Battery equalization method and device based on cloud edge collaboration and periodic hierarchical control

Abstract

The invention discloses a battery equalization method and device based on cloud edge collaboration and periodic hierarchical control. The method comprises the steps that a board end monitors whether each battery meets a local battery equalization condition or not in real time; if yes, executing a local battery equalization process; if not, determining whether a battery equalization task sent by the cloud is received; under the condition that the battery equalization task sent by the cloud is received, executing the battery equalization task sent by the cloud; judging whether a local battery equalization condition is met or not in the process of executing the battery equalization task sent by the cloud; and switching to a local battery equalization process when the local battery equalization condition is met. According to the scheme, hierarchical cooperative control with an edge end as a main part and a cloud end as an auxiliary part can be realized on a system structure; a periodic grading trigger mechanism is combined in strategy, and targeted balance control is carried out on available capacity recovery and voltage consistency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power batteries, and in particular to a battery equalization method and device based on cloud-edge collaboration and periodic hierarchical control. BACKGROUND

[0002] Under the background that lithium ion batteries are widely used in electric vehicles and energy storage power stations, how to maintain the voltage consistency between each single battery cell in the battery pack and improve the available capacity and life of the system has become a key research direction of the battery management system (BMS). With the development of edge computing and Internet of Things communication, it has become a trend to introduce cloud intelligent diagnosis and analysis capabilities into the field of battery management. Some research proposes to use the cloud platform for data modeling, anomaly detection, life prediction and other functions, while the fast response control decision is reserved in the edge BMS. However, the current mainstream cloud-edge collaborative equalization system still has the following shortcomings: Shortcoming one: the cloud master and edge auxiliary structure is difficult to respond quickly: the existing system mostly takes the cloud platform as the equalization control guide, and the edge end only serves as an executor, which has the problems of large equalization response time delay and high communication load.

[0003] Shortcoming two: lack of periodic strategy differentiation: most methods fail to differentiate short-cycle and long-cycle operations according to equalization goals, resulting in unreasonable equalization frequency, which cannot timely restore capacity and is difficult to maintain long-term consistency.

[0004] Shortcoming three: lack of edge intelligence, and cloud control generalization: in some systems, the edge device lacks autonomous judgment ability and completely relies on cloud judgment, resulting in a lack of scene adaptability of the equalization strategy.

[0005] It can be seen that there is an urgent need for a new battery equalization control method to solve at least one of the above-mentioned defects of the existing cloud-edge collaborative equalization system. SUMMARY

[0006] The purpose of the embodiments of the present application is to provide a battery equalization method and device based on cloud-edge collaboration and periodic hierarchical control, which can solve the above-mentioned problems in the prior art.

[0007] To solve the above technical problems, the present application provides the following technical solutions: The embodiments of the present application provide a battery equalization method based on cloud-edge collaboration and periodic hierarchical control, applied to a battery management system comprising a cloud end and a board end, wherein the method comprises: The board end monitors whether each battery satisfies the local battery equalization condition in real time; If it is satisfied, a local battery equalization process is performed; If not, it is determined whether a battery balancing task sent by the cloud is received, wherein the battery balancing task carries target battery cell identifiers to be balanced and a capacity to be balanced corresponding to each target battery cell to be balanced; The battery balancing task sent by the cloud is executed in a case where the battery balancing task sent by the cloud is received. In the process of executing the battery balancing task sent by the cloud, it is determined whether a local battery balancing condition is met. If the local battery balancing condition is met, a local battery balancing process is switched to.

[0008] Optionally, the local battery balancing condition comprises: The remaining capacity of the battery cell with the largest remaining capacity in the battery is greater than a preset percentage. The voltage difference between the battery cell with the largest voltage and the battery cell with the smallest voltage in the battery is less than or equal to a first preset voltage value; the battery is at rest for a preset time length, and the battery management system is in an awake state.

[0009] Optionally, the cloud analyzes the battery operation data uploaded by the board end according to a first preset time period, identifies a first preset number of target battery cells to be balanced and a capacity to be balanced corresponding to each target battery cell to be balanced, and generates a first type of battery balancing task triggered by the cloud. The cloud determines whether battery balancing occurs in the battery management system within a second preset time period. If not, the battery operation data uploaded by the board end within the second preset time period is analyzed to identify a second preset number of target battery cells to be balanced and a capacity to be balanced corresponding to each target battery cell to be balanced, and a second type of battery balancing task triggered by the cloud is generated. The second preset number is greater than the first preset number, and the second preset time period is greater than the first preset time period.

[0010] Optionally, if the condition is met, the steps of the local battery balancing process are executed, comprising: If the condition is met, it is determined for each battery cell of each battery to be balanced whether the battery cell meets a first preset battery cell balancing condition. If the condition is met, the capacity to be balanced corresponding to the battery cell is calculated according to the voltage corresponding to the battery cell. According to the capacity to be balanced, the battery cell is subjected to single battery cell balancing processing until a first single battery cell balancing stop condition is met.

[0011] Optionally, the first single battery cell balancing stop condition comprises at least one of the following: The voltage value of the battery cell with the smallest voltage among all battery cells in the battery is less than or equal to a second preset voltage value. The temperature of the battery cell with the largest temperature among all battery cells in the battery is greater than a preset temperature value. The preset fault occurs in the battery cell.

[0012] Optionally, the step of executing the battery equalization task sent by the cloud in the case of receiving the battery equalization task sent by the cloud comprises: In the case of receiving the battery equalization task sent by the cloud, it is judged whether the battery satisfies the passive equalization starting condition; If yes, it is judged whether each battery cell in the battery satisfies the second preset battery cell equalization condition; The equalization process of the battery cell satisfying the second preset battery cell equalization condition is started, and the battery cell equalization operation is performed according to the to-be-equalized capacity corresponding to the battery cell in the battery equalization task sent by the cloud.

