Battery management system and communication method thereof

Abstract

The present invention provides a battery management system and a communication method thereof, wherein the battery management system comprises multiple AFE modules, an MCU module, a first bridge module connected to the MCU module, a second bridge module and a third bridge module; the first bridge module, multiple AFE modules and the second bridge module are connected in series to form a daisy chain, the third bridge module is connected to the middle AFE module, the third bridge module is in a working state by default, the first bridge module and the second bridge module are in a standby state, and are only enabled when a communication failure occurs; the AFE module is used to collect battery cell parameters; the MCU module is configured to send forward communication instructions and reverse communication instructions to the multiple AFE modules through the third bridge module after the system is powered on, the AFE module on the left side of the middle AFE module transmits the battery cell parameters from left to right according to the forward communication instruction, and the AFE module on the right side of the middle AFE module transmits the battery cell parameters from right to left according to the reverse communication instruction, and finally the battery cell parameters are transmitted to the MCU module through the third bridge module.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of energy storage batteries, and in particular to a battery management system and a communication method thereof. Background Art

[0002] As one of the key components of an energy storage system, the Battery Management System (BMS) is an important nerve center connecting the energy storage inverter and the energy storage battery pack. It is used to monitor real-time information such as the voltage, current, and temperature of battery cells or battery packs to prevent safety issues such as overcharging, over-discharging, overheating, or overcurrent in the internal batteries.

[0003] The existing BMS control strategy is mainly based on the dual-ring daisy chain method of the battery module. Patent CN116055250A proposes a daisy chain communication method and related devices; first obtain the daisy chain forward communication data, and then verify the obtained data. If the forward communication data verification fails, it means that there is a communication link point failure in the daisy chain. Then obtain the daisy chain reverse communication data, perform data integration operations on the daisy chain forward communication data and the daisy chain reverse communication data, and obtain the target daisy chain data. The target daisy chain data is the communication data of the entire daisy chain obtained. Although the existing technical solution re-establishes communication through the daisy chain in both the forward and reverse directions, after a failure occurs at any two points, the communication is interrupted and communication cannot be re-established, resulting in a decrease in the communication stability of the BMS system, which in turn affects the stability of the entire battery compartment or energy storage system. It is also difficult to replace and the on-site maintenance cost is increased. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a battery management system and a communication method thereof, so as to solve the problem that after any two points of the daisy chain of the existing battery management system fail, communication is interrupted and communication cannot be re-established.

[0005] To solve the above technical problems, the present invention provides a battery management system, comprising: multiple AFE modules, an MCU module, a first bridge module connected to the MCU module, a second bridge module, and a third bridge module; the first bridge module, the multiple AFE modules, and the second bridge module are connected in series to form a daisy chain, the third bridge module is connected to a middle AFE module, the middle AFE module refers to the AFE module in the middle position of the daisy chain, the third bridge module is in an active state by default, and the first bridge module and the second bridge module are in a standby state and are only activated when a communication failure occurs; wherein the AFE module is used to collect battery cell parameters; the MCU module is configured to: after the system is powered on, send forward communication instructions and reverse communication instructions to the multiple AFE modules through the third bridge module, the AFE module on the left side of the middle AFE module transmits the battery cell parameters from left to right according to the forward communication instructions, and the AFE module on the right side of the middle AFE module transmits the battery cell parameters from right to left according to the reverse communication instructions, and finally transmits the battery cell parameters to the MCU module through the third bridge module.

[0006] Optionally, the MCU module is further configured to: determine whether a communication failure occurs based on the acquired battery cell parameters; if so, determine the location of the fault based on the acquired battery cell parameters; when the fault points are all located on the left side of the middle AFE module, start the first bridge module, and the AFE module on the left side of the fault point transmits the battery cell parameters from right to left to the first bridge module, and then transmits them to the MCU module through the first bridge module; when the fault points are all located on the right side of the middle AFE module, start the second bridge module, and the AFE module on the right side of the fault point transmits the battery cell parameters from left to right to the second bridge module, and then transmits them to the MCU module through the second bridge module.

[0007] Optionally, when the fault point is located on the left and right sides of the middle AFE module, the first bridge module and the second bridge module are started, and the fault points on the left and right sides of the middle AFE module are respectively recorded as the first fault point and the second fault point. The AFE module on the left side of the first fault point transmits the battery cell parameters from right to left to the first bridge module, and transmits them to the MCU module through the first bridge module. The AFE module on the right side of the second fault point transmits the battery cell parameters from left to right to the second bridge module, and transmits them to the MCU module through the second bridge module.

[0008] Optionally, it further includes: multiple wireless modules, each wireless module corresponds to an AFE module; wherein the wireless module is used to establish a wireless communication link when the daisy chain fails, and transmit the battery cell parameters through the wireless communication link.

[0009] Optionally, the communication protocol of the wireless module is consistent with the communication protocol of the daisy chain, and only supports hand-in-hand communication with the front and rear modules.

