Method for fast charging a power battery to full charge

Abstract

The embodiment of the present application discloses a method for full charging of power battery. The method comprises the following steps: obtaining the charging voltage of the power battery and the maximum charging current corresponding to each state of charge; adjusting the charging current of the power battery according to the maximum charging current corresponding to each state of charge as the upper limit of the adjusted charging current under the corresponding state of charge according to the difference between the charging voltage and the target voltage; the target voltage is less than or equal to the charging cutoff voltage of the power battery; and the adjusted charging current of the power battery is the maximum charging current without triggering the target voltage. The technical scheme provided by the embodiment can not only ensure that the power battery can be fully charged in fast charging, but also shorten the time length for full charging of the power battery in fast charging, thereby improving the charging experience of the user.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a method for fast charging a power battery to fully charge. Background Technology

[0002] With the popularization of fast charging technology, the charging current of fast charging batteries is getting larger and larger. The battery cells may not be fully charged at the end of the charging process or in the later stages of the SOH (State of Health) test, which seriously affects the vehicle's range and cannot meet user needs.

[0003] For batteries, the issue of premature charging at the end of the charging process is not due to current capacity limitations, but rather voltage limitations. High polarization at the end prevents incomplete charging because, when subjected to high current, the battery hasn't reached the target capacity, or is still far from it, before triggering the cutoff voltage and stopping charging. To address this issue of premature charging stoppage before full capacity, current technologies typically reduce the current to a smaller cutoff current, resulting in significantly longer charging times that fail to meet user needs.

[0004] Existing methods for fast charging power batteries suffer from excessively long charging times, impacting user experience. Summary of the Invention

[0005] This invention provides a method for fast charging a power battery to fully charge it, thereby solving the problem that the current fast charging method for power batteries has an excessively long charging time, which affects the user experience.

[0006] To address the aforementioned technical problems, the present invention adopts the following technical solution:

[0007] This invention provides a method for fast charging a power battery to fully charge, comprising:

[0008] Obtain the charging voltage of the power battery and the maximum charging current corresponding to each state of charge;

[0009] Based on the difference between the charging voltage and the target voltage, the maximum charging current corresponding to each state of charge is used as the upper limit of the adjusted charging current under the corresponding state of charge, and the charging current of the power battery is adjusted accordingly; the target voltage is less than or equal to the charging cut-off voltage of the power battery; the adjusted charging current of the power battery is the maximum charging current when the target voltage is not triggered.

[0010] Optionally, obtaining the maximum charging current of the power battery and the charging voltage corresponding to each state of charge includes:

[0011] Obtain the maximum allowable charging current, the charging voltage at time k, and the charging voltage at time k-1 of the power battery; k is an integer greater than or equal to 1.

[0012] Optionally, the step of adjusting the charging current of the power battery by using the maximum charging current corresponding to each state of charge as the upper limit of the adjusted charging current under the corresponding state of charge based on the difference between the charging voltage and the target voltage; the target voltage being less than or equal to the charging cutoff voltage of the power battery; and the adjusted charging current of the power battery being the maximum charging current without triggering the target voltage, includes:

[0013] The internal resistance of the power battery at time k is determined by the ratio of the difference between the charging voltage at time k and the charging voltage at time k-1 to the maximum charging current at time k-1.

[0014] Calculate the charging voltage at time k+1 based on the internal resistance at time k and the preset current value corresponding to the internal resistance at time k; the preset current value is the maximum charging current at time k.

[0015] The charging current at time k+1 is adjusted based on the difference between the charging voltage at time k+1 and the target voltage; the charging current is the maximum charging current without triggering the charging cutoff voltage.

[0016] Optionally, adjusting the charging current at time k+1 based on the difference between the charging voltage at time k+1 and the target voltage includes:

[0017] Adjust the charging current based on the difference between the charging voltage at time k+1 and the target voltage; or,

[0018] The charging current is adjusted based on the quotient of the charging voltage at time k+1 and the target voltage.

[0019] Optionally, adjusting the charging current at time k+1 based on the difference between the charging voltage at time k+1 and the target voltage includes:

[0020] When the charging voltage at time k+1 is greater than or equal to the target voltage, the charging current at time k+1 is determined based on the ratio of the target voltage to the internal resistance at time k.

[0021] When the charging voltage at time k+1 is less than the charging cutoff voltage, charging is performed using the maximum charging current at time k+1; the maximum charging current at time k+1 is greater than the charging cutoff current.

[0022] Optionally, after adjusting the charging current at time k+1 based on the difference between the charging voltage at time k+1 and the target voltage, the method further includes:

[0023] When the maximum charging current at time k+1 is equal to the charging cutoff current, and the charging voltage at time k+1 reaches the charging cutoff voltage, the power battery is fully charged and charging stops.

[0024] Optionally, obtaining the charging voltage of the power battery and the maximum charging current corresponding to each state of charge includes:

[0025] Obtain the first charging voltage of the first charging stage n and the maximum charging current of the first charging stage corresponding to each state of charge; the charging time period of the power battery includes the first charging stage, which is the charging time period when the power battery starts charging.

