Battery management system, battery system and electric device

Abstract

Embodiments of the present application provide a battery management system, a battery system and a power consumption device. The battery management system comprises a processing module and at least two battery module sensing modules connected in sequence. The battery module sensing modules are respectively connected to a next target module through a first communication link and a second communication link, and the next target module comprises the processing module or another battery module sensing module. The battery module sensing module is configured to acquire a battery state of a target battery module in a battery pack, and generate a PWM signal according to the battery state when a communication connection abnormality exists in the first communication link, and send the PWM signal to the next target module through the second communication link. The processing module is configured to receive the PWM signal sent by the battery module sensing module, analyze the PWM signal to obtain the battery state of each battery module in the battery pack, and output the battery state. The battery management system is used to improve the communication reliability and fault tolerance of the battery management system.

Description

Technical Field

[0001] This application relates to the field of battery management technology, and in particular to a battery management system, a battery system, and an electrical device. Background Technology

[0002] In traditional battery management systems, the analog front end (AFE) is responsible for collecting key parameters of the battery module, such as cell voltage, temperature, and current, and transmitting them to the microcontroller unit (MCU) for processing via communication protocols such as Serial Peripheral Interface (SPI) or Inter-Integrated Circuit (I²C). However, when the communication link is interrupted due to factors such as electromagnetic interference, line aging, physical damage, or environmental noise, the MCU will be unable to obtain real-time battery data, leading to safety hazards such as overcharging, over-discharging, and overheating, and reducing the safety and functional integrity of the electrical equipment.

[0003] Therefore, improving the communication reliability and fault tolerance of the battery management system is an urgent problem to be solved. Summary of the Invention

[0004] The battery management system, battery system, and electrical equipment provided in this application are intended to improve the communication reliability and fault tolerance of the battery management system.

[0005] In a first aspect, embodiments of this application provide a battery management system, including: a processing module and at least two battery module sensing modules cascaded in sequence;

[0006] The battery module sensing module is connected to the next target module via a first communication link and a second communication link, respectively. The next target module includes the processing module or another battery module sensing module.

[0007] The battery module sensing module is used to obtain the battery status of the target battery module in the battery pack, and when there is a communication connection abnormality in the first communication link, it generates a PWM signal according to the battery status and sends the PWM signal to the next target module through the second communication link.

[0008] The processing module is used to receive the PWM signal sent by the battery module sensing module, parse the PWM signal to obtain the battery status of each battery module in the battery pack, and output the battery status.

[0009] Optionally, the duty cycle of the PWM signal corresponding to different battery states is the same, but the level distribution is different.

[0010] Optionally, the duty cycles of the PWM signals corresponding to at least two battery states are different.

[0011] Optionally, when there is a communication connection abnormality in the first communication link, the battery module sensing module is specifically used for:

[0012] Generate a battery status PWM signal based on the battery status;

[0013] A heartbeat PWM signal is generated, which is different from the heartbeat PWM signal of the adjacent battery module sensing module of the battery module sensing module;

[0014] The PWM signal is generated based on the battery status PWM signal and the heartbeat PWM signal.

[0015] Optionally, the battery module sensing module is also connected to the previous target module via a reverse second communication link, the previous target module including the processing module or another battery module sensing module;

[0016] The battery module sensing module is also used to send the PWM signal to the previous target module through the reverse second communication link.

[0017] Optionally, the processing module is further configured to:

[0018] Receive a first PWM signal transmitted via the second communication link and a second PWM signal transmitted via the reverse second communication link;

[0019] Determine whether there are any differences between the battery status information corresponding to the first PWM signal and the battery status information corresponding to the second PWM signal;

[0020] If there are differences between the battery status information corresponding to the first PWM signal and the battery status information corresponding to the second PWM signal, an abnormal prompt message is output based on the differences and their locations.

[0021] Optionally, the signal encoding rules for the first PWM signal transmitted through the second communication link and the second PWM signal transmitted through the reverse second communication link are different for the same battery state.

[0022] Optionally, the battery module sensing module is specifically used for:

[0023] Obtain the cell status of each target cell in the target battery module;

[0024] When there is a communication connection abnormality in the first communication link, a battery cell status PWM signal is generated according to the battery cell status.

[0025] The PWM signal is generated based on the PWM signal of each cell state.

[0026] In a second aspect, embodiments of this application provide a battery system, the battery system comprising a battery management system as described in any one of the first aspects:

[0027] Thirdly, embodiments of this application provide an electrical device, the electrical device including a battery management system as described in any one of the first aspects.

