A Calculation Method, System and Device for the Deviation of the Operating Capacity of a Lithium-Ion Battery

Abstract

The present disclosure relates to a method, system and device for calculating the operating capacity deviation of a lithium-ion battery. The method includes the following steps: obtaining a set of batteries Z with inconsistent capacities, and the battery pack CZi where each single battery Zi in Z is located; obtaining the continuous operating condition data of CZi before reaching the cut-off state; obtaining the evaluation index parameters E of all single batteries in CZi at the cut-off moment t, removing Ei regarding Zi therefrom, and calculating the average value Emean,t of the evaluation index parameters of the remaining single batteries; obtaining the moment t1 corresponding to when the evaluation index parameter of Zi is equal to the average value Emean,t, and marking the time closest to the moment t1 as tzi; calculating the operating capacity deviation value according to the current data of the single battery Zi in the time period [tzi, t]. The system and device are used to execute the above method. The present disclosure can calculate the operating capacity deviation value, has a low application difficulty, is accurate and efficient in calculation, helps to achieve precise equalization enabling of batteries with inconsistent capacities, and further improves the consistency and stability of the energy storage system.

Description

Technical Field

[0001] The present disclosure relates to the technical field of lithium - ion batteries, and particularly to a method, a system and a device for calculating the deviation of the operating capacity of a lithium - ion battery. Background Art

[0002] With the wide use of electrochemical lithium - ion batteries, lithium - ion batteries are usually used in series in the form of battery packs to improve the overall capacity of the battery. When the project capacity is larger, the number of batteries connected in series is more. Especially in recent years, there are more and more large - scale energy storage projects with a capacity of hundreds of megawatts, which puts higher requirements on the capacity consistency of the battery packs operating in series.

[0003] When individual batteries are assembled into a battery pack, they are more or less affected by production manufacturing, process technology, etc., and cannot be exactly the same. This will gradually show up during the continuous charge - discharge operation of the subsequent battery pack, especially the inconsistency of the used capacity or the remaining capacity. The capacity inconsistency will affect the actual operating capacity of the battery pack.

[0004] This inconsistency is not irreversible, and it can be reduced by certain methods. The balancing enabling in the battery energy management system has such an ability. Specifically for an individual battery, the balancing enabling function is to supplement or discharge a certain amount of electricity for the single - cell batteries with inconsistent capacities to compensate for the operating capacity deviation caused by the capacity inconsistency of the single - cell battery.

[0005] How to calculate the supplemented or discharged electricity is the key to realizing the balancing enabling function. This process is usually also called the estimation of the operating capacity deviation. In the prior art, the estimation of the operating capacity deviation mainly relies on experiments, and estimates are made by referring to the voltage deviation of different individual batteries in the battery pack. However, for a lithium iron phosphate battery pack, due to its obvious non - linear electrochemical characteristics, this semi - artificial estimation method will increase the work difficulty of engineering personnel, and the effect is not ideal, and it is also inconvenient to apply in the actual operating production system. Summary of the Invention

[0006] In order to solve the problems existing in the above - mentioned prior art, the purpose of the present disclosure is to provide a method, a system and a device for calculating the deviation of the operating capacity of a lithium - ion battery. The present disclosure can calculate the operating capacity deviation value, has a low application difficulty, is accurate and efficient in calculation, helps to realize the precise balancing enabling of batteries with inconsistent capacities, and further improves the consistency and stability of the energy storage system.

[0007] A method for calculating the deviation of the operating capacity of a lithium - ion battery according to the present disclosure includes the following steps:

[0008] S01. Obtain a set of batteries Z determined to have inconsistent capacities, and each single - cell battery Z in the set of batteries Zi The battery pack where it is located is denoted as C Zi ;

[0009] S02. Obtain the continuous operating condition data of the battery pack C Zi before reaching the charging cut-off state or the discharging cut-off state;

[0010] S03. Define the moment when the battery pack C[[ID=1)]2 Zi reaches the charging cut-off state or the discharging cut-off state as the cut-off moment t, and obtain the evaluation index parameters E of all single cells of the battery pack C Zi at the cut-off moment t, and exclude the evaluation index parameters E of the single cell Z i from the evaluation index parameters E i , and calculate the average value E of the evaluation index parameters of the remaining other single cells mean,t ;

[0011] S04. Obtain the moment t1 corresponding to when the evaluation index parameter of the single cell Z i is equal to the average value E, and mark the time closest to the moment t1 as t mean,t ; zi ;

[0012] S05. According to the current data of the single cell Z i in the time period [t zi , t], calculate and obtain the operating capacity deviation value that can enable the single cell Z i to be balanced.

[0013] Preferably, the continuous operating condition data includes voltage data, current data, and time stamp data.

[0014] Preferably, the evaluation index parameter E is a voltage value.

