Background
With the development of battery technology, the retention capacity of electric vehicles is promoted year by year, and batteries of early electric vehicles are in the end of service life and are gradually eliminated and retired. However, the obsolete and retired batteries also have energy storage and charging capabilities and certain echelon utilization value, and can be used in partial fields, such as various energy storage power stations and the like.
Generally, an electric vehicle battery at the end of its life is used for thousands of times, and has high internal resistance and poor charging performance. It is common practice for battery suppliers to set the battery charging power at the end of life to 80% or less of the initial capacity, with the charging power being reduced by a proportion during use. Alternatively, a multi-dimensional parameter relationship is established using a battery model to predict battery life.
However, the existing method has the problems of poor reliability, low safety and the like.
Disclosure of Invention
In view of the above, it is necessary to provide a power testing method, system, computer device and storage medium capable of improving the charging performance, reliability and life of a battery in response to the above technical problems.
A method of power testing, the method comprising:
acquiring a charging power matrix of a battery system in an initial charging process;
taking the charging power matrix as a boundary condition of the battery system in the next charging process, and acquiring a charging cut-off voltage value of the battery system at the end of the next charging;
and if the charging cut-off voltage value reaches a preset threshold value, returning to the step of acquiring the charging power matrix of the battery system in the charging process.
In one embodiment, the obtaining the charging power matrix of the battery system during the initial charging process includes:
acquiring a maximum charging current value and a voltage value of the battery system in an initial charging process until the voltage value of at least one single battery in the battery system reaches a first preset charging cut-off voltage value;
and inputting the maximum charging current value and the voltage value into a charging power matrix model to obtain a charging power matrix of the battery system in the initial charging process.
In one embodiment, the obtaining the maximum charging current value of the battery system during the initial charging process includes:
acquiring charging current values of the battery system in corresponding charge states at different temperatures, wherein the charging current values do not exceed an initial maximum current value;
and screening the charging current value according to a preset condition to determine the maximum charging current value.
In one embodiment, the screening the charging current value according to a preset condition, and the determining a maximum charging current value includes:
acquiring a charging current value within a preset temperature range;
selecting a charging current value of which the temperature rise of the battery system does not exceed a preset temperature rise range as a maximum charging current value, and/or selecting a charging current value of which the temperature rise of the battery system exceeds the preset temperature rise range as a maximum charging current value, and/or selecting a charging current value of which the charging cut-off voltage of the battery system reaches a second preset charging cut-off voltage value as a maximum charging current value.
A power testing system, the system comprising:
the first data acquisition module is used for acquiring a charging power matrix of the battery system in an initial charging process;
the second data acquisition module is used for taking the charging power matrix as a boundary condition of the battery system in the next charging process and acquiring a charging cut-off voltage value of the battery system at the end of the next charging;
and the execution module is used for returning to the step of acquiring the charging power matrix of the battery system in the charging process if the charging cut-off voltage value reaches a preset threshold value.
In one embodiment, the first data acquisition module includes:
the third data acquisition module is used for acquiring the maximum charging current value and the voltage value of the battery system in the initial charging process until the voltage value of at least one single battery in the battery system reaches a first preset charging cut-off voltage value;
and the calculation module is used for inputting the maximum charging current value and the voltage value into a charging power matrix model to obtain a charging power matrix of the battery system in the initial charging process.
In one embodiment, the third data acquisition module includes:
the fourth data acquisition module is used for acquiring the charging current value of the battery system in the corresponding charge state at different temperatures, wherein the charging current value does not exceed the initial maximum current value;
and the data screening module is used for screening the charging current value according to preset conditions and determining the maximum charging current value.
In one embodiment, the data filtering module comprises:
the fifth data acquisition module is used for acquiring a charging current value within a preset temperature range;
and the data selecting module is used for selecting a charging current value of which the temperature rise of the battery system is not more than a preset temperature rise range as a maximum charging current value, and/or selecting a charging current value of which the temperature rise of the battery system is more than the preset temperature rise range as a maximum charging current value, and/or selecting a charging current value of which the charging cut-off voltage of the battery system reaches a second preset charging cut-off voltage value as a maximum charging current value.
A computer device comprising a memory storing a computer program and a processor implementing the steps of the method as claimed in any one of the above when the computer program is executed.
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 method according to any one of the preceding claims.
According to the power testing method, the system, the computer device and the storage medium, the charging power matrix of the battery system in the initial charging process is obtained, the charging power matrix is used as the boundary condition of the battery system in the next charging process, the charging cut-off voltage value of the battery system at the end of the next charging process is obtained, and the step of obtaining the charging power matrix of the battery system in the charging process is returned if the charging cut-off voltage value is judged to reach the preset threshold value. The charging performance and reliability of the battery can be improved and the service life of the battery can be prolonged based on the method.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
The power testing method provided by the application can be applied to the application environment shown in fig. 1. Wherein the terminal 102 communicates with the server 104 via a network. The terminal 102 acquires a charging power matrix of the battery system during an initial charging process and transmits the charging power matrix to the server 104 through a network. The server 104 takes the charging power matrix as a boundary condition of the battery system in the next charging process, and obtains a charging cut-off voltage value of the battery system at the end of the next charging. And further judging whether the charging cut-off voltage value reaches a preset threshold value or not, and returning to the step of acquiring the charging power matrix of the battery system in the charging process. The terminal 102 may be, but not limited to, various personal computers, notebook computers, smart phones, tablet computers, and portable wearable devices, and the server 104 may be implemented by an independent server or a server cluster formed by a plurality of servers.
