Battery operation protection method, device and vehicle

Abstract

The embodiment of the application relates to the technical field of vehicles, and discloses a battery operation protection method and device and a vehicle. The method comprises the following steps: in the case that a battery is in pre-under-voltage, determining a first limiting ratio based on the voltage of the battery and an under-voltage recovery trend, and performing operation protection on the battery by using the first limiting ratio. The first limiting ratio is used for representing the limiting degree of the output power of the battery, and the under-voltage recovery trend is determined based on the actual consumption power of the battery. The technical scheme provided by the embodiment of the application effectively improves the safety and stability of the battery operation.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, specifically to a battery operation protection method, device, and vehicle. Background Technology

[0002] Battery operation protection is a protective measure that ensures the safety and stability of battery operation when an abnormal state (such as overcharging, over-discharging, undervoltage, overcurrent, overheating, etc.) is detected, thereby avoiding battery damage, performance degradation, and potential safety risks.

[0003] In related technologies, battery protection is achieved by limiting the battery's output power or stopping the battery's discharge process when the voltage is undervoltage. However, current methods for judging the degree of battery undervoltage and the protection measures are too simplistic and cannot provide more precise and effective protection based on the actual state of the battery. This can easily lead to a worsening of the battery's undervoltage due to untimely protection. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this application is to provide a battery operation protection method, device and vehicle, which effectively improves the safety and stability of battery operation.

[0005] In a first aspect, embodiments of this application provide a battery operation protection method, the method comprising: when the battery is in a pre-undervoltage condition, determining a first limiting ratio based on the battery voltage and undervoltage recovery trend, and using the first limiting ratio to perform operation protection on the battery. The first limiting ratio is used to characterize the degree of limitation on the battery's output power, and the undervoltage recovery trend is determined based on the battery's actual power consumption.

[0006] The technical solution provided in this application, when the battery is in a pre-undervoltage state, determines the ratio for limiting the battery's output power by combining the voltage and the battery's actual power consumption. This allows for early prediction of the battery's undervoltage state based on its actual power consumption, enabling timely protection of the battery in response to the actual undervoltage condition. This makes battery operation protection more timely and effective, improving the safety and stability of battery operation.

[0007] One possible implementation involves determining the first limiting ratio based on the battery's voltage and undervoltage recovery trend. Specifically, this can be achieved by: identifying the pre-undervoltage zone where the voltage is located, and determining the first limiting ratio based on the pre-undervoltage zone. Here, the pre-undervoltage zone is one of multiple calibrated pre-undervoltage zones, and the multiple calibrated limiting ratios of these zones are positively correlated with the pre-undervoltage degree of each zone. This technical solution, by setting multiple calibrated pre-undervoltage zones with different limiting ratios, achieves step-by-step control of battery power, effectively avoiding damage to the battery caused by sudden power changes. One possible implementation, based on a pre-undervoltage partition to determine the first limit ratio, can be specifically implemented as follows: the calibrated limit ratio corresponding to the pre-undervoltage partition is determined as the initial limit ratio; the undervoltage recovery trend of the battery under the initial limit ratio is determined based on the actual power consumption; and the first limit ratio is determined based on the undervoltage recovery trend. This technical solution, by regulating the battery power in conjunction with the undervoltage recovery trend, can adjust the battery power in a timely manner by predicting the increase or decrease trend of battery voltage or undervoltage level, thereby improving the response speed of battery operation protection.

[0008] One possible implementation involves determining the battery's undervoltage recovery trend under an initial limit ratio based on actual power consumption. Specifically, if the battery does not meet a first preset condition, the undervoltage recovery trend is determined to be "not recovered." Here, the first preset condition indicates that after battery operation protection for a preset duration at the initial limit ratio, the actual power consumption is less than the target output power, where the target output power is the product of the battery's rated power and the initial limit ratio. This technical solution determines the battery's undervoltage recovery trend by considering the battery's actual power consumption and target output power, thus accurately measuring the degree of undervoltage protection for the battery.

[0009] One possible implementation involves determining the first limiting ratio based on the undervoltage recovery trend. Specifically, if the undervoltage recovery trend is not recovered, a second limiting ratio closest to the initial limiting ratio is found from at least one first candidate calibration limiting ratio, and this second limiting ratio is determined as the first limiting ratio. Here, at least one first candidate calibration limiting ratio is a limiting ratio smaller than the initial limiting ratio among multiple calibration limiting ratios. This technical solution, when power limiting has been implemented but the actual power consumption of the battery is still higher than the target output power, indicates insufficient protection for the battery. In this case, further reducing the battery's output power can effectively ensure the battery's operational protection effect.

[0010] One possible implementation is to determine the first limit ratio based on the undervoltage recovery trend, which can be specifically implemented as follows: when the undervoltage recovery trend is not in the unrecovered state, the initial limit ratio is determined as the first limit ratio.

