Charging control method and device, energy storage system, storage medium and program product

Abstract

The invention discloses a charging control method and device, an energy storage system, a storage medium and a program product, and the method comprises the steps: obtaining the highest voltage of a single cell of each battery pack through monitoring the voltage of the battery pack in real time, comparing the highest voltage with a preset charging threshold value of a single cell of the corresponding battery pack, and determining the charging threshold value of the single cell of the corresponding battery pack; the preset charging threshold is smaller than the charging cut-off voltage. And under the condition that the highest voltage is greater than a preset charging threshold value, determining a first request electrical parameter of the target battery pack corresponding to the highest voltage based on the increased highest voltage in the charging process, and then adjusting the first request electrical parameter based on the current operation parameter of the target battery pack corresponding to the highest voltage to obtain a second request electrical parameter. And finally, requesting to charge the target battery pack based on the second request electrical parameter. Through the charging control method provided by the invention, the problems of charging efficiency and charging safety caused by SOC forced calibration when the battery pack is not fully charged can be effectively avoided, so that the service life of the battery pack is prolonged.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, specifically to a charging control method, device, energy storage system, storage medium, and program product. Background Technology

[0002] In lithium-ion battery charging systems, due to differences in cell consistency, each battery pack exhibits different voltage characteristics at the end of charging. When the voltage of a single cell in a battery pack reaches the SOC (State of Charge, i.e., the percentage of remaining charge) calibration threshold first, the system will forcibly calibrate its SOC to 100% and stop it from absorbing current. This causes the charging current originally allocated to that battery pack to be instantly transferred to other battery packs that are not yet fully charged, resulting in a surge in current in the latter, which in turn causes the voltage to quickly approach the calibration threshold, triggering a forced SOC jump. Frequent forced SOC jumps have several negative impacts: discontinuous abrupt changes in the SOC estimation curve reduce management accuracy; based on inaccurate SOC information, the Battery Management System (BMS) may prematurely determine that the entire system is fully charged, thus terminating charging and resulting in insufficient actual charging capacity, reducing system charging efficiency; the voltage of the battery pack may rapidly approach or even trigger overvoltage protection due to current distribution issues, and frequent protection actions not only affect battery life but may also lead to safety hazards such as thermal runaway.

[0003] Existing technologies employ overall current reduction or charging voltage limiting strategies, which result in slow charging speeds and low charging efficiency in order to accommodate individual battery cells. Therefore, a more refined and efficient charging control strategy is needed to achieve a balance between safety and efficiency. Summary of the Invention

[0004] This application provides a charging control method, device, energy storage system, storage medium, and program product. The energy storage system determines the requested charging parameters based on the dynamic maximum voltage of the battery pack and the corresponding operating parameters, in order to avoid problems such as insufficient charging capacity and low charging efficiency caused by SOC fluctuations, as well as safety issues caused by frequent execution of protection actions, and to extend the service life.

[0005] In a first aspect, embodiments of this application provide a charging control method, the method comprising: Real-time monitoring of the highest voltage of each individual cell in the battery pack; If the highest voltage is greater than a preset charging threshold, the first requested electrical parameters of the target battery pack corresponding to the highest voltage are determined based on the highest voltage, wherein the preset charging threshold is less than the charging cutoff voltage. Based on the current operating parameters of the target battery pack corresponding to the highest voltage, the first requested electrical parameters are adjusted to obtain the second requested electrical parameters; The target battery pack is charged based on the second requested electrical parameters.

[0006] Secondly, embodiments of this application provide a charging control device, the device comprising: The monitoring module monitors the maximum voltage of each individual cell in the battery pack in real time. The determining module, when the highest voltage is greater than a preset charging threshold, determines the first requested electrical parameters of the target battery pack corresponding to the highest voltage based on the highest voltage, wherein the preset charging threshold is less than the charging cut-off voltage; The adjustment module adjusts the first requested electrical parameters based on the current operating parameters of the target battery pack corresponding to the highest voltage to obtain the second requested electrical parameters; The processing module charges the target battery pack based on the second requested electrical parameters.

[0007] Thirdly, embodiments of this application provide an energy storage system, the energy storage system comprising: Multiple battery packs; The processor and memory, wherein the memory stores a computer program, and the processor executes the charging control method as described in any of the above embodiments by calling the computer program stored in the memory.

[0008] Fourthly, embodiments of this application provide a non-transitory computer-readable storage medium storing a computer program adapted for loading by a processor to execute the charging control method as described in any of the above embodiments.

[0009] Fifthly, embodiments of this application provide a computer program product having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the charging control method as described in any of the above embodiments.

