CN116736157A - Early warning method, device, equipment and storage medium of power battery - Google Patents
Early warning method, device, equipment and storage medium of power battery Download PDFInfo
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Abstract
The application discloses a power battery early warning method, a device, equipment and a storage medium, wherein the power battery comprises a plurality of electric cores, and the power battery early warning method comprises the following steps: screening the voltage signals of each battery cell to obtain the voltage signals to be processed of the battery cells; determining the current change rate, the voltage change rate or the state of charge change rate of the battery cell according to the voltage signal to be processed; and outputting early warning information under the condition that any one of the current change rate, the voltage change rate or the charge state change rate exceeds a preset threshold value. The technical scheme provided by the application can actively protect the power battery from the software level, and improves the safety of the power battery.
Description
Technical Field
The application belongs to the technical field of power batteries, and particularly relates to a power battery early warning method, device, equipment and storage medium.
Background
The power battery is used as an important component part in the new energy vehicle, and whether the safety of the power battery directly influences the life and property safety of drivers and passengers and the vehicle.
The current industry performs a great deal of protection design work on the physical layer of the power battery, and achieves remarkable effects, wherein the work is reflected in the passive safety protection dimension, and when the protection design on the physical layer is damaged, the safety of the power battery is greatly reduced. Therefore, how to improve the safety of the power battery of the new energy vehicle is a problem to be solved.
Disclosure of Invention
The embodiment of the application provides a power battery early warning method, a device, equipment and a storage medium, and further solves the problem of low safety of the power battery at least to a certain extent.
Other features and advantages of the application will be apparent from the following detailed description, or may be learned by the practice of the application.
According to a first aspect of an embodiment of the present application, there is provided a method for early warning a power battery, where the power battery includes a plurality of electric cells, and the method for early warning the power battery includes:
screening the voltage signals of each battery cell to obtain the voltage signals to be processed of the battery cells;
determining the current change rate, the voltage change rate or the state of charge change rate of the battery cell according to the voltage signal to be processed;
and outputting early warning information under the condition that any one of the current change rate, the voltage change rate or the charge state change rate exceeds a preset threshold value.
In some embodiments of the present application, based on the foregoing solution, the determining the current change rate of the battery cell according to the voltage signal to be processed includes:
determining a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed;
obtaining a state of charge standard value of the power battery by using the voltage standard value lookup table;
obtaining a state of charge value of the battery cell by using a voltage value table corresponding to the voltage signal to be processed;
determining the absolute value of the difference value between the state of charge value and the state of charge standard value as a state of charge variation value;
and determining the current change rate according to the state of charge change value and the initial capacity value of the battery cell.
In some embodiments of the present application, based on the foregoing solution, the determining, according to the voltage value corresponding to the voltage signal to be processed, a voltage standard value of the power battery includes:
determining a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed and a preset formula, wherein the preset formula is as follows:
wherein U is cell,standard U is the standard voltage value of the power battery cell,n For the voltage value of the nth cell, U cell,max For the maximum value of the voltage values of n electric cores, U cell,minm And the m-th minimum value in the voltage values of the n electric cores is the number of the electric cores, and the m is the number of the minimum values in the voltage values of the n electric cores.
In some embodiments of the present application, based on the foregoing scheme, determining the state of charge change rate of the battery cell according to the voltage signal to be processed includes:
determining a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed;
obtaining a state of charge standard value of the power battery by using the voltage standard value lookup table;
determining a difference value between the state of charge standard value and the state of charge value of the power battery as a state of charge change value;
and determining the state of charge change rate according to the state of charge change value.
In some embodiments of the present application, based on the foregoing solution, determining the voltage change rate of the battery cell according to the voltage signal to be processed includes:
determining a first voltage standard value of the power battery according to a voltage value corresponding to a voltage signal to be processed of the battery cell at a first moment;
determining an absolute value of a difference value between a voltage value corresponding to a voltage signal to be processed of the battery cell at a first moment and the first voltage standard value as a first voltage change value;
determining a second voltage standard value of the power battery according to a voltage value corresponding to a voltage signal to be processed of the battery cell at a second moment;
determining an absolute value of a difference value between a voltage value corresponding to a voltage signal to be processed of the battery cell at a second moment and the second voltage standard value as a second voltage change value;
and obtaining the voltage change rate of the battery cell from the first moment to the second moment according to the difference value of the first voltage change value and the second voltage change value.
