Polarization voltage determination method and device, vehicle and equipment

Abstract

The invention relates to a polarization voltage determination method and device, a vehicle and equipment, and relates to the technical field of batteries, and the method comprises the steps: obtaining the battery parameters of a target battery; the battery parameters comprise charging and discharging parameters of the target battery in a charging and discharging state and standing time of the target battery in a standing state; based on the battery parameters, determining an electrochemical polarization voltage and an ohmic polarization voltage of the target battery; and determining the polarization voltage of the target battery based on the electrochemical polarization voltage and the ohmic polarization voltage. Therefore, the polarization voltage of the battery can be accurately calculated.

Description

Technical Field

[0001] The present application relates to the field of battery technology, in particular to the field of battery polarization voltage technology, and specifically to a method, device, vehicle and equipment for determining polarization voltage. Background Art

[0002] The terminal voltage collected by the battery management system (BMS) includes the battery polarization voltage and equilibrium voltage. Among them, the equilibrium voltage, as a direct reflection of the thermodynamic properties of the electrode material, is the voltage value of the battery in theory without external interference. The polarization voltage represents the deviation between the terminal voltage and the equilibrium voltage of the battery under actual working conditions. Accurate calculation of the polarization voltage helps the BMS to more accurately grasp the actual working state of the battery, thereby achieving accurate management of the battery. However, since the polarization voltage is affected by many factors, it is difficult to calculate the polarization voltage of the battery.

[0003] A related art proposes a method for calculating the polarization voltage of a battery by multiplying the current by the sum of the internal resistance increments. However, the polarization voltage calculated by this method increases linearly with time, which is inconsistent with the actual result.

[0004] Another related technology proposes a method based on a polarization voltage database lookup table to obtain the polarization voltage of the battery pack at the time of power failure. This solution first establishes a polarization voltage database and obtains the polarization voltage value at that moment by looking up the table. However, this method is too dependent on the offline calibration database and the accuracy of the state of charge (SOC). Summary of the invention

[0005] The present application provides a method, device, vehicle and equipment for determining polarization voltage, so as to at least solve the technical problem that it is difficult to accurately calculate the polarization voltage of a battery in the related art. The technical solution of the present application is as follows: According to the first aspect provided by the present application, a method for determining a polarization voltage is provided, including: obtaining battery parameters of a target battery; the battery parameters include charge and discharge parameters of the target battery in a charge and discharge state and a rest time in a rest state; based on the battery parameters, determining the electrochemical polarization voltage and ohmic polarization voltage of the target battery; based on the electrochemical polarization voltage and the ohmic polarization voltage, determining the polarization voltage of the target battery.

[0006] According to the above-mentioned technical means, the present application can comprehensively analyze the working state and performance of the battery, as well as the internal electrochemical reactions and resistance changes during the charging and discharging process based on the battery parameters of the target battery (including charging and discharging parameters and standing time), so as to accurately determine the electrochemical polarization voltage and ohmic polarization voltage of the target battery.

[0007] In one possible implementation, the electrochemical polarization voltage includes: an electrochemical polarization accumulation voltage generated by the target battery in a charge and discharge state and an electrochemical polarization elimination voltage generated by the target battery in a static state.

[0008] According to the above technical means, the present application can divide the electrochemical polarization voltage into electrochemical polarization accumulation voltage and electrochemical polarization elimination voltage according to the construction process, so as to accurately calculate the electrochemical polarization voltage of the target battery.

[0009] In one possible implementation, the electrochemical polarization accumulation voltage is determined as follows: based on a first mapping relationship, a first target polarization parameter matching the charge and discharge parameters is determined; the first mapping relationship includes: a plurality of first polarization parameters corresponding one-to-one to a plurality of charge and discharge parameters; the first polarization parameter is a polarization parameter actually measured by the battery during the electrochemical polarization accumulation process; based on the charge and discharge parameters and the first target polarization parameter, the electrochemical polarization accumulation voltage is determined.

[0010] According to the above technical means, the present application can pre-establish a first mapping relationship through measured data, so as to directly find the first target polarization parameter that matches the charge and discharge parameters, so as to further accurately calculate the electrochemical polarization accumulation voltage based on the first target polarization parameter and the charge and discharge parameters.

[0011] In one possible implementation, the first polarization parameter includes a rate of electrochemical polarization accumulation of the battery.

[0012] According to the above technical means, the present application can accurately reflect the accumulation speed of polarization phenomenon of the battery during the charging and discharging process through the rate of electrochemical polarization accumulation, thereby accurately calculating the polarization voltage generated by the battery during the charging and discharging process.

[0013] In one possible implementation, the electrochemical polarization elimination voltage is determined in the following manner: based on a second mapping relationship, a second target polarization parameter matching the standing time is determined; the second mapping relationship includes second polarization parameters corresponding one-to-one to multiple standing times; the second polarization parameter is a polarization parameter actually measured by the battery during the electrochemical polarization elimination process; based on the standing time and the second target polarization parameter, the electrochemical polarization elimination voltage is determined.

[0014] According to the above-mentioned technical means, the present application can establish a second mapping relationship and directly find the second target polarization parameter that matches the battery according to the standing time. This mapping relationship of the measured data can reduce the error of the theoretical model or empirical formula and improve the accuracy of determining the electrochemical polarization elimination voltage.

[0015] In a possible implementation, the second polarization parameter includes: a rate of elimination of electrochemical polarization of the battery, and at least one of a time weight, a charge and discharge voltage correction factor, and a polarization voltage correction factor.

