Battery protection method and related apparatus

Abstract

The embodiment of the application discloses a battery protection method and related device, the method comprises: calculating the whole package direct current equivalent resistance of the battery package, the maximum direct current equivalent resistance corresponding to the maximum voltage battery unit and the minimum direct current equivalent resistance corresponding to the minimum voltage battery unit; determining the charging limit power of the battery according to the whole package direct current equivalent resistance and the maximum direct current equivalent resistance; determining the discharging limit power of the battery according to the whole package direct current equivalent resistance and the minimum direct current equivalent resistance; determining the power limit range of the battery according to the charging limit power and the discharging limit power. In this way, the limit power range of the battery can be determined by three kinds of dynamic resistances calculated at different temperatures, which can make the limit power range of the battery more reasonable, thereby effectively improving the stability of the battery at different temperatures, effectively protecting the battery while exerting the performance of the battery as much as possible, and further improving the driving experience of the vehicle.

Description

Technical Field

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

[0002] Vehicles equipped with range-extended or hybrid powertrains are cars capable of using multiple power sources simultaneously. The battery is a crucial component of these vehicles and is often one of their power sources. Therefore, battery protection is paramount in range-extended or hybrid vehicles to ensure long-term safe and reliable battery operation and provide a better driving experience. A common battery protection method involves the vehicle control unit (VCU) directly using the charging and discharging power limits sent by the battery management module (BMS) as the battery's charging and discharging power limits, thus controlling the vehicle's battery power within these limits. However, this method does not consider the potential temperature variations that may occur during actual battery operation, such as high-temperature or low-temperature conditions. Temperature changes affect battery parameters such as resistance and current, thereby impacting battery power. Therefore, relying solely on the charging and discharging power limits sent by the BMS to set the battery power limit range is inaccurate. Significant temperature variations can cause repeated fluctuations in battery charging and discharging power, leading to a poor driving experience.

[0003] Therefore, a battery protection method is urgently needed to solve the above problems. Summary of the Invention

[0004] This application provides a battery protection method and related apparatus. It can determine the battery's charging power limit at the current temperature by calculating the overall DC equivalent internal resistance of the battery pack, the maximum DC equivalent internal resistance corresponding to the highest voltage battery cell, and the minimum DC equivalent internal resistance corresponding to the lowest voltage battery cell. Based on the overall DC equivalent internal resistance and the maximum DC equivalent internal resistance, it can also determine the battery's discharging power limit at the current temperature, thereby determining the battery's power limit range. This allows for a more reasonable power limit range, effectively improving battery stability at different temperatures, maximizing battery performance while effectively protecting the power battery, and enhancing the vehicle's driving experience.

[0005] In a first aspect, embodiments of this application provide a battery protection method applied to a vehicle control unit (VCU), the method comprising:

[0006] Calculate the overall DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery pack. The battery pack includes multiple battery cells. The overall DC equivalent internal resistance is the DC equivalent internal resistance of the entire battery pack. The maximum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the highest voltage. The minimum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the lowest voltage.

[0007] The battery charging limit power is determined based on the overall DC equivalent internal resistance and the maximum DC equivalent internal resistance.

[0008] The discharge limit power of the battery is determined based on the total DC equivalent internal resistance and the minimum DC equivalent internal resistance.

[0009] The power limit range of the battery is determined based on the charging limit power and the discharging limit power.

[0010] Secondly, embodiments of this application provide a battery protection device applied to the vehicle control unit (VCU) of a vehicle. The device includes a calculation unit, an acquisition unit, and a determination unit, wherein...

[0011] The calculation unit is used to calculate the overall DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery pack. The battery pack includes multiple battery cells. The overall DC equivalent internal resistance is the DC equivalent internal resistance of the entire battery pack. The maximum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the highest voltage. The minimum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the lowest voltage.

[0012] The determining unit is used to determine the battery charging limit power based on the total DC equivalent internal resistance and the maximum DC equivalent internal resistance.

[0013] The determining unit is further configured to determine the discharge limit power of the battery based on the total DC equivalent internal resistance and the minimum DC equivalent internal resistance.

[0014] The determining unit is further configured to determine the power limiting range of the battery based on the charging limiting power and the discharging limiting power.

[0015] Thirdly, embodiments of this application provide an electronic device, including a processor, a memory, a communication interface, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the processor, and the programs include instructions for performing steps in any method of the first aspect of this application.

[0016] Fourthly, embodiments of this application provide a computer-readable storage medium storing a computer program for electronic data interchange, wherein the computer program causes a computer to perform some or all of the steps described in any method of the first aspect of this application.

[0017] Fifthly, embodiments of this application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program operable to cause a computer to perform some or all of the steps described in any method of the first aspect of this application. The computer program product may be a software installation package.

[0018] Sixthly, embodiments of this application provide a vehicle, wherein the vehicle includes a vehicle control unit (VCU), the VCU being used to perform some or all of the steps described in any method of the first aspect of this application.

[0019] As can be seen from the embodiments of this application, the charging power limit of the battery pack is determined by calculating the overall DC equivalent internal resistance of the battery pack, the maximum DC equivalent internal resistance corresponding to the maximum voltage battery cell, and the minimum DC equivalent internal resistance corresponding to the minimum voltage battery cell; the charging power limit of the battery is determined based on the overall DC equivalent internal resistance and the maximum DC equivalent internal resistance; the discharging power limit of the battery is determined based on the overall DC equivalent internal resistance and the minimum DC equivalent internal resistance; and the power limit range of the battery is determined based on the charging power limit and the discharging power limit. This allows the power limit range of the battery to be determined by using three dynamic internal resistances calculated at different temperatures, making the power limit range of the battery more reasonable, thereby effectively improving the stability of the battery at different temperatures, enabling continuous operation, effectively protecting the power battery while maximizing battery performance, and thus improving the driving experience of the vehicle at low temperatures. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1A This is a schematic diagram of a common signal flow process of a vehicle control unit provided in an embodiment of this application;

[0022] Figure 1B This is a schematic diagram of a battery charging and discharging mode under conventional low-temperature conditions provided in an embodiment of this application;

[0023] Figure 1C This is a diagram of a VCU battery power limiting calculation architecture provided in an embodiment of this application;

[0024] Figure 1D This is a schematic diagram of the unit structure of a DC dynamic internal resistance observation module provided in an embodiment of this application;

[0025] Figure 2 This is a schematic flowchart of a battery protection method provided in an embodiment of this application;

[0026] Figure 3 This is a schematic diagram of the observation process of a DC dynamic internal resistance observation module provided in an embodiment of this application;

[0027] Figure 4A This is a schematic diagram of a battery charging power limit signal acquisition module provided in an embodiment of this application;

[0028] Figure 4B This is a schematic diagram of a battery discharge power limit signal acquisition module provided in an embodiment of this application;

[0029] Figure 4C This is a schematic diagram of a vehicle power unit power limiting module provided in an embodiment of this application;

[0030] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;

[0031] Figure 6 This is a schematic diagram of the functional unit structure of a battery protection device provided in an embodiment of this application. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present application.

[0033] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0034] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0035] To better understand the solutions of the embodiments of this application, the electronic devices, related terms, concepts and related background that may be involved in the embodiments of this application will be introduced below.

[0036] The electronic device can be a portable electronic device that also includes other functions such as a personal digital assistant and / or music player, such as a mobile phone, tablet computer, or wearable electronic device with wireless communication capabilities (such as a smartwatch). Exemplary embodiments of the portable electronic device include, but are not limited to, portable electronic devices running iOS, Android, Microsoft, or other operating systems. The aforementioned portable electronic device can also be other portable electronic devices, such as a laptop computer. It should also be understood that in some other embodiments, the aforementioned electronic device can also be the electronic device used to control the battery protection system in this application.