In some embodiments of the present application, based on the foregoing scheme, the method further includes:
according to the first voltage standard value table look-up, a first state of charge standard value is obtained;
acquiring a voltage change rate standard value corresponding to the first state of charge standard value;
and determining the voltage change rate standard value as a preset threshold corresponding to the voltage change rate.
In some embodiments of the present application, based on the foregoing solution, the screening the voltage signal of each of the electrical cells to obtain the voltage signal to be processed of the electrical cell includes:
acquiring a current signal and a voltage signal of each battery cell, wherein the current signal corresponds to the voltage signal;
and determining a voltage signal corresponding to a current signal meeting a preset condition as the voltage signal to be processed, wherein the preset condition is that a current value corresponding to the current signal is smaller than or equal to 5A.
According to a second aspect of the embodiment of the present application, there is provided an early warning device for a power battery, the power battery including a plurality of electric cells, the early warning device for a power battery including:
the signal screening unit is used for screening the voltage signals of each battery cell to obtain the voltage signals to be processed of the battery cells;
the change rate calculation unit is used for determining the current change rate, the voltage change rate or the state of charge change rate of the battery cell according to the voltage signal to be processed;
the early warning judging unit is used for outputting early warning information under the condition that any one of the current change rate, the voltage change rate or the charge state change rate exceeds a preset threshold value.
In some embodiments of the present application, based on the foregoing solution, the change rate calculating unit is further configured to determine a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed; obtaining a state of charge standard value of the power battery by using the voltage standard value lookup table; obtaining a state of charge value of the battery cell by using a voltage value table corresponding to the voltage signal to be processed; determining the absolute value of the difference value between the state of charge value and the state of charge standard value as a state of charge variation value; and determining the current change rate according to the state of charge change value and the initial capacity value of the battery cell.
In some embodiments of the present application, based on the foregoing solution, the change rate calculating unit is further configured to determine a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed and a preset formula, where the preset formula is:
wherein U is cell,standard U is the standard voltage value of the power battery cell,n For the voltage value of the nth cell, U cell,max For the maximum value of the voltage values of n electric cores, U cell,minm For the voltage values of n electric coresN is the number of the battery cells, and m is the number of the minimum value in the voltage values of the n battery cells.
In some embodiments of the present application, based on the foregoing solution, the change rate calculating unit is further configured to determine a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed; obtaining a state of charge standard value of the power battery by using the voltage standard value lookup table; determining a difference value between the state of charge standard value and the state of charge value of the power battery as a state of charge change value; and determining the state of charge change rate according to the state of charge change value.
In some embodiments of the present application, based on the foregoing solutions, the change rate calculating unit is further configured to determine a first voltage standard value of the power battery according to a voltage value corresponding to a voltage signal to be processed of the battery cell at a first moment; determining an absolute value of a difference value between a voltage value corresponding to a voltage signal to be processed of the battery cell at a first moment and the first voltage standard value as a first voltage change value; determining a second voltage standard value of the power battery according to a voltage value corresponding to a voltage signal to be processed of the battery cell at a second moment; determining an absolute value of a difference value between a voltage value corresponding to a voltage signal to be processed of the battery cell at a second moment and the second voltage standard value as a second voltage change value; and obtaining the voltage change rate of the battery cell from the first moment to the second moment according to the difference value of the first voltage change value and the second voltage change value.
In some embodiments of the present application, based on the foregoing solution, the change rate calculating unit is further configured to look up a table according to the first voltage standard value to obtain a first state of charge standard value; acquiring a voltage change rate standard value corresponding to the first state of charge standard value; and determining the voltage change rate standard value as a preset threshold corresponding to the voltage change rate.
In some embodiments of the present application, based on the foregoing solution, the signal screening unit is further configured to obtain a current signal and a voltage signal of each of the electrical cells, where the current signal corresponds to the voltage signal; and determining a voltage signal corresponding to a current signal meeting a preset condition as the voltage signal to be processed, wherein the preset condition is that a current value corresponding to the current signal is smaller than or equal to 5A.
According to a third aspect of embodiments of the present application, there is provided an early warning device for a power battery, comprising a processor and a memory, the memory storing computer program instructions executable by the processor, the processor executing the computer program instructions to implement the instructions of the method according to any one of the first aspects.
According to a fourth aspect of embodiments of the present application, there is provided a computer readable storage medium having stored therein computer program instructions that are loaded and executed by a processor to carry out the operations performed by the method according to any of the first aspects above.
