A dual-link heterogeneous communication method and a distributed battery management system

Abstract

This invention provides a dual-link heterogeneous communication method and a distributed battery management system. The system includes: multiple battery management chips, each connected to a single battery cell; a control module, including a main control unit and a backup control unit; and a battery pack power bus. Each battery management chip includes: a cell data sampling module, a data processing module, a first communication module, a communication link monitoring module, and a clock synchronization module. The system architecture adopted in this invention effectively solves the system paralysis problem caused by single-point failure in traditional single-controller architectures, meeting higher safety requirements for automotive applications.

Description

Technical Field

[0001] This invention relates to the field of battery management systems, and more specifically to a dual-link heterogeneous communication method and a distributed battery management system. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the power battery, as the core power component of new energy vehicles, directly determines the overall performance of the vehicle through its safety, cycle life, and performance stability. The Battery Management System (BMS) is the core control component of the power battery, responsible for collecting, analyzing, and protecting the state data of each cell in the battery pack, such as voltage, current, temperature, and internal resistance. It is the core line of defense for ensuring the safe operation of the power battery.

[0003] Currently, mainstream BMS architectures are divided into centralized and distributed types. Centralized BMS uses a single management chip to monitor multiple series-connected battery cells, which has drawbacks such as high high-voltage withstand requirements, large energy loss, complex wiring harnesses, and data loss due to chip failure. To address these issues, the industry has gradually developed a distributed BMS architecture, which uses a design where each battery cell corresponds to a single battery management chip. The chip is powered by the corresponding cell, eliminating the need to deal with the high voltage of multiple series-connected cells. This reduces the requirements for chip manufacturing processes, decreases the use of sampling wiring harnesses and connectors, and improves system flexibility, making it the mainstream development direction for automotive BMS.

[0004] However, existing distributed BMS technology solutions still have the following technical shortcomings:

[0005] First, communication reliability is insufficient and anti-interference capability is poor. Existing distributed BMS mostly adopt single-channel wireless communication or daisy-chain wired communication architecture. Under the complex operating conditions of strong electromagnetic fields and strong vibrations in vehicles, single-channel wireless communication is prone to signal attenuation, increased packet loss rate, increased latency, and even complete communication interruption. This results in the inability to upload cell data and send control commands, creating blind spots in battery pack monitoring and easily leading to safety accidents such as thermal runaway. On the other hand, daisy-chain wired communication has the drawbacks of complex wiring harnesses and the possibility of a single point of failure causing the entire link to be interrupted.

[0006] Second, communication congestion and insufficient real-time performance occur in multi-cell scenarios. As vehicle power batteries develop towards higher capacity and higher series number, the number of cells in a single battery pack can reach hundreds. In existing technologies, all battery management chips need to communicate point-to-point with the main controller, which can easily cause wireless channel congestion and lead to a significant increase in data upload latency.

[0007] Third, the control end has a single point of failure risk, and the system's functional safety level is insufficient. Existing distributed BMS generally adopts a single master controller architecture. Once the master controller or its communication module crashes or experiences hardware failure, the entire battery management system will be completely paralyzed, making it impossible to monitor and protect the power battery.

[0008] Fourth, the multi-cell sampling synchronization accuracy is insufficient in the distributed architecture. In existing distributed solutions, each battery management chip uses an independent local clock. The uncertainty of wireless transmission latency will cause the sampling clocks of each chip to be out of sync. The synchronization deviation of multi-cell data acquisition can reach the millisecond level, which directly affects the estimation accuracy of the battery pack's state of charge (SOC) and state of health (SOH), and may even cause cell overcharging and over-discharging faults, shortening the battery cycle life.

[0009] Therefore, there is an urgent need to develop a distributed battery management system with dual-link heterogeneous redundant communication, wireless distributed mesh network, dual-redundant hot standby control, and high-precision full-network synchronization to completely solve the above-mentioned defects of existing technologies and meet the higher safety level requirements of vehicle power battery BMS. Summary of the Invention

[0010] Based on the technical problems described above, this invention provides a dual-link heterogeneous communication method and a distributed battery management system, which solves the above-mentioned technical problems in the prior art and improves the safety of vehicle-mounted BMS.

