Battery protection method and related device

Abstract

The embodiment of the invention discloses a battery protection method and a related device. The method comprises the following steps: calculating the whole pack direct current equivalent internal resistance of a battery pack, the maximum direct current equivalent internal resistance corresponding to a maximum voltage battery unit and the minimum direct current equivalent internal resistance corresponding to a minimum voltage battery unit; according to the whole-pack direct current equivalent internal resistance and the maximum direct current equivalent internal resistance, the charging limit power of the battery is determined; according to the whole-pack direct current equivalent internal resistance and the minimum direct current equivalent internal resistance, the discharge limiting power of the battery is determined; and determining a power limit range of the battery according to the charging limit power and the discharging limit power. Therefore, the limited power range of the battery can be determined according to the three dynamic internal resistances calculated at different temperatures, so that the limited power range of the battery is more reasonable, the stability of the battery at different temperatures is effectively improved, the performance of the battery is exerted as much as possible while the battery is effectively protected, and the service life of the battery is prolonged. And the driving feeling of the vehicle is improved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a battery protection method and related devices. Background Art

[0002] A vehicle equipped with an extended-range or hybrid powertrain is a car that can use multiple power sources at the same time. The battery is an important component of these vehicles and is usually one of the power sources of the vehicle. Therefore, battery protection for vehicles equipped with extended-range or hybrid powertrains is crucial, which can ensure the long-term safe and reliable operation of the battery and bring a better driving experience to the owner. A common battery protection method is that the vehicle control unit VCU directly uses the charging limit power and discharge limit power sent by the battery management module BMS as the battery charging and discharging limit power, so as to control the battery power of the vehicle within the charging limit power and discharge limit power range. However, this method does not take into account the fact that the battery may experience temperature changes during actual operation, such as high temperature conditions or low temperature conditions. The change in temperature will have a certain impact on the resistance, current and other parameters of the battery, and thus will have a corresponding impact on the power of the battery. Therefore, it is not accurate enough to set the power limit range of the battery based solely on the charging limit power and discharge limit power sent by the BMS. If there is a large temperature change, it will cause the battery charging and discharging power to fluctuate repeatedly, resulting in a bad driving experience.

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

[0004] The embodiment of the present application provides a battery protection method and related device, which can determine the power limit range of the battery by calculating the DC equivalent internal resistance of the whole battery pack, the maximum DC equivalent internal resistance corresponding to the maximum voltage battery unit, and the minimum DC equivalent internal resistance corresponding to the minimum voltage battery unit, and determine the charging limit power of the battery at the current temperature according to the DC equivalent internal resistance of the whole battery pack and the maximum DC equivalent internal resistance, and determine the discharge limit power of the battery at the current temperature according to the DC equivalent internal resistance of the whole battery pack and the minimum DC equivalent internal resistance. The power limit range of the battery can be made more reasonable, thereby effectively improving the stability of the battery at different temperatures, and maximizing the performance of the battery while effectively protecting the power battery, thereby improving the driving experience of the vehicle.

[0005] In a first aspect, an embodiment of the present application provides a battery protection method, which is applied to a vehicle control unit VCU, and the method includes:

[0006] Calculate the whole pack DC equivalent internal resistance, maximum DC equivalent internal resistance and minimum DC equivalent internal resistance of the battery pack, wherein the battery pack includes multiple battery cells, the whole pack DC equivalent internal resistance 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, and the minimum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the lowest voltage;

[0007] Determining the battery charging limit power according to the whole package DC equivalent internal resistance and the maximum DC equivalent internal resistance;

[0008] Determining the discharge limit power of the battery according to the whole pack DC equivalent internal resistance and the minimum DC equivalent internal resistance;

[0009] A power limit range of the battery is determined according to the charging limit power and the discharging limit power.

[0010] In a second aspect, an embodiment of the present application provides a battery protection device, which is applied to a vehicle control unit VCU of a vehicle, and the device includes: a calculation unit, an acquisition unit and a determination unit, wherein:

[0011] The calculation unit is used to calculate the whole pack DC equivalent internal resistance, the maximum DC equivalent internal resistance and the minimum DC equivalent internal resistance of the battery pack, wherein the battery pack includes a plurality of battery cells, the whole pack DC equivalent internal resistance 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, and 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 according to the whole package DC equivalent internal resistance and the maximum DC equivalent internal resistance;

[0013] The determining unit is further used to determine the discharge limit power of the battery according to the whole package DC equivalent internal resistance and the minimum DC equivalent internal resistance;

[0014] The determining unit is further configured to determine a power limit range of the battery according to the charging limit power and the discharging limit power.

[0015] In a third aspect, an embodiment of the present application provides an electronic device, comprising 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 program includes instructions for executing the steps of any method in the first aspect of the embodiment of the present application.

[0016] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program for electronic data exchange, wherein the computer program enables a computer to execute part or all of the steps described in any method of the first aspect of the embodiment of the present application.

[0017] In a fifth aspect, an embodiment of the present application provides a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to execute some or all of the steps described in any method of the first aspect of the embodiment of the present application. The computer program product may be a software installation package.

[0018] In a sixth aspect, an embodiment of the present application provides a vehicle, wherein the vehicle includes a vehicle control unit VCU, and the vehicle control unit VCU is used to execute part or all of the steps described in any method of the first aspect of the embodiment of the present application.

[0019] It can be seen that in the embodiment of the present application, the whole pack DC equivalent internal resistance of the battery pack, the maximum DC equivalent internal resistance corresponding to the maximum voltage battery unit, and the minimum DC equivalent internal resistance corresponding to the minimum voltage battery unit are calculated; the charging limit power of the battery is determined according to the whole pack DC equivalent internal resistance and the maximum DC equivalent internal resistance; the discharge limit power of the battery is determined according to the whole pack DC equivalent internal resistance and the minimum DC equivalent internal resistance; the power limit range of the battery is determined according to the charging limit power and the discharge limit power. In this way, the power limit range of the battery can be determined by the three dynamic internal resistances calculated at different temperatures, which can make the power limit range of the battery more reasonable, thereby effectively improving the stability of the battery at different temperatures, and can work continuously, while effectively protecting the power battery and giving full play to the performance of the battery as much as possible, thereby improving the driving experience of the vehicle at low temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

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

[0022] Figure 1B This is a schematic diagram of a battery charging and discharging mode in a conventional manner at low temperature provided in an embodiment of the present application;

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

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

[0025] Figure 2 It is a flowchart of a battery protection method provided in an embodiment of the present application;

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

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

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

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

[0030] Figure 5 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application;

[0031] Figure 6 It is a schematic diagram of the functional unit structure of a battery protection device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0033] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0034] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0035] In order to better understand the solutions of the embodiments of the present application, the electronic devices, related terms, concepts and related backgrounds that may be involved in the embodiments of the present application are first introduced below.

