Battery management system and energy storage system

Abstract

The utility model discloses a battery management system and an energy storage system, and relates to the technical field of energy storage. The utility model discloses a battery management system, which comprises a battery control unit and an analog front-end module, wherein the battery control unit is used for correspondingly managing one or more battery cells connected in series; the analog front-end module is integrated on each battery cell; the analog front-end module is connected with the battery control unit based on the battery cells to form a communication link; the analog front end module is used for collecting data of the battery cell and sending the data to the battery control unit through a communication link, and the battery control unit is used for generating a control instruction according to the data and sending the control instruction to the analog front end. The battery management system and the energy storage system which are highly integrated are designed, the battery control unit directly issues an instruction to the analog front-end module and receives data collected by the analog front-end module in real time, the data transmission time is saved, the risk that data are abnormal and false alarm is triggered due to interference in the data transmission process is reduced, and the data transmission efficiency is improved. And the safety and the reliability of the system are effectively improved.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a battery management system and an energy storage system. Background Art

[0002] In modern society, environmental protection and energy conservation have become universal concerns. New energy is one of the means by which countries around the world are striving to achieve sustainable development. Within the new energy sector, the development of energy storage technology is also receiving increasing attention. New energy storage technology stores unstable electrical energy in a specific manner so that it can be released when needed, thereby achieving dynamic balance. Currently, new energy storage technology has been widely adopted and has achieved remarkable results. Energy storage technologies can be categorized into chemical energy storage, mechanical energy storage, heat and cold storage, and supercapacitors. The development of these technologies began in the 1970s, and their technical systems have gradually matured and entered a substantial stage of development. Currently, the application of energy storage technology has gradually expanded to include aviation, aerospace, transportation, military, communications, healthcare, finance, residential, and commercial sectors.

[0003] Industrial and commercial energy storage refers to energy storage systems with smaller capacity and power, used for industrial and commercial purposes. Currently, they primarily save costs for electricity users by charging from the grid when electricity prices are low and discharging for use when prices are high. The battery management system (BMS) in current mainstream industrial and commercial energy storage systems primarily consists of modules such as the battery control unit (BCU), battery sampling unit (BMU), and sensors. These BMSs typically utilize a distributed architecture for system control and data transmission. Data transmission delays lead to lags in control and protection, and prevent one-to-one monitoring and management of battery cells.

[0004] Therefore, it is necessary to propose a battery management system and energy storage system that can effectively improve the reliability and stability of system communication and control. Utility Model Content

[0005] In order to overcome the shortcomings of the existing technology, this application proposes a highly integrated battery management system and energy storage system that can be widely used in industry and commerce, which can effectively improve the reliability and stability of system communication and control.

[0006] In a first aspect, the present application provides a battery management system, comprising a battery control unit corresponding to managing one or more battery cells connected in series, and an analog front-end module integrated into each battery cell, wherein the analog front-end module is connected to the battery control unit to form a communication link based on the battery cell;

[0007] The analog front-end module is used to collect data from the battery cells and send the collected data to the battery control unit via the communication link;

[0008] The battery control unit is configured to generate a control instruction according to the data sent by the analog front-end module, and send the control instruction to the analog front-end through the communication link.

[0009] In some embodiments, the analog front-end module includes an AFE chip and a sampling circuit connected to the AFE chip;

[0010] The AFE chip and the sampling circuit are integrated on a flexible circuit board, and the flexible circuit board is connected to the positive and negative electrodes of the battery cell through soft connectors.

[0011] Preferably, the analog front-end module further includes a sensor connected to the AFE chip; the soft connector is an aluminum bar connector; and the AFE chip uses a DNB1101 chip or a DNB1168 chip.

[0012] In some implementation schemes, the data collected by the analog front-end module includes at least one of a single cell voltage, a cell temperature, and an AC impedance value of the cell.

[0013] In some embodiments, the battery control unit uses one or more MCUs, and the MCU uses a multi-core chip or a heterogeneous core chip.

[0014] In some embodiments, the battery management system further includes a storage chip connected to the battery control unit, and the storage chip is used to store the data received by the battery control unit.

[0015] In a second aspect, the present application provides an energy storage system comprising one or more battery cells connected in series, and the above-mentioned battery management system.

