Electric quantity balancing method and device, computer equipment and storage medium

Abstract

The invention relates to an electric quantity balancing method and device, computer equipment, a storage medium and a computer program product. The method comprises the following steps: acquiring a plurality of working condition judgment events in a first time period; determining a target working condition judgment event in the multiple working condition judgment events; determining an equilibrium alignment point of a second time period according to the operation condition indicated by the target condition judgment event; the first time period belongs to a historical time period of the second time period; and based on the triggering condition of the equalization event corresponding to the equalization alignment point, executing an electric quantity equalization strategy corresponding to the operation condition. By adopting the method, the equalization alignment point and the equalization event can be adaptively adjusted according to the target working condition judgment event, so that the electric quantity of each battery cell is accurately adjusted, and the electric quantity of each battery cell is more equalized.

Description

[0001] This application is a divisional application of the Chinese patent application with application number 202311054887.8, application date August 22, 2023, and invention name "Power Balancing Method, Device, Computer Equipment and Storage Medium", all contents of which are incorporated by reference in this application. Technical Field

[0002] The present application relates to the technical field of electric energy storage, and in particular to a power balancing method, apparatus, computer equipment, storage medium and computer program product. Background Art

[0003] For a battery pack with multiple cells, there is a deviation in the voltage of each cell, and this deviation causes a certain cell to be overcharged or over-discharged. In traditional technology, the balancing methods used to deal with this situation include active balancing and passive balancing. Passive balancing is low in cost and simple to implement, so it is widely used in electric vehicles, energy storage and other fields. The traditional passive balancing strategy defines the balance alignment point power state as 100%, so that when the battery pack power state is 100%, the power of each cell is controlled to be balanced.

[0004] However, if the state of charge of the battery pack during operation is lower than the state of charge of the balancing point for a long time, it will be difficult to accurately control the balance of charge of each battery cell, and over-balancing or under-balancing may occur easily. Summary of the invention

[0005] Based on this, it is necessary to provide a more accurate power balancing method, apparatus, computer device, computer readable storage medium and computer program product for the above technical problems.

[0006] In a first aspect, the present application provides a power balancing method. The method comprises:

[0007] A power balancing method, the method comprising:

[0008] Acquire multiple operating condition determination events in a first time period;

[0009] determining a target operating condition determination event among the plurality of operating condition determination events;

[0010] Determining a balance alignment point of a second time period according to the operating condition indicated by the target operating condition determination event; the first time period belongs to a historical time period of the second time period;

[0011] Based on the triggering condition of the balancing event corresponding to the balancing alignment point, the power balancing strategy corresponding to the operating condition is executed.

[0012] In one embodiment, the multiple operating condition determination events include a small current full charging event, a low power state static event, and a platform area constant current charging event for operating condition determination; the multiple operating condition determination events in the first time period are obtained, including:

[0013] Determining the small current full charging event occurring in the first time period according to the charging current value and the battery cell power state that satisfy the small current full charging event condition; and / or,

[0014] Determining the low-battery state standstill event occurring in the first time period according to the standstill time of the battery cell and the battery state of the battery cell that meet the low-battery state standstill event condition; and / or,

[0015] The platform area constant current charging event occurring in the first time period is determined according to the relative change rate between the voltage and the cell power that meets the platform area constant current charging condition, the charging current stability, and the charging current value.

[0016] In one embodiment, determining the platform area constant current charging event occurring in the first time period according to the relative change rate between the voltage and the cell power that meets the platform area constant current charging condition, the charging current stability, and the charging current value includes:

[0017] When the charging current satisfies the constant current condition and the charging current value satisfies the current threshold condition, determining the relative change rate between the voltage and the battery cell charge;

[0018] When the relative change rate is a change rate threshold value in the first time period, the platform region constant current charging event occurring in the first time period is determined according to the change rate threshold value.

[0019] In one embodiment, determining the equilibrium alignment point of the second time period according to the operating condition indicated by the target operating condition determination event includes:

[0020] If the operating condition is the full charge condition indicated by the small current full charge event, determining the balancing alignment point to be the full value of the battery cell power state;

[0021] If the operating condition is a low-battery-state static condition indicated by the low-battery-state static event, determining the balancing alignment point to be a cell battery state empty value;

[0022] If the operating condition is the platform area operating condition indicated by the platform area constant current charging event, the equilibrium alignment point is determined to be the relative change rate between the voltage and the battery cell charge, and the relative change rate reaches the change rate critical value in the first time period.

[0023] In one embodiment, determining a target operating condition determination event among the multiple operating condition determination events includes:

[0024] Determining the triggering times of the multiple operating condition determination events;

[0025] If one of the first target operating condition determination events is acquired, the first target operating condition determination event is a target operating condition determination event among the multiple operating condition determination events;

[0026] If multiple first target operating condition determination events are obtained, then according to the priorities of the multiple operating condition determination events, a second target operating condition determination event is determined from the multiple first target operating condition determination events with the same event triggering number, and the second target operating condition determination event is a target operating condition determination event among the multiple operating condition determination events.

[0027] In one of the embodiments, executing the power balancing strategy corresponding to the operating condition based on the triggering condition of the balancing event corresponding to the balancing alignment point includes:

[0028] If the balancing event corresponding to the balancing alignment point is triggered, the amount of electricity to be balanced of each battery cell is determined according to the balancing electricity calculation method under the operating condition;

[0029] Determine the time required for equalization of the amount of electricity to be equalized; the time required for equalization of the amount of electricity is the time required for release of the passive balancing current;

[0030] Passive power balancing is performed according to the time required for power balancing.

[0031] In one of the embodiments, the balancing event is a small current full charge event under a full charge condition, and the small current full charge event is triggered when the charging current value and the battery cell power meet the small current full charge event condition; or, the balancing event is a low power state static event under a low power state static condition, and the low power state static event is triggered when the battery cell static time and the battery cell power meet the low power state static event condition;

[0032] The step of determining the amount of electricity to be balanced of each battery cell according to the balanced electricity calculation method under the operating condition includes:

[0033] Under the full charge condition or the low power state static condition, obtaining the power state of each battery cell and the minimum power state of the battery cell of the battery pack;

[0034] Determining a state of charge difference between the state of charge and a minimum state of charge of the battery cell;

[0035] If the state of charge difference is not in the over-balanced state of charge interval, converting the state of charge difference into the to-be-balanced power of each of the cells through the minimum discharge capacity of the cells of the battery pack;

[0036] If the state of charge difference is in the over-balanced state of charge interval, there is no amount of power to be balanced in the battery cells.

[0037] In one of the embodiments, the balancing event is a platform area constant current charging event under the platform area operating condition, and the platform area constant current charging event is triggered when the relative change rate between the voltage and the battery cell power, the charging current stability, and the charging current value meet the platform area constant current charging conditions;

[0038] The step of determining the amount of electricity to be balanced of each battery cell according to the balanced electricity calculation method under the operating condition includes:

[0039] Under the platform area operating condition, determining the battery pack power of each battery cell when the constant current charging condition of the platform area is met, and the maximum value of the battery pack power of each battery cell when the constant current charging condition of the platform area is met;

[0040] Determine the difference between the maximum value of the battery pack power and the power of the battery pack;

[0041] If the power difference is not in the over-balanced power interval, the power difference is the power to be balanced of each of the battery cells;

[0042] If the power difference is in the over-balancing power interval, there is no power to be balanced in each of the battery cells.

[0043] In one of the embodiments, before executing the power balancing strategy corresponding to the operating condition based on the triggering condition of the balancing event corresponding to the balancing alignment point, the method includes:

[0044] According to the hardware design information and the balancing duty cycle, the start and stop states of the power balancing process are controlled; the start and stop states are the on states.

[0045] In one of the embodiments, after executing the power balancing strategy corresponding to the operating condition, the method further includes:

[0046] If the time required for power balancing is less than the duration of each power balancing process being in the on state, the time required for power balancing is cleared to stop executing the next round of the steps of the power balancing method; the time required for power balancing is obtained by executing the power balancing strategy corresponding to the operating condition;

[0047] If the operating condition does not belong to the platform area operating condition, and the cell voltage of the battery pack and the minimum cell voltage are within a preset difference range, the time required for power balancing is cleared to stop executing the next round of the power balancing method.