[0036] The electronic device may be a portable electronic device that also includes other functions such as a personal digital assistant and / or a music player function, such as a mobile phone, a tablet computer, a wearable electronic device with a wireless communication function (such as a smart watch), etc. Exemplary embodiments of portable electronic devices include but are not limited to portable electronic devices equipped with an IOS system, an Android system, a Microsoft system, or other operating systems. The above-mentioned portable electronic device may also be other portable electronic devices, such as a laptop computer (Laptop), etc. It should also be understood that in some other embodiments, the above-mentioned electronic device may also be an electronic device used to control the battery protection system in the present application scheme.

[0037] A range-extended or hybrid vehicle is a car that is able to use more than one source of power at the same time. Range-extended hybrid vehicles typically use batteries and a small fuel generator to power the electric motor, extending the battery's range. Series hybrid vehicles, on the other hand, connect the electric motor and the fuel engine together so that 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 providing a smoother ride for the driver. These vehicles can also automatically switch power sources based on driving demand to ensure the best fuel economy and maximum performance. Currently, many major automakers produce vehicles equipped with range-extended or hybrid vehicles, including different types of vehicles such as hybrid sedans, SUVs, and trucks.

[0038] See also Figure 1A , Figure 1A Schematic diagram of a common vehicle control unit signal flow process provided by an embodiment of the present application, such as Figure 1A As shown, the vehicle control unit (VCU) includes modules: a signal acquisition module, a drive target power acquisition module, a signal processing module, an energy distribution module and a power limitation module.

[0039] For example, a vehicle equipped with a hybrid control system has two power sources: a power battery and an engine, whose powers are set as P_Bat and P_Eng respectively; the vehicle's energy consumption can be divided into three parts: the drive generator P_Mdive, the transmission P_Gear, and the vehicle's power consumption P_Consume, and the generator power can be set as P_Mg. The battery's charge allowable power P_DisChargeAld and discharge allowable power P_ChargeAld.

[0040] Exemplarily, the signal acquisition module processes the pedal signal to obtain a valid signal, and then the driving target power acquisition module can obtain the valid signal obtained by the signal acquisition module through pedal signal acquisition, thereby acquiring parameters such as the vehicle accelerator and brake pedal. Furthermore, the driving target power acquisition module sends a driving target power signal to the energy distribution module, so that the capacity distribution module determines the target power information of the power unit.

[0041] Exemplarily, the signal processing module interacts with the battery management unit BMS via a battery signal. Further, the signal processing module sends a BMS power limiting parameter to the power limiting module.

[0042] Furthermore, the power limiting module calculates the torque targets of each executive component of the vehicle according to the BMS power limiting parameters and the target power information of the power unit, and sends the torque targets to the motor control unit MCU, the generator control unit GCU, the engine control unit ECU, and the transmission control unit TCU. Furthermore, the MCU, GCU, ECU, and TCU modules control the operation of each executive component according to the received torque targets. Among them, the executive components include: drive generator, generator, engine, and transmission.

[0043] Specifically, Figure 1A The VCU (vehicle control unit) shown will determine the ideal output power of the drive generator, generator, engine, and transmission according to the driver's intention; further, the target power of the drive generator, generator, engine, and transmission is limited and adjusted according to the charge and discharge power allowed by the BMS (battery management unit), so as to obtain the real target power of the effective drive generator, generator, engine, and transmission, and send it to the MCU, GCU, ECU, and TCU modules, so that the output power of the drive generator, generator, engine, and transmission follows the respective target power, thereby limiting the charge and discharge power of the battery within the allowable range; thereby preventing the power battery from being overcharged or over-discharged.

[0044] Under normal temperature conditions, the power adjustment based on the above VCU according to the charge and discharge power limit values ​​[P_DisChargeAld, P_ChargeAld] issued by the BMS can basically meet the actual needs of the vehicle. However, at low temperatures, since the dynamic internal resistance of the battery varies greatly and the dynamic internal resistance under different charging currents is also different, the charge and discharge power limit value calculated by the BMS is only an instantaneous, relatively ideal power value. Figure 1B As shown, Figure 1B Schematic diagram of a battery charging and discharging mode under conventional conditions at low temperatures provided by an embodiment of the present application. Figure 1B As shown in the figure, this charge and discharge power value can only last for 2-10 seconds, then it will quickly enter the protection mode, P_DisChargeAld and P_ChargeAld will quickly become very small; after the protection mode lasts for 2-10 seconds, it will enter the normal charging mode again. This will cause the charge and discharge process to be constantly interrupted, and the charge and discharge power will fluctuate repeatedly, resulting in a very bad driving experience.

[0045] To solve the above problems, Figure 1C The embodiment of the present application shown provides a VCU battery limited power calculation architecture diagram.

[0046] For example, Figure 1C The part corresponding to the dotted box below in the structure shown is the key technical component module of the present application solution, which is used to replace the following Figure 1A The power limiting signal set by the battery management unit BMS shown in the figure can achieve reliable protection of the battery while improving the driving experience of the hybrid vehicle at low temperatures through the original energy distribution module.

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

[0048] Exemplarily, the limited range acquisition module acquires the battery voltage mainly by setting a reasonable battery operating voltage range based on the battery temperature. The battery is safe and reliable and can work continuously within this voltage range; at the same time, the battery performance can be effectively exerted within this voltage range.

[0049] Exemplarily, 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 at low temperatures will increase a lot compared to normal 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 above DC dynamic internal resistance observation module is:

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

[0052] Among them, U in formula (1) S is the battery test voltage, I S is the actual battery current, U ref is the battery no-load voltage, R DC is the DC equivalent internal resistance of the battery pack, U error is the test error.

[0053] Specifically, during the actual operation of the battery, the actual test voltage is more accurately a value that includes, in addition to the no-load voltage corresponding to the basic state, the partial voltage occupied by the current and resistance at the current temperature and the test error voltage value.

[0054] For example, in the present application, the battery DC dynamic internal resistance observation module is configured to measure the dynamic internal resistance of the battery by using U S ,I S Observe the current current at the current temperature R DC , then modify R appropriately according to the required current DC , and finally obtain the required R DC_ I ACT ; In the battery DC dynamic internal resistance observation module, the calculation method of the dynamic DC internal resistance is as follows:

[0055]

[0056] Wherein, 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 has a value range greater than 0 and less than 1.

