Battery charging method, battery charging device and computer readable storage medium

Abstract

The invention discloses a battery charging method, a battery charging device and a computer readable storage medium, the battery comprises a plurality of battery cells connected in series, and the battery charging method comprises the following steps: in a charging process, obtaining the current electric quantity of the battery, the current voltage of each battery cell and the current temperature of each battery cell; determining a first control value according to the current electric quantity; determining a second control value according to the current temperature; determining a third control value according to the current voltage; and dynamically adjusting the charging power and / or the charging voltage according to the first control value and / or the second control value and / or the third control value. Through the mode, the charging reliability can be effectively improved, and the charging efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of electronic circuits, and in particular to a battery charging method, a battery charging device and a computer-readable storage medium. Background Art

[0002] Related charging technologies usually adopt a three-stage charging method, including: constant current charging stage, constant voltage charging stage and floating charging stage. In the constant current charging stage, the charging current remains constant, the charged amount increases rapidly, and the battery voltage rises; in the constant voltage charging stage, the charging voltage remains constant, the charged amount continues to increase, the battery voltage rises slowly, and the charging current decreases; in the floating charging stage, the charging current drops below the floating charge conversion current, and the charging voltage drops to the floating charge voltage and remains at the floating charge voltage.

[0003] The related three-stage charging method is not suitable for the situation where the voltage of multiple strings of battery cells is unbalanced. If the three-stage charging method is used when the battery cell voltage is unbalanced, it will cause problems such as overcharging of a single battery cell, reduced charging speed, and prolonged charging time, which will cause safety hazards and affect charging efficiency. Summary of the invention

[0004] To solve the above problems, the present application provides a battery charging method, a battery charging device and a computer-readable storage medium, which can improve charging safety and increase charging speed.

[0005] A technical solution adopted in the present application is: to provide a battery charging method, the battery includes a plurality of battery cells connected in series, and the battery charging method includes: during the charging process, obtaining the current power of the battery, the current voltage of each battery cell and the current temperature of each of the battery cells; determining a first control value according to the current power; determining a second control value according to the current temperature; determining a third control value according to the current voltage; and dynamically adjusting the charging power and / or charging voltage according to the first control value and / or the second control value and / or the third control value.

[0006] In one embodiment, determining the first control value based on the current power includes: in response to the current power being less than a power threshold, the first control value is a default value; in response to the current power being greater than or equal to the power threshold, determining the first control value according to a linear relationship.

[0007] In one embodiment, a second control value is determined based on the current temperature, including: in response to the presence of at least one target current temperature greater than a first temperature threshold among all current temperatures, the second control value is determined based on the maximum current temperature among the at least one target current temperature; in response to the presence of at least one target current temperature less than a second temperature threshold among all current temperatures, the second control value is determined based on the minimum current temperature among the at least one target current temperature; in response to all current temperatures being between the second temperature threshold and the first temperature threshold, the second control value is a default value.

[0008] In one embodiment, determining the second control value according to the maximum current temperature among at least one target current temperature includes: substituting the maximum current temperature into the first linear formula to determine the second control value.

[0009] In one embodiment, a second control value is determined based on a minimum current temperature among at least one target current temperature, including: substituting the minimum current temperature into a second linear formula to determine the second control value; wherein the first linear formula corresponds to a slope less than zero, and the second linear formula corresponds to a slope greater than zero.

[0010] In one embodiment, a third control value is determined based on the current voltage, including: obtaining the maximum current voltage from the current voltages of all battery cells; in response to the maximum current voltage being less than a voltage threshold, the third control value is a default value; in response to the maximum current voltage being greater than or equal to the voltage threshold, the third control value is determined based on the maximum current voltage.

[0011] In one embodiment, determining the third control value according to the maximum current voltage includes: obtaining a voltage difference between the maximum current voltage and a voltage threshold; and integrating the voltage difference to obtain the third control value.

[0012] In one embodiment, the voltage threshold is determined based on the type and working state of the battery cell.

[0013] In one embodiment, the charging power and / or charging voltage are adjusted according to the first control value, the second control value and the third control value, including: selecting the smaller of the first control value and the second control value as the target control value; compensating the target control value with the third control value; and adjusting the charging power and / or charging voltage with the compensated target control value.

[0014] The present application also provides a battery charging device, which includes: an acquisition module, used to acquire the current power of the battery, the current voltage of each battery cell and the current temperature during the charging process; a first determination module, used to determine a first control value according to the current power; a second determination module, used to determine a second control value according to the current temperature; a third determination module, used to determine a third control value according to the current voltage; and an adjustment module, used to adjust the charging power and / or charging voltage according to the first control value, the second control value and the third control value.

