Power lithium battery charging and discharging monomer voltage difference control method, electronic equipment and storage medium

Abstract

The invention discloses a power lithium battery charging and discharging monomer voltage difference control method, electronic equipment and a storage medium, and is applied to a power lithium battery charging and discharging monomer voltage difference control device, and the method comprises the following steps: carrying out the voltage collection through the collection of a battery management system; removing the voltage of the bridging copper bar from the collected voltage data; screening the maximum value of the battery voltage and the minimum value of the battery voltage from the voltage data after the voltage of the bridging copper bar is removed; and if the difference value between the battery voltage maximum value and the battery voltage minimum value is greater than a threshold value, determining that the voltage difference between the battery monomers is too large, and giving an alarm. According to the method, the divided voltage of the copper bar is regarded as a monomer voltage through the battery management system, and the voltage divided by the copper bar is eliminated through an algorithm, so that the problem of overlarge voltage difference between monomers is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium battery charging and discharging, and more specifically to a method for controlling a voltage difference between charging and discharging cells of a power lithium battery, an electronic device and a storage medium. Background Art

[0002] With the rapid development of the new energy industry, the demand for power lithium batteries is also increasing. The finished power lithium battery packs are composed of single cells connected in series and parallel and combined with electrical, structural and BMS (lithium battery management system). Most of the designs of single cells in series and parallel use jumper copper bars as the series and parallel medium. The schematic diagram of jumper copper bars is as follows Figure 1 As shown, reference numeral 6 indicates the installation hole of the jumper copper bar, and the jumper copper bar is installed and fixed between the battery cells through the installation hole 6 by screws, thereby realizing the series connection of the battery cells.

[0003] The flow chart of the existing lithium battery charge and discharge single cell pressure difference control method is as follows Figure 2 As shown, the BMS collects the voltages VB1, VB2, ..., VBn of each cell (B1, B2, ..., Bn) of the lithium battery; VBmax is the maximum value of all cell voltages; VBmin is the minimum value of all cell voltages; if VBmax-VBmin≥βmV (β is a preset voltage threshold, which can be set according to actual conditions), the BMS will report an alarm indicating that the cell voltage difference is too large. However, the existing control method does not consider the impact of each cross-connected copper busbar.

[0004] Due to the different positions, lengths and deformations of the cross-connect copper bars, the internal resistance of some cross-connect copper bars will increase, and the cross-connect copper bars will have voltage division during the charging and discharging process, which will cause a large difference between the single cell data collected and uploaded by the BMS in the entire battery pack and the actual cell voltage. This difference has a great impact on the status judgment of the entire vehicle during the operation of the vehicle. The excessive pressure difference of the vehicle will threaten the life safety of the cab occupants and passengers.

[0005] Therefore, how to solve the problem of excessive voltage difference between cells during the charging and discharging process of power lithium batteries is an issue that technical personnel in this field need to solve urgently. Summary of the invention

[0006] In view of the above problems, the present invention provides a method for controlling the voltage difference between charging and discharging cells of a power lithium battery, an electronic device and a storage medium, so as to at least solve some of the technical problems mentioned in the above background technology.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] On the one hand, the present invention provides a method for controlling the pressure difference between a charging and discharging monomer of a power lithium battery, which is applied to a device for controlling the pressure difference between a charging and discharging monomer of a power lithium battery. The method comprises the following steps:

[0009] Voltage acquisition is performed through the battery management system;

[0010] Eliminate the voltage of the cross-connected copper busbar from the collected voltage data;

[0011] The maximum battery voltage and the minimum battery voltage are screened out from the voltage data after removing the voltage of the cross-connected copper busbar; if the difference between the maximum battery voltage and the minimum battery voltage is greater than a threshold, it is determined that the voltage difference between the battery cells is too large, and an alarm is issued.

[0012] The power lithium battery charge and discharge single cell pressure difference control device comprises: a battery management system, a lithium battery pack, a battery single cell voltage collection harness, a jumper copper bar and a jumper copper bar voltage collection harness;

[0013] The lithium battery pack includes a plurality of battery cells, and each of the battery cells is connected to the battery management system via the battery cell voltage collection harness;

[0014] The jumper copper bar is connected to the battery management system through the jumper copper bar voltage collection harness;

[0015] The battery management system realizes voltage collection based on the battery cell voltage collection harness and the jumper copper bus voltage collection harness.