[0010] The charging control method, apparatus, energy storage system, storage medium, and program product provided in this application embodiment monitor the voltage of individual cells in a battery pack in real time to obtain the highest voltage in each battery pack. The highest voltage is compared with a preset charging threshold for the corresponding individual cell in the battery pack, where the preset charging threshold is less than the charging cutoff voltage. When the highest voltage exceeds the preset charging threshold, during the charging process, based on the increasing highest voltage, a first requested electrical parameter for the target battery pack corresponding to the highest voltage is determined. Then, based on the current operating parameters of the target battery pack corresponding to the highest voltage, the first requested electrical parameter is adjusted to obtain a second requested electrical parameter. Finally, based on the second requested electrical parameter, a request is made to charge the target battery pack. The charging control method provided in this application effectively avoids charging efficiency and safety issues caused by inconsistent cell voltages, where the battery pack is not fully charged when the highest voltage reaches the charging cutoff voltage, leading to forced SOC calibration parameter abrupt changes, thus extending the battery's service life.

[0011] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram illustrating an application scenario of the charging control method provided in the embodiments of this application; Figure 2 This is a first flowchart illustrating the charging control method provided in an embodiment of this application; Figure 3 This is a second flowchart illustrating the charging control method provided in an embodiment of this application; Figure 4 A schematic diagram of the third process of the charging control method provided in the embodiments of this application; Figure 5 This is a schematic diagram of the charging control device provided in an embodiment of this application. Detailed Implementation

[0014] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0015] Please see Figure 1 , Figure 1 This is an application scenario diagram of a charging control method provided in an embodiment of this application. The application scenario provided in this application includes an energy storage system 100 and an electronic device 200.

[0016] This application provides an energy storage system including multiple battery packs; a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method of this application.

[0017] It is understandable that there are inherent consistency differences between battery packs due to variations in manufacturing tolerances, initial conditions, and usage environments. These differences are mainly reflected in multiple dimensions such as voltage characteristics, DC internal resistance, and actual capacity.

[0018] The battery pack comprises multiple individual battery cells. When these cells are connected in series, the internal resistance increases, leading to an increase in the battery pack voltage while maintaining the same total capacity, thus powering devices requiring high-voltage batteries. When these cells are connected in parallel, the internal resistance decreases, the battery pack voltage remains constant, the total capacity increases, and the power supply time is extended.

[0019] The energy storage system 100 is able to communicate with the electronic device 200 to cooperate with the electronic device 200 to implement the charging control method of this application.

[0020] Optionally, the electronic device 200 includes at least one of a terminal and a server.

[0021] The terminal may include, but is not limited to: smartphones (such as Android phones, iOS phones, etc.), tablet computers, laptops, desktop computers, smart speakers, smartwatches, portable personal computers, mobile internet devices (MIDs), smart voice interaction devices, smart home appliances, vehicle terminals, aircraft, wearable devices, etc., and this application embodiment does not limit this.

[0022] The server can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms. This application does not limit this.

[0023] The charging control method of this application can be implemented by the energy storage system 100 alone, or by the energy storage system 100 in conjunction with the electronic device 200, and there is no limitation on this.

[0024] Based on the above description of the relevant scenarios, this application provides a charging control method. The technical solution of this application will be described in detail below through specific embodiments. It should be noted that the following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0025] Please see Figure 2 , Figure 2 This is a flowchart illustrating a charging control method provided in an embodiment of this application. It should be noted that the steps shown may be executed in a logical order different from that shown in the flowchart. The method may include steps 011, 012, 013, and 014, which will be described in detail below.

[0026] Step 011: Monitor the maximum voltage of each individual cell in the battery pack in real time.

[0027] Specifically, due to inherent consistency differences among individual cells in a battery pack, the cell with the highest voltage in the pack has the highest voltage. This highest voltage cell is most likely to trigger protection first, making it the most dangerous voltage and the weakest link in the battery pack during charging. Therefore, controlling the highest voltage is necessary to prevent overcharging and SOC jumps.

[0028] For example, in a lithium battery capacity expansion system, the individual cells of the battery pack may be connected in series first and then in parallel, or directly in parallel. The highest voltage is the voltage of the highest-voltage individual cell among the individual cells connected in series in each parallel branch. If there is only one individual cell in the parallel branch containing that cell, then the highest voltage is also the highest voltage across the battery pack.

[0029] Step 012: When the highest voltage is greater than the preset charging threshold, determine the first requested electrical parameters of the target battery pack corresponding to the highest voltage based on the highest voltage. The preset charging threshold is less than the charging cutoff voltage.

[0030] The charging cut-off voltage refers to the voltage threshold at which charging should stop when the battery pack voltage reaches a specific value. It is the highest safe voltage that the battery pack can reach during charging. When the battery pack voltage reaches the charging cut-off voltage, it is considered that the battery pack is fully charged and charging should be stopped. Otherwise, overcharging may occur, causing damage, aging, or safety accidents to the battery pack.

