A power-down method and apparatus of a battery management system, a processor and a readable medium

Abstract

The application discloses a battery management system power-off method and device, a processor and a readable medium. The method comprises the following steps: receiving a fault signal, identifying a fault category corresponding to the fault signal; if the identified fault category is a preset level fault, determining an abnormal power-off process to be executed based on the fault category, and executing the abnormal power-off process to be executed; wherein when the fault category is the highest level fault, the abnormal power-off process to be executed is an emergency power-off process. The application establishes corresponding abnormal power-off processes based on different fault categories, and then when a preset level fault category is identified, determines a corresponding abnormal power-off process to be executed based on the fault category, and executes the abnormal power-off process. Meanwhile, an emergency power-off process is set for the highest level fault, so that serious accidents are avoided, and the priority protection of personal safety is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power batteries, in particular to a power-off method and device of a battery management system, a processor and a readable medium. BACKGROUND

[0002] The high-voltage relay is a high-voltage switching device connecting the power battery and the vehicle electrical appliance. It is not only a controlled switching device on the high-voltage circuit, but also plays the role of a proactive protection device in the system. The battery management system (BMS) as the control unit of the power battery pack controls the relay to realize the conduction and disconnection of the power battery high-voltage main loop. The commonly used unipolar relay is very easy to stick when the current direction is opposite to the polarity of the relay under load.

[0003] At present, the existing technology in the field of relay control is mainly devoted to studying how to reduce the sticking of the relay during power-off to protect the relay. For example, the Chinese patent with the application number 2020115317414 discloses a power-off method and system for prolonging the service life of the vehicle relay, which can protect the safety of the relay, but it does not consider the fault severity, serious accidents and other factors in the development of the power-off control strategy. If the highest level of serious fault is still operated by high-voltage power-off according to the idea of protecting the relay, it may cause electric shock accidents and pose a risk to the safety of the driver. SUMMARY

[0004] The present application aims to overcome the problem that the existing relay power-off control technology does not consider the fault severity, serious accidents and other factors in the development of the power-off control strategy, and provides a power-off method and device of a battery management system, a processor and a readable medium.

[0005] In order to achieve the above-mentioned application purpose, the present application provides the following technical solutions:

[0006] A power-off method of a battery management system, comprising:

[0007] receiving a fault signal and identifying the fault category corresponding to the fault signal;

[0008] If the identified fault category is a preset level fault, determine the abnormal power-off process to be executed based on the fault category, and execute the abnormal power-off process to be executed; wherein when the fault category is the highest level fault, the abnormal power-off process to be executed is the emergency power-off process.

[0009] According to a specific embodiment, the first type of fault in the above-mentioned power-off method of a battery management system includes thermal runaway, single cell limit overvoltage, single cell limit undervoltage and collision.

[0010] The emergency power-down process comprises simultaneously disconnecting all relays.

[0011] According to a specific embodiment, in the power-down method of the battery management system, the second type of fault comprises single-cell overvoltage, single-cell undervoltage and excessively low low-voltage power supply.

[0012] According to a specific embodiment, in the power-down method of the battery management system, when the fault category is single-cell overvoltage or single-cell undervoltage, the abnormal power-down process to be executed is a first abnormal power-down process, comprising:

[0013] S101, start a first clock to time the fault signal, detect whether the vehicle speed and the current simultaneously satisfy a preset triggering condition, if not, go to S102; if yes, start a second clock to time the triggering condition, and go to S103;

[0014] S102, detect whether the first preset time is reached by the first clock, if not, continue to time the fault signal; if yes, go to S104;

[0015] S103, detect whether a first power-down signal can be received within the second preset time, wherein whether the second preset time is reached is determined based on the second clock, if yes, go to S106, if not, go to S104;

[0016] S104, issue a request for lowering high voltage, and go to S105;

[0017] S105, start a third clock, detect whether the first power-down signal can be received within a third preset time, if not, return to S104; if yes, go to S106;

[0018] S106, determine the disconnection sequence of the main positive relay and the main negative relay based on the polarity of the relay, and sequentially disconnect to complete power-down.

