Battery management method for electric vehicle, and storage medium
阅读说明：本技术 电动车辆的电池管理方法、电动车辆和存储介质 (Battery management method for electric vehicle, and storage medium ) 是由 龙成冰 文明 于 2020-07-16 设计创作，主要内容包括：本发明提供了一种电动车辆的电池管理方法、电动车辆和存储介质,其中,电动车辆的电池管理方法包括：获取电池组件的荷电状态值,根据荷电状态值生成对应的电池预警信息；响应于电池预警信息,获取电动车辆的工作状态；根据工作状态确定对应的提示信息,并显示提示信息。本发明实施例通过根据荷电状态值的具体情况生成对应的提示信息,并在仪表台、中控大屏等位置显示该提示信息,提醒用户执行完全放电或充满电等操作,避免因为荷电状态值长时间处于特定工作区间导致的SOC计算不准确等问题,有效地保证了电池组件的可靠性和使用寿命。(The invention provides a battery management method of an electric vehicle, the electric vehicle and a storage medium, wherein the battery management method of the electric vehicle comprises the following steps: acquiring a state of charge value of the battery assembly, and generating corresponding battery early warning information according to the state of charge value; responding to the battery early warning information, and acquiring the working state of the electric vehicle; and determining corresponding prompt information according to the working state, and displaying the prompt information. According to the embodiment of the invention, the corresponding prompt information is generated according to the specific condition of the state of charge value, and the prompt information is displayed at the positions of the instrument desk, the central control large screen and the like, so that a user is reminded to execute operations such as complete discharge or full charge, the problems of inaccurate SOC calculation and the like caused by the fact that the state of charge value is in a specific working interval for a long time are avoided, and the reliability and the service life of the battery pack are effectively ensured.)
1. A battery management method of an electric vehicle, the electric vehicle including a battery pack, the management method comprising:
acquiring a state of charge value of the battery assembly, and generating corresponding battery early warning information according to the state of charge value;
responding to battery early warning information, and acquiring the working state of the electric vehicle;
and determining corresponding prompt information according to the working state, and displaying the prompt information.
2. The battery management method of an electric vehicle according to claim 1, wherein the battery warning information includes first battery warning information, the battery management method further comprising:
acquiring the state of charge value in response to a power-on signal of the electric vehicle;
acquiring accumulated operation time based on the condition that the state of charge value is within a preset interval, and continuously acquiring current operation time;
updating the accumulated operation duration according to the current operation duration; and
the step of generating corresponding battery early warning information according to the state of charge value specifically includes:
and generating the first battery early warning information based on the updated condition that the accumulated running time is greater than or equal to a first threshold value.
3. The battery management method of an electric vehicle according to claim 2, characterized by further comprising:
and controlling the accumulated running time to be reset based on the condition that the state of charge value is outside the preset interval.
4. The battery management method of an electric vehicle according to claim 2, wherein the battery warning information further includes second battery warning information, the battery management method further comprising:
acquiring the state of charge value in response to a charge start signal of the electric vehicle;
acquiring the accumulated charging and discharging times based on the condition that the state of charge value is within the preset interval; and
the step of generating corresponding battery early warning information according to the state of charge value specifically includes:
and generating the second battery early warning information based on the condition that the accumulated charging and discharging times is greater than or equal to a second threshold value.
5. The battery management method of an electric vehicle according to claim 4, characterized by further comprising:
responding to any one of the electrifying signals and/or any one of the charging starting signals, and controlling the accumulated charging and discharging times to be increased by one; and
and controlling the accumulated charging and discharging times to be cleared based on the condition that the state of charge value is outside the preset interval.
6. The battery management method of an electric vehicle according to claim 4, wherein the battery warning information further includes third battery warning information, the step of obtaining a state of charge value of the battery pack and generating corresponding battery warning information according to the state of charge value further includes:
acquiring a first state of charge value in response to a power-off signal of the electric vehicle and/or a charge completion signal of the electric vehicle;
acquiring a second state of charge value in response to the power-on signal and/or the charge start signal;
calculating the difference between the first state of charge value and the second state of charge value to obtain a fourth difference value under the condition that the state of charge is within the preset interval;
and generating the third battery early warning information based on the condition that the fourth difference value is greater than or equal to a third threshold value.
7. The battery management method of an electric vehicle according to claim 1, wherein the electric vehicle further includes a battery management system, the battery warning information further includes fourth battery warning information, and the battery management method further includes:
and controlling the battery management system to generate the fourth battery early warning information under the condition of receiving the maintenance request information of the battery assembly.
8. The battery management method of an electric vehicle according to claim 4 or 5, characterized by further comprising:
based on the condition that the state of charge value is continuously greater than or equal to a fourth threshold value within a preset time length; and/or
And controlling the accumulated operation time length to be reset and controlling the accumulated charging and discharging times to be reset on the basis that the state of charge value is continuously smaller than or equal to a fifth threshold value in the preset time length.
9. The battery management method of an electric vehicle according to any one of claims 1 to 7, wherein the operating state includes a driving state and a charging state, and the step of determining the corresponding prompt information according to the operating state specifically includes:
generating first prompt information based on the condition that the working state is the driving state;
and generating second prompt information based on the condition that the working state is the charging state.
10. The battery management method of an electric vehicle according to any one of claims 1 to 7, characterized in that after the step of displaying the prompt message, the battery management method further includes:
acquiring the accumulated display duration of the prompt message;
and stopping displaying the prompt message based on the condition that the accumulated display time length is greater than or equal to a sixth threshold value or the condition that the battery assembly is subjected to complete charge-discharge cycle and the battery early warning message disappears.
11. An electric vehicle, characterized by comprising:
the power assembly is used for driving the electric vehicle to move;
the battery assembly is used for supplying power to the power assembly;
a memory having a computer program stored thereon;
a processor configured to implement the steps of the battery management method of the electric vehicle according to any one of claims 1 to 10 when executing the computer program.
12. A computer-readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the battery management method of an electric vehicle according to any one of claims 1 to 10.
