Battery management system capable of replacing flexible equalization circuit of battery pack

Abstract

The invention relates to the technical field of battery management, and discloses a battery management system capable of replacing a flexible equalization circuit of a battery pack, and the system comprises a battery pack which comprises a plurality of single batteries, and the positive and negative electrodes of each single battery are sequentially connected in series; the battery monitoring module is connected with the battery pack, the battery monitoring module is connected with the positive electrode and the negative electrode of the single battery through wires, and the battery monitoring module is used for monitoring battery pack data; the main control module is connected with the battery monitoring module and is used for receiving and processing the battery pack data; the battery driving control module is connected with the main control module, and the battery driving control module is used for receiving a control instruction of the main control module; one end of the active equalization circuit module is connected with the battery driving control module, and the other end of the active equalization circuit module is connected with positive and negative electrodes of single batteries of the battery pack. According to the invention, the battery state is monitored, the battery accident rate can be reduced, and the battery equalization efficiency and flexibility are optimized.

Description

Technical Field

[0001] This invention relates to the field of battery management technology, and more specifically, to a battery management system with a replaceable flexible balancing circuit for battery packs. Background Technology

[0002] Against the backdrop of addressing global climate change and reducing dependence on fossil fuels, the development and application of new energy technologies have become a core issue in the 21st-century energy transition. New energy systems, particularly photovoltaic and wind power, have garnered significant attention due to their renewable and environmentally friendly nature. However, the intermittent and unpredictable nature of these energy forms necessitates efficient energy storage solutions to ensure the stability and reliability of power supply. In recent years, advancements in battery technology and materials science have led to a continuous decrease in the cost and improvement in the performance of energy storage systems, making large-scale energy storage possible. Battery management systems play a crucial role in utilizing batteries to store and utilize energy.

[0003] Battery balancing management systems are designed to improve battery pack performance, safety, and lifespan while reducing costs and environmental impact. By monitoring and controlling each battery cell within the pack, they maintain a similar or identical state of charge, thus preventing performance degradation, accelerated aging, and safety hazards caused by battery inconsistencies. Battery balancing management systems are widely used in electric vehicles, hybrid vehicles, energy storage systems, and solar power generation, and are a key component in realizing new energy technologies.

[0004] Research on battery management systems (BMS) mainly focuses on two aspects: one is the energy storage system for new energy systems, especially those converting photovoltaic and wind power, and the other is the management of electric vehicle power batteries. The earliest BMS systems primarily collected and fed back data related to battery voltage, current, and temperature. However, with continuous development, the functions of BMS systems have been constantly increasing and improving, mainly focusing on two aspects: First, improving overall functionality by adding monitoring and early warning functions to prevent overcharging, over-discharging, overheating, and overcurrent during battery charging and discharging, ensuring the battery operates within a safe and reliable range and reducing the risk of accidents, especially for chemically active batteries such as lithium batteries, reducing the possibility of combustion; second, ensuring the design performance of the battery pack by addressing inconsistencies caused by battery production and use, reducing the bottleneck effect of the battery pack, increasing the energy storage capacity of energy storage stations and the driving range of electric vehicles, and extending battery life.

[0005] Therefore, it is necessary to provide a battery management system with a replaceable flexible battery pack balancing circuit to monitor battery status, reduce battery accident rate, and optimize battery balancing efficiency and flexibility. Summary of the Invention

[0006] In view of this, the present invention proposes a battery management system with a replaceable flexible battery pack balancing circuit, which aims to solve the problems of high battery accident rate and poor battery balancing efficiency caused by the inability of existing technologies to effectively detect battery status.

[0007] This invention proposes a battery management system with a replaceable flexible equalization circuit for battery packs, comprising: A battery pack includes multiple individual cells, with the positive and negative terminals of each individual cell connected in series. A battery monitoring module is connected to the battery pack. The battery monitoring module is connected to the positive and negative terminals of the individual cells via wires. The battery monitoring module is used to monitor battery pack data, which includes individual cell voltage, current, total battery pack voltage, and battery pack temperature. The main control module is connected to the battery monitoring module, and the main control module is used to receive and process the battery pack data; A battery drive control module is connected to the main control module, and the battery drive control module is used to receive control commands from the main control module. The active balancing circuit module is connected at one end to the battery drive control module, and at the other end to the positive and negative terminals of the individual cells in the battery pack.

