Battery management system and method and energy storage apparatus

Abstract

Provided in the present invention are a battery management system and method and an energy storage apparatus. The battery management system comprises micro-control units and a collection unit, wherein each micro-control unit is used for receiving and / or sending a control signal, the collection unit is used for collecting cell parameters, two ends of the collection unit are connected to the micro-control units, the collection unit comprises at least one cell management unit, each cell management unit is provided with an analog front end, each analog front end is used for connecting to one cell for collection of the cell parameters, there are two micro-control units and two cell management units, each cell management unit is connected to one micro-control unit, and the two micro-control units share parameter signals and the control signals. The battery management system of the present invention can manage each cell, so as to allow for more balanced workload of each component, thus reducing the risk of slave control failures; and the battery management system can fully use the two micro-control units, so as to make system operation safer and more reliable.

Description

Battery management system, management method and energy storage device Technical Field

[0001] The present invention relates to the technical field of battery optimization and management, and in particular to a battery management system, a management method and an energy storage device. Background Art

[0002] In recent years, the energy storage industry has experienced explosive growth. Compared to other energy storage technologies, lithium-ion batteries have become more competitive due to rapid advancements in production technology and a gradual decline in manufacturing costs, resulting in an increasing market penetration in the energy storage sector. As an electronic device that monitors and manages batteries, the Battery Management System (BMS) is one of the core components of an energy storage system. This system monitors and controls batteries, providing real-time feedback to users on collected battery information and adjusting parameters based on this information to maximize battery performance. The BMS intelligently manages and maintains each battery cell, preventing overcharging and over-discharging, extending battery life, and monitoring battery status. Its functional safety is crucial to the safe and stable operation of the entire lithium-ion energy storage power station.

[0003] In energy storage systems, the BMS typically employs a three-tier architecture (BMU, BCU, and BAU) to implement hierarchical management and control from battery modules (packs) to clusters and stacks. The BMU's primary function is to collect battery cell voltage and temperature data and execute battery balancing strategies. As energy storage cells grow in size and capacity, the demand for refined management of individual cells is increasing. However, the existing three-tier battery management system cannot provide refined management of energy storage devices without modules. Furthermore, the BMU's role in the battery management system is increasing, increasing the likelihood of BMU failure.

[0004] Furthermore, current battery management systems primarily utilize dual microcontroller units (MCUs) that operate independently. In this dual MCU configuration, the battery management system connects to the battery pack via connectors and data acquisition cables, acquires cell voltage, temperature, and other parameters, and inputs them into the first MCU for data processing. The control output interface controls and protects peripherals (external devices). The second MCU monitors the operating, control, and health status of the first MCU. When the first MCU experiences an anomaly or fails, the second MCU activates and takes over, allowing the battery management system to continue operating normally and improving its safety and reliability. This dual MCU independent operation approach has the following drawbacks: 1) The battery management system does not fully utilize the second MCU, using it only as a backup, resulting in a waste of resources. 2) Peripheral control is primarily achieved through a one-control-one mode, meaning a single MCU controls the peripheral, failing to achieve dual control and increasing system risk. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a battery management system, a management method and an energy storage device, which can manage each battery cell, and distribute the existing centralized management of the entire battery pack by the slave control to each battery cell management unit for management, so that the workload of each component is more balanced, solving the problem of easy failure of the slave control in the existing battery management system, and can fully utilize the two micro control units, making the system operation safer and more reliable.

[0006] To solve the above technical problems, in the first aspect, the present invention provides a battery management system, comprising: a microcontroller unit and an acquisition unit, wherein the microcontroller unit is used to receive and / or send control signals, and the acquisition unit is used to acquire battery cell parameters, wherein both ends of the acquisition unit are connected to the microcontroller unit, and the acquisition unit includes at least one battery cell management unit, each of the battery cell management unit has an analog front end, and the analog front end is used to connect to a battery cell and acquire battery cell parameters; the microcontroller unit includes a first microcontroller unit and a second microcontroller unit, and the battery cell management unit includes a first group of battery cell management units and a second group of battery cell management units, wherein the first group of battery cell management units is connected to the first microcontroller unit; the second group of battery cell management units is connected to the second microcontroller unit; each battery cell management unit in the first group of battery cell management units is used to connect to a battery cell, and each battery cell management unit in the second group of battery cell management units is used to connect to a battery cell to acquire the battery cell parameters; the first microcontroller unit is connected to the second microcontroller unit, and the first microcontroller unit and the second microcontroller unit share parameter signals and control signals.

[0007] Optionally, the parameter signal includes a cell parameter and an analog front-end identification code, and the control signal includes an external device control signal and an acquisition unit control signal.

[0008] Optionally, it also includes a first isolation transformer and a second isolation transformer; in the first group of battery management units, the first and last two battery management units are respectively connected to the first micro control unit through a first isolation transformer; the first isolation transformer is connected between two adjacent battery management units; in the second group of battery management units, the first and last two battery management units are respectively connected to the second micro control unit through a second isolation transformer; the second isolation transformer is connected between two adjacent battery management units.