Technical Field
The invention relates to the technical field of battery management, in particular to a battery management method of an electric vehicle, the electric vehicle and a computer readable storage medium.
Background
In the related art, when a State of Charge value such as SOC (State of Charge) of a power battery of an electric vehicle is within a specific interval, a voltage of a cell is substantially unchanged, and if the battery operates in the interval for a long time, problems such as inaccurate SOC calculation, poor cell consistency, and reduced service life may be caused.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art or the related art.
To this end, a first aspect of the invention proposes a battery management method of an electric vehicle.
A second aspect of the invention proposes an electric vehicle.
A third aspect of the invention proposes a computer-readable storage medium.
In view of this, a first aspect of the present invention provides a battery management method for an electric vehicle, the electric vehicle including a battery pack, the management method including: acquiring a state of charge value of the battery assembly, and generating corresponding battery early warning information according to the state of charge value; responding to the battery early warning information, and acquiring the working state of the electric vehicle; and determining corresponding prompt information according to the working state, and displaying the prompt information.
In the technical scheme, the electric vehicle acquires the state of charge value of the battery pack in real time, when the state of charge value meets the conditions, such as the state of charge value working in a specific interval for a long time or exceeding a risk boundary value, corresponding prompt information is generated according to the specific condition of the state of charge value, the prompt information is displayed at the instrument desk, the central control large screen and other positions, a user is reminded to execute operations such as complete discharge or full charge, the problems of inaccurate SOC calculation and the like caused by the fact that the state of charge value is in the specific working interval for a long time are avoided, and the reliability and the service life of the battery pack are effectively guaranteed.
In addition, the battery management method for the electric vehicle in the above technical solution provided by the present invention may further have the following additional technical features:
in any of the above technical solutions, the battery warning information further includes first battery warning information, and the battery management method further includes: acquiring a state of charge value in response to a power-on signal of the electric vehicle; acquiring the accumulated operation time length based on the condition that the state of charge value is within a preset interval, and continuously acquiring the current operation time length; updating the accumulated running time length according to the current running time length; and generating corresponding battery early warning information according to the state of charge value, which specifically comprises the following steps: and generating first battery early warning information based on the condition that the updated accumulated running time is greater than or equal to the first threshold.
In the technical scheme, after the electric automobile is electrified, a state of charge (SOC) value is obtained immediately, if the SOC value is within a preset interval, the accumulated running time is obtained, and the accumulated running time is continuously updated according to the current running time. Specifically, if the state of charge value of the battery pack is within the preset interval for a long time, problems of inaccurate SOC calculation, poor consistency of battery cells, reduced service life, and the like may result. Therefore, when the state of charge value is in a preset interval for a long time, namely the accumulated running time is greater than or equal to the first threshold value, first battery early warning information is generated to prompt a user to perform complete charging and discharging, the service life of the battery assembly is prevented from being reduced, and the reliability of the battery assembly and the electric vehicle is improved.
Wherein the preset interval can be expressed as: the specific values of SOC1, SOC2, SOC1 and SOC2 may be adjusted based on the specific parameters of the battery assembly or cell.
In any of the above technical solutions, the battery management method of an electric vehicle further includes: and controlling the accumulated running time to be reset based on the condition that the initial value of the state of charge is outside the preset interval.
In the technical scheme, if the state of charge value is outside the preset interval, the state of charge value of the battery assembly is separated from the preset interval, the problems of inaccurate SOC calculation, poor consistency of battery monomers, service life reduction and the like caused by long-time operation in the preset interval can be solved, at the moment, the accumulated operation time length is cleared, and the recording of the accumulated operation time length is restarted.
In any of the above technical solutions, the battery warning information further includes second battery warning information, and the battery management method further includes: acquiring a state of charge value in response to a charge start signal of the electric vehicle; acquiring the accumulated charging and discharging times based on the condition that the state of charge value is within a preset interval; and generating corresponding battery early warning information according to the state of charge value, which specifically comprises the following steps: and generating second battery early warning information based on the condition that the accumulated charging and discharging times is greater than or equal to a second threshold value.
According to the technical scheme, after the electric automobile starts, an initial state of charge (SOC) value is obtained immediately, and if the initial state of charge value is within a preset interval, the accumulated charging and discharging times are obtained. Specifically, if the SOC value of the battery assembly is maintained within the predetermined range, i.e., [ SOC1, SOC2] in a plurality of charge/discharge cycles, it indicates that the battery assembly has not been completely charged/discharged in the plurality of charge/discharge cycles, i.e., the SOC value is not lower than SOC1 (which may be regarded as "empty" charge amount) or higher than SOC2 (which may be regarded as "full" charge amount), which may cause problems of SOC calculation inaccuracy, battery cell uniformity degradation, and life reduction.
Therefore, when the charge state value is in a preset interval, the number of charge and discharge cycles is large, namely the accumulated number of charge and discharge cycles is larger than or equal to the second threshold value, second battery early warning information is generated to prompt a user to perform complete charge and discharge, the service life of the battery assembly is prevented from being reduced, and the reliability of the battery assembly and the electric vehicle is improved.
In any of the above technical solutions, the battery management method of an electric vehicle further includes: responding to any electrifying signal and/or any charging starting signal, and controlling the accumulated charging and discharging times to be increased by one; and controlling the accumulated charging and discharging times to be cleared based on the condition that the state of charge value is outside the preset interval.
In the technical scheme, the accumulated charging and discharging times are controlled to be increased by one every time the electric vehicle is electrified and/or the electric vehicle starts to be charged. And if the state of charge value is detected to be outside the preset interval, indicating that the current charge-discharge cycle leaves the preset interval, and at the moment, controlling the accumulated charge-discharge times to be cleared and accumulating the charge-discharge times again.
In any of the above technical solutions, the battery warning information further includes third battery warning information, the state of charge value of the battery assembly is obtained, and the step of generating corresponding battery warning information according to the state of charge value further includes: acquiring a first state of charge value in response to a power-off signal of the electric vehicle and/or a charge completion signal of the electric vehicle; acquiring a second state of charge value in response to the power-on signal and/or the charge start signal; calculating the difference between the first state of charge value and the second state of charge value to obtain a fourth difference value under the condition that the state of charge is within a preset interval; and generating third battery early warning information on the basis of the condition that the fourth difference value is greater than or equal to the third threshold value.