[0010] Optionally, the MCU module is further configured to: determine whether a communication failure occurs based on the acquired battery cell parameters; if so, enable the first bridge module and / or the second bridge module; determine whether the communication failure is eliminated based on the battery cell parameters acquired again; if not, determine the ID of the AFE module that failed to communicate based on the acquired battery cell parameters, and wake up the wireless module corresponding to the AFE module that failed to communicate in the following order: first wake up the wireless module from the left side of the AFE module with a smaller ID, and then wake up the wireless module from the right side of the AFE module with a larger ID.

[0011] Optionally, the wireless module is configured to be in a low-power sleep mode by default and is awakened by the AFE module when needed.

[0012] Optionally, it also includes: a first driving module and a second driving module; wherein, the first driving module and the second driving module are used to control one of the daisy chains on the left and right sides of the intermediate AFE module to be connected to the third bridge module at the same time to control the communication timing of the daisy chain.

[0013] Optionally, the first driving module and the second driving module are respectively located on the daisy chain on the left and right sides of the middle AFE module.

[0014] Optionally, the first driving module and the second driving module are respectively located on a left connection port and a right connection port of the middle AFE module.

[0015] Optionally, the first driving module and the second driving module are MOS tubes or relays.

[0016] Optionally, the AFE module is connected to one battery cell or multiple battery cells.

[0017] Optionally, it also includes: other bridge modules connected to the MCU module, the other bridge modules are connected to an AFE module or multiple AFE modules in the daisy chain, and the other bridge modules are used to establish multiple redundant communication links; the MCU module includes a signal simulation unit, the signal simulation unit is used to simulate the MCU module IO interface as an SPI interface or a UART interface, and the other bridge modules are connected to the MCU module through the simulated SPI interface or UART interface.

[0018] To solve the above technical problems, the present invention provides a communication method, which is applied to the battery management system of the present application, including: after the system is powered on, the AFE module collects the battery cell parameters, and the MCU module sends forward communication instructions and reverse communication instructions to the multiple AFE modules through the third bridge module; the AFE module on the left side of the middle AFE module transmits the battery cell parameters from left to right according to the forward communication instruction, and the AFE module on the right side of the middle AFE module transmits the battery cell parameters from right to left according to the reverse communication instruction, and finally transmits the battery cell parameters to the MCU module through the third bridge module.

[0019] Optionally, it also includes: the MCU module determines whether a communication failure occurs based on the obtained battery cell parameters, and if so, determines the location of the fault based on the obtained battery cell parameters; when the fault points are all located on the left side of the middle AFE module, the first bridge module is started, and the AFE module on the left side of the fault point transmits the battery cell parameters from right to left to the first bridge module, and then transmits them to the MCU module through the first bridge module; when the fault points are all located on the right side of the middle AFE module, the second bridge module is started, and the AFE module on the right side of the fault point transmits the battery cell parameters from left to right to the second bridge module, and then transmits them to the MCU module through the second bridge module.

[0020] Optionally, it also includes: when the fault point is located on the left and right sides of the middle AFE module, starting the first bridge module and the second bridge module, and the fault points on the left and right sides of the middle AFE module are respectively recorded as the first fault point and the second fault point, the AFE module on the left side of the first fault point transmits the battery cell parameters from right to left to the first bridge module, and transmits them to the MCU module through the first bridge module, and the AFE module on the right side of the second fault point transmits the battery cell parameters from left to right to the second bridge module, and transmits them to the MCU module through the second bridge module.

[0021] Optionally, it also includes: the MCU module determines whether a communication failure occurs based on the obtained battery cell parameters; if so, the first bridge module and / or the second bridge module is enabled, and whether the communication failure is eliminated based on the battery cell parameters obtained again; if not, the ID of the AFE module that failed to communicate is determined based on the obtained battery cell parameters, and the wireless module corresponding to the AFE module that failed to communicate is awakened in the following order: first wake up the wireless module from the left side of the AFE module with a smaller ID, and then wake up the wireless module from the right side of the AFE module with a larger ID, and transmit the battery cell parameters through the wireless communication link established by the wireless module.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The battery management system and communication method thereof of the present invention can ensure normal communication when a fault occurs at both ends of the daisy chain in the forward and reverse directions, as well as in the middle of the daisy chain, thereby improving the robustness and safety of the BMS system, thereby improving the overall stability of the battery management system and the energy storage system, and reducing after-sales and operation and maintenance costs; in addition, the battery management system of the present invention can quickly and effectively locate the fault and re-establish the communication connection after a single-point or double-point fault occurs in the daisy chain communication of the BMS, thereby improving the stability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are included to provide a further understanding of the present application. They are incorporated into and constitute a part of this application. The accompanying drawings illustrate embodiments of the present application and, together with this specification, serve to explain the principles of the present application. In the accompanying drawings:

[0025] Figure 1 FIG. 1 is a schematic diagram of a battery management system according to an embodiment of the present invention.

[0026] Figure 2 FIG. 4 is a schematic diagram of a battery management system according to another embodiment of the present invention.

[0027] Figure 3 FIG. 4 is a schematic diagram of a battery management system according to another embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of simulating the SPI interface through the IO port of the MCU module and performing daisy-chain communication.

