Distributed lithium ion battery intelligent management device

Abstract

The utility model discloses a distributed lithium ion battery intelligent management device, which comprises a main control board and a plurality of acquisition boards connected with the main control board, each acquisition board is connected with a battery pack, and each acquisition board comprises a battery sampling chip, and a temperature acquisition circuit, a voltage acquisition circuit and a current acquisition circuit which are connected with the battery sampling chip; the main control board comprises an MCU, and a relay module, a communication module, a storage module, a thermal management module and an external input signal detection module which are connected with the MCU. Through the above mode, the system employs a distributed architecture, and each battery module can carry out state monitoring, fault diagnosis and protection measures independently, thereby reducing the risk of a single point of fault, and improving the reliability of the whole system. The distributed architecture is easier to realize addition and replacement of the battery modules, the expansibility and flexibility of the system are higher, the system is convenient to adapt to battery packs with different capacities, types and combination modes, and the system is convenient to upgrade and maintain.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium-ion batteries, in particular to a distributed lithium-ion battery intelligent management device. Background Art

[0002] The current BMS architecture is mainly divided into centralized and distributed. The traditional BMS adopts a centralized architecture, integrating the master control module and the slave control module, integrating the single cell voltage acquisition, battery temperature, current acquisition, and charge and discharge control, and separating the high and low voltages, and processing the detection and communication separately. The centralized sampling channels are limited in number and have poor applicability, and are only suitable for small battery packs.

[0003] The centralized architecture requires a large number of communication lines to connect each battery module and the central control unit, which increases the complexity and cost of the system and is susceptible to interference and signal loss. When increasing the battery capacity or the number of modules, the entire system structure needs to be redesigned, and the scalability is subject to certain limits. At the same time, the centralized architecture will cause the power consumption and heat of the unit to be concentrated, resulting in local overheating and excessive energy consumption.

[0004] As the battery capacity and volume are getting larger and larger, the current BMS basically adopts a distributed architecture, which consists of multiple slave control modules, a master control module, and a high-voltage control unit. The slave control module is responsible for detecting the single cell voltage, temperature, balancing management, and diagnosis. The master control module receives the data from the slave control module, evaluates the power battery system, detects the system status, and performs thermal management, charge and discharge control, internal and external communication management, etc. Each sub-module can process part of the data independently, which reduces the burden of a single central processing unit. Each sub-module can be responsible for monitoring and managing the data of a specific area or battery pack, thereby improving the system's response speed and data processing capabilities. Therefore, the distributed BMS architecture needs to be able to flexibly configure each sub-module according to actual needs to facilitate the expansion and upgrade of the system. New battery packs can be integrated by adding corresponding sub-modules without making large-scale changes to the entire system. The various sub-modules in the distributed BMS can work in parallel to monitor and process battery data in real time, thereby improving the system's response speed and real-time performance. This is particularly important for application scenarios that require rapid adjustment of battery management strategies.

[0005] Therefore, there is an urgent need to provide a new type of distributed lithium-ion battery intelligent management device to solve the above problems. Utility Model Content

[0006] The technical problem to be solved by the utility model is to provide a distributed lithium-ion battery intelligent management device, which adopts a method of separating the main control board from the acquisition board, so that one main control board can be connected to a maximum of 15 acquisition boards. When in use, only the required number of acquisition boards need to be connected externally to quickly build the system.

[0007] In order to solve the above technical problems, a technical solution adopted by the utility model is: to provide a distributed lithium-ion battery intelligent management device, including a main control board and several acquisition boards connected thereto, each acquisition board is connected to a battery pack, the acquisition board includes a battery sampling chip, a temperature acquisition circuit connected to the battery sampling chip, a voltage acquisition circuit, and a current acquisition circuit; the main control board includes an MCU, a relay module connected to the MCU, a communication module, a storage module, a thermal management module, and an external input signal detection module;

[0008] The relay module includes several relay control circuits, which are used to control the charging, pre-charging, total positive and total negative operations of the battery pack;

[0009] The communication module includes a CAN transceiver circuit and an RS485 communication circuit. The CAN transceiver circuit is used to report battery information and new fault information to an external device via a CAN bus in real time. The RS485 communication circuit is used for communication between the main control board and the host computer.

