CN117826004A - Verification method and device for power battery equalization function, vehicle and medium - Google Patents
Verification method and device for power battery equalization function, vehicle and medium Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 101
- 238000012795 verification Methods 0.000 title claims abstract description 49
- 230000008569 process Effects 0.000 claims abstract description 54
- 238000007599 discharging Methods 0.000 claims abstract description 41
- 238000001514 detection method Methods 0.000 claims abstract description 10
- 230000006870 function Effects 0.000 claims description 154
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- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 3
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
- G01R31/396—Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery
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- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
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Abstract
The application provides a power battery equalization function verification method, a device, a vehicle and a medium, comprising the following steps: collecting a target current value of an equalization loop where a target single cell is located in real time through current detection equipment arranged in the equalization loop where the target single cell is located; controlling the target single battery cell to discharge so that the power battery meets a preset balance function starting index; verifying whether the equalization function of the power battery can be started normally according to the target current value in the discharging process; if the balance function of the power battery can be normally started, at least one round of simulated working condition circulation is performed by simulating the real vehicle working condition control power battery; and verifying whether the balance function of the power battery meets the balance requirement at any time node in the simulated working condition circulation process according to the target current value in the simulated working condition circulation process. Therefore, whether the equalization function of the power battery meets the design requirement can be accurately and effectively verified.
Description
Technical Field
The present disclosure relates to the field of vehicle battery technologies, and in particular, to a method and apparatus for verifying a power battery balancing function, a vehicle, and a medium.
Background
In the production process, the single battery core of the lithium ion power battery has different internal resistance, resistivity and the like. If the difference is obvious, the single voltage is easy to be inconsistent in the charging and discharging process, so that the driving range of the automobile is reduced, and the service life of the power battery is even influenced. In order to reasonably solve the problem, the existing power battery has an equalization function, and the battery monomers are equalized through the effective design of an equalization strategy, so that the inconsistency in the power battery is reduced to the minimum extent possible. A complete set of test methods is therefore required during the design verification phase to verify whether the balancing strategy of the power cells is effective.
The existing verification method of the equalization function is implemented by means of an equalization state signal provided by a battery management system in the power battery. However, when the equalization function of the battery management system fails, the equalization state signal provided by the battery management system is unreliable in itself, and thus the effectiveness of the equalization function of the power battery cannot be effectively verified.
Disclosure of Invention
In view of the above, the present application is directed to a method, a device, a vehicle and a medium for verifying a power battery balancing function, so as to solve the problem that the effectiveness of the power battery balancing function cannot be effectively verified in the prior art.
The embodiment of the application provides a verification method for a power battery balancing function, wherein a battery pack of a power battery comprises a plurality of single battery cells; the verification method comprises the following steps:
collecting a target current value of an equalization loop where a target single cell is located in real time through current detection equipment arranged in the equalization loop where the target single cell is located;
controlling the target single battery cell to discharge so that the power battery meets a preset balance function starting index;
verifying whether the equalization function of the power battery can be normally started according to the target current value in the discharging process;
if the balance function of the power battery can be normally started, controlling the power battery to perform at least one round of simulated working condition circulation through simulating the real vehicle working condition;
and verifying whether the balance function of the power battery meets the balance requirement at any time node in the simulated working condition circulation process according to the target current value in the simulated working condition circulation process.
Further, the discharging of the target single battery cell is controlled to enable the power battery to meet a preset balance function starting index, and the method comprises the following steps:
Performing at least one capacity test on the power battery to determine the initial capacity of the power battery;
determining discharge capacity according to the balance function starting index and the initial capacity, and controlling battery charging and discharging equipment to discharge the target single battery cell according to the discharge capacity;
after the discharge according to the discharge capacity is finished, carrying out at least one capacity test on the power battery again to determine the first capacity of the power battery;
determining whether the power battery actually meets the balance function starting index according to the initial capacity and the first capacity;
if yes, ending the discharging process of the target single battery cell;
if the balance function starting index is not met, the battery charging and discharging equipment is continuously controlled to discharge the target single battery core until the power battery is determined to meet the balance function starting index.
Further, according to the target current value in the discharging process, verifying whether the balancing function of the power battery can be started normally, includes:
and if the target current value is not 0, determining that the balancing function of the power battery can be started normally.