[0029] Figure 5 This is a schematic diagram of simulating a UART interface through the IO port of the MCU module and performing daisy-chain communication.

[0030] Figure 6 FIG. 4 is a flow chart of a communication method of a battery management system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] To more clearly illustrate the technical solutions of the embodiments of this application, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0032] Figure 1 FIG is a schematic diagram of a battery management system according to an embodiment of the present invention. Figure 1As shown, the battery management system 100 includes an MCU module, a bridge module 1, a bridge module 2, a bridge module 3, and n AFE modules, where n≥3.

[0033] The n AFE modules are denoted as AFE1, AFE2, AFE3, ..., AFEn-2, AFEn-1, and AFEn. In this embodiment, each AFE module is connected to a battery cell. For example, AFE1 collects status data for battery cell 1, and AFEn collects status data for battery cell n. This status data includes, but is not limited to, cell voltage, battery cell temperature, and battery cell AC impedance.

[0034] The MCU module is the brain of the battery management system, used to send control instructions to the AFE module and receive real-time data such as cell voltage, temperature, and cell AC impedance collected by the AFE module.

[0035] The bridge module provides direct daisy-chain communication between the MCU and AFE modules. It converts SPI or UART signals from the MCU into daisy-chain signals and sends them to the AFE for communication. It also converts daisy-chain signals returned by the AFE into SPI or UART signals and feeds them back to the MCU. Bridge module 3 is the primary communication module, while bridge modules 1 and 2 are backup bridge modules, used only in the event of a communication failure.

[0036] n AFE modules are connected in series to form a daisy chain, with the two ends of the daisy chain connected to bridge module 1 and bridge module 2, respectively. For example, bridge module 1 is connected to AFE 1, and bridge module 2 is connected to AFEn. In this embodiment, bridge module 3 is connected to one or more AFE modules in the middle of the daisy chain. For example, one end of bridge module 3 is connected to AFE 2 and AFE 3, and the other end is connected to AFEn-2 and AFE n-1.

[0037] Optionally, the bridge module 1 , the bridge module 2 and the bridge module 3 are arranged on the MCU module, and the bridge module 1 , the bridge module 2 and the bridge module 3 are connected to the MCU module respectively.

[0038] Figure 2 FIG. 1 is a schematic diagram of a battery management system according to another embodiment of the present invention. Figure 2As shown, in this embodiment, the battery management system 200 includes four AFE modules, which are respectively denoted as AFE1, AFE2, AFE3, and AFE4. The AFE modules in the middle of the daisy chain are AFE2 and AFE3. The bridge module 3 is connected to the second end of AFE2, and the bridge module 3 is connected to the first end of AFE3. In other words, the battery management system includes n AFE modules. When n is an even number, the bridge module 3 is connected to the second end of the n / 2th AFE module, and the bridge module 3 is connected to the first end of the n / 2+1th AFE module. Figure 1 As shown, the bridge module 3 is also connected to the second end of the n / 2-ith AFE module, and the bridge module 3 is also connected to the first end of the n / 2+1+ith AFE module, where i is a positive integer greater than or equal to 1.

[0039] Figure 3 FIG. 1 is a schematic diagram of a battery management system according to another embodiment of the present invention. Figure 3 As shown in FIG. 1 , in this embodiment, the battery management system 300 includes three AFE modules, which are respectively denoted as AFE1, AFE2, and AFE3. The AFE module in the middle of the daisy chain is AFE2. The bridge module 3 is connected to the first end and the second end of AFE2. In other words, the battery management system includes n AFE modules. When n is an odd number, the bridge module 3 is connected to the first end and the second end of AFE2. The first and second ends of the AFE modules are connected, wherein It represents n / 2 rounded up. For example, if n = 3, n / 2 = 1.5, which is rounded up to 2, the middle AFE module in the daisy chain is AFE2.

[0040] In addition, in this embodiment, each AFE module is connected in parallel with two battery cells, and the two battery cells are connected in series. Optionally, an AFE module is connected to one of the multiple battery cells (usually, multiple battery cells are connected in series to form a module, and only a few AFE modules are set in a module for data collection. For example, a module has 10 battery cells, and 3 AFE modules are set, which are respectively set on both sides and in the middle of the module. The advantage of this is that the cost is low, and the selection of representative battery cells for parameter collection can also represent the working status of the module. The disadvantage is that the granularity of refined monitoring is insufficient). According to the current industry development trend, large-capacity battery cells are the future development trend. Therefore, the disadvantages of selective data collection in the large-capacity battery cell solution will be magnified, so in Figure 1 and Figure 2 In the solution, one battery cell is connected to one AFE module.

[0041] Among them, the MCU module is configured as follows: after the system is powered on, forward communication instructions and reverse communication instructions are sent to multiple AFE modules through the bridge module 3. The AFE module on the left side of the middle AFE module transmits the battery cell parameters from left to right according to the forward communication instructions, and the AFE module on the right side of the middle AFE module transmits the battery cell parameters from right to left according to the reverse communication instructions. Finally, the battery cell parameters are transmitted to the MCU module through the bridge module 3.