[0015] Preferably, the operating capacity deviation value is Coulomb charge Q or electrical energy W.

[0016] Preferably, in step S05, integrate the current data of the single cell Z i in the time period [t zi , t] to obtain the Coulomb charge Q, and use the obtained Coulomb charge Q as the charge that needs to be supplemented or discharged to enable the single cell Z i to achieve balance.

[0017] A lithium-ion battery operating capacity deviation calculation system according to the present disclosure includes:

[0018] A set acquisition module, which is used to acquire a battery set Z determined to have inconsistent capacities, and the battery pack where each single cell Z i in the battery set Z is located, denoted as CZi ;

[0019] A working condition data acquisition module, which is used to acquire the continuous working condition data of the battery pack C Zi before reaching the charging cut-off voltage or the discharging cut-off voltage;

[0020] An average value calculation module, which is used to define the moment when the charging cut-off voltage or the discharging cut-off voltage is reached as the cut-off moment t, and acquire the evaluation index parameters E of all single cells at the cut-off moment t of the battery pack C Zi and eliminate the evaluation index parameters E of the single cell Z in the evaluation index parameters E i ; calculate the average value E of the evaluation index parameters of the remaining other single cells i ; mean,t ;

[0021] A time stamp acquisition module, which is used to acquire the moment t1 when the evaluation index parameter of the single cell Z i is equal to the average value E, and mark the time stamp closest to the moment t1 as t mean,t ; zi ;

[0022] An operating capacity deviation value calculation module, which is used to calculate the operating capacity deviation value that can enable the equalization of the single cell Z i according to the current data of the single cell Z zi within the time period [t i , t].

[0023] A computer device of the present disclosure includes a processor and a memory connected by a signal. At least one instruction or at least one program segment is stored in the memory. When the at least one instruction or the at least one program segment is loaded by the processor, it executes the lithium-ion battery operating capacity deviation calculation method as described above.

[0024] A computer-readable storage medium of the present disclosure stores at least one instruction or at least one program segment thereon. When the at least one instruction or the at least one program segment is loaded by a processor, it executes the lithium-ion battery operating capacity deviation calculation method as described above.

[0025] A lithium-ion battery operating capacity deviation calculation method, system and device according to the present disclosure have the advantage that the present disclosure can quickly and accurately calculate the operating capacity deviation of batteries with inconsistent capacities, has low application difficulty, accurate and efficient calculation, helps to achieve precise equalization enabling of batteries with inconsistent capacities, and further improves the consistency and stability of the energy storage system. Description of the Drawings

[0026] Figure 1is a flowchart of the steps of a method for calculating the operating capacity deviation of a lithium-ion battery according to the present disclosure;

[0027] Figure 2 It is a structural diagram of the computer device described in the embodiment.

[0028] Description of reference numerals: 101 - processor, 102 - memory. DETAILED DESCRIPTION

[0029] like Figure 1 As shown, the method for calculating the operating capacity deviation of a lithium-ion battery disclosed in the present disclosure includes the following steps:

[0030] S01, obtain the battery set Z determined to be inconsistent in capacity through the battery management system. In a specific embodiment, all single cells in the energy storage system can be uniquely numbered, and the battery set Z is represented as a set of unique cell numbers. At the same time, obtain the capacity of each single cell Z in the battery set Z. i The battery pack is marked as C Zi ;

[0031] S02. Obtain battery pack C Zi Continuous operating condition data before reaching the charge cut-off state or the discharge cut-off state, where the charge cut-off state and the discharge cut-off state may specifically be the charge cut-off voltage and the discharge cut-off voltage, and the continuous operating condition data specifically includes voltage data, current data, and time stamp data of all single cells in the battery pack;

[0032] S03, defining the battery pack C Zi The moment when the charge cut-off state or the discharge cut-off state is reached is the cut-off time t, and the battery pack C is obtained. Zi The evaluation index parameter E of all the single cells at the cut-off time t. In a specific embodiment, the evaluation index parameter may be a voltage value.

[0033] That is, get battery pack C Zi The voltage data of all single cells at the cut-off time t, excluding the voltage data of single cell Z i After the voltage value is obtained, calculate the average voltage V of the other single cells. mean,t ;

[0034] S04. Obtain single battery Z i The voltage value is equal to the average value V mean,t The time corresponding to the time t1 is taken as t zi ;

[0035] S05, according to the single battery Z i In [t ziThe current data within the time period [t, t], and calculate to obtain the monomer battery Z i The operating capacity deviation value enabling equalization. The operating capacity deviation value can specifically be the Coulomb charge Q or the electrical energy W, both of which can be used as the reference value for the monomer battery to supplement or release the charge. Taking the calculation of the Coulomb charge Q as an example:

[0036] For the monomer battery Z i Integrate the current data within the time period [t zi , t] to obtain the Coulomb charge Q, and use the obtained Coulomb charge Q as the charge that the monomer battery Z i needs to supplement or release to achieve equalization enabling.