Further, if it is verified that the balancing function of the power battery can be started normally, the power battery is controlled to perform at least one round of simulated working condition cycle through simulating the real vehicle working condition, including:
in the process of any round of simulated working condition circulation, under the preset temperature condition, charging the power battery according to a first charging strategy until the power battery reaches a preset charging cut-off condition, and standing for a first preset time;
controlling the power battery to perform working condition circulation according to the simulated operation working condition simulating the actual vehicle operation state until the power battery reaches a preset discharge cut-off condition;
charging the power battery according to a second charging strategy under the preset temperature condition until the power battery reaches the preset charging stop condition, and standing for a second preset time; wherein the first charging strategy and the second charging strategy comprise a fast charging strategy or a slow charging strategy, and the first charging strategy and the second charging strategy are different;
controlling the power battery to perform working condition circulation again according to the simulated operation working condition until the power battery reaches the preset discharge cut-off condition;
And controlling the power battery to stand for a third preset time.
Further, according to the target current value in the simulated working condition circulation process, verifying whether an equalization function of the power battery meets an equalization requirement at any time node in the simulated working condition circulation process, includes:
judging whether the target current value is larger than or equal to a preset equalizing current threshold value at any time node in the circulation process of the simulation working condition;
and if the power battery balancing function is greater than or equal to the balancing requirement, determining that the balancing function of the power battery meets the balancing requirement at the time node.
Further, the verification method further comprises the following steps:
after the circulation process of the simulated working conditions is finished, performing at least one capacity test on the power battery to determine the second capacity of the power battery;
determining an average equalization efficiency of the power battery according to the initial capacity, the first capacity and the second capacity;
and verifying the equalization effect of the equalization function of the power battery according to the average equalization efficiency.
Further, the verification method further comprises the following steps:
collecting an equilibrium state signal through a low-voltage communication interface of a battery management system connected to the power battery;
And if the balanced function state indicated by the balanced state signal is consistent with the balanced function state indicated by the target current value, verifying that the balanced state signal generated by the power battery when the balanced function is executed is accurate.
The embodiment of the application also provides a verification device for the balance function of the power battery, wherein the battery pack of the power battery comprises a plurality of single battery cells; the verification apparatus includes:
the acquisition module is used for acquiring the target current value of the equalization circuit where the target single cell is located in real time through current detection equipment arranged in the equalization circuit where the target single cell is located;
the discharging control module is used for controlling the target single battery cell to discharge so that the power battery meets a preset balance function starting index;
the first verification module is used for verifying whether the equalization function of the power battery can be normally started according to the target current value in the discharging process;
the working condition circulation module is used for controlling the power battery to perform at least one round of simulated working condition circulation through simulating a real vehicle working condition when the balance function of the power battery is verified to be capable of being started normally;
And the second verification module is used for verifying whether the balance function of the power battery meets the balance requirement at any time node in the simulated working condition circulation process according to the target current value in the simulated working condition circulation process.
The embodiment of the application also provides a vehicle, which comprises: the system comprises a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, the processor and the memory are communicated through the bus when the vehicle runs, and the machine-readable instructions are executed by the processor to perform the steps of the verification method of the power battery balancing function.
The embodiments of the present application also provide a computer readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of a method for verifying a power cell balancing function as described above.
According to the verification method, the verification device, the vehicle and the medium for the balance function of the power battery, the current detection equipment is additionally arranged in the balance loop where the target battery core is located to collect the target current value, verification experiments are designed, and verification is performed according to whether the balance function of the power battery can be normally started or not and whether the balance function meets the balance requirement or not. Therefore, whether the equalization function of the power battery meets the design requirement can be accurately and effectively verified by detecting the actual current value in the equalization loop and simulating the actual vehicle working condition for testing.
In order to make the above objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIGS. 1 (a) and (b) show one of the schematic structural diagrams of a verification system for a power battery equalization function provided in an embodiment of the present application;
fig. 2 shows a flowchart of a method for verifying a power battery equalization function according to an embodiment of the present application;
fig. 3 shows a second schematic structural diagram of a verification system for balancing a power battery according to an embodiment of the present application;
fig. 4 is a schematic structural diagram of a verification device for balancing functions of a power battery according to an embodiment of the present application;
fig. 5 shows a schematic structural diagram of a vehicle according to an embodiment of the present application.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, which are generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, as provided in the accompanying drawings, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. Based on the embodiments of the present application, every other embodiment that a person skilled in the art would obtain without making any inventive effort is within the scope of protection of the present application.
The research shows that the single battery core of the lithium ion power battery has different internal resistance, resistivity and the like in the production process. If the difference is obvious, the single voltage is easy to be inconsistent in the charging and discharging process, so that the driving range of the automobile is reduced, and the service life of the power battery is even influenced. In order to reasonably solve the problem, the existing power battery has an equalization function, and the battery monomers are equalized through the effective design of an equalization strategy, so that the inconsistency in the battery monomers is reduced to the minimum extent possible. A complete set of test methods is therefore required during the design verification phase to verify whether the balancing strategy of the power cells is effective.