[0042] like Figure 2 As shown, when there is no fault in the communication system, the default bridge module of the system is bridge module 3. After the system is powered on, the MCU module sends forward communication instructions and reverse communication instructions to multiple AFE modules through bridge module 3. AFE 4 on the right side of bridge module 3 collects battery cell 4, and then transmits the collected battery cell parameters to AFE3 according to the reverse communication instruction. AFE3 collects battery cell 3 and transmits the collected battery cell parameters and the battery cell parameters transmitted by AFE4 to bridge module 3. Bridge module 3 transmits the battery cell parameters to the MCU module. AFE 1 on the left side of bridge module 3 collects battery cell 1, and then transmits the collected battery cell parameters to AFE2 according to the forward communication instruction. AFE2 collects battery cell 2 and transmits the collected battery cell parameters and the battery cell parameters transmitted by AFE1 to bridge module 3. Bridge module 3 transmits the battery cell parameters to the MCU module.

[0043] The MCU module is also configured to: determine whether a communication failure occurs based on the obtained battery cell parameters; if so, determine the location of the fault based on the obtained battery cell parameters; when the fault points are all located on the left side of the middle AFE module, start the first bridge module, and the AFE module on the left side of the fault point transmits the battery cell parameters from right to left to the first bridge module, and then transmits them to the MCU module through the first bridge module; when the fault points are all located on the right side of the middle AFE module, start the second bridge module, and the AFE module on the right side of the fault point transmits the battery cell parameters from left to right to the second bridge module, and then transmits them to the MCU module through the second bridge module.

[0044] When the fault point is located on the left and right sides of the middle AFE module, the first bridge module and the second bridge module are started. The fault points on the left and right sides of the middle AFE module are respectively recorded as the first fault point and the second fault point. The AFE module on the left side of the first fault point transmits the battery cell parameters from right to left to the first bridge module, and then transmits them to the MCU module through the first bridge module. The AFE module on the right side of the second fault point transmits the battery cell parameters from left to right to the second bridge module, and then transmits them to the MCU module through the second bridge module.

[0045] like Figure 1As shown in FIG, when the battery management system 100 includes n AFE modules, the number of possible fault points is n+1, and the fault points are named E1, E2, E3, ..., En-1, En, En+1. When a daisy chain fault occurs, the MCU module is also used to control the communication direction of the daisy chain according to the fault point. That is, the MCU module is also used to re-establish communication according to the location of the fault point: Figure 1 As shown in the figure, if the MCU module receives status data from all cells, it is considered that there is no communication fault (faults E1 and En+1 do not affect communication). If the MCU module only fails to receive status data from cells 1 and 2, the fault is at E3. Fault E3 is located to the left of the middle AFE module, activating bridge module 1. AFE2 to the left of fault E3 transmits the status data of cell 2 from right to left to AFE1. AFE1 transmits the status data of cells 1 and 2 to bridge module 1, and then transmits it to the MCU module.

[0046] If the MCU module fails to receive only the status data for cells n-1 and n, the fault lies in En-1. En-1 is located to the right of the middle AFE module, activating bridge module 2. AFEn-1, located to the right of En-1, transmits the status data for cell n-1 to the AFEn module. The AFEn then transmits the status data for cells n-1 and n to bridge module 2, which then transmits it to the MCU module.

[0047] If the MCU module fails to receive only the status data for cells 1 and 2, and the status data for cells n-1 and n, the fault points are located simultaneously at E3 and En-1. Fault points E3 and En-1 are located on the left and right sides of the middle AFE module, which activates bridge modules 1 and 2. AFE2, located to the left of fault point E3, transmits the status data of cell 2 from right to left to AFE1. AFE1 transmits the status data of cells 1 and 2 to bridge module 1, which then transmits the data to the MCU module. AFEn-1, located to the right of fault point En-1, transmits the status data of cell n-1 from left to right to AFEn. AFEn transmits the status data of cells n-1 and n to bridge module 2, which then transmits the data to the MCU module.

[0048] When the fault occurs at E2 or E3, the MCU cannot obtain the status data of cells 1 and 2 through bridge module 3. After bridge module 1 is enabled, AFE2 cannot transmit the status data of cell 2 to AFE1 due to the presence of fault E2. AFE1 can transmit the status data of cell 1 to the MCU through bridge module 1. In other words, even after bridge module 1 is enabled, the MCU still cannot obtain the status data of cell 2.

[0049] like Figure 1As shown, the battery management system 100 also includes n wireless modules. Each AFE module corresponds to a wireless module. The n wireless modules are respectively designated as wireless module 1, wireless module 2, wireless module 3, ... wireless module n-2, wireless module n-1, and wireless module n. The wireless modules are used to establish a wireless communication link in the event of a daisy chain failure, and transmit battery cell parameters via the wireless communication link. Optionally, the wireless modules are configured in a low-power sleep mode by default and are awakened by the AFE module when needed.

