operated in open-field environments lacking power facilities by securing driving power without the need for external AC power input using a photovoltaic power generation module and a battery management system (BMS).

[0016] Furthermore, the objective of the present invention is to maintain frost protection performance by efficiently utilizing limited battery power by applying a load prediction-based battery efficiency operation algorithm that analyzes weather data and battery status data to predict the probability of frost occurrence and, based on this, preemptively determines whether to operate the frost protection fan and its operating time.

[0018] Furthermore, the objective of the present invention is to ensure management convenience and system stability by precisely controlling the rotational speed of a direct current (DC) motor, diagnosing or self-recovering in the event of an abnormal condition, and enabling remote monitoring of the status via IoT communication. means of solving the problem

[0020] According to one embodiment of the present invention for achieving the aforementioned objective, an energy-independent smart frost protection fan system for preventing frost damage to crops in an open-field environment where electricity supply is difficult comprises: a photovoltaic power generation module that generates power using external natural light; a battery management system that controls the charging of power supplied from the photovoltaic power generation module and generates battery status information including the voltage, current, and state of charge (SOC) of the battery; a sensor unit that measures weather environment data including temperature, humidity, and wind speed in real time in an area where the frost protection fan is installed; a main control unit that generates a control signal by analyzing the battery status information received from the battery management system and the weather environment data received from the sensor unit; and a drive unit including a direct current (DC) motor and a blower fan that operates according to the control signal of the main control unit to generate airflow. The main control unit operates the drive unit using only the power of the battery without the input of an external power source, and variably controls the operating time and rotation speed of the drive unit by mutually calculating the trend of change in the weather environment data and the battery state of charge (SOC).

[0022] In the aforementioned embodiment of the present invention, the main control unit performs a load prediction-based battery efficiency operation algorithm, and can perform a frost occurrence probability calculation step in which the dew point temperature is calculated using the current temperature and relative humidity measured by the sensor unit, and the probability of frost occurring within a specific time is calculated by analyzing the temperature drop slope; and an optimal wind speed calculation step in which, when the calculated frost occurrence probability exceeds a preset threshold, the drive unit is operated and the target rotational speed of the motor is determined according to the battery remaining capacity (SOC).

[0024] In the above-described embodiment of the present invention, in the optimal wind speed calculation step, the main control unit calculates the total amount of available energy that can be driven until sunrise with the current battery remaining capacity (SOC), and compares this with the required energy required to maintain the target wind speed. If it is determined that the available energy is insufficient compared to the required energy, the duty ratio of the Pulse Width Modulation (PWM) signal applied to the DC motor is lowered to a lower threshold value that can suppress frost formation, thereby extending the operating duration.

[0026] In the aforementioned embodiment of the present invention, the driving unit further includes an electronic speed controller (ESC), the main control unit controls the rotational speed of the DC motor through the electronic speed controller, and the battery management system can optimize the power generation efficiency of the photovoltaic power generation module through Maximum Power Point Tracking (MPPT) control and perform a cell balancing function that balances the voltage between a plurality of cells constituting the battery.

[0028] In the aforementioned embodiment of the present invention, the system further includes a communication module connected to the main control unit and transmitting the weather environment data and the battery status information to a remote cloud server via a wireless communication network; wherein the cloud server provides a monitoring screen to a user terminal based on the received data and transmits a remote control command input from the user terminal to the main control unit to forcibly drive the driving unit or change control parameters. Effects of the invention

[0030] According to the present invention, by linking a solar power generation system with a battery management system, independent and stable operation of a frost-prevention fan is possible even in open-field environments without external power supply, thereby reducing installation costs and overcoming location constraints. Furthermore, by applying a load prediction algorithm that fuses and analyzes weather data and remaining battery capacity, frost formation is preemptively blocked and energy efficiency is maximized, effectively preventing cold damage to crops without worrying about battery discharge during nighttime hours. In addition, through an IoT-based remote control function, real-time monitoring and control are possible even when a manager is not present on-site, which has the effect of dramatically improving the convenience and efficiency of farm operations. Brief explanation of the drawing

[0032] FIG. 1 is a block diagram schematically showing the overall configuration of an energy-independent smart anti-septic fan system according to one embodiment of the present invention. FIG. 2 is a perspective view showing the actual installation shape of a frost-proof fan system according to one embodiment of the present invention. FIG. 3 is a diagram showing the detailed circuit configuration of a photovoltaic power generation and battery management system (BMS) according to one embodiment of the present invention. FIG. 4 is a block diagram showing the hardware configuration of a sensor-fusion type motor control unit according to one embodiment of the present invention. FIG. 5 is a flowchart showing the overall operation control flow of a system according to one embodiment of the present invention. Figure 6 is a detailed logic flowchart of a load prediction-based battery efficiency operation algorithm, which is a core technology of the present invention. FIG. 7 is a conceptual diagram showing IoT-based remote monitoring and network configuration according to one embodiment of the present invention. Specific details for implementing the invention

[0033] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms.

[0035] The embodiments described herein are provided to ensure that the disclosure of the invention is complete and to fully inform those skilled in the art of the scope of the invention. The invention is defined only by the scope of the claims. Accordingly, in some embodiments, well-known components, well-known operations, and well-known techniques are not specifically described to avoid the invention being interpreted ambiguously.

[0037] Throughout the specification, the same reference numerals refer to the same components. Furthermore, the terms used (mentioned) in this specification are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. Additionally, components and operations referred to as "comprising (or comprising)" do not exclude the presence or addition of one or more other components and operations.

[0039] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless otherwise defined.

[0041] FIG. 1 is a block diagram schematically showing the overall configuration of an energy-independent smart anti-septic fan system according to one embodiment of the present invention.

