Charging method, device and system

Abstract

The invention discloses a charging method, device and system, and relates to the technical field of power supplies. Aiming at the problem that an existing charging protocol system adjusting scheme is insufficient in prolonging effect on the service life of a battery, the invention provides a charging method, and the charging method comprises the following steps of: calculating a time constant and residual charging duration of the battery in a constant-voltage charging section by obtaining a charging cut-off current value, a charging current value of a constant-current charging section, a total full-charging duration and a full-charging capacity of the battery; the accurate evaluation of the SOH of the battery is realized; and finally, adjusting the cut-off parameters of the battery through the SOH obtained through evaluation. According to the method, the adjustment of the cut-off parameters of the battery is not limited by several preset experience points any more. The method can adapt to the actual condition of the individual battery, carries out accurate battery aging SOH evaluation on each battery, and carries out targeted cut-off parameter adjustment based on the evaluated SOH. Therefore, the method can bring a better adjusting effect and further prolong the service life of the battery.

Description

TECHNICAL FIELD

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

[0002] The battery will gradually age with continuous cycle use, resulting in a lower and lower capacity retention rate. At present, in order to prolong the service life of the battery, the charging protocol system (i.e. charging cut-off voltage, charging cut-off current) of the battery will be adjusted adaptively according to the deepening of the aging degree of the battery.

[0003] At present, the five-step voltage regulation method is commonly used to perform cycle charge-discharge tests on battery samples, and the adjustment scheme of the charging protocol system of the battery at different cycle charging periods is determined in combination with actual experience. Then, in the actual application process of subsequent batteries of the same type, when a specific cycle charging period is reached, the charging protocol system is adjusted based on the corresponding adjustment scheme, so as to achieve the purpose of prolonging the service life of the battery.

[0004] However, the adjustment of the charging protocol system in the above scheme can only be made at several cycle charging period characteristic points (i.e. specific cycle charging periods such as the 100th, 200th, etc.) determined based on experience, and it is difficult to cover the entire life cycle of the battery. Therefore, the adjustment of the charge-discharge protocol system of the battery is not flexible enough, cannot better meet the actual adjustment needs in the actual application scenario of the battery, and the prolonging effect on the service life of the battery needs to be further improved.

[0005] Therefore, there is an urgent need for a charging method in the art to solve the problem of insufficient prolonging effect of the current charging protocol system adjustment scheme on the service life of the battery. SUMMARY

[0006] The purpose of the present application is to provide a charging method, device and system to solve the problem of insufficient prolonging effect of the current charging protocol system adjustment scheme on the service life of the battery.

[0007] To solve the above technical problems, the present application provides a charging method, comprising:

[0008] obtaining a charging cut-off current value, a constant current charging segment charging current value, a full charging total time length and a full charging capacity of a battery;

[0009] determining a time constant of a constant voltage charging segment and a remaining charging time length of the battery according to the charging cut-off current value, the constant current charging segment charging current value, the full charging total time length and the full charging capacity;

[0010] determining a health state value of the battery according to the time constant and the remaining charging time length;

[0011] adjusting a cutoff parameter of the battery according to the health status value, wherein the cutoff parameter comprises at least one of a charge cutoff voltage, a discharge cutoff voltage, a charge cutoff current, and a discharge cutoff current.

[0012] In an alternative embodiment, determining a time constant of the battery in the constant-voltage charging segment according to the charge cutoff current value, the constant-current charging segment charging current value, the total full-charge duration, and the full-charge capacity comprises:

[0013] establishing an equivalent relationship between the time constant and the charge cutoff current value, the constant-current charging segment charging current value, the total full-charge duration, and the full-charge capacity according to an equivalent resistance-capacitance model of the battery;

[0014] wherein the equivalent relationship is:

[0015] ;

[0016] wherein τ represents the time constant, FCC represents the full-charge capacity, ICC represents the constant-current charging segment charging current value, t represents the total full-charge duration, and I(Term) represents the charge cutoff current value. O (Chg) represents the constant-current charging segment charging current value; t last represents the total full-charge duration; and I(Term) represents the charge cutoff current value.

[0017] substituting the charge cutoff current value, the constant-current charging segment charging current value, the total full-charge duration, and the full-charge capacity into the equivalent relationship to determine the time constant.