[0019] According to a specific embodiment, in the power-down method of the battery management system, when the fault category is excessively low low-voltage power supply, the abnormal power-down process to be executed is a second abnormal power-down process, comprising:

[0020] S201, detect whether the battery voltage is continuously lower than a first voltage threshold within a first preset diagnosis period, if yes, go to S202;

[0021] S202, issue a request for lowering high voltage, and go to S203;

[0022] S203, detect whether a first power-down signal is received, if not, go to S204; if yes, go to S205;

[0023] S204, detecting whether the battery voltage is less than a second voltage threshold for a second preset diagnosis period, if not, returning to S202, if yes, entering S205;

[0024] S205, determining the disconnection order of the main positive relay and the main negative relay based on the relay polarity, and sequentially disconnecting to complete power-off.

[0025] According to a specific embodiment, the power-off method of the battery management system further comprises: in response to a first power-off signal, executing a normal power-off process when no fault signal is received or when the identified fault category is a non-pre-set level fault.

[0026] According to a specific embodiment, the power-off method of the battery management system further comprises: based on a third preset diagnosis period, continuously detecting whether the current meets a preset condition, the preset condition being that the current is lower than a threshold in n consecutive sampling periods, wherein n is an integer greater than 1.

[0027] If yes, first disconnect the main positive / pre-charging relay, and then disconnect the main negative relay;

[0028] If no, report a main relay disconnection overcurrent fault signal, and determine the disconnection order of the main positive relay and the main negative relay based on the relay polarity, and sequentially disconnect to complete power-off.

[0029] According to a specific embodiment, the power-off method of the battery management system further comprises: cyclically detecting whether a second power-off signal is received, if yes, executing the emergency power-off process in response to the second power-off signal.

[0030] According to a specific embodiment, the power-off method of the battery management system further comprises:

[0031] Detecting whether the received second power-off signal is a valid signal, if yes, executing the emergency power-off process, if no, diagnosing whether there is a VCM communication loss fault or a bus communication fault, if no, no need to execute the emergency power-off process, if yes, directly executing the emergency power-off process when a fourth preset time arrives.

[0032] Another aspect of the present application provides a power-off device of a battery management system, comprising:

[0033] A receiving unit for receiving a fault signal and sending the fault signal to a processing unit;

[0034] The processing unit is configured to identify a fault category corresponding to the fault signal when the fault signal is received, and determine an abnormal power-off process to be executed based on the fault category if the identified fault category is a preset level fault, and send the abnormal power-off process to be executed to an execution unit, wherein the abnormal power-off process to be executed is an emergency power-off process when the fault category is a highest level fault.

[0035] The execution unit is configured to receive and execute the abnormal power-off process to be executed.

[0036] According to a specific embodiment, in the power-off device of the battery management system, the highest level fault includes thermal runaway, single cell limit overvoltage, single cell limit undervoltage, and collision.

[0037] The emergency power-off process includes simultaneously disconnecting all relays.

[0038] According to a specific embodiment, in the power-off device of the battery management system, the receiving unit is further configured to receive a first power-off signal and send the first power-off signal to the execution unit.

[0039] The execution unit is configured to execute a normal power-off process based on the first power-off signal when the abnormal power-off process to be executed is not received.

[0040] According to a specific embodiment, in the power-off device of the battery management system, the receiving unit is further configured to cyclically detect whether a second power-off signal is received, and send the second power-off signal to the processing unit if the second power-off signal is received.

[0041] The processing unit is configured to detect whether the received second power-off signal is a valid signal, send an execution signal to the execution unit if the received second power-off signal is a valid signal, diagnose whether there is a VCM communication loss fault or a bus communication fault if the received second power-off signal is not a valid signal, and not send the execution signal to the execution unit if there is no VCM communication loss fault or bus communication fault, and send the execution signal to the execution unit when a fourth preset time is reached if there is a VCM communication loss fault or a bus communication fault.

[0042] The execution unit is configured to execute the emergency power-off process based on the execution signal.