[0043] Referring to FIG. 1, an energy-independent smart anti-sunlight fan system (100) according to one embodiment of the present invention includes: a photovoltaic power generation module (110) that generates power using external natural light; a battery management system (120) that converts and controls power supplied from the photovoltaic power generation module (110) and manages battery cells; a battery (121) that stores power connected to the battery management system (120); a sensor unit (140) that collects and outputs weather environment data around the anti-sunlight fan in real time; a main control unit (130) that generates an optimal driving signal based on the collected data and battery status information; and a driving unit (150) that rotates and generates airflow according to the control signal of the main control unit (130).

[0045] First, the solar power generation module (110) serves as the main power source of the system and plays the role of securing independent power in open-field environments where electricity supply is difficult. The solar power generation module (110) can be configured in the form of an array in which a plurality of solar cells are connected in series or parallel, and produces direct current (DC) power by absorbing sunlight and generating electromotive force. Considering the characteristics of the open-field environment, it is preferable that the solar power generation module (110) be finished with a reinforced glass and aluminum frame that has durability to withstand external weather conditions such as rain, strong winds, and heavy snow. In addition, it can be fixedly installed on the top of a support at an angle that maximizes power generation efficiency, taking into account the latitude of the installation area and the seasonal solar altitude. The power produced by the solar power generation module (110) is transmitted to the battery management system (120), which will be described later.

[0047] A battery management system (120, BMS) is electrically connected between a solar power generation module (110), a battery (121), and a main control unit (130) to actively control the flow of power. Specifically, the battery management system (120) performs a charging control function that converts irregular voltage and current input from the solar power generation module (110) into a constant voltage or constant current form suitable for charging the battery (121). At this time, even if the power generated fluctuates according to changes in sunlight, charging efficiency can be maximized by applying a Maximum Power Point Tracking (MPPT) control method. In addition, the battery management system (120) includes a protection circuit that prevents overcharge, over-discharge, and over-current of the battery (121), and performs a cell balancing function that balances the voltage between the battery (121) composed of multiple cells to ensure the lifespan and safety of the battery. In addition, the battery management system (120) monitors the current voltage, current, temperature, etc. of the battery (121) in real time to generate data on the remaining capacity (SOC: State of Charge) and battery life status (SOH: State of Health), and transmits this to the main control unit (130) via a communication line.

[0049] The battery (121) is charged by the battery management system (120) and serves as an energy storage device (ESS) that stores power so that the system can operate even at night or in cloudy weather when solar power generation is not taking place. The battery (121) in the present invention may be composed of a lithium-ion (Li-ion) battery with high energy density and no memory effect, or a lithium iron phosphate (LiFePO4) battery with excellent fire safety and a long lifespan. In particular, to maintain stable output even under rapid temperature changes in an open-field environment, it may be housed inside a separate housing containing insulation or combined with a constant temperature device that maintains a constant temperature. The capacity of the battery (121) is calculated by comprehensively considering the cultivation area of ​​the target crop, the power consumption of the frost fan motor, and the days of autonomy.

[0051] The sensor unit (140) detects the micro-weather environment of the area where the frost-proof fan is installed, generates data, and inputs it to the main control unit (130). As shown in FIG. 1, the sensor unit (140) may include a temperature sensor that measures the temperature in the atmosphere, a humidity sensor that measures the moisture content in the air, and a wind speed sensor that measures the wind speed. Depending on the case, a wind direction sensor, a pressure sensor, a rainfall sensor, etc. may be additionally included. In particular, the sensor unit (140) goes beyond simply measuring the current temperature to detect the temperature difference between the temperature near the ground surface and the temperature above the frost-proof fan, or provides basic data necessary to calculate the dew point temperature by combining temperature and humidity data. Data collected by the sensor unit (140) is transmitted in real time to the main control unit (130) via wired communication or short-range wireless communication, and this data is used as an input variable for an algorithm that predicts the possibility of frost occurrence.

[0053] The main controller (130) is a component corresponding to the brain of the system, and operates by receiving power from the battery management system (120) and controls the entire system. The main controller (130) may be implemented including a microprocessor (MCU) and fuses and analyzes battery status data (SOC, etc.) received from the battery management system (120) and weather data received from the sensor unit (140). The main controller (130) is equipped with a load prediction-based operation algorithm, which preemptively determines the start time, duration of operation, and target rotation speed of the frost fan by comparing the current temperature downward trend with the remaining battery charge. For example, if the main controller (130) determines that there is a high risk of frost but the remaining battery charge is insufficient, it can generate a control signal to operate in an energy-efficient mode that maximizes the operating time by adjusting the motor output.

[0055] Finally, the drive unit (150) is a device that actually generates physical airflow by receiving a control signal from the main control unit (130). The drive unit (150) includes a direct current (DC) motor that converts electrical energy into rotational kinetic energy and a blower fan coupled to the motor shaft. In the present invention, to maximize energy efficiency, a BLDC (Brushless DC) motor, which has no brushes, has low friction loss, and excellent durability, may be adopted as the motor of the drive unit (150). The drive unit (150) does not simply rotate at a fixed speed, but its rotational speed (RPM) is precisely variablely controlled by a PWM (Pulse Width Modulation) signal output from the main control unit (130). In addition, the drive unit (150) is configured to include a slewing motor that rotates the direction of the entire fan in addition to the blower fan, so that it can effectively disturb the cold air layer formed on a large area of ​​crops by rotating and blowing air within a range of 360 degrees or a specific angle.

[0057] As such, each component illustrated in FIG. 1 is organically combined to perform intelligent weather activities that produce, store, and manage power independently even in the absence of an external power supply, and actively respond to weather conditions.

