Battery management system and battery management methods

Abstract

This disclosure provides a battery management system and a battery management method, belonging to the field of electric vehicle technology. By adopting this solution, an independent memory is added. The storage space of this independent memory can be much larger than the controller's built-in cache. This allows the memory to store fault information corresponding to multiple failures of the low-voltage battery within a certain period, as well as the low-voltage battery's state information during that period. During fault repair, this information can better assist repair personnel in more comprehensively identifying each faulty component.

Description

Technical Field

[0001] This disclosure relates to the field of electric vehicle technology, and in particular to a battery management system and a method for battery management. Background Technology

[0002] Electric vehicles consist of low-voltage batteries and high-voltage batteries. Low-voltage batteries can power low-voltage electrical equipment inside the vehicle, while high-voltage batteries can charge low-voltage batteries. When a low-voltage battery malfunctions, charging and discharging of the low-voltage battery must be stopped.

[0003] In related technologies, the controller monitors the relevant parameters of the low-voltage battery in real time, analyzes the fault information of the low-voltage battery, stores it in the controller's built-in cache, and controls the charging and discharging switch of the low-voltage battery according to the stored current fault information. At the same time, it will send a prompt signal to the user (such as a fault light). After a fault occurs, the user can send the vehicle for repair. The repair personnel will determine the faulty component based on the fault information in the cache and their own experience, and then perform repairs.

[0004] The controller's built-in cache space is very small, so when new fault information needs to be stored, the old fault information will be overwritten with the new fault information. However, it is difficult to accurately locate all faulty components based solely on the latest fault information. For example, multiple faults may have occurred before the vehicle was sent for repair, and different components may have failed. Currently, only the most recent faulty component can be located. Summary of the Invention

[0005] This disclosure provides a battery management system and a battery management method, which can solve the aforementioned technical problems existing in related technologies. The technical solution is as follows:

[0006] In a first aspect, a battery management system is provided, the battery management system including a low-voltage battery (1), a detection component (2), a controller (3), a memory (4), a charging switch (5), and a discharging switch (6);

[0007] The detection component (2) is electrically connected to the low-voltage battery (1) and the controller (3) respectively. The detection component (2) is used to detect the status information of the low-voltage battery (1), wherein the status information includes current, voltage and cell temperature, and sends it to the controller (3).

[0008] The charging switch (5) is used to control the on / off connection of the low-voltage battery (1) and the high-voltage battery.

[0009] The discharge switch (6) is used to control the on / off connection of the low-voltage battery (1) and the low-voltage load.

[0010] The controller (3) is electrically connected to the detection component (2), the memory (4), the charging switch (5), and the discharging switch (6) respectively. The controller (3) is used to: store the received status information into the memory (4); when the status information meets the target status condition, determine the fault information based on the status information that meets the status condition, store the fault information into the memory (4), and control the charging switch (5) and / or the discharging switch (6) based on the fault information.

[0011] In one possible implementation, the controller (3) includes a control chip (31) and a driver chip (32);

[0012] The control chip (31) is electrically connected to the drive chip (32) and the detection component (2) respectively. The control chip (31) is used to store the received status information into the memory (4). When the status information meets the target status condition, the fault information is determined based on the status information that meets the target status condition, and the fault information is stored into the memory (4). The control command is determined based on the fault information and the control command is sent to the drive chip (32).

[0013] The driving chip (32) is electrically connected to the charging switch (5) and the discharging switch (6) respectively. The driving chip (32) is used to control the charging switch (5) and / or the discharging switch (6) based on the control command.

[0014] In one possible implementation, the controller (3) is used to:

[0015] When a target state condition exists in the first correspondence between pre-stored state conditions, state information ranges and fault levels, such that the currently received state information satisfies the target state condition, the target fault level corresponding to the target state information range to which the target state condition and the currently received state information belong is determined in the first correspondence.

[0016] Based on the second correspondence between pre-stored state conditions and fault types, the target fault type corresponding to the target state condition is determined;

[0017] The target fault type and the target fault level are determined as fault information.

[0018] In one possible implementation, the controller (3) is used to:

[0019] When the target state condition is that the discharge current is greater than the first discharge current threshold, the corresponding target fault type is determined to be a short circuit fault.

[0020] When the target state condition is that the total battery voltage is less than the total voltage threshold, the corresponding target fault type is determined to be an undervoltage fault.

[0021] When the target state condition is that the cell voltage is greater than the cell voltage threshold, the corresponding target fault type is determined to be an overvoltage fault.

[0022] When the target state condition is that the charging current is greater than the charging current threshold, the corresponding target fault type is determined to be a charging overcurrent fault.