[0009] Optionally, it also includes a first bridge unit and a second bridge unit; in the first group of battery cell management units, the first isolation transformer at the head and tail ends are respectively connected to the first micro control unit through a first bridge unit; in the second group of battery cell management units, the second isolation transformer at the head and tail ends are respectively connected to the second micro control unit through a second bridge unit.

[0010] Optionally, the first bridge unit and the second bridge unit adopt a dual-channel SPI bridge circuit.

[0011] Optionally, the signal input and output terminals of the first micro control unit and / or the second micro control unit are connected to pull-up resistors.

[0012] Optionally, the signal input and output ends of the first bridge unit and / or the second bridge unit connected to the micro control unit are connected to a current-limiting resistor or inductor.

[0013] Optionally, the signal input and output ends of the first bridge unit and / or the second bridge unit connected to the cell management unit are connected to one end of a transient voltage suppression diode, and the other end of the transient voltage suppression diode is grounded.

[0014] Optionally, a storage unit is further included, which is connected to the first micro control unit and the second micro control unit respectively and is used to store the parameter signal and the control signal.

[0015] Optionally, the first micro control unit and the second micro control unit are connected via serial or parallel communication.

[0016] Optionally, the cell management unit is further provided with a MOS tube, which is connected to the analog front end and is used to bypass the cell connected to the cell management unit when the MOS tube is turned on.

[0017] In a second aspect, the present invention provides an energy storage device comprising at least one battery cluster consisting of a plurality of battery cells connected in series, and also comprising a battery management system as described in the first aspect, wherein each analog front end in the battery management system is connected to a battery cell.

[0018] In a third aspect, the present invention provides a battery management method, which is applied to the battery management system as described in the first aspect, comprising: receiving parameters collected by the acquisition unit, wherein the parameters include an analog front-end identification code and battery cell parameters corresponding to the analog front-end; judging the operating status of the battery management system based on the parameters; controlling the battery management system and controlling external devices based on the operating status, wherein controlling the external devices includes receiving and / or sending control signals, and the control signals are used to control the external devices.

[0019] In a fourth aspect, the present invention provides a battery management method, which is applied to the battery management system as described in the first aspect, including: receiving parameters collected by the acquisition unit, wherein the parameters include an analog front-end identification code and battery cell parameters corresponding to the analog front end; judging the operating status of the battery management system based on the parameters; controlling the battery management system according to the operating status; when the parameters received by the microcontroller unit contain an analog front-end identification code and no battery cell parameters, the battery cell fails; the microcontroller unit controls the battery cell and the main circuit bypass through the MOS tube connected to the analog front end.

[0020] Optionally, judging the operating status of the battery management system based on the parameters also includes: when the number of the analog front-end identification codes in the parameters collected by the acquisition unit is less than the number of analog front-ends in the acquisition unit, comparing the analog front-end identification code returned in the acquisition parameters with the identification code of the analog front-end in the acquisition unit to determine that the analog front-end has failed; and controlling the external device to alarm to prompt the failure of the analog front-end.

[0021] In a fifth aspect, the present invention provides a battery management method, which is applied to the battery management system as described in the first aspect, comprising: receiving parameters collected by the collection unit, wherein the parameters include parameters collected by a first group of battery cell management units received by a first microcontroller unit, and parameters collected by a second group of battery cell management units received by a second microcontroller unit; the first microcontroller unit and the second microcontroller unit share parameter signals and control signals; judging the operating status of the battery management system according to the parameters; controlling the battery management system according to the operating status; when the first microcontroller unit detects that it cannot access data of the second microcontroller unit, the first microcontroller unit controls the external device to disconnect from the second microcontroller unit, and disconnects the battery cell connected to the second microcontroller unit from the main circuit; when the second microcontroller unit detects that it cannot access data of the first microcontroller unit, the second microcontroller unit controls the external device to disconnect from the first microcontroller unit, and disconnects the battery cell connected to the first microcontroller unit from the main circuit.

[0022] Compared with the prior art, the present invention has the following beneficial effects: each cell management unit in the acquisition unit is directly connected to the cell and directly manages the cell. Compared with the existing battery management system that uses one slave control to centrally control all cells in a battery pack, the present battery management system uses one cell management unit to perform refined management of one cell, distributing the existing slave control of the entire battery pack to each cell management unit for management, making the workload of each component more balanced and solving the problem of easy failure of the slave control in the existing battery management system. In addition, by providing a first micro control unit, a second micro control unit and two groups of cell management units, the first micro control unit is connected to the second micro control unit, and the first micro control unit and the second micro control unit share parameter signals and control signals. Therefore, when the battery management system is working normally, it can simultaneously use the two micro control units to control the cell management unit to collect data for all cells, balance the cells, and control external devices, giving full play to the effectiveness of the two micro control units. When one of the micro control units is abnormal, the other micro control unit can also maintain the normal operation of the battery management system, making the operation of the battery management system safer and more reliable.

