CN118322941B

CN118322941B - Equalizing method and equalizing device for vehicle battery pack, vehicle and storage medium

Info

Publication number: CN118322941B
Application number: CN202410746623.7A
Authority: CN
Inventors: 王印
Original assignee: Great Wall Motor Co Ltd
Current assignee: Great Wall Motor Co Ltd
Priority date: 2024-06-11
Filing date: 2024-06-11
Publication date: 2024-08-09
Anticipated expiration: 2044-06-11
Also published as: CN118322941A

Abstract

The application provides an equalization method, an equalization device, a vehicle and a storage medium of a vehicle battery pack, wherein the equalization method comprises the following steps: if the vehicle is in a charging working condition, acquiring the current residual electric quantity of a target battery pack in the vehicle; the voltage change rate of the target battery pack is smaller than the preset change rate when the current residual electric quantity of the target battery pack is in a first preset electric quantity range; if the current residual electric quantity is out of the first preset electric quantity range, identifying a target outlier cell of the target battery pack; if the target battery pack is in a full-charge state, controlling the target battery pack to be in a constant-voltage charge state; and (3) carrying out equalization treatment on the target outlier battery cells when the target battery pack is in a constant-voltage charging state. The balancing method can ensure the driving range of the vehicle when balancing the battery pack.

Description

Equalizing method and equalizing device for vehicle battery pack, vehicle and storage medium

Technical Field

The present application relates to the field of vehicles, and more particularly, to a balancing method of a vehicle battery pack, a balancing device, a vehicle, and a storage medium in the field of vehicles.

Background

In the prior art, because the battery pack has a short plate effect, the charge cut-off depends on a cell with higher voltage in the battery pack, and the discharge cut-off depends on a cell with lower voltage in the battery pack, so that the voltage difference of the cells in the battery pack is reduced, and the overall discharge capacity of the battery pack can be improved.

Currently, when the residual electric quantity of a part of battery packs (for example, lithium iron phosphate batteries) in actual use is in a target electric quantity area (for example, 30% -90%); as the change trend of the voltage is gentle along with the change of the residual electric quantity of the battery pack, the electric core difference cannot be determined according to the voltage, namely the electric core difference in the battery pack cannot be effectively identified, the overall discharge quantity of the battery pack is reduced, namely the driving range of a vehicle is reduced; therefore, how to ensure the driving range of the vehicle when balancing the battery pack is a problem that needs to be solved at present.

Disclosure of Invention

The application provides a balancing method and device for a vehicle battery pack, a vehicle and a storage medium.

In a first aspect, there is provided a balancing method of a vehicle battery pack, the balancing method including:

if the vehicle is in a charging working condition, acquiring the current residual electric quantity of a target battery pack in the vehicle; the voltage change rate of the target battery pack is smaller than a preset change rate when the current residual electric quantity of the target battery pack is in a first preset electric quantity range;

If the current residual electric quantity is out of the first preset electric quantity range, identifying a target outlier cell of the target battery pack;

if the target battery pack is in a full-charge state, controlling the target battery pack to be in a constant-voltage charging state;

and carrying out equalization treatment on the target outlier battery cells when the target battery pack is in the constant-voltage charging state.

In the embodiment of the application, the voltage change rate of the target battery pack has an association relationship with the residual electric quantity of the target battery pack; when the current residual electric quantity is in a first preset electric quantity range, the voltage change rate of the target battery pack is smaller than the preset change rate, namely when the residual electric quantity is out of the first preset electric quantity range, the voltage change rate is larger than or equal to the preset change rate; it can be understood that the voltage change rate is obvious when the residual electric quantity is out of the first preset electric quantity range, and when the voltage change rate of the target battery pack is obvious, the target outlier battery cells of the target battery pack are identified, so that the identification probability of identifying the target outlier battery cells can be improved; because the battery pack electric quantity is required to be consumed when the target outlier battery cells are subjected to balanced treatment; compared with the prior art, the method has the advantages that the target outlier battery cells are subjected to equalization processing under the constant-voltage charging state that the battery pack is in full power, so that the target battery pack still keeps the full power state after the target outlier battery cells are subjected to equalization processing; the battery pack is balanced, and meanwhile, the driving mileage of the vehicle is ensured.

With reference to the first aspect, in certain implementation manners of the first aspect, if the target battery pack is in a full-power state, controlling the target battery pack to be in a constant-voltage charging state includes:

If the target battery pack is in the full-power state, a constant-voltage request instruction is sent to a vehicle-mounted charger in the vehicle;

controlling the target battery pack to be in the constant-voltage charging state through the vehicle-mounted charger;

The constant voltage request command is used for requesting the vehicle-mounted charger to control the target battery pack to be in the constant voltage charging state.

In the embodiment of the application, if the target battery pack is in a full-charge state, a constant voltage request instruction is sent to the vehicle-mounted charger in the vehicle, and the target battery pack is controlled to be in a constant voltage state through the vehicle-mounted charger, so that the target battery pack can be controlled to be in the full-charge constant voltage state through the vehicle-mounted charger in the vehicle; thereby ensuring that the target battery pack is in a high-power state while balancing the battery packs in the vehicle; the driving range of the vehicle is ensured.

With reference to the first aspect and the foregoing implementation manners, in some implementation manners of the first aspect, identifying the target outlier cell of the target battery pack if the current remaining power is outside the first preset power range includes:

If the voltage change rate of the target battery pack in the second preset electric quantity range is larger than that in the third preset electric quantity range, determining the target outlier battery cells when the current residual electric quantity is in the second preset electric quantity range;

If the voltage change rate of the target battery pack in the second preset electric quantity range is smaller than that in the third preset electric quantity range, determining the target outlier battery cells when the current residual electric quantity is in the third preset electric quantity range;

Wherein, the maximum value of the second preset electric quantity range is the minimum value of the first preset electric quantity range; and the minimum value of the third preset electric quantity range is the maximum value of the first preset electric quantity range.