[0031] The preset charging threshold is a warning value that limits the maximum voltage of the battery pack. When the maximum voltage exceeds the preset charging threshold, it means that the maximum voltage is close to the charging cutoff voltage. It is necessary to enter the request mechanism for flexible control of charging parameter changes to prevent overvoltage protection from being triggered after the charging cutoff voltage is suddenly reached.

[0032] In some embodiments, multiple battery packs are connected in parallel, the first requested electrical parameter includes a first requested current, and step 012 includes: Step 0121: When the highest voltage of the target battery pack rises to a preset voltage threshold, reduce the requested current by the target ratio to determine the first requested current after reduction.

[0033] The first requested electrical parameter is a target value set for the electrical parameters that should be reached in the next charging stage to control the increase of the maximum voltage. The first requested electrical parameter includes the first requested current, which is the current value that should be reached in the next charging stage. This first requested current can be gradually reduced according to the target ratio to avoid a sudden drop in current after overvoltage protection.

[0034] It is understandable that, assuming there are three battery packs A / B / C, if the highest voltage of a single cell in battery pack A exceeds a preset voltage threshold, then only the requested charging current of battery pack A will be the first requested current, while the requested charging currents of battery packs B and C will remain unchanged if they do not exceed the preset voltage threshold.

[0035] In some embodiments, the first requested current is determined based on the following formula: Ireq(k+1)=max(Ireq(k)×(1-α), Imin), where Ireq(k+1) is the first requested current, Ireq(k) is the requested current before reduction, α is the target ratio, the target ratio is located in the interval (0,1), and Imin is the preset minimum requested current.

[0036] Where k represents the charging stage number, indicating the number of requests made since entering the request mechanism. k is an integer starting from 0, and is 0 when the maximum voltage exceeds the preset charging threshold. The first request current can be calculated using the above formula. The increment of k can be determined based on the voltage increase; for example, k can be incremented by 1 for every 2 millivolts increase in the maximum voltage.

[0037] Here, the target ratio α represents the magnitude of the current reduction each time, which is the target reduction percentage. The target ratio is a pre-set value based on experience and actual measurements, and can be adjusted according to the specific monitoring data during battery pack charging before entering the request mechanism.

[0038] The preset minimum requested current is the lowest charging current allowed by the system. This setting ensures that the charging process will not stall due to excessive current reduction, and that the battery will eventually be fully charged smoothly, guaranteeing basic charging efficiency.

[0039] Specifically, by monitoring the highest voltage, while the highest voltage is rising, the requested charging current (first requested current) for the next charging stage is controlled to decrease by a certain target ratio, and a minimum requested current that can be used for safe charging is specified to ensure that charging can be completed smoothly.

[0040] In some embodiments, multiple battery packs are connected in series. When the highest voltage is greater than a preset charging threshold, a first requested electrical parameter is determined based on the highest voltage. The first requested electrical parameter includes a first requested voltage.

[0041] In a series-connected energy storage system, the battery packs are connected end-to-end, and the total voltage equals the sum of the voltages of all connected battery packs, with each pack receiving the same charging current. During charging, the battery management system (BMS) dynamically requests a changing voltage from the charging station. This voltage must be slightly higher than the current total voltage of the battery pack to drive current inflow. As the state of charge (SOC) increases, the total voltage of the series-connected battery pack also rises, and the BMS continuously increases the requested voltage until the total voltage reaches the charging cutoff voltage. Because the current is equal everywhere, if even one individual cell is fully charged prematurely (reaching the charging cutoff voltage), the entire charging process must stop or the current must be significantly reduced; otherwise, that individual cell will be overcharged and damaged. Therefore, the biggest problem with series-connected energy storage systems is the potential difference in internal resistance and capacity among the batteries, leading to uneven charging, i.e., voltage balancing. It is necessary to ensure that each battery is fully charged, avoiding overcharging or over-discharging of some batteries.

[0042] Specifically, when the highest voltage of the target battery pack rises to a preset voltage threshold, the first requested voltage is reduced by a target ratio. By charging at the first requested voltage, which decreases as charging time increases, the overall charging current can be reduced by lowering the voltage of the battery pack that is close to the charging cutoff voltage. This achieves an overall optimization effect of fully charging each battery pack with a lower voltage.

[0043] Step 013: Based on the current operating parameters of the target battery pack corresponding to the highest voltage, adjust the first requested electrical parameters to obtain the second requested electrical parameters.

[0044] Among them, the target battery pack is the battery pack whose highest voltage reaches the preset voltage threshold and triggers the request mechanism. It is the battery pack that needs to be charged to prevent it from entering the overvoltage protection state.

