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

Abstract

The application discloses a battery equalization method and device based on cloud edge cooperation and periodic hierarchical control, and the method comprises the following steps: a board end monitors whether each battery satisfies a local battery equalization condition in real time; if yes, a local battery equalization process is executed; if no, it is determined whether a battery equalization task sent by the cloud is received; the battery equalization task sent by the cloud is executed under the condition that the battery equalization task sent by the cloud is received; whether the local battery equalization condition is satisfied is judged in the process of executing the battery equalization task sent by the cloud; and the local battery equalization process is switched to under the condition that the local battery equalization condition is satisfied. The scheme can realize hierarchical cooperative control with the edge end as the main part and the cloud as the auxiliary part on the system structure; and the periodic hierarchical triggering mechanism is combined on the strategy, and the available capacity recovery and voltage consistency are respectively subjected to targeted equalization control.

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:

[0003] 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.

[0004] Shortcoming two: lack of periodic strategy differentiation: most methods fail to differentiate short-cycle and long-cycle operations according to the equalization target, resulting in unreasonable equalization frequency, which cannot timely restore the capacity nor maintain long-term consistency.

[0005] 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.

[0006] 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

[0007] 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.

[0008] To solve the above technical problems, the present application provides the following technical solutions:

[0009] 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:

[0010] The board end monitors whether each battery satisfies the local battery equalization condition in real time;

[0011] If yes, a local battery equalization process is performed;

[0012] 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;

[0013] The battery balancing task sent by the cloud is executed in the case that the battery balancing task sent by the cloud is received.

[0014] It is determined whether a 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 met, the local battery balancing process is switched to.

[0015] Optionally, the local battery balancing condition comprises:

[0016] The remaining capacity of the battery cell with the largest remaining capacity in the battery is greater than a preset percentage;

[0017] 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.

[0018] 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.

[0019] 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 capacity to be balanced corresponding to each target battery cell to be balanced, and generates a second type of battery balancing task triggered by the cloud.

[0020] 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.

[0021] Optionally, if the condition is met, the steps of the local battery balancing process are executed, comprising:

[0022] 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.

[0023] 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.

[0024] 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.

[0025] Optionally, the first single cell equalization stop condition comprises at least one of the following:

[0026] 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;

[0027] The temperature of the maximum temperature cell among all cells included in the battery is greater than a preset temperature value;

[0028] The cell has a preset fault.

[0029] 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:

[0030] In the case of receiving the battery equalization task sent by the cloud, it is judged whether the battery satisfies a passive equalization start condition;

[0031] If yes, it is judged whether each cell in the battery satisfies a second preset cell equalization condition;

[0032] An equalization process for the cell satisfying the second preset cell equalization condition is started, and a cell equalization operation is performed according to the corresponding to-be-equalized capacity of the cell sent by the cloud.

[0033] 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:

[0034] In the case of not satisfying the local battery equalization condition, it is judged whether a second single cell equalization stop condition and a cell discharging process suspension condition are satisfied;

[0035] If yes, it is judged whether the cell satisfies a cell equalization end condition;

[0036] If the cell equalization end condition is satisfied, the equalization operation of the cell is ended; if the 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.

[0037] The embodiment of the application also provides a battery equalization device based on cloud edge cooperation and periodic hierarchical control, which is arranged at a board end of a battery management system including a cloud end and the board end, and wherein the device comprises:

[0038] A monitoring module is configured to monitor whether each battery satisfies a local battery equalization condition in real time;

[0039] A first execution module is configured to execute a local battery equalization process if yes;

[0040] determining whether a battery balancing task sent by the cloud is received if the condition is not met, 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;

[0041] a second execution module configured to execute the battery balancing task sent by the cloud if the battery balancing task sent by the cloud is received;

[0042] a switching module configured to determine whether a local battery balancing condition is met during execution of the battery balancing task sent by the cloud, and switch to a local battery balancing process if the local battery balancing condition is met.

[0043] Optionally, the local battery balancing condition comprises:

[0044] a remaining capacity of a battery cell with the largest remaining capacity in the battery is greater than a preset percentage;

[0045] a voltage difference between a battery cell with the largest voltage and a 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.

[0046] Optionally, the cloud analyzes battery operation data uploaded by the board end at 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.

[0047] The cloud determines whether battery balancing occurs in the battery management system within a second preset time period. If not, the cloud analyzes 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 capacity to be balanced corresponding to each target battery cell to be balanced, and generates a second type of battery balancing task triggered by the cloud.