[0026] Optionally, the step of adjusting the charging current of the power battery by using the maximum charging current corresponding to each state of charge as the upper limit of the adjusted charging current under the corresponding state of charge based on the difference between the charging voltage and the target voltage; the target voltage being less than or equal to the charging cutoff voltage of the power battery; and the adjusted charging current of the power battery being the maximum charging current without triggering the target voltage, includes:

[0027] In the first charging phase, based on the first charging voltage and the pre-cutoff voltage U 预 The difference between them adjusts the maximum charging current to decrease to the minimum current value I. min The minimum current value I min Less than the maximum charging current I in the first charging stage max n The pre-cutoff voltage is less than or equal to the charging cutoff voltage U. max The target voltage includes the pre-cutoff voltage;

[0028] After a first preset time, the second charging stage begins, and the second charging current I in the second charging stage is adjusted. i The maximum charging current I during the first charging phase is m times the maximum charging current I. max n m is a decimal greater than or equal to 0.5 and less than 0.99, and i is a positive integer greater than or equal to 1; the power battery charging time period also includes a second charging stage, which is after the first charging stage, and the second charging stage and the first charging stage are spaced apart by the first preset time.

[0029] Optionally, in the first charging phase, based on the first charging voltage and the pre-cutoff voltage U...预 The difference between them adjusts the maximum charging current to decrease to the minimum current value I. min ,include:

[0030] When the first charging voltage is greater than or equal to the pre-cutoff voltage, the maximum charging current of the first charging stage is controlled to decrease to the minimum current value.

[0031] When the first charging voltage is less than the pre-cutoff voltage, the charging current in the first charging stage is controlled to maintain the maximum charging current.

[0032] Optionally, after the first preset time, the second charging stage begins, and the second charging current I of the second charging stage is adjusted. i The maximum charging current I during the first charging phase is m times the maximum charging current I. max n Following that, it also includes:

[0033] Obtain the second charging voltage U during the second charging phase i The second charging current I corresponding to the second charging voltage i ;

[0034] According to the second charging voltage U i The difference between the pre-cutoff voltage and the second charging voltage during the second charging phase is adjusted so that the second charging current corresponding to the second charging voltage decreases to the minimum current value I. min ;

[0035] After a first preset time, the third charging stage begins, and the third charging current I in the third charging stage is adjusted. j The second charging current I is m times the second charging current i j is a positive integer greater than or equal to 1; the power battery charging time period also includes a third charging stage, which is after the second charging stage, and the third charging stage and the second charging stage are spaced apart by the first preset time.

[0036] When the second charging current or the third charging current is less than or equal to the cutoff current, and the second charging voltage or the third charging voltage corresponding to the third charging current reaches the pre-cutoff voltage, the power battery stops charging.

[0037] The technical solution provided by this invention includes adjusting the charging current of a power battery based on the difference between the acquired charging voltage and the target voltage during charging. The target voltage is less than or equal to the charging cutoff voltage of the power battery. When adjusting the charging current of the power battery, the maximum charging current corresponding to each state of charge is used as the upper limit of the adjusted charging current for that state of charge. The adjusted charging current of the power battery is the maximum charging current without triggering the target voltage.

[0038] Because when the charging current corresponding to each state of charge is greater than the maximum charging current for that state of charge, the battery may be charged to the target capacity before triggering the charging cutoff voltage. The technical solution provided in this invention sets the maximum charging current for each state of charge as the upper limit of the adjusted charging current for that state of charge, ensuring that the adjusted charging current is lower than the maximum charging current for that state of charge. When charging with the adjusted charging current, the charging cutoff voltage will not be triggered, thus preventing the battery from being charged to the target capacity before the charging cutoff voltage is triggered and stopping charging, thereby fully charging the battery.

[0039] During charging, if the charging voltage exceeds the charging cutoff voltage, charging will stop due to the charging voltage triggering the charging cutoff voltage. The technical solution provided in this embodiment adjusts the charging current of the power battery based on the difference between the obtained charging voltage and a target voltage that is less than or equal to the charging cutoff voltage. The adjusted charging current is the maximum charging current without triggering the target voltage. This setting ensures that charging with the adjusted charging current does not trigger the target voltage, and consequently, it does not trigger a charging cutoff voltage greater than or equal to the target voltage. This avoids the situation where charging stops before reaching the target capacity due to triggering the charging cutoff voltage, ensuring the power battery is fully charged.

[0040] Because insufficient charging current during battery charging leads to excessively long charging times, the technical solution provided in this embodiment addresses this issue by setting the adjusted charging current of the power battery to the maximum charging current that does not trigger the target voltage. This allows the power battery to be charged with the adjusted charging current, i.e., the maximum charging current that does not trigger the target voltage, effectively shortening the charging time and improving the user's charging experience. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0042] Figure 1 This is a flowchart of a method for fast charging a power battery according to an embodiment of the present invention;

[0043] Figure 2 This is a flowchart of another method for fast charging a power battery according to an embodiment of the present invention;

[0044] Figure 3 This is a flowchart of another method for fast charging a power battery according to an embodiment of the present invention;

[0045] Figure 4 This is a line graph illustrating the charging principle of a method for fast charging a power battery according to an embodiment of the present invention.