[0011] Specifically, according to one aspect of the present invention, a distributed battery management system is provided, comprising:

[0012] Multiple battery management chips, each of which is connected to a single battery cell in a one-to-one correspondence;

[0013] The control module includes a main control unit and a backup control unit. Both the main control unit and the backup control unit are equipped with dual heterogeneous communication interfaces that communicate with the battery management chip. When the main control unit is working normally, the backup control unit keeps real-time data synchronized with the main control unit. When the main control unit fails, the backup control unit takes over the communication and control authority of the system.

[0014] Battery pack power bus;

[0015] The battery management chip includes:

[0016] The cell data sampling module is used to collect the status data of the corresponding cell;

[0017] A data processing module, connected to the cell data sampling module, is used to process the cell data;

[0018] The first communication module is bidirectionally connected to the data processing module and includes a main communication link and a backup communication link. The main communication link is a wireless communication unit used for data transmission under normal operating conditions. The backup communication link is a power line carrier communication unit, whose coupling end is connected to the power bus of the battery pack.

[0019] The communication link monitoring module is used to monitor the communication quality between the main communication link and the backup communication link in real time, and when the main communication link is determined to be abnormal according to the preset abnormality judgment rules, the first communication module is controlled to switch the data transmission to the backup communication link.

[0020] The clock synchronization module is used to provide a clock reference and achieve clock synchronization with other battery management chips in the system.

[0021] According to certain preferred embodiments of the present invention, the main communication link of the first communication module supports a wireless distributed mesh network protocol, and each battery management chip is configured to act as both a communication terminal and a relay node to perform data interaction and relay forwarding with adjacent battery management chips; the data processing module includes a dynamic routing algorithm subunit, which is used to select a data transmission path based on channel quality and / or communication delay.

[0022] According to certain preferred embodiments of the present invention, the data transmission path selection rules preset by the dynamic routing algorithm subunit include:

[0023] Prioritize the selection of transmission paths with end-to-end communication latency lower than a first preset latency threshold and packet loss rate lower than a first preset packet loss rate threshold;

[0024] When the direct link between the battery management chip and the control module is interrupted, the battery management chip with communication quality that meets the preset relay conditions is automatically selected from the adjacent nodes as a relay node, and the data is transmitted through the relay node.

[0025] According to certain preferred embodiments of the present invention, the backup control unit is used to detect the working status of the main control unit in real time while maintaining real-time data synchronization with the main control unit; when it is detected that the main control unit has at least one of the following faults: core controller stops working, its own dual heterogeneous communication interface is interrupted in the entire link, or power supply is abnormal, it takes over the communication and control authority of the system within a preset time.

[0026] According to certain preferred embodiments of the present invention, the communication link monitoring module has preset anomaly determination rules including: when at least one of the following occurs, the main communication link is determined to be abnormal: the signal-to-noise ratio of the main communication link is lower than a first threshold, the continuous packet loss rate is higher than a second threshold, or the one-way transmission delay is higher than a third threshold.

[0027] According to certain preferred embodiments of the present invention, the backup communication link is a power line carrier communication unit employing narrowband power line carrier technology, with a carrier frequency band of 3kHz-500kHz, and is connected to the power bus of the battery pack via capacitive coupling.

[0028] According to certain preferred embodiments of the present invention, the clock synchronization module includes a high-precision temperature-compensated crystal oscillator and a network-wide time synchronization subunit. The network-wide time synchronization subunit is used to synchronize time with all battery management chips in the system through the network of the first communication module using a distributed bidirectional time synchronization algorithm.

[0029] According to certain preferred embodiments of the present invention, the cell data sampling module is connected to the clock synchronization module, and is used to trigger cell data sampling at the same time as other battery management chips based on the synchronized clock reference, and to make the sampled data carry a synchronization timestamp.

[0030] According to another aspect of the present invention, a dual-link heterogeneous communication method is provided, applied to the above-mentioned distributed battery management system, the dual-link heterogeneous communication method comprising the following steps:

[0031] S1. System initialization: Configure the communication parameters of the main communication link and the backup communication link for each battery management chip, and establish a real-time data synchronization channel between the main control unit and the backup control unit in the control module.