[0023] Summary of the Figures

[0024] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0025] FIG1 is a schematic structural diagram of a battery management system according to an embodiment of the present invention;

[0026] FIG2 is a schematic diagram of circuit connections of a first group of cell management units in a battery management system according to an embodiment of the present invention;

[0027] FIG3 is a circuit diagram of a second group of cell management units in a battery management system according to an embodiment of the present invention;

[0028] FIG4 is a circuit diagram of a cell management unit in a battery management system according to an embodiment of the present invention;

[0029] FIG5 is a schematic diagram of circuit connections between a first microcontroller unit and a cell management unit in a battery management system according to an embodiment of the present invention;

[0030] 6 is a schematic diagram of circuit connections between a second microcontroller unit and a cell management unit in a battery management system according to an embodiment of the present invention;

[0031] FIG7 is a flow chart of a battery management method according to an embodiment of the present invention;

[0032] FIG8 is another schematic flow chart of a battery management method according to an embodiment of the present invention;

[0033] FIG9 is another flowchart of a battery management method according to an embodiment of the present invention.

[0034] Preferred embodiments of the present invention

[0035] The present invention is further described below in conjunction with specific implementation methods and accompanying drawings. More details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific implementation method.

[0036] For example, a description later in the specification of a first feature being formed above or on a second feature may include an embodiment in which the first and second features are directly connected, or an embodiment in which an additional feature is formed between the first and second features, thereby eliminating the need for a direct connection between the first and second features. Furthermore, when a first element is described as being connected to or coupled to a second element, the description includes embodiments in which the first and second elements are directly connected or coupled to each other, as well as embodiments in which the first and second elements are indirectly connected or coupled to each other using one or more other intervening elements.

[0037] Although the present invention is disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modifications, equivalent variations, and modifications made to the above embodiments in accordance with the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection defined by the claims of the present invention.

[0038] An embodiment of the present invention provides a battery management system, including a microcontroller unit and an acquisition unit, the microcontroller unit is used to receive and / or send control signals, and the acquisition unit is used to collect battery cell parameters, wherein both ends of the acquisition unit are connected to the microcontroller unit, the acquisition unit includes at least one battery cell management unit, each battery cell management unit has an analog front end, and the analog front end is used to connect to a battery cell and collect battery cell parameters; the microcontroller unit includes a first microcontroller unit and a second microcontroller unit, the battery cell management unit includes a first group of battery cell management units and a second group of battery cell management units, wherein the first group of battery cell management units is connected to the first microcontroller unit; the second group of battery cell management units is connected to the second microcontroller unit; each battery cell management unit in the first group of battery cell management units is used to connect to a battery cell, and each battery cell management unit in the second group of battery cell management units is used to connect to a battery cell to collect battery cell parameters; the first microcontroller unit is connected to the second microcontroller unit, and the first microcontroller unit and the second microcontroller unit share parameter signals and control signals.

[0039] Furthermore, the parameter signal includes the battery cell parameters and the analog front-end identification code, and the control signal includes the external device control signal and the acquisition unit control signal.

[0040] In this embodiment, each cell management unit manages a single cell, refining management granularity. This allows for direct management of individual cells, moving beyond the management of each battery module / pack. This enables refined cell management and effectively addresses the efficiency and safety of energy storage systems. This reduces the management pressure on the slave controllers within the battery management system, lowering the risk of slave controller failure and making system operation safer and more reliable.

[0041] The battery cell management unit used in this embodiment is a single battery cell management unit, that is, each battery cell has a battery cell management unit, and one battery cell management unit only collects the parameters of one battery cell. There is no need to separately design the control module and collection module of the battery cell management unit. Each battery cell management unit can independently collect the voltage, internal resistance, temperature and other data of the battery cell, thereby reducing the total system cost.

[0042] In this embodiment, the battery management system adopts a dual microcontroller unit (MCU) architecture, including a first microcontroller unit and a second microcontroller unit. The two microcontroller units have their own strengths and run simultaneously instead of switching to avoid resource waste. Compared with the traditional solution, half of the microcontroller units are saved, and the device utilization rate of the battery management system is increased. In terms of controlling external devices, the first microcontroller unit and the second microcontroller unit can be controlled simultaneously. Even if one microcontroller unit fails, the external device can still be effectively controlled to protect the safety of the battery management system. For example, if the first microcontroller unit fails, since the first microcontroller unit and the second microcontroller unit share parameter signals and control signals in real time, the second microcontroller unit can effectively control the external device through control information to protect the safety of the battery management system. Similarly, if the second microcontroller unit fails, the first microcontroller unit can also effectively control the external device.

[0043] FIG1 is a schematic diagram of a battery management system according to an embodiment of the present invention. Referring to FIG1 , the battery management system includes a first microcontroller unit (MCU) and a second MCU. The first and second MCUs can simultaneously perform the following tasks: controlling their corresponding cell management units (CMUs) to collect data (parameter signals) from the cells. In this embodiment, the battery cluster is divided into two parts: BAT_M (a master battery cluster portion, consisting of a portion of the cells) and BAT_S (a slave battery cluster portion, consisting of the remaining cells). The first MCU controls its corresponding first group of CMUs to acquire parameters such as cell voltage and temperature from BAT_M and calculate the accuracy of these parameters. The second MCU controls its corresponding second group of CMUs to acquire parameters such as cell voltage and temperature from BAT_S and calculate the accuracy of these parameters. The first and second MCUs are connected in communication, enabling real-time data exchange and mutual monitoring of each other's operating status. Even if one MCU fails, the battery management system can continue to operate as long as the other is functioning properly, enhancing system security.

