Battery system for a vehicle, control method for a battery system, computer program product, and vehicle

Abstract

The invention relates to the technical field of batteries, in particular to a battery system for a vehicle, which comprises at least two battery packs internally provided with a plurality of mutually connected battery cells respectively; a switching matrix including a plurality of switching elements and at least one discharge resistor and connected between the at least two battery packs and a vehicle load; and when an abnormal battery pack exists in the at least two battery packs, the battery management unit controls the switch matrix to realize an emergency mode, in the emergency mode, the switch matrix disconnects the abnormal battery pack from the load and connects the abnormal battery pack to the discharge resistor for discharging, and meanwhile, the switch matrix connects the normal battery pack to the vehicle load for power supply. The invention also relates to a control method for a battery system, a computer program product and a vehicle. Therefore, the residual energy in the abnormal battery pack can be obviously reduced, the basic driving capability of the vehicle is kept, a precious emergency disposal time window is provided for a driver, and the life safety of passengers is effectively protected.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more specifically to a battery system for a vehicle, a control method for the battery system, a computer program product, and a corresponding vehicle. Background Technology

[0002] With the global energy structure transformation and increasing environmental awareness, the new energy vehicle industry has experienced unprecedented rapid development over the past decade. As the core power source of new energy vehicles, the technological advancement of power battery systems directly determines the driving range, charging efficiency, safety performance, and overall user experience of electric vehicles. Against this backdrop, high-voltage battery platforms have gradually become the mainstream trend in the industry, especially the widespread application of 800-volt high-voltage platforms, which have brought higher charging power, shorter charging time, and better power performance to electric vehicles. However, with the increase in battery system voltage levels and energy density, battery safety issues have increasingly become a key bottleneck restricting the further development of the new energy vehicle industry. Among these, battery thermal runaway is one of the most serious safety threats facing power battery systems. Thermal runaway refers to the uncontrollable temperature rise that occurs in a battery under certain abnormal conditions. This temperature rise triggers a series of exothermic chemical reactions, causing a sharp increase in the internal temperature of the battery, which may ultimately lead to battery fire or even explosion.

[0003] In existing electric vehicle power battery system designs, the industry has developed various protection technologies and solutions to address battery thermal safety issues. The most common passive protection measures include using efficient liquid cooling systems to regulate battery temperature, employing thermal insulation materials between cells to slow heat propagation within the battery pack, and using thermal phase change materials to absorb the large amounts of heat released during thermal runaway. Furthermore, the battery pack's structural design also considers venting and depressurization requirements during thermal runaway, using dedicated venting channels and explosion-proof valves to guide the high-temperature, high-pressure gases generated by thermal runaway to the outside of the vehicle, preventing direct threats to the passenger compartment. Regarding active monitoring, modern battery management systems are typically equipped with various sensors, including temperature sensors, voltage sensors, and pressure sensors, to monitor the battery's operating status in real time. Once an abnormal signal is detected, the system will issue a warning and take appropriate protective measures.

[0004] However, while the aforementioned existing technologies have improved the safety level of power battery systems to some extent, these solutions still have significant limitations in nature. First, whether it's liquid cooling systems, thermal insulation materials, or thermal phase change materials, these technologies are all passive protection measures. Their main function is to delay the development of thermal runaway or absorb some heat, but they cannot eliminate the risk of thermal runaway. Second, in the current battery system architecture, all cells are usually directly connected in series to form a complete battery pack. When a cell experiences thermal escape or thermal runaway, due to the lack of effective electrical isolation, the problematic cell remains electrically connected to the battery system. This means that the electrical energy stored in the problematic cell cannot be actively consumed or released; it can only be converted into heat energy through chemical reactions during the thermal runaway process, thus exacerbating the severity of thermal runaway. More importantly, under current technological conditions, when the power battery system detects thermal escape or thermal runaway, the usual approach is to disconnect the battery system from the vehicle load to avoid further electrical risks. While this approach protects other electrical systems of the vehicle to some extent, it also leads to a serious consequence: the vehicle loses all its power source. For electric vehicles in motion, a sudden failure of the power system can render the vehicle immobile, forcing the driver to leave it stationary and await rescue. If the vehicle is in a highway, tunnel, underground parking lot, or other hazardous environment, an immobile vehicle not only poses a greater safety threat to the occupants but may also endanger other road users and could even cause wider property damage and personal injury due to the spread of fire.

[0005] Therefore, there is still a real need for continued improvement in the design and control of battery systems used in vehicles. Summary of the Invention

[0006] In view of this, the object of the present invention is to provide an improved battery system for a vehicle, an improved control method for a battery system, an improved computer program product, and an improved vehicle, so as to at least solve some of the problems in the prior art and / or overcome other possible disadvantages not mentioned herein.

[0007] According to a first aspect of the present invention, a battery system for a vehicle is provided, wherein the battery system comprises: at least two battery packs, each battery pack including a plurality of cells interconnected with each other; a switch matrix including a plurality of switching elements and at least one discharge resistor, the switch matrix being connected between the at least two battery packs and a load of the vehicle; and a battery management unit configured to control the switch matrix to implement an emergency mode when an abnormal battery pack is present in the at least two battery packs, wherein in the emergency mode, the switch matrix disconnects the abnormal battery pack from the load and connects the abnormal battery pack to the discharge resistor for discharge, and connects a normal battery pack to the load of the vehicle for power supply.

[0008] According to an optional embodiment of the present invention, the battery management unit is further configured to control the switch matrix to achieve a first operating mode, in which the at least two battery packs are connected in series through the switch matrix to supply power to the load at a first voltage, preferably about 800V.

[0009] According to an optional embodiment of the present invention, the battery management unit is further configured to control the switch matrix to achieve a second operating mode, in which the at least two battery packs are connected in parallel through the switch matrix and charged by connecting to an external charging device at a second voltage, preferably about 400V.

[0010] According to an optional embodiment of the present invention, the switching element includes a discharge control switch and an isolating switch. The discharge control switch is adapted to connect the discharge resistor between the positive and negative terminals of the faulty battery pack, and the isolating switch is adapted to disconnect the faulty battery pack from the load. In the emergency mode, the isolating switch is opened and the discharge control switch is closed to form a discharge circuit including the faulty battery pack and the discharge resistor. The discharge circuit is electrically isolated from the power supply circuit where the load is located.

[0011] According to an optional embodiment of the present invention, in the emergency mode, the vehicle operates at reduced power.

[0012] According to an optional embodiment of the present invention, in the emergency mode, the abnormal battery pack discharges through the discharge resistor with a preset discharge current, preferably 4 to 6 amperes.

[0013] According to an optional embodiment of the present invention, in the emergency mode, the vehicle shuts down non-essential loads and maintains only the operation of essential loads, which preferably include drive motors and / or autonomous driving systems.

[0014] According to an optional embodiment of the present invention, in the emergency mode, the working port of the load is configured to receive the reduced power supply voltage.

[0015] According to an optional embodiment of the present invention, the at least two battery packs each have the same rated voltage, preferably, the rated voltage of each battery pack is 350V to 450V, and particularly preferably 400V.

[0016] According to an optional embodiment of the present invention, the at least two battery packs include two battery packs, three battery packs, or four battery packs, each battery pack including a plurality of cells connected in series.

[0017] According to an optional embodiment of the invention, the switching element includes a mechanical relay and / or a solid-state relay, the solid-state relay particularly including an IGBT and / or a MOSFET.

[0018] According to an optional embodiment of the present invention, the abnormal battery pack includes a battery pack that has been detected as having a risk of thermal runaway or a battery pack that has already experienced thermal runaway.

[0019] According to an optional embodiment of the invention, the load includes the vehicle's electronic and electrical compartment.

