Method and device for evaluating self-discharge of power battery system, and electronic equipment

Abstract

The application provides a self-discharge evaluation method and device of a power battery system and electronic equipment. The method comprises the following steps: obtaining running data corresponding to multiple running time points of the power battery system; determining at least one running time point according to the charge amount, driving mileage and charging and discharging current corresponding to the multiple running time points; and calculating a self-discharge evaluation index value of the power battery system according to a target voltage corresponding to each running time point of each running time point pair. The scheme of the application solves the problem of the limitation of the existing self-discharge evaluation method due to the long required static time, and realizes the evaluation of the health status of the power battery without affecting the normal use of the new energy vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicle battery, and particularly relates to a self-discharge evaluation method and device of a power battery system and an electronic device. BACKGROUND

[0002] Nowadays, new energy vehicles mostly use lithium ion power battery systems as power sources. Due to the physical and chemical characteristics of lithium ion batteries, self-discharge occurs. Severe self-discharge of the power battery system will affect the performance of the product, and even cause safety accidents. At present, the self-discharge of the power battery system is usually evaluated by observing the pressure drop or capacity retention rate of the single battery of the power battery system before and after standing for one week to one month under a specified environment and state of charge. However, the above-mentioned self-discharge evaluation method of the power battery system needs the vehicle to stand for a long time under a specified environment and state of charge, so that the application of the self-discharge evaluation method of the power battery system has great limitations. SUMMARY

[0003] In order to solve the above technical problems, the present application provides a self-discharge evaluation method and device of a power battery system and an electronic device, which are used to solve the problem of great application limitations of the existing self-discharge evaluation method of the power battery system.

[0004] In a first aspect, the present application provides a self-discharge evaluation method of a power battery system, comprising:

[0005] obtaining running data corresponding to a plurality of running moments of a power battery system, wherein the power battery system comprises a plurality of battery monomers, and the running data corresponding to each of the running moments comprises a target voltage, a state of charge, a driving distance and a charging and discharging current; the target voltage comprises at least one of a first voltage, a second voltage and a voltage of each battery monomer of the plurality of battery monomers; the first voltage is the maximum value of the voltages of the plurality of battery monomers, and the second voltage is the minimum value of the voltages of the plurality of battery monomers;

[0006] determining at least one running moment pair according to the state of charge, the driving distance and the charging and discharging current corresponding to the plurality of running moments, wherein the time difference between the two running moments in the running moment pair is greater than or equal to a first preset value, the difference between the state of charge corresponding to the two running moments in the running moment pair is less than or equal to a second preset value, the difference between the driving distance corresponding to the two running moments in the running moment pair is less than or equal to a third preset value, and the absolute value of the charging and discharging current corresponding to the later running moment in the running moment pair is less than or equal to a fourth preset value;

[0007] According to the target voltage corresponding to each of the operation time pairs, a self-discharge evaluation index value of the power battery system is calculated.

[0008] Optionally, the state of charge corresponding to the earlier operation time in the operation time pair is greater than or equal to a fifth preset value.

[0009] Optionally, the self-discharge evaluation index value of the power battery system is calculated according to the target voltage corresponding to each of the operation time pairs, including:

[0010] The difference between the target voltages corresponding to the two operation times of the first operation time pair is calculated, wherein the first operation time pair is any operation time pair of the at least one operation time pair;

[0011] According to the difference between the target voltages corresponding to the two operation times of the first operation time pair and a first time difference value, a self-discharge feature value corresponding to the first operation time pair is calculated, wherein the self-discharge evaluation index value includes the self-discharge feature value corresponding to the first operation time pair, the self-discharge feature value corresponding to the first operation time pair is the ratio of the difference between the target voltages corresponding to the two operation times of the first operation time pair to the first time difference value, and the first time difference value is the time difference between the two operation times of the first operation time pair.

[0012] Optionally, the method further includes: according to the target voltage corresponding to the earlier operation time in the first operation time pair and a mapping relationship between voltage and charge amount, a first charge amount corresponding to the target voltage is obtained;

[0013] A first self-discharge feature threshold value corresponding to the first charge amount is determined;

[0014] According to the comparison result of the self-discharge feature value corresponding to the first operation time pair and the first self-discharge feature threshold value, a warning process is performed.

[0015] Optionally, the target voltage includes the voltage of each battery monomer of the plurality of battery monomers, the self-discharge feature value corresponding to the first operation time pair includes the self-discharge feature value corresponding to each battery monomer of the plurality of battery monomers, and the first self-discharge feature threshold value includes the self-discharge feature threshold value corresponding to each battery monomer of the plurality of battery monomers.

[0016] The warning process according to the comparison result of the self-discharge feature value corresponding to the first operation time pair and the self-discharge feature threshold value corresponding to the first charge amount includes:

[0017] In a case where a corresponding self-discharge characteristic value of a first battery cell of the plurality of battery cells is greater than or equal to a corresponding self-discharge characteristic threshold value of the first battery cell, output a number of the first battery cell, the first battery cell being any battery cell of the plurality of battery cells.