[0023] When the target state condition is that the discharge current is greater than the second discharge current threshold, the corresponding target fault type is determined to be a discharge overcurrent fault.

[0024] When the target state condition is that the cell temperature is greater than the cell temperature threshold, the corresponding target fault type is determined to be an over-temperature fault.

[0025] When the target state condition is that the cell temperature is greater than the cell temperature threshold and the rate of temperature increase is greater than the rate of temperature increase threshold for a continuous period of time, the corresponding target fault type is determined to be thermal runaway fault.

[0026] In one possible implementation, the controller (3) is used to:

[0027] When a target state condition exists in the first correspondence between pre-stored state conditions, state information ranges, fault levels and detection durations, such that the currently received state information satisfies the target state condition, the target fault level and target detection duration corresponding to the target state information range to which the target state condition and the currently received state information belong are determined in the first correspondence. In the first correspondence, the fault level and the target detection duration are negatively correlated.

[0028] If all the state information received within the target detection time meets the target state condition, then the target fault type corresponding to the target state condition is determined based on the second correspondence between the pre-stored state condition and the fault type.

[0029] In one possible implementation, the controller (3) is used to:

[0030] Based on the third correspondence between fault type and control command, the target control command corresponding to the target fault type is determined, and the charging switch (5) and / or discharging switch (6) are controlled based on the target control command.

[0031] In one possible implementation method

[0032] The fault types include undervoltage fault, short circuit fault, overvoltage fault, charging overcurrent fault, discharging overcurrent fault, overtemperature fault, and thermal runaway fault.

[0033] The controller (3) is used for:

[0034] When the target fault type is an undervoltage fault, the target control command is determined to be to disconnect the discharge switch (6);

[0035] When the target fault type is a short circuit fault, the target control command is determined to be to disconnect the charging switch (5) and the discharging switch (6);

[0036] When the target fault type is an overvoltage fault, the target control command is determined to be to disconnect the charging switch (5);

[0037] When the target fault type is a charging overcurrent fault, the target control command is determined to be to disconnect the charging switch (5);

[0038] When the target fault type is a discharge overcurrent fault, the target control command is determined to be to disconnect the discharge switch (6);

[0039] When the target fault type is an over-temperature fault or a thermal runaway fault, the target control command is determined to be to disconnect the charging switch (5) and the discharging switch (6).

[0040] In one possible implementation, the controller (3) is used to:

[0041] When the target fault type is an over-temperature fault or a thermal runaway fault, if both the charging switch (5) and the discharging switch (6) are in the connected state, the current value of the line connecting the high-voltage battery and the low-voltage battery (1) and the current value of the line connecting the low-voltage load and the low-voltage battery (1) are determined. When the current value of the line connecting the high-voltage battery and the low-voltage battery (1) is greater than the first current threshold, the target control command is determined to include disconnecting the charging switch (5). When the current value of the line connecting the low-voltage load and the low-voltage battery (1) is greater than the second current threshold, the target control command is determined to include disconnecting the discharging switch (6). If one of the charging switch (5) and the discharging switch (6) is in the connected state, the target control command is determined to be disconnecting the one switch.

[0042] In one possible implementation, the controller (3) is used to:

[0043] When the target fault type is an over-temperature fault or a thermal runaway fault, if both the charging switch (5) and the discharging switch (6) are in the connected state, the target control command is determined to be to disconnect the discharging switch (6). After executing the target control command, if no received status information is detected that meets the target status condition, the switch state remains unchanged. If the received status information is detected again that meets the target status condition, the target control command is re-determined to be to connect the discharging switch (6) and disconnect the charging switch (5). After executing the target control command, if no received status information is detected that meets the target status condition, the switch state remains unchanged. If the received status information is detected again that meets the target status condition, the target control command is re-determined to be to disconnect the charging switch (5) and the discharging switch (6). If one of the charging switch (5) and the discharging switch (6) is in the connected state, the target control command is determined to be to disconnect the one switch.

[0044] In one possible implementation, the battery management system further includes a communication component (7) and a fault light (8);

[0045] The communication component (7) is electrically connected to the controller (3) and the fault lamp (8) respectively;

[0046] The controller (3) is also used to: when the status information meets the target status conditions, send a target indication signal to the fault lamp (8) through the communication component (7) so that the fault lamp (8) emits a light signal based on the target indication signal.

