Fault judging and processing method of battery management system, control system and vehicle

Abstract

The invention relates to a fault judging and processing method of a battery management system, a control system and a vehicle, relates to the technical field of vehicle battery management systems, and is applied to hybrid vehicles. The fault judging and processing method comprises the following steps that working parameters of a battery are obtained in real time in the vehicle running process; judging whether the working parameters of the battery change in the set monitoring period or not; if the working parameters of the battery change in the monitoring period, judging that the battery management system is normal; if the working parameters of the battery do not change in the monitoring period, it is judged that the battery management system breaks down, and an engine is controlled to drive the vehicle to run. Whether the working parameters of the battery change in the monitoring period is used as a basis for judging whether the battery management system breaks down or not, the engine is used for driving the vehicle to run when the battery management system breaks down, and adverse consequences caused by sudden power loss of the vehicle are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle battery management systems, and in particular to a battery management system fault determination and processing method, a control system, and a vehicle. BACKGROUND

[0002] With the development of the new energy automobile industry, hybrid vehicles have become an important development direction in the automobile market because they combine the energy-saving and environmental protection of pure electric driving with the reliability of fuel driving. The power system of a hybrid vehicle is composed of an engine and a battery, and the working state of the battery directly determines the power output, driving safety, and energy utilization efficiency of the vehicle. The battery management system (BMS) as the control unit of the battery plays an important role in the stable operation of the hybrid vehicle.

[0003] However, in the actual operation of a hybrid vehicle, the BMS is easily affected by complex driving environments, electromagnetic interference, hardware faults, or software abnormalities. When the BMS experiences a communication loss fault, the signal transmission between the BMS and the vehicle controller is interrupted, which may cause the vehicle to lose power instantaneously, affecting driving safety. It may also cause the battery to over-discharge due to the inability to monitor the power, damaging the battery health and even causing safety hazards. It may also cause the battery to overcharge due to the inability to control the charging process.

[0004] Therefore, BMS faults can restrict the driving reliability and safety of hybrid vehicles. SUMMARY

[0005] The present application at least partially solves one of the problems in the related art.

[0006] To this end, the present application aims to provide a battery management system fault determination and processing method, a control system, and a vehicle. By real-time detection of battery operating parameters during vehicle driving, whether the battery operating parameters change within a monitoring period is used as a basis for determining whether the battery management system is faulty. When the battery management system fails, it can be discovered in a timely manner, and the vehicle can be driven using the engine when the battery management system fails to avoid adverse consequences caused by the sudden loss of vehicle power.

[0007] To achieve the above-mentioned purpose, in a first aspect, the present application provides a battery management system fault determination and processing method applied to a hybrid vehicle. The processing method comprises the following steps: real-time acquisition of battery operating parameters during vehicle driving; determination of whether the battery operating parameters change within a set monitoring period; if the battery operating parameters change within the monitoring period, the battery management system is determined to be normal; If the working parameters of the battery do not change in the monitoring period, it is determined that the battery management system is faulty, and the engine is controlled to drive the vehicle to run.

[0008] In the technical scheme, the highest voltage, the lowest voltage and other working parameters of the battery are acquired in real time during the running of the vehicle, and whether the battery management system is faulty is determined according to whether the working parameters change in the monitoring period. If the working parameters do not change in the monitoring period, it is determined that the battery management system is faulty, and the engine is controlled to drive the vehicle to run. If the working parameters change in the monitoring period, it is determined that the battery management system is normal, and the vehicle runs normally. The fault determination method of the battery management system does not need to rely on complex fault diagnosis sensors or algorithms, and can realize the rapid determination of the fault of the battery management system only by monitoring the change state of the basic working parameters of the battery. In the case that the battery management system loses communication and other faults cause no parameter feedback, the fault state can be identified in time and the power source is switched to the engine, so that the risk of vehicle power interruption caused by the fault of the battery management system is effectively avoided, the continuous and stable running of the hybrid vehicle is ensured, and the safety and reliability of the vehicle running are improved.

[0009] In some embodiments of the present application, when it is determined that the battery management system is faulty, the maximum discharge power of the battery is set to a first set value, and the maximum charging power of the battery is set to a second set value. The first set value is less than the maximum discharge power of the battery in a normal state, and the second set value is less than the maximum charging power of the battery in a normal state.

[0010] In the technical scheme, by setting the maximum discharge power of the battery to a first set value and the maximum charging power of the battery to a second set value, the over-discharge or over-charge of the battery in a fault state is avoided, and sufficient power of the battery is ensured to meet the demand of starting the engine, so that the vehicle is prevented from being stranded due to the inability to start the engine caused by the battery running out of power. The power reliability of the hybrid vehicle in the fault working condition of the battery management system is further strengthened, and the vehicle can continuously run to a safe area or a repair site.

[0011] In some embodiments of the present application, the battery is used to supply power to a plurality of electric control components, and the working parameters of the battery at least include the highest voltage. After it is determined that the battery management system is faulty, if the voltage of any electric control component is higher than the highest voltage of the battery and lasts for a first preset time, the maximum discharge power of the battery is set to a first set value, and the maximum charging power of the battery is set to 0, so that the battery can be discharged but cannot be charged.

[0012] In the technical solutions, when the voltage of an electric control component (such as a motor controller, a direct current converter, etc.) continuously exceeds the maximum voltage of the battery, it is inferred that there is an abnormal external high-voltage backflow or a charging circuit failure risk, the maximum charging power of the battery is forcibly set to zero, and the discharging power of the battery is limited, so as to prevent the battery from being dangerously charged in the abnormal high-voltage environment, and thus the extreme safety hazards such as battery thermal runaway caused by overcharging are fundamentally avoided. Meanwhile, the limited discharging capacity ensures the maintenance of the basic functions of the vehicle.

[0013] In some embodiments of the present application, when it is determined that the battery management system fails, if the voltage of any electric control component is lower than the minimum voltage of the battery and lasts for a third preset time, the maximum charging power of the battery is set to a first set value, and the maximum discharging power of the battery is set to 0, so that the battery can be charged but cannot be discharged.

[0014] In the technical solutions, by continuously stabilizing the difference between the voltage of the electric control component and the maximum voltage of the battery in a set, non-transient high range, the moderate charging and discharging functions of the battery are maintained, the cumulative risks caused by charging in an uncertain voltage environment are avoided, the limited discharging capacity ensures the operation of the basic functions of the system, and the whole vehicle remains controllable and stable in an uncertain electrical environment.

[0015] In some embodiments of the present application, the battery is used to supply power to a plurality of electric control components; the working parameters of the battery at least include a minimum voltage; when it is determined that the battery management system fails, if the voltage of any electric control component is lower than the minimum voltage of the battery and lasts for a third preset time, the maximum charging power of the battery is set to a first set value, and the maximum discharging power of the battery is set to 0, so that the battery can be charged but cannot be discharged.

[0016] In the technical solutions, when the voltage of the electric control component continuously exceeds the minimum voltage of the battery, it is indicated that there is an abnormal voltage drop in the high-voltage loop, and the battery will face excessive loss if it continues to discharge. By setting the maximum charging power of the battery to a first set value and the maximum discharging power to 0, the discharging loop of the battery is cut off in the case of excessively low bus voltage, so as to avoid the damage of the battery caused by excessive discharge to the low-voltage bus, such as sudden voltage drop and increased internal resistance, and at the same time, the battery is allowed to receive charging to supplement the power, so as to prevent the battery from being shortened or even permanently damaged due to deep discharge, and to protect the structural integrity and service life of the battery.