[0013] Optionally, after the step of judging whether the local battery equalization condition is satisfied in the process of executing the battery equalization task sent by the cloud, the method further comprises: In the case of not satisfying the local battery equalization condition, it is judged whether the second single battery cell equalization stopping condition and the battery cell discharging process suspension condition are satisfied; If yes, it is judged whether the battery cell satisfies the battery cell equalization end condition; If the battery cell equalization end condition is satisfied, the equalization operation of the battery cell is ended; if the battery cell equalization end condition is not satisfied, the step of judging whether the local battery equalization condition is satisfied in the process of executing the battery equalization task sent by the cloud is returned to be executed.

[0014] The embodiment of the application also provides a battery equalization device based on cloud edge cooperation and periodic hierarchical control, which is arranged at the board end of a battery management system comprising a cloud end and the board end, wherein the device comprises: A monitoring module is configured to monitor whether each battery satisfies a local battery equalization condition in real time; A first execution module is configured to execute a local battery equalization process if yes; A determination module is configured to determine whether a battery equalization task sent by the cloud is received if no, wherein the battery equalization task carries a target to-be-equalized battery cell identifier and a to-be-equalized capacity corresponding to each target to-be-equalized battery cell; A second execution module is configured to execute the battery equalization task sent by the cloud in the case of receiving the battery equalization task sent by the cloud; A switching module is configured to judge whether a local battery equalization condition is satisfied in the process of executing the battery equalization task sent by the cloud, and switch to a local battery equalization process if the local battery equalization condition is satisfied.

[0015] Optionally, the local battery equalization condition comprises: The residual capacity of the battery cell with the largest residual capacity in the battery is greater than a preset percentage; The voltage difference between the maximum voltage cell and the minimum voltage cell in the battery is less than or equal to a first preset voltage value; the battery is at rest for a preset time length, and the battery management system is in an awake state.

[0016] Optionally, the cloud end analyzes the battery operation data uploaded by the board end according to a first preset time period, identifies a first preset number of target cells to be balanced and a corresponding balance capacity of each target cell to be balanced, and generates a cloud-triggered first type of battery balancing task. The cloud end determines whether battery balancing occurs in the battery management system within a second preset time period. If not, the cloud end analyzes the battery operation data uploaded by the board end within the second preset time period, identifies a second preset number of target cells to be balanced and a corresponding balance capacity of each target cell to be balanced, and generates a cloud-triggered second type of battery balancing task. The second preset number is greater than the first preset number, and the second preset time period is greater than the first preset time period.

[0017] Optionally, the first execution module is specifically configured to: If the condition is met, for each cell of each battery to be balanced, it is determined whether the cell meets a first preset cell balancing condition. If the condition is met, the balance capacity of the cell corresponding to the voltage of the cell is calculated. According to the balance capacity, the cell is subjected to single-cell balancing processing until a first single-cell balancing stop condition is met.

[0018] Optionally, the first single-cell balancing stop condition includes at least one of the following: The voltage value of the minimum voltage cell among all cells included in the battery is less than or equal to a second preset voltage value. The temperature of the maximum temperature cell among all cells included in the battery is greater than a preset temperature value. The cell has a preset fault.

[0019] Optionally, the second execution module is specifically configured to: In the case where the battery balancing task sent by the cloud end is received, it is determined whether the battery meets a passive balancing start condition. If the condition is met, it is determined whether each cell in the battery meets a second preset cell balancing condition. The balancing process of the cell meeting the second preset cell balancing condition is started, and the cell balancing operation is performed according to the balance capacity of the cell corresponding to the cloud end.

[0020] Optionally, the switching module is further configured to: After determining whether the local battery balancing condition is met in the process of executing the battery balancing task sent by the cloud, if the local battery balancing condition is not met, it is determined whether the second single cell balancing stop condition and the cell discharging process suspension condition are met; If the condition is met, it is determined whether the cell meets the cell balancing end condition; If the cell balancing end condition is met, the balancing operation of the cell ends; if the cell balancing end condition is not met, the operation of determining whether the local battery balancing condition is met in the process of executing the battery balancing task sent by the cloud is returned.

[0021] The embodiment of the application also provides an electronic device, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory complete mutual communication through the communication bus; the memory is used for storing a computer program; and the processor is used for executing the program stored in the memory to realize the battery balancing method process based on cloud edge collaboration and periodic hierarchical control.

[0022] The battery balancing scheme based on cloud edge collaboration and periodic hierarchical control disclosed by the embodiment of the application comprises the following steps: the board end monitors whether each battery meets a local battery balancing condition in real time; if the condition is met, a local battery balancing process is executed; if the condition is not met, it is determined whether a battery balancing task sent by the cloud is received; the battery balancing task sent by the cloud is executed in the case that the battery balancing task sent by the cloud is received; whether the local battery balancing condition is met in the process of executing the battery balancing task sent by the cloud is determined; and the local battery balancing process is switched to in the case that the local battery balancing condition is met. The battery balancing scheme based on cloud edge collaboration and periodic hierarchical control can realize hierarchical collaborative control taking the edge end as the main part and the cloud as the auxiliary part on the system structure, can improve the response speed, balancing efficiency and long-term stability of the battery system, and can reduce the communication pressure and cloud computing load on the strategy combined with the periodic hierarchical triggering mechanism and respectively for the available capacity recovery and voltage consistency. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a step flow chart of a battery balancing method based on cloud edge collaboration and periodic hierarchical control according to an embodiment of the application; Figure 2 It is a step flow chart of a cloud end determining a target cell to be balanced according to an embodiment of the application; Figure 3 It is a structural schematic diagram of a battery balancing device based on cloud edge collaboration and periodic hierarchical control according to an embodiment of the application. DETAILED DESCRIPTION

[0024] To make the technical problems, technical solutions and advantages to be solved by the present application clearer, specific embodiments will be described in detail below with reference to the drawings.