[0059] FIG. 2 is a perspective view showing the actual installation shape of an energy-independent smart frost-proof fan system according to one embodiment of the present invention.

[0061] Referring to FIG. 2, an energy-independent smart anti-storage fan system according to one embodiment of the present invention comprises: a support (230) that is firmly fixed to the ground and supports the entire load; a ground fixing part (250) that is coupled to the lower end of the support (230) and contacts the ground; a fan housing (210) that is rotatably coupled to the upper end of the support (230); a blower blade (211) that is rotatably driven and accommodated inside the fan housing (210); a solar panel (220) that is fixed via a bracket protruding from one side of the upper end of the support (230); and a control housing (240) that is attached to the middle outer surface of the support (230).

[0063] First, the support pole (230) is a structural element forming the framework of the system and can be made of a metal material with excellent rigidity, such as stainless steel or galvanized steel pipe, so as to be able to support the system without shaking even in strong winds or external impacts. Considering that the purpose of the anti-sinking fan is to mix the cold air at the ground surface with the warm air in the upper layer, it is preferable that the support pole (230) be extended to a height of about 6 to 10 meters from the ground. The interior of the support pole (230) is formed in a hollow shape and serves as a passageway through which power lines for transmitting power generated from the solar panel (220) or signal lines for motor control can be safely wired without being exposed to the outside. Additionally, the support pole (230) may have a structure that can be separated into multiple stages for ease of transport and installation, or a telescopic structure that allows for height adjustment.

[0065] The ground fixing part (250, Base Plate) is located at the bottom of the support (230) and serves to firmly fix the support (230) to the ground. The ground fixing part (250) may be composed of a flat base plate having a large contact area and anchor bolt fastening holes for connecting it to a concrete foundation on the ground. Since the ground may be uneven or soft due to the characteristics of the open ground, it is preferable for the ground fixing part (250) to have sufficient thickness and strength to prevent subsidence and maintain verticality.

[0067] The fan housing (210) is installed at the top of the support (230) and forms the outer shape of the drive unit (150) described in FIG. 1. The fan housing (210) has a cylindrical or trumpet-shaped duct structure with open front and rear ends, and serves to guide the flow path so that the wind generated by the blower blade (211) does not scatter but is concentrated and reaches the ground surface where the crop is located or a specific area. In particular, the fan housing (210) is configured to rotate 360 ​​degrees horizontally to the ground or tilt vertically to the ground by means of a pivot drive device (not shown) provided at the joint with the support (230). These rotation and tilting movements contribute to eliminating blind spots for frost damage by blowing wind evenly over a large area of ​​the orchard.

[0069] The fan blade (211) rotates by being directly connected to the rotation axis of a DC motor (440 in FIG. 4) located at the center inside the fan housing (210). The fan blade (211) is composed of multiple blades having an aerodynamically designed airfoil cross-section and is designed to enable low noise and high-efficiency airflow. The material used may be carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP) that simultaneously satisfies lightweighting and durability.

[0071] The solar panel (220) is a configuration in which the solar power generation module (110) of FIG. 1 is physically implemented, and is installed on the upper part of the support (230), specifically at a position that is not interfered with by the rotation radius of the fan housing (210). The solar panel (220) is connected to the support (230) through a separate fixing bracket, and the installation angle can be adjusted to optimize the angle of incidence of sunlight. Due to the nature of being installed in the open ground, an anti-contamination coating may be applied to the surface of the solar panel (220), or bird-repellent spikes may be additionally attached around the panel frame to prevent a decrease in power generation efficiency caused by bird droppings, etc.

[0073] The control box (240) is installed at the middle of the support (230), for example, at a height within reach of a manager's hand, and houses electronic components such as the battery management system (120), battery (121), and main control unit (130) of FIG. 1. The control box (240) has a waterproof and dustproof structure with an IP (Ingress Protection) rating to protect the internal circuit from external rain, snow, dust, moisture, etc. Additionally, a heat sink or vent may be formed on the side or rear of the box to effectively dissipate heat generated inside, and insulation treatment may be applied to the inner wall to maintain a stable operating temperature of the battery. A locking device is provided on the front door of the control box (240) to prevent unauthorized operation by outsiders, and if necessary, a display panel or an operation status indicator LED may be exposed so that the current system status (remaining battery level, current temperature, etc.) can be checked from the outside.

[0075] FIG. 3 is a block diagram showing the detailed circuit configuration of a photovoltaic power generation and battery management system (BMS) according to an embodiment of the present invention. Referring to FIG. 3, the power system of the present invention is largely composed of a photovoltaic array (310) that converts photovoltaic energy into electrical energy, an MPPT charging controller (320) that efficiently converts the generated power and supplies it to a battery, a battery pack (330) with a matrix structure that stores energy, and a BMS circuit section (340) that precisely diagnoses and protects the state of the battery.

[0077] First, the solar PV array (310) is a configuration that circuitously embodies the solar power generation module (110) of FIG. 1. The solar PV array (310) has a structure in which a plurality of unit solar cell modules are combined and connected in series and parallel to meet the system's required voltage (e.g., DC 24V or 48V) and target charging current amount. At this time, a bypass diode may be included inside the solar PV array (310), which serves to prevent a rapid decrease in overall power generation efficiency and prevent panel damage caused by hot spot phenomena by diverting the current flow in a part of the array even if shading occurs in that part due to leaves or bird droppings.

