Control methods and electronic equipment for underground DC grid-connected energy storage systems

Abstract

This invention provides a control method and electronic device for a buried DC grid-connected energy storage system, relating to the field of energy storage technology. The method includes: connecting a BMS module to acquire the SOC and temperature parameters of the energy storage batteries in the DC grid; integrating the BMS module and a DC-DC converter to analyze the battery state of the DC grid based on the SOC and temperature parameters, obtaining state distribution data of the DC grid; analyzing the DC-DC conversion strategy based on the state distribution data of the DC grid, and transmitting the DC-DC conversion strategy to the DC-DC converter for DC-DC conversion control. This invention solves the technical problem that traditional energy storage systems typically use separate energy management modules, with the DC-DC converter and battery management system operating independently, resulting in insufficient accuracy and response speed in battery energy dispatching, and failing to provide efficient energy dispatching support in large-scale power grid security and defense systems.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, specifically to control methods and electronic equipment for underground DC grid-connected energy storage systems. Background Technology

[0002] Currently, most traditional energy storage systems are ground-mounted, but this approach has several drawbacks, particularly in terms of large-scale grid security, intelligent dispatch systems, and power supply stability. Specific issues include: traditional energy storage systems require large land areas, impacting space utilization in urban and industrial areas and failing to meet the space efficiency requirements of smart grids and distributed energy sources; existing thermal management methods, such as air cooling or liquid cooling plates, are insufficient for high-power-density batteries, making it difficult to effectively support large-scale grid security and defense systems, potentially leading to overheating and affecting power supply stability; traditional communication cabling methods, such as CAN, fiber optics, or wireless communication, are prone to signal attenuation in complex environments, resulting in high costs and system maintenance difficulties, which contradicts the high-efficiency and stable communication requirements of intelligent dispatch systems; existing energy storage systems typically use separate energy management modules, with DC-DC converters and battery management systems operating independently, leading to insufficient accuracy and response speed in battery energy dispatch, failing to provide efficient energy dispatch support for large-scale grid security and defense systems.

[0003] Therefore, there is an urgent need for an integrated underground DC energy storage system that can improve space utilization, optimize thermal management, improve communication schemes and integrate energy management modules to meet the needs of smart grids and distributed energy for efficient, stable and safe power supply, and further enhance the dispatch flexibility, reliability and ability to cope with complex environments of the power system, so as to ensure the safe and efficient operation of large-scale power grids. Summary of the Invention

[0004] This application provides a control method and electronic equipment for a buried DC grid-connected energy storage system, aiming to solve the technical problem that traditional energy storage systems typically use separate energy management modules, with DC-DC converters and battery management systems operating independently. This results in insufficient accuracy and response speed of battery energy dispatch, making it impossible to provide efficient energy dispatch support in the security and defense system of a large-scale power grid.

[0005] The first aspect disclosed in this application provides a control method for an underground DC grid-connected energy storage system. The method includes: connecting a BMS module to obtain the SOC and temperature parameters of the energy storage battery in the DC grid; integrating the BMS module with a DC-DC converter to perform battery state analysis of the DC grid based on the SOC and temperature parameters of the energy storage battery in the DC grid, thereby obtaining state distribution data of the DC grid; and based on the heat dissipation constraints of the underground enclosure, analyzing the DC power conversion strategy according to the state distribution data of the DC grid, and transmitting the DC power conversion strategy to the DC-DC converter for DC power conversion control.

[0006] The second aspect of this application discloses an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the control method for the buried DC grid-connected energy storage system in the first aspect.

[0007] One or more technical solutions provided in this application have at least the following beneficial effects:

[0008] By integrating the BMS (Battery Management System) with the DC-DC converter, not only can battery parameters such as SOC (State of Charge) and temperature be monitored in real time, but charging and discharging strategies can also be precisely controlled to optimize the charging and discharging process, avoid overcharging or over-discharging, and extend battery life. This deep integration reduces the separation of energy management modules, improves the system's energy dispatch efficiency, and reduces the complexity of energy management modules, while ensuring the safety and defense of large-scale power grids. Battery parameters obtained through the BMS module, including SOC and temperature, enable precise battery state analysis and determine the battery pack's operating mode based on the state distribution. This control method can optimize the management of each individual cell or module in the battery pack according to different states, ensuring the balanced operation of the entire battery pack. Data transmission using power line carrier communication technology reduces the complexity and cost of traditional communication wiring. Through this communication method, the energy storage system can achieve remote monitoring and management, enhancing system reliability and flexibility, and improving the intelligent dispatching capability of power supply. The underground installation design significantly improves space utilization and reduces the occupation of ground space. The underground design not only allows the system to better adapt to environmental conditions but also reduces the impact of the external environment on the system, further improving the security and stability of power supply and ensuring the efficient operation of the smart grid.

[0009] The above description is merely an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0010] Figure 1 A schematic flowchart of the control method for a buried DC grid-connected energy storage system provided in an embodiment of this application.

[0011] Figure 2 A schematic diagram of the process for obtaining the underground distributed structure in the control method of the underground DC grid-connected energy storage system provided in the embodiments of this application.

[0012] Figure 3 A schematic diagram of the structure of an exemplary electronic device provided in an embodiment of this application.

[0013] Explanation of reference numerals in the attached drawings: Bus 300, Receiver 301, Processor 302, Transmitter 303, Memory 304, Bus Interface 305. Detailed Implementation

[0014] This application provides a control method and electronic equipment for a buried DC grid-connected energy storage system, which solves the technical problem that traditional energy storage systems typically use separate energy management modules, with DC-DC converters and battery management systems operating independently. This results in insufficient accuracy and response speed of battery energy dispatch, making it impossible to provide efficient energy dispatch support in the security and defense system of a large-scale power grid.

[0015] After introducing the basic principles of this application, various non-limiting embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0016] Example 1, as Figure 1 As shown in the embodiment of this application, a control method for a buried DC grid-connected energy storage system is provided, the method comprising:

[0017] Connect to the BMS module to obtain the SOC and temperature parameters of the energy storage battery in the DC grid.

