A battery system charging and discharging method and device

Abstract

The present application relates to the technical field of battery, especially to a battery system charging and discharging method and device, wherein the battery system comprises a voltage control module, a battery management module and N battery cells, the battery management module is used for monitoring the voltage of each battery cell, the voltage control module is connected with the charging and discharging interface of the battery system, the method comprises the following steps: obtaining the voltage of each battery cell through the battery management module; determining a target battery cell based on the voltage of each battery cell, the target battery cell is the battery cell with the highest voltage or the battery cell with the lowest voltage; generating a control strategy based on the target battery cell; charging or discharging the target battery cell based on the control strategy, so as to maximize the charging capacity of the battery system or maximize the discharging capacity of the battery system, finally the optimal power utilization efficiency can be realized and the cruising range of the vehicle can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery system charging and discharging method and device. BACKGROUND

[0002] The battery system combines a plurality of battery cells in series or in parallel, but is subject to production and manufacturing process tolerance level and raw material physical state, so that there are capacity differences, voltage differences, internal resistance differences, etc. between the battery cells of the battery system, and then in the charging process of the battery system, the voltage rising speed of the battery cells is different, for example, the voltage of some or one battery cell reaches the upper limit cut-off voltage first, while the voltage of other battery cells does not reach the cut-off voltage at this time, which leads to that these battery cells do not reach the specified charging capacity; at this time, the state of charge (SOC) levels of the battery cells are inconsistent, and the battery management system will correct the state of charge of each battery cell, and the state of charge of the battery system after correction will be between the highest state of charge of the battery cells and the lowest state of charge of the battery cells.

[0003] When discharging the battery system, the voltage drop rate of the battery cells is also different, for example, the voltage of some or one battery cell drops quickly, so the state of charge corresponding to these or this battery cell will be lower than that of other battery cells, and the depth of discharge (DOD) is determined by ampere-hour integration during the discharging process, which leads to that other battery cells do not discharge the specified capacity.

[0004] Therefore, due to the consistency problem between the battery cells, the battery system does not exert its maximum performance level, in addition, the temperature at different positions in the battery system is different, and with the increase of the number of cycles, the aging process of each battery cell is also different, which also causes the inconsistency problem between the battery cells.

[0005] How to avoid the safety hazard caused by the inconsistency problem is a technical problem to be solved at present. SUMMARY

[0006] In view of the above problems, the present application is proposed in order to provide a battery system charging and discharging method and device which overcomes the above problems or at least partially solves the above problems.

[0007] In a first aspect, the present application provides a battery system charging and discharging method, the battery system comprising a voltage control module, a battery management module and N battery cells, the battery management module being used to monitor the voltage of each battery cell, and the voltage control module being connected to the charging and discharging interface of the battery system and comprising:

[0008] obtaining the voltage of each battery cell through the battery management module;

[0009] determining a target cell based on the voltage of each cell, the target cell being the cell with the highest voltage or the cell with the lowest voltage, the target cell being one or more;

[0010] generating a control strategy based on the target cell;

[0011] charging or discharging the target cell based on the control strategy to maximize the amount of electricity charged into the battery system or the amount of electricity discharged from the battery system.

[0012] Further, the generating a control strategy based on the target cell comprises:

[0013] when charging the battery system, the target cell being the cell with the highest voltage, generating a first charging control strategy.

[0014] Further, the charging or discharging the target cell based on the control strategy to maximize the amount of electricity charged into the battery system or the amount of electricity discharged from the battery system comprises:

[0015] discharging the target cell by a preset amount of electricity based on the first charging control strategy, and then controlling the charging of the N cells of the battery system as a whole to maximize the amount of electricity charged into the battery system.

[0016] Further, the generating a control strategy based on the target cell comprises:

[0017] when charging the battery system, the target cell being the cell with the highest voltage, generating a second charging control strategy.

[0018] Further, the charging or discharging the target cell based on the control strategy to maximize the amount of electricity charged into the battery system or the amount of electricity discharged from the battery system comprises:

[0019] charging the cells other than the target cell in the battery system based on the second charging control strategy, and then charging the N cells of the battery system as a whole after a first preset time period to maximize the amount of electricity charged into the battery system.

[0020] Further, the generating a control strategy based on the target cell comprises:

[0021] when discharging the battery system, the target cell being the cell with the lowest voltage, generating a discharging control strategy.

[0022] Further, the charging or discharging of the target battery cell based on the control strategy maximizes the charging or discharging of the battery system.

