Household large-capacity energy storage system charging and discharging management method and system

Abstract

The application relates to the technical field of power system management, and discloses a household large-capacity energy storage system charging and discharging management method and system, which comprises the following steps: connecting multiple parallel battery modules to a power grid through an energy storage converter, wherein the battery modules comprise DC-DC bidirectional converters and at least one battery pack; in the charging and discharging process of the system, dynamically switching the running battery modules according to the SoC and SoH states of each battery module, and the switched running battery modules are all divided into the maximum power of the energy storage converter, and the dormant battery modules are closed DC-DC bidirectional converters; after the switched running battery modules are switched, the time interval of the switched running battery modules is dynamically adjusted in combination with the system efficiency, the SoC and SoH states of each battery module. The application can improve the operation efficiency and resource utilization, balance the SoC and SoH, and prolong the service life.

Description

Technical Field

[0001] This invention relates to the field of power system management technology, and in particular to a method and system for managing the charging and discharging of a residential large-capacity energy storage system. Background Technology

[0002] Residential large-capacity energy storage systems support the stable operation of the power grid and the utilization of renewable energy by storing and releasing electrical energy. During the operation of such systems, it is common for the total parallel power of the battery modules to exceed the maximum power of the power conversion system (PCS). In such cases, it is necessary to manage the operating power of each battery module to ensure the normal operation of the overall system.

[0003] When the total power of the parallel battery modules exceeds the maximum power of the PCS (e.g., 8 battery modules connected in parallel, each with a power of 2kW, totaling 16kW, connected to an 8kW PCS), existing technologies typically employ the following three management methods:

[0004] The first method uses power sharing, where all modules operate simultaneously and power is evenly distributed (e.g., 1kW for each of 8 battery modules). This method results in all battery modules operating at low power, wasting standby energy, and underutilization of overall capacity when there are large deviations in the battery module SoC, leading to low overall system efficiency.

[0005] The second method uses a fixed-module operation approach, selecting a fixed number of modules (e.g., 4 out of 8 battery modules) to operate, while the other modules remain idle. This method results in a high cycle count for the fixed battery modules, and overuse of these modules leads to a rapid decline in their State of Health (SoH), causing uneven lifespan across the entire battery module fleet and impacting the overall system lifespan.

[0006] The third method uses droop control to achieve power sharing based on voltage or frequency droop. This method relies on local measurement and is difficult to dynamically adapt to changes in the remaining state of charge (SoC) and soH of the battery module. At the same time, this method cannot effectively utilize the redundancy advantage that the total power of the battery module is greater than the power of the PCS, resulting in resource waste. Summary of the Invention

[0007] Therefore, the technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a charging and discharging management method and system for a residential large-capacity energy storage system, which can improve operating efficiency and resource utilization, balance SoC and SOH, and extend service life.

[0008] To address the aforementioned technical problems, this invention provides a method for managing the charging and discharging of a residential large-capacity energy storage system, comprising:

[0009] Multiple battery modules connected in parallel are connected to the power grid via an energy storage converter. Each battery module includes a DC-DC bidirectional converter and at least one battery pack.

[0010] During the charging and discharging process of the system, the operating battery modules are dynamically switched according to the SoC and SoH status of each battery module. The operating battery modules share the maximum power of the energy storage converter, and the dormant battery modules turn off the DC-DC bidirectional converter.

[0011] After switching the operating battery module, the time interval for switching the operating battery module is dynamically adjusted based on system efficiency, SoC and SoH status of each battery module.

[0012] Furthermore, the dynamic switching of the operating battery module based on the SoC and SoH state of each battery module specifically involves:

[0013] Obtain the remaining power and health status of each battery module, randomly select n battery modules, calculate the priority score of the battery modules based on their running time, select the battery modules to switch to operation based on the priority score, and determine whether the power of the selected battery modules meets the preset conditions based on the power of the battery modules and the energy storage converter. If the conditions are met, switch the operating battery modules to share the maximum power of the energy storage converter, and shut down the DC-DC bidirectional converter of the dormant battery modules. If the conditions are not met, increase the number of randomly selected battery modules, randomly select battery modules again, and return to the step of calculating the priority score of the battery modules based on their running time.

