Single-cell level wireless battery management system and control method based on near field communication

Abstract

This invention discloses a single-cell-level wireless battery management system and control method based on near-field communication, relating to battery management systems in the fields of new energy ships, electric vehicles, and energy storage. The system adopts a chip-mounted cell architecture, replacing traditional sampling harnesses and isolated communication buses with near-field non-contact radio frequency coupling, enabling wireless acquisition, synchronous transmission, and centralized management of cell-level parameters such as voltage and temperature. The cell monitor is directly mounted on the cell surface and draws power from the monitored cell. It transmits the acquired data to the communication hub via an antenna using near-field communication, and then to the host via SPI. This invention completely eliminates sampling harnesses, acquisition slave boards, and harness connectors, eliminating cable wear and short-circuit risks, improving the energy density and reliability of the battery system, and is particularly suitable for marine high-voltage battery systems with stringent requirements for reliability and electromagnetic compatibility.

Description

Technical Field

[0001] This invention relates to the field of battery management system technology, specifically to a single-cell-level wireless battery management system and control method based on near-field communication, applicable to high-voltage, high-capacity battery applications such as new energy ships, electric vehicles, and large-scale energy storage systems. Background Technology

[0002] Lithium-ion batteries, with their advantages of high energy density, long cycle life, and low self-discharge rate, have been widely used in electric vehicles (EVs), hybrid electric vehicles (HEVs), energy storage systems (ESS), and marine applications. As battery system scale continues to expand, the demands on battery pack voltage and capacity are constantly increasing, especially in marine and large-scale energy storage systems, where traditional wired BMS (Battery Management System) has revealed numerous problems.

[0003] In traditional wired BMS, each battery cell monitoring unit is connected to the main control unit via numerous low-voltage sampling and communication harnesses. These numerous harnesses not only increase the system's weight, size, and cost, but also reduce its flexibility, significantly increasing the difficulty of troubleshooting and maintenance. This is especially problematic in high-vibration environments such as those on ships, where harness wear and loose connectors exacerbate signal transmission reliability issues.

[0004] Existing wireless BMS solutions mostly employ far-field wireless communication such as Bluetooth, Zigbee, or Wi-Fi. However, in environments with metal battery packs and dense electrical wiring, radio frequency signals are easily shielded and attenuated, and electromagnetic compatibility is difficult to meet the stringent requirements of ships. Near-field communication has the advantages of strong anti-interference capabilities and high reliability in short-range transmission, but existing solutions typically suffer from limited antenna coverage and inconvenient power supply. Summary of the Invention

[0005] The purpose of this invention is to provide a single-cell-level wireless battery management system and control method based on near-field communication, which completely eliminates sampling harnesses, acquisition slave boards and harness connectors, thereby improving the energy density and reliability of the battery system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution.

[0007] A single-cell-level wireless battery management system based on near-field communication includes a host module, a communication hub module, an antenna hub, and multiple cell monitors.

[0008] The host module, as the main controller of the system, is responsible for data aggregation, status estimation, safety protection, and charge / discharge management.

[0009] The communication hub module is connected to the host module and serves as the central hub for issuing commands and collecting information from the battery cell monitor.

[0010] The antenna hub connects to the communication hub module via the antenna bus, dividing the antenna bus into multiple antenna sub-lines.

[0011] Multiple cell monitors are mounted on the surface of each cell using a chip-on-cell architecture. Each cell monitor is used to collect voltage and temperature information of the corresponding cell.

[0012] The antenna hub branches out multiple antenna sub-lines to each battery pack, and the antennas inside each battery pack communicate with the cell monitor in the near field.

[0013] The cell monitor transmits the collected information to the communication hub module via near-field communication. The communication hub module then interacts with the host module via the SPI bus.

[0014] The power supply terminals of the cell monitor are directly soldered to the positive and negative tabs of the monitored cell, respectively, drawing power from the monitored cell without the need for an external power supply line. The cell monitor includes a voltage acquisition unit, a temperature acquisition unit, a signal strength acquisition unit, and a passive equalization unit, which can respectively realize the functions of cell voltage acquisition, temperature acquisition, signal strength monitoring, and passive equalization. The chip used in this cell monitor can be the DK8x02 series chip.

[0015] The main control chip of the host module can be an ARM Cortex-M3 or Cortex-M4 series. Each cell monitor supports one voltage acquisition channel and two temperature acquisition channels.