[0015] The present application also provides a computer-readable storage medium, in which program data is stored. When the program data is executed by a processor, it is used to implement the battery charging method as described above.

[0016] The present application provides a battery charging method, the battery includes a plurality of battery cells connected in series, and the battery charging method includes: during the charging process, obtaining the current power of the battery, the current voltage of each battery cell, and the current temperature; determining a first control value according to the current power; determining a second control value according to the current temperature; determining a third control value according to the current voltage; and adjusting the charging power and / or charging voltage according to the first control value, the second control value, and the third control value. The charging control logic of the present application sets a reasonable control value for the voltage and temperature of each battery cell through the participation of multiple control parameters such as the current power of the battery, the current voltage of each battery cell, and the current temperature, accurately controls the charging process of the battery according to the first control value, the second control value, and the third control value, and dynamically adjusts the charging power and the charging voltage, so as to reduce the charging power and the charging voltage when the battery cell voltage is uneven, avoid causing the problem of overcharging the battery cell, and effectively improve the charging reliability; at the same time, this dynamic adjustment can ensure that the battery is charged in the best state, reduce unnecessary waste of charging time, avoid the charging time being prolonged, and thus improve the charging efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] in:

[0019] Figure 1 is a flowchart of a first embodiment of a battery charging method provided by the present application;

[0020] Figure 2 is a flow chart of step S12 in an embodiment provided by the present application;

[0021] Figure 3 This is a schematic diagram of a linear relationship in an embodiment provided by the present application;

[0022] Figure 4 is a flowchart of step S13 in an embodiment provided by the present application;

[0023] Figure 5 is another schematic diagram of a linear relationship in an embodiment provided by the present application;

[0024] Figure 6 is a flow chart of step S14 in an embodiment provided by the present application;

[0025] Figure 7 is a flowchart of step S15 in an embodiment provided by the present application;

[0026] Figure 8 is a structural schematic diagram of an embodiment of a battery charging device provided by the present application;

[0027] Fig. 9 It is a structural schematic diagram of an embodiment of a computer-readable storage medium provided by the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It will be appreciated that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some but not all structures related to the present application are shown in the drawings. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the art without making creative work are within the scope of protection of the present application.

[0029] The terms "first", "second", etc. in this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0030] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] At present, when charging batteries, a three-stage charging method is usually used, including: constant current charging stage, constant voltage charging stage and floating charging stage. However, this charging method is not suitable for the situation where the voltage of multiple battery cells is unbalanced. If the three-stage charging method is used when the voltage of the battery cells is unbalanced, it will cause problems such as overcharging of a single battery cell and prolonged charging time, which will cause safety hazards and affect charging efficiency.

[0032] Therefore, this solution provides a battery charging method. During the charging process, control parameters corresponding to the charging power and / or charging voltage are obtained according to the current power of the battery, the current voltage of each battery cell, and the current temperature. The charging power and charging voltage are adjusted according to the control parameters, thereby reducing the risks of overcharging of the battery cells and prolonged charging time caused by uneven battery cell voltage, thereby effectively improving the charging efficiency and reliability.

[0033] See also Figure 1 , Figure 1 1 is a flow chart of a first embodiment of a battery charging method provided by the present application. The battery includes a plurality of cells connected in series, and the battery charging method includes:

[0034] Step S11: during the charging process, the current power of the battery, the current voltage of each battery cell and the current temperature of each battery cell are obtained.

[0035] Among them, during the charging process, the battery power, the voltage of the battery cell and the temperature of the battery cell will gradually increase. Specifically, the battery power is obtained by the ampere-hour integration method, which is a method of integrating the current value during the battery charging process with time to obtain the battery power. The voltage and temperature of the battery cell are obtained by sampling, for example, using an analog-to-digital converter in a controller such as MCU (Microcontroller Unit) or DSP (Digital Signal Processor) to sample the voltage and temperature of the battery cell in real time and perform analog-to-digital conversion.

[0036] Step S12: determining a first control value according to the current power level.

[0037] Among them, when the battery pack contains multiple strings of battery cells, the differences in the initial voltage, capacity, internal resistance of each battery cell and the uneven distribution of charging current and voltage will cause the battery cell voltage to be unbalanced. In order to ensure the safety of the battery and extend the battery life, the charging power and charging voltage need to be appropriately reduced during the charging process to reduce the risk of overcharging a single battery cell. At the same time, when the current battery power is close to full charge, in order to avoid overcharging and battery damage, the charging power and charging voltage also need to be appropriately reduced.

