Battery management system and communication method thereof

Abstract

The invention provides a battery management system and a communication method thereof. The battery management system comprises a plurality of AFE modules, an MCU module, a first bridging module, a second bridging module and a third bridging module, wherein the first bridging module, the second bridging module and the third bridging module are connected with the MCU module; the first bridging module, the plurality of AFE modules and the second bridging module are connected in series to form a daisy chain, the third bridging module is connected with the middle AFE module, the third bridging module is in a working state by default, the first bridging module and the second bridging module are in a standby state, and the first bridging module and the second bridging module are started only when a communication fault occurs; the AFE module is used for collecting battery cell parameters; the MCU module is configured to send a forward communication instruction and a reverse communication instruction to the multiple AFE modules through the third bridging module after the system is powered on, the AFE module on the left side of the middle AFE module transmits 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 cell parameters are transmitted to the MCU module through the third bridging module.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of energy storage batteries, and particularly relates to a battery management system and its communication method. 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, and is used to detect real-time information such as the voltage, current, and temperature of battery cells or battery packs, so as to prevent safety problems such as overcharging, over-discharging, overheating, or overcurrent of the internal battery.

[0003] The existing BMS control strategy is mainly based on the method of double-ring network daisy chain of battery modules. Patent CN116055250A proposes a daisy chain communication method and related devices; first, obtain the forward communication data of the daisy chain, and then verify the obtained data. If the verification of the forward communication data fails, it indicates that there is a communication link point failure in the daisy chain. Then, obtain the reverse communication data of the daisy chain, and perform data integration operations on the forward communication data and the reverse communication data of the daisy chain to obtain the target daisy chain data, and the target daisy chain data is the communication data of the entire obtained daisy chain. Although the existing technical solution re-establishes communication through the daisy chain in both forward and reverse directions, after any two-point failures occur, the communication is interrupted and cannot be re-established, resulting in a decrease in the communication stability of the BMS system, thereby affecting the stability of the entire battery compartment or energy storage system, and the replacement is difficult 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 its communication method to solve the problem that after any two-point failures of the daisy chain of the existing battery management system, the communication is interrupted and cannot be re-established.

[0005] To solve the above technical problems, the present invention provides a battery management system, including: a plurality of AFE modules, an MCU module, a first bridging module, a second bridging module, and a third bridging module connected to the MCU module; the first bridging module, the plurality of AFE modules, and the second bridging module are connected in series to form a daisy chain, the third bridging module is connected to the middle AFE module, the middle AFE module refers to the AFE module in the middle position of the daisy chain, the third bridging module is default in the working state, and the first bridging module and the second bridging module are in the standby state and are only enabled when a communication failure occurs; wherein, the AFE module is used to collect cell parameters; the MCU module is configured to: after the system power-on is completed, send a forward communication instruction and a reverse communication instruction to the plurality of AFE modules through the third bridging module, the AFE modules on the left side of the middle AFE module transfer the cell parameters from left to right according to the forward communication instruction, the AFE modules on the right side of the middle AFE module transfer the cell parameters from right to left according to the reverse communication instruction, and finally transfer the cell parameters to the MCU module through the third bridging module.

[0006] Optionally, the MCU module is further configured to: judge whether a communication failure occurs according to the obtained cell parameters, if so, judge the position where the failure occurs according to the obtained cell parameters, when the failure points are all on the left side of the middle AFE module, start the first bridging module, and the AFE modules on the left side of the failure point transfer the cell parameters from right to left to the first bridging module and then to the MCU module through the first bridging module; when the failure points are all on the right side of the middle AFE module, start the second bridging module, and the AFE modules on the right side of the failure point transfer the cell parameters from left to right to the second bridging module and then to the MCU module through the second bridging module.

[0007] Optionally, when the failure points are on the left and right sides of the middle AFE module, start the first bridging module and the second bridging module. The failure points on the left and right sides of the middle AFE module are respectively recorded as the first failure point and the second failure point. The AFE modules on the left side of the first failure point transfer the cell parameters from right to left to the first bridging module and then to the MCU module through the first bridging module, and the AFE modules on the right side of the second failure point transfer the cell parameters from left to right to the second bridging module and then to the MCU module through the second bridging module.

[0008] Optionally, it further includes: a plurality of wireless modules, each wireless module corresponding to one AFE module; wherein, the wireless module is used to establish a wireless communication link when the daisy chain fails and transfer the cell parameters through the wireless communication link.

[0009] Optionally, the communication protocol of the wireless module is the same as that of the daisy chain, and it only supports communicating hand in hand with the front and rear modules.

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

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

[0012] Optionally, it further 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 middle AFE module to be connected to the third bridging module at the same time, so as 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 paths 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 the left connection port and the right connection port of the middle AFE module.