[0046] Figure 5 This is a flowchart of another method for fast charging a power battery according to an embodiment of the present invention;

[0047] Figure 6 This is a flowchart of another method for fast charging a power battery according to an embodiment of the present invention;

[0048] Figure 7 This is a line graph illustrating the charging principle of another method for fast charging a power battery according to an embodiment of the present invention.

[0049] Figure 8 This is a flowchart of another method for fast charging a power battery according to an embodiment of the present invention;

[0050] Figure 9 This is a flowchart of another method for fast charging a power battery according to an embodiment of the present invention. Detailed Implementation

[0051] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0052] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0053] Based on the above-mentioned technical problems, this embodiment proposes the following solutions:

[0054] Figure 1 This is a flowchart illustrating a method for fast-charging a power battery to full charge according to an embodiment of the present invention. The method for fast-charging a power battery to full charge according to an embodiment of the present invention includes:

[0055] S101. Obtain the charging voltage of the power battery and the maximum charging current corresponding to each state of charge.

[0056] Specifically, the charging voltage of a power battery refers to the voltage during the charging process. The voltage of a power battery changes continuously during charging. The current charging voltage and / or historical charging voltage can be obtained as needed. The maximum charging current refers to the maximum current value that the charger allows to pass through during charging. The standard for the maximum charging current varies for different types of batteries.

[0057] S102. Based on the difference between the charging voltage and the target voltage, the maximum charging current is used as the upper limit of the adjusted charging current under the corresponding state of charge, and the charging current of the power battery is adjusted; the target voltage is less than or equal to the charging cut-off voltage of the power battery; the adjusted charging current of the power battery is the maximum charging current when the target voltage is not triggered.

[0058] Specifically, the charging cut-off voltage refers to the voltage value at which the charging process automatically stops when the battery voltage reaches a preset maximum value. This preset maximum value is called the charging cut-off voltage. The issue of charging the battery at the end of its lifecycle is due to voltage limitations.

[0059] When the charging current corresponding to each state of charge exceeds the maximum charging current for that state of charge, the battery may not reach the target charge level before triggering the charging cut-off voltage, thus stopping charging. By setting the maximum charging current for each state of charge as the upper limit of the adjusted charging current for that state of charge, charging can be prevented from stopping before the target charge level is reached due to a large charging current. The target voltage can be set to a value lower than the charging cut-off voltage. For example, the target voltage can be slightly lower than the charging cut-off voltage, where target voltage = charging cut-off voltage - X, and X can be set to 0mV, 10mV, or 15mV, etc.

[0060] During charging, if the charging voltage exceeds the charging cutoff voltage, charging will stop due to the charging voltage triggering the charging cutoff voltage. The technical solution provided in this embodiment adjusts the charging current of the power battery based on the difference between the obtained charging voltage and a target voltage that is less than or equal to the charging cutoff voltage. The adjusted charging current is the maximum charging current without triggering the target voltage. This setting ensures that charging with the adjusted charging current does not trigger the target voltage, and consequently, it does not trigger a charging cutoff voltage greater than or equal to the target voltage. This avoids the situation where charging stops before reaching the target capacity due to triggering the charging cutoff voltage, ensuring the power battery is fully charged.

[0061] Because insufficient charging current during battery charging leads to excessively long charging times, adjusting the battery charging current based on the difference between the charging voltage and the target voltage, by setting the adjusted charging current to the maximum charging current that does not trigger the target voltage, the charging time can be effectively shortened. This avoids triggering the charging cutoff voltage before reaching the target charge level and ensures maximum charging current at the end of the charging process, thus reducing the time required to fully charge the battery and guaranteeing charging safety.

[0062] This embodiment provides a method for fast charging a power battery to fully charge, which includes adjusting the charging current of the power battery based on the difference between the obtained charging voltage and the target voltage during charging. The target voltage is less than or equal to the charging cutoff voltage of the power battery. When adjusting the charging current of the power battery, the maximum charging current corresponding to each state of charge is used as the upper limit of the adjusted charging current for that state of charge. The adjusted charging current of the power battery is the maximum charging current without triggering the target voltage. The technical solution provided in this embodiment sets the maximum charging current corresponding to each state of charge as the upper limit of the adjusted charging current for that state of charge, so that the adjusted charging current of the power battery is lower than the maximum charging current corresponding to the corresponding state of charge. When charging with the adjusted charging current, the charging cutoff voltage will not be triggered, thereby avoiding the charging of the power battery from being stopped before reaching the target amount of charge due to the triggering of the charging cutoff voltage, thus fully charging the power battery. By setting the charging current of the power battery to be adjusted based on the difference between the obtained charging voltage and the target voltage which is less than or equal to the charging cutoff voltage, and the adjusted charging current of the power battery being the maximum charging current without triggering the target voltage. This setting ensures that charging with the adjusted battery charging current does not trigger the target voltage, and consequently, it does not trigger a charging cutoff voltage greater than or equal to the target voltage. This prevents charging from stopping before reaching the target capacity due to triggering the charging cutoff voltage, thus guaranteeing a full charge. By setting the adjusted battery charging current to the maximum charging current that avoids triggering the target voltage, charging the battery with this adjusted current—the maximum charging current that avoids triggering the target voltage—effectively shortens the charging time and improves the user's charging experience.

