Charging and discharging control method and device of power battery pack, and power battery pack

Abstract

The application provides a charging and discharging control method and device of a power battery pack and the power battery pack. The power battery pack comprises a plurality of single cells. The method comprises the following steps: acquiring output voltages and temperature values of the plurality of single cells, and sequentially sorting the plurality of output voltages to obtain an output voltage sequence; determining the single cells corresponding to the output voltages with sequence numbers less than or equal to a target cell number in the output voltage sequence as characteristic single cells; calculating the average value of the output voltages of all the characteristic single cells to obtain a characteristic single cell voltage; calculating the average value of the temperature values of all the characteristic single cells to obtain a characteristic single cell temperature; querying a charging cutoff voltage and a discharging cutoff voltage corresponding to the characteristic single cell temperature according to a temperature-voltage mapping relationship; and in the case that the power battery pack is in a charging and discharging state and the characteristic single cell voltage reaches the corresponding cutoff voltage, controlling the power battery pack to stop charging or discharging. The method solves the problem of heavy calculation load of the power battery pack.

Description

Technical Field

[0001] This invention relates to the field of power battery management technology, and more specifically, to a charging and discharging control method, control device, computer-readable storage medium, and power battery pack for a power battery pack. Background Technology

[0002] The power battery pack in pure electric vehicles serves as the main power source for the entire vehicle. The power battery pack typically consists of many individual cells connected in series and parallel. Its charging and discharging system level is usually determined by the maximum and minimum values ​​of the individual cell voltages. Estimating the core functional state of each individual cell would incur a very high computational load. Estimating the core functional state based on the real-time maximum and minimum values ​​of the individual cell voltages would result in frequent fluctuations in the mapped cell positions and voltage values, leading to poor mapping accuracy. Furthermore, acquisition failures could easily cause misjudgments. Therefore, designing a method to reduce the computational load and accurately calculate the core functional state of the battery pack system, by selecting characteristic cells that can map the charging and discharging levels of the power battery pack system, is a crucial technical problem that needs to be solved. Summary of the Invention

[0003] The main objective of this application is to provide a charging and discharging control method, control device, computer-readable storage medium, and power battery pack, so as to at least solve the problem of high computational load in the prior art.

[0004] To achieve the above objectives, according to one aspect of this application, a charging and discharging control method for a power battery pack is provided. The power battery pack includes multiple individual battery cells. The method includes: acquiring the output voltage and temperature values ​​of the multiple individual battery cells; sorting the multiple output voltages in descending order to obtain a first output voltage sequence; sorting the multiple output voltages in ascending order to obtain a second output voltage sequence; wherein the sequence number of the output voltage sequence corresponds one-to-one with the output voltage; and determining the individual battery cell corresponding to the output voltage in the first output voltage sequence whose sequence number is less than or equal to a first target number of battery cells as the first target number of battery cells. The characteristic cell is defined as the cell whose output voltage in the second output voltage sequence is less than or equal to the number of the second target cells. The first target cell number ensures that the difference between the minimum output voltage of the first characteristic cell and the maximum output voltage of the remaining cell is greater than a first voltage difference threshold. The second target cell number ensures that the difference between the minimum output voltage of the remaining cell and the maximum output voltage of the second characteristic cell is greater than a second voltage difference threshold. The remaining cell is any cell other than the second characteristic cell. The process involves: calculating the average output voltage of all the first characteristic cells to obtain the first characteristic cell voltage; calculating the average output voltage of all the second characteristic cells to obtain the second characteristic cell voltage; calculating the average temperature of all the first characteristic cells to obtain the first characteristic cell temperature; calculating the average temperature of all the second characteristic cells to obtain the second characteristic cell temperature; querying the charging cut-off voltage corresponding to the first characteristic cell temperature based on a first temperature-voltage mapping relationship; querying the discharging cut-off voltage corresponding to the second characteristic cell temperature based on a second temperature-voltage mapping relationship. The first temperature-voltage mapping relationship is a mapping relationship between the charging cut-off voltage and the temperature value of the individual cell, and the second temperature-voltage mapping relationship is a mapping relationship between the discharging cut-off voltage and the temperature value of the individual cell. The charging cut-off voltage is the voltage value at the end of the charging state, and the discharging cut-off voltage is the voltage value at the end of the discharging state. When the power battery pack is in the charging state and the voltage of the first characteristic cell reaches the charging cut-off voltage, the power battery pack is controlled to stop charging; or, when the power battery pack is in the discharging state and the voltage of the second characteristic cell reaches the discharging cut-off voltage, the power battery pack is controlled to stop discharging.

[0005] Optionally, before determining the individual cell corresponding to the output voltage with an index less than or equal to the number of the first target cells in the first output voltage sequence as the first characteristic cell, the method further includes: sequentially calculating the voltage difference between two output voltages in all adjacent output voltage groups of the first output voltage sequence in descending order of the index, to obtain a first voltage difference sequence, wherein the adjacent output voltage group includes two output voltages and the indexes of the two first output voltages are adjacent, the first voltage difference sequence includes multiple first voltage differences, and the first voltage difference corresponds one-to-one with the adjacent output voltage groups; setting a first calculation quantity and a second calculation quantity, wherein the difference between the first calculation quantity and the second calculation quantity is 1; and a first calculation step, calculating the average value of the output voltages with an index less than or equal to the first calculation quantity in the first voltage difference sequence to obtain the first characteristic cell. The process involves several steps: 1) A first step: Calculating the average value of the output voltages whose sequence number in the first voltage difference sequence is less than or equal to the second calculated quantity, to obtain a second average voltage difference; 2) A first adjustment step: Increasing both the first and second calculated quantities by one if a first condition is met, where the first condition is that both the first and second average voltage difference values ​​are less than a third voltage difference threshold; 3) A second adjustment step: Decreasing both the first and second calculated quantities by one if a second condition is met, where the first and second average voltage difference values ​​are greater than a fourth voltage difference threshold, and the third voltage difference threshold is less than the fourth voltage difference threshold; 4) A first determination step: Determining the first calculated quantity as the first target cell quantity if neither the first nor the second condition is met.

[0006] Optionally, after increasing both the first calculated quantity and the second calculated quantity by one, or after decreasing both the first calculated quantity and the second calculated quantity by one, the method further includes: repeating the first calculation step, the second calculation step, the first adjustment step, the second adjustment step, and the first determination step at least once in sequence until the first target number of battery cells is obtained.

[0007] Optionally, before determining the individual cell corresponding to the output voltage with an index less than or equal to the number of second target cells in the second output voltage sequence as the second characteristic cell, the method further includes: calculating the voltage difference between two output voltages in all adjacent output voltage groups of the second output voltage sequence in ascending order of the index, to obtain a second voltage difference sequence, wherein the adjacent output voltage group includes two output voltages and the indexes of the two second output voltages are adjacent, the second voltage difference sequence includes multiple second voltage differences, and the second voltage differences correspond one-to-one with the adjacent output voltage groups; setting a third calculation quantity and a fourth calculation quantity, wherein the difference between the third calculation quantity and the fourth calculation quantity is 1; and a third calculation step, calculating the average value of the output voltages with an index less than or equal to the third calculation quantity in the second voltage difference sequence, to obtain the second characteristic cell. The third step involves calculating the average value of the output voltages whose serial numbers in the second voltage difference sequence are less than or equal to the fourth calculated quantity, to obtain the fourth voltage difference average value. The fourth adjustment step involves increasing both the third and fourth calculated quantities by one if the third condition is met, where the third condition is that both the third voltage difference average value and the fourth voltage difference average value are less than the fifth voltage difference threshold. The fourth adjustment step involves decreasing both the third and fourth calculated quantities by one if the fourth condition is met, where the third condition is that both the third voltage difference average value and the fourth voltage difference average value are greater than the sixth voltage difference threshold, and the fifth voltage difference threshold is less than the sixth voltage difference threshold. The second determination step involves determining the third calculated quantity as the second target cell quantity if neither the third nor the fourth condition is met.

[0008] Optionally, after increasing both the third and fourth calculated quantities by one, or after decreasing both the third and fourth calculated quantities by one, the method further includes: repeating the third calculation step, the fourth calculation step, the third adjustment step, the fourth adjustment step, and the second determination step at least once in sequence until the second target number of battery cells is obtained.

[0009] Optionally, the multiple output voltages are sorted in descending order to obtain a first output voltage sequence, and the multiple output voltages are sorted in ascending order to obtain a second output voltage sequence, wherein the sequence number of the output voltage sequence corresponds one-to-one with the output voltage. This includes: numbering the multiple individual battery cells according to the arrangement order of the individual battery cells to obtain multiple first numbers, wherein the first numbers correspond one-to-one with the individual battery cells; sorting the output voltages of all the individual battery cells in descending order to obtain the first output voltage sequence, such that the sequence number of the first output voltage sequence corresponds one-to-one with the first number; and sorting the output voltages of all the individual battery cells in ascending order to obtain the second output voltage sequence, such that the sequence number of the second output voltage sequence corresponds one-to-one with the first number.

