Intelligent bms protection board based on diode and transistor cell equalization technology

Abstract

The utility model discloses a kind of intelligent BMS protection plate based on diode battery cell equalization technology.The utility model includes MCU module, AFE front-end chip, 4G communication module, GNSS positioning module, CAN transceiver circuit, charge-discharge control circuit, equalization circuit;MCU respectively with 4G communication module, GNSS positioning module, CAN transceiver circuit, embedded flash memory and controller, RTC clock carry out data interaction;AFE chip controls the MOS pipe in charge-discharge control circuit by receiving the order of MCU, and charge-discharge control circuit controls battery pack.The utility model circuit component is fewer, more reliable, lower in cost, with real-time voltage acquisition feedback, when opening equalization control by software decision;Less component type, lower static power consumption, no self-consumption device.

Description

Technical Field

[0001] This utility model relates to the field of battery safety protection, and more specifically, to an intelligent BMS protection board based on diode and transistor circuit adjustment of series cell voltage balancing technology. Background Technology

[0002] The development of BMS (Battery Management System) protection boards stems from the urgent need to ensure battery safety and lifespan. With the widespread application of lithium batteries in electric vehicles, energy storage systems, and consumer electronics, the sensitivity of their chemical properties to parameters such as voltage, current, and temperature has spurred the iteration of protection board technology.

[0003] Limitations of traditional protection circuits: Early lithium batteries used basic protection circuits (such as discrete component designs), which could only achieve basic protection against overcharge, over-discharge, and short circuits. Discrete components (such as MOSFETs and fuses) resulted in complex circuits, large PCB space requirements, and high failure rates, making it difficult to meet the requirements of high reliability scenarios.

[0004] The existing technology solution is a battery cell balancing technology consisting of resistors and mechanical switches. It has the following drawbacks: 1. Mechanical switches are large in size and have a limited service life.

[0005] 2. It requires manual operation, which is cumbersome and time-consuming, and cannot achieve automation or intelligence.

[0006] 3. Without feedback circuitry, it is difficult to analyze the problem after failure.

[0007] The existing technical solution is to build a cell balancing circuit using discrete components such as a three-terminal voltage regulator, a PNP transistor, a capacitor, and a resistor.

[0008] The existing technology 2 has the following disadvantages: 1. The number of components is large, and the circuit is complex and not easy to maintain.

[0009] 2. The circuit has high static losses, and the voltage regulator is constantly working. Utility Model Content

[0010] The technical problem to be solved by this utility model is to overcome the shortcomings of the existing technology and provide an intelligent BMS protection board based on diode and transistor circuit adjustment series cell voltage equalization technology to improve the protection performance of lithium batteries.

[0011] This utility model discloses an intelligent BMS protection board based on diode and transistor cell balancing technology. The intelligent BMS protection board includes an MCU module, an AFE front-end chip, a 4G communication module, a GNSS positioning module, a CAN transceiver circuit, a charge / discharge control circuit, and a balancing circuit. The MCU interacts with the 4G communication module, GNSS positioning module, CAN transceiver circuit, embedded flash memory and controller, and RTC clock. The AFE chip controls the MOSFETs in the charge / discharge control circuit by receiving commands from the MCU, and the charge / discharge control circuit controls the battery pack. The 4G communication module establishes an Ethernet connection and transmits battery information to the network platform. The GNSS positioning module uploads real-time location information. The CAN transceiver circuit communicates with the external main control device for the battery. The balancing circuit, controlled by the MCU, performs active balancing of the cells.

[0012] In the equalization circuit, capacitor C2 is set between the terminals B1 and B2 of two adjacent cells. Resistor R1, equalization current limiting resistor R2, general-purpose diode D1, transistor Q1, and resistor R10 are connected in series between the terminals B1 and B2. Base current limiting resistor R3 is set between the base of transistor Q1 and terminal B1. Voltage sampling point C3 is between resistor R1 and equalization current limiting resistor R2. Voltage sampling point C1 is between the emitter of transistor Q1 and resistor R10.