[0050] Optionally, the wireless module's communication protocol is consistent with the daisy chain's communication protocol. Because the wireless module's communication protocol is consistent with the daisy chain's communication protocol, wired and wireless communication methods are compatible and can be used interchangeably. Secondly, unlike conventional wireless communication, this wireless mode, consistent with the daisy chain communication protocol, only supports hand-in-hand communication between front and rear modules. For example, wireless module n only supports hand-in-hand communication with AFEn-1, wireless module n-1, and bridge module 2. Wireless module 2 only supports hand-in-hand communication with AFE1, AFE3, wireless module 1, and wireless module 3. This structural advantage improves the stability and anti-interference capabilities of wireless communication.

[0051] Optionally, the MCU module is further configured to: determine whether a communication failure occurs based on the acquired battery cell parameters; if so, enable the first bridge module and / or the second bridge module; determine whether the communication failure is eliminated based on the battery cell parameters acquired again; if not, determine the ID of the AFE module that failed to communicate based on the acquired battery cell parameters, and wake up the wireless module corresponding to the AFE module that failed to communicate in the following order: first wake up the wireless module from the left side of the AFE module with a smaller ID, and then wake up the wireless module from the right side of the AFE module with a larger ID.

[0052] like Figure 1As shown, when the fault points are located at E1, E2, and E3, even after activating bridge module 1, the MCU module still cannot obtain the status data of cell 1 and cell 2. Therefore, the IDs of the AFE modules that are unable to communicate are determined to be AFE1 and AFE2. Therefore, wireless module 1 corresponding to AFE1 is first activated. Wireless module 1 establishes a wireless communication link with bridge module 1. Wireless module 1 transmits cell 1's status data to bridge module 1, which in turn transmits cell 1's status data to the MCU module. Wireless module 2 corresponding to AFE2 is then activated. Wireless module 2 establishes a communication link with AFE3, which transmits cell 2's status data to AFE3. AFE3 transmits cell 2's status data to the MCU module via bridge module 3. In this embodiment, the AFE modules AFE1 and AFE2 that are unable to communicate are adjacent. Imagine that there are other AFE modules between the AFE modules AFE1 and AFE2 that are unable to communicate. If there is a fault point between these other AFE modules, and the wireless modules are activated from any point instead of from both ends, many attempts to establish a communication link will be required. This application wakes up the wireless module from the left side of the AFE module with a smaller ID, and then wakes up the wireless module from the right side of the AFE module with a larger ID. This can quickly restore the communication link. In other words, starting the wireless module from both ends has the highest probability of restoring the communication link because the endpoint is closest to the normally functioning AFE module.

[0053] For example, the MCU module first determines the ID of the AFE that is unable to communicate based on the currently communicating AFEs. If the fault point is on the left or right side of the bridge module 3, the wireless communication link is first awakened from the left side of the AFE module with the smaller ID, followed by the right side of the AFE module with the larger ID, to reestablish communication. If communication is still unestablished, the MCU returns to the previous level and re-determines the ID of the AFE that is unable to communicate, then wakes up the relevant wireless communication link until communication is reestablished. If the fault point is on both sides of the bridge module 3, the MCU first determines the ID of the AFE that is unable to communicate based on the currently communicating AFEs, then performs the same wireless communication link wakeup mechanism on both sides as described above for a single-sided fault point. For a fault point on the left side, the wireless communication link is first awakened from the left side of the AFE module with the smaller ID, followed by the right side of the AFE module with the larger ID, to reestablish communication. For a fault point on the right side, the wireless communication link is first awakened from the left side of the AFE module with the smaller ID, followed by the right side of the AFE module with the larger ID, to reestablish communication.

[0054] like Figure 2As shown, the battery management system 200 also includes a driver module 1 and a driver module 2. Driver modules 1 and 2 are used to control the daisy chains on the left and right sides of the middle AFE module to connect to the bridge module 3 at the same time, thereby controlling the communication timing of the daisy chains. If the daisy chains on the left and right sides of the middle AFE module send battery cell data to the bridge module 3 at the same time, a timing conflict will occur. In this embodiment, driver modules 1 and 2 are located on the daisy chains on the left and right sides of the middle AFE module, respectively.

[0055] like Figure 3 As shown, the battery management system 300 also includes a driving module 1 and a driving module 2. In this embodiment, the driving module 1 and the driving module 2 are respectively located on the left connection port and the right connection port of the middle AFE module.

[0056] Optionally, driver module 1 and driver module 2 are switching circuits such as MOS tubes or relays. The MCU module's IO output high or low level is used for on / off control. Specifically, the MCU module controls driver module 1 to close and driver module 2 to close, thereby opening the left daisy chain communication link; the MCU controls driver module 1 to disconnect and driver module 2 to close, thereby opening the right daisy chain communication link.

[0057] When driver module 1 and driver module 2 are the normally open and normally closed contacts of a relay (the order of these contacts can be reversed), the MCU's daisy chain communication pins send high and low voltage levels to control the opening and closing of the relays. Specifically, when the MCU sends a high-level signal, the normally open contacts close and the normally closed contacts open (i.e., driver module 1 is closed and driver module 2 is closed), thus opening the left daisy chain communication link. When the MCU sends a low-level signal, the normally open contacts open and the normally closed contacts close (i.e., driver module 1 is disconnected and driver module 2 is closed), thus opening the right daisy chain communication link. When the MCU controls driver module 1 to close and driver module 2 to open, communication data for the left daisy chain is transmitted. When the MCU controls driver module 2 to close and driver module 1 to open, communication data for the right daisy chain is transmitted.

