Battery management method and battery management system

Abstract

The invention relates to a battery management method. The method comprises the following steps: acquiring the number of battery cells in a battery pack and / or the states of the battery cells; and confirming protection parameters of the battery cells of the battery pack according to the number of the battery cells and / or the states of the battery cells. The invention further provides a battery management system using the method. According to the battery management method and system, the protection parameters of the battery cells of the battery pack are confirmed according to the number of the battery cells and / or the states of the battery cells, the flexibility is high, and the battery management method and system can meet the requirements of various scenes.

Description

Technical Field

[0001] The present application relates to the field of electronic technology, and in particular to a battery management method and a battery management system. Background Art

[0002] With the rapid development of modern science and technology, battery technology has become the core force supporting various innovative applications. From electric vehicles to smartphones to renewable energy storage systems, the widespread use of batteries has promoted social progress. However, with the complexity of battery technology and the diversification of application scenarios, how to manage batteries efficiently and safely has become a challenge that needs to be solved. Battery Management System (BMS) came into being as an important part of the development of battery technology. BMS not only improves the performance and life of the battery, but also ensures safety during use.

[0003] The existing 24-63V BMS is commonly used in electric two-wheeled vehicles and drone scenarios. In the electric two-wheeled vehicle scenario, the battery capacity is large, but the discharge rate is low, which makes it difficult to meet high load or instantaneous high power requirements; in the drone scenario, the discharge rate is high and can support large current output, but the battery capacity is small, which limits the battery life of the device.

[0004] However, existing BMS are usually designed for specific battery packs. Although this customized solution can meet specific application requirements, it has the problem of insufficient adaptability. Summary of the invention

[0005] To solve the above problems, the present application provides a battery management method which is highly flexible and can meet the needs of various scenarios.

[0006] The present application provides a battery management method, which includes the following steps: obtaining the number of battery cells in a battery pack and / or the status of the battery cells; and confirming protection parameters of the battery cells of the battery pack based on the number of battery cells and / or the status of the battery cells.

[0007] In one embodiment, obtaining the number of battery cells and / or the status of the battery cells in a battery pack includes: a first step: collecting the voltage value of a reserved sampling point of each battery cell through an analog-to-digital converter to determine the number of the battery cells; and / or; a second step: obtaining at least one of the voltage status, current status, temperature status, remaining power status, or health status of each battery cell in the battery pack.

[0008] In one implementation, the protection parameter of the battery pack includes a voltage threshold of voltage protection and / or a time threshold of voltage protection.

[0009] In one embodiment, the method further includes the following steps: if a protection parameter adjustment instruction is received, then adjusting the protection parameter accordingly within a preset range according to the protection parameter adjustment instruction.

[0010] In one implementation, the protection parameter includes a voltage threshold of current protection and / or a time threshold of current protection.

[0011] In one embodiment, the method further comprises the following steps: if a protection function shut down instruction is received, adjusting the protection parameter to disable the protection function.

[0012] In one embodiment, the method further comprises the following steps: obtaining position information of the battery cells in the battery pack; The battery cells are balanced according to the position information.

[0013] In one embodiment, the method further includes the following steps: when the battery pack is not in a charging state or a discharging state, if a preset sleep condition is met, entering a sleep state, wherein the sleep condition includes a state condition of the battery pack and / or an external demand condition.

[0014] In one embodiment, the method further comprises the following steps: Start a regular inspection process, obtain the current operating data of the battery pack through various sensors, and detect whether the external device has a data receiving function; If the external device has a receiving function, the collected data will be reported through the bus.

[0015] The present application also provides a battery management system, including a memory and a processor, wherein the processor is used to execute a computer program stored in the memory and can implement the battery management method described in any one of the above embodiments.

[0016] The battery management method and system of the present application include obtaining the number of battery cells and / or the status of the battery cells in a battery pack; and confirming the protection parameters of the battery cells of the battery pack based on the number of battery cells and / or the status of the battery cells. Therefore, the protection parameters of the battery cells of the battery pack can be confirmed based on the number of battery cells and / or the status of the battery cells. It is highly flexible and can adapt to the needs of various scenarios.

[0017] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation method is described below, and the detailed explanation is as follows in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1It is a flowchart of a battery management method according to an embodiment.

[0019] Figure 2 The figure is a schematic diagram of an operation flow of a battery management system according to an embodiment.

[0020] Figure 3 The figure is a schematic diagram of a process of multi-cell voltage level adaptation of a battery management system according to an embodiment.

[0021] Figure 4 The figure is a schematic diagram of the working process of a high current management module of a battery management system according to an embodiment.

[0022] Figure 5 The figure is a schematic diagram of the working process of a data reporting module of a battery management system according to an embodiment.

