阅读说明：本技术 一种充电控制方法及装置 (Charging control method and device ) 是由 陆珂伟 王林 曹建华 李飞 孟浩田 于 2018-08-15 设计创作，主要内容包括：本申请公开了一种充电控制方法及装置,能够使不同健康状态下的电芯充满电,该方法包括：获取目标电芯在当前检测时刻的电芯参数,根据目标SOC和电芯参数,预测目标电芯的充电截止电压；检测当前电芯电压和当前充电电流；计算当前电芯电压与充电截止电压之间的电压差值；判断目标电芯是否满足充电停止条件；若是,则停止充电；若否,则利用电压差值调节当前充电电流,将下一检测时刻作为当前检测时刻,继续执行检测当前电芯电压和当前充电电流的步骤。可见,本申请通过电芯参数及目标SOC等调节了电池的充电电压和充电电流,确保了不同健康状态下的电芯能够真正充满。(The application discloses a charging control method and a charging control device, which can fully charge electric cores in different health states, and the method comprises the following steps: acquiring a cell parameter of a target cell at the current detection moment, and predicting the charge cut-off voltage of the target cell according to the target SOC and the cell parameter; detecting the current cell voltage and the current charging current; calculating a voltage difference value between the current cell voltage and the charging cut-off voltage; judging whether the target battery cell meets a charging stop condition; if yes, stopping charging; if not, adjusting the current charging current by using the voltage difference value, taking the next detection moment as the current detection moment, and continuously executing the step of detecting the current cell voltage and the current charging current. Therefore, the charging voltage and the charging current of the battery are adjusted through the cell parameters, the target SOC and the like, and the cells in different health states can be fully charged.)

1. A charge control method, comprising:

acquiring a cell parameter of a target cell at the current detection moment;

predicting a charge cut-off voltage of the target battery cell according to a target SOC and the battery cell parameter, wherein the target SOC is an SOC of the target battery cell in an open circuit state at the current moment;

detecting a current cell voltage and a current charging current, wherein the current cell voltage is a voltage of the target cell at the current moment, and the current charging current is a charging current of the target cell at the current moment;

calculating a voltage difference between the current cell voltage and the charge cutoff voltage;

judging whether the target battery cell meets a charging stop condition; if yes, stopping charging; if not, adjusting the current charging current by using the voltage difference value, taking the next detection moment as the current detection moment, and continuing to execute the step of detecting the current cell voltage and the current charging current.

2. The method of claim 1, wherein the obtaining of the cell parameter of the target cell at the current detection time comprises:

detecting the current SOC and the current temperature of a target battery cell;

and determining the cell parameters of the target cell according to the current SOC and the current temperature.

3. The method of claim 2, further comprising:

pre-establishing a first corresponding relation between different cell parameters and different calibration parameters of the target cell, wherein the calibration parameters comprise a cell SOC and a cell temperature;

then, the determining the cell parameter of the target cell according to the current SOC and the current temperature includes:

determining battery cell parameters corresponding to the current SOC and the current temperature according to the first corresponding relation;

and taking the determined cell parameters as the cell parameters of the target cell.

4. The method of claim 1, further comprising:

pre-establishing a second corresponding relation between different open circuit SOCs and different open circuit voltages of the target battery cell;

then, the predicting the charge cut-off voltage of the target battery cell according to the target SOC and the battery cell parameter includes:

determining a target open-circuit voltage corresponding to the target SOC according to the second corresponding relation;

and predicting the charging cut-off voltage of the target battery cell according to the target open-circuit voltage, the battery cell parameters and the charging cut-off current of the target battery cell.

5. The method according to any one of claims 1 to 4, wherein the determining whether the target cell satisfies a charge stop condition includes:

judging whether the voltage difference value is smaller than a preset voltage threshold value or not;

or judging whether the current charging current is less than or equal to the charging cut-off current.

6. The method of any one of claims 1 to 4, wherein said adjusting said present charging current using said voltage difference comprises:

taking the voltage difference value as an input parameter of a PI controller to obtain a current regulation value output by the PI controller;

and adjusting the current charging current by using the current adjusting value, and charging the target battery cell by using the adjusted charging current.