[0048] In a second aspect, the present application also provides a power balancing device. The device includes:

[0049] An event acquisition module, used to acquire multiple working condition determination events in a first time period;

[0050] A target event determination module, used to determine a target operating condition determination event among the multiple operating condition determination events;

[0051] an alignment point determination module, configured to determine a balanced alignment point of a second time period according to the operating condition indicated by the target operating condition determination event; the first time period being a historical time period of the second time period;

[0052] The balancing execution module is used to execute the power balancing strategy corresponding to the operating condition based on the triggering condition of the balancing event corresponding to the balancing alignment point.

[0053] In a third aspect, the present application further provides a computer device, wherein the computer device comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of power balancing in any of the above embodiments are implemented.

[0054] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of power balancing in any of the above embodiments are implemented.

[0055] In a fifth aspect, the present application further provides a computer program product, wherein the computer program product includes a computer program, and when the computer program is executed by a processor, the steps of power balancing in any of the above embodiments are implemented.

[0056] The above-mentioned power balancing method, device, computer equipment, storage medium and computer program product obtain multiple operating condition determination events in a first time period, determine a target operating condition determination event among the multiple operating condition determination events, so as to achieve comprehensive consideration of multiple operating conditions in the first time period, determine the target operating condition determination event, and determine the balance alignment point of the second time period according to the operating condition indicated by the target operating condition determination event, and the first time period is a historical time period of the second time period, so that the balance alignment point can be adaptively adjusted according to the target operating condition determination event, so that the second time period can achieve the balance event corresponding to the balance alignment point; thereby, based on the triggering of the balance event corresponding to the balance alignment point, the power balancing strategy corresponding to the operating condition is executed to accurately adjust the power of each battery cell so that the power of each battery cell is more balanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] FIG1 is a diagram of an application environment of a power balancing method according to an embodiment;

[0058] FIG2 is a schematic diagram of a flow chart of a power balancing method in an embodiment;

[0059] Figure 3 A charging schematic diagram of a power balancing method in an embodiment;

[0060] Figure 4 A graph showing a relationship between a change rate and a charge amount of a power balancing method in another embodiment;

[0061] Figure 5 is a structural block diagram of a power balancing device in one embodiment;

[0062] Figure 6 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0064] The power balancing method provided in the embodiment of the present application can be applied in the application environment shown in FIG1 . Among them, the terminal 102 is equipped with a battery management system (Battery Management System, BMS) for monitoring, controlling and protecting the battery pack. Among them, the terminal 102 can be, but is not limited to, a variety of personal computers, including the battery management system itself, a laptop computer, a smart phone, a tablet computer, an Internet of Things device and a portable wearable device. The Internet of Things device can be a smart speaker, a smart TV, a smart air conditioner, a smart car device, etc. The portable wearable device can be a smart watch, a smart bracelet, a head-mounted device, etc.

[0065] In one embodiment, as shown in FIG. 2 , a power balancing method is provided, which is described by taking the method applied to the terminal 102 in FIG. 1 as an example, and includes the following steps:

[0066] Step 202: Acquire multiple operating condition determination events in a first time period.

[0067] The first time period is a time interval for counting the operating condition determination events. The first time period may have a time length determined by a start time and an end time, which is pre-set, and the start time and the end time may be dynamically adjusted. Specifically, the time length of the first time period is preset so that the amount of data of the operating condition determination events of the first time period is moderate, so that the operating conditions during the operation of the first time period can be reflected through a variety of operating condition determination events while occupying fewer resources; the starting time point of the first time period is dynamically updated so that the various operating condition determination events in the first time period can more accurately reflect the actual operating conditions of the first time period, and more accurately and adaptively adjust the operating conditions.

[0068] The operating condition determination event is triggered during the operation of the battery pack and is used to determine the operating condition triggered by the battery pack. Optionally, the operating condition determination event is triggered when the battery pack meets the event condition and is used to characterize a certain usage condition of the battery pack. Through multiple operating condition determination events, the usage condition of the battery pack can be comprehensively considered from multiple angles.

[0069] In one embodiment, obtaining multiple operating condition determination events in the first time period includes: detecting the battery pack according to the event conditions of various operating condition determination events respectively; determining the operating condition determination event triggered by the battery pack according to the event conditions met by the battery pack; and counting the operating condition determination events in the first time period respectively according to the types of the operating condition determination events to obtain multiple operating condition determination events occurring in the first time period. Thus, the various operating condition determination events occurring in the first time period are determined in real time to more accurately obtain the operating condition determination events occurring in the first time period, and the operating condition determination events in the first time period are counted respectively according to the types of the operating condition determination events, with a faster counting speed and less accuracy impact.

[0070] The event condition of each working condition determination event corresponds to each working condition determination event one by one. Therefore, the event condition corresponds to each working condition determination event one by one, and the triggering situation of the working condition determination event can be accurately determined by the event condition.

[0071] Optionally, multiple operating condition determination events in the first time period are obtained, including: obtaining operating condition determination events according to multiple categories; when there is only one operating condition determination event in the battery pack, one operating condition determination event is obtained; when there are only two operating condition determination events in the battery pack, two operating condition determination events are obtained; when there are multiple operating condition determination events in the battery pack, multiple operating condition determination events are obtained.

[0072] Step 204 : determining a target operating condition determination event among the multiple operating condition determination events.

[0073] The target operating condition determination event is one of multiple operating condition determination events, and this event is selected by comparing multiple operating condition determination events. Different types of operating condition determination events are used to determine different operating conditions, and the operating condition indicated by the target operating condition determination event is the operating condition used to determine the equilibrium alignment point in the second time period. Optionally, the target operating condition determination event can be determined by the number of triggering of multiple operating condition determination events, or according to the priority of multiple operating condition determination events, and can be determined based on the number of triggering and priority of multiple operating condition determination events.

[0074] In one embodiment, determining a target operating condition determination event among multiple operating condition determination events includes: separately counting the operating condition determination events occurring in a first time period to obtain parameter information of various operating condition determination events; and from the various operating condition determination events, determining the target operating condition determination event according to conditions met by the parameter information; wherein the parameter information includes at least one of the triggering count and priority of the operating condition determination event.

[0075] Step 206, determining the equilibrium alignment point of the second time period according to the operating condition indicated by the target condition determination event; the first time period belongs to the historical time period of the second time period.

[0076] The operating condition is used to determine the balanced alignment point achieved in the power balancing process in the second time period, so as to adaptively adjust the balanced alignment point. Optionally, the multiple operating condition determination events include a small current full charge event, a low power state static event, and a platform area constant current charging event for indicating different operating conditions, and the target operating condition determination event can be any one of the small current full charge event, the low power state static event, and the platform area constant current charging event.

[0077] The balance alignment point is a parameter implemented by executing the power balance strategy. The parameter is dynamically adjusted according to the operating conditions indicated by the target operating condition determination event so that the corresponding parameters of the battery pack can reach this balance alignment point in the second time period. Optionally, if the target operating condition determination event is a small current full charge event, a balance alignment point of the second time period is determined according to the operating conditions indicated by the small current full charge event; if the target operating condition determination event is a low power state static event, another balance alignment point of the second time period is determined according to the operating conditions indicated by the low power state static event; if the target operating condition determination event is a platform area constant current charging event, another balance alignment point of the second time period is determined according to the operating conditions indicated by the platform area constant current charging event.

[0078] The second time period is a time period in which the power balancing strategy can be executed, and the historical time period of the second time period includes the first time period. Optionally, the first time period and the second time period have the same time length, and the first time period is a time period before the second time period.

[0079] Optionally, the first time period is the time period before the second time period, so that the operating condition has a higher timeliness, thereby more accurately determining the equilibrium alignment point applicable to the second time period. For example, the second time period is the time period of the current month, and the first time period is the month before the current month.

[0080] In one embodiment, determining the equilibrium alignment point of the second time period according to the operating condition indicated by the target operating condition determination event includes: searching for the equilibrium alignment point of the second time period from the candidate equilibrium alignment points according to the operating condition indicated by the target operating condition determination event. Wherein, the operating condition indicated by the target operating condition determination event has an operating condition identifier, and the operating condition identifier can be compared with each candidate equilibrium alignment point to obtain an equilibrium alignment point consistent with the operating condition identifier; the equilibrium alignment point consistent with the operating condition identifier is the equilibrium alignment point of the second time period.

