Battery equalization control method, device and equipment based on internal resistance evolution

Abstract

The embodiment of the invention relates to a battery equalization control method, device and equipment based on internal resistance evolution, after the internal resistance of a battery is compensated, equalization is started according to a voltage difference threshold value, and equalization dynamic adjustment is carried out through an equalization current value obtained through calculation, so that the false triggering rate of equalization starting and closing is reduced, and the battery equalization control efficiency is improved. The capacity attenuation rate of the battery pack is reduced through an internal resistance trend prediction dynamic adjustment strategy; therefore, the accuracy and risk controllability of dynamic balance control in the charging or discharging process of the battery are improved.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of energy storage, in particular to a battery equalization control method, device and equipment based on internal resistance evolution. BACKGROUND

[0002] The wide application of lithium-ion batteries in power and energy storage systems highlights the key constraints of battery pack consistency on system performance and life. The current mainstream battery equalization technology generally relies on a fixed voltage difference threshold as the equalization trigger basis, but this method has significant limitations. The internal resistance of the battery continuously changes dynamically with factors such as aging degree deepening and temperature fluctuation, resulting in a deviation between the voltage measurement value and the true state of charge (SOC) of the battery and gradually increasing, thereby causing false equalization operation, which reduces efficiency and accelerates aging. At the same time, the static equalization threshold cannot adapt to the continuous degradation process of the battery internal resistance with the use time, lacks dynamic perception and response ability to the state of health (SOH) of the battery, and makes the timeliness of the equalization strategy seriously insufficient, making it difficult to continuously maintain the consistency within the group. More alarmingly, battery monomers with high internal resistance are prone to local overheating during charging and discharging, which poses a serious safety hazard, and the traditional equalization method based on a fixed voltage difference lacks an effective early warning mechanism for such risks and cannot implement timely and targeted proactive intervention, and the system safety risk is prominent. Therefore, it is urgent to develop a new equalization control method that can overcome the above defects. SUMMARY

[0003] In view of the above problems, the present application provides a battery equalization control method, device and equipment based on internal resistance evolution, which solves the problem that in the prior art, the internal resistance of the battery continuously changes dynamically with factors such as aging degree deepening and temperature fluctuation, resulting in a deviation between the voltage measurement value and the true state of charge (SOC) of the battery and gradually increasing, thereby causing false equalization operation, which reduces efficiency and accelerates aging.

[0004] According to one aspect of the present application, a battery equalization control method based on internal resistance evolution is provided, the method comprising:

[0005] real-time acquisition of the instantaneous resistance when the battery charging or discharging produces a current mutation, current battery temperature, calculation of the average internal resistance according to the continuous instantaneous resistance;

[0006] temperature compensation calculation of the average internal resistance according to the current battery temperature to obtain a compensated internal resistance, and resistance aging prediction of the compensated internal resistance to obtain a predicted internal resistance and an internal resistance change rate;

[0007] calculation of a voltage difference threshold according to the compensated internal resistance and the internal resistance change rate, and calculation of an equalization current according to the compensated internal resistance, the predicted internal resistance and the current battery temperature;

[0008] According to the voltage difference threshold and / or the equalization current, the battery charging or discharging is dynamically equalized.

[0009] In some optional embodiments, the instantaneous resistance is collected in real time when the battery charging or discharging produces a current mutation, specifically including:

[0010] During the battery charging or discharging, it is detected whether the current mutation occurs;

[0011] If yes, the voltage change rate and the current change rate of the battery are captured, and the instantaneous resistance is obtained according to the quotient of the calculated voltage change rate and the current change rate;

[0012] Otherwise, no processing is performed.

[0013] In some optional embodiments, the average internal resistance is calculated according to the continuous instantaneous resistances, specifically including:

[0014] After N continuous instantaneous resistances are obtained, the N instantaneous internal resistances are weighted and averaged to obtain the average internal resistance.

[0015] In some optional embodiments, the average internal resistance is temperature-compensated to obtain a compensated internal resistance, specifically including:

[0016] According to a preset internal resistance-temperature relationship curve, the average internal resistance is temperature-compensated to obtain a compensated internal resistance, and the internal resistance-temperature relationship curve formula is: R comp = R current × (1 + α × (T current - T ref )), where R comp is the compensated internal resistance, R current is the average internal resistance, α is a temperature compensation coefficient, T current is the current battery temperature, and T ref is a reference battery temperature.