[0037] In this step, the Coulomb charge is derived from the ampere unit. It is defined that the charge passing through the cross-section of a wire by a current of 1 ampere in one second is 1 coulomb. According to the mathematical description of the Coulomb charge, 1 coulomb = 1 ampere · 1 second, that is, the Coulomb charge can be expressed as the integral of current with respect to time, that is, the mathematical description is: C = ∫I*dt. Therefore, the final integral value can be expressed as the cumulative Coulomb charge passing through during this period, which is the difference between the Coulomb charge of the monomer battery and the average Coulomb charge of the battery pack.

[0038] The present disclosure can automatically calculate the capacity operation deviation results of lithium-ion monomer batteries with inconsistent capacities. This method can be calculated in real time online or by using historical data measurement. It has the advantages of low application difficulty, accurate and efficient calculation, which helps to achieve precise equalization enabling for batteries with inconsistent capacities, thereby improving the consistency and stability of the energy storage system.

[0039] This embodiment also provides a lithium-ion battery operating capacity deviation calculation system, including:

[0040] A set acquisition module, which is used to acquire the battery set Z determined to have inconsistent capacities, and each monomer battery Z in the battery set Z i The battery pack where it is located, denoted as C Zi ;

[0041] A working condition data acquisition module, which is used to acquire the continuous working condition data of the battery pack C Zi Before reaching the charging cut-off voltage or the discharging cut-off voltage;

[0042] An average value calculation module, which is used to define the moment of reaching the charging cut-off voltage or the discharging cut-off voltage as the cut-off moment t, and acquire the evaluation index parameter E of all monomer batteries in the battery pack C Zi At the cut-off moment t, eliminate the evaluation index parameter E regarding the monomer battery Z i Of the evaluation index parameter E i , and calculate the average value E of the evaluation index parameters of the remaining other monomer batteries mean,t ;

[0043] The time stamp acquisition module is used to acquire the single battery Z i when the evaluation index parameter of is equal to the average value E mean,t at the corresponding moment t1, and mark the time stamp closest to the moment t1 as t zi ;

[0044] The operating capacity deviation value calculation module is used to calculate, according to the current data of the single battery Z i within the time period of [t zi , t], the operating capacity deviation value that enables the single battery Z i to be balanced and enabled.

[0045] The lithium-ion battery operating capacity deviation calculation system of this embodiment belongs to the same inventive concept as the above method embodiment, and can be understood with reference to the description of the above method embodiment, which will not be elaborated here.

[0046] As Figure 2 shown, this embodiment also provides a computer device, including a processor 101 and a memory 102 connected by a bus signal. At least one instruction or at least one program segment is stored in the memory 102. When the at least one instruction or the at least one program segment is loaded by the processor 101, it executes the lithium-ion battery operating capacity deviation calculation method as described above. The memory 102 can be used to store software programs and modules. The processor 101 executes various functional applications by running the software programs and modules stored in the memory 102. The memory 102 mainly includes a program storage area and a data storage area. Among them, the program storage area can store an operating system, application programs required for functions, etc.; the data storage area can store data created according to the use of the device, etc. In addition, the memory 102 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other volatile solid-state storage devices. Correspondingly, the memory 102 can also include a memory controller to provide the processor 101 with access to the memory 102.

[0047] The method embodiment provided by the present disclosure can be executed in a computer terminal, a server, or a similar computing device, that is, the above computer device can include a computer terminal, a server, or a similar computing device. The internal structure of the computer device can include, but is not limited to: a processor, a network interface, and a memory. Among them, the processor, network interface, and memory in the computer device can be connected by a bus or other means.

[0048] Among them, the processor 101 (or CPU (Central Processing Unit)) is the computing core and control core of the computer device. The network interface may optionally include a standard wired interface, a wireless interface (such as WI-FI, a mobile communication interface, etc.). The memory 102 (Memory) is the memory device in the computer device, used to store programs and data. It can be understood that the memory 102 here can be a high-speed RAM storage device, or a non-volatile memory device, such as at least one disk storage device; optionally, it can also be at least one storage device located far from the aforementioned processor 101. The memory 102 provides a storage space, which stores the operating system of the electronic device, including but not limited to: Windows system (an operating system), Linux (an operating system), Android (a mobile operating system) system, IOS (a mobile operating system) system, etc., and the present disclosure does not limit this; and, one or more instructions suitable for being loaded and executed by the processor 101 are also stored in this storage space, and these instructions can be one or more computer programs (including program codes). In the embodiments of this specification, the processor 101 loads and executes one or more instructions stored in the memory 102 to implement the lithium-ion battery operating capacity deviation calculation method described in the above method embodiments.