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

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

[0017] Optionally, it further includes: other bridging modules connected to the MCU module, the other bridging modules are connected to one AFE module or multiple AFE modules in the daisy chain, and the other bridging modules are used to establish multiple redundant communication links; the MCU module includes a signal simulation unit, and the signal simulation unit is used to simulate the IO interface of the MCU module as an SPI interface or a UART interface, and the other bridging 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 applied to the battery management system of the present application, including: after the system is powered on and completed, the AFE module collects cell parameters, and the MCU module sends forward communication instructions and reverse communication instructions to the multiple AFE modules through the third bridging module; the AFE modules on the left side of the middle AFE module transfer the cell parameters from left to right according to the forward communication instructions, and the AFE modules on the right side of the middle AFE module transfer the cell parameters from right to left according to the reverse communication instructions, and finally transfer the cell parameters to the MCU module through the third bridging module.

[0019] Optionally, it further includes: the MCU module determines whether a communication failure occurs according to the obtained cell parameters, and if so, determines the location where the failure occurs according to the obtained cell parameters; when the failure points are all on the left side of the middle AFE module, the first bridging module is started, and the AFE modules on the left side of the failure point transfer the cell parameters from right to left to the first bridging module, and then transfer them to the MCU module through the first bridging module; when the failure points are all on the right side of the middle AFE module, the second bridging module is started, and the AFE modules on the right side of the failure point transfer the cell parameters from left to right to the second bridging module, and then transfer them to the MCU module through the second bridging module.

[0020] Optionally, it further includes: when the failure points are on the left and right sides of the middle AFE module, the first bridging module and the second bridging module are started, and the failure points on the left and right sides of the middle AFE module are respectively recorded as the first failure point and the second failure point. The AFE modules on the left side of the first failure point transfer the cell parameters from right to left to the first bridging module, and then transfer them to the MCU module through the first bridging module. The AFE modules on the right side of the second failure point transfer the cell parameters from left to right to the second bridging module, and then transfer them to the MCU module through the second bridging module.

[0021] Optionally, it further includes: the MCU module determines whether a communication failure occurs according to the obtained cell parameters, and if so, enables the first bridging module and / or the second bridging module, and determines whether the communication failure is eliminated according to the cell parameters obtained again. If not, it determines the ID of the AFE module that fails to communicate according to the obtained cell parameters, and wakes up the wireless modules corresponding to the AFE modules that fail to communicate in the following order: first wake up the wireless modules on the left side of the AFE module with a smaller ID, and then wake up the wireless modules on the right side of the AFE module with a larger ID, and transfer the cell parameters through the wireless communication link established by the wireless modules.

[0022] Compared with the prior art, the present invention has the following advantages: The battery management system and its communication method of the present invention can ensure normal communication when faults occur at both ends of the daisy chain in both forward and reverse directions and in the middle of the daisy chain, which can improve the robustness and security of the BMS system, thereby enhancing the overall stability of the battery management system and the energy storage system and reducing after-sales and operation and maintenance costs. In addition, after single-point and two-point faults occur in the daisy chain communication of the BMS of the battery management system of the present invention, the faults can be quickly and effectively located and the communication connection can be re-established, thereby improving the stability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are provided to provide a further understanding of the present application, and they are incorporated into and constitute a part of the present application. The drawings illustrate embodiments of the present application and, together with this specification, serve to explain the principles of the present application. In the drawings: Figure 1 is a schematic diagram of a battery management system according to an embodiment of the present invention.

[0024] Figure 2 is a schematic diagram of a battery management system according to another embodiment of the present invention.

[0025] Figure 3 is a schematic diagram of a battery management system according to another embodiment of the present invention.

[0026] Figure 4 is a schematic diagram of simulating an SPI interface through the IO port of the MCU module and performing daisy chain communication.

[0027] Figure 5 is a schematic diagram of simulating a UART interface through the IO port of the MCU module and performing daisy chain communication.

[0028] Figure 6 is a flowchart of the communication method of the battery management system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, the present application can also be applied to other similar scenarios based on these drawings. Unless obvious from the language context or otherwise stated, the same reference numerals in the drawings represent the same structure or operation.

[0030] Figure 1 is a schematic diagram of a battery management system according to an embodiment of the present invention. As Figure 1As shown, the battery management system 100 includes an MCU module, bridging module 1, bridging module 2, bridging module 3, and n AFE modules, where n ≥ 3.

[0031] The n AFE modules are respectively denoted as AFE1, AFE2, AFE3, ……, AFEn-2, AFEn-1, AFEn. In this embodiment, each AFE module is connected to one battery cell. For example, AFE1 collects the status data of battery cell 1, and AFEn collects the status data of battery cell n. The status data includes but is not limited to the cell voltage, battery cell temperature, and battery cell AC impedance value.