[0018] In a second aspect, the present application provides a self-discharge evaluation device of a power battery system, comprising:

[0019] An acquisition module is configured to acquire running data corresponding to a plurality of running moments of a power battery system, wherein the power battery system comprises a plurality of battery cells, and the running data corresponding to each running moment comprises a target voltage, a state of charge, a driving distance, and a charging and discharging current; the target voltage comprises at least one of a first voltage, a second voltage, and a voltage of each battery cell of the plurality of battery cells; the first voltage is a maximum value of the voltages of the plurality of battery cells, and the second voltage is a minimum value of the voltages of the plurality of battery cells;

[0020] A first determination module is configured to determine at least one running moment pair according to the state of charge, the driving distance, and the charging and discharging current corresponding to the plurality of running moments, wherein a time difference between two running moments in the running moment pair is greater than or equal to a first preset value, a difference between the state of charge corresponding to the two running moments in the running moment pair is less than or equal to a second preset value, a difference between the driving distance corresponding to the two running moments in the running moment pair is less than or equal to a third preset value, and an absolute value of the charging and discharging current corresponding to a later running moment in the running moment pair is less than or equal to a fourth preset value;

[0021] A first calculation module is configured to calculate a self-discharge evaluation index value of the power battery system according to the target voltage corresponding to each running moment of each running moment pair.

[0022] Optionally, the state of charge corresponding to an earlier running moment in the running moment pair is greater than or equal to a fifth preset value.

[0023] Optionally, the first calculation module comprises:

[0024] A first calculation unit is configured to calculate a difference between the target voltages corresponding to the two running moments of a first running moment pair, wherein the first running moment pair is any running moment pair of the at least one running moment pair.

[0025] The second computing unit is configured to calculate a self-discharge characteristic value corresponding to the first pair of operation time points according to a difference between the target voltages corresponding to the two operation time points of the first pair of operation time points and a first time difference value, wherein the self-discharge evaluation index value comprises the self-discharge characteristic value corresponding to the first pair of operation time points, the self-discharge characteristic value corresponding to the first pair of operation time points is a ratio of the difference between the target voltages corresponding to the two operation time points of the first pair of operation time points and the first time difference value, and the first time difference value is a time difference between the two operation time points of the first pair of operation time points.

[0026] Optionally, the device further comprises:

[0027] The second computing module is configured to obtain a first charge amount corresponding to the target voltage according to a mapping relationship between the target voltage and the charge amount corresponding to the earlier operation time point in the first pair of operation time points.

[0028] The second determining module is configured to determine a first self-discharge characteristic threshold value corresponding to the first charge amount.

[0029] The warning module is configured to perform warning processing according to a comparison result of the self-discharge characteristic value corresponding to the first pair of operation time points and the first self-discharge characteristic threshold value.

[0030] Optionally, the warning module is specifically configured to:

[0031] In a case where the self-discharge characteristic value corresponding to the first battery monomer is greater than or equal to the self-discharge characteristic threshold value corresponding to the first battery monomer, the number of the first battery monomer is output, and the first battery monomer is any battery monomer in the plurality of battery monomers.

[0032] In a third aspect, the present application provides an electronic device, comprising a processor, a memory, and a program stored in the memory and executable on the processor, and when the program is executed by the processor, the steps of the self-discharge evaluation method of the power battery system provided in the first aspect are implemented.

[0033] In a fourth aspect, the present application provides a computer readable storage medium, wherein the computer readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the self-discharge evaluation method of the power battery system provided in the first aspect are implemented.

[0034] In the embodiment of the present application, the running data of the power battery system at multiple running moments is acquired, at least one running moment pair is filtered based on the running data of the multiple running moments, and the self-discharge of the power battery system is evaluated based on the running data of the at least one running moment pair. This self-discharge evaluation method is based on the actual running data of the vehicle to evaluate the self-discharge of the power battery system, compared with the self-discharge evaluation method in the prior art in which the power battery system is statically placed for a long time under a specified environment and state of charge, the self-discharge evaluation method has less application limitations and can reduce the impact on the normal use of the vehicle. In addition, the time difference between the two running moments in each filtered running moment pair is greater than or equal to a first preset value, the difference between the charge amounts corresponding to the two running moments in each running moment pair is less than or equal to a second preset value, the difference between the driving ranges corresponding to the two running moments in each running moment pair is less than or equal to a third preset value, and the absolute value of the charge-discharge current corresponding to the later running moment in each running moment pair is less than or equal to a fourth preset value. Therefore, the self-discharge of the power battery system is evaluated based on the running data of the at least one running moment pair, which can ensure the accuracy of the self-discharge evaluation result of the power battery system. BRIEF DESCRIPTION OF DRAWINGS

[0035] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a description of the preferred embodiments and are not intended to limit the scope of the present application. Moreover, the same reference numerals are used throughout the same figures. In the drawings:

[0036] Figure 1 one of the flowcharts of the self-discharge evaluation method provided by the embodiments of the present application;

[0037] Figure 2 one of the flowcharts of the self-discharge evaluation method provided by the embodiments of the present application;

[0038] Figure 3 a structural diagram of the self-discharge evaluation device provided by another embodiment of the present application;

[0039] Figure 4 a structural diagram of the electronic device provided by another embodiment of the present application. DETAILED DESCRIPTION

[0040] Exemplary embodiments of the present application will be described herein below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided so that the present application can be more thoroughly understood and the scope of the present application can be accurately conveyed to those skilled in the art.