[0018] In an alternative embodiment, determining a remaining charging duration of the battery according to the charge cutoff current value, the constant-current charging segment charging current value, the total full-charge duration, and the full-charge capacity comprises:

[0019] obtaining a current state of charge value of the battery;

[0020] determining, according to the current state of charge value, that the battery is in the constant-voltage charging segment or the constant-current charging segment;

[0021] when the battery is in the constant-current charging segment: determining a constant-current charging segment remaining charging duration according to the current state of charge value, the full-charge capacity, and the constant-current charging segment charging current value; determining a constant-voltage charging segment total charging duration according to the time constant, the constant-current charging segment charging current value, and the charge cutoff current value; and determining the remaining charging duration according to the constant-current charging segment remaining charging duration and the constant-voltage charging segment total charging duration;

[0022] determining the remaining charging duration according to the time constant, the current charging current value and the constant current charging segment charging current value.

[0023] In an alternative embodiment, determining the remaining charging duration according to the charging cutoff current value, the constant current charging segment charging current value, the full charging total duration and the full charging capacity comprises:

[0024] The remaining charging duration is determined by a first formula when the battery is in the constant current charging segment;

[0025] The remaining charging duration is determined by a second formula when the battery is in the constant voltage charging segment;

[0026] The first formula is:

[0027] ;

[0028] ATTF represents the remaining charging duration; SOC V represents the state of charge value corresponding to the turning point of the constant current charging segment and the constant voltage charging segment; SOC Current represents the current state of charge value; FCC represents the full charging capacity; τ represents the time constant; I O (Chg) represents the constant current charging segment charging current value; I(Term) represents the charging cutoff current value;

[0029] The second formula is:

[0030] ;

[0031] I now represents the current charging current value.

[0032] In an alternative embodiment, the step of determining the remaining charging duration of the battery according to the charging cutoff current value, the constant current charging segment charging current value, the full charging total duration and the full charging capacity is performed once respectively when the battery is in the constant current charging segment and when the battery is in the constant voltage charging segment in one charging cycle of the battery.

[0033] In an alternative embodiment, determining the state of health value of the battery according to the time constant and the remaining charging duration comprises:

[0034] obtaining a battery temperature value and a silicon proportion coefficient of the battery cell of the battery;

[0035] determining the state of health value through a pre-established battery aging estimation model;

[0036] The battery aging estimation model is a mathematical model constructed in advance according to physical characteristics of the battery, and is used to reflect the relationship between the health state value and the time constant, the remaining charging duration, the battery temperature value, and the proportion coefficient of the silicon proportion of the battery cell.

[0037] The adjusting the cutoff parameter of the battery according to the health state value comprises:

[0038] determining a compensation amount corresponding to the cutoff parameter according to the health state value;

[0039] adjusting the cutoff parameter according to the compensation amount.

[0040] In an optional embodiment, the determining a compensation amount corresponding to the cutoff parameter according to the health state value comprises:

[0041] determining the compensation amount through a cutoff parameter compensation model;

[0042] The establishing process of the cutoff parameter compensation model comprises: fitting a function relationship between the health state value and the compensation amount according to a plurality of sets of feature data; and sampling the function relationship with a first unit value of the compensation amount as a sampling period, and taking a discretization model sampled as the cutoff parameter compensation model.

[0043] In an optional embodiment, before the adjusting the cutoff parameter of the battery according to the health state value, the method further comprises:

[0044] determining whether the health state value decreases to a new feature interval; wherein the feature interval is a plurality of value intervals divided according to a second unit value according to a value range of the health state value;

[0045] If yes, the adjusting the cutoff parameter of the battery according to the health state value is triggered.

[0046] To solve the above technical problems, the application further provides a charging device, comprising:

[0047] a data acquisition module configured to acquire a charging cutoff current value of the battery, a constant current charging segment charging current value, a full charging total duration, and a full charging capacity;

[0048] a data processing module configured to determine a time constant of a constant voltage charging segment of the battery and a remaining charging duration of the battery according to the charging cutoff current value, the constant current charging segment charging current value, the full charging total duration, and the full charging capacity;

[0049] an aging evaluation module configured to determine a health state value of the battery according to the time constant and the remaining charging duration;

[0050] a parameter adjustment module configured to adjust a cutoff parameter of the battery according to the health status value.

[0051] To solve the above technical problems, the application further provides a charging system, comprising:

[0052] a memory configured to store a computer program;

[0053] a processor configured to implement the steps of the charging method when executing the computer program.

