Battery cell equalization method and vehicle

Abstract

The application provides a kind of electric core equalization method and vehicle, it is related to vehicle technical field, the method comprises: obtaining the historical SOC average value of battery pack and historical charging frequency;According to the state signal of battery management system, it is judged whether battery pack completes current charging action;If battery pack completes current charging action, then according to the SOC signal of battery management system and historical SOC average value, the current SOC average value of battery pack in current charging action is determined;According to historical charging frequency, it is judged whether current charging action satisfies update condition;If current charging action satisfies update condition, then current SOC average value is used as SOC equalization strategy point.The application is based on the historical SOC average value of battery and historical charging frequency, the use habit of battery pack is analyzed to obtain the SOC equalization strategy point of battery pack, which is used as the basis for equalization operation of electric core, so that the electric core of battery pack is more easily balanced, and the equalization effect of electric core is improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more specifically, to a battery cell balancing method and a vehicle. Background Technology

[0002] Currently, power batteries have wide applications in many fields. For example, in the automotive industry, pure electric vehicles or hybrid vehicles typically use power batteries to power the vehicles, thus requiring regular charging. However, due to the inherent inconsistencies among the battery cells, the State of Charge (SOC) difference and capacity between cells gradually increase during charging and discharging. Therefore, to balance the differences between cells and extend the battery's lifespan, a passive balancing strategy is usually adopted, which involves connecting a resistor in parallel with each string of cells to dissipate excess charge.

[0003] In existing technologies, the power batteries of pure electric vehicles or hybrid vehicles are not always fully charged during charging, and they are used within a certain SOC range. However, passive balancing strategies, due to the presence of resistance, try to keep the SOC of all cells around the upper limit, ignoring the different usage habits of different vehicles and different power batteries. If the power battery does not reach the balancing range corresponding to the passive balancing strategy for a long period of time, the balance state of the power battery cells will deteriorate, thereby affecting the lifespan, driving range, and safety of the power battery. Summary of the Invention

[0004] The technical problem solved by this invention is how to optimize the balancing effect of power battery cells.

[0005] This invention provides a cell balancing method, comprising:

[0006] Obtain the historical average SOC and historical number of charges of the battery pack;

[0007] Determine whether the battery pack has completed the current charging action based on the status signals of the battery management system;

[0008] If the battery pack completes the current charging action, the current average SOC value of the battery pack in the current charging action is determined based on the SOC signal of the battery management system and the historical average SOC value.

[0009] Determine whether the current charging action meets the update conditions based on the historical charging count;

[0010] If the current charging action satisfies the update condition, then the current SOC average value is used as the SOC balancing strategy point.

[0011] Optionally, after the step of using the current SOC average as the SOC balancing strategy point if the current charging action satisfies the update condition, the method further includes:

[0012] The remaining balanced capacity of each cell in the battery pack is determined based on the balanced operating conditions and the SOC balanced strategy point.

[0013] Cell balancing is performed based on the remaining balancing capacity of the cell.

[0014] Optionally, determining the current average SOC of the battery pack in the current charging action based on the SOC signal of the battery management system and the historical average SOC includes:

[0015] The SOC value of the battery pack at the current moment is determined based on the SOC signal;

[0016] The current average SOC value in the current charging action is determined based on the current SOC value, the historical average SOC value, and the historical number of charging cycles.

[0017] Optionally, determining whether the current charging action meets the update conditions based on the historical charging count includes:

[0018] When the sum of the historical charging counts and the single charge of the current charging action reaches a preset number, it is determined that the current charging action satisfies the update condition.

[0019] If the sum of the historical charging counts and the single charge of the current charging action does not reach a preset number, it is determined that the current charging action does not meet the update condition.

[0020] After determining whether the current charging action meets the update conditions based on the historical charging count, the method further includes:

[0021] If the current charging action does not meet the update condition, then the latest historical SOC balancing strategy point of the battery pack is obtained, and the latest historical SOC balancing strategy point is used as the SOC balancing strategy point.

[0022] The latest historical SOC balancing strategy point is the SOC balancing strategy point of the battery pack in the previous software running cycle.

[0023] Optionally, determining the remaining equalization capacity of each cell in the battery pack based on the equalization operating condition and the SOC equalization strategy point includes:

[0024] When the balancing condition is in driving balancing mode, it is determined whether the remaining balancing capacity needs to be updated based on the SOC balancing strategy point.

