CN114879039A - Detection method, equipment and storage medium of power battery system, vehicle - Google Patents

Abstract

The invention discloses a detection method, equipment, storage medium, and vehicle for a power battery system. The power battery system includes a plurality of cells, and the plurality of cells are connected in series. The method includes: charging the power battery system to a fully charged state; The power battery system is respectively discharged to the first preset SOC value to the Mth preset SOC value, and under each preset SOC value, a pulse test is performed on the power battery system to obtain the performance index of each unit, wherein the i-th preset SOC value is Assume that the SOC value is greater than the i+1th preset SOC value, i=1, 2, . The method conducts pulse tests on the power battery system under different SOC values, taking a single cell in the power battery system as the object, and judges the consistency of the cells of the power battery system according to the performance indicators obtained in the pulse test. Get a comprehensive understanding of the cell consistency of the power battery system under different working conditions.

Description

Detection method, equipment and storage medium of power battery system, vehicle

technical field

The invention relates to the technical field of battery detection, and in particular, to a detection method, device, storage medium and vehicle of a power battery system.

Background technique

With the widespread application of power batteries in electric vehicles, issues such as battery life and safety have become increasingly prominent. One of the main reasons is that there are differences between the cells after the batteries are grouped.

At present, the test of the consistency of power batteries is mainly based on the battery module formed by the series of monomers as the main test object, and the battery module in practical application has two structures of series and parallel. In addition, the vehicle power battery system is composed of multiple battery modules connected in series. When testing the consistency of the vehicle power battery system, it is impossible to test individual battery modules or cells one by one. In addition, the current power battery system consistency detection indicators mainly include voltage, DC internal resistance, capacity and SOC (State of Charge, remaining power). The detection conditions and indicators are single, which cannot be applied to actual scenarios, especially for extreme working conditions The judgment of the change trend of electrical properties.

SUMMARY OF THE INVENTION

The present invention aims to solve one of the technical problems in the related art at least to a certain extent. Therefore, an object of the present invention is to propose a detection method for a power battery system, which can comprehensively understand the cell consistency of the power battery system under different working conditions.

A second object of the present invention is to provide a computer-readable storage medium.

The third object of the present invention is to provide a detection device for a power battery system.

A fourth object of the present invention is to propose a vehicle.

In order to achieve the above object, an embodiment of the first aspect of the present invention provides a detection method for a power battery system, the power battery system includes a plurality of cells, and the plurality of cells are connected in series, and the method includes: connecting all the cells in series. charging the power battery system to a fully charged state; discharging the power battery system to a first preset SOC value to an Mth preset SOC value, respectively, and performing a pulse test on the power battery system at each preset SOC value , to obtain the performance index of each of the monomers, wherein the i-th preset SOC value is greater than the i+1-th preset SOC value, i=1,2,...,M, where M is an integer greater than or equal to 2; according to the The performance index is used to judge the consistency of the monomers of the power battery system.

In the power battery system detection method of the embodiment of the present invention, for the power battery system under different SOC values, a single cell in the power battery system is used as the object, and the pulse test is performed, and the power is judged according to the performance index obtained in the pulse test. The cell consistency of the battery system is to fully understand the cell consistency of the power battery system under different working conditions.

According to an embodiment of the present invention, the charging the power battery system to a fully charged state includes: acquiring the SOH value and capacity of the power battery system; determining a target rate according to the SOH value or the capacity; The target rate adopts a constant current and constant voltage charging mode to charge the power battery system to a fully charged state; wherein, when discharging the power battery system to the first preset SOC value to the Mth preset SOC value, the The target rate discharges the power battery system.