[0045] The second requested electrical parameter is an electrical parameter value requested for execution in the next charging stage, adjusted based on the current operating parameters of the target battery pack and the first requested electrical parameter. The second requested electrical parameter may include a second requested current.

[0046] In some embodiments, the current operating parameters include at least one of the following: battery pack temperature, current battery internal resistance, and number of cycles. Step 013 includes steps 0131 and 0132, which are described in detail below.

[0047] Step 0131: Determine the first adjustment factor based on the battery pack temperature, the second adjustment factor based on the current battery internal resistance, and the third adjustment factor based on the number of cycles.

[0048] Specifically, in order to control the battery pack charging more precisely and accurately based on the actual operating conditions during battery charging, it is necessary to effectively adjust the electrical parameters that require flexible and gradual changes based on the current operating parameters. These current operating parameters may include the battery pack temperature, the current internal resistance of the battery pack, and the number of battery pack cycles.

[0049] The first adjustment factor is an adjustment value set according to experience and actual measurement for different temperatures. Since the charging acceptance capability of the battery pack is different at different temperatures, the first adjustment factor can be used to more precisely monitor the charging control strategy of the battery pack at different temperatures.

[0050] Specifically, excessively high charging ambient temperatures accelerate battery pack aging, slow down charging speeds, and in severe cases, may lead to thermal runaway, causing bulging, fire, or even explosion. When the temperature exceeds the suitable range, the chemical reactions within the battery pack become abnormally intense, making heat dissipation difficult and easily causing permanent capacity loss. Excessively low charging ambient temperatures slow down the internal chemical reactions of the battery pack, thereby reducing charging efficiency, slowing down the charging speed, and potentially preventing the battery pack from charging altogether. In severe cases, low-temperature charging can cause lithium-ion precipitation in the lithium battery, resulting in permanent internal damage and shortening the battery pack's lifespan. Therefore, it is necessary to determine the primary adjustment factor based on the battery pack temperature to adjust the charging control strategy.

[0051] The second adjustment factor is an adjustment value set based on experience and actual measurement for different internal resistances. Since battery packs with different internal resistances have different charging reception capabilities, the second adjustment factor can be used to more precisely monitor the charging control strategy of battery packs with different internal resistances.

[0052] Specifically, excessive internal resistance consumes more charging energy, causing more energy to be lost as heat rather than being converted into chemical energy and stored in the battery pack. This results in lower charging efficiency and longer charging times. Severe heat generation can also accelerate battery aging, leading to excessively high charging temperatures and creating more safety hazards. Compared to battery packs or individual cells with higher internal resistance, battery packs or individual cells with lower internal resistance are more likely to reach overcharge status first. This indicates that the negative impact of excessively low internal resistance is mainly due to inconsistencies in internal resistance. Therefore, when the internal resistance may increase during charging, a second adjustment factor should be determined based on the current battery internal resistance to adjust the charging control strategy.

[0053] The third adjustment factor is an adjustment value set based on experience and actual measurement for different number of cycles. Since the charging acceptance capability of battery packs with different number of charging cycles is different, the third adjustment factor can be used to more precisely monitor the charging control strategy of battery packs with different number of cycles.

[0054] Specifically, a cycle refers to the process of completely depleting the battery pack's charge and then fully recharging it. Each cycle slightly reduces the battery's energy storage capacity. After a long period of numerous cycles, the battery's usable capacity decreases, its internal resistance increases, and its lifespan is shortened. Therefore, a third adjustment factor needs to be determined based on the number of cycles to adjust the charging control strategy.

[0055] In some embodiments, determining a first adjustment factor based on battery pack temperature includes: Step 01311: Based on the target temperature range where the target battery pack temperature is located, determine the first adjustment factor. The target temperature range is any preset temperature range, and the preset temperature range and the first adjustment factor correspond one-to-one.

[0056] Specifically, different charging control strategies for the battery pack should be adopted at different temperatures. Therefore, it is necessary to divide multiple preset temperature ranges to correspond to different first adjustment factors. The preset temperature range in which the battery pack temperature falls is the target temperature range. When the target battery pack is charging, there is a corresponding battery pack temperature at each moment of operation. The first adjustment factor can be determined based on the target temperature range in which this temperature falls.

[0057] In some embodiments, the preset temperature range includes a first temperature range, a second temperature range, and a third temperature range. The first adjustment factor corresponding to the first temperature range, the first adjustment factor corresponding to the second temperature range, and the first adjustment factor corresponding to the third temperature range decrease sequentially, and the first adjustment factor corresponding to the second temperature range is 1.

[0058] The first temperature range can be greater than 40 degrees Celsius. Charging in high-temperature environments leads to battery pack instability, requiring stricter controls to ensure safety. For example, in a capacity expansion system with multiple battery packs connected in parallel, the first adjustment factor corresponding to the first temperature range can be a value greater than 1, such as 1.2. This allows for increased current reduction to ensure charging safety in high-temperature charging environments.