In the embodiment of the application, when the current residual electric quantity is out of the first preset electric quantity range, determining the target outlier battery cells; therefore, determining a second preset electric quantity range and a third preset electric quantity range according to the first preset electric quantity range; if the voltage change rate of the second preset electric quantity range is larger than that of the third preset range, determining a target outlier cell when the current residual electric quantity is in the second preset electric quantity range; if the voltage change rate of the second preset electric quantity range is smaller than that of the third preset range, determining a target outlier cell when the current residual electric quantity is in the third preset electric quantity range; when the current residual electric quantity is in a preset electric quantity range with a large voltage change rate, the target outlier electric core is determined, and the accurate target outlier electric core can be obtained.

With reference to the first aspect and the foregoing implementation manners, in certain implementation manners of the first aspect, the method further includes:

If an opening instruction of a battery maintenance mode in the vehicle is detected, detecting whether the vehicle is in the charging working condition; the battery maintenance mode is used for identifying the target outlier battery cells in the target battery pack when the vehicle is in the charging working condition and the current residual electric quantity is out of the first preset electric quantity range, controlling the target battery pack to be in the constant-voltage charging state when the target battery pack is charged to the full-power state, and carrying out the equalization processing on the target outlier battery cells when the target battery pack is in the constant-voltage charging state;

if the vehicle is not in the charging working condition, outputting first prompt information; the first prompt message is used for prompting a user to charge the vehicle.

In the embodiment of the application, if an opening instruction of a battery maintenance mode in the vehicle is detected, whether the vehicle is in a charging working condition is detected, and if the vehicle is not in the charging working condition, a user is prompted to charge the vehicle; the method comprises the steps that when a target battery pack is in a charging working condition through a battery maintenance mode in a vehicle, a target outlier cell in the target battery pack is identified, when the battery pack is in a full-charge state, the target battery pack is controlled to be in a constant-voltage charging state, and the target outlier cell is subjected to balanced treatment when the target battery pack is in the constant-voltage charging state; and ensuring that the vehicle is in a charging working condition when the target outlier battery cells are subjected to balanced treatment.

With reference to the first aspect and the foregoing implementation manner, in some implementation manners of the first aspect, the performing, in the constant voltage charging state of the target battery pack, equalization processing on the target outlier battery cell includes:

Acquiring the current voltage of the target outlier cell, the maximum single voltage of the target battery pack and the minimum single voltage of the target battery pack when the target battery pack is in the constant voltage charging state;

Based on the current voltage, the maximum monomer voltage and the minimum monomer voltage, controlling an equalization circuit of the target outlier cell to be started so as to perform the equalization processing on the target outlier cell through the equalization circuit; wherein the equalization circuit comprises an active equalization circuit or a passive equalization circuit.

In the embodiment of the application, when a target battery pack is in a constant voltage charging state, on the basis of the current voltage, the maximum single voltage and the minimum single voltage, an equalization circuit of a target outlier cell is controlled to be started, and equalization processing is carried out on the target outlier cell through the equalization circuit; because the equalization circuit is used for carrying out equalization treatment on the target outlier battery; therefore, it is possible to ensure that the voltage of the target outlier cell and the maximum cell voltage, or the voltage difference of the voltage of the target outlier cell and the minimum cell voltage, is reduced; thereby improving the overall discharge capacity of the battery pack.

If the voltage difference between the maximum single voltage and the minimum single voltage is detected to be smaller than a first preset voltage difference value, the equalization circuit is controlled to be closed;

outputting second prompt information; the second prompt information is used for prompting completion of equalization processing on the target outlier battery cells.

In the embodiment of the application, if the voltage difference between the maximum single voltage and the minimum single voltage is detected to be smaller than the preset voltage difference value, the equalization circuit is controlled to be started; the equalization circuit is closed when the voltage difference of each battery cell in the battery pack is smaller; the equalization circuit is closed when the target outlier cells are subjected to equalization processing, so that the outlier degree of each cell in the battery pack is smaller, the capacity difference of the cells in the battery pack is reduced, and the overall discharge capacity of the battery pack is improved.

If the current residual electric quantity is out of the first preset electric quantity range, acquiring a current voltage value of each electric core in the target battery pack;

If the difference value between the current maximum single voltage and the current minimum single voltage in the target battery pack is larger than a second preset voltage difference value, determining a first voltage difference between the current voltage of the target battery cell and the current maximum single voltage and a second voltage difference between the current voltage of the target battery cell and the current minimum single voltage;

if the first voltage difference and/or the second voltage difference is greater than a first preset voltage difference value, determining that the target battery cell is the target outlier battery cell;

The first preset voltage difference value is smaller than the second preset voltage difference value.

In the embodiment of the application, when the difference value between the current maximum single voltage and the current minimum single voltage in the target battery pack is larger than the second preset voltage difference value, the poor consistency of the target battery pack is determined; at this time, determining a target outlier cell according to the current voltage, the maximum monomer voltage and the minimum monomer voltage of the target cell in each cell; under the condition that the consistency of the target battery pack is poor, determining a target outlier battery cell; and when the consistency of the battery packs is good, the extra power consumption caused by identifying the target outlier battery cells is avoided.

In a second aspect, there is provided an equalizing device of a vehicle battery pack, the equalizing device including:

The acquisition module is used for acquiring the current residual electric quantity of a target battery pack in the vehicle if the vehicle is in a charging working condition; the voltage change rate of the target battery pack is smaller than a preset change rate when the current residual electric quantity of the target battery pack is in a first preset electric quantity range;

The identification module is used for identifying a target outlier cell of the target battery pack if the current residual electric quantity is out of the first preset electric quantity range;

the control module is used for controlling the target battery pack to be in a constant voltage charging state if the target battery pack is in a full-charge state;

And the processing module is used for carrying out equalization processing on the target outlier battery cells when the target battery pack is in the constant-voltage charging state.