[0041] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe 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 can be implemented in an order other than that illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of a kind and are not limited in number, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the objects before and after are in an "or" relationship.

[0042] The embodiments of the present application provide a self-discharge evaluation method of a power battery. Referring to Figure 1 , Figure 1 The embodiments of the present application provide a flowchart of the self-discharge evaluation method, as shown in Figure 1 , comprising the following steps:

[0043] Step 101, obtaining running data corresponding to multiple running moments of a power battery system, wherein the power battery system comprises multiple battery monomers, and the running data corresponding to each of the running moments comprises a target voltage, a state of charge, a driving distance and a charging and discharging current; the target voltage comprises at least one of a first voltage, a second voltage and a voltage of each battery monomer of the multiple battery monomers; the first voltage is the maximum value of the voltages of the multiple battery monomers, and the second voltage is the minimum value of the voltages of the multiple battery monomers;

[0044] In the embodiments, the running data can be running data generated in the actual running process of a vehicle. For example, the running data corresponding to the multiple running moments of the power battery system can be obtained from the running data of the vehicle stored in the cloud.

[0045] Step 102, determining at least one running moment pair according to the state of charge, the driving distance and the charging and discharging current corresponding to the multiple running moments, wherein the time difference between the two running moments in the running moment pair is greater than or equal to a first preset value, the difference between the states of charge corresponding to the two running moments in the running moment pair is less than or equal to a second preset value, the difference between the driving distances corresponding to the two running moments in the running moment pair is less than or equal to a third preset value, and the absolute value of the charging and discharging current corresponding to the later running moment in the running moment pair is less than or equal to a fourth preset value;

[0046] In the embodiment, the first preset value, the second preset value, the third preset value and the fourth preset value can be reasonably set according to actual needs. For example, the first preset value can be 50 hours, the second preset value can be 1%, the third preset value can be 10 meters, and the fourth preset value can be 3 amperes.

[0047] It should be noted that the time difference between the two running time points in each running time point pair is greater than or equal to the first preset value, the difference between the charge amounts corresponding to the two running time points in each running time point pair is less than or equal to the second preset value, the difference between the driving distances corresponding to the two running time points in each running time point pair is less than or equal to the third preset value, and the absolute value of the charging and discharging current corresponding to the later running time point in each running time point pair is less than or equal to the fourth preset value. In this way, the running data of the running time point pair screened out can meet the requirements of the self-discharge evaluation.

[0048] In step 103, a self-discharge evaluation index value of the power battery system is calculated according to the target voltage corresponding to each running time point of each running time point pair.

[0049] For example, the self-discharge characteristic value corresponding to each running time point pair can be calculated according to the target voltage corresponding to each running time point of each running time point pair, and the self-discharge evaluation index value of the power battery system can include the self-discharge characteristic value corresponding to each running time point pair.

[0050] For example, in the case where the target voltage includes multiple voltages, the self-discharge characteristic value corresponding to each voltage corresponding to each running time point pair can be calculated according to the voltage value corresponding to each running time point of each running time point pair, and the self-discharge characteristic value corresponding to each running time point pair can include the self-discharge characteristic value corresponding to each voltage corresponding thereto. For example, in the case where the target voltage includes a first voltage and a second voltage, the self-discharge characteristic value corresponding to the first voltage can be calculated according to the first voltage corresponding to each running time point of each running time point pair, and the self-discharge characteristic value corresponding to the second voltage can be calculated according to the second voltage corresponding to each running time point of each running time point pair. The self-discharge characteristic value corresponding to each running time point pair can include the self-discharge characteristic value corresponding to the first voltage and the self-discharge characteristic value corresponding to the second voltage. It should be noted that the self-discharge characteristic value can include but is not limited to the self-discharge rate.

[0051] In the embodiment of the present application, the running data of the power battery system at multiple running moments is acquired, at least one running moment pair is filtered based on the running data at the multiple running moments, and the self-discharge of the power battery system is evaluated based on the running data of the at least one running moment pair. This self-discharge evaluation method evaluates the self-discharge of the power battery system according to the actual running data of the vehicle, which has less application limitations and can reduce the impact on the normal use of the vehicle compared with the self-discharge evaluation method in the prior art in which the vehicle is left for a long time in a specified environment and state of charge. In addition, the time difference between the two running moments in each filtered running moment pair is greater than or equal to a first preset value, the difference between the state of charge corresponding to the two running moments in each running moment pair is less than or equal to a second preset value, the difference between the driving mileage corresponding to the two running moments in each running moment pair is less than or equal to a third preset value, and the absolute value of the charging and discharging current corresponding to the later running moment in each running moment pair is less than or equal to a fourth preset value. Therefore, the self-discharge of the power battery system is evaluated based on the running data of the at least one running moment pair, which can ensure the accuracy of the self-discharge evaluation result of the power battery system.

[0052] Optionally, the state of charge corresponding to the earlier running moment in the running moment pair is greater than or equal to a fifth preset value.