[0023] Based on the discharging control strategy, the other battery cells in the battery system except the target battery cell are discharged, and after a second preset time, the N battery cells in the battery system are discharged simultaneously to maximize the discharging of the battery system.

[0024] In a second aspect, the present application further provides a battery system charging and discharging device, the battery system comprising N battery cells, a voltage control module and a battery management module, the battery management module being used to monitor the voltage of each battery cell, the voltage control module being connected to the charging and discharging interface of the battery system, comprising:

[0025] The acquisition module is used to acquire the voltage of each battery cell through the battery management module.

[0026] The determination module is used to determine a target battery cell based on the voltage of each battery cell, the target battery cell being the battery cell with the highest voltage or the battery cell with the lowest voltage.

[0027] The generation module is used to generate a control strategy based on the target battery cell.

[0028] The control module is used to charge or discharge the target battery cell based on the control strategy to maximize the charging or discharging of the battery system.

[0029] The one or more technical solutions in the embodiments of the present application have at least the following technical effects or advantages:

[0030] The present application provides a battery system charging and discharging method, wherein the battery system comprises a voltage control module, a battery management module and N battery cells, the battery management module being used to monitor the voltage of each battery cell, the voltage control module being connected to the charging and discharging interface of the battery system, the method comprising: acquiring the voltage of each battery cell through the battery management module; determining a target battery cell based on the voltage of each battery cell, the target battery cell being the battery cell with the highest voltage or the battery cell with the lowest voltage; generating a control strategy based on the target battery cell; charging or discharging the target battery cell based on the control strategy to maximize the charging or discharging of the battery system, so as to finally achieve the optimal utilization efficiency of electric energy and improve the cruising range of the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0031] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments with reference made to the accompanying drawings. The drawings are for purposes of illustration only and are not intended to limit the present application thereto, as the present application can have additional forms that fall within the scope of the same. Like reference numerals indicate like elements throughout the following figures. In the drawings:

[0032] Figure 1 A schematic diagram of a step flow of the battery system charging and discharging method in the embodiment of the present application is shown;

[0033] Figure 2 A schematic diagram of the structure of the battery system charging and discharging device in the embodiment of the present application is shown;

[0034] Figure 3 A schematic diagram of the structure of the vehicle in the embodiment of the present application is shown. DETAILED DESCRIPTION

[0035] Exemplary embodiments of the present disclosure will be described herein below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0036] Embodiment One

[0037] The embodiment of the present application provides a battery system charging and discharging method, the battery system comprising a voltage control module, a battery management module and N battery cells, the battery management module being configured to monitor the voltage of each battery cell, and the voltage control module being connected to the charging and discharging interface of the battery system, as shown in Figure 1 The method comprises:

[0038] S101, acquiring the voltage of each battery cell by the battery management module;

[0039] S102, determining a target battery cell based on the voltage of each battery cell, the target battery cell being the battery cell with the highest voltage or the battery cell with the lowest voltage, and the target battery cell being one or more;

[0040] S103, generating a control strategy based on the target battery cell;

[0041] S104, charging or discharging the target battery cell based on the control strategy, so as to maximize the charging amount of the battery system or maximize the discharging amount of the battery system.

[0042] First, the voltage of each battery cell is acquired in S101 by the battery management module, which can monitor the voltage value of each battery cell in real time.

[0043] Next, after determining the voltage of each battery cell, S102, based on the voltage of each battery cell, a target battery cell is determined, which is the battery cell with the highest voltage or the battery cell with the lowest voltage, and the target battery cell is one or more.

[0044] After determining the voltage of each battery cell, the battery cell with the highest voltage is determined therefrom as the target battery cell, or the battery cell with the lowest voltage is determined therefrom as the target battery cell.

[0045] Next, S103 is performed, and a control strategy is generated based on the target battery cell.

[0046] In a specific embodiment, different control strategies are generated for the charging state and the discharging state of the battery system.

[0047] When charging the battery system, the target battery cell is the battery cell with the highest voltage, and a first charging control strategy is generated.

[0048] The first charging control strategy is described in detail below:

[0049] Based on the first charging control strategy, the target battery cell is discharged by a preset amount of electricity, and then the N battery cells of the battery system are collectively charged to maximize the amount of electricity charged into the battery system.