[0043] Another aspect of the present application provides a processor configured to run a program, wherein the program is configured to implement the power-off method of the battery management system when the program is run.

[0044] Another aspect of the present application provides a computer readable storage medium, wherein the computer readable storage medium stores program instructions, and the program instructions are configured to implement the power-off method of the battery management system when the program instructions are executed by at least one processor.

[0045] Compared with the prior art, the present application has the following advantages:

[0046] The method provided by the embodiment of the application establishes corresponding abnormal power-off processes based on different fault categories, and then when a fault category of a preset level is identified, determines a corresponding to-be-executed abnormal power-off process based on the fault category, and executes the abnormal power-off process; meanwhile, for the highest level of fault, the to-be-executed abnormal power-off process is set as an emergency power-off process, so that the emergency high-voltage power-off mode is adopted to avoid serious accidents and realize the priority protection of personal safety. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is a power-off method flowchart of a battery management system in an embodiment of the application;

[0048] Figure 2 is a first abnormal power-off process schematic diagram in an embodiment of the application;

[0049] Figure 3 is a second abnormal power-off process schematic diagram in an embodiment of the application;

[0050] Figure 4 is a to-be-executed abnormal power-off process summary schematic diagram in an embodiment of the application;

[0051] Figure 5 is a power-off method flowchart of a battery management system in an embodiment of the application;

[0052] Figure 6 is a normal power-off process schematic diagram in an embodiment of the application;

[0053] Figure 7 is a process schematic diagram of emergency power-off in response to a second power-off signal in an embodiment of the application. DETAILED DESCRIPTION

[0054] The application will be described in further detail below with reference to the test examples and specific embodiments. However, this should not be understood as limiting the scope of the above-mentioned subject matter of the application to the following examples only, and any technology realized based on the content of the application falls within the scope of the application.

[0055] Embodiment 1

[0056] Figure 1 The power-off method of the battery management system of the exemplary embodiment of the application is shown, which comprises:

[0057] receiving a fault signal and identifying a fault category corresponding to the fault signal;

[0058] If the identified fault category is a preset level fault, an abnormal power-off process to be executed is determined based on the fault category, and the abnormal power-off process to be executed is executed; when the fault category is the highest level fault, the abnormal power-off process to be executed is an emergency power-off process.

[0059] It can be understood that for electric vehicle faults, the industry will have a special fault category division, and the faults will be divided into different levels according to the fault severity, for example: the fault level is divided into 3-4 levels, and taking a four-level fault as an example, the first level or the fourth level is the highest level (the most serious fault).

[0060] Therefore, in the embodiment, corresponding abnormal power-off processes are established based on different fault categories, and then when a preset level fault category is identified, the corresponding abnormal power-off process to be executed is determined based on the fault category, and the abnormal power-off process is executed; and for the highest level fault, the abnormal power-off process to be executed is set as an emergency power-off process, so that the emergency high voltage is adopted to avoid serious accidents and achieve the protection of personal safety.

[0061] Embodiment 2

[0062] In a possible implementation, in the power-off method of the battery management system, the highest level fault includes: thermal runaway, single cell limit overvoltage, single cell limit undervoltage, and collision.

[0063] The emergency power-off process includes simultaneously disconnecting all relays.

[0064] In the embodiment, for the detected thermal runaway, collision signal or single cell limit overvoltage / undervoltage fault signal, the safety of the driver is given priority, and the relays are immediately disconnected to emergency power-off the high voltage, so as to avoid serious accidents and achieve the protection of personal safety.

[0065] In a possible implementation, in the power-off method of the battery management system, the preset level fault includes: the highest level fault and the lower level fault.

[0066] The lower level fault includes: single cell overvoltage, single cell undervoltage, and low voltage power supply too low.

[0067] In a possible implementation, the corresponding battery fault level is determined according to the electrochemical system of the used battery (such as lithium iron phosphate and ternary). Taking a ternary system lithium ion battery as an example, in the fault diagnosis strategy, 4.28V is defined as single cell overvoltage, that is, a three-level battery fault, a lower level battery fault, and 4.3V is defined as single cell limit overvoltage, that is, a four-level battery fault, a highest level battery fault.

