Lithium battery management system and control method thereof

Abstract

The invention provides a lithium battery management system and a control method thereof, and the method comprises the following steps: each battery management module executes the power-on self-test and initializes a default CAN frame ID, and carries out the network topology detection through a CAN bus; each battery management module carries out main control module election according to a preset rule, the elected main control module allocates a unique CAN frame ID according to the preset rule and broadcasts allocation information, and each battery management module updates the CAN frame ID of the battery management module; each battery management module uses the distributed CAN frame ID to carry out CAN bus communication, and the elected main control module monitors and manages the battery management system; and when the master control module fails, a master control switching process is triggered, a new master control module is selected, and dynamic CAN frame ID distribution is performed again. When some modules fail, other modules can still work normally, and stable operation of the whole system is guaranteed.

Description

Technical Field

[0001] The present invention relates to a control method for a lithium battery management system, and in particular to realizing communication and management among multiple battery management modules through a CAN bus, aiming to improve the monitoring, management and fault switching capabilities of a lithium battery pack. Background Art

[0002] In recent years, with the continuous improvement of coal mine safety production requirements and the rapid development of intelligent mining technology, the application of mobile equipment has become more and more extensive. Traditional lead-acid batteries have been unable to meet the requirements of modern coal mine underground mobile equipment for power systems due to their low energy density, short cycle life, and high maintenance workload. Lithium-ion batteries have become an ideal choice to replace lead-acid batteries due to their high energy density, long cycle life, high safety, and zero maintenance.

[0003] However, the underground environment of coal mines is harsh, with safety risks such as gas explosion, dust explosion, high humidity, and high temperature, which puts higher requirements on the battery management system (BMS). The traditional centralized BMS architecture has a single point failure risk. Once the main control module fails, the entire battery system will be paralyzed, posing a safety hazard and making it difficult to meet the reliability requirements of underground coal mines.

[0004] In order to improve the safety and reliability of explosion-proof lithium battery systems in coal mines, decentralized BMS architecture came into being. The decentralized architecture gives each battery module certain computing and control capabilities, and works together through a communication network. Even if some modules fail, other modules can still work normally, improving the system's fault tolerance.

[0005] However, the existing decentralized BMS solution still has some shortcomings when applied to explosion-proof lithium batteries in coal mines:

[0006] Preset communication addresses limit flexibility: Many solutions rely on pre-configured fixed communication addresses. Once the battery module needs to be replaced or the system needs to be expanded, the address needs to be reconfigured, which increases maintenance costs and difficulty, and is difficult to flexibly adjust in emergency situations.

[0007] The master control switching mechanism is not perfect: some solutions lack a master control switching mechanism optimized for the underground environment of coal mines. The switching speed is slow and the reliability is low. It is difficult to cope with the challenges brought by changes in the underground environment and there are safety hazards.

[0008] Therefore, there is an urgent need for a more secure, reliable, flexible and easy-to-use decentralized BMS architecture and control method suitable for explosion-proof lithium batteries in coal mines. Summary of the invention

[0009] The present invention provides a lithium battery management system and a control method thereof to solve the above technical problems.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is: a lithium battery management system control method, comprising the following steps:

[0011] Each of the battery management modules executes a power-on self-test instruction and initializes a default CAN frame ID, and performs network topology detection through the CAN bus;

[0012] Each of the battery management modules elects a master control module according to a preset rule, and the elected master control module allocates a unique CAN frame ID according to the preset rule and broadcasts the allocation information, and each of the battery management modules updates its own CAN frame ID;

[0013] Each of the battery management modules uses the assigned CAN frame ID to perform CAN bus communication, and the elected main control module monitors and manages the battery management system;

[0014] When the main control module fails, the main control switching process is triggered, a new main control module is selected and the dynamic CAN frame ID is re-allocated.

[0015] In a possible embodiment, the preset rule is a rule based on a preset priority of a battery management module, comprising the following steps:

[0016] Each battery management module reads preset priority information;

[0017] The battery management module with the highest priority automatically becomes the master control module.

[0018] In a possible embodiment, the preset rule is a rule based on the activation sequence of the battery management modules, comprising the following steps:

[0019] Each battery management module records its own power-on activation sequence;

[0020] The main control module allocates a unique CAN frame ID according to the activation order of each battery management module.