[0047] Secondly, a battery management method is provided, the method being applied to a battery management system, the battery management system including a low-voltage battery (1), a detection component (2), a controller (3), a memory (4), a charging switch (5), and a discharging switch (6), the method comprising:

[0048] The detection component (2) detects the status information of the low-voltage battery (1), wherein the status information includes current, voltage and cell temperature, and sends it to the controller (3);

[0049] The controller (3) stores the received status information into the memory (4). When the status information meets the target status conditions, it determines the fault information based on the status information that meets the status conditions, stores the fault information into the memory (4), and controls the charging switch (5) and / or the discharging switch (6) based on the fault information.

[0050] In one possible implementation, determining fault information based on the state information that satisfies the target state condition when the state information satisfies the state condition includes:

[0051] When a target state condition exists in the first correspondence between pre-stored state conditions, state information ranges and fault levels, such that the currently received state information satisfies the target state condition, the target fault level corresponding to the target state information range to which the target state condition and the currently received state information belong is determined in the first correspondence.

[0052] Based on the second correspondence between pre-stored state conditions and fault types, the target fault type corresponding to the target state condition is determined;

[0053] The target fault type and the target fault level are determined as fault information.

[0054] In one possible implementation, determining the target fault type corresponding to the target state condition based on a pre-stored second correspondence between state conditions and fault types includes:

[0055] When the target state condition is that the discharge current is greater than the first discharge current threshold, the corresponding target fault type is determined to be a short circuit fault.

[0056] When the target state condition is that the total battery voltage is less than the total voltage threshold, the corresponding target fault type is determined to be an undervoltage fault.

[0057] When the target state condition is that the cell voltage is greater than the cell voltage threshold, the corresponding target fault type is determined to be an overvoltage fault.

[0058] When the target state condition is that the charging current is greater than the charging current threshold, the corresponding target fault type is determined to be a charging overcurrent fault.

[0059] When the target state condition is that the discharge current is greater than the second discharge current threshold, the corresponding target fault type is determined to be a discharge overcurrent fault.

[0060] When the target state condition is that the cell temperature is greater than the cell temperature threshold, the corresponding target fault type is determined to be an over-temperature fault.

[0061] When the target state condition is that the cell temperature is greater than the cell temperature threshold and the rate of temperature increase is greater than the rate of temperature increase threshold for a continuous period of time, the corresponding target fault type is determined to be thermal runaway fault.

[0062] In one possible implementation, when a target state condition exists in the pre-stored first correspondence between state conditions, state information ranges, and fault levels, such that the currently received state information satisfies the target state condition, determining the target fault level corresponding to the target state information range to which the target state condition and the currently received state information belong in the first correspondence includes:

[0063] When a target state condition exists in the first correspondence between pre-stored state conditions, state information ranges, fault levels and detection durations, such that the currently received state information satisfies the target state condition, the target fault level and target detection duration corresponding to the target state information range to which the target state condition and the currently received state information belong are determined in the first correspondence. In the first correspondence, the fault level and the target detection duration are negatively correlated.

[0064] The determination of the target fault type corresponding to the target state condition based on the second correspondence between pre-stored state conditions and fault types includes:

[0065] If all the state information received within the target detection time meets the target state condition, then the target fault type corresponding to the target state condition is determined based on the second correspondence between the pre-stored state condition and the fault type.

[0066] In one possible implementation, controlling the charging switch (5) and / or discharging switch (6) based on the fault information includes:

[0067] Based on the third correspondence between fault type and control command, the target control command corresponding to the target fault type is determined, and the charging switch (5) and / or discharging switch (6) are controlled based on the target control command.

[0068] In one possible implementation, the fault types include undervoltage fault, short circuit fault, overvoltage fault, charging overcurrent fault, discharging overcurrent fault, overtemperature fault, and thermal runaway fault.

[0069] The determination of the target control command corresponding to the target fault type based on the third correspondence between fault type and control command includes:

[0070] When the target fault type is an undervoltage fault, the target control command is determined to be to disconnect the discharge switch (6);

[0071] When the target fault type is a short circuit fault, the target control command is determined to be to disconnect the charging switch (5) and the discharging switch (6);

[0072] When the target fault type is an overvoltage fault, the target control command is determined to be to disconnect the charging switch (5);

[0073] When the target fault type is a charging overcurrent fault, the target control command is determined to be to disconnect the charging switch (5);

[0074] When the target fault type is a discharge overcurrent fault, the target control command is determined to be to disconnect the discharge switch (6);

[0075] When the target fault type is an over-temperature fault or a thermal runaway fault, the target control command is determined to be to disconnect the charging switch (5) and the discharging switch (6).