[0016] In another aspect, the present invention provides an electronic device including a plurality of processors and a memory;

[0017] The memory stores a computer program that can be executed by the processor; the computer program can be executed by at least one of the processors, so that the processor can execute the above-mentioned power lithium battery charging and discharging single cell pressure difference control method.

[0018] The present invention also provides a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the method for controlling the pressure difference between charging and discharging cells of a power lithium battery as described above is implemented.

[0019] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a method for controlling the pressure difference between charging and discharging cells of a power lithium battery, an electronic device and a storage medium, which have the following beneficial effects:

[0020] The present invention adds a sampling harness at both ends of the jumper copper bar and connects it to the battery management system, so that the battery management system can monitor the voltage division of the jumper copper bar in real time, and then eliminates and optimizes the voltage division data through a software algorithm to ensure that the jumper copper bar will not affect the collection of the elevator battery cell voltage of the battery management system during the charging and discharging process.

[0021] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention.

[0022] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0024] Figure 1 A schematic diagram of the jumper copper bus structure provided by the existing related technology.

[0025] Figure 2 A flow chart of a method for controlling the voltage difference between a charging and discharging cell of a lithium battery provided by the prior art.

[0026] Figure 3 A schematic flow chart of a method for controlling the voltage difference between charging and discharging cells of a power lithium battery provided in an embodiment of the present invention.

[0027] Figure 4 This is a schematic diagram of the structure of a power lithium battery charging and discharging single cell pressure difference control device provided by an embodiment of the present invention.

[0028] Figure 5 A schematic diagram of the pressure difference between cells during the discharge process provided by an embodiment of the present invention.

[0029] Figure 6 A schematic diagram of the pressure difference between cells during the charging process provided by an embodiment of the present invention.

[0030] Figure 7 A schematic diagram of the pressure difference between monomers during the static process provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The embodiment of the present invention learns through on-site investigation and physical inspection that the phenomenon of excessive voltage difference between cells during charging and discharging is caused by voltage division of the jumper copper bar (cell 20-cell 21): the internal resistance of the jumper copper bar is large (0.46mΩ), and there is voltage division of the copper bar during charging and discharging. During the on-site investigation, the battery pack is charged and discharged to reproduce the problem of large voltage difference collected by the BMS, and the data is recorded, some of which are shown in Table 1. The data in Table 1 shows that the voltage difference between cells (cell 20-cell 21) is about 50mV, and the system alarms for excessive voltage difference between cells.

[0033] Table 1

[0034] Single cell 20 battery voltage (mV) Single cell 21 battery voltage (mV) 3319 3318 3319 3318 3460 3511 3477 3528 3488 3539 3490 3542 3496 3548 3498 3548 3501 3553 3198 3147

[0035] Based on the above problems, the embodiment of the present invention discloses a method for controlling the pressure difference between charging and discharging monomers of a power lithium battery, which is applied to a device for controlling the pressure difference between charging and discharging monomers of a power lithium battery. Figure 3 As shown, the method includes the following steps: collecting voltage through a battery management system; removing the voltage across the copper busbar from the collected voltage data; screening out the maximum battery voltage and the minimum battery voltage from the voltage data after removing the voltage across the copper busbar; if the difference between the maximum battery voltage and the minimum battery voltage is greater than a threshold value, it is determined that the voltage difference between the battery cells is too large, and an alarm is issued.

[0036] The above steps are described in detail below.

[0037] Assuming that there are n battery cells in total, the cross-connect copper bar is also regarded as a cell (Bm), that is, there are n+1 cells in total, represented as B1, B2, ..., Bm, ..., Bn+1; voltage data is collected through the battery management system; at this time, the voltage data collected by the battery management system includes multiple battery cell voltages (B1, B2, ..., Bn+1) and the cross-connect copper bar voltage (VBm);

[0038] In order to eliminate the voltage division caused by the internal resistance of the jumper copper bar during the discharge process, the jumper copper bar voltage (VBm) is eliminated from the voltage data collected by the above-mentioned battery management system; the maximum value of the single cell voltage (Vbmax) and the minimum value of the single cell voltage (Vbmin) are screened out from the voltage data after eliminating the jumper copper bar voltage; the difference between the maximum value of the single cell voltage and the minimum value of the single cell voltage is judged, and if the difference is greater than the threshold value (i.e., Vbmax-Vbmin≥βmV), it is determined that the voltage difference between the single cells is too large, and an alarm is issued.