The existing verification method of the equalization function is implemented by means of an equalization state signal provided by a battery management system in the power battery. However, when the equalization function of the battery management system fails, the equalization state signal provided by the battery management system is unreliable in itself, and thus the effectiveness of the equalization function of the power battery cannot be effectively verified.
Based on the above, the embodiment of the application provides a method, a device, a vehicle and a medium for verifying the balance function of a power battery, so as to accurately and effectively verify whether the balance function of the power battery meets the design requirement.
The verification method in the embodiment of the application can be realized based on the verification system of the power battery balancing function. Referring to fig. 1 (a) and (b), fig. 1 (a) and (b) are schematic structural diagrams of a verification system for balancing a power battery according to an embodiment of the present application. The verification system may include a power battery under test and a battery charging and discharging device. As shown in fig. 1 (a), the battery pack of the power battery includes a plurality of unit cells, and the plurality of unit cells are exemplarily connected in series to form the battery pack of the power battery. As further shown in fig. 1 (b), the battery pack of the power battery may include a plurality of battery packs, each of which includes a plurality of unit cells, and illustratively, the plurality of unit cells are connected in series to form a battery pack, and the plurality of battery packs are connected in series to form the battery pack of the power battery. The battery charging and discharging equipment can charge or discharge any one or a plurality of single cells in the battery pack.
In order to facilitate understanding of the verification method provided in the embodiments of the present application, a description will be first given of a "barrel principle" of the power battery. The principle of the wooden barrel is that how much water is contained in a wooden barrel depends on the shortest wooden board on the barrel wall. For the power battery, if the power battery is likened to a barrel containing water, each single cell is the wood plate forming the barrel, that is to say, the single cell with the worst performance determines the overall performance of the power battery. It can be seen that the performance of each cell is preferably as good as possible, i.e. cell uniformity is of great importance for the overall performance of the battery. In the production process and along with the use process, the single battery cells are inevitably different, so that the consistency is reduced. In order to solve the problem, the battery management system of the existing power battery is provided with an equalization function, and the battery single cells are equalized through the effective design of an equalization strategy, so that the inconsistency in the battery single cells is reduced to the minimum extent as much as possible.
Referring to fig. 2 and 3, fig. 2 is a flowchart of a method for verifying a power battery balancing function according to an embodiment of the present application; fig. 3 is a second schematic structural diagram of a verification system for balancing power battery according to an embodiment of the present application. As shown in fig. 2, the verification method provided in the embodiment of the present application includes:
S301, acquiring a target current value of an equalization loop where a target single cell is located in real time through current detection equipment arranged in the equalization loop where the target single cell is located.
Referring to fig. 3 in combination, a certain single cell in a battery pack M1 included in a battery pack of a power battery is used as a target single cell, and the target single cell is connected to a battery management system BMS through an equalization loop; the equalization circuit where the target single battery cell is located is provided with a current detection device for collecting a target current value in the equalization circuit, for example, a high-precision Hall sensor is used for collecting current, and an oscilloscope connected to the Hall sensor is used for grabbing the target current value of the equalization circuit.
S302, controlling the target single battery cell to discharge so that the power battery meets a preset balance function starting index; .
In the step, the target single battery cell is controlled to discharge, so that the capacity difference and the voltage difference between the target single battery cell and other single battery cells can be manufactured, and the power battery can theoretically reach the design requirement of starting the equalization function, namely the preset equalization function starting index. And then, whether the power battery actually starts the equalization function or not can be tested through the detected current value so as to verify whether the equalization function can be started normally or not.
In one possible implementation, step S302 may include:
and S3021, performing at least one capacity test on the power battery to determine the initial capacity of the power battery.
In specific implementation, multiple standard capacity tests can be performed on the power battery, and the test results of the multiple standard capacity tests are averaged to determine the initial capacity Q1 of the power battery.
In addition, for the lithium ion power battery, a pre-treatment charge-discharge test may be performed on the power battery before step S3021 to achieve the purpose of fully activating the battery.
S3022, determining a discharge capacity according to the balance function starting index and the initial capacity, and controlling battery charging and discharging equipment to discharge the target single battery cell according to the discharge capacity.
Firstly, it should be noted that the power battery performs the balancing function according to a pre-designed balancing strategy, and the balancing strategy of the battery management system specifies a balancing function starting index, for example, when a capacity difference greater than a certain starting threshold exists between a certain single battery cell and other single battery cells, the balancing function should be started. The turn-on threshold may be set according to an equalization strategy, such as 3%, 5%, and the present application is not limited in any way.