[0081] Step 208: Based on the triggering condition of the balancing event corresponding to the balancing alignment point, execute the power balancing strategy corresponding to the operating condition.

[0082] A balancing event is an event corresponding to a balancing alignment point. If the balancing event is triggered, the power balancing strategy corresponding to the operating condition is executed to balance the power of each battery cell. The goal of balancing the power of each battery cell is to make a certain parameter of each battery cell reach a balancing alignment point.

[0083] The triggering condition of the balancing event is the condition that the event condition of the balancing event is met. Optionally, when the battery pack meets the event condition of the balancing event, the power balancing strategy corresponding to the operating condition is executed so that the parameters of each battery cell match the corresponding balancing alignment point to achieve power balancing of each battery cell; when the battery pack does not meet the event condition of the balancing event, the power balancing strategy corresponding to the operating condition is not executed.

[0084] Optionally, the balancing event and the target operating condition determination event can be triggered based on the same event condition to reuse the event triggering condition of the target operating condition determination event to avoid the data of multiple event conditions occupying too many resources. The power balancing strategy is set according to different operating conditions; each operating condition has a corresponding power balancing strategy to make the parameters of each battery cell close to the balancing alignment point.

[0085] In the above-mentioned power balancing method, multiple operating condition determination events in the first time period are obtained, and the target operating condition determination event among the multiple operating condition determination events is determined to achieve comprehensive consideration of multiple operating conditions in the first time period, and the target operating condition determination event is determined. According to the operating condition indicated by the target operating condition determination event, the balance alignment point of the second time period is determined, and the first time period is a historical time period of the second time period, so that the balance alignment point can be adaptively adjusted according to the target operating condition determination event, so that the second time period can achieve the balance event corresponding to the balance alignment point; thereby, based on the triggering of the balance event corresponding to the balance alignment point, the power balancing strategy corresponding to the operating condition is executed to accurately adjust the power of each battery cell so that the power of each battery cell is more balanced.

[0086] In one embodiment, multiple operating condition determination events include a small current full charging event, a low battery state static event and a platform area constant current charging event for operating condition determination; multiple operating condition determination events in the first time period are obtained, including: determining the small current full charging event occurring in the first time period based on the charging current value and the battery cell power state that satisfy the conditions for the small current full charging event; and / or, determining the low battery state static event occurring in the first time period based on the battery cell static time and the battery cell power state that satisfy the conditions for the low battery state static event; and / or, determining the platform area constant current charging event occurring in the first time period based on the relative change rate between the voltage and the battery cell power that satisfy the platform area constant current charging conditions, the charging current stability and the charging current value.

[0087] The conditions for a low-current full charge event include the charging current value and the full charge index required to be reached by the battery cell state of charge. The charging current value is the degree of battery cell charging, and the battery cell state of charge (SOC) refers to the current charging state of the battery cell, indicating the ratio between the available electrical energy and the total capacity of the battery; the full charge index refers to the comparison result of the charging current value with the full charge current threshold, and the comparison result of the battery cell state of charge with the full charge cell state of charge threshold, both of which represent the full charge result.

[0088] Specifically, when the charging current value of the battery cell is less than the small current threshold, and the battery cell state of charge is full, the comparison result represents the full charge result, and then determines that the battery cell has a small current full charge event. When the charging current reaches the small current threshold, it indicates that the battery cell has less power loss; and the battery cell state of charge refers to the current charging state of the battery cell, indicating the ratio between the available electrical energy and the total capacity of the battery. When the battery cell state of charge is full, it indicates that the battery cell is fully charged. Correspondingly, the small current full charge event is used to indicate that the battery pack is in a full charge condition.

[0089] The low-battery state static event conditions include the battery cell static time and the low-battery state static index that the battery cell power state needs to reach. Among them, the battery cell static time refers to the length of time that the battery cell remains static without charging or discharging activities, which can be used to estimate the battery power stability; the low-battery state static index refers to the comparison result of the battery cell static time and the low-battery state time threshold, and the comparison result of the battery cell power state and the low-battery state threshold, both of which are low-battery state static results. Optionally, the low-battery state threshold changes based on the ambient temperature, so that the low-battery state static index changes with the temperature, so that the low-battery state static event occurring in the first time period can more accurately reflect the occurrence of a low-battery state static event in the battery cell.

[0090] Specifically, when the cell rest time is longer than the cell rest threshold, and the cell state of charge is less than 30%, the comparison result is a low-power state rest result, and the cell is determined to have a low-power state rest event. If the cell rest time is longer than the cell rest threshold, it indicates that the battery cell's charge is in a relatively stable state; when the cell state of charge is less than 30%, it indicates that the cell is in a low-power state rest condition. Correspondingly, a low-power state rest event is used to indicate that the battery pack is in a low-power state rest condition.

[0091] The constant current charging conditions in the platform area include the relative change rate between voltage and cell charge, the stability of charging current, and the platform constant current index that the charging current value needs to reach. The relative change rate between voltage and cell charge refers to the speed at which the voltage affects the change of cell charge during the charging process; when the relative change rate meets a certain change rate condition, the battery pack can execute a charge balancing strategy to align the charge of each cell in the battery pack. The charging current stability is used to determine whether the cell is in a relatively stable charging state, and the charging current value is also used to determine whether the cell is in a relatively stable charging state.

[0092] Among them, the low-current full charging event, the low-power state static event and the platform area constant-current charging event can be represented by the first event, the second event and the third event in sequence to improve the processing efficiency.

[0093] The operating condition of the battery pack is determined by a small current full charging event, a low power state static event and a platform area constant current charging event respectively, so as to comprehensively consider the operating conditions in the first time period, thereby accurately determining the balancing alignment point applicable to the second time period, and determining the operating condition suitable for power balancing processing, so as to execute the power balancing strategy corresponding to the operating condition, so that the power of each cell in the battery pack is balanced.

[0094] In one embodiment, a platform area constant current charging event occurring in the first time period is determined based on the relative change rate between the voltage and the battery cell charge that meets the platform area constant current charging condition, the charging current stability, and the charging current value, including: when the charging current stability meets the constant current condition and the charging current value meets the current threshold condition, determining the relative change rate between the voltage and the battery cell charge; when the relative change rate is a critical value of the change rate in the first time period, determining the platform area constant current charging event occurring in the first time period according to the critical value of the change rate.

[0095] The constant current condition can determine whether the battery pack is in a stable constant current charging state by the degree of current change; and the current threshold condition can determine whether there is an abnormality in the charging process of the battery pack by the perspective of the current value. Optionally, the current threshold condition means that the charging current is less than a certain threshold, and the battery pack is again determined to be in a stable charging platform state by the perspective of the current value.

[0096] The rate of change critical value is the critical value at which the relative rate of change trend changes, and is used to characterize that the voltage of the battery pack is expected to reach another voltage platform or cutoff point during the charging process. Optionally, there are multiple rate of change critical values ​​in the first time period, and each rate of change critical value is used to characterize that the charging process is expected to reach a different voltage platform. For example: In a battery charging process, there is a rate of change critical value between the constant current charging platform (Constant Current, CC Stage) and the constant voltage charging platform (Constant Voltage, CV Stage).

[0097] Therefore, this embodiment does not need to judge the working condition based on the battery cell charge state, but determines the relative change rate between the voltage and the battery cell charge more accurately by the charging current condition satisfying the constant current condition and the charging current value satisfying the current threshold condition; and when the relative change rate is the critical value of the change rate in the first time period, the operating condition suitable for charge balancing can be determined more carefully based on the critical value of the change rate. Exemplarily, the voltage of the lithium iron phosphate battery pack is in the platform area most of the time, and the battery cell charge state is unknown. It is difficult to trigger a small current full charge event and a low charge state static event for charge balancing, but it can trigger a platform area constant current charging event. The platform area constant current charging event is used as the target working condition judgment event to execute steps 206-208 to achieve charge balancing of the lithium iron phosphate battery pack.

