A battery management system and its communication switching method and communication safety verification method

Abstract

The present invention provides a battery management system, in which dual wireless communication modules are integrated to realize redundant design. By setting a first wireless communication module and a second wireless communication module in a battery pack, the communication state of the battery management system is switched by switching the working states of the first wireless communication module and the second wireless communication module, and the software and hardware redundant design of the battery management system is realized, ensuring that the battery management system can switch the communication state of the battery management system to enable communication to continue when a communication hardware failure or a communication failure occurs, thereby ensuring that battery management can continue, ensuring the continuity and reliability of the system, and preventing potential safety risks caused by interruption of the battery management system. At the same time, the MCU obtains the MAC addresses of the two wireless communication modules, generates a key based on a specific algorithm, and is used to fill in the encrypted data packet of the communication to improve data security.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management system (BMS), in particular to the technical field of wireless BMS. Background Art

[0002] Most existing wireless battery management systems integrate a single Bluetooth module on the MCU for short-distance communication with the outside world. Through Bluetooth technology, the battery pack can communicate with mobile devices to achieve real-time data access and management, fault diagnosis and maintenance, etc., especially playing an important role in automation.

[0003] However, a wireless battery management system with only a single Bluetooth module has limitations in reliability and cannot cope with the situation where a single Bluetooth module fails, especially cannot meet the high reliability requirements of application scenarios such as driverless vehicles. Summary of the invention

[0004] The present invention provides a battery management system, in which dual wireless communication modules are integrated to realize redundant design. By setting a first wireless communication module and a second wireless communication module in a battery pack, the communication state of the battery management system is switched by switching the working states of the first wireless communication module and the second wireless communication module, and the software and hardware redundant design of the battery management system is realized, ensuring that the battery management system can switch the communication state of the battery management system to enable communication to continue when a communication hardware failure or a communication failure occurs, thereby ensuring that battery management can continue, ensuring the continuity and reliability of the system, and preventing potential safety risks caused by interruption of the battery management system.

[0005] Specifically, the present invention provides a battery management system, comprising: a battery pack, the battery pack comprising an MCU module and at least two wireless communication modules; the two wireless communication modules are a first wireless communication module and a second wireless communication module, wherein the first wireless communication module and the second wireless communication module respectively communicate wirelessly with a remote terminal; the battery pack is connected to the vehicle end via a CAN bus, the MCU module is connected to the first wireless communication module via a first bus, and is connected to the second wireless communication module via a second bus; the MCU module interacts with the remote terminal via the two wireless communication modules; the MCU module is used to monitor the battery pack status, the two wireless communication modules and the communication status of the two buses, and when one of the two wireless communication modules or one of the two buses fails, the MCU switches to another wireless communication module to interact with the remote terminal.

[0006] Furthermore, the first wireless communication module and the second wireless communication module may be Bluetooth, Wi-Fi, Zigbee or other wireless communication protocol modules.

[0007] Furthermore, the first wireless communication module integrates a low-power Bluetooth protocol stack, and the second wireless communication module integrates a classic Bluetooth protocol stack.

[0008] Furthermore, the first bus and the second bus may be SPI bus, I2C, UART or other bus structures.

[0009] Another aspect of the present invention further discloses a communication switching method for a battery management system, the method comprising:

[0010] The MCU module monitors the communication status of the two buses. If one of them fails, the wireless communication module connected to the normal bus is enabled for communication.

[0011] The MCU module monitors the communication status of the two wireless communication modules. If one of them fails, the other wireless communication module is enabled for communication.

[0012] Furthermore, the bus communication failure includes a hardware failure and a communication data abnormality, wherein the hardware failure is judged by the MCU module monitoring whether there is a fault code in the bus register in the MCU, and the bus communication data abnormality is judged by whether the MCU monitors the data security check of the bus to see if it passes.

[0013] Furthermore, the MCU module monitors the communication status of the two buses. When a fault is detected in one of them, the MCU module switches the other wireless communication module to normal communication mode for communication, initializes the wireless communication module connected to the faulty bus and switches it to the default mode, and reports the fault to the vehicle.