7. A charge control device, characterized by comprising:

the acquisition unit is used for acquiring the cell parameters of the target cell at the current detection moment;

the prediction unit is used for predicting the charge cut-off voltage of the target battery cell according to a target SOC and the battery cell parameter, wherein the target SOC is the SOC of the target battery cell in an open circuit state at the current moment;

a detecting unit, configured to detect a current cell voltage and a current charging current, where the current cell voltage is a voltage of the target cell at the current time, and the current charging current is a charging current of the target cell at the current time;

a calculation unit configured to calculate a voltage difference between the current cell voltage and the charge cut-off voltage;

a judging unit, configured to judge whether the target battery cell satisfies a charge stop condition; if yes, stopping charging; if not, adjusting the current charging current by using the voltage difference value, taking the next detection moment as the current detection moment, and continuing to execute the step of detecting the current cell voltage and the current charging current.

8. The apparatus according to claim 7, wherein the obtaining unit specifically includes:

the detection subunit is used for detecting the current SOC and the current temperature of the target battery cell;

and the determining unit is used for determining the battery cell parameters of the target battery cell according to the current SOC and the current temperature.

9. The apparatus of claim 8, further comprising:

a first establishing subunit, configured to pre-establish a first corresponding relationship between different cell parameters of the target cell and different calibration parameters, where the calibration parameters include a cell SOC and a cell temperature;

then, the determining unit specifically includes:

and the first determining subunit is configured to determine, according to the first corresponding relationship, the cell parameter corresponding to the current SOC and the current temperature.

10. The apparatus of claim 7, further comprising:

the second establishing subunit is used for establishing a second corresponding relation between different open circuit SOCs and different open circuit voltages of the target battery cell in advance;

then, the prediction unit specifically includes:

a second determining subunit, configured to determine, according to the second correspondence, a target open-circuit voltage corresponding to the target SOC;

and the predicting subunit is configured to predict a charge cut-off voltage of the target battery cell according to the target open-circuit voltage, the battery cell parameter, and the charge cut-off current of the target battery cell.

11. The apparatus according to any one of claims 7 to 10, wherein the determining unit specifically includes:

the first judgment subunit is used for judging whether the voltage difference value is smaller than a preset voltage threshold value or not;

or, the second judging subunit is configured to judge whether the current charging current is less than or equal to a charging cutoff current.

12. The apparatus of any one of claims 7 to 10, wherein said adjusting said present charging current using said voltage difference comprises:

a current regulation value obtaining unit, configured to obtain a current regulation value output by the PI controller by using the voltage difference value as an input parameter of the PI controller;

and the adjusting unit is used for adjusting the current charging current by using the current adjusting value and charging the target battery cell by using the adjusted charging current.

Technical Field

The present application relates to the field of charging technologies, and in particular, to a charging control method and apparatus.

Background

With the development of power battery technology, electric vehicles are gradually popularized, charging becomes a very important function of electric vehicles, and common charging methods include two modes, namely Constant current charging (abbreviated as CC) and Constant-voltage charging (abbreviated as CV). However, the most important disadvantage of this charging method is that the charging current or voltage is constant and does not change with the change of the charging state of the lithium ion battery, so that the charging effect of the lithium ion battery is not the best. Therefore, each battery manufacturer starts to adopt the intelligent charging method, and the core idea is that the charging voltage and the charging current are changed correspondingly according to the performance change of the storage battery in the charging process.

For a power battery, a charging function is very important, particularly a slow charging function, and a good slow charging habit is also very important for maintaining a battery cell, and at present, a main charging mode is classified as CC-CV (constant current-constant voltage charging), and under the condition that a cut-off voltage and a cut-off current are full, the battery cell can be basically full charged by the method at normal temperature in the initial use stage of the battery cell. However, as the number of battery cell charge-discharge cycles increases or at low temperature, the internal resistance of the battery cell increases, and compared with the previous internal resistance value, the internal resistance value may increase several times, the purpose of fully charging the battery cell cannot be achieved by singly controlling the charge cut-off voltage and the cut-off current, which may also cause the phenomenon of the degradation of the endurance mileage of the user during the use of the vehicle.

Disclosure of Invention

The embodiment of the application mainly aims to provide a charging control method and a charging control device, which can enable battery cells in different health states to be fully charged.