[0017] In some optional embodiments, the compensated internal resistance is resistance-aging predicted to obtain a predicted internal resistance and an internal resistance change rate, specifically including:

[0018] According to a preset exponential function fitting decay curve and initial internal resistance sum, the predicted internal resistance is calculated;

[0019] According to an internal resistance change rate formula, the internal resistance change rate is calculated, and the internal resistance change rate formula is:

[0020] dR / dt = (R predicted - R comp ) / △t,△t is the charging time or discharging time of the battery, R predicted is the predicted internal resistance, and dR / dt is the internal resistance change rate.

[0021] In some optional embodiments, the voltage difference threshold is calculated according to the compensated internal resistance and the internal resistance change rate, specifically comprising:

[0022] The voltage difference threshold is calculated according to the compensated internal resistance and the internal resistance change rate through a voltage difference threshold calculation formula, wherein the voltage difference threshold calculation formula is: R0 is the initial resistance, K1 is the weight of the ratio of the current internal resistance to the initial internal resistance on the threshold, K2 is the weight of the internal resistance change rate on the threshold, and AV base is the reference voltage difference.

[0023] In some optional embodiments, the equalization current is calculated according to the compensated internal resistance, the predicted internal resistance and the current battery temperature, specifically comprising:

[0024] The equalization current is calculated according to the compensated internal resistance, the predicted internal resistance and the current battery temperature through a voltage difference threshold calculation formula, wherein, wherein I balance is the equalization current, I max is the maximum allowed current, T max is the maximum allowed equalization temperature, T min is the minimum allowed equalization temperature, and R fail is the cell failure resistance.

[0025] In some optional embodiments, in the dynamic equalization control of the battery charging or discharging according to the voltage difference threshold and / or the equalization current, further comprising:

[0026] Real-time judgment is made on whether the predicted internal resistance exceeds a preset internal resistance threshold, and when the predicted internal resistance exceeds the preset internal resistance threshold, a battery alarm is triggered and the dynamic equalization control is prohibited;

[0027] And / or, real-time judgment is made on whether the current battery temperature exceeds a preset temperature threshold, and when the current battery temperature exceeds the preset temperature threshold, a battery alarm is triggered and the dynamic equalization control is prohibited.

[0028] According to another aspect of the example of the present application, a battery equalization control device based on internal resistance evolution is provided, which comprises:

[0029] An internal resistance acquisition module is configured to collect the instantaneous resistance and the current battery temperature when the current generated by the battery charging or discharging suddenly changes, and to calculate the average internal resistance according to the continuous instantaneous resistance;

[0030] A compensation and prediction module is configured to perform temperature compensation on the average internal resistance according to the current battery temperature to obtain a compensated internal resistance, and to perform resistance aging prediction on the compensated internal resistance to obtain a predicted internal resistance and an internal resistance change rate;

[0031] a balance calculation module, configured to calculate a voltage difference threshold according to the compensated internal resistance and the internal resistance change rate, and to calculate a balance current according to the compensated internal resistance, the predicted internal resistance and the current battery temperature;

[0032] and a balance processing module, configured to perform dynamic balance control on the battery charging or discharging according to the voltage difference threshold and / or the balance current.

[0033] According to still another aspect of the present application, a battery balance control device based on internal resistance evolution is provided, comprising a processor, a memory, a communication interface and a communication bus, the processor, the memory and the communication interface being capable of communicating with each other through the communication bus;

[0034] The memory is configured to store at least one executable instruction, which causes the processor to perform the operations of the battery balance control method based on internal resistance evolution as described above.

[0035] The present application provides a battery balance control method, device and equipment based on internal resistance evolution, which has the following beneficial effects:

[0036] The present application acquires the instantaneous internal resistance and the current battery temperature when the battery charging or discharging generates a current mutation, calculates the average internal resistance according to the continuous instantaneous internal resistance, performs temperature compensation on the average internal resistance according to the current battery temperature to obtain the compensated internal resistance, and performs resistance aging prediction on the compensated internal resistance to obtain the predicted internal resistance and the internal resistance change rate, calculates the voltage difference threshold according to the compensated internal resistance and the internal resistance change rate, and calculates the balance current according to the compensated internal resistance, the predicted internal resistance and the current battery temperature, and performs dynamic balance control on the battery charging or discharging according to the voltage difference threshold and / or the balance current. After the battery internal resistance is compensated, the present application starts the balance according to the voltage difference threshold, and performs dynamic balance adjustment through the calculated balance current value, reduces the false triggering rate of the balance start and stop, and reduces the battery pack capacity attenuation rate through the internal resistance trend prediction dynamic adjustment strategy, thereby improving the accuracy and risk controllability of the dynamic balance control in the battery charging or discharging process.