[0032] The MCU module is the brain of the battery management system, used to send control instructions to the AFE modules and receive in real time data such as the cell voltage, temperature, and battery cell AC impedance value collected by the AFE modules; The bridging module is the link for direct daisy-chain communication between the MCU module and the AFE modules. By converting the SPI signal or UART signal sent by the MCU module into a daisy-chain signal and then sending it to the AFE modules for communication; at the same time, converting the daisy-chain signal returned by the AFE modules into an SPI signal or UART signal and feeding it back to the MCU module. Among them, bridging module 3 is a common communication module, and bridging module 1 and bridging module 2 are backup bridging modules, which are only used when a communication failure occurs.

[0033] The n AFE modules are connected in series to form a daisy chain. The two ends of the daisy chain are respectively connected to bridging module 1 and bridging module 2. Exemplarily, bridging module 1 is connected to AFE1, and bridging module 2 is connected to AFEn. In this embodiment, bridging module 3 is connected to one or more AFE modules in the middle of the daisy chain. For example, one end of bridging module 3 is connected to AFE2 and AFE3, and the other end is connected to AFEn-2 and AFEn-1.

[0034] Optionally, bridging module 1, bridging module 2, and bridging module 3 are provided on the MCU module, and bridging module 1, bridging module 2, and bridging module 3 are respectively connected to the MCU module.

[0035] Figure 2 is a schematic diagram of a battery management system according to another embodiment of the present invention. As Figure 2 shown, in this embodiment, the battery management system 200 includes 4 AFE modules, which are respectively denoted as AFE1, AFE2, AFE3, and AFE4. Then the AFE modules in the middle of the daisy chain are AFE2 and AFE3. Bridging module 3 is connected to the second end of AFE2, and bridging 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, bridging module 3 is connected to the second end of the n / 2-th AFE module, and bridging module 3 is connected to the first end of the n / 2 + 1-th AFE module. Refer toFigure 1 As shown, the bridging module 3 is also connected to the second end of the n / 2 - i-th AFE module, and the bridging module 3 is also connected to the first end of the n / 2 + 1 + i-th AFE module, where i is a positive integer greater than or equal to 1.

[0036] Figure 3 is a schematic diagram of a battery management system according to another embodiment of the present invention. As Figure 3 shown, in this embodiment, the battery management system 300 includes 3 AFE modules, denoted as AFE1, AFE2, and AFE3 respectively. Then the middle AFE module of the daisy chain is AFE2. The bridging module 3 is connected to the first end and the second end of AFE2. In other words, when the battery management system includes n AFE modules and n is odd, the bridging module 3 is connected to the first end and the second end of the -th AFE module, where represents the ceiling of n / 2. For example, when n = 3, n / 2 = 1.5, and the ceiling is equal to 2, that is, the middle AFE module of the daisy chain is AFE2.

[0037] 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, one AFE module is connected to a certain battery cell among multiple battery cells (usually, multiple battery cells are connected in series to form a module, and several AFE modules are only set in a module for acquisition. For example, a module has 10 battery cells, and 3 AFE modules are set on both sides and in the middle of the module. The advantage of this is lower cost, and selecting representative battery cells for parameter acquisition can also represent the working conditions of the module. The disadvantage is the lack of fine-grained monitoring); according to the current industry development trend, large-capacity battery cells are the future development trend. Therefore, the disadvantages in the selective acquisition scheme will be magnified in the large-capacity battery cell solution. So in Figure 1 and Figure 2 's solution, one battery cell is connected to one AFE module.

[0038] Among them, the MCU module is configured to: after the system power-on is completed, send a forward communication instruction and a reverse communication instruction to multiple AFE modules through the bridging module 3. The AFE modules on the left side of the middle AFE module transmit battery cell parameters from left to right according to the forward communication instruction, and the AFE modules on the right side of the middle AFE module transmit battery cell parameters from right to left according to the reverse communication instruction, and finally transmit the battery cell parameters to the MCU module through the bridging module 3.

[0039] As Figure 2As shown, when there is no fault in the communication system, the default working bridging module of the system is bridging module 3. After the system powers on and completes, the MCU module sends forward communication instructions and reverse communication instructions to multiple AFE modules through bridging module 3. The AFE 4 on the right side of bridging module 3 collects the battery cell 4, and then transmits the collected battery cell parameters to AFE3 according to the reverse communication instruction. AFE3 collects the battery cell 3 and transmits the collected battery cell parameters and the battery cell parameters transmitted from AFE4 to bridging module 3. Bridging module 3 transmits the battery cell parameters to the MCU module. The AFE 1 on the left side of bridging module 3 collects the battery cell 1, and then transmits the collected battery cell parameters to AFE2 according to the forward communication instruction. AFE2 collects the battery cell 2 and transmits the collected battery cell parameters and the battery cell parameters transmitted from AFE1 to bridging module 3. Bridging module 3 transmits the battery cell parameters to the MCU module.