[0037] A range-extended or hybrid vehicle is a car that can use multiple power sources simultaneously. Range-extended hybrid vehicles typically use a battery and a small fuel cell generator to power an electric motor, thus extending the battery's range. Series hybrid vehicles, on the other hand, connect an electric motor and a combustion engine together so they can work together to provide faster acceleration and higher power output. Range-extended or hybrid vehicles offer many advantages, such as reduced emissions and improved fuel economy, while also providing a smoother driving experience. These vehicles can also automatically switch power sources based on driving needs to ensure optimal fuel economy and maximum performance. Currently, many major automakers produce range-extended or hybrid vehicles, including hybrid sedans, SUVs, and trucks.

[0038] Please see Figure 1A , Figure 1A This is a schematic diagram of a common signal flow process in a vehicle control unit provided in an embodiment of this application, such as... Figure 1A As shown, the Vehicle Control Unit (VCU) includes the following modules: signal acquisition module, drive target power acquisition module, signal processing module, energy distribution module, and power limiting module.

[0039] For example, a vehicle equipped with a hybrid control system has two power sources: a power battery and an engine, with their respective power ratings P_Bat and P_Eng. The vehicle's energy consumption can be divided into three parts: the drive generator P_Mdive, the transmission P_Gear, and the total vehicle power consumption P_Consume. The generator's power output can be set as P_Mg. The battery's allowable charging power is P_DisChargeAld, and its allowable discharging power is P_ChargeAld.

[0040] For example, the signal acquisition module processes the pedal signal to obtain a valid signal, which in turn drives the target power acquisition module to acquire the valid signal obtained by the signal acquisition module through the pedal signal, thereby realizing the acquisition of parameters such as the vehicle accelerator and brake pedals. Furthermore, the target power acquisition module sends a target power signal to the energy distribution module so that the energy distribution module can determine the target power information of the power unit.

[0041] For example, the signal processing module interacts with the battery management unit (BMS) via battery signals, and further, the signal processing module sends BMS power limiting parameters to the power limiting module.

[0042] Furthermore, the power limiting module calculates the torque target for each actuator in the vehicle based on the BMS power limiting parameters and the power unit target power information, and sends the torque target to the motor control unit (MCU), generator control unit (GCU), engine control unit (ECU), and transmission control unit (TCU), respectively. The MCU, GCU, ECU, and TCU modules then control the operation of each actuator according to the received torque target. The actuators include the drive generator, generator, engine, and transmission.

[0043] Specifically, Figure 1A The VCU (Vehicle Control Unit) shown determines the ideal output power of the drive generator, generator, engine, and transmission based on the driver's intentions. Furthermore, it limits and adjusts the target power of the drive generator, generator, engine, and transmission according to the charging and discharging power allowed by the BMS (Battery Management Unit), thereby obtaining the effective true target power of the drive generator, generator, engine, and transmission. This power is then sent to the MCU, GCU, ECU, and TCU modules, ensuring that the output power of the drive generator, generator, engine, and transmission follows their respective target power, thus limiting the battery's charging and discharging power within permissible ranges and preventing overcharging and over-discharging of the power battery.

[0044] Under normal temperature conditions, the power adjustment based on the charging and discharging power limits [P_DisChargeAld, P_ChargeAld] issued by the BMS according to the VCU can basically meet the actual needs of the vehicle. However, at low temperatures, due to the large changes in the dynamic internal resistance of the battery, and the different dynamic internal resistance under different charging currents, the charging and discharging power limits calculated by the BMS are only instantaneous and relatively ideal power values. Figure 1B As shown, Figure 1B This is a schematic diagram of a battery charging and discharging mode under conventional low-temperature conditions, provided in an embodiment of this application. Figure 1B As shown, this charging and discharging power value can only be maintained for 2-10 seconds, after which it quickly enters protection mode, and P_DisChargeAld and P_ChargeAld quickly become very small; after 2-10 seconds in protection mode, it will enter normal charging mode again. This causes the charging and discharging process to be constantly interrupted, and the charging and discharging power to fluctuate repeatedly, resulting in a very poor driving experience.

[0045] To solve the above problems, such as Figure 1C The embodiment shown in this application provides a VCU battery power limiting calculation architecture diagram.

[0046] For example, Figure 1C The part corresponding to the dashed box at the bottom of the architecture shown is the key technical component module of this application, used to replace, for example... Figure 1A The power limiting signal set by the Battery Management Unit (BMS) shown in the diagram, through the existing energy distribution module, reliably protects the battery while improving the driving experience of hybrid vehicles in low temperatures.

[0047] For example, the signal processing module is mainly used to receive the necessary battery signals from the battery management unit (BMS) to provide a basis for calculating reasonable charge and discharge limit power.

[0048] For example, the limit range acquisition module obtains the battery voltage mainly by setting a reasonable battery operating voltage range based on the battery temperature. The battery is safe and reliable to operate within this voltage range and can work continuously. At the same time, the battery performance can be effectively utilized within this voltage range.

[0049] For example, the DC dynamic internal resistance observation module mainly calculates the dynamic internal resistance of the battery based on the battery characteristics; because the internal resistance of the battery increases much more at low temperatures than at room temperature, obtaining the correct DC dynamic internal resistance of the battery is the key to calculating a reasonable battery power limit.

[0050] Specifically, the basic principle of the aforementioned DC dynamic internal resistance observation module is as follows:

[0051] U S =Uref +I S *R DC +U Error Formula (1)

[0052] In formula (1), U S For battery test voltage, I S U represents the actual current of the battery. ref R is the battery's open-circuit voltage. DC U is the DC equivalent internal resistance of the entire battery pack. error This represents the test error.

[0053] Specifically, during actual operation, the more accurate value of the actual test voltage of a battery includes not only the open-circuit voltage corresponding to the basic state, but also the voltage occupied by current and resistance at the current temperature, as well as the test error voltage value.

[0054] For example, in the solution of this application, the battery DC dynamic internal resistance observation module is implemented through U S I S Observe the current R at the current temperature DC Then adjust R appropriately according to the required current. DC Ultimately, obtain the required R DC_ I ACT The calculation method for dynamic DC internal resistance in the battery DC dynamic internal resistance observation module is as follows:

[0055]

[0056] In formula (2), R0 is the DC internal resistance of the battery at room temperature, a is the positive value of the integral correction coefficient, b is the positive value of the proportional correction coefficient, and c is the damping coefficient, which ranges from 0 to 1.

[0057] For example, the required current correction process refers to the difference between the current actual current and the dynamic current, corresponding to a resistor R(I). ACT I S According to R under the current R DC The correction is then performed to obtain the dynamic DC resistance at the current temperature.

[0058] For example, the voltage and current limiting conversion module calculates the maximum charging current and maximum discharging current of the battery based on the allowed battery voltage and battery internal resistance. Because the DC dynamic internal resistance of the battery will vary with the current, it is necessary to correct the DC resistance observed in the current state through the current signal to obtain the accurate current dynamic internal resistance, and thus obtain the accurate maximum charging current and maximum discharging current.

[0059] For example, the power limitation calculation module calculates the battery's charging power limitation and discharging power limitation based on the maximum charging current and maximum discharging current obtained from the above process and the corresponding battery voltage.

[0060] For example, the energy distribution module allocates the battery charging limit power, discharge limit power, and driving demand power reasonably according to the battery charging limit power and driving demand power calculated by the above process, so as to meet the driver's needs while reasonably protecting the power battery.

[0061] For example, Figure 1D The diagram shows a unit structure schematic of a DC dynamic internal resistance observation module. Among them, Figure 1D The DC dynamic internal resistance observation module includes: a battery DC internal resistance observation unit, a maximum voltage battery unit DC internal resistance observation unit, and a minimum voltage battery unit DC internal resistance observation unit.

[0062] To better understand the above process, this application will be described in detail below with reference to specific embodiments.

[0063] Please see Figure 2 , Figure 2 This application provides a schematic flowchart of a battery protection method, as illustrated in the embodiments below. Figure 2 As shown, this battery protection method is applied to the vehicle control unit (VCU) and specifically includes the following steps:

[0064] S201. Calculate the overall DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery pack.