In a third aspect, a vehicle is provided, comprising a memory for storing executable program code and a processor for calling and running the executable program code from the memory, such that the vehicle performs the equalisation method according to the first aspect or any one of the possible implementations of the first aspect.

In a fourth aspect, there is provided a computer program product comprising: computer program code which, when run on a computer, causes the computer to perform the equalization method of the first aspect or any one of the possible implementations of the first aspect.

In a fifth aspect, a computer readable storage medium is provided, the computer readable storage medium storing instructions that, when run on a vehicle, cause the vehicle to perform the equalisation method of the first aspect or any one of the possible implementations of the first aspect.

Drawings

Fig. 1 is a graph showing a change relation between a remaining battery pack power and a battery pack voltage according to an embodiment of the present application;

fig. 2 is a graph showing a change relation between a remaining battery capacity and a battery cell voltage of the battery pack according to the embodiment of the present application;

fig. 3 is a schematic flow chart of a method for equalizing a vehicle battery pack according to an embodiment of the present application;

fig. 4 is a schematic flow chart of another method for equalizing a vehicle battery pack provided by an embodiment of the present application;

Fig. 5 is a schematic structural diagram of an equalization apparatus for a vehicle battery pack according to an embodiment of the present application;

Fig. 6 is a schematic structural diagram of a vehicle according to an embodiment of the present application.

Detailed Description

The technical scheme of the application will be clearly and thoroughly described below with reference to the accompanying drawings. Wherein, in the description of the embodiments of the present application, unless otherwise indicated, "/" means or, for example, a/B may represent a or B: the text "and/or" is merely an association relation describing the associated object, and indicates that three relations may exist, for example, a and/or B may indicate: the three cases where a exists alone, a and B exist together, and B exists alone, and furthermore, in the description of the embodiments of the present application, "plural" means two or more than two.

The terms "first," "second," and the like, are used below for descriptive purposes only and are not to be construed as implying or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

Currently, when the residual electric quantity of a part of battery packs (for example, lithium iron phosphate batteries) in actual use is in a target electric quantity area (for example, 30% -90%); as the change trend of the voltage is gentle along with the change of the residual electric quantity of the battery pack, the electric core difference cannot be determined according to the voltage, namely the electric core difference in the battery pack cannot be effectively identified, so that the outlier electric core in the battery pack cannot be determined, the overall discharge quantity of the battery pack is reduced, namely the driving range of a vehicle is reduced; therefore, how to ensure the driving range of the vehicle when balancing the battery pack is a problem that needs to be solved at present.

Wherein, the outlier cell refers to a cell which has obvious difference compared with other cells in the battery pack, such as voltage, capacity or internal resistance. Such imbalance can reduce the amount of power available to the entire battery pack and the life of the battery pack.

In view of the above, the present application provides an equalizing method, an equalizing device, a vehicle and a storage medium for a vehicle battery pack, by which the difference between battery cells in the battery pack can be effectively identified, and the battery pack is controlled to be in a constant voltage charging state when the battery pack is in a full-charge state, and in the constant voltage charging state, an equalizing process is performed on a target outlier battery cell, that is, an outlier battery cell with a low voltage is charged by an active equalizing circuit, or an outlier battery cell with a high voltage is discharged by a passive equalizing circuit; therefore, the battery pack is balanced, and the driving range of the vehicle is ensured.

Fig. 1 is a graph showing a change relationship between a remaining battery pack power and a battery pack voltage according to an embodiment of the present application.

As shown in a change relation curve 100 in fig. 1, when the remaining capacity (SOC) of the battery pack is within a capacity range of 30% -90%, the voltage change trend of the battery pack is relatively gentle, i.e., the voltage change rate of the battery pack is relatively small, according to the change of the remaining capacity of the battery pack; and when the remaining capacity of the battery pack is less than 30% or more than 90%, the voltage change rate of the battery pack is greater as the remaining capacity of the battery pack is changed.

Fig. 2 is a graph showing a change relationship between a remaining battery capacity and a battery cell voltage according to an embodiment of the present application.

As shown in the change relation curve 200 in fig. 2, when the remaining power of the battery pack is within the power interval of 30% -90%, the voltage change trend of the battery cell is relatively gentle, that is, the voltage change rate of the battery cell is relatively small, along with the change of the remaining power of the battery pack; and when the residual electric quantity of the battery pack is less than 30% or more than 90%, the voltage change rate of the battery cell is large.

As shown in fig. 1 and 2, the voltage variation trend of the battery cell is consistent with the voltage variation trend of the battery pack; therefore, when the SOC of the battery pack is in the electric quantity interval of 30% -90%, the voltage change rate of the battery pack is smaller, namely the voltage change rate of each battery core in the battery pack is smaller, and the voltage difference distinction between the battery cores is smaller; therefore, the consistency of each cell in the battery pack cannot be identified by the voltage; when the SOC of the battery pack is less than 30% or more than 90%, the voltage change rate of the battery pack is large; the voltage change rate of each cell in the battery pack is larger, namely the voltage difference distinction between the cells is larger; therefore, when the SOC of the battery pack is less than 30% or greater than 90%, it is possible to recognize the outlier cells in the battery pack by the voltage change rate.

The equalization method of the vehicle battery pack according to the embodiment of the present application will be described in detail with reference to fig. 3 to 4.

Fig. 3 is a schematic flow chart of a method for equalizing a vehicle battery pack according to an embodiment of the present application.

By way of example, the equalization method of the vehicle battery pack shown in fig. 3 may be performed by a vehicle; or may be performed by a battery management system in the vehicle; or may be executed by a processor or chip in the vehicle.

As shown in fig. 3, the equalizing method 300 of the vehicle battery pack includes S310 to S340, and S310 to S340 are described in detail below.

S310, if the vehicle is in a charging working condition, acquiring the current residual electric quantity of a target battery pack in the vehicle.