[0025] The battery balancing method based on cloud-edge collaboration and periodic hierarchical control provided by the embodiments of the present application will be described in detail below with reference to the drawings, specific embodiments and application scenarios.

[0026] As shown in the accompanying Figure 1 The battery balancing method based on cloud-edge collaboration and periodic hierarchical control of the embodiments of the present application includes the following steps: Step 101: The board end monitors whether each battery satisfies the local battery balancing condition in real time; if yes, step 102 is executed; if not, step 103 is executed.

[0027] The battery balancing method based on cloud-edge collaboration and periodic hierarchical control provided by the embodiments of the present application is applied to a battery management system including a cloud end and a board end. The battery balancing method process is executed by the board end, and in the method, the board end can actively trigger local battery balancing, and the board end can also passively accept the battery balancing task of the cloud end to execute the battery balancing operation.

[0028] In an optional embodiment, the local battery balancing condition includes that the remaining power of the battery cell with the most remaining power in the battery is greater than a preset percentage; the voltage difference between the maximum voltage cell and the minimum voltage cell in the battery is less than or equal to a first preset voltage value; the battery is at rest for a preset time length, and the battery management system is in a wake-up state.

[0029] It should be noted that the local battery balancing condition can include at least one of the above three conditions. More preferably, to ensure the accuracy of the battery balancing judgment, it can be determined that the battery satisfies the battery balancing condition only when the above three conditions are satisfied at the same time.

[0030] The preset percentage and the first preset voltage value can be flexibly set by those skilled in the art, and the embodiments of the present application do not make specific limitations thereon. For example, the preset percentage is set to 90%, 95% or 85%, etc., and the first preset voltage value is set to 10mv, 12mv or 15mv, etc.

[0031] Step 102: If yes, execute the local battery balancing process.

[0032] In an optional embodiment, if yes, executing the local battery balancing process includes the following sub-steps: Sub-step 1: If yes, for each cell of each battery to be balanced, determine whether the cell satisfies a first preset cell balancing condition. The first preset cell equalization condition can be set as: the voltage difference between the current cell voltage and the voltage of the minimum voltage cell is less than a preset value, for example, the preset value can be set as 20mv; and the SOC difference between the SOC of the current cell and the SOC of the minimum SOC cell is greater than a preset percentage, for example, the preset percentage can be set as 4%.

[0033] In actual implementation, it is necessary to determine whether each cell in the battery to be equalized meets the first preset cell equalization condition, so as to screen out the cells that need to be equalized.

[0034] Substep 2: If yes, the equalization capacity corresponding to the cell is calculated according to the voltage corresponding to the cell. In an optional embodiment, when the equalization capacity corresponding to the cell is calculated according to the voltage corresponding to the cell, the SOC corresponding to the cell can be determined based on the SOC-OCV table through the voltage corresponding to the cell; and the rated capacity is calculated based on the SOC and a preset rated capacity calculation formula. The capacity equalization limit can be set as the smaller one of the rated capacity x 4% or 3Ah converted by time.

[0035] Substep 3: The single-cell equalization processing of the cell is performed according to the equalization capacity until the first single-cell equalization stop condition is met and terminated.

[0036] A feasible way is to set the first single-cell equalization stop condition to include at least one of the following: The voltage value of the minimum voltage cell among all cells included in the battery is less than or equal to a second preset voltage value; the temperature of the maximum temperature cell among all cells included in the battery is greater than a preset temperature value; the cell has a preset fault.

[0037] The second preset voltage value can be set by those skilled in the art according to actual needs, for example, it can be set as 2.7v, and when the voltage value of the minimum voltage cell is greater than 2.8v, the equalization will be resumed. The preset temperature value can also be set by those skilled in the art according to actual needs, for example, it can be set as 60℃, and when it is less than 58℃, the equalization will be resumed. The preset fault can be fault elimination.

[0038] The first single-cell equalization stop condition can be set as: the equalization time is 0.

[0039] If the local battery equalization condition is met, the local battery equalization process is performed, and if not, the battery equalization task sent by the cloud is executed.

[0040] Step 103: If not, it is determined whether the battery equalization task sent by the cloud is received.

[0041] Wherein, the battery equalization task carries the target to be equalized battery identification and the equalization capacity corresponding to each target to be equalized battery. The cloud executes the short-period cloud trigger mechanism and the long-period equalization strategy compensation, and the cloud selects the target to be equalized battery and reports to the board. The equalization operation is executed by the local end. Taking two to be equalized batteries in the battery equalization task sent by the cloud as an example, the electrical signals of the two to be equalized batteries are 1 and 34, and the equalization capacities corresponding to the two to be equalized batteries are 5 and 1 respectively.

[0042] The short-period cloud trigger mechanism: the cloud analyzes the battery operation data uploaded by the board according to the first preset time period, identifies the first preset number of target to be equalized batteries and the equalization capacities corresponding to each target to be equalized battery, and generates the first type of battery equalization task triggered by the cloud.

[0043] A feasible implementation manner is that the cloud platform periodically analyzes the uploaded battery operation data every 7 days, identifies 3-5 target batteries to be equalized and their equalization capacities according to the short-term voltage deviation and capacity distribution results. The cloud sends the corresponding battery equalization task to the corresponding BMS board. The BMS board starts the passive equalization process according to the received short-period equalization task, and realizes the over-equalization protection mechanism by setting a dynamic voltage threshold.