According to an embodiment of the present invention, performing a pulse test on the power battery system to obtain the performance indicators of each of the cells includes: performing pulse discharge on the power battery system for a first preset time, and recording the pulse discharge process The pulse discharge parameters of each cell in the above, wherein the pulse discharge parameters include the open circuit voltage Udis0 before each cell starts to discharge, the voltage Ud and the temperature Td during the discharge process; the first preset time, and record the pulse charging parameters of each cell during the pulse charging process, wherein the pulse charging parameters include the open-circuit voltage Ucha0 before each cell starts charging, the voltage Uc and the temperature during the charging process Tc; calculate the performance index of each cell during pulse discharge according to the pulse discharge parameter, and calculate the performance index of each cell during pulse charge according to the pulse charge parameter, wherein the performance of the pulse discharge The indicators include at least two of pulse discharge ohmic internal resistance, pulse discharge internal resistance, pulse discharge power and pulse discharge temperature difference, and the performance indicators during pulse charging include pulse charging ohmic internal resistance, pulse charging internal resistance, pulse charging power and at least two of the pulse charging temperature difference.

According to an embodiment of the present invention, after the power battery system is discharged to the i-th preset SOC value, before the pulse discharge is performed on the power battery system, the power battery system is put on hold for a second preset time; After the power battery system performs pulse discharge, before pulse charging the power battery system, the power battery system is put on hold for a third preset time; wherein, the pulse discharge current is the maximum discharge current allowed by the cell, and the pulse charge current is 0.75 times the pulse discharge current, the first preset time is 10s, the value range of the second preset time is 1-2h, and the third preset time is 40s.

According to an embodiment of the present invention, judging the consistency of the cells of the power battery system according to the performance index includes: performing statistics on the performance index during the pulse discharge according to each preset SOC value, and The performance indicators during the pulse charging are separately counted according to each preset SOC value; the consistency of the cells of the power battery system is judged according to the statistical results.

According to an embodiment of the present invention, the detection method for the power battery system further includes: calculating the voltage range between the cells according to the voltage Ud and/or the voltage Uc, and calculating the voltage range between the cells according to the temperature Td and/or the temperature Tc to calculate the temperature range between each of the monomers; according to the voltage range and the temperature range, determine an abnormal monomer.

According to an embodiment of the present invention, in the detection method of the power battery system, the voltage Ud includes the voltage Udis1 when the cell starts to discharge and the voltage Udis2 after the discharge ends, and the voltage Uc includes the voltage when the cell starts to charge Ucha1 and the voltage Ucha2 after the end of charging, the temperature Td includes the temperature Tdis1 when the cell starts to discharge and the temperature Tdis2 after the end of discharge, the temperature Tc includes the temperature Tcha1 when the cell starts to charge and the temperature Tcha2 after the end of charging , the performance index is obtained by the following formula:

RdisΩ=(Udis0-Udis1)/Imax,

RchaΩ=(Ucha1-Ucha0)/0.75Imax,

Rdis=(Udis0-Udis2)/Imax,

Rcha=(Ucha2-Ucha0)/0.75Imax,

Pdis=Udis2*(Udis0-Udis2)/Rdis=Imax*Udis2,

Pcha=Ucha2*(Ucha2-Ucha0)/Rcha=0.75Imax*Ucha2,

ΔTd=Tdis1-Tdis2,

ΔTc=Tcha1-Tcha2,

Wherein, RdisΩ is the ohmic internal resistance of the pulse discharge, RchaΩ is the ohmic internal resistance of the pulse charging, Rdis is the pulse discharge internal resistance, Rcha is the pulse charging internal resistance, Pdis is the pulse discharge power, and Pcha is the pulse discharge power. For the pulse charging power, Imax is the pulse discharge current, 0.75Imax is the pulse charge charging current, ΔTd is the pulse discharge temperature difference, and ΔTc is the pulse charge temperature difference.

In order to achieve the above object, the second embodiment of the present invention provides a computer-readable storage medium. When the computer program is executed by a processor, the detection method of the power battery system of the above-mentioned embodiment is implemented.

In order to achieve the above purpose, the third embodiment of the present invention proposes a detection device for a power battery system, including a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the The above-mentioned detection method of the power battery system.

To achieve the above objective, a fourth embodiment of the present invention provides a vehicle, including the above-mentioned detection device for a power battery system.