In the application, the voltage signal to be processed of each cell is obtained by screening the voltage signal of each cell; determining the current change rate, the voltage change rate or the state of charge change rate of the battery cell according to the voltage signal to be processed; and outputting early warning information under the condition that any one of the current change rate, the voltage change rate or the charge state change rate exceeds a preset threshold value. The technical scheme provided by the application can actively protect the power battery from the software level, and improves the safety of the power battery.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application as claimed.
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The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application. It is evident that the drawings in the following description are only some embodiments of the present application and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art. In the drawings:
FIG. 1 illustrates an application environment diagram of a power cell pre-warning method in one embodiment;
FIG. 2 is a flow chart of a method of pre-warning a power cell in one embodiment;
FIG. 3 shows a detailed schematic of step 202 in one embodiment;
FIG. 4 shows a detailed schematic of step 202 in another embodiment;
FIG. 5 shows a detailed schematic of step 202 in yet another embodiment;
FIG. 6 illustrates a block diagram of an early warning device for a power cell in one embodiment;
fig. 7 shows a schematic structural diagram of an early warning device of a power battery in one embodiment.
Detailed Description
The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the application. One skilled in the relevant art will recognize, however, that the application may be practiced without one or more of the specific details, or with other methods, components, devices, steps, etc. In other instances, well-known methods, devices, implementations, or operations are not shown or described in detail to avoid obscuring aspects of the application.
The block diagrams depicted in the figures are merely functional entities and do not necessarily correspond to physically separate entities. That is, the functional entities may be implemented in software, or in one or more hardware modules or integrated circuits, or in different networks and/or processor devices and/or microcontroller devices.
The flow diagrams depicted in the figures are exemplary only, and do not necessarily include all of the elements and operations/steps, nor must they be performed in the order described. For example, some operations/steps may be decomposed, and some operations/steps may be combined or partially combined, so that the order of actual execution may be changed according to actual situations.
It should also be noted that the terms "first," "second," and the like in the description and claims of the present application and in the above-described figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the objects so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented in other sequences than those illustrated or otherwise described.
In order to enable those skilled in the art to better understand the present application, first, an application scenario related to the present application will be briefly described with reference to fig. 1.
Referring to fig. 1, a schematic diagram of a scenario in which the early warning method of the power battery of the embodiment of the present application may be applied is shown.
The battery management system (Battery Management System, BMS) 101 communicates with the cloud big data platform 103 through a vehicle-mounted remote communication terminal (T-Box) 102. The power battery comprises a plurality of single battery cells, the BMS101 monitors and collects voltage signals, current signals and temperature signals of the single battery cells in real time, the voltage signals, the current signals and the temperature signals are uploaded to the cloud big data platform 103 through the T-BOX102, the cloud big data platform 103 processes the voltage signals, the current signals and the temperature signals, further, the current change rate, the voltage change rate, the state of charge change rate, a preset threshold value and other data of the battery cells are determined, and under the condition that any one of the current change rate, the voltage change rate or the state of charge change rate exceeds the preset threshold value, the power battery is judged to be abnormal, early warning information is output, and risk early warning is timely carried out on users and after-sales technicians.
Fig. 2 is a schematic flow chart of an early warning method of a power battery in an embodiment, and as shown in fig. 2, an early warning method of a power battery is provided, and the method is illustrated by taking the application of the method to the cloud big data platform in fig. 1 as an example, and may include the following steps:
step 201, screening the voltage signal of each cell to obtain the voltage signal to be processed of the cell.
It should be appreciated that various battery cells within a power battery system have different levels of capacity fade and internal resistance increase problems during vehicle operation due to different aging paths. In addition, the battery core with quality defects can have serious internal microscopic abnormal behaviors which affect the safety of the battery core, such as electrochemical side reactions, interfacial lithium precipitation, lithium dendrite growth and the like. The embodiment provides a big data analysis scheme capable of monitoring abnormal behaviors in the battery cell in real time and early warning in time.
The BMS can continuously monitor and collect voltage signals and current signals of each battery cell in the stationary processes of driving, parking and stopping of the vehicle, the voltage signals and the current signals are uploaded to the cloud big data platform through the T-BOX, the cloud big data platform screens the voltage signals of each battery cell, and the voltage signals obtained through screening are used as voltage signals to be processed.