[0032] S2. Communication network construction: A wireless distributed mesh network is constructed based on the main communication links of each battery management chip, so that each battery management chip acts as a node in the network and has terminal communication and relay forwarding functions.

[0033] S3. Network-wide time synchronization: The network-wide time synchronization is performed through the wireless distributed mesh network to unify the sampling time reference of all battery management chips.

[0034] S4. Data Acquisition and Upload: Based on a unified sampling time reference, each battery management chip synchronously acquires the status data of the corresponding cell and uploads the data to the main control unit via the main communication link through the wireless distributed mesh network and the dynamically selected optimal path.

[0035] S5. Communication link monitoring and switching: Real-time monitoring of the communication quality between the main communication link and the backup communication link; When the main communication link is determined to be abnormal, switching from the main communication link to the backup communication link for data transmission.

[0036] S6. Control unit switching: Real-time monitoring of the working status of the main control unit. When a fault is detected in the main control unit, the backup control unit, which has synchronized data in real time, takes over the communication and control authority of the system.

[0037] According to certain preferred embodiments of the present invention, step S5 further includes:

[0038] When the main communication link is determined to be abnormal, the backup communication link is activated and the link is verified. After the verification is successful, the data transmission service is switched to the backup communication link. When the main communication link is detected to have returned to normal and been running stably for a predetermined time, the data transmission service is switched back from the backup communication link to the main communication link.

[0039] The dual-link heterogeneous communication method and distributed management system proposed in this invention, which employs a dual-link heterogeneous communication architecture and combines the flexibility of short-range high-speed wireless communication with the strong anti-interference capability of power line carrier communication (PLC), significantly improves communication reliability and eliminates communication blind spots. This invention utilizes a wireless distributed mesh network mechanism, allowing each battery management chip to function as both a terminal and a relay, eliminating the need for point-to-point communication with the control module. This significantly reduces the communication load on the control module and the occupancy rate of the wireless channel, meeting the real-time control requirements of the vehicle-mounted BMS. Furthermore, a direct communication failure of a single chip will not affect the operation of other chips, greatly improving system robustness. In addition, the dual-redundant control module architecture adopted in this invention effectively solves the system paralysis problem caused by single-point failure in traditional single-controller architectures, meeting higher safety requirements for vehicles. Attached Figure Description

[0040] The accompanying drawings are provided in this specification to more clearly explain the technical solutions of the present invention; however, the art is not limited thereto. The flowcharts shown in the drawings are merely illustrative and do not necessarily include all contents and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be decomposed, combined, or partially merged, so the actual execution order may change according to the actual situation.

[0041] Figure 1 This is a schematic diagram of the overall architecture of a distributed battery management system according to one embodiment of the present invention;

[0042] Figure 2 This is a schematic diagram of the internal module architecture of a battery management chip according to one embodiment of the present invention;

[0043] Figure 3 This is a schematic diagram of the internal architecture of a control module according to one embodiment of the present invention;

[0044] Figure 4This is a flowchart illustrating the steps of a dual-link heterogeneous communication method according to an embodiment of the present invention.

[0045] Explanation of reference numerals in the attached figures:

[0046] S1-S6 Step-by-step flow of dual-link heterogeneous communication method; 1 Distributed battery management system; 10 Battery management chip; 101 Cell data sampling module; 102 Data processing module; 102a Dynamic routing algorithm subunit; 103 First communication module; 104 Communication link monitoring module; 105 Clock synchronization module; 105a High-precision temperature-compensated crystal oscillator; 105b Network-wide time synchronization subunit; 20 Control module; 201 Main control unit; 202 Backup control unit; 203 Dual-channel heterogeneous communication interface; 203a Wireless Mesh communication interface; 203b PLC power line carrier communication interface; 30 Battery pack power bus; 40 Cell. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0048] The definitions of all technical terms in this invention are as follows:

[0049] 1. Dual-link heterogeneous communication: refers to a redundant communication link that uses two different physical transmission media, different communication protocol stacks, and is electrically isolated from each other. In this invention, a wireless distributed mesh network (Mesh) main communication link and a power line carrier communication (PLC) backup communication link are specifically used.

[0050] 2. Wireless Distributed Mesh Network: Also known as a Mesh network, it refers to a decentralized peer-to-peer network topology in which all nodes in the network are completely equal in status. Each node has the dual functions of a communication terminal and a routing relay, which can realize multi-hop relay transmission of data and network self-healing.