[0063] Optional, Figure 2 This is a flowchart of another method for fast charging a power battery according to an embodiment of the present invention. Based on the above embodiment, see [link to related documentation]. Figure 2 The method for fast charging a power battery provided in this embodiment includes:

[0064] S201. Obtain the maximum allowable charging current, charging voltage at time k, and charging voltage at time k-1 of the power battery's state of charge; k is an integer greater than or equal to 1.

[0065] Specifically, time k is the current time, and time k-1 is the time before time k. The maximum allowable charging current for the state of charge of the power battery at time k-1, the charging voltage at time k, and the charging voltage at time k-1 are obtained.

[0066] S102. Based on the difference between the charging voltage and the target voltage, the maximum charging current is used as the upper limit of the adjusted charging current under the corresponding state of charge, and the charging current of the power battery is adjusted; the target voltage is less than or equal to the charging cut-off voltage of the power battery; the adjusted charging current of the power battery is the maximum charging current when the target voltage is not triggered.

[0067] Specifically, the maximum allowable charging current of the power battery at time k-1 is used to predict the charging voltage U at time k+1 based on the charging voltage at time k and the charging voltage at time k-1. k+1 And based on the charging voltage U at time k+1 k+1 The difference between the voltage and the target voltage is used to adjust the charging current of the power battery.

[0068] Optional, Figure 3 This is a flowchart of another method for fast charging a power battery according to an embodiment of the present invention. Figure 4 This is a line graph illustrating the charging principle of a method for fast charging a power battery according to an embodiment of the present invention. Based on the above embodiments, and combined with... Figure 3 and Figure 4 The method for fast charging a power battery according to embodiments of the present invention includes:

[0069] S201. Obtain the maximum allowable charging current, charging voltage at time k, and charging voltage at time k-1 of the power battery's state of charge.

[0070] S202. Determine the internal resistance of the power battery at time k based on the ratio of the difference between the charging voltage at time k and the charging voltage at time k-1 to the maximum charging current at time k-1.

[0071] For details, see Figure 4 The charging voltage U at time k k and the charging voltage U at time k-1 k-1 The voltage difference ΔU is obtained by subtraction. k The voltage difference ΔU k Divide by the maximum charging current I at time k-1 k-1 We obtain the internal resistance of the power battery at time k during charging.

[0072] S203. Calculate the charging voltage U at time k+1 based on the internal resistance at time k and the preset current value corresponding to the internal resistance at time k. k+1 The preset current value is the maximum charging current at time k.

[0073] Specifically, during battery charging, different internal resistances correspond to different preset current values. The preset current value corresponding to the battery's internal resistance can be determined using historical data or empirical values, forming a table showing the correspondence between the battery's internal resistance and preset current values. The preset current value corresponding to the internal resistance at time k can be determined by looking up this table.

[0074] Since the technical solution provided in this embodiment acquires the charging voltage at time k in real time, and time k+1 is the next time after time k, the internal resistance of the power battery will not change abruptly between time k and time k+1. The preset current value corresponding to the internal resistance at time k can be determined by looking up a table showing the correspondence between the internal resistance at time k and the preset current value. Since the internal resistance of the power battery will not change abruptly, the internal resistance at time k+1 can be taken as the internal resistance at time k. Therefore, the charging voltage U at time k+1 can be predicted based on the product of the internal resistance at time k and its corresponding preset current value. k+1 .

[0075] S204, based on the charging voltage U at the (k+1)th time... k+1 The difference between the current and the target voltage is used to adjust the charging current I at time k+1. k+1 The charging current I at time k+1 k+1 This is the maximum charging current without triggering the charging cutoff voltage.

[0076] Specifically, the predicted charging voltage U at time k+1... k+1 Compare with the target voltage. When the predicted charging voltage U at time k+1 is obtained... k+1 When the voltage is above the target voltage, the charging current I at time k+1 can be determined based on the ratio of the lower target voltage to the internal resistance of the power battery at time k. k+1 Reduce the current. However, it is necessary to ensure that the charging current I at time k+1 is maintained. k+1 Greater than the charging cutoff current I 截止 When the predicted charging voltage U at time k+1 is... k+1 When the voltage is less than the target voltage, the preset current value corresponding to the internal resistance at time k is used, which is the maximum charging current I at time k+1. max k+1 It charges the power battery.

[0077] It should be noted that, Figure 4 An example is shown illustrating the SOC (State of Charge) of a power battery, including SOC. k-1 SOC k SOC k+1 And the situation with a fully charged SOC. SOC k-1Let SOC be the state of charge (SOC) of the power battery at time k-1. k Let SOC be the state of charge (SOC) of the power battery at time k. k+1 Let SOC be the SOC value of the power battery at time k+1. Figure 4 U in 充 I represents the charging voltage of the power battery. 充 This indicates the charging current of the power battery.