In one embodiment, the cloud big data platform can acquire a current signal and a voltage signal of each cell, wherein the current signal corresponds to the voltage signal; and determining the voltage signal corresponding to the current signal meeting the preset condition as the voltage signal to be processed.
In a specific implementation, the preset condition is that the current value corresponding to the current signal is less than or equal to 5A, 3A, or 1A, or the like, or the current value corresponding to the current signal is less than or equal to 5A and the duration time is greater than or equal to 5min, which is not limited in this embodiment.
Of course, in the process of screening the voltage signals, the error values in the character segments of the voltage signals or the current signals can be removed, so that the accuracy of subsequent numerical calculation is prevented from being reduced due to the errors of the voltage signals.
By adopting the voltage signal and the current signal of the single battery cell as input and utilizing the effective early warning strategy and the calculation formula, the 7-24 h all-weather real-time early warning can be realized, and the accuracy of the safety risk monitoring of the power battery is improved.
Step 202, determining the current change rate, the voltage change rate or the state of charge change rate of the battery cell according to the voltage signal to be processed.
Specifically, the current change rate of the battery cell may be determined according to the voltage signal to be processed, the voltage change rate of the battery cell may be determined according to the voltage signal to be processed, or the state of charge change rate of the battery cell may be determined according to the voltage signal to be processed.
Fig. 3 is a detailed schematic diagram of step 202 in one embodiment, referring to fig. 2 and 3 together, in one embodiment, determining the current change rate of the cell based on the voltage signal to be processed may include the steps of:
step 301, determining a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed;
step 302, using a voltage standard value lookup table to obtain a state of charge standard value of the power battery;
step 303, look-up table is performed by using the voltage value corresponding to the voltage signal to be processed to obtain the state of charge value of the battery cell;
step 304, determining the absolute value of the difference between the state of charge value and the state of charge standard value as the state of charge variation value;
step 305, determining the current change rate according to the state of charge change value and the initial capacity value of the battery cell.
The voltage standard value of the power battery can be determined in various manners, and in one example, the voltage standard value of the power battery can be determined according to a voltage value corresponding to a voltage signal to be processed and a preset formula, wherein the preset formula is as follows:
wherein U is cell,standard Is the standard voltage value of the power battery, U cell,n For the nth cellVoltage value, U cell,max Is the maximum value in the voltage values of n battery cells, U cell,minm The m-th minimum value in the voltage values of the n electric cores is the number of the electric cores, and m is the number of the minimum values in the voltage values of the n electric cores.
And (3) subtracting the voltage maximum value of the battery cells from the sum of the voltage values of the 10 battery cells by using the number n=10 of the battery cells and the minimum number m=2 of the voltage values of the battery cells, subtracting the voltage minimum value of the 2 battery cells, and dividing the obtained result by 7 to obtain the voltage standard value of the power battery.
After obtaining the voltage standard value U cell,standard Later, can be according to U cell,standard OCV table lookup is carried out to obtain the SOC standard value cell,standard I.e. SOC cell,standard ＝f(OCV，U cell,standard )。
Meanwhile, the voltage value U corresponding to the voltage signal to be processed of the battery cell can be also obtained cell,i Performing OCV table lookup to obtain SOC of the battery cell cell,i I.e. SOC cell,i ＝f(OCV，U cell,i )。
Further, the state of charge change value Δsoc may utilize the formula Δsoc= |soc cell,i -SOC cell,standard I represents the current change rate I self_discharge Can utilize the formulaRepresentation, wherein C 0 Is the initial capacity value of the cell.
It should be noted that, the current change in the battery cell cannot be obtained through measurement, and the current change rate in the battery cell can be accurately calculated by using the steps 301 to 305, so that the real-time monitoring of the abnormality of the current change rate in the battery cell is realized.
Fig. 4 is a detailed schematic diagram of step 202 in another embodiment, referring to fig. 2 and 4 together, in one embodiment, determining the state of charge change rate of the cell according to the voltage signal to be processed may include the steps of:
step 401, determining a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed;
step 402, using a voltage standard value lookup table to obtain a state of charge standard value of the power battery;
step 403, determining the difference between the state of charge standard value and the state of charge value of the power battery as a state of charge variation value;
step 404, determining the state of charge change rate according to the state of charge change value.