[0008] Furthermore, the individual battery is connected to the balancing circuit of the active balancing circuit module via BPS, and the positive and negative terminals of the individual battery are connected to the energy storage element via BPS. The batteries in the battery pack are connected in parallel to the same energy storage element.

[0009] Furthermore, the positive terminal of each individual cell is connected to one end of a BPS, and the other end of the BPS is connected to an inductor. The negative terminal of each individual cell is connected to one end of a BPS, and the other end of the BPS is connected to an inductor. Each individual cell's negative terminal is also connected to one end of a BPS, the other end of which is connected to a resistor. The other end of the resistor is connected to the positive terminal of an individual cell in the battery pack that is not adjacent to the individual cell.

[0010] Furthermore, when the battery monitoring module is used to monitor battery pack data, it includes: The LTC series chips are used to monitor the voltage of individual cells and the total voltage of the battery pack, the Hall current method is used to monitor the current, the thermistor is used to monitor the temperature of the battery pack, and the LTC series chips are used to provide communication isolation for individual cells.

[0011] Furthermore, the main control module is powered by a USB interface, and the voltage level is converted by DC-DC converter inside the main control module.

[0012] Furthermore, the communication protocol for data transmission of the main control module includes: RS485 or SPI.

[0013] Furthermore, the main control module includes a master-slave control structure, with STM32C8T6 as the core for data reception and uploading to the host computer for display, and EP4CE10 as the core for data processing to generate control signals, transmitting data commands through dual-machine communication.

[0014] Furthermore, the battery drive control module includes: MOS drive voltage boost circuit, MOS fast turn-on drive circuit, drive control module power supply circuit and signal isolation circuit; The MOS drive voltage boost circuit generates a drive voltage that is connected to the signal output terminal of the MOS fast turn-on drive circuit to provide a large drive voltage for the output signal. The power supply circuit of the drive control module is connected to the input terminals of the MOS drive voltage boost circuit and the MOS fast turn-on drive circuit respectively. The signal isolation circuit is connected to the input terminal of the MOS fast turn-on drive circuit to digitally isolate the input and output signals.

[0015] Furthermore, the active balancing circuit module is used to acquire the abnormal individual cell parameters in the battery pack data and turn on the switch corresponding to the abnormal individual cell to isolate the abnormal cell.

[0016] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention employs an active balancing circuit module. By collecting and analyzing battery pack data, and controlling the corresponding switches to conduct, the system can effectively balance the battery pack, efficiently transferring battery power to low-capacity individual cells. This solves the problems of power waste and heat generation associated with passive balancing circuits, allowing the battery pack to operate at a suitable temperature and extending battery life. Simultaneously, the active balancing circuit module reduces the size and complexity of the balancing circuit. The use of BPS (Brain Power Shift) allows for bidirectional flow of battery power between cells, optimizing the problem of unidirectional power transfer in traditional active balancing circuits. Furthermore, the independent operation of each individual cell enables power flow between any two cells, optimizing the problem of power transfer only between adjacent cells in traditional balancing circuits. Finally, the use of a limit voltage difference method maximizes the battery voltage difference, improving the balancing speed and optimizing the problem of traditional active balancing circuits relying on battery voltage difference for power transfer. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A functional block diagram of a battery management system with a replaceable battery pack flexible balancing circuit provided in an embodiment of the present invention; Figure 2 A schematic diagram of the battery management system connection relationship for a replaceable battery pack flexible balancing circuit provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the main control module provided in an embodiment of the present invention; Figure 4 This is a schematic diagram showing the circuit conduction of different control strategies in the battery management system with a replaceable battery pack flexible balancing circuit provided in an embodiment of the present invention. Figure 5 This is a battery management system control command equalization conduction diagram for a replaceable battery pack flexible equalization circuit provided in an embodiment of the present invention. Figure 6 This is a flowchart of the active balancing strategy program of the battery management system with a replaceable battery pack flexible balancing circuit provided in an embodiment of the present invention. Detailed Implementation

[0018] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] In some embodiments of this application, see Figure 1-2 As shown, this embodiment provides a battery management system with a replaceable flexible battery pack balancing circuit, including: A battery pack includes multiple individual cells, with the positive and negative terminals of each individual cell connected in series. A battery monitoring module is connected to the battery pack. The battery monitoring module is connected to the positive and negative terminals of the individual cells via wires. The battery monitoring module is used to monitor battery pack data, which includes individual cell voltage, current, total battery pack voltage, and battery pack temperature. The main control module is connected to the battery monitoring module, and the main control module is used to receive and process the battery pack data; A battery drive control module is connected to the main control module, and the battery drive control module is used to receive control commands from the main control module. The active balancing circuit module is connected at one end to the battery drive control module, and at the other end to the positive and negative terminals of the individual cells in the battery pack.