[0037] The above description is only a summary of the technical solutions of the present application, in order to more clearly understand the technical means of the embodiments of the present application, the embodiments can be implemented according to the content of the description, and in order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described below. BRIEF DESCRIPTION OF DRAWINGS

[0038] The accompanying drawings are only used to show the embodiments and are not considered as limitations of the present application. Moreover, the same reference signs are used to represent the same parts throughout the drawings. In the drawings:

[0039] Figure 1 A flowchart of the battery equalization control method based on internal resistance evolution provided by the present application is shown in Figure 1.

[0040] Figure 2 A specific flowchart of step 110 of the battery equalization control method based on internal resistance evolution provided by the present application is shown in Figure 2.

[0041] Figure 3 A specific flowchart of the resistance aging prediction of the compensation internal resistance, the predicted internal resistance and the internal resistance change rate provided by the present application is shown in Figure 3.

[0042] Figure 4 A structural diagram of the battery equalization control device based on internal resistance evolution provided by the present application is shown in Figure 4.

[0043] Figure 5 A structural diagram of the battery equalization control device based on internal resistance evolution provided by the present application is shown in Figure 4.

[0044] Figure 6 A curve of the battery internal resistance and the state of health (SOH) over time provided by the present application is shown in Figure 5. DETAILED DESCRIPTION

[0045] Exemplary embodiments of the present application will be described in greater detail below with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the drawings, it is understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein.

[0046] Embodiment 1:

[0047] Figure 1 A battery equalization control method based on internal resistance evolution provided by the present application is shown in Figure 1. This method is used to solve the problem that the battery internal resistance continuously changes dynamically with the deepening of aging degree, temperature fluctuations and other factors in the prior art, resulting in a deviation between the voltage measurement value and the true state of charge (SOC) of the battery and gradually increasing, and then triggering the false equalization operation, which not only reduces the efficiency but also accelerates the aging. The method specifically includes:

[0048] 110, real-time acquisition of the instantaneous resistance when the current mutation occurs during battery charging or discharging, current battery temperature, calculation of the average internal resistance according to the continuous instantaneous resistance; in step 110, the instantaneous resistance when the current mutation occurs during battery charging or discharging is real-time acquired, specifically including: detecting whether the current mutation occurs during battery charging or discharging; if yes, capturing the voltage change rate and the current change rate of the battery, and obtaining the instantaneous resistance according to the quotient of the calculated voltage change rate and the current change rate; otherwise, no processing is performed. The average internal resistance is calculated according to the continuous instantaneous resistance, specifically including: after N instantaneous resistances are continuously obtained, the N instantaneous internal resistances are weighted and averaged to obtain the average internal resistance.

[0049] 120, obtain a compensated internal resistance by temperature compensation calculation on the average internal resistance according to the current battery temperature, and obtain a predicted internal resistance and an internal resistance change rate by resistance aging prediction on the compensated internal resistance; in step 120, the compensated internal resistance is obtained by temperature compensation calculation on the average internal resistance, specifically including: the compensated internal resistance is obtained by temperature compensation on the average internal resistance according to a preset internal resistance-temperature relationship curve, the internal resistance-temperature relationship curve formula is: R comp current × (1 + α × (T current -T ref )), wherein R comp is the compensated internal resistance, R current is the average internal resistance, α is a temperature compensation coefficient, T current is the current battery temperature, and T ref is a reference battery temperature; the predicted internal resistance and the internal resistance change rate are obtained by resistance aging prediction on the compensated internal resistance, specifically including: a predicted resistance is calculated according to a preset exponential function fitting decay curve and the sum of the initial internal resistance; the internal resistance change rate is calculated according to an internal resistance change rate formula, wherein the internal resistance change rate formula is: dR / dt = (R predicted -R comp ) / △t,△t is the charging time or the discharging time of the battery, R predicted is the predicted resistance, and dR / dt is the internal resistance change rate.