[0079] The MPPT charging controller (320, Maximum Power Point Tracking Controller) is a type of DC-DC converter placed between the solar array (310) and the battery pack (330). The output voltage and current of the solar array (310) have the characteristic of fluctuating non-linearly depending on changes in sunlight and temperature. Therefore, the MPPT charging controller (320) tracks the point where the power is maximum (MPP) in real time on the power-voltage curve (PV Curve) of the solar array (310) using the P&O (Perturb and Observe) algorithm or the Incremental Conductance algorithm. Through this, the MPPT charging controller (320) converts the input power without loss and delivers it to the battery pack (330), and automatically switches between three charging modes—constant current (Bulk), constant voltage (Absorption), and float charging (Float)—depending on the charge state of the battery, thereby preventing overcharging of the battery and extending its lifespan.

[0081] The battery pack (330) corresponds to the battery (121) of FIG. 1 and has a matrix structure in which a number of lithium-based (Li-ion or LiFePO4) unit cells, which have high energy storage density and no memory effect, are integrated. As shown in FIG. 3, the battery pack (330) is configured with a combination of serial connections for voltage increase and parallel connections for capacity increase. In particular, the battery pack (330) of the present invention has a structural feature in which a voltage sensing line and a temperature sensing line are individually drawn out for each unit cell or a cell module grouped in parallel and connected to a BMS circuit (340). This structure is intended to detect aging or defects in specific cells at an early stage and to prevent the performance of the entire pack from being limited by the lowest-performing cell.

[0083] The BMS circuit unit (340) is a core control unit of the battery management system (120) of FIG. 1 and may be configured to include an analog front end (AFE) and a microcontroller (MCU). The BMS circuit unit (340) analyzes the voltage deviation of each cell collected through connected sensing lines and performs cell balancing operations. Cell balancing may be applied using a passive method in which energy from a cell with a high voltage during charging is consumed by a resistor, or an active method in which energy is transferred to a cell with a low voltage using an inductor or capacitor, thereby controlling all cells to maintain a uniform voltage state.

[0085] In addition, the BMS circuit section (340) precisely estimates the remaining capacity (SOC: State of Charge) of the battery through an algorithm that combines current integration (Coulomb Counting) and open circuit voltage (OCV) correction methods. The calculated SOC data and battery health state (SOH: State of Health) information are transmitted in real time to the main control unit (130) of FIG. 1 via a communication line. Based on this information, the main control unit (130) predicts the remaining operating time and uses it as basic data for load prediction control to adjust the output of the anti-sink fan motor. Furthermore, when abnormal conditions such as overcurrent, overvoltage, undervoltage, or overtemperature are detected, the BMS circuit section (340) performs a multi-safety device function by immediately cutting off power MOSFETs or relays located on the charging or discharging path to prevent permanent damage to the system and fire.

[0087] Finally, the load connection terminal (TO LOAD) shown on the right side of FIG. 3 is a path through which stabilized DC power is output from the battery pack (330). This path is connected to the DC motor, which is the driving unit (150) of FIG. 1, and the main control unit (130), and additional protection elements such as a soft start circuit or a fuse to limit the inrush current generated when the motor starts can be additionally connected in series. Through this, the anti-storage fan system can be operated independently and stably using the energy stored in the battery even at night or in rainy weather when there is no solar power generation.

[0089] FIG. 4 is a detailed hardware block diagram of a sensor-fusion type motor control unit according to an embodiment of the present invention. Referring to FIG. 4, the control system of the present invention comprises: a temperature sensor (411), a humidity sensor (412), and a wind speed sensor (413) that detect changes in the physical environment; a microprocessor (420) that processes signals collected from these sensors and external communication signals; a communication module (450) that performs data transmission and reception with the microprocessor (420); an electronic transmission (430) that modulates motor driving power according to a control signal of the microprocessor (420); and a DC motor (440) whose rotational speed is controlled by the electronic transmission (430).

[0091] The temperature sensor (411), humidity sensor (412), and wind speed sensor (413) are individual sensing elements that constitute the sensor unit (140) described in FIG. 1. The temperature sensor (411) measures the ambient temperature and converts it into an analog voltage or digital signal, and collects data in conjunction with the humidity sensor (412) to calculate the wet-bulb temperature or dew point temperature, which is the most important indicator for determining whether frost has occurred. The wind speed sensor (413) detects the current natural wind speed, which is used as a basis for judgment to reduce battery consumption by using natural wind when operating the anti-frost fan, or to stop operation to protect the system in the event of strong winds. These sensor groups are connected to the GPIO (General Purpose Input / Output) or ADC (Analog-to-Digital Converter) ports of the microprocessor (420) to transmit data in real time.

[0093] The microprocessor (420, MCU: Microcontroller Unit) is a core computing device installed within the main control unit (130) of FIG. 1. The microprocessor (420) fuses the input sensor data to quantify the current weather conditions and calculates the probability of frost occurrence through a built-in load prediction algorithm (see FIG. 6). In addition, it performs a decision to determine the target rotational speed (RPM) and driving duration of the motor by considering the battery state of charge (SOC) information received from the battery management system (120) of FIG. 1.

[0095] The electronic speed controller (430, ESC) is a characteristic component of the present invention and is positioned between the microprocessor (420) and the DC motor (440). It serves as an interface that converts the control signal generated by the main control unit (130) of FIG. 1 into the operation of the actual drive unit (150). Unlike conventional anti-aircraft fans which were limited to a simple on-off control method using relays, the present invention adopts the electronic speed controller (430) by applying flight controller (FC) technology for drones. The electronic speed controller (430) precisely controls the phase and frequency of the power supplied to the motor according to the duty cycle of the Pulse Width Modulation (PWM) signal applied from the microprocessor (420). Through this, the rotational speed of the motor can be continuously varied from 0% to 100%, and fine airflow control is possible to prevent current spikes caused by sudden operation and optimize battery efficiency.