[0017] In some embodiments of the present application, when it is determined that the battery management system fails, if the voltage of any of the electric control components and the minimum voltage of the battery have a difference higher than a second threshold value and last for a fourth preset time, the maximum discharge power of the battery is set to a first set value, and the maximum charge power of the battery is set to a second set value.

[0018] In the technical solution, when the voltage of the electric control component and the minimum voltage of the battery have a difference lasting in a set low range, by setting the maximum discharge power of the battery to a first set value and the maximum charge power of the battery to a second set value, the basic charge and discharge capacity of the battery can be maintained when the voltage difference between the electric control component and the battery voltage is in a safe range, the normal operation of the vehicle is avoided due to extreme power limitation, the overcharge or overdischarge of the battery is prevented, and the operation stability and the battery safety protection effect of the hybrid vehicle in this working condition are considered.

[0019] In some embodiments of the present application, after it is determined that the battery management system fails, the working parameters of the battery are still acquired in real time, it is determined whether the working parameters of the battery change in a next set monitoring period, and if the working parameters change, it is determined that the battery management system returns to normal.

[0020] In the technical solution, after it is determined that the battery management system fails, the real-time monitoring of the working parameters of the battery is still performed, once it is detected that the battery parameters start to change normally, it is determined that the battery management system function returns to normal, and all failure limitations are automatically removed, so that the power system returns to the normal cooperation mode seamlessly, the system intelligent level is improved, the power performance loss and energy waste caused by long-term failure limitation mode are avoided, and the fault self-healing ability and operation efficiency of the hybrid vehicle are improved.

[0021] In some embodiments of the present application, when it is determined that the battery management system fails, if the vehicle currently uses the battery as the only power source, the engine is immediately started and drives the vehicle by the engine instead of the battery; if the vehicle uses the battery and the engine as power sources or uses only the engine as a power source, the engine drives the vehicle.

[0022] In the technical solution, by performing a differentiated power source seamless switching strategy according to the real-time driving mode of the vehicle at the moment when it is determined that the battery management system fails, the continuity of power output is ensured. If the vehicle completely relies on the battery when the failure occurs, the engine is immediately started and drives the vehicle instead of the battery, so that the risk of vehicle stalling due to sudden loss of power is avoided; if the vehicle is in the engine driving or hybrid driving mode, the engine continues to drive the vehicle, so that the driving safety and driving smoothness are maximally guaranteed.

[0023] In a second aspect, the application provides a control system for battery management system fault determination and processing, comprising: an engine controller configured to control starting, stopping and running of the engine; a battery management system configured to monitor working parameters of the battery and control charging and discharging of the battery; a vehicle controller connected with the battery management system and the engine controller respectively; the vehicle controller is configured to: receive the working parameters of the battery from the battery management system; determine the state of the battery management system based on the processing method provided in the first aspect; issue corresponding control instructions to the engine controller and / or the battery management system according to the determination result of the state of the battery management system.

[0024] In the technical solution, the engine controller, the battery management system and the vehicle controller are provided and a communication connection among them is built, realizing systematic integration of fault determination and control instruction execution. The vehicle controller can receive the battery working parameters transmitted by the battery management system, accurately determine the state of the battery management system based on the processing method described above, and issue control instructions to the engine controller and the battery management system, and the engine controller and the battery management system execute engine start-stop and battery charging and discharging power adjustment according to the instructions. The system architecture is clear and the division of work is clear, which can realize efficient cooperative execution of fault diagnosis and control strategy, guarantee reliable implementation of various fault processing methods, improve the response speed and control accuracy of hybrid vehicle fault processing, and strengthen the operation reliability of the vehicle.

[0025] In a third aspect, the application provides a vehicle, comprising: a memory storing executable program code; a processor configured to call and run the executable program code from the memory, so that the vehicle executes the battery management system fault determination and processing method according to the first aspect.

[0026] In the technical solution, the executable program code is stored in the memory, and the processor calls and runs the code to execute the battery management system fault processing method, realizing vehicle-mounted integrated application of the fault processing strategy. The vehicle does not need to additionally add complex hardware devices, but only needs to run the software program to determine and process the battery management system fault, reducing the hardware modification cost and assembly complexity of the vehicle. At the same time, the quick calling and execution of the program code by the processor can ensure the real-time response of the fault processing strategy, guarantee the vehicle to take timely measures when the battery management system fails, and improve the intelligent level and safe operation ability of the vehicle.

[0027] The battery management system fault processing method, control system and vehicle provided by the application can quickly determine whether the battery management system has a fault by monitoring whether the battery operating parameter changes within a set monitoring period in real time, without the need for additional high-cost diagnostic hardware, thereby effectively reducing the development and manufacturing costs of the vehicle. Meanwhile, this monitoring method based directly on the core operating parameters of the battery can capture abnormalities at the first time when the battery management system has a fault such as communication loss resulting in no feedback of the parameters, thereby avoiding diagnostic delays caused by complex algorithms and ensuring that the fault state is discovered in a timely manner. After the battery management system has a fault, the highest voltage and the lowest voltage of the battery are used in combination with the characteristics of the battery to control the operating state of the battery and reasonably control the start and stop of the engine, so as to avoid overcharging or overdischarging of the battery under the premise of ensuring safe driving of the vehicle.

[0028] It can be seen from the above technical solutions that some of the additional aspects and advantages of the application will be given in the following description, some will become apparent from the following description, or will be understood through the practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a schematic flow chart of a fault determination and processing method of a battery management system according to an embodiment of the application; Figure 2 is a cycle control flow chart of a battery management system fault processing method according to an embodiment of the application; Figure 3 is an architecture diagram of a battery management system fault control system according to an embodiment of the application; Figure 4 is an architecture diagram of a vehicle according to an embodiment of the application. DETAILED DESCRIPTION

[0030] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In the present application, unless specifically defined otherwise and limited, the terms "mount", "connect", "connection", "fixed", and like terms should be construed in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrated; can be mechanical connection, or electrical connection or communication with each other; can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In the present application, unless specifically defined otherwise and limited, the first feature is "on" or "under" the second feature. The first and second features can be in direct contact, or the first and second features can be indirectly in contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature can be the first feature directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature can be the first feature directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature. In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the specification and the features of different embodiments or examples without contradiction.

[0031] In the following, the present application is specifically described by exemplary embodiments. However, it should be understood that the elements, structures and features in one embodiment can also be beneficially combined into other embodiments without further description. With the development of new energy automobile industry, hybrid vehicles become an important development direction of automobile market because of the energy saving and environmental protection of pure electric drive and the reliability of fuel drive. The power system of hybrid vehicle is composed of engine and battery, and the working state of battery directly determines the power output, driving safety and energy utilization efficiency of vehicle. The battery management system (BMS) as the core control unit of battery plays a decisive role in the stable operation of hybrid vehicle.

