Method for determining state of charge of a battery in a high frequency pulsed ac heating mode and vehicle

Abstract

The application discloses a method for determining the state of charge of a battery in a high-frequency pulse alternating current heating mode and a vehicle. The method comprises: obtaining battery parameters of the battery in the high-frequency pulse alternating current heating mode, wherein the battery parameters comprise a first heating duration, a decay coefficient, an initial battery temperature and an initial state of charge of the battery at a starting moment of the first heating duration, wherein the initial consumed state of charge is used to represent the consumed state of charge of the battery from the initial moment to an ending moment of the first heating duration; obtaining a correction coefficient based on the initial state of charge, the initial battery temperature, the first heating duration and the decay coefficient; and obtaining a target state of charge based on the initial state of charge, the initial consumed state of charge and the correction coefficient. The application solves the technical problem of low accuracy of the state of charge caused by the failure to obtain accurate power and voltage values.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of battery, in particular to a method for determining state of charge of battery in high-frequency pulse alternating current heating mode and a vehicle. BACKGROUND

[0002] When the battery is heated in high-frequency pulse mode, the pulse frequency can reach 1000-2000Hz. In this mode, the acquisition cycle of the existing battery management system hardware acquisition device is greatly different from the pulse frequency, so that the battery and single cell voltage values collected cannot represent the real power and voltage state of the battery, and the accuracy is low. In the existing state of charge estimation method, the state of charge of the battery is usually determined by the Coulomb integration method, but the Coulomb integration method is severely dependent on the current and the single cell voltage value in the battery. Therefore, when the battery is in high-frequency pulse alternating current heating mode, it is difficult to obtain accurate state of charge.

[0003] At present, no effective solution has been proposed for the above problems. SUMMARY

[0004] The embodiments of the present application provide a method for determining state of charge of battery in high-frequency pulse alternating current heating mode and a vehicle, so as to at least solve the technical problem of low accuracy of state of charge caused by the inability to obtain accurate power and voltage values.

[0005] According to an aspect of the embodiments of the present application, a method for determining state of charge of battery in high-frequency pulse alternating current heating mode is provided, comprising: obtaining battery parameters of the battery in high-frequency pulse alternating current heating mode, wherein the battery parameters include: a first heating time length, a decay coefficient, an initial battery temperature and an initial state of charge of the battery at a starting time of the first heating time length, the first heating time length is used to represent the time length of the battery being heated by the high-frequency pulse alternating current heating mode, and the decay coefficient is used to represent the decay degree of the internal resistance of the battery; based on the initial battery temperature and the initial state of charge, obtaining an initial consumed state of charge of the battery at an ending time of the first heating time length, wherein the initial consumed state of charge is used to represent the consumed state of charge of the battery from the initial time to the ending time of the first heating time length; based on the initial state of charge, the initial battery temperature, the first heating time length and the decay coefficient, obtaining a correction coefficient; and based on the initial state of charge, the initial consumed state of charge and the correction coefficient, obtaining a target state of charge.

[0006] Optionally, obtaining the decay coefficient of the battery comprises: in response to receiving a high-frequency pulse heating signal, obtaining an actual resistance value and an initial resistance value of the internal resistance of the battery; and determining the ratio of the actual resistance value to the initial resistance value as the decay coefficient.

[0007] Optionally, obtaining the initial consumption state of the battery at the end of the first heating duration based on the initial battery temperature and the initial state of charge comprises: obtaining a first preset function, wherein the first preset function is used to represent a mapping relationship between different initial battery temperatures and initial states of charge and consumption states; and substituting the initial battery temperature and the initial state of charge into the first preset function to obtain the initial consumption state.

[0008] Optionally, obtaining the correction coefficient based on the initial state of charge, the initial battery temperature, the first heating duration and the attenuation coefficient comprises: obtaining a second preset function, wherein the second preset function is used to represent a mapping relationship between different initial battery temperatures and initial states of charge and the first heating duration; substituting the initial state of charge and the initial battery temperature into the second preset function to obtain a second heating duration of the battery; and obtaining the correction coefficient based on the first heating duration, the second heating duration and the attenuation coefficient.

[0009] Optionally, obtaining the correction coefficient based on the first heating duration, the second heating duration and the attenuation coefficient comprises: obtaining a ratio of the first heating duration to the second heating duration to obtain a time compensation coefficient; and obtaining a product of the time compensation coefficient and an inverse of the attenuation coefficient to obtain the correction coefficient.

[0010] Optionally, obtaining the target state of charge based on the initial state of charge, the initial consumption state and the correction coefficient comprises: obtaining a product of the initial consumption state and the correction coefficient to obtain a target consumption state; and obtaining a difference between the initial state of charge and the target consumption state to obtain the target state of charge.