[0051] 3. Multi-hop transmission: refers to a communication method in which data is transmitted from the source node to the destination node through one or more relay forwardings between network nodes.

[0052] 4. Network-wide time synchronization: This refers to using a distributed time synchronization algorithm to ensure that the local clocks of all battery management chips in the network are consistent with the system reference clock, thereby enabling the synchronous triggering of sampling actions by multiple nodes.

[0053] Example 1

[0054] like Figure 1 As shown, the overall architecture of the distributed battery management system in this embodiment includes multiple battery management chips, a control module, a battery pack power bus, and multiple battery cells.

[0055] Each battery management chip is connected to a single battery cell in a one-to-one manner. This means each chip is responsible for the status acquisition, data processing, and communication of only one corresponding cell, forming a distributed management architecture at the single-cell level. This avoids the risk of losing monitoring of multiple cells due to a single chip failure in a centralized BMS. All cells are connected in series to form the cell group of the power battery pack. The positive and negative output terminals of the cell group are electrically connected to the power bus of the battery pack. The power bus serves as the high-voltage DC transmission bus of the power battery pack, used both to output power to the vehicle load or energy storage converter and as the transmission medium for the backup communication link of this invention.

[0056] Specifically,

[0057] 1. Battery management chip, such as Figure 2 As shown, it includes the following functional modules:

[0058] (1) Cell data sampling module, used to collect the status data of the corresponding cell.

[0059] The sampling input terminal of the cell data sampling module is directly electrically connected to the positive and negative terminals of the corresponding cell to collect full state data of the cell, including but not limited to cell terminal voltage, charging and discharging circuit current, cell surface temperature, cell internal resistance, and tab temperature. The cell data sampling module can be configured as, for example, a 16-bit or higher high-precision analog-to-digital converter (ADC), with a configurable sampling rate, supporting synchronous sampling up to 1MS / s, meeting the requirements for accurate cell state acquisition under highly dynamic operating conditions. The output terminal of the cell data sampling module is connected to the data processing module, which can transmit the collected raw cell state data to the data processing module in real time for processing.

[0060] Specifically, the cell data sampling module is electrically connected to the clock synchronization module. Based on the synchronous clock reference output by the clock synchronization module, it can trigger cell data sampling at the same time as all other battery management chips in the system, and add a synchronization timestamp to each set of data collected, ensuring the time consistency of multi-cell sampling data and solving the problem of insufficient SOC / SOH estimation accuracy caused by asynchronous sampling in the existing technology.

[0061] (2) A data processing module, connected to the cell data sampling module, for processing the cell data.

[0062] The data processing module is configured, for example, to use a 32-bit low-power microprocessor core with built-in random access memory (RAM) and non-volatile flash memory (Flash) to perform preprocessing such as digital filtering, temperature calibration, linearity compensation, and data verification on the raw data uploaded by the cell data sampling module, while executing dynamic routing algorithms, link switching logic, clock synchronization calibration, and cell basic protection logic.

[0063] The data processing module includes a dynamic routing algorithm subunit. This subunit has preset rules for selecting data transmission paths and can select the optimal transmission path for each data transmission based on real-time monitored parameters such as channel quality, communication latency, and packet loss rate. Specifically, the path selection rules are as follows: Prioritize transmission paths with end-to-end communication latency below a first preset latency threshold (e.g., 50ms) and packet loss rate below a first preset packet loss rate threshold (e.g., 5%); when multiple paths meet these conditions, prioritize the transmission path with the fewest hops to reduce latency loss from multi-hop transmission; when the direct link between the battery management chip and the control module is interrupted, automatically select a battery management chip with communication quality meeting preset relay conditions from adjacent nodes as a relay node, and complete multi-hop data transmission through this relay node to achieve network self-healing.

[0064] (3) A first communication module, which is bidirectionally connected to the data processing module, includes a main communication link and a backup communication link; the main communication link is a wireless communication unit used for data transmission under normal operating conditions; the backup communication link is a power line carrier communication unit, whose coupling end is connected to the power bus of the battery pack.