In the technical scheme, each time the electric vehicle is powered off or when the electric vehicle is charged to the end, the current terminal state of charge value of the battery assembly, namely the first state of charge value, is recorded in response to the power-off signal and/or the charging completion signal. When the electric vehicle is powered on again or starts to be charged, the second state of charge value at the time of powering on or charging is acquired, and the difference between the first state of charge value and the second state of charge value, that is, the fourth difference, is calculated.
If the fourth difference is greater than or equal to the third threshold, it indicates that the initial SOC jitter detected by the BMS (battery Management System) is large, and at this time, third battery warning information is generated to prompt the user to perform complete charging and discharging, so that the life reduction of the battery assembly is avoided, and the reliability of the battery assembly and the electric vehicle is improved.
In any of the above technical solutions, the electric vehicle further includes a battery management system, the battery warning information further includes fourth battery warning information, and the battery management method further includes: and controlling the battery management system to generate fourth battery early warning information under the condition of receiving the maintenance request information of the battery assembly.
In the technical scheme, the electric vehicle comprises a Battery Management System (BMS), and when the BMS receives the maintenance request information of the battery assembly, if the service life reaches a preset maintenance period, or the total charging and discharging times reaches a preset maintenance time, fourth battery early warning information is generated to prompt a user to maintain the battery assembly.
In any of the above technical solutions, the battery management method of an electric vehicle further includes: based on the condition that the state of charge value is continuously greater than or equal to the fourth threshold value within the preset time length; and/or controlling the accumulated operation time length to be cleared and controlling the accumulated charging and discharging times to be cleared on the basis of the condition that the state of charge value is continuously smaller than or equal to the fifth threshold value in the preset time length.
In the technical scheme, if the state of charge value is continuously greater than or equal to the fourth threshold value within the preset time length, the battery assembly is judged to be in a full state, and if the state of charge value is continuously less than or equal to the fifth threshold value, the battery assembly is judged to be in an empty state. And at the moment, controlling the accumulated running time and the accumulated charging times to be zero.
In any of the above technical solutions, the working state includes a driving state and a charging state, and the step of determining the corresponding prompt information according to the working state specifically includes: generating first prompt information based on the condition that the working state is the driving state; and generating second prompt information based on the condition that the working state is the charging state.
In this technical solution, the operating state of the electric vehicle includes a running state and a charging state. If the electric vehicle is in a running state and the battery early warning information is detected, generating first prompt information and displaying the first prompt information through an instrument panel or a central control large screen and the like. Wherein, the first prompt message may include: please discharge the battery SOC to be lower than the SOCmin. I.e. using no electricity, SOCminThe setting may be made according to parameters of the battery assembly.
And if the electric vehicle is in a charging state and the battery early warning information is detected, generating second prompt information, and displaying the second prompt information through an instrument panel or a central control large screen and the like. Wherein, the second prompt message may include: please charge the battery to SOCmaxI.e. full charge, SOCmaxThe setting may be made according to parameters of the battery assembly.
In any of the above technical solutions, after the step of displaying the prompt information, the battery management method further includes: acquiring the accumulated display duration of the prompt message; and stopping displaying the prompt information based on the condition that the accumulated display time length is greater than or equal to the sixth threshold value or the condition that the battery assembly passes through the complete charge-discharge cycle and the battery early warning information disappears.
In the technical scheme, the accumulated display duration of the prompt message is recorded in real time when the prompt message is displayed every time. And if the accumulated display duration of the prompt message is greater than or equal to the sixth threshold, stopping displaying the prompt message, avoiding interference on user driving and ensuring driving safety. And if the battery assembly passes through at least one complete charge-discharge cycle after the prompt message is displayed and the battery early warning message is not detected again, judging that the battery assembly enters a normal working cycle, and stopping displaying the prompt message.
In the above technical solution, the battery pack includes a plurality of battery units, the battery warning information includes fifth battery warning information, the state of charge value of the battery pack is obtained, and the step of generating corresponding battery warning information according to the state of charge value specifically includes: acquiring a real-time voltage value of any battery unit, and calculating an average voltage value of a plurality of battery units in the battery assembly; calculating the absolute value of the difference between the voltage value and the average voltage value to obtain a first difference value; and generating fifth battery early warning information on the basis of the condition that the first difference value is greater than or equal to the seventh threshold value.
In this embodiment, the battery module includes a plurality of battery cells, and generally, after the plurality of battery modules are connected in series to form a group, the plurality of groups are connected in parallel to form a final battery module. In order to ensure the power supply effect, the electric quantity and the voltage of each battery pack need to be ensured to be the same as much as possible. During the operation of the electric vehicle, the real-time voltage value of each battery unit is monitored in real time, and the average voltage value of the battery units in the battery pack is calculated.
Wherein, the average voltage value Uavg ═ U ÷ X, where U is the total voltage value of the battery pack and X is the number of battery cells in the battery pack.
After the average voltage value is determined, calculating an absolute value of a difference value between a real-time voltage value and the average voltage value of the single battery unit, namely a first difference value, if the first difference value is larger than or equal to a seventh threshold value, indicating that the voltage of the single battery unit is unbalanced, and generating fifth battery early warning information at the moment, wherein the fifth battery early warning information is single unbalanced early warning information and prompts a user to perform complete charging and discharging, so that the service life of a battery assembly caused by the single battery unbalance is prevented from being reduced, and the reliability of the battery assembly and an electric vehicle is improved.
In any of the above technical solutions, the battery warning information includes sixth battery warning information, and the step of generating corresponding battery warning information according to the state of charge value specifically includes: determining a maximum real-time voltage value and a minimum real-time voltage value in the plurality of real-time voltage values according to the magnitude relation of the plurality of real-time voltage values; calculating the difference between the maximum real-time voltage value and the minimum real-time voltage value to obtain a second difference value; and generating sixth battery early warning information on the basis of the condition that the second difference value is greater than or equal to the eighth threshold value.