[0014] Furthermore, the step of determining whether the selected battery module power meets the preset conditions by combining the power of the battery module and the energy storage converter specifically involves:

[0015] During charging, determine whether the selected n battery modules meet the following requirements:

[0016] SoC_i < 100%, ∑P_i ≥ Ppcs, and Ppcs / n meets the preset threshold.

[0017] Where SoC_i represents the remaining power of the i-th battery module, P_i represents the rated power of the i-th battery module, i=1,2,…n, n represents the total number of selected battery modules, ∑P_i represents the sum of the rated power of all selected battery modules, and Ppcs represents the maximum power of the energy storage converter.

[0018] During the discharge process, determine whether the selected n battery modules meet the following requirements:

[0019] SoC_i > DOD, ∑P_i≥Ppcs and Ppcs / n meets the preset threshold.

[0020] Where DOD represents the maximum depth of discharge.

[0021] Furthermore, the priority score is calculated as follows:

[0022] During the charging process, the priority score is as follows:

[0023] Score_i=w1×(100- SoC_i)+w2×SoH_i-w3×T_i,

[0024] Where Score_i represents the priority score of the i-th battery module during charging, i=1,2,…,n, n represents the total number of selected battery modules, SoC_i represents the remaining power of the i-th battery module, SoH_i represents the health status of the i-th battery module, T_i represents the cumulative running time of the i-th battery module, and w1, w2, w3 are the preset weights of the charging process;

[0025] During the discharge process, the priority score is as follows:

[0026] Score_i'=w1'×SoC_i+w2'×SoH_i-w3'×T_i,

[0027] Where Score_i' represents the priority score of the i-th battery module during the discharge process, and w1', w2', and w3' are the preset weights for the discharge process;

[0028] If a battery module malfunctions during charging and discharging, its priority score will be set to negative, and it will be excluded from selection.

[0029] Furthermore, the preset weights of the charging process satisfy: w1 > w2 > w3, w1 + w2 + w3 = 1;

[0030] The preset weights of the discharge process satisfy: w1'>w2'>w3', w1'+w2'+w3'=1.

[0031] Furthermore, after switching the operating battery module, the time interval for dynamically adjusting the switching time is determined by considering system efficiency, the SoC and SoH status of each battery module. Specifically:

[0032] The remaining power and health status of each battery module are obtained. It is determined whether the remaining power and health status of the running battery module and the dormant battery module meet the threshold. If they meet the threshold, the time interval for the next switch to running battery module is set to the preset value. If they do not meet the threshold, the time interval is updated based on the remaining power and health status of each battery module.

[0033] After combining the remaining power and health status update interval of each battery module, it is determined whether the updated time interval meets the preset range. If it does, the updated time interval is used as the time interval for the next switch to run the battery module. If it does not meet the preset value, the time interval for the next switch to run the battery module is set to the preset value.

[0034] Furthermore, the determination of whether the remaining power and health status of the operating and dormant battery modules meet the thresholds specifically involves:

[0035] Determine if the following conditions are met: the maximum deviation of the SoC between the running and dormant battery modules, and the average efficiency or average health status of the running battery modules meet the preset thresholds.

[0036] Furthermore, the method for updating the time interval by combining the remaining power and health status of each battery module is as follows:

[0037] ,

[0038] Among them, T interval T represents the updated time interval. base Indicates the basic time interval. This indicates the maximum deviation of the SoC between the running battery module and the dormant battery module. Indicates reference SoC deviation, This indicates the average efficiency of the operating battery module. Indicates reference efficiency. This indicates the average health status of the operating battery modules. The reference SoH is represented by k1, k2, and k3, which are the time interval weights.

[0039] Furthermore, the time interval weights satisfy: k1+k2+k3=1.

[0040] This invention also provides a charging and discharging management system for a residential large-capacity energy storage system, comprising:

[0041] Energy storage converter,

[0042] DC bus

[0043] Multiple battery modules, each battery module including a DC-DC bidirectional converter and at least one battery pack, are connected in parallel through the DC bus and then connected to the power grid through the energy storage converter;

[0044] A battery management system is connected to the battery module and monitors the status of the battery module in real time.

[0045] The battery module switching module dynamically switches the operating battery modules according to the SoC and SoH status of each battery module during the charging and discharging process of the system. The operating battery modules share the maximum power of the energy storage converter, while the dormant battery modules turn off the DC-DC bidirectional converter.