[0057] For example, the correction process based on the required current refers to the difference between the actual current and the dynamic current, and the corresponding resistor R (I ACT , I S ), according to R to the current R DC Make corrections to obtain the dynamic DC resistance at the current temperature.

[0058] Exemplarily, the voltage limiting and current limiting conversion module calculates the maximum charging current and the maximum discharging current of the battery based on the allowed battery voltage and the 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 then obtain the accurate maximum charging current and the maximum discharging current.

[0059] Exemplarily, the power limit calculation module calculates the battery's charge power limit and discharge power limit according to the maximum charge current and maximum discharge current calculated by the above process and the corresponding battery voltage.

[0060] Exemplarily, the energy distribution module reasonably distributes the battery charging limit power and discharging limit power and the driving demand power calculated according to the above process, so as to meet the driver's needs while reasonably protecting the power battery.

[0061] For example, Figure 1D The unit structure diagram of a DC dynamic internal resistance observation module is shown in FIG. Figure 1D The DC dynamic internal resistance observation module comprises: a battery DC internal resistance observation unit, a maximum voltage battery cell DC internal resistance observation unit and a minimum voltage battery cell DC internal resistance observation unit.

[0062] In order to better understand the above process, the present application is described in detail below in conjunction with specific embodiments.

[0063] See also Figure 2 , Figure 2 The present application provides a flowchart of a battery protection method. Figure 2 As shown, the battery protection method is applied to the vehicle control unit VCU, and specifically includes the following steps:

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

[0065] Among them, the battery pack includes multiple battery cells, the whole pack DC equivalent internal resistance 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, and the minimum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the lowest voltage.

[0066] Exemplarily, the VCU is based on Figure 1D The working principle of the DC dynamic internal resistance observation module is to calculate the DC equivalent internal resistance of the whole package through the resistor DC internal resistance observation unit, calculate the maximum DC equivalent internal resistance corresponding to the maximum voltage battery cell through the maximum voltage battery cell DC internal resistance observation unit, and calculate the minimum DC equivalent internal resistance corresponding to the minimum voltage battery cell through the minimum voltage battery cell DC internal resistance observation unit. Wherein, the battery includes multiple cells, each cell is regarded as a battery cell, and multiple battery cells constitute a battery as a whole. The maximum voltage battery cell DC internal resistance observation unit determines the single cell with the largest current voltage value as the maximum voltage battery cell, and the minimum voltage battery cell DC internal resistance observation unit determines the single cell with the smallest current voltage value as the minimum voltage battery cell.

[0067] S202: Determine a charging limit power of the battery according to the DC equivalent internal resistance of the entire package and the maximum DC equivalent internal resistance.

[0068] For example, the three equivalent internal resistances obtained by the VCU in step S201 are respectively Figure 1C After the calculations of the limiting voltage, limiting current conversion module and limiting power calculation module, a charging power is obtained. Further, the charging limiting power of the battery is determined according to the magnitude relationship between the calculated charging power and the charging allowable power P_DisChargeAld.

[0069] S203: Determine the discharge limit power of the battery according to the whole pack DC equivalent internal resistance and the minimum DC equivalent internal resistance.

[0070] For example, the three equivalent internal resistances obtained by the VCU in step S201 are respectively Figure 1C After the calculations of the limiting voltage, limiting current conversion module and limiting power calculation module, a discharge power is obtained. Further, the charging limit power of the battery is determined according to the magnitude relationship between the calculated discharge power and the discharge allowable power P_ChargeAld.

[0071] S204: Determine a power limit range of the battery according to the charging limit power and the discharging limit power.

[0072] Exemplarily, the VCU sends the charging limit power and the discharging limit power determined in the above step S202 and step S203 to the power limiting module through the limit power calculation module.

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

[0074] It should be noted that the calculated power limit is more reasonable and stable than the power limit obtained through data table lookup. The data obtained through table lookup often isolates the current temperature as a reference indicator and sets the power limit corresponding to the current temperature. However, in actual scenarios, the temperature change of the battery environment or itself is a smooth process, and when this change is not drastic, it will not cause a large fluctuation in the power limit, and the battery can continue to work in this scenario. The power limit obtained by calculation is determined based on the data of the actual use scenario of the battery and the real-time temperature. The power limit variation range will not be too large, so that the power battery can be effectively protected while maximizing the performance of the battery, which can improve the driving experience of hybrid vehicles at low temperatures.

[0075] It can be seen that the battery protection method described in the embodiment of the present application calculates the DC equivalent internal resistance of the battery at the current battery 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 charging limit power of the battery according to the DC equivalent internal resistance of the whole package and the maximum DC equivalent internal resistance; determines the discharge limit power of the battery according to the DC equivalent internal resistance of the whole package and the minimum DC equivalent internal resistance; determines the power limit range of the battery according to the charging limit power and the discharge limit power. In this way, it can be achieved that the three dynamic internal resistances calculated at different temperatures are used to obtain accurate current dynamic internal resistance, and then obtain accurate maximum charging current and maximum discharge current, and then determine the battery limit power range. It can make the battery limit power range more reasonable, thereby effectively improving the stability of the battery at different temperatures, while effectively protecting the power battery, maximizing the performance of the battery, and improving the driving experience of the vehicle.

[0076] In one possible example, determining the charging limit power of the battery based on the whole pack 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 maximum voltage battery cell voltage, wherein the maximum 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 whole pack DC equivalent internal resistance; when the second change indicates that the maximum 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, Figure 4A As shown, Figure 4A Schematic diagram of a battery charging power limit signal acquisition module provided in an embodiment of the present application. Specifically, the VCU monitors the total battery voltage and the voltage changes of the battery cells. If the first change indicates that the current total battery voltage reaches the maximum allowable voltage RefBatVmax, the VCU calculates the corresponding first charging current ICharge_BatVmax based on the DC equivalent internal resistance DCIRAct_Bat of the battery pack and RefBatVmax.

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

[0079] Further, the battery charging limit power is determined according to the first charging current ICharge_BatVmax and the second charging current ICharge_CellMaxVolt.

[0080] It can be seen that in the example of the present application, the observed DC equivalent internal resistance of the whole package and the maximum DC equivalent internal resistance are used to monitor the total voltage of the battery and the maximum voltage unit voltage of the battery, and 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 unit is calculated according to the DC equivalent internal resistance of the whole package and the maximum DC equivalent internal resistance, thereby determining the charging limit current of the battery according to the first charging current and the second charging current.

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

[0082] Exemplarily, if the first charging current ICharge_BatVmax is less than or equal to the second charging current ICharge_CellMaxVolt, the first charging current is determined as the maximum charging current ImaxCharge_VoltAld of the battery. At this time, as long as the current charging current is less than or equal to the maximum charging current, the battery is always in a safe charging current range.