[0016] According to the above technical means, the present application can accurately reflect the disappearance rate of the polarization phenomenon of the battery during the static process through a second polarization parameter that includes the rate of electrochemical polarization elimination, thereby more accurately determining the electrochemical polarization elimination voltage, and considering the influence of the static time on the polarization elimination through the time weight, which helps to more reasonably evaluate the elimination of the polarization voltage. In addition, the charge and discharge voltage correction factor and the polarization voltage correction factor consider the influence of the voltage change during the charge and discharge process on the polarization voltage, further improving the accuracy of the polarization voltage determination.

[0017] In one possible implementation, the charge and discharge parameters include the charge and discharge current of the target battery; and determining the ohmic polarization voltage includes: determining the ohmic polarization voltage based on the charge and discharge current and ohmic resistance of the target battery.

[0018] According to the above technical means, the present application can more accurately calculate the ohmic polarization voltage by directly considering the charge and discharge current and the ohmic resistance, thereby avoiding interference from other factors.

[0019] According to the second aspect provided by the present application, a polarization voltage determination device is provided, including: an acquisition unit and a determination unit; the acquisition unit is used to acquire battery parameters of a target battery; the battery parameters include charge and discharge parameters of the target battery in a charge and discharge state and a rest time in a rest state; the determination unit is used to determine the electrochemical polarization voltage and ohmic polarization voltage of the target battery based on the battery parameters; the determination unit is also used to determine the polarization voltage of the target battery based on the electrochemical polarization voltage and the ohmic polarization voltage.

[0020] In one possible implementation, the determination unit is specifically used to: determine a first target polarization parameter that matches the charge and discharge parameters based on a first mapping relationship; the first mapping relationship includes: multiple first polarization parameters that correspond one-to-one to multiple charge and discharge parameters; the first polarization parameter is a polarization parameter actually measured by the battery during the electrochemical polarization accumulation process; determine the electrochemical polarization accumulation voltage based on the charge and discharge parameters and the first target polarization parameter.

[0021] In one possible implementation, the determination unit is specifically used to: determine a second target polarization parameter that matches the standing time based on a second mapping relationship; the second mapping relationship includes second polarization parameters that correspond one-to-one to multiple standing times; the second polarization parameter is a polarization parameter actually measured by the battery during the electrochemical polarization elimination process; and determine the electrochemical polarization elimination voltage based on the standing time and the second polarization parameter.

[0022] In a possible implementation, the determination unit is specifically configured to determine the ohmic polarization voltage based on the charge and discharge current and the ohmic resistance of the target battery.

[0023] According to a third aspect provided by the present application, a vehicle is provided, the vehicle comprising the polarization voltage determination device in the second aspect.

[0024] According to the fourth aspect provided by the present application, an electronic device is provided, comprising: a processor; a memory for storing processor executable instructions; wherein the processor is configured to execute instructions to implement the method of the above-mentioned first aspect and any possible implementation manner thereof.

[0025] According to the fifth aspect provided by the present application, a computer-readable storage medium is provided. When the instructions in the computer-readable storage medium are executed by a processor of an electronic device, the electronic device is enabled to execute the method in the above-mentioned first aspect and any possible implementation method thereof.

[0026] According to the sixth aspect provided by the present application, a computer program product is provided, the computer program product comprising computer instructions, and when the computer instructions are executed on an electronic device, the electronic device executes the method of the above-mentioned first aspect and any possible implementation manner thereof.

[0027] It should be noted that the technical effects brought about by any implementation method in the second to sixth aspects can refer to the technical effects brought about by the corresponding implementation method in the first aspect, and will not be repeated here.

[0028] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application, and do not constitute an improper limitation on the present application.

[0030] Figure 1 is a schematic diagram of a hardware structure of a vehicle according to an exemplary embodiment; Figure 2 is a flow chart of a method for determining polarization voltage according to an exemplary embodiment; Figure 3 is a schematic diagram of polarization voltage under a charging condition according to an exemplary embodiment; Figure 4 is a schematic diagram of a fitting result according to an exemplary embodiment; Figure 5 is another schematic diagram of fitting results according to an exemplary embodiment; Figure 6 is a schematic diagram showing a comparison of polarization voltages under a discharge condition according to an exemplary embodiment; Figure 7 is a schematic diagram showing a comparison result of polarization voltage under a discharge condition according to an exemplary embodiment; Figure 8 is a schematic diagram showing a comparison of polarization voltages under a charging condition according to an exemplary embodiment; Fig. 9 is a schematic diagram showing a comparison result of polarization voltage under a charging condition according to an exemplary embodiment; Fig.10 is a schematic diagram of a polarization voltage determination process according to an exemplary embodiment; Fig.11 is a block diagram of a polarization voltage determination device according to an exemplary embodiment; Fig.12 It is a block diagram of an electronic device according to an exemplary embodiment. DETAILED DESCRIPTION

[0031] In order to enable ordinary persons in the art to better understand the technical solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the attached claims.

[0033] First, some of the terms and related technologies involved in this application are explained to facilitate understanding by those skilled in the art.

[0034] The terminal voltage collected by the BMS includes polarization voltage and balance voltage.

[0035] Among them, the equilibrium voltage, as a direct reflection of the thermodynamic properties of the electrode material, is the theoretical voltage value of the battery without external interference. The polarization voltage of the vehicle power battery refers to the potential difference caused by the polarization of the battery. Polarization will cause partial energy loss in the battery, which is usually divided into ohmic polarization and electrochemical polarization. The polarization voltage affects the terminal voltage of the battery, thereby interfering with the accurate measurement and estimation of SOC.

[0036] Accurate calculation of polarization voltage helps BMS to more accurately grasp the actual working status of the battery, thereby achieving accurate management of the battery. However, since polarization voltage is affected by many factors, it is difficult to calculate the polarization voltage of the battery.

[0037] A related art proposes a method for calculating the polarization voltage of a battery by multiplying the current by the sum of the internal resistance increments. However, the polarization voltage calculated by this method increases linearly with time, which is inconsistent with the actual result.

