Controller device for independently operating photovoltaic DC microgrid

Abstract

This invention discloses a controller device for an independently operating photovoltaic DC microgrid. It includes a communication module, a solar module management module, a battery management module, a load management module, and a system control module. The solar module management module controls the connection or disconnection of the solar input relay based on the difference between the solar module voltage and the energy storage battery voltage. The battery management module controls the charging and discharging states of the energy storage battery. The load management module controls the switching of different load levels among various user loads, employing a set power priority control strategy for loop power supply management, maximizing the utilization of the limited capacity of the energy storage battery to ensure stable power supply to high-priority loads. This invention effectively reduces the impact of external factors, achieving dynamic balance between photovoltaic, energy storage, and loads within the system; simultaneously, it addresses different operating conditions, ensuring optimal power supply scheduling to the greatest extent possible.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power generation technology, specifically to a controller device for an independently operating photovoltaic DC microgrid. Background Technology

[0002] With the escalating energy crisis and environmental problems, the world has turned its attention to the development of renewable energy, with distributed power sources, represented by photovoltaics, becoming a major research focus. Photovoltaic power generation produces direct current (DC), and DC microgrids effectively integrate distributed photovoltaic power generation, energy storage batteries, and user loads through control mechanisms, providing a flexible and efficient platform for independently operating DC microgrid power generation technology, which has received widespread attention in recent years.

[0003] As the main power source of DC microgrid systems, photovoltaic power generation devices are subject to changes in external conditions such as weather, sunlight, and ambient temperature, resulting in significant randomness, intermittency, and periodicity in power output. Meanwhile, the power consumption of loads within DC microgrid systems is also significantly random due to weather conditions and the influence of day and night. Therefore, it is difficult for DC microgrid power sources and user loads to achieve dynamic balance simultaneously.

[0004] In existing technologies, DC microgrid systems lack effective control systems and reasonable strategies to effectively adapt to the coordinated operation of photovoltaic power generation, energy storage battery charging and discharging status, and load dynamic changes within the system. At the same time, they also lack the ability to distinguish the priority levels of various loads within the system, and in extreme cases, they cannot guarantee the priority power supply to high-priority loads. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention proposes a controller device for an independently operating photovoltaic DC microgrid. This device fully integrates the charging and discharging regulation function of energy storage batteries, effectively reducing the impact of external factors such as weather and load changes. It achieves dynamic balance and stable, coordinated, and independent operation of photovoltaic, energy storage, and load components within the DC microgrid system. Simultaneously, it prioritizes the power supply to user loads within the system, responding to different operating conditions and maximizing the optimal scheduling of system power supply, thus ensuring the independent, reliable, safe, and stable operation of the DC microgrid system.

[0006] To achieve the above objectives, the present invention provides a controller device for an independently operating photovoltaic DC microgrid, used to manage and control solar modules, energy storage batteries, and user loads within a DC microgrid system. Its key features include a communication module, a solar module management module, a battery management module, a load management module, and a system control module.

[0007] The communication module is used to remotely transmit real-time status data;

[0008] The solar module control module is used to monitor the voltage of the solar module and the voltage of the energy storage battery, and to control the connection or disconnection of the solar input relay according to the difference between the voltage of the solar module and the voltage of the energy storage battery.

[0009] The battery management module is used to monitor the operating status of the energy storage battery's capacity, voltage, and current, and to control the charging and discharging status of the energy storage battery.

[0010] The load management module is used to monitor the power consumption, voltage, and current of each user load, and to control the switching of different levels of loads in each user load according to the power generation of the solar modules and the power of the energy storage batteries. It adopts a set power consumption priority control strategy to manage the circuit power supply, and maximizes the use of the limited capacity of the energy storage batteries to ensure stable power supply to high priority loads.

[0011] The system control module is used to execute the DC microgrid system control strategy, and uses the solar output current = real-time current of the energy storage battery + load and real-time current of each circuit as the control target to ensure the stability and reliability of the system's dynamic operation; the real-time current of the energy storage battery is set to I. y The maximum value is Y max The load and real-time current of each circuit are I. z The maximum value is Z. max The solar output current is I. x ;

[0012] The control strategy for the DC microgrid system is as follows:

[0013] Condition 1), when Y max +Z max ≤I x Then the battery management module will control the energy storage battery to operate in a charging state, and the charging current of the energy storage battery will be allowed to be the maximum rechargeable current value Y. max The load management module allows different levels of load in each user's load to run at full capacity;

[0014] Condition 2), when I z ≤I x ≤Y max +I z If so, the battery management module will control the energy storage battery to operate in a charging state, but the charging current of the energy storage battery will be less than the maximum rechargeable current value Y. max The load management module allows the output of the maximum load current for each circuit.