[0083] Furthermore, if Figure 4A As shown, the VCU calculates the corresponding charging voltage VBat_ImaxCharge according to the ImaxCharge_VoltAld signal determined in the above steps.

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

[0085] Furthermore, if Figure 4A As shown, the battery charging power limit calculation module obtains the maximum charging power allowed by the battery voltage based on the product of the current ImaxCharge_VoltAld and the voltage VBat_ImaxCharge and reversely obtains the maximum charging power allowed by the battery voltage.

[0086] Furthermore, if Figure 4A As shown, the battery charging power limit calculation module selects a smaller absolute value as the final battery charging limit power PLLimit_Bat according to the calculated maximum charging power and the battery charging allowable power P_ChargeAld. The battery charging allowable power can be the charging allowable power originally set when the battery leaves the factory, which can be obtained through data acquisition.

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

[0089] Exemplarily, if the first charging current ICharge_BatVmax is greater than the second charging current ICharge_CellMaxVolt, the second charging current is determined as the maximum charging current ImaxCharge_VoltAld of the battery. At this time, as long as the current charging current is less than or equal to the maximum charging current, the battery is always in a safe charging current range.

[0090] Furthermore, if Figure 4A As shown, the VCU calculates the corresponding charging voltage VBat_ImaxCharge according to the ImaxCharge_VoltAld signal determined in the above steps.

[0091] Furthermore, if Figure 4A As shown, the battery charging power limit calculation module obtains the maximum charging power allowed by the battery voltage based on the product of the current ImaxCharge_VoltAld and the voltage VBat_ImaxCharge and reversely obtains the maximum charging power allowed by the battery voltage.

[0092] Furthermore, if Figure 4A As shown, the battery charging power limit calculation module selects a smaller absolute value as the final battery charging limit power PLLimit_Bat according to the calculated maximum charging power and the battery charging allowable power P_ChargeAld.

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

[0094] It can be seen that in the example of this application, the protection of each battery cell is achieved by determining the smaller value of the charging current corresponding to the battery and the maximum voltage unit as the charging current. In addition, the corresponding voltage value is calculated according to the determined maximum charging current, and the maximum charging power is finally calculated. In the process of determining the charging limit power of the battery, the maximum charging power obtained is not obtained solely based on table lookup, but taking into account the dynamic change of internal resistance and the influence of internal resistance change on power when the temperature changes, such as low temperature, so that the charging allowable power obtained is more accurate and more in line with the actual operation requirements of the battery.

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

[0096] It can be seen that in the example of this application, the protection of each battery cell is achieved by determining the smaller value of the charging current corresponding to the battery and the maximum voltage unit as the charging current. In addition, the corresponding voltage value is calculated according to the determined maximum charging current, and the maximum charging power is finally calculated, and the calculated maximum charging power is compared with the original preset charging allowable power of the battery, and the smaller value of the two is determined as the charging limit power. This can effectively avoid the situation where the battery cell may be overloaded by directly obtaining the battery charging allowable power through table lookup. Taking the smaller value of the two can effectively ensure that any charging power meets the current charging limit power, whether it is the battery or the battery cell, is in a safe and stable state.

[0097] In one possible example, determining the discharge limit power of the battery based on the whole pack 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 minimum voltage battery cell voltage, 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 discharge limit power based on the first discharge current and the second discharge current.

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

[0099] Exemplarily, if the fourth change condition indicates that the minimum voltage cell voltage of the current battery reaches the minimum battery cell discharge voltage RefCellVMin, the VCU calculates the corresponding second discharge current IDisCharge_CellMinVolt according to the minimum DC equivalent internal resistance DCIRAct_CellMinVolt and RefCellVMin.

[0100] Further, the battery discharge limit power is determined according to the first discharge current IDisCharge_BatVmin and the second discharge current IDisCharge_CellMinVolt.

[0101] It can be seen that in the example of the present application, the observed whole pack DC equivalent internal resistance and minimum DC equivalent internal resistance are used to monitor the total voltage of the battery and the minimum voltage unit voltage of the battery, and the voltage change is monitored in real time. When the voltage reaches the maximum total voltage or the minimum battery unit discharge voltage, the discharge current of the battery and the minimum voltage unit is calculated according to the whole pack DC equivalent internal resistance and the minimum DC equivalent internal resistance, and the discharge limit current of the battery is determined according to the first discharge current and the second discharge current.

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

[0103] Exemplarily, if the first discharge current IDisCharge_BatVmin is less than or equal to the second discharge current IDisCharge_CellMinVolt, the first discharge current is determined as the maximum discharge current ImaxDisCharge_VoltAld of the battery. At this time, as long as the current discharge current is less than or equal to the maximum discharge current, the battery is always in a safe discharge current range.

[0104] Furthermore, if Figure 4B As shown, the VCU calculates the corresponding charging voltage VBat_ImaxDisCharge according to the ImaxDisCharge_VoltAld signal determined in the above steps.

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

[0106] Furthermore, if Figure 4B As shown, the battery charging power limit calculation module obtains the maximum charging power allowed by the battery voltage based on the product of the current ImaxDisCharge_VoltAld and the voltage VBat_ImaxDisCharge and reversely obtains the maximum charging power allowed by the battery voltage.

[0107] Furthermore, if Figure 4B As shown, the battery charging power limit calculation module selects a smaller absolute value as the final battery discharge limit power PHLimit_Bat according to the calculated maximum discharge power and the battery discharge allowable power P_DisChargeAld. The battery discharge allowable power can be the discharge allowable power originally set when the battery leaves the factory, which can be obtained through data acquisition.

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

[0110] Exemplarily, if the first discharge current IDisCharge_BatVmin is greater than the second discharge current IDisCharge_CellMinVolt, the second discharge current is determined as the maximum discharge current ImaxDisCharge_VoltAld of the battery.

[0111] Furthermore, if Figure 4BAs shown, the VCU calculates the corresponding discharge voltage VBat_ImaxDisCharge according to the ImaxDisCharge_VoltAld signal determined in the above steps.

[0112] Furthermore, if Figure 4B As shown, the battery discharge power limit calculation module obtains the maximum discharge power allowed by the battery voltage based on the product of the current ImaxDisCharge_VoltAld and the voltage VBat_ImaxDisCharge and reversely obtains the maximum discharge power allowed by the battery voltage.

[0113] Furthermore, if Figure 4B As shown, the battery discharge power limit calculation module selects a smaller absolute value as the final charge limit power PHLimit_Bat according to the calculated maximum discharge power and the battery discharge allowable power P_DisChargeAld.