In one embodiment, as shown in fig. 2, a power testing method is provided, which is exemplified by the application of the method to the server 104 in fig. 1, and includes the following steps:
step S1: acquiring a charging power matrix of a battery system in an initial charging process;
step S2: taking the charging power matrix as a boundary condition of the battery system in the next charging process, and acquiring a charging cut-off voltage value of the battery system at the end of the next charging;
step S3: and if the charging cut-off voltage value reaches a preset threshold value, returning to the step of acquiring the charging power matrix of the battery system in the charging process.
In steps S1-S3, since the voltage of the battery cell of the battery system is continuously increased during the charging process, the power of the battery system is changed along with the change of the charging time. Taking a lithium ion battery as an example, the lithium ion battery mainly depends on the movement of lithium ions between a positive electrode and a negative electrode to work, the chemical power of the whole battery comes from the chemical reaction of the two electrodes, and the capacity of the lithium ion battery is attenuated along with the increase of the charging times.
Specifically, the initial charging process is the same as the external environment of the next charging process, such as temperature, SOC (state of charge), humidity, and the like. For example, the battery system may obtain the charging power matrix a during the initial charging process, i.e. with time and the external environment, and correspondingly, the battery system may obtain the charging power matrix B during the next charging process. Since the battery system changes with time during the initial charging process, a corresponding charging power value exists at each moment, and the charging power value P1 corresponding to each time is taken as the maximum value of the charging power P2 corresponding to the next charging of the battery system, namely P2 is less than or equal to P1.
In one embodiment, the step S1 includes:
step S11: acquiring a maximum charging current value and a voltage value of the battery system in an initial charging process until the voltage value of at least one single battery in the battery system reaches a first preset charging cut-off voltage value;
step S12: and inputting the maximum charging current value and the voltage value into a charging power matrix model to obtain a charging power matrix of the battery system in the initial charging process.
In steps S11-S12, the battery charging power matrix model is:
Pmax=Vocv×Imax(1)
wherein Pmax is the charging power of the battery system, Vocv is the voltage value of the battery system, and Imax is the maximum charging current of the battery system.
In addition, as long as the voltage value of one single battery in the battery system reaches the first preset charge cut-off voltage value, the battery system finishes charging, namely finishes measuring the charging power. Wherein the voltage value is between the charge cut-off voltage value and the maximum voltage value. The adjustment is performed as needed, and is not particularly limited herein.
In one embodiment, the step S11 includes:
step S111: acquiring charging current values of the battery system in corresponding charge states at different temperatures, wherein the charging current values do not exceed an initial maximum current value;
step S112: and screening the charging current value according to a preset condition to determine the maximum charging current value.
In steps S111-S112, the charging test of the battery system under different temperatures and different SOC conditions is performed, i.e. the charging current values under SOC conditions corresponding to different temperatures of the battery system can be obtained. In order to obtain more accurate charging power, it is necessary to screen the obtained plurality of charging current values and use the selected plurality of current values as the maximum amplification current value to determine the charging power. Wherein the charging current value does not exceed an initial maximum current value set by a battery supplier. The preset conditions are adjusted according to specific conditions, and are not particularly limited herein.
In one embodiment, the step S112 includes:
step S1121: acquiring a charging current value within a preset temperature range;
step S1122: selecting a charging current value of which the temperature rise of the battery system does not exceed a preset temperature rise range as a maximum charging current value, and/or selecting a charging current value of which the temperature rise of the battery system exceeds the preset temperature rise range as a maximum charging current value, and/or selecting a charging current value of which the charging cut-off voltage of the battery system reaches a second preset charging cut-off voltage value as a maximum charging current value.
In steps S1121 to S1122, the battery is charged for 30 seconds, taking the case where the battery system temperature is lower than 55 ℃ (region No. 1 in the following table) as an example. The charging current when the temperature rise of the battery does not exceed 5c or the temperature of the battery exceeds 60 c or the charge cutoff voltage reaches the charge cutoff voltage Vmax1 is taken as the maximum charging current Imax under this condition. The preset temperature rise range and the second preset charge cut-off voltage value are adjusted according to specific conditions, and are not particularly limited.
In order to protect the battery, the charge cut-off voltage Vmax1 is set to Vmax 1-0.1 or Vmax 1-0.2, where Vmax is the maximum charge voltage corresponding to the maximum charge current of the battery system, Imax.
TABLE 1 charging power of battery system at temperatures below 55 deg.C for different SOC conditions
The charging power value of the battery system with the temperature value of 25-55 ℃ and the SOC condition of 10-20% is calculated according to the linear difference between the two points. For example, if the charge power value of the battery system at 25 ℃ and the SOC condition of 10% is PA2 and the charge power value of the battery system at 25 ℃ and the SOC condition of 20% is PB2, the charge power of the battery system at 20 ℃ and the SOC condition of 16% is PX1 ═ PB2+ (PB2-PA2) × (16% -10%)/(20% -10%).