[0038] Exemplarily, in order to optimize the charging process and improve the charging efficiency, a certain power threshold can be set to monitor the current power of the battery in real time. When the current power is less than the set power threshold, a first control value is determined according to the current power. For example, the charging power and / or charging voltage of the battery can be adjusted to the rated charging power and / or rated charging voltage according to the first control value for charging to ensure the charging speed; when the current power is greater than the power threshold, the first control value is determined according to the current power, and the charging power and / or charging voltage are reduced according to the first control value to reduce the risk of overcharging.

[0039] Step S13: Determine a second control value according to the current temperature.

[0040] During the charging process, the temperature of the battery cell will rise due to the internal chemical reaction of the battery and the resistance heat generated by the current passing through the battery cell. Excessive temperature of the battery cell may cause thermal runaway and damage to the battery. Therefore, it is necessary to monitor the current temperature of the battery cell in real time and adjust the charging power and / or charging voltage according to the temperature change.

[0041] Exemplarily, both high and low temperatures will affect the charging efficiency and service life of the battery, so two different temperature thresholds can be set to distinguish the charging process in the low temperature and high temperature stages. Since the temperature of each battery cell may be different, when the temperature of the battery cell is high, the second control value can be determined according to the current temperature of the battery cell being greater than the highest current temperature in a certain temperature threshold; when the temperature of the battery cell is low, the second control value can be determined according to the current temperature of the battery cell being less than the lowest current temperature in a certain temperature threshold; when the temperature is moderate, such as between two temperature thresholds, the charging power and / or charging voltage of the battery can be adjusted to the rated charging power and / or rated charging voltage according to the second control value for charging to ensure the charging speed.

[0042] Step S14: determining a third control value according to the current voltage.

[0043] During the charging process, the cell voltage will gradually increase, so it is necessary to monitor in real time and adjust the charging power and charging voltage according to the changes in the current cell voltage.

[0044] Exemplarily, since the voltage of each battery cell may be different, a certain voltage threshold can be set. When the maximum voltage among the current voltages of the battery cells is less than the voltage threshold, the third control value is determined according to the current voltage. For example, the charging power and / or charging voltage of the battery can be adjusted to the rated charging power and / or rated charging voltage for charging according to the third control value to ensure the charging speed; when the maximum voltage among the current voltages of the battery cells is greater than the voltage threshold, the third control value is determined according to the maximum voltage to reduce the charging power and / or charging voltage according to the third control value to reduce the risk of overcharging.

[0045] Step S15: dynamically adjusting the charging power and / or the charging voltage according to the first control value and / or the second control value and / or the third control value.

[0046] Among them, the maximum charging power that the battery pack can safely and stably accept under specific conditions is the rated charging power. The rated charging power is the upper limit of the charging power range. Therefore, the adjusted charging power should not be greater than the rated charging power of the battery pack. The rated charging voltage is the voltage level that the battery pack should maintain during charging. It is generally determined based on the rated charging voltage of the battery pack's cells and the number of cell strings. Therefore, the adjusted charging voltage can have a certain upper and lower floating range based on the rated charging voltage and should be as close to the rated charging voltage as possible.

[0047] Exemplarily, after obtaining the first control value, the second control value and the third control value, the target control value is determined based on the first control value and the second control value, and the target control value is compensated by the third control value to adjust the charging power and / or charging voltage.

[0048] The charging control logic of the present application sets reasonable control values ​​for the voltage and temperature of each battery cell through the participation of multiple control parameters such as the current battery power, the current voltage and the current temperature of each battery cell. The charging process of the battery is accurately controlled according to the first control value, the second control value and the third control value, and the charging power and the charging voltage are dynamically adjusted. Therefore, when the battery cell voltages are uneven, the charging power and the charging voltage are reduced to avoid the problem of overcharging the battery cells, thereby effectively improving the charging reliability. At the same time, this dynamic adjustment can ensure that the battery is charged in the best state, reduce unnecessary waste of charging time, avoid prolonged charging time, and thus improve charging efficiency.

[0049] See also Figure 2 , Figure 2 is a flow chart of step S12 in one embodiment, and step S12 may specifically include:

[0050] Step S121: In response to the current power level being less than the power threshold, the first control value is a default value.

[0051] Among them, in order to limit the charging power and charging voltage within a reasonable range (the range is determined according to the rated charging power and rated charging voltage of the battery pack), the current power can be regarded as the independent variable of the charging power and charging voltage, and one of the control values ​​of the charging power and charging voltage, that is, the first control value, can be linearly derived according to the current power, and then the charging power and charging voltage can be adjusted according to the first control value.