[0032] The BMS collects key signals such as the remaining power (SOC) of the battery, the charge and discharge power limit, the battery pack temperature, and accurately judges the working state of the battery. On the one hand, it ensures that the battery operates efficiently within a safe range and avoids damage to the battery caused by overcharging and over-discharging; on the other hand, it transmits the battery state data to the vehicle control system in real time, provides a basis for the power switching of the engine and the battery, realizes seamless cooperation between the two, and further optimizes the balance between the power performance and fuel economy of the vehicle. In a word, the BMS is the core technology link that maintains the stability of the power system of the hybrid vehicle and improves the user experience of the vehicle.

[0033] However, in the actual operation of the hybrid vehicle, the BMS is easily affected by complex driving environments, electromagnetic interference, hardware failures or software abnormalities, and other factors, resulting in communication loss, deadlocks and other failures, which brings many risks to vehicle driving. When the BMS has a communication loss failure, the signal transmission between the BMS and the vehicle controller is interrupted, and the key state parameters such as the battery SOC, the charge and discharge power, and the temperature cannot be normally uploaded, resulting in the inability of the vehicle control system to accurately control the power system due to the lack of accurate battery information, often causing vehicle power interruption, significant decrease in fuel economy, and more likely overcharging due to the inability to monitor the charging state, which seriously threatens the battery life and driving safety. If the BMS has a deadlock failure, its monitoring and management functions for the battery will be completely disabled, further increasing the risk: when the vehicle is in pure electric driving mode, the BMS cannot warn the power consumption state, which easily leads to battery over-discharge damage; after starting the engine to enter the hybrid mode, the battery will be overcharged and over-discharged due to the loss of the BMS control over the charging and discharging process, which not only reduces the fuel economy, but also causes safety hazards such as battery thermal runaway, and sudden power state abnormalities are extremely easy to cause panic emotions of users, which poses a great threat to driving safety. Therefore, the BMS failure has become a key problem restricting the operation reliability and safety of the hybrid vehicle.

[0034] Based on this, the application provides a battery management system fault judgment and processing method, a control system and a vehicle. The working parameters of the battery during vehicle driving are detected in real time, and whether the working parameters of the battery change within a monitoring period is used as a judgment basis for whether the battery management system is faulty, so that the battery management system can be found in time when it fails, and the vehicle is driven using the engine when the battery management system fails, to avoid adverse consequences caused by sudden loss of vehicle power.

[0035] Figure 1 is a schematic flowchart of a battery management system fault judgment and processing method provided by the present embodiment. The battery management system fault judgment and processing method comprises the following steps: S1, acquiring the working parameters of the battery in real time during vehicle driving; S2, determining whether the working parameter of the battery changes in a set monitoring period; S3, if the working parameter of the battery changes in the monitoring period, determining that the battery management system is normal; S4, if the working parameter of the battery does not change in the monitoring period, determining that the battery management system is faulty, and controlling the engine to drive the vehicle to run.

[0036] During the running of the vehicle, the vehicle system needs to continuously calculate and adjust the energy distribution strategy according to the changing running requirements such as acceleration, deceleration, climbing or coasting, and the real-time road conditions, battery capacity and engine efficiency curve, so as to always ensure that the whole vehicle runs in the most efficient and economical state. Therefore, the voltage, current and other parameters of the battery will fluctuate with the ups and downs of power demand, the strength of energy recovery and the optimization adjustment of the system to the engine operating point. Therefore, in a hybrid vehicle, the working parameters of the battery are always in a real-time changing state, and the battery management system is used to detect and obtain the working parameters of the battery. Therefore, when the working parameters of the battery do not change in the monitoring period, it indicates that the battery management system is faulty.

[0037] In this application, the highest voltage, the lowest voltage and other working parameters of the battery are obtained in real time during the running of the vehicle. Whether the working parameters change in the monitoring period is judged to determine whether the battery management system is faulty. If the working parameters do not change in the monitoring period, it is determined that the battery management system is faulty, and the engine is controlled to drive the vehicle to run. If the working parameters change in the monitoring period, it is determined that the battery management system is normal, and the vehicle runs normally. The fault judgment method of the battery management system does not need to rely on complex fault diagnosis sensors or algorithms, but only needs to monitor the change state of the basic working parameters of the battery to realize the rapid judgment of the fault of the battery management system. In the case that the battery management system loses communication and other faults cause no parameter feedback, the fault state can be identified in time and the power source is switched to the engine, effectively avoiding the risk of vehicle power interruption caused by battery management system failure, ensuring the continuous and stable running of the hybrid vehicle, and improving the safety and reliability of the vehicle running.

[0038] According to the different power sources of the hybrid vehicle, the driving mode of the hybrid vehicle includes three kinds, one is pure battery driving, one is engine driving alone, and the other is battery and engine driving together. If the battery management system is faulty, the battery cannot be used to reliably drive the vehicle to run, therefore, the engine is used to drive the vehicle to run.

[0039] It should be noted that when the vehicle is powered by the battery, the battery management system failure may cause the battery to fail to provide power for the vehicle, which is easy to cause the vehicle to suddenly lose power and cause adverse consequences. Therefore, when the battery management system is determined to be faulty, the engine needs to be started to replace the battery to drive the vehicle. When the vehicle is powered by the battery and the engine or only the engine, since the engine is in working condition, after the battery management system fails, the engine continues to drive the vehicle, and there is no need to start the engine again.

[0040] In this application, when the battery management system is determined to be faulty, if the vehicle is currently powered by the battery as the only power source, the engine is immediately controlled to start and replace the battery to drive the vehicle. If the vehicle is powered by the battery and the engine together, or only the engine, the engine drives the vehicle.

[0041] By executing the differentiated power source seamless switching strategy according to the real-time driving mode of the vehicle at the moment of determining the battery management system failure, the continuity of power output is ensured. If the vehicle is completely dependent on the battery drive when the failure occurs, the engine is controlled to start immediately and replace the battery to drive the vehicle, avoiding the risk of vehicle stalling due to sudden loss of power. If the vehicle is in engine drive or hybrid drive mode, the engine continues to drive the vehicle, maximizing the safety and driving smoothness of the vehicle.

[0042] When the vehicle is powered by the battery and the engine together, or only the engine, the battery management system failure still has the engine to drive the vehicle. Although the vehicle does not have safety hazards due to sudden loss of power, during the vehicle driving process, the engine charges the battery, and the battery also provides power to other components of the vehicle. Since the battery management system cannot effectively monitor and control the state of the battery, the battery is easy to be overcharged or overdischarged.

[0043] Reducing the maximum charging power of the battery will reduce the charging current of the battery, increase the charging time of the battery, and thus avoid overcharging the battery. Reducing the maximum discharge power of the battery will reduce the discharge current of the battery, increase the discharge time of the battery, and thus avoid overdischarging the battery. Therefore, in this application, after the battery management system fails, the maximum charging power and the maximum discharge power of the battery are reduced to avoid overcharging or overdischarging the battery.

[0044] Since in some vehicles, the engine is started by means of battery output power, in order to ensure that the battery can start the engine, the battery needs to have a certain charging power and discharging power to ensure that the battery can output power to start the engine. Therefore, in the present application, after the battery management system fails, the maximum discharging power and the maximum charging power of the battery are reduced to set to make the battery have the ability to start the engine, but it will not cause the battery to be over-discharged or over-charged.