[0014] Furthermore, the MCU module monitors the Bluetooth protocol stacks of the two wireless communication modules. When a fault is detected in one of them, the MCU module switches the other wireless communication module to the normal communication mode for communication, initializes the faulty wireless communication module and switches it to the default mode, and the MCU reports the protocol stack fault to the vehicle end;

[0015] In the communication state, the MCU module sends or receives a connection request. If the wireless communication module that executes the request fails to connect successfully within a predetermined time, the MCU module switches the other wireless communication module to a normal communication mode for communication, and reinitializes the faulty wireless communication module. The MCU switches between the two wireless communication modules for a predetermined number of times. If the faulty wireless communication module still cannot connect, the default mode is restored, and the MCU reports the communication fault to the vehicle end;

[0016] When the first wireless communication module or the second wireless communication module is in a connected or connected state, and detects that key data has not been updated for a long time or the key data is abnormal, the MCU switches another normal wireless communication module to normal communication mode for communication, and the MCU reinitializes the faulty wireless communication module and reports the communication fault.

[0017] Furthermore, the default mode is that the first wireless communication module is in normal communication mode, broadcast is turned on, and can be actively connected or passively connected, and the second wireless communication module is in closed communication mode, broadcast is turned off, and can neither be actively connected nor passively connected.

[0018] The present invention also discloses a communication safety verification method for a battery management system, the method comprising:

[0019] The MCU and the remote terminal obtain unique identifiers of the first wireless communication module and the second wireless communication module;

[0020] The MCU generates a first key based on an encryption algorithm according to the unique identifier;

[0021] The remote terminal runs the same algorithm as the MCU to generate the second key;

[0022] After the MCU and the remote terminal establish interaction, the remote terminal obtains the first key for transmitting data, compares the first key with the second key, and determines whether the data transmission is secure.

[0023] Furthermore, the unique identifier is generated from a MAC address of the device.

[0024] Further, the MCU obtains the MAC address, generates a first key based on an encryption algorithm, fills the first key in a data packet and sends it to the remote terminal;

[0025] The remote terminal calculates the unique identifier by using the encryption algorithm that is preset and the same as that of the MCU module to obtain the second key;

[0026] The remote terminal receives a data packet, extracts a first key from the data packet, and compares and verifies the first key with the second key. If the first key is the same as the second key, it is determined that the wireless communication is secure; if the first key is different from the second key, it is determined that the wireless communication is not secure.

[0027] Furthermore, the encryption algorithm includes CRC8, CRC16, CRC32 algorithm, parity check algorithm, LRC algorithm or other algorithms.

[0028] Further, obtaining MAC addresses of the first wireless communication module and the second wireless communication module of the battery pack from the remote terminal database;

[0029] Alternatively, the RFID technology is used to scan the record label on the battery pack through a scanning instrument to obtain the MAC address of the first wireless communication module and the second wireless communication module on the battery pack.

[0030] The present invention provides an integration and application method of a dual wireless communication module on a BMS, which has the following beneficial effects compared with the prior art:

[0031] 1. Hardware redundancy design: Two wireless communication modules are integrated with the MCU and communicate with the MCU through different bus structure hardware resources. When one module fails due to hardware problems, the other module can continue to work to ensure the continuity of data transmission.

[0032] 2. Dual protocol stack communication: The first wireless communication module can use the low-power (BLE) Bluetooth protocol stack, and the second wireless communication module can use the classic (BR / EDR) Bluetooth protocol stack to avoid the communication impact caused by the failure of the software protocol stack. At the same time, the secondary Bluetooth chip module maintains a low power consumption mode when there is no communication demand to reduce power consumption.