[0065] The battery pack includes multiple battery cells. The overall DC equivalent internal resistance of the battery pack is the DC equivalent internal resistance of the entire battery pack. The maximum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the highest voltage, and the minimum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the lowest voltage.

[0066] For example, the VCU is based on, respectively, as follows Figure 1D The working principle of the DC dynamic internal resistance observation module is as follows: it calculates the equivalent DC internal resistance of the entire battery pack through the resistance DC internal resistance observation unit, calculates the maximum equivalent DC internal resistance of the maximum voltage battery unit through the maximum voltage battery unit DC internal resistance observation unit, and calculates the minimum equivalent DC internal resistance of the minimum voltage battery unit through the minimum voltage battery unit DC internal resistance observation unit. The battery comprises multiple cells, each considered a battery unit, and multiple battery units constitute a battery assembly. The maximum voltage battery unit DC internal resistance observation unit identifies the cell with the highest current voltage value as the maximum voltage battery unit, and the minimum voltage battery unit DC internal resistance observation unit identifies the cell with the lowest current voltage value as the minimum voltage battery unit.

[0067] S202. Determine the charging limit power of the battery based on the total DC equivalent internal resistance and the maximum DC equivalent internal resistance.

[0068] For example, the VCU obtains three equivalent internal resistances through step S201, which are then processed by... Figure 1C After calculations by the voltage and current limiting conversion module and the power limiting calculation module, a charging power is obtained. Further, based on the relationship between the calculated charging power and the allowable charging power P_DisChargeAld, the battery's charging limit power is determined.

[0069] S203. Determine the discharge limit power of the battery based on the total DC equivalent internal resistance and the minimum DC equivalent internal resistance.

[0070] For example, the VCU obtains three equivalent internal resistances through step S201, which are then processed by... Figure 1C After calculations by the voltage and current limiting conversion module and the power limiting calculation module, a discharge power is obtained. Further, based on the relationship between the calculated discharge power and the allowable discharge power P_ChargeAld, the battery's charging limit power is determined.

[0071] S204. Determine the power limit range of the battery based on the charging limit power and the discharging limit power.

[0072] For example, the VCU sends the charging limit power and discharging limit power determined in steps S202 and S203 above to the power limit module through the power limit calculation module.

[0073] Furthermore, the power limiting module sets the charging limit power to the upper limit of the power limiting range and the discharging limit power to the lower limit of the power limiting range, thus obtaining the power limiting range of the battery.

[0074] It's important to note that calculated power limits are more reasonable and stable than those obtained through table lookups. Table lookups often use the current temperature as an isolated reference, setting power limits accordingly. However, in real-world scenarios, the temperature of the battery's environment or the battery itself changes smoothly. Unless this change is drastic, it won't cause significant fluctuations in the power limit, and the battery can still operate continuously in this situation. Calculated power limits are determined based on the battery's actual usage scenario and real-time temperature data. This prevents excessive fluctuations in the power limit, effectively protecting the battery while maximizing its performance, thus improving the driving experience of hybrid vehicles in low temperatures.

[0075] As can be seen, the battery protection method described in this application calculates the battery's DC equivalent internal resistance at the current cell temperature, the maximum DC equivalent internal resistance corresponding to the maximum voltage battery cell, and the minimum DC equivalent internal resistance corresponding to the minimum voltage battery cell; determines the battery's charging power limit based on the overall pack's DC equivalent internal resistance and the maximum DC equivalent internal resistance; determines the battery's discharging power limit based on the overall pack's DC equivalent internal resistance and the minimum DC equivalent internal resistance; and determines the battery's power limit range based on the charging power limit and the discharging power limit. This allows for the acquisition of accurate current dynamic internal resistance through three dynamic internal resistances calculated at different temperatures, thereby obtaining accurate maximum charging current and maximum discharging current, and ultimately determining the battery's power limit range. This makes the battery's power limit range more reasonable, effectively improving the battery's stability at different temperatures, effectively protecting the power battery while maximizing battery performance, and enhancing the vehicle's driving experience.

[0076] In one possible example, determining the battery charging limit power based on the overall DC equivalent internal resistance and the maximum DC equivalent internal resistance may include the following steps: monitoring a first change in the total voltage and a second change in the voltage of the highest-voltage battery cell, wherein the highest-voltage battery cell voltage is the voltage corresponding to the battery cell with the highest voltage; when the first change indicates that the total voltage has reached the maximum total voltage, calculating a first charging current based on the overall DC equivalent internal resistance; when the second change indicates that the highest-voltage battery cell voltage has reached the maximum battery cell charging voltage, calculating a second charging current based on the maximum DC equivalent internal resistance; and determining the battery charging limit power based on the first charging current and the second charging current.

[0077] For example, such as Figure 4A As shown, Figure 4A This is a schematic diagram of a battery charging power limit signal acquisition module provided in an embodiment of this application. Specifically, the VCU monitors the changes in the total battery voltage and the voltage of the battery cells. If the first change indicates that the current total battery voltage has reached the maximum allowable voltage RefBatVmax, the VCU calculates the corresponding first charging current ICharge_BatVmax based on the overall DC equivalent internal resistance DCIRAct_Bat of the battery pack and RefBatVmax.

[0078] For example, if the second change indicates that the current maximum voltage cell voltage of the battery reaches the maximum allowable voltage RefCellVmax, the VCU calculates the corresponding second charging current ICharge_CellMaxVolt based on the maximum DC equivalent internal resistance DCIRAct_CellMaxVolt and RefCellVmax.

[0079] Furthermore, the battery charging limit power is determined based on the first charging current ICharge_BatVmax and the second charging current ICharge_CellMaxVolt.

[0080] As can be seen, in this application example, by using the observed DC equivalent internal resistance of the entire pack and the maximum DC equivalent internal resistance to monitor the total voltage of the battery and the voltage of the battery's maximum voltage cell, the voltage change is monitored in real time. When the voltage reaches the maximum total voltage or the maximum allowable voltage, the charging current of the battery and the maximum voltage cell is calculated based on the DC equivalent internal resistance of the entire pack and the maximum DC equivalent internal resistance, thereby determining the battery's charging limit current based on the first charging current and the second charging current.

[0081] In one possible example, determining the charging limit power of the battery based on a first charging current and a second charging current may include the following steps: using the larger of the first charging current and the second charging current as the maximum charging current of the battery; calculating a first charging voltage based on the maximum charging current, and calculating a maximum charging power based on the maximum charging current and the first charging voltage; and determining the maximum charging power as the charging limit power if the maximum charging power is less than or equal to the allowable charging power.

[0082] For example, if the first charging current ICharge_BatVmax is less than or equal to the second charging current ICharge_CellMaxVolt, then the first charging current is determined as the battery's maximum charging current ImaxCharge_VoltAld. In this case, as long as the current charging current is less than or equal to the maximum charging current, the battery will always be within the safe charging current range.

[0083] Furthermore, such as Figure 4A As shown, the VCU calculates the corresponding charging voltage VBat_ImaxCharge based on the ImaxCharge_VoltAld signal determined in the above steps.

[0084] It should be noted that one possible way to calculate the above charging voltage is as follows: determine the current dynamic internal resistance of the battery based on ImaxCharge_VoltAld, and obtain the corresponding charging voltage based on ImaxCharge_VoltAld, the current dynamic internal resistance, and the voltage error value.

[0085] Furthermore, such as Figure 4A As shown, the battery charging power limit calculation module obtains the maximum allowable charging power of the battery voltage by multiplying the current ImaxCharge_VoltAld and the voltage VBat_ImaxCharge and then reversing the result.

[0086] Furthermore, such as Figure 4A As shown, the battery charging power limit calculation module selects the smaller absolute value as the final battery charging limit power PLLimit_Bat based on the calculated maximum charging power and the battery's allowable charging power P_ChargeAld. The battery's allowable charging power can be the original charging allowable power set at the battery's factory settings, which can be obtained through data acquisition.