[0046] The time interval dynamic adjustment module dynamically adjusts the time interval for switching between operating battery modules after switching between them, taking into account system efficiency, SoC and SoH status of each battery module.

[0047] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0048] This invention dynamically switches the operation of battery modules based on the SoC and SoH status of each battery module, balancing the remaining power and health status of all battery modules, ensuring balanced use of battery modules, and extending the service life of battery modules; by dynamically adjusting the time interval between switching the operation of battery modules, power is allocated in the high-efficiency range, further balancing the remaining power and health status of all battery modules, improving system operating efficiency and resource utilization. Attached Figure Description

[0049] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0050] Figure 1 This is a flowchart of a method in a preferred embodiment of the present invention.

[0051] Figure 2 This is a diagram illustrating the charging management process of the system in a preferred embodiment of the present invention.

[0052] Figure 3 This is a diagram illustrating the discharge management process of the system in a preferred embodiment of the present invention.

[0053] Figure 4 This is a schematic diagram of the system structure in a preferred embodiment of the present invention. Detailed Implementation

[0054] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0055] Reference Figure 1 As shown, this invention discloses a charging and discharging management method for a residential large-capacity energy storage system, comprising the following steps:

[0056] S1: Connect multiple parallel battery modules to the power grid via an energy storage converter. The battery modules include a DC-DC bidirectional converter and at least one battery pack.

[0057] S2: During the system's charging and discharging process, the operating battery modules are dynamically switched based on the SoC and SoH status of each battery module. The operating battery modules share the maximum power of the energy storage converter, while the dormant battery modules shut down their DC-DC bidirectional converters and only maintain the operation of the Battery Monitoring and Management System (BMS), reducing standby power consumption. Through a comprehensive scoring mechanism, considering SoC, SoH, power, operating time, and the number of modules selected, the module with the lowest SoC and highest SoH is dynamically selected during charging, and the module with the highest SoC and highest SoH is dynamically selected during discharging, optimizing SoC balancing and battery life.

[0058] S2-1: Obtain the remaining power and health status of each battery module, and randomly select n battery modules. In this embodiment, the initial number of battery modules n is the smallest n that satisfies (n×P_i≥Ppcs and Ppcs / n is in the high-efficiency range), where P_i represents the rated power of the i-th battery module, Ppcs represents the maximum power of the energy storage converter, and the high-efficiency range setting is adjusted according to actual conditions.

[0059] S2-2: Calculate the priority score of the battery module based on the running time of the battery module, and select the top n1 battery modules with the largest Score_i or Score_i' as the final battery modules to be switched on and run according to the priority score. In this embodiment, the value of n1 is adjusted according to the actual situation.

[0060] During the charging process, the priority score is as follows:

[0061] Score_i=w1×(100- SoC_i)+w2×SoH_i-w3×T_i,

[0062] Wherein, Score_i represents the priority score of the i-th battery module during charging, i=1,2,…,n, where n represents the total number of selected battery modules, SoC_i represents the remaining power of the i-th battery module (in %, with a value range of [0,100]), SoH_i represents the health status of the i-th battery module (in %, with a value range of [0, 100]), T_i represents the cumulative running time of the i-th battery module (in hours), and w1, w2, and w3 are preset weights for the charging process; the priority score during charging prioritizes modules with low SoC to promote SoC balancing, prioritizes modules with high SoH to balance aging, and penalizes modules with long cumulative running time to avoid overuse.

[0063] During the discharge process, the priority score is as follows:

[0064] Score_i'=w1'×SoC_i+w2'×SoH_i-w3'×T_i,

[0065] Where Score_i' represents the priority score of the i-th battery module during the discharge process, and w1', w2', and w3' are the preset weights for the discharge process; the priority score during the discharge process prioritizes the module with the higher SoC and promotes SoC balance.

[0066] In this embodiment, the preset weights of the charging process satisfy: w1 > w2 > w3, w1 + w2 + w3 = 1; the values ​​of w1, w2, and w3 are adjusted according to actual conditions, and can be w1 = 0.6, w2 = 0.3, and w3 = 0.1; w1 > w2 > w3, with SoC as the primary factor to ensure a balanced effect, SoH as a secondary consideration to protect battery life, and cumulative running time as an auxiliary constraint to prevent overuse of a single battery module. The total weights w1 + w2 + w3 = 1 ensure score normalization. The weights can be adjusted according to actual system requirements; for example, when SoH degradation is more severe, the value of w2 can be increased.