[0098] In one embodiment, if Figure 3 As shown, according to the operating condition indicated by the target condition determination event, the balance alignment point of the second time period is determined, including: if the operating condition is a full charging condition indicated by a small current full charging event, the balance alignment point is determined to be the full value of the battery cell power state; if the operating condition is a low power state static condition indicated by a low power state static event, the balance alignment point is determined to be the empty value of the battery cell power state; if the operating condition is a platform area operating condition indicated by a platform area constant current charging event, the balance alignment point is determined to be the relative change rate between the voltage and the battery cell power, and the relative change rate reaches the critical value of the change rate in the first time period.

[0099] The operating condition indicated by the target condition determination event includes one of the following operating conditions: full charge condition, low battery state static condition, and platform area operating condition. Specifically, when the target condition determination event is a low current full charge event, the operating condition is a full charge condition; when the target condition determination event is a low battery state static event, the operating condition is a low battery state static condition; when the target condition determination event is a platform area constant current charging event, the operating condition is a platform area operating condition. Among them, the full charge condition is a condition in which the battery pack is about to be fully charged; the low battery state static condition is a condition in which the battery pack is at rest for a long time and has a low battery level; the platform area operating condition is a condition in which the relative rate of change between the voltage and the battery level of the battery pack reaches a certain rate of change critical value during the charging process of the battery pack.

[0100] The event conditions of the small current full charging event and the low battery state static event each involve the battery cell charge state, and the full charging condition indicated by the small current full charging event represents that the battery cell charge state reaches the full value, and the low battery state static condition indicated by the low battery state static event represents that the battery cell charge state passes until the battery cell charge state reaches the empty value, and both the full value of the battery cell charge state and the empty value of the battery cell charge state can be determined relatively accurately; correspondingly, the balance alignment point under the full charging condition is the full value of the battery cell charge state, and the balance alignment point under the low battery state static condition is the empty value of the battery cell charge state.

[0101] The event condition of the platform area constant current charging event involves the relative change rate between the voltage and the battery cell power; when the relative change rate reaches the critical value of the change rate in the first time period, the platform area constant current charging event of the battery pack is triggered. The relative change rate is used to characterize the rate of change between the point cloud and the power. Under the premise that the battery cell power state is neither the full value of the battery cell power state nor the empty value of the battery cell power state, the balance alignment point is more accurately determined by the critical value of the change rate in the first time period. Optionally, by adjusting the first time period, the balance alignment point can be adaptively adjusted to improve the accuracy of the power balance result.

[0102] Among them, if the balance alignment point is determined to be the full value of the battery cell power state, the goal of executing the power balancing strategy is to control the power state of each battery cell to be full value eventually; if the balance alignment point is determined to be the empty value of the battery cell power state, the goal of executing the power balancing strategy is to control the power state of each battery cell to be empty value eventually; if the balance alignment point is determined to be the relative change rate between the voltage and the battery cell power, and the relative change rate reaches the critical value of the change rate in the first time period, the goal of executing the power balancing strategy is to control the relative change rate to reach the critical value of the change rate.

[0103] For example, taking the charging process of two cells connected in series as an example, when the power of cell A is 65Ah, the power of cell B is 80Ah, and the critical value of the rate of change at this time is 65Ah, then the power to be balanced of cell B is 15Ah. Figure 4 The peak value, Figure 4 The vertical axis is the derivative value of voltage based on charge.

[0104] In this embodiment, when the respective target operating condition judgment events indicate different operating conditions, the balance alignment point is adaptively adjusted. The balance alignment point can not only still be the numerical value of the battery cell power state, but can also be determined based on the above-mentioned relative change rate reaching the change rate threshold. In order to accurately determine the balance alignment point when the battery cell power state is not an empty value or a full value, thereby making the power more balanced.

[0105] Among them, the priorities of small current full charging events, low battery state static events and platform area constant current charging events are in descending order.

[0106] In a feasible embodiment, a target operating condition determination event among multiple operating condition determination events is determined, including: when the priority usage conditions are met, according to the priorities of small current full charging events, low power state static events and platform area constant current charging events, the target operating condition determination event is determined from small current full charging events, low power state static events and platform area constant current charging events.

[0107] Specifically, from the macroscopic perspective of using a battery pack, the maximum energy can be released when the battery pack's balancing alignment point is 100% SOC, and the power balancing effect is the best. Therefore, the low-current full charge event has the highest priority, which belongs to the "charging alignment" situation. When the balancing capacity of "charging alignment" cannot be calculated, the balancing alignment point accuracy determined by "low-power state static" is higher than that of "platform area constant current charging", so the priority of the low-power state static event is higher than that of the platform area constant current charging event.

[0108] Therefore, when multiple operating condition determination events include a small current full charging event, a low battery state static event and a platform area constant current charging event for operating condition determination, the priorities of the three operating condition determination events, namely, the small current full charging event, the low battery state static event and the platform area constant current charging event, decrease in sequence, so as to determine the target operating condition determination event from the multiple operating condition determination events according to the priority.

[0109] In one embodiment, determining a target operating condition determination event among multiple operating condition determination events includes: determining the triggering times of the multiple operating condition determination events; if a first target operating condition determination event is obtained, the first target operating condition determination event is the target operating condition determination event among the multiple operating condition determination events; if multiple first target operating condition determination events are obtained, determining a second target operating condition determination event from the multiple first target operating condition determination events with the same event triggering times according to the priorities of the multiple operating condition determination events, the second target operating condition determination event being the target operating condition determination event among the multiple operating condition determination events.

[0110] The first target operating condition determination event is at least one operating condition determination event whose triggering times meet the times condition. The operating condition represented by the first target operating condition determination event has a higher probability of occurrence. Determining the balance alignment point based on the operating condition can make the balance alignment point easier to reach and the power balancing strategy easier to execute, so as to ensure that power balancing is more likely to be executed. When there is only one first target operating condition determination event, the first target operating condition determination event is the target operating condition determination event among the multiple operating condition determination events.

[0111] The second target operating condition determination event is one of the multiple first target operating condition determination events. Since the second target operating condition determination event is determined according to the priority of the multiple operating condition determination events, it can achieve good power balancing effect and high balancing alignment point accuracy.

[0112] In one embodiment, obtaining a first target operating condition determination event whose triggering times satisfy a number condition includes: searching for an operating condition determination event with the largest triggering times through the triggering times of various operating condition determination events; and determining the operating condition determination event with the largest triggering times as the first target operating condition determination event.

[0113] In a specific embodiment, a target operating condition determination event among multiple operating condition determination events is determined, including: if one operating condition determination event among a small current full charging event, a low battery state static event, and a platform area constant current charging event is the first target event with the largest number of triggering times, then the operating condition indicated by the first target event is determined as the operating condition for the first time period; if two operating condition determination events among a small current full charging event, a low battery state static event, and a platform area constant current charging event have the same number of triggering times, and both are greater than the number of triggering times of another operating condition determination event, and there are two first target operating condition determination events at this time, then according to the priorities of the two operating condition determination events, the second target event among the two first target operating condition determination events is determined, and the operating condition indicated by the second target event is determined as the operating condition for the first time period.

[0114] Among them, the operating condition indicated by the small current full charging event has the largest energy released by its power balancing strategy and the best power balancing effect, so the small current full charging event has the highest priority; and the operating condition indicated by the low power state static event has a higher balance alignment point accuracy, so the low power state static event has a higher priority than the platform area constant current charging event.

[0115] In one embodiment, based on the triggering of the balancing event corresponding to the balancing alignment point, the power balancing strategy corresponding to the operating condition is executed, including: if the balancing event corresponding to the balancing alignment point is triggered, the power to be balanced of each battery cell is determined according to the balancing power calculation method under the operating condition; the time required for power balancing of the power to be balanced is determined; the time required for power balancing is the time released by passive balancing current; and passive power balancing is performed according to the time required for power balancing.

[0116] Each cell is a cell that performs power balancing in the battery pack. Optionally, a battery pack has N cells, and the N cells can be used as cells respectively, so that the power of each cell in the entire battery pack is balanced; wherein N is a positive integer.

[0117] The amount of electricity to be balanced is the energy that each cell needs to release under the operating condition indicated by the target operating condition determination event. The amount of electricity to be balanced is calculated by the balanced electricity calculation method under the operating condition; optionally, the balanced electricity calculation methods for some operating conditions are the same, and the balanced electricity calculation methods for some operating conditions are different.