[0050] For example, the battery system has 10 battery cells, and the battery cell with the highest voltage is battery cell No. 1, and the voltages of the other battery cells are different but are all less than the voltage of battery cell No. 1. First, battery cell No. 1 with the highest voltage is discharged, specifically by a preset amount of electricity. After battery cell No. 1 is discharged by the preset amount of electricity, the voltage of battery cell No. 1 is comparable to the voltages of the remaining battery cells, specifically, the voltage difference between battery cell No. 1 and the other battery cells can be ensured to be within a preset range, such as 40 mV.

[0051] Of course, the target battery cell can also be multiple, which will not be described in detail here.

[0052] Next, the 10 battery cells of the battery system are collectively charged, so that in the case where battery cell No. 1 with the highest voltage is fully charged, the other battery cells that are not fully charged also stop charging, so that the amount of electricity charged cannot reach the specified charging amount, and by first discharging the battery cell with the highest voltage to be comparable to the voltages of the other battery cells, the amount of electricity charged is maximized.

[0053] On the other hand, when charging the battery system, the target battery cell is the battery cell with the highest voltage, and a second charging control strategy is generated.

[0054] The second charging control strategy is described in detail below:

[0055] Based on the second charging control strategy, the other cells in the battery system except the target cell are charged, and after a first preset time, the N cells in the battery system are charged simultaneously to maximize the charging capacity of the battery system.

[0056] Still taking the example of the battery system having 10 cells and the voltage of the No. 1 cell being the highest, during charging, the other cells in the battery system except the No. 1 cell are charged for a first preset time, and after the first preset time, the voltage difference between the other cells and the No. 1 cell is small, at this time, the 10 cells in the battery system are charged as a whole, that is, the No. 1 cell is also charged, and finally, the charging capacity of the battery system is maximized.

[0057] The above is the charging condition of the battery system, and the discharging condition of the battery system is described as follows:

[0058] In S103, during discharging of the battery system, the target cell is the cell with the lowest voltage, and a discharging control strategy is generated.

[0059] For the battery discharging condition, there is only one discharging control strategy.

[0060] Specifically, based on the discharging control strategy, the other cells in the battery system except the target cell are discharged, and after a second preset time, the N cells in the battery system are discharged simultaneously to maximize the discharging capacity of the battery system.

[0061] Taking the example of the battery system having 10 cells and the voltage of the No. 2 cell being the lowest, first, during discharging, the other cells except the No. 2 cell are discharged according to the discharging control strategy, and after a second preset time, when the voltage difference between the other cells and the No. 2 cell is small, the N cells in the battery system are discharged as a whole, that is, the 10 cells are discharged at this time, and the discharging capacity can be substantially balanced, so that when the No. 2 cell is discharged, the other cells also have discharging capacity and cannot be discharged, thereby improving the endurance of the battery.

[0062] The one or more technical solutions in the embodiments of the present application have at least the following technical effects or advantages:

[0063] The application provides a battery system charging and discharging method, wherein the battery system comprises a voltage control module, a battery management module and N battery cells, the battery management module is used for monitoring the voltage of each battery cell, and the voltage control module is connected with a charging and discharging interface of the battery system, the method comprises the following steps: acquiring the voltage of each battery cell through the battery management module; determining a target battery cell based on the voltage of each battery cell, the target battery cell is a battery cell with the highest voltage or a battery cell with the lowest voltage, and the target battery cell is one or more; generating a control strategy based on the target battery cell; and charging or discharging the target battery cell based on the control strategy, so as to maximize the charging capacity of the battery system or maximize the discharging capacity of the battery system, and finally realize optimal electric energy utilization efficiency and improve the cruising range of a vehicle.

[0064] Embodiment two

[0065] Based on the same inventive concept, the application further provides a battery system charging and discharging device, wherein the battery system comprises a voltage control module, a battery management module and N battery cells, the battery management module is used for monitoring the voltage of each battery cell, and the voltage control module is connected with a charging and discharging interface of the battery system, as shown in the accompanying drawings, the device comprises: Figure 2

[0066] An acquisition module 201 is configured to acquire the voltage of each battery cell through the battery management module.

[0067] A determination module 202 is configured to determine a target battery cell based on the voltage of each battery cell, the target battery cell is a battery cell with the highest voltage or a battery cell with the lowest voltage, and the target battery cell is one or more.

[0068] A generation module 203 is configured to generate a control strategy based on the target battery cell.

[0069] A control module 204 is configured to charge or discharge the target battery cell based on the control strategy, so as to maximize the charging capacity of the battery system or maximize the discharging capacity of the battery system.

[0070] In an optional embodiment, the generation module is configured to:

[0071] When charging the battery system, the target battery cell is a battery cell with the highest voltage, and a first charging control strategy is generated.