In the technical scheme, after the real-time voltage values of a plurality of battery units in the battery assembly are obtained, the obtained real-time voltage values are sequenced according to the voltage magnitude sequence, and the maximum real-time voltage value and the minimum real-time voltage value are determined. And calculating a difference value between the maximum real-time voltage value and the minimum real-time voltage value to obtain a second difference value, wherein the second difference value reflects the overall unbalance degree of the battery pack, and if the second difference value is greater than or equal to an eighth threshold, sixth battery early warning information is generated to prompt a user to perform complete charging and discharging, so that the service life of the battery pack is prevented from being reduced, and the reliability of the battery pack and the electric vehicle is improved.
In any of the above technical solutions, the state of charge value includes a state of charge value and a state of health value, the battery warning information includes seventh battery warning information, and the step of generating corresponding battery warning information according to the state of charge value specifically includes: calculating a difference between the state of charge value and the state of health value to obtain a third difference value; and generating seventh battery warning information on the basis of the condition that the third difference is greater than or equal to the ninth threshold.
In this solution, the State of charge value includes a State of charge value (SOC) and a State of health value (SOH). The vehicle can follow BMS (Battery Management System) and acquire the SOC state of precision of battery, if BMS feedback SOC's precision reduces, then the suggestion user SOC precision is not enough, need carry out complete charge-discharge, avoids battery pack life-span to reduce, improves battery pack and electric vehicle's reliability.
A second aspect of the invention provides an electric vehicle including: the power assembly is used for driving the electric vehicle to move; the battery assembly is used for supplying power to the power assembly; a memory having a computer program stored thereon; a processor configured to implement the steps of the battery management method of the electric vehicle as provided in any one of the above technical solutions when executing the computer program.
In this technical solution, the power assembly includes a driving motor, a steering motor, an electronic transmission, and the like, and meanwhile, since the electric vehicle can implement the steps of the battery management method of the electric vehicle provided in any one of the above technical solutions by executing a computer program on a memory through a processor, the electric vehicle also includes all the beneficial effects of the battery management method of the electric vehicle provided in any one of the above technical solutions, and details are not repeated herein.
A third aspect of the present invention provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps of the battery management method for an electric vehicle as provided in any one of the above technical solutions, and therefore the computer-readable storage medium also includes all the beneficial effects of the battery management method for an electric vehicle as provided in any one of the above technical solutions, which are not described herein again.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 shows one of the flowcharts of a battery management method of an electric vehicle according to one embodiment of the invention;
FIG. 2 illustrates a second flow chart of a method of battery management for an electric vehicle according to an embodiment of the present invention;
FIG. 3 illustrates a third flowchart of a method of battery management for an electric vehicle according to an embodiment of the present invention;
FIG. 4 shows a fourth flowchart of a battery management method of an electric vehicle according to an embodiment of the invention;
FIG. 5 shows a fifth flowchart of a battery management method of an electric vehicle according to an embodiment of the invention;
FIG. 6 shows six of a flow chart of a method of battery management of an electric vehicle according to one embodiment of the invention;
FIG. 7 illustrates a seventh flowchart of a battery management method of an electric vehicle according to an embodiment of the invention;
FIG. 8 shows an eighth flowchart of a method of battery management for an electric vehicle, according to an embodiment of the invention;
FIG. 9 shows nine of a flow chart of a method of battery management for an electric vehicle according to one embodiment of the present invention;
FIG. 10 shows a corresponding plot of battery voltage versus SOC;
fig. 11 shows a block diagram of the structure of a battery management system of an electric vehicle;
FIG. 12 shows ten of a flow chart of a method of battery management of an electric vehicle according to one embodiment of the invention;
FIG. 13a shows eleven of a flow chart of a method of battery management of an electric vehicle according to one embodiment of the present invention;
FIG. 13b shows twelve of a flow chart of a method of battery management for an electric vehicle according to one embodiment of the invention;
fig. 14 shows thirteen of a flowchart of a battery management method of an electric vehicle according to an embodiment of the invention;
FIG. 15 shows fourteen flow diagrams of a battery management method for an electric vehicle according to an embodiment of the invention;
FIG. 16 shows fifteen of a flow chart diagram for a method of battery management for an electric vehicle, in accordance with an embodiment of the invention;
fig. 17 shows a block diagram of the electric vehicle according to an embodiment of the invention.
Detailed Description
In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.
A battery management method of an electric vehicle, and a computer-readable storage medium according to some embodiments of the present invention are described below with reference to fig. 1 to 17.
As shown in fig. 1, in an embodiment of the present invention, there is provided a battery management method of an electric vehicle, the electric vehicle including a battery pack, the management method including:
step 102, acquiring a state of charge value of a battery assembly, and generating corresponding battery early warning information according to the state of charge value;
104, responding to the battery early warning information, and acquiring the working state of the electric vehicle;
and 106, determining corresponding prompt information according to the working state, and displaying the prompt information.
In the embodiment, the electric vehicle acquires the state of charge value of the battery assembly in real time, when the state of charge value meets the conditions, such as the state of charge value works in a specific interval for a long time or exceeds a risk boundary value, corresponding prompt information is generated according to the specific condition of the state of charge value, the prompt information is displayed at the positions of an instrument desk, a central control large screen and the like, a user is reminded to execute operations such as complete discharge or full charge, the problems of inaccurate SOC calculation and the like caused by the fact that the state of charge value is in the specific working interval for a long time are avoided, and the reliability and the service life of the battery assembly are effectively guaranteed.
In the embodiment of the present invention, the battery assembly includes a plurality of battery units, the battery warning information includes first battery warning information, and a state of charge value of the battery assembly is obtained, as shown in fig. 2, the step of generating corresponding battery warning information according to the state of charge value specifically includes:
step 202, acquiring a real-time voltage value of any battery unit, and calculating an average voltage value of a plurality of battery units in the battery pack;
step 204, calculating an absolute value of a difference between the voltage value and the average voltage value to obtain a first difference value;
and step 206, generating fifth battery early warning information based on the condition that the first difference value is greater than or equal to the seventh threshold value.