[0040] The MCU module is also configured to: determine whether a communication fault has occurred according to the obtained battery cell parameters. If so, determine the location where the fault occurs according to the obtained battery cell parameters. When the fault points are all on the left side of the middle AFE module, start the first bridging module. The AFE modules on the left side of the fault point transmit the battery cell parameters from right to left to the first bridging module, and then through the first bridging module to the MCU module. When the fault points are all on the right side of the middle AFE module, start the second bridging module. The AFE modules on the right side of the fault point transmit the battery cell parameters from left to right to the second bridging module, and then through the second bridging module to the MCU module.

[0041] When the fault points are on the left and right sides of the middle AFE module, start the first bridging module and the second bridging module. 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 modules on the left side of the first fault point transmit the battery cell parameters from right to left to the first bridging module, and then through the first bridging module to the MCU module. The AFE modules on the right side of the second fault point transmit the battery cell parameters from left to right to the second bridging module, and then through the second bridging module to the MCU module.

[0042] As Figure 1 shown, when the battery management system 100 includes n AFE modules, the number of possible fault points is n + 1, and the fault points are respectively named E1, E2, E3, ……, En-1, En, En+1. When a fault occurs in the daisy chain, 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 fault point location: As Figure 1As shown, if the MCU module receives the status data of all battery cells, it is regarded that no communication failure has occurred (the failure points E1 and En+1 do not affect communication). If the MCU module only fails to receive the status data of battery cell 1 and battery cell 2, the failure point is located at E3. The failure point E3 is on the left side of the middle AFE module, and the bridging module 1 is started. The AFE2 on the left side of the failure point E3 transmits the status data of battery cell 2 from right to left to AFE1, and AFE1 transmits the status data of battery cell 1 and battery cell 2 to the bridging module 1, and then transmits it to the MCU module through the bridging module 1.

[0043] If the MCU module only fails to receive the status data of battery cell n-1 and battery cell n, the failure point is located at En-1. The failure point En-1 is on the right side of the middle AFE module, and the bridging module 2 is started. The AFEn-1 on the right side of the failure point En-1 transmits the status data of battery cell n-1 from left to right to AFEn, and AFEn transmits the status data of battery cell n-1 and battery cell n to the bridging module 2, and then transmits it to the MCU module through the bridging module 2.

[0044] If the MCU module only fails to receive the status data of battery cell 1 and battery cell 2, and the status data of battery cell n-1 and battery cell n, the failure points are located at E3 and En-1 at the same time. The failure points E3 and En-1 are on the left and right sides of the middle AFE module, and the bridging module 1 and the bridging module 2 are started. The AFE2 on the left side of the failure point E3 transmits the status data of battery cell 2 from right to left to AFE1, and AFE1 transmits the status data of battery cell 1 and battery cell 2 to the bridging module 1, and then transmits it to the MCU module through the bridging module 1. The AFEn-1 on the right side of the failure point En-1 transmits the status data of battery cell n-1 from left to right to AFEn, and AFEn transmits the status data of battery cell n-1 and battery cell n to the bridging module 2, and then transmits it to the MCU module through the bridging module 2.

[0045] When the failure points are located at E2 and E3, through the bridging module 3, the MCU module cannot obtain the status data of battery cell 1 and battery cell 2. After enabling the bridging module 1, due to the existence of the failure point E2, AFE2 cannot transmit the status data of battery cell 2 to AFE1, and AFE1 can transmit the status data of battery cell 1 to the MCU module through the bridging module 1. In other words, after enabling the bridging module 1, the MCU module still cannot obtain the status data of battery cell 2.

[0046] As Figure 1As shown, the battery management system 100 further includes n wireless modules. Each AFE module corresponds to one wireless module. The n wireless modules are respectively denoted as wireless module 1, wireless module 2, wireless module 3... wireless module n-2, wireless module n-1, and wireless module n. Among them, 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. Optionally, the wireless module is default-configured in a low-power sleep mode and is woken up by the AFE module when needed.

[0047] Optionally, the communication protocol of the wireless module is the same as that of the daisy chain. Since the communication protocol of the wireless module is the same as that of the daisy chain, the wired communication method and the wireless communication method can be compatible and used interchangeably. Secondly, this wireless mode is different from conventional wireless communication. Since it has the same communication protocol as the daisy chain, it only supports communication between adjacent modules in a hand-in-hand manner. For example, wireless module n only supports hand-in-hand communication with AFEn-1, wireless module n-1, and bridging module 2. Wireless module 2 only supports hand-in-hand communication with AFE1, AFE3, wireless module 1, and wireless module 3. The advantage of such a structure is to improve the stability and anti-interference ability of wireless communication.

[0048] Optionally, the MCU module is further configured to: determine whether a communication failure occurs according to the obtained battery cell parameters. If so, enable the first bridging module and / or the second bridging module, and determine whether the communication failure is eliminated according to the battery cell parameters obtained again. If not, then determine the ID of the AFE module that fails to communicate according to the obtained battery cell parameters, and wake up the wireless modules corresponding to the AFE modules that fail to communicate in the following order: first wake up the wireless module on the left side of the AFE module with a smaller ID, and then wake up the wireless module on the right side of the AFE module with a larger ID.