[0118] The time required for battery balancing is the time it takes for each cell to be released through the passive balancing current. The passive balancing current can be a static parameter pre-set according to the design information of the battery pack, or a dynamic parameter adjusted according to the design information of the battery pack.

[0119] In one feasible implementation, the amount of power to be balanced of each battery cell is determined according to a method for calculating the amount of power balanced under operating conditions, including: when the battery pack triggers a certain type of balancing event under each operating condition, the amount of power to be balanced of each battery cell is determined according to the method for calculating the amount of power balanced under that operating condition.

[0120] In a feasible implementation manner, determining the time required for power balancing of the power to be balanced includes: calculating the ratio between the power to be balanced and the passive balancing current to obtain the time required for power balancing.

[0121] In a feasible implementation, performing passive power balancing according to the time required for power balancing includes: performing passive power balancing for the time required for power balancing; wherein passive power balancing is a processing method that releases the power to be balanced by heat or other means. For example, when the time required for performing power balancing is 1 second, performing passive power balancing for 1 second.

[0122] Therefore, when the balancing event corresponding to the balancing alignment point is triggered, the balancing power calculation method is adaptively determined according to the operating conditions, and the power to be balanced is accurately calculated through the balancing power calculation method, and the power to be balanced can be released through passive power balancing, with low implementation cost.

[0123] Optionally, the balancing event is a small current full charging event under a full charging condition, and the small current full charging event is triggered when the charging current value and the battery cell power meet the conditions of the small current full charging event; or, the balancing event is a low power state static event under a low power state static condition, and the low power state static event is triggered when the battery cell static time and the battery cell power meet the conditions of the low power state static event.

[0124] Therefore, different trigger events are set for the full-charge condition and the low-power static condition, so that the battery pack can trigger a balancing event, and even trigger the balancing event multiple times, so that the power of the battery pack is more balanced.

[0125] Specifically, when a small current full charging event is the target operating condition determination event, the small current full charging event indicates a full charging condition, indicating that there is at least a small current full charging event in the first time period. Therefore, taking the small current full charging event as a balancing event is an estimation of the situation that a small current full charging event may be triggered in the second time period. Moreover, if the target operating condition determination event is determined to be a small current full charging event based on the number of triggering times, it is estimated that the small current full charging event is often triggered in the second time period, so that the power balancing frequency of the second time period is increased, and the power of each battery cell can be accurately balanced.

[0126] Specifically, in the case where the low-battery state static event is the target operating condition determination event, the low-battery state static event indicates a low-battery state static operating condition, characterizing that there is at least a low-battery state static event in the first time period. Therefore, taking the low-battery state static event as a balancing event is an estimation of the situation that the low-battery state static event may be triggered in the second time period. Moreover, if the target operating condition determination event is determined to be a low-battery state static event based on the number of triggers, it is estimated that the low-battery state static event is often triggered in the second time period, so that the power balancing frequency of the second time period is increased, and the power of each battery cell is accurately balanced.

[0127] In one embodiment, the amount of electricity to be balanced of each battery cell is determined according to a method for calculating the amount of electricity to be balanced under operating conditions, including: obtaining the electricity state of each battery cell and the minimum electricity state of the battery cell of the battery pack under a fully charged condition or a low-electricity static condition; determining the difference in electricity state between the electricity state and the minimum electricity state of the battery cell; if the electricity state difference is not in an over-balanced electricity state interval, converting the electricity state difference into the electricity state to be balanced of each battery cell through the minimum discharge capacity of the battery cell of the battery pack; if the electricity state difference is in an over-balanced electricity state interval, then there is no electricity to be balanced of each battery cell.

[0128] The state of charge is the state of charge expected when the battery is balanced. The minimum state of charge of a cell is the state of charge of a cell in the battery pack, and the state of charge of this cell is the smallest. For example: if the battery pack contains cells A, B, and C, and the states of charge of cells A, B, and C are from small to large, then the state of charge of cell A is the minimum state of charge of the cell.

[0129] The over-balanced state of charge interval is an interval designed for the state of charge under full charge conditions or low-power state static conditions. The over-balanced state of charge interval includes at least one boundary value to avoid over-balancing due to the accuracy of the state of charge, the minimum state of charge of the battery cell, and the difference in the state of charge.

[0130] The minimum discharge capacity of the battery pack is the smallest discharge capacity among the discharge capacities of each battery cell. It refers to the capacity of the battery cell that is allowed to be completely discharged, and is used to characterize the minimum amount of power that can be provided during a full discharge process. Among them, the minimum battery state and the minimum discharge capacity of the battery cell are both applied under full charge conditions or low power state static conditions, because these two conditions are set based on the short board effect of the battery cell, so that each battery cell is charged evenly.

[0131] The absence of power to be balanced in each battery cell means that each battery cell has a non-discharged battery cell amount that does not need to release electricity, and the non-discharged battery cell amount is the battery cell that has achieved power balance.

[0132] Optionally, the method also includes: determining whether the power state difference is in an over-balanced power state interval; this step specifically includes: determining whether the power state difference is less than the boundary value of the over-balanced power state interval; if less than, it is in the over-balanced power state interval; if greater than, it is not in the over-balanced power state interval.

[0133] In one feasible implementation, the state of charge of each battery cell and the minimum state of charge of the battery cell of the battery pack are obtained, including: under the low-power state static condition, according to the mapping relationship between voltage and state of charge, determining the state of charge value of each battery cell of the battery pack; from the state of charge values ​​of each battery cell, determining the minimum state of charge value as the minimum state of charge of the battery cell; wherein each battery cell of the battery pack is used as each battery cell. Thus, under the low-power state static condition, the state of charge and the minimum state of charge of the battery cell can be obtained more accurately. Optionally, the mapping relationship between voltage and state of charge is determined by a mapping relationship table between state of charge and voltage (State of Charge - Open Circuit Voltage, SOC-OCV).

[0134] In another feasible implementation, the state of charge of each battery cell and the minimum state of charge of the battery cell of the battery pack are obtained, including: under the full charge condition, respectively obtaining the estimated state of charge value for each battery cell of the battery pack, and determining the minimum estimated state of charge value from the estimated state of charge values ​​of each battery cell as the minimum state of charge of the battery cell; wherein each battery cell of the battery pack is respectively used as each battery cell. Therefore, considering that the mapping relationship table and other methods are not applicable to the full charge condition, a special module is set to perform calculations to obtain the estimated state of charge value, so that the state of charge and the minimum state of charge of the battery cell of the battery pack are more accurate.

[0135] In one feasible implementation, the state of charge difference is converted into the amount of power to be balanced of each cell through the minimum discharge capacity of the battery pack, including: calculating the ratio of the state of charge difference through the minimum discharge capacity of the battery pack, which is the amount of power to be balanced of each cell.

[0136] Each battery cell has its own current state of charge, so as to determine the state of charge difference and judge the amount of power to be balanced of each battery cell. When the minimum state of charge of the battery cell is the current state of charge A1 of the battery cell A, if the state of charge difference Y1 between the current state of charge X1 of the first battery cell and the current state of charge A1 is in the over-balanced state of charge interval, there is no power to be balanced of the first battery cell; if the state of charge difference Y2 between the current state of charge X2 of the second battery cell and the current state of charge A1 of the battery cell is not in the over-balanced state of charge interval, the state of charge difference Y2 is converted into the power to be balanced of each battery cell through the minimum discharge capacity C of the battery pack.

[0137] Based on this, under full charge conditions or low-power static conditions, the power state is used as a parameter to trigger a balancing event, and based on the current power state and the minimum power state of the battery cell, the power to be balanced of each battery cell is accurately determined with less data and the minimum discharge capacity of the battery cell; and based on the over-balancing power state interval, it is judged whether the power to be balanced will cause over-balancing, thereby avoiding over-balancing of the power of each battery cell and making the balancing effect more accurate.

