An equalization control method and system for an automotive battery pack

Abstract

An embodiment of the present invention discloses an equalization control method for an automotive battery pack. When the equalization start condition of the new energy vehicle battery pack is met, the remaining driving time is used as the effective time available for equalization this time; the approximate equalization current required can be estimated based on the capacity difference and equalization time, and the pre-calibrated equalization channel number - current - temperature rise comparison table is queried to determine the optimal current for this equalization, and then the equalization processing operation is performed. An embodiment of the present invention also discloses a corresponding system. Implementing the present invention can obtain optimal equalization parameters, accurately control the heat dissipated during equalization, and improve the efficiency and safety of equalization.

Description

Technical Field

[0001] The present invention relates to the field of control of battery management systems, and more particularly to an equalization control method and system for an automotive battery pack. Background Art

[0002] Differences in capacity caused during the production process and use of battery cells will result in a loss of the capacity of the entire battery pack. To eliminate this loss as much as possible, the battery management system needs to turn on the equalization function at an appropriate time to suppress the continuous deterioration of the capacity difference. At the same time, the currently relatively mature equalization technology is passive equalization, which consumes high-SOC (state of charge) battery cells or modules to reduce the overall SOC level to the lowest SOC, thereby keeping them consistent. This is an energy-consuming process, and the consumed electrical energy is transferred to the entire battery management system (BMS) control board through heat. When equalizing, it is necessary to ensure that there is no overheating or thermal runaway.

[0003] Current equalization control mainly considers the current demand and directly controls the equalization switch, without considering other factors. After the equalization energy-consuming resistors located on the same control board are turned on, they continuously generate heat, and this heat acts on the control chip again. If not controlled, it will cause the control chips to not work in the optimal temperature range at least, and may lead to over-temperature protection or thermal runaway at worst.

[0004] Therefore, in the prior art, simply and crudely stopping the equalization function by thermal protection frequently reduces the equalization efficiency, and causes the sampling accuracy of the controller to deteriorate due to the influence of high temperature. Especially when the ambient temperature is high, turning on the equalization will cause the temperature of the control board to rise rapidly, and the thermal equilibrium temperature may exceed the allowable range of the sampling chip or the control chip. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an equalization control method and system for an automotive battery pack, which can obtain optimal equalization parameters, accurately control the heat dissipated during equalization, and improve the equalization efficiency and safety.

[0006] To solve the above technical problem, on the one hand, the present invention provides an equalization control method for an automotive battery pack, which includes the following steps:

[0007] Step S10: Collect the current voltages of all battery cells in the battery pack of a new energy vehicle, and determine whether the pressure difference between the current voltage of each battery cell and the lowest voltage among them exceeds a preset pressure difference threshold;

[0008] Step S11: When the pressure difference exceeds the pressure difference threshold, obtain the numbers and the number of channels of the channels where the voltage deviations exceed the pressure difference threshold, and determine the equalization target channel information;

[0009] Step S12: Determine the capacity to be balanced based on the pressure difference; and obtain the remaining driving time, and determine the remaining driving time as the time to be balanced;

[0010] Step S13: Calculate the preliminary balancing current based on the capacity to be balanced and the time to be balanced;

[0011] Step S14: Query the balancing channel number - current - temperature rise comparison table at the current ambient temperature based on the preliminary balancing current and the number of channels, obtain the predicted temperature rise value, and combine it with the temperature upper limit value of the battery pack control board to adjust and determine the target balancing current;

[0012] Step S15: Perform balancing processing on the corresponding battery cells in the new energy vehicle battery pack according to the balancing target channel information and the target balancing current.

[0013] Among them, it further includes:

[0014] Pre - calibrate and obtain the temperature rise data of the battery pack control board corresponding to balancing processing of new energy vehicle batteries at different ambient temperatures, with different numbers of balancing channels and different balancing currents, and generate a balancing channel number - current - temperature rise comparison table for each ambient temperature.

[0015] Among them, the specific content of step S13 includes:

[0016] Divide the capacity to be balanced by the time to be balanced to obtain the preliminary balancing current.