[0065] The main communication link is a wireless communication unit employing a short-range, low-power wireless radio frequency architecture. It supports a wireless distributed mesh network (Mesh) protocol, with each battery management chip configured as a peer node in the Mesh network. This node acts as both a communication terminal for its own data transmission and reception and a relay node for providing data forwarding services to neighboring nodes. It can perform bidirectional data interaction and relay forwarding with adjacent battery management chips. The main communication link operates in a frequency band that can be, for example, a Sub-GHz unlicensed band or a 2.4GHz unlicensed band. Its transmit power is adjustable, meeting automotive electromagnetic compatibility (EMC) standards and ensuring communication stability under complex operating conditions.

[0066] The backup communication link is a power line carrier communication unit, which can employ narrowband power line carrier technology with a carrier frequency band of 3kHz-500kHz, preferably conforming to the international standard CENELEC A band (3kHz-95kHz), effectively avoiding high-frequency electromagnetic interference in vehicles. The coupling end of the power line carrier communication unit is connected to the battery pack power bus via a high-voltage, temperature-resistant coupling capacitor. The high-frequency carrier signal is modulated onto the high-voltage DC power of the battery pack power bus through capacitive coupling, enabling bidirectional data transmission. The backup communication link incorporates a spread spectrum modulation module and a forward error correction coding module, possessing strong anti-pulse interference and anti-attenuation capabilities, ensuring continuous data transmission even in extreme conditions where the wireless link completely fails.

[0067] (4) Communication link monitoring module, used to monitor the communication quality between the main communication link and the backup communication link in real time, and when the main communication link is abnormal, control the first communication module to switch the data transmission to the backup communication link.

[0068] The communication link monitoring module is bidirectionally connected to both the main communication link and the backup communication link of the first communication module, and is also electrically connected to the data processing module. Its core function is to monitor all communication quality parameters of the main communication link and the backup communication link in real time at a preset monitoring period (preferably 1ms), including but not limited to: link signal-to-noise ratio, received signal strength indication (RSSI), continuous packet loss rate, one-way transmission delay, bit error rate, etc.; and to determine whether the main communication link is abnormal according to preset anomaly judgment rules. When the main communication link is determined to be abnormal, the module controls the first communication module to seamlessly switch the data transmission service to the backup communication link.

[0069] The specific rules for determining main communication link anomalies are as follows: When the main communication link meets at least one of the following conditions: signal-to-noise ratio below a first threshold (e.g., 25dB), continuous packet loss rate above a second threshold (e.g., 5%), or one-way transmission delay above a third threshold (e.g., 50ms), the main communication link is determined to be abnormal. The communication link monitoring module then controls the first communication module to switch data transmission to the backup communication link. Simultaneously, after switching to the backup link, the communication link monitoring module continuously monitors the status of the main communication link. When the main communication link is detected to have returned to normal and been operating stably for a preset time, the module controls the first communication module to smoothly switch back from the backup communication link to the main communication link, restoring normal operation.

[0070] (5) Clock synchronization module, used to provide a clock reference and realize clock synchronization with other battery management chips in the system.

[0071] The clock synchronization module is electrically connected to the data processing module and the cell data sampling module, and includes a high-precision temperature-compensated crystal oscillator (TCXO) and a network-wide time synchronization subunit. The high-precision TCXO has a frequency stability better than ±1ppm and an operating temperature range of -40℃ to 105℃, meeting the application requirements of wide-temperature conditions such as automotive and energy storage, and providing a stable local clock reference for the chip. The network-wide time synchronization subunit is used to construct a wireless distributed mesh network through the first communication module. It employs a distributed bidirectional time synchronization algorithm to perform clock calibration with all battery management chips in the system, achieving network-wide time synchronization.

[0072] II. Control Module

[0073] like Figure 3 As shown, the control module includes a main control unit, a backup control unit, and a dual heterogeneous communication interface that is compatible with both.

[0074] The main control unit and the backup control unit adopt a completely symmetrical architecture with the same hardware source and the same software version. Both are configured with, for example, 32-bit automotive-grade microcontrollers (MCUs) that meet functional safety level requirements. They can independently perform core functions such as battery pack state of charge (SOC), state of health (SOH), state of energy (SOE) estimation, cell balancing control, charge and discharge management, fault diagnosis and protection, and external communication and interaction.