[0021] In a possible embodiment, the preset rule is a rule based on a competition mechanism, comprising the following steps:

[0022] Each battery management module starts the built-in timing module respectively, and the timing time is related to its priority;

[0023] The battery management module that first completes the timing and sends the master control request information becomes the master control module.

[0024] In a possible embodiment, the master control switching process includes:

[0025] Each of the battery management modules monitors the status of the main control module in real time through a heartbeat mechanism;

[0026] When a master control module failure is detected, a master control election is triggered to select a new master control module;

[0027] The new master control module re-allocates the dynamic CAN frame ID and broadcasts the allocation information.

[0028] In a possible embodiment, the master control switching process includes:

[0029] Each of the battery management modules monitors the status of the main control module in real time through a heartbeat mechanism;

[0030] Pre-select a backup master control module;

[0031] When the main control module fails, the backup main control module directly takes over the system control.

[0032] In a possible embodiment, the CAN bus communication uses a broadcasting method to perform data interaction and control instruction transmission.

[0033] The present invention also provides a lithium battery management system, comprising a plurality of lithium battery power supply devices, each of which is equipped with a battery management module, each of which is connected via a CAN bus and executes the above-mentioned control method.

[0034] Beneficial effects of the present invention:

[0035] The decentralized architecture eliminates the reliance on a central control unit. Even if some modules fail, other modules can still work normally, ensuring the overall stable operation of the system.

[0036] The dynamic switching mechanism of the main control module can quickly switch to the backup module when the main control module fails, ensuring uninterrupted operation of the system and improving the fault tolerance of the system.

[0037] Dynamic frame ID allocation allows optimization of communication resources based on module priority or load conditions, obtaining higher transmission priority, thereby improving system response speed and data transmission efficiency.

[0038] When adding or removing modules, there is no need to manually change the complex CAN frame ID configuration. The system can automatically complete the allocation and update, improving the scalability and maintainability of the system.

[0039] A variety of frame ID allocation rules can adapt to different application scenarios and requirements, enhancing the flexibility of the system.

[0040] The decentralized architecture does not require an additional central control unit, which can reduce hardware costs and system complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1This is the overall architecture diagram of the lithium battery management system of the present invention.

[0042] Figure 2 This is an overall flow chart of the lithium battery management system control method of the present invention.

[0043] Figure 3 This is a flow chart of the initialization phase of the lithium battery management system control method of the present invention.

[0044] Figure 4 The present invention is a flow chart of CAN frame allocation based on the rules of preset priorities of the battery management module in the control method of the lithium battery management system.

[0045] Figure 5 This is a flow chart of the normal working phase of the lithium battery management system control method of the present invention.

[0046] Figure 6 This is a flow chart of the battery management system control method of the present invention monitoring the status of the main control battery management module in real time through the heartbeat mechanism.

[0047] Figure 7 The present invention is a flow chart of a battery management system control method for dynamically allocating CAN frame IDs according to the real-time load conditions of each battery management module.

[0048] Figure 8 The present invention is a flow chart of the battery management system control method based on the pre-selection mechanism.

[0049] Fig. 9 The present invention is a flow chart of dynamic frame ID allocation based on activation sequence in the battery management system control method.

[0050] Fig.10 The present invention is a flow chart of dynamic frame ID allocation based on the rules of the competition mechanism in the battery management system control method.

[0051] In the figure: 100, power supply device; 101, battery management module; 200, CAN bus. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings. The description in this part is only exemplary and explanatory and should not have any limiting effect on the scope of protection of the present invention.

[0053] Embodiment 1

[0054] like Figure 1As shown, the present invention provides a battery management system based on dynamic CAN frame ID allocation, which is applied to explosion-proof lithium batteries in coal mines. The system includes multiple power supply devices 100, each of which is equipped with a battery management module 101 and a CAN bus 200.

[0055] Each battery management module integrates functions such as data acquisition, charge and discharge control, fault diagnosis, and CAN communication, and has a default CAN frame ID and priority built in. Each battery management module is connected via the CAN bus 200 to achieve data interaction and control command transmission.

[0056] Each power supply device is equipped with multiple battery packs. For example, 100 single cells are installed in the power supply device, 10 of which form a module, with a total of 10 modules. Each BMU (information acquisition module) is responsible for one module, that is, collecting the voltage and temperature of 10 single cells.