[0017] Among them, the step S14 further includes:

[0018] Obtain the maximum temperature rise value based on the difference between the temperature upper limit value of the control board and the current ambient temperature;

[0019] Query the balancing channel number - current - temperature rise comparison table at the current ambient temperature based on the preliminary balancing current and the number of channels, and obtain the predicted temperature rise value;

[0020] Judge whether the predicted temperature rise value is less than the maximum temperature rise value;

[0021] If the judgment result is yes, determine the preliminary balancing current as the target balancing current;

[0022] If the judgment result is no, query the balancing channel number - current - temperature rise comparison table to obtain the balancing current corresponding to the predicted temperature rise value that is less than and closest to the maximum temperature rise value, and determine the obtained balancing current as the target balancing current.

[0023] Among them, it further includes:

[0024] Detect the current ambient temperature. When the difference between the current ambient temperature and the ambient temperature at the start of the previous equalization is greater than a predetermined temperature difference threshold, obtain the latest target equalization current again according to the foregoing steps.

[0025] Correspondingly, on the other hand, the present invention further provides an equalization control system for a new energy vehicle battery pack, which includes:

[0026] A collection and comparison unit, configured to collect the current voltages of all battery cells in the new energy vehicle battery pack, and determine whether the voltage difference between the current voltage of each battery cell and the lowest voltage among them exceeds a preset voltage difference threshold;

[0027] An equalization target channel information acquisition unit, configured to, when the voltage difference exceeds the voltage difference threshold, acquire the numbers and the quantity of channels with voltage deviations exceeding the voltage difference threshold, and determine the equalization target channel information;

[0028] An equalization parameter acquisition unit, configured to determine the capacity to be equalized according to the voltage difference; and determine the remaining driving time, and determine the remaining driving time as the equalization time to be;

[0029] A preliminary equalization current acquisition unit, configured to calculate and obtain a preliminary equalization current according to the capacity to be equalized and the equalization time to be;

[0030] A target equalization current acquisition unit, configured to query an equalization channel number - current - temperature rise comparison table at the current ambient temperature according to the preliminary equalization current and the number of channels, obtain the predicted temperature rise value, and adjust and determine the target equalization current in combination with the temperature upper limit value of the battery pack control board;

[0031] An equalization processing unit, configured to perform equalization processing on the corresponding battery monomers in the new energy vehicle battery pack according to the equalization target channel information and the target equalization current. Wherein, it further includes:

[0032] A comparison table acquisition unit, configured to pre - calibrate and obtain the temperature rise data corresponding to the battery pack control board obtained by performing equalization processing on a new energy vehicle battery at different ambient temperatures with different numbers of equalization channels and different equalization currents, and generate an equalization channel number - current - temperature rise comparison table for each ambient temperature.

[0033] Wherein, the preliminary equalization current acquisition unit specifically obtains the preliminary equalization current by using the following method:

[0034] Divide the capacity to be equalized by the equalization time to be to obtain the preliminary equalization current.

[0035] Wherein, the target equalization current acquisition unit further includes:

[0036] A maximum temperature rise calculation unit for obtaining the maximum temperature rise according to the difference between the upper limit value of the control board temperature and the current ambient temperature;

[0037] A query unit for querying an equilibrium channel number - current - temperature rise comparison table at the current ambient temperature according to the preliminary equilibrium current and the number of channels, to obtain the predicted temperature rise;

[0038] A judgment and processing unit for judging whether the predicted temperature rise is less than the maximum temperature rise; when the judgment result is yes, determining the preliminary equilibrium current as the target equilibrium current; when the judgment result is no, querying the equilibrium channel number - current - temperature rise comparison table to obtain the equilibrium current corresponding to the predicted temperature rise that is less than and closest to the maximum temperature rise, and determining the obtained equilibrium current as the target equilibrium current.

[0039] Among them, it further includes:

[0040] An ambient temperature detection and processing unit for detecting the current ambient temperature, and triggering the target equilibrium current acquisition unit to re - obtain the latest target equilibrium current when the difference between the current ambient temperature and the ambient temperature at the start of the previous equilibrium is greater than a predetermined temperature difference threshold.