[0072] In an optional embodiment, the control module is configured to:

[0073] Based on the first charging control strategy, the target battery cell is discharged by a preset amount of electric quantity, and then the N battery cells of the battery system are collectively charged, so as to maximize the charging capacity of the battery system. ​

[0074] In an alternative embodiment, the generating module is configured to:

[0075] When charging the battery system, the target cell is the cell with the highest voltage, and a second charging control strategy is generated.

[0076] In an alternative embodiment, the charging or discharging the target cell based on the control strategy to maximize the charging or discharging amount of the battery system comprises:

[0077] Based on the second charging control strategy, the cells other than the target cell in the battery system are charged, and after a first preset time, the N cells in the battery system are simultaneously charged as a whole to maximize the charging amount of the battery system.

[0078] In an alternative embodiment, the generating module is configured to:

[0079] When discharging the battery system, the target cell is the cell with the lowest voltage, and a discharging control strategy is generated.

[0080] In an alternative embodiment, the control module is configured to:

[0081] Based on the discharging control strategy, the cells other than the target cell in the battery system are discharged, and after a second preset time, the N cells in the battery system are simultaneously discharged as a whole to maximize the discharging amount of the battery system.

[0082] Embodiment Three

[0083] Based on the same inventive concept, the embodiments of the present application provide a vehicle, as shown in Figure 3 The vehicle comprises a memory 304, a processor 302, and a computer program stored in the memory 304 and executable on the processor 302, and the processor 302 implements the steps of the battery system charging and discharging method when executing the program.

[0084] In the above embodiments, the target cell is determined based on the voltage of the cells in the battery system. Figure 3In this particularized embodiment, a bus architecture (represented by bus 300) can include any number of interconnected buses and bridges, the bus 300 linking together various circuits including the processor 302 represented by one or more processors and the memory 304 represented by the memory. The bus 300 can also link various other circuits such as peripheral devices, voltage stabilizers, and power management circuits, which are well known in the art, and therefore, are not further described herein. The bus interface 306 provides an interface between the bus 300 and the receiver 301 and the transmitter 303. The receiver 301 and the transmitter 303 can be the same element, i.e., a transceiver, providing a means for communicating with various other apparatuses over a transmission medium. The processor 302 is responsible for managing the bus 300 and general processing, while the memory 304 can be used for storing data used by the processor 302 in executing operational processes.

[0085] Embodiment Four

[0086] Based on the same inventive concept, the embodiments of the present application provide a computer readable storage medium, having stored thereon a computer program, which, when executed by a processor, implements the steps of the method for design and control of a rocket as described above.

[0087] The algorithms and displays presented herein are not inherently related to any particular computer, virtual system, or other apparatus. Various general purpose systems can be used with programs in accordance with the teachings herein, or it can prove convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will be apparent from the description above. In addition, the present application is not intended to be limited to any particular programming language. It will be appreciated that there are many programming languages that can be used to implement the teachings of the present application as described herein, and any such programming language can be used in the context of the present application.

[0088] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the application can be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been described in detail in order to avoid obscuring the understanding of this description.

[0089] Similarly, it is to be understood that the embodiments of the present application can be alternately or additionally employed in combination with one another, where appropriate, even though not expressly stated in the above description. Although the present application has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and modifications of the present application, such as: to the embodiments of the present application, to the methods of the present application, and to the devices of the present application. Accordingly, many modifications can be made by one of ordinary skill in the art without departing from the scope of the present application as disclosed herein. For example, although processes are described with regard to particular operational flows, various other processes can be implemented as steps within a larger process that includes the described steps, or as at least partially parallel processes that are performed concurrently with the described processes. Accordingly, other implementations are within the scope of the following claims.

[0090] Those skilled in the art will appreciate that the modules in the apparatuses in the embodiments can be adapted and placed in one or more apparatuses other than the embodiments. The modules or units or components in the embodiments can be combined into one module or unit or component, and further can be divided into more sub-modules or sub-units or sub-components. Any combination of all the features disclosed in the specification (including the accompanying claims, abstract and drawings), and any method or of the device disclosed in the specification in combination with one or more of the features disclosed in the specification are employed, except that at least some of such features and / or processes or units are mutually exclusive. Unless explicitly stated, each feature disclosed in the specification (including the accompanying claims, abstract and drawings) can be replaced by alternative features that serve the same, equivalent or similar purpose.