[0067] The preset weights of the discharge process satisfy: w1'>w2'>w3', w1'+w2'+w3'=1.

[0068] During charging and discharging, if a battery module malfunctions (e.g., SoH_i < 50% or an abnormal alarm occurs), the priority score of the corresponding battery module will be set to negative (e.g., Score_i or Score_i' will be set to negative infinity), and the battery module will be excluded from selection.

[0069] S2-3: Determine whether the selected battery module power meets the preset conditions based on the power of the battery module and the energy storage converter. If it does, execute S2-5; otherwise, execute S2-4.

[0070] During charging, determine whether the selected n battery modules meet the following requirements:

[0071] SoC_i < 100%, ∑P_i ≥ Ppcs, and Ppcs / n meets the preset threshold.

[0072] Where SoC_i represents the remaining power of the i-th battery module, P_i represents the rated power of the i-th battery module (in kW), i=1,2,…n, n represents the total number of selected battery modules, ∑P_i represents the sum of the rated power of all selected battery modules, and Ppcs represents the maximum power of the energy storage converter (in kW).

[0073] During the discharge process, determine whether the selected n battery modules meet the following requirements:

[0074] SoC_i > DOD, ∑P_i≥Ppcs and Ppcs / n meets the preset threshold.

[0075] Wherein, DOD represents the maximum depth of discharge. In this embodiment, DOD can be set to 20%. SoC_i > DOD is used to exclude low-power modules, SoC_i < 100% is used to exclude fully charged battery modules, and Ppcs / n meeting the preset threshold can be Ppcs / n > 90%.

[0076] S2-4: Increase the number of randomly selected battery modules, re-randomize the battery modules (i.e., re-select more than n battery modules, and use the re-selected number as the updated n), and return to execute S2-2.

[0077] S2-5: Switch the operating battery modules to share the maximum power of the energy storage converter, and shut down the DC-DC bidirectional converter of the dormant battery modules, maintaining only the operation of the Battery Monitoring and Management System (BMS) to reduce standby power consumption.

[0078] S3: After switching the operating battery module, the time interval for switching the operating battery module is dynamically adjusted based on system efficiency, SoC and SoH status of each battery module. The polling charging and discharging mechanism with dynamic adjustment of the polling time interval replaces the fixed interval. Taking into account SoC deviation, efficiency and SoH, the module with the lowest SoC and high SoH is selected first when charging, and the module with the highest SoC and high SoH is selected first when discharging. This further optimizes SoC balancing and battery life, while optimizing system efficiency and reducing switching losses.

[0079] S3-1: Obtain the remaining power and health status of each battery module.

[0080] S3-2: Determine whether the remaining power and health status of the running battery module and the dormant battery module meet the threshold. If they meet the threshold, set the time interval for the next switching of the running battery module to a preset value (in this embodiment, the minimum time interval is used as the time interval for the next selection of the running battery module) and execute S4. If they do not meet the threshold, execute S3-3.

[0081] The system determines whether the remaining power and health status of the operating and dormant battery modules meet the thresholds, specifically:

[0082] Determine the maximum SoC deviation between the running battery module and the dormant battery module (denoted as ). The average efficiency of the operating battery module (denoted as ) ) or average health status (denoted as Does it meet the preset threshold (specifically, in this embodiment)? >15% or < 85% or < 70%).

[0083] S3-3: Update time interval based on the remaining power and health status of each battery module.

[0084] The time interval is updated as follows:

[0085] ,

[0086] Among them, T interval T represents the updated time interval. base This represents the basic time interval (in seconds; in this example, the value is 3600 seconds). This indicates the maximum deviation of the SoC between the running battery module and the dormant battery module (in %). This represents the reference SoC bias (10% in this embodiment) used to normalize the bias effect. This indicates the average efficiency of the operating battery module. This represents the average efficiency (in %) of the DC-DC bidirectional converters for all currently operating battery modules. This represents the reference efficiency (90% in this embodiment) and is used to normalize the efficiency impact. This indicates the average health status of the operating battery modules. This represents the average health status of all currently operating battery modules. The reference SoH (taken as 80% in this embodiment) is used to normalize the influence of SoH, and k1, k2, and k3 are time interval weights.