[0041] Implementing the embodiments of the present invention has the following beneficial effects:

[0042] The embodiments of the present invention provide an equilibrium control method and system for a new energy vehicle battery pack. By pre - obtaining an equilibrium channel number - current - temperature rise comparison table at each ambient temperature, when the battery pack in a new energy vehicle needs to be balanced, the optimal target equilibrium current can be determined according to the capacity to be balanced, the remaining driving time, and the equilibrium channel number - current - temperature rise comparison table, so as to determine the equilibrium processing scheme. Implementing the embodiments of the present invention can obtain the optimal equilibrium parameters, accurately control the heat dissipated by the equilibrium, and thus improve the efficiency and safety of the equilibrium. Description of the Drawings

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, obtaining other drawings based on these drawings still belongs to the scope of the present invention.

[0044] Figure 1 It is a main process schematic diagram of an embodiment of an equilibrium control method for an automotive battery pack provided by the present invention;

[0045] Figure 2Schematic structural diagram of an embodiment of an equalization control system for an automotive battery pack provided by the present invention;

[0046] Figure 3 For Figure 2 Schematic structural diagram of the target equalization current acquisition unit in Detailed implementation manners

[0047] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0048] As Figure 1 shown, a main flowchart of an embodiment of an equalization control method for an automotive battery pack provided by the present invention is shown; in this embodiment, the equalization control method for a new energy vehicle battery pack includes the following steps:

[0049] Step S10: Collect the current voltages of all battery cells in the battery pack of the new energy vehicle, and determine whether the pressure difference between the current voltage of each battery cell and the lowest voltage among them exceeds a preset pressure difference threshold according to the voltage distribution, where the preset pressure difference threshold is preset and determined according to different vehicle models;

[0050] Step S11: When the pressure difference exceeds the pressure difference threshold, obtain the numbers and the quantity of channels where the voltage deviations exceed the pressure difference threshold, and determine the equalization target channel information;

[0051] Step S12: Determine the capacity to be equalized according to the pressure difference; and determine the remaining driving time as the equalization time to be determined according to the remaining driving time; among them, the remaining driving time can be estimated according to the navigation information in the vehicle computer and the recent driving history data;

[0052] Step S13: Calculate a preliminary equalization current according to the capacity to be equalized and the equalization time to be determined; where step S13 specifically includes:

[0053] Divide the capacity to be equalized by the equalization time to be determined to obtain the preliminary equalization current.

[0054] Step S14: Query a pre-calibrated equalization channel number - current - temperature rise comparison table at the current ambient temperature according to the preliminary equalization current and the number of channels, obtain the predicted temperature rise value, and adjust and determine the target equalization current in combination with the temperature upper limit value of the battery pack control board; the equalization channel number - current - temperature rise comparison table records the corresponding relationship between the number of channels, the equalization current and the predicted temperature rise value;

[0055] It can be understood that it further includes:

[0056] Pre-calibrate and obtain the temperature rise data corresponding to the battery pack control board by performing equalization processing on a new energy vehicle battery at different ambient temperatures, with different numbers of equalization channels and different equalization currents, and generate an equalization channel number - current - temperature rise comparison table for each ambient temperature.

[0057] Specifically, during the vehicle model configuration development stage, corresponding data is obtained through a large number of experiments, an equalization channel number - current - temperature rise comparison table at the ambient temperature is generated, and it is pre-stored in the vehicle-mounted system. As shown in Table 1 below, it shows the equalization channel number - current - temperature rise comparison table at an ambient temperature of 25°C.

[0058] Table 1 Equalization Channel Number - Current - Temperature Rise Comparison Table at 25°C

[0059]

[0060] The above are only the temperature rise data at an ambient temperature of 25°C, where the first column is the equalization current data, the first row is the number of opened equalization channels, and other values are the temperature rise values. For example, when 5 equalization channels are opened simultaneously and the equalization current is 80 mA, the temperature will rise by 34°C, and so on. In the embodiments of the present invention, it is also necessary to obtain equalization channel number - current - temperature rise comparison tables corresponding to other ambient temperatures. For example, it is possible to obtain 0°C, 1°C, 2°C... 40°C, etc.