Additional aspects and advantages of the present invention will be set forth, in part, from the following description, and in part will be apparent from the following description, or may be learned by practice of the invention.

Description of drawings

1 is a flowchart of a detection method of a power battery system according to an embodiment of the present invention;

FIG. 2 is a flowchart of charging the power battery system to a fully charged state according to an embodiment of the present invention;

FIG. 3 is a flowchart of a pulse test on a power battery system according to a specific embodiment of the present invention;

FIG. 4 is a flow chart of judging the consistency of the cells of the power battery system according to a specific embodiment of the present invention;

FIG. 5 is a flow chart of determining abnormal cells according to a specific embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a vehicle according to an embodiment of the present invention.

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, and are intended to explain the present invention and should not be construed as limiting the present invention.

The detection method, device, storage medium, and vehicle of the power battery system according to the embodiment of the present invention will be described in detail below with reference to FIGS. 1-6 of the description and specific embodiments.

The power battery system of the embodiment of the present invention includes a plurality of cells, and the plurality of cells are connected in series.

Specifically, the power battery system of the embodiment of the present invention is composed of a plurality of cells connected in series.

FIG. 1 is a flowchart of a detection method of a power battery system according to an embodiment of the present invention. As shown in Figure 1, the detection method of the power battery system may include:

S1, charge the power battery system to a fully charged state.

As a feasible implementation manner, as shown in FIG. 2 , charging the power battery system to a fully charged state may include:

S11, obtain the SOH value and capacity of the power battery system;

S12, determine the target magnification according to the SOH value or capacity;

S13 , using the constant current and constant voltage charging mode at the target rate to charge the power battery system to a fully charged state; wherein, when discharging the power battery system to the first preset SOC value to the Mth preset SOC value, use the target The rate is to discharge the power battery system, and the target rate is 0.2-0.5C.

Specifically, the SOH value and capacity of the power battery system are obtained, where the SOH (state of health, battery health) value represents the percentage of the current capacity of the battery to the factory capacity. When charging the power battery system, the target rate is determined according to the SOH value or capacity of the power battery system, so as to charge according to the target rate. Charge to full state.

It should be noted that when the power battery system is charged in the constant current and constant voltage charging mode, the SOC value of the power battery system is displayed as 100%, the constant current charging reaches the cut-off voltage, and the charging current is 0.2C-0.5 C, ends when the current reaches 0.05C.

S2: Discharge the power battery system to the first preset SOC value to the Mth preset SOC value, respectively, and at each preset SOC value, perform a pulse test on the power battery system to obtain the performance index of each unit, wherein the first The i preset SOC value is greater than the i+1th preset SOC value, i=1, 2, . . . , M, where M is an integer greater than or equal to 2.

Specifically, when the consistency of the power battery system is checked, pulse tests are performed on the power battery system under different SOC values to fully understand the performance indicators of each unit of the power battery system under different working conditions, as well as the power battery system. The consistency of the monomers of the system, especially the consistency of the monomers of the power battery system under extreme conditions.

As a feasible implementation manner, as shown in Figure 3, the power battery system is subjected to a pulse test to obtain the performance indicators of each cell, which may include:

S21, perform pulse discharge on the power battery system for a first preset time, and record the pulse discharge parameters of each cell during the pulse discharge process, wherein the pulse discharge parameters include the open circuit voltage Udis0 before each cell starts to discharge, and the pulse discharge parameters during the discharge process. Voltage Ud and temperature Td;

S22, perform pulse charging on the power battery system for a first preset time, and record the pulse charging parameters of each cell during the pulse charging process, wherein the pulse charging parameters include the open-circuit voltage Ucha0 of each cell before charging, and the pulse charging parameters during the charging process. Voltage Uc and temperature Tc;

S23, calculate the performance index of each cell during pulse discharge according to the pulse discharge parameter, and calculate the performance index of each cell during pulse charge according to the pulse charge parameter, wherein the pulse discharge performance index includes the pulse discharge ohmic internal resistance, the pulse discharge internal resistance , at least two of pulse discharge power and pulse discharge temperature difference; performance indicators during pulse charging include at least two of pulse charging ohmic internal resistance, pulse charging internal resistance, pulse charging power and pulse charging temperature difference.