[0033] 3. MAC address encrypted data: The MCU will obtain the MAC addresses of the two wireless communication modules, generate a key based on a specific algorithm, and use it to fill in the encrypted data packet of the communication to improve data security. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic structural diagram of a battery management system according to an embodiment of the present invention;

[0035] Figure 2 A schematic diagram of a communication module failure switching of a battery management system of the present invention;

[0036] Figure 3 A schematic diagram of communication encryption of a battery management system of the present invention;

[0037] Figure 4 A schematic diagram of the steps of communication encryption of the battery management system of the present invention.

[0038] Reference numerals:

[0039] 1-vehicle end, 2-battery pack, 3-remote terminal, 4-scanning instrument, 21-MCU module, 221-first wireless communication module, 222-second wireless communication module; DETAILED DESCRIPTION

[0040] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

[0041] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments described here can be implemented in an order other than that illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or modules is not necessarily limited to the steps or modules clearly listed, but may include other steps or modules that are not clearly listed or inherent to these processes, methods, products or devices. The naming or numbering of steps in this application does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The process steps that have been named or numbered can change the execution order according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved. The division of modules in this application is a logical division. There may be other division methods when it is implemented in actual applications. For example, multiple modules can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection between modules can be electrical or other similar forms, which are not limited in this application. In addition, the modules or submodules described as separate components may or may not be physically separated, may or may not be physical modules, or may be distributed in multiple circuit modules, and some or all of the modules may be selected according to actual needs to achieve the purpose of the present application.

[0042] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication of two components, it can be a direct connection, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances. In the subsequent description, the use of suffixes such as "module", "component" or "unit" used to represent components is only to facilitate the description of the present invention, and it itself has no specific meaning. Therefore, "module" and "component" can be used interchangeably.

[0043] like Figure 1 The battery management system of a specific embodiment of the present invention is shown. The vehicle end 1 is connected to the battery pack 2 via the CAN bus. The battery pack 2 can communicate with the remote terminal 3 wirelessly.

[0044] The MCU module 21 is integrated in the battery pack 2 and connected to the vehicle end 1 via the CAN bus. The MCU is connected to the first wireless communication module 221 and the second wireless communication module 222 via the first and second buses respectively, where one wireless communication module can be used as a redundant communication module, and the two wireless communication modules communicate wirelessly with the remote terminal.

[0045] The MCU module 21 is used to detect the battery status, including the battery voltage, current, temperature, internal resistance, charging times, charging cycle, historical faults and other information. It is also used to control and detect the communication status of the first wireless communication module 221 and the second wireless communication module 222 and the communication status of the first bus and the second bus, and control the switching of the working modes between the two wireless communication modules according to the communication status of the first wireless communication module 221 and the second wireless communication module 222 and the communication status of the first bus and the second bus.

[0046] The first wireless communication module 221 is connected to the MCU module 21 through the first bus, and can communicate with the remote terminal 3 wirelessly. The second wireless communication module 222 is connected to the MCU module 21 through the second bus, and can communicate with the remote terminal 3 wirelessly.

[0047] The first wireless communication module 221 can integrate a low-power Bluetooth protocol stack, support active or passive communication mode, monitor battery health data in real time, and maintain normal communication status by default. The first wireless communication module 221 can be in normal communication mode and low power mode. When the first wireless communication module 221 is in normal communication mode, the broadcast is turned on, and it can be actively connected or passively connected; when the first wireless communication module 221 is in low power mode, the broadcast is turned off, and it cannot be actively connected or passively connected.

[0048] The second wireless communication module 222 can integrate the classic Bluetooth protocol stack, support active or passive communication mode, monitor battery health data in real time, and maintain a low-power communication state by default. The second wireless communication module 222 can be in normal communication mode and closed communication mode. When the second wireless communication module 222 is in normal communication mode, the broadcast is turned on, and it can be actively connected or passively connected; when the second wireless communication module 222 is in closed communication mode, the broadcast is turned off, and it cannot be actively connected or passively connected.

[0049] The remote terminal 3 may be a terminal supporting a low-power Bluetooth protocol stack and a classic Bluetooth protocol stack, and may communicate with the BMS via Bluetooth technology to obtain BMS battery parameters.