[0053] The fifth preset value can be reasonably set according to actual needs. For example, the fifth preset value can be 60%.

[0054] In the embodiment, the size of the state of charge corresponding to the earlier running moment in the running moment pair affects the accuracy of the evaluation result to some extent. The running data of the running moment pair at a relatively appropriate moment corresponding to the state of charge of the earlier running moment can be used for self-discharge evaluation to obtain a more accurate self-discharge evaluation result.

[0055] Optionally, the self-discharge evaluation index value of the power battery system is calculated according to the target voltage corresponding to each running moment of each running moment pair, including:

[0056] The difference between the target voltages corresponding to the two running moments of the first running moment pair is calculated, wherein the first running moment pair is any running moment pair of the at least one running moment pair;

[0057] According to the difference between the target voltages corresponding to the two operation time points of the first operation time point pair and the first time difference value, a self-discharge characteristic value corresponding to the first operation time point pair is calculated, wherein the self-discharge evaluation index value comprises the self-discharge characteristic value corresponding to the first operation time point pair, the self-discharge characteristic value corresponding to the first operation time point pair is the ratio of the difference between the target voltages corresponding to the two operation time points of the first operation time point pair and the first time difference value, and the first time difference value is the time difference between the two operation time points of the first operation time point pair.

[0058] The following is described by taking the target voltages comprising a first voltage, a second voltage and the voltages of each battery monomer, and the first operation time point pair comprising a first time point and a second time point as an example:

[0059] The difference between the first voltage corresponding to the first time point and the first voltage corresponding to the second time point is calculated to obtain a first voltage difference value, the difference between the second voltage corresponding to the first time point and the second voltage corresponding to the second time point is calculated to obtain a second voltage difference value, and the difference between the voltage of each battery monomer corresponding to the first time point and the voltage of each battery monomer corresponding to the second time point is calculated.

[0060] The calculation of the self-discharge characteristic value corresponding to the first operation time point pair comprises the calculation of the self-discharge characteristic value corresponding to the first voltage, the calculation of the self-discharge characteristic value corresponding to the second voltage, and the calculation of the self-discharge characteristic value corresponding to each battery monomer. The self-discharge characteristic value corresponding to the first voltage is the ratio of the first voltage difference value and the time difference value between the first time point and the second time point; the self-discharge characteristic value corresponding to the second voltage is the ratio of the second voltage difference value and the time difference value between the first time point and the second time point; and the self-discharge characteristic value of each battery monomer is the ratio of the difference between the voltage of each battery monomer corresponding to the first time point and the voltage of each battery monomer corresponding to the second time point and the time difference value between the first time point and the second time point.

[0061] For example, the self-discharge characteristic value corresponding to the first voltage of the first running time pair can be taken as the self-discharge evaluation index value of the power battery system, or the self-discharge characteristic value corresponding to the second voltage of the first running time pair can be taken as the self-discharge evaluation index value of the power battery system, or the self-discharge characteristic value corresponding to the voltage of each battery monomer of the first running time pair can be taken as the self-discharge evaluation index value of the power battery system, or the maximum value of the self-discharge characteristic value corresponding to the voltage of each battery monomer of the first running time pair can be taken as the self-discharge evaluation index value of the power battery system, or the minimum value of the self-discharge characteristic value corresponding to the voltage of each battery monomer of the first running time pair can be taken as the self-discharge evaluation index value of the power battery system, or the average value of the self-discharge characteristic value corresponding to the voltage of each battery monomer of the first running time pair can be taken as the self-discharge evaluation index value of the power battery system, or the self-discharge characteristic value corresponding to the first voltage and the second voltage of the first running time pair can be taken as the self-discharge evaluation index value of the power battery system, or the self-discharge characteristic value corresponding to the first voltage, the second voltage and the voltage of each battery monomer of the first running time pair can be taken as the self-discharge evaluation index value of the power battery system, and so on.

[0062] In the embodiment, the ratio of the difference between the target voltages corresponding to the two running times of the first running time pair and the first time difference is taken as the self-discharge characteristic value corresponding to the first running time pair. This calculation method can more accurately evaluate the self-discharge condition.

[0063] Optionally, the method further comprises:

[0064] obtaining a first charge amount corresponding to the target voltage according to the mapping relationship between the target voltage and the voltage and the charge amount corresponding to the earlier running time of the first running time pair;

[0065] determining a first self-discharge characteristic threshold corresponding to the first charge amount;

[0066] performing a warning process according to the comparison result of the self-discharge characteristic value corresponding to the first running time pair and the first self-discharge characteristic threshold.

[0067] In the embodiment, the mapping relationship can be obtained according to the voltage-charge amount relationship curve.

[0068] The following is described by taking the target voltage as including the first voltage, the second voltage and the voltage of each battery monomer.

[0069] The above obtaining the first charge amount corresponding to the target voltage can include: obtaining the first charge amount corresponding to the first voltage, obtaining the first charge amount corresponding to the second voltage, and obtaining the first charge amount corresponding to the voltage of each battery monomer.