The voltage standard value of the power battery can be determined in various manners, and in one example, the voltage standard value of the power battery can be determined according to a voltage value corresponding to a voltage signal to be processed and a preset formula, wherein the preset formula is as follows:
wherein U is cell,standard Is the standard voltage value of the power battery, U cell,n Is the voltage value of the nth cell, U cell,max Is the maximum value in the voltage values of n battery cells, U cell,minm The m-th minimum value in the voltage values of the n electric cores is the number of the electric cores, and m is the number of the minimum values in the voltage values of the n electric cores.
After obtaining the voltage standard value U cell,standard Later, can be according to U cell,standard OCV table lookup is carried out to obtain the SOC standard value cell,standard I.e. SOC cell,standard ＝f(OCV，U cell,standard )。
At the same time, the state of charge value SOC of the power battery can be obtained park Further, a state of charge change Δsoc is obtained, which may be represented by the formula Δsoc=soc cell,standard -SOC park The state of charge change rate SOC can be obtained by dividing Δsoc by the time on the horizontal axis by plotting the evolution curve of Δsoc and time on the vertical axis by time on the horizontal axis and Δsoc self_discharge 。
Of course, the available electric quantity loss delta E and the pure electric mileage loss delta Range can be calculated according to the state of charge change value delta SOC, the date is taken as the horizontal axis, delta E and delta Range are taken as the vertical axis, and the electric quantity and the endurance loss curve is drawn, so that the influence of delta SOC on the pure electric endurance mileage is determined.
It should be noted that, the change of the state of charge in the battery core cannot be obtained through measurement, and the change rate of the state of charge in the battery core can be accurately calculated by using the steps 401 to 404, so that the abnormal real-time monitoring of the change rate of the state of charge in the battery core is realized.
Fig. 5 shows a detailed schematic diagram of step 202 in yet another embodiment, referring to fig. 2 and 5 together, in one embodiment, determining the rate of change of the voltage of the cell based on the voltage signal to be processed may include the steps of:
step 501, determining a first voltage standard value of a power battery according to a voltage value corresponding to a voltage signal to be processed of the battery cell at a first moment;
step 502, determining an absolute value of a difference value between a voltage value corresponding to a voltage signal to be processed of the battery cell at a first moment and a first voltage standard value as a first voltage variation value;
step 503, determining a second voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed of the battery cell at the second moment;
step 504, determining an absolute value of a difference value between a voltage value corresponding to the voltage signal to be processed of the battery cell at the second moment and a second voltage standard value as a second voltage variation value;
step 505, obtaining the voltage change rate of the battery cell from the first time to the second time according to the difference value of the first voltage change value and the second voltage change value.
The first voltage standard value of the power battery can be determined in various manners, and in one example, the first voltage standard value of the power battery can be determined according to a voltage value corresponding to a voltage signal to be processed of the battery cell at a first moment and a preset formula, wherein the preset formula is as follows:
which is a kind ofIn U cell,standard Is the first voltage standard value of the power battery, U cell,n For the voltage value of the nth cell at the first moment, U cell,max For the maximum value of the voltage values of n battery cells at the first moment, U cell,minm The m-th minimum value in the voltage values of n electric cores at the first moment is n, wherein n is the number of the electric cores, and m is the number of the minimum values in the voltage values of n electric cores at the first moment.
After obtaining the first voltage standard value U cell,standard Later, the voltage value U corresponding to the voltage signal to be processed of the battery cell at the first moment can be obtained cell,i And U cell,standard Subtracting, taking the absolute value of the difference value as a first voltage variation value delta U i I.e. DeltaU i ＝|U cell,i -U cell,standard |。
The second voltage change value DeltaU can be obtained by the same method i ’＝|U cell,i ’-U cell,standard ' I. The voltage change rate k of the ith cell from the first time t to the second time t i Can be formulated asAnd (3) representing.
After all the voltage change rates k are obtained i Δu= |Δu i '-ΔU i After I, k of outliers can also be screened out i And delta U, and dividing the delta U into a self-discharge problem library so as to facilitate the subsequent increase of the early warning speed.
It should be noted that, the voltage change inside the battery cell cannot be obtained through measurement, and the voltage change rate inside the battery cell can be accurately calculated by using the steps 501 to 505, so that the real-time monitoring of the abnormality of the voltage change rate inside the battery cell is realized.
In a specific implementation, a first state of charge standard value can also be obtained according to a first voltage standard value look-up table; acquiring a voltage change rate standard value corresponding to the first state of charge standard value; and determining the standard value of the voltage change rate as a preset threshold corresponding to the voltage change rate.