[0068] In this embodiment, various faults under high voltage and load conditions are distinguished in more detail to avoid the use of a single relay control strategy for different types of faults.

[0069] In one possible implementation, in the power-off method of the battery management system, when the fault category is single overvoltage or single under-voltage, the abnormal power-off process to be executed is a first abnormal power-off process, as shown in Figure 2 The first abnormal power-off process includes:

[0070] S101, start the first clock to time the fault signal, detect whether the vehicle speed and the current simultaneously satisfy the preset triggering condition, if not, go to S102; if yes, start the second clock to time the triggering condition, and go to S103;

[0071] S102, detect whether the first clock reaches a first preset time, if not, continue to time the fault signal; if yes, go to S104;

[0072] S103, detect whether a first power-off signal can be received within a second preset time, wherein whether the second preset time is reached is determined based on the second clock, if yes, go to S106, if not, go to S104;

[0073] S104, issue a high voltage request, and go to S105;

[0074] S105, start the third clock, detect whether the first power-off signal can be received within a third preset time, if not, return to S104; if yes, go to S106;

[0075] S106, determine the disconnection order of the main positive relay and the main negative relay based on the relay polarity, and sequentially disconnect to complete power-off.

[0076] Specifically, when single overvoltage or single under-voltage occurs in the secondary high-level fault, before S104 is executed, the fault signal disappears, the timing is cleared, and the next received fault signal is waited for; if the fault signal disappears after S104 is executed, the flag bit is still set, and the sleep reset is needed.

[0077] In this embodiment, a specific abnormal power-down process is configured for single cell overvoltage or single cell undervoltage failure. The clock is started to time the fault signal, and the fault is further refined based on the preset trigger condition. When the preset condition is not triggered, the clock is used to determine whether the fault is a continuous event. When the fault is a continuous event, a low voltage request is issued, and the first power-down signal (i.e. non-emergency power-down signal) is detected to perform power-down. When the preset condition is triggered, power-down is directly performed based on the power-down signal detection. During power-down, the current direction is diagnosed, and the relays are sequentially disconnected in the same direction as the relay polarity to protect the relays. The present embodiment distinguishes between various high voltage power-down faults and load conditions to avoid using a single relay control strategy for different current sizes.

[0078] In the above method, the battery management system (BMS) determines whether to disconnect the main positive relay or the main negative relay first during the high voltage power-down process based on the relay polarity. The current direction is BMS_BatteryCurrent>0 for charging, and vice versa for discharging.

[0079] In the above method, the above-mentioned preset trigger condition, first preset time, second preset time, and third preset time can be set according to actual application scenarios. For example, the first preset time is 65s, and the second preset time and the third preset time are 5s.

[0080] In one possible implementation, the preset trigger condition is that the vehicle speed is less than or equal to 9km / h and the bus current is less than or equal to 20A.

[0081] In this embodiment, a specific preset trigger condition is determined by obtaining a large amount of fault current information, so that the current and load conditions are clearly distinguished. When the preset condition is triggered, power-down is directly performed based on the power-down signal detection without first issuing a power-down request, so as to achieve faster abnormal power-down.

[0082] In one possible implementation, the first preset time is 1000ms, and the second preset time and the third preset time are 5s.

[0083] In one possible implementation, in the power-down method of the battery management system, when the fault category is low voltage supply is too low, the abnormal power-down process to be executed is a second abnormal power-down process, as shown in Figure 3 The second abnormal power-down process includes:

[0084] S201, detecting whether the battery voltage is continuously lower than a first voltage threshold in a first preset diagnosis period. If yes, go to S202;

[0085] S202, issuing a low voltage request, and going to S203;

[0086] S203, detecting whether the first power-down signal is received, if not, entering S204; if yes, entering S205;

[0087] S204, detecting whether the battery voltage is less than the second voltage threshold for the second preset diagnosis period, if not, returning to S202; if yes, entering S205;

[0088] S205, determining the disconnection sequence of the main positive relay and the main negative relay based on the relay polarity, and sequentially disconnecting to complete the power-down.