[0050] 130, obtain a voltage difference threshold value according to the compensated internal resistance and the internal resistance change rate, and obtain an equalization current according to the compensated internal resistance, the predicted internal resistance and the current battery temperature; in step 130, the voltage difference threshold value is obtained according to the compensated internal resistance and the internal resistance change rate, specifically including: the voltage difference threshold value is obtained according to the compensated internal resistance and the internal resistance change rate through a voltage difference threshold value calculation formula, wherein the voltage difference threshold value calculation formula is: R0 is the initial resistance, K1 is the weight of the ratio of the current internal resistance to the initial resistance on the threshold value, K2 is the weight of the internal resistance change rate on the threshold value,△V base is the reference voltage difference. The equalization current is obtained according to the compensated internal resistance, the predicted internal resistance and the current battery temperature, specifically including: the equalization current is obtained according to the compensated internal resistance, the predicted internal resistance and the current battery temperature through the voltage difference threshold value calculation formula, wherein, wherein I balance is the equalization current, I max is the maximum allowed current, T max is the maximum allowed equalization temperature, T min is the minimum allowed equalization temperature, and R fail is the cell failure resistance.

[0051] ​140, dynamically balancing the battery charging or discharging according to the voltage difference threshold and / or the balancing current. In step 140, after obtaining the voltage difference threshold and / or the balancing current, the voltage difference threshold and / or the balancing current can be input into the battery management system of the current battery to adjust the voltage difference threshold or the balancing current in real time. Specifically, the DC-DC module can be used to boost the discharge balancing or step down the charging balancing of the battery, and the balancing current Icurrent calculated can be used to dynamically adjust the balancing current.

[0052] The present application collects the instantaneous resistance and the current temperature of the battery when the current of the battery charging or discharging is suddenly changed in real time, calculates the average internal resistance according to the continuous instantaneous resistance, compensates the average internal resistance according to the current battery temperature to obtain the compensated internal resistance, and predicts the resistance aging of the compensated internal resistance to obtain the predicted internal resistance and the internal resistance change rate. The voltage difference threshold is calculated according to the compensated internal resistance and the internal resistance change rate, and the balancing current is calculated according to the compensated internal resistance, the predicted internal resistance and the current battery temperature. The battery charging or discharging is dynamically balanced according to the voltage difference threshold and / or the balancing current. After the internal resistance of the battery is compensated, the balancing is started according to the voltage difference threshold, and the balancing is dynamically adjusted by the calculated balancing current value, so that the false triggering rate of the balancing start and stop is reduced, the capacity attenuation rate of the battery pack is reduced by the internal resistance trend prediction dynamic adjustment strategy, and the accuracy and risk controllability of the dynamic balancing control in the charging or discharging process of the battery are improved. In addition, the present application supports various battery systems such as lithium iron phosphate and ternary lithium, and has a wide range of applications.

[0053] In step 110, referring to Figure 2 , the instantaneous resistance when the current of the battery charging or discharging is suddenly changed is collected in real time, specifically including:

[0054] 210, detecting whether the current is suddenly changed during the charging or discharging of the battery;

[0055] 220, if yes, capturing the voltage change rate and the current change rate of the battery, and obtaining the instantaneous resistance according to the quotient of the calculated voltage change rate and the current change rate;

[0056] 230, otherwise, no processing is performed.

[0057] In steps 210-230, the present application can specifically obtain the instantaneous resistance by the dynamic pulse method. Specifically, when the current of the battery charging or discharging is suddenly changed, such as ΔI>0.5C, the voltage change rate ΔV and the current change rate ΔI are captured, and the instantaneous internal resistance R is calculated by the formula internal The method of the present application uses the current transient response to reduce the steady-state error.

[0058] ​In step 110, the average internal resistance is calculated according to the continuous instantaneous resistance, specifically including: after obtaining N instantaneous resistances, the N instantaneous internal resistances are weighted and averaged to obtain the average internal resistance. In this embodiment, the average internal resistance is obtained by sliding window averaging. Specifically, the weighted average is taken in combination with the calculation results of the most recent N, for example, N = 10, instantaneous internal resistances, short-term fluctuations are smoothed, and long-term internal resistance change trends are reflected. The sliding window average calculation formula is: where R internal is the instantaneous internal resistance, and R current is the average internal resistance.