When the current residual electric quantity of the target battery pack is in a first preset electric quantity range, the voltage change rate of the target battery pack is smaller than the preset change rate.

The voltage change rate is used for representing the change trend of the voltage along with the change of the residual electric quantity under the current residual electric quantity.

Exemplary, the correspondence between the current remaining capacity of the target battery pack and the voltage of the target battery pack is shown in fig. 1; when the residual electric quantity of the target battery pack is in low electric quantity or high electric quantity, the voltage change trend is obvious; when the residual electric quantity of the target battery pack is in the middle electric quantity, the voltage change trend is gentle.

In an exemplary embodiment, a first preset power range in which a voltage change rate of the battery pack is greater than a preset change rate is determined according to a relationship between a current remaining power of the target battery pack and the voltage change rate of the target battery pack.

For example, if the preset change rate is 0.4 and the SOC having the voltage change rate smaller than the preset change rate is determined to be 30% -90%, the determined first preset electric quantity range is 30% -90% of the SOC.

It should be noted that the foregoing is illustrative of the preset rate of change, and the present application is not limited thereto.

S320, if the current residual electric quantity is out of the first preset electric quantity range, identifying a target outlier cell of the target battery pack.

It should be noted that, because the current remaining power is outside the first preset power range, it means that the voltage change rate is greater than the preset change rate under the current remaining power; therefore, the target outlier cell of the target battery pack can be identified according to the change of the voltage.

In one implementation manner, identifying the target outlier cell of the target battery pack if the current remaining power is out of the first preset power range includes:

if the voltage change rate of the target battery pack in the second preset electric quantity range is larger than that in the third preset electric quantity range, determining a target outlier battery cell when the current residual electric quantity is in the second preset electric quantity range;

if the voltage change rate of the target battery pack in the second preset electric quantity range is smaller than that in the third preset electric quantity range, determining a target outlier battery cell when the current residual electric quantity is in the third preset electric quantity range;

Wherein the maximum value of the second preset electric quantity range is the minimum value of the first preset electric quantity range; the minimum value of the third preset electric quantity range is the maximum value of the first preset electric quantity range.

The current remaining power is outside the first preset power range, including a minimum value that the current remaining power is smaller than the first preset power range, i.e., the current remaining power is within the second preset power range; and the current residual electric quantity is larger than the maximum value of the first preset electric quantity range, namely the current residual electric quantity is in a third preset range.

Illustratively, the greater the rate of change of voltage, the more accurate the target outlier cells identified from the voltage; therefore, if the voltage change rate of the target battery pack in the second preset electric quantity range is larger than that in the third preset electric quantity range, determining the target outlier battery core when the current residual electric quantity is in the second preset electric quantity range; if the voltage change rate of the target battery pack in the second preset electric quantity range is smaller than that in the third preset electric quantity range, determining the target outlier battery core when the current residual electric quantity is in the third preset electric quantity range.

It should be understood that, since the current remaining power is in the second preset power range and the third preset power range, the voltage change rate of the target battery pack is greater than the preset change rate; therefore, the target outlier cells can be identified; however, the greater the voltage change rate, the more accurate the identified target outlier cells; therefore, in the second preset electric quantity range and the third preset electric quantity range, the electric quantity range with larger voltage change rate identifies the target outlier battery cell; the accuracy of identifying the outlier battery cells can be improved.

For example, the first preset electric quantity range is 30% to 90%, the second preset electric quantity range is determined to be 0% to 30%, and the third preset electric quantity range is determined to be 90% to 100%; if the voltage change rate in the first preset electric quantity range is 2.5, the voltage change rate in the first preset electric quantity range is 1.1; and determining the target outlier battery cell when the current residual electric quantity is in the second preset electric quantity range.

The foregoing is illustrative of the rate of change of the voltage, and the present application is not limited thereto.

if the difference value between the current maximum single voltage and the current minimum single voltage in the target battery pack is larger than the second preset voltage difference value, determining a first voltage difference between the current voltage of the target battery cell and the current maximum single voltage and a second voltage difference between the current voltage of the target battery cell and the current minimum single voltage;

If the first voltage difference and/or the second voltage difference is greater than a first preset voltage difference value, determining that the target battery cell is a target outlier battery cell;

When determining the target outlier cell in each cell, firstly judging the difference value between the current maximum cell voltage and the current minimum cell voltage in the target cell package, and when the difference value is larger than a second preset voltage difference value, indicating that the consistency of the current target cell package is poor; therefore, it is necessary to determine the target outlier cell according to the current voltage of each cell in the target battery pack; specifically, if the difference between the voltage of the target cell and the maximum cell voltage in each cell is greater than a first preset voltage difference, and/or if the difference between the voltage of the target cell and the minimum cell voltage in each cell is greater than a first preset voltage difference, determining that the target cell is a target outlier cell.

It should be noted that, the second preset voltage difference is used for determining the consistency of the battery pack, that is, for determining the overall difference of the battery cells in the battery pack; if the difference value between the current maximum single voltage and the current minimum single voltage is larger than the second preset difference value, the consistency of the battery pack is poor; under the condition of poor consistency of the battery packs, the outlier degree of each battery cell is further determined; if the difference value between the current maximum single voltage and the current minimum single voltage is smaller than or equal to the second preset difference value, the consistency of the battery pack is good, and the overall difference of each battery core is small; then there is no need to determine the target outlier cell.

For example, the second preset voltage difference is 0.1V, the first preset voltage difference is 0.05V, the first preset electric quantity range is 30% to 90%, the current residual electric quantity is 95%, the current maximum monomer voltage is 3.55V, and the current minimum monomer voltage is 3.00V outside the first preset electric quantity range; the difference between the current maximum monomer voltage and the current minimum monomer voltage is 0.55V and is larger than the second preset voltage difference; indicating that the consistency of the current battery pack is poor, and further determining a target outlier cell in the battery pack; if the voltage of the target battery cell in the battery pack is detected to be 3.40V, and the difference value between the voltage of the target battery cell and the maximum single voltage is larger than a second preset difference value, the target battery cell is determined to be the target outlier battery cell.