[0025] If not, obtain the remaining balanced capacity from the previous software running cycle;

[0026] When the remaining equalization capacity of the previous software running cycle is greater than 0 and the battery management system is not faulty, the remaining equalization capacity of the previous software running cycle is taken as the remaining equalization capacity.

[0027] If so, the remaining equalization capacity is calculated based on the SOC value of all the cells to determine the remaining equalization capacity.

[0028] Optionally, determining whether the remaining balancing capacity needs to be updated based on the SOC balancing strategy point includes:

[0029] The SOC capacity range of the battery pack is determined based on the SOC balancing strategy point;

[0030] Determine whether the maximum SOC value of all the battery cells is within the SOC capacity range and whether the current state of the battery cell is within a preset normal range;

[0031] If so, the remaining balancing capacity needs to be updated;

[0032] If not, then there is no need to update the remaining balancing capacity.

[0033] Optionally, determining the remaining equalization capacity by calculating the remaining equalization capacity based on the SOC values ​​of all the cells includes:

[0034] The remaining equalization capacity is determined based on the difference between the SOC value of all the cells and the minimum SOC value among all the cells; wherein, when the difference is less than or equal to a preset minimum threshold, the remaining equalization capacity is set to 0.

[0035] When the difference is greater than the preset minimum threshold, the remaining equalization capacity of the battery cell is determined based on the difference.

[0036] Optionally, determining the remaining equalization capacity of each cell in the battery pack based on the equalization operating condition and the SOC equalization strategy point includes:

[0037] When the balancing condition is in the timed wake-up mode, it is determined whether the remaining balancing capacity needs to be updated based on the SOC balancing strategy point and the voltage and temperature status of the battery cell.

[0038] Specifically, it is determined whether the maximum SOC value of all the cells is within the SOC capacity range, and both the current state and the voltage state are valid.

[0039] If so, the equalization capacity of the battery cell is updated to determine the remaining equalization capacity.

[0040] Optionally, the cell balancing based on the remaining balancing capacity of the cell includes:

[0041] The control equalization channel is turned on in turn according to a preset time period to perform cell equalization until the remaining equalization capacity of the cell reaches 0. The equalization channel includes a first channel and a second channel.

[0042] The control equalization channel is turned on alternately according to a preset duration to perform cell equalization, including:

[0043] The first channel and the second channel are controlled to be turned on alternately at the preset time interval to perform cell balancing.

[0044] The present invention also provides a vehicle including a computer-readable storage medium storing a computer program and a processor, wherein the computer program is read and executed by the processor to implement the cell balancing method as described above.

[0045] In this invention, the usage habits of the battery pack are analyzed by acquiring its historical average SOC and historical charging count. Specifically, by receiving the status signals of the battery management system, real-time monitoring of the battery pack's charging actions is achieved. This facilitates the acquisition of the SOC signal at the end of charging when the battery management system finishes charging. Simultaneously, by combining the historical average SOC and historical charging count, the usage habits of the battery pack are analyzed, leading to a suitable SOC balancing strategy point. Then, based on this SOC balancing strategy point, the remaining balancing capacity of each cell in the battery pack can be obtained, and cell balancing operations can be performed according to the remaining balancing capacity of each cell. This invention analyzes the battery pack's usage habits based on historical battery data, namely historical average SOC and historical charging count, to obtain a suitable SOC balancing strategy point. Based on this SOC balancing strategy point, cell balancing operations are then performed, taking into account the different driving conditions of different car owners and combining battery pack usage habits to obtain new balancing strategy points, making it easier for the battery pack's cells to achieve balancing and improving the cell balancing effect. Attached Figure Description

[0046] Figure 1 This is a schematic flowchart of a cell balancing method in one embodiment of the present invention;

[0047] Figure 2 This is a flowchart of a cell balancing method in one embodiment of the present invention;

[0048] Figure 3 This is a flowchart of a cell balancing method in another embodiment of the present invention;

[0049] Figure 4This is a flowchart of a cell balancing method in another embodiment of the present invention. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] Combination Figure 1 As shown, the present invention provides a cell balancing method, comprising:

[0052] S1: Obtain the historical average SOC and historical number of charges of the battery pack.