[0015] Condition 3), when I x ≤I zIf the energy storage battery voltage has not reached the lower limit protection warning value, the battery management module will control the energy storage battery to operate in a discharge state, and the load management module will allow the maximum current of each circuit load to be output.

[0016] Condition 4), when I x ≤I z The energy storage battery voltage is about to reach the lower limit protection warning value, and I x +I y > If the output current of a high priority circuit is high, the load management module will cut off the load output of each circuit in order of priority from low to high according to the load circuit priority control strategy.

[0017] Condition 5), when I x +I y If the load current is less than or equal to the lowest priority load current, the load control module will shut down all circuits and all solar photovoltaic energy will be used to charge the energy storage battery until the energy storage battery voltage reaches the battery over-discharge warning release value. Then, it will be determined whether the charging energy meets the power supply requirements of the high priority load in condition 4). If it does, the load output of each circuit will be controlled and put into operation in order of priority from high to low according to the load circuit priority control strategy.

[0018] Furthermore, in operating condition 4), the specific strategy for cutting off the load output of each circuit in order of priority from low to high according to the load circuit priority control strategy is as follows: the load of each circuit is set as a low priority level 3 load, a medium priority level 2 load, and a high priority level 1 load. When the energy storage battery capacity drops to 50%, the level 3 load circuit is cut off; when the energy storage battery capacity drops to 30%, the level 2 load circuit is cut off; and when the energy storage battery capacity drops to 20%, the level 1 load circuit is cut off.

[0019] Furthermore, in operating condition 5), the specific strategy for controlling the load output of each circuit according to the priority level control strategy is as follows: when the energy storage battery capacity rises to 25%, the first-level load circuit is activated; when the energy storage battery capacity rises to 40%, the second-level load circuit is activated; and when the energy storage battery capacity rises to 60%, the third-level load circuit is activated.

[0020] Furthermore, the specific strategy for the solar module control module to control the connection or disconnection of the solar input relay is as follows: during the day, when the voltage of the solar module is greater than the voltage of the energy storage battery +5V, the solar input relay is activated after a delay, and the solar module control module charges the energy storage battery; in the evening, when the voltage of the solar module is less than the voltage of the energy storage battery, the solar input relay is disconnected to prevent backflow from the energy storage battery to the solar module.

[0021] Furthermore, the battery management module uses an SOC metering chip to accurately measure the capacity of the energy storage battery; it uses an analog front-end chip to monitor the real-time voltage of individual cells in the energy storage battery and to perform equal and constant charge and discharge management.

[0022] Furthermore, during the charging process, the energy storage battery has protection functions against solar overvoltage, charging overvoltage, charging overcurrent, and power device overtemperature; during the discharging process, the energy storage battery has protection functions against overvoltage, undervoltage, overcurrent, and short circuit, providing a guarantee for the safe and reliable operation of each user load and system.

[0023] Furthermore, the system control module is executed by an MPPT controller, which uses maximum power point tracking technology to extract the maximum power from the solar photovoltaic array to charge the energy storage battery.

[0024] Furthermore, the MPPT controller is equipped with two controlled DC output terminals. The positive terminal of one controlled DC output terminal is connected to the positive terminal of the energy storage battery through a fuse, and the negative terminal of the other controlled DC output terminal is connected to the negative terminal of the energy storage battery through a MOSFET.

[0025] Furthermore, the DC output control operating modes of the MPPT controller are: output off, automatic output, time-controlled output, light-controlled output, and remote control output.

[0026] Furthermore, it also includes a data display module, which is equipped with LED indicators and an LCD display.

[0027] The advantages of this invention are:

[0028] 1. This invention monitors the voltage of solar modules, as well as the capacity, voltage, and current of energy storage batteries and the power consumption, voltage, and current of each user load. Using the solar output current = real-time current of the energy storage battery + the load and real-time current of each circuit as the control target, and combining the charging and discharging regulation function of the energy storage battery, a reasonable and efficient system control strategy is formulated to ensure the stability and reliability of the system's dynamic operation. Simultaneously, through the formulated load circuit priority control strategy, switching control is performed on different levels of loads in each user load, maximizing the utilization of the limited capacity of the energy storage battery to ensure stable power supply to high-priority loads.