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

[0115] It can be seen that in the example of this application, the protection of each battery cell is achieved by determining the smaller value of the discharge current corresponding to the battery and the minimum voltage unit as the discharge current. In addition, the corresponding voltage value is calculated according to the determined maximum discharge current, and the maximum discharge power is finally calculated. In the process of determining the discharge limit power of the battery, the maximum discharge power obtained is not obtained solely based on table lookup, but taking into account the dynamic change of internal resistance and the influence of internal resistance change on discharge power when temperature changes, such as low temperature, are taken into account. The discharge allowable power obtained is more accurate and more in line with the actual operation requirements of the battery.

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

[0117] It can be seen that in the example of this application, the protection of each battery cell is achieved by determining the smaller value of the discharge current corresponding to the battery and the minimum voltage unit as the discharge current. In addition, the corresponding voltage value is calculated according to the determined maximum discharge current, and the maximum discharge power is finally calculated, and the calculated maximum discharge power is compared with the original preset discharge allowable power of the battery, and the smaller value of the two is determined as the discharge limit power. This can effectively avoid the situation where the battery cell may be overloaded by directly obtaining the battery discharge allowable power through table lookup. The smaller value of the two can effectively ensure that any discharge power meets the current discharge limit power, and both the battery and the battery cell are in a safe and stable state.

[0118] In one possible example, the calculation of the entire battery pack DC equivalent internal resistance, the maximum DC equivalent internal resistance and the minimum DC equivalent internal resistance 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 according to the current power information of the battery; obtaining the total voltage, the total current, the maximum voltage battery cell voltage and the minimum voltage battery cell voltage; calculating the entire pack DC equivalent internal resistance according to the total voltage, the total current and the battery no-load voltage reference value; calculating the maximum DC equivalent internal resistance according to the maximum voltage battery cell voltage, the total current and the battery cell no-load voltage reference value; calculating the minimum DC equivalent internal resistance according to the minimum voltage battery cell voltage, the total current and the battery cell no-load voltage reference value.

[0119] Exemplarily, the VCU obtains the maximum total voltage RefBatVmax, the minimum total voltage RefBatVmin, the maximum battery cell charging voltage RefCellVmax and the minimum battery cell discharging voltage RefCellVmin of the battery by looking up the table according to the current battery cell temperature BatTemp.

[0120] Exemplarily, the VCU obtains a battery no-load voltage reference value VrefBat corresponding to the battery total voltage and a battery cell no-load voltage reference value VrefCell of the battery cell by looking up the table according to the battery power information BatSoc.

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

[0122] For example, Figure 3 As shown, Figure 3 Schematic diagram of the observation process of a DC dynamic internal resistance observation module provided in an embodiment of the present application. 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 according to the observed data.

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

[0124] Specifically, the maximum voltage battery cell DC internal resistance observation unit sends an input signal according to the maximum voltage battery cell voltage V_CellMaxVolt, the battery cell no-load voltage reference value VrefCell of the battery cell, and the total battery current I_Bat, and calculates the maximum DC equivalent internal resistance DCIRAct_CellMaxVolt.

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

[0126] It can be seen that in the example of the present application, by observing the three DC equivalent internal resistances DCIRAct_Bat, DCIRAct_CellMaxVolt, and DCIRAct_CellMinVolt, the three DC equivalent internal resistances are subsequently used to monitor the total voltage, the maximum voltage battery cell voltage, and the minimum voltage battery cell voltage of the battery, respectively.

[0127] In a 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; setting the discharging limit power as the lower limit of the allowable power of the power limit range.

[0128] It can be seen that in the example of the present application, 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 more reasonable and stable, especially at low temperatures, there will be no large fluctuations, and it can continue to work, effectively protecting the power battery while maximizing the performance of the battery, which can improve the driving experience of hybrid vehicles at low temperatures.

[0129] In a possible example, after determining the power limit range of the battery according to the charging limit power and the discharging limit power, the method may further include the following steps: acquiring the actual output power of the vehicle's executive components, wherein the executive components include at least one of the following: a driving generator, an engine, a generator, and a gearbox; calculating the power limit value of each of the executive components according to the power limit range and the actual output power; generating a limit signal for each of the executive components, the limit signal carrying the power limit value corresponding to the executive component.

[0130] For example, Figure 1C As shown, the vehicle's execution components include a drive generator, an engine, a generator and a gearbox.

[0131] Exemplarily, 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 calculates the power limit of the driving generator, the engine power limit, the generator power limit, and the gearbox output power according to the power limit range of the battery, the actual power of each actuator, and the vehicle load power through the power limit calculation module, and generates a limit signal carrying the power limit value of each actuator.

[0133] It can be seen that in the example of the present application, the VCU further calculates the power limit value of each execution component based on the power limit range calculated by the battery at different temperatures. Since the power limit range setting takes the temperature factor into account, the obtained power limit range is more accurate, so the power limit calculation of each execution component will also be more accurate.

[0134] In one possible example, after generating a limitation signal according to the power limitation of the execution component, the method may further include the following steps: calculating the actual required power of the execution component in response to the limitation signal for the execution component; calculating the torque of the execution component according to the actual required power and speed of the execution component; and controlling the operation of the execution component to drive the vehicle according to the torque.

[0135] For example, Figure 4C As shown, Figure 4C Schematic diagram of a vehicle power unit power limiting module provided by an embodiment of the present application. Specifically, the VCU limits the required power of the driving generator, the required power of the gearbox, the required power of the engine, and the required power of the generator through the power limiting module according to the limiting signals corresponding to each execution component calculated by the above-mentioned limiting power calculation module process, and outputs the final actual required power of the driving generator, the actual required power of the gearbox, the actual required power of the engine, and the actual required power of the generator.

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

[0137] P=T*ω Formula (3)

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

[0139] Exemplarily, based on the above formula, the VCU calculates the target torque of the drive generator, the target torque of the gearbox, the target torque of the engine, and the target torque of the generator according to the actual required power of the drive generator, the actual required power of the gearbox, the actual required power of the engine, and the actual required power of the generator, and sends them to the motor controller MCU, the gearbox controller TCU, the engine controller ECU, and the generator controller ECU; the actual output power of the drive generator, gearbox, engine, and generator follows their respective actual required power, thereby achieving the battery power P_Bat within the control range.