It should be appreciated that when the first electricity is obtainedPressure standard value U cell,standard Later, can be according to U cell,standard OCV table lookup is carried out to obtain the SOC standard value cell,standard I.e. SOC cell,standard ＝f(OCV，U cell,standard )。
Taking into account different SOCs cell,standard The lower voltage change rate is different in judgment standard, and the SOC can be obtained cell,standard And the corresponding voltage change rate standard value X is used as a preset threshold corresponding to the voltage change rate. Of course, the voltage change rate standard value X can also be related to temperature, namely different SOCs cell,standard Different from the judgment standard of the voltage change rate at different temperatures, the temperature value corresponding to the temperature signal of the battery cell and the SOC can be used at the moment cell,standard And (5) performing table lookup to obtain a corresponding voltage change rate standard value X.
Step 203, outputting the early warning information when any one of the current change rate, the voltage change rate or the state of charge change rate exceeds a preset threshold.
It should be appreciated that the preset thresholds corresponding to different rates of change are different, for example, the preset threshold corresponding to the current rate of change may be 0.1mA or greater than 0.1mA, for example, 1mA, the preset threshold corresponding to the voltage rate of change may be 0.1mV or greater than 0.1mV, for example, 0.3mV, and the preset threshold corresponding to the state of charge rate of change may be 0.5%, for example, greater than 0.5%, for example, 1%.
In a specific implementation, the early warning information can be output immediately when the current change rate of the battery core is greater than a first preset threshold value, or the early warning information can be output again when the current change rate is continuously greater than the first preset threshold value within a preset time period. For example, if the current change rate I of a certain cell or a plurality of cells is obtained by analysis within one week self_discharge And if the voltage is more than or equal to 0.1mA, outputting early warning information.
Similarly, the early warning information can be output immediately when the voltage change rate of the battery core is larger than a second preset threshold value, or the early warning information can be output again when the voltage change rate is continuously larger than the second preset threshold value within a preset time period. For example, if analyzed within a weekObtaining the current change rate SOC of one or a plurality of battery cells self_discharge And (5) outputting early warning information if the temperature is more than or equal to 0.5%.
Similarly, the early warning information can be output immediately when the state of charge change rate of the battery core is greater than a third preset threshold value, or the early warning information can be output again when the current change rate is continuously greater than the first preset threshold value within a preset time period. For example, if the voltage change rate k of a certain cell or a certain number of cells is obtained by analysis in one day i And (5) outputting early warning information if the voltage is more than or equal to 0.1 mV.
According to the embodiment, the voltage signals of each battery cell are screened to obtain the voltage signals to be processed of the battery cells; determining the current change rate, the voltage change rate or the state of charge change rate of the battery cell according to the voltage signal to be processed; and outputting early warning information under the condition that any one of the current change rate, the voltage change rate or the charge state change rate exceeds a preset threshold value. The technical scheme provided by the application can actively protect the power battery from the software level, so that the safety of the power battery is improved, and meanwhile, the cost of the power battery safety precaution is reduced as no additional hardware is required.
The following describes an embodiment of the apparatus of the present application, which may be used to perform the early warning method of the power battery in the above embodiment of the present application. For details not disclosed in the embodiment of the device of the present application, please refer to the embodiment of the early warning method of the power battery described above.
Referring to fig. 6, a block diagram of a power battery early warning device in an embodiment of the present application is shown.
As shown in fig. 6, the early warning device for a power battery according to an embodiment of the present application includes: the device comprises a signal screening unit 601, a change rate calculating unit 602 and an early warning judging unit 603, wherein the signal screening unit 601 is used for screening the voltage signal of each cell to obtain a voltage signal to be processed of the cell; the change rate calculating unit 602 is configured to determine a current change rate, a voltage change rate, or a state of charge change rate of the battery cell according to the voltage signal to be processed; the early warning judging unit 603 is configured to output early warning information when any one of the current change rate, the voltage change rate, or the state of charge change rate exceeds a preset threshold.
In some embodiments of the present application, based on the foregoing solution, the change rate calculating unit 602 is further configured to determine a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed; obtaining a state of charge standard value of the power battery by using a voltage standard value look-up table; the state of charge value of the battery cell is obtained by looking up a table by using a voltage value corresponding to the voltage signal to be processed; determining the absolute value of the difference value between the state of charge value and the state of charge standard value as a state of charge variation value; and determining the current change rate according to the state of charge change value and the initial capacity value of the battery cell.