[0039] The present invention regards the divided voltage of the copper busbar as a single cell voltage through a battery management system, and eliminates the voltage divided by the copper busbar through an algorithm, thereby solving the problem of excessive voltage difference between battery cells.

[0040] See also Figure 4 As shown, the above-mentioned power lithium battery charging and discharging single cell pressure difference control device includes: a battery management system 1, a lithium battery pack 2, a battery single cell voltage collection harness 3, a jumper copper bar 4 and a jumper copper bar voltage collection harness 5; wherein, the lithium battery pack 2 includes a plurality of battery single cells, each of which is connected to the battery management system 1 via a battery single cell voltage collection harness 3; the jumper copper bar 4 is connected to the battery management system 1 via a jumper copper bar voltage collection harness 5; the battery management system 1 realizes voltage collection based on the battery single cell voltage collection harness 3 and the jumper copper bar voltage collection harness 5.

[0041] Figure 5-Figure 7 Schematic diagram of the pressure difference between monomers during discharge, charge and rest; Figure 5-Figure 7 It can be seen that after the BMS algorithm is improved, the test results show that the voltage difference is controlled at: discharge voltage difference 6mV; charge voltage difference 6mV; static voltage difference 0mV. The problem of excessive voltage difference has been optimized, thus ensuring the fault alarm of excessive voltage difference caused by cross-connection of copper bars during the vehicle process, ensuring the personal safety of drivers and passengers.

[0042] In another embodiment, the present invention also provides an electronic device, comprising multiple processors and memories; the memories store computer programs that can be executed by the processors; the computer programs can be executed by at least one processor so that the processor can execute the above-mentioned power lithium battery charging and discharging single cell pressure difference control method.

[0043] In another embodiment, the present invention further provides a computer-readable storage medium storing a computer program, which implements the above-mentioned method for controlling the pressure difference between charging and discharging cells of a power lithium battery when executed by a processor.

[0044] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0045] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power lithium battery charge and discharge monomer pressure difference control method, applied to a power lithium battery charge and discharge monomer pressure difference control device, characterized in that: The method comprises the following steps: Voltage acquisition is performed through the battery management system; Eliminate the voltage of the cross-connected copper busbar from the collected voltage data; The maximum battery voltage and the minimum battery voltage are screened out from the voltage data after removing the voltage of the cross-connected copper busbar; if the difference between the maximum battery voltage and the minimum battery voltage is greater than a threshold, it is determined that the voltage difference between the battery cells is too large, and an alarm is issued.

2. A method for controlling the pressure difference between charging and discharging cells of a power lithium battery according to claim 1, characterized in that: The power lithium battery charge and discharge single cell pressure difference control device comprises: a battery management system, a lithium battery pack, a battery single cell voltage collection harness, a jumper copper bar and a jumper copper bar voltage collection harness; The lithium battery pack includes a plurality of battery cells, and each of the battery cells is connected to the battery management system via the battery cell voltage collection harness; The jumper copper bar is connected to the battery management system through the jumper copper bar voltage collection harness; The battery management system realizes voltage collection based on the battery cell voltage collection harness and the jumper copper bus voltage collection harness.

3. An electronic device, characterized in that: including multiple processors and memories; The memory stores a computer program that can be executed by the processor; the computer program can be executed by at least one of the processors, so that the processor can execute the power lithium battery charging and discharging single cell pressure difference control method as described in any one of claims 1 to 2.

4. A computer-readable storage medium, characterized in that: A computer program is stored, and when the computer program is executed by a processor, the method for controlling the pressure difference between charging and discharging cells of a power lithium battery as claimed in any one of claims 1 to 2 is implemented.

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