[0089] In the embodiment, the low-voltage faults are classified by voltage levels based on different voltage thresholds, so that when the first power-down signal is not received, if it is detected that the battery voltage is less than the second voltage threshold for the second preset diagnosis period, the power-down can be directly performed according to the higher level low-voltage fault, without waiting for the first power-down signal, so as to realize more rapid abnormal power-down; meanwhile, during the power-down process, the current direction is diagnosed, and the relays are sequentially cut off in the same direction of the relay polarity, so as to achieve the purpose of protecting the relays.

[0090] The first preset diagnosis period, the second preset diagnosis period, the first voltage threshold, and the second voltage threshold can be set according to actual application scenarios.

[0091] In a possible implementation, the first preset diagnosis period is 1000 ms, and the second preset diagnosis period is 100 ms.

[0092] In a possible implementation, the first voltage threshold is 9V, and the second voltage threshold is 8V.

[0093] In the embodiment, the voltage level and its duration are determined by analyzing the battery voltage information, so that the voltage and the load condition are clearly distinguished, and the power-down is directly performed when a higher level low-voltage fault occurs.

[0094] Further, Figure 4 The abnormal power-down flowchart to be performed in the exemplary embodiment of the application is shown as follows: Figure 4 As shown in the figure, the embodiment of the application formulates different abnormal power-down flows for different levels of faults, to avoid the safety hazards caused by using the same power-down flow.

[0095] In a possible implementation, the power-down method of the battery management system further includes: when the fault signal is not received, or when the identified fault category is a non-pre-set level fault, performing a normal power-down flow in response to the first power-down signal.

[0096] It can be understood that in the power-off management technology of the battery management system, a preset normal power-off process is usually configured. Therefore, in the embodiment, when no fault signal is received or the fault signal does not reach the preset level, the battery management system can execute the preconfigured normal power-off process according to the normal power-off instruction (i.e., the first power-off signal).

[0097] At this time, as shown in Figure 5 the power-off method of the battery management system specifically includes: detecting whether a fault signal is received in real time, and if not, executing a normal power-off process in response to a first power-off signal;

[0098] if yes, identifying a fault category corresponding to the fault signal, judging whether the fault category is a preset level fault, and if not, executing a normal power-off process in response to the first power-off signal;

[0099] if yes, determining an abnormal power-off process to be executed based on the fault category, and executing the abnormal power-off process to be executed; wherein when the fault category is a highest level fault, the abnormal power-off process to be executed is an emergency power-off process.

[0100] In a possible implementation, the normal power-off process includes: continuously detecting whether the current meets a preset condition based on a third preset diagnosis period, and the preset condition is that the current can be lower than a threshold value in n consecutive sampling periods, wherein n is an integer greater than 1.

[0101] if yes, first disconnecting the main positive / pre-charging relay, and then disconnecting the main negative relay;

[0102] if not, reporting a main relay disconnection overcurrent fault signal, and determining a disconnection order of the main positive relay and the main negative relay based on the polarity of the relay, and sequentially disconnecting to complete power-off.

[0103] In the normal power-off process in the embodiment, when it is detected that the current value can be lower than the threshold value in n consecutive sampling periods, the main positive / pre-charging relay is first disconnected, and then the main negative relay is disconnected. This is because the line between the main positive and the main negative is long, and the probability of short circuit is relatively high. Therefore, first disconnecting the main positive / pre-charging relay and then disconnecting the main negative relay can protect personal safety to a certain extent. When the third preset diagnosis period ends and the current still does not meet the preset condition, a main relay disconnection overcurrent fault signal is reported, and power-off is performed. The current direction is diagnosed, and the relays are sequentially cut off in the same direction of the polarity of the relays, so as to achieve the purpose of protecting the relays.