[0075] A real-time data synchronization channel is established between the main control unit and the backup control unit via a high-speed serial bus, with a synchronization period of no more than 10ms. The synchronized content includes, but is not limited to, the status data of all battery cells, system configuration parameters, control commands, fault records, operating status data, and network routing tables. When the main control unit is working normally, the backup control unit is in hot standby mode, maintaining real-time full data synchronization with the main control unit while independently monitoring the operating status of the main control unit. When the main control unit fails, the backup control unit can take over all communication and control authority of the system within a preset time (e.g., preferably no more than 100ms), preventing a single point of failure in the main control unit from paralyzing the entire battery management system.

[0076] The dual heterogeneous communication interface is configured to include two sets of communication interfaces that are fully matched with the first communication module of the battery management chip: one is a wireless Mesh communication interface corresponding to the main communication link, and the other is a PLC power line carrier communication interface corresponding to the backup communication link. The two sets of interfaces are bidirectionally connected to the main control unit and the backup control unit, respectively, to ensure that both control units can independently complete the full-link communication with all battery management chips.

[0077] Specifically, the backup control unit has a pre-set fault judgment rule for the main control unit. When it detects that the main control unit has at least one of the following faults: the core controller stops working, the entire link of its own dual heterogeneous communication interface is interrupted, or the power supply is abnormal, it immediately triggers the takeover action. The backup control unit takes over the communication and control authority of the system to ensure the continuous operation of the system.

[0078] Example 2

[0079] like Figure 4 As shown below, the process of the dual-link heterogeneous communication method applied to the above-mentioned distributed battery management system in this embodiment is described in detail below.

[0080] Step S1: System initialization.

[0081] After the power battery pack is powered on at low voltage, the control module and all battery management chips complete a hardware self-test. The self-test includes the functional integrity of the sampling module, communication module, clock module, and power module. After the self-test passes, the main control unit of the control module configures unified communication parameters for all battery management chips and assigns a unique node communication address to each battery management chip.

[0082] The unified parameters for a Mesh network include network ID, communication channel, encryption key, and communication rate.

[0083] The unified parameters for PLC communication include carrier frequency band, spreading factor, and error correction coding rules, and a unique PLC communication address is assigned to each battery management chip.

[0084] After the parameters are configured, a real-time data synchronization channel is established between the main control unit and the backup control unit to complete the full initial synchronization of system configuration parameters and operating status, and the synchronization period is set, preferably 5ms, and real-time data synchronization is maintained throughout the process thereafter.

[0085] Step S2, Communication Network Construction.

[0086] The main control unit acts as the coordinator of the mesh network, periodically sending network beacon frames. After all battery management chips complete parameter configuration, they scan beacon frames to complete network access and node registration. After registration, each battery management chip broadcasts a neighbor node discovery frame to identify neighboring nodes and perform link quality checks, generating a local neighbor table and an initial routing table, ultimately constructing a wireless distributed mesh network. After the network is built, each battery management chip has dual functions of terminal communication and relay forwarding, enabling bidirectional data interaction and relay forwarding with neighboring nodes.

[0087] After the Mesh network is built synchronously, the main control unit and all battery management chips complete the initialization configuration and handshake verification of the PLC backup communication link, so that the PLC backup link is in a hot standby state throughout the process, preparing for subsequent link switching.

[0088] Step S3: Time synchronization across the entire network.

[0089] The main control unit sends a reference clock synchronization frame through the constructed Mesh network, with the frame carrying a system reference timestamp. After receiving the synchronization frame, each battery management chip uses a distributed bidirectional time synchronization algorithm based on the high-precision temperature-compensated crystal oscillator of its local clock synchronization module to perform bidirectional timestamp interaction with adjacent nodes, calculate the frequency and phase deviations between its local clock and the reference clock, and complete local clock calibration. After calibration, all nodes in the network perform synchronization accuracy verification. When the deviations between the local clocks of all battery management chips and the system reference clock do not exceed a preset threshold (preferably ±2μs), the time synchronization of the entire network is considered complete, achieving a unified clock reference for the entire network.

[0090] The following steps S4-S6 are executed in parallel and in real-time loops, specifically:

[0091] Step S4: Data collection and uploading.