[0059] The second temperature range can be greater than or equal to 10 degrees Celsius and less than or equal to 40 degrees Celsius. This temperature is the normal charging temperature, at which point the first adjustment factor is 1 to maintain the current requested electrical parameters for charging control.

[0060] The third temperature range can be less than 10 degrees Celsius. In low-temperature environments, such as for lithium batteries, lithium ion migration is slow and internal resistance is high. A significant reduction in current would lead to excessively slow charging or even failure to charge. Therefore, the first adjustment factor can be a value less than 1, such as 0.8, to reduce the current reduction, which is equivalent to allowing a slightly larger current under safe conditions to offset the inhibition of charging by the low temperature environment.

[0061] In some embodiments, determining a second adjustment factor based on the current battery internal resistance includes: Step 01312: Based on the ratio of the current internal resistance of the target battery pack to the initial internal resistance of the battery, determine the second adjustment factor. The ratio and the second adjustment factor are positively correlated.

[0062] Specifically, different charging control strategies should be adopted for different battery pack internal resistances. The ratio of the current battery internal resistance of the target battery pack to the initial battery internal resistance (the internal resistance of the battery pack before charging begins) can be used as the basis for the second adjustment factor. The ratio is positively correlated with the second adjustment factor. The higher the ratio, the greater the increase in internal resistance, and the greater the influence of the second adjustment factor should be. For example, for the first requested current, the higher the ratio, the greater the current reduction should be to prevent the internal resistance from generating a large amount of heat, increasing the charging temperature, and reducing the charging efficiency.

[0063] In some embodiments, step 01312 includes: Step 013121: If the ratio is greater than the preset ratio threshold, determine the second adjustment factor as the first preset value; Step 013122: If the ratio is less than or equal to a preset ratio threshold, determine the second adjustment factor as a second preset value, where the second preset value is less than the first preset value.

[0064] The preset ratio threshold can be an empirical or measured preset value greater than 1, used to define the current internal resistance size that can have a significant impact.

[0065] The first preset value can be a value greater than 1, such as 1.25, which is used to increase the adjustment range of the first requested electrical parameter and strengthen the restriction.

[0066] The second preset value is a value less than the first preset value, and can generally be 1, indicating that the current adjustment strategy can be maintained.

[0067] Specifically, when the ratio is greater than a preset ratio threshold (i.e., the current internal resistance of the battery pack is greater than the initial internal resistance before charging, and the difference is significant), the excessive increase in internal resistance will cause more of the charging energy to be supplied to the internal resistance, generating Joule heat, thus reducing charging efficiency. Therefore, the restriction on the first requested electrical parameter should be strengthened, and the second adjustment factor should be determined to be a larger first preset value to strengthen the restriction on the first requested electrical parameter. When the ratio is less than or equal to the preset ratio threshold, it means that even if the current internal resistance of the battery pack is greater than the initial internal resistance before charging, the difference is not significant, and the negative impact caused by heat generation is within an acceptable range. Therefore, the adjustment strategy for this charging stage can be maintained.

[0068] In some embodiments, a third adjustment factor is determined based on the number of cycles of the target battery pack, including: Step 01313: If the number of iterations is greater than the preset threshold, determine the third adjustment factor as the third preset value; Step 01314: If the number of iterations is less than or equal to the preset threshold, determine the third adjustment factor as the fourth preset value, where the fourth preset value is less than the third preset value.

[0069] The preset number threshold is a preset number of cycles based on experience or actual measurement, used to define the current cumulative number of battery pack cycles that can have a significant impact.

[0070] The third preset value can be a value greater than 1, such as 1.3, which is used to increase the adjustment range of the first requested electrical parameter and strengthen the restriction.

[0071] The fourth preset value is a value less than the third preset value, and can generally be 1, indicating that the current adjustment strategy can be maintained.

[0072] Specifically, if the number of cycles is greater than a preset threshold (e.g., 1500 times), it indicates that the battery pack may be aging significantly, and the third adjustment factor should be set to a third preset value (e.g., 1.3). If the number of cycles is less than or equal to the preset threshold (e.g., 1500 times), it indicates that the battery pack can maintain the current adjustment strategy.

[0073] Step 0132: Adjust the target ratio based on at least one of the first adjustment factor, the second adjustment factor, and the third adjustment factor to obtain the second requested electrical parameters.

[0074] Specifically, a first adjustment factor, a second adjustment factor, and a third adjustment factor can be determined based on at least one of the three current operating parameters of the battery pack: temperature, internal resistance, and cycle number. These factors are used to adjust the target reduction ratio of the first requested current in a capacity expansion system with multiple battery packs connected in parallel, thereby obtaining the second requested electrical parameter, which is the second requested current requested to be provided in the next charging stage.