[0044] The long-period equalization strategy compensation: the cloud judges whether the battery equalization occurs in the battery management system within the second preset time period. If not, the cloud analyzes the battery operation data uploaded by the board within the second preset time period, identifies the second preset number of target to be equalized batteries and the equalization capacities corresponding to each target to be equalized battery, and generates the second type of battery equalization task triggered by the cloud.

[0045] A feasible implementation manner is that the cloud platform evaluates whether the BMS board equalization behavior occurs in the past period every 30 days: if no effective board equalization execution record is detected during this period, it is considered that the board strategy is not covered or triggered insufficiently. At this time, the cloud actively issues a long-period equalization task, specifies 100 target batteries to be equalized (i.e. target to be equalized batteries) and target capacities (i.e. equalization capacities), and forcibly triggers the board passive equalization process, which is still executed by the board and adopts the dynamic voltage threshold protection.

[0046] Wherein, the second preset number is greater than the first preset number, and the second preset time period is greater than the first preset time period. The specific values of the four preset values can be flexibly set by those skilled in the art, and the application embodiments do not make specific limitations thereon. For example, the first preset number can be set to 5, the second preset number can be set to 100, the first preset time period can be 7 days, 10 days or 5 days, etc., and the second preset time period can be 30 days, 20 days or 40 days, etc.

[0047] It should be noted that in the process of executing the battery balancing task issued by the cloud, once the BMS board end locally triggers the self-balancing condition (i.e., the board end local strategy logic is met), the system immediately suspends the cloud task execution and transfers the board end control balancing process, to ensure timely response, reasonable resource allocation, and avoid strategy conflicts caused by redundant balancing or communication delay.

[0048] Step 104: Execute the battery balancing task sent by the cloud in the case of receiving the battery balancing task sent by the cloud.

[0049] In an alternative embodiment, the manner of executing the battery balancing task sent by the cloud in the case of receiving the battery balancing task sent by the cloud includes the following sub-steps: Sub-step 1: In the case of receiving the battery balancing task sent by the cloud, judge whether the battery meets the passive balancing start condition; if it is met, execute sub-step 2, if it is not met, repeat sub-step 1 to judge.

[0050] An exemplary passive balancing start condition for a single battery can be set as: the SOC of the cell with the smallest SOC in the battery is greater than or equal to 20%, and the battery is in the charging stage. It should be noted that 20% is only an example, and the specific value can be flexibly set by those skilled in the art.

[0051] Sub-step 2: If it is met, judge whether each cell in the battery meets the second preset cell balancing condition; The second preset cell balancing condition can be flexibly set by those skilled in the art, and the present application embodiment does not make specific limitations on this.

[0052] Sub-step 3: Start the balancing process for the cells that meet the second preset cell balancing condition, and perform cell balancing operation according to the corresponding to-be-balanced capacity of the cell sent by the cloud.

[0053] Step 105: Judge whether the local battery balancing condition is met in the process of executing the battery balancing task sent by the cloud.

[0054] In the case of meeting the local battery balancing condition, execute step 106; in the case of not meeting the local battery balancing condition, continue to execute the battery balancing task sent by the cloud.

[0055] In an alternative embodiment, after judging whether the local battery balancing condition is met in the process of executing the battery balancing task sent by the cloud, the method further includes the following process: Step 1: In the case of not meeting the local battery balancing condition, judge whether the second single cell balancing stop condition and the cell discharging process suspension condition are met; In an exemplary embodiment, the second single cell balancing stop condition can be set to meet any of the following conditions: 1) the voltage of the minimum voltage cell in the battery is less than or equal to 2.7v, if greater than 2.8v, resume balancing; 2) the temperature of the cell with the highest temperature in the battery is higher than 60℃, if lower than 55.8℃, resume balancing; 3) the cell has a preset fault; 4) the threshold limit of the discharge phase is met.

[0056] In an exemplary embodiment, the cell discharge process suspension condition can be set to meet any of the following conditions: 1) the cell current <50A, the voltage is less than 8mv; 2) the cell current is between 50A-200A, the voltage is less than 10mv; 3) the cell current is between 200A-300A, the voltage is less than 15mv; 4) the cell current is greater than 300A, the voltage is less than 20mv.

[0057] Step 2: If yes, determine whether the cell meets the cell balancing end condition; In actual implementation, the cell balancing end condition can be flexibly set by those skilled in the art, and the present embodiment does not make specific limitations thereon.

[0058] In an alternative embodiment, the cell balancing end condition can be set to meet any of the following conditions: 1) the balancing time is 0; 2) the cell is in the charging phase: 0-25% and 90-100%: less than 20mv; or, 25-90%: less than 15mv; 3) the static threshold is met: the voltage difference between the current cell monomer and the minimum voltage cell in the battery is less than 8mv.

[0059] In the case of meeting any of the above three conditions, it is determined that the cell balancing end condition is met.

[0060] Step 3: If the cell balancing end condition is met, the balancing operation of the cell is ended; if the cell balancing end condition is not met, return to execute the step of determining whether the local battery balancing condition is met in the process of executing the battery balancing task sent by the cloud, i.e., return to execute step 105.

[0061] Step 106: Under the condition that the local battery balancing condition is met, switch to the local battery balancing process.

[0062] Switching to the local battery balancing process means executing step 102 after switching.