[0078] An alternative implementation method is described below. Figure 4 The charging voltage U at time k+1 k+1 The difference between the current and the target voltage is used to adjust the charging current I at time k+1. k+1 This includes: based on the charging voltage U at time k+1. k+1 Adjust the charging current based on the difference between the current and the target voltage; or, adjust the charging current based on the charging voltage U at the (k+1)th time. k+1 The charging current is adjusted based on the quotient of the target voltage.

[0079] Specifically, the difference or quotient can be used to calculate the predicted charging voltage U at time k+1. k+1 The charging voltage U at time k+1 is determined by comparing it with the charging cutoff voltage. k+1 Does it exceed the target voltage?

[0080] Another optional implementation is that the charging voltage U at the (k+1)th time is... k+1 The difference between the current and the target voltage is used to adjust the charging current I at time k+1. k+1 This includes: the charging voltage U at the (k+1)th time. k+1 When the voltage is greater than or equal to the target voltage, the charging current I at time k+1 is determined based on the ratio of the target voltage to the internal resistance at time k. k+1 When the charging voltage U at the (k+1)th time... k+1 When the voltage is less than the target voltage, the maximum charging current I at time k+1 is used. k+1 Charging is performed; the maximum charging current I at time k+1 is... k+1 When the current exceeds the charging cutoff current, the power battery is charged. The maximum charging current I at time k+1 is... k+1 When the charging current is less than or equal to the charging cutoff current, charging of the power battery will stop.

[0081] Specifically, when the charging voltage I at time k+1... k+1 When the voltage is greater than or equal to the charging cutoff voltage, the charging current I at time k+1 is calculated based on the product of the lower target voltage and the internal resistance at time k. k+1The calculated charging current I at time k+1 is used. k+1 It charges the power battery.

[0082] Optional, Figure 5 This is a flowchart illustrating another method for fast charging a power battery according to an embodiment of the present invention. Based on the above embodiments, and combined with... Figure 4 and Figure 5 The method for fast charging a power battery according to embodiments of the present invention includes:

[0083] S201. Obtain the maximum allowable charging current, charging voltage at time k, and charging voltage at time k-1 of the power battery's state of charge.

[0084] S202. Determine the internal resistance of the power battery at time k based on the ratio of the difference between the charging voltage at time k and the charging voltage at time k-1 to the maximum charging current at time k-1.

[0085] S203. Calculate the charging voltage at time k+1 based on the internal resistance at time k and the preset current value corresponding to the internal resistance at time k; the preset current value is the maximum charging current at time k.

[0086] S204. Adjust the charging current at time k+1 according to the difference between the charging voltage at time k+1 and the target voltage; the charging current is the maximum charging current without triggering the charging cutoff voltage.

[0087] S301. When the maximum charging current at time k+1 is equal to the charging cut-off current, and the charging voltage at time k+1 reaches the charging cut-off voltage, the power battery is fully charged and charging stops.

[0088] Specifically, as the charging time increases, the charging voltage U at time k+1 is determined cyclically. k+1 This allows for real-time adjustment of the charging current I at time k+1. k+1 The charging current I at time k+1 k+1 This refers to the maximum charging current at time k+1 without triggering the target voltage. When the charging current I at time k+1... k+1 When the charging current drops to the charging cutoff current and the charging voltage at time k+1 reaches the charging cutoff voltage, charging stops and the power battery is fully charged.

[0089] The method for fast charging a power battery provided in this embodiment calculates the resistance change at time k in real time, and calculates the charging voltage at time k+1 based on the resistance change at time k and its corresponding preset current value. Furthermore, based on the difference between the charging voltage at time k+1 and the target voltage, the charging current at time k+1 is adjusted to maximize the charging current without triggering the charging cutoff voltage. This effectively improves the efficiency of fully charging the power battery at the end of the charging process, reduces charging time, and ensures rapid charging of the power battery.

[0090] Optional, Figure 6 This is a flowchart of another method for fast charging a power battery according to an embodiment of the present invention. Figure 7 This is a line graph illustrating the charging principle of another method for fast charging a power battery according to an embodiment of the present invention. Based on the above embodiments, and combined with... Figure 6 and Figure 7 The method for fast charging a power battery according to embodiments of the present invention includes:

[0091] S401. Obtain the first charging voltage U of the first charging stage n. n The maximum charging current I corresponding to each state of charge in the first charging stage n max n n is an integer greater than 0; the charging time period of the power battery includes a first charging stage n, which is the charging time period when the power battery starts charging.

[0092] Specifically, the first charging stage n refers to the stage when the power battery begins charging. In the first charging stage n, the maximum charging current I corresponding to each state of charge in the first charging stage n is... max n This refers to the maximum charging current that a battery cell can tolerate at different states of charge (SOC).

[0093] S102. Based on the difference between the charging voltage and the target voltage, the maximum charging current is used as the upper limit of the adjusted charging current under the corresponding state of charge, and the charging current of the power battery is adjusted; the target voltage is less than or equal to the charging cut-off voltage of the power battery; the adjusted charging current of the power battery is the maximum charging current when the target voltage is not triggered.