[0038] Another related technology proposes a method based on a polarization voltage database lookup table to obtain the polarization voltage of the battery pack at the time of power-off. This solution first establishes a polarization voltage database and obtains the polarization voltage value at that moment by looking up the table. However, this method is too dependent on the offline calibration database and the accuracy of SOC.

[0039] As mentioned in the background technology, in order to solve the problem that it is difficult to accurately measure in the related art, a polarization voltage determination method is provided, which can obtain the battery parameters of the target battery, and determine the electrochemical polarization voltage and ohmic polarization voltage of the target battery based on the battery parameters, so as to further determine the polarization voltage of the target battery based on the electrochemical polarization voltage and the ohmic polarization voltage. Among them, the battery parameters include the charge and discharge parameters of the target battery in the charge and discharge state and the rest time in the rest state.

[0040] Based on this, the present application can comprehensively analyze the working state and performance of the battery, as well as the internal electrochemical reactions and resistance changes during the charging and discharging process based on the battery parameters of the target battery (including charging and discharging parameters and standing time), thereby accurately determining the electrochemical polarization voltage and ohmic polarization voltage of the target battery.

[0041] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0042] The polarization voltage determination method provided in the embodiment of the present application can be applied in a vehicle. A vehicle can also be referred to as a vehicle, a mobile carrier, an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a fuel cell vehicle (FCV), an autonomous vehicle, an intelligent and connected vehicle (ICV), a driverless vehicle, etc.

[0043] In the embodiments of the present application, the vehicle may be a sedan, a sport utility vehicle (SUV), a truck, an electric vehicle, a motorcycle, a tricycle, a special vehicle (such as an ambulance, a fire truck, a police car, etc.), an unmanned taxi, an intelligent networked bus, an automatic driving logistics vehicle, an electric truck, etc. In addition, the method is also applicable to various special vehicles, such as agricultural vehicles, mining vehicles, forestry vehicles, airport vehicles, port vehicles, etc. This application does not impose specific restrictions on this.

[0044] Figure 1 A schematic diagram of the hardware structure of a vehicle is shown according to an exemplary embodiment.

[0045] In a possible implementation, the vehicle 100 may include a polarization voltage determination device 101 , a data acquisition device 102 , and a target battery 103 .

[0046] Optionally, Figure 1 A communication connection can be established between the polarization voltage determination device 101 and the data acquisition device 102. A connection can be established between the data acquisition device 102 and the target battery 103. A connection can be established between the polarization voltage determination device 101 and the target battery 103.

[0047] In practical applications, the polarization voltage determination device 101 may be communicatively connected to one or more data acquisition devices 102 .

[0048] For ease of understanding, the present application takes the communication connection between a polarization voltage determination device 101 and a data acquisition device 102 as an example for explanation.

[0049] Optional, Figure 1The polarization voltage determination device 101 and the data acquisition device 102 may be functional modules integrated into the same device, or may be devices independently arranged from each other. This application does not impose any limitation on this.

[0050] It is easy to understand that when the polarization voltage determination device 101 and the data acquisition device 102 are functional modules integrated in the same device, the communication between the polarization voltage determination device 101 and the data acquisition device 102 is the communication between the modules inside the device. In this case, the communication process between the two is the same as the "communication process when the polarization voltage determination device 101 and the data acquisition device 102 are independently set".

[0051] For ease of understanding, the present application is mainly explained by taking the example that the polarization voltage determination device 101 and the data acquisition device 102 are independently configured.

[0052] Figure 1 The data acquisition device 102 in the apparatus can acquire the battery parameters of the target battery 103. The polarization voltage determination device 101 can obtain the battery parameters acquired by the data acquisition device 102, and determine the electrochemical polarization voltage and ohmic polarization voltage of the target battery based on the battery parameters, and determine the polarization voltage of the target battery based on the electrochemical polarization voltage and ohmic polarization voltage.

[0053] Optionally, Figure 1 The polarization voltage determination device 101 in the embodiment may be a terminal, a server, or other types of electronic devices. Figure 1 What is shown in the figure is only an example of the device form of the polarization voltage determination device 101 and does not constitute a limitation thereto.

[0054] In the case where the polarization voltage determination device 101 is a terminal, the terminal may be a device for providing voice and / or data connectivity to a user, a handheld device with a wireless connection function, or other processing devices connected to a wireless modem. The terminal may communicate with one or more core networks via a radio access network (RAN). The terminal may be a mobile terminal, such as a computer with a mobile terminal, or a mobile device built into the vehicle 100, which exchanges language and / or data with a radio access network, such as a mobile phone, a tablet computer, a laptop computer, a netbook, a personal digital assistant (PDA). This application does not impose any restrictions on this.

[0055] When the polarization voltage determination device 101 is a server, the server may be a single server, or a server cluster composed of multiple servers. In some implementations, the server cluster may also be a distributed cluster. This application does not impose any restrictions on this.

[0056] It should be noted that the structure illustrated in the embodiment of the present application does not constitute a limitation on the vehicle 100. It may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0057] For ease of understanding, the polarization voltage determination method provided in the present application is specifically introduced below with reference to the accompanying drawings.

[0058] Figure 2 is a flow chart of a method for determining polarization voltage according to an exemplary embodiment. Figure 2 As shown, the polarization voltage determination method includes the following steps: S201-S203.

[0059] S201. Obtain battery parameters of a target battery.

[0060] The battery parameters may include the charge and discharge parameters of the target battery in the charge and discharge state and the rest time in the rest state. The rest state is a state in which the current of the target battery is zero. The charge and discharge parameters of the target battery may include at least one of the charging current, the charging voltage, the battery temperature during charging, the discharging current, the discharging voltage, and the battery temperature during discharging.