In a first aspect of the present application, a charging control method is provided, including:

acquiring a cell parameter of a target cell at the current detection moment;

predicting a charge cut-off voltage of the target battery cell according to a target SOC and the battery cell parameter, wherein the target SOC is an SOC of the target battery cell in an open circuit state at the current moment;

detecting a current cell voltage and a current charging current, wherein the current cell voltage is a voltage of the target cell at the current moment, and the current charging current is a charging current of the target cell at the current moment;

calculating a voltage difference between the current cell voltage and the charge cutoff voltage;

judging whether the target battery cell meets a charging stop condition; if yes, stopping charging; if not, adjusting the current charging current by using the voltage difference value, taking the next detection moment as the current detection moment, and continuing to execute the step of detecting the current cell voltage and the current charging current.

In an optional implementation manner, the obtaining of the cell parameter of the target cell at the current detection time includes:

detecting the current SOC and the current temperature of a target battery cell;

and determining the cell parameters of the target cell according to the current SOC and the current temperature.

In an optional implementation, the method further includes:

pre-establishing a first corresponding relation between different cell parameters and different calibration parameters of the target cell, wherein the calibration parameters comprise a cell SOC and a cell temperature;

then, the determining the cell parameter of the target cell according to the current SOC and the current temperature includes:

determining battery cell parameters corresponding to the current SOC and the current temperature according to the first corresponding relation;

and taking the determined cell parameters as the cell parameters of the target cell.

In an optional implementation, the method further includes:

pre-establishing a second corresponding relation between different open circuit SOCs and different open circuit voltages of the target battery cell;

then, the predicting a charge cut-off voltage of the target battery cell according to the target SOC and the battery cell parameter includes:

determining a target open-circuit voltage corresponding to the target SOC according to the second corresponding relation;

and predicting the charge cut-off voltage of the target battery cell according to the target open-circuit voltage, the battery cell parameters and the charge cut-off current of the target battery cell.

In an optional implementation manner, the determining whether the target battery cell satisfies a charge stop condition includes:

judging whether the voltage difference value is smaller than a preset voltage threshold value or not;

or judging whether the current charging current is less than or equal to the charging cut-off current.

In an optional implementation, the adjusting the current charging current using the voltage difference value includes:

taking the voltage difference value as an input parameter of a PI controller to obtain a current regulation value output by the PI controller;

and adjusting the current charging current by using the current adjusting value, and charging the target battery cell by using the adjusted charging current.

Corresponding to the above charging control method, the present application provides a charging control apparatus, including:

the acquisition unit is used for acquiring the cell parameters of the target cell at the current detection moment;

a predicting unit, configured to predict a charge cut-off voltage of the target battery cell according to a target SOC and the battery cell parameter, where the target SOC is an SOC of the target battery cell in an open circuit state at the current time;

a detecting unit, configured to detect a current cell voltage and a current charging current, where the current cell voltage is a voltage of the target cell at the current time, and the current charging current is a charging current of the target cell at the current time;

a calculating unit, configured to calculate a voltage difference value between the current cell voltage and the charge cut-off voltage;

a judging unit, configured to judge whether the target battery cell satisfies a charge stop condition; if yes, stopping charging; if not, adjusting the current charging current by using the voltage difference value, taking the next detection moment as the current detection moment, and continuing to execute the step of detecting the current cell voltage and the current charging current.

In an optional implementation manner, the obtaining unit specifically includes:

the detection subunit is used for detecting the current SOC and the current temperature of the target battery cell;

and the determining unit is used for determining the battery cell parameters of the target battery cell according to the current SOC and the current temperature.

In an optional implementation, the apparatus further includes:

a first establishing subunit, configured to pre-establish a first corresponding relationship between different cell parameters of the target cell and different calibration parameters, where the calibration parameters include a cell SOC and a cell temperature;

then, the determining unit specifically includes:

the first determining subunit is configured to determine, according to the first corresponding relationship, a cell parameter corresponding to the current SOC and the current temperature;

in an optional implementation, the apparatus further includes:

the second establishing subunit is used for establishing a second corresponding relation between different open circuit SOCs and different open circuit voltages of the target battery cell in advance;

then, the prediction unit specifically includes:

a second determining subunit, configured to determine, according to the second correspondence, a target open-circuit voltage corresponding to the target SOC;

and the predicting subunit is configured to predict a charge cut-off voltage of the target battery cell according to the target open-circuit voltage, the battery cell parameter, and the charge cut-off current of the target battery cell.

In an optional implementation manner, the determining unit specifically includes:

the first judgment subunit is used for judging whether the voltage difference value is smaller than a preset voltage threshold value or not;

or, the second judging subunit is configured to judge whether the current charging current is less than or equal to a charging cutoff current.