[0049] As Figure 1As shown, when the fault point is located at E1, E2, or E3, after enabling the bridging module 1, the MCU module still cannot obtain the status data of battery cell 1 and battery cell 2. From this, it can be determined that the IDs of the AFE modules that failed to communicate are AFE1 and AFE2. Therefore, first start the wireless module 1 corresponding to AFE1. The wireless module 1 establishes a wireless communication link with the bridging module 1. The wireless module 1 sends the status data of battery cell 1 to the bridging module 1, and the bridging module 1 sends the status data of battery cell 1 to the MCU module. Then start the wireless module 2 corresponding to AFE2. The wireless module 2 establishes a communication link with AFE3. The wireless module 2 sends the status data of battery cell 2 to AFE3, and AFE3 sends the status data of battery cell 2 to the MCU module through the bridging module 3. In this embodiment, the non-communicating AFE modules AFE1 and AFE2 are adjacent. Imagine that if there are other AFE modules between the non-communicating AFE modules AFE1 and AFE2, and if there are fault points between other AFE modules, if the wireless module is started from any point instead of starting from both ends, the number of times of attempting to establish a communication link will be relatively large. In this application, the wireless module is woken up from the left side of the AFE module with a smaller ID, and then the wireless module is woken up from the right side of the AFE module with a larger ID, which can restore the communication link fastest. In other words, starting the wireless module from both ends, since the endpoints are closest to the normally operating AFE modules, the probability of restoring the communication link may be the highest.

[0050] Exemplarily, the MCU module first determines the ID of the AFE that failed to communicate based on the currently communicable AFE. If the fault point is on the left or right side of the bridging module 3, first wake up the wireless communication link from the left side of the AFE module with a smaller ID, and then wake up the wireless communication link from the right side of the AFE module with a larger ID to re-establish communication; if the communication still cannot be established, return to the upper level, the MCU module re-determines the ID of the AFE that failed to communicate, and then wakes up the relevant wireless communication link until the communication is re-established. If the fault point is on both sides of the bridging module 3, the MCU first determines the ID of the AFE that failed to communicate based on the currently communicable AFE, and then executes the same wireless communication link wake-up mechanism for the single-sided fault point on both sides. For the fault point on the left side, first wake up the wireless communication link from the left side of the AFE module with a smaller ID, and then wake up the wireless communication link from the right side of the AFE module with a larger ID to re-establish communication; for the fault point on the right side, first wake up the wireless communication link from the left side of the AFE module with a smaller ID, and then wake up the wireless communication link from the right side of the AFE module with a larger ID to re-establish communication.

[0051] As Figure 2As shown in the figure, the battery management system 200 further includes a driving module 1 and a driving module 2. Among them, the driving module 1 and the driving module 2 are used to control one of the left and right daisy chains of the intermediate AFE module to be connected to the bridging module 3 at the same time, so as to control the communication timing of the daisy chain. If the left and right daisy chains of the intermediate AFE module send cell data to the bridging module 3 at the same time, it will cause timing conflicts. In this embodiment, the driving module 1 and the driving module 2 are respectively located on the left and right daisy chain paths of the intermediate AFE module.

[0052] As Figure 3 shown in the figure, 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 intermediate AFE module.

[0053] Optionally, the driving module 1 and the driving module 2 are switching circuits such as MOS transistors or relays. The on and off control is performed by the high or low level output of the IO of the MCU module. The specific method is as follows: when the MCU module controls the driving module 1 to close and the driving module 2 to turn off, the left daisy chain communication link is opened; when the MCU controls the driving module 1 to disconnect and the driving module 2 to close, the right daisy chain communication link is opened.

[0054] When the driving module 1 and the driving module 2 are respectively the normally open contact and the normally closed contact of the relay (the order of the two can be replaced), the on and off control is performed by sending high and low levels through the daisy chain communication pins of the MCU. The specific method is as follows: when the MCU sends a high level signal, the normally open contact closes and the normally closed contact disconnects, that is, the driving module 1 closes and the driving module 2 turns off, then the left daisy chain communication link is opened; when the MCU sends a low level signal, the normally open contact disconnects and the normally closed contact closes, that is, the driving module 1 disconnects and the driving module 2 closes, then the right daisy chain communication link is opened. After the MCU controls the driving module 1 to close and the driving module 2 to disconnect, it sends the communication data of the left daisy chain. After the MCU controls the driving module 2 to close and the driving module 1 to disconnect, it sends the communication data of the right daisy chain.