[0018] Connecting the BMS (Battery Management System) module is crucial for monitoring, protecting, and managing the battery pack. In this step, the BMS module is used to acquire the SOC (State of Charge) and temperature parameters of the energy storage battery pack. SOC reflects the battery's current charge level, representing the percentage of its charge capacity. Battery operating temperature is a critical factor affecting battery performance, lifespan, and safety; real-time temperature monitoring ensures the battery operates within a safe temperature range. The BMS module connects to each battery pack via sensors and communication lines. It calculates SOC by real-time monitoring of battery voltage, current, and temperature, and monitors temperature distribution. The SOC and temperature data for each cell in the battery pack are centrally collected by the BMS and transmitted to the control system.

[0019] By integrating the BMS module with the DC-DC converter, the battery status of the DC network is analyzed based on the SOC and temperature parameters of the energy storage battery in the DC network, and the status distribution data of the DC network is obtained.

[0020] The BMS module is integrated with the DC-DC converter, whose task is to regulate the battery voltage and current to achieve the required energy output. The BMS module and the DC-DC converter work closely together through data transmission and signal transmission to ensure that the battery charging and discharging process is effectively controlled and optimized.

[0021] Based on the SOC data of the battery pack, the remaining capacity of each battery cell can be understood, which is used to manage the battery charging and discharging process and help determine which battery cells need to be charged and which need to be discharged. Temperature has a significant impact on battery performance and safety. By monitoring temperature data, it is possible to analyze whether the battery is within its optimal operating temperature range. If the temperature of some batteries is too high or too low, additional measures need to be taken, such as activating the cooling system or stopping charging and discharging. Based on the acquired SOC and temperature data, the overall state of the battery pack is analyzed, including the charging state of each battery cell, temperature distribution, and whether there are any abnormal states, such as overcharging, over-discharging, and excessive temperature. Through data analysis methods, such as cluster analysis and state estimation, the operating state of each battery cell is classified, and based on this, the state distribution data of the battery pack is generated. This state distribution data is the basis for the battery management system's decision-making and helps in the formulation of subsequent battery scheduling and control strategies.

[0022] Based on the heat dissipation constraints of the underground hull, the DC-DC conversion strategy is analyzed according to the state distribution data of the DC network, and the DC-DC conversion strategy is transmitted to the DC-DC converter for DC-DC conversion control.

[0023] In buried environments, heat dissipation is limited, especially in underground spaces. Heat dissipation efficiency can be affected by factors such as the thermal conductivity of the surface soil, humidity, and airflow. For example, the thermal conductivity of the soil determines whether heat can be effectively conducted from the battery pack to the underground space, affecting the overall heat dissipation effect. Therefore, the heat dissipation constraints of the buried enclosure actually reflect the feasibility and effectiveness of battery pack heat dissipation under specific environments, including how heat is conducted from the battery pack to the soil or air, and the efficiency of this process. Based on this, the safe operation of the battery in buried environments can be ensured by optimizing heat dissipation paths and strategies. For example, if the battery pack is at a high temperature and the thermal conductivity of the surface soil is low, additional heat dissipation measures are needed, such as increasing the heat dissipation area or using coolant.

[0024] After analyzing the heat dissipation constraints, the DC-DC conversion strategy is analyzed based on the DC network state distribution data. Specifically, based on the battery's SOC and temperature distribution, priority is given to which battery cells need charging and which need discharging. Through differentiated strategies, overcharging or over-discharging of batteries is avoided. Based on SOC and temperature data, charging and discharging priorities are configured for each battery cell. Some cells in the battery pack may need to temporarily stop charging or discharging or adjust the charging and discharging rate due to excessively high or low temperatures. Based on the strategy analysis of SOC and temperature states, a battery protection mechanism is implemented. For example, if the temperature of some batteries is too high, the charging process of those batteries will be suspended and the cooling system will be activated.

[0025] The obtained DC-DC conversion strategy is transmitted to the DC-DC converter. Specifically, based on the obtained DC-DC conversion strategy, the conversion operations that the DC-DC converter needs to perform are calculated, including the conversion voltage value, power distribution, discharge current, etc. These control signals are transmitted to the DC-DC converter through a communication interface, such as power line carrier communication or CAN bus. The DC-DC converter adjusts the input and output current and voltage values ​​according to the received control signals in order to control the battery charging and discharging according to the optimized strategy.

[0026] After receiving a control signal, the DC-DC converter operates according to the set conversion parameters. For example, if a reduced battery discharge rate is required, the DC-DC converter will decrease the output current; if charging is required, it will adjust the current and voltage to match the battery's charging needs. Furthermore, while performing control tasks, the DC-DC converter will provide real-time feedback of current and voltage values ​​and status information to the BMS module. The BMS module will further optimize its strategy based on the feedback data, adjusting the control parameters during battery charging and discharging to ensure the battery operates in a safe and healthy state.

[0027] Furthermore, integrating the BMS module with the DC-DC converter includes:

[0028] Based on power line carrier communication technology, control commands are transmitted through the power line network. The BMS module and DC-DC converter are integrated and connected through the power line network for control command transmission.

[0029] Power line carrier (PLC) communication technology is a technology that transmits communication signals through power lines (i.e., power grids). It uses high-frequency electrical signals to superimpose control data or information onto the AC signals of the power lines for data transmission. The basic working principle of PLC communication technology includes high-frequency carrier signal injection, signal demodulation, and bidirectional communication. This technology uses existing power lines as the communication medium, avoiding the wiring complexity of traditional communication networks, and has the advantages of low cost and easy installation.

[0030] Power line carrier communication modules are installed at both ends of the BMS module and the DC-DC converter. These modules are responsible for transmitting control signals through the power line network. Each module has signal modulation and demodulation functions, converting control commands from digital signals to carrier signals and transmitting them through the power lines. By using existing power lines as communication channels, there is no need to lay additional communication cables. Through power line carrier communication technology, the BMS module and the DC-DC converter are integrated into the power line network to form a closed-loop control system.