[0061] In one possible implementation, the polarization voltage determination device can measure and record the voltage, current, battery temperature and other data of the target battery in the charging and discharging state as charging and discharging parameters. The polarization voltage determination device can also detect and record the rest time of the target battery in the static state. When the current of the target battery drops to zero, that is, the target battery is in a non-working state, the polarization voltage determination device can start timing and accurately record the rest time of the battery.

[0062] Optionally, the polarization voltage determination device may periodically acquire the battery parameters of the target battery, or may acquire the battery parameters of the target battery at any time. This application does not impose any specific limitation on this.

[0063] S202: Determine the electrochemical polarization voltage and ohmic polarization voltage of the target battery based on the battery parameters.

[0064] The electrochemical polarization voltage includes: the electrochemical polarization accumulation voltage generated by the target battery in the charge and discharge state and the electrochemical polarization elimination voltage generated by the target battery in the static state.

[0065] For example, Figure 3 As shown, Figure 3 is a schematic diagram of polarization voltage under a charging condition according to an exemplary embodiment.

[0066] When the time t is less than t1 second (second, s), the charging current is 0 ampere (ampere, A), at which time the target battery is in equilibrium and the voltage is the equilibrium voltage. When the time t is at t1s, the target battery starts to be charged with a constant current based on a current of 20A. At this time, the ohmic polarization responds instantaneously and the voltage suddenly changes to the ohmic polarization voltage. When time t is greater than t1s and less than t2s, the charge transfer polarization and mass transfer polarization of the target battery respond in sequence until the mass transfer polarization tends to be stable, that is, the target battery is in the electrochemical polarization accumulation process (charge and discharge process), and the electrochemical polarization accumulation voltage in the electrochemical polarization accumulation process from t1s to t2s is When time t is equal to t2s, constant current charging ends. At this time, the target battery is in a static state. The polarization voltage generated by the target battery in a static state is called the electrochemical polarization elimination voltage of the electrochemical polarization elimination process. .

[0067] Among them, charge transfer polarization refers to the polarization phenomenon caused by the inability of the charge transfer speed on the electrode to keep up with the current change speed during the operation of the battery. This is mainly due to the limitation of the electrode reaction kinetics, which causes the electrode potential to deviate from the equilibrium potential. In the process of establishing electrochemical polarization, the charge transfer polarization response time is about 1ms, and the charge transfer polarization tends to stabilize after 1s. The mass transfer polarization response time is sub-second, and the stabilization time of mass transfer polarization under constant current conditions is minute-level.

[0068] Mass transfer polarization refers to the polarization phenomenon caused by the change in concentration of reactants or products near the electrode, which is mainly caused by the fact that the material transfer rate cannot keep up with the electrode reaction rate.

[0069] In one possible implementation, the polarization voltage determination device may determine a first target polarization parameter that matches the charge and discharge parameters based on the first mapping relationship. The polarization voltage determination device may determine the electrochemical polarization accumulation voltage based on the charge and discharge parameters and the first target polarization parameter. The specific implementation method of the polarization voltage determination device determining the electrochemical polarization accumulation voltage may refer to S301-S302 below.

[0070] In another possible implementation, the polarization voltage determination device may determine a second target polarization parameter that matches the rest time based on the second mapping relationship. The polarization voltage determination device may determine the electrochemical polarization elimination voltage based on the rest time and the first target polarization parameter. The specific implementation method of the polarization voltage determination device determining the electrochemical polarization elimination voltage may refer to S401-S402 below.

[0071] In a possible implementation, the polarization voltage determining device determines the ohmic polarization voltage based on the charge and discharge current and ohmic resistance of the target battery.

[0072] Among them, ohmic resistance can be used to characterize the resistance formed by the material itself and the contact part in the target battery due to the resistance to the current. Ohmic resistance can reflect the resistance encountered when the current is transmitted inside the battery. Ohmic resistance can be obtained through AC impedance technology, multimeter direct measurement method and other methods.

[0073] It should be noted that when the target battery starts to charge, the ohmic polarization will respond instantaneously, so it can be considered that the relationship between the ohmic polarization voltage and time can be ignored. The ohmic polarization voltage can satisfy the following first formula:

[0074] in, It can be used to characterize the ohmic polarization voltage of the target battery. Can be used to characterize the ohmic resistance of the target battery. It can be used to characterize the charge and discharge current of the target battery. The current is positive during charging and negative during discharging.

[0075] S203. Determine the polarization voltage of the target battery based on the electrochemical polarization voltage and the ohmic polarization voltage.

[0076] In one possible implementation, the polarization voltage determining device may determine the sum of the electrochemical polarization voltage and the ohmic polarization voltage as the polarization voltage of the target battery.

[0077] Exemplarily, the polarization voltage of the target battery satisfies the following second formula:

[0078] in, It can be used to characterize the polarization voltage of the target battery. It can be used to characterize the ohmic polarization voltage of the target battery. It can be used to characterize the electrochemical polarization accumulation voltage. It can be used to characterize the electrochemical polarization elimination voltage.

[0079] In one possible implementation, the polarization voltage determining device may determine the SOC value of the target battery based on the polarization voltage of the target voltage.

[0080] Specifically, the polarization voltage determining device can determine the terminal voltage of the target battery. The polarization voltage determining device can determine the equilibrium voltage of the target battery based on the polarization voltage and terminal voltage of the target battery. The polarization voltage determining device can determine the SOC value of the target battery based on the equilibrium voltage of the target battery. The polarization voltage, terminal voltage and equilibrium voltage of the target battery satisfy the following third formula:

[0081] in, It can be used to characterize the terminal voltage. V0 can be used to characterize the equilibrium voltage. Can be used to characterize polarization voltage.