[0048] 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.

[0049] Optionally, the first execution module is specifically configured to:

[0050] If the condition is met, it is determined whether each battery cell of each battery to be balanced meets a first preset battery cell balancing condition.

[0051] 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.

[0052] The battery cell is subjected to single battery cell balancing processing according to the capacity to be balanced until a first single battery cell balancing stop condition is met.

[0053] Optionally, the first single cell equalization stop condition comprises at least one of the following:

[0054] 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;

[0055] The temperature of the maximum temperature cell among all cells included in the battery is greater than a preset temperature value;

[0056] The cell occurs a preset fault.

[0057] Optionally, the second execution module is specifically configured to:

[0058] In a case where the battery equalization task sent by the cloud is received, it is judged whether the battery satisfies a passive equalization start condition;

[0059] If yes, it is judged whether each cell in the battery satisfies a second preset cell equalization condition;

[0060] An equalization process for the cell satisfying the second preset cell equalization condition is started, and a cell equalization operation is performed according to the to-be-equalized capacity of the cell corresponding to the battery equalization task sent by the cloud.

[0061] Optionally, the switching module is further configured to:

[0062] After it is judged whether the local battery equalization condition is satisfied in the process of executing the battery equalization task sent by the cloud, it is judged whether the second single cell equalization stop condition and the cell discharging process suspension condition are satisfied in a case where the local battery equalization condition is not satisfied;

[0063] If yes, it is judged whether the cell satisfies a cell equalization end condition;

[0064] If the cell equalization end condition is satisfied, the equalization operation for the cell is ended; if the cell equalization end condition is not satisfied, the operation 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.

[0065] The embodiment of the application further 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 equalization method process based on cloud edge collaboration and periodic hierarchical control.

[0066] The battery equalization scheme based on cloud edge collaboration and periodic hierarchical control disclosed by the embodiment of the application comprises the following steps: The battery equalization scheme based on cloud edge collaboration and periodic hierarchical control, on the one hand, can realize hierarchical collaborative control with edge as the main part and cloud as the auxiliary part in the system structure; on the second aspect, in terms of strategy, the periodic hierarchical triggering mechanism is combined to carry out targeted equalization control for available capacity recovery and voltage consistency respectively; on the third aspect, the response speed, equalization efficiency and long-term stability of the battery system can be improved, and the communication pressure and cloud computing load can be reduced. BRIEF DESCRIPTION OF DRAWINGS

[0067] Figure 1 is a step flow chart representing a battery equalization method based on cloud edge collaboration and periodic hierarchical control according to an embodiment of the application;

[0068] Figure 2 is a step flow chart representing a cloud end determining a target battery cell to be equalized according to an embodiment of the application;

[0069] Figure 3 is a structural schematic diagram of a battery equalization device based on cloud edge collaboration and periodic hierarchical control according to an embodiment of the application. DETAILED DESCRIPTION

[0070] In order to make the technical problems, technical solutions and advantages of the application clearer, the following will be described in detail in combination with the drawings and specific embodiments.

[0071] The battery equalization method based on cloud edge collaboration and periodic hierarchical control according to the embodiment of the application will be described in detail in combination with the drawings, specific embodiments and application scenarios.

[0072] As shown in the accompanying Figure 1 The battery equalization method based on cloud edge collaboration and periodic hierarchical control according to the embodiment of the application comprises the following steps:

[0073] Step 101: The board end monitors whether each battery satisfies the local battery equalization condition in real time; if yes, step 102 is executed; if not, step 103 is executed.

[0074] The battery equalization method based on cloud edge cooperation and periodic hierarchical control provided by the embodiment of the application is applied to a battery management system including a cloud end and a board end. The battery equalization method process is executed by the board end. In the method, the board end can actively trigger local battery equalization, and the board end can passively accept the battery equalization task of the cloud end to perform the battery equalization operation.

[0075] In an optional embodiment, the local battery equalization condition includes that the residual capacity of the cell with the largest residual capacity in the battery is greater than a preset percentage; the voltage difference between the cell with the largest voltage and the 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 a wake-up state.

[0076] It should be noted that the local battery equalization condition can include at least one of the three conditions listed above. More preferably, to ensure the accuracy of the battery equalization judgment, it is determined that the battery satisfies the battery equalization condition only when the above three conditions are satisfied at the same time.

