Charging control method and system for power battery

Abstract

The application provides a charging control method and system for a power battery, the method comprising: acquiring a maximum single battery voltage of the power battery during charging; when the maximum single battery voltage is greater than or equal to a preset current reduction voltage, acquiring a current charging request current and controlling the current charging request current to decrease at a first preset rate, when the maximum single battery voltage after current reduction is less than or equal to a preset current stabilization voltage and the current charging request current does not reach a first preset charging current, controlling the current charging request current after current reduction to increase at a second preset rate until the maximum single battery voltage after current increase is greater than or equal to a difference between the preset current reduction voltage and a first set value, and maintaining the current charging request current after current increase for continuous charging until a current power value of the power battery reaches a preset power value. The maximum single battery voltage of the power battery is judged during charging, so that the current charging request current is adjusted in real time, and the charging performance of the power battery is optimized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power battery charging, in particular to a power battery charging control method and system. BACKGROUND

[0002] The power battery charging performance is a key factor affecting the cruising range of new energy vehicles. In the current power battery charging process, in order to avoid the problem of high terminal voltage, small current charging is adopted after the voltage threshold is exceeded at the charging terminal, so as to improve the charging capacity and reduce the problem of low cruising caused by the virtual high power.

[0003] However, this process also increases the charging time, and even under low temperature conditions, the polarization voltage of the battery is large, and the end of the charging process is easily triggered, resulting in long charging time and low charging efficiency of the power battery. SUMMARY

[0004] Therefore, the present application provides a power battery charging control method, which solves the technical problems of long charging time and low charging efficiency of the power battery. In the charging process, the maximum single voltage of the power battery is judged to adjust the current charging request current in real time, and the charging performance of the power battery is optimized by combining the methods of current reduction and current increase, so as to shorten the charging time and improve the charging efficiency.

[0005] In order to achieve the above purpose, the present application provides the following technical scheme: obtaining the maximum single voltage of the power battery in the charging process, the maximum single voltage representing the maximum value of the voltage corresponding to the plurality of battery monomers of the power battery, and the maximum single voltage dynamically changing with the charging process; when the maximum single voltage is greater than or equal to the preset current reduction voltage, the current charging request current is obtained, and the current charging request current is controlled to decrease at a first preset rate, and it is judged whether the maximum single voltage after current reduction is less than or equal to the preset stable current voltage; wherein the current charging request current is dynamically adjusted with the charging process; when the maximum single voltage after current reduction is less than or equal to the preset stable current voltage and the current charging request current does not reach the first preset charging current, the current charging request current after current reduction is controlled to increase at a second preset rate until the maximum single voltage after current increase is greater than or equal to the difference between the preset current reduction voltage and the first set value, and the current charging request current after current increase is maintained for continuous charging until the current power of the power battery reaches the preset power value, and the current power is dynamically adjusted with the charging process.

[0006] In an embodiment of the present application, the method further comprises: when the maximum single cell voltage after the current reduction is less than or equal to the preset steady current voltage, maintaining the preset steady current voltage for charging until the current power of the power battery reaches the preset power value.

[0007] In an embodiment of the present application, the method further comprises: when the maximum single cell voltage after the current reduction is less than the preset current reduction voltage minus the first set value, and when the current charging request current after the current increase reaches the first preset charging current, maintaining the first preset charging current for charging until the current power of the power battery reaches the preset power value, wherein the first preset charging current is a charging current obtained by looking up the current power and the ambient temperature of the power battery.

[0008] In an embodiment of the present application, the method further comprises: when the maximum single cell voltage is less than the preset current reduction voltage, determining the current charging request current as the first preset charging current, maintaining the first preset charging current for charging until the current power of the power battery reaches the preset power value.

[0009] In an embodiment of the present application, the method further comprises: obtaining the maximum single cell voltage of the power battery in a charging starting stage, and when the maximum single cell voltage in the charging starting stage is less than the preset current reduction voltage, obtaining a second preset charging current and controlling the second preset charging current to increase at a third preset rate; wherein the current power corresponding to the second preset charging current is higher than the current power corresponding to the first preset charging current; when the maximum single cell voltage after the current increase is greater than or equal to the preset current reduction voltage minus the first set value, or when the current charging request current after the current increase reaches the first preset charging current, maintaining the current charging request current after the current increase for charging until the current power of the power battery reaches the preset power value.

[0010] In an embodiment of the present application, the method further comprises: obtaining the maximum single cell voltage of the power battery in a charging starting stage, and when the maximum single cell voltage in the charging starting stage is less than the preset current reduction voltage, obtaining a second preset charging current and controlling the second preset charging current to increase at a third preset rate; wherein the current power corresponding to the second preset charging current is higher than the current power corresponding to the first preset charging current; when the maximum single cell voltage after the current increase is greater than or equal to the preset current reduction voltage minus the first set value, or when the current charging request current after the current increase reaches the first preset charging current, maintaining the current charging request current after the current increase for charging until the current power of the power battery reaches the preset power value.

[0011] In an embodiment of the present application, the method further comprises: when the maximum single cell voltage is greater than or equal to the preset current reduction voltage, determining the current charging request current as the preset charging cutoff current, and maintaining the preset charging cutoff current for charging until the current power of the power battery reaches the preset power value.