[0028] The battery management system, battery system, and electrical equipment provided in this application embodiment, by setting up multiple battery module sensing modules in a cascaded manner, and configuring two communication paths, a first communication link and a second communication link, for each battery module sensing module, can automatically switch to the second communication link and use PWM signal to transmit battery status when the first communication link is abnormal. This effectively solves the problem that a single point of communication failure in the battery management system may lead to the paralysis of the entire system, thereby improving the communication reliability and fault tolerance of the battery management system. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0030] Figure 1 This is a schematic diagram of the structure of a battery management system provided in an embodiment of this application;

[0031] Figure 2 This is a schematic diagram of the structure of a PWM signal provided in an embodiment of this application;

[0032] Figure 3 This is a schematic diagram of another PWM signal structure provided in an embodiment of this application;

[0033] Figure 4 This is a schematic diagram of another PWM signal structure provided in an embodiment of this application;

[0034] Figure 5 This is a schematic diagram of another battery management system provided in an embodiment of this application;

[0035] Figure 6 This is a schematic diagram of another PWM signal structure provided in an embodiment of this application;

[0036] Figure 7 This is a schematic diagram of another PWM signal structure provided in an embodiment of this application;

[0037] Figure 8 This is a schematic diagram of another battery management system provided in an embodiment of this application;

[0038] Figure 9 This is a schematic diagram of another PWM signal structure provided in an embodiment of this application.

[0039] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0040] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0041] Currently, the communication architecture of battery management systems (BMS) is mainly wired. For example, a daisy-chain cascade architecture is commonly used to implement the communication architecture within the BMS. In existing solutions, to improve data transmission reliability, the daisy-chain cascade architecture often uses a bidirectional data transmission mode to build redundant links, adds a communication diagnostic and verification mechanism to monitor the status of data packets, and configures isolation communication modules (such as optocouplers and magnetic couplers) to achieve high and low voltage signal isolation, ensuring the safety and accuracy of signal transmission under high voltage environments.

[0042] However, the bidirectional loopback transmission of the daisy-chain cascade architecture requires signal conversion through a unified isolated communication module. This isolated communication module becomes a critical point of failure, posing a risk of common-cause failure. If the isolated communication module fails, the entire communication link will be interrupted, causing the battery management system (BMS) to fail to monitor the battery. Simultaneously, the AFE (Automatic Front-End) in the BMS needs to access the communication link through its own communication module. If the AFE fails, the battery data of the corresponding battery module cannot be uploaded to the BMS's MCU, resulting in a loss of connection at the monitoring point and further exacerbating the risk to the battery system.

[0043] To address the drawbacks of wired links, existing technologies have further proposed wireless communication modes to realize the communication architecture of battery management systems. By using wireless technology to achieve data transmission, the constraints of physical wiring harnesses can be eliminated, and independent communication isolation of multiple modules can be achieved. A communication failure in one module will not affect the normal transmission of other modules, thus reducing the scope of the fault's impact.

[0044] However, wireless communication solutions can only isolate the faulty module from the overall system, and cannot continuously acquire the key battery parameters and operating status of the faulty module when communication fails. Once module communication is lost, the battery management system will still lose its ability to monitor the faulty module, cannot identify its safety hazards, cannot achieve effective safety control, and cannot fundamentally guarantee the overall safety of the battery system.

[0045] Therefore, existing battery management systems suffer from low communication reliability and poor fault tolerance.

[0046] In view of this, this application provides a battery management system that sets up multiple battery module sensing modules in a cascaded manner and configures two communication paths, a first communication link and a second communication link, for each battery module sensing module. When the first communication link fails, it can automatically switch to the second communication link and use PWM signals to transmit the battery status. This effectively solves the problem that a single point of communication failure in the battery management system may cause the entire system to crash, thereby improving the communication reliability and fault tolerance of the battery management system.

[0047] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0048] Figure 1 This is a schematic diagram of a battery management system provided in an embodiment of this application, such as... Figure 1 As shown, the system includes: a processing module and at least two battery module sensing modules cascaded in sequence.

[0049] The battery module sensing module is connected to the next target module via a first communication link and a second communication link. The next target module includes a processing module or another battery module sensing module. For example, for a non-cascaded end battery module sensing module, it is connected to the next battery module sensing module via the first communication link and the second communication link. For a cascaded end battery module sensing module, it is connected to the processing module via the first communication link and the second communication link.

[0050] The first communication link can be, for example, a daisy-chain-based communication link, or a wired or wireless communication link using communication protocols such as SPI or I²C. This first communication link is used to transmit the battery status data collected by the battery module's sensing module to the processing module for processing and analysis.

[0051] The second communication link is a redundant communication link of the first communication link. It is used to transmit a Pulse Width Modulation (PWM) signal generated by the battery module sensing module based on the battery state of the battery module when the first communication link experiences a communication failure. This allows the processing module to receive the PWM signal and analyze it to obtain the battery state of the battery module. For example, the battery module sensing module can transmit the PWM signal to its adjacent battery module sensing module in the cascaded structure through its General Purpose Input Output (GPIO) interface, and the battery module sensing module at the end of the cascade can also transmit the PWM signal to the processing module through its GPIO interface.