In this embodiment, the battery assembly includes a plurality of battery cells, and generally, after a plurality of battery assemblies are serially connected to each other to form a group, the plurality of groups are connected in parallel to each other to form a final battery assembly. In order to ensure the power supply effect, the electric quantity and the voltage of each battery pack need to be ensured to be the same as much as possible. During the operation of the electric vehicle, the real-time voltage value of each battery unit is monitored in real time, and the average voltage value of the battery units in the battery pack is calculated.
Wherein, the average voltage value Uavg ═ U ÷ X, where U is the total voltage value of the battery pack and X is the number of battery cells in the battery pack.
The seventh threshold is related to parameter attributes such as the capacity of the battery unit, and may be specifically set according to the parameter attributes of the battery unit.
After the average voltage value is determined, calculating an absolute value of a difference value between a real-time voltage value and the average voltage value of the single battery unit, namely a first difference value, if the first difference value is larger than or equal to a seventh threshold value, indicating that the voltage of the single battery unit is unbalanced, and generating fifth battery early warning information at the moment, wherein the fifth battery early warning information is single unbalanced early warning information and prompts a user to perform complete charging and discharging, so that the service life of a battery assembly caused by the single battery unbalance is prevented from being reduced, and the reliability of the battery assembly and an electric vehicle is improved.
In the embodiment of the present invention, the battery warning information includes second battery warning information, and as shown in fig. 3, the step of generating corresponding battery warning information according to the state of charge value specifically includes:
and step 306, generating sixth battery early warning information based on the condition that the second difference is greater than or equal to the eighth threshold.
In this embodiment, after the real-time voltage values of the plurality of battery units in the battery assembly are acquired, the acquired real-time voltage values are sorted according to the order of voltage magnitude, and the maximum real-time voltage value and the minimum real-time voltage value are determined. And calculating a difference value between the maximum real-time voltage value and the minimum real-time voltage value to obtain a second difference value, wherein the second difference value reflects the overall unbalance degree of the battery pack, and if the second difference value is greater than or equal to an eighth threshold, sixth battery early warning information is generated to prompt a user to perform complete charging and discharging, so that the service life of the battery pack is prevented from being reduced, and the reliability of the battery pack and the electric vehicle is improved.
The eighth threshold is related to parameter attributes such as the capacity of the battery unit, and may be specifically set according to the parameter attributes of the battery unit.
In the embodiment of the present invention, the state of charge value includes a state of charge value and a state of health value, the battery warning information includes third battery warning information, and as shown in fig. 4, the step of generating corresponding battery warning information according to the state of charge value specifically includes:
step 402, calculating a difference between the state of charge value and the state of health value to obtain a third difference value;
and step 404, generating seventh battery warning information based on the condition that the third difference value is greater than or equal to the ninth threshold value.
In this embodiment, the State of charge values include a State of charge value (SOC) and a State of health value (SOH). The vehicle can follow BMS (Battery Management System) and acquire the SOC state of precision of battery, if BMS feedback SOC's precision reduces, then the suggestion user SOC precision is not enough, need carry out complete charge-discharge, avoids battery pack life-span to reduce, improves battery pack and electric vehicle's reliability.
The ninth threshold is related to parameter attributes such as the composition, the connection mode, and the capacity of the battery assembly, and may be specifically set according to the parameter attributes of the battery assembly.
In this embodiment of the present invention, the battery warning information further includes first battery warning information, and as shown in fig. 5, the battery management method further includes:
step 502, responding to a power-on signal of an electric vehicle, and acquiring a state of charge value;
step 504, acquiring an accumulated operation time length based on the condition that the state of charge value is within a preset interval, and continuously acquiring a current operation time length;
step 506, based on the updated accumulated running time being greater than or equal to the first threshold, generating first battery warning information.
In the embodiment, after the electric vehicle is powered on, a state of charge (SOC) value is acquired immediately, if the SOC value is within a preset interval, the accumulated running time is acquired, and the accumulated running time is continuously updated according to the current running time. Specifically, if the state of charge value of the battery pack is within the preset interval for a long time, problems of inaccurate SOC calculation, poor consistency of battery cells, reduced service life, and the like may result. Therefore, when the state of charge value is in a preset interval for a long time, namely the accumulated running time is greater than or equal to the first threshold value, first battery early warning information is generated to prompt a user to perform complete charging and discharging, the service life of the battery assembly is prevented from being reduced, and the reliability of the battery assembly and the electric vehicle is improved.
Wherein the preset interval can be expressed as: specific values of SOC1, SOC2, SOC1 and SOC2 may be adjusted according to specific parameters of the battery pack or the battery unit, and the specific range of the preset range is not limited in the embodiment of the present invention.
The first threshold is related to parameter attributes such as the composition, the connection mode, and the capacity of the battery assembly, and may be specifically set according to the parameter attributes of the battery assembly.
In an embodiment of the present invention, the battery management method of an electric vehicle further includes: and controlling the accumulated running time to be reset based on the condition that the state of charge value is outside the preset interval.
In this embodiment, if the state of charge value is outside the preset interval, it represents that the state of charge value of the battery assembly has deviated from the preset interval, and can avoid the problems of inaccurate SOC calculation, poor consistency of battery cells, reduced service life and the like caused by long-time operation in the preset interval, at this time, the accumulated operation duration is cleared, and the recording of the accumulated operation duration is restarted.
In this embodiment of the present invention, the battery warning information further includes second battery warning information, and as shown in fig. 6, the battery management method further includes:
step 602, responding to a charging start signal of an electric vehicle, and acquiring a state of charge value;
step 604, acquiring accumulated charging and discharging times based on the condition that the state of charge value is within a preset interval;
and 606, generating second battery early warning information based on the condition that the accumulated charging and discharging times are larger than or equal to a second threshold value.