[0052] Exemplarily, when the current power level is less than the power threshold, the first control value is a default value, which may be the rated charging power and / or charging voltage. The current charging power and / or charging voltage are adjusted according to the first control value so that the battery is charged at the rated charging power and / or charging voltage to ensure the charging efficiency at this stage.

[0053] Step S122: In response to the current power level being greater than or equal to the power level threshold, a first control value is determined according to a linear relationship.

[0054] Among them, when the current power is greater than or equal to the power threshold, the current power of the battery and the charging power and / or charging voltage satisfy a linear relationship, and a first control value is determined according to the linear relationship, thereby adjusting the charging power and / or charging voltage according to the first control value.

[0055] See also Figure 3 As shown in the linear relationship diagram, it is assumed that the x-axis represents the battery power, the y-axis represents the charging power and / or charging voltage, x0 represents the initial derating power value, x1 represents the derating cut-off power value (i.e., the power value corresponding to the minimum charging power or the minimum charging voltage), y0 represents the rated charging power and / or the rated charging voltage, y1 represents the derating cut-off charging power and / or the derating cut-off charging voltage, and the cut-off charging power is usually 0W. Figure 3 It can be seen that when the current battery power is between x0 and x1, according to Figure 3 The linear relationship shown can determine the charging power and / or charging voltage. Exemplarily, when the current battery charge is x0, the charging power and / or charging voltage is adjusted to y0.

[0056] In an application scenario, taking a 1000Wh, 10-cell lithium iron phosphate battery pack as an example, its rated charging power is 1000W (1P), the rated charging voltage is 36V (3.6V*cell number S), the charging power range is 0P~1P; the charging voltage range is 3300mV*S~3600mV*S. If x0=90% at this time, the initial derating power is 90%; x1=100%, the derating cutoff power value is 100%; y0=1P, the rated charging power is 1P (1000W); y1=0P, the derating cutoff charging power is 0P (0W). The maximum charging power can be adjusted to 1P and the minimum can be 0P according to the current battery power. When the current battery power is less than 90%, the charging power is adjusted to 1P according to the default value; when the current battery power is greater than 90%, the first control value is obtained according to the linear relationship, thereby adjusting the charging power.

[0057] In the above scheme, when the battery power is less than the threshold, the charging speed is prioritized and charging is performed with a fixed charging power and / or charging voltage; when the battery power is greater than the power threshold, the charging power and / or charging voltage are reduced to prevent problems such as uneven battery charging and overcharging of some cells, thereby optimizing the charging process, improving the reliability and durability of the battery, and protecting the charging equipment and battery management system from damage caused by abnormal conditions such as overcurrent and overvoltage.

[0058] See also Figure 4 , Figure 4 is a flow chart of step S13 in one embodiment, and step S13 may specifically include:

[0059] Step S131: In response to at least one target current temperature greater than a first temperature threshold existing among all current temperatures, a second control value is determined according to a maximum current temperature among the at least one target current temperature.

[0060] Among them, in order to limit the charging power and charging voltage within a reasonable range, the current temperature of each battery cell can be regarded as an independent variable of the charging power and charging voltage, and one of the control values ​​of the charging power and charging voltage, that is, the second control value, can be linearly obtained according to the current temperature, and then the charging power and charging voltage can be adjusted according to the second control value.

[0061] In some embodiments, determining the second control value based on the maximum current temperature among at least one target current temperature includes: substituting the maximum current temperature into the first linear formula to determine the second control value.

[0062] Among them, when the current temperature of the battery cell is greater than the first temperature threshold, the current temperature of the battery cell and the charging power and / or charging voltage satisfy a first linear relationship, and the corresponding slope of the first linear formula is less than zero, that is, the higher the current temperature of the battery cell, the lower the charging power and / or charging voltage. The second control value is determined according to the first linear relationship, and the charging power and / or charging voltage are adjusted according to the second control value.

[0063] See also Figure 3 The linear relationship diagram shown in the figure assumes that the x-axis represents the battery cell temperature, the y-axis represents the charging power and / or charging voltage, x0 represents the derating initial temperature value, x1 represents the derating cut-off temperature value (the maximum battery cell temperature), y0 represents the rated charging power and / or rated charging voltage, y1 represents the derating cut-off charging power and / or derating cut-off charging voltage, and the cut-off charging power is usually 0W. Figure 3 It can be seen that when the current temperature of the battery cell is between x0 and x1, according to Figure 3 The linear relationship shown may determine the charging power and / or the charging voltage.