[0010] The storage module includes a storage module circuit for storing system historical measurement data and battery pack operation information;

[0011] The external input signal detection module includes an external input signal detection circuit, which is used for inputting an external wake-up signal.

[0012] In a preferred embodiment of the present invention, the battery sampling chip adopts a lithium-ion battery controller MC33771, which adopts a daisy chain communication method and a transformer to isolate signals.

[0013] In a preferred embodiment of the present invention, the MCU adopts the chip MPC5748G.

[0014] In a preferred embodiment of the utility model, the relay control circuit includes a pre-charge control circuit, a charge control circuit, a total positive control circuit, and a total negative control circuit. The pre-charge control circuit includes a relay K1, a diode D18, a transistor V20, a capacitor C126, a resistor R155, a resistor R158, and a resistor R148. The diode D18 is connected in parallel between the 7th and 8th pins of the relay K1, the collector of the transistor V20 is connected to the 7th pin of the relay K1 and the positive electrode of the diode D18, the resistor R155 is connected to the base of the transistor V20, the resistor R158 and the capacitor C126 form an RC filter circuit connected in parallel between the base and the emitter of the transistor V20, and the resistor R148 is connected in series with the 6th pin of the relay K1.

[0015] In a preferred embodiment of the utility model, the CAN transceiver circuit includes a CAN transceiver U1, capacitors C2, C4, an inductor L1, and a resistor R1. The CAN transceiver U1 adopts TJA1042T, the capacitor C2 is connected to the third pin of U1, and the capacitor C4 is connected to the fifth pin of U1.

[0016] In a preferred embodiment of the present invention, the battery sampling chip is connected to the MCU via an isolation network high-speed transceiver circuit.

[0017] Furthermore, the isolation network high-speed transceiver circuit includes an isolation network high-speed transceiver and its peripheral circuits, and the isolation network high-speed transceiver adopts MC33664.

[0018] The beneficial effects of the utility model are as follows: the utility model adopts a distributed architecture, and each battery module can perform status monitoring, fault diagnosis and protection measures relatively independently, reducing the risk of single point failure and improving the reliability of the entire system. The distributed architecture makes it easier to add and replace battery modules, and the system has higher scalability and flexibility, which is convenient for adapting to battery packs of different capacities, types and combinations, and is convenient for system upgrades and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a structural block diagram of a preferred embodiment of a distributed lithium-ion battery intelligent management device of the utility model;

[0020] Figure 2 is a circuit diagram of the battery sampling chip and peripheral circuits;

[0021] Figure 3 is a circuit diagram of the isolation network high-speed transceiver circuit;

[0022] Figure 4 is a circuit diagram of the voltage acquisition circuit;

[0023] Figure 5 is a circuit diagram of the relay module;

[0024] Figure 6 is a circuit diagram of the CAN transceiver circuit;

[0025] Figure 7 is a circuit diagram of the storage module;

[0026] Figure 8 is a circuit diagram of the external input signal detection module;

[0027] Fig. 9 is the pin circuit diagram of the MCU. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0029] See also Figure 1 , the utility model embodiment includes:

[0030] A distributed lithium-ion battery intelligent management device includes a main control board and several acquisition boards connected thereto, each acquisition board is connected to a battery pack, and in this example, a battery pack includes 14 batteries. The acquisition board includes a battery sampling chip, a temperature acquisition circuit connected to the battery sampling chip, a voltage acquisition circuit, and a current acquisition circuit. The main control board includes an MCU, a relay module connected to the MCU, a communication module, a storage module, a thermal management module, and an external input signal detection module; the relay module includes several relay control circuits, which are respectively used to control the charging, pre-charging, total positive, and total negative operations of the battery pack; the communication module includes a CAN transceiver circuit and an RS485 communication circuit. The CAN transceiver circuit is used to report battery information and new fault information to an external device through the CAN bus in real time, and the RS485 communication circuit is used for communication between the main control board and the host computer; the storage module includes a storage module circuit for storing system historical measurement data and battery pack operation information; the external input signal detection module includes an external input signal detection circuit for inputting an external wake-up signal.