[0082] Based on the above technical solution, the present application can comprehensively analyze the working state and performance of the battery, as well as the internal electrochemical reactions and resistance changes during the charging and discharging process based on the battery parameters of the target battery (including charging and discharging parameters and standing time), thereby accurately determining the electrochemical polarization voltage and ohmic polarization voltage of the target battery.

[0083] In some embodiments, in order to determine the electrochemical polarization accumulation voltage of the target battery, the polarization voltage determination method provided in the present application further includes the following steps: S301-S302.

[0084] S301. Determine a first target polarization parameter that matches a charge and discharge parameter based on a first mapping relationship.

[0085] The first mapping relationship may include: a plurality of first polarization parameters corresponding to the plurality of charge and discharge parameters. The first polarization parameter may be a polarization parameter actually measured by the battery during the electrochemical polarization accumulation process. The battery may be a battery of the same model as the target battery.

[0086] In one possible implementation, the first polarization parameter may include a polarization factor. The polarization factor may be used to characterize the rate of electrochemical polarization accumulation of the battery. In one possible implementation, the polarization voltage determination device may determine the first polarization parameter based on the following steps.

[0087] S3001. Establish an experimental test table.

[0088] As shown in Table 1, Table 1 shows the experimental test table.

[0089] Table 1

[0090] Among them, T1, T2, T3, and T4 can be used to characterize the battery temperature, and I1, I2, I3, and I4 can be used to characterize the current.

[0091] It should be noted that the parameters shown in Table 1 do not constitute a limitation on the parameters in the experimental test table. The experimental test table may include more or fewer parameters than those in Table 1. The following steps S3002-S3012 are steps embodied in combination with Table 1. When Table 1 is changed, the parameters involved in steps S3002-S3012 should also correspond to Table 1.

[0092] S3002. Adjust the temperature to T1 and let it stand for 2 hours.

[0093] S3003 . Discharge the target battery based on the first constant current until the voltage of the target battery is at a cut-off voltage.

[0094] Optionally, the first constant current can be set according to actual needs. The first constant current can be 0.5 coulomb (C) or 1C. This application does not impose any specific restrictions on this.

[0095] S3004 , charging the target battery with a first constant current until the SOC of the target battery reaches X1.

[0096] S3005: Leave the target battery to rest for a first preset time period.

[0097] Optionally, the first preset duration can be set according to actual needs. The first preset duration can be 2 hours or 3 hours. This application does not make specific restrictions on this.

[0098] S3006, charging the target battery for a second preset time using I1 in the experimental test table.

[0099] Optionally, the second preset time length can be set according to actual needs. The second preset time length can be 5 minutes or 10 minutes. This application does not make specific restrictions on this.

[0100] S3007 , leaving the target battery to rest for a third preset time period.

[0101] Optionally, the third preset time length can be set according to actual needs. The third preset time length can be 1 hour or 3 hours. This application does not make specific restrictions on this.

[0102] S3008. Charge the target battery for a fourth preset time using I1 in the experimental test table.

[0103] Optionally, the fourth preset time length can be set according to actual needs. The fourth preset time length can be 5 minutes or 10 minutes. This application does not make specific restrictions on this.

[0104] S3009, leaving the target battery to rest for a fifth preset time period.

[0105] Optionally, the fifth preset time length can be set according to actual needs. The fifth preset time length can be 1 hour or 2 hours. This application does not make specific restrictions on this.

[0106] S3010. Adjust the current to I2, I3, I4 in the experimental test table, and repeat steps S3006-S3009.

[0107] S3011. Repeat steps S3004-S3010, and replace SOC with x2, x3, x4, ..., 100%.

[0108] S3012. Set the ambient temperature to T2, T3, and T4 in the experimental test table respectively, and repeat S3002-S3012.

[0109] S3013. Based on the following fourth formula, the charge and discharge parameters and polarization voltage values ​​obtained by the test are fitted to obtain the first polarization parameters corresponding to the charge and discharge parameters.

[0110]

[0111] in, It can be used to characterize the electrochemical polarization accumulation voltage. , It can be used to characterize the polarization factor, that is, the first target polarization parameter. α and β can be used to characterize the transfer coefficient, which is the weight of charge transfer polarization and mass transfer polarization. It can be used to characterize the base of natural logarithms. I can be used to characterize the charge and discharge current, the current is positive when charging and negative when discharging. R can be used to characterize the gas constant, which can be 8.314. T can be used to characterize the battery temperature.

[0112] For example, Figure 4 As shown, Figure 4 is a schematic diagram of a fitting result according to an exemplary embodiment. Figure 4 The measured polarization accumulation voltage curve and the fitted polarization accumulation voltage curve determined based on the fourth formula are included. Figure 4 The horizontal axis is used to represent time, using seconds (s) as the unit of measurement. The vertical axis is used to represent polarization voltage, using volts (V) as the unit of measurement.

[0113] Exemplarily, based on the fourth formula, the charge and discharge parameters and polarization voltage values ​​obtained by the test are fitted to obtain the first polarization parameter corresponding to the charge and discharge parameters: =0.0561, =0.02367.

[0114] In one possible implementation, based on S3002-S3013, the present application can determine a first polarization parameter of the target battery under multiple charge and discharge parameters.

[0115] Exemplarily, in combination with Table 1, as shown in Table 2, Table 2 shows the first polarization parameters corresponding to each of the multiple charge and discharge parameters in Table 1.

[0116] Table 2

[0117] Exemplarily, in combination with Table 1, the first polarization parameter corresponding to the charge and discharge parameters T1 and I1 is parameter 1, or the first polarization parameter corresponding to the charge and discharge parameters T2 and I1 is parameter 2.

[0118] S302: Determine an electrochemical polarization accumulation voltage based on the charge and discharge parameters and the first target polarization parameter.