[0012] In an embodiment of the present application, the method further comprises: the current charging request current is based on the current power of the power battery; when the current power of the power battery is less than a preset power value, a product of a first preset charging current and the preset power value is obtained; a minimum value of the second preset charging current and the product is obtained, and the minimum value is determined as the second preset charging current; a minimum value of the current charging request current and the product is obtained, and the minimum value is determined as the current charging request current; a minimum value of a preset charging cutoff current and the product is obtained, and the minimum value is determined as the preset charging cutoff current.

[0013] In an embodiment of the present application, after the current power of the power battery reaches the preset power value, the method further comprises: determining that the current charging request current after the current charging request current is increased is zero, and stopping charging.

[0014] As a second aspect of the present application, the present application further provides a charging control system of a power battery, the charging control system comprising a processor, the processor being configured to execute any of the charging control methods of the power battery.

[0015] As a third aspect of the present application, the present application further provides a computer program product comprising a computer program, the computer program being configured to implement any of the charging control methods of the power battery when executed by a processor.

[0016] The charging control method of the power battery provided by the present application comprises: obtaining a maximum single cell voltage of the power battery during charging; when the maximum single cell voltage is greater than or equal to a preset current reduction voltage, obtaining a current charging request current, and controlling the current charging request current to decrease at a first preset rate; when the maximum single cell voltage after the current charging request current is reduced is less than or equal to a preset stable current voltage and the current charging request current does not reach a first preset charging current, controlling the current charging request current after the current charging request current is reduced to increase at a second preset rate until the maximum single cell voltage after the current charging request current is increased is greater than or equal to a difference between the preset current reduction voltage and a first set value, and maintaining the current charging request current after the current charging request current is increased for continuous charging until the current power of the power battery reaches a preset power value. It is easy to note that, during the charging process, the maximum single cell voltage of the power battery is judged in real time, the current charging request current is reduced when the maximum single cell voltage is greater than or equal to the preset current reduction voltage, and the current charging request current after the current charging request current is reduced is controlled to increase when the maximum single cell voltage is less than or equal to the preset stable current voltage. By adopting the combination of current reduction and current increase, the current charging request current is adjusted in real time, the charging performance of the power battery is optimized, the technical effect of shortening the charging time and improving the charging efficiency is achieved, and the technical problems of long charging time and low charging efficiency of the power battery are solved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on the provided drawings.

[0018] Figure 1 A flow chart of a charging control method of a power battery is shown.

[0019] Figure 2 A control flow chart in a charging process is shown.

[0020] Figure 3 A control flow chart in a charging starting stage is shown. DETAILED DESCRIPTION

[0021] The charging performance of the power battery is a key factor affecting the cruising range of the new energy vehicle. In the current charging process of the power battery, in order to avoid the problem of false high voltage at the end of charging, small current charging is performed after exceeding the voltage threshold at the end of charging, so as to improve the charging capacity and reduce the problem of low cruising caused by false high voltage. However, this process also increases the charging time, and even under low temperature conditions, the polarization voltage of the battery is large, and the end of the charging process is easily triggered, resulting in long charging time and low charging efficiency of the power battery.

[0022] The present inventors have proposed, through research, that the maximum single cell voltage of the power battery in the charging process is obtained; when the maximum single cell voltage is greater than or equal to a preset current reduction voltage, the current charging request current is obtained, and the current charging request current is controlled to decrease at a first preset rate, when the maximum single cell voltage after current reduction is less than or equal to a preset current stabilization voltage and the current charging request current does not reach a first preset charging current, the current charging request current after current reduction is controlled to increase at a second preset rate, until the maximum single cell voltage after current increase is greater than or equal to a difference between the preset current reduction voltage and a first set value, and the current charging request current after current increase is maintained for continuous charging, until the current capacity of the power battery reaches a preset capacity value, and the current capacity is dynamically adjusted with the charging process. In the charging process, the maximum single cell voltage of the power battery is judged, so as to adjust the current charging request current in real time, and the charging performance of the power battery is optimized by combining current reduction and current increase, so as to shorten the charging time and improve the charging efficiency.

[0023] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below, obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0024] As a first aspect of the present application, the present application provides a charging control method of a power battery, Figure 1 As shown in the figure, the charging control method comprises the following steps: Figure 1 As shown in the figure, the charging control method comprises the following steps:

[0025] S101, obtaining the maximum single cell voltage of the power battery in the charging process, the maximum single cell voltage representing the maximum value of the corresponding voltage of the plurality of battery cells of the power battery, and the maximum single cell voltage dynamically changing with the charging process;

[0026] Specifically, the maximum single cell voltage can be obtained by the power battery management system. Specifically, the voltage information can be obtained by installing voltage sensors on both ends of each single cell. These voltage sensors can convert the voltage signal into an electrical signal and then transmit it to the control unit of the battery management system. The control unit processes and analyzes these signals to obtain the voltage value of each single cell. By obtaining the maximum voltage value from the voltage value of each single cell, the above-mentioned maximum single cell voltage can be obtained.