[0087] In this embodiment, the time interval weights satisfy: k1+k2+k3=1. The values ​​of k1, k2, and k3 can be adjusted according to actual conditions, and can be k1=0.5, k2=0.3, and k3=0.2.

[0088] T interval In the update formula, Larger intervals and faster polling are used to balance the performance of the SoC. Extending the interval during high-time periods reduces switching losses, while shortening the interval during low-time periods redistributes power. Shorten the intervals in a short time and prioritize healthy modules to balance aging.

[0089] S3-4: Determine whether the updated time interval meets the preset range (in this embodiment, specifically, determine whether the updated time interval is within [T_min, T_max], where T_min is the minimum time interval and T_max is the maximum time interval. The values ​​of T_min and T_max are adjusted according to the actual situation; in this embodiment, T_min = 600 seconds and T_max = 7200 seconds). If it meets the requirement, then update the time interval (T_min, T_max) to the specified range. interval The time interval for the next switch to operate the battery module is set as S4. If the condition is not met, then S3-5 are executed.

[0090] S3-5: If the updated time interval (T) interval If the updated time interval (T_min) is less than the minimum time interval (T_min), then the minimum time interval (T_min) will be used as the time interval for the next switch to operate the battery module; if ... interval If the time interval is greater than the maximum time interval (T_max), then the maximum time interval (T_max) will be used as the time interval for the next switch to run the battery module.

[0091] S4: Continue charging and discharging. After the time interval for the next switch of the running battery module has elapsed, determine whether the remaining power of all battery modules meets the conditions. If it does, complete the charging and discharging. If it does not, execute S2 to switch the running battery module and continue charging and discharging until the charging and discharging is completed.

[0092] To determine whether the remaining power of all battery modules meets the conditions, the following steps are taken:

[0093] During charging, check if the remaining power of all battery modules is 100%.

[0094] During discharge, determine whether the remaining charge of all battery modules is less than the maximum depth of discharge (DOD).

[0095] In this embodiment, as Figure 2 As shown, the management process during the charging phase is as follows:

[0096] Obtain the parameters of the battery module and PCS, and calculate the number n of battery modules to be switched to operation initially;

[0097] Using a scoring mechanism (Score_i), select the n1 battery modules with the lowest SoC and the highest SoH;

[0098] The charging power of the PCS is evenly distributed to n1 battery modules, while the DC-DC bidirectional converters and BMS of the remaining battery modules remain operational.

[0099] The charging time interval is dynamically adjusted. After the dynamically adjusted time interval, if the remaining power of all battery modules is 100%, the charging is complete. Otherwise, a battery module is selected from the dormant battery modules according to the scoring mechanism for charging until the charging is complete.

[0100] In this embodiment, as Figure 3 As shown, the discharge management process is as follows:

[0101] Obtain the parameters of the battery module and PCS, and calculate the number n of battery modules to be switched to operation initially;

[0102] Using a scoring mechanism (Score_i'), select the n1 battery modules with the highest SoC and the highest SoH;

[0103] The discharge power of the PCS is evenly distributed to n1 battery modules, while the DC-DC bidirectional converters and BMS of the remaining battery modules remain operational.

[0104] The time interval is dynamically adjusted. After the time interval is dynamically adjusted, if the remaining power of all battery modules is less than the DOD, the discharge is complete. Otherwise, a battery module is selected from the dormant battery modules according to the scoring mechanism for discharge until the discharge is complete.

[0105] This invention also discloses a charging and discharging management system for a residential large-capacity energy storage system, such as... Figure 4 As shown, it includes:

[0106] Energy storage converters connect the DC bus to the power grid (or load) and support charging and discharging.

[0107] The DC bus connects to the DC-DC bidirectional converters of all the battery modules, converging power to the energy storage converter.

[0108] Multiple battery modules, each including a DC-DC bidirectional converter and at least one battery pack, are connected in parallel via the DC bus and then connected to the power grid via the energy storage converter.

[0109] A battery management system is connected to the battery module and monitors the status of the battery module in real time.

[0110] The battery module switching module dynamically switches the operating battery modules according to the SoC and SoH status of each battery module during the charging and discharging process of the system. The operating battery modules share the maximum power of the energy storage converter, while the dormant battery modules turn off the DC-DC bidirectional converter.