It is noted that, in order to avoid lithium dendrite generation and battery safety deterioration during charging at 0 ℃ or lower, the charging current is controlled to 0.5C or lower, preferably 0.2C or lower. Where C is the capacity, such as a 2000mAh battery with a nominal current of 2000mA, then 0.2C is 400mA, 0.5C is 1000mA, and 2C is 4000 mA.
According to the power testing method, the charging power matrix of the battery system in the initial charging process is obtained, the charging power matrix is used as the boundary condition of the battery system in the next charging process, the charging cut-off voltage value of the battery system at the end of the next charging process is obtained, and then the step of obtaining the charging power matrix of the battery system in the charging process is returned if the charging cut-off voltage value reaches the preset threshold value. The method can improve the charging performance and reliability of the battery and prolong the service life of the battery. The method is used for measuring the charging power of the battery to form a charging power matrix, so that the charging power is limited, and the phenomenon of overcharge can be effectively avoided. After a period of charging operation, when the state of the battery system reaches the threshold value for carrying out the charging power test again, the measurement is carried out again, so that the phenomenon of overcharge can be avoided in the whole using process, and the service life of the battery system can be prolonged.
It should be understood that, although the steps in the flowchart of fig. 2 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least a portion of the steps in fig. 2 may include multiple sub-steps or multiple stages that are not necessarily performed at the same time, but may be performed at different times, and the order of performance of the sub-steps or stages is not necessarily sequential, but may be performed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.
In one embodiment, as shown in fig. 3, there is provided a power test system comprising: a first data acquisition module 10, a second data acquisition module 20 and an execution module 30, wherein:
the first data acquisition module 10 is configured to acquire a charging power matrix of the battery system in an initial charging process;
the second data acquisition module 20 is configured to use the charging power matrix as a boundary condition of the battery system in the next charging process, and acquire a charging cut-off voltage value of the battery system at the end of the next charging;
and the executing module 30 is configured to, if the charge cut-off voltage value reaches a preset threshold, return to the step of acquiring the charge power matrix of the battery system in the charging process.
In one embodiment, the first data acquisition module 10 includes:
a third data obtaining module 101, configured to obtain a maximum charging current value and a voltage value of the battery system in an initial charging process until a voltage value of at least one single battery in the battery system reaches a first preset charging cut-off voltage value;
and the calculating module 102 is configured to input the maximum charging current value and the voltage value into a charging power matrix model to obtain a charging power matrix of the battery system in an initial charging process.
In one embodiment, the third data obtaining module 101 includes:
a fourth data obtaining module 1011, configured to obtain a charging current value of the battery system in a state of charge corresponding to different temperatures, where the charging current value does not exceed an initial maximum current value;
and a data filtering module 1012, configured to filter the charging current value according to a preset condition, and determine a maximum charging current value.
In one embodiment, the data filtering module 1012 comprises:
a fifth data obtaining module 1012a, configured to obtain a charging current value within a preset temperature range;
the data selecting module 1012b is configured to select a charging current value at which the temperature rise of the battery system does not exceed a preset temperature rise range as a maximum charging current value, and/or select a charging current value at which the temperature rise of the battery system exceeds the preset temperature rise range as a maximum charging current value, and/or select a charging current value at which the charging cutoff voltage of the battery system reaches a second preset charging cutoff voltage value as a maximum charging current value.
For the specific definition of a power testing device, see the above definition of a power testing method, which is not described herein again. The various modules in a power test described above may be implemented in whole or in part by software, hardware, and combinations thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.
In one embodiment, a computer device is provided, which may be a server, the internal structure of which may be as shown in fig. 4. The computer device includes a processor, a memory, a network interface, and a database connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The database of the computer device is used for storing relevant data. The network interface of the computer device is used for communicating with an external terminal through a network connection. The computer program is executed by a processor to implement a power testing method.
Those skilled in the art will appreciate that the architecture shown in fig. 4 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects apply, as particular computing devices may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.
In one embodiment, a computer device is provided, comprising a memory and a processor, the memory having a computer program stored therein, the processor implementing the following steps when executing the computer program:
acquiring a charging power matrix of a battery system in an initial charging process;
taking the charging power matrix as a boundary condition of the battery system in the next charging process, and acquiring a charging cut-off voltage value of the battery system at the end of the next charging;
and if the charging cut-off voltage value reaches a preset threshold value, returning to the step of acquiring the charging power matrix of the battery system in the charging process.
In one embodiment, a computer-readable storage medium is provided, having a computer program stored thereon, which when executed by a processor, performs the steps of:
acquiring a charging power matrix of a battery system in an initial charging process;
taking the charging power matrix as a boundary condition of the battery system in the next charging process, and acquiring a charging cut-off voltage value of the battery system at the end of the next charging;
and if the charging cut-off voltage value reaches a preset threshold value, returning to the step of acquiring the charging power matrix of the battery system in the charging process.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.