[0104] In a possible implementation, the preset condition can be set according to an actual application scenario, and the specific threshold range of the current can be set according to the bus current size required by the relay specification book for the number of safe cut-offs in the actual application scenario, and the n continuous sampling periods, where n can be set according to the current sampling period and the current stability judgment condition.

[0105] Specifically, as shown in Figure 6 the normal power-down process specifically includes: receiving a first power-down signal and starting t0 timing;

[0106] Based on t0, it is judged whether the current can be detected to meet the preset condition within the third preset diagnosis period; if yes, the main positive / pre-charging relay is disconnected first, and then the main negative relay is disconnected; if no, when the third preset diagnosis period arrives, a main relay disconnection overcurrent fault signal is reported, and power-down is performed: the current direction is diagnosed, and the relays are sequentially cut off in the same direction according to the polarity of the relays; the preset condition is that the current value is less than 5A for 60ms, n is 6, and 60ms is 6 sampling periods.

[0107] Wherein, the battery management system (BMS) will judge the current method based on the relay polarity during the high voltage process, and determine whether to disconnect the main positive relay or the main negative relay according to the current method; the current direction: BMS_BatteryCurrent> 0; otherwise, it is discharging.

[0108] In a possible implementation, the power-down method of the battery management system further includes: while detecting whether the fault signal is received, the second power-down signal is cyclically detected, if yes, the emergency power-down process is executed in response to the second power-down signal.

[0109] As shown in Figure 7 the emergency power-down process executed in response to the second power-down signal includes:

[0110] Detect whether the received second power-down signal is a valid signal, if yes, execute the emergency power-down process; if no, diagnose whether there is a VCM communication loss fault or a bus communication fault, if no, the emergency power-down process does not need to be executed; if yes, directly execute the emergency power-down process when the fourth preset time arrives.

[0111] In summary, the method provided by the embodiment has the following advantages:

[0112] 1. Different relay control strategies are provided for different driving scenarios, and a trade-off is made between relay protection and driver protection to maximize the risk of high-voltage electric shock;

[0113] 2. More detailed distinction is made for triggering high-voltage electrical multiple faults and load conditions, avoiding the use of a relay control strategy for different levels of faults and current sizes;

[0114] 3. According to the judgment of the polarity of the relay and the direction of the current, the sticking of the relay is avoided as much as possible, and the risk of disassembling the package for electric shock due to the sticking of the relay is reduced.

[0115] Embodiment 3

[0116] In another aspect of the present application, a power-down device of a battery management system is provided for implementing the power-down method of the battery management system of Embodiment 1 or Embodiment 2. The device comprises:

[0117] A receiving unit is configured to receive a fault signal and send the fault signal to a processing unit;

[0118] The processing unit is configured to identify a fault category corresponding to the fault signal when the fault signal is received, determine an abnormal power-down process to be executed based on the fault category if the fault category is a preset level fault, and send the abnormal power-down process to be executed to an execution unit. When the fault category is the highest level fault, the abnormal power-down process to be executed is an emergency power-down process.

[0119] The execution unit is configured to receive and execute the abnormal power-down process to be executed.

[0120] In a possible implementation, the highest level fault includes thermal runaway, single cell limit overvoltage, single cell limit undervoltage, and collision.

[0121] The emergency power-down process includes simultaneously disconnecting all relays.

[0122] In a possible implementation, the receiving unit is further configured to receive a first power-down signal and send it to the execution unit.

[0123] The execution unit is configured to execute a normal power-down process based on the first power-down signal when the abnormal power-down process to be executed is not received.

[0124] In a possible implementation, the receiving unit is further configured to cyclically detect whether a second power-down signal is received, and if so, send the second power-down signal to the processing unit.

[0125] The processing unit is configured to detect whether the received second power-down signal is a valid signal, and if so, send an execution signal to the execution unit; if not, diagnose whether there is a VCM communication loss fault or a bus communication fault, and if not, do not send the execution signal to the execution unit; if so, send the execution signal to the execution unit when the fourth preset time arrives.

[0126] An execution unit is configured to execute the emergency power-off process based on the execution signal.