In specific implementation, the battery management system can directly detect the voltage of each single cell in real time in the discharging process, so as to determine the voltage difference between the target single cell and other single cells. Because the capacity difference and the voltage difference have a certain mapping relation, the battery management system can judge whether the capacity difference meets the equalization function starting index according to the detected voltage difference and the mapping relation, and further control whether the equalization function is started.
In the step, according to the balance function starting index and the initial capacity, the discharge capacity can be determined so as to quantitatively discharge the target single battery cell, thereby designing the capacity difference meeting the balance function starting index. In the implementation, a certain capacity floating interval can be set, so that the produced monomer pressure difference (capacity difference) is slightly higher than the pressure difference (capacity difference) corresponding to the balance function starting index, and the balance function of the power battery is ensured to be normally started in theory when certain experimental errors exist.
Referring back to fig. 1 (a) and (b), a battery charge and discharge device may be connected to both ends of any single cell inside the power battery pack to charge and discharge each single cell inside the power battery individually. The discharge parameters of the battery charging and discharging equipment, such as the magnitude of the discharged current and the discharge duration, can be controlled according to the discharge capacity.
And S3023, after the discharge according to the discharge capacity is finished, carrying out capacity test on the power battery at least once again to determine the first capacity of the power battery.
In this step, the power battery is subjected to at least one capacity test again, and the first capacity Q2 of the power battery can be determined.
S3024, determining whether the power battery actually meets the balance function starting index according to the initial capacity and the first capacity.
In this step, the value of (Q1-Q2)/Q1 may be compared with an on threshold set in the equalization function on index, and when the value of (Q1-Q2)/Q1 is greater than the on threshold, it is determined that the power battery actually satisfies the equalization function on index.
And S3025, if the current is satisfied, ending the discharging process of the target single battery cell.
In the step, if the current is satisfied, discharging of the target single battery cell is ended, and the connection between the battery charging and discharging equipment and the target single battery cell is disconnected.
And S3026, if the balance function starting index is not met, continuing to control the battery charging and discharging equipment to discharge the target single battery core until the power battery is determined to meet the balance function starting index.
In this step, due to the existence of experimental error, even if the quantitative discharge occurs, the power battery may not actually meet the equalization function starting index, at this time, the target single battery cell may be discharged again according to the gap between the value of (Q1-Q2)/Q1 and the starting threshold, and the first capacity Q2 may be retested to determine whether the power battery actually meets the equalization function starting index; this process is repeated until it is determined that the power cell satisfies the equalization function on index.
And S303, verifying whether the equalization function of the power battery can be normally started according to the target current value in the discharging process.
In particular implementation, step S303 may include: and if the target current value is not 0, determining that the balancing function of the power battery can be started normally.
When the target current value is not 0, the generation of the balance current in the balance loop is indicated, and then the normal starting of the balance function of the power battery is indicated, the power battery can normally enter the balance state, and the balance strategy is effective.
And S304, if the balance function of the power battery can be normally started, controlling the power battery to perform at least one round of simulated working condition circulation through simulating the real vehicle working condition.
In the step, the actual vehicle working conditions comprise charging, discharging, driving, standing and the like; in order to fully simulate various working conditions in the running of the real vehicle, whether the balancing function of the power battery can meet the balancing requirement under various working conditions is verified, and at least one round of simulated working condition circulation can be performed on the control power battery. The number of cycles n0 of the specific simulated condition cycle may be determined according to the actual project requirement, and the embodiment of the present application is not limited in any way herein. Meanwhile, a preset thermal management strategy is adopted in the circulation process of each round of simulation working conditions to control the temperature of the battery cell running environment, so that the temperature environment of the battery running by a real vehicle is fully simulated.
In one possible implementation, step S304 may include:
in the process of any round of simulated working condition circulation, under the preset temperature condition, charging the power battery according to a first charging strategy until the power battery reaches a preset charging cut-off condition, and standing for a first preset time; controlling the power battery to perform working condition circulation according to the simulated operation working condition simulating the actual vehicle operation state until the power battery reaches a preset discharge cut-off condition; charging the power battery according to a second charging strategy under the preset temperature condition until the power battery reaches the preset charging stop condition, and standing for a second preset time; wherein the first charging strategy and the second charging strategy comprise a fast charging strategy or a slow charging strategy, and the first charging strategy and the second charging strategy are different; controlling the power battery to perform working condition circulation again according to the simulated operation working condition until the power battery reaches the preset discharge cut-off condition; and controlling the power battery to stand for a third preset time.