[0055] For the battery management system of the present invention, after single-point and two-point failures occur in the daisy chain communication of the BMS, the faults can be quickly and effectively located and the communication connection can be re-established, thereby improving the stability of the product, ensuring a good user experience, and enhancing the product competitiveness. When the faults occur at both ends of the positive and negative directions of the daisy chain and in the middle part of the daisy chain, the communication can be ensured to be normal, which can improve 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 the after-sales and operation and maintenance costs.

[0056] In a battery pack with an extremely large capacity, when the number of AFE increases, when using the concept of this application to solve possible faults, theoretically, only the bridging module needs to be added. However, there are certain problems in actual applications. For example, the number of communication ports between the MCU module and the bridging module is limited. Limited by the number of communication ports of the MCU module, the number of bridging modules will be restricted. To solve this problem, the MCU module further includes a signal simulation unit, which is used to simulate the MCU module's IO interface as an SPI interface or a UART interface, and multiple bridging modules are connected to the MCU module through the simulated SPI interface or UART interface.

[0057] Figure 4 Schematic diagram for simulating the SPI interface through the IO port of the MCU module and performing daisy-chain communication. As Figure 4 shown, IO1, IO2, IO3, and IO4 of the MCU module are ordinary IO interfaces. First, configure the communication rates of the IO1, IO2, IO3, and IO4 interfaces to the communication rates required by the bridging module, and then simulate the CS pin function through IO1: pull up or pull down the pin signal of this IO when writing and reading data (specifically according to the CS communication requirements of the AFE); set the level of the IO according to the SPI bus timing of the AFE to simulate the MOSI pin function through IO2, and MISO is the signal received by the MCU. Just simulate and set IO3 as an input signal interface; set the level of the IO according to the bus timing of the AFE to simulate the SCK pin function through IO4. After completing the functions of simulating the four SPI interfaces of IO1, IO2, IO3, and IO4, the communication between the MCU module and the AFE module can be established.

[0058] Figure 5 Schematic diagram for simulating the UART interface through the IO port of the MCU module and performing daisy-chain communication.

[0059] IO1 and IO2 of the MCU module are ordinary IO interfaces. First, configure the communication rates of the IO1 and IO2 interfaces to the communication rates required by the bridging module, and then simulate the RX and TX pin functions through IO1 and IO2 in sequence: according to the UART data transmission format, pull up or pull down the IO port level through software delay, timer, etc., so as to realize the input and output of UART signals through the IO, and the communication between the MCU module and the AFE module can be established.

[0060] The present invention also provides a communication method for a battery management system. Figure 6 It is a flowchart of the communication method of the battery management system according to an embodiment of the present invention. As Figure 6 shown, the communication method 600 of the battery management system includes the following steps: Step S61: After the system powers on and completes, the AFE module collects cell parameters, and the MCU module sends forward communication instructions and reverse communication instructions to multiple AFE modules through the third bridging module; Step S62: The AFE modules on the left of the middle AFE module transfer cell parameters from left to right according to the forward communication instructions, and the AFE modules on the right of the middle AFE module transfer cell parameters from right to left according to the reverse communication instructions, and finally transfer the cell parameters to the MCU module through the third bridging module.

[0061] Step S63: The MCU module determines whether a communication fault has occurred according to the acquired cell parameters. If so, it determines the location where the fault occurred according to the acquired cell parameters; Step S64: When the fault points are all on the left side of the middle AFE module, the first bridging module is started. The AFE modules on the left of the fault points transfer the cell parameters from right to left to the first bridging module, and then to the MCU module through the first bridging module; Step S65: When the fault points are all on the right side of the middle AFE module, the second bridging module is started. The AFE modules on the right of the fault points transfer the cell parameters from left to right to the second bridging module, and then to the MCU module through the second bridging module.

[0062] Step S66: When the fault points are on the left and right sides of the middle AFE module, the first bridging module and the second bridging 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 modules on the left of the first fault point transfer the cell parameters from right to left to the first bridging module, and then to the MCU module through the first bridging module. The AFE modules on the right of the second fault point transfer the cell parameters from left to right to the second bridging module, and then to the MCU module through the second bridging module.

[0063] Optionally, the communication method 600 of the battery management system further includes: the MCU module determines whether a communication fault has occurred according to the acquired cell parameters. If so, the first bridging module and / or the second bridging module is enabled, and it is determined whether the communication fault has been eliminated according to the cell parameters acquired again. If not, the ID of the AFE module that fails to communicate is determined according to the acquired cell parameters, and the wireless modules corresponding to the AFE modules that fail to communicate are awakened in the following order: first, the wireless module on the left of the AFE module with a smaller ID is awakened, and then the wireless module on the right of the AFE module with a larger ID is awakened, and the cell parameters are transmitted through the wireless communication link established by the wireless module.

[0064] The communication method of the battery management system of the present invention is based on a multi-level daisy chain topology architecture, and different control strategies for re-establishing communication after a fault are formulated according to the location of the fault point, effectively improving the stability of daisy chain communication.