[0045] Specifically, when it is determined that the battery management system fails, the maximum discharging power of the battery is set to a first set value, and the maximum charging power of the battery is set to a second set value; wherein the first set value is less than the maximum discharging power of the battery in a normal state, and the second set value is less than the maximum charging power of the battery in a normal state, to avoid the situation that the battery is over-discharged or over-charged in a fault state, and at the same time, it can also ensure that the battery has enough power to meet the demand of starting the engine, and prevent the vehicle from being stranded due to the battery being unable to start the engine because of power loss.

[0046] It should be noted that the first set value and the second set value can be equal or not equal, but it can be determined that the first set value is less than the maximum discharging power of the battery in a normal working state, and the second set value is less than the maximum charging power of the battery in a normal working state.

[0047] Preferably, the first set value is the minimum discharging power of the battery, and the second set value is the minimum charging power of the battery.

[0048] In some embodiments, the first set value is 7kw, and the second set value is 7kw.

[0049] It should be noted that the maximum discharging power of the battery includes the instantaneous maximum discharging power and the continuous maximum discharging power. In the present embodiment, the instantaneous maximum discharging power of the battery refers to the maximum power that the battery can provide within 2 seconds; and the continuous maximum discharging power of the battery refers to the maximum power that the battery can provide within 10 seconds.

[0050] After the battery management system fails, the instantaneous maximum discharging power and the continuous maximum discharging power of the battery can be set to the same value or different values, but it can be determined that the instantaneous maximum discharging power of the battery when the battery management system fails is less than the instantaneous maximum discharging power of the battery when the battery management system is normal, and the continuous maximum discharging power of the battery when the battery management system fails is less than the continuous maximum discharging power of the battery when the battery management system is normal.

[0051] In some embodiments, when the battery management system fails, the instantaneous maximum discharging power and the continuous maximum discharging power of the battery are both set to 7kw to prevent the battery from being over-charged and causing the battery to be damaged due to power loss.

[0052] Similarly, the maximum charging power of the battery includes a transient maximum charging power and a sustained maximum charging power. In this embodiment, the transient maximum charging power of the battery refers to the maximum power that the battery can provide within 2 seconds; and the sustained maximum charging power of the battery refers to the maximum power that the battery can provide within 10 seconds.

[0053] After the battery management system fails, the transient maximum charging power and the sustained maximum charging power of the battery can be set to the same value or different values. However, it can be determined that the transient maximum charging power of the battery when the battery management system fails is less than the transient maximum charging power of the battery when the battery management system is normal, and the sustained maximum charging power of the battery when the battery management system fails is less than the sustained maximum charging power of the battery when the battery management system is normal.

[0054] In some embodiments, the transient maximum charging power and the sustained maximum charging power of the battery are both set to 7kw when the battery management system fails, so as to prevent the battery from being damaged due to overcharging.

[0055] It should be noted that the purpose of setting the maximum discharging power of the battery to the first set value and setting the maximum charging power of the battery to the second set value after the battery management system fails is to start the engine. Therefore, after the engine is started, although setting the maximum discharging power of the battery to the first set value and setting the maximum charging power of the battery to the second set value can increase the discharging time and the charging time of the battery, the maximum discharging power of the battery is always set to the first set value, and the maximum charging power of the battery is always set to the second set value, which will also cause the battery to be overcharged and overdischarged.

[0056] The working parameters of the battery include a maximum voltage. The maximum voltage refers to the maximum allowable voltage value that the battery pack can reach in a full charge state or a transient peak discharging working condition. This parameter is determined by the chemical system of the battery, the series-parallel connection structure of the battery cell, and the software calibration of the battery management system (BMS). Its core function is to provide a stable upper voltage threshold for the vehicle driving system, to ensure sufficient power supply for the motor in high-power output working conditions (such as acceleration and climbing), and to prevent safety hazards such as decomposition of electrolyte inside the battery cell, damage to the positive and negative electrode material structure, and the like caused by overvoltage. It is a key upper limit indicator for defining the safe working range of the battery.

[0057] The working parameters of the battery include a minimum voltage, which refers to a minimum allowable voltage value of the battery pack in a deep discharge cutoff state or an extremely low power condition, and is a lower limit critical parameter of the battery discharge depth. The parameter functions to avoid over-discharge of the battery, prevent irreversible capacity decay, rapid increase of internal resistance, difficulty in voltage recovery, and other permanent damage caused by excessively low voltage of the battery cell, and reserves basic power supply support for the low-voltage system of the vehicle (such as vehicle-mounted electrical appliances and control systems), thereby ensuring that the hybrid vehicle can still maintain basic operation through engine direct drive or energy recovery in a low power state of the battery.

[0058] The working parameters of the battery also include a battery state of charge (SOC), which refers to a percentage of the current remaining capacity of the battery to the rated capacity of the battery, and is a core parameter reflecting the energy state of the battery. In a hybrid vehicle, the SOC provides real-time power basis for the energy management system (EMS) of the vehicle, and supports intelligent switching of the hybrid mode. For example, when the SOC is in a high range, the pure electric driving mode is preferred to reduce fuel consumption; when the SOC is lower than a set threshold, the engine is automatically started to charge the battery or directly participates in driving; meanwhile, the SOC data also provides a remaining endurance reference for the driver, and provides a decision basis for the charging and discharging strategy (such as current limiting charging and balance control) of the battery management system.

[0059] The working parameters of the battery also include a battery current, which refers to the directional movement rate of electric charge of the battery during charging and discharging, and is divided into charging current and discharging current. The value is determined by the working condition of the vehicle (such as acceleration, braking, and idling) and the dynamic regulation of the battery management system. In a hybrid vehicle, the discharging current functions to provide an energy carrier for power output of the driving motor, and the current size directly corresponds to the power output level of the motor, thereby meeting the power demand of the vehicle in different driving conditions; the charging current functions to store energy, including engine power generation charging and braking energy recovery charging, and reasonable charging current can ensure rapid energy compensation of the battery and avoid overcurrent damage.

[0060] The working parameters of the battery also include a maximum single cell voltage of the battery, which refers to a real-time voltage value of a single cell with the highest voltage among all cells in the battery pack. The parameter is affected by factors such as consistency of the cells, charging and discharging rate, and temperature difference. The core function is to provide a targeting basis for balance control of the battery management system. When the voltage of a single cell is significantly higher than that of other cells, the BMS will start an active balance strategy to transfer the excess energy of the cell to a cell with lower voltage, thereby avoiding the situation that the entire pack cannot be normally charged and discharged due to the protection mechanism triggered by overvoltage of a single cell, and preventing safety risks such as lithium precipitation and thermal runaway of a high-voltage single cell.

[0061] The working parameters of the battery further include a minimum single-cell voltage of the battery, which refers to a real-time voltage value of a single cell with the lowest voltage among all cells in the battery pack, and is a key indicator reflecting the consistency of the cells and the depth of discharge. In a hybrid vehicle, its role is to prevent over-discharge of a single cell - when the voltage of a single cell drops to the lowest allowable threshold, the battery management system will immediately shut down the discharge circuit or limit the discharge current to prevent irreversible capacity loss due to under-voltage of the cell; at the same time, the minimum single-cell voltage data is also an important input for battery equalization control, and the BMS can improve the voltage level of the low-voltage single cell through the equalization strategy to ensure that the voltages of the cells in the whole pack tend to be consistent, thereby ensuring the charge-discharge performance and cycle life of the battery pack.