[0049] The embodiments of the present disclosure also provide a computer-readable storage medium, on which at least one instruction or at least one segment of program is stored, and when the at least one instruction or the at least one segment of program is loaded by the processor 101, it executes the lithium-ion battery operating capacity deviation calculation method as described above. The above computer-readable storage medium carries one or more programs, and when the one or more programs are executed, the method according to the embodiments of the present disclosure is implemented.

[0050] According to the embodiments of the present disclosure, the computer-readable storage medium can be a non-volatile computer-readable storage medium. For example, it can include but not be limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In the present disclosure, the computer-readable storage medium can be any tangible medium that contains or stores a program, and this program can be used by or combined with an instruction execution system, device, or component.

[0051] In the description of the present disclosure, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present disclosure and simplifying the description. Without contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present disclosure.

[0052] For those skilled in the art, various corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all these changes and deformations should fall within the protection scope of the claims of the present disclosure.

Claims

1. A method for calculating the deviation of the operating capacity of a lithium-ion battery, characterized in that, including the following steps: S01, obtaining a battery set Z determined to have inconsistent capacities, and each single battery Z in the battery set Z i The battery pack is marked as C Zi ; S02. Obtain the battery pack C Zi Continuous operating condition data before reaching the charging cut-off state or the discharging cut-off state; The continuous operating condition data includes voltage data, current data and time stamp data; S03. Define the battery pack C Zi The moment when the charging cut-off state or the discharging cut-off state is reached is the cut-off moment t, and obtain the battery pack C Zi At the cut-off moment t, the evaluation index parameter E of all single cells, where the evaluation index parameter E is a voltage value, and eliminate the evaluation index parameter E of the single cell Z i from the evaluation index parameter E i , and calculate the average value E of the evaluation index parameters of the remaining other single cells mean,t ; S04. Obtain the single cell Z i whose evaluation index parameter is equal to the average value E mean,t at the corresponding moment t1, and mark the time closest to the moment t1 as t zi ; S05. According to the single cell Z i In the current data within the time period of [t zi , t], calculate to obtain an operating capacity deviation value that enables the equalization of the single cell Z i . The operating capacity deviation value is the Coulomb charge Q or the electrical energy W; In step S05, for the single cell Z i Integrate the current data of the single cell Z zi during the time period [t i , t] to obtain the Coulomb charge Q, and use the obtained Coulomb charge Q as the charge that needs to be supplemented or released to enable the equalization of the single cell Z 2. A lithium-ion battery operating capacity deviation calculation system, characterized in that including: A set acquisition module, which is used to acquire a battery set Z determined to have inconsistent capacities, and each single battery Z in the battery set Z i wherein the battery pack to which it belongs is denoted as C Zi ; The operating condition data acquisition module is configured to acquire the continuous operating condition data of the battery pack C before reaching the charging cut-off voltage or the discharging cut-off voltage; the continuous operating condition data includes voltage data, current data, and time scale data; Zi ​ A mean calculation module, which is used to define the moment when the charging cut-off voltage or the discharging cut-off voltage is reached as the cut-off moment t, and obtain all the evaluation index parameters E of the single cells of the battery pack C Zi at the cut-off moment t, and the evaluation index parameter E of all the single cells is a voltage value, and the evaluation index parameter E regarding the single cell Z is removed from the evaluation index parameter E i of the single cell i , and calculate the average value E of the evaluation index parameters of the remaining other single cells mean,t ; The time stamp acquisition module is used to acquire the single cell Z i when the evaluation index parameter of mean,t is equal to the average value E zi ; take the time stamp closest to the time t1 corresponding to the time t1 as t An operating capacity deviation value calculation module, which is used to calculate, according to the current data of the single cell Z i within the time period of [t zi , t], an operating capacity deviation value that enables the equalization of the single cell Z i , where the operating capacity deviation value is the Coulomb charge Q or the electrical energy W; For the single cell Z i Integrate the current data of zi during the time period [t i , t] to obtain the Coulomb charge Q, and use the obtained Coulomb charge Q as the charge that needs to be supplemented or released to enable the equalization of the single cell Z.

3. A computer device, comprising a processor and a memory connected by signals, characterized in that, At least one instruction or at least one program is stored in the memory, and when the at least one instruction or the at least one program is loaded by the processor, it executes the method for calculating the deviation of the operating capacity of the lithium-ion battery as described in claim 1.

4. A computer-readable storage medium having at least one instruction or at least one program stored thereon, characterized in that, When the at least one instruction or the at least one program is loaded by the processor, it executes the method for calculating the deviation of the operating capacity of the lithium-ion battery as described in claim 1.

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