[0138] In another embodiment, the balancing event is a platform area constant current charging event under the platform area operating condition, and the platform area constant current charging event is triggered when the relative change rate between the voltage and the battery cell power, the charging current stability, and the charging current value meet the platform area constant current charging conditions. For the platform area operating conditions, special trigger events are set respectively so that the battery pack can trigger the balancing event, and even the balancing event can be triggered multiple times to make the battery pack more balanced. Specifically, in the case where the platform area constant current charging event is the target operating condition determination event, the platform area constant current charging event indicates the platform area operating condition, indicating that there is at least a platform area constant current charging event in the first time period, and thus the platform area constant current charging event is used as a balancing event, which is an estimate of the situation that the second time period can trigger the platform area constant current charging event; and, if the target operating condition determination event is determined to be a platform area constant current charging event based on the number of triggers, it is estimated that the second time period often triggers the platform area constant current charging event, so that the power balancing frequency of the second time period can be increased, and the power of each battery cell can be accurately balanced.

[0139] Correspondingly, according to the balanced power calculation method under the operating conditions, the power to be balanced of each battery cell is determined, including: under the platform area operating conditions, determining the battery pack power of each battery cell when the constant current charging conditions in the platform area are met, and the maximum value of the battery pack power of each battery cell when the constant current charging conditions in the platform area are met; determining the power difference between the maximum value of the battery pack power and the battery pack power; if the power difference is not in the over-balanced power interval, the power difference is the power to be balanced of each battery cell; if the power difference is in the over-balanced power interval, there is no power to be balanced of each battery cell.

[0140] The battery pack power is the accumulated power of the battery pack when each battery cell meets the constant current charging condition in the platform area. Optionally, when a certain battery cell meets the constant current charging condition in the platform area, the battery pack power of this battery cell is obtained; when the next battery cell of this battery cell meets the constant current charging condition in the platform area, the battery pack power of the next battery cell is obtained.

[0141] The maximum value of the battery pack power is the maximum value of the accumulated power of the battery pack when each battery cell meets the constant current charging condition in the platform area. Optionally, when a battery cell meets the constant current charging condition in the platform area, the battery pack power is obtained once; when the next battery cell of this battery cell meets the constant current charging condition in the platform area, the battery pack power is obtained again, until the last battery cell meets the constant current charging condition in the platform area, the last battery pack power of this round of power balancing strategy is obtained; then the maximum value is determined from the battery pack power obtained each time to obtain the maximum value of the battery pack power.

[0142] The over-balanced power interval is the interval designed for the battery pack power under the platform area operating conditions. The over-balanced power interval includes at least one boundary value to avoid over-balancing due to the accuracy problem of the critical value of the rate of change. Optionally, the critical value of the over-balanced power interval is dynamically adjusted based on the minimum state discharge capacity of the battery cells of different battery packs.

[0143] Optionally, the method further includes: a step of determining a critical value of an over-balanced power interval; the step of determining includes: obtaining a boundary value of the over-balanced power state interval; adjusting the boundary value according to the minimum state discharge capacity of the battery cell to obtain a critical value of the over-balanced power interval. Optionally, the product of the minimum state discharge capacity of the battery cell and the boundary value of the over-balanced power state interval is the critical value of the over-balanced power interval.

[0144] In a feasible implementation, the method also includes a step of determining whether the power difference is in an over-balanced power interval, and the determination step includes: determining whether the power difference is greater than a critical value of the over-balanced power interval; if greater than or equal to a critical value of the over-balanced power interval, the power difference is not in the over-balanced power interval; if less than a critical value, the power difference is in the over-balanced power interval.

[0145] Optionally, the batteries of the battery pack are connected in series so that the batteries of the battery pack have the same current and can release electricity.

[0146] Therefore, under the operating conditions in the platform area, the amount of electricity to be balanced can be determined more accurately through the battery pack power and the maximum battery pack power, and whether the amount of electricity to be balanced will cause over-balancing can be judged based on the over-balancing power range, thereby avoiding over-balancing of the power of each battery cell and making the balancing effect more accurate.

[0147] In a specific embodiment, the calculation methods of the power to be balanced under the full charging condition, the low power state static condition and the platform area operation condition are respectively described.

[0148] Under full charge conditions, after estimating the power state of the nth battery cell, the expression used to determine whether the nth battery cell has power to be balanced is:

[0149]

[0150] Correspondingly, the amount of battery balance waiting for the nth cell is:

[0151]

[0152] Under full charge conditions, the expression used to determine whether the nth cell has no amount of electricity to be balanced is:

[0153]

[0154] Correspondingly, the amount of electricity to be balanced for the nth cell is:

[0155]

[0156] In the low-power static condition, by querying the static SOC-OCV table, the power state of the nth battery cell is obtained from the static battery cell voltage, and the expression used to determine whether the nth battery cell has power to be balanced is:

[0157]

[0158] Correspondingly, the amount of battery balance waiting for the nth cell is:

[0159]

[0160] In the low-power state and static condition, the expression used to determine whether the nth battery cell has no power to be balanced is:

[0161]

[0162] Correspondingly, the amount of electricity to be balanced for the nth cell is:

[0163]

[0164] in, The minimum power state of the battery cell; is the power state of the nth battery cell; is the amount of electricity to be balanced in the nth cell; It is the minimum discharge capacity of the battery pack.

[0165] Under the operating condition of the platform area, during the charging process, the voltage of each battery cell is detected to see if it passes through the characteristic point. When passing through the characteristic point, the total charge capacity of the current system is recorded to obtain the cumulative charge capacity of the system when the nth battery cell passes through the characteristic point. At this time, the expression used to determine whether the nth battery cell has the amount of electricity to be balanced is:

[0166]

[0167] Correspondingly, the amount of battery balance waiting for the nth cell is:

[0168]

[0169] Under the operating condition in the platform area, the expression used to determine whether the nth battery cell has no amount of electricity to be balanced is:

[0170]

[0171] Correspondingly, the expression of the amount of electricity that needs to be balanced for the nth battery cell is:

[0172]

[0173] in, is the cumulative battery pack charge when the nth cell passes the characteristic point, It is the maximum value of the battery pack power when each cell meets the constant current charging condition in the platform area. is the amount of electricity to be balanced in the nth cell; It is the minimum discharge capacity of the battery pack.

[0174] In one embodiment, the expression for the balancing time required for each battery cell is:

[0175]

[0176] in, is the time required for power balancing, is the amount of electricity to be balanced in the nth cell, Passive balancing current.

[0177] In one embodiment, based on the triggering of the balancing event corresponding to the balancing alignment point, before executing the power balancing strategy corresponding to the operating condition, it includes: controlling the start and stop state of the power balancing processing according to the hardware design information and the balancing duty cycle; the start and stop state is the on state.

[0178] The hardware design information includes the hardware information of the battery pack, including the maximum charging voltage, charging current, and other power performance information. For example, some hardware designs result in two consecutive cells not being able to be turned on at the same time, and each time the balancing circuit is turned on for 1 minute, in this case, when passive balancing is performed, the odd-numbered cells will be balanced for 1 minute, and the even-numbered cells will be balanced for 1 minute, and the cycle will be performed.

[0179] The balancing duty cycle is used to determine the time period that can be used to perform the power balancing method and the time period that cannot be used to perform the power balancing method. For example: based on the balancing duty cycle, the total balancing time of each battery cell in the second time period is determined, and within the total balancing time, it is determined whether to perform steps 202-208 and corresponding embodiments.

[0180] The start-stop state includes an on state and a stop state. In the on state, each battery cell can execute the power balancing strategy, while in the stop state, each battery cell cannot execute the power balancing strategy. In one embodiment, controlling the start-stop state of the power balancing process includes: controlling the start-stop state of the power balancing processing circuit.

[0181] Therefore, by combining the hardware design information with the balancing duty cycle, it is determined from the perspective of the battery pack whether to execute the power balancing strategy. The power balancing method is only executed when the power balancing is turned on to ensure energy efficiency and avoid system overload or failure.

[0182] In one embodiment, after executing the power balancing strategy corresponding to the operating condition, it also includes: if the time required for power balancing is less than the duration of each power balancing process being in the on state, then clearing the time required for power balancing to stop executing the next round of power balancing method steps; the time required for power balancing is obtained by executing the power balancing strategy corresponding to the operating condition; if the operating condition does not belong to the platform area operating condition, and the cell voltage of the battery pack and the minimum cell voltage are within a preset difference range, then clearing the time required for power balancing to stop executing the next round of power balancing method steps.