In the embodiment of the present invention, the pulse test performed on the power battery system includes a pulse discharge test and a pulse charge test.

In this embodiment, after the power battery system is discharged to the i-th preset SOC value, and before pulse discharge is performed on the power battery system, the power battery system is put on hold for a second preset time; after the power battery system is pulsed discharged, Before the pulse charging of the power battery system, the power battery system is put on hold for a third preset time; wherein, the pulse discharge current is the maximum discharge current allowed by the monomer, the pulse charge current is 0.75 times the pulse discharge current, and the first preset time is 10s, the value range of the second preset time is 1-2h, and the third preset time is 40s.

In the embodiment of the present invention, the voltage Ud includes the voltage Udis1 when the cell starts to discharge and the voltage Udis2 after the discharge ends, the voltage Uc includes the voltage Ucha1 when the cell starts charging and the voltage Ucha2 after the charging ends, and the temperature Td includes the single The temperature Tdis1 when the cell starts to discharge and the temperature Tdis2 after the discharge ends, and the temperature Tc includes the temperature Tcha1 when the cell starts to charge and the temperature Tcha2 after the charging ends. The performance index can be obtained by the following formula:

RdisΩ=(Udis0-Udis1)/Imax,

RchaΩ=(Ucha1-Ucha0)/0.75Imax,

Rdis=(Udis0-Udis2)/Imax,

Rcha=(Ucha2-Ucha0)/0.75Imax,

Pdis=Udis2*(Udis0-Udis2)/Rdis=Imax*Udis2,

Pcha=Ucha2*(Ucha2-Ucha0)/Rcha=0.75Imax*Ucha2,

ΔTd=Tdis1-Tdis2,

ΔTc=Tcha1-Tcha2,

Among them, RdisΩ is the ohmic internal resistance of pulse discharge, RchaΩ is the ohmic internal resistance of pulse charging, Rdis is the internal resistance of pulse discharge, Rcha is the internal resistance of pulse charging, Pdis is the pulse discharge power, Pcha is the pulse charging power, Imax is the pulse discharge current, 0.75Imax is the pulse charging charging current, ΔTd is the pulse discharge temperature difference, and ΔTc is the pulse charging temperature difference.

S3, according to the performance index, determine the consistency of the monomers of the power battery system.

In the embodiment of the present invention, as shown in FIG. 4 , according to the performance index, judging the consistency of the cells of the power battery system may include:

S31 , performing statistics on performance indicators during pulse discharge according to each preset SOC value, and performing statistics on performance indicators during pulse charging according to each preset SOC value;

S32, according to the statistical result, determine the consistency of the cells of the power battery system.

Specifically, after obtaining the pulse discharge performance indicators and the performance indicators during pulse charging corresponding to multiple different preset SOC values of the power battery system, the pulse discharge performance indicators and the performance indicators during pulse charging are respectively determined according to the preset SOC values. Statistics are performed to judge the consistency of the cells of the battery system. Exemplarily, the obtained pulse discharge performance indicators and performance indicators during pulse charging corresponding to different preset SOC values may be drawn into a table or icon according to the pulse discharge performance indicators, the performance during pulse charging, and the corresponding preset SOC values. , by detecting whether there is abnormal data or data trend, to judge the consistency of the battery system. When abnormal data or abnormal trends appear, it indicates that the cells of the battery system are inconsistent.

In an embodiment of the present invention, as shown in FIG. 5 , the detection method of the power battery system may further include:

S41, calculating the voltage range between the cells according to the voltage Ud and/or the voltage Uc, and calculating the temperature range between the cells according to the temperature Td and/or the temperature Tc;

S42, according to the voltage range and the temperature range, determine the abnormal single cell.