[0029] 2. This invention distinguishes and sorts the power supply priority of loads within the system. When the solar output current is less than the load and real-time current of each circuit, during the discharge process of the energy storage battery, as the capacity of the energy storage battery decreases, the load output of each circuit is disconnected in order of priority from low to high. When the sum of the solar output current and the real-time current of the energy storage battery is less than the lowest priority load current, during the charging process of the energy storage battery, as the capacity of the energy storage battery increases, the load output of each circuit is connected in order of priority from high to low, thereby maximizing the utilization of solar photovoltaic power.

[0030] The controller device of this invention, which operates independently as a photovoltaic DC microgrid, fully integrates the charging and discharging regulation function of the energy storage battery to effectively reduce the impact of external factors such as weather and load changes. It achieves dynamic balance and stable, coordinated, and independent operation of photovoltaic, energy storage, and load within the DC microgrid system. At the same time, it prioritizes the power supply to user loads within the system to cope with different operating conditions and maximize the optimal scheduling of system power supply. This improves the reliability, stability, and efficiency of the overall dynamic independent operation of the system under various application scenarios. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the control principle of the controller device for the independently operating photovoltaic DC microgrid of the present invention;

[0032] In the diagram: 1. Communication module; 2. Solar module management module; 3. Battery management module; 4. Load management module; 5. System control module; 6. Data display module. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0035] Example 1

[0036] like Figure 1As shown, this invention discloses a controller device for an independently operating photovoltaic DC microgrid, used to manage and control solar modules, energy storage batteries, and user loads within the DC microgrid system. It includes a communication module 1, a solar module management module 2, a battery management module 3, a load management module 4, and a system control module 5.

[0037] This DC microgrid system uses solar panels as the power input to provide power to the system. Based on various external conditions such as daytime and nighttime, as well as the real-time dynamic status of user loads, it manages the switching of solar panel input, energy storage battery charging and discharging, and different levels of loads in the system.

[0038] The communication module 1 is used to remotely transmit real-time status data. Preferably, the communication module 1 is an RS485 communication interface.

[0039] The solar module control module 2 is used to monitor the voltage of the solar module and the voltage of the energy storage battery, and to control the connection or disconnection of the solar input relay according to the difference between the voltage of the solar module and the voltage of the energy storage battery.

[0040] Specifically, the specific strategy for the solar module control module 2 to control the connection or disconnection state of the solar input relay is as follows:

[0041] During the day, when the voltage of the solar module is greater than the voltage of the energy storage battery +5V, the solar input relay is activated after a delay, and the solar module management module 2 charges the energy storage battery. The system control module 5 dynamically adjusts the charging strategy according to the current energy storage battery and user load. In the evening, when the voltage of the solar module is less than the voltage of the energy storage battery, the solar input relay is disconnected to prevent backflow from the energy storage battery to the solar module.

[0042] The battery management module 3 is used to monitor the operating status of the energy storage battery's capacity, voltage, and current, and to control the charging and discharging status of the energy storage battery.

[0043] Specifically, the battery management module 3 exchanges data with the system control module 5 via an internal bus. The battery management module 3 uses a SOC metering chip to accurately measure the capacity of the energy storage battery; it uses an analog front-end chip to monitor the real-time voltage of individual cells in the energy storage battery and performs constant charge and discharge management. The battery management module 3 performs protection operations against abnormal states of the cells such as overvoltage, undervoltage, overtemperature, short circuit, and overcurrent, ensuring the safe and reliable operation of the energy storage battery.

[0044] Multiple charging parameters, including battery type, battery voltage level (including automatic identification of lead-acid batteries), equalization charge voltage (only effective for lead-acid batteries), float charge voltage, and charging current, can be set by the user. During charging, the energy storage battery features protection against solar overvoltage, charging overvoltage, charging overcurrent, and power device overtemperature. During discharging, the battery provides protection against overvoltage, undervoltage, overcurrent, and short circuit, ensuring the safe and reliable operation of user loads and the system.