[0020] Understandably, this invention employs an active balancing circuit module. By collecting and analyzing battery pack data, and controlling the corresponding switches, the system effectively balances the battery pack, efficiently transferring battery power to low-capacity individual cells. This solves the problems of wasted power and heat generation associated with passive balancing circuits, allowing the battery pack to operate at a suitable temperature and extending battery life. Simultaneously, the active balancing circuit module reduces the size and complexity of the balancing circuit. The use of BPS (Brain Power Shift) allows for bidirectional power flow between cells, optimizing the traditional active balancing circuit's unidirectional power transfer limitation. By enabling independent power flow between individual cells, it further optimizes the traditional balancing circuit's limitation to adjacent cells. The use of extreme voltage difference maximizes the battery voltage difference, improving balancing speed and optimizing the traditional active balancing circuit's reliance on battery voltage difference for power transfer.

[0021] Specifically, the individual cells of the battery pack are connected in series in positive and negative order, and wires are led out from the positive and negative terminals of the individual cells to connect to the battery monitoring module. The battery monitoring module is connected to the main control module's data receiving and transmitting chip through a four-wire interface. The data receiving chip communicates with the data processing chip. The battery drive control module is connected to the data processing chip. The battery active balancing circuit module is connected to the battery drive control module. The battery pack is connected to the battery active balancing circuit module. Figure 2 This is a schematic diagram of the connection relationship of the battery management system of the replaceable battery pack flexible balancing circuit provided in an embodiment of the present invention.

[0022] Preferably, the limiting voltage difference manifests as follows: During battery use, inconsistencies arise due to differences in manufacturing processes, materials, and transportation and usage, leading to variations in remaining charge capacity and actual voltage under the same conditions. The calculation of the limiting voltage difference uses a four-cell battery array as an example. Assuming the four cells have different capacities, first, the average voltage is calculated based on their magnitude. The voltages of the four cells are compared to this average; cells with voltages greater than the average are discharged, and those with voltages less than the average are charged. If two cells are discharged and two are charged, the difference between the average voltage of the two discharging cells and the average voltage of the four cells, as well as the difference between the voltage of a single cell and the average voltage of the four cells, are calculated. These differences are compared to determine whether to discharge the two cells in series or discharge a single cell. The calculation for two charging cells is the same. The results of these calculations generate corresponding control signals to activate the corresponding MOSFETs, resulting in different circuit structures.

[0023] In one embodiment of the present invention, four individual batteries BT1, BT2, BT3, and BT4 are used to form a series battery pack. Each battery has the same parameters, but each individual battery has a different initial charge. The batteries are connected to the corresponding monitoring I / O port of the battery monitoring module to monitor the data. The individual batteries are connected to the corresponding I / O port of the battery monitoring module to power the LTC chip.

[0024] In some embodiments of this application, the individual battery is connected to the balancing circuit of the active balancing circuit module via BPS, the positive and negative terminals of the individual battery are connected to the energy storage element via BPS, and the batteries in the battery pack are connected in parallel to the same energy storage element.

[0025] Specifically, a bidirectional power switch (BPS) is an active device built using MOSFETs or IGBTs that allows bidirectional current flow when powered on and blocks bidirectional voltage flow when powered off. A single battery cell is connected in parallel with other energy storage components such as inductors and capacitors.

[0026] In some embodiments of this application, the positive terminal of each individual cell is connected to one end of a BPS, and the other end of the BPS is connected to an inductor. The negative terminal of each individual cell is connected to one end of a BPS, and the other end of the BPS is connected to an inductor. Each individual cell's negative terminal is also connected to one end of a BPS, the other end of which is connected to a resistor. The other end of the resistor is connected to the positive terminal of an individual cell in the battery pack that is not adjacent to the individual cell.