It should be noted that, as described above, based on the "barrel principle", the capacity of the single cell with the smallest capacity in the power battery determines the capacity of the entire power battery. When in charging, the single battery core with small capacity is fully charged, the power battery reaches the charging cut-off condition, and the capacity of the power battery is fully charged and cannot be charged continuously. When discharging, the monomer battery core with small capacity emits all available energy, and the power battery reaches the discharge cut-off condition to stop discharging immediately.
In step S304 of the embodiment of the present application, since the target single cell is discharged in advance in S302, the remaining battery capacity of the target single cell is minimum and the chargeable capacity is maximum at the start of the simulated condition cycle. Therefore, when the power battery is charged according to the first charging strategy, when the capacity of other single battery cells which are not discharged except the target single battery cell is full, the power battery can not continue to charge until the power battery reaches the charging cut-off condition, and at the moment, the capacity of the target single battery cell is not full yet; then, the power battery is controlled to circulate according to the simulated operation condition simulating the actual vehicle operation state, and the power battery discharges outwards; the capacity rate of the target single battery core is firstly reduced to a critical value set by a preset discharge cut-off condition, and the power battery reaches the preset discharge cut-off condition at the moment and cannot continue to discharge outwards; then, the power battery is charged again according to the second charging strategy, and the capacity of the target single battery core is smaller than that of other single battery cores, so that similarly, when the capacities of other single battery cores are full, the power battery reaches a charging stop condition, and the capacity of the target single battery core is not full yet; when discharging again, the capacity rate of the target single battery cell is firstly reduced to a critical value set by a preset discharge cut-off condition, but the capacities of other single battery cells do not reach the critical value yet.
It can be seen that without the presence of the balancing function, the power cell capacity is limited by the capacity of the target cell and cannot be fully discharged. The equalization function is designed to gradually realize capacity equalization among all single battery cells in the charge-discharge cycle process so as to recover the capacity of the power battery and improve the battery performance.
For example, first, under the environment of 25+/-2 ℃, the battery pack is fully charged according to a quick charge strategy and stands for 5 minutes; then, controlling the power battery to carry out WLTC circulation to a preset discharge cut-off condition, wherein the capacity is lower than 5%; the WLTC cycle is a working condition cycle adopted by the global unified light vehicle emission test procedure (Worldwide Light Vehicles Test Cycle) and comprises a plurality of speed intervals of low speed, medium and low speed, high speed, ultra-high speed and the like; in the embodiment of the application, the power consumption of the power battery during driving is simulated according to the speed interval specified by WLTC circulation; it should be noted that, one WLTC cycle generally cannot consume the power battery to the preset discharge cutoff condition, so the power battery can be consumed to the preset discharge cutoff condition through multiple WLTC cycles; then, fully charging the battery pack according to a slow charging strategy in an environment of 25+/-2 ℃ and standing for 5 minutes; then, the power battery is controlled again in a similar way to carry out WLTC circulation until the preset discharge cut-off condition is reached; finally, the power battery is controlled to stand for 2 hours. Thus, a round of working condition simulation cycle process is completed.
And S305, verifying whether the balance function of the power battery meets the balance requirement at any time node in the simulated working condition circulation process according to the target current value in the simulated working condition circulation process.
In one possible implementation, step S305 may include:
judging whether the target current value is larger than or equal to a preset equalizing current threshold value at any time node in the circulation process of the simulation working condition; and if the power battery balancing function is greater than or equal to the balancing requirement, determining that the balancing function of the power battery meets the balancing requirement at the time node.
In the step, the target current value is collected and monitored in the whole process of the circulation process of the simulation working condition, and whether the target current value is larger than or equal to a preset equalizing current threshold value is judged, so that whether the actual real-time equalizing capacity meets the equalizing requirement of the design of the tested sample can be verified. The preset equalization current threshold may be set according to requirements, such as 5mA, which is not limited in this application.
Further, the verification method further comprises the following steps:
after the circulation process of the simulated working conditions is finished, performing at least one capacity test on the power battery to determine the second capacity of the power battery; determining an average equalization efficiency of the power battery according to the initial capacity, the first capacity and the second capacity; and verifying the equalization effect of the equalization function of the power battery according to the average equalization efficiency.
Here, the determination formula of the average equalization efficiency can be expressed as:
δ＝(Q3-Q2)/Q1×100％
wherein Q3 represents a second capacity; delta represents the average equalization efficiency.
If the average equalization efficiency is larger than the preset index threshold, the equalization function effectively improves the capacity of the power battery, and the equalization effect of the equalization function of the power battery can be verified to meet the design requirement.