[0140] It can be seen that in the example of the present application, the VCU calculates the actual required power of each execution component through the power limiting module, rather than directly obtaining the target required power of each execution component based on a table lookup, thereby improving the accuracy of the actual required power calculation. In addition, the torque of each execution component is calculated based on the actual required power, and the operation of each execution component is controlled based on the calculated torque, thereby achieving better control of the vehicle and improving the driving experience of the vehicle.

[0141] See also Figure 5 , Figure 5 It 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, wherein the one or more programs are 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 above program includes instructions for executing the following steps:

[0142] Calculate the whole pack DC equivalent internal resistance, maximum DC equivalent internal resistance and minimum DC equivalent internal resistance of the battery pack, wherein the battery pack includes multiple battery cells, the whole pack DC equivalent internal resistance 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, and the minimum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the lowest voltage;

[0143] Determining a charging limit power of the battery according to the entire DC equivalent internal resistance and the maximum DC equivalent internal resistance;

[0144] Determining the discharge limit power of the battery according to the whole pack DC equivalent internal resistance and the minimum DC equivalent internal resistance;

[0145] A power limit range of the battery is determined according to the charging limit power and the discharging limit power.

[0146] It can be seen that the battery protection method described in the embodiment of the present application calculates the DC equivalent internal resistance, the maximum DC equivalent internal resistance and the minimum DC equivalent internal resistance of the battery at the current battery cell temperature; determines the battery's charging limit power based on the DC equivalent internal resistance of the whole pack and the maximum DC equivalent internal resistance; determines the battery's discharge limit power based on the DC equivalent internal resistance of the whole pack and the minimum DC equivalent internal resistance; determines the battery's power limit range based on the charging limit power and the discharge limit power. In this way, it can be achieved that the battery's limited power range is determined by the three dynamic internal resistances calculated at different temperatures, which can make the battery's limited power range more reasonable, thereby effectively improving the battery's stability at different temperatures, allowing it to work continuously, while effectively protecting the power battery and maximizing the battery's performance, thereby improving the vehicle's driving experience at low temperatures.

[0147] In a possible example, the charging limit power of the battery is determined according to the DC equivalent internal resistance of the whole pack and the maximum DC equivalent internal resistance, and the above program includes instructions for performing the following steps:

[0148] Monitoring a first change in the total voltage and a second change in the maximum voltage battery cell voltage, wherein the maximum voltage battery cell voltage is a voltage corresponding to the battery cell with the highest voltage;

[0149] When the first change condition indicates that the total voltage reaches the maximum total voltage, calculating a first charging current according to 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, calculating a second charging current according to the maximum DC equivalent internal resistance;

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

[0152] In a possible example, the charging limit power of the battery is determined according to the first charging current and the second charging current, and the program includes instructions for executing the following steps:

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

[0154] calculating a first charging voltage according to the maximum charging current, and calculating a maximum charging power according to the maximum charging current and the first charging voltage; and,

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

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

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

[0158] In a possible example, the discharge limit power of the battery is determined according to the whole pack DC equivalent internal resistance and the minimum DC equivalent internal resistance, and the above program includes instructions for performing the following steps:

[0159] Monitoring a third change of the total voltage and a fourth change of the minimum voltage battery cell voltage, wherein the minimum voltage battery cell voltage is a voltage corresponding to the battery cell with the lowest voltage;

[0160] When the third change condition indicates that the total voltage reaches the minimum total voltage, calculating a first discharge current according to the DC equivalent internal resistance of the whole package;

[0161] When the fourth change condition indicates that the minimum voltage battery cell voltage reaches the minimum battery cell discharge voltage, calculating a second discharge current according to the minimum DC equivalent internal resistance;

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

[0163] In a possible example, the battery discharge limit power is determined according to the first discharge current and the second discharge current, and the program includes instructions for executing the following steps:

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

[0165] calculating the first discharge voltage according to the maximum discharge current, and calculating the maximum discharge power according to the maximum discharge current and the first discharge voltage; and,

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

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

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

[0169] In a possible example, the calculation of the entire DC equivalent internal resistance, the maximum DC equivalent internal resistance, and the minimum DC equivalent internal resistance of the battery pack includes instructions for performing the following steps:

[0170] Obtaining a battery no-load voltage reference value and a battery unit no-load voltage reference value by looking up a table according to the current power information of the battery;

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

[0172] Calculating the DC equivalent internal resistance of the whole package according to the total voltage, the total current and the battery no-load voltage reference value;

[0173] Calculating the maximum DC equivalent internal resistance according to the maximum voltage battery cell voltage, the total current and the battery cell no-load voltage reference value;

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

[0175] In a possible example, the power limit range of the battery is determined according to the charging limit power and the discharging limit power, and the program includes instructions for performing the following steps:

[0176] Setting the charging limit power to the upper limit of the allowable power in the power limit range;

[0177] The discharge limit power is set as the allowable power lower limit of the power limit range.

[0178] In a possible example, after determining the power limit range of the battery according to the charging limit power and the discharging limit power, the program includes instructions for executing the following steps:

[0179] Acquiring actual output power of an execution component of the vehicle, wherein the execution component includes at least one of the following: a drive generator, an engine, a generator, and a gearbox;

[0180] Calculating the power limit value of each execution component according to the power limit range and the actual output power;

[0181] A limit signal is generated for each of the execution components, wherein the limit signal carries the power limit value corresponding to the execution component.

[0182] In a possible example, after generating a limit signal according to the power limit of the execution component, the program includes instructions for executing the following steps:

[0183] In response to the limit signal for the execution component, calculating the actual required power of the execution component;

[0184] Calculating the torque of the actuator according to the actual required power and speed of the actuator;

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

[0186] The above mainly introduces the scheme of the embodiment of the present application from the perspective of the execution process on the method side. It is understandable that, in order to realize the above functions, the electronic device includes a hardware structure and / or software module corresponding to the execution of each function. It should be easily appreciated by those skilled in the art that, in combination with the units and algorithm steps of each example described in the embodiments provided herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is executed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present application.

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

[0188] In the case of dividing each functional module into corresponding functional modules, Figure 6 A schematic diagram of the functional unit structure of a battery protection device is shown, and the device is applied to a 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 whole pack DC equivalent internal resistance, the maximum DC equivalent internal resistance and the minimum DC equivalent internal resistance of the battery pack, wherein the battery pack includes a plurality of battery cells, the whole pack DC equivalent internal resistance 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, and 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 according to the DC equivalent internal resistance of the whole package and the maximum DC equivalent internal resistance;

[0191] The determining unit 602 is further configured to determine the discharge limit power of the battery according to the DC equivalent internal resistance of the whole package and the minimum DC equivalent internal resistance;

[0192] The determining unit 602 is further configured to determine a power limit range of the battery according to the charging limit power and the discharging limit power.