[0065] Flowcharts are used in the present application to illustrate the operations performed by the systems according to the embodiments of the present application. It should be understood that the operations above or below do not necessarily have to be performed precisely in order. On the contrary, various steps can be processed in reverse order or simultaneously. Also, one or more other operations can be added to these processes, or one or more steps can be removed from these processes.

[0066] The basic concepts have been described above. Obviously, for those skilled in the art, the above invention disclosure is only an example and does not constitute a limitation to the present application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to the present application. Such modifications, improvements, and corrections are proposed in the present application, so such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of the present application.

[0067] Meanwhile, the present application uses specific terms to describe the embodiments of the present application. Such as "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the present application can be appropriately combined.

[0068] Some aspects of the present application can be executed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software can all be referred to as "data blocks", "modules", "engines", "units", "components", or "systems". The processor can be one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DAPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, or combinations thereof. In addition, aspects of the present application may be embodied as a computer product located in one or more computer-readable media, which includes computer-readable program code. For example, the computer-readable media can include, but is not limited to, magnetic storage devices (such as hard disks, floppy disks, magnetic tapes...), optical discs (such as compact discs CD, digital versatile discs DVD...), smart cards, and flash memory devices (such as cards, sticks, key drives...).

[0069] Similarly, it should be noted that, in order to simplify the description of the disclosure of the present application and thus help the understanding of one or more embodiments of the invention, in the foregoing description of the embodiments of the present application, sometimes multiple features are incorporated into one embodiment, drawing or description thereof. However, this disclosure method does not mean that the features required by the subject matter of the present application are more than the features mentioned. In fact, the features of the embodiments are fewer than all the features of the single embodiments disclosed above.

[0070] As shown in the present application, unless the context clearly indicates otherwise, words such as "a", "an", "one" and / or "the" are not specifically singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0071] Unless otherwise specifically stated, the relative arrangements, numerical expressions and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for the sake of convenience of description, the sizes of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the said technologies, methods and devices should be regarded as part of the description. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0072] In the description of the present application, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Without contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present application; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0073] In addition, it should be noted that the use of terms such as "first" and "second" to define components is only for the convenience of distinguishing the corresponding components. Without additional statements, the above terms have no special meanings, so they should not be construed as limiting the protection scope of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of this description. In addition, it is required to understand this application not only through the actual terms used, but also through the meanings implied by each term.

[0074] It should be understood that when a component is referred to as "on another component", "connected to another component", "coupled to another component" or "in contact with another component", it can be directly on, connected to, or coupled to, or in contact with the other component, or there may be an intervening component. In contrast, when a component is referred to as "directly on another component", "directly connected to", "directly coupled to" or "directly in contact with" another component, there is no intervening component. Similarly, when the first component is referred to as "electrically contacting" or "electrically coupled to" the second component, there is an electrical path allowing current to flow between the first component and the second component. The electrical path may include capacitors, coupled inductors, and / or other components allowing current to flow, even if there is no direct contact between the conductive components.

[0075] In some embodiments, numbers are used to describe components and attribute quantities. It should be understood that such numbers used in the description of embodiments are modified by the modifiers "about", "approximate" or "substantially" in some examples. Unless otherwise stated, "about", "approximate" or "substantially" indicate that the said numbers allow a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification are all approximate values, and these approximate values may change according to the characteristics required by individual embodiments. In some embodiments, the numerical parameters should consider the specified significant digits and adopt the method of retaining general digits. Although the numerical ranges and parameters used to confirm the scope breadth in some embodiments of this application are approximate values, in specific embodiments, the setting of such numerical values is as precise as possible within the feasible range.

[0076] Although this application has been described with reference to current specific embodiments, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate this application, and various equivalent changes or substitutions can be made without departing from the spirit of this application. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of this application, they will fall within the scope of this application.

Claims

1. A battery management system, characterized in that, Comprising: A plurality of AFE modules, an MCU module, a first bridging module, a second bridging module, and a third bridging module connected to the MCU module; The first bridging module, the plurality of AFE modules, and the second bridging module are connected in series to form a daisy chain. The third bridging module is connected to the middle AFE module. The middle AFE module refers to the AFE module in the middle position of the daisy chain. The third bridging module is in the default working state, and the first bridging module and the second bridging module are in the standby state and are only enabled when a communication failure occurs; Wherein, the AFE module is used to collect battery cell parameters; the MCU module is configured as follows: after the system power-on is completed, a forward communication instruction and a reverse communication instruction are sent to the plurality of AFE modules through the third bridging module. The AFE modules on the left side of the middle AFE module transmit the battery cell parameters from left to right according to the forward communication instruction, and the AFE modules on the right side of the middle AFE module transmit the battery cell parameters from right to left according to the reverse communication instruction, and finally transmit the battery cell parameters to the MCU module through the third bridging module.