[0077] The preset percentage and the first preset voltage value can be flexibly set by a person skilled in the art, and the embodiment of the application does not make specific limitations thereon. For example, the preset percentage is set to 90%, 95% or 85%, and the first preset voltage value is set to 10 mv, 12 mv or 15 mv.

[0078] Step 102: If yes, a local battery equalization process is performed.

[0079] In an optional embodiment, if yes, performing the local battery equalization process includes the following sub-steps:

[0080] Sub-step 1: If yes, for each cell of each battery to be equalized, it is determined whether the cell satisfies a first preset cell equalization condition.

[0081] The first preset cell equalization condition can be set to that the voltage difference between the current cell voltage and the voltage of the cell with the smallest voltage is less than a preset value, for example, the preset value can be set to 20 mv; and the SOC difference between the SOC of the current cell and the SOC of the cell with the smallest SOC is greater than a preset percentage, for example, the preset percentage can be set to 4%.

[0082] In actual implementation, it is necessary to determine whether each cell in the battery to be equalized satisfies the first preset cell equalization condition, so as to screen out the cells that need to be equalized.

[0083] Sub-step 2: If yes, the equalization capacity corresponding to the cell is calculated according to the voltage corresponding to the cell.

[0084] In an optional embodiment, when calculating the to-be-balanced capacity corresponding to the voltage of the battery cell, the SOC corresponding to the voltage of the battery cell can be determined based on the SOC-OCV table, and the rated capacity can be calculated based on the SOC and a preset rated capacity calculation formula. The capacity balancing limit can be set as the smaller one of the rated capacity x 4% or 3 Ah converted in time.

[0085] Sub-step 3: According to the to-be-balanced capacity, the battery cell is subjected to single-cell balancing processing until the first single-cell balancing stop condition is met and the processing is terminated.

[0086] In a feasible manner, the first single-cell balancing stop condition includes at least one of the following:

[0087] The voltage value of the minimum voltage battery cell among all battery cells included 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 included in the battery is greater than a preset temperature value; the battery cell has a preset fault.

[0088] The second preset voltage value can be set by a person skilled in the art according to actual needs, for example, it can be set to 2.7v, and when the voltage value of the minimum voltage battery cell is greater than 2.8v, the balancing will be resumed. The preset temperature value can also be set by a person skilled in the art according to actual needs, for example, it can be set to 60℃, and when it is less than 58℃, the balancing will be resumed. The preset fault can be fault elimination.

[0089] The first single-cell balancing stop condition can be set as: the balancing time is 0.

[0090] If the local battery balancing condition is met, the local battery balancing process is performed, and if it is not met, the battery balancing task sent by the cloud is executed.

[0091] Step 103: If it is not met, it is determined whether the battery balancing task sent by the cloud is received.

[0092] The battery balancing task carries the target to-be-balanced battery cell identifier and the to-be-balanced capacity corresponding to each target to-be-balanced battery cell. The cloud executes the short-period cloud triggering mechanism and the long-period balancing strategy compensation, the cloud selects the to-be-balanced target battery cell and reports it to the board, and the balancing operation is executed by the local end. Taking two to-be-balanced battery cells in the battery balancing task sent by the cloud as an example, the electrical signals of the two to-be-balanced battery cells are 1 and 34, and the to-be-balanced capacities of the two to-be-balanced battery cells are 5 and 1 respectively.

[0093] Short-period cloud triggering mechanism: 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 to-be-balanced battery cells and the to-be-balanced capacities corresponding to the target to-be-balanced battery cells, and generates a first type of battery balancing task triggered by the cloud.

[0094] One feasible implementation manner is that the cloud platform periodically analyzes the uploaded battery operation data every 7 days, identifies 3-5 target battery cells that need to be balanced and their to-be-balanced capacities according to the short-term voltage deviation and capacity distribution results. The cloud sends the corresponding battery balancing task to the corresponding BMS board end. The BMS board end starts the passive balancing process according to the received short-period balancing task, and sets a dynamic voltage threshold to realize the over-balancing protection mechanism.

[0095] Long-period balancing strategy compensation: the cloud judges 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 the to-be-balanced capacities corresponding to each target battery cell to be balanced, and generates a second type of battery balancing task triggered by the cloud.

[0096] One feasible implementation manner is that the cloud platform evaluates whether BMS board balancing behavior has occurred in the past period every 30 days: if no valid board balancing 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 will actively issue a long-period balancing task, specify 100 battery cells that need to be balanced (i.e., target battery cells to be balanced) and target capacities (i.e., to-be-balanced capacities), and forcibly trigger the board passive balancing process, which is still executed by the board and uses a dynamic voltage threshold for protection.