[0054] The application provides a charging method, which obtains a cutoff current value of a battery, a constant current charging segment current value, a full charging total duration and a full charging capacity, calculates a time constant of the battery in a constant voltage charging segment and a remaining charging duration of the battery, and then accurately evaluates a state of health (SOH) of the battery based on the time constant and the remaining charging duration, and finally adjusts a cutoff parameter of the battery based on the SOH obtained through the evaluation. In the method, the adjustment of the cutoff parameter of the battery is no longer limited to several empirical points (specific charging cycle numbers) set in advance, and can be adapted to the actual situation of the battery, accurately evaluate the SOH of the battery for each battery, and then adjust the cutoff parameter based on the SOH obtained through the evaluation. Therefore, the method can bring better adjustment effect and further prolong the service life of the battery.

[0055] The charging device and the charging system provided by the application correspond to the charging method and have the same effects. BRIEF DESCRIPTION OF DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the application, the drawings needed in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0057] Figure 1 A flowchart of a charging method provided by an embodiment of the application;

[0058] Figure 2 A statistical diagram of charging data provided by an embodiment of the application;

[0059] Figure 3 A diagram showing the relationship between a compensation amount and SOH provided by an embodiment of the application;

[0060] Figure 4 A structural diagram of a charging device provided by an embodiment of the application;

[0061] Figure 5A structural diagram of a charging system provided by an embodiment of the present application. DETAILED DESCRIPTION

[0062] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, any other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0063] The core of the present application is to provide a charging method, device and system.

[0064] In order to enable the persons in the technical field to better understand the present application, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0065] In the related art, several feature points (experience points) are determined by the experience of technicians, that is, the battery will show different aging degrees in specific cycle charging periods. Then, cycle charging and discharging tests based on the five-step voltage regulation method (also known as Base5 step voltage regulation method) are performed for these feature points, so as to obtain a better charging system adjustment scheme. For example, a specific charging system of the above scheme is shown in Table 1 as follows:

[0066] Table 1 Charging system table based on Base5 step voltage regulation

[0067]

[0068] As in Table 1 above, the feature points are the 200th (cycle charging) period, the 300th period, etc. And each step voltage value in the "five-step voltage regulation" is also determined based on the experience of technicians, only the better experience value is selected by testing. Therefore, the charging system adjustment based on the above scheme is limited by the feature points, and the subsequent battery can only adjust the charging system when reaching the feature points in actual application, and cannot cover the complete life cycle of the battery. And this feature point adjustment scheme cannot adapt to the differences between different battery individuals (even if they are of the same type). The above reasons lead to the need for further improvement of the effect of prolonging the service life of the battery by this scheme.

[0069] In summary, the present application provides a charging method, as shown in Figure 1 , comprising:

[0070] S1: obtaining the charging cutoff current value, the constant current charging segment charging current value, the full charging total time length and the full charging capacity of the battery.

[0071] S2: Based on the charging cutoff current value, the constant current charging section charging current value, the total full charging time, and the full charging capacity, determine the battery's time constant in the constant voltage charging section and the remaining charging time of the battery.

[0072] S3: Determine the battery's health status value based on the time constant and remaining charging time.

[0073] S4: Adjust the battery's cutoff parameters based on the health status value;

[0074] The cutoff parameters include at least one of the following: charging cutoff voltage, discharging cutoff voltage, charging cutoff current, or discharging cutoff current.

[0075] The aforementioned cutoff parameters include at least one of the following: charging cutoff voltage (upper limit of cutoff voltage), discharging cutoff voltage (lower limit of cutoff voltage), charging cutoff current (upper limit of cutoff current), and discharging cutoff current (lower limit of cutoff current).

[0076] For step S1, the battery's charging cutoff current, constant current charging current, total full charge time, and full charge capacity can be obtained by monitoring characteristics such as the battery's voltage, current, charging time, and state of charge during a charging cycle. Specifically, as follows... Figure 2 As shown, the current value at which battery charging is cut off is the aforementioned charging cutoff current value I(Term); the battery current during the constant current charging stage (CC stage) is the aforementioned constant current charging stage charging current value I. O (Chg); The total time required for the battery to complete one charging cycle is the total full charge time t mentioned above. last The state of charge (FCC) of a battery at the end of a charging cycle is the full charge capacity mentioned above. It should be noted that while these four parameters can be obtained by testing sample batteries of the same model, the most accurate method is through historical data from the previous charging cycle of the current battery. Furthermore, they can also be obtained by statistically analyzing historical data from multiple charging cycles of the current battery; however, it is important to note that charging cycles closer to the current time should have higher weightings to ensure data timeliness.