In some embodiments of the present application, based on the foregoing solution, the change rate calculating unit 602 is further configured to determine a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed and a preset formula, where the preset formula is:
wherein U is cell,standard Is the standard voltage value of the power battery, U cell,n Is the voltage value of the nth cell, U cell,max Is the maximum value in the voltage values of n battery cells, U cell,minm The m-th minimum value in the voltage values of the n electric cores is the number of the electric cores, and m is the number of the minimum values in the voltage values of the n electric cores.
In some embodiments of the present application, based on the foregoing solution, the change rate calculating unit 602 is further configured to determine a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed; obtaining a state of charge standard value of the power battery by using a voltage standard value look-up table; determining a difference value between the state of charge standard value and the state of charge value of the power battery as a state of charge change value; and determining the state of charge change rate according to the state of charge change value.
In some embodiments of the present application, based on the foregoing solution, the change rate calculating unit 602 is further configured to determine a first voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed of the battery cell at the first moment; determining an absolute value of a difference value between a voltage value corresponding to a voltage signal to be processed of the battery cell at a first moment and a first voltage standard value as a first voltage change value; determining a second voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed of the battery cell at a second moment; determining the absolute value of the difference value between the voltage value corresponding to the voltage signal to be processed of the battery cell at the second moment and the second voltage standard value as a second voltage variation value; and obtaining the voltage change rate of the battery cell from the first moment to the second moment according to the difference value of the first voltage change value and the second voltage change value.
In some embodiments of the present application, based on the foregoing scheme, the change rate calculating unit 602 is further configured to look up a table according to the first voltage standard value to obtain a first state of charge standard value; acquiring a voltage change rate standard value corresponding to the first state of charge standard value; and determining the standard value of the voltage change rate as a preset threshold corresponding to the voltage change rate.
In some embodiments of the present application, based on the foregoing solution, the signal filtering unit 601 is further configured to obtain a current signal and a voltage signal of each cell, where the current signal corresponds to the voltage signal; and determining a voltage signal corresponding to the current signal meeting a preset condition as a voltage signal to be processed, wherein the preset condition is that the current value corresponding to the current signal is smaller than or equal to 5A.
Based on the same inventive concept, an embodiment of the present application further provides an early warning device for a power battery, referring to fig. 7, which shows a schematic structural diagram of the early warning device for a power battery in the embodiment of the present application, where the early warning device for a power battery includes one or more memories 704, one or more processors 702, and at least one computer program (computer program instructions) stored on the memories 704 and capable of running on the processors 702, and when the processors 702 execute the computer program, the method as described above is implemented.
Where in FIG. 7 a bus architecture (represented by bus 700), bus 700 may comprise any number of interconnected buses and bridges, with bus 700 linking together various circuits, including one or more processors, as represented by processor 702, and memory, as represented by memory 704. Bus 700 may also link together various other circuits such as peripheral devices, voltage regulators, power management circuits, etc., as are well known in the art and, therefore, will not be described further herein. Bus interface 705 provides an interface between bus 700 and receiver 701 and transmitter 703. The receiver 701 and the transmitter 703 may be the same element, i.e. a transceiver, providing a unit for communicating with various other apparatus over a transmission medium. The processor 702 is responsible for managing the bus 700 and general processing, while the memory 704 may be used to store data used by the processor 702 in performing operations.
Based on the same inventive concept, embodiments of the present application provide a computer-readable storage medium having stored therein at least one computer program instruction that is loaded and executed by a processor to implement operations performed by the method as described above.
The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software that is executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the application and the appended claims. For example, due to the nature of software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwired, or a combination of any of these. In addition, each functional unit may be integrated in one processing unit, each unit may exist alone physically, or two or more units may be integrated in one unit.
In the several embodiments provided in the present application, it should be understood that the disclosed technology may be implemented in other manners. The above-described embodiments of the apparatus are merely exemplary, and the division of the units, for example, may be a logic function division, and may be implemented in another manner, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some interfaces, units or modules, or may be in electrical or other forms.
The units described as separate components may or may not be physically separate, and components as control devices may or may not be physical units, may be located in one place, or may be distributed over a plurality of units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in part or all of the technical solution or in part in the form of a software product stored in a storage medium, including instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a usb disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a removable hard disk, a magnetic disk, or an optical disk, or other various media capable of storing computer program instructions.
The above description is only an example of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.