[0052] The battery module sensing module is used to obtain the battery status of the target battery module in the battery pack, and when there is a communication connection abnormality in the first communication link, it generates a PWM signal according to the battery status and sends the PWM signal to the next target module through the second communication link.

[0053] The battery module sensing module can be, for example, an AFE (Automatic External Frame), a battery acquisition chip, or a cell monitoring unit. It can acquire the battery status (or battery data) of the battery pack, the battery modules within the battery pack, or the cells within the battery modules. This battery status can include, for example, temperature, current, voltage, and fault conditions. Fault conditions can include, for example, overvoltage (OV), undervoltage (UV), overcurrent (OC), undertemperature (UT), and overtemperature (OT). Each battery module sensing module can correspond to one battery module in the battery pack to acquire the battery status of that module.

[0054] The duty cycle (e.g., the ratio of high-level time to signal period) and / or phase encoding of a PWM signal can be used to encode different information. Therefore, taking the transmission of fault status as an example, the battery module sensing module can generate PWM signals with different duty cycles and / or phase encodings based on the different fault statuses of its corresponding battery module, in order to characterize different fault statuses.

[0055] Under normal circumstances, the battery module sensing module packages and sends the collected battery status data to the next target module via a first communication link (such as a daisy chain). The next target module may be another battery module sensing module cascaded with it, or it may be the final processing module. The battery status data is forwarded level by level in a cascading manner, eventually converging at the processing module.

[0056] When the battery module sensing module detects a communication connection abnormality in the first communication link, such as failing to receive a handshake response signal for several consecutive communication cycles or detecting that the bus level is in a recessive state for an extended period, the battery module sensing module can switch to a backup communication mode. In the backup communication mode, the battery module sensing module converts the battery status into the duty cycle of a PWM signal according to a preset encoding rule, and sends the PWM signal to the next target module through the second communication link. The PWM signal is forwarded stage by stage in a cascade manner, eventually converging to the processing module.

[0057] The processing module receives the PWM signal sent by the battery module sensing module, parses the PWM signal to obtain the battery status of each battery module in the battery pack, and outputs the battery status. The processing module can be, for example, the main control chip in the Battery Management Unit (BMU), and its core can be, for example, an MCU, a microcontroller, or a digital signal processor (DSP).

[0058] The processing module integrates a storage unit (such as Flash memory or RAM) to store the mapping relationship between the parsing algorithm, duty cycle, and / or phase encoding and the battery state. Based on the PWM signal received from the sensing module of the cascaded end battery module, the battery state of each battery module included in the PWM signal is parsed using the mapping relationship between the duty cycle and / or phase encoding and the battery state. The processing module can then output this battery state to achieve functions such as battery status monitoring and fault indication. For example, taking the battery management system of an electric vehicle as an example, the processing module can send the output battery state to the vehicle controller or instrument panel for display or fault indication via the Controller Area Network (CAN) bus.

[0059] The battery management system provided in this application embodiment sets up multiple battery module sensing modules in sequence and configures two communication paths, a first communication link and a second communication link, for each battery module sensing module. When the first communication link fails, it can automatically switch to the second communication link and use PWM signal to transmit the battery status. This effectively solves the problem that a single point of communication failure in the battery management system may cause the entire system to crash, thereby improving the communication reliability and fault tolerance of the battery management system.

[0060] The following section will take battery statuses such as OV, UT, and OT as examples to explain in detail how to transmit the battery status of the battery module through PWM signals.

[0061] In one possible implementation, the PWM signals corresponding to different battery states have the same duty cycle but different level distributions. In this implementation, the duty cycle of the PWM signals corresponding to all battery states is the same; for example, the duty cycle of the PWM signals corresponding to different battery states is 50% (i.e., high level occupies 50% of the PWM signal in the time domain, and low level also occupies 50% of the PWM signal in the time domain). However, the level distributions of different battery states are different; for example, the order of the high and low levels in the time domain is different.

[0062] For example, taking a PWM signal generated by a battery module sensing module as 4 bits, with high level recorded as 1 and low level recorded as 0, the PWM transmission encoding design in this embodiment can be as shown in Table 1 below:

[0063] Table 1

[0064]

[0065] Correspondingly, for ease of understanding, Figure 2 This is a schematic diagram of the structure of a PWM signal provided in an embodiment of this application. Figure 2 As shown, the PWM signal has the same transmission encoding design as in Table 1 above, with low level recorded as 0 and high level recorded as 1.