In an optional implementation, the adjusting the current charging current using the voltage difference value includes:

a current regulation value obtaining unit, configured to obtain a current regulation value output by the PI controller by using the voltage difference as an input parameter of the PI controller;

and the adjusting unit is used for adjusting the current charging current by using the current adjusting value and charging the target battery cell by using the adjusted charging current.

Therefore, the embodiment of the application has the following beneficial effects:

the embodiment of the application provides a charging control method and a charging control device, which comprises the steps of firstly obtaining a cell parameter of a target cell at the current detection time, and then predicting the charging cut-off voltage of the target cell according to a target SOC and the cell parameter, wherein the target SOC is the SOC of the target cell in an open circuit state at the current time; then, detecting the current cell voltage and the current charging current, wherein the current cell voltage is the voltage of the target cell at the current moment, and the current charging current is the charging current of the target cell at the current moment; further, calculating a voltage difference value between the current cell voltage and the charge cut-off voltage; finally, judging whether the target electric core meets the charging stop condition; if yes, stopping charging; if not, adjusting the current charging current by using the voltage difference value, taking the next detection moment as the current detection moment, and continuously executing the step of detecting the current cell voltage and the current charging current. The first-order RC model is established for the battery, the charging voltage and the charging current of the battery are adjusted through the battery cell parameters, the target SOC and the like, the battery cell is ensured to be fully charged, the problem that the current single control charging cut-off voltage and cut-off current cannot reach the state that the battery cell is fully charged is solved, and the battery cells in different health states can be fully charged.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a flowchart of a charging control method according to an embodiment of the present disclosure;

fig. 2 is an overall flowchart of a charging control method according to an embodiment of the present application;

fig. 3 is a schematic diagram of a charging control apparatus according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without any creative effort belong to the protection scope of the present application.

Along with the rapid development of electric and hybrid vehicles, batteries are used as the source of power carried by electric and hybrid vehicles, the internal resistance of the battery cell can be increased along with the increase of the charging and discharging cycle times of the battery cell, or under the condition of low temperature, compared with the former internal resistance value, the internal resistance value can be increased by multiple times.

Based on this, the application provides a charging control method and device, so that the battery cells in different states can be fully charged.

The charging control method provided by the embodiments of the present application will be described in detail below with reference to the accompanying drawings. Referring to fig. 1, which shows a flowchart of an embodiment of a charging control method provided in an embodiment of the present application, the embodiment may include the following steps:

step 101: and acquiring the cell parameters of the target cell at the current detection moment.

In practical application, in order to ensure that the battery cell can be truly fully charged, a battery model is firstly established for a target battery, and meanwhile, the battery cell parameters of the target battery cell at the current detection moment are acquired, so that the cutoff voltage U for subsequently estimating the full charge of the target battery cell can be conveniently estimated_targetAnd calculating the charging voltage U of the target battery cell, and controlling the charging current of the battery cell through the voltage PI to ensure that the battery cell can be fully charged under the conditions of low temperature, cyclic charge and discharge and the like. Wherein, the battery model adopts a first-order RC model; the target cell refers to a cell of a target battery that needs to be charged.

In step 101, an optional implementation manner is that obtaining a cell parameter of a target cell at a current detection time includes:

detecting the current SOC and the current temperature of a target battery cell;

and determining the battery cell parameters of the target battery cell according to the current SOC and the current temperature.

In practical application, after a charged target battery is determined, a first-order RC model is established for the target battery, meanwhile, a current SOC value and a current temperature of a target battery cell are detected, and then, according to the detected current SOC value and the detected current temperature value of the target battery cell, battery cell parameters U such as resistance and capacity of the target battery cell are determined.

In some optional implementation manners of the present application, a first corresponding relationship between different cell parameters of a target cell and different calibration parameters is pre-established, where the calibration parameters include a cell SOC and a cell temperature;

then, the determining the cell parameter of the target cell according to the current SOC and the current temperature includes:

determining battery cell parameters corresponding to the current SOC and the current temperature according to the first corresponding relation;

and taking the determined cell parameters as the cell parameters of the target cell.

In practical application, a first corresponding relationship between different electric core parameters and different calibration parameters of a target electric core may be pre-established, and the first corresponding relationship is stored in an offline table, which is used as an offline calibration electric core parameter table, so as to perform subsequent inquiry on the electric core parameters according to the stored first corresponding relationship. The calibration parameters include a cell SOC and a cell temperature.