[0077] Steps S2 and S3 are the core steps of this method. This method calculates the time constant and remaining charging time using the four parameters obtained in step S1; then, it calculates the battery's State of Health (SOH) value based on the time constant and remaining charging time; finally, it adjusts the battery's cutoff parameters based on the SOH value.

[0078] The principle of the above steps is that as the battery continuously cycles and ages, the ohmic polarization, electrochemical polarization, and concentration polarization of the battery will gradually intensify. The deterioration of the kinetic performance means that under a large current in the CC segment, ions cannot be embedded in the electrode interior in time, resulting in a rapid rise in voltage. After entering the CV segment, only a small current can be used to "patiently wait" for the ions to slowly diffuse to the position. Thus, the system needs more time to "relax", which is manifested as the gradual extension of the overall charging time, especially the charging time in the CV segment. As can be seen, the charging time in the CV segment can directly reflect the aging degree of the battery. The charging time in the CV segment can be obtained through the total charging time and the charging time in the CC segment. The CC segment has a fixed charging current, that is, I O (Chg) is fixed, and its corresponding determination formula can be derived from the mechanism characteristics of the battery. Specifically, the determination formula can be obtained through the following three basic formulas of the battery mechanism:

[0079] 1. Total charging time t last :

[0080] ;

[0081] In the formula, t CC is the charging time in the CC segment, and t CV is the charging time in the CV segment.

[0082] 2. Full charging capacity FCC:

[0083] ;

[0084] In the formula, I st is the starting current, and I(t) is the variable of the current with respect to time.

[0085] 3. Charging current in the CV segment:

[0086] ;

[0087] In the formula, e is a natural constant.

[0088] Further, the present application provides an alternative embodiment for determining the time constant τ. The process of determining the time constant τ in the above step S2 specifically includes:

[0089] S2-A1: According to the equivalent resistance-capacitance model of the battery, an equivalent relationship formula is established between the time constant and the charging cutoff current value, the constant current charging segment charging current value, the total charging time, and the full charging capacity.

[0090] The equivalent relationship formula is:

[0091] ;

[0092] Wherein, τ represents the time constant; FCC represents the full charge capacity; I O (Chg) represents the constant current charging segment charging current value; t last represents the full charge total duration; I(Term) represents the charging cutoff current value.

[0093] S2-A2: Substitute the obtained charging cutoff current value, constant current charging segment charging current value, full charge total duration and full charge capacity into the equivalent relationship formula to determine the time constant.

[0094] Similarly, the application also provides an alternative embodiment for how to determine the remaining charging duration ATTF of the battery. The process of determining the remaining charging duration ATTF in step S2 specifically includes:

[0095] S2-B1: Obtain the current state of charge value of the battery.

[0096] Wherein, the current state of charge value is subsequently used as SOC Current .

[0097] S2-B2: Determine whether the battery is in the constant voltage charging segment or the constant current charging segment according to the current state of charge value.

[0098] Wherein, whether the current battery is in the CC segment or the CV segment can be determined by the size relationship between the current state of charge value SOC Current and the state of charge value SOC V of the battery at the charging turning point of the CC segment and the CV segment. If SOC Current <SOC V , it indicates that the current battery is in the CC segment. If SOC Current >SOC V , it indicates that the current battery is in the CV segment.

[0099] S2-B3: When the battery is in the constant current charging segment: determine the constant current charging segment remaining charging duration according to the current state of charge value, full charge capacity and constant current charging segment charging current value; determine the constant voltage charging segment total charging duration according to the time constant, constant current charging segment charging current value and charging cutoff current value; determine the remaining charging duration according to the constant current charging segment remaining charging duration and the constant voltage charging segment total charging duration.

[0100] S2-B4: When the battery is in the constant voltage charging segment: obtain the current charging current value of the battery; determine the remaining charging duration according to the time constant, current charging current value and constant current charging segment charging current value.

[0101] From the above steps S2-B3 and S2-B4, it can be seen that the present embodiment provides a corresponding remaining charging time ATTF calculation scheme for the battery in the CC segment and the CV segment respectively. The complete charging cycle of the battery can be covered, so that the battery cutoff parameter (charging protocol system) adjustment based on the method can occur at any time during the battery charging process. The flexibility of adjustment is improved, and better adjustment effect is also brought about.

[0102] Further, the determination process of the CC segment remaining charging time ATTF in the above step S2-B3 can be further realized by the following first formula:

[0103] ;

[0104] Similarly, the determination process of the CV segment remaining charging time ATTF in the above step S2-B4 can be further realized by the following second formula:

[0105] The second formula is:

[0106] ;

[0107] I now represents the current charging current value.