[0070] The determining the first self-discharge characteristic threshold corresponding to the first charge amount can include: determining the first self-discharge characteristic threshold corresponding to the first charge amount corresponding to the first voltage, determining the first self-discharge characteristic threshold corresponding to the first charge amount corresponding to the second voltage, and determining the first self-discharge characteristic threshold corresponding to the first charge amount corresponding to each battery monomer voltage.

[0071] The pre-warning processing according to the comparison result of the self-discharge characteristic value corresponding to the first running time and the first self-discharge characteristic threshold can include:

[0072] The self-discharge characteristic value corresponding to the first voltage at the first running time is compared with the corresponding first self-discharge characteristic threshold. If the self-discharge characteristic value corresponding to the first voltage is greater than or equal to the first self-discharge characteristic threshold, pre-warning processing is performed. For example, first warning information can be output to prompt that the self-discharge of the power battery system is abnormal, or that the self-discharge characteristic value corresponding to the first voltage is greater than or equal to the corresponding first self-discharge characteristic threshold.

[0073] The self-discharge characteristic value corresponding to the second voltage at the first running time is compared with the corresponding first self-discharge characteristic threshold. If the self-discharge characteristic value corresponding to the second voltage is greater than or equal to the corresponding first self-discharge characteristic threshold, pre-warning processing is performed. For example, second warning information can be output to prompt that the self-discharge of the power battery system is abnormal, or that the self-discharge characteristic value corresponding to the second voltage is greater than or equal to the corresponding first self-discharge characteristic threshold.

[0074] The self-discharge characteristic value corresponding to each battery monomer voltage at the first running time is compared with the corresponding first self-discharge characteristic threshold. If the self-discharge characteristic value corresponding to a certain battery monomer voltage is greater than or equal to the corresponding first self-discharge characteristic threshold, pre-warning processing is performed. For example, third warning information can be output to prompt that the self-discharge of the power battery system is abnormal, or that the self-discharge characteristic value corresponding to the battery monomer voltage is greater than or equal to the corresponding first self-discharge characteristic threshold.

[0075] For example, when the first charge amount corresponding to the target voltage at the first running time is greater than or equal to 70%, and the first self-discharge characteristic threshold corresponding to the first charge amount is 0.06 mV / h, if the self-discharge characteristic value corresponding to the target voltage is greater than or equal to 0.06 mV / h, pre-warning processing is performed.

[0076] In the embodiments of the present application, the pre-warning processing according to the comparison result of the self-discharge characteristic value corresponding to the first running time and the first self-discharge characteristic threshold realizes the evaluation and pre-warning of the battery self-discharge condition.

[0077] Optionally, the target voltage comprises a voltage of each battery cell of the plurality of battery cells, the first running time corresponding self-discharge characteristic value comprises a first running time corresponding self-discharge characteristic value of each battery cell of the plurality of battery cells, and the first self-discharge characteristic threshold comprises a first self-discharge characteristic threshold corresponding to each battery cell of the plurality of battery cells.

[0078] The warning processing according to the comparison result of the first running time corresponding self-discharge characteristic value and the first charge amount corresponding self-discharge characteristic threshold comprises:

[0079] In a case where the first battery cell corresponding self-discharge characteristic value is greater than or equal to the first battery cell corresponding self-discharge characteristic threshold, the number of the first battery cell is outputted, and the first battery cell is any battery cell of the plurality of battery cells.

[0080] For example, when the first battery cell corresponding first charge amount is greater than or equal to 70%, the first charge amount corresponding self-discharge characteristic threshold is 0.06 mV / h, and the first battery cell corresponding self-discharge characteristic value is greater than or equal to 0.06 mV / h, an alarm signal can be outputted to prompt the existence of self-discharge abnormality, and the number of the first battery cell is outputted.

[0081] In the embodiment, in a case where the first battery cell corresponding self-discharge characteristic value is greater than or equal to the first battery cell corresponding self-discharge characteristic threshold, the number of the first battery cell is outputted, so as to quickly locate the battery cell with self-discharge abnormality.

[0082] Referring to Figure 2 , Figure 2 is a flowchart of a self-discharge evaluation method provided by the embodiment. As shown in Figure 2 The self-discharge evaluation method of the power battery system provided by the embodiment comprises the following steps:

[0083] In step 201, running data corresponding to a plurality of running times of a power battery system is acquired, wherein the power battery system comprises a plurality of battery cells, and the running data corresponding to each running time comprises a first voltage, a second voltage, a voltage of each battery cell of the plurality of battery cells, a state of charge, a driving distance and a charging and discharging current; the first voltage is a maximum value of the voltages of the plurality of battery cells, and the second voltage is a minimum value of the voltages of the plurality of battery cells.

[0084] In step 202, at least one operation time pair is determined according to the charge amount and the driving distance corresponding to the plurality of operation time points, wherein the difference between the charge amounts corresponding to the two operation time points in the operation time pair is less than or equal to a first preset value, and the difference between the driving distances corresponding to the two operation time points in the operation time pair is less than or equal to a second preset value.

[0085] In step 203, the time increment ΔT of the latter time T2 and the former time T1 in the operation time pair is calculated, and it is determined whether the time increment ΔT is greater than or equal to a third preset value, and the operation data of the operation time pair whose time increment ΔT is greater than or equal to the third preset value is reserved.