[0087] For example, if the maximum charging power is less than or equal to the allowable charging power, then the maximum charging power is determined as the charging limit power.

[0088] In another possible example, if the first charging current is greater than the second charging current, then the second charging current is determined as the maximum charging current; and, the first charging voltage is calculated based on the maximum charging current, and the maximum charging power is calculated based on the maximum charging current and the first charging voltage; and, if the maximum charging power is less than or equal to the allowable charging power, then the maximum charging power is determined as the charging limit power.

[0089] For example, if the first charging current ICharge_BatVmax is greater than the second charging current ICharge_CellMaxVolt, then the second charging current is determined as the battery's maximum charging current ImaxCharge_VoltAld. In this case, as long as the current charging current is less than or equal to the maximum charging current, the battery will always be within the safe charging current range.

[0090] Furthermore, such as Figure 4A As shown, the VCU calculates the corresponding charging voltage VBat_ImaxCharge based on the ImaxCharge_VoltAld signal determined in the above steps.

[0091] Furthermore, such as Figure 4A As shown, the battery charging power limit calculation module obtains the maximum allowable charging power of the battery voltage by multiplying the current ImaxCharge_VoltAld and the voltage VBat_ImaxCharge and then reversing the result.

[0092] Furthermore, such as Figure 4A As shown, the battery charging power limit calculation module selects the value with the smaller absolute value as the final battery charging limit power PLLimit_Bat based on the calculated maximum charging power and the battery charging allowable power P_ChargeAld.

[0093] For example, if the maximum charging power is less than or equal to the allowable charging power, then the maximum charging power is determined as the charging limit power.

[0094] As can be seen, in this application example, protection for each battery cell is achieved by determining the smaller value of the charging current corresponding to the battery and the cell with the maximum voltage as the charging current. Furthermore, in the process of calculating the corresponding voltage value based on the determined maximum charging current and finally calculating the maximum charging power used to determine the battery's charging limit power, the obtained maximum charging power is not simply obtained based on a lookup table. Instead, it takes into account temperature changes, such as at low temperatures, the dynamic changes in internal resistance, and the impact of these changes on power. This results in a more accurate and realistic allowable charging power that better meets the actual operational needs of the battery.

[0095] In one possible example, the method may further include the following step: if the maximum charging power is greater than the allowable charging power, then the allowable charging power is determined as the charging limit power.

[0096] As can be seen, in this example, protection for each battery cell is achieved by determining the smaller value of the charging current corresponding to the battery and the cell with the maximum voltage as the charging current. Furthermore, the corresponding voltage value is calculated based on the determined maximum charging current, and the maximum charging power is ultimately calculated. The calculated maximum charging power is then compared with the battery's original preset allowable charging power, and the smaller value is determined as the charging limit power. This effectively avoids the possibility of battery cell overload that might occur if the allowable charging power is directly obtained from a table. Taking the smaller value ensures that as long as the charging power meets the current charging limit power, both the battery and the battery cell remain in a safe and stable state.

[0097] In one possible example, determining the battery's discharge limit power based on the overall DC equivalent internal resistance and the minimum DC equivalent internal resistance includes the following steps: monitoring a third change in the total voltage and a fourth change in the voltage of the minimum voltage battery cell, wherein the minimum voltage battery cell voltage is the voltage corresponding to the battery cell with the lowest voltage; when the third change indicates that the total voltage has reached the minimum total voltage, calculating a first discharge current based on the DC equivalent internal resistance; when the fourth change indicates that the minimum voltage battery cell voltage has reached the minimum battery cell discharge voltage, calculating a second discharge current based on the minimum DC equivalent internal resistance; and determining the battery's discharge limit power based on the first discharge current and the second discharge current.

[0098] Specifically, such as Figure 4B As shown, Figure 4BThis is a schematic diagram of a battery discharge power limit signal acquisition module provided in an embodiment of this application. The VCU monitors the changes in the total battery voltage and the voltage of the battery cells. If the third change indicates that the current total battery voltage has reached the minimum battery cell discharge voltage RefBatVmin, the VCU calculates the corresponding first discharge current IDisCharge_BatVmin based on the overall DC equivalent internal resistance DCIRAct_Bat of the battery pack and RefBatVmin.

[0099] For example, if the fourth change indicates that the current minimum voltage cell voltage of the battery reaches the minimum battery cell discharge voltage RefCellVMin, the VCU calculates the corresponding second discharge current IDisCharge_CellMinVolt based on the minimum DC equivalent internal resistance DCIRAct_CellMinVolt and RefCellVMin.

[0100] Furthermore, the battery discharge limit power is determined based on the first discharge current IDisCharge_BatVmin and the second discharge current IDisCharge_CellMinVolt.

[0101] As can be seen, in this application example, by using the observed DC equivalent internal resistance of the entire pack and the minimum DC equivalent internal resistance to monitor the total voltage of the battery and the voltage of the minimum voltage cell of the battery, the voltage change is monitored in real time. When the voltage reaches the maximum total voltage or the minimum battery cell discharge voltage, the discharge current of the battery and the minimum voltage cell is calculated based on the DC equivalent internal resistance of the entire pack and the minimum DC equivalent internal resistance, and the discharge limit current of the battery is determined based on the first discharge current and the second discharge current.

[0102] In one possible example, determining the battery discharge limit power based on a first discharge current and a second discharge current may include the following steps: taking the smaller of the first discharge current and the second discharge current as the maximum discharge current of the battery; calculating a first discharge voltage based on the maximum discharge current, and calculating a maximum discharge power based on the maximum discharge current and the first discharge voltage; and determining the maximum discharge power as the discharge limit power if the maximum discharge power is less than or equal to the allowable discharge power.

[0103] For example, if the first discharge current IDisCharge_BatVmin is less than or equal to the second discharge current IDisCharge_CellMinVolt, then the first discharge current is determined as the battery's maximum discharge current ImaxDisCharge_VoltAld. In this case, as long as the current discharge current is less than or equal to the maximum discharge current, the battery will always be within the safe discharge current range.

[0104] Furthermore, such as Figure 4B As shown, the VCU calculates the corresponding charging voltage VBat_ImaxDisCharge based on the ImaxDisCharge_VoltAld signal determined in the above steps.

[0105] It should be noted that one possible way to calculate the above charging voltage is as follows: determine the current dynamic internal resistance of the battery based on ImaxDisCharge_VoltAld, and obtain the corresponding charging voltage based on ImaxDisCharge_VoltAld, the current dynamic internal resistance, and the voltage error value.

[0106] Furthermore, such as Figure 4B As shown, the battery charging power limit calculation module obtains the maximum allowable charging power of the battery voltage by multiplying the current ImaxDisCharge_VoltAld and the voltage VBat_ImaxDisCharge and then reversing the result.

[0107] Furthermore, such as Figure 4B As shown, the battery charging power limit calculation module selects the smaller absolute value as the final battery discharge limit power PHLimit_Bat based on the calculated maximum discharge power and the battery's allowable discharge power P_DisChargeAld. The battery's allowable discharge power can be the discharge power originally set at the battery's factory settings, which can be obtained through data acquisition.

[0108] For example, if the maximum discharge power is less than or equal to the allowable discharge power, then the maximum discharge power is determined as the discharge limit power.

[0109] In another possible example, if the first discharge current is greater than the second discharge current, then the second discharge current is determined as the maximum discharge current; and the first discharge voltage is calculated based on the maximum discharge current, and the maximum discharge power is calculated based on the maximum discharge current and the first discharge voltage; and if the maximum discharge power is less than or equal to the discharge allowable power, then the maximum discharge power is determined as the discharge limit power.

[0110] For example, if the first discharge current IDisCharge_BatVmin is greater than the second discharge current IDisCharge_CellMinVolt, then the second discharge current is determined as the battery's maximum discharge current ImaxDisCharge_VoltAld.