[0061] Among them, step S14 further includes:

[0062] Obtain the maximum temperature rise value according to the difference between the temperature upper limit value of the control board and the current ambient temperature;

[0063] Query the equalization channel number - current - temperature rise comparison table at the current ambient temperature according to the preliminary equalization current and the number of channels to obtain the predicted temperature rise value;

[0064] Judge whether the predicted temperature rise value is less than the maximum temperature rise value;

[0065] If the judgment result is yes, determine the preliminary equalization current as the target equalization current;

[0066] If the judgment result is no, query the equalization channel number - current - temperature rise comparison table to obtain the equalization current corresponding to the predicted temperature rise value that is less than and closest to the maximum temperature rise value, and determine the obtained equalization current as the target equalization current.

[0067] Step S15: Perform equalization processing on the corresponding battery cells in the new energy vehicle battery pack according to the equalization target channel information and the target equalization current.

[0068] Among them, it further includes:

[0069] Detect the current ambient temperature. When the difference between the current ambient temperature and the ambient temperature at the start of the previous equalization is greater than a predetermined temperature difference threshold, obtain the latest target equalization current again according to the foregoing steps; wherein, the predetermined temperature difference threshold can be set in advance, for example, 3°C.

[0070] For ease of understanding, the following will be described with a specific example:

[0071] For example: The current ambient temperature is 25°C, and the board temperature needs to be controlled not to exceed 55°C, that is, Δt < 30°C. In the current battery pack, the voltages of the 3rd / 6th / 9th / 22nd series of battery cells are higher than others, and they need to be equalized. The equalization channel numbers A{3, 6, 9, 22} are obtained, and the equalization quantity M = 4. Suppose the capacity difference caused by the current imbalance is 80 mAh, and the predicted driving time output by the navigation is 1 h. Then, the required equalization current is 80 mA. However, when operating at full load of 80 mA, querying the data in Table 1, the corresponding temperature rise is 32°C, exceeding the temperature control target. Therefore, it is necessary to lower the equalization current. It can be seen from the table that it can be first lowered to 70 mA. When checking the table and obtaining 4 channels of equalization channels, the temperature rise is about 28°C, meeting the requirements. Therefore, it is finally determined that the equalization is started for 1 h this time, the channels are A{3, 6, 9, 22}, and the equalization current is 70 mA, and the temperature can always be controlled within 50°C. If the ambient temperature changes during the process, the above process is carried out again to adjust the current value to ensure the most efficient operation of the equalization.

[0072] As Figure 2 shown, a schematic structural diagram of an embodiment of an equalization control system for an automotive battery pack provided by the present invention is shown. In combination with Figure 3 shown, in this embodiment, the equalization control system 1 includes:

[0073] A collection and comparison unit 10, configured to collect the current voltages of all battery cells in the new energy vehicle battery pack, and judge whether the voltage difference between the current voltage of each battery cell and the lowest voltage among them exceeds a preset voltage difference threshold according to the voltage distribution;

[0074] An equalization target channel information acquisition unit 11, configured to, when the voltage difference exceeds the voltage difference threshold, acquire the numbers and quantities of the channels with voltage deviations exceeding the voltage difference threshold, and determine the equalization target channel information;

[0075] An equalization parameter acquisition unit 12, configured to determine the capacity to be equalized according to the voltage difference; and determine the remaining driving time, and determine the remaining driving time as the equalization time to be performed;

[0076] A preliminary equalization current acquisition unit 13, configured to calculate and obtain a preliminary equalization current according to the capacity to be equalized and the equalization time to be performed;

[0077] The target balanced current acquisition unit 14 is configured to query a pre-calibrated balanced channel number-current-temperature rise comparison table at the current ambient temperature according to the preliminary balanced current and the number of channels, obtain the predicted temperature rise value, and combine the upper limit value of the battery pack control board temperature to adjust and determine the target balanced current; the corresponding relationship between the number of channels, the balanced current, and the predicted temperature rise value is recorded in the balanced channel number-current-temperature rise comparison table.

[0078] The balancing processing unit 15 is configured to perform balancing processing on the corresponding battery cells in the new energy vehicle battery pack according to the balanced target channel information and the target balanced current.