[0031] The BMS module generates control commands based on the battery pack's state. These commands typically include specific requirements for charging and discharging operations, such as charging current and voltage settings, and discharging current and voltage limits. These commands are optimized based on the battery's current state and safety requirements. The control commands are converted into high-frequency carrier signals via the power line carrier communication module and transmitted through the power line network. The carrier signals can traverse existing power lines to reach the DC-DC converter. The DC-DC converter receives the carrier signals via the power line carrier communication module and demodulates the original control commands. These commands are then parsed by the DC-DC converter, driving it to adjust the voltage and current. The use of power line carrier communication technology not only simplifies wiring and reduces costs but also enables efficient bidirectional communication over existing power lines.

[0032] Furthermore, such as Figure 2 As shown, the process of obtaining the SOC and temperature parameters of the energy storage battery for DC grid connection includes the following:

[0033] Environmental parameters of the underground installation environment are detected to obtain underground environmental characteristics, including temperature and humidity; the installation space constraints and heat dissipation-space influence relationship of the immersion cooling system are analyzed; based on the parameter characteristics, installation space constraints, and heat dissipation-space influence relationship of the underground DC network, the underground cabin structure installation strategy is optimized to maximize the underground space utilization and space temperature stability, and the underground distribution structure is obtained.

[0034] A comprehensive environmental parameter test is conducted on the installation environment of the buried DC grid-connected energy storage system to ensure its safe and stable operation under suitable environmental conditions. These environmental parameters include key factors such as temperature and humidity. Specifically, temperature and humidity sensors are used to monitor the temperature and humidity in the buried environment in real time. The sensors can sense the temperature and humidity in the air, record the monitored temperature and humidity data, and generate buried environment characteristics. If necessary, soil temperature sensors and humidity sensors can also be used to monitor the temperature and humidity of the soil, especially in deep buried environments where changes in soil temperature and humidity directly affect the system's operation.

[0035] Immersion cooling systems are a method of heat dissipation that involves immersing the battery in an insulating coolant. The coolant directly contacts the battery, carrying away the heat generated during charging and discharging, effectively preventing the battery from overheating. This system can improve heat dissipation efficiency and help maintain stable battery temperature.

[0036] Analyzing the installation space constraints, underground installation environments are usually limited by space. Therefore, the design of the cooling system must fully consider space utilization efficiency. The layout of the cooling system needs to be determined based on the arrangement of the battery packs and the spatial characteristics of the underground compartment. In order to ensure the effectiveness of the cooling system, the coolant needs to cover each battery cell to avoid local overheating.

[0037] Analyzing the relationship between heat dissipation and space, the heat dissipation effect is closely related to factors such as the installation density of the battery pack, the design of the coolant flow channels, and the temperature and humidity of the underground environment. If the temperature of the underground environment is high, it may be necessary to increase the flow rate of the coolant or increase the heat exchange area of ​​the coolant to improve heat dissipation efficiency. Furthermore, within a limited space, the battery density and the layout of the cooling system must be balanced to avoid insufficient cooling due to insufficient space. For example, the laying of cooling pipes and the flow channels of the coolant need to be precisely planned to ensure that the temperature of each battery cell can be kept within a suitable range.

[0038] The parameter characteristics of the underground DC-DC grid are analyzed, including but not limited to the type, capacity, energy requirements, and charge / discharge characteristics of the battery pack. Based on these parameter characteristics, installation space constraints, and the heat dissipation-space influence relationship, the installation strategy of the enclosure structure is optimized with the goal of maximizing the utilization rate of underground space and the stability of space temperature. Specifically, the utilization rate of underground space is maximized by rationally planning the layout of components such as battery packs, DC-DC converters, and cooling systems. For example, the arrangement of battery packs, such as matrix or honeycomb, is optimized to minimize gaps. Considering the impact of temperature on battery performance and lifespan, the design needs to avoid the formation of heat concentration areas. Therefore, the battery packs should be rationally laid out according to thermal management requirements to ensure good heat convection and heat exchange. At the same time, the layout of the cooling system should cover each battery cell to ensure uniform temperature distribution.

[0039] Through the above optimization process, the final underground distribution structure is obtained, ensuring that all equipment and components, such as batteries, DC-DC converters, control systems, and cooling systems, can be reasonably distributed and meet the safety distance requirements between equipment to avoid problems such as overheating and equipment interference.

[0040] Furthermore, based on the parameter characteristics of the underground DC network, installation space constraints, and the heat dissipation-space influence relationship, the installation strategy for the underground cabin structure is optimized to maximize the utilization rate of underground space and the stability of space temperature. This includes:

[0041] The control relationships of the battery packs in the underground DC network are analyzed, and the topology node relationships are constructed based on these relationships. A node switch matrix is ​​configured, which is used for energy routing control of the battery packs in the topology nodes. Based on the control relationships of the node switch matrix, an integrated connection matching analysis of the DC-DC converter and the BMS module is performed. The integrated connection relationships of the matched DC-DC converter and the BMS module are connected according to the signal transmission characteristics of the power line network to obtain the topology of the underground DC network. Based on the topology of the underground DC network, the topology control requirement characteristics are decomposed according to the node switch matrix, the integrated connection relationships of the DC-DC converter and the BMS module, and the signal transmission characteristics of the power line network to obtain the parameter characteristics of the underground DC network.

[0042] Battery pack control relationships refer to how battery packs in a buried DC grid energy storage system are managed and scheduled through a control system to achieve rational energy allocation and control. Specifically, battery pack control relationships include: State of Charge (SOC) management: the SOC value of different battery packs determines whether they are in a charging or discharging state. By analyzing the SOC of each battery pack, it can be determined which batteries need charging and which can discharge; Battery health management: the health status of batteries, such as temperature and internal resistance, directly affects their charging and discharging behavior. Through the analysis of control relationships, the operating status of batteries can be monitored and optimized in real time to avoid damage and overheating; and charging and discharging strategies: the charging and discharging strategies of each battery pack must be dynamically adjusted according to its own state. For example, battery packs in good health are given priority for discharging, while battery packs in poor health may be isolated or have their charging and discharging restricted. By analyzing these battery pack control relationships, energy transfer and control strategies between individual battery packs can be constructed.

[0043] Topology nodes refer to the different constituent units of a battery pack in a system. The connections between nodes determine how energy is exchanged between battery packs. Each battery pack can be regarded as a node. These nodes are interconnected through a power network. The topology structure shows the energy transmission path between battery packs through the interconnection of nodes.