[0053] Specifically, cell balancing is generally controlled by the balancing module of the battery management system. In this embodiment, considering the different driving conditions of different car owners and their driving habits, i.e., the battery pack's usage habits, a new SOC (State of Charge) balancing strategy point is calculated to make it easier for the balancing module to meet the conditions for balancing. The analysis of battery pack usage habits requires combining historical data, i.e., the historical average SOC and the historical number of charges. In a preferred embodiment of the invention, non-volatile memory is typically used to store the historical number of charges and the historical average SOC. Obtaining the historical average SOC and the historical number of charges of the battery pack can be achieved by reading the non-volatile memory.

[0054] S2: Determine whether the battery pack has completed the current charging action based on the status signal of the battery management system.

[0055] Specifically, in combination Figure 2 As shown, in a preferred embodiment of the present invention, the status signal of the battery management system can be received in real time through the data abuse module. The charging status can be AC ​​fully charged or DC fast charging. The charging status is monitored, and if the charging status changes to another rising edge, it means that the current charging action of the battery pack has been completed. At this time, the SOC signal can be processed. If the charging status does not change to another rising edge, it means that the current charging action is still continuing, and it is necessary to continue to receive the status signal of the battery management system to ensure continuous monitoring of the charging status.

[0056] S3: If the battery pack completes the current charging action, the current average SOC value of the battery pack in the current charging action is determined based on the SOC signal of the battery management system and the historical average SOC value.

[0057] Specifically, when the battery pack completes the current charging action, a cell balancing operation needs to be performed. This is achieved by calculating the current average SOC based on the SOC signal from the battery management system and the historical average SOC, using historical data as a reference. The current average SOC incorporates the influence of the historical average SOC and serves as an important parameter reflecting battery usage habits. In a preferred embodiment of the invention, when the battery pack changes from an AC fully charged state or a DC fast charging state to another state, it can be determined that the current charging action has been completed. At this time, the historical average SOC is obtained by reading from the non-volatile memory and processing it with the current SOC signal to obtain the current average SOC. The historical charging count can be understood as the cumulative number of charging attempts for the battery pack. When the cumulative number of charging attempts reaches a certain value, it indicates that the number of charging attempts has exceeded the limit. To ensure data accuracy, the count can be updated.

[0058] S4: Determine whether the current charging action meets the update conditions based on the historical charging count.

[0059] Specifically, in a preferred embodiment of the present invention, the historical number of times can be added to the single time of the current charging action to obtain the total number of times the battery pack is charged. When the total number of times is charged exceeds a preset range, it means that the current charging action meets the update conditions.

[0060] S5: If the current charging action satisfies the update condition, then the current SOC average value is used as the SOC balancing strategy point.

[0061] Specifically, when the current charging action meets the update conditions, the latest average SOC value, i.e., the current average SOC value obtained by averaging the above with the historical average SOC values, can be used as the strategy point for subsequent cell balancing. It is worth mentioning that, since this invention considers that directly judging the voltage difference to control balancing at any SOC value would cause the battery management system to be in a constant balancing state, resulting in the hardware in the battery management system being constantly at a high temperature, this invention will adopt single-point balancing, i.e., selecting a SOC balancing strategy point and balancing each cell based on that point.

[0062] In this embodiment, the battery pack's usage habits are analyzed by acquiring its historical average SOC and historical charging count. This involves receiving status signals from the battery management system (BMS) to achieve real-time monitoring of the battery pack's charging actions. This facilitates the acquisition of the SOC signal at the end of charging. Furthermore, by combining the historical average SOC and historical charging count, the battery pack's usage habits are analyzed to obtain a suitable SOC balancing strategy point. Based on this SOC balancing strategy point, the remaining balancing capacity of each cell in the battery pack can be obtained, and cell balancing operations can be performed according to the remaining balancing capacity of each cell. This invention analyzes the battery pack's usage habits based on historical battery data, namely the historical average SOC and historical charging count, to obtain a suitable SOC balancing strategy point. Using this SOC balancing strategy point as a basis, cell balancing operations are then performed, taking into account the different driving conditions of different car owners and combining battery pack usage habits to obtain new balancing strategy points. This makes it easier for the battery pack's cells to achieve balancing, improving the cell balancing effect.

[0063] In a preferred embodiment of the present invention, after the step of using the current SOC average as the SOC balancing strategy point if the current charging action satisfies the update condition, the method further includes:

[0064] The remaining balanced capacity of each cell in the battery pack is determined based on the balanced operating conditions and the SOC balanced strategy point.