[0058] The battery management system of the present invention can quickly and effectively locate the fault and re-establish communication connections after single-point or dual-point failures occur in the BMS's daisy chain communication, thereby improving product stability, ensuring a good user experience, and enhancing product competitiveness. When the fault occurs at both ends of the daisy chain in both directions, as well as in the middle of the daisy chain, normal communication is maintained, improving the robustness and safety of the BMS system, thereby enhancing the overall stability of the battery management system and energy storage system, and reducing after-sales and operation and maintenance costs.

[0059] In ultra-large capacity battery packs, when the number of AFEs increases, using the ideas of this application to resolve possible faults, theoretically, it is sufficient to simply add bridge modules. However, in actual applications, there are certain problems. For example, the number of communication ports in the MCU module that communicate with the bridge module is limited. Due to the limitation on the number of communication ports of the MCU module, the number of bridge modules will be limited. To solve this problem, the MCU module also includes a signal simulation unit, which is used to simulate the MCU module IO interface as an SPI interface or a UART interface. Multiple bridge modules are connected to the MCU module through the simulated SPI interface or UART interface.

[0060] Figure 4 This is a schematic diagram of simulating the SPI interface through the IO port of the MCU module and performing daisy chain communication. Figure 4 As shown, the MCU module's IO1, IO2, IO3, and IO4 are standard IO interfaces. First, configure the IO1, IO2, IO3, and IO4 interface communication rates to the bridge module's required communication rate. Then, use IO1 to simulate the CS pin function: pull the IO pin signal high or low when writing and reading data (specifically, based on the AFE's CS communication requirements). Use IO2 to simulate the MOSI pin function by setting the IO level according to the AFE's SPI bus timing. MISO is the signal received by the MCU, and this is achieved by setting IO3 to simulate the input signal interface. Use IO4 to simulate the SCK pin function by setting the IO level according to the AFE's bus timing. Once IO1, IO2, IO3, and IO4 have simulated the SPI interface functions, communication between the MCU and AFE modules can be established.

[0061] Figure 5 This is a schematic diagram of simulating a UART interface through the IO port of the MCU module and performing daisy-chain communication.

[0062] The IO1 and IO2 of the MCU module are ordinary IO interfaces. First, configure the IO1 and IO2 interface communication rates to the communication rate required by the bridge module. Then, IO1 and IO2 are used to simulate the RX and TX pin functions in sequence: according to the UART data transmission format, the IO port level is pulled high or low through software delays, timers, etc., so that UART signal input and output can be realized through IO, and communication between the MCU module and the AFE module can be established.

[0063] The present invention also provides a communication method for a battery management system. Figure 6 FIG. 1 is a flow chart of a communication method of a battery management system according to an embodiment of the present invention. Figure 6 As shown, the communication method 600 of the battery management system includes the following steps:

[0064] Step S61: After the system is powered on, the AFE module collects battery cell parameters, and the MCU module sends forward communication instructions and reverse communication instructions to multiple AFE modules through the third bridge module;

[0065] Step S62: The AFE module on the left side of the middle AFE module transmits the cell parameters from left to right according to the forward communication instruction, and the AFE module on the right side of the middle AFE module transmits the cell parameters from right to left according to the reverse communication instruction, and finally transmits the cell parameters to the MCU module through the third bridge module.

[0066] Step S63: The MCU module determines whether a communication fault occurs based on the acquired battery cell parameters. If so, the MCU module determines the location of the fault based on the acquired battery cell parameters.

[0067] Step S64: When the fault points are all located on the left side of the middle AFE module, the first bridge module is started, and the AFE module on the left side of the fault point transmits the cell parameters from right to left to the first bridge module, and then transmits the parameters to the MCU module through the first bridge module;

[0068] Step S65: When the fault points are all located on the right side of the middle AFE module, the second bridge module is started, and the AFE module on the right side of the fault point transmits the cell parameters from left to right to the second bridge module, and then transmits them to the MCU module through the second bridge module.

[0069] Step S66: When the fault point is located on the left and right sides of the middle AFE module, the first bridge module and the second bridge module are started. The fault points on the left and right sides of the middle AFE module are respectively recorded as the first fault point and the second fault point. The AFE module on the left side of the first fault point transmits the battery cell parameters from right to left to the first bridge module, and then transmits them to the MCU module through the first bridge module. The AFE module on the right side of the second fault point transmits the battery cell parameters from left to right to the second bridge module, and then transmits them to the MCU module through the second bridge module.

[0070] Optionally, the communication method 600 of the battery management system also includes: the MCU module determines whether a communication failure occurs based on the obtained battery cell parameters; if so, the first bridge module and / or the second bridge module is enabled, and whether the communication failure is eliminated based on the battery cell parameters obtained again; if not, the ID of the AFE module that failed to communicate is determined based on the obtained battery cell parameters, and the wireless module corresponding to the AFE module that failed to communicate is awakened in the following order: first wake up the wireless module from the left side of the AFE module with a smaller ID, and then wake up the wireless module from the right side of the AFE module with a larger ID, and transmit the battery cell parameters through the wireless communication link established by the wireless module.