[0063] The battery balancing scheme based on cloud-edge collaboration and periodic hierarchical control provided in this application embodiment monitors in real time whether each battery meets the local battery balancing conditions. If it does, the local battery balancing process is executed; if not, it determines whether a battery balancing task sent from the cloud has been received. If a battery balancing task sent from the cloud has been received, the cloud-sent battery balancing task is executed. During the execution of the cloud-sent battery balancing task, it is determined whether the local battery balancing conditions are met. If the local battery balancing conditions are met, the system switches to the local battery balancing process. This battery balancing scheme based on cloud-edge collaboration and periodic hierarchical control achieves several advantages. First, it enables hierarchical collaborative control with the edge as the primary focus and the cloud as a secondary focus in the system structure. Second, it combines a periodic hierarchical triggering mechanism to perform targeted balancing control for available capacity recovery and voltage consistency. Third, it improves the response speed, balancing efficiency, and long-term stability of the battery system while reducing communication pressure and cloud computing load.

[0064] Figure 2 A flowchart illustrating the steps for determining a target battery cell to be balanced in the cloud, as described in this application embodiment; When the cloud executes short-cycle cloud-triggered mechanisms or long-cycle balancing strategies for compensation, it follows the... Figure 2 The method shown identifies the target cell to be balanced and generates a battery balancing task based on the identified target cell identifier and the capacity to be balanced, which is then sent to the battery management system board.

[0065] As attached Figure 2 As shown in the figure, the cloud-based method for determining the target battery cell to be balanced in this application embodiment includes the following steps: Step 201: If no battery equalization occurs within the first preset time period and there are at least a first preset number of fully charged segments in a single battery, determine the resting segment duration corresponding to the fully charged segment.

[0066] Steps 201 to 203 involve modeling based on short-term historical data within a first preset time period, and then selecting cells to be balanced based on the model. The specific value of the first preset time period can be set by those skilled in the art according to actual needs; this embodiment does not impose specific limitations on it. For example, the first preset time period can be set to 7 days, 10 days, or 5 days, etc. The first preset quantity can be set to 3, 4, or 5, etc.

[0067] A feasible criterion for determining a fully charged segment can be set as follows: the battery's State of Charge (SOC) is less than or equal to 60% at the start of charging, and the battery's SOC equals 100% at the end of charging, where SOC represents the percentage of the battery's current remaining capacity. It should be noted that the above is merely an example of a criterion for determining a fully charged segment, and in actual implementation, it is not limited to this. Step 202: determining the screening strategy of the to-be-balanced battery cell according to the static segment duration.

[0068] In the actual implementation process, different static segment durations correspond to different screening strategies of the to-be-balanced battery cell. At least two screening strategies are preset in the system, and the target screening strategy is selected from the preset screening strategies in the system according to the static segment duration to screen the to-be-balanced battery cell.

[0069] In a feasible implementation manner, the static segment duration is compared with a preset duration in the system. If the static segment duration is less than the preset duration, screening strategy one is adopted, and if the static segment duration is greater than or equal to the preset duration, screening strategy two is adopted. The preset duration can be set to 30 min, 35 min, or 40 min, etc., which is not specifically limited in the embodiments of the present application.

[0070] Step 203: screening the to-be-balanced battery cell according to the screening strategy of the to-be-balanced battery cell and the terminal voltage change data of at least one full charging segment.

[0071] An optional process of screening the to-be-balanced battery cell according to the screening strategy of the to-be-balanced battery cell and the terminal voltage change data of at least one full charging segment includes the following sub-steps: Sub-step 1: in the case that the static segment duration is less than the preset duration, for each full charging segment in the first preset time period, the second preset number of battery cells are screened according to the terminal voltage change segment of the full charging segment, and the to-be-balanced capacity corresponding to each battery cell is screened.

[0072] The second preset number can be set to 5, 6, or 7, etc., which is not specifically limited in the embodiments of the present application.

[0073] In the specific implementation process, the total current and single battery cell voltage information contained in the terminal voltage change segment of each full charging segment in the past 7 days can be screened to obtain the to-be-balanced battery cell TOP5 and calculate the corresponding to-be-balanced capacity. Each full charging segment corresponds to a to-be-balanced battery cell TOP5, and n full charging segments correspond to n TOP5 battery cells.

[0074] Sub-step 2: comparing the second preset number of battery cells corresponding to each full charging segment to screen the second preset number of first battery cells.

[0075] In the specific implementation process, the TOP5 battery cells corresponding to the screened multiple full charging segments can be compared and judged to output the unique TOP5 battery cell and the to-be-balanced capacity of the TOP5 battery cell.

[0076] Sub-step 3: screening the balanced battery cell white list according to the interrupted single battery cell voltage in each full charging segment in the first preset time period.

[0077] The full-charge segment is a charging segment with a battery SOC of 40%-70%. The specific rules for screening the cell white list can be flexibly set by those skilled in the art, and the embodiments of the present application do not make specific limitations thereon.

[0078] Substep 4: The intersection of the second preset number of first cells and the cells in the balanceable cell white list is determined as the cells to be balanced.

[0079] This optional method for determining the cells to be balanced is more accurate in screening the cells to be balanced.

[0080] In another optional embodiment, the process of screening the cells to be balanced according to the cell screening strategy and the voltage change data of the end of at least one full-charge segment includes the following substeps: Substep 1: In the case where the length of the static segment is greater than or equal to the preset length, the total current and single cell voltage at the end of the full-charge segment of the last static segment of the battery are screened to obtain a third preset number of cells and the corresponding balanceable capacity of each cell.

[0081] The third preset number and the second preset number can be equal or not equal.

[0082] In actual implementation, the cells to be balanced TOP5 can be screened according to the total current and single cell voltage at the end of the full-charge segment of the last static segment of the battery, and the balanceable capacity of each cell in the cells to be balanced TOP5 can be calculated.