[0044] A node switch matrix is ​​a core tool for controlling energy routing between topology nodes. It controls the power transmission path between nodes through switches, ensuring that the energy flow of each node conforms to the battery pack's control strategy and system requirements. The switch matrix uses electronic switches, such as relays and solid-state switches, to connect or disconnect nodes, thereby controlling the direction of energy flow in the battery pack. A node switch matrix is ​​typically a multi-dimensional matrix, where each cell represents a switch that connects different nodes in the system. Based on the topology, the switches in the matrix will open or close according to control signals to achieve energy routing control of the battery pack.

[0045] Each battery pack is connected to other nodes in the system via control switches. When a battery pack needs to discharge, the node switch matrix determines whether it should be connected to the load or other battery packs. The node switch matrix also determines the connection method between the DC-DC converter and the BMS module. Specifically, when the DC-DC converter needs to adjust its charging and discharging strategy, the BMS module sends control signals; conversely, when the BMS module needs to obtain real-time battery status information, the DC-DC converter feeds back the corresponding data to the BMS module. To ensure efficient transmission of this information and control commands, the connections must be optimized according to the characteristics of the power line network.

[0046] Power line carrier communication technology modulates signals onto power lines for transmission. Therefore, when configuring the connection between the DC-DC converter and the BMS module, the signal transmission characteristics of the power line network, such as signal frequency, transmission stability, and anti-interference capability, need to match the control signal formats of the DC-DC converter and the BMS module. Through power line carrier technology, the BMS module and the DC-DC converter establish a stable communication channel via the power line network. The BMS module sends control commands through the power line network, and the DC-DC converter adjusts the charging and discharging state of the battery pack according to these commands, establishing an integrated connection.

[0047] Once the control relationship of the node switch matrix is ​​established and the integration connection between the DC-DC converter and the BMS module is matched, the topology of the entire system is determined. This includes the connection between the battery pack and other system components, and the integration of the DC-DC converter and the BMS module. This topology ensures the efficient operation and reliability of the battery pack, avoids energy waste and overload problems, and maintains the stability and safety of the system.

[0048] Based on the integrated connection relationships of the node switching matrix, DC-DC converter, and BMS module, as well as the signal transmission characteristics of the power line network, the control requirement characteristics of the topology are decomposed. Specifically, by analyzing the battery pack's SOC, load demand, and charging / discharging strategy, the load allocation requirements of the battery pack under different operating states are decomposed, i.e., under specific conditions, which battery packs should be prioritized and which need to be charged or discharged. Based on information such as the battery pack's health status, temperature, and SOC, the charging / discharging strategy characteristics of different battery packs are decomposed. For example, healthy batteries are prioritized for discharge, while battery packs with higher temperatures may be temporarily isolated or have their charging / discharging rates limited. Through the control relationships of the node switching matrix, the energy flow path characteristics are decomposed, enabling the switching of paths by the switching matrix under different demands to optimize the energy transmission efficiency of the battery pack. The control signal transmission characteristics between the DC-DC converter and the BMS module are analyzed to determine the system's response speed, stability, and accuracy to input signals. By optimizing the integrated connection relationships, latency can be reduced and the system's responsiveness improved.

[0049] Through the above decomposition, the parameter characteristics of the underground DC network are obtained, including the charging and discharging capacity of the battery pack, the flexibility of the topology, the stability of signal transmission, and the control optimization characteristics. These characteristics help to gain a deeper understanding of the system's battery pack management, energy distribution, signal transmission, and control strategies, thus providing an important basis for the system's optimized design, control strategy formulation, and performance evaluation.

[0050] Furthermore, the analysis of the installation space constraints and heat dissipation-space influence relationship of the immersion cooling system includes:

[0051] Obtain heat dissipation test data of the insulating coolant; based on the heat dissipation test data, perform fitting analysis on the spatial installation parameters, heat dissipation effect and sustainability in the test data with heat dissipation stability as the target, and obtain the heat dissipation-space influence relationship; based on the heat dissipation-space influence relationship, screen spatial parameters with the minimum threshold of heat dissipation effect to obtain the installation space constraints.

[0052] In underground DC grid-connected energy storage systems, insulating coolant is used in immersion cooling systems to keep the battery pack's operating temperature within a safe range. Common insulating coolants include mineral oil and synthetic oil, which can effectively dissipate heat and prevent short circuits or electrical faults in the battery pack.

[0053] Design a set of test conditions that include different coolant temperatures, flow rates, and pressures. Typically, the test is conducted under different ambient temperatures and coolant flow rates to simulate the heat dissipation effect in actual use. Using devices such as temperature sensors and flow meters, the coolant's temperature changes, thermal conductivity, and flow rate are monitored in real time. Coolant heat dissipation data under each condition are recorded, such as the initial temperature, final temperature, flow rate, and cooling effect of the coolant. Through this data, a comprehensive understanding of the coolant's heat dissipation performance can be obtained.

[0054] Thermal stability refers to the coolant's ability to maintain temperature during long-term use, preventing temperature fluctuations from negatively impacting the battery pack and cooling system. Better thermal stability results in more reliable cooling performance. Fitting analysis was performed on spatial installation parameters, heat dissipation effect, and sustainability in the experimental data, with thermal stability as the target.

[0055] Specifically, the fitting of spatial installation parameters includes parameters such as coolant flow path, spatial layout, pipe curvature, and coolant volume. Through experimental data, the effects of these installation parameters on coolant flowability and heat dissipation are evaluated. For example, for coolant flow path, different flow paths are set up, and the flow rate, heat transfer efficiency, and temperature change of coolant on each path are measured. For spatial layout, the impact of each layout on coolant flow is tested under different spatial layouts. For example, whether there are dead zones, whether the space is large enough to ensure unrestricted flow, or whether pipe curvature increases flow resistance. For pipe curvature and coolant volume, pipes with different curvatures and volumes are used to test their impact on cooling effect.

[0056] Fitting the relationship between heat dissipation effect and space involves identifying which spatial parameters have the greatest impact on heat dissipation, such as space height, width, depth, coolant flow rate, and path length. These relationships help to understand how the coolant effectively dissipates heat under different spatial layouts. For example, for space height, width, and depth, the heat dissipation effect under different space dimensions is measured, and the temperature change of the coolant during the flow process and the size of the heat exchange area are recorded. For coolant flow rate, the heat exchange efficiency of the coolant is tested at different flow rates. For path length, the impact of different path lengths on the heat conduction effect of the coolant is recorded.