[0011] One possible implementation, as provided in this application, further includes: after protecting the battery with a first limiting ratio, determining whether the voltage is within a target pre-undervoltage zone. If the voltage is within the target pre-undervoltage zone, updating the first limiting ratio to a third limiting ratio, and using the third limiting ratio to protect the battery. Here, the target pre-undervoltage zone is a calibrated pre-undervoltage zone corresponding to the third limiting ratio, and the third limiting ratio is the limiting ratio closest to the first limiting ratio found from at least one second candidate calibrated limiting ratio. The at least one second candidate calibrated limiting ratio is a limiting ratio greater than the first limiting ratio among multiple calibrated pre-undervoltage zones. In this technical solution, once the battery voltage has recovered, the limitation on the battery output power is gradually lifted, and the battery slowly returns to normal operating status through a gradual increase in power.

[0012] One possible implementation involves updating the first limiting ratio to a third limiting ratio when the voltage is within the target pre-undervoltage zone. Specifically, this can be achieved by updating the first limiting ratio to the third limiting ratio at a second recovery rate when the voltage is within the target pre-undervoltage zone and the battery meets a second preset condition. Conversely, if the voltage is within the target pre-undervoltage zone but the battery does not meet the second preset condition, the first limiting ratio is updated to the third limiting ratio at a first recovery rate. The second preset condition indicates that the time during which the actual power consumption is less than the output power corresponding to the first limiting ratio exceeds a preset time threshold, and the power difference between the actual power consumption and the output power corresponding to the first limiting ratio is greater than a preset power difference. The second recovery rate is greater than the first recovery rate. This technical solution increases the battery's output power using two different power recovery rates based on actual conditions. The first recovery rate prevents the power increase from being too rapid, causing the battery to repeatedly enter the power limiting process, while the second recovery rate avoids the problem of excessively long power recovery times.

[0013] One possible implementation involves using a power battery in the vehicle. The second preset condition further indicates that the accelerator pedal opening is less than a preset threshold. This technical solution, when the accelerator pedal opening is less than the preset threshold, the actual power consumption is less than the output power corresponding to the first limit ratio for a period longer than a preset time threshold, and the power difference between the actual power consumption and the output power corresponding to the first limit ratio is greater than a preset power difference, increases the battery's output power through a higher recovery rate. This approach, considering both the user's actual power demand and the battery's actual energy consumption, avoids the battery repeatedly entering the power limiting process due to excessively rapid power increases caused by high power demand.

[0014] One possible implementation is that the condition for determining that the battery is in a pre-undervoltage state is: the absolute voltage difference between the voltage and the battery's cutoff voltage is less than a preset voltage difference.

[0015] Secondly, this application provides an apparatus comprising a processing module and a protection module.

[0016] The aforementioned processing module is used to determine a first limiting ratio based on the battery voltage and undervoltage recovery trend when the battery is in a pre-undervoltage state. The first limiting ratio characterizes the degree of limitation on the battery's output power, and the undervoltage recovery trend is determined based on the battery's actual power consumption.

[0017] The aforementioned protection module is used to protect the battery during operation using a first limiting ratio.

[0018] One possible implementation is that the aforementioned processing module is specifically used to: determine the pre-undervoltage zone in which the voltage is located, and determine a first limit ratio based on the pre-undervoltage zone. Here, the pre-undervoltage zone is one of multiple calibrated pre-undervoltage zones, and the multiple calibration limit ratios of the multiple calibrated pre-undervoltage zones are positively correlated with the pre-undervoltage degree of the multiple calibrated pre-undervoltage zones.

[0019] One possible implementation is that the above processing module is specifically used to: determine the calibration limit ratio corresponding to the pre-undervoltage zone as the initial limit ratio, determine the undervoltage recovery trend of the battery under the initial limit ratio based on the actual power consumption, and determine the first limit ratio based on the undervoltage recovery trend.

[0020] One possible implementation is that the aforementioned processing module is specifically used to: determine that the undervoltage recovery trend is "not recovered" when the battery does not meet the first preset condition. The first preset condition indicates that after battery operation protection for a preset duration at an initial limit ratio, the actual power consumption is less than the target output power, where the target output power is the product of the battery's rated power and the initial limit ratio.

[0021] One possible implementation is that the aforementioned processing module is specifically used to: when the undervoltage recovery trend is not recovered, find the second limit ratio that is closest to the initial limit ratio from at least one first candidate calibration limit ratio, and determine the second limit ratio as the first limit ratio. Here, at least one first candidate calibration limit ratio is a limit ratio among multiple calibration limit ratios that is smaller than the initial limit ratio.

[0022] One possible implementation is that the above processing module is specifically used to: determine the initial limit ratio as the first limit ratio when the undervoltage recovery trend is not in the unrecovered state.

[0023] In one possible implementation, the processing module is further configured to: after performing operational protection on the battery at a first limiting ratio, determine whether the voltage is within a target pre-undervoltage zone. If the voltage is within the target pre-undervoltage zone, update the first limiting ratio to a third limiting ratio. The protection module is further configured to: perform operational protection on the battery using the third limiting ratio. Wherein, the target pre-undervoltage zone is a calibrated pre-undervoltage zone corresponding to the third limiting ratio, and the third limiting ratio is the limiting ratio closest to the first limiting ratio found from at least one second candidate calibrated limiting ratio, where at least one second candidate calibrated limiting ratio is a limiting ratio greater than the first limiting ratio among multiple calibrated pre-undervoltage zones.