[0020] According to an optional embodiment of the present invention, the battery management unit determines whether there is an abnormal battery pack among the at least two battery packs based on at least one of the following parameters: battery pack voltage data, particularly detecting a sudden drop in voltage, for example, the voltage of a single cell dropping from the normal operating voltage to below a preset threshold, preferably 2V; battery pack temperature data, particularly detecting a continuous increase in the values ​​of multiple temperature sensors in the same battery pack; gas pressure data within the battery pack, particularly detecting a gas pressure increase exceeding a safety threshold; and battery pack electrochemical impedance spectroscopy data, particularly detecting abnormal electrochemical impedance spectroscopy data of the battery pack.

[0021] According to an optional embodiment of the present invention, the battery management unit is configured to: first control the vehicle to perform a power-down operation during the process of controlling the switch matrix to switch to the emergency mode, and then perform a power-on operation after the switching action of the switch element is completed.

[0022] According to a second aspect of the present invention, a control method for a battery system provided in the embodiments of the first aspect is provided, wherein the control method includes the following steps: S100: monitoring the operating state of the at least two battery packs, wherein the operating state preferably includes at least one of the cell voltage in the battery pack, the multi-point temperature of the battery pack, and the air pressure in the battery pack; S200: determining whether there is an abnormal battery pack among the at least two battery packs based on the operating state; S300: when it is determined that there is an abnormal battery pack, controlling the switch matrix to enter an emergency mode, wherein the switch element is controlled to operate to disconnect the abnormal battery pack from the load of the vehicle and connect the abnormal battery pack to the discharge resistor for discharge, and connect the normal battery pack to the load of the vehicle for power supply.

[0023] According to an optional embodiment of the present invention, in step S300, an additional warning is issued to the driver of the vehicle, reminding the driver to drive the vehicle to a safe location, or informing the driver to abandon the vehicle and control the vehicle to automatically drive to a safe location.

[0024] According to an optional embodiment of the present invention, step S300 includes the following sub-steps: S301: controlling the vehicle to perform a power-down operation; S302: controlling the corresponding switching element of the switch matrix to operate (in particular, disconnecting the isolating switch associated with the abnormal battery pack) to electrically isolate the abnormal battery pack from the power supply circuit where the load is located; S303: controlling the corresponding switching element of the switch matrix to operate (in particular, closing the discharge control switch associated with the abnormal battery pack) to connect the abnormal battery pack to the discharge resistor for discharge; S304: controlling the corresponding switching element of the switch matrix to operate (in particular, closing the isolating switch associated with the normal battery pack) to connect the normal battery pack to the load of the vehicle; S305: controlling the vehicle to perform a power-on operation to supply power to the load by the normal battery pack, wherein the vehicle preferably operates at derating power.

[0025] According to a third aspect of the present invention, a computer program product is provided, comprising computer program instructions, wherein the computer program instructions, when executed by a processor, implement the steps of the control method provided in the embodiments of the second aspect described above.

[0026] According to a fourth aspect of the present invention, a vehicle (especially an electric vehicle) is provided, wherein the vehicle includes the battery system provided in the embodiments of the first aspect and / or the computer program product provided in the embodiments of the third aspect.

[0027] According to certain embodiments of the present invention, by switching the switch matrix, when an abnormal battery pack is detected, on the one hand, the abnormal battery pack is electrically isolated from the vehicle load to prevent the fault from spreading to the entire vehicle electrical system; on the other hand, the abnormal battery pack is connected to a discharge resistor for controlled discharge, actively consuming its stored electrical energy. This active energy management strategy can significantly reduce the residual energy inside the abnormal battery pack, mitigating the severity of subsequent potential thermal runaway reactions. Simultaneously, the normal battery pack continues to supply power to the vehicle load, maintaining the vehicle's basic driving capability and providing the driver with a valuable emergency response window, thereby effectively protecting the lives of the vehicle occupants. Attached Figure Description

[0028] The invention will now be described in more detail with reference to the accompanying drawings, which will provide a better understanding of its principles, features, and advantages. The drawings include: Figure 1 A schematic diagram of a vehicle according to an exemplary embodiment of the present invention is shown; Figure 2 A schematic frame diagram of a battery system for a vehicle according to an exemplary embodiment of the present invention is shown; Figure 3 A schematic circuit connection diagram of a battery system for a vehicle according to an exemplary embodiment of the present invention is shown; Figure 4 It shows Figure 3 A schematic circuit diagram of the battery system in emergency mode; Figure 5 It shows Figure 3 Another schematic circuit connection diagram of the battery system in emergency mode; Figure 6 It shows Figure 3 A schematic circuit connection diagram of the battery system in its first operating mode; Figure 7 It shows Figure 3 A schematic circuit connection diagram of the battery system in the second operating mode; Figure 8 A schematic flowchart of a control method for a battery system according to an exemplary embodiment of the present invention is shown; and Figure 9 A structural framework diagram of a computer system according to an exemplary embodiment of the present invention is shown. Detailed Implementation

[0029] To make the technical problems to be solved, the technical solutions, and the beneficial technical effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and several exemplary embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the scope of protection of the present invention. Various embodiments may share the same view or multiple views for description, but not all features appearing in the same view should be interpreted as features that must be present in the exemplary embodiments.

[0030] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings.

[0031] Figure 1 A schematic diagram of a vehicle 2000 according to an exemplary embodiment of the present invention is shown.

[0032] like Figure 1 As shown, vehicle 2000 is preferably an electric vehicle and includes a battery system 1000, which will be described in detail below. In embodiments not specifically shown, vehicle 2000 may not be limited to passenger cars, but may also include electric trucks, electric forklifts, AGV logistics vehicles, and hybrid vehicles using power batteries. Vehicle 2000 also includes a vehicle control unit (VCU) not specifically shown.

[0033] Figure 2 A schematic frame diagram of a battery system 1000 for a vehicle 2000 according to an exemplary embodiment of the present invention is shown.

[0034] like Figure 2As illustrated, the battery system 1000 includes at least two independent battery packs (exemplarily, a first battery pack 100 and a second battery pack 200). The battery system 1000 also includes a switch matrix 1100 connected between the first battery pack 100 and the second battery pack 200 and a load 2100 of the vehicle 2000. Here, the term "switch matrix" can be a circuit topology including multiple switching elements 1110 and at least one discharge resistor 1120 capable of handling high power or a specific current. The battery system 1000 also includes a battery management unit 1200, configured, for example, as a battery management system (BMS), which can monitor the State of Health (SOH) and safety status of all battery packs in real time. When the battery management unit 1200 determines, through sensor data analysis, that the first battery pack 100 or the second battery pack 200 is an abnormal battery pack (e.g., with a risk of thermal runaway), the battery management unit 1200 controls the switch matrix 1100 to implement emergency mode M0. In Emergency Mode M0, the Battery Management Unit 1200 sends instructions to the Switch Matrix 1100 to execute a series of actions: First, it physically disconnects the abnormal battery pack from the high-voltage bus of the vehicle 2000 to prevent high-voltage short circuits or heat conduction to the load 2100 through electrical connections; second, it closes the discharge circuit switching element 1110, forming a closed loop between the abnormal battery pack and the discharge resistor 1120, actively dissipating the chemical energy within the abnormal battery pack through resistor heating, thereby reducing the severity of thermal runaway; simultaneously, the Switch Matrix 1100 reconfigures the battery pack as a normal, undamaged battery pack, connecting it independently to the vehicle load 2100. Although the supply voltage may decrease at this time, the vehicle 2000 can still obtain power, thus maintaining basic driving capability.