[0076] In one possible implementation, the battery management system further includes a communication component (7) and a fault light (8), and the method further includes;

[0077] When the status information meets the target status conditions, the controller (3) sends a target indication signal to the fault lamp (8) through the communication component (7) so that the fault lamp (8) emits a light signal based on the target indication signal.

[0078] In this disclosure, an independent memory is added. The storage space of the independent memory can be much larger than the cache built into the controller. In this way, the memory can store the fault information corresponding to multiple failures of the low-voltage battery within a certain period of time and the status information of the low-voltage battery during this period of time. During the fault repair process, this information can better assist the repair personnel in more comprehensively identifying each faulty component. Attached Figure Description

[0079] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0080] Figure 1 This is a schematic diagram showing the location of a battery management system provided in an embodiment of this disclosure;

[0081] Figure 2 This is a schematic diagram of the structure of a battery management system shown in an embodiment of this disclosure;

[0082] Figure 3 This is a schematic diagram of the structure of a controller 3 shown in an embodiment of this disclosure;

[0083] Figure 4 This is a schematic diagram of the structure of a battery management system shown in an embodiment of this disclosure;

[0084] Figure 5 This is a schematic diagram of the structure of a battery management system shown in an embodiment of this disclosure;

[0085] Figure 6 This is a schematic diagram of a processing flow for determining control commands, as shown in an embodiment of this disclosure;

[0086] Figure 7 This is a schematic diagram of the structure of a battery management system shown in an embodiment of this disclosure.

[0087] Figure label:

[0088] 1. Low-voltage battery;

[0089] 2. Detection components;

[0090] 3. Controller; 31. Control chip; 32. Driver chip; 33. Interference removal chip;

[0091] 4. Memory;

[0092] 5. Charging switch;

[0093] 6. Discharge switch;

[0094] 7. Communication components;

[0095] 8. Fault light. Detailed Implementation

[0096] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0097] Electric vehicles consist of low-voltage and high-voltage batteries. The low-voltage battery supplies power to low-voltage electrical equipment within the vehicle, while the high-voltage battery charges the low-voltage battery. When a low-voltage battery malfunctions, its charging and discharging must be stopped. In related technologies, the controller monitors relevant parameters of the low-voltage battery in real time, analyzes fault information, stores it in its built-in cache, and controls the charging and discharging switch of the low-voltage battery based on the stored fault information. After a fault occurs, repair personnel, based on the fault information in the cache and their experience, identify the faulty component and perform repairs. The controller's built-in cache space is small, so when new fault information needs to be stored, the old fault information is overwritten. However, relying solely on the most recent fault information makes it difficult to accurately locate all faulty components. For example, if multiple faults occurred before the vehicle was sent for repair, and different components failed, only the most recent faulty component can be identified.

[0098] To address the aforementioned issues, this disclosure provides a battery management system, in which the vehicle's low-voltage electrical system is applied, for example... Figure 1 As shown, the battery management system includes a low-voltage battery 1, a detection component 2, a controller 3, a memory 4, a charging switch 5, and a discharging switch 6. The low-voltage battery 1 is located in the vehicle's engine compartment. The detection component 2, controller 3, memory 4, charging switch 5, and discharging switch 6 are respectively installed near the low-voltage battery 1. The distribution of the vehicle's low-voltage electrical system on the vehicle can be, for example... Figure 1 As shown, the detection component 2, controller 3, memory 4, charging switch 5, and discharging switch 6 are all located in... Figure 1 The location of detection component 2 is specified. Detection component 2 is electrically connected to both the low-voltage battery 1 and the controller 3. Detection component 2 detects the status information of the low-voltage battery 1, including current, voltage, and cell temperature, and sends this information to the controller 3. Detection component 2 can detect the status information of the low-voltage battery 1 in real time or periodically. The detection period can be preset by technicians, for example, 10 milliseconds. Detection component 2 may include current sensors, voltage sensors, and temperature sensors. The current sensor detects the discharge current and charging current, the voltage sensor detects the total battery voltage and cell voltage, and the temperature sensor detects the cell temperature. Charging switch 5 is used to control the electrical connection between the low-voltage battery 1 and the high-voltage battery. When the remaining charge percentage of the low-voltage battery 1 is lower than a threshold, the high-voltage battery can charge the low-voltage battery 1. Discharge switch 6 is used to control the electrical connection between the low-voltage battery 1 and the low-voltage load. The vehicle has multiple low-voltage loads, such as speakers and instrument displays. Low-voltage battery 1 is electrically connected to each of these low-voltage loads. When the user starts a low-voltage load, low-voltage battery 1 can supply power to it. Controller 3 is electrically connected to detection component 2, memory 4, charging switch 5, and discharging switch 6, respectively. Figure 2 As shown. Controller 3 is used to store the received status information into memory 4. When the status information meets the target status conditions, it determines the fault information based on the status information that meets the status conditions, stores the fault information into memory 4, and controls the charging switch 5 and / or the discharging switch 6 based on the fault information.