[0111] The time interval dynamic adjustment module dynamically adjusts the time interval for switching between operating battery modules after switching between them, taking into account system efficiency, SoC and SoH status of each battery module.

[0112] This invention is applicable to scenarios such as power grid peak shaving and valley filling, frequency regulation, and renewable energy integration. It uses a scoring mechanism to dynamically select battery modules to operate based on the System-on-Chips (SoC) and SoH (Sort of Health) status of each module, reducing SoC deviation, balancing the remaining power and health status of all battery modules, ensuring balanced battery module usage, significantly extending battery life and reducing standby losses. By dynamically adjusting the time interval for switching battery module operation, extending the interval when efficiency is high, and reducing DC-DC start-stop losses, power is allocated within the high-efficiency range, further balancing the remaining power and health status of all battery modules, improving system operating efficiency and resource utilization. During dynamic selection of battery modules and dynamic adjustment of time intervals, SoH weight and operating time penalize module aging to balance battery aging and extend overall lifespan. Not only is the control logic simple, but it also fully utilizes redundant power and avoids overuse of any single module.

[0113] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0114] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0115] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0116] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0117] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for managing the charging and discharging of a residential large-capacity energy storage system, characterized in that, include: Multiple battery modules connected in parallel are connected to the power grid via an energy storage converter. Each battery module includes a DC-DC bidirectional converter and at least one battery pack. During the charging and discharging process of the system, the operating battery modules are dynamically switched according to the SoC and SoH status of each battery module. The operating battery modules share the maximum power of the energy storage converter, and the dormant battery modules turn off the DC-DC bidirectional converter. After switching the operating battery module, the time interval for switching the operating battery module is dynamically adjusted based on system efficiency, the SoC and SoH status of each battery module; specifically, the dynamic switching of the operating battery module based on the SoC and SoH status of each battery module involves: Obtain the remaining power and health status of each battery module, randomly select n battery modules, calculate the priority score of the battery modules based on their running time, select the battery modules to switch to operation based on the priority score, and determine whether the power of the selected battery modules meets the preset conditions based on the power of the battery modules and the energy storage converter. If the conditions are met, switch the operating battery modules to share the maximum power of the energy storage converter, and turn off the DC-DC bidirectional converter of the dormant battery modules. If the conditions are not met, increase the number of randomly selected battery modules, randomly select battery modules again, and return to the step of calculating the priority score of the battery modules based on their running time. After switching the operating battery module, the time interval for switching the operating battery module is dynamically adjusted based on system efficiency, the SoC and SoH status of each battery module, as follows: The remaining power and health status of each battery module are obtained. It is determined whether the remaining power and health status of the running battery module and the dormant battery module meet the threshold. If they meet the threshold, the time interval for the next switch to running battery module is set to the preset value. If they do not meet the threshold, the time interval is updated based on the remaining power and health status of each battery module. After combining the remaining power and health status update interval of each battery module, it is determined whether the updated time interval meets the preset range. If it does, the updated time interval is used as the time interval for the next switch to run the battery module. If it does not meet the preset value, the time interval for the next switch to run the battery module is set to the preset value.

2. The charging and discharging management method for a residential large-capacity energy storage system according to claim 1, characterized in that: The determination of whether the selected battery module power meets the preset conditions by combining the power of the battery module and the energy storage converter is as follows: During charging, determine whether the selected n battery modules meet the following requirements: SoC_i < 100%, ∑P_i ≥ Ppcs and Ppcs / n meets the preset threshold, where SoC_i represents the remaining power of the i-th battery module, P_i represents the rated power of the i-th battery module, i = 1, 2, ..., n, n represents the total number of selected battery modules, ∑P_i represents the sum of the rated power of all selected battery modules, and Ppcs represents the maximum power of the energy storage converter; During the discharge process, determine whether the selected n battery modules meet the following requirements: SoC_i>DOD, ∑P_i≥Ppcs and Ppcs / n satisfies a preset threshold, where DOD represents the maximum depth of discharge.