[0119] In one possible implementation, the charge and discharge parameters, the first target polarization parameter, and the electrochemical polarization accumulation voltage satisfy the fourth formula in S301.

[0120] Exemplarily, in combination with the example in S301, the first target polarization parameter is =0.0561, =0.02367. The following fifth formula is satisfied between the charge and discharge parameters, the first target polarization parameter and the electrochemical polarization accumulation voltage:

[0121] Based on this, the present application can pre-establish a first mapping relationship through measured data, so as to directly find the first target polarization parameter that matches the charge and discharge parameters, so as to further accurately calculate the electrochemical polarization accumulation voltage based on the first target polarization parameter and the charge and discharge parameters.

[0122] In some examples, in order to determine the electrochemical polarization elimination voltage, the polarization voltage determination method provided in the present application further includes the following steps: S401-S402.

[0123] S401. Determine a second target polarization parameter matching a rest time based on a second mapping relationship.

[0124] The second mapping relationship may include a second polarization parameter corresponding to a plurality of resting times. The second polarization parameter may be a polarization parameter actually measured by the battery during the electrochemical polarization elimination process.

[0125] In a possible implementation, the second polarization parameter may include: a rate of electrochemical polarization elimination, and at least one of a time weight, a charge and discharge voltage correction factor, and a polarization voltage correction factor.

[0126] S402: Determine an electrochemical polarization elimination voltage based on the standing time and the second target polarization parameter.

[0127] In a possible implementation, the standing time, the second target polarization parameter, and the electrochemical polarization elimination voltage satisfy the following sixth formula:

[0128] in, It can be used to characterize the electrochemical polarization elimination voltage. It can be used to characterize the depolarization factor, which is the rate at which the electrochemical polarization of the battery is eliminated. Can be used to characterize the voltage correction factor. Can be used to characterize the rest time. Can be used to characterize time weight. Can be used to measure polarization voltage correction factor.

[0129] In a possible implementation, the polarization voltage determination device may determine the measured polarization voltage value and the standing time based on the steps in S3001-S3012. Thus, the polarization voltage determination device may fit the standing time and the polarization voltage value obtained by the test based on the sixth formula to obtain the second polarization parameter corresponding to the charge and discharge parameter.

[0130] For example, Figure 5 As shown, Figure 5 is another schematic diagram of fitting results shown according to an exemplary embodiment. Figure 5 The measured polarization elimination voltage curve and the fitted polarization elimination voltage curve determined based on the fourth formula are included. Figure 5 The horizontal axis is used to represent time, using seconds (s) as the unit of measurement. The vertical axis is used to represent polarization voltage, using volts (V) as the unit of measurement.

[0131] Exemplarily, based on the sixth formula, the standing time and polarization voltage values ​​obtained by the test are fitted to obtain a second mapping relationship. The polarization voltage determination device can determine that the second target polarization parameter corresponding to the standing time is μ=-0.003403, ε=1, θ=0.03, δ=0.8 based on the second mapping relationship. Based on this, the standing time, the second target polarization parameter and the electrochemical polarization elimination voltage satisfy the following seventh formula:

[0132] in, It can be used to characterize the electrochemical polarization elimination voltage. Can be used to characterize the rest time.

[0133] In one possible implementation, the polarization voltage determining device may determine the electrochemical polarization voltage based on the electrochemical polarization accumulation voltage and the electrochemical polarization elimination voltage.

[0134] Specifically, the polarization voltage determining device may determine the sum of the electrochemical polarization accumulation voltage and the electrochemical polarization elimination voltage as the electrochemical polarization voltage.

[0135] Based on this, in combination with the first formula, the second formula, the fourth formula and the sixth formula, the polarization voltage of the target battery can be determined to satisfy the following eighth formula:

[0136] in, It can be used to characterize the polarization voltage of the target battery. Can be used to characterize the ohmic resistance of the target battery. It can be used to characterize the charge and discharge current of the target battery. The current is positive during charging and negative during discharging. , It can be used to characterize the first target polarization parameter, that is, the rate of electrochemical polarization accumulation of the battery. α and β can be used to characterize the transfer coefficient, which is the weight of charge transfer polarization and mass transfer polarization. It can be used to characterize the base of natural logarithms. I can be used to characterize the charge and discharge current, the current is positive when charging and negative when discharging. R can be used to characterize the gas constant, which can be 8.314. T can be used to characterize the battery temperature. It can be used to characterize the depolarization factor, which is the rate at which the electrochemical polarization of the battery is eliminated. Can be used to characterize the voltage correction factor. Can be used to characterize the rest time. Can be used to characterize time weight. Can be used to measure polarization voltage correction factor.

[0137] By combining the first formula, the second formula, and the examples of the first target polarization parameter and the second target polarization parameter in the fifth formula and the seventh formula, the polarization voltage of the target battery can be determined, satisfying the following ninth formula:

[0138] Based on this, the present application can establish a second mapping relationship and directly find the second target polarization parameter that matches the battery according to the standing time. This mapping relationship of measured data can reduce the error of the theoretical model or empirical formula and improve the accuracy of determining the electrochemical polarization elimination voltage.

[0139] In some embodiments, Figure 6 As shown, Figure 6is a schematic diagram showing a comparison of polarization voltages under a discharge condition according to an exemplary embodiment.

[0140] It should be noted that Figure 6 The first calculated polarization voltage curve under the target battery discharge condition and the first measured polarization voltage curve under the target battery discharge condition are included. Figure 6 The horizontal axis is used to represent time, using seconds (s) as the unit of measurement. The vertical axis is used to represent polarization voltage, using volts (v) as the unit of measurement.

