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CN-122025877-A - Double-link heterogeneous communication method and distributed battery management system

CN122025877ACN 122025877 ACN122025877 ACN 122025877ACN-122025877-A

Abstract

The invention provides a double-link heterogeneous communication method and a distributed battery management system, wherein the system comprises a plurality of battery management chips, a plurality of communication units and a plurality of communication units, wherein each battery management chip is correspondingly connected with a single battery cell; the battery management chip comprises a battery core 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 by the invention can effectively solve the system paralysis problem caused by single-point faults of the traditional single-controller architecture, and meets the requirement of higher safety level of the vehicle.

Inventors

  • SUN HUAPENG
  • LI TAISHI
  • XU JIANJUN

Assignees

  • 郴州新能源电池材料研究中心
  • 郴州市尚亿新能源有限公司
  • 郴江实验室

Dates

Publication Date
20260512
Application Date
20260409

Claims (10)

  1. 1. A distributed battery management system, comprising: Each battery management chip is connected with a single battery cell in a one-to-one correspondence manner; The control module comprises a main control unit and a standby control unit, wherein the main control unit and the standby control unit are respectively provided with a two-way heterogeneous communication interface for communicating with the battery management chip; A battery pack power bus; wherein, the battery management chip includes: the battery core data sampling module is used for collecting state data of the corresponding battery core; the data processing module is connected with the electric core data sampling module and is used for processing the state data; The system comprises a data processing module, a first communication module, a second communication module and a power line carrier communication module, wherein the data processing module is in bidirectional connection with the first communication module and comprises a main communication link and a standby communication link; The communication link monitoring module is used for monitoring the communication quality of the main communication link and the standby communication link in real time, and controlling the first communication module to switch data transmission to the standby communication link when the main communication link is abnormal according to a preset abnormality judgment rule; And the clock synchronization module is used for providing a clock reference and realizing clock synchronization with other battery management chips in the system.
  2. 2. The system of claim 1, wherein the primary communication link of the first communication module supports a wireless distributed mesh protocol, each of the battery management chips being configured to act as both a communication terminal and a relay node for data interaction and relay forwarding with an adjacent battery management chip, the data processing module comprising a dynamic routing algorithm subunit for selecting a data transmission path based on channel quality and/or communication latency.
  3. 3. The distributed battery management system of claim 2, wherein the selection rules of the data transmission paths preset by the dynamic routing algorithm subunit include: preferentially selecting a transmission path with end-to-end communication time delay lower than a first preset time delay 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 the communication quality meeting the preset relay condition is automatically selected from the adjacent nodes to serve as a relay node, and the multi-hop transmission of the data is completed through the relay node.
  4. 4. The distributed battery management system according to claim 1, wherein the standby control unit is configured to detect an operation state of the main control unit in real time while maintaining real-time data synchronization with the main control unit, and take over communication and control rights of the system within a preset time when it is detected that the main control unit has at least one of a core controller stop operation, a full link interrupt of a self two-way heterogeneous communication interface, and a power abnormality.
  5. 5. The distributed battery management system of claim 1, wherein the anomaly determination rules preset by the communication link monitoring module include determining that the primary communication link is anomalous when at least one of a signal-to-noise ratio of the primary communication link is below a first threshold, a continuous packet loss rate is above a second threshold, or a unidirectional transmission delay is above a third threshold.
  6. 6. The distributed battery management system of claim 1, wherein the backup communication link is a power line carrier communication unit adopting a narrowband power line carrier technology, and the carrier frequency band is 3kHz-500kHz and is connected with the battery pack power bus by a capacitive coupling mode.
  7. 7. The distributed battery management system of claim 1, wherein the clock synchronization module comprises a high-precision temperature compensation crystal oscillator and a full-network time synchronization subunit, and the full-network time synchronization subunit is configured to perform time synchronization with all battery management chips in the system by using a distributed bidirectional time synchronization algorithm through the network of the first communication module.
  8. 8. The distributed battery management system of claim 7, wherein the cell data sampling module is connected to the clock synchronization module and configured to trigger cell data sampling at the same time as other battery management chips based on the synchronized clock reference, and to cause the sampled data to carry a synchronization timestamp.
  9. 9. A double-link heterogeneous communication method applied to the distributed battery management system according to any one of claims 1 to 8, characterized by comprising the steps of: S1, initializing a system, configuring communication parameters of a main communication link and a standby communication link for each battery management chip, and establishing a real-time data synchronization channel between a main control unit and a standby control unit in a control module; S2, constructing a communication network, and constructing a wireless distributed mesh network based on a main communication link of each battery management chip, so that each battery management chip is used as a node in the network and has the functions of terminal communication and relay forwarding; S3, performing whole-network time synchronization through the wireless distributed mesh network, and unifying sampling time references of all battery management chips; s4, data acquisition and uploading, wherein based on a unified sampling time reference, each battery management chip synchronously acquires state data of a corresponding battery core, and uploads the data to the main control unit through the main communication link according to a dynamically selected optimal path through the wireless distributed mesh network; S5, monitoring and switching a communication link, monitoring the communication quality of the main communication link and the standby communication link in real time, and switching from the main communication link to the standby communication link for data transmission when the main communication link is abnormal; S6, switching the control unit, monitoring the working state of the main control unit in real time, and taking over the communication and control authority of the system by the standby control unit which has synchronized data in real time when the fault of the main control unit is monitored.
  10. 10. The double-link heterogeneous communication method according to claim 9, wherein the step S5 further comprises: When the main communication link is judged to be abnormal, the standby communication link is started and link verification is carried out, and after the verification is passed, the data transmission service is switched to the standby communication link; and switching data transmission traffic from the backup communication link back to the primary communication link after monitoring that the primary communication link has resumed normal and stable operation for a predetermined time.