[0193] It can be seen that the battery protection device provided in the embodiment of the present application calculates the whole pack DC equivalent internal resistance, the maximum DC equivalent internal resistance and the minimum DC equivalent internal resistance of the battery at the current battery cell temperature through the calculation unit; the determination unit determines the battery charging limit power according to the whole pack DC equivalent internal resistance and the maximum DC equivalent internal resistance; the determination unit determines the battery discharge limit power according to the whole pack DC equivalent internal resistance and the minimum DC equivalent internal resistance; the determination unit determines the battery power limit range according to the charging limit power and the discharging limit power. In this way, it can be achieved that the battery power limit range is determined by the three dynamic internal resistances calculated at different temperatures, which can make the battery power limit range more reasonable, thereby effectively improving the stability of the battery at different temperatures, and can work continuously, while effectively protecting the power battery, the battery performance is maximized, thereby improving the driving experience of the vehicle at low temperatures.

[0194] In a possible example, the charging limit power of the battery is determined according to the whole pack DC equivalent internal resistance and the maximum DC equivalent internal resistance, and the calculation unit 601 is further used to perform the following steps:

[0195] Monitoring a first change in the total voltage and a second change in the maximum voltage battery cell voltage, wherein the maximum voltage battery cell voltage is a voltage corresponding to the battery cell with the highest voltage;

[0196] When the first change condition indicates that the total voltage reaches the maximum total voltage, calculating a first charging current according to 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, calculating a second charging current according to the maximum DC equivalent internal resistance;

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

[0199] In a possible example, the charging limit power of the battery is determined according to the first charging current and the second charging current, and the calculation unit 601 is further configured to perform the following steps:

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

[0201] calculating a first charging voltage according to the maximum charging current, and calculating a maximum charging power according to the maximum charging current and the first charging voltage; and,

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

[0203] In a possible example, the calculation unit 601 is further configured to perform the following steps:

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

[0205] In a possible example, the discharge limit power of the battery is determined according to the whole pack DC equivalent internal resistance and the minimum DC equivalent internal resistance, and the calculation unit 601 is further used to perform the following steps:

[0206] Monitoring a third change of the total voltage and a fourth change of the minimum voltage battery cell voltage, wherein the minimum voltage battery cell voltage is a voltage corresponding to the battery cell with the lowest voltage;

[0207] When the third change condition indicates that the total voltage reaches the minimum total voltage, calculating a first discharge current according to the DC equivalent internal resistance of the whole package;

[0208] When the fourth change condition indicates that the minimum voltage battery cell voltage reaches the minimum battery cell discharge voltage, calculating a second discharge current according to the minimum DC equivalent internal resistance;

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

[0210] In a possible example, the battery discharge limit power is determined according to the first discharge current and the second discharge current, and the calculation unit 601 is further configured to perform the following steps:

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

[0212] calculating a first discharge voltage according to the maximum discharge current, and calculating a maximum discharge power according to the maximum discharge current and the first discharge voltage; and,

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

[0214] In a possible example, the calculation unit 601 is further configured to perform the following steps:

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

[0216] In a possible example, the calculation of the entire DC equivalent internal resistance, the maximum DC equivalent internal resistance and the minimum DC equivalent internal resistance of the battery pack is performed by the calculation unit 601 further configured to perform the following steps:

[0217] Obtaining a battery no-load voltage reference value and a battery unit no-load voltage reference value by looking up a table according to the current power information of the battery;

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

[0219] Calculating the DC equivalent internal resistance of the whole package according to the total voltage, the total current and the battery no-load voltage reference value;

[0220] Calculating the maximum DC equivalent internal resistance according to the maximum voltage battery cell voltage, the total current and the battery cell no-load voltage reference value;

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

[0222] In a possible example, the power limit range of the battery is determined according to the charging limit power and the discharging limit power, and the calculation unit 601 and the determination unit 602 are further configured to perform the following steps:

[0223] Setting the charging limit power to the upper limit of the allowable power in the power limit range;

[0224] The discharge limit power is set as the allowable power lower limit of the power limit range.

[0225] In a possible example, after determining the power limit range of the battery according to the charging limit power and the discharging limit power, the calculating unit 601 and the determining unit 602 are further configured to perform the following steps:

[0226] Acquiring actual output power of an execution component of the vehicle, wherein the execution component includes at least one of the following: a drive generator, an engine, a generator, and a gearbox;

[0227] Calculating the power limit value of each execution component according to the power limit range and the actual output power;

[0228] A limit signal is generated for each of the execution components, wherein the limit signal carries the power limit value corresponding to the execution component.

[0229] In a possible example, after the limiting signal is generated according to the power limit of the execution component, the calculating unit 601 and the determining unit 602 are further configured to perform the following steps:

[0230] In response to the limit signal for the execution component, calculating the actual required power of the execution component;

[0231] Calculating the torque of the actuator according to the actual required power and speed of 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 contents of each step involved in the above method embodiment can be referred to 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-mentioned battery protection method, and thus can achieve the same effect as the above-mentioned implementation method.

[0235] In the case of using integrated units, the electronic device may include a processing module, a storage module and a communication module. Among them, the processing module can be used to control and manage the actions of the electronic device, for example, it can be used to support the electronic device to execute the steps performed by the above-mentioned calculation unit 601 and determination unit 602. The storage module can be used to support the electronic device to execute stored program codes and data, etc. The communication module can be used to support the communication between the electronic device and other devices.

[0236] Among them, the processing module can be a processor or a controller. It can implement or execute various exemplary logic boxes, modules and circuits described in conjunction with the disclosure of this application. The processor can also be a combination that implements computing functions, 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 device that interacts with other electronic devices, such as a radio frequency circuit, a Bluetooth chip, a Wi-Fi chip, etc.

[0237] An embodiment of the present application also provides a computer storage medium, wherein the computer storage medium stores a computer program for electronic data exchange, wherein the computer program enables a computer to execute part or all of the steps of any method described in the above method embodiments, and the above computer includes an electronic device.

[0238] The embodiment of the present application also provides a computer program product, the computer program product includes a non-transitory computer-readable storage medium storing a computer program, the computer program is operable to cause a computer to execute some or all of the steps of any method described in the method embodiment. The computer program product may be a software installation package, and the computer includes an electronic device.

[0239] An embodiment of the present application also provides a vehicle, including a vehicle control unit VCU, wherein the vehicle control unit VCU is used to execute part or all of the steps of any method recorded in the above method embodiments.