[0062] It should be noted that the working parameters of the battery are well known in the art and will not be described here.

[0063] In a hybrid vehicle, the battery is also connected to the electric control components on the vehicle for supplying power to the electric control components and the corresponding electrical equipment of the electric control components, which include but are not limited to a traction motor controller (TMCU), a DC-DC converter (DCDC), and a rear axle motor controller (P4M). The traction motor controller realizes precise speed regulation, torque control, and operation state management of the main drive motor according to the vehicle control command. The DC-DC converter is used to realize bidirectional or unidirectional conversion of different voltage level direct current power, to ensure power supply of the low-voltage electrical equipment of the whole vehicle and adjustment of power battery energy recovery. The rear axle motor controller is used to control the operation of the rear axle motor to realize four-wheel drive, torque vector distribution, and multi-mode power coordination of the vehicle.

[0064] For convenience of description, the traction motor controller, the DC-DC converter, and the rear axle motor controller are referred to as electric control components, and the traction motor connected to the traction motor controller and the rear axle motor connected to the rear axle motor controller are referred to as electrical equipment.

[0065] Since the battery is connected to the electric control components and the electrical equipment, if the maximum voltage of the battery is lower than the voltage of the electric control components or the voltage of the electrical equipment, external high voltage may flow back, causing current to flow reversely into the battery, which may cause overcharging of the battery, accumulation of internal heat, and even thermal runaway and other serious safety accidents. If the voltage of the electric control components or the voltage of the electrical equipment is lower than the minimum voltage of the battery, the battery may discharge to the electric control components or the electrical equipment with excessive current, which may cause the battery to be excessively pulled down in voltage and enter an over-discharge state, damaging the battery health and shortening the life.

[0066] It should be noted that the bus voltage of the electric control component is higher than the voltage of the electrical equipment, and therefore, in the present application, the bus voltage of the electric control component is compared with the maximum voltage and the minimum voltage of the battery for judgment.

[0067] Based on this, in the present application, after the battery management system fails, the working state of the battery is controlled and the start-stop of the engine is reasonably controlled based on the highest voltage and the lowest voltage of the battery in combination with the characteristics of the battery, so as to avoid overcharging or overdischarging of the battery on the premise of ensuring safe driving of the vehicle.

[0068] Specifically, after it is determined that the battery management system fails, if the voltage of any electric control component is higher than the highest voltage of the battery and lasts for a first preset time, the maximum discharging power of the battery is set to a first set value, and the maximum charging power of the battery is set to 0, so that the battery can be discharged but cannot be charged.

[0069] By forcibly setting the maximum charging power of the battery to zero, the battery is prevented from being dangerously charged in this abnormally high voltage environment, thereby fundamentally avoiding the extreme safety hazards such as battery thermal runaway that may be caused by overcharging. At the same time, the limited discharging capability ensures the maintenance of the basic functions of the vehicle.

[0070] In some embodiments, the first preset time is 5s.

[0071] After the battery can only be discharged but cannot be charged, as the battery discharges, the remaining power of the battery decreases, and the highest voltage of the battery decreases. When the difference between the voltage of any electric control component and the highest voltage of the battery is lower than a first threshold and lasts for a second preset time, the voltage of the battery management system continues to be in a high critical state. The battery continues to discharge, and the battery may be overdischarged. Therefore, in the present application, by setting the maximum discharging power of the battery to a first set value and setting the maximum charging power of the battery to a second set value, the battery can be charged and discharged, thereby maintaining the moderate charging and discharging function of the battery, avoiding the cumulative risks that may be caused by charging in an uncertain voltage environment, and ensuring the operation of the basic functions of the system by maintaining the limited discharging capability, so that the whole vehicle remains controllable and stable in an uncertain electrical environment.

[0072] Specifically, after it is determined that the battery management system fails, if the difference between the voltage of any electric control component and the highest voltage of the battery is lower than a first threshold and lasts for a second preset time, the maximum discharging power of the battery is set to a first set value, and the maximum charging power of the battery is set to a second set value.

[0073] In some embodiments, the first threshold is -10V, and the second preset time is 5s.

[0074] After it is determined that the battery management system fails, if the voltage of any electric control component is lower than the lowest voltage of the battery and lasts for a third preset time, the maximum charging power of the battery is set to a first set value, and the maximum discharging power of the battery is set to 0, so that the battery can be charged but cannot be discharged.

[0075] In some embodiments, the third preset time is 5s.

[0076] When the difference between the voltage of the electric control component and the minimum voltage of the battery is higher than the second threshold value and lasts for the fourth preset time after the battery can only be charged but cannot be discharged, the battery is more and more charged, and if the battery continues to be charged without being discharged, the battery is easy to be damaged due to overcharging. When the minimum voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter and the bus voltage of the rear axle motor controller is higher than the second threshold value and lasts for the fourth preset time, it indicates that the battery is in a safe interval. In this application, when the system monitors that the difference between the minimum bus voltage and the minimum voltage of the battery lasts in a set low range, the maximum discharge power of the battery is set to a first set value, and the maximum charging power of the battery is set to a second set value, so as to maintain the basic charging and discharging capacity of the battery when the difference between the bus voltage and the battery voltage is in the safe interval, avoid the influence of extreme power limitation on the normal operation of the vehicle, prevent the overcharging or overdischarging of the battery, and balance the operation stability of the hybrid vehicle in this working condition and the safety protection effect of the battery.

[0077] Specifically, when it is determined that the battery management system fails, if the difference between the voltage of any electric control component and the minimum voltage of the battery is higher than the second threshold value and lasts for the fourth preset time, the maximum discharge power of the battery is set to a first set value, and the maximum charging power of the battery is set to a second set value.

[0078] In some embodiments, the second threshold value is 10V, and the fourth preset time is 5s.

[0079] It should be noted that the voltage of the electric control component is usually fixed, and the voltage of the electric control component cannot be both higher than the maximum voltage of the battery and lower than the minimum voltage of the battery. The comparison of the voltage of the electric control component with the maximum voltage and the minimum voltage of the battery is independent of each other. In actual application, the voltage of the electric control component can be compared with the maximum voltage of the battery first, and then compared with the minimum voltage of the battery; or the voltage of the electric control component can be compared with the minimum voltage of the battery first, and then compared with the maximum voltage of the battery; or the voltage of the electric control component can be compared with the maximum voltage and the minimum voltage of the battery at the same time.

[0080] It should also be noted that the bus voltage of the electric control component is usually the highest voltage region in the electric control component.

[0081] In some embodiments, when the battery management system is determined to be faulty, the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter, and the bus voltage of the rear axle motor controller are acquired in real time, the maximum and minimum values thereof are extracted, and the highest or lowest voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter, and the bus voltage of the rear axle motor controller is compared with the highest or lowest voltage of the battery, so as to determine the maximum discharge power and the maximum charge power of the battery under the premise of ensuring the safety of the battery.

[0082] It should be noted that the bus voltage of the traction motor controller (TMCU) refers to the DC bus voltage between the battery and the motor controller, which is used to transmit high-voltage power to drive the motor to operate. The bus voltage of the DC-DC converter (DCDC) refers to the DC voltage at the input side (such as the high-voltage side of the battery) or the output side (such as the low-voltage system side) of the converter, which is used to realize conversion between different voltage levels. The bus voltage of the rear axle motor controller (P4M) is similar to the bus voltage of the TMCU in an electric vehicle or a hybrid vehicle, which refers to the DC bus voltage between the high-voltage power supply and the motor controller. The bus voltage of the electric control components, the bus voltage of the electrical equipment in the vehicle, and the like are well known in the art, and will not be described here.