[0086] In step 204, the operation data of the operation time pair whose charge amount corresponding to the former time T1 in the operation time pair is greater than or equal to a fourth preset value is reserved.

[0087] In step 205, the operation data of the operation time pair whose absolute value of the charge and discharge current corresponding to the latter time T2 in the operation time pair is less than or equal to a fifth preset value is reserved.

[0088] It should be noted that in the above steps, after layer-by-layer screening, the difference between the charge amounts corresponding to the two operation time points in each operation time pair is less than or equal to the first preset value, the difference between the driving distances corresponding to the two operation time points in each operation time pair is less than or equal to the second preset value, the time increment ΔT of the two operation time points in each operation time pair is greater than or equal to the third preset value, the charge amount corresponding to the former time T1 in each operation time pair is greater than or equal to the fourth preset value, and the absolute value of the charge and discharge current corresponding to the latter time T2 in each operation time pair is less than or equal to the fifth preset value, so that the operation data of the operation time pair screened can meet the requirements of self-discharge evaluation.

[0089] In step 206, the voltage difference ΔV of the T1 and T2 time points is calculated according to the first voltage Vmax, the second voltage Vmin and the voltage Vi of each battery cell of the T1 and T2 time points of the first operation time pair, and the self-discharge rate K = ΔV / ΔT is calculated, wherein ΔT is the time difference of the T1 and T2 time points, and the first operation time pair is any operation time pair in the at least one operation time pair screened in the previous step.

[0090] In the above step, the calculation of the self-discharge rate includes: calculating the self-discharge rate Kmax = ΔVmax / ΔT corresponding to the first voltage Vmax; calculating the self-discharge rate Kmin = ΔVmin / ΔT corresponding to the second voltage Vmin; and calculating the self-discharge rate Ki = ΔVi / ΔT of each battery cell.

[0091] In the above steps, by calculating the first voltage, the second voltage, and the self-discharge rate corresponding to each battery monomer, the self-discharge condition of the power battery system is evaluated.

[0092] In step 207, according to the voltage of T1 of the first running time point, the corresponding first charge amount is obtained by linear interpolation table lookup, and the self-discharge early warning threshold corresponding to the first charge amount is determined.

[0093] In the above steps, determining the self-discharge early warning threshold comprises: according to the first voltage Vmax of T1, the corresponding first charge amount is obtained by linear interpolation table lookup, and the self-discharge early warning threshold corresponding to the first charge amount is determined; according to the second voltage Vmin of T1, the corresponding first charge amount is obtained by linear interpolation table lookup, and the self-discharge early warning threshold corresponding to the first charge amount is determined; according to the voltage Vi of each battery monomer of T1, the corresponding first charge amount is obtained by linear interpolation table lookup, and the self-discharge early warning threshold corresponding to the first charge amount is determined.

[0094] In step 208, it is judged whether K reaches the self-discharge early warning threshold.

[0095] In the above steps, the self-discharge rate Kmax corresponding to the first voltage Vmax is compared with the corresponding self-discharge early warning threshold; the self-discharge rate Kmin corresponding to the second voltage Vmin is compared with the corresponding self-discharge early warning threshold; the self-discharge rate Ki of each battery monomer is compared with the corresponding self-discharge early warning threshold.

[0096] In step 209, when K reaches the self-discharge early warning threshold, a self-discharge early warning signal is sent.

[0097] In the above steps, when the self-discharge rate Kmax corresponding to the first voltage Vmax is greater than or equal to the corresponding self-discharge early warning threshold, the self-discharge early warning signal is sent; when the self-discharge rate Kmin corresponding to the second voltage Vmin is greater than or equal to the corresponding self-discharge early warning threshold, the self-discharge early warning signal is sent; when the self-discharge rate Ki of any battery monomer in each battery monomer is greater than or equal to the corresponding self-discharge early warning threshold, the self-discharge early warning signal is sent, and the number of the battery monomer is output.

[0098] For example, the first preset value can be set to 1%, the second preset value can be set to 10 meters, the third preset value can be set to 50 hours, the fourth preset value can be set to 60%, and the fifth preset value can be set to 3 amperes.

[0099] For example, when the first charge amount corresponding to the first voltage or the second voltage is greater than or equal to 70%, the self-discharge early warning threshold corresponding to the first charge amount is 0.06 mV / h, and if the self-discharge rate is greater than or equal to 0.06 mV / h, the self-discharge early warning signal is sent.

[0100] For example, when the first charge amount of one of the plurality of battery monomers is greater than or equal to 70%, and the self-discharge early warning threshold corresponding to the first charge amount is 0.06 mV / h, if the self-discharge rate of the battery monomer is greater than or equal to 0.06 mV / h, an alarm signal is output to prompt the existence of self-discharge abnormality, and the number of the battery monomer is output.

[0101] Referring to Figure 3 , Figure 3 is a structural diagram of a charging control device of a power battery provided by the embodiment of the present application.