Further, the verification method further comprises the following steps:
collecting an equilibrium state signal through a low-voltage communication interface of a battery management system connected to the power battery; and if the balanced function state indicated by the balanced state signal is consistent with the balanced function state indicated by the target current value, verifying that the balanced state signal generated by the power battery when the balanced function is executed is accurate.
Referring back to fig. 3, the low-voltage communication interface is connected to the battery management system BMS of the power battery, and the balanced state signal is collected through the low-voltage communication interface; the equalization status signal may indicate an equalization function status including an equalization function on Active and an equalization function off No Active.
By comparing whether the equalization function state indicated by the equalization state signal is consistent with the equalization function state indicated by the target current value, whether the equalization state signal generated by the power battery when executing the equalization function is accurate can be verified. Specifically, when the target current value is 0, the equalization state signal indicates that the equalization function is turned off; when the target current value is not 0, the equalization state signal indicates that the equalization function is started, the equalization function state indicated by the equalization state signal is judged to be consistent with the equalization function state indicated by the target current value, and the equalization state signal generated by the power battery when the equalization function is executed is verified to be accurate; otherwise, the generated balanced state signal is judged to be inaccurate.
According to the verification method for the power battery equalization function, firstly, the current detection equipment is additionally arranged in the equalization circuit, so that the current value of the equalization circuit can be collected in real time to confirm the real equalization state of the power battery, and whether the equalization function of the power battery can be normally started and whether the actual real-time equalization capacity meets the design requirement is verified; secondly, by designing a simulation working condition cycle simulating the working condition of the real vehicle, the running state (comprising the running, fast and slow charging and standing processes) of the real vehicle can be simulated, and the balance effect of the power battery is comprehensively verified by calculating the average balance efficiency of the whole simulation working condition cycle; thirdly, verifying whether the generated balanced state signal is accurate or not by comparing the balanced state signal with the current value of the balanced circuit, namely whether the balanced state displayed by the balanced state signal is consistent with the actual balanced state or not; finally, the battery cell differential pressure states with different degrees can be manufactured according to the requirements through the battery charging and discharging equipment, and the requirements of simulating the battery pack states under different balanced opening conditions are met.
Through the mode, the purpose of accurately and effectively verifying whether the balance function of the power battery meets the design requirement can be achieved.
Referring to fig. 4, fig. 4 is a schematic structural diagram of a verification device for balancing a power battery according to an embodiment of the present application. The battery pack of the power battery comprises a plurality of single battery cores; as shown in fig. 4, the authentication apparatus 400 includes:
the acquisition module 410 is configured to acquire, in real time, a target current value of an equalization loop where a target single cell is located through a current detection device disposed in the equalization loop where the target single cell is located;
the discharging control module 420 is configured to control the target single battery cell to discharge, so that the power battery meets a preset equalization function starting index;
a first verification module 430, configured to verify whether the equalization function of the power battery can be normally started according to the target current value in the discharging process;
the working condition circulation module 440 is configured to control the power battery to perform at least one round of simulated working condition circulation by simulating a real vehicle working condition when it is verified that the balancing function of the power battery can be started normally;
and the second verification module 450 is configured to verify whether the equalization function of the power battery meets an equalization requirement at any time node in the simulated working condition circulation process according to the target current value in the simulated working condition circulation process.
Further, when the discharging control module 420 is configured to control the target single cell to discharge so that the power battery meets a preset equalization function starting index, the discharging control module 420 is configured to:
performing at least one capacity test on the power battery to determine the initial capacity of the power battery;
determining discharge capacity according to a preset balance function starting index and the initial capacity, and controlling battery charging and discharging equipment to discharge the target single battery cell according to the discharge capacity;
after the discharge according to the discharge capacity is finished, carrying out at least one capacity test on the power battery again to determine the first capacity of the power battery;
determining whether the power battery actually meets the balance function starting index according to the initial capacity and the first capacity;
if yes, ending the discharging process of the target single battery cell;
if the balance function starting index is not met, the battery charging and discharging equipment is continuously controlled to discharge the target single battery core until the power battery is determined to meet the balance function starting index.
Further, when the first verification module 430 is configured to verify whether the equalization function of the power battery can be normally started according to the target current value in the discharging process, the first verification module 430 is configured to:
And if the target current value is not 0, determining that the balancing function of the power battery can be started normally.