[0127] Embodiment 4

[0128] Another aspect of the present application also provides a processor configured to execute a program, wherein the program is configured to execute the power-off method of the battery management system of Embodiment 1 or Embodiment 2 when executed.

[0129] Another aspect of the present application also provides a computer readable storage medium, wherein the computer readable storage medium stores program instructions, and the program instructions are configured to implement the power-off method of the battery management system of Embodiment 1 or Embodiment 2 when executed by at least one processor.

[0130] In the embodiments of the present application, the processor can be an integrated circuit chip with signal processing capability. The processor can be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0131] The disclosed methods, steps and logic block diagrams in the embodiments of the present application can be implemented or executed. The general purpose processor can be a microprocessor or the processor can be any conventional processor. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as a hardware code processor for execution, or a combination of hardware and software modules in the code processor for execution. The software module can be located in a random access memory, a flash memory, a read only memory, a programmable read only memory or an electrically erasable programmable memory, a register or other mature storage medium in the art. The processor reads the information in the storage medium and combines the hardware to complete the steps of the above method.

[0132] The storage medium can be a memory, for example, can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories.

[0133] The non-volatile memory can be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically EPROM (EEPROM) or a flash memory.

[0134] The volatile memory can be Random Access Memory (RAM), used as external cache. By way of example, and not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic Random Access Memory (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and direct Rambus RAM (DRRAM). The below-described memory is intended to include, without being limited to, these and any other suitable types of memory.

[0135] The storage media described in the implementation of the present application is intended to include, but not limited to, these and any other suitable types of memory.

[0136] It should be understood that the system disclosed in the present application can be implemented in other ways. For example, the division of the modules is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the communication connection between the modules can be indirect coupling or communication connection through some interfaces, servers or units, which can be electrical or other forms.

[0137] In addition, each function module in each embodiment of the present application can be integrated in one processing unit, or each module can exist physically alone, or two or more modules can be integrated in one processing unit. The integrated unit can be realized in the form of hardware or in the form of a software function unit.

[0138] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application, essentially or in other words, the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a number of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in various embodiments of the present application. The aforementioned storage medium includes: a U disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store program codes.

[0139] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A power-off method for a battery management system, characterized in that, include: Receive fault signals and identify the fault category corresponding to the fault signals; Preset fault levels include: the highest level fault and the second highest level fault; The second-highest level faults include: individual overvoltage, individual undervoltage, and low voltage power supply. If the identified fault category is a preset level fault, then an abnormal power-down procedure to be executed is determined based on the fault category, and the abnormal power-down procedure to be executed is executed; wherein, when the fault category is the highest level fault, the abnormal power-down procedure to be executed is an emergency power-down procedure. When the fault category is single-cell overvoltage or single-cell undervoltage, the abnormal power-down process to be executed is the first abnormal power-down process based on clock and preset triggering mechanism. The first abnormal power-down procedure includes: S101. Start the first clock to time the fault signal and check whether the vehicle speed and current simultaneously meet the preset trigger conditions. If not, proceed to S102; if yes, start the second clock to time the trigger conditions and proceed to S103. S102. Detect whether the first clock has reached the first preset time. If not, continue timing the fault signal. If yes, proceed to S104. S103. Detect whether the first power-down signal can be received within a second preset time. The second preset time is determined based on the second clock. If yes, proceed to S106; otherwise, proceed to S104. S104, Issue a request to lower the voltage and proceed to S105; S105. Start the third clock and check whether the first power-down signal can be received within a third preset time. If not, return to S104; if yes, proceed to S106. S106. Determine the disconnection sequence of the main positive relay and the main negative relay based on the relay polarity, and disconnect them sequentially to complete the power-off process; When the fault category is low voltage power supply, the abnormal power-down process to be executed is the second abnormal power-down process based on the diagnostic cycle and threshold judgment mechanism. The second abnormal power-down procedure includes: S201. Detect whether the battery voltage remains within the first voltage threshold during the first preset diagnostic cycle. If so, proceed to S202; S202, Issue a request to lower the voltage and proceed to S203; S203. Detect whether the first electrical signal has been received. If not, proceed to S204; if yes, proceed to S205. S204. Detect whether the battery voltage is continuously lower than the second voltage threshold within the second preset diagnostic cycle. If not, return to S202; if yes, proceed to S205. S205. Determine the disconnection sequence of the main positive relay and the main negative relay based on the relay polarity, and disconnect them sequentially to complete the power-off process.