[0064] In an application scenario, taking a 1000Wh, 10-cell lithium iron phosphate battery pack as an example, its rated charging power is 1000W (1P), the rated charging voltage is 36V (3.6V*number of cell strings S), the charging power range is 0P~1P; the charging voltage range is 3300mV*S~3600mV*S. If x0=47.0℃ at this time, the initial derating temperature is 47.0℃; x1=50.0℃, the derating cutoff temperature value is 50.0℃; y0=1P, the rated charging power is 1P (1000W); y1=0P, the derating cutoff charging power is 0P (0W). Adjust the charging power according to the current temperature of the cell. The maximum value can be adjusted to 1P and the minimum value can be adjusted to 0P. The first temperature threshold is 47.0℃. When the current temperature of the cell is greater than 47.0℃, the current temperature of the cell and the charging power and / or charging voltage meet the requirements. Figure 3 The linear relationship shown is shown, the maximum current temperature is substituted into the first linear formula to determine the second control value.

[0065] Step S132: In response to at least one target current temperature being less than a second temperature threshold among all current temperatures, a second control value is determined according to a minimum current temperature among the at least one target current temperature.

[0066] In some embodiments, a second control value is determined based on the minimum current temperature among at least one target current temperature, including: substituting the minimum current temperature into a second linear formula to determine the second control value; wherein the slope corresponding to the first linear formula is less than zero, and the slope corresponding to the second linear formula is greater than zero.

[0067] See also Figure 5 The linear relationship diagram shown in the figure assumes that the x-axis represents the battery cell temperature, the y-axis represents the charging power and / or charging voltage, x1 represents the derating initial temperature value, x0 represents the derating cut-off temperature value (battery cell minimum temperature), y0 represents the rated charging power and / or rated charging voltage, y1 represents the derating cut-off charging power and / or derating cut-off charging voltage, and the cut-off charging power is usually 0W. Figure 5 It can be seen that when the current temperature of the battery cell is between x0 and x1, the charging power and / or charging voltage can be determined according to the linear relationship. Exemplarily, when the current temperature of the battery cell is x0, the charging power and / or charging voltage is adjusted to y1.

[0068] Among them, when the current temperature of the battery cell is less than the second temperature threshold, the current temperature of the battery cell and the charging power and / or charging voltage satisfy the second linear relationship, and the corresponding slope of the second linear formula is greater than zero, that is, the higher the current temperature of the battery cell, the higher the charging power and / or charging voltage. The second control value is determined according to the second linear relationship, and the charging power and / or charging voltage are adjusted according to the second control value.

[0069] For example, when the battery cell is in a low temperature environment, the conductivity of the active material of the battery cell decreases, the internal resistance of the electrode increases, resulting in reduced charging performance and extended charging time. By increasing the charging power and / or charging voltage, the charging speed can be accelerated, the charging time can be shortened, and the charging efficiency can be improved. When the battery cell is in a high temperature environment, the chemical reaction of the battery cell is more intense, which can easily lead to overheating and safety problems. Reducing the charging power and / or charging voltage as the temperature rises can slow down the heating rate of the battery cell, ensure the safety of the charging process, maintain the relative stability of the battery cell performance, and improve the reliability and durability of the battery.

[0070] In one application scenario, taking a 1000Wh, 10-cell lithium iron phosphate battery pack as an example, its rated charging power is 1000W (1P), the rated charging voltage is 36V (3.6V*number of cell strings S), the charging power range is 0P~1P; the charging voltage range is 3300mV*S~3600mV*S. If x1=15.0℃ at this time, that is, the initial derating temperature is 15.0℃; x0=0.0℃, that is, the derating cutoff temperature value is 0.0℃; y0=1P, that is, the rated charging power is 1P (1000W); y1=0P, that is, the derating cutoff charging power is 0P (0W). The second temperature threshold is 15.0℃. When the current temperature of the cell is less than 15.0℃, the current temperature of the cell and the charging power and / or charging voltage meet the requirements. Figure 5 The linear relationship shown is shown, the minimum current temperature is substituted into the second linear formula to determine the second control value.

[0071] Step S133: In response to all current temperatures being between the second temperature threshold and the first temperature threshold, the second control value is a default value.

[0072] When the current temperature is between the second temperature threshold and the first temperature threshold, the charging power and / or charging voltage of the battery cell is adjusted to a default value, which may be a rated charging power and / or charging voltage.

[0073] In the above scheme, the charging power and / or charging voltage are dynamically adjusted according to the current temperature of the battery cell, and a linear relationship with different slopes is adopted for adaptive adjustment at low and high temperatures, so that the charging process is more adapted to the actual state of the battery cell, the flexibility and adaptability of charging are improved, the charging efficiency is optimized, and the battery life is extended.