[0024] One possible implementation is that the aforementioned processing module is specifically used to: update the first limiting ratio to a third limiting ratio at a second recovery rate when the voltage is in the target pre-undervoltage zone and the battery meets the second preset condition; and update the first limiting ratio to a third limiting ratio at a first recovery rate when the voltage is in the target pre-undervoltage zone and the battery does not meet the second preset condition. The second preset condition indicates that the time during which the actual power consumption is less than the output power corresponding to the first limiting ratio is greater than a preset time threshold, and the power difference between the actual power consumption and the output power corresponding to the first limiting ratio is greater than a preset power difference. The second recovery rate is greater than the first recovery rate.

[0025] One possible implementation is that the battery is a power battery in the vehicle, and the second preset condition is also used to indicate that the accelerator pedal opening degree of the vehicle is less than a preset opening degree threshold.

[0026] One possible implementation is that the condition for determining that the battery is in a pre-undervoltage state is: the absolute voltage difference between the voltage and the battery's cutoff voltage is less than a preset voltage difference.

[0027] One possible implementation is that, when the battery is in a pre-undervoltage state and the undervoltage recovery trend is recovery, the battery power first recovers at a first recovery rate for a first preset duration, and then recovers at a second recovery rate. The second recovery rate is greater than the first recovery rate.

[0028] The technical effects of any implementation method in the second aspect can be found in the technical effects of any implementation method in the first aspect mentioned above, and will not be repeated here.

[0029] Thirdly, this application provides a vehicle that includes the battery protection device in any of the embodiments of the second aspect described above, or the vehicle uses the battery operation protection method in any of the embodiments of the first aspect described above to achieve battery operation protection.

[0030] Fourthly, this application provides a computer-readable storage medium storing at least one computer program, which is loaded and executed by a processor to implement the battery operation protection method in any of the embodiments of the first aspect described above.

[0031] Fifthly, this application provides a computer program product, which includes a computer program or instructions that, when executed by a processor, implement the battery operation protection method in any of the embodiments of the first aspect described above.

[0032] The solutions provided in the third to fifth aspects above can realize the battery operation protection method in any embodiment of the first aspect above, and their specific implementations will not be described in detail here. The technical effects corresponding to any implementation of the solutions provided in the third to fifth aspects above can be found in the technical effects corresponding to any implementation of the first aspect above, and will not be described in detail here.

[0033] It should be noted that any of the possible implementations of any of the above aspects can be combined, provided that the solutions do not contradict each other. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application will be described below.

[0035] Figure 1 This is a schematic diagram of the structure of a battery protection device provided in an embodiment of this application; Figure 2 A schematic flowchart illustrating a battery operation protection method provided in an embodiment of this application; Figure 3 A schematic flowchart illustrating another battery operation protection method provided in this application embodiment; Figure 4 A schematic flowchart illustrating a method for limiting battery output power provided in an embodiment of this application; Figure 5 A schematic flowchart illustrating a method for increasing battery output power provided in an embodiment of this application; Figure 6 A schematic flowchart illustrating another battery operation protection method provided in an embodiment of this application; Figure 7 This is a schematic diagram of a battery operation protection device provided in an embodiment of this application. Detailed Implementation

[0036] To enable those skilled in the art to better understand the technical solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0037] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0038] In the embodiments of this application, the words "exemplary," "for example," or "e.g.," are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "e.g.," in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of the words "exemplary," "for example," or "e.g.," is intended to present the relevant concepts in a specific manner.

[0039] The embodiments of this application are described below with reference to the accompanying drawings.

[0040] This application provides a vehicle.

[0041] Alternatively, a vehicle may also be referred to as a vehicle, mobile carrier, electric vehicle (EV), hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV), fuel cell vehicle (FCV), autonomous vehicle, intelligent and connected vehicle (ICV), driverless vehicle, or new energy vehicle. In this application embodiment, the vehicle may be a sedan, sport utility vehicle (SUV), truck, electric vehicle, motorcycle, tricycle, special vehicle (such as ambulance, fire truck, police car, etc.), driverless taxi, intelligent connected bus, autonomous logistics vehicle, electric truck, etc. The method provided in this application embodiment is also applicable to various special-purpose vehicles, such as agricultural vehicles, mining vehicles, forestry vehicles, airport vehicles, and port vehicles; this application does not impose specific limitations on these.

[0042] In some embodiments, the vehicle includes a battery protection device.

[0043] Among them, battery protection equipment is used to protect the operation of batteries.

[0044] Battery operation protection refers to monitoring parameters such as voltage, current, temperature, and insulation of a battery throughout its entire life cycle, including charging, discharging, standby, and storage. When an abnormal state is detected (such as overcharging, over-discharging, undervoltage, overcurrent, or overheating), protective measures (such as early warning, current limiting, and circuit disconnection) are implemented to ensure the safety and stability of battery operation and prevent battery damage, performance degradation, and potential safety risks.