[0010] Optionally, the average temperature value of all the first characteristic cells is calculated to obtain the temperature of the first characteristic cell, and the average temperature value of all the second characteristic cells is calculated to obtain the temperature of the second characteristic cell, including: grouping multiple individual cells to obtain multiple individual cell groups, such that one individual cell group corresponds to one temperature sensor, wherein each individual cell group includes one individual cell or multiple adjacent individual cells, and the temperature sensor is used to collect the temperature of the corresponding individual cell group; numbering multiple temperature sensors according to the arrangement order of the temperature sensors to obtain multiple second numbers, wherein the second numbers correspond one-to-one with the temperature sensors; determining multiple first target numbers according to the first number of each first characteristic cell, wherein the first... The target number is the second number corresponding to the cell group where the first characteristic cell is located, and the detected temperature of the temperature sensor corresponding to each first target number is determined as the temperature value of the corresponding first characteristic cell; multiple second target numbers are determined according to the first number of each second characteristic cell, the second target number is the second number corresponding to the cell group where the second characteristic cell is located, and the detected temperature of the temperature sensor corresponding to each second target number is determined as the temperature value of the corresponding second characteristic cell; the average value of the temperature values ​​of all first characteristic cells is calculated to obtain the temperature of the first characteristic cell, and the average value of the temperature values ​​of all second characteristic cells is calculated to obtain the temperature of the second characteristic cell.

[0011] To achieve the above objectives, according to one aspect of this application, a charging and discharging control device for a power battery pack is provided. The power battery pack includes multiple individual battery cells. The device includes: an acquisition unit, configured to acquire the output voltage and temperature values ​​of the multiple individual battery cells, sort the multiple output voltages in descending order to obtain a first output voltage sequence, and sort the multiple output voltages in ascending order to obtain a second output voltage sequence, wherein the sequence number of the output voltage sequence corresponds one-to-one with the output voltage; and a determination unit, configured to determine the output voltages in the first output voltage sequence whose sequence number is less than or equal to the number of a first target battery cell. The individual battery cell is identified as the first characteristic cell. The individual battery cells corresponding to the output voltages in the second output voltage sequence whose serial numbers are less than or equal to the number of second target battery cells are identified as the second characteristic cells. This is achieved such that the difference between the minimum output voltage of the first characteristic cell and the maximum output voltage of the remaining individual battery cells is greater than a first voltage difference threshold, and the difference between the minimum output voltage of the remaining individual battery cells and the maximum output voltage of the second characteristic cell is greater than a second voltage difference threshold. The remaining individual battery cells are those other than the second characteristic cell and the second characteristic cell. A first calculation unit is used to calculate all the first... The system comprises: a first characteristic cell voltage, obtained by averaging the output voltages of the characteristic cells; a second characteristic cell voltage, obtained by averaging the output voltages of all the second characteristic cells; a second calculation unit, used to calculate the average temperature values ​​of all the first characteristic cells to obtain the first characteristic cell temperature, and to calculate the average temperature values ​​of all the second characteristic cells to obtain the second characteristic cell temperature; a query unit, used to query the charging cut-off voltage corresponding to the first characteristic cell temperature according to a first temperature-voltage mapping relationship, and to query the discharging cut-off voltage corresponding to the second characteristic cell temperature according to a second temperature-voltage mapping relationship, wherein the first temperature-voltage mapping relationship is a mapping relationship between the charging cut-off voltage and the temperature value of the individual cell, and the second temperature-voltage mapping relationship is a mapping relationship between the discharging cut-off voltage and the temperature value of the individual cell, wherein the charging cut-off voltage is the voltage value at the end of the charging state, and the discharging cut-off voltage is the voltage value at the end of the discharging state; and a control unit, used to control the power battery pack to stop charging when the power battery pack is in the charging state and the first characteristic cell voltage reaches the charging cut-off voltage, or to control the power battery pack to stop discharging when the power battery pack is in the discharging state and the second characteristic cell voltage reaches the discharging cut-off voltage.

[0012] To achieve the above objectives, according to one aspect of this application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform any of the methods described.

[0013] To achieve the above objectives, according to one aspect of this application, a power battery pack is provided, comprising: a single battery cell, one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include methods for performing any one of the methods described above.

[0014] By applying the technical solution of this application, in the charging and discharging control method of the power battery pack, this application monitors the output voltage and temperature of all individual cells in real time, and arranges the output voltages in order. The average value of the adjacent output voltage difference of the sorted large-end portion of individual cells that is less than the voltage difference threshold is used to map the voltage level of the largest characteristic cell, and the average value of the adjacent output voltage difference of the sorted small-end portion of individual cells that is less than the voltage difference threshold is used to map the voltage level of the smallest characteristic cell. At the same time, the temperature of the characteristic cells is calculated, which achieves the effect of real-time updating and effective online estimation of the core functions of the power battery pack, and solves the problem of large computational load. Attached Figure Description

[0015] Figure 1 A hardware structure block diagram of a mobile terminal for performing a charging and discharging control method for a power battery pack, according to an embodiment of this application, is shown.

[0016] Figure 2 A schematic flowchart of a method for controlling the charging and discharging of a power battery pack according to an embodiment of this application is shown.

[0017] Figure 3 A flowchart illustrating a method for obtaining the first target number of cells in a power battery pack, according to an embodiment of this application, is shown.

[0018] Figure 4 A schematic flowchart of a method for obtaining the temperature of a characteristic cell in a power battery pack, according to an embodiment of this application, is shown.

[0019] Figure 5 A schematic flowchart illustrating a specific method for implementing charge and discharge control of a power battery pack according to an embodiment of this application is shown.

[0020] Figure 6 A structural block diagram of a power battery pack charging and discharging control device according to an embodiment of this application is shown.

[0021] The above figures include the following reference numerals:

[0022] 102. Processor; 104. Memory; 106. Transmission device; 108. Input / output device. Detailed Implementation

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] As described in the background section, the existing technology involves estimating the core functional state of each individual cell, which results in a very large computational load. To address the problem of high computational load, embodiments of this application provide a charging and discharging control method, control device, computer-readable storage medium, and power battery pack for a power battery pack.

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0028] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a power battery pack charging and discharging control method according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0029] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the device information display method in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the mobile terminal via a network. Examples of the aforementioned networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof. The transmission device 106 is used to receive or send data via a network. Specific examples of the aforementioned networks may include wireless networks provided by the mobile terminal's communication provider. In one example, the transmission device 106 includes a network interface controller (NIC), which can be connected to other network devices via a base station to communicate with the Internet. In one example, the transmission device 106 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0030] This embodiment provides a charging and discharging control method for a power battery pack that runs on a mobile terminal, computer terminal, or similar computing device. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Also, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0031] Figure 2 This is a flowchart of a charging and discharging control method for a power battery pack according to an embodiment of this application. Figure 2 As shown, the method includes the following steps:

[0032] Step S201: Obtain the output voltage and temperature values ​​of multiple individual battery cells, sort the multiple output voltages in descending order to obtain the first output voltage sequence, sort the multiple output voltages in ascending order to obtain the second output voltage sequence, and the sequence number of the output voltage sequence corresponds one-to-one with the output voltage;

[0033] Specifically, the voltage and temperature acquisition unit detects and obtains real-time information on the voltage and temperature of individual cells in the power battery pack system, and then sends it to the control and execution unit through the communication network. After receiving the data, the control and execution unit sorts the multiple output voltages in descending order to obtain the first output voltage sequence, and sorts the multiple output voltages in ascending order to obtain the second output voltage sequence.

[0034] Step S202: The individual cells corresponding to the output voltages in the first output voltage sequence whose serial numbers are less than or equal to the number of the first target cells are determined as the first characteristic cells; the individual cells corresponding to the output voltages in the second output voltage sequence whose serial numbers are less than or equal to the number of the second target cells are determined as the second characteristic cells. The number of the first target cells is such that the difference between the minimum output voltage of the first characteristic cells and the maximum output voltage of the remaining individual cells is greater than a first voltage difference threshold. The number of the second target cells is such that the difference between the minimum output voltage of the remaining individual cells and the maximum output voltage of the second characteristic cells is greater than a second voltage difference threshold. The remaining individual cells are individual cells other than the second characteristic cells.

[0035] Specifically, the first N cells arranged from largest to smallest are used as the first characteristic cells, where N is the number of cells mapped to the first characteristic cells, which is the number of the first target cells. The output voltage of the Nth cell is inconsistent with the output voltage of the (N+1)th cell, meaning the difference between the minimum output voltage of the first characteristic cell and the maximum output voltage of the remaining cells is greater than the first voltage difference threshold. Similarly, the first M cells arranged from smallest to largest are used as the second characteristic cells, where M is the number of cells mapped to the second characteristic cells, which is the number of the second target cells. The output voltage of the Mth cell is inconsistent with the output voltage of the (M+1)th cell, meaning the difference between the maximum output voltage of the second characteristic cell and the minimum output voltage of the remaining cells is greater than the second voltage difference threshold.

[0036] Step S203: Calculate the average value of the output voltage of all first characteristic cells to obtain the first characteristic cell voltage, and calculate the average value of the output voltage of all second characteristic cells to obtain the second characteristic cell voltage.

[0037] Specifically, the average value of the output voltage of all the first characteristic cells is calculated, which is the first characteristic cell voltage. Similarly, the average value of the output voltage of all the second characteristic cells is calculated, which is the second characteristic cell voltage.

[0038] Step S204: Calculate the average temperature value of all first characteristic monomers to obtain the temperature of the first characteristic monomer, and calculate the average temperature value of all second characteristic monomers to obtain the temperature of the second characteristic monomer.