[0044] In this embodiment, a centralized battery management system using daisy chain communication technology has a cost advantage over the original distributed architecture battery management system. Daisy chain communication eliminates the CAN (Controller Area Network) chip on the master and slave boards and replaces it with a conversion chip. The cost of these conversion chips is more advantageous than that of the CAN chip.

[0045] FIG2 is a schematic diagram of the circuit connection of the first group of battery cell management units in the battery management system according to an embodiment of the present invention, and FIG3 is a schematic diagram of the circuit connection of the second group of battery cell management units in the battery management system according to an embodiment of the present invention. In fact, all the battery cells in FIG2 and FIG3 are connected in series. For the convenience of display, this embodiment shows the first micro control unit and the second micro control unit separately. Referring to FIG2 and FIG3, the micro control units of the battery management system (such as the first micro control unit and the second micro control unit) can convert the signal into a differential signal through the communication conversion chip, which communicates with the first battery cell management unit in the form of a differential signal. After the differential signal comes out of the first battery cell management unit, it enters the subsequent battery cell management unit in sequence, so that the micro control unit is finally able to communicate with all battery cell management units. In this embodiment, the serial communication signal is converted into a daisy chain differential communication signal, which effectively enhances the robustness and anti-interference ability of the battery management system.

[0046] As a preferred method, the first group of cell management units collects parameters of half of the cells in the battery cluster, and the second group of cell management units collects parameters of the other half of the cells in the battery cluster. Therefore, when the battery management system is operating normally, the control functions, data receiving and sending functions, cell balancing functions, etc. of the two microcontrollers can be most fully and coordinated to make the operation efficiency of the battery management system higher.

[0047] In this embodiment, the first micro control unit and the second micro control unit may be connected via a serial bus, such as a SPI (Serial Peripheral Interface) connection, to achieve data interaction, or may be connected via a parallel communication connection to achieve data interaction.

[0048] Exemplarily, the battery management system adopts the form of dual microcontroller units, the first microcontroller unit is responsible for all data processing of the battery management system and controlling the battery cell management unit to collect half of the battery cell parameters, the second microcontroller unit is responsible for controlling the battery cell management unit to collect the other half of the battery cell parameters, the second microcontroller unit processes the received data and transmits it to the first microcontroller unit through the communication interface, and the first microcontroller unit uniformly completes data accuracy judgment, SOC (State of Charge) calculation, system status judgment, etc., and the first microcontroller unit and the second microcontroller unit simultaneously control two pins of the external device. When the first microcontroller unit is damaged or the second microcontroller unit fails, the other microcontroller unit can also control the external device to protect the safety of the external device.

[0049] As shown in Figures 2 and 3, all cells are connected in series via their positive and negative terminals to form a battery cluster. This battery cluster consists of 416 cells with a DC voltage of 1500V. The first and second microcontroller units are responsible for acquiring voltage, temperature, and other data for the 208 cells in the lower and upper circuits, respectively. The battery cluster's main negative terminal, BAT-, to the main positive terminal, BAT+, is divided into two sections. A 1500V battery cluster consists of 416 cells, so n in the figure represents 208. This means the first microcontroller unit manages the lower 208 cells (CELL_M1, CELL_M2, ..., CELL_Mn), while the second microcontroller unit manages the upper 208 cells (CELL_S1, CELL_S2, ..., CELL_Sn).

[0050] In existing battery management systems, one BMU (slave control unit) manages one battery pack and cannot provide detailed management of each battery cell. When a cell failure is detected, the entire battery pack, the entire battery cluster, or even the entire energy storage device can only be shut down, which has a significant impact on system operation.

[0051] Based on the above considerations, in one example, the cell management unit is further provided with a MOS transistor, which is connected to the analog front end and is used to bypass the cells connected to the cell management unit when the MOS transistor is turned on. As shown in Figures 2 and 3, the MOS transistors corresponding to cells CELL_M1, CELL_M2, and CELL_Mn are Q_M1, Q_M2, and Q_Mn, respectively, and the MOS transistors corresponding to cells CELL_S1, CELL_S2, and CELL_Sn are Q_S1, Q_S2, and Q_Sn, respectively.

[0052] For example, referring to FIG4 , FIG4 is a circuit diagram of a cell management unit in a battery management system according to an embodiment of the present invention. The cell management unit (including the AFE chip) is connected to the positive and negative poles of the cell through VBAT and VSS to provide power for the chip operation; VCH and VCL are the chip voltage acquisition ports; VCHR and VCLR are the functional interfaces for the chip to acquire the internal resistance of the cell; VSW is used for the bypass function when the cell fails, and is connected to the MOS tube; a built-in temperature measurement module can collect cell temperature data; VBAT_FIL is the cell fault output pin, VHP is the overvoltage protection pin, and IMA, IMB and IPA, IPB respectively constitute a two-channel differential communication function interface. Based on the above circuit, when a cell is undervoltage or fails, the first microcontroller unit or the second microcontroller unit can control the cell management unit to turn on the MOS tube Q, bypassing the corresponding faulty cell without affecting the normal operation of the battery management system, thereby enhancing the robustness of the system.