[0097] 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 present application does 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.

[0098] It should be noted that during the execution of the battery balancing task issued by the cloud, as soon as the BMS board locally judges that the balancing condition is triggered (i.e., the board local strategy logic is met), the system immediately suspends the execution of the cloud task and transfers the balancing process to the board control to ensure timely response, reasonable resource allocation, and avoid strategy conflicts caused by redundant balancing or communication delay.

[0099] Step 104: executing the battery balancing task sent by the cloud in the case of receiving the battery balancing task sent by the cloud.

[0100] In an optional 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:

[0101] Sub-step 1: In the case of receiving the battery balancing task sent by the cloud, it is judged whether the passive balancing starting condition is met; if met, sub-step 2 is executed, and if not met, sub-step 1 is repeatedly executed for judgment.

[0102] An exemplary passive balancing starting condition of a single battery can be set as: the SOC of the cell with the minimum SOC in the battery is greater than or equal to 20%, and the battery is in a 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.

[0103] Sub-step 2: If met, it is judged whether each cell in the battery meets the second preset cell balancing condition.

[0104] 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 thereon.

[0105] Sub-step 3: Start the balancing process of the cell meeting the second preset cell balancing condition, and perform cell balancing operation according to the cell corresponding to the balancing capacity sent by the cloud.

[0106] Step 105: In the process of executing the battery balancing task sent by the cloud, it is judged whether the local battery balancing condition is met.

[0107] In the case of meeting the local battery balancing condition, step 106 is executed; in the case of not meeting the local battery balancing condition, the battery balancing task sent by the cloud is continuously executed.

[0108] 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:

[0109] Step 1: In the case of not meeting the local battery balancing condition, it is judged whether the second single cell balancing stop condition and the cell discharging process suspension condition are met.

[0110] In an exemplary embodiment, the second single cell balancing stop condition can be set to meet any of the following conditions:

[0111] 1) The voltage value of the minimum voltage cell in the battery is less than or equal to 2.7v, and if greater than 2.8v, the balancing is resumed; 2) The temperature value of the cell with the highest temperature in the battery is higher than 60℃, and if lower than 55.8℃, the balancing is resumed; 3) The cell occurs a preset fault; 4) The discharge stage threshold limit is met.

[0112] In an exemplary embodiment, the cell discharging process suspension condition can be set to meet any of the following conditions:

[0113] 1) the cell current < 50A, the voltage less than 8mv; 2) the cell current between 50A-200A, the voltage less than 10mv; 3) the cell current between 200A-300A, the voltage less than 15mv; 4) the cell current greater than 300A, the voltage less than 20mv.

[0114] Step 2: if yes, determine whether the cell satisfies the cell equalization end condition;

[0115] In the actual implementation process, the cell equalization end condition can be flexibly set by those skilled in the art, and the present application embodiment does not make specific limitation on this.

[0116] In an optional embodiment, the cell equalization end condition can be set to satisfy any one of the following conditions:

[0117] 1) the equalization time is 0;

[0118] 2) the cell is in the charging stage: 0-25% and 90-100%: less than 20mv; or, 25-90%: less than 15mv;

[0119] 3) the static threshold satisfies: the voltage difference between the current cell monomer and the minimum voltage cell in the battery is less than 8mv.

[0120] In the case of satisfying any one of the above three conditions, it is determined that the cell equalization end condition is satisfied.

[0121] Step 3: if the cell equalization end condition is satisfied, the equalization operation of the cell is ended; if the cell equalization end condition is not satisfied, return to execute the step of determining whether the local battery equalization condition is satisfied in the process of executing the battery equalization task sent by the cloud, that is, return to execute step 105.

[0122] Step 106: under the condition that the local battery equalization condition is satisfied, switch to the local battery equalization process.

[0123] Switching to the local battery equalization process means executing step 102 after switching.

[0124] The battery balancing scheme based on cloud edge collaboration and periodic hierarchical control provided by the embodiments of the present application can realize hierarchical collaborative control with the edge end as the main part and the cloud end as the auxiliary part in the system structure. On the second aspect, the periodic hierarchical triggering mechanism is combined in the strategy, and the available capacity recovery and voltage consistency are balanced respectively. On the third aspect, the response speed, balancing efficiency and long-term stability of the battery system can be improved, and the communication pressure and cloud computing load can be reduced.