Claims (10)
1. The early warning method of the power battery is characterized in that the power battery comprises a plurality of electric cores, and comprises the following steps:
screening the voltage signals of each battery cell to obtain the voltage signals to be processed of the battery cells;
determining the current change rate, the voltage change rate or the state of charge change rate of the battery cell according to the voltage signal to be processed;
and outputting early warning information under the condition that any one of the current change rate, the voltage change rate or the charge state change rate exceeds a preset threshold value.
2. The method for early warning of a power battery according to claim 1, wherein the determining the current change rate of the battery cell according to the voltage signal to be processed includes:
determining a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed;
obtaining a state of charge standard value of the power battery by using the voltage standard value lookup table;
obtaining a state of charge value of the battery cell by using a voltage value table corresponding to the voltage signal to be processed;
determining the absolute value of the difference value between the state of charge value and the state of charge standard value as a state of charge variation value;
and determining the current change rate according to the state of charge change value and the initial capacity value of the battery cell.
3. The method for early warning of a power battery according to claim 2, wherein determining a voltage standard value of the power battery according to the voltage value corresponding to the voltage signal to be processed includes:
determining a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed and a preset formula, wherein the preset formula is as follows:
wherein U is cell,standard U is the standard voltage value of the power battery cell,n For the voltage value of the nth cell, U cell,max For the maximum value of the voltage values of n electric cores, U cell,minm And the m-th minimum value in the voltage values of the n electric cores is the number of the electric cores, and the m is the number of the minimum values in the voltage values of the n electric cores.
4. The method of claim 1, wherein determining the state of charge change rate of the battery cell from the voltage signal to be processed comprises:
determining a voltage standard value of the power battery according to a voltage value corresponding to the voltage signal to be processed;
obtaining a state of charge standard value of the power battery by using the voltage standard value lookup table;
determining a difference value between the state of charge standard value and the state of charge value of the power battery as a state of charge change value;
and determining the state of charge change rate according to the state of charge change value.
5. The method of claim 1, wherein determining the voltage change rate of the battery cell according to the voltage signal to be processed comprises:
determining a first voltage standard value of the power battery according to a voltage value corresponding to a voltage signal to be processed of the battery cell at a first moment;
determining an absolute value of a difference value between a voltage value corresponding to a voltage signal to be processed of the battery cell at a first moment and the first voltage standard value as a first voltage change value;
determining a second voltage standard value of the power battery according to a voltage value corresponding to a voltage signal to be processed of the battery cell at a second moment;
determining an absolute value of a difference value between a voltage value corresponding to a voltage signal to be processed of the battery cell at a second moment and the second voltage standard value as a second voltage change value;
and obtaining the voltage change rate of the battery cell from the first moment to the second moment according to the difference value of the first voltage change value and the second voltage change value.
6. The method for pre-warning a power battery according to claim 5, further comprising:
according to the first voltage standard value table look-up, a first state of charge standard value is obtained;
acquiring a voltage change rate standard value corresponding to the first state of charge standard value;
and determining the voltage change rate standard value as a preset threshold corresponding to the voltage change rate.
7. The method for early warning of a power battery according to any one of claims 1 to 6, wherein the step of screening the voltage signal of each of the electric cells to obtain the voltage signal to be processed of the electric cell includes:
acquiring a current signal and a voltage signal of each battery cell, wherein the current signal corresponds to the voltage signal;
and determining a voltage signal corresponding to a current signal meeting a preset condition as the voltage signal to be processed, wherein the preset condition is that a current value corresponding to the current signal is smaller than or equal to 5A.
8. The utility model provides a power battery's early warning device which characterized in that, power battery includes a plurality of electric cores, power battery's early warning device includes:
the signal screening unit is used for screening the voltage signals of each battery cell to obtain the voltage signals to be processed of the battery cells;
the change rate calculation unit is used for determining the current change rate, the voltage change rate or the state of charge change rate of the battery cell according to the voltage signal to be processed;
the early warning judging unit is used for outputting early warning information under the condition that any one of the current change rate, the voltage change rate or the charge state change rate exceeds a preset threshold value.
9. A power cell warning device comprising a processor and a memory, wherein the memory stores computer program instructions executable by the processor, the processor executing the computer program instructions to implement the method of any one of claims 1 to 7.
10. A computer readable storage medium having stored therein computer program instructions that are loaded and executed by a processor to implement operations performed by the method of any one of claims 1 to 7.
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