[0083] Substep 2: The single cell voltage contained in the static segment is analyzed to identify abnormal cells.

[0084] In the specific implementation process, the Isolation Forest algorithm can be used to identify abnormal cells. Of course, it is not limited thereto, and other adaptive algorithms can also be used to identify abnormal cells, and the embodiments of the present application do not make specific limitations thereon.

[0085] Substep 3: The intersection of the third preset number of cells and the abnormal cells is determined as the cells to be balanced.

[0086] This optional method for screening the cells to be balanced has small calculation amount and accurate screening result.

[0087] Step 204: Determine the cell black list based on the discharge history data of each cell in the battery within the second preset time period.

[0088] The second preset time period is greater than the first preset time period. The specific value of the second preset time period can be set by a person skilled in the art according to actual needs, and the present embodiment does not make a specific limitation on this. For example, the second preset time period can be set to 2 months, 1 month or 3 months, etc. In actual implementation, the data corresponding to the discharge segment at which each cell ends discharging can be extracted for analysis, wherein the discharge segment at which each cell ends discharging is a segment in which the SOC of the battery is less than or equal to 15%.

[0089] In an optional embodiment, the manner of determining the cell blacklist based on the discharge history data of each cell in the battery within the second preset time period can include the following sub-steps: Sub-step 1: Extracting the discharge segment at which each cell in the battery ends discharging within the second preset time period; Sub-step 2: Calculating the voltage ranking and voltage degradation trend of each cell after discharging ends; Sub-step 3: Determining the cell blacklist based on the voltage ranking and voltage degradation trend.

[0090] In actual implementation, the cells with a stable low voltage or a significant degradation trend can be determined to form the cell blacklist.

[0091] Step 205: Determining the target cell to be balanced as the difference set between the cell to be balanced and the cell blacklist.

[0092] After the cell to be balanced is determined through step 203 and the cell blacklist is determined through step 204, the cell to be balanced is screened again based on the cell blacklist, and finally the accurate target cell to be balanced is obtained.

[0093] After the target cell to be balanced is determined, the battery balancing task can be generated according to the identification of the target cell to be balanced and the balancing capacity corresponding to each target cell to be balanced, and the generated battery balancing task is issued from the cloud to the board.

[0094] The method for determining the target cell to be balanced provided in this application embodiment, when no battery balancing occurs within a first preset time period and a single cell has at least a first preset number of fully charged segments, determines the resting segment duration corresponding to the fully charged segment; determines the cell selection strategy to be balanced based on the resting segment duration; selects the cells to be balanced based on the cell selection strategy and the end voltage change data of at least one fully charged segment; determines the cell blacklist based on the discharge history data of each cell in the battery within a second preset time period; and determines the target cell to be balanced by the difference between the cell to be balanced and the cell blacklist. This method uses the isolated forest algorithm to select target cells and updates the list in real time with short-cycle data. On average, only a few cells need to be intervened in each balancing iteration, significantly reducing the number of invalid operations. Secondly, by establishing a cell blacklist mechanism, irreversible abnormal cells are actively excluded from participating in balancing, which can avoid energy waste and excessive interference.

[0095] Figure 3 The structural block diagram of the battery balancing device based on cloud-edge collaboration and periodic hierarchical control in this application embodiment is shown.

[0096] The battery balancing device based on cloud-edge collaboration and periodic hierarchical control provided in this application embodiment is deployed on the board side of a battery management system that includes cloud and board side components. The device includes the following functional modules: Monitoring module 301 is used to monitor in real time whether each battery meets the local battery balancing conditions; The first execution module 302 is used to execute the local battery balancing process if the conditions are met. The determination module 303 is used to determine whether a battery balancing task sent from the cloud has been received if the conditions are not met. The battery balancing task carries the identifier of the target cell to be balanced and the capacity to be balanced corresponding to each target cell. The second execution module 304 is used to execute the battery balancing task sent by the cloud upon receiving the battery balancing task sent by the cloud. The switching module 305 is used to determine whether the local battery balancing conditions are met during the execution of the battery balancing task sent from the cloud; if the local battery balancing conditions are met, the module switches to the local battery balancing process.

[0097] Optionally, the local battery balancing conditions include: The battery cell with the most remaining charge has a remaining charge percentage greater than a preset percentage; The voltage difference between the highest voltage cell and the lowest voltage cell in the battery is less than or equal to a first preset voltage value; the battery has been left to stand for a preset time; and the battery management system is in a wake-up state.

[0098] Optionally, the cloud analyzes the battery operation data uploaded by the board end according to a first preset time period, identifies a first preset number of target battery cells to be balanced and a corresponding balance capacity of each target battery cell to be balanced, and generates a first type of battery balancing task triggered by the cloud. The cloud determines whether battery balancing occurs in the battery management system within a second preset time period. If not, the cloud analyzes the battery operation data uploaded by the board end within the second preset time period, identifies a second preset number of target battery cells to be balanced and a corresponding balance capacity of each target battery cell to be balanced, and generates a second type of battery balancing task triggered by the cloud. The second preset number is greater than the first preset number, and the second preset time period is greater than the first preset time period.

[0099] Optionally, the first execution module is specifically configured to: If the condition is met, for each battery cell to be balanced, it is determined whether the battery cell meets a first preset battery cell balancing condition. If the condition is met, the balance capacity of the battery cell is calculated according to the voltage corresponding to the battery cell. According to the balance capacity, the battery cell is subjected to single-cell balancing processing until a first single-cell balancing stop condition is met.

[0100] Optionally, the first single-cell balancing stop condition includes at least one of the following: The voltage value of the minimum voltage battery cell among all battery cells in the battery is less than or equal to a second preset voltage value. The temperature of the maximum temperature battery cell among all battery cells in the battery is greater than a preset temperature value. The battery cell has a preset fault.