S330, if the target battery pack is in the full state, the target battery pack is controlled to be in the constant voltage charging state.

The constant voltage charge state refers to a state in which the target battery pack is charged with a constant voltage. The SOC in the target battery pack increases during charging, and the voltage gradually approaches a set voltage (e.g., 12V), and the current in the target battery pack gradually decreases in order to maintain a constant voltage.

Illustratively, when the target battery pack is in the full state, the total voltage of the current target battery pack is determined, and the voltage when the target battery pack is in the constant voltage charge state is controlled to be the total voltage of the battery pack in the full state.

In one implementation manner, if the target battery pack is in the full-charge state, controlling the target battery pack to be in the constant-voltage charge state includes:

if the target battery pack is in a full-charge state, a constant voltage request instruction is sent to a vehicle-mounted charger in the vehicle;

the target battery pack is controlled to be in a constant-voltage charging state through the vehicle-mounted charger;

The constant voltage request command is used for requesting the vehicle-mounted charger to control the target battery pack to be in a constant voltage charging state.

An On Board Charger (OBC) is an apparatus for converting ac power to dc power, for example, installed in a vehicle. It converts the ac voltage of the charging station to the dc voltage required by the battery.

Illustratively, the vehicle requests the OBC control target battery pack to be in a constant voltage charge state by sending a constant voltage request command to an on-board charger in the vehicle.

Optionally, if the target battery pack is not in the full state, after the target battery pack is charged to the full state, the target battery pack is controlled to be in the constant voltage charging state.

And S340, performing equalization processing on the target outlier battery cells when the target battery pack is in a constant voltage charging state.

In one implementation manner, the equalizing the target outlier battery cells when the target battery pack is in the constant voltage charging state includes:

acquiring the current voltage of a target outlier cell, the maximum single voltage of the target battery pack and the minimum single voltage of the target battery pack when the target battery pack is in a constant voltage charging state;

Based on the current voltage, the maximum monomer voltage and the minimum monomer voltage, controlling an equalization circuit of the target outlier cell to be started so as to perform equalization treatment on the target outlier cell through the equalization circuit; the equalization circuit comprises an active equalization circuit or a passive equalization circuit.

The active equalization circuit charges the low-voltage battery cells in the target battery pack to reduce the voltage difference of the battery cells in the target battery pack, so that the battery cells are equalized; the passive equalization circuit discharges a high-voltage battery cell in the target battery pack to reduce the voltage difference of the battery cell in the target battery pack; the voltage difference between the low-voltage battery cell and the high-voltage battery cell is reduced through the active equalization circuit or the passive equalization circuit, so that the battery cell equalization is realized, and the overall discharge capacity of the battery pack is improved.

The power consumption of the target outlier cell balanced by the active balancing circuit is different from the power consumption of the target outlier cell balanced by the passive balancing circuit.

For example, the target battery pack comprises 5 electric cores, and the difference value between the voltage value of 1 outlier electric core in the 5 electric cores and the maximum single voltage is larger than the first preset voltage difference value; at this time, if the outlier battery cells are subjected to equalization processing by the active equalization circuit, the outlier battery cells need to be charged, so that the voltage of the outlier battery cells is increased, and the difference between the voltage of the outlier battery cells and the maximum monomer voltage is reduced; if the equalization processing is carried out by the passive equalization circuit, 4 electric cores except for the outlier electric core are required to be discharged, so that the maximum monomer voltage is reduced, and the difference between the voltage of the outlier electric core and the maximum monomer voltage is reduced; therefore, when the battery pack of the vehicle is subjected to the equalization processing, the power consumption of the active equalization circuit is lower than that of the passive equalization circuit; by performing active equalization processing on the battery pack, the available discharge amount of the vehicle can be increased, thereby ensuring the driving range of the vehicle.

It should be noted that the foregoing is illustrative of the battery cells in the target battery pack, and the present application is not limited thereto.

Exemplary, when the target outlier battery cells are subjected to equalization processing, the method comprises the steps of performing equalization processing on the target outlier battery cells through an active equalization circuit or performing equalization processing on the outlier battery cells through a passive equalization circuit; the processing methods in these two cases are described in detail below.

Case 1: and carrying out equalization treatment on the target outlier battery cells through an active equalization circuit.

For example, if the target battery pack is in a full state, the voltages of the cells in the target battery pack are shown in table 1.

TABLE 1

Illustratively, as shown in table 1, the target battery pack is composed of 5 cells, including: a No. 1 electric core, a No. 2 electric core, a No. 3 electric core, a No. 4 electric core and a No. 5 electric core; wherein the cell voltage of the cell number 1 is 3.55V; the cell voltage of the cell number 2 is 3.28V; the cell voltage of the cell number 3 is 3.25V; the cell voltage of the cell number 4 is 3.40V; the cell voltage of cell number 5 is 3.50V.

It should be noted that the foregoing is illustrative of the number of the battery cells and the voltage of the battery cells in the target battery pack, and the present application is not limited thereto; the active equalization circuit and the passive equalization circuit are illustrated in table 1 below.

For example, according to table 1, it may be determined that the maximum cell voltage in the target battery pack is 3.55V corresponding to the No. 1 cell, and the minimum cell voltage in the target battery pack is 3.25V corresponding to the No. 3 cell; the difference between the maximum monomer voltage and the minimum monomer voltage is 0.3V and is larger than the second preset voltage difference by 0.1V; indicating poor consistency of the target battery pack; determining that the battery cells with the difference value between the battery cell voltage and the maximum monomer voltage in each battery cell being larger than the first preset voltage difference value by 0.5V are target outlier battery cells; determining that the target outlier cell is a No. 2 cell, a No. 3 cell and a No. 4 cell; therefore, the active equalization circuit of the No. 2 battery cell, the active equalization circuit of the No. 3 battery cell and the active equalization circuit of the No. 4 battery cell are controlled to be started, and the No. 2 battery cell, the No. 3 battery cell and the No. 4 battery cell are charged; so that the voltage of the target outlier cell rises to a voltage difference with the cell number 1 which is smaller than a first preset voltage difference value.