[0075] In some embodiments, step 0132 includes: Step 01321: Adjust the target ratio based on the product of the first adjustment factor, the second adjustment factor, and the third adjustment factor to obtain the second requested electrical parameters.

[0076] Specifically, based on the current operating parameters and the corresponding adjustment factors, the total adjustment factor can be obtained by multiplying the first adjustment factor, the second adjustment factor and the third adjustment factor. This total adjustment factor is used to adjust the target ratio in the capacity expansion system of multiple battery packs connected in parallel, so as to obtain the second requested electrical parameter, that is, the second requested current to be provided in the next charging stage.

[0077] Step 014: Charge the target battery pack based on the second requested electrical parameters.

[0078] Specifically, the energy storage system ultimately uses this personalized second request electrical parameter, which has been adjusted after multi-factor evaluation, to charge the target battery pack, in order to achieve a smooth, gradual, and stable charging process, effectively preventing current surges or voltage spikes.

[0079] In some embodiments, the charging control method further includes: If the voltage of the target battery pack is greater than or equal to the charging cutoff voltage and this condition is maintained for a preset duration, the target battery pack is determined to be fully charged.

[0080] Specifically, the charging termination condition for determining that the target battery pack is fully charged is as follows: the voltage of the target battery pack reaches the charging cutoff voltage and must remain at this voltage for a certain period of time to ensure that it is truly fully charged rather than experiencing momentary fluctuations. At this time, the charging current, after being controlled by the aforementioned request mechanism, is also in a relatively low state, and charging will actively terminate after a preset time, thus fundamentally different from overcharging. Once the system determines that the battery pack is fully charged, it will perform a forced calibration to set the SOC to 100%.

[0081] The following describes the workflow of an energy storage system 100 that expands capacity by connecting a lithium battery pack in parallel, thus explaining the charging control method provided in this application.

[0082] The energy storage system 100 comprises three battery packs, A, B, and C, connected in parallel and of the same model. During the charging process of the battery packs by receiving external electrical energy, the energy storage system 100 monitors the maximum voltage of each individual cell in each battery pack, as well as the externally supplied charging current, in real time. It also collects the battery pack temperature and current internal resistance, and queries and records the number of charge-discharge cycles for each battery pack. The charging cutoff voltage of the battery pack is 3.500 volts (V), the preset charging threshold is 3.490V, the target ratio is 20%, and the preset minimum requested current is 2 amperes (A). A charging stage is defined as an increase of 2 millivolts (mV) in the maximum voltage, which updates the requested current once. The initial requested current decreases proportionally as the maximum voltage of the battery pack increases.

[0083] For example, when the highest voltage of battery pack A reaches 3.490 V, since it has just reached the preset charging threshold but has not exceeded it, the current charging current of 10 A can continue to be maintained. When the highest voltage rises to 3.492 V, battery pack A requests a 20% decrease in the current to 8 A according to the formula for determining the first requested current. When the highest voltage rises to 3.494 V, it decreases again by 20%, to 6.4 A. For every 2 millivolts increase in the highest voltage, the requested current decreases by 20% until a first requested current value of less than 2 A is found before charging is complete. In this case, the actual first requested current for this charging stage remains at 2 A. When the voltage of a single cell in battery pack A reaches 3.500 V and the duration reaches or exceeds 5 seconds, the SOC is forcibly calibrated to 100%, and charging is complete.

[0084] After the first requested current is determined, the second requested current can be determined based on the collected current operating parameters.

[0085] For example, assuming battery pack B is currently at 3.494 V, and its temperature, internal resistance, and cycle count are all relatively normal and will not significantly affect the charging process, its first requested current decreases by 20%. During a certain charging phase, data collection reveals that battery pack B's temperature is 45℃, which is greater than 40℃. Therefore, based on its corresponding preset temperature range, the first adjustment factor is set to 1.2. The internal resistance of battery pack B has increased by 30% compared to its initial value, resulting in a ratio of 1.3, which is greater than the preset ratio threshold of 1.2. Therefore, the second adjustment factor is the first preset value of 1.25. The cycle count of battery pack B has exceeded 2000, which is greater than the preset count threshold of 1500. Therefore, the third adjustment factor is the third preset value of 1.3. Multiplying the values ​​of the first, second, and third adjustment factors yields a total adjustment factor of 1.95, which is applied to the target ratio of 0.2. Multiplying these two values ​​yields a new target ratio of 0.39. Based on this updated target ratio, the second requested current can be obtained.

[0086] Thus, even if battery pack A is fully charged in advance, the current flowing to battery packs B and C will only increase slowly, and the SOC curve will remain smooth without any sudden jumps.