[0011] Optionally, the method further comprises: heating the battery multiple times using a high-frequency pulse alternating current heating mode, wherein the state of charge of the battery before each heating is a preset state of charge, and the battery temperature of the battery is a preset battery temperature; heating the battery multiple times using the high-frequency pulse alternating current heating mode, wherein the state of charge of the battery before each heating is the preset state of charge, and the battery temperature of the battery is the preset battery temperature; in response to the battery temperature reaching a target temperature, obtaining a voltage value of the battery and a third heating duration, wherein the third heating duration is used to represent a duration of each heating process of the battery from being heated to the battery temperature reaching the target temperature; determining a first consumption state of the battery in each heating process based on the preset state of charge, the preset battery temperature, the voltage value and the third heating duration; and generating a first preset function and a second preset function based on the preset state of charge, the preset battery temperature, the third heating duration and the first consumption state.

[0012] Optionally, generating the first preset function and the second preset function based on the preset state of charge, the preset battery temperature, the third heating duration and the first consumed state of charge comprises: generating the first preset function based on the preset state of charge and the preset battery temperature and the first consumed state of charge; and generating the second preset function based on the preset state of charge and the preset battery temperature and the third heating duration.

[0013] Optionally, the first preset function and the second preset function are a linear difference table or a two-dimensional fitting function of the initial battery temperature and the initial state of charge.

[0014] According to another aspect of the embodiment of the present application, a vehicle is also provided, comprising a device for determining a state of charge of a battery in a high-frequency pulse alternating current heating mode, the device comprising: a parameter acquisition module configured to acquire battery parameters of the battery in the high-frequency pulse alternating current heating mode, wherein the battery parameters comprise a first heating duration, a decay coefficient, an initial battery temperature and an initial state of charge of the battery at a starting moment of the first heating duration, the first heating duration being used to represent a duration for which the battery is heated by the high-frequency pulse alternating current heating mode, and the decay coefficient being used to represent a degree of decay of an internal resistance of the battery; a first state of charge obtaining module configured to obtain an initial consumed state of charge of the battery at an ending moment of the first heating duration based on the initial battery temperature and the initial state of charge, wherein the initial consumed state of charge is used to represent a state of charge consumed by the battery from the starting moment to the ending moment of the first heating duration; a correction coefficient obtaining module configured to obtain a correction coefficient based on the initial state of charge, the initial battery temperature, the first heating duration and the decay coefficient; and a target state of charge obtaining module configured to obtain a target state of charge based on the initial state of charge, the initial consumed state of charge and the correction coefficient.

[0015] Optionally, the parameter acquisition module comprises: a heating signal response unit configured to acquire an actual resistance value and an initial resistance value of the internal resistance of the battery in response to receiving a high-frequency pulse heating signal; and a decay coefficient determination unit configured to determine a ratio of the actual resistance value to the initial resistance value as the decay coefficient.

[0016] Optionally, the first state of charge obtaining unit comprises: a first function acquisition unit configured to acquire a first preset function, wherein the first preset function is used to represent a mapping relationship between different initial battery temperatures and initial states of charge and consumed states of charge; and a first state of charge obtaining unit configured to substitute the initial battery temperature and the initial state of charge into the first preset function to obtain the initial consumed state of charge.

[0017] Optionally, the correction coefficient obtaining module comprises: a second function obtaining unit, configured to obtain a second preset function, wherein the second preset function is used to represent a mapping relationship between different initial battery temperatures and initial state of charge and the first heating duration; a heating duration obtaining unit, configured to substitute the initial state of charge and the initial battery temperature into the second preset function to obtain a second heating duration of the battery; and a correction coefficient obtaining unit, configured to obtain the correction coefficient based on the first heating duration, the second heating duration and the attenuation coefficient.

[0018] Optionally, the correction coefficient obtaining unit comprises: a time compensation coefficient obtaining sub-unit, configured to obtain a ratio of the first heating duration to the second heating duration to obtain a time compensation coefficient; and a correction coefficient obtaining sub-unit, configured to obtain a product of the time compensation coefficient and an inverse of the attenuation coefficient to obtain the correction coefficient.

[0019] Optionally, the target state of charge obtaining module comprises: a heating module, configured to heat the battery multiple times in a high-frequency pulse alternating current heating mode, wherein the state of charge of the battery before each heating is a preset state of charge, and the battery temperature of the battery is a preset battery temperature; a voltage and time obtaining module, configured to obtain a voltage value of the battery and a third heating duration in response to the battery temperature reaching a target temperature, wherein the third heating duration is used to represent a duration of each heating process of the battery from being heated to the battery temperature reaching the target temperature; a first state of charge obtaining module, configured to determine a first consumed state of charge of the battery in each heating process based on the preset state of charge, the preset battery temperature, the voltage value and the third heating duration; and a function generating module, configured to generate the first preset function and the second preset function based on the preset state of charge, the preset battery temperature, the third heating duration and the first consumed state of charge.

[0020] Optionally, the function generating module comprises: a first function generating unit, configured to generate the first preset function based on the preset state of charge and the preset battery temperature and the first consumed state of charge; and a second function generating unit, configured to generate the second preset function based on the preset state of charge and the preset battery temperature and the third heating duration.

[0021] Optionally, the first preset function and the second preset function are a linear difference table of the initial battery temperature and the initial state of charge or a two-dimensional fitting function.