[0097] The DC motor (440) is configured to correspond to the drive unit (150) of FIG. 1 and rotates according to the output of the electronic transmission (430). Since power efficiency is very important due to the characteristics of the energy-independent system, it is desirable to use a brushless DC (BLDC) motor with low mechanical friction and a long lifespan for the DC motor (440).

[0099] The communication module (450) is connected to the microprocessor (420) and serves as an interface for exchanging data with an external system, and forms the basis of the remote monitoring system described in FIG. 7. Depending on the installation environment, the communication module (450) can be implemented as a LoRa (Long Range) module capable of long-distance low-power communication or an LTE / 5G module capable of transmitting large amounts of data, and performs the role of transmitting collected sensor data and system status information to a server or receiving remote control commands from a user.

[0101] FIG. 5 is a flowchart illustrating the overall control process of an energy-independent smart frost-proof fan system according to an embodiment of the present invention in chronological order. As shown in FIG. 5, the control method according to the present invention comprises an environmental data measurement step (S510), a battery status check step (S520), a frost risk determination step (S530), and a motor driving step (S540). Below, the specific operation mechanisms performed for each step will be described in detail.

[0103] First, in step S510, the main control unit (130) of the system collects current weather environment data of the area where the anti-septic fan is installed through the sensor unit (140). Specifically, when the system wakes up or a preset period (e.g., 1 minute or 5-minute interval) arrives, the main control unit (130) applies power to the sensor unit (140) to activate the sensors. At this time, the activated temperature sensor (411) measures the dry-bulb temperature in the atmosphere, converts it into an analog voltage value or a digital signal, and transmits it to the main control unit (130), and the humidity sensor (412) measures and transmits relative humidity data. In addition, the wind speed sensor (413) detects the speed of the natural wind currently blowing and inputs data. The main control unit (130) can perform signal processing such as a moving average filter or a Kalman filter to remove noise that may be included in the received raw data, and calculates the dew point temperature at which water vapor in the current air begins to condense into water droplets by calculating the corrected temperature and humidity data and stores it in internal memory.

[0105] In the subsequent step S520, the main control unit (130) communicates with the battery management system (120) to precisely diagnose the current state of the power supply unit. Specifically, the main control unit (130) receives data on the current voltage, charge / discharge current, and remaining capacity (SOC: State of Charge) of the battery (121) from the battery management system (120). At this stage, the main control unit (130) primarily determines whether the current remaining battery capacity is sufficient to drive the anti-sunlight fan. For example, if the current time is night after sunset and the remaining battery capacity is below the minimum operating limit set by the system (e.g., SOC 20%), the main control unit (130) may control the system to forcibly switch to a power-saving mode or send a "low battery warning" message to the administrator terminal to prevent battery damage caused by over-discharge. On the other hand, if it is determined that the battery level is sufficient, the main control unit (130) calculates the estimated time that can be maintained when driving at maximum output with the current level and prepares to use it as an output control variable in the driving step described later.

[0107] Next, in step S530, the main control unit (130) comprehensively analyzes the weather data collected in step S510 and the battery data confirmed in step S520 to determine whether there is a risk of frost at the current time. Specifically, the main control unit (130) calculates whether the current temperature has dropped below a preset frost threshold temperature (e.g., 2°C) or whether the probability of condensation and freezing occurring on the crop surface has increased as the current temperature approaches the dew point temperature. At this time, it is desirable to consider not only a simple temperature comparison but also whether the rate of temperature drop per hour (slope) is rapid. If the current temperature is above freezing but the rate of temperature drop is very rapid and it is expected to enter sub-zero temperatures within a few hours, the main control unit (130) may determine this as a 'frost risk state (YES)'. In addition, if the speed of the natural wind input from the wind speed sensor (413) is above a certain level (e.g., 3 m / s), frost does not form easily due to the natural mixing of the air, so a logic can be applied to evaluate the risk level as low even if the temperature is low.

[0109] If the judgment result indicates that there is no risk of frost (NO), the system does not drive the motor to prevent unnecessary power consumption and returns to a standby state, or maintains sleep mode until the next measurement cycle and then returns to step S510.

[0111] On the other hand, if it is determined that there is a risk of frost (YES), the process enters step S540 and performs the motor driving step. Specifically, the main control unit (130) applies a driving command signal to the electronic transmission (430) to rotate the DC motor (440). At this time, it is desirable for the main control unit (130) to perform soft start control by gradually increasing the duty cycle to suppress the inrush current that occurs when the motor accelerates rapidly from a stationary state to the target rotational speed. As the motor rotates, the blower blade (211) blows warm air from the upper layer down to the lower layer or circulates the air to raise the temperature around the crop. In addition, at this stage, the main control unit (130) simultaneously operates a swivel motor (not shown) that rotates the fan housing (210) to control the blowing direction to rotate 360 ​​degrees in all directions, thereby preventing the frost effect from being concentrated in a specific area.

[0113] Furthermore, the motor drive of step S540 may include real-time feedback control rather than simply maintaining a turned-on state. That is, even while the motor is running, the main control unit (130) continuously monitors temperature changes and performs variable control to reduce the rotational speed of the motor or stop the drive when the temperature recovers to a safe range or the remaining battery charge drops below a threshold. When this series of processes is completed, the system returns to an initial state or terminates.

[0115] FIG. 6 is a flowchart illustrating the detailed logical flow of a load prediction-based battery efficiency operation algorithm, which is a core technical feature of the present invention. Since the present invention is an energy-independent system that uses limited battery power, it requires an intelligent algorithm that goes beyond one-dimensional control, such as simply turning on a fan when frost occurs, to predict 'when' frost will occur and determine 'how much' energy is needed to last until morning. FIG. 6 illustrates this decision-making process.