[0092] Based on a unified synchronous clock reference, all battery management chips trigger cell data sampling at the same time, synchronously collecting cell status data such as voltage, current, temperature, and internal resistance of the corresponding cells. The data processing module performs digital filtering, temperature calibration, and linearity compensation on the sampled data, and adds a synchronization timestamp and a unique node ID to the data packets. The dynamic routing algorithm subunit in the data processing module selects the optimal transmission path based on real-time monitored link quality, communication latency, and packet loss rate, and uploads the data packets to the main control unit through the Mesh main link. After receiving the data packets from all cells, the main control unit completes the estimation of battery pack status such as SOC, SOH, and SOE, performs fault diagnosis and cell balancing control, and uploads the overall battery pack status data to the vehicle controller.

[0093] Step S5: Communication link monitoring and switching.

[0094] The communication link monitoring module monitors the communication quality parameters of the Mesh main link in real time at a certain period (preferably 1ms), such as signal-to-noise ratio, received signal strength, continuous packet loss rate, and one-way transmission delay. When the main link meets any abnormal judgment condition for 10 consecutive monitoring cycles, the PLC backup communication link is immediately started, and a link handshake frame is sent to the control module to complete the link verification. After the verification is successful, all data transmission services are seamlessly switched to the PLC backup link. After the switch is completed, the communication quality of the Mesh main link is continuously monitored. When the main link is found to have returned to normal and the communication quality meets the preset qualified threshold for 100 consecutive monitoring cycles, the data transmission services are smoothly switched back from the PLC backup link to the Mesh main link.

[0095] Step S6: Switch control unit.

[0096] The backup control unit monitors the operating status of the main control unit in real time at a certain period (preferably 1ms). The monitoring content includes, but is not limited to, the operating status of the MCU core, the status of the dual communication interface, the power supply status, and the program running status. When the main control unit is found to have any of the preset fault types for 10 consecutive monitoring cycles, the takeover action is immediately triggered. Within 50ms, the takeover of all communication and control permissions of the system is completed. Based on the real-time synchronized data, the monitoring, protection and control of the battery pack are continued, and the fault information of the main control unit is reported at the same time.

[0097] By employing the dual-link heterogeneous communication method and distributed battery management system of this invention, the problems of poor anti-interference capability of single-channel wireless communication, easy communication interruption under complex vehicle operating conditions, and insufficient reliability are solved, ensuring the full controllability of the battery management system. This invention, through a distributed mesh self-organizing network mechanism, enables each battery management chip to have both terminal and relay functions, solving the problems of channel congestion and insufficient real-time data transmission caused by point-to-point communication in multi-cell scenarios. The dual-redundant control module architecture adopted by this invention solves the problem that single-control module architecture has a single point of failure, which can easily lead to the paralysis of the entire system. In addition, time synchronization of all battery management chips is achieved by relying on the distributed mesh self-organizing network.

[0098] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus or device (such as a computer system, a system including a processor or other system that can fetch and execute instructions from an instruction execution system, apparatus or device).

[0099] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. The same applies to "target," "original," etc., and will not be repeated here. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0100] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0101] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0102] It should also be further understood that the term "and / or" as used in this specification refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes such combinations.

[0103] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A distributed battery management system, characterized by, include: Multiple battery management chips, each of which is connected to a single battery cell in a one-to-one correspondence; The control module includes a main control unit and a backup control unit. Both the main control unit and the backup control unit are equipped with dual heterogeneous communication interfaces that communicate with the battery management chip. When the main control unit is working normally, the backup control unit keeps real-time data synchronized with the main control unit. When the main control unit fails, the backup control unit takes over the communication and control authority of the system. Battery pack power bus; The battery management chip includes: The cell data sampling module is used to collect the status data of the corresponding cell; A data processing module, connected to the cell data sampling module, is used to process the status data; The first communication module is bidirectionally connected to the data processing module and includes a main communication link and a backup communication link. The main communication link is a wireless communication unit used for data transmission under normal operating conditions. The backup communication link is a power line carrier communication unit, whose coupling end is connected to the power bus of the battery pack. The communication link monitoring module is used to monitor the communication quality between the main communication link and the backup communication link in real time, and when the main communication link is determined to be abnormal according to the preset abnormality judgment rules, the first communication module is controlled to switch the data transmission to the backup communication link. The clock synchronization module is used to provide a clock reference and achieve clock synchronization with other battery management chips in the system.