[0125] Figure 2 A step flowchart for determining the target battery cell to be balanced by the cloud end according to an embodiment of the present application is provided.

[0126] When the cloud end executes the short-period cloud triggering mechanism or the long-period balancing strategy compensation, the cloud end determines the target battery cell to be balanced according to the method shown in Figure 2 The cloud end determines the target battery cell to be balanced according to the method shown in

[0127] As shown in the accompanying Figure 2 The method for determining the target battery cell to be balanced by the cloud end according to an embodiment of the present application includes the following steps:

[0128] Step 201: In the case that no battery balancing occurs within a first preset time period and there are at least a first preset number of full charging segments in a single battery, the length of the rest segment corresponding to the full charging segment is determined.

[0129] Steps 201 to 203 are the process of modeling based on the short-term historical data within the first preset time period, and selecting the battery cell to be balanced based on the built model. The specific value of the first preset time period can be set by the person skilled in the art according to the actual demand, and the embodiments of the present application do not make specific limitations thereon. For example, the first preset time period can be set to 7 days, 10 days or 5 days, etc. The first preset number can be set to 3, 4 or 5, etc.

[0130] A feasible criterion for judging whether a full-charge segment is present can be set as: the SOC of the battery at the beginning of charging is less than or equal to 60%, and the SOC of the battery after the end of charging is equal to 100%, wherein the SOC is the percentage of the current remaining capacity of the battery. It should be noted that the above is only an example of a criterion for judging whether a full-charge segment is present, and in actual implementation, it is not limited thereto,

[0131] Step 202: Determine the selection strategy for the battery cells to be balanced according to the length of the static segment.

[0132] In actual implementation, different lengths of static segments correspond to different selection strategies for the battery cells to be balanced. At least two selection strategies are preset in the system, and the target selection strategy is selected from the preset selection strategies in the system according to the length of the static segment to select the battery cells to be balanced.

[0133] In a feasible implementation, the length of the static segment is compared with a preset length in the system, and if it is less than the preset length, selection strategy one is adopted, and if it is greater than or equal to the preset length, selection strategy two is adopted. The preset length can be set to 30 min, 35 min, or 40 min, etc., which is not specifically limited in the embodiments of the present application.

[0134] Step 203: Select the battery cells to be balanced according to the selection strategy for the battery cells to be balanced and the terminal voltage change data of at least one full-charge segment.

[0135] An optional process for selecting the battery cells to be balanced according to the selection strategy for the battery cells to be balanced and the terminal voltage change data of at least one full-charge segment includes the following sub-steps:

[0136] Sub-step 1: In the case where the length of the static segment is less than the preset length, for each full-charge segment within a first preset time period, the second preset number of battery cells and the corresponding capacity to be balanced for each battery cell are selected according to the terminal voltage change segment of the full-charge segment.

[0137] 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.

[0138] In specific implementation, the total current and single battery cell voltage information contained in the terminal voltage change segment of each full-charge segment in the past 7 days can be used to select the top 5 battery cells to be balanced and calculate the corresponding capacity to be balanced. Each full-charge segment corresponds to a top 5 battery cell to be balanced, and n full-charge segments correspond to n top 5 battery cells.

[0139] Sub-step 2: Compare the second preset number of battery cells corresponding to each full-charge segment to select the second preset number of first battery cells.

[0140] In the implementation process, for the TOP5 battery cells corresponding to the plurality of full-charge segments screened, a unique TOP5 battery cell and a to-be-balanced capacity of the TOP5 battery cell can be output by comparison and judgment.

[0141] Substep 3: For the single-cell voltage interrupted in each full-charge segment in the first preset time period, a white list of balanceable battery cells is screened out.

[0142] The full-charge segment middle segment is a charging segment with a battery SOC of 40%-70%. The specific rules for screening the white list of battery cells can be flexibly set by those skilled in the art, and the embodiments of the present application do not make specific limitations thereon.

[0143] Substep 4: The intersection of the first battery cells of the second preset number and the battery cells in the white list of balanceable battery cells is determined as the to-be-balanced battery cells.

[0144] This optional method for determining the to-be-balanced battery cells is more accurate.

[0145] In another optional embodiment, according to the to-be-balanced battery cell screening strategy and the terminal voltage change data of at least one full-charge segment, the process of screening the to-be-balanced battery cells includes the following substeps:

[0146] Substep 1: In the case where the length of the static segment is greater than or equal to a preset length, for the total current and single-cell voltage at the end of the full-charge segment of the most recent static segment of the battery, a third preset number of battery cells and the to-be-balanced capacity corresponding to each battery cell are screened out.