2. The battery management system according to claim 1, wherein, The MCU module is further configured as follows: to determine whether a communication failure has occurred based on the acquired battery cell parameters. If so, to determine the location where the failure occurred based on the acquired battery cell parameters. When the failure points are all on the left side of the middle AFE module, the first bridging module is started, and the AFE modules on the left side of the failure point transmit the battery cell parameters from right to left to the first bridging module, and then to the MCU module through the first bridging module; when the failure points are all on the right side of the middle AFE module, the second bridging module is started, and the AFE modules on the right side of the failure point transmit the battery cell parameters from left to right to the second bridging module, and then to the MCU module through the second bridging module.

3. The battery management system according to claim 2, wherein, Further comprising: When the failure points are on the left and right sides of the middle AFE module, the first bridging module and the second bridging module are started. The failure points on the left and right sides of the middle AFE module are respectively recorded as the first failure point and the second failure point. The AFE modules on the left side of the first failure point transmit the battery cell parameters from right to left to the first bridging module, and then to the MCU module through the first bridging module. The AFE modules on the right side of the second failure point transmit the battery cell parameters from left to right to the second bridging module, and then to the MCU module through the second bridging module.

4. The battery management system according to claim 1, characterized in that, Further comprising: A plurality of wireless modules, each wireless module corresponding to one 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.

5. The battery management system according to claim 4, characterized in that The communication protocol of the wireless module is the same as that 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, wherein, The MCU module is further configured to: determine whether a communication failure occurs according to the obtained cell parameters. If so, enable the first bridging module and / or the second bridging module, and determine whether the communication failure is eliminated according to the cell parameters obtained again. If not, determine the ID of the AFE module that fails to communicate according to the obtained cell parameters, and wake up the wireless module corresponding to the AFE module that fails 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, characterized in that, The wireless module is default configured in a low-power sleep mode and is woken up by the AFE module when needed.

8. The battery management system according to claim 1, characterized in that, It further 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 middle AFE module to be connected to the third bridging module at the same time, so as to control the communication timing of the daisy chain.

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

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

11. The battery management system according to claim 8, characterized in that, The first driving module and the second driving module are MOS transistors or relays.

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

13. The battery management system according to claim 1, characterized in that, It further includes: Other bridging modules connected to the MCU module, the other bridging modules are connected to one AFE module or multiple AFE modules in the daisy chain, and the other bridging modules are used to establish multiple redundant communication links; The MCU module includes a signal simulation unit, and the signal simulation unit is used to simulate the IO interface of the MCU module as an SPI interface or a UART interface, and the other bridging 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 It includes: After the system power-on is completed, the AFE module collects cell parameters, and the MCU module sends a forward communication instruction and a reverse communication instruction to the multiple AFE modules through the third bridging module; The AFE modules on the left side of the middle AFE module transfer the cell parameters from left to right according to the forward communication instruction, and the AFE modules on the right side of the middle AFE module transfer the cell parameters from right to left according to the reverse communication instruction, and finally transfer the cell parameters to the MCU module through the third bridging module.

15. The communication method according to claim 14, characterized in that, It further includes: The MCU module determines whether a communication failure occurs according to the obtained cell parameters. If so, determines the location where the failure occurs according to the obtained cell parameters; When the fault points are all located on the left side of the middle AFE module, start the first bridging module, and the AFE modules on the left side of the fault point transfer the cell parameters from right to left to the first bridging module, and then transfer them to the MCU module through the first bridging module; When all the fault points are located on the right side of the middle AFE module, the second bridging module is activated. The AFE modules on the right side of the fault points transmit the cell parameters from left to right to the second bridging module, and then through the second bridging module to the MCU module.

16. The communication method according to claim 15, wherein It further includes: When the fault points are located on both the left and right sides of the middle AFE module, the first bridging module and the second bridging module are activated. The fault points on the left and right sides of the middle AFE module are respectively denoted as the first fault point and the second fault point. The AFE modules on the left side of the first fault point transmit the cell parameters from right to left to the first bridging module, and then through the first bridging module to the MCU module. The AFE modules on the right side of the second fault point transmit the cell parameters from left to right to the second bridging module, and then through the second bridging module to the MCU module.

17. The communication method according to claim 14, characterized in that, It further includes: The MCU module determines whether a communication fault has occurred based on the acquired cell parameters. If so, the first bridging module and / or the second bridging module is enabled. Then, it determines whether the communication fault has been eliminated based on the cell parameters acquired again. If not, it determines the ID of the AFE module that fails to communicate based on the acquired cell parameters, and wakes up the wireless modules corresponding to the AFE modules that fail to communicate in the following order: first wake up the wireless module on the left side of the AFE module with a smaller ID, and then wake up the wireless module on the right side of the AFE module with a larger ID, and transmit the cell parameters through the wireless communication link established by the wireless module.

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