[0013] In the equalization circuit, B1 and B2 are the terminals of two adjacent cells, and C1 and C2 are voltage sampling points. Capacitor C2 serves as a filter and decoupler. Transistor Q1 controls the equalization current passing through it, diverting the charge from high-energy cells to low-energy cells for lossless energy dispatch. When the sampled voltage C2 is higher than C1, equalization control is activated, a forward voltage drop is generated at the base of the transistor, and the collector-emitter junction conducts, allowing current to flow from B2 to B1 until the voltages at both ends are equal. At this point, equalization control is deactivated, eliminating individual cell differences within the battery pack and improving safety and lifespan. D1 is a general-purpose diode, primarily preventing current from flowing from B1 to B2, providing unidirectional conduction. R3 is the base current limiter, and R2 is the equalization current-limiting resistor.

[0014] The CAN data transceiver module includes a CAN isolation transceiver, an interface protection circuit, and a matching circuit.

[0015] The charging and discharging circuit consists of a charging MOSFET and a discharging MOSFET connected in parallel, as well as a driving circuit.

[0016] Compared with the prior art, the beneficial effects of this utility model are: This invention solves the problem of active cell balancing in BMS management systems. Compared with existing technologies, it requires fewer circuit components, has higher reliability, and lower cost. It uses electronic switches, eliminating the need for manual intervention and having no lifespan limitation. It features real-time voltage acquisition and feedback, with software determining when to activate balancing control. It uses fewer components, including only diodes, transistors, resistors, and capacitors; and it has low static power consumption with no self-consuming components. Attached Figure Description

[0017] Figure 1 This is a system block diagram of the present invention; Figure 2 This is a schematic diagram of an equalization circuit. Detailed Implementation

[0018] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. Many specific details are set forth in the following description to provide a thorough understanding of this utility model; the described embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this utility model pertains. The terminology used in this specification of the utility model is for the purpose of describing particular embodiments only and is not intended to limit the utility model.

[0019] like Figure 1 As shown, the intelligent BMS protection board includes an MCU module, an AFE front-end chip, a 4G communication module, a GNSS positioning module, a CAN transceiver circuit, a charge / discharge control circuit, and an equalization circuit. The MCU interacts with the 4G communication module, the GNSS positioning module, the CAN transceiver circuit, the embedded flash memory and controller (eMMC), and the RTC clock. The AFE chip controls the MOSFETs in the charge / discharge control circuit by receiving commands from the MCU, and the charge / discharge control circuit controls the battery pack. The 4G communication module establishes an Ethernet connection and transmits battery information to the network platform. The GNSS positioning module uploads real-time location information. The CAN transceiver circuit communicates with the external main control device of the battery. The equalization circuit, controlled by the MCU, performs active equalization processing on the battery cells.

[0020] The intelligent BMS management system uses a front-end chip to collect battery information and status, and simultaneously uploads it to the monitoring platform via a 4G network. The communication module integrates a high-precision positioning module, which can accurately acquire battery location information and upload it to the monitoring platform. When the battery voltage is lower than the undervoltage protection threshold, the battery pack enters a low-voltage protection state, and the discharge MOSFET is disconnected or disabled. When the battery voltage rises above the undervoltage protection threshold by a certain value, the battery pack should be awakened and enter normal operating mode, reporting the latest operating status to the server.

[0021] Module description: 1) MCU chip and peripheral circuits, with a maximum clock frequency of 120MHz, FLASH size of 256KB, and RAM size of 128KB. It has one CAN2.0A / B interface, and other interfaces include UART, LIN, SPI, and I2C.

[0022] 2) The CAN data transceiver module mainly consists of a CAN isolation transceiver, interface protection circuit, and matching circuit. Its main function is to communicate with external devices, receive and send CAN messages, parse them, package them according to the protocol, and upload them to the monitoring platform.

[0023] 3) The communication module mainly consists of a 4G module, a module power supply circuit, a module startup circuit, a data SIM card chip circuit, and an antenna interface circuit. The main functions of 4G are registration and network access, platform login, and periodically sending messages to the platform.