[0071] The communication method of the battery management system of the present invention is based on a multi-level daisy chain topology architecture. According to the location of the fault point, different control strategies for re-establishing communication after a fault are formulated, thereby effectively improving the stability of daisy chain communication.

[0072] Flowcharts are used in this application to illustrate the operations performed by systems according to embodiments of the present application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the various steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0073] 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.

[0074] At the same time, this application uses specific terms to describe the embodiments of this application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that "one embodiment," "an embodiment," or "an alternative embodiment" mentioned twice or multiple times in different locations in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application may be appropriately combined.

[0075] Some aspects of this application may be implemented entirely in hardware, entirely in software (including firmware, resident software, microcode, etc.), or a combination of hardware and software. These hardware and software components may be referred to as "data blocks," "modules," "engines," "units," "components," or "systems." A processor may be one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. Furthermore, various aspects of this application may be embodied as computer products embodied in one or more computer-readable media, including computer-readable program code. For example, computer-readable media may include, but are not limited to, magnetic storage devices (e.g., hard disks, floppy disks, magnetic tapes), optical disks (e.g., compact disks, digital versatile disks, DVDs), smart cards, and flash memory devices (e.g., cards, sticks, key drives, etc.).

[0076] Similarly, it should be noted that, in order to simplify the presentation of this disclosure and thereby facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this application sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of this application requires more features than those mentioned. In fact, an embodiment may have fewer features than all of the features of a single embodiment disclosed above.

[0077] As used herein, unless the context clearly indicates otherwise, the terms "a," "an," "an," and / or "the" are not intended to refer to the singular but may include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0078] Unless otherwise specified, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. Technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0079] In the description of this application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of this application; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0080] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is solely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. Furthermore, while the terms used in this application are selected from commonly known and commonly used terms, some terms mentioned in this specification may have been selected by the applicant at his or her discretion, and their detailed meanings are explained in the relevant sections of this description. Furthermore, this application should be understood not only by the actual terms used, but also by the meaning implied by each term.

[0081] It should be understood that when a component is referred to as being “on another component,” “connected to another component,” “coupled to another component,” or “contacting another component,” it can be directly on, connected to, coupled to, or contacting the other component, or intervening components may be present. In contrast, when a component is referred to as being “directly on another component,” “directly connected to,” “directly coupled to,” or “directly contacting” another component, there are no intervening components. Similarly, when a first component is referred to as being “electrically in contact with” or “electrically coupled to” a second component, an electrical path exists between the first and second components that allows current to flow. This electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even without direct contact between the conductive components.

[0082] In some embodiments, numbers describing the number of components and attributes are used. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification are approximate values, which may vary according to the characteristics required by the individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining the digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of the present application are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0083] Although the present application has been described with reference to the current specific embodiments, ordinary technicians in this technical field should recognize that the above embodiments are only used to illustrate the present application, and various equivalent changes or substitutions can be made without departing from the spirit of the present application. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of the present application, they will fall within the scope of the present application.

Claims

1. A battery management system, characterized in that: include: A plurality of AFE modules, an MCU module, a first bridge module, a second bridge module, and a third bridge module connected to the MCU module; The first bridge module, the multiple AFE modules, and the second bridge module are connected in series to form a daisy chain, the third bridge module is connected to an intermediate AFE module, the intermediate AFE module refers to an AFE module in the middle of the daisy chain, the third bridge module is in an active state by default, and the first bridge module and the second bridge module are in a standby state and are activated only when a communication failure occurs; Among them, the AFE module is used to collect battery cell parameters; the MCU module is configured as follows: after the system is powered on, forward communication instructions and reverse communication instructions are sent to the multiple AFE modules through the third bridge module, the AFE module on the left side of the middle AFE module transmits the battery cell parameters from left to right according to the forward communication instructions, and the AFE module on the right side of the middle AFE module transmits the battery cell parameters from right to left according to the reverse communication instructions, and finally the battery cell parameters are transmitted to the MCU module through the third bridge module.

2. The battery management system according to claim 1, wherein: The MCU module is also configured to: determine whether a communication failure occurs based on the acquired battery cell parameters; if so, determine the location of the fault based on the acquired battery cell parameters; when the fault points are all located on the left side of the middle AFE module, start the first bridge module, and the AFE module on the left side of the fault point transmits the battery cell parameters from right to left to the first bridge module, and then transmits them to the MCU module through the first bridge module; when the fault points are all located on the right side of the middle AFE module, start the second bridge module, and the AFE module on the right side of the fault point transmits the battery cell parameters from left to right to the second bridge module, and then transmits them to the MCU module through the second bridge module.