[0108] From the above embodiment, it can be seen that the calculation of the remaining charging time ATTF in step S2 of the present method can occur at any time during the battery life cycle. Based on this, the present embodiment provides an optional scheme: the calculation of the remaining charging time ATTF in step S2 is performed once in a charging cycle of the battery, respectively when the battery is in the constant current charging segment and when the battery is in the constant voltage charging segment.

[0109] And the calculation of the time constant τ above can also be. Correspondingly, the calculation of the health state value SOH of the battery in step S3 can also occur at any time, which is not limited by the present embodiment. That is, a further embodiment is that the calculation of the time constant τ is performed once in a charging cycle of the battery (the specific time is not limited). The calculation of the remaining charging time ATTF is performed once in the CC segment and the CV segment of a charging cycle of the battery, respectively realized by the first formula and the second formula provided by the above embodiment, further improving the calculation accuracy. The health state value SOH is calculated after the time constant τ and the remaining charging time ATTF are determined, that is, also performed once in the CC segment and the CV segment of a charging cycle of the battery.

[0110] After that, the specific calculation of step S3. The corresponding prediction model can be trained by sample data through machine learning algorithm or fitting algorithm, or a corresponding mathematical model can be constructed based on the physical characteristics of the battery, and then the key parameters are solved through historical data or simulation test, so as to obtain the determined mathematical model. No matter which way is adopted, the core is to determine the relationship between the time constant τ, the remaining charging time ATTF (input quantity) and the SOH (output quantity).

[0111] But it needs to be noted that the present embodiment is also not limited to only using the time constant τ and the remaining charging time ATTF as the input quantity. In order to further improve the prediction accuracy, other parameters can also be added. But it needs to be explained that only by the time constant τ and the remaining charging time ATTF, the SOH value of the battery can be determined. In a possible application scenario, the battery is a lithium battery, and the present application also provides a further embodiment for the implementation of the above step S3:

[0112] S31: Obtain the battery temperature value and the silicon proportion coefficient of the battery cell of the battery.

[0113] S32: Determine the health state value through the pre-established battery aging estimation model.

[0114] Among them, the battery aging estimation model is pre-established according to the physical characteristics of the battery, which is a mathematical model for reflecting the relationship between the health state value and the time constant, the remaining charging time, the battery temperature value and the silicon proportion coefficient of the battery cell, such as: SOH = f(ATTF, τ, K Si , T).

[0115] Among them, K Si represents the silicon proportion coefficient of the battery cell of the battery. If the battery is a battery other than lithium battery, the silicon proportion coefficient of the battery cell here can also be replaced by the proportion related coefficient of other battery active material, and the present embodiment does not limit this. T represents the temperature of the battery, and this parameter is not limited by the type of battery, and any type of battery can be used to improve the prediction accuracy of the SOH value. In addition, it needs to be explained that the silicon proportion coefficient K Si of the battery cell is known when the battery is designed and produced, and can be directly obtained. The battery temperature value T can be obtained by actual measurement, which is equivalent to a known quantity.

[0116] For the above SOH value prediction model, the present application also provides an optional further embodiment, and the prediction model is as follows:

[0117] ;

[0118] In the formula, ω1 and ω2 are weight coefficients corresponding to ATTF and τ respectively, and the sum of the two is 1; ω1 can be taken from the interval of 0.6-0.7, because the capacity is more sensitive to SOH; correspondingly, ω2 can be taken from the interval of 0.3-0.4. ATTF0 and τ0 are ATTF and τ (experimental calibration value) of the sample battery under the same conditions. f(T) is a temperature correction function (Arrhenius type), f(T) = exp[-(Ea / Rg)*(1 / T-1 / T0)]; Ea is the activation energy of the charging reaction; Rg is a constant, Rg = 8.314 J / (mol*K); T0 is the reference temperature (such as 298K). g(K Si ) is a carbon-silicon ratio correction function, which can be obtained based on linear fitting, such as: g(K Si ) = 1-k* K Si . Wherein, k is a fitting function, which can be determined by aging experiments on different K Si .

[0119] The embodiment provides a prediction model of weighted fusion of double feature quantities, which takes into account the aging characteristics of capacity-type and resistance-type batteries, and can provide more accurate battery SOH prediction function.

[0120] After obtaining the battery SOH, the cutoff parameter can be adjusted according to the battery SOH, as in step S4. An optional embodiment of step S4 is:

[0121] S41: determining the compensation amount corresponding to the cutoff parameter according to the health state value.