[0035] In a preferred embodiment, the discharge resistor 1120 is a dedicated discharge resistor element disposed in the switch matrix 1100. This dedicated discharge resistor element is one or more power resistors specifically designed to dissipate the energy of the abnormal battery pack in emergency mode M0, such as a wire-wound power resistor made of metal alloy resistance wire. In another alternative embodiment, the discharge resistor 1120 is an existing electrical component of the vehicle 2000, which is reused as a load for dissipating the energy of the abnormal battery pack in emergency mode M0. Specifically, this electrical component can be the winding of the motor of the vehicle 2000. The vehicle 200 is, for example, a four-wheel drive electric vehicle equipped with dual motors, with a front drive motor on the front axle and a rear drive motor on the rear axle, each motor being a three-phase permanent magnet synchronous motor. When the battery system 1000 enters emergency mode M0, if the second battery pack 200 is determined to be an abnormal battery pack, the switch matrix 1100 connects the first battery pack 100 to the power supply port of the electronic and electrical compartment, and the first battery pack 100 drives the rear motor to maintain vehicle operation. Simultaneously, the switch matrix 1100 connects the second battery pack 200 to the winding port of the front motor. The inverter of the front motor operates under the control of the battery management unit 1200 with a specific modulation strategy, causing the front motor windings to act as a discharge resistor 1120 to consume the energy of the second battery pack 200. The advantages of using the motor windings as the discharge resistor 1120 are: no additional dedicated discharge resistor element is required, reducing system cost and weight; motors are typically equipped with sophisticated cooling systems that effectively dissipate the heat generated during discharge; and the motor control system has precise current control capabilities, allowing for flexible adjustment of the discharge current. It should be noted that when the motor windings are used for discharge, the motor cannot simultaneously drive the vehicle; therefore, this solution is more suitable for vehicles equipped with dual or multiple motors.

[0036] In a preferred embodiment, the battery management unit 1200 is configured to monitor the operating status of each battery pack and determine whether there are any abnormal battery packs. The abnormal battery packs can include two scenarios: battery packs detected to have a risk of thermal runaway, or battery packs that have already experienced thermal runaway. A battery pack detected to have a risk of thermal runaway refers to a battery pack that has not yet entered a thermal runaway state, but the battery management unit 1200 determines, based on various monitored parameter data, that the battery pack has a potential risk of thermal runaway, i.e., the so-called pre-thermal runaway stage. The criteria for determining the risk of thermal runaway can include: the voltage of some cells showing an abnormal downward trend but not yet reaching the drastic jump required for thermal runaway; the temperature sensor within the battery pack detecting a continuous and slow temperature increase but not yet reaching a dangerous threshold; the pressure sensor within the battery pack detecting an upward trend in pressure but not yet drastic venting; and electrochemical impedance spectroscopy showing abnormal changes in the battery's internal resistance, etc. For battery packs with a risk of thermal runaway, switching them to emergency mode M0 for discharge as early as possible can reduce the battery's state of charge and energy storage level before actual thermal runaway occurs, preventively reducing the severity of potential thermal runaway. A battery pack that has already experienced thermal runaway refers to a battery pack that has entered a state of thermal runaway, characterized by violent exothermic chemical reactions within the cells, a sharp drop in voltage, a rapid rise in temperature, and possibly accompanied by exhaust, smoke, or even combustion. While connecting a battery pack that has already experienced thermal runaway to a discharge resistor cannot stop the already initiated thermal runaway reaction, the discharge process can consume some electrical energy, creating competition with the thermal runaway reaction. This can, to some extent, slow down the development of thermal runaway, reduce the peak temperature and total energy release, buy more time and margin for passive safety measures such as liquid cooling systems and thermal barrier materials, and provide a valuable window of opportunity for the safe evacuation of occupants.

[0037] In order to accurately identify abnormal battery packs, the battery management unit 1200 can monitor at least one of the following parameters in real time: battery pack voltage data, battery pack temperature data, battery pack internal pressure data, and battery pack electrochemical impedance spectroscopy data.

[0038] Voltage data is one of the most basic and important monitoring parameters of a battery management system. The voltage of each cell directly reflects its state of charge and health status. Under normal operating conditions, the terminal voltage of a lithium-ion cell is related to its chemical system. The normal operating voltage range of a ternary lithium cell is typically 2.8V to 4.2V, and that of a lithium iron phosphate cell is typically 2.5V to 3.65V, remaining relatively stable within most of the state of charge ranges. However, when thermal runaway occurs inside a cell, its voltage exhibits a characteristic sudden and drastic drop (sudden drop). This is because the intense exothermic reaction occurring inside the cell during thermal runaway damages the electrode structure and separator, leading to internal short circuits and rapid self-discharge. Therefore, the battery management unit 1200 is specifically configured to monitor situations where a sudden voltage drop occurs, such as detecting a single cell voltage dropping from its normal operating voltage to below a preset threshold, preferably 2V. When the battery management unit 1200 detects that the voltage of a cell in a battery pack suddenly drops sharply from approximately 3.6V (the normal operating voltage of a ternary lithium battery cell) to below 2V, and this drop is not a gradual decrease caused by normal discharge but a sudden and drastic change within a short period of time, the battery management unit 1200 determines that the battery pack containing that cell is an abnormal battery pack, and identifies that the battery pack has experienced or is experiencing thermal runaway. It then controls the switch matrix 1100 to enter emergency mode M0. Thermal runaway diagnosis through voltage drop detection is a fast, reliable, and cost-effective method because voltage monitoring is a standard function of the battery management system and can be implemented without additional sensors.

[0039] Temperature data is a key parameter for battery management systems to monitor battery safety status, as thermal runaway is essentially an uncontrolled exothermic reaction process, the most direct external manifestation of which is an abnormal rise in temperature. In the battery system 1000 according to an embodiment of the present invention, each battery pack is equipped with multiple temperature sensors, for example, three to six temperature sensors per battery pack. These temperature sensors are distributed in different locations within the battery pack, such as the cell surface, near the battery pack inlet and outlet, and the central area of ​​the battery module, to comprehensively monitor the temperature conditions of various areas of the battery pack. The battery management unit 1200 is configured to specifically monitor situations where the values ​​of multiple temperature sensors within the same battery pack continuously rise. Under normal operating conditions, the temperature of the battery pack will rise due to electrochemical reactions and internal resistance heating during charging and discharging. However, under the regulation of the liquid cooling system, the temperature will remain within a safe range and tend to stabilize or decrease as the load decreases. However, when a cell within a battery pack begins to experience thermal runaway or is at risk of thermal runaway, that cell will continuously release a large amount of heat, causing an abnormal rise in the temperature of its surrounding area, which then spreads outwards, affecting adjacent areas. This situation manifests as a continuous upward trend in the values ​​detected by multiple temperature sensors in the battery pack, rather than a normal stable or fluctuating state. When the battery management unit 1200 detects, for example, that the values ​​from multiple temperature sensors in the second battery pack 200 continuously rise over a period of time (e.g., tens of seconds to several minutes), and this upward trend cannot be contained by strengthening the operation of the liquid cooling system, the battery management unit 1200 determines that the second battery pack 200 is an abnormal battery pack and then controls the switch matrix 1100 to enter emergency mode M0. Thermal runaway diagnosis based on continuous temperature increases at multiple points can provide early warnings in the early stages of thermal runaway development, buying more time for emergency measures.