2. The distributed battery management system of claim 1, wherein, The main communication link of the first communication module supports the wireless distributed mesh network protocol. Each battery management chip is configured to act as both a communication terminal and a relay node to perform data interaction and relay forwarding with adjacent battery management chips. The data processing module includes a dynamic routing algorithm subunit, which is used to select a data transmission path based on channel quality and / or communication delay.

3. The distributed battery management system of claim 2, wherein, The preset data transmission path selection rules of the dynamic routing algorithm subunit include: Prioritize the selection of transmission paths with end-to-end communication latency lower than a first preset latency threshold and packet loss rate lower than a first preset packet loss rate threshold; When the direct link between the battery management chip and the control module is interrupted, the battery management chip with communication quality that meets the preset relay conditions is automatically selected from the adjacent nodes as a relay node, and the data is transmitted through the relay node.

4. The distributed battery management system of claim 1, wherein, The backup control unit is used to detect the working status of the main control unit in real time while maintaining real-time data synchronization with the main control unit; when it detects that the main control unit has at least one of the following faults: core controller stops working, its own dual heterogeneous communication interface is interrupted in the entire link, or power supply is abnormal, it takes over the communication and control authority of the system within a preset time.

5. The distributed battery management system of claim 1, wherein, The communication link monitoring module has preset anomaly determination rules, including: when at least one of the following occurs, the main communication link is determined to be abnormal: the signal-to-noise ratio of the main communication link is lower than the first threshold, the continuous packet loss rate is higher than the second threshold, or the one-way transmission delay is higher than the third threshold.

6. The distributed battery management system of claim 1, wherein, The backup communication link is a power line carrier communication unit using narrowband power line carrier technology, with a carrier frequency band of 3kHz-500kHz, and is connected to the power bus of the battery pack via capacitive coupling.

7. The distributed battery management system according to claim 1, characterized in that, The clock synchronization module includes a high-precision temperature-compensated crystal oscillator and a network-wide time synchronization subunit. The network-wide time synchronization subunit is used to synchronize time with all battery management chips in the system through the network of the first communication module using a distributed bidirectional time synchronization algorithm.

8. The distributed battery management system according to claim 7, characterized in that, The cell data sampling module is connected to the clock synchronization module and is used to trigger cell data sampling at the same time as other battery management chips based on the synchronized clock reference, and to make the sampled data carry a synchronization timestamp.

9. A dual-link heterogeneous communication method, applied to a distributed battery management system according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1. System initialization: Configure the communication parameters of the main communication link and the backup communication link for each battery management chip, and establish a real-time data synchronization channel between the main control unit and the backup control unit in the control module. S2. Communication network construction: A wireless distributed mesh network is constructed based on the main communication links of each battery management chip, so that each battery management chip acts as a node in the network and has terminal communication and relay forwarding functions. S3. Network-wide time synchronization: The network-wide time synchronization is performed through the wireless distributed mesh network to unify the sampling time reference of all battery management chips. S4. Data Acquisition and Upload: Based on a unified sampling time reference, each battery management chip synchronously acquires the status data of the corresponding cell and uploads the data to the main control unit via the main communication link through the wireless distributed mesh network and the dynamically selected optimal path. S5. Communication link monitoring and switching: Real-time monitoring of the communication quality between the main communication link and the backup communication link; When the main communication link is determined to be abnormal, switching from the main communication link to the backup communication link for data transmission. S6. Control unit switching: Real-time monitoring of the working status of the main control unit. When a fault is detected in the main control unit, the backup control unit, which has synchronized data in real time, takes over the communication and control authority of the system.

10. The dual-link heterogeneous communication method according to claim 9, characterized in that, Step S5 further includes: When the main communication link is determined to be abnormal, the backup communication link is activated and the link is verified. After the verification is successful, the data transmission service is switched to the backup communication link. When the main communication link is detected to have returned to normal and been running stably for a predetermined time, the data transmission service is switched back from the backup communication link to the main communication link.

Images