In this embodiment, after the electric vehicle starts, a state of charge (SOC) value is obtained immediately, and if the SOC value is within a preset interval, the accumulated charge and discharge times are obtained. Specifically, if the SOC value of the battery assembly is maintained within the predetermined range, i.e., [ SOC1, SOC2] in a plurality of charge/discharge cycles, it indicates that the battery assembly has not been completely charged/discharged in the plurality of charge/discharge cycles, i.e., the SOC value is not lower than SOC1 (which may be regarded as "empty" charge amount) or higher than SOC2 (which may be regarded as "full" charge amount), which may cause problems of SOC calculation inaccuracy, battery cell uniformity degradation, and life reduction.
Therefore, when the charge state value is in a preset interval, the number of charge and discharge cycles is large, namely the accumulated number of charge and discharge cycles is larger than or equal to the second threshold value, second battery early warning information is generated to prompt a user to perform complete charge and discharge, the service life of the battery assembly is prevented from being reduced, and the reliability of the battery assembly and the electric vehicle is improved.
The second threshold is related to parameter attributes such as the composition, the connection mode, and the capacity of the battery assembly, and may be specifically set according to the parameter attributes of the battery assembly.
In an embodiment of the present invention, as shown in fig. 7, the battery management method of an electric vehicle further includes:
and 704, controlling the accumulated charging and discharging times to be cleared based on the condition that the state of charge value is outside the preset interval.
In this embodiment, the accumulated number of charge and discharge times is controlled to be increased by one each time the electric vehicle is powered on and/or the electric vehicle starts charging. And if the state of charge value is detected to be outside the preset interval, indicating that the current charge-discharge cycle leaves the preset interval, and at the moment, controlling the accumulated charge-discharge times to be cleared and accumulating the charge-discharge times again.
In the embodiment of the present invention, the battery early warning information further includes third battery early warning information, the state of charge value of the battery assembly is obtained, and as shown in fig. 8, the step of generating corresponding battery early warning information according to the state of charge value further includes:
and 808, generating third battery early warning information based on the condition that the fourth difference value is greater than or equal to the third threshold value.
In this embodiment, the present terminal state of charge value of the battery assembly, i.e., the first state of charge value, is recorded in response to the power-off signal and/or the charge completion signal each time the electric vehicle is powered down, or at the end of charging the electric vehicle. When the electric vehicle is powered on again or starts to be charged, the second state of charge value at the time of powering on or charging is acquired, and the difference between the first state of charge value and the second state of charge value, that is, the fourth difference, is calculated.
If the fourth difference is greater than or equal to the third threshold, it indicates that the initial SOC jitter detected by the BMS (battery Management System) is large, and at this time, third battery warning information is generated to prompt the user to perform complete charging and discharging, so that the life reduction of the battery assembly is avoided, and the reliability of the battery assembly and the electric vehicle is improved.
The third threshold is related to parameter attributes such as the composition, the connection mode, and the capacity of the battery assembly, and may be specifically set according to the parameter attributes of the battery assembly.
In an embodiment of the present invention, the electric vehicle further includes a battery management system, the battery warning information further includes fourth battery warning information, and the battery management method further includes: and controlling the battery management system to generate fourth battery early warning information under the condition of receiving the maintenance request information of the battery assembly.
In this embodiment, the electric vehicle includes a Battery Management System (BMS), and when the BMS receives a maintenance request message for the battery assembly, such as when a usage duration reaches a preset maintenance time limit or a total charge/discharge frequency reaches a preset maintenance frequency, fourth battery warning message is generated to prompt a user to perform maintenance on the battery assembly.
In an embodiment of the present invention, the battery management method of an electric vehicle further includes: based on the condition that the state of charge value is continuously greater than or equal to the fourth threshold value within the preset time length; and/or controlling the accumulated operation time length to be cleared and controlling the accumulated charging and discharging times to be cleared on the basis of the condition that the state of charge value is continuously smaller than or equal to the fifth threshold value in the preset time length.
In this embodiment, if the state of charge value is continuously greater than or equal to the fourth threshold value within the preset time period, it is determined that the battery assembly is in the full state, and if the state of charge value is continuously less than or equal to the fifth threshold value, it is determined that the battery assembly is in the empty state. And at the moment, controlling the accumulated running time and the accumulated charging times to be zero.
In the embodiment of the present invention, the working state includes a driving state and a charging state, and the step of determining the corresponding prompt information according to the working state specifically includes: generating first prompt information based on the condition that the working state is the driving state; and generating second prompt information based on the condition that the working state is the charging state.
In this embodiment, the operating state of the electric vehicle includes a running state and a charging state. If the electric vehicle is in a running state and the battery early warning information is detected, generating first prompt information and displaying the first prompt information through an instrument panel or a central control large screen and the like. Wherein, the first prompt message may include: please discharge the battery SOC to be lower than the SOCmin. I.e. using no electricity, SOCminThe setting may be made according to parameters of the battery assembly.
And if the electric vehicle is in a charging state and the battery early warning information is detected, generating second prompt information, and displaying the second prompt information through an instrument panel or a central control large screen and the like. Wherein, the second prompt message may include: please charge the battery SOC to 100%, i.e. prompt the user to fully charge the battery.
In this embodiment of the present invention, after the step of displaying the prompt message, as shown in fig. 9, the battery management method further includes:
step 902, acquiring the accumulated display duration of the prompt message;
and 904, stopping displaying the prompt message based on the condition that the accumulated display duration is greater than or equal to the sixth threshold or the battery assembly is subjected to complete charge-discharge cycle and the battery early warning message disappears.
In this embodiment, each time the prompt message is displayed, the accumulated display duration of the prompt message is recorded in real time. And if the accumulated display duration of the prompt message is greater than or equal to the sixth threshold, stopping displaying the prompt message, avoiding interference on user driving and ensuring driving safety. And if the battery assembly passes through at least one complete charge-discharge cycle after the prompt message is displayed and the battery early warning message is not detected again, judging that the battery assembly enters a normal working cycle, and stopping displaying the prompt message.
In one embodiment of the present invention, the embodiment of the present invention is explained in detail based on an operation scenario of an electric vehicle.
In the related art, when the electric vehicle is in use, the capacity of the power battery is attenuated, so that the SOC (State of Charge) precision of the power battery is reduced, the unbalance degree of the power battery is increased, and the service life of the power battery is greatly influenced.