Then, after the current SOC and the current temperature of the target battery cell are detected, the current SOC and the battery cell parameter R corresponding to the current temperature of the target battery cell may be obtained by querying the off-line calibration battery cell parameter table which is pre-established and stores the first corresponding relationship between the different battery cell parameters and the different calibration parameters of the target battery cell₀、R₁And C₁Wherein R is₀Ohmic resistance, R, of a first-order RC model₁Polarization internal resistance of first-order RC model, C₁Polarization capacitance of a first order RC model.

After the cell parameters of the target cell at the current detection time are acquired, step 102 may be continuously executed.

Step 102: and predicting the charge cut-off voltage of the target battery cell according to the target SOC and the battery cell parameters, wherein the target SOC is the SOC of the target battery cell in an open circuit state at the current moment.

In practical application, after the cell parameters of the target cell at the current detection moment are acquired, the charging cut-off voltage U of the target cell can be predicted by combining the detected target SOC_targetAnd the target SOC is the SOC of the target cell in an open circuit state at the current moment.

In the specific implementation process, the target SOC of the target battery cell and the battery cell parameter R corresponding to the current temperature are obtained₀、R₁And C₁In pairsIn a first-order RC model established by the target battery, a formula for calculating the first-order charging voltage of the target battery cell is as follows:

wherein U represents the first-order charging voltage of the target cell, U_ocvAnd the current SOC value is used for obtaining the open-circuit voltage of the battery through a back-lookup table, I represents the charging current for charging the target battery cell, and t represents the charging time of the target battery.

And, due to the time constant R for different cells₁C₁Are all small, and charging is a long process, with few tens of minutes and many hours, when

When the temperature of the water is higher than the set temperature,

as the time of the charge increases,

cell polarization voltage approximate IR₁Therefore, the above formula for calculating the first-order charging voltage of the target cell can be simplified as follows:

U＝U_ocv+I(R₀+R₁)

in step 102, an optional implementation manner is to pre-establish a second corresponding relationship between different open circuit SOCs and different open circuit voltages of the target electrical core;

then, the predicting the charge cut-off voltage of the target battery cell according to the target SOC and the battery cell parameter includes:

determining a target open-circuit voltage corresponding to the target SOC according to the second corresponding relation;

and predicting the charge cut-off voltage of the target battery cell according to the target open-circuit voltage, the battery cell parameters and the charge cut-off current of the target battery cell.

In practical application, the method establishes different storage target battery cells in advanceAn off-line table of second correspondence between the open circuit SOC and the different open circuit voltages, from which a target open circuit voltage U corresponding to the target SOC can be calculated according to the value of the target SOC and the second correspondence between the different open circuit SOCs and the different open circuit voltages_ocvMeanwhile, the charging cut-off current I of the target battery cell is preset_target。

Then, according to the simplified formula for calculating the first-order charging voltage of the target cell, a formula for predicting the charging cut-off voltage of the target cell can be obtained as follows:

U_target＝U_ocv+I_target(R₀+R₁)

wherein, U_targetRepresents the predicted charge cutoff voltage, U, of the target cell_ocvRepresents a target open circuit voltage, I, corresponding to the target SOC_targetIndicates a preset charge cutoff current, R, of the target cell₀、R₁Cell parameters are represented.

In the charging process of the target battery, both the charged electric quantity and the charging time length are considered, so that the charging cut-off voltage U of the target battery cell is predicted_targetAnd preset charging cut-off current I of target battery cell_targetThen, when the first-order charging voltage U of the target battery cell is not less than the predicted charging cut-off voltage U of the target battery cell_targetAnd the charging current I for charging the target cell is not more than the preset charging cut-off current I of the target cell_targetAnd if so, indicating that the battery cell is full and the charging is finished.

Further, as can be seen from the above equation for predicting the charge cut-off voltage of the target cell, the charge cut-off current I_targetAnd under the condition that the target SOC is determined, the service life of the battery cell is attenuated, and the internal resistance R of the battery cell is determined₀Increasing and predicting the charge cut-off voltage U of the target battery cell_targetAnd the size of the battery cell is increased, so that U is limited to ensure that the battery cell can be fully charged in a safe voltage range_targetSatisfies the range of U_Lowlmt≤U_target≤U_UplmtWherein, U_LowlmtRepresenting target cellsLower limit charge cut-off voltage, U_UplmtIt represents the upper limit charge cut-off voltage of the target cell, when U_targetAnd if the limit value exceeds the limit range, taking the corresponding limit value.