[0111] Furthermore, such as Figure 4BAs shown, the VCU calculates the corresponding discharge voltage VBat_ImaxDisCharge based on the ImaxDisCharge_VoltAld signal determined in the above steps.

[0112] Furthermore, such as Figure 4B As shown, the battery discharge power limit calculation module obtains the maximum allowable discharge power of the battery voltage by multiplying the current ImaxDisCharge_VoltAld and the voltage VBat_ImaxDisCharge and then reversing the result.

[0113] Furthermore, such as Figure 4B As shown, the battery discharge power limit calculation module selects the value with the smaller absolute value as the final charging limit power PHLimit_Bat based on the calculated maximum discharge power and the battery discharge allowable power P_DisChargeAld.

[0114] For example, if the maximum discharge power is less than or equal to the allowable discharge power, the maximum discharge power is determined as the discharge limit power PHLimit_Bat.

[0115] As can be seen, in this example, protection for each battery cell is achieved by determining the smaller value of the discharge current corresponding to the smallest voltage cell. Furthermore, in determining the battery's discharge limit power, the maximum discharge power is not simply obtained from a lookup table, but rather takes into account temperature changes, such as at low temperatures, the dynamic changes in internal resistance, and the impact of these changes on the discharge power. This results in a more accurate and realistic allowable discharge power that better meets the actual operational needs of the battery.

[0116] In one possible example, the method may further include the step of: if the maximum discharge power is greater than the allowable discharge power, then determining the allowable discharge power as the discharge limit power.

[0117] As can be seen, in this example, protection for each battery cell is achieved by determining the smaller value of the discharge current corresponding to the smallest voltage cell. Furthermore, the corresponding voltage value is calculated based on the determined maximum discharge current, and the maximum discharge power is ultimately calculated. The calculated maximum discharge power is then compared with the battery's original preset allowable discharge power, and the smaller value is determined as the discharge limit power. This effectively avoids the possibility of battery cell overload that might result from directly looking up the allowable discharge power in a table. Taking the smaller value ensures that as long as the discharge power meets the current discharge limit power, both the battery and the battery cell remain in a safe and stable state.

[0118] In one possible example, calculating the overall DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery pack may include the following steps: obtaining the battery no-load voltage reference value and the battery cell no-load voltage reference value by looking up a table based on the current battery charge information; obtaining the total voltage, total current, maximum voltage battery cell voltage, and minimum voltage battery cell voltage; calculating the overall DC equivalent internal resistance of the battery pack based on the total voltage, the total current, and the battery no-load voltage reference value; calculating the maximum DC equivalent internal resistance based on the maximum voltage battery cell voltage, the total current, and the battery cell no-load voltage reference value; and calculating the minimum DC equivalent internal resistance based on the minimum voltage battery cell voltage, the total current, and the battery cell no-load voltage reference value.

[0119] For example, the VCU looks up the maximum allowable total voltage RefBatVmax, minimum total voltage RefBatVmin, maximum cell charging voltage RefCellVmax, and minimum cell discharging voltage RefCellVmin of the battery cell based on the current cell temperature BatTemp of the battery.

[0120] For example, the VCU looks up the battery open-circuit voltage reference value VrefBat corresponding to the total battery voltage and the battery cell open-circuit voltage reference value VrefCell of the battery cell according to the battery power information BatSoc.

[0121] For example, the values ​​RefBatVmax and RefBatVmin are the maximum and minimum voltages allowed by the battery at the current temperature, and can be calibrated according to the characteristics of the battery; RefCellVmax and RefCellVmin are the maximum and minimum voltages allowed by the battery cell at the current temperature, and can also be calibrated according to the characteristics of the battery.

[0122] For example, such as Figure 3 As shown, Figure 3 This is a schematic diagram of the observation process of a DC dynamic internal resistance observation module provided in an embodiment of this application. The VCU respectively uses, as shown in... Figure 1D The battery DC internal resistance observation unit, the maximum voltage battery unit DC internal resistance observation unit, and the minimum voltage battery unit DC internal resistance observation unit calculate three dynamic internal resistances based on the observed data.

[0123] Specifically, the battery DC internal resistance observation unit calculates the current battery pack's equivalent DC internal resistance DCIRAct_Bat in real time based on the input signals of the battery total voltage V_Bat, battery total current I_Bat, and the battery no-load voltage reference value VrefBat.

[0124] Specifically, the maximum voltage battery cell DC internal resistance observation unit calculates the maximum DC equivalent internal resistance DCIRAct_CellMaxVolt based on the maximum voltage battery cell voltage V_CellMaxVolt, the battery cell no-load voltage reference value VrefCell, and the total battery current I_Bat.

[0125] Specifically, the minimum voltage battery cell DC internal resistance observation unit calculates the minimum DC equivalent internal resistance DCIRAct_CellMinVolt of the battery based on the minimum voltage battery cell voltage V_CellMinVolt, the battery cell no-load voltage reference value VrefCell, and the battery total current I_Bat input signal.

[0126] As can be seen, in this example, three DC equivalent internal resistances, DCIRAct_Bat, DCIRAct_CellMaxVolt, and DCIRAct_CellMinVolt, are observed, and subsequently used to monitor the total voltage, maximum voltage cell voltage, and minimum voltage cell voltage of the battery, respectively.

[0127] In one possible example, determining the power limit range of the battery based on the charging limit power and the discharging limit power may include the following steps: setting the charging limit power as the upper limit of the allowable power of the power limit range; and setting the discharging limit power as the lower limit of the allowable power of the power limit range.

[0128] As can be seen, in this example, by calculating the charging power PLLimit_Bat when the battery voltage reaches the upper limit and the discharging power PHLimit_Bat when the battery voltage reaches the lower limit, and limiting the battery power P_Bat to [PLLimit_BaPHLimit_Bat], the power limit range of the battery is made more reasonable and stable. Especially at low temperatures, there will be no large fluctuations, and it can work continuously. This effectively protects the power battery while maximizing the battery's performance, and can improve the driving experience of hybrid vehicles at low temperatures.

[0129] In one possible example, after determining the power limit range of the battery based on the charging limit power and the discharging limit power, the above method may further include the following steps: obtaining the actual output power of the vehicle's actuators, wherein the actuators include at least one of the following: a drive generator, an engine, a generator, and a transmission; calculating a power limit value for each actuator based on the power limit range and the actual output power; and generating a limit signal for each actuator, the limit signal carrying the power limit value corresponding to the actuator.

[0130] For example, such as Figure 1C As shown, the vehicle's actuators include a drive generator, an engine, a generator, and a transmission.

[0131] For example, the VCU uses the charging limit power PLLimit_Bat and the discharging limit power PHLimit_Bat calculated by the above process as the power limit range of the battery power P_Bat.

[0132] Furthermore, the VCU uses a power limiting calculation module to calculate the power limits of the drive generator, engine, generator, and transmission output power based on the battery's power limit range, the actual power of each actuator, and the vehicle load power, and generates a limiting signal carrying the power limit values ​​of each actuator.

[0133] As can be seen, in this example, the VCU calculates the power limit value of each actuator based on the power limit range obtained by the battery at different temperatures. Since the power limit range setting takes temperature factors into account, the obtained power limit range is more accurate, and therefore the power limit calculation for each actuator is also more accurate.

[0134] In one possible example, after generating a limiting signal based on the power limit of the actuator, the method may further include the following steps: calculating the actual power demand of the actuator in response to the limiting signal for the actuator; calculating the torque of the actuator based on the actual power demand and rotational speed of the actuator; and controlling the actuator to operate to drive the vehicle based on the torque.

[0135] For example, such as Figure 4C As shown, Figure 4C This is a schematic diagram of a vehicle power unit power limiting module provided in an embodiment of this application. Specifically, the VCU limits the required power of the drive generator, transmission, engine, and generator respectively based on the limiting signals corresponding to each execution component calculated by the aforementioned power limiting calculation module, and outputs the final actual required power of the drive generator, transmission, engine, and generator.