[0122] S42: adjusting the cutoff parameter according to the compensation amount.

[0123] However, it should be noted that from the above embodiment, it can be seen that the calculation of the SOH value of the method can be performed twice in one battery charging cycle. In this case, if the adjustment of the cutoff parameter is performed once for each new determination of the SOH value, the cutoff parameter needs to be adjusted twice in one battery charging cycle. On the one hand, too frequent adjustment is not easy to implement. On the other hand, in actual application, such high frequency adjustment is generally not required, and may even adversely affect the service life of the battery. Based on this, the embodiment further provides an optional implementation scheme, before step S4, the above method further comprises:

[0124] S5: determining whether the health state value has dropped to a new feature interval, if so, triggering step S4.

[0125] The characteristic intervals are multiple value intervals divided according to the range of health status values ​​based on the second unit value. This embodiment does not limit the specific value of the second unit value; one possible solution is 5%. That is, each time the SOH value first decreases to below 95%, 90%, 85%, etc., the cutoff parameter adjustment in step S4 is triggered. This avoids the problem of overly frequent adjustments being difficult to implement and potentially negatively impacting battery lifespan.

[0126] Furthermore, regarding how to determine the compensation amount in step S41 of the above embodiment, this embodiment also provides a further implementation scheme: determining the compensation amount through a cutoff parameter compensation model; wherein, the process of establishing the cutoff parameter compensation model includes: fitting a functional relationship between the health status value and the compensation amount based on multiple sets of feature data; sampling the functional relationship with the first unit value of the compensation amount as the sampling period, and using the discretized model obtained from the sampling as the cutoff parameter compensation model.

[0127] For example, since each of the cutoff parameters can be determined based on the above principles, the corresponding cutoff parameter compensation model is used as an example to illustrate the determination of the cutoff parameter compensation model in this embodiment. The principles for the other three parameters are the same. In a possible practical scenario, the functional relationship between the health status value and the compensation amount is obtained from the measured data as follows: Figure 3 As shown, specifically: Y log (X) = K*ln(X-1). Where X represents the percentage (absolute value) of the SOH deviation, i.e., X = 100 * (1 - SOH), in %. K is the fitting coefficient; in this example, K = 34.7. Y log The millivolt value representing the voltage deviation (continuous type) is calculated using the formula Y. log =1000*(V0-V), in millivolts (mV); where V0 is the base charging cutoff voltage and V is the current charging cutoff voltage (experimental or empirical value, assumed to be 4.51V).

[0128] Depend on Figure 3 As can be seen from the specific functional relationship described above, the voltage deviation (compensation amount) and the SOH value in this example have a logarithmic relationship. This is a continuous functional relationship, so the corresponding compensation amount can be determined at any SOH value point for adjusting the charging cutoff voltage. However, in practical applications, such fine-grained adjustment is usually unnecessary. For example, as illustrated in the above embodiment, this method can calculate the SOH value twice in one charging cycle (τ once, ATTF twice, therefore the SOH value is twice). Therefore, this example samples the above continuous curve with a first preset unit (e.g., 10mV) on the horizontal axis (SOH deviation) to obtain the actual step-down curve (Y). step )like Figure 3The complete mathematical expression of this process is shown as follows:

[0129] ;

[0130] In actual engineering implementation, only continuous function relationship can be saved. After obtaining the SOH value, calculation is performed through the continuous function relationship, and then the result value Y log is discretely processed (divided by the first preset unit and rounded down) based on the first preset unit to obtain the final compensation amount; or the discrete function relationship can be directly stored, and the corresponding Y step value is found based on the obtained SOH value as the compensation amount; this embodiment is not limited to this. Based on the above, the corresponding relationship between the SOH value and the compensation amount corresponding to the present example is shown in Table 2.

[0131] Table 2: SOH value and compensation amount based on the present method

[0132]

[0133] Further, based on Table 2, the adjustment scheme of the charging cutoff voltage based on the present method is obtained, which is shown in Table 3 as follows:

[0134] Table 3: Charging cutoff voltage adjustment table based on the present method

[0135]

[0136] Further, Table 3 is arranged in the same form as Table 1 to facilitate comparison between the present method and the Base5 step-up scheme in related art, and Table 4 is obtained as follows:

[0137] Table 4: Charging cutoff voltage adjustment table based on the present method

[0138]

[0139] Based on the comparison between Table 1 and Table 4, it is not difficult to see that the adjustment of the battery cutoff parameters (including the charging protocol system) of the present method is not limited to a few empirical points (specific cycle numbers). Instead, the adjustment is performed after the battery is aged to a certain extent based on real-time evaluation of the SOH of the battery (which can be performed once in the CC segment and once in the CV segment in each charging cycle). Thus, the capacity retention rate of the battery is improved, and the service life of the battery is prolonged.