[0045] Optionally, battery protection devices include sensors, battery protection boards, battery management systems (BMS), battery protection circuit modules (PCM), undervoltage lockout (UVLO) chips, fuses, insulation monitoring systems, and high-voltage control systems.

[0046] For example, to avoid battery undervoltage caused by over-discharge or battery damage leading to undervoltage due to overcharging, the battery voltage is monitored in real time using BMS, UVLO, etc. If the voltage falls below the over-discharge protection threshold or rises above the overcharge protection threshold, the charging and discharging process is stopped. When the battery is undervoltage, the internal positive and negative electrode materials are in a vulnerable state with low charge. High-power discharge will cause the voltage to drop rapidly to the deep undervoltage range, leading to irreversible capacity decay, increased internal resistance, lithium plating, and bulging, reducing battery life and safety. Therefore, in the case of battery undervoltage, the rate of voltage drop can be slowed down by limiting the battery's output power to avoid permanent damage caused by deep discharge. For example, such as... Figure 1 As shown, the BMS monitors the battery voltage in real time, calculates and issues power adjustment commands based on the battery voltage, and the PCM receives the power adjustment commands from the BMS to physically limit the battery's output power. Simultaneously, the vehicle control unit (VCU) receives the power adjustment commands from the BMS and adjusts the input power of the motor connected to the battery, indirectly limiting the battery's output power. However, current methods for judging and protecting against battery undervoltage are too simplistic and cannot provide more precise and effective protection based on the actual state of the battery. This can easily lead to a worsening of the battery's undervoltage due to untimely protection, failing to effectively avoid the risk of battery undervoltage.

[0047] Based on this, the embodiments of this application provide a battery operation protection method with better operation protection effect, and the method can be applied to, for example... Figure 1 The battery protection device shown can also be applied to other devices, equipment, or systems capable of protecting battery operation, including: Step S201: When the battery is in a pre-undervoltage condition, the battery protection device determines a first limit ratio based on the battery voltage and undervoltage recovery trend.

[0048] The first limiting ratio characterizes the degree of limitation on the battery's output power. For example, when the battery is not undervoltage, the BMS calculates the maximum power (allowable power) that the battery can safely output based on the battery's remaining charge, temperature, and cell consistency. If the first limiting power is 80%, the battery's output power is limited to 80% of the allowable power. The allowable power is less than or equal to the battery's rated power.

[0049] Pre-undervoltage refers to the battery being about to enter an undervoltage state, or the battery entering an undervoltage state for less than a preset duration.

[0050] For example, the condition for determining that the battery is in a pre-undervoltage state is: the absolute voltage difference between the voltage and the battery's cutoff voltage is less than a preset voltage difference.

[0051] Among them, the cutoff voltage refers to the over-discharge protection threshold set manually during the battery discharge process to prevent permanent damage caused by over-discharge. When the voltage is lower than the cutoff voltage, it indicates that the battery has entered an under-voltage state.

[0052] For example, the cutoff voltage of a battery varies at different temperatures. In low-temperature environments, the battery's internal resistance is higher, resulting in a lower voltage after releasing the same capacity. Therefore, the cutoff voltage of the battery at different temperatures is determined experimentally. At the temperature critical point, the relationship between the cutoff voltage and temperature is set to be linear to avoid temperature fluctuations causing cutoff voltage fluctuations and thus falsely triggering undervoltage protection. For example, the formula for the cutoff voltage can be expressed as: =

[0053] in, Indicates the cutoff voltage. Indicates temperature, at temperatures higher than Under these conditions, the cutoff voltage is 2.25V, and the temperature is below -5°C. Under these conditions, the cutoff voltage is 1.9V, and the temperature is greater than or equal to -5°C. Less than or equal to In the case of cutoff voltage at Linear interpolation is obtained within the range.

[0054] The undervoltage recovery trend is the trend of voltage recovery after a battery becomes undervoltage, and it can be determined based on the actual power consumption of the battery. Optionally, the undervoltage recovery trend includes recovery and no recovery. For example: after a battery becomes undervoltage, limiting the battery's output power reduces the battery's polarization effect, and the electrochemical reaction inside the battery tends to stabilize. At this time, the voltage will recover slightly (e.g., from 2.6V to 2.7~2.8V), and the undervoltage recovery trend is recovery. Alternatively, after a battery becomes undervoltage, charging increases the battery voltage, and the undervoltage recovery trend is recovery. As another example: after limiting the battery's output power, the battery voltage drops further, or the actual power consumption of the battery remains at a high level, and the undervoltage recovery trend is no recovery.

[0055] In some embodiments, a pre-undervoltage zone is determined, and a first limit ratio is determined based on the pre-undervoltage zone.

[0056] The pre-undervoltage partition is one of multiple calibrated pre-undervoltage partitions. The multiple calibration limit ratios of the multiple calibrated pre-undervoltage partitions are positively correlated with the pre-undervoltage degree of the multiple calibrated pre-undervoltage partitions.