[0066] Specifically, when the battery status of the battery module corresponding to the battery module sensing module (AFE#1~AFE#3) is normal, the PWM signal generated by the battery module sensing module is 0011; when the battery status of the battery module corresponding to the battery module sensing module is 0V, the PWM signal generated by the battery module sensing module is 1010; when the battery status of the battery module corresponding to the battery module sensing module is UV, the PWM signal generated by the battery module sensing module is 0101; and when the battery status of the battery module corresponding to the battery module sensing module is OT, the PWM signal generated by the battery module sensing module is 1001.

[0067] As shown in Table 1 and Figure 2 It is known that the duty cycle of the PWM signal corresponding to different battery states is 50%, and the battery states corresponding to different PWM signals are distinguished only by the level distribution. The subsequent processing module can also parse the received PWM signal according to this PWM transmission encoding design to obtain the battery state of each battery module.

[0068] In another possible implementation, the duty cycles of the PWM signals corresponding to at least two battery states are different.

[0069] In this implementation, the duty cycle of the PWM signal corresponding to different battery states is different. For example, the duty cycle corresponding to OV is 25%, that corresponding to UV is 50%, and that corresponding to OT is 75%. The level distribution of different battery states can be the same or different, and the battery state is mainly distinguished by the difference in duty cycle.

[0070] For example, the PWM transmission encoding design in the embodiments of this application can be as shown in Table 2 below:

[0071] Table 2

[0072]

[0073] Correspondingly, for ease of understanding, Figure 3 This is a schematic diagram of another PWM signal structure provided in an embodiment of this application. Figure 3 As shown, the PWM signal corresponds to the transmission encoding design in Table 2 above, and the ratio of high level to low level in each cycle corresponds to different battery states.

[0074] Specifically, when the battery status of the battery module corresponding to the battery module sensing module (AFE#1~AFE#n) is normal, the duty cycle of the PWM signal generated by the battery module sensing module is 50%, that is, the high level and the low level each occupy 50% of the signal cycle; when the battery status of the battery module corresponding to the battery module sensing module is 0V, the duty cycle of the PWM signal is 80%, that is, the high level occupies 80% and the low level occupies 20%; when the battery status of the battery module corresponding to the battery module sensing module is UV, the duty cycle of the PWM signal is 20%, that is, the high level occupies 20% and the low level occupies 80%.

[0075] From Table 2 and Figure 3 It is known that the duty cycles of the PWM signals corresponding to different battery states are different (50%, 80%, and 20%, respectively). Different battery states can be distinguished by detecting the duty cycle of the PWM signal. The subsequent processing module can parse the received PWM signal according to this PWM transmission encoding design. For example, when the parsed duty cycle is 80%, it is determined to be OV; when the duty cycle is 20%, it is determined to be UV; and when the duty cycle is 50%, it is determined to be no abnormality.

[0076] It should be noted that the duty cycle values ​​and corresponding battery states mentioned above are merely examples. In practical applications, other duty cycle combinations can be selected as needed, and more battery states can be extended (such as OT state corresponding to 30% high level and 70% low level, etc.). In addition, the specific order of the levels corresponding to different battery states within a cycle can be the same or different, mainly relying on the difference in duty cycle to distinguish the states. This application does not impose any restrictions on this.

[0077] Optionally, the PWM signal generated by the battery module sensing module may include, in addition to the PWM signal used to characterize the battery state as described in the previous embodiments (hereinafter referred to as the battery state PWM signal), the heartbeat PWM signal of the battery module sensing module. That is, the PWM signal generated by the battery module sensing module is a concatenation of the heartbeat PWM signal and the battery state PWM signal. In this way, the lag faults of the battery module sensing module can be reduced, the online working status and operational health of the battery module sensing module can be fed back in real time, and abnormal operating conditions such as module crashes, program freezes, and communication interruptions can be easily identified, enabling timely early warning and rapid fault location, thereby improving the operational stability, reliability, and fault tolerance of the battery management system.

[0078] In this implementation, when a communication connection anomaly occurs in the first communication link, the battery module sensing module is specifically used to acquire the battery status of the target battery module, generate a battery status PWM signal based on the battery status, and generate a heartbeat PWM signal corresponding to the battery module sensing module itself. This heartbeat PWM signal changes according to a preset rule in each communication cycle, for example, changing its duty cycle or encoding value periodically according to a cyclically increasing sequence or a pseudo-random sequence.

[0079] The battery module sensing module combines the heartbeat PWM signal and the battery status PWM signal in a preset order (e.g., heartbeat signal first, battery status signal second) to generate the PWM signal for the current communication cycle, and sends it to the next target module through the second communication link.