Further, the duty cycle module 440 is configured to, when verifying that the balancing function of the power battery can be started normally, control the power battery to perform at least one round of simulated duty cycle by simulating the actual vehicle conditions, where the duty cycle module 440 is configured to:
in the process of any round of simulated working condition circulation, under the preset temperature condition, charging the power battery according to a first charging strategy until the power battery reaches a preset charging cut-off condition, and standing for a first preset time;
controlling the power battery to perform working condition circulation according to the simulated operation working condition simulating the actual vehicle operation state until the power battery reaches a preset discharge cut-off condition;
charging the power battery according to a second charging strategy under the preset temperature condition until the power battery reaches the preset charging stop condition, and standing for a second preset time; wherein the first charging strategy and the second charging strategy comprise a fast charging strategy or a slow charging strategy, and the first charging strategy and the second charging strategy are different;
Controlling the power battery to perform working condition circulation again according to the simulated operation working condition until the power battery reaches the preset discharge cut-off condition;
and controlling the power battery to stand for a third preset time.
Further, when the second verification module 450 is configured to verify whether the equalization function of the power battery meets the equalization requirement according to the target current value in the simulated working condition cycle process, the second verification module 450 is configured to:
judging whether the target current value is larger than or equal to a preset equalizing current threshold value at any time node in the circulation process of the simulation working condition;
and if the power battery balancing function is greater than or equal to the balancing requirement, determining that the balancing function of the power battery meets the balancing requirement at the time node.
Further, the verification apparatus 400 includes: an efficiency determination module; the efficiency determination module is used for:
after the circulation process of the simulated working conditions is finished, performing at least one capacity test on the power battery to determine the second capacity of the power battery;
determining an average equalization efficiency of the power battery according to the initial capacity, the first capacity and the second capacity;
And verifying the equalization effect of the equalization function of the power battery according to the average equalization efficiency.
Further, the verification apparatus 400 includes: a third verification module; the third verification module is used for:
collecting an equilibrium state signal through a low-voltage communication interface of a battery management system connected to the power battery;
and if the balanced function state indicated by the balanced state signal is consistent with the balanced function state indicated by the target current value, verifying that the balanced state signal generated by the power battery when the balanced function is executed is accurate.
Referring to fig. 5, fig. 5 is a schematic structural diagram of a vehicle according to an embodiment of the present application. As shown in fig. 5, the vehicle 500 includes a processor 510, a memory 520, and a bus 530.
The memory 520 stores machine-readable instructions executable by the processor 510, and when the vehicle 500 runs, the processor 510 communicates with the memory 520 through the bus 530, and when the machine-readable instructions are executed by the processor 510, the steps of a method for verifying a power battery balancing function in the method embodiment shown in fig. 2 can be executed, and a specific implementation manner may refer to the method embodiment and will not be described herein.
The embodiment of the present application further provides a computer readable storage medium, where a computer program is stored on the computer readable storage medium, and the computer program may execute the steps of a power battery equalization function verification method in the method embodiment shown in fig. 2 when the computer program is executed by a processor, and a specific implementation manner may refer to the method embodiment and will not be described herein.
It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.
In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. The above-described apparatus embodiments are merely illustrative, for example, the division of the units is merely a logical function division, and there may be other manners of division in actual implementation, and for example, multiple units or components may be combined or 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 communication interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a non-volatile computer readable storage medium executable by a processor. Based on such understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, including several 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 methods described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
Finally, it should be noted that: the foregoing examples are merely specific embodiments of the present application, and are not intended to limit the scope of the present application, but the present application is not limited thereto, and those skilled in the art will appreciate that while the foregoing examples are described in detail, the present application is not limited thereto. Any person skilled in the art may modify or easily conceive of the technical solution described in the foregoing embodiments, or make equivalent substitutions for some of the technical features within the technical scope of the disclosure of the present application; such modifications, changes or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (10)
1. The verification method of the power battery equalization function is characterized in that a battery pack of the power battery comprises a plurality of single battery cells; the verification method comprises the following steps:
collecting a target current value of an equalization loop where a target single cell is located in real time through current detection equipment arranged in the equalization loop where the target single cell is located;
Controlling the target single battery cell to discharge so that the power battery meets a preset balance function starting index;
verifying whether the equalization function of the power battery can be normally started according to the target current value in the discharging process;
if the balance function of the power battery can be normally started, controlling the power battery to perform at least one round of simulated working condition circulation through simulating the real vehicle working condition;
and verifying whether the balance function of the power battery meets the balance requirement at any time node in the simulated working condition circulation process according to the target current value in the simulated working condition circulation process.