[0027] In some embodiments of this application, when the battery monitoring module is used to monitor battery pack data, it includes: The LTC series chips are used to monitor the voltage of individual cells and the total voltage of the battery pack, the Hall current method is used to monitor the current, the thermistor is used to monitor the temperature of the battery pack, and the LTC series chips are used to provide communication isolation for individual cells.

[0028] Specifically, when the main control chip of the main control module is powered on and the data acquisition button is pressed, the LTC battery monitoring module program is executed to perform cyclic monitoring of the battery pack data. The individual battery voltage and the battery pack voltage are calculated by ADC sampling, the battery current is calculated by Hall current, and the battery temperature is calculated by NTC thermistor.

[0029] In some embodiments of this application, the main control module is powered by a USB interface, and the voltage level is converted by DC-DC converter inside the main control module.

[0030] In some embodiments of this application, the communication protocol for data transmission by the main control module includes: RS485 or SPI.

[0031] In some embodiments of this application, the main control module includes a master-slave control structure, with STM32C8T6 as the core for data reception and uploading to the host computer for display, and EP4CE10 as the core for data processing to generate control signals, and transmits data commands through dual-machine communication.

[0032] Specifically, in this embodiment of the invention, the main control module uses an STM32C8T6 as the core to transmit command control data to the battery monitoring module, and uses an FPGA EP4CE10 as the core to process the data and issue control commands.

[0033] Preferably, the main control module is powered by a USB interface. Pressing the reset button and the data acquisition button executes commands from the data monitoring module, including initializing the communication protocol, initializing the I / O ports, starting the ADC conversion command, and initiating data monitoring on the corresponding I / O ports. It collects individual battery voltage and total battery pack voltage data from the battery voltage register, and battery current, current data, and temperature data from the current register. The data from the four individual battery cells is transmitted to the main control chip via SPI communication, and then from the main control chip to the host computer for display and to the FPGA chip for data processing. In this case, the monitored battery capacities were BT1 4.20V, BT2 4.00V, BT3 3.80V, and BT4 3.65V.

[0034] In this invention, the battery drive control module uses an LM2577 boost chip to obtain the high-side gate drive level of the MOSFET, converting 5V to 25V. It uses a MOSFET driver chip UCC2512 to isolate the signals transmitted by the main control chip and control the corresponding MOSFET to turn on and off, for a total of 10 channels.

[0035] In some embodiments of this application, the battery drive control module includes: MOS drive voltage boost circuit, MOS fast turn-on drive circuit, drive control module power supply circuit and signal isolation circuit; The MOS drive voltage boost circuit generates a drive voltage that is connected to the signal output terminal of the MOS fast turn-on drive circuit to provide a large drive voltage for the output signal. The power supply circuit of the drive control module is connected to the input terminals of the MOS drive voltage boost circuit and the MOS fast turn-on drive circuit respectively. The signal isolation circuit is connected to the input terminal of the MOS fast turn-on drive circuit to digitally isolate the input and output signals.

[0036] In some embodiments of this application, the active balancing circuit module is used to obtain the abnormal individual cell parameters in the battery pack data and turn on the switch corresponding to the abnormal individual cell to isolate the abnormal cell.

[0037] Specifically, the battery drive control module IO receives the PWM signal controlled by the main control module, transmits the signal to the gate of the corresponding MOSFET to turn on the MOSFET, controls the conduction time according to the period of the signal, and connects the corresponding battery to the equalization circuit for power transfer.

[0038] Preferably, in the embodiments of the present invention, the active equalization circuit module is as follows: Figure 4 As shown, different equalization circuits are generated based on the received control signal, different series structures are generated based on different control signals, equalization circuits with different numbers of batteries are generated, and battery isolation circuits with abnormal parameters are generated based on different control signals.

[0039] Preferably, the active equalization circuit module is as follows: Figure 5 The diagram shows different balancing circuits generated based on the battery pack's charge level.

[0040] Preferably, the active balancing control strategy in this invention primarily determines the control signal by calculating the maximum battery difference, while preserving the possibility of using various algorithms.