[0057] Continuous fit includes assessing the stability of the cooling system during long-term operation, observing whether the cooling effect remains stable over different time periods, and how factors such as coolant flow resistance and heat capacity affect the heat dissipation effect. For example, for the long-term stability of the cooling system, long-term operation tests are conducted to record whether the coolant maintains a constant temperature during operation over several weeks or months; for flow resistance and heat capacity, the changes in coolant flow resistance during long-term operation are measured to assess its impact on the cooling effect, and the heat capacity of the coolant is tested to ensure that it can maintain sufficient heat retention capacity during long-term use.

[0058] Through the above data fitting analysis, the specific impact of each parameter on heat dissipation effect and stability is analyzed, and the heat dissipation-space influence relationship is finally obtained, including the relationship between space size and heat dissipation efficiency, and the relationship between pipe design and cooling effect. For example, the size of the space (height, width, depth) directly affects the length of the coolant flow path and the heat exchange surface area. The larger the space, the better the heat dissipation effect, but an excessively long flow path may increase flow resistance, leading to reduced efficiency. The greater the pipe curvature, the greater the flow resistance, which will affect the cooling effect. By optimizing the pipe layout and reducing curvature, flow efficiency and heat dissipation effect can be improved.

[0059] The minimum threshold for heat dissipation is a pre-set minimum standard for heat dissipation, which is a necessary condition to ensure the safe operation of the battery pack. This threshold is usually set based on factors such as the operating temperature range of the battery pack, the heat dissipation capacity of the coolant, and the influence of the external environment.

[0060] Based on the heat dissipation-space impact relationship, the influence of different spatial parameters on heat dissipation effect is evaluated, such as space height, width, depth, and coolant flow rate. Spatial parameter configurations that meet the minimum heat dissipation effect threshold are selected. The coolant flow path design, including flow rate, volume, and pipe layout, is considered to ensure that the coolant can fully cover the battery pack and effectively remove heat. The optimal combination of spatial parameters is selected based on actual conditions to optimize heat dissipation. Based on the selected spatial parameters, the installation space constraints of the buried chamber structure are defined. These conditions ensure that the cooling system operates efficiently within a limited space, avoiding space waste and uneven heat dissipation.

[0061] Furthermore, the installation space constraints include: the volume ratio of insulating coolant and the reserved pipe width.

[0062] Installation space constraints refer to the physical limitations and design requirements on the installation space while ensuring the normal operation and maintenance of the system. These mainly include the volume ratio of the insulating coolant and the reserved pipe width. The volume ratio of the insulating coolant refers to the proportion of the coolant's volume within the entire battery pack or battery system. A reasonable coolant volume ratio is crucial for ensuring effective heat dissipation during battery operation. The design must consider the ratio of coolant volume to battery pack volume to ensure a proper match. Too much coolant may lead to wasted space, while too little coolant may fail to dissipate heat adequately, affecting battery performance and lifespan. The optimal ratio needs to be determined based on the battery pack's power requirements, heat dissipation requirements, and coolant specifications. The flow characteristics should be considered to rationally plan the proportion of coolant volume; the reserved pipe width refers to the minimum width left in the installation space for coolant pipes. These pipes are used to transport coolant and ensure that the coolant can effectively flow to various parts of the battery pack for heat dissipation. Too small a pipe width will lead to increased coolant flow resistance, thereby affecting the heat dissipation effect, and may even lead to problems such as unstable flow or pipe blockage. Too large a reserved pipe width will occupy too much space and affect the compactness of the overall layout. It is necessary to accurately calculate the required pipe width according to the design requirements of the cooling system, the coolant flow rate, and the system's heat dissipation efficiency target to ensure smooth fluid flow and effective use of installation space.

[0063] Furthermore, based on the heat dissipation constraints of the underground hull, the DC-DC conversion strategy is analyzed according to the state distribution data of the DC network, including:

[0064] Obtain the SOC difference gradient distribution and temperature distribution of the battery pack; configure charging and discharging priorities based on the SOC difference gradient distribution and temperature distribution; analyze the heat dissipation conditions of the battery pack in the underground compartment according to the underground distribution structure to obtain the heat dissipation constraints of the battery distribution; analyze the control conversion strategy according to the charging and discharging priorities and the corresponding heat dissipation constraints of the batteries to obtain the conversion control path and conversion parameters; perform response decomposition on the conversion control path and conversion parameters according to the topology of the underground DC network to obtain the control parameters of the node switching matrix and the mapping relationship with the DC conversion parameters, and obtain the DC conversion strategy.

[0065] State of charge (SOC) difference refers to the difference in state of charge between different cells within a battery pack. If some cells have a lower SOC while others have a higher SOC, it may lead to reduced charging and discharging efficiency, performance imbalance, and even shortened battery life. By installing SOC monitoring devices on each cell in the battery pack, the SOC value of each cell can be monitored in real time. By analyzing the differences in these SOC values, the gradient of SOC difference can be calculated. Common methods for calculating the difference include the difference in SOC between adjacent cells or the difference between the maximum and minimum SOC in the entire battery pack.

[0066] Temperature differences in the battery pack also have a significant impact on the battery's performance. Excessively high or low battery temperatures can affect its charging and discharging efficiency and may even lead to battery failure in severe cases. By installing temperature sensors at multiple locations within the battery pack, the temperature of each individual cell and the overall battery pack can be monitored to obtain the temperature distribution within the battery pack.

[0067] Based on the obtained SOC difference gradient distribution and temperature distribution, the charging and discharging priorities of the batteries are configured to optimize the utilization efficiency of the battery pack and extend its lifespan. Specifically, when the SOC of some cells in the battery pack is high, these cells can be preferentially used as discharge sources to prevent overcharging; when the SOC of some cells in the battery pack is low, these cells are preferentially charged to ensure that all cells maintain a balanced SOC level; when the temperature of some cells is too high, the load on these cells is preferentially reduced by decreasing the charging or discharging rate; when the temperature of some cells in the battery pack is low, the low temperature environment may lead to a decrease in the charging and discharging efficiency of the battery, in this case, these low-temperature cells are preferentially charged.