[0080] Specifically, in the PWM signals sent by each battery module sensing module, the heartbeat PWM signal includes its own heartbeat identifier, but does not include the heartbeat identifier of the upstream battery module sensing module; the battery status PWM signal adopts a step-by-step accumulation method, which includes the battery status data of all upstream battery module sensing modules as well as its own.

[0081] After receiving the PWM signal from the upstream, the downstream battery module sensing module or processing module first parses the heartbeat PWM signal and, based on the internally stored heartbeat change rules, determines whether the heartbeat signal has changed as expected compared to the previous communication cycle.

[0082] If the heartbeat signal changes normally according to a set pattern, it indicates that the upstream battery module sensing module is functioning well. If the heartbeat signals received in multiple consecutive communication cycles are identical (i.e., do not change according to a set pattern), it can be determined that the upstream battery module sensing module has experienced a jamming fault. This fault information can be further transmitted downstream by the downstream module through its own battery status PWM signal, and finally, the processing module outputs a corresponding abnormality prompt. Furthermore, even if the battery status PWM signal remains unchanged for multiple cycles due to slow changes in battery status, the periodic changes in the heartbeat signal can still prove to the receiver that the battery module sensing module is in normal working condition, thus avoiding misjudging normal conditions as faults.

[0083] The processing module receives the PWM signal from the end battery module sensing module, parses the end heartbeat PWM signal and monitors its periodic changes to confirm the working status of the end module; at the same time, the processing module extracts the battery status PWM signal of each battery module sensing module sequentially from the PWM signal and parses it to obtain the battery status of each battery module.

[0084] For example, taking the battery module sensing module as an analog front-end chip (AFE) as an example, the PWM signal generated by the AFE can be as shown in Table 3 below:

[0085] Table 3

[0086]

[0087] In this signal, 0101 represents the battery status PWM signal, assuming it indicates a battery state of 0V. When the AFE generates PWM signals in different cycles, it simultaneously generates the aforementioned battery status PWM signal (0V) and the heartbeat PWM signal (10, 01, 10, etc.). The AFE uses different heartbeat PWM signals for adjacent cycles to indicate that it is operating normally, avoiding misjudgments of stagnation or failure due to prolonged output of the same heartbeat signal, thus improving the system's accuracy in monitoring the AFE's health status. By observing the alternating changes in the heartbeat PWM signal between adjacent cycles (e.g., 10, 01, 10…), subsequent processing modules can determine whether the AFE is continuously operating normally. If the expected changing heartbeat signal is not received within a certain cycle, or if the signal remains unchanged, it can be determined that the AFE may have stagnation, crashes, or other faults, thereby triggering corresponding alarms or redundant processing mechanisms.

[0088] Correspondingly, for ease of understanding, Figure 4 This is a schematic diagram illustrating the structure of yet another PWM signal provided in an embodiment of this application. For example... Figure 4As shown, this PWM signal corresponds to the PWM signal design in Table 3 above. The PWM signal generated by the AFE in period t1 includes the preceding heartbeat PWM signal 10 and the following battery state PWM signal 0101 (representing that the battery state of the battery module corresponding to the AFE is 0V); the PWM signal generated by the AFE in period t2 includes the preceding heartbeat PWM signal 01 and the following battery state PWM signal 0101 (representing that the battery state of the battery module corresponding to the AFE is 0V); the PWM signal generated by the AFE in period t3 includes the preceding heartbeat PWM signal 10 and the following battery state PWM signal 0101 (representing that the battery state of the battery module corresponding to the AFE is 0V).

[0089] The battery management system provided in this application provides a real-time monitoring system for the transmission status of each module in the cascaded link and accurate identification of jamming faults by configuring an independent heartbeat PWM signal that changes every communication cycle for each battery module sensing module, and by having each module independently insert its own heartbeat during cascaded transmission and simultaneously accumulating the battery status PWM signal level by level. Downstream modules, by monitoring the periodic changes of the upstream heartbeat, can effectively distinguish between data stagnation and module jamming, avoiding misjudgments caused by slow changes in battery status, thereby improving the fault diagnosis capability and system robustness of the battery management system in the backup PWM communication mode.

[0090] Optional, Figure 5 This is a schematic diagram of another battery management system provided in an embodiment of this application, as shown below. Figure 5 As shown, the battery module sensing module is also connected to the previous target module via a reverse second communication link. This previous target module includes a processing module or another battery module sensing module. The battery module sensing module is also used to send PWM signals to the previous target module via the reverse second communication link.

[0091] exist Figure 5 In the structure shown, with Figure 1 In comparison, a second reverse communication link has been added. Figure 1 The second communication link can be considered a forward link, used to send PWM signals step-by-step from the end battery module sensing module (farthest from the processing module) towards the processing module. The reverse second communication link, on the other hand, sends PWM signals step-by-step from the beginning battery module sensing module (closest to the processing module) towards the end battery module sensing module. The two communication links are independent of each other. Each battery module sensing module is connected to both links and has the ability to send and receive PWM signals simultaneously or separately on both links.