[0053] In one example, the battery management system further includes a first isolation transformer and a second isolation transformer. In a first group of cell management units, the first and last cell management units are each connected to the first microcontroller unit via a first isolation transformer, with the first isolation transformer connected between adjacent cell management units. In a second group of cell management units, the first and last cell management units are each connected to the second microcontroller unit via a second isolation transformer, with the second isolation transformer connected between adjacent cell management units. Typically, isolated communication between cell management units is required, and the isolation devices used are often isolation transformers or high-voltage capacitors.

[0054] In one example, the battery management system also includes a first bridge unit and a second bridge unit; in the first group of battery cell management units, the first isolation transformers at the head and tail ends are connected to the first micro control unit through a first bridge unit respectively, and in the second group of battery cell management units, the second isolation transformers at the head and tail ends are connected to the second micro control unit respectively through a second bridge unit.

[0055] More optimally, the first and second bridge units can employ dual-channel SPI bridge circuits. For example, a DNB1168 chip is used as the first or second bridge unit (the bridge unit comprises a bridge chip), connected between the first or second microcontroller unit and the cell management unit, providing bidirectional ring network SPI communication, and connected in series using a pulse communication transformer to achieve excellent electrical isolation and data transmission.

[0056] Using the cell management unit shown in Figure 4, with the chip DNB1168 as the bridge chip of the first bridge unit, as shown in Figure 2, the communication ports IPA and IPB of the first cell management unit are connected to the first isolation transformer, the other side of which is connected to the bridge chip. The bridge chip converts the differential signals of the daisy chain communication into SPI communication signals to enable data exchange with the first micro-control unit. The communication ports IMA and IMB of the last cell management unit are connected to another first isolation transformer, the other side of which is connected to another bridge chip. This bridge chip converts the differential signals of the daisy chain communication into SPI communication signals to enable data exchange with the first micro-control unit. The cell management units form a communication channel through the first isolation transformer or capacitor, thereby communicating with each other through IPA, IPB and IMA, IMB, and connecting to the first micro-control unit to achieve daisy chain serial communication for the lower 208 cells. It is understandable that the second micro-control unit can also achieve serial communication for the upper 208 cells in the same way as above, which will not be described here.

[0057] When hundreds of battery cells in a battery cluster are connected in series, the first microcontroller unit or the second microcontroller unit outputs an SPI communication instruction, which is transmitted to the communication port of the first battery cell management unit through the communication bridge chip (such as chip DNB1168) and the isolation transformer. The data of the first battery cell will be packaged and pushed to the second battery cell management unit. The second battery cell management unit collects the battery cell parameters and packages them together with the first battery cell data and pushes them to the third battery cell management unit. This process continues until the last battery cell management unit is finally received by the terminal bridge chip (such as chip DNB1168) and converted into an SPI communication signal and input into the first microcontroller unit / second microcontroller unit. At this point, all battery cell parameters (including battery cell voltage, temperature, internal resistance, etc.) will be obtained by the first microcontroller unit / second microcontroller unit. The communication circuit is designed as a daisy chain ring network, and the first microcontroller unit / second microcontroller unit can also obtain all battery cell parameters from the terminal battery cell management unit to the first battery cell management unit. When the communication port of a battery management unit in the ring network communication topology circuit is broken, the first micro control unit / second micro control unit can send instructions from both ends at the same time to obtain all battery cell parameters from both ends, eliminating the impact of incomplete data acquisition caused by the break.

[0058] In one example, the signal input and output terminals of the first micro control unit and / or the second micro control unit are connected to pull-up resistors.

[0059] In one example, the signal input and output terminals of the first bridge unit and / or the second bridge unit connected to the micro control unit are connected to current-limiting resistors or inductors.

[0060] In one example, the signal input and output ends of the first bridge unit and / or the second bridge unit connected to the cell management unit are connected to one end of a transient voltage suppressor diode (TVS tube), and the other end of the transient voltage suppressor diode is grounded.

[0061] FIG5 is a schematic diagram of a circuit connection between a first microcontroller unit and a cell management unit in a battery management system according to an embodiment of the present invention, and FIG6 is a schematic diagram of a circuit connection between a second microcontroller unit and a cell management unit in a battery management system according to an embodiment of the present invention. Referring to FIG5 and FIG6 , the microcontroller unit (the first microcontroller unit or the second microcontroller unit) leads out two SPI communication signals and connects to the bridge circuits UB1 and UB2. The microcontroller unit is connected to the bridge unit through four communication lines, wherein CS_BF1 represents the chip select signal line of the SPI communication of the bridge unit UB1, and MOSI_BF2 represents the bridge circuit. The master-output and slave-input signal lines for SPI communication in bridge unit UB1 are connected. SCK_BF1 represents the clock signal line for SPI communication in bridge unit UB1, and MISO_BF1 represents the master-input and slave-output signal lines for SPI communication in bridge unit UB1. CS_BF2 represents the chip select signal line for SPI communication in bridge unit UB2, MOSI_BF2 represents the master-output and slave-input signal lines for SPI communication in bridge unit UB2, SCK_BF2 represents the clock signal line for SPI communication in bridge unit UB2, and MISO_BF2 represents the master-input and slave-output signal lines for SPI communication in bridge unit UB2. To ensure the initial state of the signals, pull-up resistors are connected to the signal input and output terminals of the microcontroller unit, such as resistors RB1, RB2, RB3, RB4, and resistors RB7, RB8, RB9, and RB10.