Predicting the charge cut-off voltage U of the target battery cell_targetThereafter, execution may continue at step 103.

Step 103: and detecting the current cell voltage and the current charging current, wherein the current cell voltage is the voltage of the target cell at the current moment, and the current charging current is the charging current of the target cell at the current moment.

In practical application, the charge cut-off voltage U of the target battery cell is predicted_targetThen, the current cell voltage CellMaxVolt and the current charging current CellCurrent of the target cell are detected, where the current cell voltage CellMaxVolt refers to the voltage of the target cell at the current time, and the current charging current CellCurrent refers to the charging current of the target cell at the current time. After the current cell voltage cellmaxvult and the current charging current CellCurrent of the target cell are detected, step 104 is continuously performed.

Step 104: and calculating a voltage difference value between the current cell voltage and the charging cut-off voltage.

In practical application, after the current cell voltage cellmaxvult and the current charging current CellCurrent of the target cell are detected, the predicted charging cut-off voltage U of the target cell can be calculated through the following formula_targetThe voltage difference from the current cell voltage cellmaxvult:

DetaV＝U_target-CellMaxVol t

wherein, U_targetIndicates the predicted charge cut-off voltage of the target cell, cellmaxvult indicates the current cell voltage of the target cell, and DetaV indicates the predicted charge cut-off voltage U of the target cell_targetAnd the current cell voltage cellmaxvult.

Calculating the predicted charge cut-off voltage U of the target battery cell_targetAnd after the voltage difference DetaV between the current cell voltage cellmaxvult, step 105 is executed.

Step 105: judging whether the target battery cell meets a charging stop condition; if yes, stopping charging; if not, adjusting the current charging current by using the voltage difference value, taking the next detection moment as the current detection moment, and continuously executing the step of detecting the current cell voltage and the current charging current.

In practical applications, through the steps 101 to 104, the charge cut-off voltage U of the target cell is predicted respectively_targetDetecting the current cell voltage CellMaxVolt and the current charging current CellCurrent and calculating the charging cut-off voltage U of the target cell_targetAnd after the voltage difference value DetaV between the current cell voltage cellmaxvult, whether the target cell meets the charging stop condition can be judged according to the obtained parameter values.

In some optional implementation manners of the present application, determining whether the target battery cell satisfies the charging stop condition includes:

judging whether the voltage difference value is smaller than a preset voltage threshold value or not;

or, judging whether the current charging current is less than or equal to the charging cut-off current.

In practical application, whether the target battery cell meets the charging stop condition or not can be judged by two methods, namely, the predicted charging cut-off voltage U of the target battery cell is judged_targetWhether a voltage difference DetaV between the current cell voltage CellMaxVolt and the current cell voltage is smaller than a preset voltage threshold value or not, wherein the preset voltage threshold value is preset, and a charging cut-off voltage U is set_targetThe minimum value of the voltage difference between the current cell voltage cellmaxvult and the current cell voltage cellmaxvult is used as a critical value, when the voltage difference DetaV is smaller than the critical value, the charging stop condition is satisfied, for example, the value may be-10 mv, and when the voltage difference DetaV is used<And at-10 mv, meeting a charging stop condition, and stopping charging, namely, the target battery cell is full, otherwise, not meeting the charging stop condition.

Another method for determining whether the target battery cell meets the charge stop condition is to determine whether the current charging current CellCurrent is less than or equal to a preset charge cut-off current I of the target battery cell_targetIf CellCurrent is less than or equal toI_targetIf yes, the target battery cell meets the charging stop condition, otherwise, the target battery cell does not meet the charging stop condition.

When both of the above two methods determine that the target electric core does not satisfy the charging stop condition, the calculated voltage difference DetaV is needed to adjust the current charging current CellCurrent, and the next detection time is taken as the current detection time, and the step of detecting the current electric core voltage cellmaxvult and the current charging current CellCurrent is continuously performed, that is, step 103.

In some optional implementations of the present application, adjusting the present charging current by using the voltage difference may specifically include:

the voltage difference value is used as an input parameter of the PI controller to obtain a current regulation value output by the PI controller;

and adjusting the current charging current by using the current adjusting value, and charging the target battery cell by using the adjusted charging current.