[0027] In an optional embodiment, during the charging process of the power battery, the maximum single cell voltage of the power battery in the charging process can be obtained. By judging the maximum single cell voltage, the charging request current in the charging process can be determined. Specifically, if the maximum single cell voltage in the charging process has reached the drop voltage threshold at the end of charging, it can be determined that the charging request current in the charging process is small, otherwise, if the maximum single cell voltage in the charging process has not reached the drop voltage threshold at the end of charging, the charging request current in the charging process can be controlled to gradually increase, etc.

[0028] It should be noted that the above-mentioned maximum single cell voltage dynamically changes with the charging process. With the progress of the charging process, the maximum single cell voltage may increase rapidly, and after reaching the drop voltage threshold at the end of charging, it may grow slowly until the power battery is fully charged.

[0029] S102, when the maximum single cell voltage is greater than or equal to the preset drop voltage, obtaining the current charging request current and controlling the current charging request current to decrease at a first preset rate, and simultaneously judging whether the maximum single cell voltage after the drop is less than or equal to the preset steady voltage; wherein the current charging request current is dynamically adjusted with the charging process;

[0030] Specifically, the preset drop current voltage can be used to represent a preset drop current voltage threshold at the end of charging. Generally, the preset drop current voltage can be 3.5V, 4V, or the like. In this case, the preset drop current voltage is not specifically set, and can be dynamically adjusted according to the characteristics of the power battery cell.

[0031] The current charging request current can be obtained by looking up a table of the current power battery power and the ambient temperature. Specifically, the current charging request current can be obtained by looking up a MAP table of the current power battery power and the ambient temperature. It should be noted that, in order to avoid the inaccuracy of the current charging request current due to external factors, the maximum single cell voltage of the power battery can be determined after the current charging request current is obtained, so as to accurately control the current charging request current.

[0032] For example, if the current power of the power battery is displayed as being too high due to external factors, the current charging request current obtained by looking up the table can be less than the normal request current. However, after the current charging request current is obtained, if it is determined that the maximum single cell voltage of the power battery has not reached the preset drop current voltage, it indicates that the current power of the power battery has not reached the power value corresponding to the preset drop current voltage, and thus it can be verified that the current power of the power battery is displayed as being too high.

[0033] The first preset rate can be used to represent a preset current drop rate, which can be calculated by a current change difference and a current drop time. For example, if the current charging request current needs to be reduced from I1 to I2, and the drop is required to be completed within t1 time, the first preset rate can be obtained by (I1-I2) / t1.

[0034] The preset stable current voltage can be used to represent a preset voltage threshold at a relatively stable state. When the power battery is charged at the preset stable current voltage, the maximum single cell voltage will not suddenly increase. In addition, the preset stable current voltage is less than the preset drop current voltage. The preset stable current voltage can be 2.5V, 3V, or the like. In this case, the preset stable current voltage is not specifically set, and can be dynamically adjusted according to the characteristics of the power battery cell.

[0035] It should be noted that the current charging request current is dynamically adjusted during the charging process. Specifically, the current charging request current is dynamically changed with the real-time maximum single cell voltage. If the maximum single cell voltage is large, the charging request current can be reduced. Conversely, if the maximum single cell voltage is small, the charging request current can be gradually increased.

[0036] In an optional embodiment, after obtaining the maximum single cell voltage during the charging process of the power battery, the maximum single cell voltage is determined, i.e., whether the maximum single cell voltage is greater than or equal to the preset current reduction voltage. If the maximum single cell voltage is greater than or equal to the preset current reduction voltage, it means that the maximum single cell voltage reaches the current reduction voltage threshold at the end of charging, and the current reduction operation needs to be performed. The current charging request current is obtained, and the current charging request current is controlled to decrease at a first preset rate. The maximum single cell voltage obtained after current reduction is determined, i.e., whether the maximum single cell voltage after current reduction is less than or equal to the preset current stabilization voltage. Through the determination of the maximum single cell voltage after current reduction and the preset current stabilization voltage, the current charging request current can be further dynamically adjusted, so that the power battery is fully charged in a short time, and the charging performance and charging time are considered.

[0037] S103, when the maximum single cell voltage after current reduction is less than or equal to the preset current stabilization voltage and the current charging request current does not reach the first preset charging current, the current charging request current after current reduction is controlled to increase at a second preset rate until the maximum single cell voltage after current increase is greater than or equal to the difference between the preset current reduction voltage and the first set value, and the current charging request current after current increase is maintained to continue charging until the current power of the power battery reaches the preset power value. The current power is dynamically adjusted with the charging process.

[0038] Specifically, the second preset rate described above can be used to represent the preset current increase rate, which can be calculated by the current change difference and the current increase time. For example, if the current charging request current needs to be increased from I2 to I3, and the current reduction needs to be completed within t2, the first preset rate can be obtained by (I3-I2) / t2.

[0039] The first set value described above represents the preset voltage fluctuation value, which can be 10mV or 12mV. Here, the first set value is not specifically set, and can be adjusted according to the actual situation.

[0040] The preset power value described above can be used to represent the preset power of the power battery. Generally, it is 100%, but the preset power value is not specifically set here, and can be adaptively adjusted according to the battery cell characteristics in actual application.