[0031] The following is a detailed description of each module circuit in conjunction with the accompanying drawings:

[0032] See also Figure 2 , the battery sampling chip adopts NXP's lithium-ion battery controller MC33771, and the components of its peripheral circuit and their connection relationship are shown in the figure. The controller adopts a daisy chain communication method, which can effectively reduce the cost of single-cell voltage acquisition. Only one isolation transformer is needed to realize the data transmission of two MC33771s. The daisy chain uses differential signal lines to transmit data, and the data format introduces an 8-bit CRC check code to ensure accurate data transmission. The daisy chain tail-biting mode is designed, and the signal conversion can be completed at the head and tail of the daisy chain to ensure communication reliability. The battery sampling chip is powered by a power circuit connected to the battery pack, and the power circuit also powers the MCU.

[0033] The battery sampling chip is connected to the MCU via an isolated network high-speed transceiver circuit. The isolated network high-speed transceiver circuit includes an isolated network high-speed transceiver and its peripheral circuits. The components and their connection relationships are as follows: Figure 3As shown. Preferably, the isolation network high-speed transceiver adopts MC33664, which serves as the communication conversion hub between the MCU and the lithium-ion battery controller MC33771, and a transformer is used to isolate the signal on the daisy chain link of the MC33771. The communication between the MC33771 and between the MC33771 and the CPU adopts a daisy chain mode, and the MC33771 at the end is also used to collect the current of the power battery pack. The fault alarm pin of the MC33771 is directly connected to the MCU through an optical coupler.

[0034] The acquisition board described in this example is connected to 14 single-cell battery voltage acquisition channels and 7 temperature acquisition channels. Figure 4 , the figure shows 14 voltage acquisition circuits and 7 temperature acquisition circuits, and the structures of each acquisition circuit are the same.

[0035] The BMS power battery pack needs to be charged and discharged during use, so it is necessary to accurately control many relays, such as charging, pre-charging, total positive, and total negative relays. Therefore, the relay control circuit includes a pre-charging control circuit, a charging control circuit, a total positive control circuit, and a total negative control circuit. The components and their connection relationships are as follows: Figure 5 Taking the pre-charging control circuit as an example, the pre-charging control circuit includes a relay K1, a diode D18, a transistor V20, a capacitor C126, a resistor R155, a resistor R158, and a resistor R148. The diode D18 is connected in parallel between the 7th and 8th pins of the relay K1, the collector of the transistor V20 is connected to the 7th pin of the relay K1 and the positive electrode of the diode D18, the resistor R155 is connected to the base of the transistor V20, the resistor R158 and the capacitor C126 form an RC filter circuit connected in parallel between the base and the emitter of the transistor V20, and the resistor R148 is connected in series with the 6th pin of the relay K1.

[0036] In order to ensure the accurate transmission of data between various parts, the device uses CAN bus for data communication, and reports battery information and fault information to other external devices through CAN bus in real time. Preferably, the CAN transceiver uses TJA1042T, and the components and their connection relationships are as follows: Figure 6 This BMS device also implements the CAN network management function (passive wake-up).

[0037] The battery management device needs to store many important operating parameters during use, such as the SOC information of the last power failure, charge and discharge information, fault information, etc. These parameters are related to the judgment of the state of the electric vehicle. The circuit components of the storage module and their connection relationships are as follows Figure 7As shown. In order to ensure the reliable storage of the device's historical measurement data and BMS operation information, the device uses an external SD card. SD storage has a large memory and can achieve reliable storage of key data of the battery management system such as historical data and operation data. SD card reading and writing uses the SDIO interface that comes with the storage module.

[0038] The circuit components and their connection relationships of the external input signal detection circuit are as follows: Figure 8 As shown, it includes an external signal input interface P9 and an external signal input circuit. The external signal input circuit is composed of a photocoupler and several resistors. The external signals include ON signal, START signal, and CHARGE signal. When the power supply part of the BMS is awakened, the entire device starts to power on and initialize and enter the working state. The working states of the battery management device are divided into charging and discharging. The wake-up signal can be an ON gear signal or a charging mode CHARGE signal. After the device is awakened, it cannot be confirmed whether it is in charging mode or discharging mode, so it is necessary to specifically identify these two signals. Both signals are a high level of 12V or a low level of 0V. Through optocoupler isolation detection, when the charging mode CHARGE or ON gear signal is 12V, the optocoupler transmitting end forms a loop, the receiving end is turned on, and the MCU detects a high level, otherwise it is a low level.