[0074] See also Figure 6 , Figure 6 is a flow chart of step S14 in one embodiment. Step S14 may specifically include:

[0075] Step S141: obtaining the maximum current voltage from the current voltages of all the battery cells.

[0076] Step S142: In response to the maximum current voltage being less than the voltage threshold, the third control value is a default value.

[0077] Step S143: in response to the maximum current voltage being greater than or equal to the voltage threshold, determining a third control value according to the maximum current voltage.

[0078] In some embodiments, determining the third control value according to the maximum current voltage includes: obtaining a voltage difference between the maximum current voltage and a voltage threshold; and integrating the voltage difference to obtain the third control value.

[0079] Among them, when the battery cells are charged at a certain target charging voltage value, when the battery cell voltages are unbalanced, the voltage of a single battery cell will reach the target charging voltage value ahead of time. At this time, the charging power and charging voltage will be reduced on the current basis. The specific derating value of the voltage is determined by the maximum current voltage. After reducing the charging power and charging voltage, the battery cell voltage will be reduced synchronously to achieve the purpose of safe charging.

[0080] See also Figure 3 The linear relationship diagram shown in the figure assumes that the x-axis represents the cell voltage, the y-axis represents the charging power and / or charging voltage, x0 represents the derating initial voltage, x1 represents the derating cut-off voltage (the maximum current voltage of the cell), which means the stop charging voltage, y0 represents the rated charging power and / or the rated charging voltage, y1 represents the derating cut-off charging power and / or the derating cut-off charging voltage, and the cut-off charging power is usually 0W. Figure 3 It can be seen that when the current voltage of the battery cell is between x0 and x1, according to Figure 3 The linear relationship shown may determine the charging power and / or the charging voltage.

[0081] In some embodiments, the voltage threshold is determined based on the type and operating status of the battery cell.

[0082] In one application scenario, taking a 1000Wh, 10-cell lithium iron phosphate battery pack as an example, its rated charging power is 1000W (1P), the rated charging voltage is 36V (3.6V*number of cell strings S), the charging power range is 0P~1P; the charging voltage range is 3300mV*S~3600mV*S. Taking the voltage threshold of 3600 mV as an example, when the maximum current voltage of a battery cell is greater than or equal to 3600 mV, the voltage exceeding 3600 mV is integrated for 3 seconds, and the integrated value is / 3s. Assuming that the charging voltage derating value is ΔChgV; the charging power derating value ΔChgP is: ΔChgP=1P*ΔChgV / (3600mV-3300mV), the charging power derating is in the same proportion as the charging voltage, and the third control value is determined according to the voltage value between the maximum current voltage of the battery cell and the voltage threshold, reducing the charging power to a minimum of 0.1P and the charging voltage to a minimum of 3300mV*S.

[0083] In the above scheme, when the battery voltage is less than the voltage threshold, the charging speed is prioritized and charging is performed with a fixed charging power and / or charging voltage; when the battery voltage is greater than or equal to the voltage threshold, the charging power and / or charging voltage are reduced to prevent problems such as uneven battery charging and overcharging of some cells, thereby optimizing the charging process. Through precise control, the charging time can be shortened as much as possible and the charging efficiency can be improved while ensuring the safety of the cells.

[0084] See also Figure 7 , Figure 7 is a flow chart of step S15 in one embodiment, and step S15 may specifically include:

[0085] Step S151: Select the smaller one of the first control value and the second control value as the target control value.

[0086] Step S152: using the third control value to compensate the target control value.

[0087] Step S153: adjusting the charging power and / or charging voltage using the compensated target control value.

[0088] Among them, the charging power and / or charging voltage calculated according to the third control value is the compensation value of the charging power and / or charging voltage, which is a derating compensation value based on the minimum value of the charging power calculated according to the first control value and the second control value. For example: the charging power calculated according to the current battery power is 0.8P, the charging power calculated according to the current temperature of the battery cell is 0.4P, and the power compensation calculated according to the current voltage of the battery cell is 0.1P. The smaller of the two, 0.4P, is selected as the target charging power, and the compensation value is 0.1P, then the final charging power should be adjusted to 0.4-0.1=0.3P.

[0089] The charging control logic of the present application sets reasonable control values ​​for the voltage and temperature of each battery cell through the participation of multiple control parameters such as the current battery power, the current voltage and the current temperature of each battery cell. The charging process of the battery is accurately controlled according to the first control value, the second control value and the third control value, and the charging power and the charging voltage are dynamically adjusted. Therefore, when the battery cell voltages are uneven, the charging power and the charging voltage are reduced to avoid the problem of overcharging the battery cells, thereby effectively improving the charging reliability. At the same time, this dynamic adjustment can ensure that the battery is charged in the best state, reduce unnecessary waste of charging time, avoid prolonged charging time, and thus improve charging efficiency.