In practical application, when it is determined that the target electric core does not satisfy the charging stop condition, the current charging current CellCurrent may be adjusted by the voltage difference DetaV, and the specific adjustment manner is as follows: and taking the voltage difference DetaV as an input parameter of the PI controller, and outputting a current regulation value DetaI through the control regulation of the PI controller, wherein a specific calculation formula is as follows:

where DetaI denotes a current regulation value regulated by control of the PI controller, K_pDenotes the scale factor, K_iRepresenting an integration factor.

After the current adjustment value DetaI is calculated, the current charging current CellCurrent can be adjusted by using the current adjustment value DetaI, and a specific adjustment formula is as follows:

CellCurent＝CellCurent+DetaI

therefore, the adjusted current charging current CellCurrent can be obtained, and further, the adjusted current charging current CellCurrent is used as the charging current at the current moment, and then the current cell voltage cellmaxvult at the current moment is detected, that is, step 103 is continuously executed until the target cell is judged to meet the charging stop condition.

In this way, according to the charge control method provided by the embodiment of the application, the battery cell parameter of the target battery cell at the current detection time is obtained, and the charge cut-off voltage of the target battery cell is predicted according to the target SOC and the battery cell parameter, wherein the target SOC is the SOC of the target battery cell in the open circuit state at the current time; detecting the current cell voltage and the current charging current, wherein the current cell voltage is the voltage of the target cell at the current moment, and the current charging current is the charging current of the target cell at the current moment; further, calculating a voltage difference value between the current core voltage and the charge cut-off voltage; finally, judging whether the target battery cell meets the charging stop condition; if yes, stopping charging; if not, adjusting the current charging current by using the voltage difference value, taking the next detection moment as the current detection moment, and continuously executing the step of detecting the current cell voltage and the current charging current. Therefore, the charging voltage and the charging current of the battery are adjusted through the battery core parameters, the target SOC and the like, and the fact that the battery cores in different health states can be fully charged is ensured.

For ease of understanding, an overall flow chart of a charge control method is shown in fig. 2. A process of implementing the charging control method provided in the embodiment of the present application is described.

Step 201: first, a first-order RC model is established for the target battery, and meanwhile, the current SOC and the current temperature Celltem of the target battery are obtained, and then step 202 is executed.

Step 202: according to the current SOC and the current temperature Celltem of the obtained target battery cell, by inquiring an offline calibration battery cell parameter table, according to the corresponding relation (R) of the battery cell parameter, the battery cell SOC and the battery cell temperature₀，R₁,C₁) F (SOC, CellTem), and cell parameter R is obtained₀、R₁And C₁The specific implementation process of step 201 to step 202 is shown in step 101.

Step 203: predicting the charging cut-off voltage U of the target battery cell according to the target SOC and the battery cell parameters_targetThe implementation process proceeds to step 102.

Predicting the charge cutoff voltage U of the target cell through steps 201 to 203_targetThereafter, step 204 is performed.

Step 204: and detecting the current cell voltage cellmaxvult and the current charging current CellCurrent, and particularly joining the implementation process in step 103.

Step 205: calculating the current cell voltage CellMaxVolt and the predicted charging cut-off voltage U of the target cell_targetThe voltage difference of (D) is DetaV, and the formula is DetaV ═ U_targetCellMaxVol t, see step 104.

Step 206: if the preset voltage threshold is 10mv, judging whether the voltage difference DetaV is smaller than the preset voltage threshold, namely judging whether DetaV is smaller than-10 mv; or, judging whether the current charging current CellCurrent is less than or equal to the charging cut-off current I_targetThen, it is judged that CellCurent is less than or equal to I_targetIf the two inequalities are true, if one or both of the two inequalities are true, the standard battery cell meets the charging stop condition, namely the charging is finished; if neither of the two inequalities is true, go to step 207.

Step 207: the PI control calculates a current adjustment value DetaI, that is,

step 208 is then performed.

Step 208: the present charging current CellCurrent, that is, CellCurrent + DetaI, is adjusted by using the value, and then step 209 is performed.

Step 209: and controlling the charger to issue the adjusted current charging current CellCurrent as the current charging current CellCurrent at the current detection time, and continuing to execute the step of detecting the current cell voltage and the current charging current, namely step 204, until the charging is finished. The specific implementation process of steps 206 to 209 is referred to as step 105.

And step 204 to step 209 are used for judging whether the target battery cell is fully charged or not until the charging is finished.