[0092] By setting up a reverse second communication link, each battery module's sensing module can send PWM signals not only to the next target module (towards the processing module) but also to the previous target module (away from the processing module). This bidirectional redundancy structure ensures that data transmission can still be completed via the reverse link even if the forward second communication link fails.

[0093] Optionally, the reverse second communication link can also provide the processing module with the ability to diagnose and locate anomalies in the communication link itself. Specifically, the processing module can also be used for:

[0094] Receive a first PWM signal sent through a second communication link and a second PWM signal sent through a reverse second communication link; determine whether there is a difference between the battery status information corresponding to the first PWM signal and the battery status information corresponding to the second PWM signal; if there is a difference between the battery status information corresponding to the first PWM signal and the battery status information corresponding to the second PWM signal, output an abnormal prompt message according to the difference and the location of the difference.

[0095] Specifically, with Figure 5 Taking the structure shown as an example, assume that the entire cascaded system contains three battery module sensing modules: AFE1, AFE2, and AFE3. The processing module is simultaneously connected to the forward second communication link (from AFE1→AFE2→AFE3→processing module) and the reverse second communication link (from processing module→AFE1→AFE2→AFE3).

[0096] Under normal circumstances, the processing module can receive all PWM signals (first PWM signals) from AFE1, AFE2, and AFE3 via the forward link, and simultaneously receive all PWM signals (second PWM signals) from AFE1, AFE2, and AFE3 via the reverse link. Since the two links transmit the same battery status data (only in opposite directions), theoretically, the battery status information parsed by the processing module should be completely consistent.

[0097] The processing module can compare the battery status information obtained from parsing these two signals level by level and module by module. If it is found that the battery status reported by a certain battery module sensing module (e.g., AFE2) is 0101 (i.e., OV) in the forward link and 0011 (i.e., no anomaly) in the reverse link, it indicates that there is a discrepancy. In this case, the processing module can determine that there may be an anomaly in AFE2 itself or in the link between it and adjacent modules.

[0098] Furthermore, if the signal of AFE2 is lost in the forward link but the signal of AFE2 is normal in the reverse link, it can be preliminarily determined that there is a fault in the communication line from AFE2 to AFE3 in the forward link. The processing module generates targeted abnormal prompt information based on the specific nature of the discrepancy (such as data value deviation or signal loss) and the location of the battery module sensing module corresponding to the discrepancy (i.e., the location of the discrepancy).

[0099] This fault message can include the fault type (e.g., "AFE2 battery status reporting inconsistency"), fault location (e.g., "AFE2" or "forward link AFE2→AFE3 segment"), and possible causes. It is displayed on the instrument panel via the CAN bus or readable by an external diagnostic tool via the On-Board Diagnostic (OBD) interface. Maintenance personnel can quickly locate the fault based on this precise message, improving the maintainability of the battery system.

[0100] Through a bidirectional comparison mechanism, the embodiments of this application not only provide redundant data backup after a fault occurs, but also realize proactive health monitoring of the communication link and precise fault location, thereby further improving the reliability and diagnosability of the battery management system.

[0101] Optionally, the signal encoding rules for the first PWM signal transmitted via the second communication link and the second PWM signal transmitted via the reverse second communication link for the same battery state can be the same or different.

[0102] Specifically, in order to further improve the robustness and anti-interference capability of communication and avoid confusion or mutual interference between the forward and reverse PWM signals at the receiving end (e.g., when there is crosstalk between the two links), different encoding rules can be set for the forward link (second communication link) and the reverse link (reverse second communication link).

[0103] For example, when the duty cycle of the PWM signal corresponding to different battery states is the same but the level distribution is different, taking the PWM signal generated by a certain battery module sensing module as 4 bits, with high level recorded as 1 and low level recorded as 0, the PWM transmission encoding design in this application embodiment can be as shown in Table 4 below:

[0104] Table 4

[0105]

[0106] Correspondingly, for ease of understanding, Figure 6 This is a schematic diagram illustrating the structure of another PWM signal provided in an embodiment of this application. For example... Figure 6 As shown, corresponding to Table 4 above, the signal encoding for the same battery state is different in forward PWM and reverse PWM.

[0107] For example, when the PWM signal includes a heartbeat PWM signal, the PWM transmission encoding design in the embodiments of this application can also be as shown in Table 5 below:

[0108] Table 5

[0109]

[0110] Correspondingly, for ease of understanding, Figure 7 This is a schematic diagram illustrating the structure of another PWM signal provided in an embodiment of this application. For example... Figure 7 As shown, corresponding to Table 5 above, the signal encoding for the same battery state is different in forward PWM and reverse PWM, while the heartbeat PWM signal for the same period is the same.