[0059] In step 120, the average internal resistance is temperature compensated to obtain the compensated internal resistance, specifically including: according to the preset internal resistance-temperature relationship curve, the average internal resistance is temperature compensated to obtain the compensated internal resistance, and the internal resistance-temperature relationship curve formula is: R comp = R current × (1 + α × (T current -T ref )), where R comp is the compensated internal resistance, R current is the average internal resistance, α is the temperature compensation coefficient, T current is the current battery temperature, and T ref is the reference battery temperature. In this embodiment, the internal resistance-temperature relationship curve under the state of health SOH of different batteries is established through experiments. The battery internal resistance is measured at -20℃, -10℃, 0℃, 15℃, 25℃, 35℃, 45℃, and 60℃. Taking the 25℃ internal resistance as the reference, the temperature compensation coefficient α at different temperature points is calculated. Then, the compensated internal resistance is calculated and obtained through the temperature compensation coefficient α and the difference between the current battery temperature and the reference battery temperature.

[0060] In step 120, referring to Figure 3 , the compensated internal resistance is resistance aging predicted to obtain the predicted internal resistance and the internal resistance change rate, specifically including:

[0061] 310, the predicted resistance is calculated according to the preset exponential function fitting decay curve and the sum of the initial internal resistance;

[0062] 320, the internal resistance change rate is calculated and obtained according to the internal resistance change rate formula, where the internal resistance change rate formula is:

[0063] dR / dt = (R predicted -R comp ) / △t,△t is the charging time or discharging time of the battery, R predicted is the predicted resistance, and dR / dt is the internal resistance change rate.

[0064] In steps 310-320, referring to Figure 6 , Figure 6The curves showing the change in battery internal resistance and state of health (SOH) over time are presented. Based on historical internal resistance data, an exponential function is used to fit the decay curve to calculate the predicted internal resistance and the rate of change of internal resistance, and to predict the future rate of change of internal resistance. The formula for calculating the predicted internal resistance can be R. predicted =R0+A(1-e kt ), where A(1-e kt The preset exponential function fitting decay curve is A(1-e^( ... kt The parameters A and k in the equation can be calculated from historical internal resistance data. Figure 6 In the example shown, A(1-e) kt ) can be 21.0(1-e -0.41t When R0 = 22.6 ohms, R predicted =22.6+21.0(1-e -0.41t ).from Figure 6 It can be seen that when the predicted resistance R predicted The larger the value, the lower the battery health. After obtaining the predicted internal resistance, the formula for the rate of change of internal resistance, dR / dt, can be used. predicted -R comp The rate of change of internal resistance is calculated using dR / dt. In a specific example, dR / dt can be equal to 0.0002 ohms / month.

[0065] In some optional implementations, the voltage difference threshold is calculated based on the compensated internal resistance and the rate of change of internal resistance. Specifically, this includes: calculating the voltage difference threshold using a voltage difference threshold calculation formula based on the compensated internal resistance and the rate of change of internal resistance. The voltage difference threshold calculation formula is as follows:

[0066] R0 is the initial resistance, K1 is the weight of the ratio of the current internal resistance to the initial internal resistance on the threshold, K2 is the weight of the rate of change of internal resistance on the threshold, and ΔV base The reference voltage difference is used. In a specific example, based on the change in internal resistance, the present invention can dynamically adjust the voltage difference threshold for switching on and off. In the above method, k1∈[0.1, 0.5], based on the fact that the internal resistance of an aged battery can reach 1.5 to 2 times the nominal value. k2∈[1.0, 5.0], based on the typical order of magnitude of the rate of change of internal resistance, such as 0.0001 to 0.001 ohms / month.

[0067] In some optional embodiments, the equalization current is calculated based on the compensated internal resistance, the predicted internal resistance, and the current battery temperature. Specifically, this includes: calculating the equalization current using a voltage difference threshold calculation formula, based on the compensated internal resistance, the predicted internal resistance, and the current battery temperature. Among them, I balance To balance the current, I maxFor the maximum allowable current, T max For the maximum permissible equilibrium temperature, T min For the minimum permissible equilibrium temperature, R fail This refers to the cell failure resistance. In this embodiment, the balancing current is limited in real time based on the compensated internal resistance and the current battery temperature using the method described above; wherein, R... fail T max T min According to the battery's parameter manual, R fail It can be twice R0. The current battery temperature is obtained in real time by a temperature sensor.