Specifically, when judging whether a cell is abnormal, the voltage range between the cells is calculated according to the recorded voltage Ud and/or voltage Uc of each cell, and the temperature Td and/or temperature of each cell are recorded according to the recorded temperature Td and/or temperature. Tc, calculate the temperature range between each cell, compare the voltage range and temperature range of each cell in the power battery system, and find out the abnormal cell.

Taking M=3, the power battery system in a fully charged state is discharged to the first preset SOC value of 80%, the second preset SOC value of 50% and the third preset SOC value of 10 as an example, for the power battery system The pulse test is explained:

Before testing the monomer consistency of the power battery system, prepare a good power battery system with an SOH value of about 95%, such as a vehicle power lithium-ion battery system. According to the SOH value of the power battery system, after the target rate is determined to be 0.5C, the power battery system is charged in the mode of constant current and constant voltage at the target rate of 0.5C, and charged to a fully charged state (that is, the power battery system is fully charged). SOC value is 100%).

Discharge the charged power battery system with constant current to SOC=80%.

Put the discharged power battery system on hold for 2h.

After the shelf time is over, use the maximum discharge current (pulse discharge current) allowed by the cell to conduct a pulse discharge test on the power battery system, pulse discharge for 10s, and record the pulse discharge parameters during the pulse discharge process: the open circuit before each cell starts to discharge The voltage Udis0, the voltage Ud during the discharge process (the voltage Udis1 when the cell starts to discharge and the voltage Udis2 after the discharge ends) and the temperature Td (the temperature Tdis1 when the cell starts to discharge and the temperature Tdis2 after the discharge ends).

Put the discharged power battery system on hold for 40s.

After the resting time is over, the power battery system is charged for 10s with a pulse discharge current of 0.75 times, and the pulse charging parameters during the pulse charging process are recorded: the open-circuit voltage Ucha0 of each cell before charging, the voltage Uc ( The voltage Ucha1 at the time of starting charging of the cell and the voltage Ucha2 after the end of charging) and the temperature Tc (the temperature Tcha1 at the time of starting the charging of the cell and the temperature Tcha2 after the end of charging).

According to the recorded pulse discharge parameters with the first preset SOC value of 80% and the known pulse discharge current, the above corresponding formula is used to calculate the performance index of the pulse discharge of each cell with the first preset SOC value of 80%: pulse discharge Discharge ohmic internal resistance, pulse discharge internal resistance, pulse discharge power and pulse discharge temperature difference.

According to the recorded pulse charging parameters with the first preset SOC value of 80% and the known pulse discharge current, the above corresponding formula is used to calculate the performance index of each cell with the first preset SOC value of 80% during pulse charging: pulse Charging ohmic internal resistance, pulse charging internal resistance, pulse charging power and pulse charging temperature difference.

Under the same test environment, discharge the power battery system at a target rate of 0.5C to SOC values of 50% and 10%, and repeat the above steps to obtain preset SOC values of 80%, 50% and 10%. The performance indicators of each monomer during pulse discharge and the performance indicators during pulse charging.

The obtained preset SOC values of 80%, 50% and 10% of the performance indicators of each cell during pulse discharge and the performance indicators of each cell during pulse charging are based on the performance indicators of pulse discharge, performance during pulse charging and corresponding The preset SOC value of the battery is drawn into a table, and the consistency of the battery system is judged by detecting whether there is abnormal data. When abnormal data occurs, it indicates that the cells of the battery system are inconsistent. The voltage range and temperature range of each cell in the power battery system can be compared to find out abnormal cells.

As another specific embodiment, before testing the unit consistency of the power battery system, a complete vehicle power lithium-ion battery system with a capacity of about 90% can be prepared. According to the capacity of the power battery system, after the target rate is determined to be 0.3C, the power battery system is charged in a constant current and constant voltage mode with a target rate of 0.3C and charged to a fully charged state.