[0023] Figure 6 The figure is a schematic diagram of a flow chart of modifying a protection parameter threshold of a battery management system according to an embodiment. DETAILED DESCRIPTION

[0024] In order to facilitate the understanding of the present application, the present application will be described in more detail below with reference to the relevant drawings. The drawings provide specific implementation methods of the present application, and the present application will be described in detail below in conjunction with the drawings and examples.

[0025] Figure 1 1 is a flow chart of a battery management method according to an embodiment. In one embodiment of the present application, the battery management method is executed by a BMS, and the BMS is used to manage a battery pack, wherein the battery pack includes at least one battery or cell, wherein each battery includes at least one cell.

[0026] In one embodiment of the present application, the battery pack can be used as a power supply device for robots, drones, etc.

[0027] like Figure 1 As shown, the battery management method of this embodiment includes the following steps: S10: Obtaining the number of cells in the battery pack and / or the status of the cells; S11: Confirming protection parameters of the battery cells of the battery pack according to the number of battery cells and / or the status of the battery cells.

[0028] Specifically, in one embodiment, step S10 includes: collecting the voltage value of the reserved sampling point of each battery cell through an analog-to-digital converter to determine the number of battery cells; and / or; obtaining the status of each battery cell in the battery pack.

[0029] The state of the battery cell may include at least one of the voltage state, current state, temperature state, capacity of the battery cell, remaining power state, or health state. In one embodiment, after the BMS is started, the timed data reporting will be turned on and the data will be reported to the external device. The external device can analyze the state of the battery cell based on the reported data, wherein the state of the battery cell includes: the capacity of the battery cell, the health state of the battery cell (also known as health), etc. Specifically, it can be determined whether the health state of the battery cell has entered the end-of-life state (also known as the state of low health) by two methods based on the data collected locally. Method 1: BMS calculates the number of battery pack discharges by recording the integral of current and time during discharge. When the cumulative number of battery pack discharges reaches a preset cycle, such as 300 cycles (300 cycles are from the battery cell manual); Method 2: BMS records the charging data of the battery pack from completely empty to fully charged (this method is easier to estimate the current remaining capacity of the battery pack, and it is also a common method that can obtain accurate capacity). When the remaining capacity is less than 80% (the industry generally believes that the battery pack has reached the end of life when the maximum capacity of the battery pack drops to 80% of the factory maximum capacity), BMS believes that the battery pack has entered the end of life state. Whether it is method 1 or method 2, it has entered the end of life state. In this state, some cells in the battery pack may have reduced capacity and increased internal resistance due to life, so it is necessary to lower the protection parameters such as temperature protection, current protection, and charging cut-off voltage threshold; Method 3: MS will also report data to the controller, and the controller will be connected to the network to determine the battery pack capacity and further optimize the battery cell management. In addition, since the estimation of the health status of the battery cell is affected by many factors, such as the depth of charge and discharge of the battery cell, the operating temperature of the battery cell, the consistency of the battery cell, the discharge rate of the battery cell, the factory time of the battery cell and other parameters, the estimation of the health status is actually quite inaccurate if it only relies on the data collected locally. Therefore, when this battery pack is used with a controller, the current, voltage, and temperature data during discharge will be reported to the controller in real time. The controller can judge the health and capacity of the battery cell through the reported data, and upload the data to the server via 4G or WiFi, which also provides a data basis for further optimization of the battery health estimation.

[0030] In one embodiment, the protection parameters of the battery pack may include voltage protection thresholds, and / or voltage protection time thresholds, and / or voltage protection parameters such as charge cut-off voltage. In other embodiments, the protection parameters of the battery pack may also include current protection parameters such as short-circuit current thresholds, overcurrent current thresholds, and / or other protection parameters such as cell temperature protection thresholds.

[0031] Among them, the voltage threshold includes at least one of the following: maximum cell voltage threshold, minimum cell voltage threshold, minimum total voltage of the battery pack, minimum power supply voltage, etc. Among them, the maximum cell voltage threshold refers to the maximum voltage that any cell voltage can reach. The minimum cell voltage threshold refers to the minimum voltage that any cell voltage can reach. The minimum total voltage of the battery pack refers to the minimum total voltage of the cells connected in series in the battery pack. The minimum power supply voltage refers to the minimum power supply voltage that the battery pack can provide.