[0016] The system also includes a display screen that communicates with the host module via an RS-485 bus to display the system's total voltage, total current, state of charge, individual cell voltage, individual cell temperature, system operating status, and fault alarm information, enabling human-machine interaction.

[0017] This invention also provides a control method, including the steps of system power-on, command transmission, system networking, data acquisition and uploading, and data reception. After powering the wireless battery management system with a regulated power supply, the host module establishes communication with the communication hub module and sends a networking command. The communication hub module sends a networking request based on the ID information pre-stored in the cell monitor. After being awakened, the cell monitor enters active mode and begins to collect cell voltage and temperature information, transmitting it to the communication hub module via near-field communication through an antenna. The host module receives the battery information forwarded by the communication hub module through the SPI bus, completing data acquisition.

[0018] The communication hub module wakes up each cell monitor one by one and establishes a communication connection based on the unique identifier pre-stored in the cell monitor. The number of cell monitors that can be networked by one communication hub module does not exceed a preset limit to ensure communication stability and data acquisition efficiency.

[0019] The high-voltage charging power-on and power-off process includes: When charging is powered on, the charger is turned on, and the charger's auxiliary power supply supplies power to the wireless battery management system and the display screen. The system performs cell monitoring network setup and self-test. If there is no fault after the self-test, the main negative relay is closed and a communication connection is established with the charger. After the connection is normal, the charging relay is closed and charging begins. When charging is powered off, if the battery system meets the full charge conditions, receives a manual stop charging command, or a serious charging fault occurs, the system disconnects the main negative relay and the charging relay, sets all cell monitors to sleep mode, and exits the network.

[0020] The high-voltage discharge power-on and power-off process includes: When powering on, the wireless battery management system and display screen power supply are turned on. The system forms a network and performs a self-test. If there is no fault after the self-test, the main negative relay and the pre-charge relay are closed to perform pre-charge. After the pre-charge is completed, the discharge relay is closed and the pre-charge relay is opened to start discharging. When powering off, if the battery system meets the full discharge conditions, receives a manual stop discharge command, or a serious discharge fault occurs, the system disconnects the main negative relay and the discharge relay, sets all cell monitors to sleep mode, and exits the network.

[0021] This invention uses "cell-level distributed acquisition - hub-and-spoke centralized forwarding" as its core logic, achieving cell-level wireless acquisition based on near-field communication. Compared to existing technologies: First, the cell monitor is directly mounted on the surface of the cell and draws power from the monitored cell, eliminating the need for additional external power supply lines and further simplifying the system structure; second, the chip-mounted cell architecture completely eliminates sampling harnesses and connectors, significantly reducing the number of components, system weight and volume, and increasing energy density; third, near-field coupled communication has strong anti-interference capabilities, no radio frequency blind spots or transmission delays, making it particularly suitable for complex and harsh environments with strong vibrations and electromagnetic interference, such as those on ships; fourth, the system supports flexible expansion and full lifecycle data management of the cell, outperforming wired and far-field wireless solutions in terms of performance, reliability, and deployment efficiency. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the system structure in the embodiment; Figure 2 This is a schematic diagram of the battery cell monitor connection in the embodiment. Figure 3 This is a flowchart of the high-voltage charging power-on process of the system of the present invention; Figure 4 This is a flowchart of the high-voltage charging power-off process of the system of the present invention; Figure 5 This is a flowchart of the high-voltage discharge power-on process of the system of the present invention; Figure 6 This is a flowchart of the high-voltage discharge power-on process of the system of the present invention; Figure 7 This is a flowchart of the system fault handling process of the present invention. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments, but the implementation of the present invention is not limited thereto. Example

[0024] like Figure 1 As shown, the single-cell-level wireless battery management system (hereinafter referred to as wireless BMS) based on near-field communication in this embodiment includes: a host module, a communication hub module, an antenna bus, an antenna hub, an antenna sub-line, a cell monitor, and a display screen.

[0025] The host module, as the main controller of the system, uses STM32F4 series chips. It is responsible for aggregating information such as individual cell voltage and temperature collected by each cell monitor, realizing multi-level safety protection such as overvoltage, overcurrent, and overheating, and interacting with the inverter and charger through the CAN bus to complete the charging and discharging strategy management.

[0026] The display screen communicates with the host module via RS-485 bus, displaying real-time individual unit voltage, temperature, total voltage, total current, state of charge, system operating status, and alarm information.

[0027] The communication hub module is connected to the host module via the SPI bus. As the hub module for issuing commands and collecting information from all cell monitors, it enables synchronous acquisition of cell-level data, low-latency transmission, and reliable control.