[0016] In some embodiments, the energy storage system further includes a liquid cooler and an energy storage converter connected to the battery management system; the battery management system implements charge and discharge control of the battery based on the liquid cooler and the energy storage converter.

[0017] The above one or more technical solutions of this application have at least one or more of the following beneficial effects:

[0018] In the technical solution for implementing the present application, the battery management system includes a battery control unit corresponding to one or more battery cells connected in series, and an analog front-end module integrated into each battery cell. The analog front-end module is connected to the battery control unit based on the battery cell to form a communication link; the analog front-end module and the battery control unit communicate data based on the communication link. In the present application, one battery cell is connected to one analog front-end module, which realizes "one-cell-one-management". The analog front-end module directly performs data acquisition and balancing, impedance measurement and other controls on the battery cell, thereby achieving refined management of the battery cell and effectively improving the reliability and safety warning function of the system. In addition, based on the integrated relationship between the battery control unit and the analog front-end module, the battery control unit directly issues instructions to the analog front-end module and receives the battery cell-related data collected by the analog front-end module in real time, saving data transmission time, reducing the risk of data anomalies and triggering false alarms due to interference during data transmission, and effectively improving the safety and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The disclosure of this application will be more easily understood with reference to the accompanying drawings. Those skilled in the art will readily appreciate that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. Furthermore, similar numbers in the figures represent similar components, where:

[0020] Figure 1 This is a schematic diagram of the communication architecture of an existing industrial and commercial energy storage system;

[0021] Figure 2 This is a communication topology diagram of a BMS system in an existing industrial and commercial energy storage system;

[0022] Figure 3 This is a communication rack topology diagram of an energy storage system provided in an embodiment of the present application;

[0023] Figure 4 This is a communication topology diagram of a BMS system in an energy storage system provided in an embodiment of the present application;

[0024] Figure 5 yes Figure 4 Schematic diagram of the integrated relationship between battery cells and AFE modules in the BMS system. DETAILED DESCRIPTION

[0025] Some embodiments of the present application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application and are not intended to limit the scope of protection of the present application.

[0026] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, indirect connection through an intermediate medium, internal communication between two components, or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0027] In the description of this application, "module", "processor" and "chip" may include hardware, software or a combination of the two. A module may include hardware circuits, various suitable sensors, communication ports, memory, and may also include software components, such as program code, or a combination of software and hardware. The processor may be a central processing unit, a microprocessor, an image processor, a digital signal processor or any other suitable processor. The processor and chip have data and / or signal processing functions. The processor and chip can be implemented in software, hardware or a combination of the two. The term "A and / or B" means all possible combinations of A and B, such as only A, only B or A and B. The term "at least one A or B" or "at least one of A and B" has a similar meaning to "A and / or B" and may include only A, only B or A and B. The singular terms "one" and "the" may also include plural forms.

[0028] Here we first explain some terms involved in the embodiments of this application.

[0029] BMS (Battery Management System) battery management system.

[0030] AFE (Ana l og Front End) analog front end.

[0031] FPC (Flexible Printed Circuit) flexible circuit board.

[0032] MCU (Microcontroller Unit) microcontroller.

[0033] SOC (State of Charge) battery state of charge.

[0034] SOH (State of Health) battery health status.

[0035] SOE (State of Energy) battery remaining energy.

[0036] PCS (Power Conversion System) energy storage converter.

[0037] The battery management system and energy storage system of the present application are described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] like Figure 1 As shown, the existing energy storage system usually includes a battery management system (BMS), a local controller (LC) and a power storage converter (PCS). The BMS and LC communicate with each other through a local area network (LAN), and the BMS and PCS communicate with each other through a controller area network (CAN). The LC and PCS are connected through an RS485 interface. In actual application scenarios, the LC is usually also connected to a dehumidifier and a liquid cooler through an RS485 interface. The BMS in existing energy storage systems used in industry and commerce generally adopts a distributed communication architecture, that is, the BMS usually includes a BCU and multiple BMUs and sensors. The BCU collects data such as battery module voltage, single cell voltage, charge and discharge current, and battery cell temperature collected by the BMU and sensors, and performs state estimation, fault diagnosis, etc. based on the collected data, and sends the data to the LC in real time for data storage and data analysis. Further, as Figure 2 As shown in the figure, the BMS generally adopts the BCU-BMU communication architecture. The BMU is used to collect data such as battery module voltage, current cell voltage, and cell temperature, and then send the data to the BCU in real time. The BCU mainly adopts the MCU module. The MCU is connected to the BMU in parallel with each cell module through a bridge module to form a communication link. The MCU forms a master-slave control relationship with each BMU. The MCU module controls and manages each cell module based on each BMU.