[0062] To protect the bridge chip port, the signal input and output terminals of the bridge chip connected to the microcontroller unit are connected to current-limiting resistors or inductors, such as resistors RB5\RB6 and inductor LV1 set in the bridge chip UB1, and resistors RB11\RB12 and inductor LV2 set in the bridge chip UB2.

[0063] At the signal input and output end DIOTO of the bridge chip, in order to ensure long-distance transmission and electrical isolation characteristics of the differential communication signal, the coil turns ratio of the isolation transformers TB1 and TB2 of this embodiment can be set to 1:1. The isolation transformer shown can also have high frequency, common-mode suppression and other performance to realize data interaction with the battery management unit.

[0064] Continuing with Figures 5 and 6, transient voltage suppressor diodes (TVS diodes) are installed to protect the signal input and output ports of the bridge chip. The signal input and output ports connecting the bridge chip to the cell management unit are connected to one end of a TVS diode, with the other end of the TVS diode grounded. For example, TVS diodes ZD1 and ZD2 are installed on bridge chip UB1, and TVS diodes ZD3 and ZD4 are installed on bridge chip UB2. The installation of TVS diodes effectively resists surges and prevents damage to the bridge chip.

[0065] In one example, the battery management system further includes a storage unit, which is connected to the first micro control unit and the second micro control unit respectively and is used to store parameter signals and control signals.

[0066] In some cases, the microcontroller unit mainly includes a controller, an arithmetic unit and a register, and does not have a storage unit. Therefore, it is necessary to set up a separate storage unit for storing parameter signals and control signals. After the battery management system is provided with a storage unit, in this embodiment, the battery cell voltage, temperature and other parameter acquisition and transmission of BAT_M are realized by the battery cell management unit through daisy chain communication, and with the help of the first bridge unit and the first microcontroller unit to realize signal conversion, thereby calculating the acquisition accuracy of the battery cell voltage, temperature and other parameters, and transferring the characteristic data to the storage unit. The battery cell voltage, temperature and other parameter acquisition and transmission of BAT_S are realized by the battery cell management unit in another circuit through daisy chain communication, and with the help of the second bridge unit and the second microcontroller unit to realize signal conversion, thereby calculating the acquisition accuracy of the battery cell voltage, temperature and other parameters, and transferring the characteristic data to the storage unit. When it is necessary to read or write data to the storage unit, the first microcontroller unit or the second microcontroller unit performs data read and write operations through serial or parallel communication.

[0067] In the battery management system provided by this embodiment, each cell management unit in the collection unit is directly connected to the cell and directly manages the cell. Compared with the existing battery management system that uses a slave control to centrally control all cells in a battery pack, this battery management system uses a cell management unit to perform refined management of each cell, distributing the existing slave control of the entire battery pack to each cell management unit, making the workload of each component more balanced and solving the problem of slave control failure in the existing battery management system. In addition, by providing a first micro control unit, a second micro control unit and two groups of cell management units, the first micro control unit is connected to the second micro control unit, and the first micro control unit and the second micro control unit share parameter signals and control signals. Therefore, when the battery management system is operating normally, it can simultaneously use the two micro control units to control the cell management unit to collect data from all cells, balance the cells, and control external devices, giving full play to the effectiveness of the two micro control units. When one of the micro control units is abnormal, the other micro control unit can also maintain the normal operation of the battery management system, making the operation of the battery management system safer and more reliable.

[0068] Another embodiment of the present invention provides an energy storage device comprising at least one battery cluster consisting of a plurality of battery cells connected in series, and also comprising a battery management system as described in the aforementioned embodiment, wherein each analog front end in the battery management system is connected to a battery cell. The specific details of the relevant units or modules in the battery management system of this embodiment can be found in the aforementioned embodiments and will not be elaborated upon here. Furthermore, other essential components or assemblies of the illustrated energy storage device are not further described here.

[0069] The energy storage device provided in this embodiment has an improved battery management system. Each cell management unit in the acquisition unit is directly connected to the cell, and the cell is directly managed. This allows for more refined management of the cell, making the workload of each component more balanced. This solves the problem of easy failure of the slave controller in existing battery management systems, and can fully utilize the two microcontroller units, making the system operation safer and more reliable.

[0070] Another embodiment of the present invention provides a battery management method, as shown in Figure 7, which can be applied to the battery management system of the aforementioned embodiment. Method 700 includes: S710, receiving parameters collected by the acquisition unit, wherein the parameters include an analog front-end identification code and battery cell parameters corresponding to the analog front-end; S720, judging the operating status of the battery management system based on the parameters; S730, controlling the battery management system and controlling external devices based on the operating status, wherein controlling the external device includes receiving and / or sending control signals, and the control signals are used to control the external devices.