[0101] Optionally, the second execution module is specifically configured to: In the case where the battery balancing task sent by the cloud is received, it is determined whether the battery meets a passive balancing start condition. If the condition is met, it is determined whether each battery cell in the battery meets a second preset battery cell balancing condition. The balancing process of the battery cell that meets the second preset battery cell balancing condition is started, and the battery cell balancing operation is performed according to the balance capacity corresponding to the battery cell sent by the cloud.

[0102] Optionally, the switching module is further configured to: After determining whether the local battery balancing condition is met during the execution of the battery balancing task sent by the cloud, if the local battery balancing condition is not met, it is determined whether a second single-cell balancing stop condition and a battery cell discharging process suspension condition are met. If yes, it is determined whether the battery satisfies a battery equalization end condition. If the battery equalization end condition is satisfied, the equalization operation of the battery ends; if the battery equalization end condition is not satisfied, the operation of determining whether the local battery equalization condition is satisfied in the process of executing the battery equalization task sent by the cloud is returned.

[0103] The battery equalization device based on cloud-edge collaboration and periodic hierarchical control provided by the embodiment of the application can realize the layered collaborative control taking the edge as the main part and the cloud as the auxiliary part in the system structure; secondly, in the strategy, the periodic hierarchical triggering mechanism is combined to perform the targeted equalization control for the available capacity recovery and the voltage consistency respectively; thirdly, the response speed, the equalization efficiency and the long-term stability of the battery system can be improved, and the communication pressure and the cloud computing load can be reduced.

[0104] The battery equalization device based on cloud-edge collaboration and periodic hierarchical control provided by the embodiment of the application can realize the layered collaborative control taking the edge as the main part and the cloud as the auxiliary part in the system structure; secondly, in the strategy, the periodic hierarchical triggering mechanism is combined to perform the targeted equalization control for the available capacity recovery and the voltage consistency respectively; thirdly, the response speed, the equalization efficiency and the long-term stability of the battery system can be improved, and the communication pressure and the cloud computing load can be reduced. Figure 3 The battery equalization device based on cloud-edge collaboration and periodic hierarchical control provided by the embodiment of the application can realize the layered collaborative control taking the edge as the main part and the cloud as the auxiliary part in the system structure; secondly, in the strategy, the periodic hierarchical triggering mechanism is combined to perform the targeted equalization control for the available capacity recovery and the voltage consistency respectively; thirdly, the response speed, the equalization efficiency and the long-term stability of the battery system can be improved, and the communication pressure and the cloud computing load can be reduced. Figure 1 The processes realized by the method embodiment are not repeated here to avoid repetition.

[0105] The embodiment of the application further provides an electronic device which is a board end of a battery management system and includes a processor, a communication interface, a memory and a communication bus.

[0106] The memory is used to store a computer program. The processor is used to execute the program stored in the memory to realize the battery equalization method based on cloud-edge collaboration and periodic hierarchical control shown in the method embodiment.

[0107] The communication bus mentioned above can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0108] The communication interface is used for communication between the terminal and other devices.

[0109] The memory can include a Random Access Memory (RAM) and can also include a non-volatile memory, such as at least one disk memory. Optionally, the memory can also be at least one storage device located away from the aforementioned processor.

[0110] In yet another embodiment provided by the present application, a computer readable storage medium is provided, and the computer readable storage medium stores instructions, when the instructions are run on an electronic device, the electronic device implements the battery equalization method based on cloud edge collaboration and periodic hierarchical control according to any one of the above embodiments.

[0111] In yet another embodiment provided by the present application, a computer program product containing instructions is provided, and when the instructions are run on an electronic device, the electronic device implements the battery equalization method based on cloud edge collaboration and periodic hierarchical control according to any one of the above embodiments.

[0112] It should be noted that in this document, the term "comprising" or "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or apparatus including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such a process, method, article or apparatus. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or apparatus including the element.

[0113] The above is the preferred embodiment of the present application. It should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A battery balancing method based on cloud-edge collaboration and periodic hierarchical control, applied to a battery management system including cloud and board-side components, characterized in that... The method includes: The board monitors in real time whether each battery meets the local battery balancing conditions. If the conditions are met, then execute the local battery balancing process; If not satisfied, determine whether a battery balancing task sent from the cloud has been received, wherein the battery balancing task carries the identifier of the target cell to be balanced and the capacity to be balanced corresponding to each target cell to be balanced. Execute the battery balancing task sent by the cloud upon receiving the battery balancing task sent by the cloud; During the execution of the battery balancing task sent from the cloud, it is determined whether the local battery balancing conditions are met; if the local battery balancing conditions are met, the process switches to the local battery balancing process.

2. The method according to claim 1, characterized in that, The local battery balancing conditions include: The battery cell with the most remaining charge has a remaining charge percentage greater than a preset percentage; The voltage difference between the highest voltage cell and the lowest voltage cell in the battery is less than or equal to a first preset voltage value; the battery has been left to stand for a preset time; and the battery management system is in a wake-up state.

3. The method according to claim 1, characterized in that: The cloud analyzes the battery operation data uploaded by the board according to a first preset time period, identifies a first preset number of target cells to be balanced and the capacity to be balanced corresponding to each target cell to be balanced, and generates a first type of battery balancing task triggered by the cloud. The cloud determines whether battery balancing has occurred within the battery management system within the second preset time period. If not, it analyzes the battery operation data uploaded by the board within the second preset time period to identify the second preset number of target cells to be balanced and the capacity to be balanced corresponding to each target cell; and generates a second type of battery balancing task triggered by the cloud. Wherein, the second preset quantity is greater than the first preset quantity, and the second preset time period is greater than the first preset time period.