2. The power-off method of the battery management system according to claim 1, characterized in that, The highest level of fault includes: thermal runaway, single-cell ultimate overvoltage, single-cell ultimate undervoltage, and collision; the emergency power-down procedure includes: simultaneously disconnecting all relays.

3. The power-off method of the battery management system according to any one of claims 1 to 2, characterized in that, The method further includes: when no fault signal is received, or when the identified fault category is not a preset level fault, performing a normal power-down procedure in response to a first power-down signal.

4. The power-off method of the battery management system according to claim 3, characterized in that, The normal power-down process includes: continuously detecting whether the current meets a preset condition based on a third preset diagnostic cycle, wherein the preset condition is that the current can be lower than a threshold for n consecutive sampling cycles, where n is an integer greater than 1. If so, first disconnect the main positive / precharge relay, then disconnect the main negative relay; If not, a main relay disconnection overcurrent fault signal is reported, and the disconnection sequence of the main positive relay and the main negative relay is determined based on the relay polarity, and the relays are disconnected sequentially to complete the power-off.

5. The power-off method of the battery management system according to any one of claims 1 to 2, characterized in that, The method further includes: cyclically detecting whether a second power-down signal is received; if so, executing the emergency power-down procedure in response to the second power-down signal.

6. The power-off method of the battery management system according to claim 5, characterized in that, The emergency power-down procedure, executed in response to the second power-down signal, includes: If the received second power-down signal is valid, the emergency power-down procedure is executed. If not, the system diagnoses whether there is a VCM communication loss or bus communication failure. If not, the emergency power-down procedure is not required. If so, the emergency power-down procedure is executed directly when the fourth preset time arrives.

7. A power-off device for a battery management system, characterized in that, For performing the method according to any one of claims 1-6, comprising: A receiving unit is used to receive fault signals and send the fault signals to a processing unit; The processing unit is configured to, upon receiving the fault signal, identify the fault category corresponding to the fault signal; if the identified fault category is a preset level fault, determine the abnormal power-down procedure to be executed based on the fault category, and send the abnormal power-down procedure to be executed to the execution unit; wherein, when the fault category is the highest level fault, the abnormal power-down procedure to be executed is an emergency power-down procedure. An execution unit is used to receive and execute the abnormal power-down process to be executed.

8. The power-off device of the battery management system as described in claim 7, characterized in that, The highest level of fault includes: thermal runaway, single-cell ultimate overvoltage, single-cell ultimate undervoltage, and collision; The emergency power-down procedure includes: simultaneously disconnecting all relays.

9. The power-off device of the battery management system as described in claim 7, characterized in that, The receiving unit is also used to receive the first power-down signal and send it to the execution unit; The execution unit is used to execute a normal power-down process based on the first power-down signal when no abnormal power-down process to be executed is received.

10. The power-off device of the battery management system as described in any one of claims 7 to 9, characterized in that, The receiving unit is also used to cyclically detect whether a second power-down signal has been received; if so, it sends a second power-down signal to the processing unit. The processing unit is used to detect whether the received second electrical signal is a valid signal. If it is, it sends an execution signal to the execution unit. If it is not, it diagnoses whether there is a VCM communication loss fault or a bus communication fault. If not, it does not need to send an execution signal to the execution unit. If it is, it sends an execution signal to the execution unit when the fourth preset time arrives. An execution unit is used to execute the emergency power-down procedure based on the execution signal.

11. A processor, characterized in that, The processor is used to run a program, wherein the program executes the power-down method of the battery management system according to any one of claims 1 to 6.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores program instructions that, when executed by at least one processor, implement the power-off method of the battery management system as described in any one of claims 1 to 6.

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