[0045] The load management module 4 is used to monitor the power consumption, voltage, and current of each user load, and to control the switching of different levels of loads in each user load according to the power generation of the solar modules and the power of the energy storage batteries. It adopts a set power consumption priority control strategy to manage the circuit power supply, and maximizes the use of the limited capacity of the energy storage batteries to ensure stable power supply to high priority loads.

[0046] When there is insufficient sunlight or at night, and the energy of the solar modules cannot meet the power consumption required by the user's load, the system control module 5 manages the power supply of the circuit according to the current energy storage battery capacity and the set load circuit priority control strategy, so as to maximize the use of the limited capacity of the energy storage battery to ensure stable power supply to important loads.

[0047] The system control module 5 is used to execute the DC microgrid system control strategy, and uses the solar output current = real-time current of the energy storage battery + load and real-time current of each circuit as the control target to ensure the stability and reliability of the system's dynamic operation; the real-time current of the energy storage battery is set to I. y The maximum value is Y max The load and real-time current of each circuit are I. z The maximum value is Z. max The solar output current is I. x .

[0048] This DC microgrid system has been categorized and analyzed based on possible operating conditions in actual operation, and the following control strategies for the DC microgrid system have been formulated for each type of operating condition. The control strategies for the DC microgrid system are as follows:

[0049] Condition 1), when Y max +Z max ≤I x Then, the battery management module 3 controls the operation mode of the energy storage battery to the charging state, and the charging current of the energy storage battery is allowed to be the maximum rechargeable current value Y. max The load management module 4 allows different levels of load in each user's load to run at full capacity.

[0050] Condition 2), when I z ≤I x ≤Y max+I z Then, the battery management module 3 controls the operation mode of the energy storage battery to a charging state, but the charging current of the energy storage battery is less than the maximum rechargeable current value Y. max The load management module 4 allows the output of the maximum current of each circuit load.

[0051] Condition 3), when I x ≤I z If the energy storage battery voltage has not reached the lower limit protection warning value, the battery management module 3 will control the operation mode of the energy storage battery to discharge state, and the load management module 4 will allow the output of the maximum load current of each circuit.

[0052] Condition 4), when I x ≤I z The energy storage battery voltage is about to reach the lower limit protection warning value, and I x +I y > If the output current of a high priority circuit is high, then the load management module 4 will cut off the load output of each circuit in order of priority from low to high according to the load circuit priority control strategy.

[0053] Specifically, the strategy for cutting off the load output of each circuit in order of priority from low to high according to the load circuit priority control strategy is as follows: each circuit load is set as a low priority level 3 load, a medium priority level 2 load, and a high priority level 1 load. When the energy storage battery capacity drops to 50%, the level 3 load circuit is cut off; when the energy storage battery capacity drops to 30%, the level 2 load circuit is cut off; and when the energy storage battery capacity drops to 20%, the level 1 load circuit is cut off.

[0054] Condition 5), when I x +I y If the current is less than or equal to the lowest priority load current, the load control module 4 shuts down all circuits, and all solar photovoltaic energy is used to charge the energy storage battery until the energy storage battery voltage reaches the battery over-discharge warning release value. Then, it is determined whether the charging energy meets the power supply requirements of the high priority load in operating condition 4). If it does, the load output of each circuit is put into operation in order of priority from high to low according to the load circuit priority control strategy.

[0055] Specifically, the load output of each circuit is activated in descending order of priority according to the load circuit priority control strategy. The specific strategy is as follows: when the energy storage battery capacity rises to 25%, the first-level load circuit is activated; when the energy storage battery capacity rises to 40%, the second-level load circuit is activated; and when the energy storage battery capacity rises to 60%, the third-level load circuit is activated.

[0056] This invention monitors the voltage of solar modules, as well as the capacity, voltage, and current of energy storage batteries and the power consumption, voltage, and current of each user load. Using the solar output current = real-time current of the energy storage battery + the load and real-time current of each circuit as the control target, and combining the charging and discharging regulation function of the energy storage battery, a reasonable and efficient system control strategy is formulated to ensure the stability and reliability of the system's dynamic operation. Simultaneously, through the formulated load circuit priority control strategy, different levels of loads in each user load are switched on and off, maximizing the utilization of the limited capacity of the energy storage battery to ensure stable power supply to high-priority loads.