[0090] See also Figure 8 , Figure 8 It is a structural schematic diagram of an embodiment of a battery charging device provided by the present application. The battery charging device 100 includes: an acquisition module 10, a first determination module 20, a second determination module 30, a third determination module 40 and an adjustment module 50. The acquisition module 10 is used to acquire the current power of the battery, the current voltage of each battery cell and the current temperature of each battery cell during the charging process; the first determination module 20 is used to determine a first control value according to the current power; the second determination module 30 is used to determine a second control value according to the current temperature; the third determination module 40 is used to determine a third control value according to the current voltage; and the adjustment module 50 is used to dynamically adjust the charging power and / or charging voltage according to the first control value and / or the second control value and / or the third control value.

[0091] The first determination module 20 is used to determine the first control value as a default value in response to the current power being less than the power threshold; and to determine the first control value according to a linear relationship in response to the current power being greater than or equal to the power threshold.

[0092] The second determination module 30 is used to determine a second control value based on the maximum current temperature among at least one target current temperature in response to at least one target current temperature being greater than the first temperature threshold among all current temperatures; to determine a second control value based on the minimum current temperature among at least one target current temperature in response to at least one target current temperature being less than the second temperature threshold among all current temperatures; and to set the second control value to a default value in response to all current temperatures being between the second temperature threshold and the first temperature threshold.

[0093] The second determination module 30 is further configured to substitute the maximum current temperature into the first linear formula to determine a second control value.

[0094] The second determination module 30 is further used to substitute the minimum current temperature into a second linear formula to determine a second control value; wherein the first linear formula corresponds to a slope less than zero, and the second linear formula corresponds to a slope greater than zero.

[0095] The third determination module 40 is used to obtain the maximum current voltage from the current voltages of all battery cells; in response to the maximum current voltage being less than the voltage threshold, the third control value is a default value; in response to the maximum current voltage being greater than or equal to the voltage threshold, the third control value is determined according to the maximum current voltage.

[0096] The third determination module 40 is further configured to obtain a voltage difference between the maximum current voltage and the voltage threshold; and integrate the voltage difference to obtain a third control value.

[0097] The adjustment module 50 is used to select the smaller one of the first control value and the second control value as the target control value; compensate the target control value using the third control value; and adjust the charging power and / or charging voltage using the compensated target control value.

[0098] See also Fig. 9 , Fig. 9 8 is a schematic diagram of a computer-readable storage medium according to an embodiment of the present application. The computer-readable storage medium 800 stores program data 810, and when the program data 810 is executed by a processor, the following battery charging method is implemented:

[0099] During the charging process, the current charge of the battery, the current voltage of each battery cell, and the current temperature of each battery cell are obtained; a first control value is determined based on the current charge; a second control value is determined based on the current temperature; a third control value is determined based on the current voltage; and the charging power and / or charging voltage are dynamically adjusted based on the first control value and / or the second control value and / or the third control value.

[0100] In one embodiment, when the program data 810 is executed by the processor, it is used to implement: in response to the current power being less than the power threshold, the first control value is a default value; in response to the current power being greater than or equal to the power threshold, the first control value is determined according to a linear relationship.

[0101] In one embodiment, when the program data 810 is executed by the processor, it is used to achieve: in response to the existence of at least one target current temperature greater than a first temperature threshold among all current temperatures, a second control value is determined based on the maximum current temperature among the at least one target current temperature; in response to the existence of at least one target current temperature less than a second temperature threshold among all current temperatures, a second control value is determined based on the minimum current temperature among the at least one target current temperature; in response to all current temperatures being between the second temperature threshold and the first temperature threshold, the second control value is a default value.

[0102] In one embodiment, when the program data 810 is executed by the processor, it is used to implement: substituting the maximum current temperature into the first linear formula to determine the second control value.

[0103] In one embodiment, when the program data 810 is executed by the processor, it is used to implement: substituting the minimum current temperature into the second linear formula to determine the second control value; wherein the first linear formula corresponds to a slope less than zero, and the second linear formula corresponds to a slope greater than zero.

[0104] In one embodiment, when the program data 810 is executed by the processor, it is used to achieve: obtaining the maximum current voltage from the current voltages of all battery cells; in response to the maximum current voltage being less than a voltage threshold, the third control value is a default value; in response to the maximum current voltage being greater than or equal to the voltage threshold, determining the third control value based on the maximum current voltage.