[0183] If the time required for power balancing is less than the duration of each power balancing process being turned on, clear the time required for power balancing to prevent the continued execution of the power balancing method from affecting the normal operation of the battery pack; if the operating condition does not belong to the platform area operating condition, and the battery cell voltage and the minimum battery cell voltage of the battery pack are within the preset difference range, clear the time required for power balancing to avoid excessive balancing in the next round of power balancing methods, resulting in waste of resources. For example: According to the hardware design information and the balancing duty cycle, it is determined that cell i can only be balanced for 10.5 minutes, and each time the power balancing takes 1 minute. When there is 0.5 minutes left, it is not enough time to turn on the next round of balancing circuit, so it is cleared to 0.

[0184] In one embodiment, the solution can adaptively adjust the passive balancing strategy of power: it can identify the battery operating conditions within a specific time range online, set balancing targets according to the identified conditions, and execute the balancing strategy.

[0185] In one embodiment, a small current full charging event, a low power state static event, and a platform area constant current charging event are defined to determine the working conditions and trigger logic of each event: the small current full charging event, the low power state static event, and the platform area constant current charging event are numbered as event 1, event 2, and event 3, respectively, as shown in Table 1.

[0186] Table 1

[0187]

[0188] In a specific implementation, step 202, obtaining multiple operating condition determination events in the first time period, includes: counting the cumulative triggering times of the above events within the month of the determination time, clearing the cumulative triggering times of the events at the end of the month, re-timing for one month and counting the times.

[0189] Correspondingly, step 204 determines the target operating condition determination event among the multiple operating condition determination events, including: when the one-month detection time arrives, the battery system operating condition is determined according to the cumulative number of event triggers; if the number of event statistics is the same, the priority of event 1, event 2 and event 3 is judged, and the priority of event 1, event 2 and event 3 decreases in sequence. Specifically, if event 1 is triggered the most times, it is a full charge condition; if event 2 is triggered the most times, it is a low SOC static condition; if event 3 is triggered the most times, it is a platform area operating condition; in addition, the first month of the initial operation of the system defaults to a low SOC static condition. Determine and record the operating condition determined this time, and the operating condition determined this time is the operating condition indicated by the target operating condition determination event.

[0190] Step 206, according to the operating condition indicated by the target operating condition determination event, determine the equilibrium alignment point of the second time period, including: according to the operating condition of the previous month of this month, set the passive equilibrium target SOC of this month. Specifically, if it is a full charge condition, the equilibrium target is 100% SOC; if it is a low SOC static condition, the equilibrium target is 0% SOC; if it is a platform area operating condition, the equilibrium target is a characteristic point between the platform areas, and the characteristic point is to determine the equilibrium alignment point as the relative change rate between the voltage and the battery cell charge, and the relative change rate reaches the critical value of the change rate in the first time period, which is the characteristic peak of the dV / dQ curve.

[0191] Step 208, based on the triggering of the balancing event corresponding to the balancing alignment point, execute the power balancing strategy corresponding to the operating condition, including: when the balancing event corresponding to the balancing alignment point is triggered, calculate the power to be balanced of each battery cell, calculate the time required for power balancing of each battery cell based on the power to be balanced and the passive balancing current, and perform passive power balancing according to the time required for power balancing.

[0192] Optionally, the method includes: controlling the start and stop state of the passive balancing circuit of each battery cell according to the balancing duty cycle set by the hardware design information; when the passive balancing circuit is in the on state, executing steps 202 to 208 to update the time required for power balancing; and the time required for power balancing is deleted when any of the following conditions is met: the time required for power balancing is less than the duration of each balancing on state; in the non-plateau period, the battery cell voltage is within 5 millivolts (mV) of the minimum value of the battery cell voltage.

[0193] Based on this, the above scheme identifies the battery operating conditions within a specific time range online, and according to the identified conditions, the balancing strategy is adaptively adjusted according to the battery operating conditions to improve the accuracy of the balanced power calculation. In the battery management system, other strategies can also be considered to be adaptively adjusted according to the operating conditions; if the impact of temperature on the strategy is considered, it is necessary to add temperature and temperature difference dimensions to the judgment conditions; Events and operating conditions include but are not limited to the above descriptions, which can be adjusted or increased or decreased according to actual conditions. In addition, the battery operating conditions within a specific time range are identified online. This operating condition information can reflect the system usage status and provide effective information for the algorithms and strategies of the battery management system.

[0194] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0195] Based on the same inventive concept, the embodiment of the present application also provides a power balancing device for implementing the power balancing method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more power balancing device embodiments provided below can refer to the limitations of the power balancing method above, and will not be repeated here.

[0196] In one embodiment, Figure 5 As shown, a power balancing device is provided, comprising:

[0197] An event acquisition module 502 is used to acquire multiple operating condition determination events in a first time period;

[0198] A target event determination module 504 is used to determine a target operating condition determination event among the multiple operating condition determination events;

[0199] An alignment point determination module 506 is used to determine a balanced alignment point of a second time period according to the operating condition indicated by the target operating condition determination event; the first time period belongs to a historical time period of the second time period;

[0200] The balancing execution module 508 is used to execute the power balancing strategy corresponding to the operating condition based on the triggering condition of the balancing event corresponding to the balancing alignment point.

[0201] In one embodiment, the multiple operating condition determination events include a small current full charging event, a low power state static event, and a platform area constant current charging event for operating condition determination; the event acquisition module 502 is used to:

[0202] Determining the small current full charging event occurring in the first time period according to the charging current value and the battery cell power state that satisfy the small current full charging event condition; and / or,

[0203] Determining the low-battery state standstill event occurring in the first time period according to the standstill time of the battery cell and the battery state of the battery cell that meet the low-battery state standstill event condition; and / or,

[0204] The platform area constant current charging event occurring in the first time period is determined according to the relative change rate between the voltage and the cell power that meets the platform area constant current charging condition, the charging current stability, and the charging current value.

[0205] In one embodiment, the event acquisition module 502 is used to:

[0206] When the charging current satisfies the constant current condition and the charging current value satisfies the current threshold condition, determining the relative change rate between the voltage and the battery cell charge;

[0207] When the relative change rate is a change rate threshold value in the first time period, the platform region constant current charging event occurring in the first time period is determined according to the change rate threshold value.

[0208] In one embodiment, the alignment point determination module 506 is used to:

[0209] If the operating condition is the full charge condition indicated by the small current full charge event, determining the balancing alignment point to be the full value of the battery cell power state;

[0210] If the operating condition is a low-battery-state static condition indicated by the low-battery-state static event, determining the balancing alignment point to be a cell battery state empty value;

[0211] If the operating condition is the platform area operating condition indicated by the platform area constant current charging event, the equilibrium alignment point is determined to be the relative change rate between the voltage and the battery cell charge, and the relative change rate reaches the change rate critical value in the first time period.

[0212] In one embodiment, the target event determination module 504 is used to:

[0213] Determining the triggering times of the multiple operating condition determination events;

[0214] Acquire a first target operating condition determination event in which the triggering number satisfies the number condition;

[0215] If one of the first target operating condition determination events is acquired, the first target operating condition determination event is a target operating condition determination event among the multiple operating condition determination events;

[0216] If multiple first target operating condition determination events are obtained, then according to the priorities of the multiple operating condition determination events, a second target operating condition determination event is determined from the multiple first target operating condition determination events with the same event triggering number, and the second target operating condition determination event is a target operating condition determination event among the multiple operating condition determination events.

[0217] In one embodiment, the balancing execution module 508 is used to:

[0218] If the balancing event corresponding to the balancing alignment point is triggered, the amount of electricity to be balanced of each battery cell is determined according to the balancing electricity calculation method under the operating condition;

[0219] Determine the time required for equalization of the amount of electricity to be equalized; the time required for equalization of the amount of electricity is the time required for release of the passive balancing current;

[0220] Passive power balancing is performed according to the time required for power balancing.