Particularly, for pure electric commercial vehicles and engineering machinery, in order to guarantee driving range, the electric quantity of the power battery is large, a voltage platform is mainly 600V, a 2-in-series or 3-in-series scheme is generally adopted, the number of the single batteries in series is 180-200, the total number of the single batteries of the power battery is 360-600, and therefore the control difficulty of the unbalance degree of the single batteries is higher.
In order to ensure the safety of vehicles, commercial vehicles or engineering machinery mainly adopt lithium iron phosphate batteries, and generally when the SOC is in the interval of [0.3, 0.8], the voltage of a single battery cell is basically kept unchanged, and if the battery works in the interval for a long time, the calculated SOC may be inaccurate.
Therefore, after the lithium iron phosphate battery works for a period of time, the SOC of the battery can be effectively corrected by performing a complete charge-discharge cycle on the battery. When the SOC of the power battery is inaccurate, the consistency of the single power battery is also poor, the SOC precision of the power battery is easy to reduce, and the service life of the power battery is shortened.
Since the vehicle is a tool, the use environment, manner, etc. of the user cannot be restricted. The abuse of the power battery is easy to cause that the service life of the power battery is sharply reduced, the performance is seriously reduced, and the performance phenomena of the power battery are that the SOC precision is reduced or the monomer unbalance is aggravated. A BMS (battery Management System) System generally has SOC self-correction and self-balancing (active balancing or passive balancing) functions, but it is necessary to ensure that the power battery is subjected to a completed charge and discharge cycle to ensure that the power battery completes the SOC self-correction and self-balancing. If a customer uses the vehicle, the power battery does not enter SOC self-correction and self-balancing for a long time, so that the SOC precision of the vehicle is easily reduced, the monomer unbalance degree is aggravated, and the service life of the power battery is reduced.
Fig. 10 shows a corresponding graph of battery voltage and SOC, which may result in inaccurate SOC calculation and easily increase the unbalance degree of the cells when the battery operates in the SOC1 and SOC2 interval for a long time.
In the running process of the actual vehicle, the actual running interval is comprehensively determined by the habit of the driver, the vehicle path, the running distance, the control algorithm and the like, and cannot be completely estimated and limited. The battery SOC correction is essentially to correct the SOC error by calculating the variation relation between the discharge capacity and the cell voltage of the battery through current integration, so that the SOC can be corrected when the battery works in two intervals of 0, 1 and 2, 100 percent.
Therefore, the embodiment of the invention provides that the BMS and the VCU (Vehicle Control Unit) are used for realizing the corresponding prompt for the driver according to the state of charge value of the battery. As shown in fig. 11, BMS1102 and VCU1104 interact with each other in data commands, and send prompt information to dashboard 1106 via communication bus, and finally are observed by driver 1108.
The specific flow is shown in fig. 12:
step 1202, determining that the power battery needs to enter SOC correction early warning;
and step 1204, reminding the driver to perform related operations.
Wherein, accessible BMS requests to get into SOC and corrects the early warning, and triggering condition includes:
(a1) the BMS detects the single body unbalance fault;
(b1) the BMS detects the fault of insufficient SOC precision;
(c1) the BMS requests manual maintenance of the battery.
And if the conditions a1, b1 and c1 are in a OR relationship, the condition A is satisfied, and the condition A triggers the entering of the SOC correction early warning.
The method can also request to enter SOC correction early warning through the VCU, and the triggering conditions comprise:
(a2) the VCU calculates that the difference value between the maximum cell voltage and the minimum cell voltage is greater than a threshold value u _ set;
(b2) the VCU accumulatively calculates the working time of the battery SOC between [ SOC1, SOC2] to be more than T _ set;
(c2) the VCU accumulatively calculates that the number of charge-discharge cycles of the battery SOC between [ SOC1, SOC2] is greater than Nset.
And if the conditions a2, b2 and c2 are in a OR relationship, the condition A is satisfied, and the condition A triggers the entering of the SOC correction early warning.
After getting into SOC and correcting the early warning mode, the panel board shows tip information according to the vehicle state, includes:
if the vehicle is in a running working state, displaying 'please discharge the SOC of the battery to be lower than SOCmin';
if the vehicle is in a charging working state, displaying 'please charge the SOC of the battery to 100%';
the early warning mode can be exited only when the battery undergoes a complete [ 100%, SOCmin ] charge-discharge cycle and the SOC correction early warning triggering condition disappears.
If the client does not perform related charging and discharging operations according to the prompt all the time, the charging and discharging operations disappear after continuously displaying for X minutes after each time of power-on. Wherein, the X minutes can be set according to the habit of the user, such as 10 minutes, 5 minutes or 30 minutes.
The specific flow is shown in fig. 13 a:
in
Or as shown in figure 13b of the drawings,
step 1302b, the VCU requests to enter SOC correction early warning;
step 1304b, the BMS responds that the VCU enters SOC correction early warning;
step 1306b, the VCU detects the running state of the whole vehicle;
step 1308b, the VCU requests a meter or a central control screen to display;
in step 1310b, the VUC requests the meter or central control screen to dismiss the display.
Specifically, for the BMS, when the BMS detects the monomer unbalance degree fault, the BMS detects the SOC insufficient precision fault or the BMS requests the battery to be manually maintained, the BMS requests the VCU to enter the correction early warning, and the monomer unbalance degree fault and the insufficient precision fault are processed by the BMS.
For the cell unbalance fault, for example, an average voltage Uavg ═ U ÷ X of the battery cells is calculated, where U is a total voltage value of the battery assembly, and X is the number of battery cells in the battery assembly.
And calculating the absolute value delta ui of the voltage difference between each single battery and the average voltage Uavg of the battery cells, and if the quantity of delta ui which is greater than delta uset is greater than nset1, the cell unbalance fault occurs.
For the SOC precision fault, for example, the difference between SOC and SOH (State Of Health) is calculated in real time, and when the difference is greater than Aset, the SOC precision fault occurs.
For a battery requiring manual maintenance, for example, the BMS sends a request to the VCU through a CAN (Controller Area Network) message.