[0041] In an optional embodiment, in the process of judging the maximum single cell voltage after current reduction and the preset steady current voltage, if the maximum single cell voltage after current reduction is less than or equal to the preset steady current voltage and the current charging request current does not reach the first preset charging current, it indicates that the maximum single cell voltage after current reduction has not reached the relatively stable charging voltage threshold. If the current charging request current after current reduction is continued to be used for charging, the charging time will be relatively long. In order to avoid the charging time being too long, the current charging request current after current reduction is adjusted again, that is, the current charging request current after current reduction is controlled to increase at a second preset rate, and the maximum single cell voltage during the current increase process is continuously monitored, until the maximum single cell voltage after current increase is greater than or equal to the difference between the preset current reduction voltage and the first set value, which indicates that the maximum single cell voltage after current increase is close to the current reduction voltage threshold at the end of charging, but has not reached the preset current reduction voltage. The current charging request current after current increase can be maintained for continuous charging until the current power of the power battery reaches the preset power value, and the charging is stopped.

[0042] By real-time judging the maximum single cell voltage during charging, the charging request current at the end of charging can be dynamically adjusted. It should be noted that the current reduction control and the current increase control during charging are not limited to one or two times, and the current reduction process or the current increase process can be repeatedly triggered based on the real-time change of the maximum single cell voltage, that is, the current reduction process is triggered when the maximum single cell voltage is greater than or equal to the preset current reduction voltage, and the current charging request current is reduced; the current increase process is triggered when the maximum single cell voltage is less than or equal to the preset steady current voltage, and the current charging request current is increased. By repeatedly triggering the current reduction process and the current increase process, the charging performance and the charging time are considered, and the charging efficiency of the power battery is improved.

[0043] The application provides a power battery charging control method, which comprises the following steps: acquiring the maximum single battery voltage of the power battery in a charging process; when the maximum single battery voltage is greater than or equal to a preset current reduction voltage, acquiring a current charging request current and controlling the current charging request current to decrease at a first preset rate; when the maximum single battery voltage after current reduction is less than or equal to a preset stable current voltage and the current charging request current does not reach a first preset charging current, controlling the current charging request current after current reduction to increase at a second preset rate until the maximum single battery voltage after current increase is greater than or equal to a difference between the preset current reduction voltage and a first set value, and keeping the current charging request current after current increase to continue charging until the current power of the power battery reaches a preset power value, and the current power is dynamically adjusted during the charging process. It is easy to note that the maximum single battery voltage of the power battery is judged in real time during the charging process, the current charging request current is reduced when the maximum single battery voltage is greater than or equal to the preset current reduction voltage, and the current charging request current after current reduction is controlled to increase when the maximum single battery voltage is less than or equal to the preset stable current voltage, so that the current charging request current is adjusted in real time by adopting the combination of current reduction and current increase, the charging performance of the power battery is optimized, the technical effects of shortening the charging time and improving the charging efficiency are achieved, and the technical problems of long charging time and low charging efficiency of the power battery are solved.

[0044] In an embodiment of the application, whether the maximum single battery voltage after current reduction is less than or equal to the preset stable current voltage comprises: when the maximum single battery voltage after current reduction is greater than the preset stable current voltage, and when the current charging request current after current reduction reaches a preset charging cutoff current, keeping the preset charging cutoff current to continue charging until the current power of the power battery reaches the preset power value; and when the current charging request current after current reduction does not reach the preset charging cutoff current, controlling the current charging request current after current reduction to continue to decrease at the first preset rate.

[0045] Specifically, the preset charging cutoff current can be used to represent the minimum current at the end of charging, and the current charging request current during the current reduction process should not be less than the preset charging cutoff current.

[0046] In an optional embodiment, if the maximum single battery voltage after current reduction is greater than the preset stable current voltage, it indicates that the maximum single battery voltage after current reduction has reached a relatively stable charging voltage threshold. When the current charging request current after current reduction reaches the preset charging cutoff current, it indicates that the current charging request current after current reduction has met the minimum current setting at the end of charging, and cannot continue to reduce. The preset charging cutoff current can be kept to continue charging, that is, the minimum current at the end of charging can be kept to continue charging until the current power of the power battery reaches the preset power value.

[0047] Conversely, if the current charging request current after the current reduction does not reach the preset charging cutoff current, it indicates that the current charging request current after the current reduction has not yet dropped to the minimum current setting at the end of charging, at which time the current charging request current after the current reduction can be controlled to continue to drop at the first preset rate, and the maximum single cell voltage after the current reduction and the preset steady current voltage are re-judged until the maximum single cell voltage after the current reduction is greater than the preset steady current voltage, and the current charging request current after the current reduction reaches the preset charging cutoff current.

[0048] In an embodiment of the present application, the method further comprises: when the maximum single cell voltage after the current increase is less than the difference between the preset current reduction voltage and the first set value, and when the current charging request current after the current increase reaches the first preset charging current, maintaining the first preset charging current for continuous charging until the current power of the power battery reaches the preset power value, wherein the first preset charging current represents a charging current obtained by looking up a table of the current power of the power battery and the ambient temperature.

[0049] Specifically, the first preset charging current described above can be used to represent a preset charging current obtained by looking up a table of the current power of the power battery and the ambient temperature. Generally, the preset charging current is obtained by looking up a MAP table of the battery power and the ambient temperature, which records the relationship between different step battery powers, ambient temperatures, and charging request currents.