[0050] The first wireless communication module 221 and the second wireless communication module 222 may also be Wi-Fi, Zigbee or other wireless communication protocol modules.

[0051] The first bus and the second bus may be SPI bus, I2C, UART or other bus structures.

[0052] See also Figure 2 As shown in Table 1, the present invention also discloses a specific embodiment of a communication switching method for a battery management system, including the following application scenarios:

[0053] The first wireless communication module 221 is a Bluetooth chip module, which integrates a low-power Bluetooth protocol stack, and the default mode is a normal communication mode;

[0054] Normal communication mode: Broadcast is turned on, and both active and passive connections are possible.

[0055] The second wireless communication module 222 is a Bluetooth chip module, which integrates the classic Bluetooth protocol stack and has a default mode of closed communication mode;

[0056] Communication mode off: Broadcast is off, and neither active connection nor passive connection is possible.

[0057] In the following specific embodiments, the first and second buses are exemplified by the SPI bus.

[0058] Scenario 1: When SPI fails or communication data is abnormal.

[0059] Detection: The MCU module monitors the two-way SPI communication status. SPI communication failure includes SPI hardware failure and SPI communication data abnormality. The SPI hardware failure is determined by the MCU monitoring whether the MCU's SPI register has a fault code, and the SPI communication data abnormality is determined by the MCU monitoring whether the SPI data CRC check passes.

[0060] Processing: Taking the first wireless communication module 221 as the working communication unit, the MCU module 21 detects the fault code from the SPI register, and the MCU module 21 switches the second wireless communication module 222 from the closed communication mode to the normal communication mode and switches the first wireless communication module 221 from the normal communication mode to the low power mode. The MCU module 21 switches from communicating with the remote terminal 3 through the first wireless communication module 221 to communicating with the remote terminal 3 through the second wireless communication module 222. If the communication task is not completed, continue the communication task. The MCU reinitializes the first wireless communication module 221 and keeps the low power mode, closes the broadcast, and reports the hardware fault to the vehicle end 1.

[0061] Scenario 2: When a protocol stack failure occurs in the working communication unit.

[0062] Detection: The MCU monitors the Bluetooth protocol stacks of the first wireless communication module 221 and the second wireless communication module 222. The protocol stacks open a fault readback interface. The MCU monitors this part of the fault and reports it.

[0063] Processing: Take the first wireless communication module 221 as an example of a working communication unit. When the protocol stack of the first wireless communication module 221 fails, the MCU module 21 switches the second wireless communication module 222 from the closed communication mode to the normal communication mode and switches the first wireless communication module 221 to the low power consumption mode after reading the fault. The MCU module 21 switches from communicating with the remote terminal 3 through the first wireless communication module 221 to communicating with the remote terminal 3 through the second wireless communication module 222. If the communication task is not completed, continue the communication task. The MCU reinitializes the first wireless communication module 221 and maintains the low power consumption mode, closes the broadcast, and reports the protocol stack failure to the vehicle end 1.

[0064] Scenario 3: When the vehicle side actively communicates and the remote terminal passively communicates, the MCU module 21 sends a connection request to the battery pack 2. After the Bluetooth chip module that actually executes the request performs the requested connection action, no connection is successful within the preset time.

[0065] Processing: Take the first wireless communication module 221 as an example of a working communication unit. When the first wireless communication module 221 fails, the MCU module 21 switches the second wireless communication module 222 from the closed communication mode to the normal communication mode and the first wireless communication module 221 from the normal communication mode to the low power mode. The MCU module 21 switches from trying to establish a connection with the remote terminal 3 through the first wireless communication module 221 to trying to establish a connection with the remote terminal 3 through the second wireless communication module 222, continues to process the connection request task, and reinitializes the first wireless communication module 221. The MCU attempts to switch between the first wireless communication module 221 and the second wireless communication module 222 for 3 times. If it still cannot establish a connection with the remote terminal 3, it restores the default state. At this time, the first wireless communication module 221 is in the normal communication mode, the broadcast is turned on, and there is no connection request task. The second wireless communication module 222 is in the closed communication mode, the broadcast is turned off, and it cannot be actively connected or passively connected. The MCU module 21 continues to try to request a connection to the remote terminal 3 and reports the communication failure to the vehicle end 1.