[0140] In summary, the present method provides a method for accurately evaluating the SOH of the battery, which is realized based on the calculation of the CV segment time constant and the remaining charging time of the battery. After obtaining the SOH value of the battery, the battery can be adjusted based on the SOH value. The adjustment is more flexible and targeted, and the service life of the battery can be better prolonged.

[0141] In the above embodiment, a charging method is described in detail, and the present application also provides a corresponding embodiment of a charging device. It should be noted that the embodiment of the device part is described from two angles, one is based on the functional module, and the other is based on the hardware.

[0142] Based on the functional module, as shown in Figure 4 The embodiment provides a charging device, which comprises:

[0143] The data acquisition module 11 is configured to acquire the charge cut-off current value of the battery, the constant current charging segment charging current value, the full charging total duration and the full charging capacity.

[0144] The data processing module 12 is configured to determine the time constant of the battery in the constant voltage charging segment and the remaining charging duration of the battery according to the charge cut-off current value, the constant current charging segment charging current value, the full charging total duration and the full charging capacity.

[0145] The aging evaluation module 13 is configured to determine the health state value of the battery according to the time constant and the remaining charging duration.

[0146] The parameter adjustment module 14 is configured to adjust the cut-off parameter of the battery according to the health state value.

[0147] Since the embodiment of the device part corresponds to the embodiment of the method part, the embodiment of the device part is described in the description of the embodiment of the method part, and will not be described here.

[0148] Figure 5 The structure diagram of a charging system provided by another embodiment of the present application is shown in Figure 5 The charging system comprises a memory 20 configured to store a computer program.

[0149] A processor 21 is configured to execute the computer program to realize the steps of the charging method in the above embodiment.

[0150] The charging system provided by the embodiment can include but is not limited to a battery management system (BMS), a battery control unit (BCU) and the like.

[0151] The processor 21 may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor 21 may be implemented using at least one of the following hardware forms: Digital Signal Processor (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor, also known as the Central Processing Unit (CPU), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 21 may integrate a Graphics Processing Unit (GPU), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor 21 may also include an Artificial Intelligence (AI) processor, which is used to handle computational operations related to machine learning.

[0152] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In this embodiment, the memory 20 is used to store at least the following computer program 201, which, after being loaded and executed by the processor 21, is capable of implementing the relevant steps of a charging method disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202 and data 203, and the storage method may be temporary or permanent storage. The operating system 202 may include Windows, Unix, Linux, etc. The data 203 may include, but is not limited to, a charging method.

[0153] In some embodiments, a charging system may further include a display screen 22, an input / output interface 23, a communication interface 24, a power supply 25, and a communication bus 26. Those skilled in the art will understand that... Figure 5 The structures shown are not intended to limit a charging system and may include more or fewer components than illustrated. An embodiment of this application provides a charging system including a memory and a processor. When the processor executes a program stored in the memory, it can implement a charging method.

[0154] Finally, this application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps described in the above method embodiments.

[0155] It is understood that if the methods in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0156] The charging method, apparatus, and system provided in this application have been described in detail above. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of this application.

[0157] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A charging method, characterized in that, include: Obtain the battery's charging cutoff current value, constant current charging segment charging current value, total full charge time, and full charge capacity; Based on the charging cutoff current value, the constant current charging section charging current value, the total full charge time, and the full charge capacity, determine the time constant of the battery in the constant voltage charging section and the remaining charging time of the battery. The battery health status value is determined based on the time constant and the remaining charging time. Adjust the battery's cutoff parameters based on the health status value; The cutoff parameters include at least one of the following: charging cutoff voltage, discharging cutoff voltage, charging cutoff current, and discharging cutoff current.

2. The charging method according to claim 1, characterized in that, The time constant of the battery in the constant voltage charging section is determined based on the charging cutoff current value, the constant current charging section charging current value, the total full charge time, and the full charge capacity, including: Based on the equivalent resistance-capacitance model of the battery, establish the equivalent relationship between the time constant and the charging cutoff current value, the constant current charging segment charging current value, the total full charge time and the full charge capacity; The equivalent relation is as follows: ； Wherein, τ represents the time constant; FCC represents the full charge capacity; I O (Chg) represents the charging current value of the constant current charging section; t last The total charging time is indicated by I; I(Term) represents the charging cutoff current value. The obtained charging cutoff current value, constant current charging segment charging current value, total full charge duration, and full charge capacity are substituted into the equivalent relationship to determine the time constant.