[0141] Among them, the first calculated polarization voltage curve is a curve formed by the polarization voltage determined by the polarization voltage determination method provided in this application under the target battery discharge condition. The first measured polarization voltage curve can be a curve formed by the polarization voltage determined based on the calibration method under the target battery discharge condition. This application does not make specific restrictions on this.

[0142] Optionally, the target battery can be set according to actual needs. For example, the target battery can be a lithium iron phosphate (LEP) battery or a ternary lithium battery. This application does not impose specific restrictions on this.

[0143] For example, in combination Figure 6 ,like Figure 7 As shown, Figure 7 is a schematic diagram showing a comparison result of polarization voltage under a discharge condition according to an exemplary embodiment.

[0144] Figure 7 Shows Figure 6 Comparison results of the first calculated polarization voltage curve and the first measured polarization voltage curve. Figure 7 The horizontal axis is used to represent time, using seconds (s) as the unit of measurement. The vertical axis is used to represent error, using volts (V) as the unit of measurement. Figure 7 It can be seen that under the same discharge duration, the maximum error of the polarization voltage between the first calculated polarization voltage curve and the first measured polarization voltage curve is about 0.01V, i.e., 10mV. For example, when the discharge duration is about 16s, the error of the polarization voltage between the first calculated polarization voltage curve and the first measured polarization voltage curve is about 10mV.

[0145] In some embodiments, Figure 8 As shown, Figure 8 It is a schematic diagram showing a comparison of polarization voltages under a charging condition according to an exemplary embodiment. Figure 8 The horizontal axis is used to represent time, using seconds (s) as the unit of measurement. The vertical axis is used to represent polarization voltage, using volts (V) as the unit of measurement.

[0146] It should be noted that Figure 8 The method includes a second calculated polarization voltage curve under the target battery charging condition and a second measured polarization voltage curve under the target battery charging condition.

[0147] Among them, the second calculated polarization voltage curve is a curve formed by the polarization voltage determined by the polarization voltage determination method provided in this application under the target battery charging condition. The second measured polarization voltage curve can be a curve formed by the polarization voltage determined based on the calibration method under the target battery charging condition. This application does not make specific restrictions on this.

[0148] For example, in combination Figure 8 ,like Fig. 9 As shown, Fig. 9 It is a schematic diagram showing the comparison results of polarization voltage under a charging condition according to an exemplary embodiment. Fig. 9 The horizontal axis is used to represent time, using seconds (s) as the unit of measurement. The vertical axis is used to represent error, using volts (V) as the unit of measurement.

[0149] Fig. 9 Shows Figure 8 The comparison result of the second calculated polarization voltage curve and the second measured polarization voltage curve in . Fig. 9 It can be seen that when the battery capacity is low, the error in polarization voltage between the second calculated polarization voltage curve and the second measured polarization voltage curve is about 0.03V. When the battery capacity is high, the error in polarization voltage between the second calculated polarization voltage curve and the second measured polarization voltage curve is within 0.02V.

[0150] In some embodiments, Fig.10 As shown, Fig.10 is a schematic diagram showing a polarization voltage determination process according to an exemplary embodiment.

[0151] In a possible implementation, the polarization voltage determining device may obtain an ohmic polarization voltage caused by an ohmic resistance. The polarization voltage determining device may obtain an electrochemical polarization accumulation voltage. The polarization voltage determining device may obtain an electrochemical polarization elimination voltage. The polarization voltage determining device may determine the polarization voltage of the battery based on the ohmic polarization voltage, the electrochemical polarization accumulation voltage, and the electrochemical polarization elimination voltage.

[0152] Fig.11 is a block diagram of a polarization voltage determination device according to an exemplary embodiment. Fig.11 The polarization voltage determination device includes: an acquisition unit 501 and a determination unit 502.

[0153] In a possible implementation, the acquisition unit 501 is used to acquire battery parameters of a target battery; the battery parameters include charge and discharge parameters of the target battery in a charge and discharge state and a rest time of the target battery in a rest state.

[0154] In a possible implementation, the determination unit 502 is used to determine the electrochemical polarization voltage and the ohmic polarization voltage of the target battery based on the battery parameters.

[0155] In a possible implementation, the determination unit 502 is further configured to determine the polarization voltage of the target battery based on the electrochemical polarization voltage and the ohmic polarization voltage.

[0156] In a possible implementation, the determination unit 502 is specifically configured to: determine a first target polarization parameter matching the charge and discharge parameter based on the first mapping relationship, and determine an electrochemical polarization accumulation voltage based on the charge and discharge parameter and the first target polarization parameter.

[0157] In a possible implementation, the determination unit 502 is specifically configured to: determine a second target polarization parameter that matches the rest time based on a second mapping relationship; the second mapping relationship includes second polarization parameters that correspond one to one with a plurality of rest times; and determine an electrochemical polarization elimination voltage based on the rest time and the second polarization parameter.

[0158] In a possible implementation, the determination unit 502 is specifically configured to determine the ohmic polarization voltage based on the charge and discharge current and the ohmic resistance of the target battery.

[0159] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0160] Fig.12 FIG. 1 is a block diagram of an electronic device according to an exemplary embodiment. Fig.12 As shown, the electronic device includes but is not limited to: a processor 601 and a memory 602 .

[0161] The memory 602 is used to store executable instructions of the processor 601. It can be understood that the processor 601 is configured to execute instructions to implement the polarization voltage determination method in the above embodiment.

[0162] It should be noted that those skilled in the art can understand that Fig.12 The electronic device structure shown in the figure does not constitute a limitation on the electronic device, and the electronic device may include Fig.12 More or fewer components may be shown, or certain components may be combined, or the components may be arranged differently.