[0087] The charging control method provided in this application includes: real-time monitoring of the battery pack voltage to obtain the highest voltage in each battery pack; comparing the highest voltage with a preset charging threshold for a single cell in the corresponding battery pack, where the preset charging threshold is less than the charging cut-off voltage; when the highest voltage is greater than the preset charging threshold, during the charging process, based on the increasing highest voltage, determining a first requested electrical parameter that decreases with the target ratio; then, based on the current operating parameters of the target battery pack corresponding to the real-time collected highest voltage, determining first, second, and third adjustment factors in a non-linear manner; adjusting the first requested electrical parameter according to the combined effect of each adjustment factor to obtain a second requested electrical parameter; finally, based on the second requested electrical parameter, requesting charging of the target battery pack until the charging cut-off voltage is reached and maintained for a certain period of time, at which point charging is complete. The charging control method provided in this application can prevent false full charging due to overcharging caused by inconsistent single cells reaching the charging cut-off voltage, and can effectively avoid current jumps caused by forced SOC calibration, thereby achieving a balance between safety and efficiency. The slow charging method can also ensure the battery pack's lifespan, achieving sustainable charging control.

[0088] All of the above technical solutions can be combined in any way to form optional embodiments of this application, and will not be described in detail here.

[0089] This application embodiment also provides a charging control device 300 for executing the steps in the above-described charging control method. Please refer to... Figure 5 , Figure 5 This is a schematic diagram of a charging control device 300 provided in an embodiment of this application. The charging control device 300 includes: Monitoring module 301 monitors the maximum voltage of individual cells in each battery pack in real time; The determining module 302 determines the first requested electrical parameters of the target battery pack corresponding to the highest voltage based on the highest voltage when the highest voltage is greater than the preset charging threshold. The preset charging threshold is less than the charging cutoff voltage. The adjustment module 303 adjusts the first requested electrical parameters based on the current operating parameters of the target battery pack corresponding to the highest voltage, so as to obtain the second requested electrical parameters; Processing module 304 charges the target battery pack based on the second requested electrical parameters.

[0090] It should be noted that the specific details of each module unit in the charging control device 300 have been described in detail in the embodiments of the charging control method, and will not be repeated here.

[0091] In the embodiments of this application, the terms "module" or "unit" refer to a computer program or part of a computer program that has a predetermined function and works with other related parts to achieve a predetermined goal, and can be implemented wholly or partially using software, hardware (such as processing circuitry or memory), or a combination thereof. Similarly, a processor (or multiple processors or memory) can be used to implement a... There may be multiple modules or units. Furthermore, each module or unit can be a complete module containing the functions of that module or unit. The charging control device 300 can be integrated into a terminal or server that has storage and a processor, thus possessing computing capabilities, or the charging control device 300 can be the terminal or server itself.

[0092] This application also provides a computer-readable storage medium for storing a computer program. This computer-readable storage medium can be applied to a computer device, and the computer program causes the computer device to execute the corresponding processes in the charging control method of the embodiments of this application; for the sake of brevity, these will not be elaborated further here.

[0093] This application also provides a computer program product including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the corresponding process in the charging control method of the embodiments of this application. For simplicity, further details are omitted here.

[0094] It should be understood that the processor in this application may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method embodiments can be completed by integrated logic circuits in the processor's hardware or by instructions in software form. The processor described above can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (aSIC), a field-programmable gate array (FPGa), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0095] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RaM), which is used as an external cache. By way of example, but not limitation, many forms of RaM are available, such as Static RaM (SRaM), Dynamic RaM (DRaM), Synchronous DRaM (SDRaM), Double Data Rate SRaM (DDR SRaM), Enhanced SRaM (ESDRaM), Synchronous Linked DRaM (SLDRaM), and Direct Rambus RaM (DR RaM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0096] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0097] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0098] In the embodiments of this application, the terms "module" or "unit" refer to a computer program or part of a computer program that has a predetermined function and works with other related parts to achieve a predetermined goal, and can be implemented wholly or partially using software, hardware (such as processing circuitry or memory), or a combination thereof. Similarly, a processor (or multiple processors or memory) can be used to implement one or more modules or units. Furthermore, each module or unit can be part of an overall module or unit that includes the functionality of that module or unit.

[0099] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0100] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0101] In addition, the functional units in this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0102] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer or a server) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0103] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A charging control method, characterized in that, Applied to an energy storage system, the energy storage system comprising multiple battery packs, the method includes: Real-time monitoring of the highest voltage of each individual cell in the battery pack; When the highest voltage is greater than a preset charging threshold, the first requested electrical parameters of the target battery pack corresponding to the highest voltage are determined based on the highest voltage, wherein the preset charging threshold is less than the charging cut-off voltage. Based on the current operating parameters of the target battery pack corresponding to the highest voltage, the first requested electrical parameters are adjusted to obtain the second requested electrical parameters; The target battery pack is charged based on the second requested electrical parameters.