[0022] According to an aspect of the embodiments of the present application, a computer readable storage medium is also provided, and the computer readable storage medium stores a computer program, wherein the computer program is configured to execute the method for determining the state of charge of the battery in the high-frequency pulse alternating current heating mode when running.

[0023] In the embodiment of the present application, after the battery parameters under the high-frequency pulse alternating current heating mode are obtained, the initial consumption state of charge at the end of the first heating duration is obtained based on the initial battery temperature and the initial state of charge; then the correction coefficient is obtained based on the initial state of charge, the initial battery temperature, the first heating duration and the attenuation coefficient; and then the target state of charge is obtained based on the initial state of charge, the initial consumption state of charge and the correction coefficient. It is easy to note that in the process of obtaining the target state of charge in the present application, the current value and the voltage value in the battery do not need to be measured, and the target state of charge can be directly obtained according to the initial battery temperature, the initial state of charge and the heating duration of the battery collected, so that the technical effect of improving the accuracy of the state of charge obtained under the high-frequency pulse alternating current heating mode is realized, and the technical problem of low accuracy of the state of charge caused by the inability to obtain accurate power and voltage values is solved. BRIEF DESCRIPTION OF DRAWINGS

[0024] The accompanying drawings, which are included to provide a further understanding of the present application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and together with the description serve to explain the present application. In the drawings:

[0025] Figure 1 is a flowchart of a method for determining the state of charge of a battery under a high-frequency pulse alternating current heating mode according to an embodiment of the present application;

[0026] Figure 2 is a flowchart of an offline measurement method for consumption SOC in a method for determining the state of charge of a battery under a high-frequency pulse alternating current heating mode;

[0027] Figure 3 is a structural schematic diagram of an offline measurement environment in a method for determining the state of charge of a battery under a high-frequency pulse alternating current heating mode in a preferred embodiment of the present application;

[0028] Figure 4 is a functional diagram of battery temperature and heating time in a method for determining the state of charge of a battery under a high-frequency pulse alternating current heating mode in an embodiment of the present application;

[0029] Figure 5 is a structural schematic diagram of a vehicle in an embodiment of the present application. DETAILED DESCRIPTION

[0030] In the following, the technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort should fall into the protective scope of the present application.

[0031] It should be noted that the terms "first", "second" and the like in the description and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to include all the steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0032] According to an embodiment of the present application, a method for determining the state of charge of a battery in a high-frequency pulse alternating current heating mode is provided. It should be noted that the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0033] Figure 1 is a flowchart of a method for determining the state of charge of a battery in a high-frequency pulse alternating current heating mode according to an embodiment of the present application, as shown in Figure 1 the method comprises the following steps:

[0034] In step S102, the battery parameters of the battery in the high-frequency pulse alternating current heating mode are obtained, wherein the battery parameters include: a first heating time, a decay coefficient, an initial battery temperature and an initial state of charge of the battery at the start time of the first heating time, the first heating time is used to represent the time length of the battery being heated by the high-frequency pulse alternating current heating mode, and the decay coefficient is used to represent the degree of attenuation of the internal resistance of the battery.

[0035] Specifically, the above-mentioned battery can be a battery pack in a vehicle. The above-mentioned first heating time is the time length of continuous heating of the battery from the time when the high-frequency pulse heating signal is received to the current time.

[0036] As an optional embodiment, when the pulse heating signal is received, the controller starts timing and records the initial battery temperature T init and the initial state of charge SOC init When the heating stops, the first heating duration Δt from the starting time to the ending time is recorded. It should be noted that in actual use, the high-frequency pulse heating of the battery is usually stopped after the battery temperature reaches the target temperature. When the heating is stopped without reaching the target temperature, the time when the heating is stopped is taken as the ending time, and the first heating duration is determined.

[0037] In an optional embodiment, obtaining the attenuation coefficient of the battery includes: in response to receiving the high-frequency pulse heating signal, obtaining an actual resistance value and an initial resistance value of the battery internal resistance; and determining the ratio of the actual resistance value to the initial resistance value as the attenuation coefficient. For example, R BOL is the initial resistance value of the battery internal resistance, i.e., the resistance value of the battery internal resistance when it leaves the factory, and R EOL is the actual resistance value of the battery. The attenuation coefficient Factor of the battery internal resistance can be obtained by the following formula: R : Factor R > 1.

[0038] In step S104, based on the initial battery temperature and the initial state of charge, an initial consumed state of charge of the battery at the ending time of the first heating duration is obtained, wherein the initial consumed state of charge is used to represent the consumed state of charge of the battery from the initial time to the ending time of the first heating duration.

[0039] In an optional embodiment, based on the initial battery temperature and the initial state of charge, obtaining the initial consumed state of charge of the battery at the ending time of the first heating duration includes: obtaining a first preset function, wherein the first preset function is used to represent the mapping relationship between different initial battery temperatures and initial states of charge and consumed states of charge; and substituting the initial battery temperature and the initial state of charge into the first preset function to obtain the initial consumed state of charge.