[0091] Further, those skilled in the art will appreciate that a combination of features of different embodiments means that such combination is within the scope of the application and forms a different embodiment. For example, in the following claims, any one of the claimed embodiments can be used in any combination.

[0092] The various component embodiments of the present application can be implemented in hardware, or as software modules running in one or more processors, or in combinations thereof. As will be appreciated by one skilled in the art, microprocessors or digital signal processors (DSPs) can be used to implement some or all of the functionality of the battery system charge and discharge apparatus, some or all of the components in the vehicle, according to embodiments of the present application, in practice. The present application can also be implemented as a program of instructions for performing part or all of the methods described herein, e.g., a computer program and a computer program product. Such a program of instructions can be stored on a computer readable medium, or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, or provided on a carrier signal, or in any other form.

[0093] It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that one skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word 'comprising' does not exclude the presence of elements or steps other than those listed in a claim. The word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements. The application can be implemented by means of both hardware and software, and any combination thereof. In a unit claim, several devices can be listed with a conjunction like 'or', but it is to be understood that each of these devices can be implemented by its own hardware item. The use of the words 'first','second', and 'third', etc. do not imply any ordering. These words are to be interpreted as names.

Claims

1. A battery system charging and discharging method, the battery system comprising a voltage control module, a battery management module and N battery cells, the battery management module being configured to monitor the voltage of each battery cell, the voltage control module being connected to a charging and discharging interface of the battery system, characterized in that, The method comprises the following steps: obtaining the voltage of each battery cell through the battery management module; determining a target battery cell based on the voltage of each battery cell, the target battery cell being the battery cell with the highest voltage or the battery cell with the lowest voltage, the target battery cell being one or more, wherein the target battery cell is the battery cell with the highest voltage when charging the battery system and the target battery cell is the battery cell with the lowest voltage when discharging the battery system; generating a control strategy based on the target battery cell, wherein the control strategy comprises a first charging control strategy, a second charging control strategy and a discharging control strategy, the first charging control strategy being generated when charging the battery system, the second charging control strategy being generated when charging the battery system, and the discharging control strategy being generated when discharging the battery system; charging or discharging the target battery cell based on the control strategy to maximize the amount of electricity charged into the battery system or maximize the amount of electricity discharged from the battery system, comprising one of the following: based on the first charging control strategy, discharging the target battery cell by a preset amount of electricity and then controlling the overall charging of the N battery cells in the battery system to maximize the amount of electricity charged into the battery system; based on the second charging control strategy, charging the battery cells other than the target battery cell in the battery system and then simultaneously charging the N battery cells in the battery system after a first preset time period to maximize the amount of electricity charged into the battery system; and based on the discharging control strategy, discharging the battery cells other than the target battery cell in the battery system and then simultaneously discharging the N battery cells in the battery system after a second preset time period to maximize the amount of electricity discharged from the battery system.

2. A battery system charging and discharging device, the battery system comprising N battery cells, a voltage control module and a battery management module, the battery management module being configured to monitor the voltage of each battery cell, the voltage control module being connected to a charging and discharging interface of the battery system, characterized in that, The method comprises the following steps: obtaining the voltage of each battery cell through the battery management module; determining a target battery cell based on the voltage of each battery cell, the target battery cell being the battery cell with the highest voltage or the battery cell with the lowest voltage, the target battery cell being one or more, wherein the target battery cell is the battery cell with the highest voltage when charging the battery system and the target battery cell is the battery cell with the lowest voltage when discharging the battery system; generating a control strategy based on the target battery cell, wherein the control strategy comprises a first charging control strategy, a second charging control strategy and a discharging control strategy, the first charging control strategy being generated when charging the battery system, the second charging control strategy being generated when charging the battery system, and the discharging control strategy being generated when discharging the battery system; The control module is configured to charge or discharge the target battery cell based on the control strategy, so as to maximize the charging power of the battery system or maximize the discharging power of the battery system, including one of the following: based on the first charging control strategy, discharging the target battery cell by a preset power, and then charging the N battery cells of the battery system as a whole, so as to maximize the charging power of the battery system; based on the second charging control strategy, charging the battery cells other than the target battery cell in the battery system, and then charging the N battery cells of the battery system as a whole after a first preset time period, so as to maximize the charging power of the battery system; based on the discharging control strategy, discharging the battery cells other than the target battery cell in the battery system, and then discharging the N battery cells of the battery system as a whole after a second preset time period, so as to maximize the discharging power of the battery system.

3. A vehicle comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to implement the method steps of claim 1.

4. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to implement the method steps of claim 1.

Images