[0083] In actual applications, the battery management system may only be temporarily faulty due to other factors, and may automatically recover to normal after the influencing factors are eliminated. After the battery management system is faulty, the maximum charge power and the maximum discharge power of the battery are both reduced, which reduces the performance of the vehicle. If the battery management system is only temporarily faulty, and the maximum charge power and the maximum discharge power of the battery are still low after the battery management system recovers to normal, the power performance of the vehicle will be wasted and energy will be wasted.

[0084] Therefore, in the present application, after the battery management system is determined to be faulty, the real-time monitoring of the working parameters of the battery is still performed. Once it is detected that the battery parameters start to change normally again, it is determined that the battery management system has recovered, and all fault restrictions are automatically removed, so that the power system seamlessly recovers to the normal cooperation mode. This not only improves the intelligent level of the system, but also avoids the power performance loss and energy waste caused by long-term operation in the fault limitation mode, and improves the fault self-healing ability and operating efficiency of the hybrid vehicle.

[0085] Specifically, after the battery management system is determined to be faulty, the working parameters of the battery are still acquired in real time, it is determined whether the working parameters of the battery change in the next set monitoring period, if the working parameters change, it is determined that the battery management system has recovered to normal, and the battery and the engine are controlled to recover to the operating state before the fault is determined; if the working parameters do not change, the battery and the engine continue to execute the fault control logic.

[0086] For example, Figure 2The fault determination and processing method of the battery management system is introduced in detail, for example, comparing the voltage of the electric control component with the highest voltage of the battery first, and then comparing the voltage of the electric control component with the lowest voltage of the battery, including the following steps: acquiring the working parameters of the battery in real time during the driving of the vehicle; the working parameters of the battery at least include the highest voltage and the lowest voltage; judging whether the working parameters of the battery change in a set monitoring period; if the working parameters of the battery change in the monitoring period, determining that the battery management system is normal; if the working parameters of the battery do not change in the monitoring period, determining that the battery management system is faulty; when determining that the battery management system is faulty, controlling the engine to drive the vehicle to drive; setting the maximum discharge power of the battery as a first set value and setting the maximum charge power of the battery as a second set value; acquiring the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter and the bus voltage of the rear axle motor controller; acquiring the current highest voltage and the current lowest voltage of the battery; further judging whether the highest voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter and the bus voltage of the rear axle motor controller is higher than the highest voltage of the battery and lasts for a first preset time; if the highest voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter and the bus voltage of the rear axle motor controller is higher than the highest voltage of the battery and lasts for the first preset time, setting the maximum discharge power of the battery as the first set value and setting the maximum charge power of the battery as 0; if the highest voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter and the bus voltage of the rear axle motor controller is lower than the highest voltage of the battery or does not last for the first preset time, further judging whether the difference between the highest voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter and the bus voltage of the rear axle motor controller and the highest voltage of the battery is lower than a first threshold value and lasts for a second preset time; if the difference between the highest voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter and the bus voltage of the rear axle motor controller and the highest voltage of the battery is lower than the first threshold value and lasts for the second preset time, setting the maximum discharge power of the battery as the first set value and setting the maximum charge power of the battery as the second set value; If the difference between the highest voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter, the bus voltage of the rear axle motor controller and the highest voltage of the battery is higher than the first threshold value or does not last for the second preset time, it is further judged whether the lowest voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter, the bus voltage of the rear axle motor controller is lower than the lowest voltage of the battery and lasts for the third preset time; If the lowest voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter, the bus voltage of the rear axle motor controller is lower than the lowest voltage of the battery and lasts for the third preset time, the maximum charging power of the battery is set as the first set value and the maximum discharging power of the battery is set as 0. If the lowest voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter, the bus voltage of the rear axle motor controller is higher than the lowest voltage of the battery or does not last for the third preset time, it is further judged whether the difference between the lowest voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter, the bus voltage of the rear axle motor controller and the lowest voltage of the battery is higher than the second threshold value and lasts for the fourth preset time. If the difference between the lowest voltage value among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter, the bus voltage of the rear axle motor controller and the lowest voltage of the battery is higher than the second threshold value and lasts for the fourth preset time, the maximum discharging power of the battery is set as the first set value and the maximum charging power of the battery is set as the second set value; if not, the highest voltage and the lowest voltage of the battery are re-acquired and compared with the highest voltage and the lowest voltage among the bus voltage of the traction motor controller, the bus voltage of the DC-DC converter, the bus voltage of the rear axle motor controller again. After the battery management system is judged to be faulty or normal, the working parameters of the battery are still acquired in real time, it is judged whether the working parameters of the battery change in the next set monitoring period, if yes, the battery management system is judged to be normal again; if not, the control logic in the fault state is still executed on the battery.

[0087] As Figure 3As shown, the application provides a battery management system fault determination and processing control system, which includes an engine controller, a battery management system and a vehicle controller; the engine controller is configured to control the start, stop and operation of the engine; the battery management system is configured to monitor the working parameters of the battery and control the charging and discharging of the battery; the vehicle controller is connected with the battery management system and the engine controller; the vehicle controller is configured to: receive the working parameters of the battery from the battery management system; determine the state of the battery management system based on the fault determination and processing method of the battery management system; and issue corresponding control instructions to the engine controller and / or the battery management system according to the determination result of the state of the battery management system.

[0088] In the application, by setting the engine controller, the battery management system and the vehicle controller and constructing the communication connection among them, the systematic integration of fault determination and control instruction execution is realized. The vehicle controller can receive the battery working parameters transmitted by the battery management system, accurately determine the state of the battery management system based on the previous processing method, and issue control instructions to the engine controller and the battery management system, and the engine controller and the battery management system complete the engine start-stop and battery charging-discharging power adjustment operations according to the instructions. The system architecture is clear, the division of labor is clear, and the efficient cooperative execution of fault diagnosis and control strategy can be realized, the reliable implementation of various fault processing methods can be ensured, the response speed and control accuracy of hybrid vehicle fault processing can be improved, and the operation reliability of the whole vehicle can be strengthened.