[0117] Referring to FIG. 6, the algorithm is broadly composed of a data input step (S610), a frost occurrence probability calculation step (S620), a threshold comparison step (S630), an optimal wind speed (duty ratio) calculation step (S640), and a final control output step (S650). The specific calculation and control processes for each step are described below.

[0119] First, step S610 (data input step) is a process of collecting and preprocessing basic variables required for algorithm operation. The main control unit (130) receives real-time data on current temperature (T_current), relative humidity (H_current), and wind speed (W_current) from the sensor unit (140). At the same time, the main control unit (130) communicates with the battery management system (120) to collect information on the battery's current remaining capacity (SOC_current), battery voltage (V_batt), and battery health status (SOH).

[0121] At this stage, it is desirable for the main control unit (130) not only to read the data at the current time but also to analyze the trend of data change over a certain period of time in the past (e.g., the last hour) to calculate the 'slope of the data'. For example, even if the current temperature is 5 degrees above zero, if the temperature has dropped rapidly over the last 30 minutes, this becomes an important input variable indicating a situation where there is a high risk of frost. In addition, signal processing such as a low-pass filter may be performed first to remove transient noise that may be included in the sensor data.

[0123] In step S620 (step for calculating the probability of frost occurrence), the main control unit (130) performs a multi-stage calculation process based on input data to accurately calculate the probability of frost occurrence (P_frost). Specifically, this process may include the following detailed calculation processes.

[0125] First, the 'dew point temperature (T_dp) calculation process'. The main control unit (130) calculates the dew point temperature using the dry-bulb temperature (T_dry) and relative humidity (RH) received from the sensor unit.

[0127] In this case, the Magnus Formula using saturated water vapor pressure can be applied as a computational algorithm. In addition, the Arden Buck Equation, which has high precision in sub-zero temperature ranges, or the Tetens Equation, which is widely used for meteorological observation, can be selectively applied.

[0129] In addition, to reduce the computational load of the main control unit (130), a linear approximation using the temperature and humidity difference is applied, or a method of deriving the dew point temperature by referring to a look-up table that maps pre-stored temperature-humidity dew point data is also included within the scope of the present invention.

[0131] Since frost occurs when water vapor in the air sublimates onto the surface of an object below its freezing point, the dew point temperature is a key indicator for frost prediction rather than the simple air temperature.

[0133] Second, there is a ‘future temperature prediction process based on cooling rate.’ The main control unit (130) calculates the temperature drop slope (Cooling Rate, ΔT / Δt) by performing regression analysis on temperature data stored in memory for a certain period of time in the past (e.g., t-30 minutes to t), as well as the temperature at the current time (t). Through this, the main control unit (130) applies Newton's Law of Cooling to predict the expected temperature to be reached (T_pred) after a specific time (e.g., 1 hour) from the current time. That is, even if the current temperature is above freezing, if the temperature drop slope is steep, the expected temperature to be reached (T_pred) may be predicted to be below freezing or below the dew point temperature (T_dp).

[0135] Third, the process of deriving the final probability with applied wind speed weighting. The main control unit (130) converts the difference value (Gap) between the predicted 'expected temperature reached (T_pred)' and the 'dew point temperature (T_dp)' into a first risk index. Here, wind speed data (W_speed) measured from the wind speed sensor is applied as a weighting factor. Specifically, if the wind speed is less than the preset 'convection threshold (e.g., 2 m / s)', a high risk weighting factor (e.g., x 1.2) is assigned because radiative cooling of the surface is accelerated. Conversely, if the wind speed is greater than the convection threshold, a low risk weighting factor (e.g., x 0.8) is assigned because the possibility of frost formation is lower due to the natural mixing effect of the air, or the probability is reset to 0.

[0137] Finally, the main control unit (130) combines the above operations and calculates the probability of frost occurrence (P_frost) as a quantitative value between 0% and 100% using the logic of [Equation 1].

[0139] [Equation 1]

[0140] P_frost = f(T_pred - T_dp) × K_wind (where f is a function inversely proportional to the temperature difference, and K_wind is a correction factor inversely proportional to the wind speed)

[0142] In this way, by combining the dew point based on humidity, the cooling rate based on time, and the natural convection effect based on wind speed, rather than simple temperature sensing, the present invention can perform precise frost prediction with a significantly reduced error range.

[0144] Next, in step S630 (threshold comparison step), the calculated probability of frost occurrence (P_frost) is compared with a reference threshold (P_th) pre-set in the system. This threshold (P_th) is not a fixed constant, but a dynamic parameter that is set variably by considering the phenological characteristics and economic value of the target crop.

[0146] Specifically, crops have the characteristic that the 'Critical Killing Temperature' at which they suffer cold damage varies depending on their growth stage. For example, apple trees can withstand temperatures as low as -10 degrees during dormancy, but during the flowering or fruit set stages, they can suffer fatal damage from even mild cold temperatures of -1 to -2 degrees.

[0148] Accordingly, in this stage, the main control unit (130) is configured to automatically correct the threshold value (P_th) by referring to a 'growth stage risk database (DB)' in which the type of crop and the threshold killing temperature data of the current growth stage are mapped, or to automatically change the threshold value to an optimal sensitivity corresponding to the current crop status (e.g., full bloom stage, fruiting stage, etc.) when an administrator inputs it through a user terminal (740). In addition, a 'Risk Management Margin' may be additionally applied, which lowers the threshold value (increases sensitivity) to actively defend when the battery level is sufficient, and raises the threshold value to operate only at critical moments when the battery is low, depending on the administrator's settings.