[0039] Specifically, the average temperature value of all first characteristic monomers is calculated, which is the temperature of the first characteristic monomer. Similarly, the average temperature value of all second characteristic monomers is calculated, which is the temperature of the second characteristic monomer.

[0040] Step S205: Query the charging cut-off voltage corresponding to the temperature of the first characteristic cell according to the first temperature-voltage mapping relationship, and query the discharging cut-off voltage corresponding to the temperature of the second characteristic cell according to the second temperature-voltage mapping relationship. The first temperature-voltage mapping relationship is the mapping relationship between the charging cut-off voltage and the temperature value of the individual cell, and the second temperature-voltage mapping relationship is the mapping relationship between the discharging cut-off voltage and the temperature value of the individual cell. The charging cut-off voltage is the voltage value at the end of the charging state, and the discharging cut-off voltage is the voltage value at the end of the discharging state.

[0041] Specifically, based on the mapping relationship between charging cut-off voltage and temperature value, the charging cut-off voltage corresponding to the temperature of the first characteristic cell is queried. Similarly, based on the mapping relationship between discharging cut-off voltage and temperature value, the discharging cut-off voltage corresponding to the temperature of the second characteristic cell is queried.

[0042] Step S206: When the power battery pack is in a charging state and the voltage of the first characteristic cell reaches the charging cutoff voltage, control the power battery pack to stop charging; or, when the power battery pack is in a discharging state and the voltage of the second characteristic cell reaches the discharging cutoff voltage, control the power battery pack to stop discharging.

[0043] Specifically, when the power battery pack is in a charging state and the voltage of the first characteristic cell reaches the charging cutoff voltage, it indicates the highest voltage value reached by the power battery pack during the charging process. When the battery voltage reaches the charging cutoff voltage, the charging process will stop to avoid overcharging, which could lead to safety issues or damage to the battery. Similarly, when the power battery pack is in a discharging state and the voltage of the second characteristic cell reaches the discharging cutoff voltage, it indicates the lowest voltage value reached by the power battery pack during the discharging process. When the battery voltage reaches the discharging cutoff voltage, the discharging process will stop to protect the battery from over-discharge and damage.

[0044] In this embodiment, firstly, the output voltage and temperature values ​​of multiple individual battery cells are acquired, and the multiple output voltages are sorted in descending order to obtain a first output voltage sequence. Then, the multiple output voltages are sorted in ascending order to obtain a second output voltage sequence. The sequence number of the output voltage sequence corresponds one-to-one with the output voltage. Next, the individual battery cells corresponding to the output voltages in the first output voltage sequence whose sequence number is less than or equal to the number of first target battery cells are identified as first characteristic cells. The individual battery cells corresponding to the output voltages in the second output voltage sequence whose sequence number is less than or equal to the number of second target battery cells are identified as second characteristic cells. The first target battery cell number ensures that the difference between the minimum output voltage of the first characteristic cells and the maximum output voltage of the remaining individual battery cells is greater than a first voltage difference threshold. The second target battery cell number ensures that the difference between the minimum output voltage of the remaining individual battery cells and the maximum output voltage of the second characteristic cells is greater than a second voltage difference threshold. The remaining individual battery cells are those other than the second characteristic cells. Finally, the average value of the output voltages of all the first characteristic cells is calculated to obtain the first... The system calculates the voltage of each first-characteristic cell and the average of the output voltages of all second-characteristic cells to obtain the second-characteristic cell voltage. Then, it calculates the average of the temperature values ​​of all first-characteristic cells to obtain the first-characteristic cell temperature, and the average of the temperature values ​​of all second-characteristic cells to obtain the second-characteristic cell temperature. Next, it queries the charging cut-off voltage corresponding to the first-characteristic cell temperature based on a first temperature-voltage mapping relationship, and the discharging cut-off voltage corresponding to the second-characteristic cell temperature based on a second temperature-voltage mapping relationship. The first temperature-voltage mapping relationship is the mapping relationship between the charging cut-off voltage and the temperature value of a single cell, and the second temperature-voltage mapping relationship is the mapping relationship between the discharging cut-off voltage and the temperature value of a single cell. The charging cut-off voltage is the voltage value at the end of the charging state, and the discharging cut-off voltage is the voltage value at the end of the discharging state. Finally, when the power battery pack is in a charging state and the first-characteristic cell voltage reaches the charging cut-off voltage, the system controls the power battery pack to stop charging; or, when the power battery pack is in a discharging state and the second-characteristic cell voltage reaches the discharging cut-off voltage, the system controls the power battery pack to stop discharging. This application monitors the output voltage and temperature of all individual battery cells in real time, and arranges the output voltages sequentially. The maximum characteristic cell voltage level is mapped based on the average value of adjacent cells with an output voltage difference less than the voltage difference threshold in the sorted large-end portion, and the minimum characteristic cell voltage level is mapped based on the average value of adjacent cells with an output voltage difference less than the voltage difference threshold in the sorted small-end portion. At the same time, the temperature of the characteristic cells is calculated, achieving the effect of real-time updating and effective online estimation of the core functions of the power battery pack, and solving the problem of high computational load.

[0045] To enable those skilled in the art to better understand the technical solution of this application, the implementation process of the charging and discharging control method of the power battery pack of this application will be described in detail below with reference to specific embodiments.

[0046] To improve computational efficiency, in one optional implementation, step S201 further includes:

[0047] Step S2011: Number the multiple individual cells according to the arrangement order of the individual cells to obtain multiple first numbers, and the first numbers correspond one-to-one with the individual cells.

[0048] Specifically, individual battery cells are numbered based on their physical location at the point where the actual output voltage is collected.

[0049] Step S2012: Sort the output voltages of all the above-mentioned individual cells in descending order to obtain the first output voltage sequence, such that the sequence number of the first output voltage sequence corresponds one-to-one with the first number.

[0050] Specifically, the output voltages of all the aforementioned individual battery cells are sorted in descending order to obtain the first output voltage sequence. The sorting method includes, but is not limited to, bubble sort, selection sort, and other methods that can achieve sorting by size.

[0051] Step S2013: Sort the output voltages of all the above-mentioned individual cells in ascending order to obtain the second output voltage sequence, such that the sequence number of the second output voltage sequence corresponds one-to-one with the first number.

[0052] Specifically, the output voltages of all the aforementioned individual battery cells are sorted in ascending order to obtain the second output voltage sequence. The sorting method includes, but is not limited to, bubble sort, selection sort, and other methods that can achieve sorting by size.

[0053] To ensure the consistency of the first characteristic monomer, in an optional implementation, before step S202, as follows: Figure 3 As shown, the method also includes:

[0054] Step S301: Calculate the voltage difference between two output voltages in all adjacent output voltage groups of the first output voltage sequence in descending order of serial number to obtain the first voltage difference sequence. The adjacent output voltage group includes two output voltages and the serial numbers of the two first output voltages are adjacent. The first voltage difference sequence includes multiple first voltage differences, and the first voltage difference corresponds one-to-one with the adjacent output voltage group.

[0055] Specifically, the adjacent voltage differences of individual cell voltages arranged from largest to smallest are calculated and denoted as UCellH2Ldiff1, UCellH2Ldiff2...UCellH2LdiffN-1. For example, UCellH2Ldiff1 = UCellH2L(1) - UCellH2L(2). By analogy, all adjacent voltage differences can be obtained. That is, the voltage difference between two output voltages in all adjacent output voltage groups of the first output voltage sequence is calculated to obtain the first voltage difference sequence.

[0056] Step S302: Set the first calculation quantity and the second calculation quantity, and the difference between the first calculation quantity and the second calculation quantity is 1.

[0057] Specifically, in order to avoid calculating the average adjacent voltage difference of all individual cells, it is necessary to first set two calculation quantities to determine the number of individual cells whose average adjacent voltage difference needs to be calculated, denoted as x1 and x2, which are the first calculation quantity and the second calculation quantity.

[0058] Step S303, first calculation step, calculate the average value of the output voltages whose serial numbers are less than or equal to the first number of calculations in the first voltage difference sequence, and obtain the first voltage difference average value.

[0059] Specifically, the average value of the first x1 adjacent voltage differences is calculated, which is the average value of the first voltage difference.

[0060] Step S304, the second calculation step, calculates the average value of the output voltages whose serial numbers are less than or equal to the second calculation quantity in the first voltage difference sequence, and obtains the second average voltage difference.

[0061] Specifically, the average value of the first x2 adjacent voltage differences is calculated, which is the average value of the second voltage difference.

[0062] Step S305, first adjustment step: under the condition that the first calculation quantity and the second calculation quantity are both increased by one, the first condition is that the average value of the first voltage difference and the average value of the second voltage difference are both less than the third voltage difference threshold.

[0063] Specifically, when the average value of the first voltage difference and the average value of the second voltage difference are both less than the third voltage difference threshold, it indicates that the voltage consistency of the individual cells is very good and can reflect the charging level of the power battery pack. Then, the first and second calculation quantities are both increased by one to further filter out more individual cells that can reflect the charging level of the power battery pack.

[0064] Step S306, second adjustment step: under the condition that the first calculation quantity and the second calculation quantity are both reduced by one, the second condition is that the average value of the first voltage difference and the average value of the second voltage difference are both greater than the fourth voltage difference threshold, and the third voltage difference threshold is less than the fourth voltage difference threshold.