[0028] The antenna hub divides the antenna bus into N antenna sub-lines, which are connected in parallel to N battery packs, greatly shortening the distance from a single battery pack to the communication hub module and improving the stability of near-field communication.

[0029] Each cell monitor is mounted on the surface of the cell using a chip-on-cell architecture. Each battery cell has an independent cell monitor node, which is responsible for collecting data such as voltage, temperature and signal strength of the cell, and transmitting the data directly to the communication hub module via an antenna using near-field communication.

[0030] The cell monitor uses the DK8x02 series chip, supports one-channel voltage acquisition and two-channel temperature acquisition, and has a built-in passive balancing circuit for passive balancing functionality. Figure 2 As shown, the positive and negative terminals of the battery cell monitor are directly soldered to the positive and negative tabs of the monitored battery cell, respectively, and power is drawn directly from the monitored battery cell.

[0031] Figure 3 The high-voltage charging power-on process is illustrated. After the charger's 24V auxiliary power supply powers the wireless battery management system and display screen, the system sends a network setup command to the communication hub. Within a certain time, it determines whether all cell monitors have successfully formed a network: if the network is successful, it begins collecting battery voltage, temperature, and other information and performs a self-test; if the network fails, it reports a system initialization fault. If the self-test is successful, the main negative relay closes and establishes a communication connection with the charger. Once the connection is normal, the charging relay closes, and charging is successfully powered on. The system then requests charging voltage and current from the charger as needed to begin charging.

[0032] Figure 4 The high-voltage charging power-off process is illustrated. During normal charging, the system continuously monitors for full charge, manual charging stop, or serious charging malfunction. If any of these conditions occur, the system disconnects the charging relay and the main negative relay, sets the cell monitor to sleep mode, and the charging power-off process is successful.

[0033] like Figure 5 As shown, during the high-voltage discharge power-on process, the system's 24V power supply is turned on to power the wireless BMS and display screen. After power-on, the wireless BMS begins transmitting system information to the screen and sends a network command to the communication hub. While waiting for network formation, the system checks whether all cell monitors have successfully formed a network within a certain time. If network formation is successful, the wireless BMS begins collecting battery voltage, temperature, and other information and performs a self-test. If network formation fails, the BMS reports a system initialization fault to the screen, indicating a high-voltage discharge power-on failure. If the self-test is successful, the wireless BMS controls the main negative and pre-charge relays to close, initiating pre-charging. If the self-test fails, the BMS reports a system initialization fault to the screen, indicating a high-voltage discharge power-on failure. If pre-charging is successful, the discharge relay is closed first, then the pre-charge relay is opened, indicating a successful high-voltage discharge power-on. If pre-charging fails, the pre-charge and main negative relays are opened, the BMS reports a system initialization fault to the screen, indicating a high-voltage discharge power-on failure. After the high-voltage discharge power-on is complete, the battery system begins output.

[0034] like Figure 6 As shown, during the high-voltage discharge power-off process of the system, the wireless BMS determines in real time whether the battery system has experienced full discharge, manual discharge stop, or a serious discharge fault. If any of the three events occurs, a discharge end flag is set; the wireless BMS disconnects the battery system's discharge relay and main negative relay; the cell monitor is set to sleep mode; and the wireless BMS successfully discharges and powers off.

[0035] Figure 5 and Figure 6The high-voltage discharge power-on and power-off processes are shown separately. The basic logic is similar to the charging process, but a pre-charging step is added when discharging and powering on. That is, the main negative relay and the pre-charging relay are closed first. After the pre-charging is completed, the discharge relay is closed and the pre-charging relay is opened to protect the high-voltage system from instantaneous current surges.

[0036] like Figure 7 The system's fault handling process is shown below. The wireless BMS collects real-time battery voltage data and compares it with fault alarm parameter thresholds. If the primary fault alarm threshold is reached for 3 seconds, a primary audible and visual alarm is triggered, sounding for 1 second every 5 seconds, and the alarm information is uploaded to the display screen. If the primary alarm release value is reached for 3 seconds during this period, the primary fault alarm is released. If operation continues after the primary alarm and the intermediate over-discharge fault alarm threshold is reached for 3 seconds, an intermediate audible and visual alarm is triggered, sounding for 1 second every 3 seconds, and the alarm information is uploaded to the display screen. If the intermediate over-discharge fault release value is reached for 3 seconds during this period, the intermediate fault alarm is released. If operation continues after the intermediate alarm and the advanced over-discharge fault alarm threshold is reached for 3 seconds, an advanced audible and visual alarm is triggered, sounding for 1 second every 1 second, and the alarm information is uploaded to the display screen. Simultaneously, the high-voltage circuit of the battery system is disconnected. The fault requires a system restart to be released.