[0071] The battery management method provided in this embodiment, in which the acquisition unit can directly manage the battery cells, manage the battery cells more finely, so as to collect battery cell parameters and judge the operating status of the battery management system based on the parameters, thereby improving battery management efficiency and reducing the risk of battery management system failure.

[0072] Another embodiment of the present invention provides a battery management method, as shown in Figure 8, which can be applied to the battery management system of the aforementioned embodiment. Method 800 includes: S810, receiving parameters collected by the acquisition unit, wherein the parameters include an analog front-end identification code and battery cell parameters corresponding to the analog front end; S820, judging the operating status of the battery management system based on the parameters; S830, controlling the battery management system according to the operating status; when the parameters received by the microcontroller contain an analog front-end identification code and no battery cell parameters, the battery cell fails; the microcontroller controls the battery cell and the main circuit bypass through the MOS tube connected to the analog front end.

[0073] In this embodiment, under normal circumstances, the microcontroller receives an identification code from the corresponding analog front-end, an identification code corresponding to the battery cell, and data such as the battery cell's temperature, voltage, and current. If a battery cell is abnormal, the microcontroller receives only the identification code from the analog front-end, without the battery cell parameters. The collected parameters can be used to determine whether an abnormality exists. If a battery cell is abnormal, the microcontroller controls the MOS transistor to bypass the faulty battery cell, allowing the other batteries to continue operating.

[0074] In one example, judging the operating status of the battery management system based on parameters also includes comparing the analog front-end identification code returned in the collected parameters with the identification code of the analog front-end in the collection unit when the number of analog front-end identification codes in the parameters collected by the collection unit is less than the number of analog front-ends in the collection unit, determining that the analog front-end has failed, and controlling the external device to alarm to prompt the failure of the analog front-end.

[0075] In this embodiment, if an AFE fails, the faulty AFE will not collect parameters for the battery cell, so no data from that AFE will be collected. For example, if there are 10 AFEs and one fails, the battery cell will continue to operate, but only 9 will return data. In this case, the faulty AFE can be determined by comparing the missing AFE identification code. If a faulty AFE is determined, the battery management system will issue an alarm and provide the identification code of the faulty AFE.

[0076] Other details of the battery management system that executes the method of this embodiment can be referred to the aforementioned embodiment and will not be elaborated here.

[0077] The battery management method provided in this embodiment can effectively determine the abnormal conditions of the battery cells and the analog front-end in the battery management system. When the battery cells fail, the microcontroller unit controls the bypass of the battery cells and the main circuit through the MOS tube connected to the analog front-end. When the analog front-end is abnormal, the microcontroller unit controls the external device to alarm and prompt the failure of the analog front-end, making the operation of the battery management system safer and more reliable.

[0078] Another embodiment of the present invention provides a battery management method, as shown in Figure 9, which can be applied to the battery management system of the aforementioned embodiment. Method 900 includes: S910, receiving parameters collected by the collection unit, wherein the parameters include parameters collected by a first group of battery cell management units received by a first microcontroller unit, and parameters collected by a second group of battery cell management units received by a second microcontroller unit; the first microcontroller unit and the second microcontroller unit share parameter signals and control signals; S920, judging the operating status of the battery management system according to the parameters; S930, controlling the battery management system according to the operating status; when the first microcontroller unit detects that it cannot access the data of the second microcontroller unit, the first microcontroller unit controls the external device to disconnect from the second microcontroller unit, and disconnects the battery cell connected to the second microcontroller unit from the main circuit; when the second microcontroller unit detects that it cannot access the data of the first microcontroller unit, the second microcontroller unit controls the external device to disconnect from the first microcontroller unit, and disconnects the battery cell connected to the first microcontroller unit from the main circuit.

[0079] Other details of the battery management system that executes the method of this embodiment can be referred to the aforementioned embodiment and will not be elaborated here.

[0080] The battery management method provided in this embodiment can, during normal operation, simultaneously utilize two microcontroller units to control the cell management unit to perform tasks such as data collection for all cells, cell balancing, and control external devices, thereby giving full play to the effectiveness of the two microcontroller units. When one of the microcontroller units is abnormal, the other microcontroller unit can also maintain the normal operation of the battery management system, making the operation of the battery management system safer and more reliable.

[0081] The basic concepts have been described above. It will be apparent to those skilled in the art that the above disclosures are merely illustrative and do not constitute limitations on this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and amendments to this application. Such modifications, improvements, and amendments are suggested in this application and remain within the spirit and scope of the exemplary embodiments of this application.