3. The battery management system according to claim 2, wherein: Also includes: When the fault point is located on the left and right sides of the middle AFE module, the first bridge module and the second bridge module are started, and the fault points on the left and right sides of the middle AFE module are respectively recorded as the first fault point and the second fault point. The AFE module on the left side of the first fault point transmits the battery cell parameters from right to left to the first bridge module, and then transmits them to the MCU module through the first bridge module. The AFE module on the right side of the second fault point transmits the battery cell parameters from left to right to the second bridge module, and then transmits them to the MCU module through the second bridge module.

4. The battery management system according to claim 1, wherein: Also includes: Multiple wireless modules, each wireless module corresponds to an AFE module; The wireless module is used to establish a wireless communication link when the daisy chain fails, and transmit the battery cell parameters through the wireless communication link.

5. The battery management system according to claim 4, wherein: The communication protocol of the wireless module is consistent with the communication protocol of the daisy chain, and only supports hand-in-hand communication with the front and rear modules.

6. The battery management system according to claim 5, characterized in that: The MCU module is further configured to: determine whether a communication failure occurs based on the acquired battery cell parameters; if so, enable the first bridge module and / or the second bridge module; determine whether the communication failure is eliminated based on the battery cell parameters acquired again; if not, determine the ID of the AFE module that failed to communicate based on the acquired battery cell parameters, and wake up the wireless module corresponding to the AFE module that failed to communicate in the following order: first wake up the wireless module from the left side of the AFE module with a smaller ID, and then wake up the wireless module from the right side of the AFE module with a larger ID.

7. The battery management system according to claim 4, wherein: The wireless module is configured to be in a low-power sleep mode by default and is awakened by the AFE module when needed.

8. The battery management system according to claim 1, wherein: Also includes: a first driving module and a second driving module; The first driving module and the second driving module are used to control one of the daisy chains on the left and right sides of the middle AFE module to be connected to the third bridge module at the same time, so as to control the communication timing of the daisy chains.

9. The battery management system according to claim 8, characterized in that: The first driver module and the second driver module are respectively located on the left and right sides of the middle AFE module in a daisy chain.

10. The battery management system according to claim 8, wherein: The first driving module and the second driving module are respectively located on a left connection port and a right connection port of the middle AFE module.

11. The battery management system according to claim 8, wherein: The first driving module and the second driving module are MOS tubes or relays.

12. The battery management system according to claim 1, wherein: The AFE module is connected to one battery cell or multiple battery cells.

13. The battery management system according to claim 1, wherein: Also includes: Another bridge module connected to the MCU module, the other bridge module connected to one AFE module or multiple AFE modules in the daisy chain, the other bridge module being used to establish multiple redundant communication links; The MCU module includes a signal simulation unit, which is used to simulate the IO interface of the MCU module as an SPI interface or a UART interface. The other bridge modules are connected to the MCU module through the simulated SPI interface or UART interface.

14. A communication method, applied to the battery management system according to any one of claims 1 to 13, characterized in that: include: After the system is powered on, the AFE module collects the battery cell parameters, and the MCU module sends forward communication instructions and reverse communication instructions to the multiple AFE modules through the third bridge module; The AFE module on the left side of the middle AFE module transmits the cell parameters from left to right according to the forward communication instruction, and the AFE module on the right side of the middle AFE module transmits the cell parameters from right to left according to the reverse communication instruction, and finally transmits the cell parameters to the MCU module through the third bridge module.

15. The communication method according to claim 14, wherein: Also includes: The MCU module determines whether a communication failure occurs based on the obtained battery cell parameters, and if so, determines the location of the failure based on the obtained battery cell parameters; When all fault points are located on the left side of the middle AFE module, the first bridge module is started, and the AFE module on the left side of the fault point transmits the cell parameters from right to left to the first bridge module, and then transmits the parameters to the MCU module through the first bridge module; When the fault points are all located on the right side of the middle AFE module, the second bridge module is started, and the AFE module on the right side of the fault point transmits the cell parameters from left to right to the second bridge module, and then transmits them to the MCU module through the second bridge module.

16. The communication method according to claim 15, wherein: Also includes: When the fault point is located on the left and right sides of the middle AFE module, the first bridge module and the second bridge module are started, and the fault points on the left and right sides of the middle AFE module are respectively recorded as the first fault point and the second fault point. The AFE module on the left side of the first fault point transmits the battery cell parameters from right to left to the first bridge module, and transmits them to the MCU module through the first bridge module. The AFE module on the right side of the second fault point transmits the battery cell parameters from left to right to the second bridge module, and transmits them to the MCU module through the second bridge module.

17. The communication method according to claim 14, wherein: Also includes: The MCU module determines whether a communication failure occurs based on the obtained battery cell parameters. If so, the first bridge module and / or the second bridge module is enabled, and whether the communication failure is eliminated based on the battery cell parameters obtained again. If not, the ID of the AFE module that failed to communicate is determined based on the obtained battery cell parameters, and the wireless module corresponding to the AFE module that failed to communicate is awakened in the following order: first wake up the wireless module from the left side of the AFE module with a smaller ID, and then wake up the wireless module from the right side of the AFE module with a larger ID, and transmit the battery cell parameters through the wireless communication link established by the wireless module.

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