[0057] Furthermore, this invention distinguishes and sorts the power supply priority levels of loads within the system. When the solar output current is less than the load and real-time current of each circuit, during the discharge process of the energy storage battery, as the capacity of the energy storage battery continuously decreases, the load output of each circuit is disconnected in order of increasing priority. When the sum of the solar output current and the real-time current of the energy storage battery is less than the lowest priority load current, during the charging process of the energy storage battery, as the capacity of the energy storage battery continuously increases, the load output of each circuit is connected in order of decreasing priority, thereby maximizing the utilization of solar photovoltaic power.

[0058] The system control module 5 is executed by the MPPT controller, which stands for "Maximum Power Point Tracking" solar controller. It is an upgraded product of the traditional solar charge and discharge controller.

[0059] The MPPT controller can detect the voltage generated by the solar panel in real time and track the highest voltage and current values, enabling the system to charge the energy storage battery at maximum power output. Applied in solar photovoltaic systems, it coordinates the operation of solar panels, energy storage batteries, and user loads, acting as the brain of the photovoltaic system.

[0060] The MPPT controller utilizes maximum power point tracking (MPPT) technology to extract the maximum power from the solar photovoltaic array to charge the energy storage battery. MPPT is fully automatic and requires no user adjustment. As the array's maximum power point changes with environmental conditions, the controller automatically tracks the array's maximum power point to ensure that the maximum energy is extracted from the photovoltaic array throughout the day.

[0061] The MPPT controller is equipped with two controlled DC output terminals. The positive terminal of one controlled DC output terminal is connected to the positive terminal of the energy storage battery through a fuse, and the negative terminal of the other controlled DC output terminal is connected to the negative terminal of the energy storage battery through a MOSFET.

[0062] Specifically, the DC output control operating modes of the MPPT controller are: output off, automatic output, time-controlled output, light-controlled output, and remote control output.

[0063] Example 2

[0064] The difference between Embodiment 2 and Embodiment 1 is that Embodiment 2 also includes a data display module 6. This data display module 6 is equipped with LED indicator lights, an LCD display, and buttons for human-machine interaction. The LCD display allows setting the battery type, energy storage battery charging and discharging parameters, and corresponding DC microgrid system control strategies.

[0065] The controller device of this invention, which operates independently as a photovoltaic DC microgrid, fully integrates the charging and discharging regulation function of the energy storage battery to effectively reduce the impact of external factors such as weather and load changes. It achieves dynamic balance and stable, coordinated, and independent operation of photovoltaic, energy storage, and load within the DC microgrid system. At the same time, it prioritizes the power supply to user loads within the system to cope with different operating conditions and maximize the optimal scheduling of system power supply. This improves the reliability, stability, and efficiency of the overall dynamic independent operation of the system under various application scenarios.

[0066] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A controller device for an independently operating photovoltaic DC microgrid, used to manage and control solar modules, energy storage batteries, and user loads within the DC microgrid system, characterized in that: It includes a communication module (1), a solar module management module (2), a battery management module (3), a load management module (4), and a system control module (5); The communication module (1) is used to remotely transmit real-time status data; The solar module control module (2) is used to monitor the voltage of the solar module and the voltage of the energy storage battery, and to control the connection or disconnection of the solar input relay according to the difference between the voltage of the solar module and the voltage of the energy storage battery. The battery management module (3) is used to monitor the operating status of the energy storage battery capacity, voltage and current, and to control the charging and discharging status of the energy storage battery. The load management module (4) is used to monitor the power consumption, voltage and current of each user load, and to control the switching of different levels of loads in each user load according to the power generation of the solar module and the power of the energy storage battery. The set power consumption priority control strategy is used to manage the circuit power supply, and to maximize the use of the limited capacity of the energy storage battery to ensure stable power supply to high priority loads. The system control module (5) is used to execute the DC microgrid system control strategy, and takes the solar output current = real-time current of the energy storage battery + load and real-time current of each circuit as the control target to ensure the stability and reliability of the system's dynamic operation; the real-time current of the energy storage battery is set to I. y The maximum value is Y max The load and real-time current of each circuit are I. z The maximum value is Z. max The solar output current is I. x ; The control strategy for the DC microgrid system is as follows: Condition 1), when Y max +Z max ≤I x Then the battery management module (3) controls the operation mode of the energy storage battery to the charging state, and the charging current of the energy storage battery is allowed to be the maximum rechargeable current value Y. max The load management module (4) allows different levels of load in each user's load to run at full capacity; Condition 2), when I z ≤I x ≤Y max +I z Then the battery management module (3) controls the operation mode of the energy storage battery to the charging state, but the charging current of the energy storage battery is less than the maximum rechargeable current value Y. max The load management module (4) allows the output of the maximum load current of each circuit; Condition 3), when I x ≤I z If the energy storage battery voltage does not reach the lower limit protection warning value, the battery management module (3) controls the operation mode of the energy storage battery to discharge state, and the load management module (4) allows the output of the maximum current of each circuit load. Condition 4), when I x ≤I z The energy storage battery voltage is about to reach the lower limit protection warning value, and I x +I y > If the high priority level output circuit current is reached, then the load management module (4) will manage and cut off the load output of each circuit in order of priority from low to high according to the load circuit priority level control strategy. Condition 5), when I x +I y If the load current is less than or equal to the lowest priority load current, the load control module (4) will shut down all circuits and all solar photovoltaic energy will be used to charge the energy storage battery until the energy storage battery voltage reaches the battery over-discharge warning release value. Then, it will be determined whether the charging energy meets the power supply requirements of the high priority load in working condition 4). If it does, the load output of each circuit will be put into operation in the order of priority from high to low according to the load circuit priority control strategy.