3. The charging method according to claim 1, characterized in that, The remaining charging time of the battery is determined based on the charging cutoff current value, the constant current charging segment charging current value, the total full charging time, and the full charging capacity, including: Obtain the current state of charge value of the battery; The battery is determined to be in a constant voltage charging segment or a constant current charging segment based on the current state of charge value. When the battery is in the constant current charging segment: the remaining charging time of the constant current charging segment is determined based on the current state of charge value, the full charge capacity, and the charging current value of the constant current charging segment; the total charging time of the constant voltage charging segment is determined based on the time constant, the charging current value of the constant current charging segment, and the charging cutoff current value; the remaining charging time is determined based on the remaining charging time of the constant current charging segment and the total charging time of the constant voltage charging segment. When the battery is in the constant voltage charging stage: obtain the current charging current value of the battery; determine the remaining charging time based on the time constant, the current charging current value, and the constant current charging stage charging current value.

4. The charging method according to claim 3, characterized in that, The remaining charging time is determined based on the charging cutoff current value, the constant current charging segment charging current value, the total full charging time, and the full charging capacity, including: When the battery is in the constant current charging stage, the remaining charging time is determined by the first formula; When the battery is in the constant voltage charging stage, the remaining charging time is determined by the second formula; The first formula is: ； ATTF represents the remaining charging time; SOC V This indicates the state of charge (SOC) value of the battery at the transition point between the constant current charging stage and the constant voltage charging stage. Current The current state of charge (FSC) value represents the current state of charge (FCC); FCC represents the full charge capacity; τ represents the time constant; I O (Chg) represents the constant current charging segment charging current value; I(Term) represents the charging cutoff current value; The second formula is: ； I now This indicates the current charging current value.

5. The charging method according to claim 3, characterized in that, The step of determining the remaining charging time of the battery based on the charging cutoff current value, the constant current charging segment charging current value, the total full charging time, and the full charging capacity is performed once each during one charging cycle of the battery, when the battery is in the constant current charging segment and when the battery is in the constant voltage charging segment.

6. The charging method according to any one of claims 1 to 5, characterized in that, Determining the battery's health status value based on the time constant and the remaining charging time includes: Obtain the battery temperature value and the silicon ratio coefficient of the battery cell; The health status value is determined by a pre-established battery aging estimation model; The battery aging estimation model is a mathematical model pre-constructed based on the physical characteristics of the battery, used to reflect the relationship between the health status value and the time constant, the remaining charging time, the battery temperature value and the silicon ratio coefficient of the cell. The step of adjusting the battery's cutoff parameters based on the health status value includes: The compensation amount corresponding to the cutoff parameter is determined based on the health status value; The cutoff parameter is adjusted according to the compensation amount.

7. The charging method according to claim 6, characterized in that, Determining the compensation amount corresponding to the cutoff parameter based on the health status value includes: The compensation amount is determined using a cutoff parameter compensation model. The process of establishing the cutoff parameter compensation model includes: fitting a functional relationship between the health status value and the compensation amount based on multiple sets of feature data; sampling the functional relationship with the first unit value of the compensation amount as the sampling period; and using the discretized model obtained from the sampling as the cutoff parameter compensation model.

8. The charging method according to claim 6, characterized in that, Before adjusting the battery's cutoff parameters based on the health status value, the method further includes: Determine whether the health status value has decreased to a new characteristic interval; wherein, the characteristic interval is a plurality of value intervals divided according to the value range of the health status value based on the second unit value; If so, the step of adjusting the battery's cutoff parameters based on the health status value is triggered.

9. A charging device, characterized in that, include: The data acquisition module is used to acquire the battery's charging cutoff current value, constant current charging segment charging current value, total full charging time, and full charging capacity. The data processing module is used to determine the time constant of the battery in the constant voltage charging section and the remaining charging time of the battery based on the charging cutoff current value, the constant current charging section charging current value, the total full charging time and the full charging capacity. An aging assessment module is used to determine the battery's health status value based on the time constant and the remaining charging time. The parameter adjustment module is used to adjust the battery's cutoff parameters according to the health status value.

10. A charging system, characterized in that, include: Memory, used to store computer programs; A processor, configured to implement the steps of the charging method as described in any one of claims 1 to 8 when executing the computer program.

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