[0032] Specifically, in one embodiment, the voltage threshold includes the minimum total voltage of the battery pack. Usually, external powered devices often require a stable voltage source, and the physical properties of battery packs, such as lithium battery packs, cause the total voltage of the battery pack to continue to drop during use. Taking the common 48V battery pack as an example, the voltage of the battery pack is actually 54.6V when it is fully charged, and the lowest battery is 35.1V, which will undoubtedly have an impact on the powered device, such as the maximum speed of the motor. Therefore, the present application can adjust the protection threshold of the minimum total voltage of the battery pack's external power supply by obtaining the number of battery cells connected in series, thereby reducing the possible accidents caused by low power supply voltage when the powered device is low in power.

[0033] Specifically, in one embodiment, the more the number of battery cells connected in series in the battery pack is, the greater the minimum value of the total voltage of the battery pack is.

[0034] Figure 2 A schematic diagram of the operation flow of a battery management system provided in one embodiment of the present application is shown in FIG. Figure 2 As shown, the operation process of the battery management system may include: Step S21: Initialize hardware peripheral pins and states; Step S22, determining the state of the battery pack at this time; proceeding to step S23a, checking whether the battery pack is in a discharging state; If the battery pack is in a discharging state, the process proceeds to step S24a to perform a discharging state operation; If the battery pack is not in a discharging state, proceed to step S23b to check whether the battery pack is in a charging state; If the battery pack is in a charging state, the process proceeds to step S24b to perform a charging state operation; If the battery pack is not in a charging state, the process proceeds to step S23c to detect whether the battery pack needs to be dormant, and then proceeds to step S24c to enter a dormant state; Among them, when the system process enters step S24a, S24b or S24c, it will detect the exit conditions that meet the corresponding status and enter step S25. If the exit conditions of the corresponding status of the battery pack are detected, it returns to step S22.

[0035] In one embodiment, after the microcontroller unit (MCU) is started, the process proceeds to step S21 .

[0036] Specifically, step S21 includes: configuring peripheral pins for functions such as voltage detection, temperature detection, and communication interface, in preparation for subsequent battery pack status determination and control operations; In one embodiment, step S21, initializing hardware peripheral pins and states, includes performing a multi-cell voltage level adaptation operation.

[0037] Please refer to Figure 3 , Figure 3 A schematic diagram of a process flow of multi-cell voltage level adaptation of a battery management system shown in an embodiment of the present application; In one embodiment, the multi-cell voltage level adaptation operation includes the following steps: Step S30: obtaining the current state of the battery pack, the number of cells actually installed in the battery pack, and the installation positions of the cells in the battery pack through the independent voltage sampling points and analog-to-digital converters reserved on the cells; Step S31: dynamically configuring the protection parameters of the battery pack according to the current state of the battery pack and the number of cells; Step S32: setting equalization parameters according to the state of the battery cells to achieve voltage balance between the battery cells.

[0038] The state of the battery pack includes the state of the battery cells.

[0039] Specifically, in one embodiment, the cell balancing may be turned on for the cells whose voltage is higher than the median of the cell voltage, and the electricity may be released through the resistor to achieve voltage balance between the cells.

[0040] In order to meet the high current demand scenario, the BMS can also communicate with the powered external device through the Controller Area Network (CAN) bus to analyze the needs of the external device. At the hardware level, the carrying capacity of the printed circuit board can be improved by increasing the copper thickness of the hard brush circuit board, optimizing the ordinary, and selecting high voltage resistance level measures. At the software level, by adding a large current management module, the battery cell protection module can be temporarily disabled to meet the operation requirements. In one embodiment, in order to meet the high current demand scenario, a large current management method can be performed during the discharge stage. Specifically, step S24a, performing the discharge state operation may include controlling the large current management module to perform a large current management method.

[0041] Figure 4 A schematic diagram of the working process of a high current management module of a battery management system according to an embodiment of the present application; Please also refer to Figure 2 and Figure 4 , the working process of the high current management module is as follows: S40: start regular inspection; S41: Check the CAN data parsing module to parse the data packet from the CAN bus; S42: Check whether the "close the battery protection function" data packet is received; If a "turn off the battery protection function" data packet is received, go to step S43; If the "disable battery protection function" data packet is not received, proceed to step S44; S43: adjusting the protection parameters to disable the protection function of the BMS; S44: ending the waiting to enter the next cycle, the high current management function enters the standby state, and if the protection function of the BMS has been disabled when entering the next cycle, the BMS protection function will be automatically restored before entering the next cycle.

[0042] In one embodiment, in order to enable the battery cell to work normally in a specific high current scenario, the adjusted protection parameter may be a threshold and duration of short-circuit current protection.