[0150] If the calculated probability is below the threshold (NO), meaning the risk of frost is determined to be low, the system proceeds to step S650 by maintaining standby mode to conserve battery power or, if currently operating, stopping operation. Conversely, if the calculated probability exceeds the threshold (YES), meaning frost damage is anticipated, the system enters step S640 to perform active frost protection activities.

[0152] Step S640 (the step of calculating the optimal wind speed and duty cycle) is the most characteristic part of the present invention, and is a step of determining 'how' to turn on the fan by considering the battery status rather than simply 'turning on' the fan. The main control unit (130) calculates the 'total amount of available energy (E_avail)' that allows the system to be continuously operated until sunrise time with the current battery level (SOC_current). Then, it compares the 'minimum required wind speed (RPM_min)' for frost prevention with the 'estimated energy consumption (E_req)' required to maintain it.

[0154] During this process, the main control unit (130) performs the following 'energy-efficient operation strategy'.

[0155] [Sufficient Mode]: This is the case where the battery charge is sufficient (E_avail > E_req) so there is no risk of discharge even if the device is operated at maximum wind speed until morning. In this case, to ensure a reliable frost prevention effect, the target rotational speed of the motor is set high, and a corresponding high duty cycle (e.g., 80~100%) is calculated.

[0156] [Economy Mode]: This is a case where the battery level is low (E_avail < E_req) and there is a risk that the system will shut down in the early morning if maximum output is generated in the current state. In this case, the main control unit (130) adopts a strategy to extend the operating time by lowering the fan's rotational speed to a critical limit that can suppress frost formation. That is, by lowering the target rotational speed and adjusting the duty cycle (e.g., 40~60%) downward, the system is controlled so that it can survive without shutting down until the early morning hours when the temperature is lowest, even if the instantaneous frost effect is slightly reduced.

[0158] Finally, in step S650 (final control output step), the main control unit (130) generates a Pulse Width Modulation (PWM) control signal containing the target duty ratio determined in step S640 and outputs it to the electronic transmission (430, ESC) of the drive unit. If it is determined that there is no danger in step S630 (NO path), the main control unit (130) may output a signal with a duty ratio of 0% to stop the motor, or periodically output only a minimal 'idling' signal to check the status of the system.

[0160] On the other hand, when the optimal wind speed is determined through the YES path, the electronic transmission (430) switches and controls the power supplied from the battery pack (330) to the DC motor (440) according to the applied PWM signal to precisely rotate the motor at the target speed. At this time, the main control unit (130) monitors the actual rotational speed (Feedback RPM) of the motor in real time and performs feedback control (PID Control) to correct any error with the target speed caused by external wind or the like, thereby implementing reliable wind-up operation.

[0162] These steps S610 through S650 are not performed once, but are repeated in short cycles of seconds or minutes while the system is operating. Therefore, if weather conditions change rapidly or battery consumption is faster than expected, the system immediately modifies its driving strategy to maintain an optimal state.

[0164] FIG. 7 is a conceptual diagram showing the overall network configuration for remote monitoring and control of an energy-independent smart anti-septic fan system according to one embodiment of the present invention.

[0166] Referring to FIG. 7, the remote monitoring system of the present invention includes a smart anti-septic fan (710) installed at the site; a wireless communication network (720) that transmits data generated from the smart anti-septic fan (710); a cloud control server (730) that stores and analyzes received data and provides services; and a user terminal (740) that allows a user to check information and input control commands remotely.

[0168] The smart frost-proof fan (710) is the energy-independent frost-proof fan system itself, as described above through FIGS. 1 to 4, and in this network configuration, it performs the role of an 'Edge Device' or 'IoT Node' that generates and transmits data. The main control unit of the smart frost-proof fan (710) periodically processes environmental data such as temperature, humidity, and wind speed collected from the sensor unit, and status data such as voltage, current, SOC (remaining capacity), and SOH (life state) collected from the battery management system (BMS) into packet form. At this time, the data packet includes the unique identifier (ID) of the frost-proof fan, a data generation timestamp, and information on the current operating mode (standby / operation / error) in the header. The smart frost-proof fan (710) is configured to check the status of the wireless communication network (720), upload data at preset intervals (e.g., 1 minute), or immediately transmit data asynchronously when an emergency event, such as a frost risk warning, occurs.

[0170] A wireless communication network (720) provides a data transmission path between a smart frost-proof fan (710) and a cloud control server (730). Given that the environment to which the present invention is applied is primarily a remote mountainous area or a wide plain where power and communication infrastructure is weak, the wireless communication network (720) may selectively or in combination apply Low Power Wide Area (LPWA) technology or broadband mobile communication technology. In one embodiment, when communication cost reduction and low-power operation are prioritized, a LoRa (Long Range) communication method may be applied. In this case, a LoRa gateway connected to the internet is installed within the farm to collect data from multiple smart frost-proof fans (710) distributed within a radius of several km, convert the data into a TCP / IP protocol, and transmit it to a server. In another embodiment, when large-capacity data transmission or real-time performance is important, an LTE-M, NB-IoT, or commercial LTE / 5G network may be applied. In this case, a communication module equipped with a USIM chip is installed inside the smart thermal fan (710) and communicates directly with the cloud control server (730) through the base station. It is desirable that the security of the data transmitted through the wireless communication network (720) be ensured by applying an SSL / TLS encryption protocol or using a lightweight encryption algorithm (such as AES-128) to prevent hacking or tampering during the transmission process.