[0068] In some optional implementations, in the dynamic equalization control of battery charging or discharging based on voltage difference thresholds and / or equalization current, an equalization protection mechanism is also provided, specifically including:

[0069] The system can determine in real time whether the predicted internal resistance exceeds the preset internal resistance threshold. If the predicted internal resistance exceeds the preset internal resistance threshold, a battery alarm is triggered and dynamic equalization control is disabled. The preset internal resistance threshold can be twice R0. When the predicted internal resistance is greater than or equal to 2R0, an alarm is triggered and equalization control is disabled.

[0070] And / or, determine in real time whether the current battery temperature exceeds a preset temperature threshold. If the current battery temperature exceeds the preset temperature threshold, trigger a battery alarm and disable dynamic equalization control. The preset temperature threshold can be 60℃. When the current battery temperature is greater than or equal to 60℃, trigger an alarm and disable equalization control.

[0071] This invention can protect the battery's charging or discharging equalization control through any one or two of the above methods, so as to enable the battery to exit equalization control, or even disconnect charging or discharging.

[0072] Example 2:

[0073] Figure 4 An embodiment of a battery equalization control device based on internal resistance evolution according to the present invention is shown, which is used to implement the battery equalization control method based on internal resistance evolution in Embodiment 1. The battery equalization control device 400 based on internal resistance evolution includes an internal resistance acquisition module 410, a compensation and prediction module 420, an equalization calculation module 430, and an equalization processing module 440.

[0074] The internal resistance obtaining module 410 is configured to execute step 110 in Embodiment 1, and specifically comprises: detecting whether the current is mutated during the charging or discharging of the battery; if yes, capturing the voltage change rate and the current change rate of the battery, and obtaining the instantaneous internal resistance according to the quotient of the calculated voltage change rate and the current change rate; and if not, not performing processing. The average internal resistance is calculated according to the continuous instantaneous internal resistance, and specifically comprises: after N instantaneous internal resistances are continuously obtained, performing weighted average on the N instantaneous internal resistances to obtain the average internal resistance.

[0075] The compensation and prediction module 420 is configured to execute step 120 in Embodiment 1, and specifically comprises: performing temperature compensation on the average internal resistance to obtain the compensated internal resistance, and specifically comprises: performing temperature compensation on the average internal resistance according to a preset internal resistance-temperature relationship curve to obtain the compensated internal resistance, and the internal resistance-temperature relationship curve formula is R comp current = R current × (1 + α × (T ref - T comp )), wherein R current is the compensated internal resistance, R current is the average internal resistance, α is a temperature compensation coefficient, T ref is the current battery temperature, and T predicted is a reference battery temperature. The predicted internal resistance and the internal resistance change rate are obtained by performing resistance aging prediction on the compensated internal resistance, and specifically comprises: calculating the predicted internal resistance according to the sum of the preset exponential function fitting decay curve and the initial internal resistance; and calculating the internal resistance change rate according to the internal resistance change rate formula, wherein the internal resistance change rate formula is dR / dt = (R comp - R predicted ) / △t,△t is the charging time or the discharging time of the battery, R base is the predicted internal resistance, and dR / dt is the internal resistance change rate.

[0076] The balancing calculation module 430 is configured to execute step 130 in Embodiment 1, and specifically comprises: calculating the voltage difference threshold according to the compensated internal resistance and the internal resistance change rate, and specifically comprises: calculating the voltage difference threshold according to the compensated internal resistance and the internal resistance change rate through the voltage difference threshold calculation formula, wherein the voltage difference threshold calculation formula is: R0 is the initial internal resistance, K1 is the weight of the influence of the ratio of the current internal resistance to the initial internal resistance on the threshold, K2 is the weight of the influence of the internal resistance change rate on the threshold, and△V balance is the reference voltage difference. The balancing current is calculated according to the compensated internal resistance, the predicted internal resistance, and the current battery temperature, and specifically comprises: calculating the balancing current according to the compensated internal resistance, the predicted internal resistance, and the current battery temperature through the voltage difference threshold calculation formula, wherein, wherein I max is the balancing current, I max ​Tmax is the maximum allowed equalization temperature min Tmin is the minimum allowed equalization temperature fail R is the cell failure resistance.