[0043] Figure 5 FIG. 1 is a schematic diagram of a working process of a data reporting module of a battery management system according to an embodiment. Figure 5 As shown in the figure, the operation process of the data reporting module is as follows: S50: start the regular inspection process; S51: acquiring data through sensors, wherein the sensors include a power meter, an analog-to-digital converter, and a temperature sensor; S52: Detect whether the external power supply device has a data receiving function; If the external power supply device has a data receiving function, proceed to step S53; If the external power supply device does not have the function of receiving data, proceed to step S54; S53: Sending battery pack data collected by the sensor; S54: End waiting for the next cycle to start.

[0044] In one embodiment, the BMS may send the collected battery pack data via the CAN bus, and after the battery pack data is sent, proceed to step S54; In one embodiment, when the battery pack enters a dormant state, some functions of the BMS are turned off to save power consumption. To ensure the safety of the battery pack, the BMS retains some necessary functions.

[0045] Specifically, the necessary functions retained by the BMS when the battery pack enters the dormant state include: the data reporting module of the battery management system, which provides a continuous data basis for the subsequent calculation of the battery pack's state of health (SOH) and the battery pack's remaining capacity percentage (SOC).

[0046] In one embodiment, after the BMS determines the initialization hardware peripheral pin and determines the cell voltage level, the BMS protection parameter can be adjusted according to the external device requirements. Specifically, the method further includes: if a protection parameter adjustment instruction is received, the protection parameter is correspondingly adjusted within a preset range according to the protection parameter adjustment instruction.

[0047] Also refer to Figure 2 Figure 6 ,in, Figure 6 The flowchart of modifying the protection parameter threshold of the battery management system shown in the embodiment of the present application is as follows: In step S21, the hardware peripheral pins and states are initialized, and the operation of modifying the protection parameters according to the data packet is performed after performing the multi-cell voltage level adaptation operation. The process of BMS modifying the protection parameters is as follows: S60: receiving and parsing data packets sent by external devices via the CAN bus; S61: Determine whether a "modify protection parameters" data packet is received; If a "Modify protection parameters" data packet is received, proceed to step S62; If the "Modify Protection Parameters" data packet is not received, proceed to step S63; S62: modifying the protection parameters according to the protection parameters required by the internal and external devices; S63: Wait for the inspection instruction of the next cycle.

[0048] Specifically, the protection parameter modified by the BMS includes at least one of the following: a duration of overcurrent protection or short-circuit current protection, and a current threshold of overcurrent protection or short-circuit current protection.

[0049] Through the above examples, the present application can confirm the protection parameters of the battery cells of the battery pack according to the number of battery cells and / or the status of the battery cells. It is highly flexible and can adapt to the needs of various scenarios. It can adjust the protection parameters according to external equipment, leaving room for the subsequent use of aggressive circuit load strategies.

[0050] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A battery management method, characterized in that: The method comprises the following steps: Get the number of cells in the battery pack and / or the status of the cells; According to the number of the battery cells and / or the status of the battery cells, protection parameters of the battery cells of the battery pack are confirmed.

2. The battery management method according to claim 1, characterized in that: Get the number of cells in the battery pack and / or the status of the cells, including: Collecting the voltage value of the reserved sampling point of each battery cell through an analog-to-digital converter to determine the number of the battery cells; and / or; Obtain at least one of the voltage state, current state, temperature state, remaining power state, or health state of each battery cell in the battery pack.

3. The battery management method according to claim 1, characterized in that: The protection parameter of the battery pack includes a voltage threshold of voltage protection and / or a time threshold of voltage protection.

4. The battery management method according to claim 1, characterized in that: The method further comprises: If a protection parameter adjustment instruction is received, the protection parameter is correspondingly adjusted within a preset range according to the protection parameter adjustment instruction.

5. The battery management method according to claim 1 or 4, characterized in that: The protection parameter includes a voltage threshold of current protection and / or a time threshold of current protection.

6. The battery management method according to claim 1, characterized in that: The method further comprises: If a protection function shut down instruction is received, the protection parameter is adjusted to disable the protection function.

7. The battery management method according to claim 1, characterized in that: The method further comprises: Obtaining location information of the battery cells in the battery pack; The battery cells are balanced according to the position information.

8. The battery management method according to claim 1, characterized in that: The method further comprises: When the battery pack is not in a charging state or a discharging state, if a preset sleep condition is met, the battery pack enters a sleep state, wherein the sleep condition includes a state condition of the battery pack and / or an external demand condition.

9. The battery management method according to claim 1, characterized in that: The method further comprises: Start a regular inspection process, obtain the current operating data of the battery pack through various sensors, and detect whether the external device has a data receiving function; If the external device has a receiving function, the collected data will be reported through the bus.

10. A battery management system, characterized in that: It comprises a memory and a processor, wherein the processor is used to execute a computer program stored in the memory, and can implement the battery management method as claimed in any one of claims 1 to 9.

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