[0065] Specifically, when the average value of the first voltage difference and the average value of the second voltage difference are both greater than the fourth voltage difference threshold, it indicates that the voltage consistency of the individual cells is very poor and cannot reflect the charging level of the power battery pack. Therefore, the first and second calculation quantities are both reduced by one to find multiple individual cells that can reflect the charging level of the power battery pack.

[0066] Step S307, the first determining step, in the case that neither the first condition nor the second condition is met, determines the first calculated quantity as the first target number of battery cells.

[0067] Specifically, if the average value of the first voltage difference and the average value of the second voltage difference are both greater than the fourth voltage difference threshold, and if the average value of the first voltage difference and the average value of the second voltage difference are both greater than the fourth voltage difference threshold, it indicates that multiple individual cells capable of mapping the charging level of the power battery pack have been found.

[0068] To improve the screening and updating efficiency of the first feature monomer, in an optional embodiment, after step S305 or step S306, the method further includes:

[0069] Step S401: Repeat the first calculation step, the second calculation step, the first adjustment step, the second adjustment step, and the first determination step at least once in sequence until the first target number of battery cells is obtained.

[0070] Specifically, the first calculation step, the second calculation step, the first adjustment step, the second adjustment step, and the first determination step are repeated continuously. When the difference between the minimum output voltage of the first characteristic cell and the maximum output voltage of the remaining cell is greater than the first voltage difference threshold, the number of first characteristic cells that meet the requirements is found, that is, the number of first target cells.

[0071] To ensure the consistency of the second characteristic monomer, in an optional implementation, before step S202, the method further includes:

[0072] Step S501: Calculate the voltage difference between two output voltages in all adjacent output voltage groups of the second output voltage sequence in ascending order of serial number to obtain the second voltage difference sequence. The adjacent output voltage group includes two output voltages and the serial numbers of the two second output voltages are adjacent. The second voltage difference sequence includes multiple second voltage differences, and the second voltage differences correspond one-to-one with the adjacent output voltage groups.

[0073] Specifically, the adjacent voltage differences of individual cell voltages are calculated in ascending order, denoted as UCellH2Ldiff1', UCellH2Ldiff2'...UCellH2Ldiff(N-1)', for example: UCellH2Ldiff1'=UCellH2L(1)'-UCellH2L(2)', and so on, to obtain all the adjacent voltage differences. That is, the voltage difference between two output voltages in all adjacent output voltage groups of the second output voltage sequence is calculated sequentially to obtain the second voltage difference sequence.

[0074] Step S502: Set the third calculation quantity and the fourth calculation quantity, with the difference between the third calculation quantity and the fourth calculation quantity being 1.

[0075] Specifically, in order to avoid calculating the average adjacent voltage difference of all individual cells, two calculation quantities need to be set first to determine the number of individual cells whose average adjacent voltage difference needs to be calculated, denoted as y1 and y2, which are the third and fourth calculation quantities.

[0076] Step S503, the third calculation step, calculates the average value of the output voltages in the second voltage difference sequence whose serial numbers are less than or equal to the third calculation quantity, and obtains the third voltage difference average value.

[0077] Specifically, the average value of the first y1 adjacent voltage differences is calculated, which is the average value of the third voltage difference.

[0078] Step S504, fourth calculation step: calculate the average value of the output voltages whose serial numbers are less than or equal to the fourth calculation quantity in the second voltage difference sequence, and obtain the fourth voltage difference average value.

[0079] Specifically, the average value of the first y2 adjacent voltage differences is calculated, which is the average value of the fourth voltage difference.

[0080] Step S505, the third adjustment step: under the condition that the third calculation quantity and the fourth calculation quantity are both increased by one, the third condition is that the average value of the third voltage difference and the average value of the third voltage difference are both less than the fifth voltage difference threshold.

[0081] Specifically, when the average values ​​of the third and fourth voltage differences are both less than the fifth voltage difference threshold, it indicates that the voltage consistency of the individual cells is very good and can reflect the discharge level of the power battery pack. In this case, the number of cells calculated in the third and fourth calculations is increased by one to further filter out more individual cells that can reflect the discharge level of the power battery pack.

[0082] Step S506, the fourth adjustment step, under the condition that the third calculation quantity and the fourth calculation quantity are both reduced by one, the fourth condition is that the average value of the third voltage difference and the average value of the fourth voltage difference are both greater than the sixth voltage difference threshold, and the fifth voltage difference threshold is less than the sixth voltage difference threshold.

[0083] Specifically, when the average value of the third voltage difference and the average value of the fourth voltage difference are both greater than the sixth voltage difference threshold, it indicates that the voltage consistency of the individual cells is very poor and cannot reflect the discharge level of the power battery pack. Therefore, the first and second calculation quantities are both reduced by one to find multiple individual cells that can reflect the discharge level of the power battery pack.

[0084] Step S507, Determine the third calculation quantity as the second target cell quantity if neither the third nor the fourth condition is met.

[0085] Specifically, if the average values ​​of the third and fourth voltage differences are not greater than the fifth voltage difference threshold and the average values ​​of the third and fourth voltage differences are not greater than the sixth voltage difference threshold, it indicates that multiple individual cells capable of mapping the discharge level of the power battery pack have been found.

[0086] To improve the screening and updating efficiency of the second feature monomer, in an optional embodiment, after step S505 or step S506, the method further includes:

[0087] Step S601: Repeat the third calculation step, the fourth calculation step, the third adjustment step, the fourth adjustment step, and the second determination step at least once in sequence until the second target number of battery cells is obtained.

[0088] Specifically, the third calculation step, the fourth calculation step, the third adjustment step, the fourth adjustment step, and the second determination step are repeated continuously. When the difference between the maximum value of the output voltage of the second characteristic cell and the minimum value of the output voltage of the remaining cell is greater than the second voltage difference threshold, the number of second characteristic cells that meet the requirements is found, that is, the number of second target cells.

[0089] To improve the safety of a single battery cell, in one optional implementation, such as Figure 4 As shown, step S204 further includes:

[0090] Step S2041: Group the multiple individual cells to obtain multiple individual cell groups, such that one individual cell group corresponds to one temperature sensor. The individual cell group includes one individual cell or multiple adjacent individual cells, and the temperature sensor is used to collect the temperature of the corresponding individual cell group.

[0091] Specifically, multiple individual cells are grouped to obtain multiple individual cell groups. Each individual cell group includes one or more adjacent individual cells. Each individual cell group is equipped with a temperature sensor to collect the temperature of the corresponding individual cell group.

[0092] Step S2042: Number the multiple temperature sensors according to their arrangement order to obtain multiple second numbers, and each second number corresponds to a temperature sensor.

[0093] Specifically, multiple temperature sensors are numbered according to their arrangement order to obtain multiple second numbers, and each second number corresponds one-to-one with the corresponding temperature sensor.

[0094] Step S2043: Determine multiple first target numbers based on the first number of each first characteristic cell. The first target number is the second number corresponding to the cell group where the first characteristic cell is located. And determine the detected temperature of the temperature sensor corresponding to each first target number as the temperature value of the corresponding first characteristic cell.

[0095] Specifically, based on the first number of the first characteristic cell, multiple first target numbers are determined. The first target number is the second number corresponding to the cell group where the first characteristic cell is located. The temperature detected by the temperature sensor corresponding to each first target number is determined as the temperature value of the corresponding first characteristic cell.

[0096] Step S2044: Determine multiple second target numbers based on the first number of each second characteristic cell. The second target number is the second number corresponding to the cell group where the second characteristic cell is located. And determine the detected temperature of the temperature sensor corresponding to each second target number as the temperature value of the corresponding second characteristic cell.

[0097] Specifically, based on the first number of the second characteristic cell, multiple second target numbers are determined. The second target number is the second number corresponding to the cell group to which the second characteristic cell belongs, and the temperature detected by the temperature sensor corresponding to each second target number is determined as the temperature value of the corresponding second characteristic cell.

[0098] Step S2045: Calculate the average temperature value of all first characteristic monomers to obtain the temperature of the first characteristic monomer, and calculate the average temperature value of all second characteristic monomers to obtain the temperature of the second characteristic monomer.

[0099] Specifically, the average temperature value of all first characteristic monomers is calculated to obtain the temperature of the first characteristic monomer, and the average temperature value of all second characteristic monomers is calculated to obtain the temperature of the second characteristic monomer.

[0100] This embodiment relates to a specific charging and discharging control method for a power battery pack, such as... Figure 5As shown, it includes the following steps:

[0101] Step S1: Based on the actual physical location collected, number the individual cell voltages as Ucell1, Ucell2, Ucell3...UcellN, with corresponding positions as idUcell1, idUcell2, idUcell3...idUcellN;

[0102] Step S2: Use the bubble sort method to compare the voltage values ​​of adjacent elements in turn, so that the element with the larger voltage value is placed at the front of the sequence and the smaller element is gradually moved from the front to the back. Set up two loops. In each loop of the inner loop, find the smallest voltage value participating in the loop and place it at the end. In the second loop, find the second smallest voltage value and place it at the second to last position, and so on.

[0103] Step S3: Calculate the adjacent voltage differences UCellH2Ldiff1, UCellH2Ldiff2...UCellH2LdiffN-1 of the individual cell voltages arranged from largest to smallest. For example: UCellH2Ldiff1=UCellH2L(1)-UCellH2L(2), and so on.