2. The charging control method according to claim 1, characterized in that, Multiple battery packs are connected in parallel, the first requested electrical parameter includes a first requested current, the determination of the first requested electrical parameter is based on the highest voltage, and the preset charging threshold is less than the charging cutoff voltage, including: When the maximum voltage of the target battery pack rises to a preset voltage threshold, the requested current is reduced by a target ratio to determine the reduced first requested current.

3. The charging control method according to claim 2, characterized in that, The first requested current is determined based on the following formula: Ireq(k+1)=max(Ireq(k)×(1-α), Imin), where Ireq(k+1) is the first requested current, Ireq(k) is the requested current before reduction, α is the target ratio, the target ratio is located in the interval (0,1), and Imin is the preset minimum requested current.

4. The charging control method according to claim 2 or 3, characterized in that, The current operating parameters include at least one of battery pack temperature, current battery internal resistance, and cycle count. Adjusting the first requested electrical parameters based on the current operating parameters of the target battery pack corresponding to the highest voltage to obtain the second requested electrical parameters includes: A first adjustment factor is determined based on the battery pack temperature, a second adjustment factor is determined based on the current battery internal resistance, and a third adjustment factor is determined based on the number of cycles. The target ratio is adjusted based on at least one of the first adjustment factor, the second adjustment factor, and the third adjustment factor to obtain the second requested electrical parameters.

5. The charging control method according to claim 4, characterized in that, The step of determining the first adjustment factor based on the battery pack temperature includes: Based on the target temperature range in which the target battery pack temperature is located, a first adjustment factor is determined. The target temperature range is any preset temperature range, and the preset temperature range and the first adjustment factor correspond one-to-one.

6. The charging control method according to claim 5, characterized in that, The preset temperature range includes a first temperature range, a second temperature range, and a third temperature range. The first adjustment factor corresponding to the first temperature range, the first adjustment factor corresponding to the second temperature range, and the first adjustment factor corresponding to the third temperature range decrease sequentially, and the first adjustment factor corresponding to the second temperature range is 1.

7. The charging control method according to claim 4, characterized in that, The step of determining the second adjustment factor based on the current battery internal resistance includes: A second adjustment factor is determined based on the ratio of the current internal resistance of the target battery pack to the initial internal resistance of the battery pack, and the ratio and the second adjustment factor are positively correlated.

8. The charging control method according to claim 7, characterized in that, The determination of the second adjustment factor based on the ratio of the current internal resistance to the initial internal resistance of the target battery pack includes: If the ratio is greater than a preset ratio threshold, the second adjustment factor is determined to be a first preset value; If the ratio is less than or equal to the preset ratio threshold, the second adjustment factor is determined to be a second preset value, which is less than the first preset value.

9. The charging control method according to claim 4, characterized in that, The determination of the third adjustment factor based on the number of cycles of the target battery pack includes: If the number of cycles is greater than a preset threshold, the third adjustment factor is determined to be a third preset value; If the number of cycles is less than or equal to the preset number threshold, the third adjustment factor is determined to be a fourth preset value, which is less than the third preset value.

10. The charging control method according to claim 4, characterized in that, The step of adjusting the target ratio based on at least one of the first adjustment factor, the second adjustment factor, and the third adjustment factor to obtain the second requested electrical parameter includes: The target ratio is adjusted based on the product of the first adjustment factor, the second adjustment factor, and the third adjustment factor to obtain the second requested electrical parameters.

11. The charging control method according to claim 1, characterized in that, Also includes: If the voltage of the target battery pack is greater than or equal to the charging cutoff voltage and this condition is maintained for a preset duration, the target battery pack is determined to be fully charged.

12. A charging control device, characterized in that, The device is used in an energy storage system, which includes multiple battery packs, and includes: The monitoring module monitors the maximum voltage of each individual cell in the battery pack in real time. The determining module, when the highest voltage is greater than a preset charging threshold, determines the first requested electrical parameters of the target battery pack corresponding to the highest voltage, where the preset charging threshold is less than the charging cutoff voltage; The adjustment module adjusts the first requested electrical parameters based on the current operating parameters of the target battery pack corresponding to the highest voltage, so as to obtain the second requested electrical parameters; The processing module charges the target battery pack based on the second requested electrical parameters.

13. An energy storage system, characterized in that, include: Multiple battery packs; A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the method as described in any one of claims 1-11.

14. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1-11.

15. A computer program product, characterized in that, Includes a computer program that, when executed by a processor, implements the method described in claims 1-11.

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