3. The charging and discharging management method for a residential large-capacity energy storage system according to claim 1, characterized in that: The priority score is calculated as follows: During the charging process, the priority score is as follows: Score_i=w1×(100-SoC_i)+w2×SoH_i-w3×T_i, Where Score_i represents the priority score of the i-th battery module during charging, i = 1, 2, ..., n, n represents the total number of selected battery modules, SoC_i represents the remaining power of the i-th battery module, SoH_i represents the health status of the i-th battery module, T_i represents the cumulative running time of the i-th battery module, and w1, w2, w3 are the preset weights of the charging process; During the discharge process, the priority score is as follows: Score_i'=w1'×SoC_i+w2'×SoH_i-w3'×T_i, Where Score_i' represents the priority score of the i-th battery module during the discharge process, and w1', w2', and w3' are the preset weights for the discharge process; If a battery module malfunctions during charging and discharging, its priority score will be set to negative, and it will be excluded from selection.

4. The charging and discharging management method for a residential large-capacity energy storage system according to claim 3, characterized in that: The preset weights of the charging process satisfy: w1 > w2 > w3, w1 + w2 + w3 = 1; The preset weights of the discharge process satisfy: w1' > w2' > w3', w1' + w2' + w3' = 1.

5. The charging and discharging management method for a residential large-capacity energy storage system according to claim 1, characterized in that: The determination of whether the remaining power and health status of the operating and dormant battery modules meet the thresholds specifically involves: Determine if the following conditions are met: the maximum deviation of the SoC between the running and dormant battery modules, and the average efficiency or average health status of the running battery modules meet the preset thresholds.

6. The charging and discharging management method for a residential large-capacity energy storage system according to claim 5, characterized in that: The method for updating the time interval by combining the remaining power and health status of each battery module is as follows: Among them, T interval T represents the updated time interval. base ΔSoC represents the base time interval. max ΔSoC represents the maximum deviation of the System-on-Chip (SoC) between the running and dormant battery modules. ref Indicates the reference SoC deviation, η avg η represents the average efficiency of the operating battery module. ref SoH represents the reference efficiency. avg SoH represents the average health status of the operating battery module. ref This indicates that the reference SoH is used, and k1, k2, and k3 are the time interval weights.

7. The charging and discharging management method for a residential large-capacity energy storage system according to claim 6, characterized in that: The time interval weights satisfy: k1+k2+k3=1.

8. A charging and discharging management system for a residential large-capacity energy storage system, characterized in that, include: Energy storage converter, DC bus Multiple battery modules, each battery module including a DC-DC bidirectional converter and at least one battery pack, are connected in parallel through the DC bus and then connected to the power grid through the energy storage converter; A battery management system is connected to the battery module and monitors the status of the battery module in real time. The battery module switching module dynamically switches the operating battery modules according to the SoC and SoH status of each battery module during the charging and discharging process of the system. The operating battery modules share the maximum power of the energy storage converter, while the dormant battery modules turn off the DC-DC bidirectional converter. The time interval dynamic adjustment module dynamically adjusts the time interval for switching between operating battery modules after switching the operating battery module, taking into account system efficiency, SoC and SoH status of each battery module. The method of dynamically switching the operation of battery modules based on the SoC and SoH status of each battery module is as follows: Obtain the remaining power and health status of each battery module, randomly select n battery modules, calculate the priority score of the battery modules based on their running time, select the battery modules to switch to operation based on the priority score, and determine whether the power of the selected battery modules meets the preset conditions based on the power of the battery modules and the energy storage converter. If the conditions are met, switch the operating battery modules to share the maximum power of the energy storage converter, and turn off the DC-DC bidirectional converter of the dormant battery modules. If the conditions are not met, increase the number of randomly selected battery modules, randomly select battery modules again, and return to the step of calculating the priority score of the battery modules based on their running time. After switching the operating battery module, the time interval for switching the operating battery module is dynamically adjusted based on system efficiency, the SoC and SoH status of each battery module, as follows: The remaining power and health status of each battery module are obtained. It is determined whether the remaining power and health status of the running battery module and the dormant battery module meet the threshold. If they meet the threshold, the time interval for the next switch to running battery module is set to the preset value. If they do not meet the threshold, the time interval is updated based on the remaining power and health status of each battery module. After combining the remaining power and health status update interval of each battery module, it is determined whether the updated time interval meets the preset range. If it does, the updated time interval is used as the time interval for the next switch to run the battery module. If it does not meet the preset value, the time interval for the next switch to run the battery module is set to the preset value.

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