[0136] Furthermore, based on the following formula, the actual power requirement of each actuator is converted into power torque, and the torque of each actuator is calculated separately:

[0137] P=T*ω Formula (3)

[0138] Where P is the actual power required, T is the torque, and ω is the rotational speed of the actuator.

[0139] For example, based on the above formula, the VCU calculates the target torque of the drive generator, the target torque of the transmission, the target torque of the engine, and the target torque of the generator according to the actual power demand of the drive generator, the actual power demand of the transmission, the actual power demand of the engine, and the actual power demand of the generator, and sends them to the motor controller MCU, the transmission controller TCU, the engine controller ECU, and the generator controller ECU; so that the actual output power of the drive generator, transmission, engine, and generator follows their respective actual power demand, thereby ensuring that the battery power P_Bat is within the control range.

[0140] As can be seen, in this example, the VCU calculates the actual power demand of each actuator through the power limiting module, rather than directly obtaining the target power demand of each actuator by looking up a table. This improves the accuracy of the actual power demand calculation. In addition, the torque of each actuator is calculated based on the actual power demand, and the operation of each actuator is controlled based on the calculated torque, thereby achieving better control of the vehicle and improving the driving experience.

[0141] Please see Figure 5 , Figure 5 This is a schematic diagram of the structure of an electronic device, such as... Figure 5 As shown, the electronic device includes a processor, a memory, a communication interface, and one or more programs stored in the memory and configured to be executed by the processor. The electronic device is applied to a vehicle control unit (VCU), and the programs include instructions for performing the following steps:

[0142] Calculate the overall DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery pack. The battery pack includes multiple battery cells. The overall DC equivalent internal resistance is the DC equivalent internal resistance of the entire battery pack. The maximum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the highest voltage. The minimum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the lowest voltage.

[0143] The charging limit power of the battery is determined based on the total DC equivalent internal resistance and the maximum DC equivalent internal resistance.

[0144] The discharge limit power of the battery is determined based on the total DC equivalent internal resistance and the minimum DC equivalent internal resistance.

[0145] The power limit range of the battery is determined based on the charging limit power and the discharging limit power.

[0146] As can be seen, the battery protection method described in this application calculates the DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery at the current cell temperature; determines the charging limit power of the battery based on the overall DC equivalent internal resistance and the maximum DC equivalent internal resistance; determines the discharging limit power of the battery based on the overall DC equivalent internal resistance and the minimum DC equivalent internal resistance; and determines the power limit range of the battery based on the charging limit power and the discharging limit power. This allows the battery's power limit range to be determined by using three dynamic internal resistances calculated at different temperatures, making the power limit range more reasonable. This effectively improves the battery's stability at different temperatures, enabling continuous operation and maximizing battery performance while effectively protecting the power battery, thereby enhancing the driving experience of the vehicle at low temperatures.

[0147] In one possible example, the procedure for determining the charging limit power of the battery based on the overall DC equivalent internal resistance and the maximum DC equivalent internal resistance includes instructions for performing the following steps:

[0148] The system monitors a first change in the total voltage and a second change in the voltage of the battery cell with the highest voltage, wherein the voltage of the battery cell with the highest voltage is the voltage corresponding to the battery cell with the highest voltage.

[0149] When the first change indicates that the total voltage has reached the maximum total voltage, the first charging current is calculated based on the DC equivalent internal resistance of the entire package.

[0150] When the second change condition indicates that the maximum voltage battery cell voltage reaches the maximum battery cell charging voltage, the second charging current is calculated based on the maximum DC equivalent internal resistance;

[0151] The battery charging limit power is determined based on the first charging current and the second charging current.

[0152] In one possible example, the procedure for determining the charging limit power of the battery based on a first charging current and a second charging current includes instructions for performing the following steps:

[0153] The maximum charging current of the battery is the larger of the first charging current and the second charging current; and,

[0154] The first charging voltage is calculated based on the maximum charging current, and the maximum charging power is calculated based on the maximum charging current and the first charging voltage; and,

[0155] If the maximum charging power is less than or equal to the allowable charging power, then the maximum charging power is determined as the charging limit power.

[0156] In one possible example, the above procedure includes instructions for performing the following steps:

[0157] If the maximum charging power is greater than the allowable charging power, then the allowable charging power is determined as the charging limit power.

[0158] In one possible example, the procedure for determining the discharge limit power of the battery based on the overall DC equivalent internal resistance and the minimum DC equivalent internal resistance includes instructions for performing the following steps:

[0159] The third change in total voltage and the fourth change in the voltage of the lowest voltage battery cell are monitored, wherein the voltage of the lowest voltage battery cell is the voltage corresponding to the battery cell with the lowest voltage.

[0160] When the third change indicates that the total voltage has reached the minimum total voltage, the first discharge current is calculated based on the DC equivalent internal resistance of the entire package.

[0161] When the fourth change condition indicates that the minimum voltage battery cell voltage reaches the minimum battery cell discharge voltage, the second discharge current is calculated based on the minimum DC equivalent internal resistance;

[0162] The battery discharge limit power is determined based on the first discharge current and the second discharge current.

[0163] In one possible example, the process of determining the battery discharge limit power based on a first discharge current and a second discharge current includes instructions for performing the following steps:

[0164] If the first discharge current is greater than the second discharge current, then the second discharge current is determined as the maximum discharge current; and,

[0165] The first discharge voltage is calculated based on the maximum discharge current, and the maximum discharge power is calculated based on the maximum discharge current and the first discharge voltage; and,

[0166] If the maximum discharge power is less than or equal to the allowable discharge power, then the maximum discharge power is determined as the discharge limit power.

[0167] In one possible example, the above procedure includes instructions for performing the following steps:

[0168] If the maximum discharge power is greater than the allowable discharge power, then the allowable discharge power is determined as the discharge limit power.

[0169] In one possible example, the procedure for calculating the overall DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery pack includes instructions for performing the following steps:

[0170] The battery open-circuit voltage reference value and the battery cell open-circuit voltage reference value are obtained by looking up the table based on the current battery power information.

[0171] Obtain the total voltage, total current, maximum voltage battery cell voltage, and minimum voltage battery cell voltage;

[0172] Calculate the equivalent DC internal resistance of the entire battery pack based on the total voltage, the total current, and the battery open-circuit voltage reference value;

[0173] The maximum DC equivalent internal resistance is calculated based on the maximum voltage of the battery cell, the total current, and the reference value of the battery cell no-load voltage.

[0174] The minimum DC equivalent internal resistance is calculated based on the minimum voltage of the battery cell, the total current, and the reference value of the battery cell no-load voltage.

[0175] In one possible example, the procedure for determining the power limit range of the battery based on the charging limit power and the discharging limit power includes instructions for performing the following steps:

[0176] Set the charging power limit to the upper limit of the allowable power within the power limit range;

[0177] Set the discharge limiting power to the lower limit of the allowable power of the power limiting range.

[0178] In one possible example, after determining the power limit range of the battery based on the charging limit power and the discharging limit power, the above procedure includes instructions for performing the following steps:

[0179] The actual output power of the vehicle's actuators is obtained, wherein the actuators include at least one of the following: a drive generator, an engine, a generator, and a transmission;

[0180] Calculate the power limit value for each of the execution components based on the power limit range and the actual output power.

[0181] A limiting signal is generated for each of the aforementioned actuators, the limiting signal carrying the power limiting value corresponding to the actuator.

[0182] In one possible example, after generating the limiting signal based on the power limit of the execution unit, the above procedure includes instructions for performing the following steps:

[0183] In response to the limiting signal for the actuator, the actual power requirement of the actuator is calculated;

[0184] The torque of the actuator is calculated based on the actual power and rotational speed required by the actuator.