Claims

1. A battery management system, characterized in that: include: A microcontrol unit and a collection unit, wherein the microcontrol unit is used to receive and / or send control signals, and the collection unit is used to collect battery cell parameters, wherein: Both ends of the acquisition unit are connected to the micro control unit, and the acquisition unit includes at least one battery management unit, each of which has an analog front end, and the analog front end is used to connect to a battery cell and collect battery cell parameters; The micro control unit includes a first micro control unit and a second micro control unit, and the battery cell management unit includes a first group of battery cell management units and a second group of battery cell management units, wherein: A first group of cell management units is connected to the first micro control unit; a second group of cell management units is connected to the second micro control unit; Each cell management unit in the first group of cell management units is used to connect to a cell, and each cell management unit in the second group of cell management units is used to connect to a cell, so as to collect the cell parameters; The first micro control unit is connected to the second micro control unit, and the first micro control unit and the second micro control unit share parameter signals and control signals.

2. The battery management system according to claim 1, wherein: The parameter signal includes a cell parameter and an analog front-end identification code, and the control signal includes an external device control signal and an acquisition unit control signal.

3. The battery management system according to claim 1, wherein: Also included is a first isolation transformer and a second isolation transformer; In the first group of cell management units, the first and last cell management units are respectively connected to the first micro control unit via a first isolation transformer; and the first isolation transformer is connected between two adjacent cell management units; In the second group of battery cell management units, the first and last two battery cell management units are respectively connected to the second micro control unit through a second isolation transformer; the second isolation transformer is connected between two adjacent battery cell management units.

4. The battery management system according to claim 3, characterized in that: Also includes a first bridging unit and a second bridging unit; In the first group of battery cell management units, the first isolation transformers at both ends are connected to the first micro control unit via a first bridge unit respectively; In the second group of battery cell management units, the second isolation transformers at both ends are connected to the second micro control unit via a second bridge unit respectively.

5. The battery management system according to claim 4, wherein: The first bridge unit and the second bridge unit adopt a dual-channel SPI bridge circuit.

6. The battery management system according to claim 4, wherein: The signal input and output terminals of the first micro control unit and / or the second micro control unit are connected to pull-up resistors.

7. The battery management system according to claim 4, wherein: The signal input and output ends of the first bridge unit and / or the second bridge unit connected to the micro control unit are connected to a current-limiting resistor or inductor.

8. The battery management system according to claim 4, wherein: The signal input and output ends of the first bridge unit and / or the second bridge unit connected to the cell management unit are connected to one end of a transient voltage suppression diode, and the other end of the transient voltage suppression diode is grounded.

9. The battery management system according to claim 1, wherein: It also includes a storage unit, which is connected to the first micro control unit and the second micro control unit respectively and is used to store the parameter signal and the control signal.

10. The battery management system according to claim 1, wherein: The first micro control unit and the second micro control unit are connected in serial or parallel communication.

11. The battery management system according to any one of claims 1 to 10, characterized in that: The cell management unit is further provided with a MOS tube, which is connected to the analog front end and is used to bypass the cell connected to the cell management unit when the MOS tube is turned on.

12. An energy storage device comprising at least one battery cluster consisting of a plurality of battery cells connected in series, characterized in that: It also includes a battery management system according to any one of claims 1 to 11, wherein each analog front end in the battery management system is connected to a battery cell.

13. A battery management method, characterized in that: The battery management system according to any one of claims 1 to 11 comprises: Receiving parameters collected by the collection unit, wherein the parameters include an analog front-end identification code and cell parameters corresponding to the analog front-end; judging the operating status of the battery management system according to the parameters; The battery management system and the external device are controlled according to the operating status, wherein controlling the external device includes receiving and / or sending a control signal, and the control signal is used to control the external device.

14. A battery management method, characterized in that: The battery management system according to any one of claims 11, comprising: Receiving parameters collected by the collection unit, wherein the parameters include an analog front-end identification code and cell parameters corresponding to the analog front-end; judging the operating status of the battery management system according to the parameters; The battery management system is controlled according to the operating status; when the parameters received by the microcontroller contain an analog front-end identification code but no battery cell parameters, the battery cell fails; the microcontroller controls the battery cell and the main circuit bypass through the MOS tube connected to the analog front-end.

15. The battery management method according to claim 14, wherein: Determining the operating status of the battery management system according to the parameters further includes: When the number of analog front-end identification codes in the parameters collected by the acquisition unit is less than the number of analog front-ends in the acquisition unit, the analog front-end identification code returned in the acquisition parameters is compared with the identification code of the analog front-end in the acquisition unit to determine that the analog front-end has failed; and the external device is controlled to alarm to prompt the failure of the analog front-end.

16. A battery management method, characterized in that: The battery management system according to any one of claims 1 to 11 comprises: Receive parameters collected by the collection unit, wherein the parameters include parameters collected by the first group of battery cell management units received by the first microcontroller unit and parameters collected by the second group of battery cell management units received by the second microcontroller unit; the first microcontroller unit and the second microcontroller unit share parameter signals and control signals; judging the operating status of the battery management system according to the parameters; controlling the battery management system according to the operating status; When the first micro control unit detects that it cannot access the data of the second micro control unit, the first micro control unit controls the external device to be disconnected from the second micro control unit, and disconnects the battery cell connected to the second micro control unit from the main circuit; When the second micro control unit detects that it cannot access the data of the first micro control unit, the second micro control unit controls the external device to be disconnected from the first micro control unit, and disconnects the battery cell connected to the first micro control unit from the main circuit.

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