[0057] For example, the battery is divided into multiple pre-undervoltage zones based on its voltage, and each pre-undervoltage zone corresponds to its own calibration limit ratio. For instance, when the battery voltage is less than or equal to... and greater than or equal to Under these conditions, the battery is determined to be in a pre-undervoltage state. The pre-undervoltage calibration includes four zones: Zone 1, Zone 2, Zone 3, and Zone 4. When the battery voltage is less than or equal to... and greater than In this case, the battery voltage is determined to be in the first zone. When the battery voltage is less than or equal to... and greater than In this case, the battery voltage is determined to be in the second zone. When the battery voltage is less than or equal to... and greater than In this case, the battery voltage is determined to be in the third zone. When the battery voltage is less than or equal to... and greater than or equal to In this case, the battery voltage is determined to be in the fourth zone. Among them, > > > ≥ > The calibration limit ratio corresponding to the first zone is 75%, the second zone is 50%, the third zone is 25%, and the fourth zone is 0%. This application does not limit the division of calibration pre-undervoltage zones or the size of the calibration limit ratios; they can be flexibly adjusted according to battery characteristics and user needs. For example, the calibration limit ratios and the judgment voltage for calibration undervoltage zones can be comprehensively determined based on cell test data, battery tests, and vehicle calibration verification to ensure that the battery power is smoothly limited during actual operation, preventing abrupt power limit changes that could cause instantaneous power interruption in the vehicle, and effectively avoiding over-discharge problems. For example... The default setting is the static cell voltage corresponding to 5% SOC and below, which facilitates early discharge power limitation when the SOC is low. , , According to and Perform linear settings, and then adjust them through experiments and calibrations to determine the final value.

[0058] For example, the calibration limit ratio corresponding to the pre-undervoltage zone is determined as the initial limit ratio, the undervoltage recovery trend of the battery under the initial limit ratio is determined based on the actual power consumption, and the first limit ratio is determined based on the undervoltage recovery trend.

[0059] For example, if the battery does not meet the first preset condition, the undervoltage recovery trend is determined to be unrecovered.

[0060] The first preset condition indicates that after battery operation protection for a preset duration at the initial limit ratio, the actual power consumption is less than the target output power. The target output power is the product of the battery's rated power and the initial limit ratio. The actual power consumption refers to the sum of the battery's external output power and internal power loss.

[0061] Alternatively, the target output power can also be the product of the battery's allowable power (output power when the battery is not undervoltage) and the initial limit ratio.

[0062] As an example, if the undervoltage recovery trend is not recovered, find the second limit ratio that is closest to the initial limit ratio from at least one first candidate calibrated limit ratio. This second limit ratio is then determined as the first limit ratio.

[0063] Among them, at least one first candidate calibration limit ratio is a limit ratio that is less than the initial limit ratio among multiple calibration limit ratios.

[0064] For example, if the battery voltage is in the first zone with an initial limit of 75%, and after a preset duration of battery operation protection at the 75% limit, if the actual power consumption is greater than or equal to 75% of the allowable power, it indicates that the output power limitation is insufficient and the battery is not protected according to the protection requirements. In this case, the initial limit of the second zone (50%) is used as the first limit for battery operation protection. This process continues until the actual power consumption is consistently greater than or equal to the target output power, at which point a lower first limit is determined, until the first limit reaches 0%.

[0065] As an example, if the undervoltage recovery trend is not in the unrecovered state, the initial limiting ratio is determined as the first limiting ratio. For instance, if the battery voltage is in the first zone and the actual power consumption is less than the target output power, the battery output power is limited to 75% of the limiting ratio.

[0066] As an example, when the battery is in a pre-undervoltage state and the undervoltage recovery trend is towards recovery, the battery power first recovers at a first recovery rate for a first preset duration, and then recovers at a second recovery rate. This avoids excessive power usage during the battery power recovery process, which could lead to frequent power limiting processes.

[0067] The second recovery rate is greater than the first recovery rate.

[0068] For example, after providing operational protection to the battery at a first limiting ratio, it is determined whether the voltage is in the target pre-undervoltage zone. If the voltage is in the target pre-undervoltage zone and the actual power consumption is less than the target output power, the undervoltage recovery trend is determined to be recovery, the limiting ratio is updated to a third limiting ratio, and the battery is provided with operational protection using the third limiting ratio.

[0069] Among them, the target pre-undervoltage partition is the calibration pre-undervoltage partition corresponding to the third limit ratio. The third limit ratio is the limit ratio that is closest to the first limit ratio found from at least one second candidate calibration limit ratio. At least one second candidate calibration limit ratio is the limit ratio that is greater than the first limit ratio among multiple calibration pre-undervoltage partitions.