Case 2: and carrying out equalization treatment on the outlier battery cells through a passive equalization circuit.

For example, according to table 1, it is determined that the maximum cell voltage in the target battery pack is 3.55V corresponding to the No. 1 cell, and the minimum cell voltage in the target battery pack is 3.25V corresponding to the No. 3 cell; determining that the battery cells with the difference value between the battery cell voltage and the minimum monomer voltage in each battery cell being larger than the first preset voltage difference value by 0.5V are target outlier battery cells; determining that the target outlier cell is a cell number 1, a cell number 4 and a cell number 5; therefore, the passive equalization circuit of the No. 1 cell, the passive equalization circuit of the No. 4 cell and the passive equalization circuit of the No. 5 cell are controlled to be started, and the No. 1 cell, the No. 4 cell and the No. 5 cell are discharged; so that the voltage of the No. 1 electric core, the No. 4 electric core and the No. 5 electric core is reduced to a voltage difference with the No. 1 electric core which is smaller than a first preset voltage difference value.

The foregoing is illustrative of the number of the cells and the cell voltage, which is not limited by the present application.

In one implementation, the equalization method further includes:

if the voltage difference between the maximum single voltage and the minimum single voltage is detected to be smaller than the first preset voltage difference value, the equalization circuit is controlled to be closed;

outputting second prompt information; the second prompt information is used for prompting that the equalization processing of the target outlier battery cells is completed.

Illustratively, the cell voltage in the target battery pack is monitored while the target outlier cells are being equalized; when the voltage difference between the maximum single voltage and the minimum single voltage is smaller than the first preset voltage, the consistency of the current target battery pack is better, namely the difference of each battery core in the battery pack is smaller; therefore, the equalization circuit is controlled to be closed, and a second prompt message is sent to prompt that the equalization processing of the target outlier battery cells is completed.

In one implementation, the equalization method further includes:

If an opening instruction of a battery maintenance mode in the vehicle is detected, detecting whether the vehicle is in a charging working condition; the battery maintenance mode is used for identifying a target outlier cell in the target battery pack when the vehicle is in a charging working condition and the current residual electric quantity is out of a first preset electric quantity range, controlling the target battery pack to be in a constant voltage charging state when the target battery pack is charged to a full electric state, and carrying out balanced treatment on the target outlier cell when the target battery pack is in the constant voltage charging state;

For example, if an instruction for starting a battery maintenance mode in the vehicle is detected, for example, a user is detected to click on the battery maintenance mode on a control screen in the vehicle; detecting whether the vehicle is in a charging working condition, if the vehicle is in the charging working condition and the current residual electric quantity is out of a first preset electric quantity range, identifying a target outlier cell in a target battery pack, controlling the target battery pack to be in a constant-voltage charging state when the target battery pack is charged to a full-charge state, and carrying out balanced treatment on the target outlier cell in the constant-voltage charging state; if the vehicle is not in the charging working condition, outputting first prompt information to prompt a user to charge the vehicle.

For example, it may be determined whether the vehicle is in a charged state by detecting a charging gun of the vehicle; if the charging gun of the vehicle is not in a connection state, outputting prompt information; for example, "please connect the charging device" is displayed on the center control screen of the vehicle.

In the embodiment of the application, if an opening instruction of a battery maintenance mode in the vehicle is detected, whether the vehicle is in a charging working condition is detected, and if the vehicle is not in the charging working condition, a user is prompted to charge the vehicle; the method comprises the steps that a target outlier cell in a target battery pack can be identified through a battery maintenance mode in a vehicle, when the battery pack is in a full-charge state, the target battery pack is controlled to be in a constant-voltage charge state, and in the constant-voltage charge state, the target outlier cell is subjected to balanced treatment; and ensuring that the vehicle is in a charging working condition when the target outlier battery cells are subjected to balanced treatment.

In the above embodiment, since the voltage change rate of the target battery pack has an association relationship with the remaining power of the target battery pack; when the current residual electric quantity is in a first preset electric quantity range, the voltage change rate of the target battery pack is smaller than the preset change rate, namely when the residual electric quantity is out of the first preset electric quantity range, the voltage change rate is larger than or equal to the preset change rate; it can be understood that the voltage change rate is obvious when the residual electric quantity is out of the first preset electric quantity range, and when the voltage change rate of the target battery pack is obvious, the target outlier battery cells of the target battery pack are identified, so that the identification probability of identifying the target outlier battery cells can be improved; because the battery pack electric quantity is required to be consumed when the target outlier battery cells are subjected to balanced treatment; compared with the prior art, the method has the advantages that the target outlier battery cells are subjected to equalization processing under the constant-voltage charging state that the battery pack is in full power, so that the target battery pack still keeps the full power state after the target outlier battery cells are subjected to equalization processing; the method and the device realize the balance of the target battery pack and ensure the driving range of the vehicle.

Fig. 4 is a schematic flow chart of another method for equalizing a vehicle battery pack according to an embodiment of the present application.

Illustratively, and exemplary, the method of balancing a vehicle battery pack shown in fig. 4 may be performed by a vehicle; or may be performed by a battery management system in the vehicle; or may be executed by a processor or chip in the vehicle.

As shown in fig. 4, the equalizing method 400 of the vehicle battery pack includes S401 to S412, and S401 to S412 are described in detail below.

S401, if the vehicle is in a charging working condition, acquiring the current residual electric quantity of a target battery pack in the vehicle.

Alternatively, implementation of S401 may be described with reference to S310 in fig. 3; and will not be described in detail herein.

S402, determining a first preset electric quantity range with a voltage change rate smaller than a preset change rate based on a corresponding relation between the residual electric quantity of the target battery pack and the voltage of the target battery pack.