[0111] When the processing module receives signals from two links, its internal parsing process can automatically distinguish the signals due to the different encoding rules, effectively preventing "echo" interference or logical confusion caused by signals with the same frequency and code, thereby further enhancing the identification capability and fault tolerance of the battery management system.

[0112] The battery management system provided in this application constructs a fully redundant, self-diagnostic communication network by setting up a bidirectional second communication link and using differentiated coding rules. This enables the processing module to compare the consistency of data from both paths, locate faulty nodes in the link, and output corresponding error messages, thereby further improving the reliability, safety, and maintainability of the battery management system.

[0113] For ease of understanding, an exemplary structure of a battery management system according to an embodiment of this application is provided below. Figure 8 This is a schematic diagram of another battery management system provided in an embodiment of this application. Figure 8 As shown, the battery management system includes three battery module sensing modules, namely AFE#1, AFE#2 and AFE#3, as well as a processing module (i.e. MCU).

[0114] Among them, AFE#1 obtains the battery status of its corresponding battery module as OV, AFE#2 obtains the battery status of its corresponding battery module as Normal, and AF1#3 obtains the battery status of its corresponding battery module as OT.

[0115] The second communication link is a forward link, with data transmission direction AFE#1→AFE#2→AFE#3→MCU; the reverse second communication link is a reverse link, with data transmission direction AFE#3→AFE#2→AFE#1→MCU.

[0116] When a fault occurs in the first communication link of the battery management system, during the first cycle, AFE#1 generates a battery status PWM signal 0101 corresponding to OV and a heartbeat PWM signal 10 corresponding to the first cycle in the forward link, combining them into a PWM signal 10 0101, and sends this PWM signal to AFE#2 through the forward link. Then, AFE#2 generates a battery status PWM signal 0011 corresponding to no fault and a heartbeat PWM signal 10 corresponding to the first cycle, combining them into a PWM signal 1001010011, and sends this PWM signal to AFE#3 through the forward link. Next, AFE#3 generates a battery status PWM signal 1001 corresponding to OT and a heartbeat PWM signal 10 corresponding to the first cycle, combining them into a PWM signal 10 010100111001. This PWM signal is then sent to the MCU via the forward link. By parsing the PWM signal received from AFE#3, the MCU can determine the battery status of the battery modules corresponding to AFE#1, AFE#2, and AFE#3, and output corresponding error messages to indicate that the battery module corresponding to AFE#1 has an OV (Out of Voltage) error and the battery module corresponding to AFE#3 has an OT (Over-Temperature) error. Correspondingly, the difference in the PWM signals transmitted in the forward link during the second and third cycles lies only in the heartbeat PWM signal that changes with the cycle; this will not be elaborated further here.

[0117] During the first cycle, AFE#3 generates a battery status PWM signal 1001 corresponding to OT and a heartbeat PWM signal 10 corresponding to the first cycle in the reverse link, combining them into a PWM signal 10 1001, and sends this PWM signal to AFE#2 through the reverse link. Next, AFE#2 generates a battery status PWM signal 0011 corresponding to no anomaly and a heartbeat PWM signal 10 corresponding to the first cycle, combining them into a PWM signal 10 10010011, and sends this PWM signal to AFE#1 through the reverse link. Next, AFE#1 generates a battery status PWM signal 0101 corresponding to OV and a heartbeat PWM signal 10 corresponding to the first cycle, combining them into a PWM signal 10 100100110101. This PWM signal is then sent to the MCU via the reverse link. By parsing the PWM signal received from AFE#1, the MCU can determine the battery status of the battery modules corresponding to AFE#1, AFE#2, and AFE#3, and output corresponding error messages to indicate that the battery module corresponding to AFE#1 has an OV abnormality and the battery module corresponding to AFE#3 has an OT abnormality. Correspondingly, the difference in the PWM signals transmitted in the reverse link during the second and third cycles lies only in the heartbeat PWM signal that changes with the cycle, which will not be elaborated here.

[0118] Optionally, the battery module sensing module can also be specifically used to: acquire the cell status of each target cell in the target battery module. When there is a communication connection anomaly in the first communication link, a cell status PWM signal is generated based on the cell status, and a PWM signal is generated based on the cell status PWM signals.

[0119] Specifically, a battery module typically consists of multiple cells connected in series or parallel. A high-precision battery management system needs to monitor the status of each cell (i.e., the target cell). The battery module sensing module can be, for example, an integrated multi-channel AFE (Automatic Front-End Controller) used to poll and collect battery status data for each cell within the battery module.