Discharge the charged power battery system with constant current to SOC value=80%. Put the discharged vehicle power lithium-ion battery system on hold for 1 hour. After the shelving time is over, conduct a pulse discharge test and a pulse charge test on the power battery system with the maximum allowable discharge current (pulse discharge current) of the monomer (wherein, the pulse discharge test and the pulse charge test are as described above, after the pulse discharge test , it is necessary to put the discharged power battery system on hold for 40s), and record the pulse discharge and charging parameters of each cell during the pulse discharge and charging process: the open circuit voltage of each cell before discharging/charging, the voltage during discharging/charging and temperature;

Under the same test environment, the vehicle power lithium-ion battery system was then discharged at a target rate of 0.3C to SOC=50% and then put on hold for 1h, followed by a pulse discharge test and a pulse charge test, recording the same parameters as above. , and finally the power battery system was discharged at a target rate of 0.3C to SOC=10% and then put on hold for 1 hour, followed by a pulse discharge test and a pulse charge test, and the same parameters as above were recorded.

The specific test data processing scheme is the same as the data processing scheme of the above-mentioned specific embodiment. Finally, the statistical performance indicators of each monomer during pulse discharge and pulse charge are drawn into a table according to pulse charge, pulse discharge and SOC value respectively. , and judge the monomer consistency of the power battery system according to the data in the table.

As another specific embodiment, before testing the unit consistency of the power battery system, a vehicle power lithium-ion battery system with an intact appearance and an SOH value of about 85% can be prepared. According to the SOH value of the power battery system, after determining the target rate of 0.2C, the power battery system is charged in the constant current and constant voltage mode with the target rate of 0.2C, and charged to a fully charged state.

Discharge the charged power battery system with constant current to SOC value=80%. Put the discharged vehicle power lithium-ion battery system on hold for 1 hour. After the shelving time is over, conduct a pulse discharge test and a pulse charge test on the power battery system with the maximum allowable discharge current (pulse discharge current) of the monomer (wherein, the pulse discharge test and the pulse charge test are as described above, after the pulse discharge test , it is necessary to put the discharged power battery system on hold for 40s), and record the pulse discharge and charging parameters of each cell during the pulse discharge and charging process: the open circuit voltage of each cell before discharging/charging, the voltage during discharging/charging and temperature;

Under the same test environment, the vehicle power lithium-ion battery system was then discharged at a target rate of 0.2C to SOC=50% and then put on hold for 1 hour, followed by a pulse discharge test and a pulse charge test, recording the same parameters as above. , and finally the power battery system was discharged at a target rate of 0.2C to SOC=10% and then put on hold for 1 hour, followed by a pulse discharge test and a pulse charge test, and the same parameters as above were recorded.

The specific test data processing scheme is the same as the data processing scheme of the above-mentioned specific embodiment. Finally, the statistical performance indicators of each monomer during pulse discharge and pulse charge are drawn into a table according to pulse charge, pulse discharge and SOC value respectively. , and judge the monomer consistency of the power battery system according to the data in the table.

In the embodiment of the present invention, the single cell in the power battery system is used as the object to perform the pulse test, which makes up for the defect of complicated operation when the battery module formed by the single cell connected in series is used as the test object. At the same time, the pulse test of the power battery system under different SOC values can detect the unit consistency of the power battery system under the extreme working conditions, which makes the consistency detection of the battery system under the extreme working conditions more practical.

In the power battery system detection method of the embodiment of the present invention, for the power battery system under different SOC values, a single cell in the power battery system is used as the object, and the pulse test is performed, and the power is judged according to the performance index obtained in the pulse test. The cell consistency of the battery system is to fully understand the cell consistency of the power battery system under different working conditions.

Based on the above-mentioned detection method for a power battery system, the present invention provides a computer-readable storage medium.

In the embodiment of the present invention, when the computer program is executed by the processor, the detection method of the power battery system of the above-mentioned embodiment is implemented.

Based on the above detection method for the power battery system, the present invention also provides a detection device for the power battery system.

In this embodiment, the detection device 10 of the power battery system includes a memory and a processor, and the memory stores a computer program for implementing the detection method of the power battery system in the above-mentioned embodiment. When the computer program is executed by the processor, the above-mentioned power is realized. Detection method of battery system.