Exemplary, the correspondence between the remaining capacity of the target battery pack and the voltage of the target battery pack is shown in fig. 1; if the voltage change rate corresponding to the current residual electric quantity is smaller than the preset change rate, the fact that the target outlier battery cells cannot be accurately identified according to the voltage under the current residual electric quantity is indicated.

S403, if the residual electric quantity is out of the first preset electric quantity range, acquiring the current voltage value of each electric core in the target battery pack.

For example, if the remaining power is out of the first preset power range, it indicates that the voltage change rate corresponding to the remaining power is greater than the preset change rate, that is, the target outlier battery cell can be identified according to the voltage under the current remaining power.

S404, judging whether the difference value between the current maximum single voltage and the current minimum single voltage is larger than a second preset voltage difference value; if yes, S405 and S406 are executed.

Exemplary, judging whether the difference between the current maximum cell voltage and the minimum cell voltage is greater than a second preset voltage difference; if the difference value is larger than the second preset voltage difference value, the consistency of the current target battery pack is poor; therefore, it is necessary to determine the target outlier cell according to the current voltage of each cell in the target battery pack; i.e. S405 and S406 are performed.

S405, determining a first voltage difference between the current voltage of the target battery cell and the maximum cell voltage.

S406, determining a second voltage difference between the current voltage of the target battery cell and the minimum cell voltage.

Alternatively, implementation of S405 and S406 may be described with reference to S320 in fig. 3; and will not be described in detail herein.

S407, if the first voltage difference and/or the second voltage difference is greater than the first preset voltage difference, determining the target cell as the target outlier cell.

The first preset voltage difference is used for determining the outlier degree of the target battery cells in the target battery pack; when the first voltage difference and/or the second voltage difference is larger than the first preset voltage difference, the outlier degree of the target battery cell is larger, namely the target battery cell is determined to be the target outlier battery cell.

S408, judging whether the target battery pack is in a full-power state; if yes, executing S309; if not, S310 is performed.

Illustratively, determining whether the target Battery pack is in a full state by a Battery management system (Battery MANAGEMENT SYSTEM, BMS) of the vehicle; if yes, controlling the target battery pack to be in a constant voltage charging state; and if not, charging the target battery pack to a full-charge state.

S409, the control target battery pack is in a constant voltage charge state.

The method comprises the steps of sending a constant voltage request instruction to a vehicle-mounted charger in a vehicle; and controlling the target battery pack to be in a constant-voltage charging state through the vehicle-mounted charger.

Optionally, the implementation of S409 may be referred to as related description in S330 in fig. 3; and will not be described in detail herein.

And S410, charging the target battery pack to a full state.

For example, any charging method may be used when charging the target battery pack; for example, a target battery pack of a vehicle is charged by connecting a charging gun, or a battery pack in a vehicle is wirelessly charged by electromagnetic induction, electric field coupling, magnetic resonance, radio waves, or the like.

S411, acquiring the current voltage of the target outlier cell, and the maximum single voltage and the minimum single voltage of the target battery pack.

Alternatively, implementation of S411 may be described with reference to S340 in fig. 3; and will not be described in detail herein.

And S412, controlling the equalization circuit of the target outlier cell to be started based on the current voltage, the maximum monomer voltage and the minimum monomer voltage.

The equalization circuit comprises an active equalization circuit and a passive equalization circuit.

Optionally, the implementation of S412 may refer to the description related to case 1 and case 2 in S340 in fig. 3; and will not be described in detail herein.

In the embodiment of the application, when the voltage change rate of the target battery pack is larger than the preset change rate, the target outlier battery cells of the target battery pack are identified, and the identification probability of identifying the target outlier battery cells is improved; the method comprises the steps that under the constant voltage charging state that the battery pack is in full power, the target outlier battery cells are subjected to balanced treatment, and the target battery pack is still kept in the full power state after the target outlier battery cells are subjected to balanced treatment; the method and the device realize the balance of the target battery pack and ensure the driving range of the vehicle.

The balancing method of the vehicle battery pack provided by the embodiment of the application is described in detail above with reference to fig. 3 and 4; an embodiment of the device of the present application will be described in detail with reference to fig. 5 and 6. It should be understood that the apparatus in the embodiments of the present application may perform the methods of the foregoing embodiments of the present application, that is, specific working procedures of the following various products may refer to corresponding procedures in the foregoing method embodiments.

Fig. 5 is a schematic structural diagram of an equalization apparatus for a vehicle battery pack according to an embodiment of the present application.

As shown in fig. 5, an equalization apparatus 500 of a vehicle battery pack includes:

the obtaining module 510 is configured to obtain a current remaining capacity of a target battery pack in the vehicle if the vehicle is in a charging condition; the voltage change rate of the target battery pack is smaller than the preset change rate when the current residual electric quantity of the target battery pack is in a first preset electric quantity range;

The identifying module 520 is configured to identify a target outlier cell of the target battery pack if the current remaining power is outside the first preset power range;

The control module 530 is configured to control the target battery pack to be in a constant voltage charging state if the target battery pack is in a full power state;

the processing module 540 is configured to perform equalization processing on the target outlier battery cells when the target battery pack is in a constant voltage charging state.

Optionally, as an embodiment, the control module 530 is specifically configured to:

Optionally, as an embodiment, the identification module 520 is specifically configured to:

Optionally, as an embodiment, the device further includes a detection module, where the detection module is specifically configured to:

If an opening instruction of a battery maintenance mode in the vehicle is detected, detecting whether the vehicle is in a charging working condition; the battery maintenance mode is used for carrying out equalization processing on the target outlier battery cells when the target outlier battery cells exist in the target battery pack;

if the vehicle is not in the charging working condition, outputting first prompt information; wherein the first prompt message is used for prompting a user to charge the vehicle

Optionally, as an embodiment, the processing module 540 is specifically configured to:

Optionally, as an embodiment, the processing module 540 is further configured to:

The equalization device of the vehicle is embodied in the form of a functional unit. The term "module" herein may be implemented in software and/or hardware, and is not specifically limited thereto.