For the VCU, when the VCU detects that one of the following 4 conditions is met, entering an SOC correction early warning:
under the condition one, the difference value between the maximum cell voltage and the minimum cell voltage is calculated by the VCU to be more than u _ set;
under the second condition, the working time of the VCU for accumulatively calculating the SOC of the battery between [ SOC1 and SOC2] is more than T _ set;
thirdly, the VCU accumulatively calculates that the number of charge-discharge cycles of the battery SOC between [ SOC1 and SOC2] is more than Nset;
and in the fourth condition, the BMS initial SOC jump is large.
Wherein the relationship between the condition one and the condition four is OR.
For the condition one, the BMS sends the maximum voltage of the battery cell and the minimum voltage of the battery cell in real time through a CAN protocol, the VCU calculates the absolute value of the two voltage differences, and when the voltage difference is greater than u _ set and the duration is greater than t1, the VCU requests to enter SOC correction early warning.
For condition two, the specific flow is shown in fig. 14:
1402, starting the vehicle;
step 1404, recording an initial value of the accumulated time length;
step 1406, judging whether the SOC is between [ SOC1 and SOC2 ]; if yes, go to step 1408, otherwise go to step 1410;
step 1408, accumulating the accumulated duration;
step 1410, clearing the accumulated time length;
step 1412, acquiring that the SOC is between [ SOC1 and SOC2], and timing again;
step 1414, judging whether the accumulated time length is greater than T _ set; if yes, go to step 1416, otherwise go to step 1418;
step 1416, the VCU requests to enter an SOC early warning state;
step 1418, detecting a lower electric signal, and storing a battery SOC end value;
step 1420, judging whether the SOC tail end value is between [ SOC1 and SOC2 ]; if yes, go to step 1424, otherwise go to step 1422;
step 1422, clearing the accumulated duration;
in step 1424, the SOC end value is used as the initial value for the next power-up.
For condition three, the specific flow is shown in fig. 15:
step 1502, the vehicle is started;
step 1504, recording the initial value of the accumulated charge-discharge cycle times;
step 1506, judging whether the SOC is between [ SOC1 and SOC2 ]; if yes, go to step 1510, otherwise go to step 1508;
step 1508, clearing the accumulated charge-discharge cycle times;
step 1510, determining whether the accumulated charge-discharge cycle number is greater than Nset; if yes, go to step 1512, otherwise go to step 1514;
step 1512, the VCU requests to enter an SOC early warning state;
step 1514, detecting the lower electric signal, and storing the battery SOC end value;
step 1516, judging whether the SOC terminal value is between [ SOC1, SOC2 ]; if yes, go to step 1520, otherwise go to step 1518;
1518, clearing the accumulated charge-discharge cycle times;
step 1520, take the SOC end value as the initial value for the next power-up.
And when the vehicle is in operation, comparing the SOC value in real time, and if the SOC is greater than or equal to 99% and the duration is greater than 30s, performing accumulated zero clearing on the charge and discharge cycle times of the battery, and performing accumulated timing again.
And if the SOC is less than or equal to 10% and the duration is more than 30s, performing accumulated zero clearing on the charge-discharge cycle times of the battery, and performing accumulated timing again.
For condition three, the specific flow may also be as shown in fig. 16:
in step 1620, the SOC end value is used as the initial value for the next power-on.
And when the vehicle is in operation, comparing the SOC value in real time, and if the SOC is greater than or equal to 99% and the duration is greater than 30s, performing accumulated zero clearing on the charge and discharge cycle times of the battery, and performing accumulated timing again.
For the fourth condition, when the vehicle starts, the initial value of the battery SOC is compared with the terminal value of the battery SOC stored in the last running or charging of the vehicle, and if the difference value is larger than Bset (5%), the VCU requests to enter the SOC correction early warning.
When the vehicle charging is started, the initial value of the battery SOC is compared with the terminal value of the battery SOC stored in the last vehicle running or charging, if the difference value is larger than Bset (5%), the VCU requests to enter SOC correction early warning.
If the end value of the SOC of the battery stored in the last vehicle driving or charging is not in the range of [ SOC1, SOC2], the initial SOC jump of the BMS is not detected.
If the VCU responds that the BMS enters the SOC correction early warning, if the VCU detects that the whole vehicle has no fault, the response is allowed.
If BMS responds that VCU gets into SOC and corrects the early warning, if BMS detects that the battery is trouble-free, respond to the permission.
The VCU judges whether the whole vehicle is in a running state or a charging state, and if the vehicle is in a running working state, the VCU displays' please discharge the SOC of the battery to be lower than the SOCminIf the customer does not carry out related charging and discharging operations according to the prompt all the time, the operation disappears after continuously displaying Xmin.
If the vehicle is in a charging working state, displaying 'please charge the SOC of the battery to 100%', and if the customer does not perform related charging and discharging operations according to prompts all the time, continuously displaying Xmin and then disappearing.
And the VCU continuously calculates the number of times of requesting to enter SOC correction when the vehicle starts to charge or starts to run, and if the number of times of continuously requesting to enter SOC correction reaches Cset times, the meter displays 'please to perform manual after-sales maintenance', and disappears after continuously displaying Xmin until the SOC correction early warning mode exits.
The early warning mode can be exited only when the battery undergoes a complete charge-discharge cycle and the SOC correction early warning triggering condition disappears.
As shown in fig. 17, an embodiment of the present invention provides an
In this embodiment, the power assembly includes a driving motor, a steering motor, an electronic transmission, and the like, and meanwhile, since the electric vehicle can implement the steps of the battery management method of the electric vehicle provided in any one of the above embodiments by executing the computer program on the memory through the processor, the electric vehicle also includes all the beneficial effects of the battery management method of the electric vehicle provided in any one of the above embodiments, and details are not repeated herein.
Embodiments of the present invention provide a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps of the battery management method for an electric vehicle provided in any of the above embodiments, and therefore the computer-readable storage medium also includes all the beneficial effects of the battery management method for an electric vehicle provided in any of the above embodiments, and details are not repeated herein.
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