[0039] Figure 1 and Figure 2 Although the energy storage system and battery management system shown in the figure can meet the basic requirements of energy storage, they still have some deficiencies in data transmission, system control, and refined management of battery cells. To this end, the embodiment of the present application proposes a highly integrated energy storage system and a communication architecture for the battery management system, as shown in the following example. Figure 3 and Figure 4 shown.

[0040] like Figure 3 As shown, the architecture of the energy storage system provided by this application is obviously different from Figure 1The communication architecture of the existing energy storage system shown in the figure, the energy storage system provided in this application includes a BMS and a PCS, wherein the BMS mainly includes a battery control unit (BCU), and multiple analog front-end (AFE) modules are integrated on the BMS. Multiple AFEs are connected in series to form a link, and both ends of the link are connected to the BCU to form a communication link. Among them, data communication is carried out between the BMS and the PCS via CAN or RS485, and the BMS is directly connected to the PCS and the dehumidifier and liquid cooler through the RS485 interface, so that the BCU can control the dehumidifier and liquid cooler in real time, and exchange data with the PCS to control charging and discharging. For example: the battery management system can control the PCS to charge and discharge the battery by sending instructions to the PCS, and control the liquid cooler to work when abnormal battery temperature is detected to ensure that the battery temperature is kept within the appropriate range to prevent thermal runaway of the battery; the battery management system can also control the dehumidifier to work to provide corrosion protection for the battery.

[0041] like Figure 4 As shown, the battery management system provided by the embodiment of the present application adopts the BCU-AFE communication architecture. The embodiment of the present application provides a battery management system (BMS), including a battery control unit (BCU) corresponding to the management of one or more series-connected battery cells. For example, the battery control unit specifically adopts an MCU module, and includes an analog front-end module (AFE module) integrated into each battery cell. The analog front-end module is connected to the battery control unit based on the battery cell to form a communication link. Figure 4 Based on the BCU-AFE communication architecture shown, the working method of the BMS of this embodiment includes: the BCU obtains sampled data such as single cell voltage, current, cell temperature, and cell AC impedance of the battery cell from the AFE module, performs state estimation, insulation detection, charge and discharge control, etc., and performs fault protection control in real time based on the sampled data and environmental data.

[0042] In this embodiment, the analog front-end module is used to collect data from the battery cells and transmit the collected data to the battery control unit via the communication link. The battery control unit is used to generate control instructions based on the data transmitted by the analog front-end module and transmit the control instructions to the analog front-end via the communication link. In actual application scenarios, the data collected by the analog front-end module may include at least one of the battery cell voltage, battery cell temperature, and battery cell AC impedance.

[0043] In a specific embodiment, Figure 5The figure shows a schematic diagram of the composition structure of an analog front-end module integrated into a battery cell provided by an embodiment of the present application, wherein the analog front-end module specifically includes an AFE chip and a sampling circuit connected to the AFE chip; wherein the AFE chip and the sampling circuit are integrated on a flexible printed circuit board (FPC), and the flexible printed circuit board is connected to the positive and negative poles of the battery cell through a soft connector. Preferably, the soft connector is an aluminum bar connector, such as the aluminum bar connector specifically shown as the rectangular box indicated by the arrow in the figure. It can be understood that the symbols "+" and "-" shown in the figure are used to indicate the positive and negative poles of the battery cell; in this embodiment, the analog front-end module can collect and obtain data such as the single cell voltage, battery cell temperature and battery cell AC impedance value of the battery cell based on the sampling circuit, and send the collected data to the battery control unit for analysis and processing.

[0044] In a specific embodiment, an analog front-end module integrated into a battery cell provided in an embodiment of the present application may further specifically include an AFE chip and a sampling circuit and a sensor connected to the AFE chip. The AFE chip and the sampling circuit are integrated on a flexible printed circuit (FPC), and the flexible printed circuit board is connected to the positive and negative poles of the battery cell through a soft connector such as an aluminum bar. It is understandable that the analog front-end module can acquire the battery cell temperature based on the sensor, acquire the battery cell voltage, battery cell AC impedance value and other data based on the sampling circuit, and send the acquired data to the battery control unit for analysis and processing.