[0040] The above-mentioned first preset function can be as follows: ΔSOC = F ΔSOC (T, initial SOC), wherein ΔSOC is used to represent the initial consumed state of charge, T is used to represent the initial battery temperature, and initial SOC (State of charge) is used to represent the initial state of charge. F ΔSOC (T, initial SOC) is used to represent a two-dimensional fitting function or a linear interpolation table of the initial battery temperature and the initial state of charge. After obtaining the initial battery temperature and the initial state of charge, they are substituted into F ΔSOC (T, initial SOC) to obtain the initial consumed state of charge ΔSOC.

[0041] In step S106, a correction coefficient is obtained based on the initial state of charge, the initial battery temperature, the first heating duration, and the attenuation coefficient.

[0042] Optionally, obtaining the correction coefficient based on the initial state of charge, the initial battery temperature, the first heating duration, and the attenuation coefficient comprises: obtaining a second preset function, wherein the second preset function is used to represent a mapping relationship between different initial battery temperatures and initial states of charge and the first heating duration; substituting the initial state of charge and the initial battery temperature into the second preset function to obtain a second heating duration of the battery; and obtaining the correction coefficient based on the first heating duration, the second heating duration, and the attenuation coefficient.

[0043] As an optional implementation, the second preset function can be as follows:

[0044] ΔT = F Δtime (T, initial SOC), wherein ΔT is used to represent the second heating duration, T is used to represent the initial battery temperature, and initial SOC is used to represent the initial state of charge. After obtaining the initial state of charge and the initial battery temperature, they are substituted into the second preset function to obtain the second heating duration. Then, the correction coefficient can be calculated in the following manner: correction coefficient = (first heating duration / second heating duration) / attenuation coefficient. Δtime A two-dimensional fitting function or a linear interpolation table used to represent the initial battery temperature and the initial state of charge.

[0045] In step S108, a target state of charge is obtained based on the initial state of charge, the initial consumed state of charge, and the correction coefficient.

[0046] Specifically, the target state of charge can be obtained in the following manner:

[0047] Target state of charge = initial state of charge - initial state of charge * correction coefficient.

[0048] Through the above steps, after obtaining the battery parameters of the battery in the high-frequency pulse alternating current heating mode, the initial consumed state of charge of the battery at the end of the first heating duration is obtained based on the initial battery temperature and the initial state of charge; then, the correction coefficient is obtained based on the initial state of charge, the initial battery temperature, the first heating duration, and the attenuation coefficient; and then, the target state of charge is obtained based on the initial state of charge, the initial consumed state of charge, and the correction coefficient. It is easy to note that in the process of obtaining the target state of charge in the present application, it is not necessary to measure the current value and the voltage value in the battery, and the target state of charge can be directly obtained according to the initial battery temperature, the initial state of charge, and the heating duration of the battery collected, thereby realizing the technical effect of improving the accuracy of the state of charge obtained in the high-frequency pulse alternating current heating mode, and further solving the technical problem of low accuracy of the state of charge caused by the inability to obtain accurate power and voltage values.

[0049] Optionally, obtaining the correction coefficient based on the first heating duration, the second heating duration and the attenuation coefficient comprises: obtaining a ratio of the first heating duration and the second heating duration to obtain a time compensation coefficient; and obtaining a product of the time compensation coefficient and an inverse of the attenuation coefficient to obtain the correction coefficient.

[0050] Specifically, the time compensation coefficient = the first heating duration / the second heating duration, and the correction coefficient = the time compensation coefficient / the attenuation coefficient.

[0051] Optionally, obtaining the target state of charge based on the initial state of charge, the initial consumed state of charge and the correction coefficient comprises: obtaining a product of the initial consumed state of charge and the correction coefficient to obtain a target consumed state of charge; and obtaining a difference between the initial state of charge and the target consumed state of charge to obtain the target state of charge.

[0052] Specifically, the target consumed state of charge = the initial consumed state of charge*the correction coefficient, and the target state of charge = the initial state of charge-the target consumed state of charge.

[0053] Optionally, the method further comprises: heating the battery multiple times by using the high-frequency pulse alternating current heating mode, wherein the state of charge of the battery before each heating is a preset state of charge, and the battery temperature of the battery before each heating is a preset battery temperature; heating the battery multiple times by using the high-frequency pulse alternating current heating mode, wherein the state of charge of the battery before each heating is the preset state of charge, and the battery temperature of the battery before each heating is the preset battery temperature; in response to the battery temperature reaching a target temperature, obtaining a voltage value of the battery and a third heating duration, wherein the third heating duration is used to represent a duration of each heating process of the battery from being heated to the battery temperature reaching the target temperature; determining a first consumed state of charge of the battery in each heating process based on the preset state of charge, the preset battery temperature, the voltage value and the third heating duration; and generating a first preset function and a second preset function based on the preset state of charge, the preset battery temperature, the third heating duration and the first consumed state of charge.

[0054] Specifically, the preset state of charge can be an initial state of charge set by a worker according to requirements, which can be set to 80%, or 50%, or 30%, for example. The current battery temperature can be an initial battery temperature set by a worker according to requirements, which can be set to -20℃, or -10℃, or 0℃, for example. The voltage value can be an open circuit voltage (OCV) of a battery cell in the battery. The first consumed state of charge can be a state of charge consumed in a process of heating the temperature of the battery from the preset battery temperature to the target temperature in each heating process.