[0099] In one possible implementation, such as Figure 3As shown, the controller 3 includes a control chip 31 and a driver chip 32. The control chip 31 is electrically connected to the driver chip 32 and the detection component 2, respectively. The control chip 31 is used to store the received status information into the memory 4. When the status information meets the target status condition, based on the status information that meets the target status condition, fault information is determined and stored in the memory 4. Based on the fault information, a control command is determined and sent to the driver chip 32. The driver chip 32 is electrically connected to the charging switch 5 and the discharging switch 6, respectively. The driver chip 32 is used to control the charging switch 5 and / or the discharging switch 6 based on the control command.

[0100] The control chip 31 can perform various calculations, receive and store the collected data, etc.

[0101] The control chip 31 may include a processor 311 and a memory 312, such as Figure 4 As shown.

[0102] The processor 311 can be a central processing unit (CPU) or a system on chip (SoC), etc. The processor 311 can be used to process various operation instructions, such as determining whether the received status information meets the status conditions.

[0103] The memory 312 may include various volatile or non-volatile memories, such as solid-state disks (SSDs) and dynamic random access memory (DRAM). The memory 312 can be used to store initial data, intermediate data, and result data used in related processing, such as pre-storing state conditions, state information ranges, and the first correspondence between fault levels.

[0104] In one possible implementation, since control commands may encounter interference signals during transmission, controller 3 may also include a de-interference chip 33, such as... Figure 5As shown, the interference removal chip 33 is electrically connected to both the control chip 31 and the driver chip 3. The interference removal chip 33 processes the control commands issued by the control chip 31, removing interference signals other than the control commands from the signals issued by the control chip 31. It then sends the interference-removed control commands to the driver chip 32. Optionally, there can be two interference removal chips 33, one as the primary interference removal chip and the other as a backup. The control chip 31 sends the control commands to both interference removal chips 33 simultaneously. After receiving the control commands, the two interference removal chips 33 process the control commands to remove interference and then send the interference-removed control commands to the driver chip 32. In this way, the interference removal chip 33 can remove interference signals from the environment and improve the signal quality of the control commands.

[0105] In one possible implementation, controller 3 determines the processing flow of control commands as follows: Figure 6 As shown, it includes the following steps:

[0106] 601, When the controller 3 has a target state condition in the first correspondence between the pre-stored state conditions, state information range and fault level, such that the currently received state information meets the target state condition, it determines the target fault level corresponding to the target state information range to which the target state condition and the currently received state information belong in the first correspondence.

[0107] The same state conditions can include different fault levels, and within the same state conditions, different ranges of state information correspond to different fault levels. The first correspondence between state conditions, state information ranges, fault levels, and detection duration can be shown in Table 1, for example.

[0108] Table 1

[0109]

[0110] After receiving the status information, controller 3 compares the status information with the status conditions one by one. If a target status condition exists in the pre-stored first correspondence between status conditions, status information ranges, fault levels, and detection durations, and the currently received status information meets the target status condition, then the controller determines the target fault level and target detection duration corresponding to the target status information range to which the target status condition and the currently received status information belong in the first correspondence. In the first correspondence, the fault level and the target detection duration are negatively correlated. For example, if the charging current in the status information currently received by controller 3 is 215 amps, and the target status condition is "charging current greater than 200 amps", and the target status information range is further determined to be "(210, 220]" in the first correspondence, then the corresponding target fault level is level two, and the target detection duration is 15 seconds.

[0111] 602, The controller 3 determines the target fault type corresponding to the target state condition based on the second correspondence between the pre-stored state conditions and fault types.

[0112] If all the state information received within the target detection time meets the target state condition, then the target fault type corresponding to the target state condition is determined based on the second correspondence between the pre-stored state condition and the fault type.