[0172] The cloud control server (730) is a central processing unit that stores and analyzes vast amounts of collected data and provides web or app services to users. The cloud control server (730) can be broadly configured to include a database (DB) server, a computational processing server, and a web application server. The database server accumulates and stores time-series data received from each frost fan. This data is used as a training dataset for machine learning to analyze the annual weather change patterns of the farm in the future or to improve frost occurrence prediction models. The computational processing server performs diagnostic logic to re-verify the risk of frost occurrence by analyzing received real-time data or to detect abnormal signs early by analyzing battery remaining charge trends. For example, if the rate of battery voltage drop of a specific frost fan is abnormally fast compared to other adjacent frost fans, the server can diagnose this as 'battery aging' or 'circuit leakage' and generate a maintenance alert for the administrator. In addition, the cloud control server (730) is linked via API (Application Programming Interface) with an external weather agency server or an agricultural technology center server, and receives information on local weather forecasts or special warnings for the area, and performs a relay role to reflect this in the frost fan control logic or deliver it to the user as a push notification.

[0174] The user terminal (740) provides an interface that allows the farm owner or manager to access the system regardless of time and place. The user terminal (740) can be implemented as a smartphone, tablet PC, or desktop PC, and accesses the control system through a dedicated application (App) or a web browser. The screen of the user terminal (740) may be provided with a GIS-based dashboard that displays the locations of the frost protection fans installed on the farm on a map. By touching a specific icon, the user can check the current temperature, humidity, remaining battery level, motor rotation speed (RPM), and communication sensitivity of the corresponding frost protection fan in real time. Additionally, through a data visualization function, daily / weekly / monthly temperature change graphs or battery charge / discharge history graphs can be viewed intuitively. This serves as important auxiliary data for the user to understand the micro-weather environment of the farm and to formulate farming plans.

[0176] Furthermore, the user terminal (740) provides bidirectional control functions beyond simple monitoring. For example, if the user determines that the frost protection fan needs to be operated urgently, separate from the system's automatic operation algorithm, they can press the 'forced operation' button on the app to send a remote control command to the server. This command is transmitted to the smart frost protection fan (710) via the cloud control server (730) and the wireless communication network (720), and the fan immediately starts operating and responds to the user with the result. Additionally, the user can remotely modify control parameters (OTA: Over The Air), such as the critical temperature value that serves as the criterion for determining frost risk or the target rotation speed of the motor, through the app.

[0178] Through such an organic network configuration, the present invention realizes an unmanned automated agricultural environment capable of immediately responding to unexpected weather anomalies or system failures even when a manager is not stationed on-site.

[0180] Although preferred embodiments of the present invention have been described in detail above, this is merely an example to aid in understanding the invention, and the present invention is not limited to the above embodiments. Those skilled in the art to which the present invention pertains can make various modifications, variations, and applications without departing from the technical spirit or scope of the present invention, and it is obvious that such modified embodiments are also included within the scope of protection of the present invention. Accordingly, the scope of protection of the present invention is determined by the appended claims, and all technical ideas within the scope equivalent to the claims should be interpreted as being included within the scope of rights of the present invention. Explanation of the symbols

[0182] 100 : Energy-independent smart frost-proof fan system 110: Solar power generation module 120 : Battery Management System (BMS) 121 : Battery (ESS) 130 : Main control unit 140 : Sensor section 150 : Drive unit

Claims

Claim 1 An energy-independent smart frost fan system for preventing frost damage to crops in open-field environments where electricity supply is difficult, comprising: a photovoltaic power generation module that generates power using external natural light; a battery management system that controls the charging of power supplied from the photovoltaic power generation module and generates battery status information including the voltage, current, and state of charge (SOC) of the battery; a sensor unit that measures weather environment data in real time, including temperature, humidity, and wind speed of an area where the frost fan is installed; and a main control unit that generates a control signal by analyzing the battery status information received from the battery management system and the weather environment data received from the sensor unit. The energy-independent smart frost-proof fan system comprises: a drive unit including a DC motor and a blower fan that operates according to a control signal from the main control unit to generate airflow; wherein the main control unit operates the drive unit using only the power of the battery without the input of an external power source, and variably controls the operating time and rotational speed of the drive unit by mutually calculating the change trend of the weather environment data and the battery state of charge (SOC); wherein the main control unit performs a load prediction-based battery efficiency operation algorithm, and performs a frost occurrence probability calculation step that calculates the dew point temperature using the current temperature and relative humidity measured by the sensor unit and calculates the probability of frost occurring within a specific time in the future by analyzing the temperature drop slope; and an optimal wind speed calculation step that operates the drive unit when the calculated frost occurrence probability exceeds a preset threshold, and determines the target rotational speed of the motor according to the battery state of charge (SOC). Claim 2 delete Claim 3 An energy-independent smart frost-proof fan system according to claim 1, wherein in the optimal wind speed calculation step, the main control unit calculates the total amount of available energy capable of driving until sunrise with the current battery remaining capacity (SOC), compares this with the required energy required to maintain the target wind speed, and if it is determined that the available energy is insufficient compared to the required energy, lowers the duty ratio of the Pulse Width Modulation (PWM) signal applied to the DC motor to a lower threshold capable of suppressing frost formation to extend the operating duration. Claim 4 An energy-independent smart anti-storage fan system according to claim 1, wherein the drive unit further includes an electronic speed controller (ESC), the main control unit controls the rotational speed of the direct current (DC) motor through the electronic speed controller, and the battery management system optimizes the power generation efficiency of the photovoltaic power generation module through Maximum Power Point Tracking (MPPT) control and performs a cell balancing function that balances the voltage between a plurality of cells constituting the battery. Claim 5 The energy-independent smart frost-proof fan system according to claim 1 further comprises a communication module connected to the main control unit and transmitting the weather environment data and the battery status information to a remote cloud server via a wireless communication network, wherein the cloud server provides a monitoring screen to a user terminal based on the received data and transmits a remote control command input from the user terminal to the main control unit to forcibly drive the drive unit or change control parameters.

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