[0089] The working process of the battery management system fault determination and processing control system is as follows: The battery management system sends the maximum voltage, minimum voltage, SOC, current, maximum single cell voltage and minimum single cell voltage of the battery to the vehicle controller; The vehicle controller receives the maximum voltage, minimum voltage, SOC, current, maximum single cell voltage and minimum single cell voltage of the battery sent by the battery management system; When the hybrid vehicle is driving, the vehicle controller needs to continuously determine the SOC, current, maximum single cell voltage and minimum single cell voltage of the battery management system; When the vehicle controller determines that the SOC, current, maximum single cell voltage and minimum single cell voltage of the battery management system remain unchanged for 1 min, the vehicle controller determines that the battery management system has an abnormal dead fault; during the 1 min, if any of the SOC, current, maximum single cell voltage and minimum single cell voltage of the battery management system changes, the vehicle controller should cancel the 1 min timing; When the vehicle controller judges the dead fault of the battery management system, the vehicle controller sends the instruction of starting the engine to the engine controller, and at the same time, sends the instruction to the battery management system, so that the instantaneous maximum discharge power and the continuous maximum discharge power of the battery are set to 7kw, and the instantaneous maximum charging power and the continuous maximum charging power of the battery are set to 7kw; When the vehicle controller detects that Max (TMCU bus voltage, DCDC bus voltage, P4M bus voltage) is higher than the highest voltage of the battery management system for 5s, the vehicle controller sends an instruction to the battery management system to set the instantaneous maximum discharge power and the continuous maximum discharge power of the battery to 7kw, and the instantaneous maximum charging power and the continuous maximum charging power of the battery to 0kw; When the vehicle controller detects that Max (TMCU bus voltage, DCDC bus voltage, P4M bus voltage) is lower than the highest voltage of the battery management system-10V for 5s, the vehicle controller sends an instruction to the battery management system to set the instantaneous maximum discharge power and the continuous maximum discharge power of the battery to 7kw, and the instantaneous maximum charging power and the continuous maximum charging power of the battery to 7kw; When the vehicle controller detects that Min (TMCU bus voltage, DCDC bus voltage, P4M bus voltage) is lower than the lowest voltage of the battery management system for 5s, the vehicle controller sends an instruction to the battery management system to set the instantaneous maximum discharge power and the continuous maximum discharge power of the battery to 0kw, and the instantaneous maximum charging power and the continuous maximum charging power of the battery to 7kw; When the vehicle controller detects that Min (TMCU bus voltage, DCDC bus voltage, P4M bus voltage) is higher than the lowest voltage of the battery management system+10V for 5s, the vehicle controller sends an instruction to the battery management system to set the instantaneous maximum discharge power and the continuous maximum discharge power of the battery to 7kw, and the instantaneous maximum charging power and the continuous maximum charging power of the battery to 7kw; When the vehicle controller detects that the SOC, current, maximum single cell voltage and minimum single cell voltage sent by the battery management system have any value change, the vehicle controller judges that the battery management system has no dead fault, and the vehicle controller controls the battery management system to clear the instructions received in the battery management system fault process.

[0090] As shown in Figure 4 The application provides a vehicle, which comprises a memory and a processor; the memory stores executable program code; the processor is used to call and run the executable program code from the memory, so that the vehicle executes the fault judgment and processing method of the battery management system.

[0091] In the present application, by storing executable program code in the memory and calling the code by the processor to execute the battery management system fault handling method, the vehicle-mounted integrated application of the fault handling strategy is realized. The vehicle does not need to additionally add complex hardware devices, and only through the running of the software program can the determination and processing of the battery management system fault be completed, reducing the hardware modification cost and assembly complexity of the whole vehicle. At the same time, the quick calling and execution of the program code by the processor can ensure the real-time response of the fault handling strategy, ensure that the vehicle takes timely measures when the battery management system fails, and improve the intelligent level and safe operation ability of the vehicle.

[0092] In the embodiment of the present application, a power indicator light is provided on the vehicle instrument panel. When it is determined that the battery management system fails, the power indicator light changes to prompt the driver and passenger that the battery management system fails.

[0093] The power indicator light is connected with the vehicle controller, and the vehicle controller controls the power indicator light to adjust the brightness or the color of the light according to the fault judgment result of the battery management system.

[0094] In some embodiments, when the maximum discharge power of the battery is set to a first set value and the maximum charging power of the battery is set to a second set value, the power indicator light is bright in a first color; when the maximum discharge power of the battery is set to the first set value and the maximum charging power of the battery is set to 0, the power indicator light is bright in a second color; when the maximum charging power of the battery is set to the first set value and the maximum discharge power of the battery is set to 0, the power indicator light is bright in a third color; when the battery is working normally, the power indicator light is bright in a fourth color.

[0095] During the driving of the vehicle, the battery management system sends the highest voltage, the lowest voltage, the SOC, the current, the maximum single cell voltage and the minimum single cell voltage of the battery to the vehicle controller; the vehicle controller receives the highest voltage, the lowest voltage, the SOC, the current, the maximum single cell voltage and the minimum single cell voltage of the battery sent by the battery management system.

[0096] When the hybrid vehicle is driving, the vehicle controller needs to continuously judge the SOC, the current, the maximum single cell voltage and the minimum single cell voltage of the battery management system; when the vehicle controller judges that the SOC, the current, the maximum single cell voltage and the minimum single cell voltage of the battery management system do not change continuously for 1 min, the vehicle controller judges that the battery management system has an abnormal dead fault; during the 1 min, when any one of the SOC, the current, the maximum single cell voltage and the minimum single cell voltage of the battery management system changes, the vehicle controller should cancel the 1 min timing.

[0097] When the vehicle controller judges the dead fault of the battery management system, the following control strategy of the battery fault should be executed: a. Request engine start, prohibit shutdown; b. Power reduction indicator light; c. The vehicle controller sets the instantaneous maximum discharge power and the continuous maximum discharge power of the battery management system to 7kw, and sets the instantaneous maximum charging power and the continuous maximum charging power of the battery management system to 7kw; d. When the vehicle controller detects that Max (TMCU bus voltage, DCDC bus voltage, P4M bus voltage) is higher than the maximum voltage of the battery management system for 5s, the vehicle controller sets the instantaneous maximum discharge power and the continuous maximum discharge power of the battery management system to 7kw, and sets the instantaneous maximum charging power and the continuous maximum charging power of the battery management system to 0kw. At this time, only battery discharge is allowed, and charging is not allowed, so as to avoid causing the battery pack to be overcharged. When the vehicle controller detects that Max (TMCU bus voltage, DCDC bus voltage, P4M bus voltage) is lower than the maximum voltage of the battery management system-10V for 5s, the vehicle controller sets the instantaneous maximum discharge power and the continuous maximum discharge power of the battery management system to 7kw, and sets the instantaneous maximum charging power and the continuous maximum charging power of the battery management system to 7kw; e. When the vehicle controller detects that Min (TMCU bus voltage, DCDC bus voltage, P4M bus voltage) is lower than the minimum voltage of the battery management system for 5s, the vehicle controller sets the instantaneous maximum discharge power and the continuous maximum discharge power of the battery management system to 0kw, and sets the instantaneous maximum charging power and the continuous maximum charging power of the battery management system to 7kw. At this time, only battery charging is allowed, and battery discharge is not allowed; when the vehicle controller detects that Min (TMCU bus voltage, DCDC bus voltage, P4M bus voltage) is higher than the minimum voltage of the battery management system+10V for 5s, the vehicle controller sets the instantaneous maximum discharge power and the continuous maximum discharge power of the battery management system to 7kw, and sets the instantaneous maximum charging power and the continuous maximum charging power of the battery management system to 7kw; When the vehicle controller detects that any one of the SOC, current, maximum single cell voltage and minimum single cell voltage sent by the battery management system changes, the vehicle controller judges that the battery management system has no dead machine fault, and the vehicle controller clears all control strategies of the battery fault.

[0098] In the present application, when the battery management system is determined to be faulty, the vehicle power is switched first to ensure the reliability of vehicle driving, and then the battery is processed for fault, so as to avoid overcharging or overdischarging of the battery.