[0113] When the target state condition is that the discharge current is greater than the first discharge current threshold, the corresponding target fault type is determined to be a short circuit fault. When the target state condition is that the total battery voltage is less than the total voltage threshold, the corresponding target fault type is determined to be an undervoltage fault. When the target state condition is that the cell voltage is greater than the cell voltage threshold, the corresponding target fault type is determined to be an overvoltage fault. When the target state condition is that the charging current is greater than the charging current threshold, the corresponding target fault type is a charging overcurrent fault. When the target state condition is that the discharge current is greater than the second discharge current threshold, the corresponding target fault type is a discharge overcurrent fault, where the second discharge current threshold is less than the first discharge current threshold. When the target state condition is that the cell temperature is greater than the cell temperature threshold, the corresponding target fault type is an overtemperature fault. When the target state condition is that the cell temperature is greater than the cell temperature threshold and the rate of temperature increase is continuously greater than the rate of temperature increase threshold within the target duration, the corresponding target fault type is a thermal runaway fault. The second correspondence between state conditions and fault types can be shown in Table 2, for example, with different state conditions corresponding to different fault types.

[0114] Table 2

[0115]

[0116]

[0117] If a second detection duration exists within the first detection duration (target detection duration), and in the first correspondence, the second detection duration and the target state condition correspond to the second fault level and the second state information range, and all state information received within the second detection duration meets the second state information range, then at the end of the second detection duration, the first fault type and the second fault level are determined as fault information, the fault information is stored in the memory 4, and based on the fault information, the charging switch 5 and / or the discharging switch 6 are controlled. The second detection duration is shorter than the first detection duration (target detection duration).

[0118] 603, Controller 3 determines the target fault type and target fault level as fault information.

[0119] The controller 3 sends the fault information to the memory 4 for storage.

[0120] 604. The controller 3 determines the target control command corresponding to the target fault type based on the third correspondence between the fault type and the control command, and controls the charging switch 5 and / or the discharging switch 6 based on the target control command.

[0121] The third correspondence between fault types and control commands can be shown in Table 3.

[0122] Table 3

[0123] Fault type Control commands Short circuit Disconnect charging switch 5 and discharging switch 6 undervoltage Disconnect discharge switch 6 …… ……

[0124] Fault types include undervoltage fault, short circuit fault, overvoltage fault, charging overcurrent fault, discharging overcurrent fault, overtemperature fault, and thermal runaway fault. When the target fault type is undervoltage fault, the target control command is to disconnect discharge switch 6. When the target fault type is short circuit fault, the target control command is to disconnect both charging switch 5 and discharge switch 6. When the target fault type is overvoltage fault, the target control command is to disconnect charging switch 5. When the target fault type is charging overcurrent fault, the target control command is to disconnect charging switch 5. When the target fault type is discharging overcurrent fault, the target control command is to disconnect discharge switch 6.

[0125] When the target fault type is an over-temperature fault or a thermal runaway fault, the target control command corresponding to the current target operating condition and target fault type of the low-voltage battery 1 is determined based on the fourth correspondence between the operating condition, fault type and control command of the low-voltage battery 1.

[0126] Table 4

[0127]

[0128] When the target fault type is an over-temperature fault or a thermal runaway fault, if both charging switch 5 and discharging switch 6 are in the connected state, the current value of the connection line between the high-voltage battery and the low-voltage battery 1 and the current value of the connection line between the low-voltage load and the low-voltage battery 1 are determined. When the current value of the connection line between the high-voltage battery and the low-voltage battery 1 is greater than the first current threshold, the target control command is determined to include disconnecting charging switch 5. When the current value of the connection line between the low-voltage load and the low-voltage battery 1 is greater than the second current threshold, the target control command is determined to include disconnecting discharging switch 6. If one of the charging switch 5 and the discharging switch 6 is in the connected state, the target control command is determined to be to disconnect one switch.

[0129] Optionally, when the target fault type is an over-temperature fault or a thermal runaway fault, if both charging switch 5 and discharging switch 6 are in the connected state, the target control command is determined to be to disconnect discharging switch 6. After executing the target control command, if no received status information is detected that meets the target status condition, the switch state remains unchanged. If the received status information is detected again that meets the target status condition, the target control command is redefined to be to connect discharging switch 6 and disconnect charging switch 5. After executing the target control command, if no received status information is detected that meets the target status condition, the switch state remains unchanged. If the received status information is detected again that meets the target status condition, the target control command is redefined to be to disconnect charging switch 5 and discharging switch 6. If one of the charging switch 5 and discharging switch 6 is in the connected state, the target control command is determined to be to disconnect one switch.