[0050] In an optional embodiment, if the maximum single cell voltage after the current increase is less than the difference between the preset current reduction voltage and the first set value, it indicates that the maximum single cell voltage after the current increase is at a relatively stable charging voltage threshold, and when the current charging request current after the current increase reaches the first preset charging current, the first preset charging current can be maintained for continuous charging until the current power of the power battery reaches the preset power value.

[0051] In an embodiment of the present application, the method further comprises: when the maximum single cell voltage is less than the preset current reduction voltage, determining the current charging request current as the first preset charging current, maintaining the first preset charging current for continuous charging until the current power of the power battery reaches the preset power value.

[0052] Specifically, if the maximum single cell voltage is less than the preset current reduction voltage, it indicates that the maximum single cell voltage has not yet reached the current reduction voltage threshold at the end of charging, the current charging request current can be determined as the first preset charging current, which is a preset charging current obtained by looking up a table of the current power of the power battery and the ambient temperature, and the first preset charging current is maintained for continuous charging until the current power of the power battery reaches the preset power value.

[0053] Figure 2 A control flowchart during charging is shown in an embodiment of the present application. As shown in FIG. 1, the control flowchart includes the following steps. Figure 2As shown, the current control during the charging process includes the following steps:

[0054] S201, During charging, determine the maximum single-cell voltage. If so, then confirm. If not, then execute S202;

[0055] That is, to determine the maximum single-cell voltage of the power battery. Is it less than the preset current reduction voltage? If so, determine the current charging request current. The first preset charging current .

[0056] S202, Control It decreases at a rate of b A / s;

[0057] That is, control the current of the current charging request. It decreases at a rate of b A / s, which is the first preset rate.

[0058] S203, judgment If yes, then execute S204; otherwise, execute S207.

[0059] That is, to determine the maximum single-cell voltage after current reduction. Is it less than or equal to the preset constant current voltage? .

[0060] S204, Control It increases at a rate of c A / s;

[0061] That is, controlling the current charging request current after current reduction. It rises at a rate of the second preset rate c A / s.

[0062] S205, Judgment If yes, then execute S206; otherwise, execute S208.

[0063] That is, to determine the maximum single-cell voltage after the current boost. Is it greater than or equal to the preset current reduction voltage? Subtract the first set value The difference.

[0064] S206, Hold, and then jump to S201;

[0065] That is, maintain the current charging request current after the current boost. Continue charging until the current charge level of the power battery reaches the preset charge level.

[0066] S207, judgment ; if yes, the current charging request current after the current is reduced maintain the preset charging cutoff current continue charging and jump to S203; if no, jump to S202;

[0067] that is, judge whether the current charging request current after the current is reduced reaches the preset charging cutoff current .

[0068] S208, judge , if yes, the current charging request current after the current is increased maintain the first preset charging current , if no, jump to S204.

[0069] It should be noted that, in any of the above steps, if the current power of the power battery reaches the preset power value, the current charging request current is determined to be 0, and the charging process is stopped.

[0070] In an embodiment of the present application, the method further comprises: obtaining the maximum single cell voltage of the power battery in the charging starting stage, and when the maximum single cell voltage in the charging starting stage is less than the preset current reduction voltage, obtaining the second preset charging current, and controlling the second preset charging current to increase at a third preset rate; wherein the current power corresponding to the second preset charging current is higher than the current power corresponding to the first preset charging current; when the maximum single cell voltage after the current is increased is greater than or equal to the difference between the preset current reduction voltage and the first set value, or when the current charging request current after the current is increased reaches the first preset charging current, the current charging request current after the current is increased is maintained to continue charging until the current power of the power battery reaches the preset power value.

[0071] Specifically, the above-mentioned second preset charging current is generally obtained by searching a MAP according to the current power of the power battery and the ambient temperature, and the current power corresponding to the second preset charging current is higher than the current power corresponding to the first preset charging current.

[0072] The above-mentioned third preset rate can be used to represent the increasing rate of the second preset charging current, and the third preset rate is not specifically limited here and can be adaptively adjusted according to the actual situation and the characteristics of the power battery.

[0073] In an optional embodiment, the maximum single cell voltage of the power battery in the charging starting stage is obtained, and when the maximum single cell voltage in the charging starting stage is less than the preset current reduction voltage, it indicates that the maximum single cell voltage of the power battery in the charging starting stage is small and has not reached the current reduction voltage threshold at the end of charging. The second preset charging current is obtained by searching the MAP according to the current power and the ambient temperature of the power battery. It should be noted that the current corresponding to the second preset charging current is higher than the current corresponding to the first preset charging current. The second preset charging current is controlled to rise at a third preset rate, and the maximum single cell voltage is continuously monitored during the current rise process. When the maximum single cell voltage after current rise is greater than or equal to the difference between the preset current reduction voltage and the first set value, it indicates that the maximum single cell voltage after current rise is close to the current reduction voltage threshold at the end of charging, or when the current charging request current after current rise reaches the first preset charging current, the current charging request current after current rise is maintained for continuous charging until the current power of the power battery reaches the preset power value.