[0077] The equalization processing module 440 is configured to perform step 140 in Embodiment 1, and specifically includes: after the voltage difference threshold and / or the equalization current are obtained, the voltage difference threshold and / or the equalization current can be input to a battery management system of the current battery to adjust the voltage difference threshold or the equalization current in real time. Specifically, the battery can be boosted and discharged for equalization or stepped down and charged for equalization by a DC-DC module, and the equalization current Icurrent is calculated to achieve dynamic adjustment of the equalization current.

[0078] Embodiment 3:

[0079] Figure 5 The structure diagram of the embodiment of the battery equalization control device based on resistance evolution of the application is shown, and the specific implementation of the battery equalization control device based on resistance evolution is not limited by the specific embodiments of the application.

[0080] As Figure 5 shown, the simulation device can include: a processor 502, a communications interface 504, a memory 506, and a communications bus 508.

[0081] The processor 502, the communications interface 504, and the memory 506 communicate with each other through the communications bus 508. The communications interface 504 is configured to communicate with network elements such as clients or other servers. The processor 502 is configured to execute the program 510, and specifically can execute the related steps in the above-mentioned embodiments of the battery equalization control method based on resistance evolution.

[0082] Specifically, the program 510 can include program code, which includes computer executable instructions.

[0083] The processor 502 can be a central processing unit CPU, or an application specific integrated circuit ASIC, or one or more integrated circuits configured to implement embodiments of the application. The one or more processors included in the container structure simulation device based on substructure can be the same type of processor, such as one or more CPUs; or can be different types of processors, such as one or more CPUs and one or more ASICs.

[0084] a memory 506, storing a program 510. The memory 506 can contain a high-speed RAM memory and can also include a non-volatile memory, such as at least one disk memory.

[0085] The program 510 can specifically be called by the processor 502 to cause the battery equalization control device based on internal resistance evolution to perform the steps 110-140 of the embodiment 1.

[0086] The algorithms or displays presented herein are not inherently related to any particular computer, virtual system, or other apparatus. Furthermore, embodiments of the present application are not described with reference to any particular programming language. It is appreciated that a variety of programming languages can be used to implement the teachings of the application as described herein.

[0087] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the application can be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been described in detail in order to avoid obscuring the understanding of this description. Also, the description is presented in terms of exemplary embodiments, which are shown and described as overbroad as possible so as to encompass numerous alternatives, modifications and equivalents. Likewise, the specific

[0088] It will be appreciated by persons skilled in the art that modules in the devices of the embodiments can be adapted and placed in one or more devices other than the embodiments. Modules or units or components in the embodiments can be combined into one module or unit or component and further can be divided into sub-modules or sub-units or sub-components. Except that at least some of such features and / or processes or units are mutually exclusive.

[0089] It is to be noted that the above-mentioned embodiments illustrate rather than limit the application, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The application can be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the system claims enumerating several means, several of these means can be embodied by one and the same item of hardware. The use of the word at, when, wherein in the claims is not to be interpreted as being confined to a strictly logical or temporal relationship. The steps of the methods presented can be carried out in an order different from the order presented.

Claims

1. A battery equalization control method based on internal resistance evolution, characterized in that, The method comprises: Real-time acquisition of instantaneous resistance when current mutation occurs during battery charging or discharging, current battery temperature, calculation of average internal resistance according to continuous instantaneous resistance; According to the current battery temperature, the average internal resistance is temperature compensated to obtain the compensated internal resistance, and the compensated internal resistance is resistance aging prediction to obtain the predicted internal resistance and the internal resistance change rate; According to the compensated internal resistance and the internal resistance change rate, a voltage difference threshold is calculated, and according to the compensated internal resistance, the predicted internal resistance and the current battery temperature, an equalization current is calculated; According to the voltage difference threshold and / or equalization current, dynamic equalization control is performed on the battery charging or discharging.

2. The battery equalization control method based on internal resistance evolution according to claim 1, characterized in that, Real-time acquisition of instantaneous resistance when current mutation occurs during battery charging or discharging, specifically including: During the battery charging or discharging process, it is detected whether the current is mutated; If yes, the voltage change rate and the current change rate of the battery are captured, and the instantaneous resistance is obtained according to the quotient of the calculated voltage change rate and the current change rate; Otherwise, no processing is performed.