[0104] Step S4: Calculate the average values ​​of the first N / 4 and N / 5 pressure differences, denoted as UCellH2Ldiffmaxavge1 and UCellH2Ldiffmaxavge2 respectively. Here, pressure difference thresholds Udiff1 and Udiff2 (Udiff1 < Udiff2) are set. When both UCellH2Ldiffmaxavge1 and 2 are less than Udiff1, let NUMR = M + 1. NUMR is the number of mapped cells of the largest characteristic cell. (M is usually related to the number of cells in series, and is generally selected as N / 5. To avoid large fluctuations and jumps, it should be kept at least no less than 3. The specific selection can be determined according to actual needs.) When both UCellH2Ldiffmaxavge1 and 2 are greater than Udiff2, let NUMR = M - 1. In other cases, let NUMR = M.

[0105] Step S5: Similarly, calculate the average values ​​of the N / 4 and N / 5 pressure differences, and denot them as UCellH2Ldiffminavge1 and UCellH2Ldiffminavge2, respectively. Here, pressure difference thresholds Udiff1' and Udiff2' (Udiff1' < Udiff2') are set. When both UCellH2Ldiffminavge1 and 2 are less than Udiff1', let NUMR1 = M1 + 1, where NUMR1 is the number of mapped cells of the smallest characteristic cell (M1 is usually related to the number of cells in series, and is generally selected as N / 5. To avoid large fluctuations and jumps, it should be kept at least no less than 3. The specific selection can be determined according to actual needs). When both UCellH2Ldiffminavge1 and 2 are greater than Udiff2', let NUMR1 = M1 - 1. In other cases, let NUMR1 = M1.

[0106] Step S6: Calculate the average voltage of the first NUMR bits and the average voltage of the last NUMR1 bits of the individual cell voltages UCellH2L arranged from largest to smallest, and output the voltage of the largest characteristic cell UCellmaxavge and the voltage of the smallest characteristic cell UCellminavge.

[0107] Step S7: Place a temperature sensor for every three individual battery cells. For the real-time temperature data of the individual battery cells in the power battery pack system, similarly, number the individual cell temperatures based on their actual physical location, denoted as Temp1, Temp2, Temp3...TempN / 3. Determine the nearest temperature values ​​of the X highest and Y lowest real-time individual cell voltages (the nearest temperature of individual cell Ucelli is: Temp(id / 3+1)), where id is the number of these X and Y real-time individual cell voltages. Calculate the average of the nearest temperature values ​​corresponding to the X highest and Y lowest values ​​of the individual cell voltage UCellH2L, and output the temperature of the largest characteristic cell TCellmaxavge and the temperature of the smallest characteristic cell TCellminavge. Here, X = NUMR and Y = NUMR1 can be directly set; or, when the number of temperature sensors in the power battery pack is small, X = Y = N / 5 (ensuring the minimum value is not less than 2).

[0108] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0109] This application also provides a charging and discharging control device for a power battery pack. It should be noted that the charging and discharging control device for the power battery pack in this application can be used to execute the charging and discharging control method for a power battery pack provided in this application. This device is used to implement the embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0110] The following describes the charging and discharging control device for the power battery pack provided in the embodiments of this application.

[0111] Figure 6 This is a structural block diagram of a charging and discharging control device for a power battery pack according to an embodiment of this application. Figure 6 As shown, the device includes:

[0112] The acquisition unit 10 is used to acquire the output voltage and temperature values ​​of multiple individual battery cells, sort the multiple output voltages in descending order to obtain a first output voltage sequence, and sort the multiple output voltages in ascending order to obtain a second output voltage sequence. The sequence number of the output voltage sequence corresponds one-to-one with the output voltage.

[0113] Specifically, the voltage and temperature acquisition unit detects and obtains real-time information on the voltage and temperature of individual cells in the power battery pack system, and then sends it to the control and execution unit through the communication network. After receiving the data, the control and execution unit sorts the multiple output voltages in descending order to obtain the first output voltage sequence, and sorts the multiple output voltages in ascending order to obtain the second output voltage sequence.

[0114] The determining unit 20 is configured to determine the individual cells corresponding to the output voltages in the first output voltage sequence whose serial numbers are less than or equal to the number of the first target cells as first characteristic cells, and to determine the individual cells corresponding to the output voltages in the second output voltage sequence whose serial numbers are less than or equal to the number of the second target cells as second characteristic cells, such that the difference between the minimum value of the output voltage of the first characteristic cells and the maximum value of the output voltage of the remaining individual cells is greater than a first voltage difference threshold, and the difference between the minimum value of the output voltage of the remaining individual cells and the maximum value of the output voltage of the second characteristic cells is greater than a second voltage difference threshold, wherein the remaining individual cells are individual cells other than the second characteristic cells and the second characteristic cells.

[0115] Specifically, the first N cells arranged from largest to smallest are used as the first characteristic cells, where N is the number of cells mapped to the first characteristic cells, which is the number of the first target cells. The output voltage of the Nth cell is inconsistent with the output voltage of the (N+1)th cell, meaning the difference between the minimum output voltage of the first characteristic cell and the maximum output voltage of the remaining cells is greater than the first voltage difference threshold. Similarly, the first M cells arranged from smallest to largest are used as the second characteristic cells, where M is the number of cells mapped to the second characteristic cells, which is the number of the second target cells. The output voltage of the Mth cell is inconsistent with the output voltage of the (M+1)th cell, meaning the difference between the maximum output voltage of the second characteristic cell and the minimum output voltage of the remaining cells is greater than the second voltage difference threshold.

[0116] The first calculation unit 30 is used to calculate the average value of the output voltage of all the first characteristic cells to obtain the first characteristic cell voltage, and to calculate the average value of the output voltage of all the second characteristic cells to obtain the second characteristic cell voltage.

[0117] Specifically, the average value of the output voltage of all the first characteristic cells is calculated, which is the first characteristic cell voltage. Similarly, the average value of the output voltage of all the second characteristic cells is calculated, which is the second characteristic cell voltage.

[0118] The second calculation unit 40 is used to calculate the average of the temperature values ​​of all the first characteristic monomers to obtain the temperature of the first characteristic monomer, and to calculate the average of the temperature values ​​of all the second characteristic monomers to obtain the temperature of the second characteristic monomer.

[0119] Specifically, the average temperature value of all first characteristic monomers is calculated, which is the temperature of the first characteristic monomer. Similarly, the average temperature value of all second characteristic monomers is calculated, which is the temperature of the second characteristic monomer.

[0120] The query unit 50 is used to query the charging cut-off voltage corresponding to the temperature of the first characteristic cell according to the first temperature-voltage mapping relationship, and to query the discharging cut-off voltage corresponding to the temperature of the second characteristic cell according to the second temperature-voltage mapping relationship. The first temperature-voltage mapping relationship is the mapping relationship between the charging cut-off voltage and the temperature value of the cell, and the second temperature-voltage mapping relationship is the mapping relationship between the discharging cut-off voltage and the temperature value of the cell. The charging cut-off voltage is the voltage value at the end of the charging state, and the discharging cut-off voltage is the voltage value at the end of the discharging state.

[0121] Specifically, based on the mapping relationship between charging cut-off voltage and temperature value, the charging cut-off voltage corresponding to the temperature of the first characteristic cell is queried. Similarly, based on the mapping relationship between discharging cut-off voltage and temperature value, the discharging cut-off voltage corresponding to the temperature of the second characteristic cell is queried.

[0122] The control unit 60 is configured to control the power battery pack to stop charging when the power battery pack is in the charging state and the voltage of the first characteristic cell reaches the charging cutoff voltage, or to control the power battery pack to stop discharging when the power battery pack is in the discharging state and the voltage of the second characteristic cell reaches the discharging cutoff voltage.

[0123] Specifically, when the power battery pack is in a charging state and the voltage of the first characteristic cell reaches the charging cutoff voltage, it indicates the highest voltage value reached by the power battery pack during the charging process. When the battery voltage reaches the charging cutoff voltage, the charging process will stop to avoid overcharging, which could lead to safety issues or damage to the battery. Similarly, when the power battery pack is in a discharging state and the voltage of the second characteristic cell reaches the discharging cutoff voltage, it indicates the lowest voltage value reached by the power battery pack during the discharging process. When the battery voltage reaches the discharging cutoff voltage, the discharging process will stop to protect the battery from over-discharge and damage.