[0074] It should be noted that when the maximum single cell voltage after current rise is greater than or equal to the difference between the preset current reduction voltage and the first set value, the current charging request current after current rise may not have reached the first preset charging current, and therefore the current charging request current after current rise can be maintained for continuous charging. Conversely, if the current charging request current after current rise has reached the first preset charging current, the first preset charging current can be maintained for continuous charging.

[0075] In an embodiment of the present application, the second preset charging current is controlled to rise at a third preset rate, including: controlling the second preset charging current to rise at a third preset rate within a preset time period, wherein the third preset rate is equal to the quotient obtained by dividing the charging current difference by the preset time period, and the charging current difference is equal to the difference between the first preset charging current and the second preset charging current.

[0076] Specifically, the above-mentioned preset time period can be used to represent the time for the preset charging request current to rise from an initial value to a high-order value. Generally, it can be 10s or 12s. In this case, the preset time period is not specifically set and can be adjusted according to actual conditions.

[0077] In an optional embodiment, during the process of controlling the second preset charging current to rise at a third preset rate, the second preset charging current can be controlled to rise at a third preset rate within a preset time period. That is, after the second preset charging current and the first preset charging current are determined, the difference between the first preset charging current and the second preset charging current is calculated, and the difference is divided by the preset time period to obtain the rising rate of the second preset charging current within the preset time period.

[0078] In an embodiment of the present application, the method further comprises: when the maximum single-cell voltage is greater than or equal to the preset current reduction voltage, determining the current charging request current as the preset charging cutoff current, and maintaining the preset charging cutoff current for charging until the current power of the power battery reaches the preset power value.

[0079] Specifically, if the maximum single-cell voltage is greater than or equal to the preset current reduction voltage, it indicates that the maximum single-cell voltage reaches the current reduction threshold at the end of charging, and at this time, the end of charging needs to perform a current reduction operation, i.e., determining the current charging request current as the preset charging cutoff current, and maintaining the preset charging cutoff current for charging until the current power of the power battery reaches the preset power value.

[0080] In an embodiment of the present application, the method further comprises: the current charging request current is based on the current power of the power battery; when the current power of the power battery is less than the preset power value, obtaining the product of the first preset charging current and the preset power value; obtaining the minimum value of the second preset charging current and the product, and determining the minimum value as the second preset charging current; obtaining the minimum value of the current charging request current and the product, and determining the minimum value as the current charging request current; obtaining the minimum value of the preset charging cutoff current and the product, and determining the minimum value as the preset charging cutoff current.

[0081] Specifically, in the process of determining the second preset charging current, the current charging request current, and the preset charging cutoff current, since the current charging request current is based on the current power of the power battery, and the second preset charging current, the current charging request current, and the preset charging cutoff current are preset before the power battery decays, but the power battery may decay during the actual charging process, which leads to that the preset second preset charging current, the current charging request current, and the preset charging cutoff current may exceed the limit. Therefore, when the current power of the power battery is less than 100%, the second preset charging current, the current charging request current, and the preset charging cutoff current can be compared with the product of the first preset charging current and the preset power value, i.e., the product is used as a limit value to compare with the preset second preset charging current, the current charging request current, and the preset charging cutoff current. Specifically, the minimum value of the second preset charging current and the product is obtained, and the minimum value is determined as the currently allowed second preset charging current; the minimum value of the current charging request current and the product is obtained, and the minimum value is determined as the currently allowed current charging request current; the minimum value of the preset charging cutoff current and the product is obtained, and the minimum value is determined as the currently allowed preset charging cutoff current.

[0082] Figure 3 Fig. 1 shows a control flowchart of a charging starting stage according to an embodiment of the present application. As shown in Fig. 1, the current control of the charging starting stage comprises the following steps: Figure 3 As shown in Fig. 1, the current control of the charging starting stage comprises the following steps:

[0083] S301, enters the charging stage, determines the maximum single-cell voltage. If not, then confirm. If so, then execute S302;

[0084] That is, determining the maximum single-cell voltage of the power battery at the beginning of the charging process. Is it less than the preset current reduction voltage? If not, determine the current charging request current at the start of the charging phase. Preset charging cutoff current .

[0085] S302, ;

[0086] That is, determining the current charging request current at the start of the charging phase. For the second preset charging current .

[0087] S303, Control It rises at a rate of a A / s;

[0088] That is, controlling the current charging request current during the initial charging phase. It rises at a rate of the third preset rate a A / s.

[0089] S304, judgment / / If so, then execute S305;

[0090] That is, to determine the maximum single-cell voltage after the current boost. Is it greater than or equal to the preset current reduction voltage? Subtract the first set value The difference, or the current charging request current after the current boost. Has the first preset charging current been reached? .

[0091] S305, Keep.

[0092] That is, maintain the current charging request current after the current boost. Continuous charging.

[0093] It should be noted that if the current charge level of the power battery reaches the preset charge level in any of the above steps, the current charging request current will be determined to be 0, and the charging process will be stopped.

[0094] In one embodiment of this application, after the current charge level of the power battery reaches a preset charge level, the method further includes: determining that the current charging request current after the current boost is zero, and stopping charging.

[0095] Specifically, after the current power of the power battery reaches the preset power value, it indicates that the power battery is in a full state, at this time the current charging request current after the current is determined to be zero, and the charging is stopped.