[0057] refer to Figure 2 The present invention also provides a battery management system control method based on dynamic frame ID allocation, comprising the following steps:

[0058] Step 1: System initialization phase

[0059] refer to Figure 3 After each battery management module is powered on, it first performs a self-test to ensure that its hardware and software are normal, and reads the preset default CAN frame ID and priority information. Each battery management module sends a broadcast message through the CAN bus 200 to detect the network topology and obtain the number of currently activated battery management modules.

[0060] Step 2: Dynamic CAN frame ID allocation stage

[0061] refer to Figure 4 Each battery management module elects a master according to a preset rule. This embodiment adopts a rule based on the preset priority of the battery management module, and the module with the highest priority automatically becomes the master battery management module. Priority is usually expressed in numbers, and a larger value represents a higher priority.

[0062] Specifically, a timer is set in each battery management module, and the timing time is inversely proportional to its priority, and the timing time of the module with a high priority is short. After the timing ends, the module that first sends the master control request information becomes the master control module.

[0063] The master battery management module collects information about all battery management modules in the network, including the default CAN frame ID and priority.

[0064] The main control battery management module assigns a unique CAN frame ID to each battery management module according to the activation order. To avoid conflicts, the assigned CAN frame ID increases from the preset value, for example, starting from 0x100, followed by 0x101, 0x102, etc.

[0065] The master battery management module broadcasts the allocated CNA frame ID information to other battery management modules via the CAN bus 200 .

[0066] After receiving the broadcast information, each battery management module updates its own CAN frame ID and stores it in the local memory for use after the next power-on.

[0067] Step 3: Normal working stage

[0068] refer to Figure 5 , each battery management module uses the assigned unique frame ID to communicate on the CAN bus 200, periodically reports its own data (voltage, current, temperature, etc.) to the main control battery management module, and receives instructions from the main control battery management module.

[0069] The master battery management module sends charge and discharge control instructions to each slave battery management module according to the system status and preset control strategy to achieve balanced management of the battery system.

[0070] The main control battery management module monitors the status of each module in real time, performs fault diagnosis, such as overvoltage, overtemperature, etc., and takes corresponding protection measures, such as sounding an alarm, cutting off the circuit, etc., to ensure the safe operation of the system.

[0071] Step 4: Master control switching stage

[0072] refer to Figure 6 Each battery management module monitors the status of the master battery management module in real time through a heartbeat mechanism. Specifically, the master battery management module periodically sends a heartbeat signal, and if other battery management modules do not receive the heartbeat signal within a preset time, the master module is determined to be faulty.

[0073] When a main control battery management module failure is detected, the main control switching process is triggered.

[0074] The remaining battery management modules re-election the master control and select a new master battery management module.

[0075] The new master battery management module re-executes step 2 to perform dynamic CAN frame ID allocation to ensure normal communication.

[0076] Embodiment 2

[0077] This embodiment is basically the same as the first embodiment, except that the rule for allocating CAN frame IDs in step 2 is different.

[0078] refer to Figure 7 In this embodiment, the main control battery management module dynamically allocates CAN frame IDs according to the real-time load conditions of each battery management module. For example, according to parameters such as current size and temperature, the battery management module with higher load is allocated to a better communication time slot. For example, a smaller CAN frame ID is allocated to obtain a higher priority, so as to improve communication efficiency and system response speed.

[0079] Embodiment 3

[0080] This embodiment is basically the same as the first embodiment, except that the master control switching mechanism in step 4 is different.

[0081] refer to Figure 8 This embodiment adopts a fast master control switching mechanism based on a pre-election mechanism. Specifically, in addition to the master control battery management module, a backup master control module is pre-selected in the system. When the master control module fails, the backup master control module can directly take over the system control without re-election, thereby shortening the switching time and improving the system reliability.

[0082] Embodiment 4

[0083] This embodiment is basically the same as the first embodiment, except that the rule for allocating CAN frame IDs in step 2 is based on activation order.

[0084] refer to Fig. 9 , the activation sequence of dynamic CAN frame ID allocation includes the following steps:

[0085] Record activation sequence: After each battery management module 101 is powered on, it immediately records its own activation timestamp.