[0079] Among them, it further includes:

[0080] The comparison table acquisition unit 16 is configured to pre-calibrate and obtain the temperature rise data corresponding to the battery pack control board by performing balancing processing on a new energy vehicle battery at different ambient temperatures with different numbers of balanced channels and different balanced currents, and generate a balanced channel number-current-temperature rise comparison table for each ambient temperature.

[0081] The ambient temperature detection and processing unit 17 is configured to detect the current ambient temperature, and when the difference between the current ambient temperature and the ambient temperature at the start of the previous balance is greater than a predetermined temperature difference threshold, trigger the target balanced current acquisition unit 14 to re-obtain the latest target balanced current.

[0082] In a specific example, the preliminary balanced current acquisition unit 13 specifically obtains the preliminary balanced current by using the following method:

[0083] Dividing the capacity to be balanced by the time to be balanced to obtain the preliminary balanced current.

[0084] Among them, the target balanced current acquisition unit 14 further includes:

[0085] The maximum temperature rise value calculation unit 140 is configured to obtain the maximum temperature rise value according to the difference between the upper limit value of the control board temperature and the current ambient temperature.

[0086] The query unit 141 is configured to query the balanced channel number-current-temperature rise comparison table at the current ambient temperature according to the preliminary balanced current and the number of channels, and obtain the predicted temperature rise value.

[0087] The judgment processing unit 142 is configured to judge whether the predicted temperature rise value is less than the maximum temperature rise value; when the judgment result is yes, the preliminary balanced current is determined as the target balanced current; when the judgment result is no, query the balanced channel number-current-temperature rise comparison table to obtain the balanced current corresponding to the predicted temperature rise value that is less than and closest to the maximum temperature rise value, and determine the obtained balanced current as the target balanced current.

[0088] For more details, reference may be made to the foregoing description of Figure 1 which will not be elaborated herein.

[0089] Implementing the embodiments of the present invention has the following beneficial effects:

[0090] The embodiments of the present invention provide an equalization control method and system for a battery pack of a new energy vehicle. By pre-obtaining a look-up table of equalization channel number - current - temperature rise at each ambient temperature, when the battery pack in the new energy vehicle needs to be equalized, the optimal target equalization current can be determined according to the capacity to be equalized, the remaining driving time, and the look-up table of equalization channel number - current - temperature rise, so as to determine the equalization processing scheme. Implementing the embodiments of the present invention can obtain the optimal equalization parameters, accurately control the heat dissipated by equalization, and thus improve the efficiency and safety of equalization.

[0091] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, apparatus, or computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0092] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0093] The foregoing disclosure is only a preferred embodiment of the present invention, and of course, it cannot be used to limit the scope of the rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A method for balancing control of an automotive battery pack, characterized in that It includes the following steps: Step S10: Collect the current voltages of all the battery cells in the battery pack of the new energy vehicle, and determine whether the voltage difference between the current voltage of each battery cell and the lowest voltage among them exceeds a preset voltage difference threshold; Step S11: When the voltage difference exceeds the voltage difference threshold, obtain the numbers and the quantity of the channels whose voltage deviations exceed the voltage difference threshold, and determine the equalization target channel information; Step S12: Determine the capacity to be equalized according to the voltage difference, and obtain the remaining driving time, and determine the remaining driving time as the equalization time to be; Step S13: Calculate the preliminary equalization current according to the capacity to be equalized and the equalization time to be; Step S14: According to the preliminary equalization current and the quantity of channels, query the equalization channel number - current - temperature rise comparison table at the current ambient temperature that has been pre - calibrated, obtain the predicted temperature rise value, and combine it with the upper limit value of the temperature of the battery pack control board to adjust and determine the target equalization current; Step S15: Perform equalization processing on the corresponding battery monomers in the battery pack of the new energy vehicle according to the equalization target channel information and the target equalization current.

2. The method according to claim 1, characterized in that, It further includes: Pre - calibrate and obtain the temperature rise data corresponding to the battery pack control board when equalization processing is performed on the new energy vehicle battery at different ambient temperatures, with different quantities of equalization channels and different equalization currents, and generate the equalization channel number - current - temperature rise comparison table for each ambient temperature.