[0094] Specifically, the charging voltage U of the first charging stage n n Compared with the target voltage, when the charging voltage U of the first charging stage n... n When the voltage is greater than or equal to the target voltage, the charging voltage U of the first charging stage n will be... n The corresponding maximum charging current I max nAdjust to minimum charging current I min After the first preset time period t1, the charging voltage U 充 It will decrease. The charging current in the next charging stage will be lowered to charge the power battery with the lowered charging current.

[0095] The power battery charging time period also includes a second charging stage i, which follows the first charging stage n, and the second charging stage i and the first charging stage n are separated by the first preset time t1. In the second charging stage or the subsequent charging stage, the charging current of the power battery can be a fraction of the maximum charging current of the previous charging stage, for example, 0.9 times or 0.95 times. This process can be repeated until the power battery is fully charged. This design allows the power battery to shorten charging time and fully charge during fast charging, improving the user's charging experience.

[0096] Optional, Figure 8 This is a flowchart illustrating another method for fast charging a power battery according to an embodiment of the present invention. Based on the above embodiments, and combined with... Figure 7 and Figure 8 The method for fast charging a power battery according to embodiments of the present invention includes:

[0097] S401. Obtain the first charging voltage U of the first charging stage n. n The maximum charging current I corresponding to each state of charge in the first charging stage n max n n is an integer greater than 0; the charging time period of the power battery includes a first charging stage n, which is the charging time period when the power battery starts charging.

[0098] S402, in the first charging stage n, according to the first charging voltage U n With pre-cutoff voltage U 预 The difference between them adjusts the maximum charging current I. max n Drop to minimum current value I min The minimum current value I min The maximum charging current I less than the first charging stage n max n The pre-cutoff voltage U 预 Less than or equal to the charging cutoff voltage U max The target voltage includes the pre-cutoff voltage U. 预 .

[0099] Specifically, set the pre-cutoff voltage U 预A current value less than or equal to the charging cutoff voltage allows the charging voltage at the current charging stage to trigger a reduction in the charging current to the minimum value at the next moment when the pre-cutoff voltage is reached. The minimum current value is lower than the maximum charging current at the current moment. The minimum current value can be 0 amperes.

[0100] An alternative implementation method is described below. Figure 7 In the first charging stage n, according to the first charging voltage U n With pre-cutoff voltage U 预 The difference between them adjusts the maximum charging current I. max n Drop to minimum current value I min This includes: when the first charging voltage U n Greater than or equal to the pre-cutoff voltage U 预 At that time, control the maximum charging current I in the first charging stage n. max n Drop to minimum current value I min When the first charging voltage U n Less than the pre-cutoff voltage U 预 At the same time, the charging current of the first charging stage n is controlled to maintain the maximum charging current I. max n .

[0101] Specifically, this setting allows the power battery to reach the pre-cutoff voltage U during fast charging. 预 The charging current will be lowered soon to better avoid charging voltage U. 充 Exceeding the charging cutoff voltage U max This results in the charging stopping before the battery is fully charged. By setting the charging voltage U during the first charging phase n... 充 Less than the pre-cutoff voltage U 预 During this time, the charging current in the first charging stage n is controlled to maintain the maximum charging current I. max n This results in higher charging efficiency and shortens the charging time for power batteries.

[0102] S403. After a first preset time t1, the second charging stage i is entered, and the second charging current I of the second charging stage i is adjusted. i The maximum charging current I during the first charging stage n is m times the maximum charging current I during the first charging stage n. max n m is a decimal greater than or equal to 0.5 and less than 0.99, and i is a positive integer greater than or equal to 1; the power battery charging time period also includes a second charging stage i, which is after the first charging stage n, and the second charging stage i and the first charging stage n are spaced apart by the first preset time t1.

[0103] Specifically, setting a first preset delay t1 can make the charging voltage U 充 From the pre-cutoff voltage U 预 The voltage drops by a certain amount. Then, it enters the second charging stage (i) to continue charging, avoiding triggering the cutoff voltage (U). max In the second charging phase i, the second charging current I is adjusted. i The maximum charging current I during the first charging stage n is m times the maximum charging current. max n This design allows the charging current to be reduced during the second charging stage i, enabling the battery to be fully charged in multiple stages. Preferably, m is a decimal greater than 0.5 and less than 0.99. This setting ensures that the maximum charging current, which is m times the maximum current during the second charging stage i, is relatively large, resulting in faster charging, improved charging efficiency, and a shorter charging time for the battery.

[0104] Optional, Figure 9 This is a flowchart illustrating another method for fast charging a power battery according to an embodiment of the present invention. Based on the above embodiments, and combined with... Figure 7 and Figure 9 The method for fast charging a power battery according to embodiments of the present invention includes:

[0105] S401. Obtain the first charging voltage U of the first charging stage n. n The maximum charging current I corresponding to each state of charge in the first charging stage n max n The power battery charging time period includes a first charging stage n, which is the charging time period when the power battery starts charging.