[0065] Cell balancing is performed based on the remaining balancing capacity of the cell.

[0066] In this embodiment, since the battery pack has multiple balancing conditions, and these balancing conditions are the focus of cell balancing, different balancing conditions will lead to the determination of the remaining balancing capacity of each cell in the battery pack. In a preferred embodiment of the present invention, the balancing conditions may include a timed wake-up mode and a driving balancing mode, representing different states of the vehicle, respectively. After obtaining the SOC balancing strategy point, the remaining balancing capacity of each cell can be calculated by the balancing module in conjunction with the balancing conditions. After obtaining the remaining balancing capacity of the cell, the balancing of the cell begins. Specifically, a certain cell or a certain SOC value among all cells in the battery management system is used as the target, and other cells are balanced by using the target as a benchmark and controlling the switching of the balancing channel for discharge balancing.

[0067] In this embodiment, the battery cells are balanced based on the SOC balancing strategy point. The usage conditions of different car owners are taken into account, and a new balancing strategy point is obtained by combining the battery pack usage habits. This makes it easier for the battery cells in the battery pack to achieve balance and improves the balancing effect of the battery cells.

[0068] In a preferred embodiment of the present invention, determining the current average SOC value of the battery pack in the current charging operation based on the SOC signal of the battery management system and the historical average SOC value includes:

[0069] The SOC value of the battery pack at the current moment is determined based on the SOC signal;

[0070] The current average SOC value in the current charging action is determined based on the current SOC value, the historical average SOC value, and the historical number of charging cycles.

[0071] In this embodiment, the SOC signal from the battery management system is received in real time. In a preferred embodiment of the invention, the SOC signal can be received in real time through a data abuse module. The SOC signal represents the overall state of charge of the battery pack. Based on the overall state of charge, the SOC value of the battery pack at the current moment, i.e., the SOC value at the end of charging, can be obtained. In a preferred embodiment of the invention, based on the SOC value at the end of charging and the historical average SOC value obtained before this charging action, an averaging algorithm can be used to add the current charging action to the calculation count, and simultaneously add the SOC value at the end of charging to the historical charging count, thus obtaining the current average SOC value in the current charging action. The formula for calculating the current average SOC value can be:

[0072] Soc 平均 =(Soc) 历史平均 ×N+Soc 当前 ) / N+1;

[0073] Among them, Soc 平均 Let SOC be the current mean SOC. 当前 The SOC value at the current moment, Soc 历史平均 Let N be the historical average SOC, and N be the historical number of charging cycles. Combining the above formula, N+1 is the sum of the current charging cycle and the historical charging cycle, while SOC... 历史平均 ×N+

[0074] Soc 当前 This is the sum of the product of the historical SOC average and the historical number of charging cycles, and the SOC value. Based on the averaging principle, the current SOC average during the previous charging operation can be obtained.

[0075] In this embodiment, the historical average SOC is included in the calculation range, and the historical data of the battery pack is calculated to realize the analysis based on battery usage habits.

[0076] In a preferred embodiment of the present invention, determining whether the current charging action meets the update condition based on the historical charging count includes:

[0077] When the sum of the historical charging counts and the single charge of the current charging action reaches a preset number, it is determined that the current charging action satisfies the update condition.

[0078] If the sum of the historical charging counts and the single charge of the current charging action does not reach a preset number, it is determined that the current charging action does not meet the update condition.

[0079] After determining whether the current charging action meets the update conditions based on the historical charging count, the method further includes:

[0080] If the current charging action does not meet the update condition, then the latest historical SOC balancing strategy point of the battery pack is obtained, and the latest historical SOC balancing strategy point is used as the SOC balancing strategy point.

[0081] The latest historical SOC balancing strategy point is the SOC balancing strategy point of the battery pack in the previous software running cycle.