[0068] Heat dissipation in buried environments is influenced by various factors, such as soil thermal conductivity, humidity, and underground air circulation. Under such conditions, the heat dissipation efficiency of batteries can be significantly reduced. Therefore, it is necessary to analyze the heat dissipation conditions of the battery pack. This analysis requires evaluating the thermal conductivity, heat dissipation path, and heat dissipation effect of each battery cell in a specific buried environment. This involves considering factors such as the thermal conductivity of the battery casing material, soil temperature variations, and ambient humidity. By matching the heat dissipation requirements of the battery pack with the heat dissipation conditions of the buried environment, the heat dissipation constraints of each battery cell are obtained. These constraints reflect which battery cells have difficulty dissipating heat in a specific environment and which battery cells have better heat dissipation performance.

[0069] After acquiring information such as SOC difference gradient, temperature distribution, and heat dissipation constraints, the control switching strategy is analyzed based on this data. This analysis involves a comprehensive consideration of charge / discharge priorities and battery heat dissipation constraints. Specifically, it calculates how to arrange the battery charging and discharging processes under different heat dissipation constraints to ensure that the battery pack achieves energy balance while maintaining a safe temperature range. The control switching strategy refers to adjusting the charging and discharging process through appropriate control mechanisms based on factors such as the battery pack's SOC, temperature, and heat dissipation constraints to ensure that each battery cell in the battery pack can operate under optimal conditions, including controlling parameters such as the battery's charging rate, discharging rate, and charging voltage.

[0070] For example, different charging and discharging priorities are set according to the SOC difference gradient, that is, batteries with lower SOCs are charged first. Specifically, the charging current allocation can be based on the difference between the battery SOC and the target SOC. For example, for multiple battery cells, the charging current can be allocated according to the following formula:

[0071]

[0072] Among them, I charge，i It is the charging current of battery cell i, SOC i It is the current SOC of battery cell i. j It is the SOC of any other battery cell j besides the current battery cell i. target The target SOC, I charge，total This is the total charging current.

[0073] Based on the temperature distribution, different charging and discharging priorities are set, that is, batteries with higher temperatures are discharged first to help them cool down. Assuming that some batteries in the battery pack have higher temperatures and that the discharge capacity of the batteries is closely related to their temperature, the formula for discharging current distribution is the same as above. For the sake of brevity in the manual, it will not be elaborated here.

[0074] In buried environments, batteries may have poor heat dissipation capabilities, especially with long heat dissipation paths, high soil temperatures, or high humidity. Therefore, it is necessary to consider the heat dissipation constraints of each battery. That is, when the battery temperature is high, under limited heat dissipation conditions, the discharge current should be limited to prevent the battery temperature from rising further. In this case, the calculation of the discharge current can incorporate temperature and heat dissipation constraints to ensure that the discharge process does not lead to battery overheating. For example, the charging current can be allocated according to the following formula:

[0075]

[0076] Where β is the heat dissipation coefficient, which depends on the environmental heat dissipation capacity, T battery，i T is the current temperature of battery cell i. max This is the battery's maximum safe temperature.

[0077] Based on the aforementioned charging and discharging priorities and the corresponding heat dissipation constraints of the batteries, a switching path is designed to dynamically adjust the charging and discharging processes between individual battery cells. Specifically, under heat dissipation constraints, starting from the control priority, the state of each battery cell is analyzed step by step to formulate the optimal control path. First, the high SOC battery is discharged, and then the low SOC battery is charged. At the same time, it is considered that batteries with higher or lower temperatures need to have their load adjusted or be charged first. The core task of the switching control path is to avoid over-discharging or over-charging of some battery cells and to avoid excessively high or low temperatures by adjusting the energy flow path between batteries. The path design includes how to adjust the current, voltage, and power of each battery cell to ensure the balance of the battery pack's operating state.

[0078] Conversion parameters refer to the specific parameters required during the control path conversion process, including charging current, discharging current, battery voltage, and converter conversion ratio. These parameters need to be dynamically adjusted according to changes in battery SOC, temperature, and operating environment. During the control process, the adjustment of conversion parameters needs to ensure that each cell in the battery pack maintains a stable temperature and voltage during charging and discharging to avoid extreme situations.

[0079] By combining the changes in the conversion control path with the node responses of the topology, it is possible to determine how to adjust the energy flow path by changing the node switching state under different operating conditions. This includes how the battery packs are interconnected during charging and discharging, and how the DC-DC converter interacts with different battery cells. The purpose of response decomposition is to clarify the performance of different nodes under different operating conditions and to provide a basis for subsequent control strategies.

[0080] Based on topology analysis, control parameters for the node switching matrix are obtained, including switching frequency, control mode, and energy transfer path selection rules. By adjusting these control parameters, energy flow between individual battery cells can be precisely controlled. The control parameters of the node switching matrix need to be mapped to DC-DC conversion parameters to ensure optimal energy transfer between the battery pack and the DC-DC converter under different operating modes. DC-DC conversion parameters, such as conversion ratio and output voltage, affect voltage and current distribution between nodes. The mapping relationship ensures that these parameters can work collaboratively under different operating conditions.

[0081] The DC-DC conversion strategy is a complete set of charging and discharging control strategies based on the mapping relationship between the node switching matrix and the DC-DC converter. It determines how to adjust the connection between the nodes in the battery pack and how to optimize the DC-DC conversion process to maximize the energy efficiency and lifespan of the battery pack.

[0082] Furthermore, it also includes:

[0083] Historical monitoring data of each battery pack is acquired, and the charging and discharging parameter curves of the historical monitoring data are analyzed to obtain the charging and discharging abnormal thresholds and habitual state parameters of each battery pack. Based on the charging and discharging abnormal thresholds and habitual state parameters of each battery pack, the SOC and temperature parameter thresholds of each battery pack are set. When the SOC and temperature parameter thresholds of the battery pack are triggered, incremental priority is configured to perform priority charging and discharging control adjustment. When the charging and discharging control parameters are not met, an early warning isolation signal is generated, and isolation control is performed through the node switch matrix.