For example, a "module" may be a software program, a hardware circuit, or a combination of both that implements the functionality described above. The hardware circuitry may include Application Specific Integrated Circuits (ASICs), electronic circuits, processors (e.g., shared, proprietary, or group processors, etc.) and memory for executing one or more software or firmware programs, merged logic circuits, and/or other suitable components that support the described functions.

Thus, the elements of the examples described in the embodiments of the present application can be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

Illustratively, the vehicle 600 includes: a processor 610, a memory 620, and executable program code 630.

Illustratively, the vehicle 600 includes one or more processors 610, the one or more processors 610 may support the vehicle 600 to implement the vehicle battery pack balancing method in the method embodiments. The processor 610 may be a general purpose processor or a special purpose processor. For example, the processor 610 may be a central processing unit (central processing unit, CPU), a digital signal processor (DIGITAL SIGNAL processor, DSP), an Application Specific Integrated Circuit (ASIC), a field programmable gate array (field programmable GATE ARRAY, FPGA), or other programmable logic device such as discrete gates, transistor logic, or discrete hardware components.

For example, the processor 610 may be configured to control the vehicle 600, execute a software program, and process data of the software program. The vehicle 600 may also include a communication unit to enable input (reception) and output (transmission) of signals.

For example, the vehicle 600 may include one or more memories 620 having executable program code 630 stored thereon, the executable program code 630 being executable by the processor 610 to generate instructions such that the processor 610 performs the method of balancing a vehicle battery pack described in the above method embodiments according to the instructions.

Optionally, the memory 620 may also have data stored therein. Optionally, the processor 610 may also read data stored in the memory 620, which may be stored at the same memory address as the executable program code 630, or which may be stored at a different memory address than the executable program code 630.

The processor 610 and the memory 620 may be provided separately or may be integrated together, for example, on a System On Chip (SOC) of the terminal device.

Illustratively, the memory 620 may be used to store a program related to the method for balancing a vehicle battery pack provided in the embodiment of the present application, and the processor 620 may be used to invoke the executable program code 630 stored in the memory 620 when controlling the vehicle, to perform the method for balancing a vehicle battery pack of the embodiment of the present application; for example, if the vehicle is in a charging condition, acquiring the current residual capacity of a target battery pack in the vehicle; the voltage change rate of the target battery pack is smaller than the preset change rate when the current residual electric quantity of the target battery pack is in a first preset electric quantity range; if the current residual electric quantity is out of the first preset electric quantity range, identifying a target outlier cell of the target battery pack; if the target battery pack is in a full-charge state, controlling the target battery pack to be in a constant-voltage charge state; and (3) carrying out equalization treatment on the target outlier battery cells when the target battery pack is in a constant-voltage charging state.

The present application also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of the equalizing method of a vehicle battery pack of any of the foregoing embodiments.

The computer readable storage medium may include, among other things, any type of disk including floppy disks, optical disks, digital versatile disks (Digital Video Disc, DVD), compact disk Read-Only Memory (CD-ROM), micro-drives, and magneto-optical disks, read-Only Memory (ROM), random access Memory (Random Access Memory, RAM), erasable programmable Read-Only Memory (Erasable Programmable Read-Only Memory, EPROM), electrically erasable programmable Read-Only Memory (ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY, EEPROM), dynamic random access Memory (Dynamic Random Access Memory, DRAM), image random access Memory (Video Random Access Memory, VRAM), flash Memory devices, magnetic or optical cards, nanosystems (including molecular Memory ICs), or any type of medium or device suitable for storing instructions and/or data.

The present application also provides a computer program product which, when run on a computer, causes the computer to perform the above-described related steps to implement a method of equalizing a vehicle battery pack in the above-described embodiments.

In addition, the electronic device provided by the embodiment of the application can be a chip, a component or a module, and the electronic device can comprise a processor and a memory which are connected; the memory is used for storing instructions, and when the electronic device is running, the processor can call and execute the instructions to enable the chip to execute the balancing method of the vehicle battery pack in the embodiment.

The vehicle, the computer readable storage medium, the computer program product or the chip provided by the application are used for executing the corresponding vehicle battery pack balancing method provided above, so that the beneficial effects of the method can be referred to as beneficial effects in the corresponding vehicle battery pack balancing method provided above, and are not repeated herein.

It will be appreciated by those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional modules is illustrated, and in practical application, the above-described functional allocation may be performed by different functional modules according to needs, i.e. the internal structure of the apparatus is divided into different functional modules to perform all or part of the functions described above.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of modules or units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another apparatus, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims

1. A method of equalizing a vehicle battery pack, the method comprising:

2. The equalization method of claim 1, wherein controlling the target battery pack to be in a constant voltage charge state if the target battery pack is in a full charge state comprises:

3. The method of claim 1, wherein identifying the target outlier cell of the target battery pack if the current remaining power is outside the first preset power range comprises:

4. The equalization method of claim 1, further comprising:

5. The equalization method of claim 1, wherein the equalizing the target outlier cells while the target battery pack is in the constant voltage charge state comprises:

6. The equalization method of claim 5, further comprising:

7. The method of claim 1, wherein identifying the target outlier cell of the target battery pack if the current remaining power is outside the first preset power range comprises:

8. An equalizing device for a vehicle battery pack, the equalizing device comprising:

9. A vehicle, characterized in that the vehicle comprises:

a memory for storing executable program code;

Processor for calling and running the executable program code from the memory, causing the vehicle to perform the equalisation method according to any one of the claims 1 to 7.

10. A computer readable storage medium, characterized in that the computer readable storage medium has stored therein instructions, which when run on a vehicle, cause the vehicle to perform the equalisation method according to any one of the claims 1 to 7.