[0163] The processor 601 is the control center of the electronic device. It uses various interfaces and lines to connect various parts of the entire electronic device. By running or executing software programs and / or modules stored in the memory 602, and calling data stored in the memory 602, it performs various functions of the electronic device and processes data, thereby monitoring the electronic device as a whole. The processor 601 may include one or more processing units. Optionally, the processor 601 may integrate an application processor and a modem processor, wherein the application processor mainly processes the operating system, user interface, and application programs, and the modem processor mainly processes wireless communications. It is understandable that the above-mentioned modem processor may not be integrated into the processor 601.

[0164] The memory 602 may be used to store software programs and various data. The memory 602 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application program required by at least one functional module (such as a determination unit, a processing unit, etc.), etc. In addition, the memory 602 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0165] In an exemplary embodiment, a computer-readable storage medium including instructions is also provided, such as a memory 602 including instructions, and the above instructions can be executed by a processor 601 of an electronic device to implement the method in the above embodiment.

[0166] In actual implementation, Fig.11 The functions of the acquisition unit 501 and the determination unit 502 in the above embodiment can be obtained by Fig.12 The processor 601 in the embodiment calls the computer program stored in the memory 602. The specific execution process can refer to the description of the method part in the above embodiment, which will not be repeated here.

[0167] Optionally, the computer-readable storage medium may be a non-temporary computer-readable storage medium, for example, the non-temporary computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0168] In an exemplary embodiment, the present application also provides a computer program product including one or more instructions, and the one or more instructions can be executed by the processor 601 of the electronic device to complete the method in the above embodiment.

[0169] It should be noted that when the instructions in the above-mentioned computer-readable storage medium or one or more instructions in the computer program product are executed by the processor of the electronic device, the various processes of the above-mentioned method embodiment are implemented, and the same technical effect as the above-mentioned method can be achieved. To avoid repetition, they will not be repeated here.

[0170] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0171] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0172] The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0173] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0174] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or the full classification part or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute the full classification part or part of the steps of each embodiment method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, ROM, RAM, disk or CD and other media that can store program code.

[0175] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for determining polarization voltage, characterized in that: The method comprises: Acquire battery parameters of the target battery; the battery parameters include charge and discharge parameters of the target battery in a charge and discharge state and a rest time of the target battery in a rest state; Based on the battery parameters, determining the electrochemical polarization voltage and the ohmic polarization voltage of the target battery; Based on the electrochemical polarization voltage and the ohmic polarization voltage, a polarization voltage of the target battery is determined.

2. The method according to claim 1, characterized in that The electrochemical polarization voltage includes: an electrochemical polarization accumulation voltage generated by the target battery in a charge and discharge state and an electrochemical polarization elimination voltage generated by the target battery in a static state.

3. The method according to claim 2, characterized in that The electrochemical polarization accumulation voltage is determined in the following manner: Based on a first mapping relationship, determining a first target polarization parameter that matches the charge and discharge parameter; the first mapping relationship includes: a plurality of first polarization parameters corresponding to a plurality of charge and discharge parameters one by one; the first polarization parameter is a polarization parameter actually measured by the battery during the electrochemical polarization accumulation process; The electrochemical polarization accumulation voltage is determined based on the charge and discharge parameters and the first target polarization parameter.

4. The method according to claim 3, characterized in that The first polarization parameter includes a rate of electrochemical polarization accumulation of the battery.

5. The method according to claim 2, characterized in that: The electrochemical polarization elimination voltage is determined in the following manner: Based on a second mapping relationship, determining a second target polarization parameter that matches the rest time; the second mapping relationship includes second polarization parameters that correspond one-to-one to a plurality of rest times; the second polarization parameter is a polarization parameter actually measured by the battery during the electrochemical polarization elimination process; The electrochemical polarization elimination voltage is determined based on the standing time and the second target polarization parameter.

6. The method according to claim 5, characterized in that The second polarization parameter includes: the rate of elimination of electrochemical polarization of the battery, and at least one of a time weight, a charge and discharge voltage correction factor, and a polarization voltage correction factor.

7. The method according to claim 1, characterized in that The charge and discharge parameters include the charge and discharge current of the target battery; determining the ohmic polarization voltage includes: The ohmic polarization voltage is determined based on the charge and discharge current and the ohmic resistance of the target battery.

8. A polarization voltage determination device, characterized in that: The device comprises: an acquisition unit and a determination unit; The acquisition unit is used to acquire battery parameters of the target battery; the battery parameters include charge and discharge parameters of the target battery in a charge and discharge state and a rest time of the target battery in a rest state; The determining unit is used to determine the electrochemical polarization voltage and the ohmic polarization voltage of the target battery based on the battery parameters; The determination unit is further used to determine the polarization voltage of the target battery based on the electrochemical polarization voltage and the ohmic polarization voltage.

9. The device according to claim 8, characterized in that A determination unit is specifically used to: determine a first target polarization parameter matching the charge and discharge parameter based on a first mapping relationship; the first mapping relationship includes: a plurality of first polarization parameters corresponding to a plurality of charge and discharge parameters one by one; the first polarization parameter is a polarization parameter actually measured by the battery during the electrochemical polarization accumulation process; Based on the charge and discharge parameters and the first target polarization parameter, an electrochemical polarization accumulation voltage is determined.

10. The device according to claim 8, characterized in that Determine the unit, specifically for: Based on a second mapping relationship, determining a second target polarization parameter that matches the rest time; the second mapping relationship includes second polarization parameters that correspond one-to-one to a plurality of rest times; the second polarization parameter is a polarization parameter actually measured by the battery during the electrochemical polarization elimination process; An electrochemical polarization elimination voltage is determined based on the rest time and the second polarization parameter.

11. A vehicle, characterized in that: The vehicle comprises the apparatus of any one of claims 8-10.

12. An electronic device, characterized in that: include: processor; a memory for storing instructions executable by the processor; The processor is configured to execute the instructions to implement the method according to any one of claims 1 to 7.

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