[0040] Gas pressure data is an important auxiliary parameter for monitoring the safety status of batteries. When a lithium-ion battery experiences thermal runaway or is in its early stages, chemical reactions such as electrolyte decomposition, negative electrode SEI film decomposition, and positive electrode decomposition occur internally, generating a large amount of gas. This gas initially causes the battery cell to swell. If the accumulated gas pressure exceeds the capacity of the cell casing or safety valve, the gas will escape from the cell and enter the sealed cavity containing the battery pack, causing an increase in pressure within the cavity. In the battery system 1000 according to an embodiment of the present invention, a gas pressure sensor is installed on the battery pack casing or battery pack housing to monitor gas pressure changes in the sealed space containing the battery pack in real time. The battery management unit 1200 is specifically configured to monitor situations where the gas pressure rises above a safety threshold. The setting of the safety threshold needs to consider the range of gas pressure fluctuations under normal operating conditions (such as gas expansion due to temperature changes) and the rate and magnitude of gas pressure rise during battery pack venting. When the battery management unit 1200 detects, for example, a rapid increase in air pressure within the cavity containing the second battery pack 200 exceeding a preset safety threshold, it indicates that there is a high probability of air venting within the battery pack. Based on this, the battery management unit 1200 determines the second battery pack 200 to be an abnormal battery pack and immediately controls the switch matrix 1100 to enter emergency mode M0. The advantage of using air pressure data for thermal runaway detection is that increased air pressure is often one of the early signs of thermal runaway, potentially occurring before a significant voltage drop or a sharp temperature increase, thus providing an earlier warning opportunity.

[0041] Electrochemical impedance spectroscopy (EIS) is a technique for analyzing the internal electrochemical processes of a battery by measuring its impedance response under AC signal excitation at different frequencies. EIS reflects various physicochemical properties within the battery, including charge transfer resistance, diffusion impedance, SEI film impedance, and electrolyte resistance. These parameters are closely related to the battery's health, aging level, and safety risks. In the battery system 1000 according to an embodiment of the present invention, the battery management unit 1200 is preferably equipped with an EIS detection function, capable of periodically or under specific conditions measuring the impedance spectrum of each battery pack. The battery management unit 1200 is specifically configured to monitor abnormal EIS data of the battery packs. Abnormal impedance data can manifest as: a significant deviation of the impedance value from historical reference values; abnormal changes in the shape of the impedance spectrum characteristic curve; and abnormal increases or decreases in the impedance component at specific frequencies. These abnormal changes may indicate structural damage within the battery cell, such as the formation of internal short circuits, electrolyte decomposition, or separator damage. These internal damages are potential causes of thermal runaway. When the battery management unit 1200 detects a significant anomaly in the electrochemical impedance spectroscopy (EIS) data of the second battery pack 200 during routine monitoring, and this anomaly cannot be explained by normal aging processes or changes in operating conditions, the battery management unit 1200 determines that the second battery pack 200 has a risk of thermal runaway, identifies it as an abnormal battery pack, and can control the switch matrix 1100 to enter emergency mode M0. EIS-based thermal runaway risk assessment is a predictive diagnostic method that can identify battery packs with safety hazards earlier than actual thermal runaway occurs. However, this method requires measurement hardware and data analysis algorithms.

[0042] In a preferred embodiment, load 2100 includes the electrical and electronic compartment of vehicle 2000. The electrical and electronic compartment is the core area of ​​an electric vehicle, integrating high-voltage electrical equipment and electronic control units. It is typically located in the front compartment or chassis area and integrates key components of the electric vehicle's high-voltage system. Specifically, the electrical and electronic compartment typically includes the following main components: a motor controller (inverter), which converts the DC power supplied by the battery into AC power required to drive the motor and controls the motor's speed and torque output; a DC-DC converter, which converts the voltage of the high-voltage power battery to low voltage (typically 12V or 48V) for use by the vehicle's low-voltage electrical systems, such as lighting, signaling, and entertainment systems; an onboard charger (OBC), which converts AC power from an AC charging station or household power supply into DC power to charge the power battery; an electric compressor and its controller, used to provide refrigerant compression power for the vehicle's air conditioning system; a power distribution unit (PDU), used to distribute and manage high-voltage power to various electrical devices and provide protection functions; and other high-voltage electrical equipment. The electronic and electrical compartment, as the core load of the vehicle's high-voltage system, is the primary source of power for the battery system.

[0043] In a preferred embodiment, under emergency mode M0, the abnormal battery pack discharges through the discharge resistor 1120 at a preset discharge current, which is preferably set in the range of 4 to 6 amperes, for example, about 5 amperes. The specific value of the discharge current depends on the resistance of the discharge resistor 1120 and the real-time voltage of the corresponding battery pack. For example, when the voltage of the abnormal battery pack is about 400V and the resistance of the discharge resistor is about 80 to 100 ohms, the discharge current is about 4 to 5 amperes according to Ohm's law. This discharge current level is set based on the following technical considerations: First, the discharge current should not be too large, because an excessively large discharge current will cause the discharge resistor to generate a large amount of heat, requiring a higher-specification heat dissipation design, and may also cause additional electrochemical stress inside the battery; second, the discharge current should not be too small, because the purpose of discharge is to effectively reduce the state of charge and energy storage level of the abnormal battery pack within a reasonable time. An excessively small discharge current will make the discharge process too slow, making it difficult to effectively reduce battery energy within the time window of thermal runaway development. Discharging a battery pack experiencing thermal runaway with a moderate current of 4 to 6 amps can create a competition between the discharge reaction and the thermal runaway reaction. Specifically, the thermal runaway process is essentially a series of uncontrollable redox reactions that release a large amount of heat energy; while controlled discharge with a preset discharge current is a controllable electrochemical reduction reaction that consumes the active materials and energy in the battery, thereby reducing the total amount of energy available for the thermal runaway reaction, which helps to slow down the development of thermal runaway and reduce its severity.

[0044] In a preferred embodiment, in emergency mode M0, due to a significant decrease in power supply capacity, to ensure that the limited electrical energy can support the vehicle 2000 in completing the most critical safety tasks, the vehicle 2000 can shut down unnecessary loads in emergency mode M0, maintaining only the operation of necessary loads. Necessary loads refer to electrical equipment and systems indispensable for the vehicle 2000 to complete safe evacuation or safe parking in emergency mode M0, particularly including drive motors and / or autonomous driving systems. Unnecessary loads that are shut down may include, for example, comfort and convenience electrical equipment such as air conditioning compressors, seat heating and ventilation systems, audio entertainment systems, power seat adjustments, power tailgates, and ambient lighting. Shutting down these loads can significantly reduce energy consumption, concentrating limited battery power on drive motors and safety-critical systems, thereby extending the driving range or operating time of the vehicle 2000 in emergency mode M0. When entering emergency mode M0, the battery management unit 1200 preferably sends a corresponding command to the vehicle control unit, which can automatically execute the shutdown operation of unnecessary loads and maintain the power supply to necessary loads according to a preset load priority strategy.

[0045] exist Figure 2 In the embodiments shown in the following figures, the battery system 1000 specifically includes two battery packs, namely a first battery pack 100 and a second battery pack 200. Each battery pack includes multiple cells connected in series. These cells are connected end-to-end via electrical connectors or busbars to form a cell series chain. The negative terminal of the first cell in the series chain serves as the negative output terminal of the battery pack, and the positive terminal of the last cell serves as the positive output terminal of the battery pack. Taking a typical 800V high-voltage platform electric vehicle as an example, if ternary lithium cells with a rated voltage of approximately 3.7V are used, each battery pack requires approximately 108 cells connected in series to form a rated voltage of approximately 400V, and the two battery packs have a total of approximately 216 cells. If lithium iron phosphate cells with a rated voltage of approximately 3.2V are used, each battery pack requires approximately 125 cells connected in series to form a rated voltage of approximately 400V, and the two battery packs have a total of approximately 250 cells. In embodiments not specifically shown, the battery system 1000 may include three or four, and other numbers of battery packs, in which case the complexity of the switch matrix 1100 increases accordingly.