[0066] Scenario 4: When the remote terminal actively communicates and the vehicle end passively communicates, the MCU module 21 needs to communicate in a passive communication state. If the MCU module 21 receives a connection request but the first wireless communication module 221 or the second wireless communication module 222 is not connected within a certain period of time.

[0067] Processing: Taking the first wireless communication module 221 as the working communication unit, when the first wireless communication module 221 fails, the MCU module 21 switches the second wireless communication module 222 from the closed communication mode to the normal communication mode for broadcasting, and switches the first wireless communication module 221 from the normal communication mode to the low power consumption mode. The MCU module 21 switches from the first wireless communication module 221 passively establishing a connection with the remote terminal 3 to attempting to passively establish a connection with the remote terminal 3 through the second wireless communication module 222. The second wireless communication module 222 broadcasts and waits for connection. The MCU attempts to switch between the first wireless communication module 221 and the second wireless communication module 222 for 3 times. If it still cannot establish a connection with the remote terminal 3, it restores the default state. At this time, the first wireless communication module 221 is in the normal communication mode, broadcasting is turned on, and there is no connection request task. The second wireless communication module 222 is in the closed communication mode, broadcasting is turned off, and it cannot be actively connected or passively connected. The MCU module 21 reports the communication failure to the vehicle end 1.

[0068] Scenario 5: When the first wireless communication module 221 or the second wireless communication module 222 is in a connected or connected state, but key data such as life frames are not updated for a long time or the key data is abnormal, the MCU module 21 determines that the communication is unstable.

[0069] Processing: Taking the first wireless communication module 221 as the working communication unit, the MCU module 21 switches the second wireless communication module 222 from the closed communication mode to the normal communication mode for broadcasting. The MCU module 21 switches from communicating with the remote terminal 3 through the first wireless communication module 221 to communicating with the remote terminal 3 through the second wireless communication module 222. If the communication task is not completed, continue the communication task. The first wireless communication module 221 is reinitialized, the low power consumption mode is maintained, and the broadcast is turned off. The MCU module 21 reports the communication failure to the vehicle end 1.

[0070] Life frame: indicates normal communication. It will be updated every time data is received normally. If it is not updated, it means there is a connection but no interactive data. The data may be interfered by electromagnetic interference or other interference.

[0071] Table 1 Application scenario of a communication switching method for a battery management system (taking the failure of the first wireless communication module as an example)

[0072]

[0073]

[0074] Preferably, the MCU module 21 can encrypt the data segment sent to the remote terminal 3 during the communication interaction with the remote terminal 3. Figure 3-Figure 4An embodiment of the present invention provides a communication encryption and verification method for a battery management system, which specifically includes the following steps:

[0075] The MCU and the remote terminal obtain unique identifiers of the first wireless communication module and the second wireless communication module;

[0076] The unique identifier can be used to identify a unique device. In some feasible embodiments, the unique identifier is generated by the MAC address of the device. The MAC (Media Access Control Address) can be used to confirm the location of the device. The length of the MAC address is 48 bits (6 bytes). In the embodiments of this specification, the unique identifier can be generated by the MAC address; it can also be generated by part of the MAC address. For example, the unique identifier can be generated based on the last four bits of the MAC address. In some feasible embodiments, the unique identifier can be obtained by methods such as cyclic shift processing of all or part of the MAC address. Therefore, to a certain extent, the difficulty of stealing the MAC address of the smart device through the unique identifier can be increased, thereby protecting the security of device information.