[0106] S402, in the first charging stage n, according to the first charging voltage U n With pre-cutoff voltage U 预 The difference between them adjusts the maximum charging current I. max n Drop to minimum current value I min The minimum current value I min The maximum charging current I less than the first charging stage n max n The pre-cutoff voltage U 预 Less than or equal to the charging cutoff voltage U max The target voltage includes the pre-cutoff voltage U. 预 .

[0107] S403. After a first preset time t1, the second charging stage i is entered, and the second charging current I of the second charging stage i is adjusted. i The maximum charging current I during the first charging stage n is m times the maximum charging current I during the first charging stage n. max n m is a decimal greater than or equal to 0.5 and less than 0.99, and i is a positive integer greater than or equal to 1; the power battery charging time period also includes a second charging stage i, which is after the first charging stage n, and the second charging stage i and the first charging stage n are spaced apart by the first preset time t1.

[0108] S501, Obtain the second charging voltage U of the second charging stage i. i and the second charging voltage U i The corresponding second charging current I i .

[0109] Specifically, in the second charging stage i, with the second charging voltage U i Second charging current I i Charge the power battery.

[0110] S502, according to the second charging voltage U i With pre-cutoff voltage U 预 The difference between them adjusts the second charging voltage U in the second charging stage i. i The corresponding second charging current I i Drop to minimum current value I min .

[0111] Specifically, when the second charging voltage U i Greater than or equal to the pre-cutoff voltage U 预 At that time, adjust the second charging voltage U i The corresponding second charging current I i Drop to minimum current value I min For example, Figure 7 An exemplary illustration shows that, in the second charging phase i, SOC i The second charging voltage U at the corresponding moment i Reaching the pre-cutoff voltage U 预 Adjust the second charging current I i Drop to minimum current value I min Maintain minimum current value I min The duration is the first time period t1. SOC i+t1 The charging voltage at the corresponding moment is U i+t1 .

[0112] S503. After a first preset time t1, the third charging stage j is entered, and the third charging current I of the third charging stage j is adjusted. j The second charging current I is m times the second charging current i , j is a positive integer greater than or equal to 1; the power battery charging time period also includes a third charging stage j, the third charging stage j is after the second charging stage i, and the third charging stage j and the second charging stage i are spaced apart by the first preset time t1.

[0113] Specifically, in the third charging stage j, the third charging current I is adjusted. j The second charging current I is m times the current I i That is, m 2 * I max n .

[0114] S504, when the second charging current I i Or the third charging current I j Less than or equal to the cutoff current I 截止 And the second charging voltage U i Or the third charging current I j The corresponding third charging voltage U j Reaching the pre-cutoff voltage U 预 At that time, the power battery stops charging.

[0115] Specifically, as the charging time increases, the charging voltage corresponding to each charging stage is cyclically determined, and the charging current is gradually reduced stage by stage. When the second charging current I... i As low as the charging cutoff current I 截止 And the second charging voltage U i Reaching the pre-cutoff voltage U 预 When the third charging current I stops, the power battery is fully charged. Alternatively, when the third charging current I... j As low as the charging cutoff current I 截止 And the third charging current I j The corresponding third charging voltage U j Reaching the pre-cutoff voltage U 预 When the battery is fully charged, charging stops.

[0116] It should be noted that, Figure 7 An example is shown showing the SOC of a power battery, including SOC. n SOC n+t1 SOC i SOC i+t1 And the situation with a fully charged SOC. SOC n This refers to the State of Charge (SOC) value of the power battery during the first charging stage.n+t1 Let U be the SOC value of the power battery at time n+t1. n+t1 For SOC n+t1 The corresponding charging voltage value. SOC i The State of Charge (SOC) value of the power battery during the second charging stage. i+t1 U represents the SOC value of the power battery at time i+t1. i+t1 For SOC i+t1 The corresponding charging voltage value. Figure 7 U in 充 This indicates the charging voltage of the power battery, and no specific limit is imposed here.

[0117] The method for fast charging a power battery provided in this embodiment reduces the charging current in the next charging stage in stages when the charging voltage triggers the pre-cutoff voltage. This allows for a larger charging current without triggering the charging cutoff voltage, effectively improving the efficiency of fully charging the power battery at the end of the charging process and shortening the charging time. This provides a new approach to fast charging a power battery.

[0118] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for fast charging a power battery to fully charge it, characterized in that, include: Obtain the charging voltage of the power battery and the maximum charging current corresponding to each state of charge; Based on the difference between the charging voltage and the target voltage, the maximum charging current corresponding to each state of charge is used as the upper limit of the adjusted charging current under the corresponding state of charge, and the charging current of the power battery is adjusted accordingly. The target voltage is less than or equal to the charging cutoff voltage of the power battery; The adjusted charging current of the power battery is the maximum charging current without triggering the target voltage.

2. The method according to claim 1, characterized in that, The process of obtaining the maximum charging current of the power battery and the charging voltage corresponding to each state of charge includes: Obtain the maximum allowable charging current, the charging voltage at time k, and the charging voltage at time k-1 of the power battery; k is an integer greater than or equal to 1.