[0096] It should be noted that when charging the power battery, the battery management system sends a charging demand message to the charging pile device, wherein the charging demand current in the charging demand message is smaller than the maximum current of the charging pile device, so as to ensure that the charging demand current cannot exceed the current output capability of the charging pile device.

[0097] As a second aspect of the present application, the present application also provides a charging control system of a power battery, the charging control system comprising a processor, the processor being capable of executing the following steps:

[0098] S1, obtaining the maximum single cell voltage of the power battery in the charging process, the maximum single cell voltage representing the maximum value of the corresponding voltages of a plurality of battery cells of the power battery, and the maximum single cell voltage dynamically changing with the charging process;

[0099] S2, when the maximum single cell voltage is greater than or equal to a preset current reduction voltage, obtaining a current charging request current, and controlling the current charging request current to decrease at a first preset rate, while judging whether the maximum single cell voltage after the current reduction is less than or equal to a preset constant current voltage; wherein the current charging request current is dynamically adjusted with the charging process;

[0100] S3, when the maximum single cell voltage after the current reduction is less than or equal to the preset constant current voltage and the current charging request current does not reach a first preset charging current, controlling the current charging request current after the current reduction to increase at a second preset rate until the maximum single cell voltage after the current increase is greater than or equal to a difference value of the preset current reduction voltage minus a first set value, and maintaining the current charging request current after the current increase to continue charging until the current power of the power battery reaches a preset power value, the current power being dynamically adjusted with the charging process.

[0101] The power battery charging control method provided in the application includes the following steps: obtaining the maximum single battery voltage of the power battery during the charging process; when the maximum single battery voltage is greater than or equal to a preset current reduction voltage, obtaining the current charging request current and controlling the current charging request current to decrease at a first preset rate; when the maximum single battery voltage after current reduction is less than or equal to a preset current stabilization voltage and the current charging request current does not reach a first preset charging current, controlling the current charging request current after current reduction to increase at a second preset rate until the maximum single battery voltage after current increase is greater than or equal to the difference between the preset current reduction voltage and a first set value, and maintaining the current charging request current after current increase to continue charging until the current power of the power battery reaches a preset power value. It is easy to note that the maximum single battery voltage of the power battery is judged in real time during the charging process, the current charging request current is reduced when the maximum single battery voltage is greater than or equal to the preset current reduction voltage, and the current charging request current after current reduction is controlled to increase after the maximum single battery voltage is less than or equal to the preset current stabilization voltage. By adopting the combination of current reduction and current increase, the current charging request current is adjusted in real time, the charging performance of the power battery is optimized, the technical effect of shortening the charging time and improving the charging efficiency is achieved, and the technical problems of long charging time and low charging efficiency of the power battery are solved.

[0102] As a third aspect of the application, the application further provides a computer program product comprising a computer program which, when executed by a processor, implements any of the power battery charging control methods described above.

[0103] The method in the application can be implemented by software, hardware, firmware or any combination thereof, in whole or in part. When implemented by software, it can be implemented in the form of a computer program product in whole or in part. The computer program product includes one or more computer programs or instructions, which, when loaded and executed on a computer, perform all or part of the processes or functions described in the application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, a core network device, an OAM or other programmable devices.

[0104] The computer program product can be written in any combination of one or more programming languages to perform the operations of the embodiments of the application, including object-oriented programming languages such as Java, C++, etc., and conventional procedural programming languages such as "C" language or similar programming languages. Program code can be executed entirely on a user computing device, partially on a user device, as a separate software package, partially on a user computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0105] The computer program or instructions can be stored in or transferred from one computer-readable medium to another computer-readable medium, such as from one website, computer, server, or data center to another website, computer, server, or data center, via a wired or wireless connection. The computer-readable medium can be any available medium or data storage device that can be accessed by a computer, or a data storage device such as a server, data center, or the like that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, a hard disk, or a magnetic tape; an optical medium, such as a digital video disc; or a semiconductor medium, such as a solid-state disk. The computer-readable medium can be a volatile or non-volatile storage medium, or can include both volatile and non-volatile storage media.

[0106] In addition, an embodiment of the present application can also be a storage medium having a computer program stored thereon, and the computer program is executed by a processor to perform the steps of a method described in any of the embodiments of the present application.

[0107] For each of the foregoing method embodiments, in order to simply describe, each is expressed as a combination of a series of actions, but those skilled in the art should know that the present application is not limited to the order of the actions described, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0108] It should be noted that each of the embodiments in the specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can be referred to each other. For device embodiments, since they are basically similar to method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the method embodiment.

[0109] The steps in the method of each embodiment of the present application can be adjusted, combined, and reduced in sequence according to actual needs, and the technical features recorded in each embodiment can be replaced or combined. The devices in each embodiment of the present application can be combined, divided, and reduced according to actual needs.