[0124] In this embodiment, an acquisition unit is used to acquire the output voltage and temperature values ​​of multiple individual battery cells, sort the multiple output voltages in descending order to obtain a first output voltage sequence, and sort the multiple output voltages in ascending order to obtain a second output voltage sequence, with the sequence number of the output voltage sequence corresponding one-to-one with the output voltage; a determination unit is used to determine the individual battery cells corresponding to the output voltages in the first output voltage sequence whose sequence number is less than or equal to the number of the first target battery cells as first characteristic cells, and to determine the individual battery cells corresponding to the output voltages in the second output voltage sequence whose sequence number is less than or equal to the number of the second target battery cells as second characteristic cells, such that the difference between the minimum value of the output voltage of the first characteristic cells and the maximum value of the output voltage of the remaining individual battery cells is greater than a first voltage difference threshold, and the difference between the minimum value of the output voltage of the remaining individual battery cells and the maximum value of the output voltage of the second characteristic cells is greater than a second voltage difference threshold, and the remaining individual battery cells are individual battery cells other than the second characteristic cells; a first calculation unit is used to calculate the average value of the output voltages of all the first characteristic cells to obtain the first characteristic cell voltage, and calculate... The system calculates the average output voltage of all second-characteristic cells to obtain the voltage of the second-characteristic cell; a second calculation unit calculates the average temperature value of all first-characteristic cells to obtain the temperature of the first-characteristic cell, and calculates the average temperature value of all second-characteristic cells to obtain the temperature of the second-characteristic cell; a query unit queries the charging cut-off voltage corresponding to the temperature of the first-characteristic cell according to the first temperature-voltage mapping relationship, and queries the discharging cut-off voltage corresponding to the temperature of the second-characteristic cell according to the second temperature-voltage mapping relationship. The first temperature-voltage mapping relationship is the mapping relationship between the charging cut-off voltage and the temperature value of the individual cell, and the second temperature-voltage mapping relationship is the mapping relationship between the discharging cut-off voltage and the temperature value of the individual cell. The charging cut-off voltage is the voltage value at the end of the charging state, and the discharging cut-off voltage is the voltage value at the end of the discharging state; a control unit controls the power battery pack to stop charging when the power battery pack is in the charging state and the voltage of the first-characteristic cell reaches the charging cut-off voltage, or controls the power battery pack to stop discharging when the power battery pack is in the discharging state and the voltage of the second-characteristic cell reaches the discharging cut-off voltage. This application monitors the output voltage and temperature of all individual battery cells in real time, and arranges the output voltages sequentially. The maximum characteristic cell voltage level is mapped based on the average value of adjacent cells with an output voltage difference less than the voltage difference threshold in the sorted large-end portion, and the minimum characteristic cell voltage level is mapped based on the average value of adjacent cells with an output voltage difference less than the voltage difference threshold in the sorted small-end portion. At the same time, the temperature of the characteristic cells is calculated, achieving the effect of real-time updating and effective online estimation of the core functions of the power battery pack, and solving the problem of high computational load.

[0125] To improve computational efficiency, in one optional implementation, the acquisition unit further includes:

[0126] The first numbering module assigns numbers to multiple individual battery cells according to their arrangement order, resulting in multiple first numbers, each corresponding to a single individual battery cell. Specifically, the individual battery cells are numbered based on their physical location at the point where the actual output voltage is collected.

[0127] The first sorting module sorts the output voltages of all the aforementioned individual battery cells in descending order to obtain the aforementioned first output voltage sequence, such that the sequence number of the aforementioned first output voltage sequence corresponds one-to-one with the aforementioned first number; specifically, the sorting of the output voltages of all the aforementioned individual battery cells in descending order to obtain the aforementioned first output voltage sequence, and the sorting method used includes, but is not limited to, bubble sort, selection sort, and other methods that can achieve size sorting.

[0128] The second sorting module sorts the output voltages of all the aforementioned individual battery cells in ascending order to obtain the second output voltage sequence, such that the sequence number of the second output voltage sequence corresponds one-to-one with the first number. Specifically, the second output voltage sequence is obtained by sorting the output voltages of all the aforementioned individual battery cells in descending order. The sorting method includes, but is not limited to, bubble sort, selection sort, and other methods that can achieve size sorting.

[0129] To ensure the consistency of the first characteristic unit, in an optional embodiment, the device further includes, before determining the unit:

[0130] The third calculation unit is used to calculate the voltage difference between two output voltages in all adjacent output voltage groups of the first output voltage sequence in descending order of the serial number before determining the single cell corresponding to the output voltage with a serial number less than or equal to the number of the first target cells in the first output voltage sequence as the first characteristic single cell. The first voltage difference sequence includes two output voltages and the serial numbers of the two first output voltages are adjacent. The first voltage difference sequence includes multiple first voltage differences, and the first voltage difference corresponds one-to-one with the adjacent output voltage groups. Specifically, the adjacent voltage differences of the single cell voltages arranged in descending order are calculated and denoted as UCellH2Ldiff1, UCellH2Ldiff2...UCellH2LdiffN-1. For example, UCellH2Ldiff1=UCellH2L(1)-UCellH2L(2), and so on, so that all the adjacent voltage differences can be obtained. That is, the voltage difference between two output voltages in all adjacent output voltage groups of the first output voltage sequence is calculated to obtain the first voltage difference sequence.

[0131] The first setting unit sets a first calculation quantity and a second calculation quantity, with the difference between the first calculation quantity and the second calculation quantity being 1. Specifically, in order to avoid calculating the average adjacent voltage difference of all individual cells, it is necessary to first set two calculation quantities to determine the number of individual cells whose average adjacent voltage difference needs to be calculated, denoted as x1 and x2, which are the first calculation quantity and the second calculation quantity.

[0132] The fourth calculation unit is used to perform the first calculation step, calculate the average value of the output voltages whose serial numbers are less than or equal to the first calculation quantity in the first voltage difference sequence, and obtain the first voltage difference average value; specifically, calculate the average value of the first x1 adjacent voltage differences, which is the first voltage difference average value.

[0133] The fifth calculation unit is used to perform the second calculation step, calculate the average value of the output voltages whose serial numbers are less than or equal to the second calculation quantity in the first voltage difference sequence, and obtain the second voltage difference average value; specifically, calculate the average value of the first x2 adjacent voltage differences, which is the second voltage difference average value.

[0134] The first adjustment unit is used to perform the first adjustment step. Under the condition that the first calculation quantity and the second calculation quantity are both increased by one, the first condition is that the average value of the first voltage difference and the average value of the second voltage difference are both less than the third voltage difference threshold. Specifically, when the average value of the first voltage difference and the average value of the second voltage difference are both less than the third voltage difference threshold, it means that the voltage consistency of the individual cells is very good and can reflect the charging level of the power battery pack. Then, the first calculation quantity and the second calculation quantity are both increased by one to further filter out more individual cells that can reflect the charging level of the power battery pack.

[0135] The second adjustment unit is used to execute the second adjustment step. Under the condition that the first calculation quantity and the second calculation quantity are both reduced by one, the second condition is that the average value of the first voltage difference and the average value of the second voltage difference are both greater than the fourth voltage difference threshold, and the third voltage difference threshold is less than the fourth voltage difference threshold. Specifically, when the average value of the first voltage difference and the average value of the second voltage difference are both greater than the fourth voltage difference threshold, it means that the voltage consistency of the individual cells is very poor and cannot reflect the charging level of the power battery pack. Therefore, the first calculation quantity and the second calculation quantity are both reduced by one so as to find multiple individual cells that can reflect the charging level of the power battery pack.

[0136] The second determining unit is used to execute the first determining step, and determine the first calculated quantity as the first target number of cells if neither the first condition nor the second condition is met. Specifically, if the first voltage difference average value and the second voltage difference average value are both greater than the fourth voltage difference threshold and the first voltage difference average value and the second voltage difference average value are both greater than the fourth voltage difference threshold, it indicates that multiple individual cells that can map the charging level of the power battery pack have been found.

[0137] To improve the screening and updating efficiency of the first feature monomer, in an optional embodiment, after the first adjustment unit or the second adjustment unit, the device further includes:

[0138] The first repeating unit repeats the first calculation step, the second calculation step, the first adjustment step, the second adjustment step, and the first determination step at least once in sequence until the first target number of cells is obtained. Specifically, the first calculation step, the second calculation step, the first adjustment step, the second adjustment step, and the first determination step are repeated continuously. When the difference between the minimum value of the output voltage of the first characteristic cell and the maximum value of the output voltage of the remaining cell is greater than the first voltage difference threshold, the number of the first characteristic cells that meet the requirements is found, that is, the number of the first target number of cells.

[0139] To ensure the consistency of the second characteristic monomer, in one optional embodiment, the device further includes, before determining the unit:

[0140] The sixth calculation unit is used to calculate the voltage difference between two output voltages in all adjacent output voltage groups of the second output voltage sequence in ascending order of serial number before determining the single cell corresponding to the output voltage with serial number less than or equal to the number of the first target cells in the first output voltage sequence as the first characteristic single cell. The second voltage difference sequence includes two output voltages and the serial numbers of the two second output voltages are adjacent. The second voltage difference sequence includes multiple second voltage differences, and the second voltage differences correspond one-to-one with the adjacent output voltage groups. Specifically, the adjacent voltage differences of the single cell voltages are calculated in ascending order and denoted as UCellH2Ldiff1', UCellH2Ldiff2'...UCellH2Ldiff(N-1)'. For example, UCellH2Ldiff1'=UCellH2L(1)'-UCellH2L(2)', and so on, so that all the adjacent voltage differences can be obtained. That is, the voltage difference between two output voltages in all adjacent output voltage groups of the second output voltage sequence is calculated in ascending order to obtain the second voltage difference sequence.

[0141] The second setting unit is used to set the third calculation quantity and the fourth calculation quantity, and the difference between the third calculation quantity and the fourth calculation quantity is 1. Specifically, in order not to calculate the average adjacent voltage difference of all individual cells, it is necessary to first set two calculation quantities to determine the number of individual cells whose average adjacent voltage difference needs to be calculated, denoted as y1 and y2, which are the third calculation quantity and the fourth calculation quantity.

[0142] The seventh calculation unit is used to perform the third calculation step, calculate the average value of the output voltages in the second voltage difference sequence whose serial number is less than or equal to the third calculation quantity, and obtain the third voltage difference average value; specifically, calculate the average value of the first y1 adjacent voltage differences, which is the third voltage difference average value.