[0084] Historical monitoring data for each battery pack is obtained from the battery management system. This data includes information such as voltage, current, temperature, and SOC value of the battery pack at different time periods. The data can be arranged in time series, and the charge and discharge state of the battery is recorded for each cycle. The charge and discharge curve is a graph showing the changes of parameters such as voltage, SOC, and current over time during the actual charge and discharge process of the battery pack. By analyzing these curves, the normal charge and discharge characteristics of the battery pack and potential abnormalities can be identified.

[0085] Obtain abnormal charging and discharging thresholds for each battery pack, including abnormal voltage thresholds, abnormal current thresholds, abnormal SOC fluctuations, and excessively high or low temperatures. For example, if the battery pack voltage exceeds or falls below a certain critical value, it indicates that the battery pack is overcharged or over-discharged, which requires adjustment or protective measures.

[0086] Each battery pack will have some typical charge and discharge characteristics during its long-term use. For example, some batteries may habitually operate at a specific charging rate, while others perform best within certain temperature ranges. By analyzing historical monitoring data, these habitual state parameters can be identified and a basis can be provided for subsequent battery health management.

[0087] Based on the abnormal charging and discharging thresholds and habitual state parameters of each battery pack, SOC (State of Charge) and temperature thresholds are set for each battery pack. These thresholds are used in the battery management system as monitoring and protection standards for the battery packs. The SOC threshold refers to the safe range that the battery pack's state of charge should maintain during charging and discharging. For example, when the SOC falls below a certain value, such as 20%, the battery pack should begin charging; when the SOC exceeds a certain value, such as 80%, the battery pack should stop charging or switch to discharging mode. By setting reasonable SOC thresholds, unhealthy charging and discharging ranges can be avoided, ensuring efficiency and battery life during charging.

[0088] Temperature threshold parameters refer to the temperature range of individual battery cells and the battery pack during charging and discharging. Within a certain operating temperature range, the battery can maintain efficient operation, while exceeding this range will cause performance degradation and may even lead to thermal runaway. Based on historical temperature data of the battery pack, temperature fluctuations under different charging and discharging states are analyzed to set a safe temperature range. Generally, the operating temperature of the battery should be controlled between 0℃ and 45℃; excessively low or high temperatures will affect battery performance and lifespan.

[0089] Incremental priority refers to dynamically adjusting the charging and discharging priority based on parameters such as the battery pack's SOC and temperature. For example, when the SOC of a battery is below a threshold, that battery should be charged first. Conversely, batteries with higher SOC or higher temperature should be discharged first or have their charging rate adjusted. When the battery pack's SOC or temperature reaches a preset threshold, incremental priority is automatically activated, and the charging and discharging rate of the battery pack is dynamically adjusted according to the incremental priority configuration.

[0090] When the battery's charge / discharge rate cannot meet current demands, a warning isolation signal is triggered. These signals indicate an abnormality in the battery pack that may lead to battery damage or system malfunction. Examples include excessively high or low SOC, battery temperature exceeding the safe operating range, or overcharging / discharging of the battery pack. Warning signals are generated based on these conditions to allow for timely remedial action. When a warning signal is triggered, an isolation control mechanism is activated to ensure the problematic battery does not continue to affect the overall battery pack operation. The warning signal immediately isolates the faulty battery cell or module, preventing it from impacting other batteries.

[0091] Furthermore, propagating control commands through the power line network includes:

[0092] The DC-DC conversion strategy is converted into a high-frequency carrier signal; the high-frequency carrier signal converted from the data is coupled into the power line and transmitted through the power line network; the control module uses a demodulator to obtain the signal from the power line to extract the data, obtain the DC-DC conversion strategy, and implement DC-DC conversion control for the DC-DC converter.

[0093] Modulation techniques, such as frequency modulation and amplitude modulation, are used to convert DC-DC conversion strategies into high-frequency signals. Typically, the frequencies of these signals are set within the power line communication band to ensure that they can avoid the main operating frequencies of the power system. The frequency of the high-frequency carrier signal must be selected within a frequency band that does not affect the operation of the power system, usually in the range of tens to hundreds of kHz. After modulation, these carrier signals can carry system commands and be transmitted through the power line.

[0094] To couple high-frequency carrier signals to power lines, specific couplers are required. These couplers can simultaneously transmit AC power and high-frequency carrier signals over the power line. Couplers typically employ either inductive or capacitive coupling, effectively separating the high-frequency signal from the AC signal on the power line for transmission. This coupling method allows the power line to carry both AC power and high-frequency data carrier signals simultaneously. Through the power line network, the carrier signal is transmitted from the source to the receiver. During transmission, the signal may be affected by power line noise; therefore, error detection and correction algorithms are needed to ensure correct data transmission.

[0095] The demodulator is used to acquire the high-frequency carrier signal transmitted from the power line and demodulate it into the original control data. The demodulation process includes filtering, demodulation and data recovery. The demodulated signal contains control parameters, such as battery charging voltage, current and discharging voltage. The control module obtains the DC-DC conversion strategy by parsing these data.

[0096] Based on the data obtained from the power line, the control module sends control signals to the DC-DC converter to adjust its output voltage, current and other parameters. Through these adjustments, the DC-DC converter can perform operations such as charging and discharging regulation and temperature control of the battery pack, ensuring the safe and efficient operation of the battery pack.

[0097] In summary, the control method for the buried DC grid-connected energy storage system provided in this application has the following technical effects:

[0098] By integrating a BMS (Battery Management System) with a DC-DC converter, not only can battery parameters such as SOC (State of Charge) and temperature be monitored in real time, but charging and discharging strategies can also be precisely controlled to optimize the charging and discharging process, avoid overcharging or over-discharging, and extend battery life. This deep integration reduces the separation of energy management modules, improves the system's energy dispatch efficiency, and reduces the complexity of energy management modules, while ensuring the safety and defense of large-scale power grids. Battery parameters obtained through the BMS module, including SOC and temperature, enable precise battery state analysis and determine the battery pack's operation based on the state distribution. This control method optimizes the management of each individual cell or module within the battery pack, ensuring balanced operation of the entire battery pack. It employs power line carrier communication technology for data transmission, reducing the complexity and cost of traditional communication wiring. This communication method enables remote monitoring and management of the energy storage system, enhancing its reliability, flexibility, and intelligent scheduling capabilities. The underground installation design significantly improves space utilization and reduces ground space occupation. The underground design not only allows the system to better adapt to environmental conditions but also reduces the impact of the external environment on the system, further enhancing the security and stability of power supply and ensuring the efficient operation of the smart grid.