3. The method according to claim 2, characterized in that, The charging current of the power battery is adjusted by taking the maximum charging current corresponding to each state of charge as the upper limit of the adjusted charging current under the corresponding state of charge based on the difference between the charging voltage and the target voltage. The target voltage is less than or equal to the charging cutoff voltage of the power battery; The adjusted charging current of the power battery is the maximum charging current without triggering the target voltage, including: The internal resistance of the power battery at time k is determined by the ratio of the difference between the charging voltage at time k and the charging voltage at time k-1 to the maximum charging current at time k-1. Calculate the charging voltage at time k+1 based on the internal resistance at time k and the preset current value corresponding to the internal resistance at time k; the preset current value is the maximum charging current at time k. The charging current at time k+1 is adjusted based on the difference between the charging voltage at time k+1 and the target voltage; the charging current is the maximum charging current without triggering the charging cutoff voltage.

4. The method according to claim 3, characterized in that, The step of adjusting the charging current at time k+1 based on the difference between the charging voltage at time k+1 and the target voltage includes: Adjust the charging current based on the difference between the charging voltage at time k+1 and the target voltage; or, The charging current is adjusted based on the quotient of the charging voltage at time k+1 and the target voltage.

5. The method according to claim 3, characterized in that, The step of adjusting the charging current at time k+1 based on the difference between the charging voltage at time k+1 and the target voltage includes: When the charging voltage at time k+1 is greater than or equal to the target voltage, the charging current at time k+1 is determined based on the ratio of the target voltage to the internal resistance at time k. When the charging voltage at time k+1 is less than the charging cutoff voltage, charging is performed using the maximum charging current at time k+1; the maximum charging current at time k+1 is greater than the charging cutoff current.

6. The method according to claim 3, characterized in that, After adjusting the charging current at time k+1 based on the difference between the charging voltage at time k+1 and the target voltage, the method further includes: When the maximum charging current at time k+1 is equal to the charging cutoff current, and the charging voltage at time k+1 reaches the charging cutoff voltage, the power battery is fully charged and charging stops.

7. The method according to claim 1, characterized in that, The process of obtaining the charging voltage of the power battery and the maximum charging current corresponding to each state of charge includes: The first charging voltage of the first charging stage and the maximum charging current of the first charging stage corresponding to each state of charge are obtained; the charging time period of the power battery includes the first charging stage, which is the charging time period when the power battery starts charging.

8. The method according to claim 7, characterized in that, The charging current of the power battery is adjusted by taking the maximum charging current corresponding to each state of charge as the upper limit of the adjusted charging current under the corresponding state of charge based on the difference between the charging voltage and the target voltage. The target voltage is less than or equal to the charging cutoff voltage of the power battery; The adjusted charging current of the power battery is the maximum charging current without triggering the target voltage, including: In the first charging phase, based on the first charging voltage and the pre-cutoff voltage U 预 The difference between them adjusts the maximum charging current to decrease to the minimum current value I. min The minimum current value I min Less than the maximum charging current I in the first charging stage maxn The pre-cutoff voltage is less than or equal to the charging cutoff voltage U. max The target voltage includes the pre-cutoff voltage U. 预 ; After a first preset time, the second charging stage begins, and the second charging current I in the second charging stage is adjusted. i The maximum charging current I during the first charging phase is m times the maximum charging current I. maxn m is a decimal greater than or equal to 0.5 and less than 0.99, and i is a positive integer greater than or equal to 1; the power battery charging time period also includes a second charging stage, which is after the first charging stage, and the second charging stage and the first charging stage are spaced apart by the first preset time.

9. The method according to claim 8, characterized in that, In the first charging phase, based on the first charging voltage and the pre-cutoff voltage U 预 The difference between them adjusts the maximum charging current to decrease to the minimum current value I. min ,include: When the first charging voltage is greater than or equal to the pre-cutoff voltage, the maximum charging current of the first charging stage is controlled to decrease to the minimum current value. When the first charging voltage is less than the pre-cutoff voltage, the charging current in the first charging stage is controlled to maintain the maximum charging current.

10. The method according to claim 8, characterized in that, After a first preset time, the second charging stage begins, and the second charging current I of the second charging stage is adjusted. i The maximum charging current I during the first charging phase is m times the maximum charging current I. maxn Following that, it also includes: Obtain the second charging voltage U during the second charging phase i The second charging current I corresponding to the second charging voltage i ; According to the second charging voltage U i The difference between the pre-cutoff voltage and the second charging voltage during the second charging phase is adjusted so that the second charging current corresponding to the second charging voltage decreases to the minimum current value I. min ; After a first preset time, the third charging stage begins, and the third charging current I in the third charging stage is adjusted. j The second charging current I is m times the second charging current i j is a positive integer greater than or equal to 1; the power battery charging time period also includes a third charging stage, which is after the second charging stage, and the third charging stage and the second charging stage are spaced apart by the first preset time. When the second charging current or the third charging current is less than or equal to the cutoff current, and the second charging voltage or the third charging voltage corresponding to the third charging current reaches the pre-cutoff voltage, the power battery stops charging.

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