[0120] When the first communication link is normal, the battery module sensing module can transmit the battery status of each cell through the first communication link. When the first communication link is abnormal, it can switch to the PWM mode of the second communication link. In this mode, the battery module sensing module can further increase the period of the PWM signal, so that each period corresponds to a cell. This allows the PWM signal generated by the battery module sensing module (such as the battery status PWM signal part included in the PWM signal) to correspond to the battery status of different cells under the battery module through different periods.

[0121] For example, Figure 9 This is a schematic diagram illustrating the structure of another PWM signal provided in an embodiment of this application. For example... Figure 9 As shown, a certain battery module sensing module corresponds to a battery module containing 5 cells (Cell#1, Cell#2, Cell#3, Cell#4, Cell#5). The PWM signal or battery status PWM signal generated by the battery module sensing module corresponds to the battery status of each cell through five cycles. That is, in cycle 1, the level is 50% high and 50% low, which indicates that the battery status of Cell#1 is normal; in cycle 2, the level is 20% high and 80% low, which indicates that the battery status of Cell#2 is UV; in cycle 3, the level is 50% high and 50% low, which indicates that the battery status of Cell#3 is normal; in cycle 4, the level is 80% high and 20% low, which indicates that the battery status of Cell#4 is 0V; and in cycle 5, the level is 50% high and 50% low, which indicates that the battery status of Cell#5 is normal.

[0122] The system provided in this application embodiment uses time-division multiplexing of the PWM signals of each cell's status, so that even in the event of a failure of the first communication link, the battery management system can still monitor the health status of each cell in the battery pack in detail, thereby further improving the accuracy of battery fault detection.

[0123] This application also provides a battery system, which includes a battery management system as described in any of the foregoing embodiments.

[0124] This application also provides an electrical device that includes a battery management system as described in any of the foregoing embodiments, or includes the aforementioned battery system.

[0125] The division of units in the embodiments of this application is merely a logical functional division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interfaces, devices, or units, and may be electrical, mechanical, or other forms.

[0126] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0127] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0128] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0129] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0130] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A battery management system, characterized in that, The battery management system includes: a processing module and at least two battery module sensing modules cascaded in sequence; The battery module sensing module is connected to the next target module via a first communication link and a second communication link, respectively. The next target module includes the processing module or another battery module sensing module. The battery module sensing module is used to obtain the battery status of the target battery module in the battery pack, and when there is a communication connection abnormality in the first communication link, it generates a PWM signal according to the battery status and sends the PWM signal to the next target module through the second communication link. The processing module is used to receive the PWM signal sent by the battery module sensing module, parse the PWM signal to obtain the battery status of each battery module in the battery pack, and output the battery status.

2. The system according to claim 1, characterized in that, The duty cycle of the PWM signal is the same but the level distribution is different for different battery states.

3. The system according to claim 1, characterized in that, The duty cycles of the PWM signals corresponding to at least two battery states are different.

4. The system according to claim 1, characterized in that, When a communication connection anomaly occurs in the first communication link, the battery module sensing module is specifically used for: Generate a battery status PWM signal based on the battery status; A heartbeat PWM signal is generated, which is different from the heartbeat PWM signal of the adjacent battery module sensing module of the battery module sensing module; The PWM signal is generated based on the battery status PWM signal and the heartbeat PWM signal.

5. The battery management system according to claim 1, characterized in that, The battery module sensing module is also connected to the previous target module via a reverse second communication link. The previous target module includes the processing module or another battery module sensing module. The battery module sensing module is also used to send the PWM signal to the previous target module through the reverse second communication link.

6. The battery management system according to claim 5, characterized in that, The processing module is further configured to: Receive a first PWM signal transmitted via the second communication link and a second PWM signal transmitted via the reverse second communication link; Determine whether there are any differences between the battery status information corresponding to the first PWM signal and the battery status information corresponding to the second PWM signal; If there are differences between the battery status information corresponding to the first PWM signal and the battery status information corresponding to the second PWM signal, an abnormal prompt message is output based on the differences and their locations.

7. The battery management system according to claim 5, characterized in that, The first PWM signal transmitted via the second communication link has a different signal encoding rule for the same battery state than the second PWM signal transmitted via the reverse second communication link.

8. The battery management system according to any one of claims 1-7, characterized in that, The battery module sensing module is specifically used for: Obtain the cell status of each target cell in the target battery module; When there is a communication connection abnormality in the first communication link, a battery cell status PWM signal is generated according to the battery cell status. The PWM signal is generated based on the PWM signal of each cell state.

9. A battery system, characterized in that, The battery system includes a battery management system as described in any one of claims 1-8.

10. An electrical appliance, characterized in that, The electrical equipment includes a battery management system as described in any one of claims 1-8.

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