[0046] Figure 3 A schematic circuit connection diagram of a battery system 1000 for a vehicle 2000 according to an exemplary embodiment of the present invention is shown.

[0047] like Figure 3 Combination Figure 2As shown, the switching element 1110 may include a discharge control switch 1111 and an isolating switch 1112. The isolating switch 1112 may be located at the main circuit output terminal of the battery pack, and its main function is to control the switching of large currents, connecting or disconnecting the first battery pack 100 and the second battery pack 200 from the power bus of the vehicle 2000. The discharge control switch 1111 is located in a separate branch, which is connected in series with a discharge resistor 1120 and is connected across the positive and negative terminals of the corresponding battery pack.

[0048] exist Figure 3 In embodiments shown in the following figures, the discharge control switch 1111 includes a first discharge control switch K11 and a second discharge control switch K12, the isolating switch 1112 includes a first isolating switch K21, a second isolating switch K22, a third isolating switch K23, and a fourth isolating switch K24, and the discharge resistor 1120 includes a first discharge resistor 1121 and a second discharge resistor 1122. In embodiments not specifically shown, the switch matrix 1100 may include only a single discharge resistor 1120, and in emergency mode M0, the faulty battery can be connected to this single discharge resistor 1120 for discharge through more complex circuit connections and switch switching.

[0049] Figure 4 It shows Figure 3 The schematic circuit connection diagram of the battery system in emergency mode M0.

[0050] like Figure 4 Combination Figure 2 As shown, when the battery management unit 1200 detects an abnormality in the first battery pack 100, such as thermal runaway, the battery management unit 1200 controls the switch matrix 1100 to enter emergency mode M0. Figure 4 In the emergency mode M0 shown, the first disconnect switch K21 and the second disconnect switch K22 are disconnected, causing the abnormal first battery pack 100 to disconnect from the load 2100, and the first discharge control switch K11 is closed, allowing the first battery pack 100 to discharge through the first discharge resistor 1121. At the same time, the third disconnect switch K23 and the fourth disconnect switch K24 are closed, allowing the normal second battery pack 200 to supply power to the load 2100, such as the electronic and electrical compartment of the vehicle 2000, independently.

[0051] Figure 5 It shows Figure 3 Another schematic circuit connection diagram of the battery system 1000 in emergency mode M0.

[0052] and Figure 4Corresponding to the scenario shown, when the battery management unit 1200 detects an abnormality in the second battery pack 200, such as thermal runaway, the battery management unit 1200 controls the switch matrix 1100 to enter emergency mode M0. In such cases... Figure 5 In the emergency mode M0 shown, the third disconnect switch K23 and the fourth disconnect switch K24 are disconnected, causing the abnormal second battery pack 200 to disconnect from the load 2100. At the same time, the second discharge control switch K12 is closed, and the second battery pack 200 is connected to the second discharge resistor 1122 for discharge. Simultaneously, the first disconnect switch K21 and the second disconnect switch K22 are closed, allowing the normal first battery pack 100 to supply power to the load 2100, such as the electronic and electrical compartment of the vehicle 2000, independently.

[0053] Regardless of Figure 5 As shown, the first battery pack 100 is normal or as... Figure 4 As shown, when the second battery pack 200 supplies power to the load 2100 of the vehicle 2000 alone, its output voltage is approximately 400V, half that of the normal operating voltage of 800V. In the power system of an electric vehicle, the power of the drive motor is proportional to the product of the supply voltage and current. When the supply voltage drops from 800V to 400V, the power available to the motor will decrease accordingly while the current remains the same. Therefore, in emergency mode M0, the vehicle 2000 preferably operates at dated power, meaning that the vehicle's drive power, acceleration performance, and maximum speed are significantly reduced compared to normal operating mode, typically to half or less of the normal power. For example, an electric vehicle with a peak power of 400kW during normal operation may have its usable peak power reduced to below 200kW in emergency mode M0, resulting in a longer 0-100km / h acceleration time and a limited maximum speed. In Emergency Mode M0, Vehicle 2000 operates at derating power. The purpose is not to pursue normal driving performance, but to ensure that Vehicle 2000 maintains basic driving capability even in the event of a dangerous battery situation. This allows the driver to safely move Vehicle 2000 from its current location at a low speed to a safe area such as the roadside, parking lot, or repair shop. In Emergency Mode M0, Battery Management Unit 1200 sends a power limiting command to the Vehicle Control Unit. The Vehicle Control Unit then adjusts its motor control strategy accordingly to adapt to the reduced supply voltage and power capacity, ensuring stable and reliable operation of the power system even in derating mode.

[0054] In a preferred embodiment, the battery management unit 1200 is configured to follow a timing control strategy of powering down first, then switching, and then powering up during the process of controlling the switch matrix 1100 to switch to emergency mode M0. When the battery management unit 1200 detects that a battery pack is abnormal and determines that emergency mode M0 is triggered, the switching process can be executed in the following order: First, the battery management unit 1200 sends a power-down command to the vehicle control unit, and the vehicle control unit coordinates each high-voltage load to stop working in sequence, the motor inverter stops outputting, the DC-DC converter stops working, and the air conditioning compressor stops running, and the vehicle high-voltage system enters a no-load state; then, the battery management unit 1200 controls the main positive relay and the main negative relay to disconnect, completely electrically isolating the battery system 1000 from the load 2100. At this time, there is no current flowing between all battery packs and the switch matrix 1100, and between the switch matrix 1100 and the load 2100, and the system is in a safe power-down state. After confirming that the power-off has been completed (e.g., by detecting that the high-voltage bus voltage has dropped below a safe level), the battery management unit 1200 begins to execute the switching actions of the switch matrix 1100: First, it controls the disconnecting switch 1112 associated with the abnormal battery pack to open, ensuring complete isolation between the abnormal battery pack and the power supply circuit of the load 2100; then, it controls the closing of the discharge control switch 1111 associated with the abnormal battery pack, connecting the abnormal battery pack to the discharge resistor 1120; next, it controls the closing of the power supply switch between the normal battery pack and the load 2100 (such as the disconnecting switch 1112 associated with the normal battery pack), preparing for power supply after power-on. After all switching actions are completed, the battery management unit 1200 can perform status confirmation, for example, by detecting the auxiliary contacts or feedback signals of each switch to verify that all switches have reached the target position. After the status confirmation is passed, the battery management unit 1200 sends a power-on command to the vehicle control unit, the vehicle control unit controls the main relay to close, the normal battery pack begins to supply power to the load 2100, and the vehicle 2000 enters the emergency mode M0 operating state. The process from power-off to switching completion and then power-on should ideally be completed within 5 to 15 seconds. This timing control has significant safety implications: switching the switch under load may cause arcing, damage to switch contacts, or even short circuits; by powering off first, the switch is ensured to operate in a current-free state, avoiding these risks; the status confirmation before powering on further ensures that the new circuit configuration is correct.

[0055] Figure 6 It shows Figure 3 A schematic circuit connection diagram of the battery system 1000 in the first operating mode M1.