4. The method according to claim 1, characterized in that, If satisfied, the following steps of the local battery balancing process are executed: If satisfied, then for each cell of each battery to be balanced, determine whether the cell satisfies the first preset cell balancing condition. If satisfied, the capacity to be balanced for the cell is calculated based on the corresponding voltage of the cell. Based on the capacity to be balanced, the cells are balanced individually until the first single-cell balancing stop condition is met.

5. The method according to claim 4, characterized in that, The first single-cell equalization stop condition includes at least one of the following: The voltage value of the lowest voltage cell among all the cells in the battery is less than or equal to the second preset voltage value; The temperature of the cell with the highest temperature among all the cells in the battery is greater than the preset temperature value. The battery cell has a pre-set fault.

6. The method according to claim 1, characterized in that, The steps for executing the battery balancing task sent by the cloud upon receiving the battery balancing task sent by the cloud include: Upon receiving a battery balancing task from the cloud, determine whether the battery meets the conditions for passive balancing to start. If satisfied, determine whether each cell in the battery satisfies the second preset cell balancing condition; Initiate the balancing process for cells that meet the second preset cell balancing conditions, and perform cell balancing operations based on the cell capacity to be balanced corresponding to the cell sent from the cloud.

7. The method according to claim 1, characterized in that, After the step of determining whether the local battery balancing conditions are met during the execution of the battery balancing task sent from the cloud, the method further includes: If the local battery balancing condition is not met, determine whether the second single cell balancing stop condition and the cell discharge process pause condition are met. If satisfied, determine whether the cell meets the cell balancing termination condition; If the cell balancing termination condition is met, the cell balancing operation ends; if the cell balancing termination condition is not met, the process returns to the step of determining whether the local battery balancing condition is met during the execution of the battery balancing task sent from the cloud.

8. A battery balancing device based on cloud-edge collaboration and periodic hierarchical control, the device being deployed on the board of a battery management system comprising cloud and board-side components, characterized in that... The device includes: The monitoring module is used to monitor in real time whether each battery meets the local battery balancing conditions; The first execution module is used to execute the local battery balancing process if the conditions are met. The determination module is used to determine whether a battery balancing task sent from the cloud has been received if the conditions are not met. The battery balancing task carries the identifier of the target cell to be balanced and the capacity to be balanced corresponding to each target cell. The second execution module is used to execute the battery balancing task sent by the cloud upon receiving the battery balancing task sent by the cloud. The switching module is used to determine whether the local battery balancing conditions are met during the execution of the battery balancing task sent from the cloud; if the local battery balancing conditions are met, the module switches to the local battery balancing process.

9. The apparatus according to claim 8, characterized in that, The local battery balancing conditions include: The battery cell with the most remaining charge has a remaining charge percentage greater than a preset percentage; The voltage difference between the highest voltage cell and the lowest voltage cell in the battery is less than or equal to a first preset voltage value; the battery has been left to stand for a preset time; and the battery management system is in a wake-up state.

10. The apparatus according to claim 8, characterized in that: The cloud analyzes the battery operation data uploaded by the board according to a first preset time period, identifies a first preset number of target cells to be balanced and the capacity to be balanced corresponding to each target cell to be balanced, and generates a first type of battery balancing task triggered by the cloud. The cloud determines whether battery balancing has occurred within the battery management system within the second preset time period. If not, it analyzes the battery operation data uploaded by the board within the second preset time period to identify the second preset number of target cells to be balanced and the capacity to be balanced corresponding to each target cell; and generates a second type of battery balancing task triggered by the cloud. Wherein, the second preset quantity is greater than the first preset quantity, and the second preset time period is greater than the first preset time period.

11. The apparatus according to claim 8, characterized in that, The first execution module is specifically used for: If satisfied, then for each cell of each battery to be balanced, determine whether the cell satisfies the first preset cell balancing condition. If satisfied, the capacity to be balanced for the cell is calculated based on the corresponding voltage of the cell. Based on the capacity to be balanced, the cells are balanced individually until the first single-cell balancing stop condition is met.

12. The apparatus according to claim 11, characterized in that, The first single-cell equalization stop condition includes at least one of the following: The voltage value of the lowest voltage cell among all the cells in the battery is less than or equal to the second preset voltage value; The temperature of the cell with the highest temperature among all the cells in the battery is greater than the preset temperature value. The battery cell has a pre-set fault.

13. The apparatus according to claim 8, characterized in that, The second execution module is specifically used for: Upon receiving a battery balancing task from the cloud, determine whether the battery meets the conditions for passive balancing to start. If satisfied, determine whether each cell in the battery satisfies the second preset cell balancing condition; Initiate the balancing process for cells that meet the second preset cell balancing conditions, and perform cell balancing operations based on the cell capacity to be balanced corresponding to the cell sent from the cloud.

14. The apparatus according to claim 8, characterized in that, The switching module is also used for: During the execution of the battery balancing task sent from the cloud, after determining whether the local battery balancing conditions are met, if the local battery balancing conditions are not met, it is determined whether the second single cell balancing stop condition and the cell discharge process pause condition are met. If satisfied, determine whether the cell meets the cell balancing termination condition; If the cell balancing termination condition is met, the balancing operation on the cell ends. If the cell balancing termination condition is not met, the process of determining whether the local battery balancing condition is met during the execution of the battery balancing task sent from the cloud will be returned.

15. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other through the communication bus; Memory, used to store computer programs; The processor, when executing a program stored in memory, implements the battery balancing method based on cloud-edge collaboration and periodic hierarchical control as described in any one of claims 1-7.

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