[0082] Combination Figure 3 As shown, in this embodiment, the analysis focuses on determining whether the current charging action meets the update conditions based on the historical charging count. The sum of the historical charging count and the single charge of the current charging action is the historical charging count plus one additional charge, representing the cumulative charging count of the battery pack. The relationship between the cumulative charging count and a preset number of charges is then determined. If the cumulative charging count reaches the preset number, the current charging action meets the update conditions. In this case, to ensure data accuracy, the obtained current average SOC is used as the SOC balancing strategy point, and this SOC balancing strategy point is stored in non-volatile memory, while the historical charging count is cleared. If the cumulative charging count does not reach the preset number, the latest historical SOC balancing strategy point of the battery pack is retrieved from the non-volatile memory and used as the current SOC balancing strategy point. The latest historical SOC balancing strategy point is the target SOC balancing strategy point from the previous software cycle, i.e., the previous cell balancing operation.

[0083] In a preferred embodiment of the present invention, it is determined whether the cumulative number of charging cycles has reached 100. If the cumulative number of charging cycles has not reached 100 (which can be calibrated), the rising edge of the next charging completion is detected. It is worth mentioning that if the battery pack does not complete 100 charging cycles in one operation, a default balanced SOC strategy point is output. The default balanced SOC strategy point can be set to 95% SOC value.

[0084] In this embodiment, whether the cumulative number of charging times has reached a preset number is used as the basis for judging whether the current charging action meets the update conditions, so as to ensure the accuracy and timeliness of historical data and prevent the data from being inaccurate due to too much historical data and too long time.

[0085] In this embodiment of the invention, determining the remaining equalization capacity of each cell in the battery pack based on the equalization operating condition and the SOC equalization strategy point includes:

[0086] When the balancing condition is in driving balancing mode, it is determined whether the remaining balancing capacity needs to be updated based on the SOC balancing strategy point.

[0087] If not, obtain the remaining balanced capacity from the previous software running cycle;

[0088] When the remaining equalization capacity of the previous software running cycle is greater than 0 and the battery management system is not faulty, the remaining equalization capacity of the previous software running cycle is taken as the remaining equalization capacity.

[0089] If so, the remaining equalization capacity is calculated based on the SOC value of all the cells to determine the remaining equalization capacity.

[0090] In this embodiment, the remaining equalization capacity of each cell in the battery management system is obtained based on the battery pack's equalization operating conditions and SOC equalization strategy point. The equalization operating conditions affect cell equalization; therefore, after obtaining the SOC equalization strategy point, the specific mode of the equalization operating conditions needs to be determined. When the equalization operating conditions are in driving equalization mode, online SOC equalization capacity judgment is required. Using the SOC equalization strategy point, it is determined whether the remaining equalization capacity of all cells needs to be updated. If not, it means that the remaining equalization capacity of the cells does not need to be updated. At this time, the remaining equalization capacity of each cell in the previous software running cycle is obtained, and it is determined whether it is less than or equal to 0. If the remaining equalization capacity in the previous software running cycle is greater than 0, it means that the remaining equalization capacity of the cells is still available. At this time, it is determined whether there is a fault in the battery management system, i.e., fault diagnosis is performed. If no fault is found after fault diagnosis, the remaining equalization capacity of the previous software running cycle is used as the remaining equalization capacity of the cells, meaning that the remaining equalization capacity of the previous software running cycle can be used for the current cell equalization operation.

[0091] In this embodiment, the remaining equalization capacity of each cell in the battery management system is determined by judging the equalization operating condition and combining it with the SOC equalization strategy point. The equalization strategy point is calculated by considering different operating conditions and battery pack usage habits, making it easier for the equalization module to meet the conditions for activating equalization.

[0092] In a preferred embodiment of the present invention, determining whether the remaining balancing capacity needs to be updated based on the SOC balancing strategy point includes:

[0093] The SOC capacity range of the battery pack is determined based on the SOC balancing strategy point;

[0094] Determine whether the maximum SOC value of all the battery cells is within the SOC capacity range and whether the current state of the battery cell is within a preset normal range;

[0095] If so, the remaining balancing capacity needs to be updated;

[0096] If not, then there is no need to update the remaining balancing capacity.

[0097] In this embodiment, the remaining equalization capacity of all cells in the battery pack is analyzed based on the SOC equalization strategy point to determine whether an update of the remaining equalization capacity is needed. The SOC equalization strategy point determines the range of remaining equalization capacity to be updated, i.e., the SOC capacity range. If the maximum SOC value of all cells falls within this range and the cell's current state is within a preset normal range, it can be determined that the remaining equalization capacity of the cells needs to be updated. In a preferred embodiment of the invention, the result of the determination can be assigned a numerical value, which is a calculation mode. The larger the value of the calculation mode, the higher the calculation priority.