[0039] Preferably, the MCU uses the chip MPC5748G, and the names of the pins of the chip and the connection ports are as follows: Fig. 9 In addition, there is a thermal management system connected to the MCU output end, which is used to control the temperature of the battery. If the temperature is too high, a fan is used to cool it down.

[0040] The device adopts a method of separating the main control board from the acquisition board, which enables one main control board to connect to up to 15 acquisition boards. When in use, you only need to connect the required number of acquisition boards to quickly build the system.

[0041] The utility model adopts a distributed architecture, and each battery module can perform status monitoring, fault diagnosis and protection measures relatively independently, reducing the risk of single point failure and improving the reliability of the entire system. The distributed architecture makes it easier to add and replace battery modules, and the system has higher scalability and flexibility, which is easy to adapt to battery packs of different capacities, types and combinations, and is convenient for system upgrades and maintenance.

[0042] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A distributed lithium-ion battery intelligent management device, comprising a main control board and several acquisition boards connected thereto, each acquisition board being connected to a battery pack, characterized in that: The acquisition board includes a battery sampling chip, a temperature acquisition circuit connected to the battery sampling chip, a voltage acquisition circuit, and a current acquisition circuit; the main control board includes an MCU, a relay module connected to the MCU, a communication module, a storage module, a thermal management module, and an external input signal detection module; The relay module includes several relay control circuits, which are used to control the charging, pre-charging, total positive and total negative operations of the battery pack; The communication module includes a CAN transceiver circuit and an RS485 communication circuit. The CAN transceiver circuit is used to report battery information and new fault information to an external device via a CAN bus in real time. The RS485 communication circuit is used for communication between the main control board and the host computer. The storage module includes a storage module circuit for storing system historical measurement data and battery pack operation information; The external input signal detection module includes an external input signal detection circuit, which is used for inputting an external wake-up signal.

2. The distributed lithium-ion battery intelligent management device according to claim 1 is characterized in that: The battery sampling chip adopts the lithium-ion battery controller MC33771, which adopts a daisy chain communication method and a transformer to isolate signals.

3. The distributed lithium-ion battery intelligent management device according to claim 1 is characterized in that: The MCU adopts the chip MPC5748G.

4. The distributed lithium-ion battery intelligent management device according to claim 1, characterized in that: The relay control circuit includes a pre-charge control circuit, a charge control circuit, a total positive control circuit, and a total negative control circuit. The pre-charge control circuit includes a relay K1, a diode D18, a transistor V20, a capacitor C126, a resistor R155, a resistor R158, and a resistor R148. The diode D18 is connected in parallel between the 7th and 8th pins of the relay K1, the collector of the transistor V20 is connected to the 7th pin of the relay K1 and the positive electrode of the diode D18, the resistor R155 is connected to the base of the transistor V20, the resistor R158 and the capacitor C126 form an RC filter circuit connected in parallel between the base and the emitter of the transistor V20, and the resistor R148 is connected in series with the 6th pin of the relay K1.

5. The distributed lithium-ion battery intelligent management device according to claim 1, characterized in that: The CAN transceiver circuit includes a CAN transceiver U1, capacitors C2, C4, an inductor L1, and a resistor R1. The CAN transceiver U1 adopts TJA1042T, the capacitor C2 is connected to the third pin of U1, and the capacitor C4 is connected to the fifth pin of U1.

6. The distributed lithium-ion battery intelligent management device according to claim 1, characterized in that: The battery sampling chip is connected to the MCU via an isolation network high-speed transceiver circuit.

7. The distributed lithium-ion battery intelligent management device according to claim 6, characterized in that: The isolation network high-speed transceiver circuit comprises an isolation network high-speed transceiver and its peripheral circuits, and the isolation network high-speed transceiver adopts MC33664.

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