[0105] In one embodiment, when the program data 810 is executed by the processor, it is used to implement: obtaining the voltage difference between the maximum current voltage and the voltage threshold; integrating the voltage difference to obtain the third control value.

[0106] In one embodiment, when the program data 810 is executed by the processor, it is used to implement: selecting the smaller of the first control value and the second control value as the target control value; compensating the target control value using the third control value; and adjusting the charging power and / or charging voltage using the compensated target control value.

[0107] The charging control logic of the present application sets reasonable control values ​​for the voltage and temperature of each battery cell through the participation of multiple control parameters such as the current battery power, the current voltage and the current temperature of each battery cell. The charging process of the battery is accurately controlled according to the first control value, the second control value and the third control value, and the charging power and the charging voltage are dynamically adjusted. Therefore, when the battery cell voltages are uneven, the charging power and the charging voltage are reduced to avoid the problem of overcharging the battery cells, thereby effectively improving the charging reliability. At the same time, this dynamic adjustment can ensure that the battery is charged in the best state, reduce unnecessary waste of charging time, avoid prolonged charging time, and thus improve charging efficiency.

[0108] In the several embodiments provided in this application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device implementation described above is only illustrative, for example, the division of the modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0109] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0110] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0111] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A battery charging method, characterized in that: The battery comprises a plurality of cells connected in series, and the method comprises: During the charging process, obtaining the current power of the battery, the current voltage of each of the battery cells, and the current temperature of each of the battery cells; Determining a first control value according to the current power; Determining a second control value according to the current temperature; Determine a third control value according to the current voltage; The charging power and / or the charging voltage are dynamically adjusted according to the first control value and / or the second control value and / or the third control value.

2. The battery charging method according to claim 1, characterized in that: The determining the first control value according to the current power includes: In response to the current power being less than a power threshold, the first control value being a default value; In response to the current power level being greater than or equal to the power threshold, the first control value is determined according to a linear relationship.

3. The battery charging method according to claim 1, characterized in that: The determining of the second control value according to the current temperature includes: In response to at least one target current temperature greater than a first temperature threshold existing among all the current temperatures, determining a second control value according to a maximum current temperature among the at least one target current temperature; In response to at least one target current temperature being less than a second temperature threshold among all the current temperatures, determining a second control value according to a minimum current temperature among the at least one target current temperature; In response to all of the current temperatures being between the second temperature threshold and the first temperature threshold, the second control value is a default value.

4. The battery charging method according to claim 3, characterized in that: The determining the second control value according to the maximum current temperature among the at least one target current temperature comprises: Substituting the maximum current temperature into the first linear formula to determine the second control value; The determining the second control value according to the minimum current temperature among the at least one target current temperature comprises: Substituting the minimum current temperature into a second linear formula to determine the second control value; The first linear formula corresponds to a slope less than zero, and the second linear formula corresponds to a slope greater than zero.

5. The battery charging method according to claim 1, characterized in that: The determining a third control value according to the current voltage includes: Obtaining a maximum current voltage from the current voltages of all the battery cells; In response to the maximum current voltage being less than a voltage threshold, the third control value is a default value; In response to the maximum current voltage being greater than or equal to the voltage threshold, the third control value is determined according to the maximum current voltage.

6. The battery charging method according to claim 5, characterized in that: The determining the third control value according to the maximum current voltage includes: Acquire a voltage difference between the maximum current voltage and the voltage threshold; The voltage difference is integrated to obtain the third control value.

7. The battery charging method according to claim 5 or 6, characterized in that: The voltage threshold is determined based on the type and working state of the battery cell.

8. The battery charging method according to claim 1, characterized in that: The adjusting the charging power and / or the charging voltage according to the first control value, the second control value, and the third control value includes: Selecting the smaller of the first control value and the second control value as the target control value; Compensating the target control value using the third control value; The charging power and / or the charging voltage are adjusted using the compensated target control value.

9. A battery charging device, characterized in that: The battery charging device comprises: An acquisition module, used for acquiring the current power of the battery, the current voltage and the current temperature of each of the battery cells during the charging process; A first determining module, configured to determine a first control value according to the current power; A second determining module, configured to determine a second control value according to the current temperature; A third determining module, configured to determine a third control value according to the current voltage; An adjustment module is used to adjust the charging power and / or charging voltage according to the first control value, the second control value and the third control value.

10. A computer-readable storage medium, characterized in that: The computer-readable and writable storage medium stores program data, and when the program data is executed by the processor, it is used to implement the battery charging method according to any one of claims 1 to 8.

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