[0070] For example, when the battery voltage recovers from the third zone to the second zone, the first limit ratio needs to be increased from 25% to 50%. At this time, it is first determined whether the time when the actual power consumption of the battery is lower than the limit power (25% of the allowable power) corresponding to the third zone is less than the first preset time. If it is less than the first preset time, the battery power is first restored at the first recovery rate (e.g., 1 kW / s). If it is greater than or equal to the first preset time, the battery power is directly restored at the second recovery power (e.g., 10 kW / s).

[0071] For example, when the voltage is in the target pre-undervoltage zone and the battery meets the second preset condition, the first limit ratio is updated to the third limit ratio at the second recovery rate. When the voltage is in the target pre-undervoltage zone and the battery does not meet the second preset condition, the first limit ratio is updated to the third limit ratio at the first recovery rate.

[0072] The second preset condition indicates that the time during which the actual power consumption is less than the output power corresponding to the first limit ratio is greater than a preset time threshold, and the power difference between the actual power consumption and the output power corresponding to the first limit ratio is greater than a preset power difference. The second recovery rate is greater than the first recovery rate.

[0073] For example, when the battery voltage recovers from the third zone to the second zone, the first limit ratio needs to be increased from 25% to 50%. At this time, it is determined whether the time during which the actual power consumption of the battery is lower than the limit power (25% of the allowable power) corresponding to the third zone is greater than a preset time threshold, and whether the power difference between the actual power consumption and the limit power corresponding to the third zone is greater than a preset power difference. If the time during which the actual power consumption is lower than the limit power corresponding to the third zone is greater than the preset time threshold, and the power difference between the actual power consumption and the limit power corresponding to the third zone is greater than the preset power difference, the battery power is directly restored to the second recovery power (e.g., 10 kW / s).

[0074] In some embodiments, the battery is a power battery in the vehicle, and the second preset condition is further used to indicate that the accelerator pedal opening of the vehicle is less than a preset opening threshold. For example, if the actual power consumption is lower than the limit power corresponding to the third zone for a period of time longer than a preset time threshold, and the power difference between the actual power consumption and the limit power corresponding to the third zone is greater than a preset power difference, and the accelerator pedal opening of the vehicle is less than the preset opening threshold, the battery power is directly restored with the second recovery power (e.g., 10 kW / s).

[0075] Among them, the accelerator pedal opening of the vehicle is used to represent the user's power demand. When the user's power demand is high, the battery is not easy to restore power at a high power recovery speed (second recovery power).

[0076] Optionally, the user's power demand can be characterized by actual power consumption change rate, pedal change rate, load request, vehicle speed, navigation and driving style, etc. When the user's power demand is low, the battery restores power at a higher power recovery rate (second recovery power); when the user's power demand is high, no power recovery is performed, or power recovery is performed at a lower power recovery rate (first recovery power).

[0077] Step S202: The battery protection device uses the first limiting ratio to protect the battery during operation.

[0078] For example, the BMS generates a power adjustment command based on a first limit ratio, limiting the battery's output power to the product of the rated power and the first limit ratio, or limiting the battery's output power to the product of the allowable power and the first limit ratio.

[0079] In some embodiments, in the event of an undervoltage fault, the battery is protected based on its voltage.

[0080] Undervoltage fault refers to a state where the battery voltage cannot be restored after it becomes low, or a state where the battery cannot function properly after the voltage is restored. For example, when the battery voltage is less than... In this case, it is determined that the battery is in an undervoltage fault state.

[0081] For example, when the battery is in an undervoltage fault, the fault zone in which the battery voltage is located is determined, and the corresponding fault handling strategy is executed according to the fault zone in which the voltage is located.

[0082] Among them, the fault partition is one of multiple calibrated fault partitions, and the fault handling strategies corresponding to the multiple calibrated fault partitions are positively correlated with the fault degree of the multiple calibrated fault partitions.

[0083] For example, the fault zones are calibrated as a first fault zone, a second fault zone, and a third fault zone. When the voltage is less than... Greater than or equal to In this case, the voltage is determined to be in the first fault zone. When the voltage is less than... Greater than or equal to In this case, the voltage is determined to be in the second fault zone. When the voltage is less than... In this case, the voltage is determined to be in the third fault zone. > > , , and The relative cutoff voltage can be gradually reduced by 0.1V. The fault handling strategy for the first fault zone is: limit the battery output power to 0kW, and disconnect the battery from the load within a second preset time period to ensure that the battery is powered down (high voltage) within the second preset time period. The fault handling strategy for the second fault zone is: limit the battery output power to 0kW, and request the VCU to immediately control the battery to power down. The fault handling strategy for the third fault zone is: limit the battery output power to 0kW, and immediately control the battery to power down.

[0084] In some embodiments, when determining the calibration undervoltage zone or calibration fault zone based on the battery voltage, to avoid false triggering caused by voltage fluctuations, the voltage needs to remain in the calibration undervoltage zone or calibration fault zone for more than a third preset duration. For example, when the battery voltage is less than... and greater than or equal to If the time exceeds the third preset duration, the voltage is determined to be in the second fault zone.

[0085] In some embodiments, when the voltage is in the first zone or the first fault zone, if the actual output power of the battery is less than the target output power, it indicates that there is an abnormality in the battery or software strategy, which is not allowed to be recovered and requires technical personnel to handle.