[0056] like Figure 6 Combination Figure 3As shown, the switching element 1110 of the switch matrix 1100 includes an auxiliary switch 1113. The battery management unit 1200 is also configured to control the switch matrix 1100 to implement a first operating mode M1 when the vehicle 2000 is in normal driving or charging with a high-voltage charging station. In the first operating mode M1, the first disconnect switch K21 and the fourth disconnect switch K24 are closed, the second disconnect switch K22 and the third disconnect switch K23 are open, the auxiliary switch 1113 is closed, and the first discharge control switch K11 and the second discharge control switch K12 are open, so that the first battery pack 100 and the second battery pack 200 are connected in series. Under this series configuration, the approximately 400V rated voltage of the first battery pack 100 is superimposed with the approximately 400V rated voltage of the second battery pack 200 to form a first voltage of approximately 800V. This first voltage is supplied to the loads 2100 such as the electronic and electrical compartment of the vehicle 2000 to provide power to the drive motor, air conditioning compressor, electronic control unit and other high-voltage loads of the vehicle 2000. The first operating mode M1 is the most commonly used operating mode for the vehicle 2000 during daily operation. In the first operating mode M1, the vehicle 2000 can utilize its full performance, including maximum acceleration and top speed. When the vehicle 2000 needs to be fast-charged using a high-voltage (e.g., 800V) charging station, the first operating mode M1 is also maintained, allowing the charging station to charge the vehicle 2000's battery system at an 800V voltage level, achieving a charging power of up to 350kW or even higher, significantly shortening charging time. Preferably, the battery management unit 1200 continuously monitors all switching elements 1110 of the switch matrix 1100 and the voltage, current, and temperature parameters of the two battery packs to ensure stable operation of the first operating mode M1, and can promptly switch to emergency mode M0 when a battery pack abnormality is detected.

[0057] In a preferred embodiment, the operating port of the load 2100 (e.g., the electrical and electronic compartment) of the vehicle 2000 is configured to receive a reduced supply voltage. In the normal first operating mode M1, the first battery pack 100 and the second battery pack 200, connected in series, supply a first voltage of approximately 800V to the load, and the operating port of the load 2100 is designed to operate normally at this voltage level. When the battery system 1000 enters the emergency mode M0, only the normal battery pack (either the first battery pack 100 or the second battery pack 200) supplies power to the load 2100, and the supply voltage is reduced to approximately 400V. The operating ports and internal power electronics of the load 2100 are configured to operate within a wide voltage range of 400V to 800V. Specifically, the internal drive motor inverter of the load 2100 employs a wide voltage input design, with a DC bus voltage range of 350V to 850V. When the input voltage drops from 800V to 400V, the inverter automatically adjusts its PWM modulation strategy and control parameters to adapt to the new voltage level, resulting in a corresponding reduction in output power while still being able to drive the motor normally. The internal DC-DC converter (used to convert the high-voltage battery voltage to 12V or 48V low-voltage power supply) also employs a wide input voltage design, covering an input voltage range of 400V to 800V, enabling it to continue supplying power to the low-voltage system of the vehicle 2000 in emergency mode M0. The high-voltage input port of the on-board charger is also designed with a wide voltage range; although charging is not performed in emergency mode M0, its input circuit will not be damaged by voltage changes. The configuration of the load 2100's operating port to receive the reduced supply voltage also includes corresponding software adaptation. After receiving the emergency mode signal from the battery management unit 1200, the vehicle control unit sends a voltage level change notification to the control units of each high-voltage load. Each control unit then switches to low-voltage operating mode and adjusts its control algorithm and protection thresholds accordingly. For example, after receiving the low-voltage operating mode command, the motor control unit adjusts the DC bus undervoltage protection threshold from the normal 650V to 300V to avoid false protection triggering and system shutdown due to voltage drop. Through the combined hardware and software configuration, the load 2100's operating port can smoothly adapt to voltage changes from approximately 800V to approximately 400V, ensuring that the necessary loads of the vehicle 2100 can still operate normally in emergency mode M0.

[0058] Figure 7 It shows Figure 3 The schematic circuit connection diagram of the battery system 1000 in the second operating mode M2.

[0059] like Figure 7As shown, the battery management unit 1200 of the battery system 1000 is also configured to control the switch matrix 1100 to implement a second operating mode M2 ​​when the vehicle 2000 needs to be charged using a low-voltage charging pile (e.g., a charging pile with a rated voltage of 500V to 750V). After the vehicle 2000 connects to the charging pile and completes handshake communication, if the battery management unit 1200 detects, for example, that the output voltage of the charging pile is lower than the 800V charging voltage required for the first operating mode M1 of the battery system 1000, it can control the vehicle 2000 to perform a power-down operation, and then control the switching element 1110 inside the switch matrix 1100 to switch to a parallel connection state. Specifically, the first isolating switch K21, the second isolating switch K22, the third isolating switch K23, and the fourth isolating switch K24 are closed, and the first discharge control switch K11, the second discharge control switch K12, and the auxiliary switch 1113 are opened, so that the first battery pack 100 and the second battery pack 200 are configured in parallel. In this parallel configuration, the first battery pack 100 and the second battery pack 200 share a second voltage of approximately 400V. This second voltage matches the output voltage of the low-voltage charging pile, enabling the charging pile to normally supply power to the battery system 1000. Since the two battery packs are connected in parallel, the total capacity of the system is the sum of the capacities of the two battery packs, and the charging current is distributed to both battery packs for simultaneous charging, improving charging efficiency and balancing the charging load of each battery pack. For example, when using a charging pile with a rated voltage of 750V and a rated power of 120kW to charge the battery system 1000, in the first operating mode M1, the charging pile is incompatible because the battery system 1000 requires an 800V charging voltage. However, in the second operating mode M2, the battery system 1000 connects to the charging pile with a second voltage of approximately 400V, and the charging pile can normally output 750V to charge the battery, achieving backward compatibility with low-voltage charging infrastructure. After switching to the second operating mode M2, the battery management unit 1200 controls the vehicle 2000 to perform a power-on operation, and the charging process officially begins. After charging is complete or when normal driving needs to be resumed, the battery management unit 1200 controls the vehicle 2000 to power down again, switches the switch matrix 1100 back to the series configuration of the first working mode M1, and then performs the power-on operation.

[0060] In a preferred embodiment, the switching elements 1110 of the switching matrix 1100 may include mechanical relays and / or solid-state relays, wherein solid-state relays particularly include insulated-gate bipolar transistors (IGBTs) and / or metal-oxide-semiconductor field-effect transistors (MOSFETs). Specifically, in the topology design of the switch matrix 1100, different types of devices are used for the switching elements 1110 with different functions according to their operating characteristics: the isolating switch 1112 used to realize electrical isolation between the battery pack and the load 2100 can be a mechanical relay, such as a high-voltage DC contactor with a rated voltage of 1000V and a rated current of 500A. This mechanical relay drives the silver alloy contacts to close and open through an electromagnetic coil. In the open state, there is reliable electrical isolation between the contacts (insulation resistance greater than 100MΩ), and in the closed state, the contact resistance is extremely low (less than 0.5mΩ), which can conduct large current with minimal power loss; the auxiliary switch 1113 used to control the series or parallel connection between battery packs can also be a mechanical relay to ensure reliable conduction and safe disconnection under high voltage and high current conditions. The discharge control switch 1111, used to control the connection between the abnormal battery pack and the discharge resistor, preferably employs a solid-state relay. Specifically, it can be implemented based on an IGBT power module with a rated voltage of 1200V and a rated current of 100A, sufficient to withstand a 400V voltage and a discharge current of 4A to 6A. The IGBT's switching action is controlled by a gate drive circuit, with a response time in the microsecond range, enabling rapid switching after a command is issued by the battery management unit 1200. The IGBT module preferably also integrates overcurrent protection, overtemperature protection, and short-circuit protection functions, automatically shutting off if an abnormal condition is detected during discharge. This combination of mechanical and solid-state relays leverages the advantages of both devices: the mechanical relay ensures low loss and high reliability in the main current path, while the solid-state relay provides fast response and flexible adjustment capabilities in the control and protection circuits. Each switching element 1110 in the switch matrix 1100 can be connected to the battery management unit 1200 via a control bus, allowing the battery management unit 1200 to independently control the state of each switching element 1110.