[0147] The third preset number and the second preset number can be equal or not equal.

[0148] In actual implementation, the to-be-balanced battery cells TOP5 can be screened out according to the total current and single-cell voltage at the end of the full-charge segment of the most recent static segment of the battery, and the to-be-balanced capacity corresponding to each battery cell in the to-be-balanced battery cells TOP5 is calculated.

[0149] Substep 2: For the most recent static segment of the battery, the single-cell voltage contained in the static segment is analyzed to identify abnormal battery cells.

[0150] In the implementation process, the Isolation Forest algorithm can be used to identify abnormal battery cells. Of course, it is not limited thereto, and other adaptive algorithms can also be used for abnormal battery cell identification, and the embodiments of the present application do not make specific limitations thereon.

[0151] Substep 3: The intersection of the third preset number of battery cells and the abnormal battery cells is determined as the to-be-balanced battery cells.

[0152] This optional method for screening the to-be-balanced battery cells has small calculation amount in the screening process and accurate screening result.

[0153] Step 204: determining the black list of the battery cells based on the discharge history data of each battery cell in the battery within the second preset time period.

[0154] 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 application embodiment does not make specific limitations thereon. For example, the second preset time period can be set to 2 months, 1 month or 3 months, etc. In actual implementation process, the data corresponding to the discharge segment at the end of the discharge of each battery cell can be extracted for analysis, wherein the discharge segment at the end of the discharge is the segment with the SOC of the battery less than or equal to 15%.

[0155] In an optional embodiment, the way of determining the black list of the battery cells based on the discharge history data of each battery cell in the battery within the second preset time period can include the following sub-steps:

[0156] Sub-step 1: extracting the discharge segment at the end of the discharge of each battery cell in the battery within the second preset time period;

[0157] Sub-step 2: calculating the voltage ranking and voltage degradation trend of each battery cell after the end of the discharge;

[0158] Sub-step 3: determining the black list of the battery cells based on the voltage ranking and voltage degradation trend.

[0159] In actual implementation process, the battery cells with stable low or obvious degradation trend can be determined to form the black list of the battery cells.

[0160] Step 205: determining the target battery cells to be balanced as the difference set of the battery cells to be balanced and the black list of the battery cells.

[0161] After determining the battery cells to be balanced through step 203 and determining the black list of the battery cells through step 204, the battery cells to be balanced are screened again based on the black list of the battery cells, and finally the accurate target battery cells to be balanced are obtained.

[0162] After determining the target battery cells to be balanced, the battery balancing task can be generated according to the identification of the target battery cells to be balanced and the balancing capacity corresponding to each target battery cell to be balanced, and the generated battery balancing task is issued from the cloud to the board.

[0163] The method for determining the target battery cell provided in the embodiments of the present application determines the duration of the static segment corresponding to the full-charge segment when the battery balancing does not occur in the first preset time period and there are at least the first preset number of full-charge segments; determines the cell screening strategy according to the duration of the static segment; screens the target battery cell according to the cell screening strategy and the terminal voltage change data of at least one full-charge segment; determines the cell blacklist based on the discharge history data of each cell in the battery in the second preset time period; and determines the target battery cell as the difference set of the target battery cell and the cell blacklist. The method uses the isolation forest algorithm to screen the target cell, updates the list in real time in combination with the short-period data, and only needs to intervene in a few cells on average each time balancing iteration, thereby significantly reducing the number of invalid operations. In the second aspect, the irreversible abnormal cell is actively excluded from participating in balancing by establishing a cell blacklist mechanism, thereby avoiding energy waste and excessive interference behavior.

[0164] Figure 3 To realize the structure block diagram of the battery balancing device based on cloud edge collaboration and periodic hierarchical control in the embodiments of the present application.

[0165] The battery balancing device based on cloud edge collaboration and periodic hierarchical control provided in the embodiments of the present application is deployed at the board end of the battery management system including the cloud end and the board end, and the device includes the following functional modules.

[0166] The monitoring module 301 is configured to monitor whether each battery satisfies the local battery balancing condition in real time.

[0167] The first execution module 302 is configured to execute the local battery balancing process if the condition is satisfied.