[0102] As Figure 3 indicated, the self-discharge evaluation device 300 of the power battery comprises:

[0103] The acquisition module 301 is configured to acquire running data corresponding to a plurality of running moments of a power battery system, wherein the power battery system comprises a plurality of battery monomers, and the running data corresponding to each of the running moments comprises a target voltage, a state of charge, a driving distance, and a charging and discharging current; the target voltage comprises at least one of a first voltage, a second voltage, and a voltage of each of the plurality of battery monomers; the first voltage is the maximum value of the voltages of the plurality of battery monomers, and the second voltage is the minimum value of the voltages of the plurality of battery monomers.

[0104] The first determination module 302 is configured to determine at least one running moment pair according to the state of charge, the driving distance, and the charging and discharging current corresponding to the plurality of running moments, wherein the time difference between the two running moments in the running moment pair is greater than or equal to a first preset value, the difference between the states of charge corresponding to the two running moments in the running moment pair is less than or equal to a second preset value, the difference between the driving distances corresponding to the two running moments in the running moment pair is less than or equal to a third preset value, and the absolute value of the charging and discharging current corresponding to the later running moment in the running moment pair is less than or equal to a fourth preset value.

[0105] The first calculation module 303 is configured to calculate a self-discharge evaluation index value of the power battery system according to the target voltage corresponding to each of the running moments of each of the running moment pairs.

[0106] Optionally, the state of charge corresponding to the earlier running moment in the running moment pair is greater than or equal to a fifth preset value.

[0107] Optionally, the first calculation module comprises:

[0108] The first calculation unit is configured to calculate the difference between the target voltages corresponding to the two running moments of the first running moment pair, wherein the first running moment pair is any running moment pair of the at least one running moment pair.

[0109] a second calculation unit, configured to calculate a self-discharge characteristic value corresponding to the first pair of operation time according to a difference between the target voltages corresponding to the two operation times of the first pair of operation time and a first time difference value, wherein the self-discharge evaluation index value comprises the self-discharge characteristic value corresponding to the first pair of operation time, the self-discharge characteristic value corresponding to the first pair of operation time is a ratio of the difference between the target voltages corresponding to the two operation times of the first pair of operation time and the first time difference value, and the first time difference value is a time difference between the two operation times of the first pair of operation time. Optionally, the self-discharge evaluation device, wherein the device further comprises:

[0110] a second calculation module, configured to obtain a first charge amount corresponding to the target voltage according to a mapping relationship between the target voltage corresponding to the earlier operation time of the first pair of operation time and the voltage and the charge amount;

[0111] a second determination module, configured to determine a first self-discharge characteristic threshold value corresponding to the first charge amount;

[0112] a warning module, configured to perform warning processing according to a comparison result of the self-discharge characteristic value corresponding to the first pair of operation time and the first self-discharge characteristic threshold value.

[0113] Optionally, the warning module is specifically configured to:

[0114] in a case where the self-discharge characteristic value corresponding to the first battery monomer of the plurality of battery monomers is greater than or equal to the self-discharge characteristic threshold value corresponding to the first battery monomer, outputting a number of the first battery monomer, and the first battery monomer is any battery monomer in the plurality of battery monomers.

[0115] Referring to Figure 4 , Figure 4 is a structural diagram of an electronic device provided by the embodiment of the present application, as shown in Figure 4 the electronic device 400 comprises a processor 401, a memory 402, and a program or instruction stored on the memory and executable on the processor; the program or instruction is executed by the processor 401 to realize each process of the self-discharge evaluation method embodiment, and can achieve the same technical effect, to avoid repetition, which will not be described here.

[0116] An embodiment of the present application provides a computer readable storage medium. The computer readable storage medium stores a program, and the program is executed by a processor to implement each process of the self-discharge evaluation method embodiment and achieve the same technical effects. To avoid repetition, details are not described herein. The readable storage medium can be any available medium or data storage device accessible by the processor, including but not limited to a magnetic memory (for example, a floppy disk, a hard disk, a magnetic tape, a magneto-optical disk (MO) and the like), an optical memory (for example, a CD, a DVD, a BD, a HVD and the like), and a semiconductor memory (for example, a ROM, an EPROM, an EEPROM, a non-volatile memory (NAND FLASH), a solid state disk (SSD)) and the like.

Claims

1. A method for evaluating the self-discharge of a power battery system, characterized in that, include: The system acquires operational data corresponding to multiple operating moments of a power battery system, wherein the power battery system comprises multiple battery cells, and the operational data corresponding to each operating moment includes: target voltage, charge capacity, driving range, and charging / discharging current; the target voltage includes at least one of the following: a first voltage, a second voltage, and the voltage of each of the multiple battery cells; the first voltage is the maximum value among the voltages of the multiple battery cells, and the second voltage is the minimum value among the voltages of the multiple battery cells; Based on the charge, mileage, and charging / discharging current corresponding to the plurality of operating times, at least one pair of operating times is determined, wherein the time difference between the two operating times in the pair is greater than or equal to a first preset value, the difference between the charge corresponding to the two operating times in the pair is less than or equal to a second preset value, the difference between the mileage corresponding to the two operating times in the pair is less than or equal to a third preset value, and the absolute value of the charging / discharging current corresponding to the later operating time in the pair is less than or equal to a fourth preset value. The self-discharge evaluation index value of the power battery system is calculated based on the target voltage corresponding to each operating time of each operating time pair; The step of calculating the self-discharge evaluation index value of the power battery system based on the target voltage corresponding to each operating time of each operating time pair includes: Calculate the difference in target voltages corresponding to the two operating times of the first operating time pair, wherein the first operating time pair is any one of the at least one operating time pair; Based on the difference in target voltage corresponding to the two operating times of the first operating time pair and the first time difference, the self-discharge characteristic value corresponding to the first operating time pair is calculated. The self-discharge evaluation index value includes the self-discharge characteristic value corresponding to the first operating time pair. The self-discharge characteristic value corresponding to the first operating time pair is the ratio of the difference in target voltage corresponding to the two operating times of the first operating time pair to the first time difference. The first time difference is the time difference between the two operating times of the first operating time pair.