[0061] Figure 8 A schematic flowchart of a control method 3000 for a battery system 1000 according to an exemplary embodiment of the present invention is shown. Figure 8 As shown, the control method 3000 includes steps S100, S200 and S300.

[0062] In step S100, the operating status of at least two battery packs (such as the first battery pack 100 and the second battery pack 200 in the above embodiment) of the battery system 1000 is monitored. Here, the battery management unit 1200 continuously collects operating status data of each battery pack using sensors installed within each battery pack. The operating status data preferably includes at least one of the following: the voltage of each cell in the battery pack, sampled at a frequency of 10 to 100 times per second by a voltage acquisition circuit, with a sampling accuracy of ±5mV; the multi-point temperature of the battery pack, collected by 4 to 6 NTC temperature sensors distributed within the battery pack, with a sampling frequency of 1 to 10 times per second and a sampling accuracy of ±1℃; and the air pressure within the battery pack, collected by an air pressure sensor installed within the sealed housing of the battery pack, with a sampling frequency of 1 time per second and a sampling accuracy of ±1kPa. The battery management unit 1200 filters and preprocesses the collected data and stores it in a buffer for subsequent analysis.

[0063] In step S200, based on the operating status of each battery pack, it is determined whether there is an abnormal battery pack. Here, the battery management unit 1200 can perform real-time analysis of the collected operating status data, comparing the current data with preset anomaly judgment conditions. Anomaly judgment conditions may include, for example: any cell voltage below 2V, any cell voltage dropping by more than 1V within 10 seconds, multiple temperature sensor values ​​within the same battery pack continuously rising by more than 15°C within 5 minutes, and the internal air pressure of the battery pack exceeding 130kPa. When any anomaly judgment condition is met, the battery management unit 1200 determines the battery pack meeting that condition as an abnormal battery pack and records the anomaly type, timestamp, and related data for subsequent diagnostic analysis. If no abnormal battery pack is found in step S200 based on the operating status of each battery pack, the process returns to step S100 to continue monitoring the operating status of each battery pack.

[0064] In step S300, when an abnormal battery pack is detected, the control switch matrix 1100 enters emergency mode M0. Here, the battery management unit 1200 sends control commands to the switch matrix 1100 to control the operation of each switch element 1110 to achieve the following functions: disconnecting the abnormal battery pack from the load 2100 of the vehicle 2000 to prevent the safety risks that may arise from the abnormal battery pack continuing to supply power to the load 2100 of the vehicle 200; connecting the abnormal battery pack to the discharge resistor 1120 for discharge, actively consuming the electrical energy of the abnormal battery pack to reduce the risk of thermal runaway; and connecting the normal battery pack to the load 2100 for power supply to maintain the basic operating functions of the vehicle 2000.

[0065] In an optional embodiment, when the control switch matrix 1100 enters emergency mode M0 in step S300, an additional warning is issued to the driver of vehicle 2000. This warning can be implemented in various ways, including combinations of the following: displaying prominent warning icons and text information on the vehicle's dashboard and central display screen, such as displaying a red battery warning icon and the message "Battery system failure - please proceed to a safe location," with the warning message having the highest priority and overriding other displayed content; playing a voice warning through the vehicle's audio system, such as "Warning, the battery system has detected an anomaly; please drive the vehicle to a safe location or the nearest service station"; transmitting warning information to the driver through vibration feedback from the dashboard or steering wheel, especially suitable for situations where the driver may not notice visual and auditory warnings; and automatically sending fault information and vehicle location to the emergency service center or the vehicle manufacturer's backend through the vehicle communication system to obtain external assistance when needed. The warning information is categorized into different levels based on the severity of the anomaly: when a risk of thermal runaway is detected in the battery pack but has not yet actually occurred (e.g., only a slight voltage drop or slow temperature rise is detected), a Level 1 warning is issued, reminding the driver to drive the vehicle to the nearest 4S shop or service station for inspection; when thermal runaway characteristics are detected in the battery pack (e.g., a sudden voltage drop below 2V or a rapid temperature rise), a Level 2 warning is issued, notifying the driver to abandon the vehicle and providing guidance on safe evacuation. After the driver abandons the vehicle, if the vehicle is equipped with an autonomous driving function, the control method 3000 according to an embodiment of the present invention may further include controlling the vehicle 2000 to autonomously drive to a safe location, for example: the vehicle autonomously chooses to drive to an open area on the roadside, a parking lot, or an area away from gas stations and buildings based on the current road conditions and surrounding environment; if road conditions do not allow autonomous driving (e.g., narrow roads or complex traffic environments), the vehicle may choose to remain in place and activate its hazard warning lights to alert other road users. The warning function in Emergency Mode M0 ensures that the driver and passengers can understand the vehicle status immediately and take appropriate action, maximizing the protection of personal safety.

[0066] exist Figure 8 In the preferred embodiment shown, step 300 includes sub-steps S301, S302, S303, S304, and S305.

[0067] In sub-step S301, the vehicle 2000 is controlled to perform a power-down operation. When the battery management unit 1200 determines that there is an abnormal battery pack, it first sends a power-down command to the vehicle control unit. The vehicle control unit coordinates the various systems to stop working in sequence: the motor inverter stops outputting torque (if the vehicle is moving, the inverter first sets the motor to zero torque mode, and the vehicle coasts by inertia), the DC-DC converter reduces its output power until it stops, the air conditioning compressor stops running, and unnecessary loads are shut down; after all loads stop working, the main positive relay and the main negative relay are disconnected, and the battery system is completely disconnected from the loads; the battery management unit 1200 confirms that the power-down is complete by detecting the high-voltage bus voltage. Usually, the bus voltage needs to drop below 60V to be considered a safe power-down state, and the power-down process takes about 2 to 5 seconds.

[0068] In sub-step S302, the corresponding switching element 1110 of the control switch matrix 1100 is activated, specifically disconnecting the isolating switch 1112 associated with the faulty battery pack, thereby electrically isolating the faulty battery pack from the power supply circuit of the load 2100. For example, if Figure 3 If the second battery pack 200 is an abnormal battery pack, then disconnect the third disconnect switch K23 and the fourth disconnect switch K24 to ensure that the second battery pack 200 has no electrical connection with the power supply circuit to be formed.

[0069] In sub-step S303, the corresponding switching element 1110 of the control switch matrix 1100 is activated, specifically closing the discharge control switch 1111 associated with the abnormal battery pack, so that the abnormal battery pack is connected to the discharge resistor for discharge. For example, if Figure 3 If the second battery pack 200 is an abnormal battery pack, the second discharge control switch K12 will be closed, so that the second battery pack 200 is connected to the second discharge resistor 1122 to form an independent discharge circuit. Thus, the second battery pack 200, as an abnormal battery pack, can discharge through the second discharge resistor 1122 with a preset current (such as 5 amps).

[0070] Sub-step S304: The corresponding switching element 1110 of the control switch matrix 1100 is activated, specifically closing the isolating switch 1112 associated with the normal battery pack, thereby connecting the normal battery pack to the load 2100 of the vehicle 2000. For example, if... Figure 3 If the second battery pack 200 is an abnormal battery pack while the first battery pack 100 is a normal battery pack, then the first disconnect switch K21 and the second disconnect switch K22 are closed, so that the positive terminal of the first battery pack 100 is connected to the positive terminal of the load and the negative terminal is connected to the negative terminal of the load, in preparation for subsequent power-on.