[0143] The eighth calculation unit is used to perform the fourth calculation step, calculate the average value of the output voltages in the second voltage difference sequence whose serial number is less than or equal to the fourth calculation quantity, and obtain the fourth voltage difference average value; specifically, calculate the average value of the first y2 adjacent voltage differences, which is the fourth voltage difference average value.

[0144] The third adjustment unit is used to execute the third adjustment step. Under the condition that the third calculation quantity and the fourth calculation quantity are both increased by one, the third condition is that the average value of the third voltage difference and the average value of the fourth voltage difference are both less than the fifth voltage difference threshold. Specifically, when the average value of the third voltage difference and the average value of the fourth voltage difference are both less than the fifth voltage difference threshold, it means that the voltage consistency of the individual cells is very good and can reflect the discharge level of the power battery pack. Then, the third calculation quantity and the fourth calculation quantity are both increased by one to further screen out more individual cells that can reflect the discharge level of the power battery pack.

[0145] The fourth adjustment unit is used to execute the fourth adjustment step. Under the condition that the fourth condition is met, the number of calculations in the third and fourth calculations is reduced by one. The fourth condition is that the average value of the third voltage difference and the average value of the fourth voltage difference are both greater than the sixth voltage difference threshold, and the fifth voltage difference threshold is less than the sixth voltage difference threshold. Specifically, when the average value of the third voltage difference and the average value of the fourth voltage difference are both greater than the sixth voltage difference threshold, it means that the voltage consistency of the individual cells is very poor and cannot reflect the discharge level of the power battery pack. Therefore, the number of calculations in the first and second calculations is reduced by one so as to find multiple individual cells that can reflect the discharge level of the power battery pack.

[0146] The third confirmation unit is used to perform the determination step. If the third condition and the fourth condition are not met, the third calculated quantity is determined to be the second target cell quantity. Specifically, if the third voltage difference average value and the fourth voltage difference average value are not both greater than the fifth voltage difference threshold and the third voltage difference average value and the fourth voltage difference average value are not both greater than the sixth voltage difference threshold, it indicates that multiple individual cells that can map the discharge level of the power battery pack have been found.

[0147] To improve the screening and updating efficiency of the second feature monomer, in an optional embodiment, after the third or fourth adjustment unit, the device further includes:

[0148] The second repeating unit repeats the third calculation step, the fourth calculation step, the third adjustment step, the fourth adjustment step, and the second determination step at least once in sequence until the second target number of cells is obtained. Specifically, the third calculation step, the fourth calculation step, the third adjustment step, the fourth adjustment step, and the second determination step are repeated continuously. When the difference between the maximum value of the output voltage of the second characteristic cell and the minimum value of the output voltage of the remaining cell is greater than the second voltage difference threshold, the number of second characteristic cells that meet the requirements is found, that is, the number of second target cells.

[0149] To improve the safety of a single battery cell, in one optional implementation, the second computing unit further includes...

[0150] The grouping module groups multiple individual battery cells into multiple individual battery cell groups, such that each individual battery cell group corresponds to a temperature sensor. Each individual battery cell group includes one or more adjacent individual battery cells, and the temperature sensor is used to collect the temperature of the corresponding individual battery cell group. Specifically, multiple individual battery cells are grouped into multiple individual battery cell groups, and each individual battery cell group includes one or more adjacent individual battery cells. Each individual battery cell group is equipped with a temperature sensor to collect the temperature of the corresponding individual battery cell group.

[0151] The second numbering module numbers multiple temperature sensors according to their arrangement order, resulting in multiple second numbers, each corresponding to a temperature sensor. Specifically, multiple temperature sensors are numbered according to their arrangement order to obtain multiple second numbers, each corresponding to a specific temperature sensor.

[0152] The first determining module determines multiple first target numbers based on the first number of each first characteristic cell. The first target number is the second number corresponding to the cell group to which the first characteristic cell is located. The module also determines the temperature detected by the temperature sensor corresponding to each first target number as the temperature value of the corresponding first characteristic cell. Specifically, based on the first number of the first characteristic cell, multiple first target numbers are determined. The first target number is the second number corresponding to the cell group to which the first characteristic cell is located. The module also determines the temperature detected by the temperature sensor corresponding to each first target number as the temperature value of the corresponding first characteristic cell.

[0153] The second determining module determines multiple second target numbers based on the first number of each second characteristic cell. Each second target number corresponds to the second number of the cell group to which the second characteristic cell belongs. The module then determines the temperature detected by the temperature sensor corresponding to each second target number as the temperature value of the corresponding second characteristic cell. Specifically, multiple second target numbers are determined based on the first number of the second characteristic cell. The second target number corresponds to the second number of the cell group to which the second characteristic cell belongs, and the temperature detected by the temperature sensor corresponding to each second target number is determined as the temperature value of the corresponding second characteristic cell.

[0154] The calculation module calculates the average temperature value of all first characteristic cells to obtain the temperature of the first characteristic cell, and calculates the average temperature value of all second characteristic cells to obtain the temperature of the second characteristic cell. Specifically, it calculates the average temperature value of all first characteristic cells to obtain the temperature of the first characteristic cell, and calculates the average temperature value of all second characteristic cells to obtain the temperature of the second characteristic cell.

[0155] The charging and discharging control device for the power battery pack includes a processor and a memory. Acquisition units, determination units, and first calculation units are all stored as program units in the memory. The processor executes these program units to achieve the corresponding functions. Modules can all reside in the same processor; alternatively, modules can be located in different processors in any combination.

[0156] A processor contains a kernel, which retrieves the corresponding program units from memory. One or more kernels can be configured, and the problem of high computational load can be addressed by adjusting kernel parameters.

[0157] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0158] This invention provides a computer-readable storage medium including a stored program, wherein the program controls the device containing the computer-readable storage medium to perform a charging and discharging control method for a power battery pack when it is running.

[0159] This invention provides a power battery pack, which includes a single battery cell, a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, it is suitable for executing a charging and discharging control method for the power battery pack.

[0160] This application also provides a computer program product that, when executed on a data processing device, is suitable for performing a charging and discharging control method for a power battery pack.

[0161] It is obvious to those skilled in the art that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those described herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0162] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0163] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0164] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0165] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0166] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0167] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0168] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0169] 1) The charging and discharging control method of the power battery pack in this application monitors the output voltage and temperature of all individual cells in real time, and arranges the output voltages in order. The maximum characteristic cell voltage level is mapped based on the average value of the adjacent output voltage difference of the large-end portion of the sorted cells that is less than the voltage difference threshold, and the minimum characteristic cell voltage level is mapped based on the average value of the adjacent output voltage difference of the small-end portion of the sorted cells that is less than the voltage difference threshold. At the same time, the temperature of the characteristic cells is calculated, which achieves the effect of real-time updating and effective online estimation of the core functions of the power battery pack, and solves the problem of large computational load.

[0170] 2) The charging and discharging control device for the power battery pack of this application monitors the output voltage and temperature of all individual cells in real time, and arranges the output voltages in order. The average value of the adjacent output voltage difference of the sorted large-end portion of individual cells that is less than the voltage difference threshold is used to map the voltage level of the largest characteristic cell, and the average value of the adjacent output voltage difference of the sorted small-end portion of individual cells that is less than the voltage difference threshold is used to map the voltage level of the smallest characteristic cell. At the same time, the temperature of the characteristic cells is calculated, which achieves the effect of real-time updating and effective online estimation of the core functions of the power battery pack, and solves the problem of large computational load.

[0171] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A charging and discharging control method for a power battery pack, characterized in that, The power battery pack includes multiple individual battery cells, and the method includes: The output voltage and temperature values ​​of multiple individual battery cells are obtained, and the multiple output voltages are sorted in descending order to obtain a first output voltage sequence. The multiple output voltages are sorted in ascending order to obtain a second output voltage sequence. The sequence number of the output voltage sequence corresponds one-to-one with the output voltage. The individual cells corresponding to the output voltages in the first output voltage sequence whose serial numbers are less than or equal to the first target cell quantity are identified as first characteristic cells. The individual cells corresponding to the output voltages in the second output voltage sequence whose serial numbers are less than or equal to the second target cell quantity are identified as second characteristic cells. The first target cell quantity is such that the difference between the minimum output voltage of the first characteristic cell and the maximum output voltage of the remaining individual cells is greater than a first voltage difference threshold. The second target cell quantity is such that the difference between the minimum output voltage of the remaining individual cells and the maximum output voltage of the second characteristic cell is greater than a second voltage difference threshold. The remaining individual cells are individual cells other than the first and second characteristic cells. The average value of the output voltages of all the first characteristic cells is calculated to obtain the first characteristic cell voltage, and the average value of the output voltages of all the second characteristic cells is calculated to obtain the second characteristic cell voltage. Calculate the average of the temperature values ​​of all the first characteristic monomers to obtain the temperature of the first characteristic monomer, and calculate the average of the temperature values ​​of all the second characteristic monomers to obtain the temperature of the second characteristic monomer; The charging cutoff voltage corresponding to the temperature of the first characteristic cell is queried according to the first temperature-voltage mapping relationship, and the discharging cutoff voltage corresponding to the temperature of the second characteristic cell is queried according to the second temperature-voltage mapping relationship. The first temperature-voltage mapping relationship is the mapping relationship between the charging cutoff voltage and the temperature value of the single cell, and the second temperature-voltage mapping relationship is the mapping relationship between the discharging cutoff voltage and the temperature value of the single cell. The charging cutoff voltage is the voltage value at the end of the charging state, and the discharging cutoff voltage is the voltage value at the end of the discharging state. When the power battery pack is in the charging state and the voltage of the first characteristic cell reaches the charging cutoff voltage, the power battery pack is controlled to stop charging; or, when the power battery pack is in the discharging state and the voltage of the second characteristic cell reaches the discharging cutoff voltage, the power battery pack is controlled to stop discharging.