[0055] In an optional embodiment, generating the first preset function and the second preset function based on the preset state of charge, the preset battery temperature, the third heating duration, and the first consumed state of charge comprises: generating the first preset function based on the preset state of charge and the preset battery temperature, and the first consumed state of charge; and generating the second preset function based on the preset state of charge and the preset battery temperature, and the third heating duration.

[0056] In an optional embodiment, the first preset function and the second preset function are a linear difference table or a two-dimensional fitting function of the initial battery temperature and the initial state of charge.

[0057] In a preferred embodiment of the present application, Figure 2 is a flowchart of an offline determination method of a consumed state of charge in a method for determining a state of charge of a battery in a high-frequency pulse alternating current heating mode, comprising:

[0058] Step S202, a high-frequency pulse heating offline determination environment is built.

[0059] Specifically, Figure 3 is a structural schematic diagram of an offline determination environment in a method for determining a state of charge of a battery in a high-frequency pulse alternating current heating mode in a preferred embodiment of the present application, comprising: a battery pack charging and discharging device, a battery pack oven, a motor, a battery pack, a motor controller, a battery controller, a low-voltage power supply device, a data acquisition device, and a data recording device. Among them, the battery pack charging and discharging device is connected with the battery pack through a high-voltage connecting part, the battery pack and the motor are connected by high voltage, the motor and the motor controller are connected by low voltage, the battery pack and the battery controller are connected by low voltage, the low-voltage power supply device can supply low-voltage power to the motor controller and the battery controller, and the battery controller can communicate with the data acquisition device and the data recording device.

[0060] Step S204, calibrate the battery pack capacity, and adjust the battery pack temperature.

[0061] Specifically, first, the capacity of the battery pack to be tested is tested to determine the actual capacity of the battery pack, then the capacity of the battery pack is adjusted to the actual full capacity (i.e. the preset state of charge is 100%), the temperature of the battery pack oven is set to T, and then the battery pack is fully immersed to make the temperature of the battery pack close to the temperature of the battery pack oven. It should be noted that in order to ensure the accuracy of the determination result, the temperature of the battery pack and the temperature of the battery pack oven do not exceed 2℃.

[0062] Step S206, high-frequency pulse heating calibration test at different SOC points at the same temperature is performed.

[0063] Specifically, the preset state of charge of the battery can be set as SOC1=100%, and the preset battery temperature can be set as T1=-30℃. Then, the battery pack is heated by the motor in high-frequency pulse until the temperature of the battery pack reaches the target temperature, and the time Δt used from starting to heat the battery pack until the temperature of the battery pack reaches the target temperature is obtained 11 , and the cell voltage value CellV of the battery pack after sufficient standing 11 .

[0064] Then, the preset state of charge is adjusted to SOC2=80%, SOC3=50% and SOC4=30% in turn, and the above steps are repeated to obtain Δt 12 , CellV 12 , Δt 13 , CellV 13 , Δt 14 , CellV 14 .

[0065] Step S208, high-frequency pulse heating calibration test at different SOC points under different temperatures is performed.

[0066] Specifically, the preset battery temperature is adjusted to T2=-20℃, and the third heating duration in the heating process of heating the battery pack by the motor until the temperature of the battery pack reaches the target temperature, and the cell voltage value of the battery pack after the battery reaches the target temperature and sufficient standing under the conditions that the preset state of charge is SOC1, SOC2, SOC3 and SOC4 respectively are measured in turn. Then, the preset battery temperature is adjusted to T3=-10℃ and T4=0℃ in turn, and the above steps are repeated.

[0067] After the calibration test is completed, the obtained data is summarized to obtain the following Table 1:

[0068] Temperature / SOC [CAT] SOC1 [SOCl2] [SOCl] <![CDATA[SOC4]]> [T1] Delta T 11 , Cell V 11 ]]> Delta t i2 , Cell V 12 ]] Delta T 13 , Cell V 13 ]] Delta T 14 , Cell V 14 ]]> [T2] Delta T 21 , Cell V 21 ]] Delta T 22 , Cell V 22 ]]> Delta T 23 Delta T 23 ]]> Delta T 24 , Cell V 24 ]] [T3] Delta T 31 , Cell V 31 ]] Delta T 32 Delta T 32 ]]> Delta T 33 , Cell V 33 ]]> Delta T 34 , Cell V 34 ]]> [CD AT T4] Delta T 41 , Cell V 41 ]]> Delta T 42 , Cell V 42 ]]> Delta T 43 , Cell V 43 ]] Delta T 44 , Cell V 44 ]]>

[0069] After obtaining the above table, according to the corresponding relationship between SOC and OCV, the collected cell voltage value of the battery pack is converted into the corresponding SOC value, and the formula is as follows:

[0070] SOC ij =a1CellV ij n +a2CellVi j n-1 +…+a n CellV ij+a0, where i is used to represent the index number of preset battery temperature, and j is used to represent the index number of preset state of charge. After converting all the monomer voltage values in Table 1 into corresponding SOC values, Table 2 is obtained as follows:

[0071] Temperature / SOC <![CDATA[SOC1]]> [SOCl2] [["soc3"]] [SOCl2] <![CDATA[T1]]> Delta T 11 SOC 11 ]]> Delta T 12 SOC 12 ]]> Delta T 13 SOC 13 ]]> Delta T 14 , SOC 14 ]]> [T2] Delta T 21 SOC 21 ]]> Delta T 22 SOC 22 ]]> Delta T 23 SOC 23 ]]> Delta T 24 SOC 24 ]]> [CD AT T3] Delta T 31 SOC 31 ]]> Delta T 32 SOC 32 ]]> Delta T 33 SOC 33 ]]> Delta T 34 SOC 34 ]]> T4 Delta T 41 SOC 41 ]]> Delta T 42 SOC 42 ]]> Delta T 43 SOC 43 ]]> Delta T 44 SOC 44 ]]>

[0072] Utilizing the state of charge SOC of the battery after heating is completed ij and the preset state of charge SOC corresponding thereto j , the state of charge consumed in the heating process, i.e., the first consumed state of charge, can be obtained by using the following formula: ij : ΔSOC ij = SOC j - SOC ij , and Table 3 is obtained as follows:

[0073] Temperature / SOC <![CDATA[SOC1]]> [SOCl2]

[00100] SOC3 <![CDATA[SOC4]]> [T1] Delta t 11 Delta SOC 11 ]]> Delta t 12 Delta SOC 12 ]] Delta t 13 Delta SOC 13 ]]> Delta t 14 Delta SOC 14 ]] [ T2 ] Delta t 21 Delta SOC 21 ]]> Delta t 22 Delta SOC 22 ]]> Delta t 23 Delta SOC 23 ]]> Delta t 24 Delta SOC 24 ]]> [CD AT T3] Delta t 31 Delta SOC 31 ]]> Delta t 32 Delta SOC 32 ]]> Delta t 33 Delta SOC 33 ]]> Delta t 34 Delta SOC 34 ]]> T4 Delta t 41 Delta SOC 41 ]]> Delta t 42 Delta SOC 42 ]]> Delta t 43 Delta SOC 43 ]]> Delta t 44 Delta SOC 44 ]]>

[0074] Utilizing the preset state of charge SOC j , the preset battery temperature T i and the first consumed state of charge ΔSOC ij , a first preset function ΔSOC = F ΔSOC (T, SOC j ) is generated.

[0075] Utilizing the state of charge SOCj, the preset battery temperature Ti and the obtained third heating duration Δt, a second preset function Δt = F Δtime (T, SOC j ) is generated.

[0076] In an actual application scenario, when the battery system of the vehicle receives a high-frequency pulse heating signal, the controller starts timing, records the SOC value at the starting time as SOC init , and the starting time temperature as T init When the battery temperature does not reach the target temperature and the heating is stopped unexpectedly, i.e., if the battery temperature does not reach the target temperature, the time Δt from the start to the current time is recorded, and the calculation formula of the consumed SOC ΔSOC consume is as follows:

[0077]

[0078] It should be noted that, since the battery pack of the vehicle is usually aged during use, when the aging occurs, the high-frequency pulse heating actually generates heat in the battery internal resistance, which generates heat in the battery pack. When the heating temperature rises by a certain value, the greater the internal resistance, the shorter the heating time required. Therefore, when calculating the state of charge, the attenuation coefficient of the internal resistance needs to be introduced, and the specific derivation process is as follows: Q = I 2 Rt = CM * DeltaTemp, wherein Q is the heat generated, R is the internal resistance of the battery, t is the heating time, C is the specific heat capacity of the battery pack, m is the mass of the battery pack, and DeltaTemp is the temperature difference between the temperature T after heating and the initial temperature T0 of the battery, i.e. the temperature rise of the battery pack during heating. Assume that the internal resistance attenuation coefficient Factor R , Factor R > 1, wherein R BOL is the initial resistance value of the internal resistance of the battery, R EOL is the actual resistance value of the internal resistance of the battery, and the following formula is obtained: After transforming the formula, the following can be obtained: Figure 4 is a function diagram of battery temperature and heating time in a high-frequency pulse alternating current heating mode in the method for determining the state of charge of the battery in the embodiments of the present application, as shown in Figure 4 , Figure 4 The straight line with a larger slope in the function is a schematic diagram of the battery temperature and heating time when the internal resistance of the battery decays. The slope of the straight line is The other straight line is a schematic diagram when the internal resistance of the battery does not decay. The slope of the straight line is As can be seen, the heating time is inversely proportional to the internal resistance growth coefficient Factor R , and thus the compensation formula of the internal resistance attenuation is derived:

[0079] DeltaT R = DeltaT * Lambda, then wherein DeltaT R is used to represent the change in temperature of the battery after introducing the internal resistance compensation factor, DeltaT is the change in temperature of the battery without introducing the internal resistance compensation factor, and Lambda is the internal resistance compensation factor. The formula of the consumed SOC (DeltaSOC consume ) after introducing the internal resistance attenuation coefficient is:

[0080]

[0081] After the temperature of the battery pack reaches the target temperature, the calculation formula of the current SOC (SOC init ) is: SOC real = SOC init - DeltaSOC consume .