[0077] The MCU generates a first key based on the encryption algorithm using the two MAC addresses, and fills the first key in the encrypted data packets of the two wireless communication modules;

[0078] Specifically, the algorithm includes a CRC algorithm, including CRC8, CRC16, CRC32, etc. The algorithm can also be replaced by a parity check algorithm, an LRC algorithm (Longitudinal Redundancy Check), etc., which is not specifically limited in the present invention.

[0079] In this embodiment, the MCU obtains the MAC address, gives the MAC address to the CRC32 algorithm logic, generates a first key, fills the first key value in the data packet, and then sends the data to the remote terminal 3.

[0080] After the remote terminal 3 obtains the MAC address of the wireless communication module in the battery pack, it runs the same algorithm as the MCU to generate a second key.

[0081] In the embodiment of this specification, the remote terminal 3 calculates the second key by using the encryption algorithm preset the same as that of the MCU module on the unique identifier. That is, the remote terminal 3 and the MCU module can be preset to use the same encryption algorithm.

[0082] After the MCU and the remote terminal establish interaction, the remote terminal obtains the first key for transmitting data and compares the first key with the second key to determine whether the data transmission is secure.

[0083] Specifically, the remote terminal 3 receives the data packet, extracts the first key from the data packet, and compares and verifies the first key with the second key. If the first key is the same as the second key, the wireless communication is determined to be secure; if the first key is different from the second key, the wireless communication is determined to be unsafe.

[0084] In this embodiment, the MAC addresses of the first wireless communication module 221 and the second wireless communication module 222 are recorded in the database of the remote terminal 3 , and the remote terminal 3 reads the MAC address of the first wireless communication module 221 or the second wireless communication module 222 from the database.

[0085] In other embodiments, RFID technology may also be used to obtain the MAC address of the wireless communication module, specifically, Figure 4 As shown, the scanning instrument 4 is connected to the remote terminal 3, and a recording label is pre-set on the battery pack 2. The label records production information such as the MAC addresses of the first wireless communication module 221 and the second wireless communication module 222. The scanning instrument scans the label to obtain the MAC addresses of the first wireless communication module 221 and the second wireless communication module 222, and sends them to the remote terminal 3.

[0086] The present invention provides a method for realizing redundant design by integrating dual wireless communication modules in a battery management system. By setting a first wireless communication module and a second wireless communication module in a battery pack, the communication state of the battery management system can be switched by switching the working states of the first wireless communication module and the second wireless communication module, and the software and hardware redundant design of the battery management system is realized, thereby ensuring that the battery management system can continue the communication by switching the communication state of the battery management system when a communication hardware failure or a communication failure occurs, thereby ensuring that the battery management can continue, ensuring the continuity and reliability of the system, and preventing potential safety risks caused by the interruption of the battery management system. At the same time, the MCU obtains the MAC addresses of the two wireless communication modules, generates a key based on a specific algorithm, and is used to fill in the encrypted data packet of the communication to improve data security.

[0087] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A battery management system, comprising: A battery pack, characterized in that The battery pack includes an MCU module and at least two wireless communication modules; The two wireless communication modules are a first wireless communication module and a second wireless communication module, wherein the first wireless communication module and the second wireless communication module respectively communicate wirelessly with the remote terminal; The battery pack is connected to the vehicle end via a CAN bus, the MCU module is connected to the first wireless communication module via a first bus, and is connected to the second wireless communication module via a second bus; The MCU module interacts with the remote terminal through the two wireless communication modules; The MCU module is used to monitor the battery pack status, the two wireless communication modules and the communication status of the two buses. When one of the two wireless communication modules or one of the two buses fails, the MCU switches to another wireless communication module to interact with the remote terminal.

2. The battery management system according to claim 1, characterized in that: The first wireless communication module and the second wireless communication module may be Bluetooth, Wi-Fi, Zigbee or other wireless communication protocol modules.

3. The battery management system according to claim 2, characterized in that: The first wireless communication module integrates a low-power Bluetooth protocol stack, and the second wireless communication module integrates a classic Bluetooth protocol stack.

4. The battery management system according to claim 1, characterized in that: The first bus and the second bus may be SPI bus, I2C, UART or other bus structures.