[0221] In one embodiment, the balancing event is a small current full charge event under a full charge condition, and the small current full charge event is triggered when the charging current value and the battery cell power meet the small current full charge event condition; or, the balancing event is a low power state static event under a low power state static condition, and the low power state static event is triggered when the battery cell static time and the battery cell power meet the low power state static event condition; the balancing execution module 508 is used to:

[0222] Under the full charge condition or the low power state static condition, obtaining the power state of each battery cell and the minimum power state of the battery cell of the battery pack;

[0223] Determining a state of charge difference between the state of charge and a minimum state of charge of the battery cell;

[0224] If the state of charge difference is not in the over-balanced state of charge interval, converting the state of charge difference into the to-be-balanced power of each of the cells through the minimum discharge capacity of the cells of the battery pack;

[0225] If the state of charge difference is in the over-balanced state of charge interval, there is no amount of power to be balanced in the battery cells.

[0226] In one of the embodiments, the balancing event is a platform area constant current charging event under the platform area operating condition, and the platform area constant current charging event is triggered when the relative change rate between the voltage and the battery cell power, the charging current stability, and the charging current value meet the platform area constant current charging conditions;

[0227] Correspondingly, the balancing execution module 508 is used to:

[0228] Under the platform area operating condition, determining the battery pack power of each battery cell when the constant current charging condition of the platform area is met, and the maximum value of the battery pack power of each battery cell when the constant current charging condition of the platform area is met;

[0229] Determine the difference between the maximum value of the battery pack power and the power of the battery pack;

[0230] If the power difference is not in the over-balanced power interval, the power difference is the power to be balanced of each of the battery cells;

[0231] If the power difference is in the over-balancing power interval, there is no power to be balanced in each of the battery cells.

[0232] In one embodiment, the balancing execution module 508 is used to:

[0233] According to the hardware design information and the balancing duty cycle, the start and stop states of the power balancing process are controlled; the start and stop states are the on states.

[0234] In one embodiment, the balancing execution module 508 is used to:

[0235] If the time required for power balancing is less than the duration of each power balancing process being in the on state, the time required for power balancing is cleared to stop executing the next round of the steps of the power balancing method; the time required for power balancing is obtained by executing the power balancing strategy corresponding to the operating condition;

[0236] If the operating condition does not belong to the platform area operating condition, and the cell voltage of the battery pack and the minimum cell voltage are within a preset difference range, the time required for power balancing is cleared to stop executing the next round of the power balancing method.

[0237] Each module in the above power balancing device can be implemented in whole or in part by software, hardware or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module.

[0238] In one embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as follows: Figure 6 As shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a power balancing method is implemented. The display unit of the computer device is used to form a visually visible image, and can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covered on the display screen, or a button, trackball or touchpad set on the computer device casing, or an external keyboard, touchpad or mouse, etc.

[0239] Those skilled in the art will understand that Figure 6 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0240] In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0241] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0242] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0243] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant laws, regulations and standards of relevant countries and regions.

[0244] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0245] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0246] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A power balancing method, characterized in that: The method comprises: Acquire multiple operating condition determination events in a first time period; determining a target operating condition determination event among the plurality of operating condition determination events; Determining a balance alignment point of a second time period according to the operating condition indicated by the target operating condition determination event; the first time period belongs to a historical time period of the second time period; If the balancing event corresponding to the balancing alignment point is triggered, the amount of power to be balanced of each battery cell is determined according to the balancing power calculation method under the operating conditions; the time required for power balancing of the power to be balanced is determined; the time required for power balancing is the time for releasing the passive balancing current; and passive power balancing is performed according to the time required for power balancing.

2. The method according to claim 1, characterized in that: The multiple operating condition determination events include a platform area constant current charging event, a small current full charging event, and a low power state static event for operating condition determination; the multiple operating condition determination events in the first time period are obtained, including: When the charging current stability condition satisfies constant current charging and the charging current value satisfies the current threshold condition, determining the relative change rate between the voltage and the battery cell charge; when the relative change rate is the change rate critical value in the first time period, determining the platform area constant current charging event occurring in the first time period according to the change rate critical value; and / or, Determining the small current full charging event occurring in the first time period according to the charging current value and the battery cell power state that satisfy the small current full charging event condition; and / or, The low-battery state standstill event occurring in the first time period is determined according to the standstill time length of the battery cell and the battery state of the battery cell that satisfy the low-battery state standstill event condition.

3. The method according to claim 2, characterized in that Determining the equilibrium alignment point of the second time period according to the operating condition indicated by the target condition determination event includes: If the operating condition is the full charge condition indicated by the small current full charge event, determining the balancing alignment point to be the full value of the battery cell power state; If the operating condition is a low-battery-state static condition indicated by the low-battery-state static event, determining the balancing alignment point to be a cell battery state empty value; If the operating condition is the platform area operating condition indicated by the platform area constant current charging event, the equilibrium alignment point is determined to be the relative change rate between the voltage and the battery cell charge, and the relative change rate reaches the change rate critical value in the first time period.

4. The method according to claim 1, characterized in that: The balancing event is a small current full charge event under a full charge condition, and the small current full charge event is triggered when the charging current value and the battery cell power meet the small current full charge event condition; or, the balancing event is a low power state static event under a low power state static condition, and the low power state static event is triggered when the battery cell static time and the battery cell power meet the low power state static event condition; The step of determining the amount of electricity to be balanced of each battery cell according to the balanced electricity calculation method under the operating condition includes: Under the full charge condition or the low power state static condition, obtaining the power state of each battery cell and the minimum power state of the battery cell of the battery pack; Determining a state of charge difference between the state of charge and a minimum state of charge of the battery cell; If the state of charge difference is not in the over-balanced state of charge interval, converting the state of charge difference into the to-be-balanced power of each of the cells through the minimum discharge capacity of the cells of the battery pack; If the state of charge difference is in the over-balanced state of charge interval, there is no amount of power to be balanced in the battery cells.

5. The method according to claim 1, characterized in that The balancing event is a platform area constant current charging event under the platform area operating condition, and the platform area constant current charging event is triggered when the relative change rate between the voltage and the battery cell power, the charging current stability, and the charging current value meet the platform area constant current charging conditions; The step of determining the amount of electricity to be balanced of each battery cell according to the balanced electricity calculation method under the operating condition includes: Under the platform area operating condition, determining the battery pack power of each battery cell when the constant current charging condition of the platform area is met, and the maximum value of the battery pack power of each battery cell when the constant current charging condition of the platform area is met; Determine the difference between the maximum value of the battery pack power and the power of the battery pack; If the power difference is not in the over-balanced power interval, the power difference is the power to be balanced of each of the battery cells; If the power difference is in the over-balancing power interval, there is no power to be balanced in each of the battery cells.

6. The method according to claim 1, characterized in that Before executing the power balancing strategy corresponding to the operating condition based on the triggering condition of the balancing event corresponding to the balancing alignment point, the method includes: According to the hardware design information and the balancing duty cycle, the start and stop states of the power balancing process are controlled; the start and stop states are the on states.

7. The method according to claim 1, characterized in that After the balancing event corresponding to the balancing alignment point is triggered, the method further includes: If the time required for power balancing is less than the duration of each power balancing process being in the on state, the time required for power balancing is cleared to stop executing the next round of the steps of the power balancing method; the time required for power balancing is obtained by executing the power balancing strategy corresponding to the operating condition; the on state is one of the start-stop states; If the operating condition does not belong to the platform area operating condition, and the difference between the cell voltage of the battery pack and the minimum cell voltage is within a preset difference range, the time required for power balancing is cleared to stop executing the next round of the power balancing method.

8. A power balancing device, characterized in that: The device comprises: An event acquisition module, used to acquire multiple working condition determination events in a first time period; A target event determination module, used to determine a target operating condition determination event among multiple operating condition determination events; an alignment point determination module, configured to determine a balanced alignment point of a second time period according to the operating condition indicated by the target operating condition determination event; the first time period being a historical time period of the second time period; The balancing execution module is used to determine the amount of electricity to be balanced of each battery cell according to the balancing electricity calculation method under the operating conditions if the balancing event corresponding to the balancing alignment point is triggered; determine the time required for electricity balancing of the amount of electricity to be balanced; the time required for electricity balancing is the time for releasing the passive balancing current; and perform passive electricity balancing according to the time required for electricity balancing.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

11. A computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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