[0240] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0241] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0242] In the several embodiments provided in the present application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the above-mentioned units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

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

[0244] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0245] If the above-mentioned integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application is essentially 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, and the computer software product is stored in a memory, including a number of instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the above-mentioned methods of each embodiment of the present application. The aforementioned memory includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or CD-ROM and other media that can store program codes.

[0246] A person skilled in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable memory, and the memory can include: a flash drive, a read-only memory (English: Read-Only Memory, abbreviated as: ROM), a random access memory (English: Random Access Memory, abbreviated as: RAM), a magnetic disk or an optical disk, etc.

[0247] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A battery protection method, characterized in that: Applied to a vehicle control unit VCU, the method comprises: Calculate the DC equivalent internal resistance, maximum DC equivalent internal resistance and minimum DC equivalent internal resistance of the battery pack. Wherein, the battery pack includes a plurality of battery cells, the whole pack DC equivalent internal resistance 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, and the minimum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the lowest voltage; Determining a charging limit power of the battery according to the entire DC equivalent internal resistance and the maximum DC equivalent internal resistance; Determining the discharge limit power of the battery according to the whole pack DC equivalent internal resistance and the minimum DC equivalent internal resistance; A power limit range of the battery is determined according to the charging limit power and the discharging limit power.

2. The method according to claim 1, characterized in that The determining the charging limit power of the battery according to the whole pack DC equivalent internal resistance and the maximum DC equivalent internal resistance includes: Monitoring a first change in the total voltage and a second change in the maximum voltage battery cell voltage, wherein the maximum voltage battery cell voltage is a voltage corresponding to the battery cell with the highest voltage; When the first change condition indicates that the total voltage reaches the maximum total voltage, calculating a first charging current according to the DC equivalent internal resistance of the entire package; When the second change condition indicates that the maximum voltage battery cell voltage reaches the maximum battery cell charging voltage, calculating a second charging current according to the maximum DC equivalent internal resistance; The battery charging limit power is determined according to the first charging current and the second charging current.

3. The method according to claim 2, characterized in that The step of determining the charging limit power of the battery according to the first charging current and the second charging current includes: The larger value of the first charging current and the second charging current is used as the maximum charging current of the battery; and calculating a first charging voltage according to the maximum charging current, and calculating a maximum charging power according to the maximum charging current and the first charging voltage; and, If the maximum charging power is less than or equal to the charging allowable power, the maximum charging power is determined as the charging limit power.

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

5. The method according to claim 1, characterized in that The step of determining the discharge limit power of the battery according to the whole pack DC equivalent internal resistance and the minimum DC equivalent internal resistance includes: Monitoring a third change of the total voltage and a fourth change of the minimum voltage battery cell voltage, wherein the minimum voltage battery cell voltage is a voltage corresponding to the battery cell with the lowest voltage; When the third change condition indicates that the total voltage reaches the minimum total voltage, calculating a first discharge current according to the DC equivalent internal resistance of the whole package; When the fourth change condition indicates that the minimum voltage battery cell voltage reaches the minimum battery cell discharge voltage, calculating a second discharge current according to the minimum DC equivalent internal resistance; The battery discharge limit power is determined according to the first discharge current and the second discharge current.

6. The method according to claim 5, characterized in that The determining the battery discharge limit power according to the first discharge current and the second discharge current includes: The smaller value of the first discharge current and the second discharge current is used as the maximum discharge current of the battery; and calculating a first discharge voltage according to the maximum discharge current, and calculating a maximum discharge power according to 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, the maximum discharge power is determined as the discharge limit power.

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

8. The method according to claim 1, characterized in that The calculation of the entire battery pack DC equivalent internal resistance, the maximum DC equivalent internal resistance and the minimum DC equivalent internal resistance includes: Obtaining a battery no-load voltage reference value and a battery unit no-load voltage reference value by looking up a table according to the current power information of the battery; Obtaining total voltage, total current, maximum voltage battery cell voltage, and minimum voltage battery cell voltage; Calculating the DC equivalent internal resistance of the whole package according to the total voltage, the total current and the battery no-load voltage reference value; Calculating the maximum DC equivalent internal resistance according to the maximum voltage battery cell voltage, the total current and the battery cell no-load voltage reference value; The minimum DC equivalent internal resistance is calculated according to the minimum voltage battery cell voltage, the total current and the battery cell no-load voltage reference value.

9. The method according to claim 1, characterized in that: The determining the power limit range of the battery according to the charging limit power and the discharging limit power includes: Setting the charging limit power to the upper limit of the allowable power in the power limit range; The discharge limit power is set as the allowable power lower limit of the power limit range.

10. The method according to claim 1 or 9, characterized in that: After determining the power limit range of the battery according to the charging limit power and the discharging limit power, the method further includes: Acquiring actual output power of an execution component of the vehicle, wherein the execution component includes at least one of the following: a drive generator, an engine, a generator, and a gearbox; Calculating the power limit value of each execution component according to the power limit range and the actual output power; A limit signal is generated for each of the execution components, wherein the limit signal carries the power limit value corresponding to the execution component.

11. The method according to claim 10, characterized in that After generating a limit signal according to the power limit of the execution component, the method further includes: In response to the limit signal for the execution component, calculating the actual required power of the execution component; Calculating the torque of the actuator according to the actual required power and speed of the actuator; The actuator is controlled to operate according to the torque to drive the vehicle.

12. A battery protection device, characterized in that: A vehicle control unit VCU applied to a vehicle, the device comprises: a calculation unit, an acquisition unit and a determination unit, wherein: The calculation unit is used to calculate the whole pack DC equivalent internal resistance, the maximum DC equivalent internal resistance and the minimum DC equivalent internal resistance of the battery pack, wherein the battery pack includes a plurality of battery cells, the whole pack DC equivalent internal resistance 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, and the minimum DC equivalent internal resistance is the equivalent internal resistance corresponding to the battery cell with the lowest voltage; The determining unit is used to determine the charging limit power of the battery according to the DC equivalent internal resistance of the whole package and the maximum DC equivalent internal resistance; The determining unit is further used to determine the discharge limit power of the battery according to the whole package DC equivalent internal resistance and the minimum DC equivalent internal resistance; The determining unit is further configured to determine a power limit range of the battery according to the charging limit power and the discharging limit power.

13. An electronic device, characterized in that: The method comprises 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 executing the steps in the method as described in any one of claims 1 to 11.

14. A computer-readable storage medium, characterized in that: A computer program for electronic data exchange is stored, wherein the computer program causes a computer to execute the method according to any one of claims 1 to 11.

15. A vehicle, characterized in that: It comprises a vehicle control unit VCU, and the vehicle control unit VCU is used to execute the method as described in any one of claims 1-11.

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