[0045] In the embodiments of the present application, the AFE chip can preferably be a DNB1101 chip or a DNB1168 chip. It is understood that the number of AFE chips in the embodiments of the present application is not limited and can be designed based on the actual needs of the system. The BCU in the embodiments of the present application can utilize one or more MCUs, which can be multi-core or heterogeneous core chips. The sampling circuit in the embodiments of the present application can include at least a voltage acquisition circuit, a current acquisition circuit, and a temperature acquisition circuit, each of which is electrically connected to the AFE chip.

[0046] In practical applications, the BMS of the present application may further include a storage chip connected to the battery control unit, the storage chip being used to store the data received by the battery control unit. For example, a storage chip such as a TF card or NAND Flash may be installed on the BCU to store and manage the historical data of the BMS.

[0047] Furthermore, the present application also provides an energy storage system, comprising one or more battery cells connected in series, and a battery management system, wherein the battery management system can be specifically Figure 4The battery management system shown is not described here in detail. In practical applications, the energy storage system provided in this application may further include a dehumidifier, a liquid cooler, and an energy storage converter connected to the battery management system; the battery management system controls battery charge and discharge and protects battery performance based on the dehumidifier, the liquid cooler, and the energy storage converter.

[0048] It can be seen that the BMS system provided in the embodiment of the present application adopts a BCU-AFE communication architecture. On the one hand, one battery cell is connected to one AFE module, realizing "one-cell-one-management". The AFE module directly performs data acquisition and balancing, impedance measurement and other controls on the battery cell. The impedance data of each battery cell can be used for SOC and SOH estimation, battery internal temperature estimation, battery cell outlier judgment, etc., so as to achieve refined management of the battery cell and effectively improve the reliability and safety warning function of the system. On the other hand, based on the integrated relationship between the BCU and the AFE module, the data transmission from the control module or the local controller is eliminated. As the brain of the BMS, the BCU can directly issue instructions to the AFE module and receive the battery cell-related data collected by the AFE module in real time, saving data transmission time and reducing the risk of data anomalies and false alarms caused by interference during data transmission.

[0049] Thus far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A battery management system, characterized in that: It includes a battery control unit for managing one or more battery cells connected in series, and an analog front-end module integrated into each battery cell, wherein the analog front-end module is connected to the battery control unit based on the battery cell to form a communication link; The analog front-end module is used to collect data from the battery cell and send the collected data to the battery control unit through the communication link; the analog front-end module includes an AFE chip and a sampling circuit connected to the AFE chip; the AFE chip and the sampling circuit are integrated on a flexible circuit board, and the flexible circuit board is connected to the positive and negative electrodes of the battery cell through a soft connector; the analog front-end module collects the AC impedance value of the battery cell based on the sampling circuit; The battery control unit is configured to generate a control instruction according to the data sent by the analog front-end module, and send the control instruction to the analog front-end through the communication link.

2. The battery management system according to claim 1, characterized in that: The analog front-end module also includes a sensor connected to the AFE chip.

3. The battery management system according to claim 1 or 2, characterized in that: The soft connector is an aluminum bar connector.

4. The battery management system according to claim 1 or 2, characterized in that: The AFE chip is a DNB1101 chip or a DNB1168 chip.

5. The battery management system according to claim 1, characterized in that: The data collected by the analog front-end module includes at least one of a single cell voltage, a cell temperature, and an AC impedance value of the cell.

6. The battery management system according to claim 1, characterized in that: The battery control unit adopts one or more MCUs, and the MCU adopts a multi-core chip or a heterogeneous core chip.

7. The battery management system according to claim 1, characterized in that: It also includes a storage chip connected to the battery control unit, and the storage chip is used to store the data received by the battery control unit.

8. An energy storage system, characterized in that: The battery management system comprises one or more battery cells connected in series and the battery management system according to any one of claims 1 to 7.

9. The energy storage system according to claim 8, characterized in that: It also includes a liquid cooler and an energy storage converter connected to the battery management system; the battery management system realizes charging and discharging control of the battery based on the liquid cooler and the energy storage converter.

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