[0130] Different fault types correspond to different faulty components. Undervoltage, overvoltage, and discharge overcurrent faults correspond to the controller; short-circuit faults correspond to the low-voltage battery (where the distance between the positive and negative terminals of the low-voltage battery connected to the electrical equipment is too small); and charging overcurrent, overtemperature, and thermal runaway faults also correspond to the low-voltage battery. Controller 3 can send the status and fault information stored in memory 4 for a specified historical period to the target device. The specified historical period can be set before the vehicle leaves the factory. The target device displays the status and fault information within the specified historical period. The faulty component can be determined by maintenance personnel based on the status and fault information, and the target device receives the input faulty component. Alternatively, a machine learning model can determine the faulty component. The status and fault information within the specified historical period are input into the faulty component determination model, and the model outputs the faulty component. The faulty component determination model can be a decision tree model, convolutional neural network, etc. For example, if the fault type is thermal runaway, the maintenance personnel can check the table to determine that the corresponding faulty component is the low-voltage battery. Then, based on the cell temperatures of multiple low-voltage batteries sampled in the status information, they can further determine the location of the low-voltage battery with the highest cell temperature where the fault occurred.

[0131] In one possible implementation, the battery management system also includes a communication component 7 and a fault indicator 8, for example... Figure 7 As shown. The communication component 7 is electrically connected to the control chip 31 and the fault lamp 8, respectively. The fault lamp 8 can be installed on the dashboard. When the status information meets the target status conditions, the controller 3 sends a target indication signal to the fault lamp 8 through the communication component 7, so that the fault lamp 8 emits a light signal based on the target indication signal.

[0132] In this embodiment, an independent memory is added. The storage space of the independent memory can be much larger than the cache built into the controller. In this way, the memory can store the fault information corresponding to multiple failures of the low-voltage battery within a certain period of time and the status information of the low-voltage battery during this period of time. During the fault repair process, this information can better assist the repair personnel in more comprehensively identifying each faulty component.

[0133] In the description of this specification, the references to "certain embodiments," "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples" refer to specific features, structures, materials, or characteristics described in connection with the described embodiment or example, which are included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0134] It is understood that in this disclosure, "multiple" refers to two or more, and other quantifiers are similar. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. The singular forms "a," "the," and "the" are also intended to include the plural forms unless the context clearly indicates otherwise.

[0135] It is further understood that the terms "first," "second," etc., are used to describe various types of information, but this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another, and do not indicate a specific order or degree of importance. In fact, the expressions "first," "second," etc., are completely interchangeable. For example, without departing from the scope of this disclosure, first information can also be referred to as second information, and similarly, second information can also be referred to as first information.

[0136] It is further understood that the terms “center,” “longitudinal,” “lateral,” “front,” “rear,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation.

[0137] It is further understood that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral molding; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between the two components; they can refer to a direct connection between two components without the presence of other components, or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0138] It is further understood that although operations are described in a specific order in the accompanying drawings in the embodiments of this disclosure, this should not be construed as requiring these operations to be performed in the specific order or serial order shown, or requiring all of the shown operations to be performed to obtain the desired result. In certain environments, multitasking and parallel processing may be advantageous.

[0139] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the solutions disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the scope of the claims.

[0140] It should be understood that this disclosure 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 this disclosure is limited only by the appended claims.

Claims

1. A battery management system, characterized in that, The battery management system includes a low-voltage battery (1), a detection component (2), a controller (3), a memory (4), a charging switch (5), and a discharging switch (6); The detection component (2) is electrically connected to the low-voltage battery (1) and the controller (3) respectively. The detection component (2) is used to detect the status information of the low-voltage battery (1), wherein the status information includes current, voltage and cell temperature, and sends it to the controller (3). The charging switch (5) is used to control the on / off connection of the low-voltage battery (1) and the high-voltage battery. The discharge switch (6) is used to control the on / off connection of the low-voltage battery (1) and the low-voltage load. The controller (3) is electrically connected to the detection component (2), the memory (4), the charging switch (5), and the discharging switch (6) respectively. The controller (3) is used to: store the received status information into the memory (4); when the status information meets the target status condition, determine the fault information based on the status information that meets the status condition, store the fault information into the memory (4), and control the charging switch (5) and / or the discharging switch (6) based on the fault information. The controller (3) is used for: When a target state condition exists in the first correspondence between pre-stored state conditions, state information ranges and fault levels, such that the currently received state information satisfies the target state condition, the target fault level corresponding to the target state information range to which the target state condition and the currently received state information belong is determined in the first correspondence. Based on the second correspondence between pre-stored state conditions and fault types, the target fault type corresponding to the target state condition is determined; The target fault type and the target fault level are determined as fault information.

2. The battery management system according to claim 1, characterized in that, The controller (3) includes a control chip (31) and a driver chip (32); The control chip (31) is electrically connected to the drive chip (32) and the detection component (2) respectively. The control chip (31) is used to store the received status information into the memory (4). When the status information meets the target status condition, the fault information is determined based on the status information that meets the target status condition, and the fault information is stored into the memory (4). The control command is determined based on the fault information and the control command is sent to the drive chip (32). The driving chip (32) is electrically connected to the charging switch (5) and the discharging switch (6) respectively. The driving chip (32) is used to control the charging switch (5) and / or the discharging switch (6) based on the control command.