[0082] According to another aspect of the embodiments of the present application, there is also provided a vehicle, Figure 5 Fig. 1 is a schematic structural diagram of a vehicle according to an embodiment of the present application, which comprises a device for determining the state of charge of a battery in a high-frequency pulse alternating current heating mode, the device comprising:

[0083] The parameter acquisition module 52 is configured to acquire battery parameters of the battery in the high-frequency pulse alternating current heating mode, wherein the battery parameters comprise a first heating duration, an attenuation coefficient, an initial battery temperature and an initial state of charge of the battery at a starting moment of the first heating duration, the first heating duration being used to represent a duration for which the battery is heated by the high-frequency pulse alternating current heating mode, and the attenuation coefficient being used to represent an attenuation degree of the internal resistance of the battery.

[0084] The first state of charge obtaining module 54 is configured to obtain an initial consumed state of charge of the battery at an ending moment of the first heating duration based on the initial battery temperature and the initial state of charge, wherein the initial consumed state of charge is used to represent a consumed state of charge of the battery from the initial moment to the ending moment of the first heating duration.

[0085] The correction coefficient obtaining module 56 is configured to obtain a correction coefficient based on the initial state of charge, the initial battery temperature, the first heating duration and the attenuation coefficient.

[0086] The target state of charge obtaining module 58 is configured to obtain a target state of charge based on the initial state of charge, the initial consumed state of charge and the correction coefficient.

[0087] Optionally, the parameter acquisition module comprises a heating signal response unit configured to acquire an actual resistance value and an initial resistance value of the internal resistance of the battery in response to receiving the high-frequency pulse heating signal, and an attenuation coefficient determination unit configured to determine a ratio of the actual resistance value to the initial resistance value as the attenuation coefficient.

[0088] Optionally, the first state of charge obtaining unit comprises a first function acquisition unit configured to acquire a first preset function, wherein the first preset function is used to represent a mapping relationship between different initial battery temperatures and initial states of charge and consumed states of charge, and a first state of charge obtaining unit configured to substitute the initial battery temperature and the initial state of charge into the first preset function to obtain the initial consumed state of charge.

[0089] Optionally, the correction coefficient obtaining module comprises a second function acquisition unit configured to acquire a second preset function, wherein the second preset function is used to represent a mapping relationship between different initial battery temperatures and initial states of charge and first heating durations, a heating duration obtaining unit configured to substitute the initial state of charge and the initial battery temperature into the second preset function to obtain a second heating duration of the battery, and a correction coefficient obtaining unit configured to obtain the correction coefficient based on the first heating duration, the second heating duration and the attenuation coefficient.

[0090] Optionally, the correction coefficient obtaining unit comprises: a supplementary coefficient obtaining subunit, configured to obtain a ratio of the first heating duration to the second heating duration to obtain a time compensation coefficient; and a correction coefficient obtaining subunit, configured to obtain a product of the time compensation coefficient and an inverse of the attenuation coefficient to obtain the correction coefficient.

[0091] Optionally, the target state of charge obtaining module comprises: a heating module, configured to heat the battery multiple times in a high-frequency pulse alternating current heating mode, wherein the state of charge of the battery before each heating is a preset state of charge, and the battery temperature of the battery is a preset battery temperature; a voltage and time obtaining module, configured to obtain a voltage value of the battery and a third heating duration in response to the battery temperature reaching a target temperature, wherein the third heating duration is used to represent a duration of each heating process of the battery from the start of being heated to the battery temperature reaching the target temperature; a first state of charge obtaining module, configured to determine a first consumed state of charge of the battery in each heating process based on the preset state of charge, the preset battery temperature, the voltage value and the third heating duration; and a function generating module, configured to generate the first preset function and the second preset function based on the preset state of charge, the preset battery temperature, the second heating duration and the first consumed state of charge.

[0092] Optionally, the function generating module comprises: a first function generating unit, configured to generate the first preset function based on the preset state of charge and the preset battery temperature and the first consumed state of charge; and a second function generating unit, configured to generate the second preset function based on the preset state of charge and the preset battery temperature and the third heating duration.

[0093] Optionally, the first preset function and the second preset function are a linear difference table of the initial battery temperature and the initial state of charge or a two-dimensional fitting function.

[0094] According to an aspect of the embodiments of the present application, a computer readable storage medium is also provided, and the computer readable storage medium stores a computer program, wherein the computer program is configured to execute the method for determining the state of charge of the battery in the high-frequency pulse alternating current heating mode.

[0095] The serial numbers of the above embodiments of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0096] In the above embodiments of the present application, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0097] In several embodiments provided in the present application, it should be understood that the disclosed technology can be implemented by other means. Among them, the above-mentioned device embodiments are only schematic, for example, the division of the units can be a logical function division, and actual implementation can have another division mode, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed each other can be through some interface, indirect coupling or communication connection between units or modules, which can be electrical or other forms.