2. The method according to claim 1, characterized in that, The charge corresponding to the earlier running time in the running time pair is greater than or equal to the fifth preset value.

3. The method according to claim 1, characterized in that, The method further includes: Based on the target voltage corresponding to the earlier operating time in the first operating time pair and the mapping relationship between voltage and charge, the first charge corresponding to the target voltage is obtained; Determine the first self-discharge characteristic threshold corresponding to the first charge amount; An early warning process is performed based on the comparison result between the corresponding self-discharge characteristic value and the first self-discharge characteristic threshold at the first operating time.

4. The method according to claim 3, characterized in that, The target voltage includes the voltage of each individual battery cell in the plurality of battery cells, the self-discharge characteristic value corresponding to the first operating time includes the self-discharge characteristic value corresponding to each individual battery cell in the plurality of battery cells, and the first self-discharge characteristic threshold includes the self-discharge characteristic threshold corresponding to each individual battery cell in the plurality of battery cells. The step of performing early warning processing based on the comparison result between the self-discharge characteristic value corresponding to the first operating time and the self-discharge characteristic threshold corresponding to the first charge quantity includes: If the self-discharge characteristic value of the first battery cell in the plurality of battery cells is greater than or equal to the self-discharge characteristic threshold of the first battery cell, the number of the first battery cell is output, where the first battery cell is any one of the plurality of battery cells.

5. A self-discharge assessment device for a power battery system, characterized in that, include: The acquisition module is used to acquire operating data corresponding to multiple operating moments of the power battery system. The power battery system includes multiple battery cells, and the operating data corresponding to each operating moment includes: target voltage, charge capacity, driving range, and charging / discharging current. The target voltage includes at least one of the following: a first voltage, a second voltage, and the voltage of each of the multiple battery cells. The first voltage is the maximum value among the voltages of the multiple battery cells, and the second voltage is the minimum value among the voltages of the multiple battery cells. The first determining module is used to determine at least one pair of operating times based on the charge, mileage and charging / discharging current corresponding to the plurality of operating times, wherein the time difference between two operating times in the pair of operating times is greater than or equal to a first preset value, the difference between the charge corresponding to two operating times in the pair of operating times is less than or equal to a second preset value, the difference between the mileage corresponding to two operating times in the pair of operating times is less than or equal to a third preset value, and the absolute value of the charging / discharging current corresponding to the later operating time in the pair of operating times is less than or equal to a fourth preset value. The first calculation module is used to calculate the self-discharge evaluation index value of the power battery system based on the target voltage corresponding to each operating time of each operating time pair. The first calculation module includes: The first calculation unit is used to calculate the difference of the target voltage corresponding to the two running times of the first running time pair, wherein the first running time pair is any running time pair of the at least one running time pair; The second calculation unit is used to calculate the self-discharge characteristic value corresponding to the first operating time pair based on the difference of the target voltage corresponding to the two operating times of the first operating time pair and the first time difference. The self-discharge evaluation index value includes the self-discharge characteristic value corresponding to the first operating time pair. The self-discharge characteristic value corresponding to the first operating time pair is the ratio of the difference of the target voltage corresponding to the two operating times of the first operating time pair to the first time difference. The first time difference is the time difference between the two operating times of the first operating time pair.

6. The apparatus according to claim 5, characterized in that, The charge corresponding to the earlier running time in the running time pair is greater than or equal to the fifth preset value.

7. The apparatus according to claim 5, characterized in that, The device further includes: The second calculation module is used to obtain the first charge corresponding to the target voltage based on the target voltage corresponding to the earlier running time in the first running time pair and the mapping relationship between voltage and charge. The second determining module is used to determine the first self-discharge characteristic threshold corresponding to the first charge amount; The early warning module is used to perform early warning processing based on the comparison result between the corresponding self-discharge characteristic value and the first self-discharge characteristic threshold at the first operating time.

8. The apparatus according to claim 7, characterized in that, The early warning module is specifically used for: If the self-discharge characteristic value of the first battery cell in the plurality of battery cells is greater than or equal to the self-discharge characteristic threshold of the first battery cell, the number of the first battery cell is output, where the first battery cell is any one of the plurality of battery cells.

9. An electronic device, characterized in that, It includes a processor, a memory, and a program stored in the memory and running on the processor, wherein when the program is executed by the processor, it implements the self-discharge assessment method for a power battery system as described in any one of claims 1 to 4.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the self-discharge assessment method for a power battery system as described in any one of claims 1 to 4.

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