3. The battery management system according to claim 1, characterized in that, The controller (3) is used for: When the target state condition is that the discharge current is greater than the first discharge current threshold, the corresponding target fault type is determined to be a short circuit fault. When the target state condition is that the total battery voltage is less than the total voltage threshold, the corresponding target fault type is determined to be an undervoltage fault. When the target state condition is that the cell voltage is greater than the cell voltage threshold, the corresponding target fault type is determined to be an overvoltage fault. When the target state condition is that the charging current is greater than the charging current threshold, the corresponding target fault type is determined to be a charging overcurrent fault. When the target state condition is that the discharge current is greater than the second discharge current threshold, the corresponding target fault type is determined to be a discharge overcurrent fault, wherein the second discharge current threshold is less than the first discharge current threshold. When the target state condition is that the cell temperature is greater than the cell temperature threshold, the corresponding target fault type is determined to be an over-temperature fault. When the target state condition is that the cell temperature is greater than the cell temperature threshold and the rate of temperature increase is greater than the rate of temperature increase threshold for a continuous period of time, the corresponding target fault type is determined to be thermal runaway fault.

4. The battery management system according to claim 1, characterized in that, The controller (3) is used for: When a target state condition exists in the first correspondence between pre-stored state conditions, state information ranges, fault levels and detection durations, such that the currently received state information satisfies the target state condition, the target fault level and target detection duration corresponding to the target state information range to which the target state condition and the currently received state information belong are determined in the first correspondence. In the first correspondence, the fault level and the target detection duration are negatively correlated. If all the state information received within the target detection time meets the target state condition, then the target fault type corresponding to the target state condition is determined based on the second correspondence between the pre-stored state condition and the fault type.

5. The battery management system according to claim 1, characterized in that, The controller (3) is used for: Based on the third correspondence between fault type and control command, the target control command corresponding to the target fault type is determined, and the charging switch (5) and / or discharging switch (6) are controlled based on the target control command.

6. The battery management system according to claim 5, characterized in that, The fault types include undervoltage fault, short circuit fault, overvoltage fault, charging overcurrent fault, discharging overcurrent fault, overtemperature fault, and thermal runaway fault. The controller (3) is used for: When the target fault type is an undervoltage fault, the target control command is determined to be to disconnect the discharge switch (6); When the target fault type is a short circuit fault, the target control command is determined to be to disconnect the charging switch (5) and the discharging switch (6); When the target fault type is an overvoltage fault, the target control command is determined to be to disconnect the charging switch (5); When the target fault type is a charging overcurrent fault, the target control command is determined to be to disconnect the charging switch (5); When the target fault type is a discharge overcurrent fault, the target control command is determined to be to disconnect the discharge switch (6); When the target fault type is an over-temperature fault or a thermal runaway fault, the target control command is determined to be to disconnect the charging switch (5) and the discharging switch (6).

7. The battery management system according to claim 1, characterized in that, The battery management system also includes a communication component (7) and a fault indicator (8); The communication component (7) is electrically connected to the controller (3) and the fault lamp (8) respectively; The controller (3) is also used to: when the status information meets the target status conditions, send a target indication signal to the fault lamp (8) through the communication component (7) so that the fault lamp (8) emits a light signal based on the target indication signal.

8. A battery management method, characterized in that, The method is applied to a battery management system, which includes a low-voltage battery (1), a detection component (2), a controller (3), a memory (4), a charging switch (5), and a discharging switch (6). The method includes: The detection component (2) detects the status information of the low-voltage battery (1), wherein the status information includes current, voltage and cell temperature, and sends it to the controller (3); The controller (3) stores the received status information into the memory (4). When the status information meets the target status conditions, it determines the fault information based on the status information that meets the status conditions, stores the fault information into the memory (4), and controls the charging switch (5) and / or the discharging switch (6) based on the fault information. Wherein, when the state information satisfies the target state condition, determining the fault information based on the state information that satisfies the state condition includes: When a target state condition exists in the first correspondence between pre-stored state conditions, state information ranges and fault levels, such that the currently received state information satisfies the target state condition, the target fault level corresponding to the target state information range to which the target state condition and the currently received state information belong is determined in the first correspondence. Based on the second correspondence between pre-stored state conditions and fault types, the target fault type corresponding to the target state condition is determined; The target fault type and the target fault level are determined as fault information.

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