[0086] In some embodiments, when the battery comprises multiple cells, the battery voltage refers to the minimum value among the voltages of the multiple cells.

[0087] For example, such as Figure 3 As shown in the embodiments of this application, another battery operation protection method includes: Step S301: Obtain the battery status parameters.

[0088] Optionally, the battery's state parameters include total battery voltage, battery current, minimum cell voltage, cell temperature, cutoff voltage, and allowable battery power (calculated based on SOC, temperature, etc.).

[0089] Step S302: Is the minimum cell voltage less than... If yes, proceed to step S307; otherwise, proceed to step S303.

[0090] Step S303: Is the minimum cell voltage less than... If yes, proceed to step S304; otherwise, proceed to step S308.

[0091] Step S304: Limit the battery's output power.

[0092] Step S305: Has the minimum cell voltage been restored? If yes, proceed to step S306; otherwise, continue to step S304.

[0093] Step S306: Increase the output power of the battery.

[0094] Step S307: Execute the fault handling strategy.

[0095] Step S308: End.

[0096] For example, such as Figure 4 As shown in the embodiments of this application, a method for limiting battery output power includes: Step S400: Begin.

[0097] Step S401: Is the voltage in the fourth zone? If yes, proceed to step S405; otherwise, proceed to step S402.

[0098] Step S402: Is the voltage in the third zone? If yes, proceed to step S406; otherwise, proceed to step S403.

[0099] Step S403: Is the voltage in the second zone? If yes, proceed to step S408; otherwise, proceed to step S404.

[0100] Step S404: Is the voltage in the first zone? If yes, proceed to step S410; otherwise, proceed to step S412.

[0101] Step S405: Limit the battery output power to 0% of the allowable power.

[0102] Step S406: Limit the battery output power to 25% of the allowable power.

[0103] Step S407: Does the actual power consumption of the battery exceed 25% of the allowable power? If yes, proceed to step S405; otherwise, proceed to step S406.

[0104] Step S408: Limit the battery output power to 50% of the allowable power.

[0105] Step S409: Does the actual power consumption of the battery exceed 50% of the allowable power? If yes, proceed to step S406; otherwise, proceed to step S408.

[0106] Step S410: Limit the battery output power to 75% of the allowable power.

[0107] Step S411: Does the actual power consumption of the battery exceed 75% of the allowable power? If yes, proceed to step S408; otherwise, proceed to step S410.

[0108] Step S412: End.

[0109] For example, such as Figure 5 As shown in the embodiment of this application, a method for increasing battery output power includes: Step S500: Begin.

[0110] Step S501: Is the undervoltage recovery trend a recovery? If yes, proceed to step S502; otherwise, proceed to step S505.

[0111] Step S502: Does the time during which the actual power consumption of the battery is less than the target output power exceed the first preset duration? If yes, proceed to step S503; otherwise, proceed to step S504.

[0112] Step S503: Increase the battery output power at the second recovery rate.

[0113] Step S504: Increase the battery output power at the first recovery rate.

[0114] The second recovery rate is higher than the first recovery rate.

[0115] Step S505: End.

[0116] For example, such as Figure 6 As shown in the embodiments of this application, another battery operation protection method includes: Step S600: Begin.

[0117] Step S601: Is the voltage in the third fault zone? If yes, proceed to step S604; otherwise, proceed to step S602.

[0118] Step S602: Is the voltage in the second fault zone? If yes, proceed to step S605; otherwise, proceed to step S603.

[0119] Step S603: Is the voltage in the first fault zone? If yes, proceed to step S606; otherwise, proceed to step S607.

[0120] Step S604: Execute the fault handling strategy corresponding to the third fault partition.

[0121] Step S605: Execute the fault handling strategy corresponding to the second fault partition.

[0122] Step S606: Execute the fault handling strategy corresponding to the first fault partition.

[0123] Step S607: End.

[0124] This application also provides a battery operation protection device, such as... Figure 7 As shown in the figure, a battery operation protection device provided in this application embodiment may include a processing module 701 and a protection module 702. The processing module 701 is used to execute... Figure 2 In the illustrated method, step S201 is performed by the protection module 702. Figure 2 The illustrated method includes step S202.

[0125] The foregoing mainly describes the solutions provided by the embodiments of this application from the perspective of methods and apparatus. To achieve the above functions, the battery protection device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0126] This application embodiment can, based on the above-described battery operation protection method, exemplarily divide the battery protection device into functional modules. For example, the battery protection device may include functional modules corresponding to each functional division, or two or more functions may be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division; in actual implementation, there may be other division methods.

[0127] This application also provides a computer-readable storage medium storing at least one computer program, which is loaded and executed by a processor to implement the battery operation protection method provided in the above-described method embodiments.

[0128] Optionally, the computer-readable storage medium may be a non-transitory computer-readable storage medium, such as a read-only memory (ROM), random access memory (RAM), magnetic tape, floppy disk, and optical data storage device.