[0099] The battery management system fault processing method, control system and vehicle provided by the application can quickly determine whether the battery management system has a fault by monitoring whether the battery operating parameters change within a set monitoring period. The traditional mode of relying on complex fault diagnosis sensors or algorithms is abandoned, and the determination logic of "monitoring whether the battery operating parameters change within a set period" is adopted. The fluctuation state of the basic operating parameters such as the highest voltage, the lowest voltage, the remaining power and the current of the battery is tracked, so that the quick identification of the battery management system fault can be completed, without the need for additional high-cost diagnostic hardware, thereby effectively reducing the research and development and manufacturing costs of the vehicle. At the same time, the monitoring method based on the core parameters of the battery operation can capture the abnormality at the first time when the battery management system has a fault such as communication loss, which leads to no feedback of the parameters, thereby avoiding the diagnostic delay caused by the complex algorithm and ensuring that the fault state is discovered in time.

[0100] Once it is determined that the battery management system has a fault, the system immediately adopts a differentiated power source switching strategy according to the current driving mode of the vehicle. If the vehicle is driven by the battery only, the engine is controlled to start and replace the driving. If the engine or the hybrid driving is used, the engine continues to work. The strategy ensures that the vehicle will not suddenly lose power due to the battery management system fault in any working condition, effectively avoids the driving safety hazards caused thereby, and ensures the driving safety.

[0101] After the battery management system fails, the system dynamically adjusts the maximum charging and discharging power of the battery, and introduces an intelligent control logic based on the comparison between the bus voltage of the high-voltage component and the battery voltage. When it is detected that the bus voltage is abnormally high and lasts for a certain period of time, the charging is prohibited and only limited discharging is allowed to prevent overcharging risk. When the bus voltage is abnormally low and lasts for a certain period of time, the discharging is prohibited and only limited charging is allowed to avoid overdischarging damage. When the voltage difference is within a safe range, the charging and discharging power is maintained at a low level to balance the battery protection and basic function demand. The overcharging and discharging of the battery caused by the loss of control of the battery management system are effectively avoided in the fault state of the battery management system, thereby prolonging the service life of the battery.

[0102] During the fault processing process, the system continuously monitors the change of the battery parameters. Once the dynamic change of the parameters is detected again, it is automatically determined that the battery management system returns to normal, and all fault limitation measures are immediately removed, so that the power system returns to the normal cooperation mode. The unnecessary performance limitation and energy waste caused by the continuous fault state are avoided, and the intelligent level and operating economy of the vehicle are improved.

[0103] Through the cooperative architecture of the vehicle controller, the battery management system and the engine controller, seamless integration of fault determination, instruction issuing and execution is realized, ensuring the rapid response and accurate implementation of the fault handling strategy. At the same time, the power indicator light equipped on the vehicle instrument panel can display different colors according to different fault states, directly prompting the system state to the driver and passenger, and enhancing the friendliness of human-computer interaction and the transparency of driving situation.

[0104] The fault handling method is realized by software program integration, and the executable program code is stored in the memory, which can be called and run by the processor to complete the entire fault determination and processing flow. No additional complex hardware devices are needed, which greatly reduces the hardware modification cost and assembly complexity of the vehicle. At the same time, the power indicator light prompt function is also designed, which can intuitively feedback the fault state of the battery management system through the change of different colors or brightness, so that the driver and passenger can timely perceive the abnormal operation of the vehicle, and improve the perception and safety in the process of using the vehicle. This software implementation method also has strong adaptability and can be flexibly applied to different types of hybrid electric vehicles, and has wide popularization value.

[0105] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method for fault diagnosis and handling in a battery management system, characterized in that, Applied to hybrid vehicles; the processing method includes the following steps: The battery's operating parameters are acquired in real time while the vehicle is in motion; Determine whether the battery's operating parameters have changed within the set monitoring period; If the battery's operating parameters change during the monitoring period, the battery management system is deemed to be functioning normally. If the battery's operating parameters do not change during the monitoring period, the battery management system is determined to be faulty, and the engine is controlled to drive the vehicle.

2. The fault diagnosis and handling method for the battery management system according to claim 1, characterized in that, When the battery management system is determined to be faulty, the maximum discharge power of the battery is set to a first set value, and the maximum charging power of the battery is set to a second set value. Wherein, the first set value is less than the maximum discharge power of the battery under normal conditions, and the second set value is less than the maximum charging power of the battery under normal conditions.

3. The fault diagnosis and handling method for the battery management system according to claim 1, characterized in that, The battery is used to power multiple electronic control components; the operating parameters of the battery include at least the maximum voltage; when the battery management system is determined to be faulty, if the voltage of any of the electronic control components is higher than the maximum voltage of the battery and continues for a first preset time, the maximum discharge power of the battery is set to a first preset value, and the maximum charging power of the battery is set to 0, so that the battery can discharge but cannot be charged.

4. The fault diagnosis and handling method for the battery management system according to claim 3, characterized in that, When a fault is determined in the battery management system, if the difference between the voltage of any electronic control component and the highest voltage of the battery is lower than a first threshold and continues for a second preset time, then the maximum discharge power of the battery is set to a first preset value and the maximum charging power of the battery is set to a second preset value.

5. The fault diagnosis and handling method for the battery management system according to claim 1, characterized in that, The battery is used to power multiple electronic control components; the operating parameters of the battery include at least a minimum voltage; when the battery management system is determined to be faulty, if the voltage of any electronic control component is lower than the minimum voltage of the battery and this condition persists for a third preset time, the maximum charging power of the battery is set to a first preset value, and the maximum discharging power of the battery is set to 0, so that the battery can be charged but cannot be discharged.

6. The fault diagnosis and handling method for the battery management system according to claim 5, characterized in that, When a fault is determined in the battery management system, if the difference between the voltage of any electronic control component and the minimum voltage of the battery is higher than a second threshold and continues for a fourth preset time, then the maximum discharge power of the battery is set to a first preset value and the maximum charging power of the battery is set to a second preset value.

7. The fault diagnosis and handling method for the battery management system according to claim 1, characterized in that, When the battery management system is determined to be faulty, the operating parameters of the battery are still acquired in real time to determine whether the operating parameters of the battery have changed in the next set monitoring cycle. If they have changed, the battery management system is determined to have returned to normal.

8. The fault diagnosis and handling method for the battery management system according to claim 1, characterized in that, When the battery management system is determined to be faulty, if the vehicle is currently using the battery as the sole power source, the engine will be started immediately and the engine will take over from the battery to drive the vehicle. If the vehicle uses both the battery and the engine as a power source, or uses the engine alone as a power source, then the engine will continue to drive the vehicle.

9. A control system for fault diagnosis and handling in a battery management system, characterized in that, include: Engine controller, configured to control the starting, stopping and running of the engine; A battery management system configured to monitor the operating parameters of the battery and control the charging and discharging of the battery; The vehicle controller is connected to the battery management system and the engine controller respectively; the vehicle controller is configured as follows: Receive operating parameters of the battery from the battery management system; The state of the battery management system is determined based on the processing method according to any one of claims 1 to 8; Based on the determination result of the battery management system status, corresponding control commands are issued to the engine controller and / or the battery management system.

10. A vehicle, characterized in that, include: Memory, which stores executable program code; A processor is configured to call and run the executable program code from the memory, causing the vehicle to perform the fault determination and handling method of the battery management system as described in any one of claims 1 to 8.

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