[0098] Combination Figure 4 As shown, in a preferred embodiment of the present invention, the range from the SOC balancing strategy point to 2% above the SOC balancing strategy point is defined as the SOC capacity range. First, the current state of the battery cell is acquired. A preset normal range is defined as a current less than or equal to 10A with a current change rate less than or equal to 5A / s for 5 seconds. If the current state of the battery cell is abnormal, its remaining balancing capacity calculation mode is set to 0. If the current state of the battery cell is normal, the maximum SOC value of the battery cell is acquired, and it is determined whether the maximum SOC value is within the SOC capacity range. If yes, its remaining balancing capacity calculation mode is set to 8; otherwise, its remaining balancing capacity calculation mode is set to 0. Finally, the relationship between the calculated mode value and the calculated mode value of the previous cycle is determined. If it is greater than the calculated mode value of the previous cycle, the remaining balancing capacity of the battery cell is updated.

[0099] In this embodiment, the current state and SOC value range are combined to achieve SOC balancing of the battery. The battery's operating state is comprehensively considered, and corresponding balancing measures are taken according to different situations to ensure the normal operation and lifespan of the battery.

[0100] In a preferred embodiment of the present invention, the step of calculating the remaining equalization capacity based on the SOC values ​​of all the battery cells includes:

[0101] The remaining equalization capacity is determined based on the difference between the SOC value of all the cells and the minimum SOC value among all the cells; wherein, when the difference is less than or equal to a preset minimum threshold, the remaining equalization capacity is set to 0.

[0102] When the difference is greater than the preset minimum threshold, the remaining equalization capacity of the battery cell is determined based on the difference.

[0103] In this embodiment, the remaining equalization capacity of all the battery cells is obtained based on the difference between the SOC value of all the battery cells and the minimum SOC value among all the battery cells. The remaining SOC difference to be equalized is obtained by subtracting the minimum SOC value from the total SOC value of all the battery cells. This difference is used to judge each battery cell. When the difference corresponding to a battery cell is greater than the preset minimum threshold, it means that the remaining equalization capacity can be used for equalization operation. At this time, the accurate remaining equalization capacity is calculated using the remaining capacity calculation formula. When the difference corresponding to a battery cell is less than the preset minimum threshold, since the remaining equalization capacity is too low, no equalization operation is required, and the remaining equalization capacity is set to 0. In this embodiment of the invention, the remaining equalization capacity calculation formula can be: ΔSoc × C p -0.05 = Soc 剩余 ;

[0104] Where ΔSoc is the difference corresponding to the battery cell, C p The rated capacity of the battery cell, Soc 剩余 The remaining equalization capacity of the battery cell.

[0105] In a preferred embodiment of the present invention, a preset minimum threshold can be set to 1%. When the difference corresponding to the battery cell is greater than 1%, the remaining equalization capacity is calculated; when the difference corresponding to the battery cell is less than or equal to 1%, the remaining equalization capacity is set to 0.

[0106] In this embodiment, by analyzing and judging the differences in SOC values ​​between different cells, the optimal balancing operation is achieved, thereby improving the overall performance and reliability of the battery pack.

[0107] In a preferred embodiment of the present invention, determining the remaining equalization capacity of each cell in the battery pack based on the equalization operating condition and the SOC equalization strategy point includes:

[0108] When the balancing condition is in the timed wake-up mode, it is determined whether the remaining balancing capacity needs to be updated based on the SOC balancing strategy point and the voltage and temperature status of the battery cell.

[0109] Specifically, it is determined whether the maximum SOC value of all the cells is within the SOC capacity range, and both the current state and the voltage state are valid.

[0110] If so, the equalization capacity of the battery cell is updated to determine the remaining equalization capacity.

[0111] In this embodiment, if the balancing condition is determined to be a timed wake-up mode, then based on the SOC balancing strategy point and the current and voltage states of the cells, it is determined whether the remaining balancing capacity of the cells is needed. Specifically, based on the relationship between the maximum SOC value and the SOC capacity range among all cells, and whether the voltage and temperature states of the cells are valid, if so, the balancing capacity of the cells is updated to obtain the remaining balancing capacity of each cell.