[0086] The main control module collects information: After the election is completed, the main control battery management module collects the activation timestamp information of all battery management modules 101 through the CAN bus 200.

[0087] Sorting and assigning frame IDs: The main control battery management module sorts the modules according to the activation timestamps of the modules, assigns the smallest CAN frame ID (for example, 0x100) to the first activated module, and assigns CAN frame IDs to the subsequently activated modules in increasing order (for example, 0x101, 0x102...).

[0088] Broadcast frame ID information: The master battery management module broadcasts the allocated CAN frame ID information to other battery management modules 101 .

[0089] Update frame ID: After receiving the broadcast information, each battery management module 101 updates its own CAN frame ID.

[0090] Embodiment 5

[0091] This embodiment is basically the same as the first embodiment, except that the rule for allocating CAN frame IDs in step 2 adopts a rule based on a competition mechanism.

[0092] refer to Fig.10 , dynamic frame ID allocation in a rule-based manner based on a competition mechanism, including the following steps:

[0093] Start timer: After each battery management module 101 is powered on, a timer is started according to its own preset priority. The higher the priority, the shorter the timing time.

[0094] Sending a master control request: After the timer expires, the battery management module 101 immediately broadcasts a master control request message through the CAN bus 200, which includes its own priority information.

[0095] Receiving master control request: All battery management modules 101 will receive master control request information sent by other modules.

[0096] Priority determination: Each battery management module 101 compares the received master control request information with its own:

[0097] If its own priority is higher, it will continue to monitor the network and wait to become the master control module;

[0098] If its own priority is lower, it will give up the competition and enter the slave module state.

[0099] Confirming the master control identity: If a battery management module 101 does not receive a master control request with a higher priority than itself within a preset time, it will identify itself as the new master control module.

[0100] Subsequent steps: The new master control module continues to execute the subsequent steps of step 2, including collecting module information, allocating CAN frame IDs, and broadcasting allocation information.

[0101] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0102] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. A control method for a lithium battery management system, characterized in that: The following steps are involved: Each of the battery management modules executes a power-on self-test instruction and initializes a default CAN frame ID, and performs network topology detection through the CAN bus; Each of the battery management modules elects a master control module according to a preset rule, and the elected master control module allocates a unique CAN frame ID according to the preset rule and broadcasts the allocation information, and each of the battery management modules updates its own CAN frame ID; Each of the battery management modules uses the assigned CAN frame ID to perform CAN bus communication, and the elected main control module monitors and manages the battery management system; When the main control module fails, the main control switching process is triggered, a new main control module is selected and the dynamic CAN frame ID is re-allocated.

2. The control method according to claim 1, characterized in that: The preset rule is a rule based on the preset priority of the battery management module, comprising the following steps: Each battery management module reads preset priority information; The battery management module with the highest priority automatically becomes the master control module.

3. The control method according to claim 1, characterized in that: The preset rule is a rule based on the activation sequence of the battery management modules, comprising the following steps: Each battery management module records its own power-on activation sequence; The main control module allocates a unique CAN frame ID according to the activation order of each battery management module.

4. The control method according to claim 1, characterized in that: The preset rules are rules based on a competition mechanism, and include the following steps: Each battery management module starts the built-in timing module respectively, and the timing time is related to its priority; The battery management module that first completes the timing and sends the master control request information becomes the master control module.

5. The control method according to claim 1, characterized in that: The master control switching process includes: Each of the battery management modules monitors the status of the main control module in real time through a heartbeat mechanism; When a master control module failure is detected, a master control election is triggered to select a new master control module; The new master control module re-allocates the dynamic CAN frame ID and broadcasts the allocation information.

6. The control method according to claim 1, characterized in that: The master control switching process includes: Each of the battery management modules monitors the status of the main control module in real time through a heartbeat mechanism; Pre-select a backup master control module; When the main control module fails, the backup main control module directly takes over the system control.

7. The control method according to claim 1, characterized in that: The CAN bus communication uses a broadcasting method to perform data interaction and control instruction transmission.

8. A lithium battery management system, characterized in that: It comprises a plurality of lithium battery power supply devices, each of which is provided with a battery management module, each of which is connected via a CAN bus and executes the control method described in any one of claims 1 to 7.

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