[0185] The actuator is controlled to operate according to the torque to drive the vehicle.

[0186] The above primarily describes the solutions of the embodiments of this application from the perspective of the method execution process. It is understood that, in order to achieve the above functions, the electronic device includes corresponding hardware structures and / or software modules for executing 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 provided herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by 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.

[0187] This application embodiment can divide the electronic device into functional units according to the above method example. For example, each function can be divided into a separate functional unit, or two or more functions can be integrated into one processing unit. The integrated unit can be implemented in hardware or as a software functional unit. It should be noted that the unit division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0188] When dividing each function into modules according to its corresponding function. Figure 6 A schematic diagram of the functional unit structure of a battery protection device is shown. This device is applied to the vehicle control unit (VCU), such as... Figure 6 As shown, the battery protection device 600 may include a calculation unit 601 and a determination unit 602; wherein,

[0189] The calculation unit 601 is used to calculate the overall DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery pack. The battery pack includes multiple battery cells. The overall DC equivalent internal resistance is the DC equivalent internal resistance of the entire battery pack. The maximum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the highest voltage. The minimum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the lowest voltage.

[0190] The determining unit 602 is used to determine the charging limit power of the battery based on the total DC equivalent internal resistance and the maximum DC equivalent internal resistance.

[0191] The determining unit 602 is further configured to determine the discharge limit power of the battery based on the total DC equivalent internal resistance and the minimum DC equivalent internal resistance.

[0192] The determining unit 602 is further configured to determine the power limiting range of the battery based on the charging limiting power and the discharging limiting power.

[0193] As can be seen, the battery protection device provided in this application calculates the overall DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery pack at the current cell temperature using a calculation unit; a determination unit determines the charging limit power of the battery based on the overall DC equivalent internal resistance and the maximum DC equivalent internal resistance; a determination unit determines the discharging limit power of the battery based on the overall DC equivalent internal resistance and the minimum DC equivalent internal resistance; and a determination unit determines the power limit range of the battery based on the charging limit power and the discharging limit power. This allows the battery's power limit range to be determined using three dynamic internal resistances calculated at different temperatures, making the power limit range more reasonable and effectively improving the battery's stability at different temperatures. This enables continuous operation, effectively protecting the power battery while maximizing its performance, thereby improving the driving experience of the vehicle at low temperatures.

[0194] In one possible example, the calculation unit 601, which determines the charging limit power of the battery based on the overall DC equivalent internal resistance and the maximum DC equivalent internal resistance, is further configured to perform the following steps:

[0195] The system monitors a first change in the total voltage and a second change in the voltage of the battery cell with the highest voltage, wherein the voltage of the battery cell with the highest voltage is the voltage corresponding to the battery cell with the highest voltage.

[0196] When the first change indicates that the total voltage has reached the maximum total voltage, the first charging current is calculated based on the DC equivalent internal resistance of the entire package.

[0197] When the second change condition indicates that the maximum voltage battery cell voltage reaches the maximum battery cell charging voltage, the second charging current is calculated based on the maximum DC equivalent internal resistance;

[0198] The battery charging limit power is determined based on the first charging current and the second charging current.

[0199] In one possible example, the calculation unit 601, which determines the charging limit power of the battery based on the first charging current and the second charging current, is further configured to perform the following steps:

[0200] The maximum charging current of the battery is the larger of the first charging current and the second charging current; and,

[0201] The first charging voltage is calculated based on the maximum charging current, and the maximum charging power is calculated based on the maximum charging current and the first charging voltage; and,

[0202] If the maximum charging power is less than or equal to the allowable charging power, then the maximum charging power is determined as the charging limit power.

[0203] In one possible example, the above-mentioned computing unit 601 is also used to perform the following steps:

[0204] If the maximum charging power is greater than the allowable charging power, then the allowable charging power is determined as the charging limit power.

[0205] In one possible example, the calculation unit 601, which determines the discharge limit power of the battery based on the overall DC equivalent internal resistance and the minimum DC equivalent internal resistance, is further configured to perform the following steps:

[0206] The third change in total voltage and the fourth change in the voltage of the lowest voltage battery cell are monitored, wherein the voltage of the lowest voltage battery cell is the voltage corresponding to the battery cell with the lowest voltage.

[0207] When the third change indicates that the total voltage has reached the minimum total voltage, the first discharge current is calculated based on the DC equivalent internal resistance of the entire package.

[0208] When the fourth change condition indicates that the minimum voltage battery cell voltage reaches the minimum battery cell discharge voltage, the second discharge current is calculated based on the minimum DC equivalent internal resistance;

[0209] The battery discharge limit power is determined based on the first discharge current and the second discharge current.

[0210] In one possible example, the calculation unit 601, which determines the battery discharge limit power based on the first discharge current and the second discharge current, is further configured to perform the following steps:

[0211] If the first discharge current is less than or equal to the second discharge current, then the first discharge current is determined as the maximum discharge current of the battery; and,

[0212] The first discharge voltage is calculated based on the maximum discharge current, and the maximum discharge power is calculated based on the maximum discharge current and the first discharge voltage; and,

[0213] If the maximum discharge power is less than or equal to the allowable discharge power, then the maximum discharge power is determined as the discharge limit power.

[0214] In one possible example, the above-mentioned computing unit 601 is also used to perform the following steps:

[0215] If the maximum discharge power is greater than the allowable discharge power, then the allowable discharge power is determined as the discharge limit power.

[0216] In one possible example, the calculation unit 601, which calculates the overall DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery pack, is further configured to perform the following steps:

[0217] The battery open-circuit voltage reference value and the battery cell open-circuit voltage reference value are obtained by looking up the table based on the current battery power information.

[0218] Obtain the total voltage, total current, maximum voltage battery cell voltage, and minimum voltage battery cell voltage;

[0219] Calculate the equivalent DC internal resistance of the entire battery pack based on the total voltage, the total current, and the battery open-circuit voltage reference value;

[0220] The maximum DC equivalent internal resistance is calculated based on the maximum voltage of the battery cell, the total current, and the reference value of the battery cell no-load voltage.

[0221] The minimum DC equivalent internal resistance is calculated based on the minimum voltage of the battery cell, the total current, and the reference value of the battery cell no-load voltage.

[0222] In one possible example, to determine the power limit range of the battery based on the charging limit power and the discharging limit power, the calculation unit 601 and the determination unit 602 are further configured to perform the following steps:

[0223] Set the charging power limit to the upper limit of the allowable power within the power limit range;

[0224] Set the discharge limiting power to the lower limit of the allowable power of the power limiting range.

[0225] In one possible example, after determining the power limit range of the battery based on the charging limit power and the discharging limit power, the calculation unit 601 and the determination unit 602 are further configured to perform the following steps:

[0226] The actual output power of the vehicle's actuators is obtained, wherein the actuators include at least one of the following: a drive generator, an engine, a generator, and a transmission;

[0227] Calculate the power limit value for each of the execution components based on the power limit range and the actual output power.

[0228] A limiting signal is generated for each of the aforementioned actuators, the limiting signal carrying the power limiting value corresponding to the actuator.

[0229] In one possible example, after generating the limiting signal based on the power limit of the execution component, the calculation unit 601 and the determination unit 602 are further configured to perform the following steps:

[0230] In response to the limiting signal for the actuator, the actual power requirement of the actuator is calculated;

[0231] The torque of the actuator is calculated based on the actual power and rotational speed required by the actuator.

[0232] The actuator is controlled to operate according to the torque to drive the vehicle.

[0233] It should be noted that all relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0234] The electronic device provided in this embodiment is used to execute the above-described battery protection method, and therefore can achieve the same effect as the above-described implementation method.

[0235] When using integrated units, the electronic device may include a processing module, a storage module, and a communication module. The processing module can be used to control and manage the actions of the electronic device; for example, it can support the electronic device in executing the steps performed by the calculation unit 601 and the determination unit 602. The storage module can support the electronic device in executing stored program code and data. The communication module can support communication between the electronic device and other devices.