[0168] The determination module 303 is configured to determine whether the battery balancing task sent by the cloud end is received if the condition is not satisfied, wherein the battery balancing task carries the target battery cell identifier and the target balancing capacity corresponding to each target battery cell.

[0169] The second execution module 304 is configured to execute the battery balancing task sent by the cloud end if the battery balancing task sent by the cloud end is received.

[0170] The switching module 305 is configured to determine whether the local battery balancing condition is satisfied in the process of executing the battery balancing task sent by the cloud end, and switches to the local battery balancing process if the local battery balancing condition is satisfied.

[0171] Optionally, the local battery balancing condition includes:

[0172] The residual capacity of the cell with the largest residual capacity in the battery is greater than a preset percentage;

[0173] 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.

[0174] 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 cells to be balanced and a target capacity corresponding to each of the target cells to be balanced, and generates a first type of battery balancing task triggered by the cloud;

[0175] 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 cells to be balanced and a target capacity corresponding to each of the target cells to be balanced, and generates a second type of battery balancing task triggered by the cloud;

[0176] 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.

[0177] Optionally, the first execution module is specifically configured to:

[0178] 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;

[0179] If the condition is met, the target capacity corresponding to the cell is calculated according to the voltage of the cell;

[0180] According to the target capacity, the cell is subjected to single-cell balancing processing until a first single-cell balancing stop condition is met.

[0181] Optionally, the first single-cell balancing stop condition includes at least one of the following:

[0182] 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;

[0183] The temperature of the maximum temperature cell among all cells included in the battery is greater than a preset temperature value;

[0184] The cell has a preset fault.

[0185] Optionally, the second execution module is specifically configured to:

[0186] In the case of receiving a battery balancing task sent by the cloud, it is determined whether the battery meets a passive balancing start condition;

[0187] If the condition is met, it is determined whether each cell in the battery meets a second preset cell balancing condition;

[0188] 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.

[0189] Optionally, the switching module is further configured to:

[0190] 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.

[0191] If satisfied, determine whether the cell meets the cell balancing termination condition;

[0192] 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 operation of determining whether the local battery balancing condition is met during the execution of the battery balancing task sent from the cloud.

[0193] The battery balancing device 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 determines whether the local battery balancing conditions are met. If the local battery balancing conditions are met, it switches to the local battery balancing process. This battery balancing device based on cloud-edge collaboration and periodic hierarchical control can, on the one hand, achieve hierarchical collaborative control with the edge as the main component and the cloud as the auxiliary component in the system structure; on the other hand, it combines a periodic hierarchical triggering mechanism to perform targeted balancing control for available capacity recovery and voltage consistency; and on the third hand, it can improve the response speed, balancing efficiency, and long-term stability of the battery system, while reducing communication pressure and cloud computing load.

[0194] The embodiments provided in this application Figure 3 The battery balancing device shown, based on cloud-edge collaboration and periodic hierarchical control, can achieve... Figure 1 The various processes implemented in the method implementation examples will not be described again here to avoid repetition.

[0195] This invention also provides an electronic device, which serves as the board of a battery management system, including 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.

[0196] Memory, used to store computer programs;

[0197] The processor is configured to implement the cloud edge collaboration and periodic hierarchical control based battery equalization method shown in the above method embodiments when executing the program stored in the memory.

[0198] The communication bus of the terminal 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 only one type of bus.

[0199] The communication interface is configured to communicate between the terminal and other devices.

[0200] 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.

[0201] In another embodiment provided by the application, a computer readable storage medium is also provided, and the computer readable storage medium stores instructions, and when the instructions are executed on an electronic device, the electronic device implements the cloud edge collaboration and periodic hierarchical control based battery equalization method in any of the above embodiments.

[0202] In another embodiment provided by the application, a computer program product containing instructions is also provided, and when the instructions are executed on an electronic device, the electronic device implements the cloud edge collaboration and periodic hierarchical control based battery equalization method in any of the above embodiments.

[0203] 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 another identical element in the process, method, article or apparatus including the element.

[0204] 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 described in the present application, can also make several improvements and refinements, these improvements and refinements should also be considered as the scope of protection of the present application.