2. The controller device for an independently operating photovoltaic DC microgrid according to claim 1, characterized in that, In operating condition 4), the specific strategy for controlling and cutting off the load output of each circuit according to the priority level control strategy is as follows: each circuit load is set as a low-priority level 3 load, a medium-priority level 2 load, and a high-priority level 1 load. When the energy storage battery capacity drops to 50%, the level 3 load circuit is cut off; when the energy storage battery capacity drops to 30%, the level 2 load circuit is cut off; and when the energy storage battery capacity drops to 20%, the level 1 load circuit is cut off.

3. The controller device for an independently operating photovoltaic DC microgrid according to claim 2, characterized in that, In operating condition 5), the specific strategy for activating the load output of each circuit in descending order of priority according to the load circuit priority control strategy is as follows: when the energy storage battery capacity rises to 25%, the first-level load circuit is activated; when the energy storage battery capacity rises to 40%, the second-level load circuit is activated; and when the energy storage battery capacity rises to 60%, the third-level load circuit is activated.

4. The controller device for an independently operating photovoltaic DC microgrid according to claim 1, characterized in that, The specific strategy of the solar module control module (2) to control the access or disconnection of the solar input relay is as follows: During the day, when the voltage of the solar module is greater than the voltage of the energy storage battery +5V, the solar input relay is activated after a delay, and the solar module control module (2) charges the energy storage battery; in the evening, when the voltage of the solar module is less than the voltage of the energy storage battery, the solar input relay is disconnected to prevent the energy storage battery from flowing back to the solar module.

5. The controller device for an independently operating photovoltaic DC microgrid according to claim 4, characterized in that: The battery management module (3) uses an SOC metering chip to accurately measure the capacity of the energy storage battery; it uses an analog front-end chip to monitor the real-time voltage of individual cells in the energy storage battery and to perform constant charging and discharging management.

6. The controller device for an independently operating photovoltaic DC microgrid according to claim 5, characterized in that: During the charging process, the energy storage battery has protection functions against solar overvoltage, charging overvoltage, charging overcurrent, and power device overtemperature; during the discharging process, the energy storage battery has protection functions against overvoltage, undervoltage, overcurrent, and short circuit, providing a guarantee for the safe and reliable operation of each user load and system.

7. The controller device for an independently operating photovoltaic DC microgrid according to claim 1, characterized in that: The system control module (5) is executed by the MPPT controller, which uses maximum power point tracking technology to extract the maximum power from the solar photovoltaic array to charge the energy storage battery.

8. The controller device for an independently operating photovoltaic DC microgrid according to claim 7, characterized in that: The MPPT controller is equipped with two controlled DC output terminals. The positive terminal of one controlled DC output terminal is connected to the positive terminal of the energy storage battery through a fuse, and the negative terminal of the other controlled DC output terminal is connected to the negative terminal of the energy storage battery through a MOSFET.

9. The controller device for an independently operating photovoltaic DC microgrid according to claim 8, characterized in that: The DC output control modes of the MPPT controller are: output off, automatic output, time-controlled output, light-controlled output, and remote control output.

10. The controller device for an independently operating photovoltaic DC microgrid according to claim 1, characterized in that: It also includes a data display module (6), which is equipped with LED indicator lights and LCD data display.

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