Therefore, the charging voltage and the charging current of the battery are adjusted through the parameters of the battery cell, the target SOC and the like, and the battery cells in different health states can be fully charged.

Referring to fig. 3, the present application further provides an embodiment of a charging control apparatus, which may include:

an obtaining unit 301, configured to obtain a cell parameter of a target cell at a current detection time;

a predicting unit 302, configured to predict a charge cut-off voltage of the target battery cell according to a target SOC and the battery cell parameter, where the target SOC is an SOC of the target battery cell in an open circuit state at the current time;

a detecting unit 303, configured to detect a current cell voltage and a current charging current, where the current cell voltage is a voltage of the target cell at the current time, and the current charging current is a charging current of the target cell at the current time;

a calculation unit 304, configured to calculate a voltage difference between the current cell voltage and the charge cut-off voltage;

a determination unit 305 configured to determine whether the target battery cell satisfies a charge stop condition; if yes, stopping charging; if not, adjusting the current charging current by using the voltage difference value, taking the next detection time as the current detection time, and continuing to execute the step of detecting the current cell voltage and the current charging current.

In some possible implementation manners of the present application, the obtaining unit 301 specifically includes:

the detection subunit is used for detecting the current SOC and the current temperature of the target battery cell;

and the determining unit is used for determining the battery cell parameters of the target battery cell according to the current SOC and the current temperature.

In some possible implementations of the present application, the apparatus further includes:

a first establishing subunit, configured to pre-establish a first corresponding relationship between different cell parameters of the target cell and different calibration parameters, where the calibration parameters include a cell SOC and a cell temperature;

then, the determining unit specifically includes:

the first determining subunit is configured to determine, according to the first corresponding relationship, a cell parameter corresponding to the current SOC and the current temperature;

in some possible implementations of the present application, the apparatus further includes:

the second establishing subunit is used for establishing a second corresponding relation between different open circuit SOCs and different open circuit voltages of the target battery cell in advance;

then, the prediction unit 302 specifically includes:

a second determining subunit, configured to determine, according to the second correspondence, a target open-circuit voltage corresponding to the target SOC;

and the predicting subunit is configured to predict a charge cut-off voltage of the target battery cell according to the target open-circuit voltage, the battery cell parameter, and the charge cut-off current of the target battery cell.

In some possible implementation manners of the present application, the determining unit 305 specifically includes:

the first judgment subunit is used for judging whether the voltage difference value is smaller than a preset voltage threshold value or not;

or, the second judging subunit is configured to judge whether the current charging current is less than or equal to a charging cutoff current.

In some possible implementations of the present application, the adjusting the present charging current by using the voltage difference value includes:

a current regulation value obtaining unit, configured to obtain a current regulation value output by the PI controller by using the voltage difference as an input parameter of the PI controller;

and the adjusting unit is used for adjusting the current charging current by using the current adjusting value and charging the target battery cell by using the adjusted charging current.

As can be seen from the foregoing embodiments, the charging control apparatus provided in the present application predicts the charging cutoff voltage of the target electrical core according to the target SOC and the electrical core parameter by acquiring the electrical core parameter of the target electrical core at the current detection time, where the target SOC is the SOC of the target electrical core in the open circuit state at the current time; then, detecting a current cell voltage and a current charging current, wherein the current cell voltage is the voltage of the target cell at the current moment, and the current charging current is the charging current of the target cell at the current moment; further, calculating a voltage difference value between the current cell voltage and the charge cut-off voltage; finally, judging whether the target electric core meets the charging stop condition; if yes, stopping charging; if not, adjusting the current charging current by using the voltage difference value, taking the next detection moment as the current detection moment, and continuously executing the step of detecting the current cell voltage and the current charging current. According to the battery charging method and device, the charging voltage and the charging current of the battery are adjusted through the battery cell parameters, the target SOC and the like, and the fact that the battery cells in different health states can be truly full of electricity is guaranteed.

As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that all or part of the steps in the above embodiment methods can be implemented by software plus a necessary general hardware platform. Based on such understanding, the technical solutions of the present application may be essentially implemented or are part of the contribution to the prior art, and the computer software product may be stored in a storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network communication device such as a media gateway, etc.) to execute the method described in the embodiments or some parts of the embodiments of the present application.

It should be noted that, in the present specification, the embodiments are described in a progressive manner, each embodiment focuses on the differences from the other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

It is further noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.