[0112] In a preferred embodiment of the present invention, the range from the SOC balancing strategy point to 2% above the SOC balancing strategy point is defined as the SOC capacity range. When the maximum SOC value is within the SOC capacity range and the voltage and temperature status are both valid, the calculation mode is set to 9 (timing mode - timing mode has the highest priority), and the remaining balancing capacity is updated. When the maximum SOC value is not within the SOC capacity range, the calculation mode is not updated, and the balancing capacity is not updated.

[0113] In this embodiment, the need for balancing operations is determined by considering the relationship between the maximum SOC value and the SOC capacity range of all cells, as well as the effectiveness of the cell's voltage and temperature status. Targeted balancing operations are then performed, and any shortages in balancing capacity are effectively supplemented based on real-time conditions to maintain the overall performance of the battery pack.

[0114] In a preferred embodiment of the present invention, the cell balancing based on the remaining balancing capacity of the cell includes:

[0115] The control equalization channel is turned on in turn according to a preset time period to perform cell equalization until the remaining equalization capacity of the cell reaches 0. The equalization channel includes a first channel and a second channel.

[0116] The control equalization channel is turned on alternately according to a preset duration to perform cell equalization, including:

[0117] The first channel and the second channel are controlled to be turned on alternately at the preset time interval to perform cell balancing.

[0118] In this embodiment, the equalization channel can be turned on and off by controlling the equalization switch. Therefore, the first channel and the second channel can be controlled to turn on for a preset duration until the remaining equalization capacity of the cell reaches 0.

[0119] In a preferred embodiment of the present invention, the first and second channels can be configured as odd-even channels, and when they are turned on alternately, an odd-even switching mechanism can be used. A preset duration of 30 seconds is set, with either the odd or even channel continuously open for 30 seconds, followed by an odd-even switching. When the odd or even channel is balancing, the remaining balancing capacity of each cell string is determined, and the capacity balanced out within the current balancing cycle (1 second) is calculated. The capacity balanced out within the cycle is calculated as: (current cell voltage / balancing circuit resistance) × balancing switch control duty cycle × balancing cycle duration. This calculation yields the remaining balancing capacity for the current cell in the next cycle, and the remaining balancing capacity is then checked sequentially to determine if it reaches 0. The preferred embodiment of the present invention employs an alternating odd-even channel balancing method, reducing heat generation during the balancing process and extending hardware lifespan.

[0120] In this embodiment, by accurately calculating the equalization capacity of each cell during the equalization cycle, it can be ensured that the heat generated by the hardware during the equalization process is minimized, thereby extending the hardware lifespan.

[0121] Another embodiment of the present invention includes a computer-readable storage medium storing a computer program and a processor, the computer program being read and executed by the processor to implement the cell balancing method as described above.

[0122] In this embodiment, the battery pack's usage habits are analyzed by acquiring its historical average SOC and historical charging count. This involves receiving status signals from the battery management system (BMS) to achieve real-time monitoring of the battery pack's charging actions. This facilitates the acquisition of the SOC signal at the end of charging. Furthermore, by combining the historical average SOC and historical charging count, the battery pack's usage habits are analyzed to obtain a suitable SOC balancing strategy point. Based on this SOC balancing strategy point, the remaining balancing capacity of each cell in the battery pack can be obtained, and cell balancing operations can be performed according to the remaining balancing capacity of each cell. This invention analyzes the battery pack's usage habits based on historical battery data, namely the historical average SOC and historical charging count, to obtain a suitable SOC balancing strategy point. Using this SOC balancing strategy point as a basis, cell balancing operations are then performed, taking into account the different driving conditions of different car owners and combining battery pack usage habits to obtain new balancing strategy points. This makes it easier for the battery pack's cells to achieve balancing, improving the cell balancing effect.

[0123] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided by this invention can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0124] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0125] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A cell balancing method, characterized in that, include: Obtain the historical average SOC and historical number of charges of the battery pack; Determine whether the battery pack has completed the current charging action based on the status signals of the battery management system; If the battery pack completes the current charging action, the current average SOC value of the battery pack in the current charging action is determined based on the SOC signal of the battery management system and the historical average SOC value. Determine whether the current charging action meets the update conditions based on the historical charging count; If the current charging action satisfies the update condition, then the current SOC average value is used as the SOC balancing strategy point.