[0037] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A single-cell-level wireless battery management system based on near-field communication, characterized in that, include: The host module serves as the system's main controller. The communication hub module is communicatively connected to the host module; The antenna hub is connected to the communication hub module via an antenna bus. Multiple cell monitors are mounted on the surface of each cell using a chip-on-cell architecture. Each cell monitor is used to collect voltage and temperature information of the corresponding cell. The antenna hub branches out multiple antenna sub-lines to each battery pack, and the antennas within each battery pack communicate with the cell monitor in the near field. The cell monitor transmits the collected information to the communication hub module via near field communication, and the communication hub module interacts with the host module via the SPI bus.

2. The single-cell-level wireless battery management system based on near-field communication according to claim 1, characterized in that: The positive and negative terminals of the battery cell monitor are directly soldered to the positive and negative tabs of the monitored battery cell, respectively, and draw power from the monitored battery cell.

3. The single-cell-level wireless battery management system based on near-field communication according to claim 1, characterized in that: The cell monitor includes a voltage acquisition unit, a temperature acquisition unit, a signal strength acquisition unit, and a passive equalization unit.

4. The single-cell-level wireless battery management system based on near-field communication according to claim 1, characterized in that: Each cell monitor supports one voltage acquisition channel and two temperature acquisition channels.

5. The single-cell-level wireless battery management system based on near-field communication according to claim 1, characterized in that: The system also includes a display screen, which communicates with the host module via an RS-485 bus to display the system's total voltage, total current, state of charge, individual cell voltage, individual cell temperature, system operating status, and fault alarm information.

6. A control method for a single-cell-level wireless battery management system based on near-field communication, used in the wireless battery management system as described in any one of claims 1 to 5, characterized in that, Includes the following steps: (1) System power-on: The wireless battery management system is powered by a regulated power supply to enable it to enter the working state; (2) Sending instructions: The host module establishes communication with the communication hub module and sends a network configuration instruction; (3) System networking: The communication hub module sends a networking request based on the ID information pre-stored in the cell monitor. After receiving the networking request, the cell monitor is woken up and enters active mode. (4) Data acquisition and uploading: The cell monitor acquires the voltage and temperature information of the cell and transmits it to the communication hub module via the antenna in a near-field communication manner; (5) Data reception: The host module receives battery information forwarded by the communication hub module via the SPI bus.

7. The control method according to claim 6, characterized in that: The ID information pre-stored by the cell monitor in step (3) is the unique identifier of each cell monitor. The communication hub module wakes up the cell monitor one by one and establishes a communication connection based on the unique identifier.

8. The control method according to claim 6 or 7, characterized in that, The high-voltage charging power-on and power-off process includes: (1) Powering on: Turn on the charger and the charger's auxiliary power supply supplies power to the wireless battery management system and the display screen; after the wireless battery management system is powered on, it will network the cell monitor and perform a self-test; after the self-test is completed, if there is no fault, it will close the main negative relay and establish a communication connection with the charger. After the communication connection is normal, it will close the charging relay and start charging. (2) Charging off: When the battery system meets the full charge condition, receives a manual stop charging command, or a serious charging fault occurs, the wireless battery management system disconnects the main negative relay and the charging relay, sets all cell monitors to sleep mode and exits the network, and cuts off the power supply.

9. The control method according to claim 6 or 7, characterized in that, The high-voltage discharge power-on / off process includes: (1) Powering on and discharging: Turn on the power supply of the wireless battery management system and the display screen. After the wireless battery management system is powered on, it will network the cell monitor and perform a self-test. After the self-test is completed, if there is no fault, close the main negative relay and then close the pre-charge relay to perform pre-charge. After the pre-charge is completed, close the discharge relay and disconnect the pre-charge relay to start discharging. (2) Discharge and power off: When the battery system meets the full discharge condition, receives a manual stop discharge command, or a serious discharge fault occurs, the wireless battery management system disconnects the main negative relay and the discharge relay, sets all cell monitors to sleep mode and exits the network, and cuts off the power supply.

10. The control method according to claim 8, characterized in that: The number of cell monitors that can be networked by a single communication hub module shall not exceed a preset limit.

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