3. The method according to claim 2, wherein The specific content of step S13 includes: Divide the capacity to be equalized by the equalization time to be to obtain the preliminary equalization current.

4. The method according to claim 3, wherein The further content of step S14 includes: Obtain the maximum temperature rise value according to the difference between the upper limit value of the control board temperature and the current ambient temperature; According to the preliminary equalization current and the quantity of channels, query the equalization channel number - current - temperature rise comparison table at the current ambient temperature, and obtain the predicted temperature rise value; Judge whether the predicted temperature rise value is less than the maximum temperature rise value; If the judgment result is yes, determine the preliminary equalization current as the target equalization current; If the judgment result is no, query the equalization channel number - current - temperature rise comparison table, and obtain the equalization current corresponding to the predicted temperature rise value that is less than and closest to the maximum temperature rise value, and determine the obtained equalization current as the target equalization current.

5. The method according to any one of claims 1 to 4, characterized in that It further includes: Detect the current ambient temperature. When the difference between the current ambient temperature and the ambient temperature at the start of the previous equalization is greater than a predetermined temperature difference threshold, obtain the latest target equalization current again according to the foregoing steps.

6. An equalization control system for an automotive battery pack, characterized in that, It includes: A collection and comparison unit, which is used to collect the current voltages of all the battery cells in the battery pack of the new energy vehicle, and determine whether the voltage difference between the current voltage of each battery cell and the lowest voltage among them exceeds a preset voltage difference threshold; An equalization target channel information acquisition unit, which is used to obtain the numbers and the quantity of the channels whose voltage deviations exceed the voltage difference threshold when the voltage difference exceeds the voltage difference threshold, and determine the equalization target channel information; An equalization parameter acquisition unit, which is used to determine the capacity to be equalized according to the voltage difference; and determine the remaining driving time, and determine the remaining driving time as the equalization time to be; The preliminary balanced current acquisition unit is used to calculate and obtain a preliminary balanced current according to the to-be-balanced capacity and the to-be-balanced time; The target balanced current acquisition unit is used to query the balanced channel number-current-temperature rise comparison table at the current ambient temperature calibrated in advance according to the preliminary balanced current and the number of channels, obtain the predicted temperature rise value, and adjust and determine the target balanced current in combination with the upper limit value of the temperature of the battery pack control board; The balanced processing unit is used to perform balanced processing on the corresponding battery monomers in the new energy vehicle battery pack according to the balanced target channel information and the target balanced current.

7. The system according to claim 6, wherein It further includes: The comparison table acquisition unit is used to calibrate and obtain the temperature rise data corresponding to the battery pack control board by performing balanced processing on the new energy vehicle battery at different ambient temperatures with different numbers of balanced channels and different balanced currents, and generate a balanced channel number-current-temperature rise comparison table for each ambient temperature.

8. The system according to claim 7, wherein The preliminary balanced current acquisition unit specifically obtains the preliminary balanced current by using the following method: Dividing the to-be-balanced capacity by the to-be-balanced time to obtain a preliminary balanced current.

9. The system according to claim 8, wherein The target balanced current acquisition unit further includes: The maximum temperature rise value calculation unit is used to obtain the maximum temperature rise value according to the difference between the upper limit value of the control board temperature and the current ambient temperature; The query unit is used to query the balanced channel number-current-temperature rise comparison table at the current ambient temperature according to the preliminary balanced current and the number of channels to obtain the predicted temperature rise value; The judgment processing unit is used to judge whether the predicted temperature rise value is less than the maximum temperature rise value; when the judgment result is yes, the preliminary balanced current is determined as the target balanced current; when the judgment result is no, the balanced channel number-current-temperature rise comparison table is queried to obtain the balanced current corresponding to the predicted temperature rise value that is less than and closest to the maximum temperature rise value, and the obtained balanced current is determined as the target balanced current.

10. The system according to any one of claims 6 to 8, characterized in that, It further includes: The ambient temperature detection and processing unit is used to detect the current ambient temperature, and when the difference between the current ambient temperature and the ambient temperature at the start of the previous balance is greater than a predetermined temperature difference threshold, trigger the target balanced current acquisition unit to re-obtain the latest target balanced current.

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