2. The method according to claim 1, characterized in that, Before determining the individual cell corresponding to the output voltage whose sequence number is less than or equal to the number of the first target cells in the first output voltage sequence as the first characteristic cell, the method further includes: According to the order of the serial numbers from largest to smallest, the voltage difference between two output voltages in all adjacent output voltage groups of the first output voltage sequence is calculated sequentially to obtain the first voltage difference value sequence. The adjacent output voltage group includes two output voltages and the serial numbers of the two first output voltages are adjacent. The first voltage difference value sequence includes multiple first voltage differences, and the first voltage difference value corresponds one-to-one with the adjacent output voltage group. Set a first calculation quantity and a second calculation quantity, with the difference between the first calculation quantity and the second calculation quantity being 1; The first calculation step is to calculate the average value of the output voltages whose serial numbers are less than or equal to the first calculated quantity in the first voltage difference sequence, and obtain the first average voltage difference. The second calculation step is to calculate the average value of the output voltages whose serial numbers are less than or equal to the second calculated quantity in the first voltage difference sequence, and obtain the second average voltage difference. The first adjustment step is to increase both the first calculation quantity and the second calculation quantity by one if the first condition is met. The first condition is that the average value of the first voltage difference and the average value of the second voltage difference are both less than the third voltage difference threshold. The second adjustment step is to reduce both the first calculation quantity and the second calculation quantity by one when the second condition is met. The second condition is that the average value of the first voltage difference and the average value of the second voltage difference are both greater than the fourth voltage difference threshold, and the third voltage difference threshold is less than the fourth voltage difference threshold. The first determining step is to determine the first calculated quantity as the first target cell quantity if neither the first condition nor the second condition is met.

3. The method according to claim 2, characterized in that, After increasing both the first calculation quantity and the second calculation quantity by one, or after decreasing both the first calculation quantity and the second calculation quantity by one, the method further includes: Repeat the first calculation step, the second calculation step, the first adjustment step, the second adjustment step, and the first determination step at least once in sequence until the first target number of battery cells is obtained.

4. The method according to claim 1, characterized in that, Before determining the individual cell corresponding to the output voltage whose sequence number is less than or equal to the number of the second target cells in the second output voltage sequence as the second characteristic cell, the method further includes: According to the sequence number in ascending order, the voltage difference between two output voltages in all adjacent output voltage groups of the second output voltage sequence is calculated sequentially to obtain the second voltage difference sequence. The adjacent output voltage group includes two output voltages and the sequence numbers of the two second output voltages are adjacent. The second voltage difference sequence includes multiple second voltage differences, and the second voltage difference corresponds one-to-one with the adjacent output voltage group. Set a third calculation quantity and a fourth calculation quantity, wherein the difference between the third calculation quantity and the fourth calculation quantity is 1; The third calculation step is to calculate the average value of the output voltages whose serial numbers in the second voltage difference sequence are less than or equal to the third calculation quantity, and obtain the third average voltage difference. The fourth calculation step is to calculate the average value of the output voltages whose serial numbers in the second voltage difference sequence are less than or equal to the fourth calculation quantity, and obtain the fourth average voltage difference value. The third adjustment step is to increase both the third calculation quantity and the fourth calculation quantity by one if the third condition is met. The third condition is that both the average value of the third voltage difference and the average value of the third voltage difference are less than the fifth voltage difference threshold. The fourth adjustment step is to reduce both the third and fourth calculation quantities by one if the fourth condition is met. The fourth condition is that both the average value of the third voltage difference and the average value of the fourth voltage difference are greater than the sixth voltage difference threshold, and the fifth voltage difference threshold is less than the sixth voltage difference threshold. The second determining step is to determine the third calculated quantity as the second target cell quantity if neither the third nor the fourth condition is met.

5. The method according to claim 4, characterized in that, After increasing both the third and fourth calculation quantities by one, or after decreasing both the third and fourth calculation quantities by one, the method further includes: Repeat the third calculation step, the fourth calculation step, the third adjustment step, the fourth adjustment step, and the second determination step at least once in sequence until the second target number of battery cells is obtained.

6. The method according to claim 1, characterized in that, The multiple output voltages are sorted in descending order to obtain a first output voltage sequence, and the multiple output voltages are sorted in ascending order to obtain a second output voltage sequence. The sequence number of each output voltage corresponds one-to-one with the output voltage, including: The individual battery cells are numbered according to their arrangement order to obtain multiple first numbers, and each first number corresponds one-to-one with an individual battery cell. The output voltages of all the individual battery cells are sorted in descending order to obtain the first output voltage sequence, such that the sequence number of the first output voltage sequence corresponds one-to-one with the first number. The output voltages of all the individual battery cells are sorted in ascending order to obtain the second output voltage sequence, such that the sequence number of the second output voltage sequence corresponds one-to-one with the first number.

7. The method according to claim 6, characterized in that, Calculating the average of the temperature values ​​of all the first characteristic monomers to obtain the temperature of the first characteristic monomer, and calculating the average of the temperature values ​​of all the second characteristic monomers to obtain the temperature of the second characteristic monomer, including: Multiple individual battery cells are grouped to obtain multiple individual battery cell groups, such that one individual battery cell group corresponds to one temperature sensor. The individual battery cell group includes one individual battery cell or multiple adjacent individual battery cells, and the temperature sensor is used to collect the temperature of the corresponding individual battery cell group. The multiple temperature sensors are numbered according to their arrangement order to obtain multiple second numbers, and each second number corresponds one-to-one with a temperature sensor. Multiple first target numbers are determined based on the first number of each first feature cell, where the first target number is the second number corresponding to the cell group to which the first feature cell is located, and the detected temperature of the temperature sensor corresponding to each first target number is determined as the temperature value of each first feature cell. Multiple second target numbers are determined based on the first number of each second characteristic cell, where the second target number is the second number corresponding to the cell group to which the second characteristic cell is located, and the detection temperature of the temperature sensor corresponding to each second target number is determined as the temperature value of each second characteristic cell. The average temperature of all the first characteristic monomers is calculated to obtain the temperature of the first characteristic monomer, and the average temperature of all the second characteristic monomers is calculated to obtain the temperature of the second characteristic monomer.

8. A charging and discharging control device for a power battery pack, characterized in that, The power battery pack includes multiple individual battery cells, and the device includes: The acquisition unit is used to acquire the output voltage and temperature values ​​of multiple individual battery cells, sort the multiple output voltages in descending order to obtain a first output voltage sequence, and sort the multiple output voltages in ascending order to obtain a second output voltage sequence, wherein the sequence number of the output voltage sequence corresponds one-to-one with the output voltage; A determining unit is configured to determine the individual cells corresponding to the output voltages in the first output voltage sequence whose serial numbers are less than or equal to the number of the first target cells as first characteristic cells, and to determine the individual cells corresponding to the output voltages in the second output voltage sequence whose serial numbers are less than or equal to the number of the second target cells as second characteristic cells, such that the difference between the minimum value of the output voltage of the first characteristic cell and the maximum value of the output voltage of the remaining individual cells is greater than a first voltage difference threshold, and the difference between the minimum value of the output voltage of the remaining individual cells and the maximum value of the output voltage of the second characteristic cell is greater than a second voltage difference threshold, wherein the remaining individual cells are individual cells other than the first characteristic cells and the second characteristic cells; The first calculation unit is used to calculate the average value of the output voltage of all the first feature cells to obtain the first feature cell voltage, and to calculate the average value of the output voltage of all the second feature cells to obtain the second feature cell voltage. The second calculation unit is used to calculate the average of the temperature values ​​of all the first feature cells to obtain the temperature of the first feature cell, and to calculate the average of the temperature values ​​of all the second feature cells to obtain the temperature of the second feature cell. The query unit is used to query the charging cut-off voltage corresponding to the temperature of the first characteristic cell according to the first temperature-voltage mapping relationship, and to query the discharging cut-off voltage corresponding to the temperature of the second characteristic cell according to the second temperature-voltage mapping relationship. The first temperature-voltage mapping relationship is the mapping relationship between the charging cut-off voltage and the temperature value of the cell, and the second temperature-voltage mapping relationship is the mapping relationship between the discharging cut-off voltage and the temperature value of the cell. The charging cut-off voltage is the voltage value at the end of the charging state, and the discharging cut-off voltage is the voltage value at the end of the discharging state. The control unit is configured to control the power battery pack to stop charging when the power battery pack is in the charging state and the voltage of the first characteristic cell reaches the charging cutoff voltage, or to control the power battery pack to stop discharging when the power battery pack is in the discharging state and the voltage of the second characteristic cell reaches the discharging cutoff voltage.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 7.

10. A power battery pack, characterized in that, include: A single battery cell, one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing any one of claims 1 to 7.

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