Description

Double-link heterogeneous communication method and distributed battery management system Technical Field The invention relates to the field of battery management systems, in particular to a double-link heterogeneous communication method and a distributed battery management system. Background Along with the rapid development of the new energy automobile industry, the power battery is used as a core power component of the new energy automobile, and the use safety, the cycle life and the performance stability of the power battery directly determine the comprehensive performance of the whole automobile. The Battery management system (Battery MANAGEMENT SYSTEM, BMS) is a core control component of the power Battery, is responsible for collecting, analyzing and protecting state data such as voltage, current, temperature, internal resistance and the like of each Battery cell in the Battery pack, and is a core defense line for guaranteeing the safe operation of the power Battery. Currently, the mainstream BMS architecture is divided into two types, centralized and distributed. The centralized BMS monitors multiple strings of series-connected battery cells by adopting a single management chip, and has the defects of high-voltage tolerance requirement, large energy loss, complex wiring harness, loss of data of the whole package caused by chip failure and the like. Aiming at the problems, a distributed BMS architecture is gradually developed in the industry, a single battery cell is adopted to correspond to a design of a single battery management chip, the chip is powered by the corresponding battery cell, the high voltage of series connection of multiple battery cells is not required, the production process requirement of the chip is reduced, the use of sampling wire harnesses and connectors is reduced, the system flexibility is improved, and the distributed BMS architecture becomes the main stream development direction of the vehicle-mounted BMS. However, the distributed BMS technical solution of the prior art still has the following technical drawbacks: First, communication reliability is insufficient and anti-interference capability is poor. The existing distributed BMS mostly adopts a single-path wireless communication or a daisy chain wired communication architecture, the problems of signal attenuation, increased packet loss rate, increased time delay and even complete communication interruption are easy to occur in the single-path wireless communication under the complex working conditions of strong electromagnetic and strong vibration of the vehicle, so that the battery cell data cannot be uploaded and the control instruction cannot be issued, a battery pack monitoring blind area is formed, safety accidents such as thermal runaway and the like are easy to occur, and the defects of complex wiring harness and interruption of the whole link communication caused by single-point faults exist in the daisy chain wired communication. Secondly, communication is jammed in a multi-cell scene, and instantaneity is insufficient. Along with the development of the vehicle-mounted power battery to the directions of high capacity and high serial number, the number of battery cells in a single battery pack can reach hundreds of battery cells, and all battery management chips in the prior art need to be communicated with a main controller point to point, so that wireless channel congestion is easily caused, and the time delay of data uploading is greatly increased. Thirdly, the control end has single-point fault risk, and the safety level of the system function is insufficient. The existing distributed BMS generally adopts a single main controller architecture, and once the main controller or a communication module thereof is down and has hardware faults, the whole battery management system is completely paralyzed, and the power battery cannot be monitored and protected. Fourth, the sampling synchronization accuracy of multiple cells under the distributed architecture is not enough. In the existing distributed scheme, each battery management chip adopts an independent local clock, the sampling clock of each chip is not synchronous due to the uncertainty of wireless transmission, the synchronous deviation of multi-cell data acquisition can reach millisecond level, the estimation accuracy of the battery pack state of charge (SOC) and the state of health (SOH) is directly affected, even the over-charge and over-discharge faults of the cell can be caused, and the cycle life of the battery is shortened. Therefore, there is a need to develop a distributed battery management system with dual-link heterogeneous redundancy communication, wireless distributed mesh network, dual redundancy hot standby control and high-precision full network synchronization, which thoroughly solves the above-mentioned drawbacks of the prior art and meets the requirements of higher safety level of the vehicle-mounted power battery BMS. Disclosure of Invention