[0024] 4) The main function of the GNSS positioning module is to acquire satellite positioning information and support full constellation positioning and navigation systems such as GPS, Beidou, and GLONASS.

[0025] 4) The RTC clock uses an integrated module within the MCU. Its main function is to provide a time base for the system and realize functions such as time, calendar, alarm clock, and device sleep / wake-up.

[0026] 5) eMMC uses an external NOR FLASH. The FLASH is used to store fault information and upgrade files, while eMMC can be used as a local message storage medium.

[0027] 6) The AFE chip uses a high-precision battery monitoring and protection chip, integrates a charge pump, and includes voltage, temperature and current acquisition and diagnostic functions. It supports high-precision voltage measurement <10mV and supports IIC and SPI communication modes.

[0028] 7) The charging and discharging circuit mainly consists of parallel charging MOS and discharging MOS and driving circuit.

[0029] Depend on Figure 2As shown, capacitor C2 is set through the circuit between the two adjacent cell terminals B1 and B2. Resistor R1, equalizing current limiting resistor R2, general-purpose diode D1, transistor Q1, and resistor R10 are connected in series between the two adjacent cell terminals B1 and B2. Base current limiting resistor R3 is set between the base of transistor Q1 and cell terminal B1. Voltage sampling point C3 is between resistor R1 and equalizing current limiting resistor R2. Voltage sampling point C1 is between the emitter of transistor Q1 and resistor R10.

[0030] In the equalization circuit, B1 and B2 are the terminals of two adjacent cells, and C1 and C2 are voltage sampling points. Capacitor C2 serves as a filter and decoupler. Transistor Q1 controls the equalization current passing through it, diverting the charge from high-energy cells to low-energy cells for lossless energy dispatch. When the sampled voltage C2 is higher than C1, equalization control is activated, a forward voltage drop is generated at the base of the transistor, and the collector-emitter junction conducts, allowing current to flow from B2 to B1 until the voltages at both ends are equal. At this point, equalization control is deactivated, eliminating individual cell differences within the battery pack and improving safety and lifespan. D1 is a general-purpose diode, primarily preventing current from flowing from B1 to B2, providing unidirectional conduction. R3 is the base current limiter, and R2 is the equalization current-limiting resistor.

[0031] The above description is only a preferred embodiment of the present utility model. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A smart BMS protection board based on diode and transistor cell balancing technology, characterized in that, The system includes an MCU module, an AFE front-end chip, a 4G communication module, a GNSS positioning module, a CAN transceiver circuit, a charge / discharge control circuit, and an equalization circuit. The MCU interacts with the 4G communication module, the GNSS positioning module, the CAN transceiver circuit, the embedded flash memory and controller, and the RTC clock. The AFE chip receives commands from the MCU to control the MOSFETs in the charge / discharge control circuit, which in turn controls the battery pack. The 4G communication module establishes an Ethernet connection and transmits battery information to the network platform. The GNSS positioning module uploads real-time location information. The CAN transceiver circuit communicates with the external main control device for the battery. The equalization circuit, controlled by the MCU, performs active equalization processing on the battery cells.

2. The intelligent BMS protection board based on diode and transistor cell balancing technology according to claim 1, characterized in that, In the equalization circuit, capacitor C2 is set between the terminals B1 and B2 of two adjacent cells. Resistor R1, equalization current limiting resistor R2, general-purpose diode D1, transistor Q1, and resistor R10 are connected in series between the terminals B1 and B2. Base current limiting resistor R3 is set between the base of transistor Q1 and terminal B1. Voltage sampling point C3 is between resistor R1 and equalization current limiting resistor R2. Voltage sampling point C1 is between the emitter of transistor Q1 and resistor R10.

3. The intelligent BMS protection board based on diode and transistor cell balancing technology according to claim 1, characterized in that, The CAN data transceiver module includes a CAN isolation transceiver, an interface protection circuit, and a matching circuit.

4. The intelligent BMS protection board based on diode and transistor cell balancing technology according to claim 1, characterized in that, The charging and discharging circuit mainly consists of a charging MOSFET and a discharging MOSFET connected in parallel, as well as a driving circuit.

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