[0099] Example 2, as Figure 3 The diagram shown is a schematic representation of the structure of an exemplary electronic device of this application. Figure 3 In this document, the bus architecture is represented by bus 300. Bus 300 may include any number of interconnected buses and bridges, and bus 300 connects various circuits including one or more processors represented by processor 302 and memory represented by memory 304. Bus 300 may also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 305 provides an interface between bus 300 and receiver 301 and transmitter 303. Receiver 301 and transmitter 303 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 302 is responsible for managing bus 300 and general processing, while memory 304 can be used to store data used by processor 302 during operation.

[0100] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0101] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method of a buried direct current networking energy storage system, characterized in that, The method includes: Connect to the BMS module to obtain the SOC and temperature parameters of the energy storage battery in the DC grid; By integrating the BMS module and the DC-DC converter, the battery status of the DC network is analyzed based on the SOC and temperature parameters of the energy storage battery in the DC network, and the status distribution data of the DC network is obtained. Based on the heat dissipation constraints of the underground cabin, the DC conversion strategy is analyzed according to the state distribution data of the DC network, and the DC conversion strategy is transmitted to the DC-DC converter for DC conversion control. To obtain the SOC and temperature parameters of the energy storage battery in the DC grid, the following steps are required: Environmental parameters of the underground installation environment are detected to obtain the characteristics of the underground environment, including temperature and humidity; Analysis of the installation space constraints and heat dissipation-space influence relationship of immersion cooling systems; Based on the parameter characteristics, installation space constraints, and heat dissipation-space influence relationship of the underground DC network, the installation strategy of the underground cabin structure is optimized to maximize the underground space utilization and space temperature stability, thereby obtaining the underground distribution structure. Based on the parameter characteristics of the underground DC network, installation space constraints, and the heat dissipation-space influence relationship, the installation strategy for the underground cabin structure is optimized to maximize underground space utilization and space temperature stability. This includes: The control relationship of the battery packs in the underground DC network is analyzed, and the topology node relationship is constructed based on the control relationship of the battery packs. The node switch matrix is ​​configured and the node switch matrix is ​​used for the energy routing switch control of the battery packs in the topology nodes. Based on the control relationship of the node switch matrix, the integration connection relationship matching analysis of the DC-DC converter and the BMS module is performed. According to the signal transmission characteristics of the power line network, the integrated connection relationship of the matching DC-DC converter and the BMS module is connected to obtain the topology of the buried DC network. Based on the topology of the underground DC network, the topology control requirements are decomposed according to the node switch matrix, the integrated connection relationship between the DC-DC converter and the BMS module, and the signal transmission characteristics of the power line network, so as to obtain the parameter characteristics of the underground DC network. Analysis of the installation space constraints and heat dissipation-space influence relationship of the immersion cooling system, including: Obtain heat dissipation test data for the insulating coolant; Based on the heat dissipation test data, the space installation parameters, heat dissipation effect and sustainability in the test data were fitted and analyzed with heat dissipation stability as the target, so as to obtain the heat dissipation-space influence relationship; Based on the heat dissipation-space influence relationship, spatial parameters are screened using the minimum threshold for heat dissipation effect to obtain installation space constraints. 2.The control method of the underground direct current networking energy storage system according to claim 1, characterized in that, The BMS module and DC-DC converter are integrated, including: Based on power line carrier communication technology, control commands are transmitted through the power line network. The BMS module and DC-DC converter are integrated and connected through the power line network for control command transmission. 3.The control method of the underground direct current networking energy storage system according to claim 1, characterized in that, The installation space constraints include: the volume ratio of insulating coolant and the reserved pipe width. 4.The control method of the underground direct current networking energy storage system according to claim 1, characterized in that, Based on the heat dissipation constraints of the underground hull, the DC conversion strategy is analyzed according to the state distribution data of the DC network, including: Obtain the SOC difference gradient distribution and temperature distribution of the battery pack; According to the SOC difference gradient distribution, temperature distribution configuration charge and discharge priority; According to the heat dissipation condition analysis of the battery group in the buried cabin body according to the buried distribution structure, obtain the heat dissipation constraint condition of the battery distribution, according to the charge and discharge priority and the heat dissipation constraint condition of the corresponding battery, control conversion strategy analysis, obtain the conversion control path and conversion parameter; According to the response decomposition of the conversion control path and conversion parameter according to the topological structure of the buried direct current networking, obtain the control parameter of the node switch matrix and the mapping relationship with the direct current conversion parameter, obtain the direct current conversion strategy.

5. The control method of the underground direct current networking energy storage system according to claim 4, characterized in that, Also includes: Obtain the historical monitoring data of each battery group, and obtain the charge and discharge abnormal threshold and habit state parameter of each battery group according to the charge and discharge parameter curve analysis of the historical monitoring data; According to the SOC, temperature parameter threshold of each battery group, set the SOC, temperature parameter threshold of each battery group; When the SOC, temperature parameter threshold of the battery group is triggered, configure the incremental priority, and carry out the priority charge and discharge control adjustment, when the charge and discharge control parameter is not satisfied, generate a warning isolation signal, and carry out isolation control through the node switch matrix. 6.The control method of the underground direct current networking energy storage system according to claim 2, characterized in that, The control instruction is propagated through the power line network, including: Convert the direct current conversion strategy into high frequency carrier signal; Couple the data conversion high frequency carrier signal into the power line, and transmit the carrier signal through the power line network; The control module uses the demodulator to obtain the signal from the power line to extract the data, obtains the direct current conversion strategy, and carries out the direct current conversion control implementation of the DC-DC converter. 7.An electronic device comprising a memory and a processor, the memory storing a computer program, wherein, The processor executes the computer program to realize the steps of the control method of the buried direct current networking energy storage system in any one of claims 1 to 6.

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