[0041] Preferably, the present invention controls, such as Figure 5 The circuit shown uses switches S11 and S12 in the first half-cycle to connect battery BT1 to the equalization circuit, and switches S32 and S43 in the second half-cycle to connect battery BT4 to the equalization circuit. Simultaneously, depending on the control signal, switches S11, S22, S32, and S43 connect BT1, BT2, and BT4 to the equalization circuit. Similarly, depending on the control signal, switches S11, S32, and S43 connect BT1, BT2, BT3, and BT4 to the equalization circuit. Finally, depending on the control signal, switches S11, S13, S32, and S43 connect BT1, BT3, and BT4 to the equalization circuit.

[0042] Specifically, Figure 6 This is a flowchart of the active balancing strategy program of the battery management system with a replaceable battery pack flexible balancing circuit provided in an embodiment of the present invention.

[0043] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program goods embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0044] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0045] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0046] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A battery management system with a replaceable flexible battery pack balancing circuit, characterized in that, include: A battery pack includes multiple individual cells, with the positive and negative terminals of each individual cell connected in series. A battery monitoring module is connected to the battery pack. The battery monitoring module is connected to the positive and negative terminals of the individual cells via wires. The battery monitoring module is used to monitor battery pack data, which includes individual cell voltage, current, total battery pack voltage, and battery pack temperature. The main control module is connected to the battery monitoring module, and the main control module is used to receive and process the battery pack data; A battery drive control module is connected to the main control module, and the battery drive control module is used to receive control commands from the main control module. The active balancing circuit module is connected at one end to the battery drive control module, and at the other end to the positive and negative terminals of the individual cells in the battery pack.

2. The battery management system with a replaceable battery pack flexible balancing circuit according to claim 1, characterized in that, The individual battery cells are connected to the balancing circuit of the active balancing circuit module via BPS. The positive and negative terminals of the individual battery cells are connected to the energy storage element via BPS. The batteries in the battery pack are connected in parallel to the same energy storage element.

3. The battery management system with a replaceable battery pack flexible balancing circuit according to claim 2, characterized in that, The positive terminal of each individual cell is connected to one end of the BPS, and the other end of the BPS is connected to an inductor. The negative terminal of each individual cell is connected to one end of the BPS, and the other end of the BPS is connected to an inductor. The negative terminal of each individual cell is connected to one end of the BPS, and the other end of the BPS is connected to a resistor. The other end of the resistor is connected to the positive terminal of one individual cell in the battery pack that is not adjacent to the individual cell.

4. The battery management system with a replaceable battery pack flexible balancing circuit according to claim 1, characterized in that, When the battery monitoring module is used to monitor battery pack data, it includes: The LTC series chips are used to monitor the voltage of individual cells and the total voltage of the battery pack, the Hall current method is used to monitor the current, the thermistor is used to monitor the temperature of the battery pack, and the LTC series chips are used to provide communication isolation for individual cells.

5. The battery management system with a replaceable battery pack flexible balancing circuit according to claim 1, characterized in that, The main control module is powered by a USB interface, and the voltage level is converted by DC-DC converter inside the main control module.

6. The battery management system with a replaceable battery pack flexible balancing circuit according to claim 1, characterized in that, The communication protocol for data transmission in the main control module includes: RS485 or SPI.

7. The battery management system with a replaceable battery pack flexible balancing circuit according to claim 1, characterized in that, The main control module includes a master-slave control structure, with STM32C8T6 as the core for data reception and uploading to the host computer for display, and EP4CE10 as the core for data processing to generate control signals, and transmits data commands through dual-machine communication.

8. The battery management system with a replaceable battery pack flexible balancing circuit according to claim 1, characterized in that, The battery drive control module includes: MOS drive voltage boost circuit, MOS fast turn-on drive circuit, drive control module power supply circuit and signal isolation circuit; The MOS drive voltage boost circuit generates a drive voltage that is connected to the signal output terminal of the MOS fast turn-on drive circuit to provide a large drive voltage for the output signal. The power supply circuit of the drive control module is connected to the input terminals of the MOS drive voltage boost circuit and the MOS fast turn-on drive circuit respectively. The signal isolation circuit is connected to the input terminal of the MOS fast turn-on drive circuit to digitally isolate the input and output signals.

9. The battery management system with a replaceable battery pack flexible balancing circuit according to claim 1, characterized in that, The active balancing circuit module is used to obtain the abnormal individual cell parameters in the battery pack data and turn on the switch corresponding to the abnormal individual cell to isolate the abnormal cell.

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