2. The method according to claim 1, wherein controlling the target cell to discharge so that the power cell satisfies a preset equalization function on index comprises:
performing at least one capacity test on the power battery to determine the initial capacity of the power battery;
determining discharge capacity according to the balance function starting index and the initial capacity, and controlling battery charging and discharging equipment to discharge the target single battery cell according to the discharge capacity;
After the discharge according to the discharge capacity is finished, carrying out at least one capacity test on the power battery again to determine the first capacity of the power battery;
determining whether the power battery actually meets the balance function starting index according to the initial capacity and the first capacity;
if yes, ending the discharging process of the target single battery cell;
if the balance function starting index is not met, the battery charging and discharging equipment is continuously controlled to discharge the target single battery core until the power battery is determined to meet the balance function starting index.
3. The authentication method according to claim 1 or 2, characterized in that the authentication of whether the equalization function of the power battery can be normally started or not according to the target current value during the discharging process, comprises:
and if the target current value is not 0, determining that the balancing function of the power battery can be started normally.
4. A method of verifying as defined in claim 3, wherein if the balancing function of the power cell is verified to be able to be started normally, controlling the power cell to perform at least one cycle of simulated operating conditions by simulating actual operating conditions comprises:
In the process of any round of simulated working condition circulation, under the preset temperature condition, charging the power battery according to a first charging strategy until the power battery reaches a preset charging cut-off condition, and standing for a first preset time;
controlling the power battery to perform working condition circulation according to the simulated operation working condition simulating the actual vehicle operation state until the power battery reaches a preset discharge cut-off condition;
charging the power battery according to a second charging strategy under the preset temperature condition until the power battery reaches the preset charging stop condition, and standing for a second preset time; wherein the first charging strategy and the second charging strategy comprise a fast charging strategy or a slow charging strategy, and the first charging strategy and the second charging strategy are different;
controlling the power battery to perform working condition circulation again according to the simulated operation working condition until the power battery reaches the preset discharge cut-off condition;
and controlling the power battery to stand for a third preset time.
5. The method according to claim 1, wherein verifying whether an equalization function of the power battery satisfies an equalization requirement at any time node during the simulated condition cycle according to the target current value during the simulated condition cycle, comprises:
Judging whether the target current value is larger than or equal to a preset equalizing current threshold value at any time node in the circulation process of the simulation working condition;
and if the power battery balancing function is greater than or equal to the balancing requirement, determining that the balancing function of the power battery meets the balancing requirement at the time node.
6. The authentication method of claim 2, wherein the authentication method further comprises:
after the circulation process of the simulated working conditions is finished, performing at least one capacity test on the power battery to determine the second capacity of the power battery;
determining an average equalization efficiency of the power battery according to the initial capacity, the first capacity and the second capacity;
and verifying the equalization effect of the equalization function of the power battery according to the average equalization efficiency.
7. The authentication method of claim 1, wherein the authentication method further comprises:
collecting an equilibrium state signal through a low-voltage communication interface of a battery management system connected to the power battery;
and if the balanced function state indicated by the balanced state signal is consistent with the balanced function state indicated by the target current value, verifying that the balanced state signal generated by the power battery when the balanced function is executed is accurate.
8. The verification device for the balance function of the power battery is characterized in that a battery pack of the power battery comprises a plurality of single battery cores; the verification apparatus includes:
the acquisition module is used for acquiring the target current value of the equalization circuit where the target single cell is located in real time through current detection equipment arranged in the equalization circuit where the target single cell is located;
the discharging control module is used for controlling the target single battery cell to discharge so that the power battery meets a preset balance function starting index;
the first verification module is used for verifying whether the equalization function of the power battery can be normally started according to the target current value in the discharging process;
the working condition circulation module is used for controlling the power battery to perform at least one round of simulated working condition circulation through simulating a real vehicle working condition when the balance function of the power battery is verified to be capable of being started normally;
and the second verification module is used for verifying whether the balance function of the power battery meets the balance requirement at any time node in the simulated working condition circulation process according to the target current value in the simulated working condition circulation process.
9. A vehicle, characterized by comprising: a processor, a memory and a bus, said memory storing machine readable instructions executable by said processor, said processor and said memory communicating via said bus when the vehicle is running, said machine readable instructions when executed by said processor performing the steps of a method of verifying a power cell balancing function according to any one of claims 1 to 7.
10. A computer-readable storage medium, characterized in that the computer-readable storage medium has stored thereon a computer program which, when executed by a processor, performs the steps of a method for verifying a power cell balancing function according to any one of claims 1 to 7.
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| CN202311866512.1A CN117826004A (en) | 2023-12-29 | 2023-12-29 | Verification method and device for power battery equalization function, vehicle and medium |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202311866512.1A CN117826004A (en) | 2023-12-29 | 2023-12-29 | Verification method and device for power battery equalization function, vehicle and medium |
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