3. The battery equalization control method based on internal resistance evolution according to claim 2, characterized in that, The average internal resistance is calculated according to the continuous instantaneous resistance, specifically including: After obtaining N instantaneous resistances, the N instantaneous internal resistances are weighted and averaged to obtain the average internal resistance.

4. The battery equalization control method based on internal resistance evolution according to claim 1, characterized in that, The average internal resistance is temperature compensated to obtain the compensated internal resistance, specifically including: According to a preset internal resistance-temperature relation curve, the average internal resistance is temperature compensated to obtain a compensated internal resistance, the internal resistance-temperature relation curve formula is: R comp = R current ×(1+α×(T current -T ref )) , wherein R comp is the compensated internal resistance, R current is the average internal resistance, α is a temperature compensation coefficient, T current is a current battery temperature, and T ref is a reference battery temperature.

5. The battery equalization control method based on internal resistance evolution according to claim 4, characterized in that, The compensated internal resistance is resistance aging prediction to obtain the predicted internal resistance and the internal resistance change rate, specifically including: According to the sum of the preset exponential function fitting decay curve and the initial internal resistance, the predicted resistance is calculated; According to the internal resistance change rate formula, the internal resistance change rate is calculated, wherein the internal resistance change rate formula is: dR / dt = (R predicted -R comp ) / △t,△t is the charging time or discharging time of the battery, R predicted is the predicted resistance, and dR / dt is the internal resistance change rate.

6. The battery equalization control method based on internal resistance evolution according to claim 5, characterized in that, According to the compensated internal resistance and the internal resistance change rate, a voltage difference threshold is calculated, specifically including: The voltage difference threshold is calculated according to the compensation internal resistance and the internal resistance change rate through a voltage difference threshold calculation formula, wherein the voltage difference threshold calculation formula is: R0 is an initial resistance, K1 is a weight of the ratio of the current internal resistance to the initial internal resistance on the threshold, K2 is a weight of the internal resistance change rate on the threshold, and AV base is a reference voltage difference.

7. The battery equalization control method based on internal resistance evolution according to claim 5, characterized in that, According to the compensated internal resistance, the predicted internal resistance and the current battery temperature, an equalization current is calculated, specifically including: The equalization current is calculated according to the compensation internal resistance, the predicted internal resistance and the current battery temperature through a voltage difference threshold calculation formula, wherein, I balance is the equalization current, I max is the maximum allowed current, T max is the maximum allowed equalization temperature, T min is the minimum allowed equalization temperature, R fail is the cell failure resistance.

8. The battery equalization control method based on internal resistance evolution according to claim 1, characterized in that, In the dynamic equalization control of the battery charging or discharging according to the voltage difference threshold and / or equalization current, it further includes: Real-time judgment of whether the predicted internal resistance exceeds the preset internal resistance threshold, when the predicted internal resistance exceeds the preset internal resistance threshold, triggering the battery alarm and prohibiting the dynamic equalization control; And / or, real-time judgment of whether the current battery temperature exceeds the preset temperature threshold, when the current battery temperature exceeds the preset temperature threshold, triggering the battery alarm and prohibiting the dynamic equalization control.

9. A battery equalization control device based on internal resistance evolution, characterized by, The device comprises: An internal resistance acquisition module for real-time acquisition of instantaneous resistance when current mutation occurs during battery charging or discharging, current battery temperature, calculation of average internal resistance according to continuous instantaneous resistance; A compensation and prediction module for temperature compensation calculation of the average internal resistance according to the current battery temperature to obtain the compensated internal resistance, and resistance aging prediction of the compensated internal resistance to obtain the predicted internal resistance and the internal resistance change rate; An equalization calculation module for calculating a voltage difference threshold according to the compensated internal resistance and the internal resistance change rate, and calculating an equalization current according to the compensated internal resistance, the predicted internal resistance and the current battery temperature; And an equalization processing module for dynamic equalization control of the battery charging or discharging according to the voltage difference threshold and / or equalization current.

10. A battery equalization control device based on internal resistance evolution, characterized by, Including: a processor, a memory, a communication interface, and a communication bus, which are used for communication among each other through the communication bus; the memory is used for storing at least one executable instruction, which makes the processor execute the operation of the battery equalization control method based on internal resistance evolution as claimed in any one of claims 1-8.

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