[0098] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or they can be distributed to multiple units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0099] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0100] The integrated unit, if realized in the form of a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a plurality of instructions for causing a computer device (which can be a personal computer, a server or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: a U disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0101] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A method of determining the state of charge of a battery in a high frequency pulsed alternating current heating mode, characterized by, The method comprises: obtaining a battery parameter of a battery in a high-frequency pulse alternating current heating mode, wherein the battery parameter comprises: a first heating duration, a decay coefficient, an initial battery temperature and an initial state of charge of the battery at a starting moment of the first heating duration, the first heating duration being used to represent a duration in which the battery is heated by the high-frequency pulse alternating current heating mode, and the decay coefficient being used to represent a degree of attenuation of the battery internal resistance; obtaining an initial consumed state of charge of the battery at an ending moment of the first heating duration based on the initial battery temperature and the initial state of charge, wherein the initial consumed state of charge is used to represent a consumed state of charge of the battery from the initial moment to the ending moment of the first heating duration; obtaining a correction coefficient based on the initial state of charge, the initial battery temperature, the first heating duration and the decay coefficient; obtaining a target state of charge based on the initial state of charge, the initial consumed state of charge and the correction coefficient.

2. The method of claim 1, wherein, The method further comprises: obtaining an actual resistance value and an initial resistance value of the battery internal resistance in response to receiving a high-frequency pulse heating signal; determining the decay coefficient as a ratio of the actual resistance value to the initial resistance value.

3. The method of claim 1, wherein, The method further comprises: obtaining a first preset function, wherein the first preset function is used to represent a mapping relationship between different initial battery temperatures and initial states of charge and consumed states of charge; obtaining the initial consumed state of charge by substituting the initial battery temperature and the initial state of charge into the first preset function.

4. The method of claim 1, wherein, The method further comprises: obtaining a second preset function, wherein the second preset function is used to represent a mapping relationship between different initial battery temperatures and initial states of charge and first heating durations; obtaining a second heating duration of the battery by substituting the initial state of charge and the initial battery temperature into the second preset function; obtaining the correction coefficient based on the first heating duration, the second heating duration and the decay coefficient.

5. The method of claim 4, wherein, The method further comprises: obtaining a time compensation coefficient by obtaining a ratio of the first heating duration to the second heating duration; obtaining the correction coefficient by obtaining a product of the time compensation coefficient and an inverse of the decay coefficient.

6. The method of claim 1, wherein, The method further comprises: obtaining a target consumed state of charge by obtaining a product of the initial consumed state of charge and the correction coefficient; obtaining the target state of charge by obtaining a difference between the initial state of charge and the target consumed state of charge.

7. The method according to claim 3 or 4, characterized in that, The method further comprises: The battery is heated multiple times by using the high-frequency pulse alternating current heating mode, wherein, before each heating, the state of charge of the battery is a preset state of charge, and a battery temperature of the battery is a preset battery temperature; In response to the battery temperature reaching a target temperature, a voltage value of the battery and a third heating duration are obtained, wherein the third heating duration is used to represent a duration of each heating process of the battery from the start of being heated to the battery temperature reaching the target temperature; A first consumed state of charge of the battery in the each heating process is determined based on the preset state of charge, the preset battery temperature, the voltage value and the third heating duration; A first preset function and a second preset function are generated based on the preset state of charge, the preset battery temperature, the third heating duration and the first consumed state of charge.

8. The method of claim 7, wherein, Generating the first preset function and the second preset function based on the preset state of charge, the preset battery temperature, the third heating duration and the first consumed state of charge includes: The first preset function is generated based on the preset state of charge and the preset battery temperature, and the first consumed state of charge; The second preset function is generated based on the preset state of charge and the preset battery temperature, and the third heating duration.

9. The method of claim 7, wherein, The first preset function and the second preset function are linear difference tables or two-dimensional fitting functions of the initial battery temperature and the initial state of charge.

10. A vehicle characterized by comprising: The device for determining a state of charge of a battery in a high-frequency pulse alternating current heating mode includes: A parameter obtaining module is configured to obtain battery parameters of the battery in the high-frequency pulse alternating current heating mode, wherein the battery parameters include a first heating duration, a decay coefficient, an initial battery temperature and an initial state of charge of the battery at a starting time of the first heating duration, the first heating duration is used to represent a duration of the battery being heated by using the high-frequency pulse alternating current heating mode, and the decay coefficient is used to represent a decay degree of a battery internal resistance; A first state of charge obtaining module is configured to obtain an initial consumed state of charge of the battery at an ending time of the first heating duration based on the initial battery temperature and the initial state of charge, wherein the initial consumed state of charge is used to represent a consumed state of charge of the battery in a process from the starting time to the ending time of the first heating duration; A correction coefficient obtaining module is configured to obtain a correction coefficient based on the initial state of charge, the initial battery temperature, the first heating duration and the decay coefficient; A target state of charge obtaining module is configured to obtain a target state of charge based on the initial state of charge, the initial consumed state of charge and the correction coefficient.

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