[0110] Those skilled in the art will further appreciate that the units and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various examples have been described herein in terms of their functionality, their composition, and their manner of operation. Whether such functionality is implemented in hardware or software depends on the particular application and design constraints imposed on the overall system. Skilled persons can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

[0111] The steps of a method or algorithm described in connection with the embodiments disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module can reside in random access memory (RAM), flash memory, read-only memory (ROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0112] Finally, it should be noted that the terms "first", "second", and the like, herein do not denote any order, quantity, combination, or importance, but rather are used to distinguish one element from another, and are more especially used for the purpose of identification in claims. Moreover, the terms "comprise", "include" or "contain" or any other variant thereof, are intended to cover non-exclusive inclusions, such that processes, methods, articles, or apparatuses that comprise, include, or contain a list of elements, not only include those elements, but also other elements not expressly listed or otherwise inherent to such processes, methods, articles, or apparatuses. Without further limitation, an element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0113] The above description of disclosed embodiments provides enabling disclosure for those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art, and generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A charging control method for a power battery, characterized in that, The method includes: The maximum single-cell voltage of the power battery during the charging process is obtained. The maximum single-cell voltage is characterized as the maximum value of the voltages of multiple battery cells of the power battery, and the maximum single-cell voltage changes dynamically with the charging process. When the maximum single-cell voltage is greater than or equal to a preset current reduction voltage, the current charging request current is obtained, and the current charging request current is controlled to decrease at a first preset rate. At the same time, it is determined whether the maximum single-cell voltage after current reduction is less than or equal to a preset stabilizing voltage. The current charging request current is dynamically adjusted during the charging process. The preset current reduction voltage is used to represent a preset current reduction voltage threshold at the end of charging. The preset stabilizing voltage is used to represent a preset voltage threshold at which the voltage is relatively stable, and the preset stabilizing voltage is less than the preset current reduction voltage. When the maximum single-cell voltage after current reduction is less than or equal to the preset stabilizing voltage and the current charging request current does not reach the first preset charging current, the current charging request current after current reduction is controlled to rise at a second preset rate until the maximum single-cell voltage after current increase is greater than or equal to the difference between the preset current reduction voltage and the first set value, and the current charging request current after current increase is maintained to continue charging until the current charge of the power battery reaches the preset charge value, and the current charge is dynamically adjusted during the charging process; The method further includes: The maximum single-cell voltage of the power battery at the start of charging is obtained. When the maximum single-cell voltage at the start of charging is less than the preset current reduction voltage, a second preset charging current is obtained, and the second preset charging current is controlled to increase at a third preset rate. The current charge level corresponding to the second preset charging current is higher than the current charge level corresponding to the first preset charging current. When the maximum single-cell voltage after current increase is greater than or equal to the difference between the preset current reduction voltage and the first set value, or when the current charging request current after current increase reaches the first preset charging current, the current charging request current after current increase is maintained to continue charging until the current charge level of the power battery reaches the preset charge level. The method further includes: when the maximum single-cell voltage at the start of charging is greater than or equal to the preset current reduction voltage, determining the current charging request current as the preset charging cut-off current, and maintaining the preset charging cut-off current to continue charging until the current charge of the power battery reaches the preset charge value. The method further includes: the current charging request current is based on the current charge change of the power battery; when the current charge of the power battery is less than the preset charge value, obtaining the product of the first preset charging current and the preset charge value; obtaining the minimum value of the product of the second preset charging current and determining the minimum value as the second preset charging current; obtaining the minimum value of the product of the current charging request current and determining the minimum value as the current charging request current; obtaining the minimum value of the product of the preset charging cutoff current and determining the minimum value as the preset charging cutoff current.

2. The charging control method for a power battery according to claim 1, characterized in that, The determination of whether the maximum single-cell voltage after current reduction is less than or equal to the preset regulated voltage includes: When the maximum single-cell voltage after current reduction is greater than the preset stabilizing voltage, and when the current charging request current after current reduction reaches the preset charging cutoff current, the preset charging cutoff current is maintained to continue charging until the current charge of the power battery reaches the preset charge value. If the current charging request current after the current reduction does not reach the preset charging cutoff current, the current charging request current after the current reduction is controlled to continue to decrease at the first preset rate.

3. The charging control method for a power battery according to claim 1, characterized in that, The method further includes: When the maximum single-cell voltage after the current boost is less than the difference between the preset current reduction voltage and the first set value, and when the current charging request current after the current boost reaches the first preset charging current, the first preset charging current is maintained to continue charging until the current charge of the power battery reaches the preset charge value. Here, the first preset charging current is characterized as the charging current obtained by looking up a table based on the current charge of the power battery and the ambient temperature.

4. The charging control method for a power battery according to claim 1, characterized in that, The method further includes: When the maximum single-cell voltage is less than the preset current reduction voltage, the current charging request current is determined to be the first preset charging current, and the first preset charging current is maintained to continue charging until the current charge of the power battery reaches the preset charge value.

5. The charging control method for a power battery according to claim 1, characterized in that, The control of the second preset charging current to increase at a third preset rate includes: The second preset charging current is controlled to increase at a third preset rate within a preset time period, wherein the third preset rate is equal to the quotient obtained by dividing the charging current difference by the preset time period, and the charging current difference is equal to the difference between the first preset charging current and the second preset charging current.

6. The charging control method for a power battery according to claim 1, characterized in that, After the current charge level of the power battery reaches a preset charge value, the method further includes: The system determines that the current charging request current after the current boost is zero and stops charging.

7. A charging control system for a power battery, characterized in that, The charging control system includes a processor, which is used to execute the charging control method for the power battery according to any one of claims 1-6.

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