Based on the above-mentioned detection device for the power battery system, the present invention also provides a vehicle.

FIG. 6 is a schematic structural diagram of a vehicle according to an embodiment of the present invention. As shown in FIG. 6 , the vehicle 100 includes the above-mentioned detection device 10 of the power battery system.

The computer-readable storage medium, the power battery system detection device and the vehicle implemented in the present invention detect the consistency of the cells of the power battery system through the above-mentioned power battery system detection method.

It should be noted that the logic and/or steps represented in the flowcharts or otherwise described herein, for example, may be considered as an ordered listing of executable instructions for implementing the logical functions, and may be embodied in any computer readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device), or in combination with these used to execute a system, device or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport the program for use by or in connection with an instruction execution system, apparatus, or apparatus. More specific examples (non-exhaustive list) of computer readable media include the following: electrical connections with one or more wiring (electronic devices), portable computer disk cartridges (magnetic devices), random access memory (RAM), Read Only Memory (ROM), Erasable Editable Read Only Memory (EPROM or Flash Memory), Fiber Optic Devices, and Portable Compact Disc Read Only Memory (CDROM). In addition, the computer readable medium may even be paper or other suitable medium on which the program may be printed, as the paper or other medium may be optically scanned, for example, followed by editing, interpretation, or other suitable medium as necessary process to obtain the program electronically and then store it in computer memory.

It should be understood that various parts of the present invention may be implemented in hardware, software, firmware or a combination thereof. In the above-described embodiments, various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one or a combination of the following techniques known in the art: Discrete logic circuits, application specific integrated circuits with suitable combinational logic gates, Programmable Gate Arrays (PGA), Field Programmable Gate Arrays (FPGA), etc.

In the description of this specification, description with reference to the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples", etc., mean specific features described in connection with the embodiment or example , structure, material or feature is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", " Rear, Left, Right, Vertical, Horizontal, Top, Bottom, Inner, Outer, Clockwise, Counterclockwise, Axial, The orientations or positional relationships indicated by "radial direction", "circumferential direction", etc. are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the indicated devices or elements. It must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention.

In addition, the terms "first" and "second" are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between the two elements, unless otherwise specified limit. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the present invention, unless otherwise expressly specified and limited, a first feature "on" or "under" a second feature may be in direct contact between the first and second features, or the first and second features indirectly through an intermediary touch. Also, the first feature being "above", "over" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is level higher than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

Although the embodiments of the present invention have been shown and described above, it should be understood that the above-mentioned embodiments are exemplary and should not be construed as limiting the present invention. Embodiments are subject to variations, modifications, substitutions and variations.

Claims (10)