[0236] The processing module can be a processor or a controller. It can implement or execute various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor can also be a combination of functions that implement computing capabilities, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module can be a memory. The communication module can specifically be a radio frequency circuit, a Bluetooth chip, a Wi-Fi chip, or other devices that interact with other electronic devices.

[0237] This application also provides a computer storage medium storing a computer program for electronic data interchange, which causes a computer to perform some or all of the steps of any of the methods described in the above method embodiments, wherein the computer includes an electronic device.

[0238] This application also provides a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program operable to cause a computer to perform some or all of the steps of any of the methods described in the above method embodiments. The computer program product may be a software installation package, and the computer may include an electronic device.

[0239] This application also provides a vehicle including a vehicle control unit (VCU), which is used to perform some or all of the steps of any of the methods described in the above method embodiments.

[0240] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0241] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0242] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above 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 system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0243] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0244] 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.

[0245] If the integrated units described above are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0246] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, which may include: flash drive, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0247] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A battery protection method, characterized in that, Applied to a vehicle control unit (VCU), the method includes: Calculate the overall DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery pack. The battery pack includes multiple battery cells. The DC equivalent internal resistance of the entire pack is the DC equivalent internal resistance of the battery pack as a whole. The maximum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the highest voltage. The minimum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the lowest voltage. The charging limit power of the battery is determined based on the overall DC equivalent internal resistance and the maximum DC equivalent internal resistance. This involves monitoring a first change in the total voltage and a second change in the voltage of the highest-voltage battery cell, where the highest-voltage battery cell is the voltage corresponding to the highest-voltage battery cell. When the first change indicates that the total voltage has reached its maximum, a first charging current is calculated based on the overall DC equivalent internal resistance. When the second change indicates that the voltage of the highest-voltage battery cell has reached its maximum charging voltage, a second charging current is calculated based on the maximum DC equivalent internal resistance. The charging limit power of the battery is then determined based on the first and second charging currents. The discharge limit power of the battery is determined based on the total DC equivalent internal resistance and the minimum DC equivalent internal resistance. The power limit range of the battery is determined based on the charging limit power and the discharging limit power.

2. The method according to claim 1, characterized in that, Determining the charging limit power of the battery based on the first charging current and the second charging current includes: The maximum charging current of the battery is the larger of the first charging current and the second charging current; and, The first charging voltage is calculated based on the maximum charging current, and the maximum charging power is calculated based on the maximum charging current and the first charging voltage; and, If the maximum charging power is less than or equal to the allowable charging power, then the maximum charging power is determined as the charging limit power.

3. The method according to claim 2, characterized in that, The method further includes: If the maximum charging power is greater than the allowable charging power, then the allowable charging power is determined as the charging limit power.

4. The method according to claim 1, characterized in that, Determining the discharge limit power of the battery based on the overall DC equivalent internal resistance and the minimum DC equivalent internal resistance includes: The third change in total voltage and the fourth change in the voltage of the lowest voltage battery cell are monitored, wherein the voltage of the lowest voltage battery cell is the voltage corresponding to the battery cell with the lowest voltage. When the third change indicates that the total voltage has reached the minimum total voltage, the first discharge current is calculated based on the DC equivalent internal resistance of the entire package. When the fourth change condition indicates that the minimum voltage battery cell voltage reaches the minimum battery cell discharge voltage, the second discharge current is calculated based on the minimum DC equivalent internal resistance; The battery discharge limit power is determined based on the first discharge current and the second discharge current.

5. The method according to claim 4, characterized in that, Determining the battery discharge limit power based on the first discharge current and the second discharge current includes: The smaller of the first discharge current and the second discharge current is taken as the maximum discharge current of the battery; and, The first discharge voltage is calculated based on the maximum discharge current, and the maximum discharge power is calculated based on the maximum discharge current and the first discharge voltage; and, If the maximum discharge power is less than or equal to the allowable discharge power, then the maximum discharge power is determined as the discharge limit power.

6. The method according to claim 5, characterized in that, The method further includes: If the maximum discharge power is greater than the allowable discharge power, then the allowable discharge power is determined as the discharge limit power.

7. The method according to claim 1, characterized in that, The calculation of the overall DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery pack includes: The battery open-circuit voltage reference value and the battery cell open-circuit voltage reference value are obtained by looking up the table based on the current battery power information. Obtain the total voltage, total current, maximum voltage battery cell voltage, and minimum voltage battery cell voltage; Calculate the equivalent DC internal resistance of the entire battery pack based on the total voltage, the total current, and the battery open-circuit voltage reference value; The maximum DC equivalent internal resistance is calculated based on the maximum voltage of the battery cell, the total current, and the reference value of the battery cell no-load voltage. The minimum DC equivalent internal resistance is calculated based on the minimum voltage of the battery cell, the total current, and the reference value of the battery cell no-load voltage.

8. The method according to claim 1, characterized in that, Determining the power limit range of the battery based on the charging limit power and the discharging limit power includes: Set the charging power limit to the upper limit of the allowable power within the power limit range; Set the discharge limiting power to the lower limit of the allowable power of the power limiting range.

9. The method according to claim 1 or 8, characterized in that, After determining the power limit range of the battery based on the charging limit power and the discharging limit power, the method further includes: The actual output power of the vehicle's actuators is obtained, wherein the actuators include at least one of the following: a drive generator, an engine, a generator, and a transmission; Calculate the power limit value for each of the execution components based on the power limit range and the actual output power. A limiting signal is generated for each of the aforementioned actuators, the limiting signal carrying the power limiting value corresponding to the actuator.

10. The method according to claim 9, characterized in that, After generating the limiting signal based on the power limit of the execution unit, the method further includes: In response to the limiting signal for the actuator, the actual power requirement of the actuator is calculated; The torque of the actuator is calculated based on the actual power and rotational speed required by the actuator. The actuator is controlled to operate according to the torque to drive the vehicle.

11. A battery protection device, characterized in that, A vehicle control unit (VCU) for use in vehicles, the device comprising: a computing unit, an acquisition unit, and a determination unit, wherein, The calculation unit is used to calculate the overall DC equivalent internal resistance, maximum DC equivalent internal resistance, and minimum DC equivalent internal resistance of the battery pack. The battery pack includes multiple battery cells. The overall DC equivalent internal resistance is the DC equivalent internal resistance of the entire battery pack. The maximum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the highest voltage. The minimum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the lowest voltage. The determining unit is configured to determine the charging limit power of the battery based on the overall DC equivalent internal resistance and the maximum DC equivalent internal resistance, wherein it monitors a first change in the total voltage and a second change in the voltage of the battery cell with the highest voltage, wherein the voltage of the battery cell with the highest voltage is the voltage corresponding to the highest voltage cell; when the first change indicates that the total voltage has reached the maximum total voltage, a first charging current is calculated based on the overall DC equivalent internal resistance; when the second change indicates that the voltage of the battery cell with the highest voltage has reached the maximum battery cell charging voltage, a second charging current is calculated based on the maximum DC equivalent internal resistance; and the charging limit power of the battery is determined based on the first charging current and the second charging current. The determining unit is further configured to determine the discharge limit power of the battery based on the total DC equivalent internal resistance and the minimum DC equivalent internal resistance. The determining unit is further configured to determine the power limiting range of the battery based on the charging limiting power and the discharging limiting power.

12. An electronic device, characterized in that, The method includes a processor, a memory, a communication interface, and one or more programs stored in the memory and configured to be executed by the processor, the programs including instructions for performing the steps of the method as described in any one of claims 1-10.

13. A computer-readable storage medium, characterized in that, A computer program for storing electronic data interchange is provided, wherein the computer program causes a computer to perform the method as described in any one of claims 1-10.

14. A vehicle, characterized in that, It includes a vehicle control unit (VCU) for performing the method as described in any one of claims 1-10.

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