5. A communication switching method applied to the battery management system according to claims 1-4, characterized in that: The method comprises: The MCU module monitors the communication status of the two buses. If one of them fails, the wireless communication module connected to the normal bus is enabled for communication. The MCU module monitors the communication status of the two wireless communication modules. If one of them fails, the other wireless communication module is enabled for communication.

6. The method according to claim 5, characterized in that The bus communication failure includes hardware failure and communication data abnormality. The hardware failure is judged by the MCU module monitoring whether there is a fault code in the bus register in the MCU, and the bus communication data abnormality is judged by whether the MCU monitors the data security check of the bus to see if it passes.

7. The method according to claim 6, characterized in that The method further comprises: The MCU module monitors the communication status of the two buses. When a fault is detected in one of them, the MCU module switches the other wireless communication module to normal communication mode for communication, initializes the wireless communication module connected to the faulty bus and switches it to the default mode, and reports the fault to the vehicle.

8. The method according to claim 6, characterized in that The method further comprises: The MCU module monitors the Bluetooth protocol stacks of the two wireless communication modules. When a fault is detected in one of them, the MCU module switches the other wireless communication module to normal communication mode for communication, initializes the faulty wireless communication module and switches it to the default mode. The MCU reports the protocol stack fault to the vehicle end. In the communication state, the MCU module sends or receives a connection request. If the wireless communication module that executes the request fails to connect successfully within a predetermined time, the MCU module switches the other wireless communication module to a normal communication mode for communication, and reinitializes the faulty wireless communication module. The MCU switches between the two wireless communication modules for a predetermined number of times. If the faulty wireless communication module still cannot connect, the default mode is restored, and the MCU reports the communication fault to the vehicle end; When the first wireless communication module or the second wireless communication module is in a connected or connected state, and detects that key data has not been updated for a long time or the key data is abnormal, the MCU switches another normal wireless communication module to normal communication mode for communication, and the MCU reinitializes the faulty wireless communication module and reports the communication failure.

9. The fault detection and communication switching method according to claim 7 or 8, characterized in that: The default mode is that the first wireless communication module is in normal communication mode, broadcast is turned on, and can be actively connected or passively connected, and the second wireless communication module is in closed communication mode, broadcast is turned off, and can neither be actively connected nor passively connected.

10. A communication security verification method applied to the battery management system according to claims 1-4, characterized in that: The method comprises the following steps: The MCU and the remote terminal obtain unique identifiers of the first wireless communication module and the second wireless communication module; The MCU generates a first key based on an encryption algorithm according to the unique identifier; The remote terminal runs the same algorithm as the MCU to generate the second key; After the MCU and the remote terminal establish interaction, the remote terminal obtains the first key for transmitting data, compares the first key with the second key, and determines whether the data transmission is secure.

11. The method according to claim 10, characterized in that The unique identifier is generated from the MAC address of the device.

12. The method according to claim 11, characterized in that The method further comprises: The MCU module obtains the MAC address, generates a first key based on an encryption algorithm, fills the first key in a data packet and sends it to the remote terminal; The remote terminal calculates the unique identifier by using the encryption algorithm that is preset and the same as that of the MCU module to obtain the second key; The remote terminal receives a data packet, extracts a first key from the data packet, and compares and verifies the first key with the second key. If the first key is the same as the second key, the wireless communication is determined to be secure; if the first key is different from the second key, the wireless communication is determined to be unsafe.

13. The method according to claim 11, characterized in that The encryption algorithm includes CRC8, CRC16, CRC32 algorithm, parity check algorithm, LRC algorithm or other algorithms.

14. The method according to claim 12, characterized in that Methods for a remote terminal to obtain a MAC address include: Acquire the MAC addresses of the first wireless communication module and the second wireless communication module of the battery pack from the remote terminal database; Alternatively, the RFID technology is used to scan the record label on the battery pack through a scanning instrument to obtain the MAC address of the first wireless communication module and the second wireless communication module on the battery pack.

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