[0071] In sub-step S305: The vehicle 2000 is powered on to supply power to the load 2100 from the normal battery pack. At this time, the vehicle 2000 preferably operates at derating power. After confirming that all switching elements 1110 have reached their target positions, a power-on command is sent to the vehicle control unit. The main relay closes, and the normal battery pack supplies power to the load. The vehicle control unit notifies each load to enter low-voltage operating mode, driving the motor inverter to output at derating power. At this time, the vehicle 2000 regains its driving capability but its power is limited.

[0072] Figure 9 A structural framework diagram of a computer system according to an exemplary embodiment of the present invention is shown. This computer system is configured to perform various steps of the control method 3000 provided according to the above embodiments of the present invention. Figure 9 As shown, the computer system includes a memory 1, a processor 2, a communication interface 3, and a bus 4. Here, the memory 1, processor 2, and communication interface 3 are interconnected via the bus 4. According to one aspect of the invention, a computer program product is also provided, comprising computer program instructions, wherein when executed by a processor, particularly by the processor 2 of the aforementioned computer system, the computer program instructions implement the steps of the control method 3000 provided according to the above embodiments of the invention.

[0073] Although specific embodiments of the invention have been described in detail herein, they are given for illustrative purposes only and should not be construed as limiting the scope of the invention. Various substitutions, alterations, and modifications can be conceived without departing from the spirit and scope of the invention.

Claims

1. A battery system (1000) for a vehicle (2000), wherein, The battery system (1000) includes: At least two battery packs (100, 200), each battery pack containing multiple cells connected to each other; A switching matrix (1100), comprising a plurality of switching elements (1110) and at least one discharge resistor (1120), the switching matrix (1100) being connected between the at least two battery packs (100, 200) and a load (2100) of the vehicle (2000); and A battery management unit (1200) is configured to control a switch matrix (1100) to implement an emergency mode (M0) when an abnormal battery pack is present in at least two battery packs (100, 200). In the emergency mode (M0), the switch matrix (1100) disconnects the abnormal battery pack from the load (2100) and connects the abnormal battery pack to the discharge resistor (1120) for discharge, and connects the normal battery pack to the load (2100) of the vehicle (2000) for power supply.

2. The battery system (1000) according to claim 1, wherein, The battery management unit (1200) is also configured to control the switch matrix (1100) to implement a first operating mode (M1), in which the at least two battery packs (100, 200) are connected in series through the switch matrix (1100) to supply power to the load (2100) at a first voltage, preferably about 800V; and / or The battery management unit (1200) is also configured to control the switch matrix (1100) to implement a second operating mode (M2), in which at least two battery packs (100, 200) are connected in parallel through the switch matrix (1100) and charged by connecting to an external charging device at a second voltage, preferably about 400V.

3. The battery system (1000) according to claim 1 or 2, wherein, The switching element (1110) includes a discharge control switch (1111) and an isolating switch (1112). The discharge control switch (1111) is adapted to connect the discharge resistor (1120) between the positive and negative terminals of the faulty battery pack. The isolating switch (1112) is adapted to disconnect the faulty battery pack from the load (2100). In the emergency mode (M0), the isolating switch (1112) is open and the discharge control switch (1111) is closed to form a discharge circuit including the faulty battery pack and the discharge resistor (1120). The discharge circuit is electrically isolated from the power supply circuit of the load (2100); and / or In the emergency mode (M0), the vehicle (2000) operates at derating power; and / or In the emergency mode (M0), the faulty battery pack discharges through the discharge resistor (1120) at a preset discharge current, preferably 4 to 6 amperes; and / or In the emergency mode (M0), the vehicle (2000) shuts down non-essential loads and maintains operation only on essential loads, which preferably include drive motors and / or automatic driving systems; and / or In the emergency mode (M0), the operating port of the load (2100) is configured to receive the reduced supply voltage.

4. The battery system (1000) according to any one of claims 1 to 3, wherein, The at least two battery packs (100, 200) each have the same rated voltage, preferably, the rated voltage of each battery pack is 350V to 450V, particularly preferably 400V; and / or The at least two battery packs (100, 200) include two, three, or four battery packs, each battery pack including multiple cells connected in series; and / or The switching element (1110) includes a mechanical relay and / or a solid-state relay, the solid-state relay particularly including an IGBT and / or a MOSFET; and / or The abnormal battery packs include those detected as having a risk of thermal runaway or those that have already experienced thermal runaway; and / or The load (2100) includes the electronic and electrical compartment of the vehicle (2000).

5. The battery system (1000) according to any one of claims 1 to 4, wherein, The battery management unit (1200) determines whether there is an abnormal battery pack among the at least two battery packs (100, 200) based on at least one of the following parameters: Battery pack voltage data, especially the detection of sudden voltage drops, such as a single cell voltage dropping from the normal operating voltage to below a preset threshold, preferably 2V; The temperature data of the battery pack, especially the values ​​detected by multiple temperature sensors on the same battery pack, showed a continuous increase. The air pressure data within the battery pack, especially when the air pressure rises above the safety threshold; and Electrochemical impedance spectroscopy (EIS) data of the battery pack, especially anomalies were detected in the EIS data of the battery pack.

6. The battery system (1000) according to any one of claims 1 to 5, wherein, The battery management unit (1200) is configured to: first control the vehicle (2000) to perform a power-down operation during the process of controlling the switch matrix (1100) to switch to the emergency mode (M0), and then perform a power-on operation after the switching action of the switch element (1110) is completed.

7. A control method (3000) for a battery system (1000) according to any one of claims 1 to 6, wherein, The control method (3000) includes the following steps: S100: Monitor the operating status of the at least two battery packs (100, 200), wherein the operating status preferably includes at least one of the cell voltage in the battery pack, the multi-point temperature of the battery pack, and the air pressure in the battery pack; S200: Based on the operating state, determine whether there is an abnormal battery pack among the at least two battery packs (100, 200); S300: When an abnormal battery pack is detected, the switch matrix (1100) is controlled to enter emergency mode (M0), wherein the switch element (1110) is controlled to disconnect the abnormal battery pack from the load (2100) of the vehicle (2000) and connect the abnormal battery pack to the discharge resistor (1120) for discharge, and connect the normal battery pack to the load (2100) of the vehicle (2000) for power supply.

8. The control method (3000) according to claim 7, wherein, In step S300, an additional warning is issued to the driver of the vehicle (2000), reminding the driver to move the vehicle (2000) to a safe location, or instructing the driver to abandon the vehicle and control the vehicle (2000) to automatically drive to a safe location; and / or Step S300 includes the following sub-steps: S301: Control the vehicle (2000) to perform a power-down operation; S302: Control the operation of the corresponding switching elements (1110) of the switch matrix (1100), especially disconnecting the isolating switch (1112) associated with the abnormal battery pack, so as to electrically isolate the abnormal battery pack from the power supply circuit where the load (2100) is located; S303: Control the operation of the corresponding switching element (1110) of the switch matrix (1100), especially close the discharge control switch (1111) associated with the abnormal battery pack, so that the abnormal battery pack is connected to the discharge resistor (1120) for discharge; S304: Control the operation of the corresponding switching element (1110) of the switch matrix (1100), in particular closing the disconnect switch (1112) associated with the normal battery pack, so that the normal battery pack is connected to the load (2100) of the vehicle (2000). S305: Control the vehicle (2000) to perform a power-on operation so that the normal battery pack supplies power to the load (2100), wherein the vehicle (2000) preferably operates at derating power.

9. A computer program product comprising computer program instructions, wherein, When the computer program instructions are executed by the processor, they implement the steps of the control method (3000) according to claim 7 or 8.

10. A vehicle (2000), particularly an electric vehicle, wherein, The vehicle (2000) includes a battery system (1000) according to any one of claims 1 to 6 and / or a computer program product according to claim 9.

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