2. The cell balancing method according to claim 1, characterized in that, After stating that if the current charging action satisfies the update condition, the current average SOC is used as the SOC balancing strategy point, the following is also included: The remaining balanced capacity of each cell in the battery pack is determined based on the balanced operating conditions and the SOC balanced strategy point. Cell balancing is performed based on the remaining balancing capacity of the cell.

3. The cell balancing method according to claim 1, characterized in that, Determining the current average SOC of the battery pack during the current charging action based on the SOC signal of the battery management system and the historical average SOC includes: The SOC value of the battery pack at the current moment is determined based on the SOC signal; The current average SOC value in the current charging action is determined based on the current SOC value, the historical average SOC value, and the historical number of charging cycles.

4. The cell balancing method according to claim 1, characterized in that, The step of determining whether the current charging action meets the update condition based on the historical charging count includes: When the sum of the historical charging counts and the single charge of the current charging action reaches a preset number, it is determined that the current charging action satisfies the update condition. If the sum of the historical charging counts and the single charge of the current charging action does not reach a preset number, it is determined that the current charging action does not meet the update condition. After determining whether the current charging action meets the update conditions based on the historical charging count, the method further includes: If the current charging action does not meet the update condition, then the latest historical SOC balancing strategy point of the battery pack is obtained, and the latest historical SOC balancing strategy point is used as the SOC balancing strategy point; wherein, the latest historical SOC balancing strategy point is the SOC balancing strategy point of the battery pack in the previous software running cycle.

5. The cell balancing method according to claim 2, characterized in that, Determining the remaining equalization capacity of each cell in the battery pack based on the equalization operating conditions and the SOC equalization strategy point includes: When the balancing condition is in driving balancing mode, it is determined whether the remaining balancing capacity needs to be updated based on the SOC balancing strategy point. If not, obtain the remaining balanced capacity from the previous software running cycle; When the remaining equalization capacity of the previous software running cycle is greater than 0 and the battery management system is not faulty, the remaining equalization capacity of the previous software running cycle is taken as the remaining equalization capacity. If so, the remaining equalization capacity is calculated based on the SOC value of all the cells to determine the remaining equalization capacity.

6. The cell balancing method according to claim 5, characterized in that, The step of determining whether the remaining balancing capacity needs to be updated based on the SOC balancing strategy point includes: The SOC capacity range of the battery pack is determined based on the SOC balancing strategy point; Determine whether the maximum SOC value of all the battery cells is within the SOC capacity range and whether the current state of the battery cell is within a preset normal range; If so, the remaining balancing capacity needs to be updated; If not, then there is no need to update the remaining balancing capacity.

7. The cell balancing method according to claim 5, characterized in that, The step of calculating the remaining equalization capacity based on the SOC values ​​of all the battery cells includes: The remaining equalization capacity is determined based on the difference between the SOC value of all the cells and the minimum SOC value among all the cells; wherein, when the difference is less than or equal to a preset minimum threshold, the remaining equalization capacity is set to 0. When the difference is greater than the preset minimum threshold, the remaining equalization capacity of the battery cell is determined based on the difference.

8. The cell balancing method according to claim 6, characterized in that, Determining the remaining equalization capacity of each cell in the battery pack based on the equalization operating conditions and the SOC equalization strategy point includes: When the balancing condition is in the timed wake-up mode, it is determined whether the remaining balancing capacity needs to be updated based on the SOC balancing strategy point and the voltage and temperature status of the battery cell. The step of determining whether the remaining equalization capacity needs to be updated based on the SOC equalization strategy point and the voltage and temperature status of the battery cell includes: Determine whether the maximum SOC value of all the cells is within the SOC capacity range, while both the current state and the voltage state are valid; If so, the equalization capacity of the battery cell is updated to determine the remaining equalization capacity.

9. The cell balancing method according to claim 2, characterized in that, The cell balancing based on the remaining balancing capacity of the cell includes: The control equalization channel is turned on in turn according to a preset time to perform cell equalization until the remaining equalization capacity of the cell reaches 0. The equalization channel includes a first channel and a second channel. The control equalization channel is turned on alternately according to a preset duration to perform cell equalization, including: The first channel and the second channel are controlled to be turned on alternately at the preset time interval to perform cell balancing.

10. A vehicle, characterized in that, The method includes a computer-readable storage medium storing a computer program and a processor, the computer program being read and executed by the processor to implement the cell balancing method as described in any one of claims 1 to 9.

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