Claims

1. A battery equalization method based on cloud-edge collaboration and periodic hierarchical control, applied to a battery management system comprising a cloud and a board, characterized in that, The method comprises: The plate end monitors whether each battery meets the local battery balancing condition in real time; If yes, a local battery balancing process is performed; If no, 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 performed in the case of receiving the battery balancing task sent by the cloud; In the process of performing the battery balancing task sent by the cloud, it is determined whether the local battery balancing condition is met; and the local battery balancing process is switched to when the local battery balancing condition is met; The cloud analyzes battery operation data uploaded by the plate 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, and if not, analyzes battery operation data uploaded by the plate end within the second preset time period, identifies 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 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. If yes, it is determined whether each battery cell of each battery to be balanced meets a first preset battery cell balancing condition; If yes, the capacity to be balanced corresponding to the battery cell is calculated according to the voltage of the battery cell; The battery cell is subjected to single battery cell balancing treatment according to the capacity to be balanced until a first single battery cell balancing stop condition is met and terminated. The first single battery cell balancing stop condition comprises 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. The local battery balancing condition comprises:

2. The method of claim 1, wherein, 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 maximum voltage battery cell and the minimum voltage battery cell in the battery is less than or equal to a first preset voltage value; the battery is at rest for a preset time period, and the battery management system is in an awake state. In the case of receiving the battery balancing task sent by the cloud, the battery balancing task sent by the cloud is performed.

3. The method of claim 1, wherein, If yes, 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 meeting the second preset battery cell balancing condition is started, and the battery cell balancing operation is performed according to the capacity to be balanced corresponding to the battery cell sent by the cloud. After the step of determining whether the local battery balancing condition is met in the process of performing the battery balancing task sent by the cloud, the method further comprises: ​ 4. The method of claim 1, wherein, ​ If the local battery balancing condition is not met, it is determined whether a second single-cell balancing stop condition and a cell discharging process suspension condition are met; If the second single-cell balancing stop condition is met, it is determined whether the cell meets a 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 step 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.

5. A battery equalization device based on cloud-edge collaboration and periodic hierarchical control, the device is deployed at the board end of the battery management system containing the cloud end and the board end, characterized in that, The device comprises: A monitoring module for monitoring whether each battery meets a local battery balancing condition in real time; A first execution module for executing a local battery balancing process if the local battery balancing condition is met; A determination module for determining whether a battery balancing task sent by the cloud is received if the local battery balancing condition is not met, wherein the battery balancing task carries a target cell to be balanced identifier and a capacity to be balanced corresponding to each target cell to be balanced; A second execution module for executing the battery balancing task sent by the cloud if the battery balancing task sent by the cloud is received; A switching module for determining whether the local battery balancing condition is met in the process of executing the battery balancing task sent by the cloud; and switching to the local battery balancing process if the local battery balancing condition is met. 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 cells to be balanced and a 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 occurs in the battery management system within a second preset time period, and if not, 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 capacity to be balanced corresponding to each target 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; The first execution module is specifically configured to: if the first preset cell balancing condition is met, it is determined whether the cell meets the first preset cell balancing condition for each cell of each battery to be balanced; if the first preset cell balancing condition is met, the capacity to be balanced corresponding to the cell is calculated according to the voltage of the cell; and the single-cell balancing process is performed on the cell according to the capacity to be balanced until the first single-cell balancing stop condition is met. The first single-cell balancing stop condition comprises 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.

6. The apparatus of claim 5, wherein, The local battery balancing condition comprises: The remaining capacity of the cell with the most remaining 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 period, and the battery management system is in an awake state.

7. The apparatus of claim 5, wherein, The second execution module is specifically configured to: In a case that the battery equalization task sent by the cloud is received, it is judged whether the battery satisfies a passive equalization starting condition; If yes, it is judged whether each cell in the battery satisfies a second preset cell equalization condition; An equalization process of the cell satisfying the second preset cell equalization condition is started, and a cell equalization operation is performed according to the to-be-equalized capacity corresponding to the cell sent by the cloud.

8. The apparatus of claim 5, wherein, The switching module is further configured to: After judging whether the local battery equalization condition is satisfied in the process of executing the battery equalization task sent by the cloud, it is judged whether a second single-cell equalization stopping condition and a cell discharging process suspension condition are satisfied in a case that the local battery equalization condition is not satisfied; If yes, it is judged whether the cell satisfies a cell equalization ending condition; If the cell equalization ending condition is satisfied, the equalization operation of the cell is ended; If the cell equalization ending condition is not satisfied, the operation 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.

9. An electronic device, comprising: The device comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are in communication with each other through the communication bus; The memory is used for storing a computer program; The processor is used for executing the program stored on the memory, and realizes the battery equalization method based on cloud-edge collaboration and periodic hierarchical control according to any one of claims 1-4.

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