1. A detection method for a power battery system, wherein the power battery system comprises a plurality of cells, and the plurality of cells are connected in series, and the method comprises: charging the power battery system to a fully charged state; Discharge the power battery system to the first preset SOC value to the Mth preset SOC value, respectively, and at each preset SOC value, perform a pulse test on the power battery system to obtain the performance index of each of the cells , where the i-th preset SOC value is greater than the i+1-th preset SOC value, i=1,2,...,M, where M is an integer greater than or equal to 2; According to the performance index, the unit consistency of the power battery system is judged. 2 . The detection method for a power battery system according to claim 1 , wherein the charging the power battery system to a fully charged state comprises: 2 . Obtain the SOH value and capacity of the power battery system; Determine the target magnification according to the SOH value or the capacity; Using a constant current and constant voltage charging mode at the target rate to charge the power battery system to a fully charged state; Wherein, when the power battery system is discharged to the first preset SOC value to the Mth preset SOC value, respectively, the power battery system is discharged by using the target rate. 3. The detection method of the power battery system according to claim 2, wherein the power battery system is subjected to a pulse test to obtain the performance index of each of the monomers, comprising: Perform pulse discharge on the power battery system for a first preset time, and record the pulse discharge parameters of each cell during the pulse discharge process, wherein the pulse discharge parameters include the open-circuit voltage Udis0, Voltage Ud and temperature Td during discharge; Pulse charging the power battery system for the first preset time, and record the pulse charging parameters of each cell during the pulse charging process, wherein the pulse charging parameters include the open-circuit voltage of each cell before charging begins Ucha0, voltage Uc and temperature Tc during charging; Calculate the performance index of each cell during pulse discharge according to the pulse discharge parameter, and calculate the performance index of each cell during pulse charge according to the pulse charge parameter, wherein the performance index during pulse discharge includes: At least two of pulse discharge ohmic resistance, pulse discharge internal resistance, pulse discharge power and pulse discharge temperature difference, the performance indicators during pulse charging include pulse charging ohmic internal resistance, pulse charging internal resistance, pulse charging power and pulse charging At least two of the charging temperature differences. 4. The detection method of the power battery system according to claim 3, wherein, After discharging the power battery system to the i-th preset SOC value, before performing pulse discharge on the power battery system, shelve the power battery system for a second preset time; After the power battery system is pulse-discharged and before the power battery system is pulse-charged, the power battery system is put on hold for a third preset time; The pulse discharge current is the maximum discharge current allowed by the monomer, the pulse charging current is 0.75 times the pulse discharge current, the first preset time is 10s, and the value range of the second preset time is 1-2h , the third preset time is 40s. 5 . The detection method of the power battery system according to claim 3 , wherein, according to the performance index, judging the consistency of the cells of the power battery system comprises: 5 . Counting the performance indicators during the pulse discharge according to each preset SOC value, and performing statistics on the performance indicators during the pulse charging according to each preset SOC value; According to the statistical results, the unit consistency of the power battery system is judged. 6. The detection method of a power battery system according to claim 3, wherein the method further comprises: Calculate the voltage range between the cells according to the voltage Ud and/or the voltage Uc, and calculate the temperature range between the cells according to the temperature Td and/or the temperature Tc ; Based on the voltage range and the temperature range, abnormal cells are determined. 7 . The detection method of a power battery system according to claim 3 , wherein the voltage Ud includes the voltage Udis1 at the time when the cell starts to discharge and the voltage Udis2 after the discharge ends, and the voltage Uc includes the cell starts to charge. 8 . The voltage Ucha1 at the time and the voltage Ucha2 after the end of charging, the temperature Td includes the temperature Tdis1 at the time when the cell starts to discharge and the temperature Tdis2 after the end of discharge, and the temperature Tc includes the temperature at the time when the cell starts to charge Tcha1 and after the end of charging. The temperature Tcha2 is obtained by the following formula: RdisΩ=(Udis0-Udis1)/Imax, RchaΩ=(Ucha1-Ucha0)/0.75Imax, Rdis=(Udis0-Udis2)/Imax, Rcha=(Ucha2-Ucha0)/0.75Imax, Pdis=Udis2*(Udis0-Udis2)/Rdis=Imax*Udis2, Pcha=Ucha2*(Ucha2-Ucha0)/Rcha=0.75Imax*Ucha2, ΔTd=Tdis1-Tdis2, ΔTc=Tcha1-Tcha2, Wherein, RdisΩ is the ohmic internal resistance of the pulse discharge, RchaΩ is the ohmic internal resistance of the pulse charging, Rdis is the pulse discharge internal resistance, Rcha is the pulse charging internal resistance, Pdis is the pulse discharge power, and Pcha is the pulse discharge power. For the pulse charging power, Imax is the pulse discharge current, 0.75Imax is the pulse charge charging current, ΔTd is the pulse discharge temperature difference, and ΔTc is the pulse charge temperature difference. 8. A computer-readable storage medium on which a computer program is stored, characterized in that, when the computer program is executed by a processor, the detection of the power battery system according to any one of claims 1-7 is realized. method. 9. A detection device for a power battery system, comprising a memory and a processor, wherein a computer program is stored on the memory, characterized in that, when the computer program is executed by the processor, the computer program as in claims 1-7 is implemented. The detection method of any one of the power battery systems. 10. A vehicle, characterized by comprising the detection device of the power battery system as claimed in claim 9.

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