[0129] This application also provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are executed by a processor, they implement the battery operation protection method provided in the above-described method embodiments.

[0130] It should be noted that when one or more instructions in the computer-readable storage medium or computer program product are executed by the processor of a computing device, they implement the various processes of the above-described method embodiments and achieve the same technical effects as the above-described methods. To avoid repetition, they will not be described again here.

[0131] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0132] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another apparatus, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0133] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0134] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, essentially, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0135] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Those skilled in the art can understand that implementing all or part of the processes of the above embodiments and making equivalent changes according to the claims of this application still fall within the scope of this application.

Claims

1. A battery operation protection method, characterized in that, The battery operation protection method includes: When the battery is in a pre-undervoltage condition, a first limiting ratio is determined based on the battery's voltage and undervoltage recovery trend; the first limiting ratio is used to characterize the degree of limitation on the battery's output power; the undervoltage recovery trend is determined based on the battery's actual power consumption. The battery is protected during operation using the first limiting ratio.

2. The battery operation protection method according to claim 1, characterized in that, Determining the first limiting ratio based on the battery's voltage and undervoltage recovery trend includes: The voltage is located in a pre-undervoltage zone; wherein the pre-undervoltage zone is one of a plurality of calibrated pre-undervoltage zones; the plurality of calibration limit ratios of the plurality of calibrated pre-undervoltage zones are positively correlated with the pre-undervoltage degree of the plurality of calibrated pre-undervoltage zones; The calibration limit ratio corresponding to the pre-undervoltage partition is determined as the initial limit ratio; The undervoltage recovery trend of the battery under the initial limit ratio is determined based on the actual power consumption. The first limiting ratio is determined based on the undervoltage recovery trend.

3. The battery operation protection method according to claim 2, characterized in that, Determining the undervoltage recovery trend of the battery under the initial limit ratio based on the actual power consumption includes: If the battery does not meet the first preset condition, the undervoltage recovery trend is determined to be unrecovered. Wherein, the first preset condition is used to indicate that after the battery operates for a preset duration with the initial limit ratio, the actual power consumption is less than the target output power; the target output power is the product of the battery's rated power and the initial limit ratio.

4. The battery operation protection method according to claim 2, characterized in that, Determining the first limiting ratio based on the undervoltage recovery trend includes: If the undervoltage recovery trend is not recovered, find the second limit ratio that is closest to the initial limit ratio from at least one first candidate calibration limit ratio; wherein, the at least one first candidate calibration limit ratio is a limit ratio that is smaller than the initial limit ratio among the plurality of calibration limit ratios; The second restriction ratio is determined to be the first restriction ratio.

5. The battery operation protection method according to claim 2, characterized in that, The battery operation protection method further includes: After performing operational protection on the battery at the first limiting ratio, it is determined whether the voltage is within the target pre-undervoltage zone; wherein, the target pre-undervoltage zone is the calibration pre-undervoltage zone corresponding to the third limiting ratio; the third limiting ratio is the limiting ratio closest to the first limiting ratio found from at least one second candidate calibration limiting ratio; the at least one second candidate calibration limiting ratio is the limiting ratio among the plurality of calibration pre-undervoltage zones that is greater than the first limiting ratio; If the voltage is within the target pre-undervoltage zone, the first limit ratio is updated to the third limit ratio; The battery is protected during operation using the third limiting ratio.

6. The battery operation protection method according to claim 5, characterized in that, When the voltage is within the target pre-undervoltage zone, updating the limiting ratio to the third limiting ratio includes: When the voltage is in the target pre-undervoltage zone and the battery meets the second preset condition, the first limit ratio is updated to the third limit ratio at the second recovery rate; the second preset condition is used to indicate that the time when the actual power consumption is less than the output power corresponding to the first limit ratio is greater than a preset time threshold, and the power difference between the actual power consumption and the output power corresponding to the first limit ratio is greater than a preset power difference. When the voltage is in the target pre-undervoltage zone and the battery does not meet the second preset condition, the first limit ratio is updated to the third limit ratio at a first recovery rate; wherein the second recovery rate is greater than the first recovery rate.

7. The battery operation protection method according to claim 6, characterized in that, The battery is the power battery in the vehicle, and the second preset condition is also used to indicate that the accelerator pedal opening of the vehicle is less than a preset opening threshold.

8. The battery operation protection method according to claim 1, characterized in that, The condition for determining that the battery is in a pre-undervoltage state is: the absolute voltage difference between the voltage and the battery's cutoff voltage is less than a preset voltage difference.

9. A battery operation protection device, characterized in that, include: The processing module is used to determine a first limiting ratio based on the battery's voltage and undervoltage recovery trend when the battery is in a pre-undervoltage condition; The first limiting ratio is used to characterize the degree of limitation on the output power of the battery, and the undervoltage recovery trend is determined based on the actual power consumption of the battery; A protection module is used to protect the battery during operation using the first limiting ratio.

10. A vehicle, characterized in that, The vehicle includes the battery operation protection device as described in claim 9.

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